Background: Heavy metals are known to be harmful for neurodevelopment and they may correlate to attention deficit/hyperactivity disorder (ADHD). In this study, we aim to explore the relationships between multiple heavy metals , neurocognitive function, and ADHD symptoms. Methods: We recruited 29 patients with ADHD inattentive type (ADHD-I), 47 patients with ADHD hyperactivity/impulsivity type (ADHD-H/I), and 46 healthy control children. Urine samples were obtained to measure the levels of the aforementioned heavy metals in each child. Participants’ cognitive function and clinical symptoms were assessed, respectively. Results: We found ADHD-H/I patients demonstrated the highest antimony levels (p = 0.028), and ADHD-I patients demonstrated the highest cadmium levels (p = 0.034). Antimony levels were positively correlated with the severity of ADHD symptoms that were rated by teachers, and cadmium levels were negatively correlated with the Full Scale Intelligence Quotient. Lead levels were negatively correlated with most indices of the Wechsler Intelligence Scale for Children–Fourth Edition (WISC-IV), but positively correlated with inattention and hyperactivity/impulsivity symptoms (p < 0.05). Conclusion: Lead, cadmium and antimony were associated with susceptibility to ADHD and symptom severity in school-age children. Eliminating exposure to heavy metals may help to prevent neurodevelopmental disorders in children. Attention deficit/hyperactivity disorder (ADHD), which is characterized by inattention, impulsivity, and hyperactivity, is among the most common psychiatric disorders occurring in children ,2. The APrevious studies have reported that environmental toxicants, especially lead (Pb) and mercury (Hg), contribute to the risk of ADHD . A meta-Hjortenkrans et al. reported that brake linings was an important source of zinc (Zn), cooper (Cu), and antimony (Sb) emissions and tires are one of the main sources of Zn and cadmium (Cd) emissions . Cd is bSb is frequently used as a catalyst in the polycondensation reaction to produce polyethylene terephthalate (PET) and it may leach from PET and recycled bottles into drinking water. Humans can be exposed to Sb by breathing air, drinking water, and eating foods that contain it, as well as by skin contact with substances that contain it. The effect of Sb on human heath has not yet been fully established. Only one study has reported no significant association between prenatal exposure to Sb and cognitive function at the age of four years . BismuthBased on clinical characteristics, the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR) classified ADHD into three subtypes  . PreviouOur research protocol was approved by the Institutional Review Board at Chang Gung Hospital in Taiwan. We recruited patients with ADHD who were treated in the outpatient Department of Child Psychiatry at Chang Gung Children’s Hospital in Taiwan for this cross-sectional study. We obtained written informed consent from all of the participants or their guardians. The inclusion criteria consisted of the following: (a) clinical diagnosis of ADHD by a senior child psychiatrist based on the DSM-IV-TR through structured interviews using the Chinese version of the Schedule for Affective Disorders and Schizophrenia for School-Age Children, epidemiologic version (K-SADS-E) ; (b) betThe control subjects (children without ADHD) consisted of healthy children from communities surrounding Kaohsiung Chang Gung Memorial Hospital or children that were suffering from upper respiratory tract infection (URI) whose symptoms were currently in remission. We excluded any patients with major psychiatric disorders  or major physical illnesses . In total, 46 healthy control children, 48 patients with ADHD inattentive type (ADHD-I), and 65 patients with ADHD hyperactivity/impulsivity type (ADHD-H/I) were recruited for this study. Because maturation processes and education effects could be diverse with age, we selected patents <10 years old into analyses.A urine sample (10 mL) was collected from each child and sent to the Chang Gung Memorial Hospital laboratory. We measured metal concentrations, including Mn, Pb, Cd, Hg, Sb, and Bi, using inductively coupled plasma mass spectrometry (ICP/MASS) and mass spectrometry in order to simultaneously measure the concentration of various heavy metals. ICP/MASS uses argon to generate high temperature plasma (6000K) in order to atomize and then ionize the heavy metal compounds. The mass spectrometer then directed the metal ions and analyzed each metal’s content based on its mass.Each ADHD patient was interviewed by a senior psychiatrist using the K-SADS-E diagnostic tool. An experienced child psychologist conducted the Wechsler Intelligence Scale for Children–Fourth Edition (WISC-IV). Furthermore, the Swanson, Nolan, and Pelham Version IV Scale (SNAP-IV) parent form and SNAP-IV teacher form were completed by each patient’s parents and a teacher, respectively.The K-SADS-E is a semi-structured diagnostic interview that is designed to evaluate current and past episodes of psychopathology in children and adolescents, according to the criteria of the DSM-III-R and DSM-IV . The K-SThe Chinese version of the WISC-IV is an individually administered and norm-referenced instrument developed to measure the intelligence of children aged from 6 to 16 years old . The WISThe SNAP-IV is a 26-item questionnaire for evaluating ADHD symptoms and severity, and it needs to be completed by parents or teachers . The 26 p-values of <0.05 were considered statistically significant.Data were analyzed using the statistical software package SPSS, version 16.0 . Variables are presented as either the mean (standard deviation) or frequency. Two-tailed Categorical variables among the healthy control group, ADHD-I group, and ADHD-H/I group were compared using the chi-square test. We adopted one-way analysis of variance (ANOVA) to compare the continuous variables among groups, followed by a post-hoc Least Significant Difference (LSD) test. Levels of heavy metals in the urine samples demonstrated a significant level of positive skewness. Therefore, the Kruskal-Wallis test was adopted to compare continuous variables among the three groups. Spearman’s correlation was performed to analyze the relationships between heavy metal levels, neuropsychological functions, and ADHD clinical symptoms.Our study sample consisted of 46 healthy control children (mean age 8.1 years), 29 ADHD-I children (mean age 8.0 years), and 47 ADHD-H/I children (mean age 7.7 years). Among these groups , ADHD-H/p = 0.034) levels. Compared to the healthy controls and ADHD-I group, children with ADHD-H/I demonstrated the highest Sb levels (p = 0.028). However, we observed no significant differences among the groups for Mn (p = .485), Pb (p = 0.125), Hg (p = 0.132), or Bi (p = 0.434).n = 122). We found that Pb levels negatively correlated with FSIQ, VCI, WMI, and PSI of the WISC-IV and positively correlated with the inattention, hyperactivity/impulsivity, and oppositional scores rated by parents and teachers, respectively. Cd levels were negatively correlated with FSIQ scores, while Sb levels were positively correlated with inattention, hyperactivity/impulsivity, and oppositional scores that were rated by teachers. Levels of Hg were positively correlated to hyperactivity/impulsivity scores rated by parents. Levels of Mn and Bi were observed to not have a significant association with ADHD clinical symptoms or cognitive functions.In the present study, we investigated the exposure of such metals as Mn, Pb, Cd, Hg, Sb, and Bi and its relationship to the specificity of ADHD symptomatology, measuring severity and cognitive function with WISC-IV. We found that Pb levels were positively correlated with ADHD symptomatology, including inattention, hyperactivity, and impulsivity. From previous studies, we know that Pb interrupts the dopamine pathway, which is one of the major neurotransmitter pathways that is involved in ADHD, resulting in dopaminergic neuron damage and the disruption of the homeostasis of calcium-dependent neurotransmitters . PreviouOur study also suggested that Pb levels were negatively correlated with FSIQ, VCI, WMI, and PSI of the WISC-IV. Such cognitive function impairment may result from Pb-induced directed cell death and the interruption of intracellular biological activities . Our finAnother interesting finding in our study is that the highest Sb levels presented in the ADHD-H/I group and were lower in both the ADHD-I group and the healthy control group. Furthermore, Sb levels were positively correlated with the inattention, hyperactivity/impulsivity, and oppositional scores rated by teachers. Other experimental studies and case reports have suggested that Sb may cause peripheral neurotoxicity , cerebelWhen compared to the healthy controls and the ADHD-H/I group, children with ADHD-I demonstrated the highest Cd levels. We also found in our study that levels of Cd were negatively correlated with FSIQ scores. A prospective study of 1305 subjects identified significantly inverse associations between urinary Cd levels and VIQ and FSIQ . AnotherIn the present study, we also found that the levels of Hg were positively correlated to hyperactivity/impulsivity scores rated by parents. Hg exerts the detrimental effect on enzymes, cellular membrane function, and neurotransmitter levels . A meta-This study has certain limitations. First, the cross-sectional nature of the study design and the single measurement of Pb and the other environmental chemicals were not sufficient to establish a definite causal relationship. In addition, the range of the half-life of these heavy metals was widely dispersed. For example, Sb had the shortest half-life with 95 hours after exposure, but Cd had the longest half-life for decades. The single measurement of urine sample may reflect recent exposure. However, it is difficult to clarify the effect of heavy metals during the critical period of neurodevelopment. Second, using urine samples to measure chemicals may be related to more individual variations, especially in Pb. Furthermore, urinary Pb levels are less sensitive in the low range of exposures  . As for Our study’s strength came from measuring various metals, as well as demonstrating the effect in subjects with a formal ADHD diagnosis that is based on DSM-IV-TR criteria. Our findings indicate metals’ relationship to susceptibility to ADHD, especially for Pb, Cd, and Sb. Children’s neurocognitive function is particularly correlated to Pb levels. These findings suggest that children should avoid heavy metal exposure and prevent the adverse effect of metals on children’s neurodevelopment. However, Taiwan is a cramped and densely populated country. The demarcation of the cultivated field, industrial area, and the residential area was often not clear. Therefore, it is crucial for legislating public health policy for reduction of the environmental heavy metals exposure.


Self-care ability was considered as a mechanism to improve the quality of life and reducing the high costs of medical services for elder people. Iran is experiencing increased elder people and healthy aging is one of the challenges. This study aimed to investigate self-care ability of elder people in Shahid Chamran and Dr. Shadpour health complexes, Tabriz- Iran.This was a cross-sectional study done in 2015. “The Self-care Ability Scale for the Elderly (SASE)” valid and reliable questionnaire (Persian version) was used for data collection. Totally, 220 samples were selected using G-Power 3.1.5 software. Sampling was conducted through systematic random method. Data were analyzed using SPSS 21 software. Descriptive statistics and independent t-test, one-way ANOVA, Mann-Whitney, Kruskal-Wallis test and Kolmogorov-Smirnov test were used.P<0.05). However, gender, income source, and insurance status had no relations with self-care ability of the elder people (P>0.05).The mean of self-care ability in elder people was calculated as 56.69± 15.07 (out of 100). 96.8% of participating elderlies, had poor self-care ability. Significant relations were found between elder people self-care ability and their educational level, life status, employment status, and marital status (Self-care ability of elder people in Tabriz was at weak level. Regarding, health providers must employ the programs to promote older people self-care ability including improving self-esteem, receiving family help, improved nutrition and mental health improving elderly’s quality of life. Aging is one of the phenomenon in the global health area  and it wThe ability to take care of elder people is very important source of health and it might be considered as a determining factor to manage everyday lives of elder people. Due to aging, self-care ability reduces in many people because of one or several factors, leading to a decrease in the life satisfaction of the elder people. As a result, gaining insight and understanding of the influential factors will be important . Self-caIn a Swedish study, self-care ability decreases with aging . Self-caThis study was conducted to investigate self-care ability of urban living elder people in Shahid Chamran and Dr. Shadpour health complexes, Tabriz -Iran.This cross-sectional study was conducted in Shahid Chamran and Dr. Shadpour health complexes in Tabriz, Iran 2015. Health complexes are new health facilities in which PHC services are provided with some professional services. Each health complex contains 4–5 health centers covering 10000–30000 people. Health centers, generally, provide PHC services and in a need, refers the people for professional services to health complex clinics. Shahid Chamran health complex is in suburban area of Tabriz located at seventh region of municipality and at 3 km southwest of this city. It has lower socioeconomic status than other parts of Tabriz. In return, Shadpour Health complex is located in Zafaranieh district of Tabriz that is one of the areas with high socioeconomic situation in Tabriz.Study population consisted of all elder people who had health file in Shahid Chamran and Dr. Shadpour health complexes of Tabriz. Totally, 220 samples were calculated to include in the study using G-Power 3.1.5 software. Sample allocation to each center was equally. Sampling was conducted by systematic random method using list of elder people.The questionnaire had consisted of two parts, first, demographic characteristics of elder people and the second17-item self-care ability of elder people questionnaire (SASE) , 26. ResData were analyzed using SPSS 21 software . Descriptive statistics (Mean and SD) were used to report self-care ability status in elder people. Moreover, independent t-test was used to compare self-care ability among elder people, and two-state (binary) independent variables  and ANOVA were used to compare self-care ability according to more than two states variables (such as academic groups). Kolmogorov-Smirnov test was used to investigate the normality of data and non-normal data were analyzed using the Mann-Whitney and Kruskal-Wallis test. With an adoption on Söderhamn et al studies , 15, theThe study was approved by the Ethical Committee of Tabriz University of Medical Science.t-test results, significant relation was found in self-care ability of elderly’s belonging to each of health complexes. The mean of self-care ability and its dimensions in elder people of Chamran Health Complex were higher compared to Shadpour Health Complex elderlies (P<0.05)  .According to LSD Post-Hoc multiple comparisons results, significant differences were appeared between elder people educational level and their self-care ability, as it was different in elder people who were illiterate and those who had associate, graduate, and master degree. In marital status variable, significant correlation was found between elder people married and those who were living with spouse and their self-care ability. In addition, in the variables of employment, significant relationship was found between elder people retired and unemployed and their self-care ability. In the variable of life status, significant correlation was observed between elder people with spouse and children variable (vice versa) and between alone and with children elder people variable in self-care ability of elder people.The aging issue of world population is a relatively new phenomenon. Therefore, to cope with the challenges of this phenomenon, adopting appropriate policies in order to improve the elder people status is very important and it has been included in the agenda of international organizations . Self-caSignificant difference was found between elderlies of health complexes in the self-care ability and its dimensions so that self-care ability in elder people of Shahid Chamran Health Complex was higher than that in elder people of Shadpour Health Complex. As the socio-economic status of the elder people was lower in the Shahid Chamran Health Complex, this can affect their self-care ability. People who have lower financial power showed greater willingness to use preventive measures  and elder people are not exception in this regard . This miP>0.05), but other factors such as education, life status, employment and marital status had significant relation with self-care ability of elder people (P<0.05). Males had higher self-care ability than females, while significant difference was not reported in self-care ability of two genders statistically  have been completely observed by the authors.


Electronic noses recognize odors using sensor arrays, and usually face difficulties for odor complicacy, while animals have their own biological sensory capabilities for various types of odors. By implanting electrodes into the olfactory bulb of mammalian animals, odors may be recognized by decoding the recorded neural signals, in order to construct a bioelectronic nose. This paper proposes a spiking neural network (SNN)-based odor recognition method from spike trains recorded by the implanted electrode array. The proposed SNN-based approach exploits rich timing information well in precise time points of spikes. To alleviate the overfitting problem, we design a new SNN learning method with a voltage-based regulation strategy. Experiments are carried out using spike train signals recorded from the main olfactory bulb in rats. Results show that our SNN-based approach achieves the state-of-the-art performance, compared with other methods. With the proposed voltage regulation strategy, it achieves about 15% improvement compared with a classical SNN model. Electronic noses usually use sensor arrays to recognize odors ,2. HowevNeural signals recorded from the olfactory bulb are temporal spike trains from multiple channels. For most machine learning algorithms requiring vector-based inputs, existing neural signal decoders transform spike trains into firing rates in time windows (bin-based approaches) as features . The binSpiking neural networks (SNNs)  mimic biIn this study, we propose a novel spiking neural network(SNN)-based neural signal decoder to recognize odors with spike train signals recorded from olfactory bulb in rats. Unlike most previous work that requires bin-based inputs, our approach exploits rich timing information in precise time points of spikes. To deal with a small amount of training data, we especially propose a new SNN learning method with a voltage-based regulation strategy (SNN-VR), in order to alleviate the overfitting problem during training. Experiments are carried out using spike train signals recorded from olfactory bulb in rats. Results show that, compared with bin-based odor decoders, the SNN approaches achieve better performance in two-class, three-class, and four-class odor recognition tasks. With the proposed voltage-based regulation strategy, the SNN-VR approach obtains about 15% improvement compared with the classical SNN model. SNN-VR demonstrates better generalization ability especially with small training sets.In this section, we present the SNN-VR odor recognition method in detail. Firstly, we describe neural signal acquisition and processing procedure to record spike trains from olfactory bulb areas in rats. Then, we briefly introduce some typical classifiers using bin-based features. After that, we elaborate on how to effectively decode odor information from spike trains using SNNs, and give details of the proposed SNN-VR approach. The framework of the BMI-based bioelectronic nose is illustrated in Spike train signals are recorded by implanting electrodes into the main olfactory bulb of rats . MicroelThe odor stimuli were given by glass dishes containing the odor solutions in front of the rats’ nose. The concentration of all odor solutions was controlled to 10odor map , a totalIn the dataset, there are a total of 80 samples of neural signals (20 samples per odor). The experiments are carried out using random test, that is, a total of 100 experimental trials are conducted and the average accuracy is presented. In an experimental trial, for each odor type, 16 samples are randomly selected for training, and the 4 remaining samples are used for testing.n represents the n-th neuron, k represents the odor type, and i is the index of the bin. The feature vector of each neuron is:M represents the number of bins in the time period, taking a bin of 0.5 s and time period of 5.0 s as an example, M = 5.0 s/0.5 s = 10. Then the feature vectors of all neurons during each odor stimulation are combined into a new feature vector With bin-based classifiers, we use spike counts in small time bins for each neuron as the features. We calculate the spike counts After feature extraction, classifiers including decision tree (DT), k-nearest neighbors (KNN), linear discriminant analysis (LDA), maximum likelihood estimation (MLE) and supporting vector machine (SVM) can be used for odor recognition.Spiking neural networks (SNNs)  are biolm representing one odor type) in output layer which fire zero or one spike. All neurons are fully connected.In this study, we use a two-layer spiking neural network consisting of an input and an output layer for neural signals decoding. The number of neurons in the input layer is same as the recorded neurons, and there are groups of neurons  neuron model. The voltage of LIF neuron is determined by exponentially decayed synaptic current induced by input spikes. Each input spike from a presynaptic neuron t, the membrane voltage of the postsynaptic neuron j is a weighted sum of all PSPs contributed by input spikes before time t:i and postsynaptic neuron j. When there is no input spike, the postsynaptic neuron j maintains the resting potential j if At time j fires an error spike (spike fired by the group of neurons which represent wrong odor type), synaptic weight j does not fire the expected spike (spike fired by the group of neurons which represent correct odor type), synaptic weight Tempotron is a classic learning rule for SNN in binary classification tasks . Based oSince the Tempotron rule adjusts synaptic weights according to the classification errors, it does not update synaptic weights when training samples are correctly classified. However, when the training set is small, it usually causes that the membrane voltage thresholds of some neurons could be approached easily. When disturbances occur in spike trains, the neurons can fire mistakenly. In odor recognition tasks, the training data set is usually small. Therefore, we propose a new voltage-based regulation strategy called Tempotron-VR, to improve the training effectiveness.Different from the Tempotron rule, the proposed Tempotron with voltage-based regulation strategy (Tempotron-VR) approach adopts a nth neuron in the group m. To obtain the factor, we need to know the ratio of t denotes the target group) to the sum of all groups Compared with Δωi in , TempotrWe use t and other groups can be computed by:The derivative of Finally we multiply While m which represents the mth odor type, we use training samples with class label m as positive samples and others as negative samples. During the process of testing, we use the majority voting method to predict the most likely odor type. By counting the firing neurons (neuron that fires a spike) in each group, the class represented by the group which has the maximal number of firing neurons is the predicted odor type.During the process of training, for neurons in group In this section, comprehensive experiments are conducted to demonstrate the effectiveness of our approach in odor recognition tasks. Firstly, we present the odor recognition performance of SNN-VR in comparison with other approaches. Secondly, we compare the SNN-VR approach with typical bin-based methods to show the effectiveness of adopting precise timing information. Thirdly, we compare SNN-VR approach with classical SNN model to demonstrate the strengths of the voltage-based regulation strategy in neural signals. After that, we investigate the recognition performance under different time periods to show the ability of SNN-VR for quick recognition. Finally, we briefly discuss the pros and cons of SNN-VR.In this experiment, we present the odor recognition performance of Tempotron-VR in comparison with Tempotron and bin-based approaches. Considering the odor stimulation time is 4–5 s, we choose the 5-s-long spike trains to fully use the information of neural signals in olfactory bulb during odor stimulation. For the model parameters, all the parameters in the method are selected with cross validation. In each experimental trial, 20% of the training set is used for validation. For KNN, we select the number of nearest neighbors. For SVM, we select both parameters of C and gamma. For SNN, we choose the As shown in Compared with bin-based approaches, the SNN models obtain higher recognition accuracy. In bin-based classifiers, MLE achieves the highest recognition accuracy, while Tempotron-VR shows similar (two-class 82%∖83%) and better (three-class 71%∖69% & four-class 63%∖57%) performance than MLE. Since the SNN models do not rely on bin-based inputs, they better exploit the temporal information in spike trains, which leads to higher decoding performance.Compared with Tempotron, the Tempotron-VR approach obtains better recognition performance. As shown in In this experiment, we compare our method with bin-based approaches using different bin sizes. For bin-based classifiers, bin size is a crucial parameter that influences the odor recognition performance. Therefore, we evaluate the bin-based classifiers with different settings of bin sizes, and the results are shown in As shown in Compared with bin-based classifiers, one advantage of SNN is that it can directly input the time points of spike trains, which avoids the bin size selection process. As shown in In this experiment, we evaluate the odor recognition performance of Tempotron-VR with different training set sizes. Since data acquisition of neural signals is expensive, the training dataset is usually small, which can cause an overfitting problem in Tempotron-based model learning. In Tempotron-VR, the voltage-based regulation strategy strengthens synaptic weights to enhance the maximal membrane voltage of neurons in the target group at each iteration and improves recognition performance.To demonstrate the strengths of the proposed voltage-based regulation strategy, we compare Tempotron-VR with Tempotron using different training data sizes. We tune the number of training sample groups from 1 to 16, where each sample group contains one sample from each class. The sample groups are randomly shuffled. The rest of the samples are used for testing. The results are shown in As shown in In BMI-based bioelectronic noses, the response time is an important criterion. In this experiment, we test the recognition performance of our method under different time periods (from 0.1 s to 1 s), to evaluate the performance for quick recognition. The results are shown in As shown in Experimental results show that the proposed Tempotron-VR approach achieves the state-of-the-art performance compared with bin-based classifiers and Tempotron. The results also demonstrate the advantages of Tempotron-VR. Compared with bin-based classifiers, our method avoids the selection of bin size by directly using spike timings as input, which make it more feasible for practical applications. In addition, the timing information of spikes can be better exploited to achieve higher odor recognition performance. Compared with Tempotron, the proposed Tempotron-VR strategy can learn more effectively from small training data, which is crucial in neural signal-based odor decoding where signal acquisition can be extremely expensive.One drawback of SNN-based odor recognition is that the computational cost of SNNs is relatively higher. We evaluate the time cost of each experimental trial in the training stage and the run time of each sample in test stages with SNN and SNN-VR. The experiments are carried out on a desktop computer with an Intel(R) Core(TM) i5-4590 CPU, 8 GB RAM memory and 64 bit operating system. In an experimental trial, for each odor type, 16 samples are randomly selected for training, and the four remaining samples are used for testing. It is repeatedly executed ten times for measuring the average results and the time is measured in seconds. As shown in In this study, we propose a novel spiking neural network (SNN)-based neural signal decoder to recognize odors with spike train signals recorded from the main olfactory bulb in rats. The proposed SNN-based approach exploits rich timing information well in precise time points of spikes. To deal with small training data, we especially propose a new SNN learning method with a voltage-based regulation strategy (Tempotron-VR), in order to alleviate the overfitting problem. Results show that, compared with bin-based odor decoders, the SNN approaches achieve better performance in two-class, three-class, and four-class odor recognition tasks. With the proposed voltage-based regulation strategy, the SNN-VR approach obtains about 15% improvement compared with classical SNN models, while SNN-VR demonstrates better generalization ability especially with small training sets.


Early diagnosis of inflammatory bowel disease (IBD), including Crohn’s disease (CD) and ulcerative colitis (UC), remains a clinical challenge with current tests being invasive and costly. The analysis of volatile organic compounds (VOCs) in exhaled breath and biomarkers in stool ) show increasing potential as non-invasive diagnostic tools. The aim of this pilot study is to evaluate the efficacy of breath analysis and determine if FCP can be used as an additional non-invasive parameter to supplement breath results, for the diagnosis of IBD. Thirty-nine subjects were recruited . Breath samples were analysed using an in-house built electronic nose (Wolf eNose) and commercial gas chromatograph–ion mobility spectrometer (G.A.S. BreathSpec GC-IMS). Both technologies could consistently separate IBD and controls , eNose: ; GC-IMS: . Furthermore, we could separate CD from UC, eNose: ; GC-IMS: . Including FCP did not improve distinction between CD vs. UC; eNose: , but rather, improved separation of CD vs. controls and UC vs. controls; eNose:  and  without FCP,  and  with FCP, respectively. These results confirm the utility of breath analysis to distinguish between IBD-related diagnostic groups. FCP does not add significant diagnostic value to breath analysis within this study. Inflammatory bowel disease (IBD) is a chronic condition of unknown aetiology, which includes Crohn’s disease (CD) and ulcerative colitis (UC) . Both coIn recent years, breath and stool analysis have shown increasing potential as non-invasive diagnostic tools. This includes the analysis of exhaled volatile organic compounds (VOCs) and biomarkers of inflammation. There are an estimate of over 3000 VOCs in human breath , which aIn the domain of measurable objective biomarkers, C-reactive protein (CRP) and faecal calprotectin (FCP) have been gaining clinical research interest. CRP correlates reasonably well with CD activity, but has poor sensitivity . MoreoveThe aim of this pilot study is to evaluate the efficacy of breath analysis and determine if FCP can be used to supplement breath results for the diagnosis of IBD. The first objective of this study is to determine whether exhaled VOCs can be used to distinguish IBD from healthy controls and CD from UC, using a commercial gas chromatograph—ion mobility spectrometer (GC-IMS) and an in-house built electronic nose (eNose). To the best of our knowledge, this breath study is the first to investigate CD, UC and healthy controls using GC-IMS and eNose technology. The key advantages of these technologies are that they are non-invasive, portable, relatively inexpensive, applicable for high-throughputs and have sampling procedures suitable for nearly all patient demographics, including vulnerable subjects such as children and the elderly. Confounding factors, such as BMI, smoking habits and gender will be used to verify analysis efficacy. The second objective of this study is to determine whether FCP, used as an additional non-invasive parameter, adds diagnostic value to breath analysis in IBD.A total of 39 subjects were recruited for this pilot study, as part of the larger ‘Famished’ study. Ethical approval was obtained from the Warwickshire research ethics committee (IRAS ref: 18717). 30 patients had a histologically confirmed IBD , as well as 9 healthy control volunteers. IBD patients were recruited from dedicated IBD clinics at University Hospitals Coventry and Warwickshire (UHCW), UK. Details of medication and disease activity were recorded and simple colitis activity index (SCAI) for UC and Harvey Bradshaw index (HBI) for CD were calculated at the time of recruitment. Healthy controls were volunteers who did not report any overt gastrointestinal symptoms and were not on routine oral medication or recovering from any recent illnesses. An overview of the demographic data of IBD patients and healthy controls is shown in As shown in The term ‘eNose’ describes an instrument formed from an array of sensors with overlapping sensitivity . ElectroSince the Wolf eNose was designed and developed in-house, there is a high level of freedom allowing the instrument to be tailored to specific applications. A custom sample injection system was developed for this study, to enhance the capabilities of the Wolf eNose to analyse breath samples.Alveolar breath samples, for Wolf eNose analysis, were collected using a commercially-available breath sampling device, known as the Bio-VOC . Alveolar breath refers to the last portion (350 mL) of exhaled breath, expelled from within the lungs and the lower-airways, which have undergone gaseous exchange with the blood in the alveoli . A healtA more recent, alternative approach to eNoses has been the use of portable GC-IMS analysers, which have demonstrated capabilities in medical diagnostics . The BreThe Bio-VOC was not required for G.A.S. BreathSpec GC-IMS analysis. Subjects were provided with a disposable plastic mouthpiece, which pushes into the mouthpiece holder/sample inlet and connects directly to the side-panel of the instrument. This sampling procedure also collects end-tidal breath, since only the last four seconds of exhaled breath are collected for analysis . The G.Ak-fold cross-validation method, where k = 10. This method involves partitioning the original data set into 10 equally-sized subsets. Of the 10 subsets, a single subset is retained as the validation data for testing the model, and remaining subsets are used as training data. This process is repeated 10 times (number of folds), with each subset used once as validation data. The 10 results are then combined to produce a single estimation. This method for cross-validation is commonly used in breath analysis, to ensure robustness and avoid ‘false-negative’ errors  . While IBD generally affects men and women equally, some studies from North America show that UC is more common in men than women . The unbResults from the analysis combining breath analysis with FCP caused specificity, PPV and AUC to reduce, compared to those without FCP. While the differences in mean FCP scores between CD and UC is almost 300 ug/g (414.1–116.9 ug/g), this feature is prone to misclassification because all CD scores fall within the lower range of UC scores. Thus, including FCP with breath analysis does not improve distinction between CD vs. UC within this study. However, as shown in The results from this pilot study confirm the utility of breath VOC analysis to distinguish between IBD and healthy control volunteers, and CD from UC. To the best of our knowledge, this study was the first breath-based investigation of IBD utilising GC-IMS and eNose technology. Both technologies consistently showed the ability to separate those with IBD and controls , eNose:  and GC-IMS: . Furthermore, we were able to separate CD from UC, eNose:  and GC-IMS: . The G.A.S. BreathSpec GC-IMS is better suited towards distinguishing between IBD and controls, while the Wolf eNose can better separate between CD and UC. Compound analysis has identified two breath VOCs, which are likely to have a direct link to IBD: butanoic acid and ethanoic acid. These compounds played a crucial role in separating those with IBD from controls. Analysis of possible confounding factors indicate that BMI, smoking habits and gender have insignificant influence on breath content. Wolf eNose analysis was repeated on a reduced dataset, with FCP scores serving as an additional feature. This resulted in a poorer separation of CD and UC, which indicates that the efficacy of breath analysis is reduced, when supplemented with FCP;  without FCP, and  with FCP. The inclusion of FCP was able to improve diagnostic performance for CD vs. controls and UC vs. controls; however, this application has limited clinical value. Thus, the G.A.S. BreathSpec GC-IMS and Wolf eNose instruments offer the greatest potential as non-invasive, high-throughput, real-time diagnostic and screening tools for IBD, in point-of-care use. Moreover, since breath testing using these technologies could be undertaken during routine consultancy appointments, it has the potential to fundamentally change the current clinical diagnostic and assessment pathways for IBD.


Targeting nanoparticle (NP) carriers to sites of disease is critical for their successful use as drug delivery systems. Along with optimization of physicochemical properties, researchers have focused on surface modification of NPs with biological ligands. Such ligands can bind specific receptors on the surface of target cells. Furthermore, biological ligands can facilitate uptake of modified NPs, which is referred to as ‘active targeting’ of NPs. In this review, we discuss recent applications of biological ligands including proteins, polysaccharides, aptamers, peptides, and small molecules for NP-mediated drug delivery. We prioritized studies that have demonstrated targeting in animals over in vitro studies. We expect that this review will assist biomedical researchers working with NPs for drug delivery and imaging. The site where a drug is administered is most often very distant from the site of expected therapeutic effect. Thus, there has been significant research in the field of targeted drug delivery. Nanoparticle (NP) drug delivery systems represent the cumulative research efforts of numerous fields, including chemistry, biology, material science, pharmaceutics, and clinical medicine . CommercWith respect to targeted drug delivery, NPs utilize two basic strategies comprising either passive or active targeting . PassiveA large number of biological ligands have been identified and studied for facilitating active targeting of NPs . Such biAmong biological ligands, antibodies have the longest history with respect to targeting specific receptors . AntibodAffibodies (Afbs) are engineered, high-affinity proteins that are smaller than normal antibodies . RecentlTransferrin (Tf) is an iron-binding glycoprotein that is responsible for iron transport in the body . Tf receHyaluronic acid (HA) is a polymer capable of binding cell surface receptors for active targeting. HA is a polysaccharide and one the main components of the extracellular matrix along with collagen. HA binds CD44, which is often overexpressed on the surface of cancer cells and is believed to be a representative marker of cancer stem cells . InteresAmong targeting ligands, peptides have several advantages such as low cost of production, good stability, and ease of conjugation to the surface of NPs at a high density due to their small size . To targThe arginylglycylaspartic acid (RGD) peptide binds integrins, which are particularly overexpressed in vascular endothelial cells present in tumor tissue, and for this reason is a well-known tumor-targeting peptide . The seqIn addition to the RGD peptide, the iRGD peptide represents an RGD-containing peptide sequence initially characterized by its ability to bind αv integrins expressed on tumor endothelial cells. Interestingly, when the iRGD peptide is cleaved by proteases in tumor cells, it produces a CRGDK/R derivative peptide that has diminished affinity for αv integrin but increased affinity for neuropilin-1 (NRP-1) . This swAptamers are a class of short nucleic acid (DNA or RNA) comprising several nucleotides. Aptamers are small, highly sensitive, biodegradable, and have immunogenicity, making them good candidates for active targeting ligands . In 201850 than CPP modified NPs (CPP-CPTD NPs) due to the camouflaged CPP. However, Xi et al. asserted that GBI-10 aptamers detach from Apt/CPP-CPTD NPs in tumors secondary to the high-affinity relationship between GBI-10 and tenascin-C. Recovered cell-penetrating ability of Apt/CPP-CPTD NPs was demonstrated by Miapaca 3D tumor spheroid microscopic images. Finally, the Apt/CPP-CPTD NPs were injected intravenously into orthotopic pancreatic cancer xenograft mouse models. Fluorescent images of mice also showed high accumulation in tumor sites at all time points. Accordingly, Apt/CPP-CPTD NPs showed enhanced antitumor efficacy and survival rates in vivo over other control groups, thereby demonstrating successful active targeting of NPs with the GBI-10 aptamer and CPP.Recently, Xi et al. used the GBI-10 aptamer for tumor-targeting of NPs . GBI-10 Folate (FA) receptors are well known to be overexpressed in solid tumor cells and macrophages, making them attractive targets for many NPs via receptor-mediated endocytosis ,37,38. Fb-PM) modified with anisamide. In B16F10-tumor bearing mice treated with these modified NPs, the tumor inhibition ratio was the greatest for Trp2 + SUNb-PM. Furthermore, as a result of the immune response elicited by Trp2, the number of CD8+ T cells in Trp2+SUNb-PM groups was significantly increased. On the other hand, there was a decrease in the abundance of myeloid-derived suppressor cells and T regulator cells, both of which play important roles in immune suppression. They found that T helper 1 and 2 cytokine levels were appropriately altered in order to enhance antitumor immune responses. Based on these findings, the authors concluded that anisamide-modified NPs containing tyrosine kinase inhibitors combined with a vaccine may afford synergistic antitumor effects. The mechanism of anisamide remains controversial. The Leroux group insisted that cellular uptake of anisamide-modified NPs is not related to Sigma-1 receptors . In. In44]. To date, we have summarized the representative examples of biological ligands for targeting of NPs. Various ligands including proteins, carbohydrates, nucleic acids, peptides, and small molecules are capable of increasing the specific binding of NPs containing drugs to disease cells to increase the efficacy of chemotherapy. Active targeting is a term that is often misunderstood as the ability of a ligand to control and direct the movement of conjugated NPs to target cells in vivo like guided missiles. However, dramatic changes in organ distribution of NPs do not occur in many cases, and the ligands present on NPs only help the binding of NPs on target cells. As observed in the studies of the Davis group, biodistribution and organ distribution of NPs in vivo changed only slightly following conjugation of biological ligands, especially on whole-body imaging . NeverthPhysicochemical properties such as size, shape, rigidity, or surface properties are very important to determine the large-scale distribution of NPs. It is known that nanoparticles from 10 to 500 nm can move through vessels and accumulate in tumor tissue . Strong Another important consideration of NP ligands is their cost . For exa


Curcumin has demonstrated anti-inflammatory properties and has been investigated as an adjuvant therapy of ulcerative colitis (UC). The scope of this study was to systematically review and meta-analyze the efficacy of oral curcumin administration as an adjuvant therapy of UC. MEDLINE, Cochrane/CENTRAL, ClinicalTrials.gov, WHO-ICT Registry, EMBASE and grey literature were searched for relevant randomized controlled trials (RCTs). The primary outcome was clinical remission (attainment) and the secondary outcome was clinical response (maintenance/failure). Risk of bias was assessed with the Cochrane tool. Odds ratios (OR) were calculated with a Mantel-Haenszel (M-H) random effects model and with a beta-binomial (B-B) random effects model when zero events/cells occurred. Four RCTs met the criteria, but one was removed from the analyses due to inconsistency in protocol details. With the M-H method, treatment with curcumin was significantly superior to placebo in attaining remission in the per-protocol (PP) analysis , but not in the intention-to-treat (ITT) analysis . However, with the more accurate B-B method, both analyses were insignificant . Based on the current available evidence, oral curcumin administration does not seem superior to placebo in attaining remission in patients with UC. Future RCTs should be planned more cautiously with sufficient size and adhere to the ITT analysis in all outcomes. Inflammatory bowel disease (IBD) is a blanket term used to define chronic inflammatory conditions of the colon and small intestine. IBD’s most typical forms include ulcerative colitis (UC) and Crohn’s disease (CD), both demonstrating an increasing prevalence globally, in particular in Europe and North America . Though Curcuma longa) has been suggested to yield many health-related benefits and pharmacological effects, including its anti-inflammatory [Among the most promising recent therapeutic advances, curcumin, a polyphenol derived from the turmeric plant  evaluating the efficacy of oral curcumin administration, in patients with ulcerative colitis.Eligibility criteria were specified for the search procedure and meta-analysis, using the PICO format (Population (P), Intervention (I), Comparison (C), and Outcomes (O)). The research question was: What is the effect of oral adjuvant curcumin therapy on achieving remission in adult UC patients? The study population was UC (1) adults, (2) with a clinically and endoscopic confirmed diagnosis of UC, (3) having active mild-to-moderate disease activity (defined by a disease-specific activity index) at baseline, while (4) lacking any concomitant diagnosis of an active autoimmune disease, hepatic, renal, or neurological disorder. Intervention involved RCTs comparing oral adjuvant curcumin therapy vs. placebo, or no adjuvant among patients receiving the same pharmacotherapy. The selected primary outcome of the analysis was the proportion of patients attaining remission, as defined by a decreased disease-specific activity score, such as the colitis activity index (CAI) , simple Curcuma longa)). In a successive search, the use of a sensitivity filter for the identification of RCTs was applied, according to the Cochrane Handbook guidelines [We performed a comprehensive literature search that included studies from inception until 1 August 2018, using a combination of free-text and MeSH terms. Relevant studies were identified using PubMed/Medline, Web of Science, Cochrane CENTRAL, EMBASE, Clinical Trials, WHO International Clinical Trials Registry, Scopus and Google, for grey literature. Reference lists of included studies were also explored. Only studies published in the English language were selected. The search strategy was based on the Peer Review of Electronic Search Strategies (PRESS) Guidelines . The priidelines . The proInitially, two independent reviewers (M.G.G. and K.G.) identified studies from their titles and abstracts. Full-text articles were retrieved to assist decision-making in cases when deemed necessary. Disagreement between the two reviewers was resolved by a third researcher (D.P.B.). per os.RCTs published in the English language were selected when meeting all of the following criteria: (1) having been performed on adult humans, (2) with oral intervention of curcumin vs. either placebo, or no intervention, as an adjuvant therapy. Exclusion criteria involved RCTs performed (1) on animals or (2) children, (3) curcumin intervention delivered in the form of enema instead of Two reviewers (M.G.G. and K.G.) independently extracted characteristics of the retrieved studies and outcomes of interest. The PRISMA flowchart for systematic reviews was applied to capture the step-by-step exclusion of unrelated/duplicate retrieved records. When disagreement was evident, a third reviewer (D.P.B.) resolved the issue.Data was extracted from all RCTs in a predefined data extraction form, including study and participant baseline characteristics, intervention details , comparators, and clinical outcomes to produce summary tables of included studies .The Grading of Recommendations Assessment, Development and Evaluation (GRADE)  was usedMeta-analysis was considered when available information was found from at least three studies, thus it was run only for the primary outcome (remission). Remission was treated as dichotomous variable in the analyses and its available data from the included RCTs were pooled by calculating odds ratios (OR) along with their respective 95% confidence intervals (CI) with the Mantel–Haenszel (M-H) method , in a ra2 statistic. The estimation of OR with their confidence intervals (CI) and the presence of heterogeneity were analyzed with RevMan as specified in the protocol  [® University Edition  with the macro suggested by Sharma et al. [Heterogeneity of included data was assessed with the use of the chi-square test and the In, 2014) . Howevern, 2014) ,31. The The Banerjee trial  demonstrp = 0.02; I2 = 73%) and a moderate level of heterogeneity in the respective PP analysis .According to the M-H method of calculating the OR in RevMan, treatment with curcumin was superior to placebo for achieving remission in the PP analysis of the included studies  should be avoided .Finally, at the time this manuscript was drafted, a meta-analysis on the same topic has appeared in press , publishIn conclusion, the present analyses showed that based on the current available evidence, oral adjuvant curcumin therapy does not appear to contribute to either attaining remission, or ameliorating clinical response among patients with UC. However, absence of evidence is not evidence of absence and, given the heterogeneity demonstrated herein, and the fact that curcumin research is still in the pipeline, caution in needed in data interpretation. Further, well-designed, standardized, long-term RCTs are required, with adequate sample size, rigorous intention-to-treat analyses, sufficient doses and less bias, in order to add weight to the current analyses, produce more robust results and guide clinicians towards/against curcumin supplementation in patients with UC.


Parkinson disease (PD) is the second most common neurodegenerative disease and approximately half of those diagnosed with PD will experience freezing of gait (FOG). FOG is a severe motor disturbance that prevents stepping despite the intention to do so and may be associated with anxiety, decreased cognitive functioning, depression, and poorer quality of life. In this study, we administered the short-form Quality of Life in Neurological Disorders (Neuro-QOL) measurement system to 43 people with PD (28 non-freezers and 15 freezers) and determined freezing status using the New Freezing of Gait-Questionnaire. Freezers had greater motor severity as measured with the MDS-UPDRS-III (p =.003) and poorer balance using the Mini-BESTest (p = .017). Data from the Neuro-QOL battery indicated freezers had greater difficulty with Lower Extremity Function (p = .019) and Upper Extremity Function (p = .027). Freezers also had poorer scores on the Positive Affect and Well-Being (p = .005), Satisfaction with Social Roles and Activities (p = .005), and Stigma (p = .026) scales, but less difficulty on the Communication scale (p = .005) than non-freezers. There were no differences between freezers and non-freezers on the Ability to Participate in Social Roles and Activities, Anxiety, Cognitive Function, Depression, Emotional and Behavioral Dyscontrol, Fatigue, or Sleep Disturbance scales. These findings suggest freezers are less likely to have a positive outlook and satisfaction with their daily lives in combination with poorer functioning. Interventions that target freezing with the potential to improve functioning may result in better quality of life among freezers.


More than ten years ago, artificial restriction DNA cutters were developed by combining two pseudo-complementary peptide nucleic acid (pcPNA) strands with either Ce(IV)/EDTA or S1 nuclease. They have remarkably high site-specificity and can cut only one predetermined site in the human genome. In this article, recent progress of these man-made tools have been reviewed. By cutting the human genome site-selectively, desired fragments can be clipped from either the termini of chromosomes (telomeres) or from the middle of genome. These fragments should provide important information on the biological functions of complicated genome system. DNA/RNA hybrid duplexes, which are formed in living cells, are also site-selectively hydrolyzed by these cutters. In order to further facilitate the applications of the artificial DNA cutters, various chemical modifications have been attempted. One of the most important successes is preparation of PNA derivatives which can form double-duplex invasion complex even under high salt conditions. This is important for in vivo applications, since the inside of living cells is abundant of metal ions. Furthermore, site-selective DNA cutters which require only one PNA strand, in place of a pair of pcPNA strands, are developed. This progress has opened a way to new fields of PNA-based biochemistry and biotechnology. Site-selective scission of DNA is one of the key techniques in DNA manipulation and DNA nanotechnology . In orde9 bp) can be selectively cut at only one site with this man-made cutter (420 >> 3 × 109) . A . A 35]. The next target is consecutive homopyrimidine/homopurine sequences which are also crucial for a range of cell functions  ,37. Doub+, Na+, and Mg2+ in the typical living cells are 140, 10, and 0.5 mM, respectively).High salt conditions are unfavorable for double-duplex invasion of pcPNA, since DNA duplex is stabilized under these conditions due to decreased electrostatic repulsions between negatively charged phosphodiester linkages. Thus, site-selective DNA scission by ARCUT, which is based on the invasion of pcPNA, is inefficient . This shortcoming must be solved for further applications, especially in vivo, since the inside of cells is abundant in metal ions . Upon the addition of Ce(IV)/EDTA, the target site was successfully cut . In this strategy, a 16 bp sequence in DNA was precisely recognized (10 bp by the double-duplex invasion of the two pcPNAs and 6 bp by the minor groove binding of the polyamide.The first strategy to solve this problem is to take advantage of the cooperation of double-duplex invasion of pcPNA with minor groove binding of a pyrrole/imidazole (Py-Im) polyamide  39]. Th. Th39]. Conjugation of pcPNA with a nuclear localization signal (NLS) peptide allows the double-duplex invasion to occur under high salt conditions (a PKKKRKV peptide is attached to the terminus of PNA) . PrimariIn the first-generation ARCUT, the scission site is activated by double-duplex invasion of two pcPNA strands to DNA. Two pcPNA strands are required to bind to the two DNA strands through Watson-Crick pairing and sufficiently compensate the energy loss due to the partial raveling of double-stranded DNA. In new strategies, however, only one PNA can successfully bind to double-stranded DNA through covalent or non-covalent approaches. By combining these strategies with Ce(IV)/EDTA (or S1 nuclease), a site-selective DNA cutter using only one PNA derivative has been developed see .In one-PNA systems, pseudo-complementary bases to suppress the formation of PNA/PNA duplexes are unnecessary. Furthermore, they are advantageous from both kinetic and thermodynamic viewpoints, especially for in vivo applications.The conjugate of PNA with NLS, presented in The PNA-NLS conjugates are easily transfected into cells without any transfection agent and preferentially localized in nuclei there. Thus, these conjugates are highly promising as antigene agents . Recentl(s)−Meγ-PNA of 15 nucleobases successfully invaded to the complementary site in either strand of double-stranded DNA. There was no specific limitation in the sequence, and the mismatch recognition was satisfactory. This efficient one-strand invasion is ascribed to preorganization of this DNA analog in a right-handed helix, which stabilizes the duplex with complementary DNA. The energy, required to invade to double-stranded DNA, can be satisfactorily paid off by the formation of only one DNA/(s)−Meγ-PNA duplex (15 bp). Consistently, the one-strand invasion never occurred when the (s)−Meγ-PNA was shorter .Several strategies were reported to promote unimolecular invasion of PNA. When an (S)-methyl stereogenic center is introduced to the γ-position of PNA backbone , only onAddition of single-stranded DNA binding protein is effective for unimolecular invasion of PNA to double-stranded DNA . There, The inside of living cells is largely occupied by proteins and other biomolecules and, thus, its physicochemical properties are much different from the bulk aqueous phase. These intracellular environments (molecular crowding effects) have been successfully simulated by the addition of polyethylene glycol to aqueous solutions. It was shown that molecular crowding conditions greatly promote the invasion of a pair of pcPNA to double-stranded DNA . Under mAccording to Sugimoto et al. ,51, bothAt present, PNA invasion have been detected and analyzed mostly by electrophoretic mobility shift assay. The band shift observed in these assays is mainly due to the induction of a kink or a bend by the invasion. In some cases, however, it is difficult to tell whether the invasion does not really occur or the structural change is simply too small. More universal assay systems are required to facilitate the study of PNA invasion. In order to obtain a more definite conclusion through visual information, a “single-molecule” visual probe was developed using nanomechanical DNA origami pliers  52]. Th. Th52]. Site-selective DNA cutters (ARCUT), previously developed by our group, are composed of two strands of pcPNA and Ce(IV)/EDTA complex. For some purposes, S1 nuclease can be used, in place of Ce(IV)/EDTA. Recently, these man-made cutters have been employed for various practical applications. One of the promising examples is to use the genomic fragments for the construction of nanoarchitectures. Since the epigenetic information is kept intact, they should be much different from the ones involving unmodified DNA in structures and other physicochemical properties. At the same time, various covalent and non-covalent modifications of ARCUT have been attempted to promote the invasion and improve the site-selective DNA scission. Some problems of the first-generation ARCUT  have been solved. Site-selective activation of double-stranded DNA by a single PNA strand has been also accomplished to provide new types of site-selective DNA cutters. Furthermore, the “molecular crowding effect”, which characterizes the specific environments in cells, has shown to facilitate the double-duplex invasion. All these results confirm that ARCUT, based on double-duplex invasion of pcPNA, should be highly promising for future applications in biochemistry, biology, medicine, and biotechnology. Compared with currently available protein-based DNA cutters , ARCUT is completely chemistry-based and advantageous in that any functional group can be straightforwardly introduced through chemical modification. Based on sophisticated molecular design, unprecedented functions, which cannot be exhibited by protein-based cutters, should be accomplished both in vivo and in vitro.


Furthermore, to reduce the drain field influence on the channel region, we also studied the effect of asymmetric drain extension length on a Dual-kk FinFET structure. It can be observed that the new asymmetric drain extension structures significantly improve the cutoff frequency (Tf) and maximum oscillation frequency (maxf) given the significant reduction of inner fringe capacitance towards drain side due to the shifting of the drain extension’s doping concentration away from the gate edge. Therefore, the asymmetric drain extension Dual-kk trigate FinFET (AsymD-kkDE) is a new structure that combines different Dual-k spacers on the source and drain and asymmetric drain extension on a single silicon on insulator (SOI) platform to enhance the almost all analog/RF FOM. The proposed structure is verified by technology computer-aided design (TCAD) simulations with varying device physical parameters such as fin height, fin width, aspect ratio, spacer width, spacer material, etc. From comprehensive 3D device simulation, we have demonstrated that the proposed device is superior in performance to a conventional trigate FinFET and can be used to design low-power digital circuits.Among multi-gate field effect transistor (FET) structures, FinFET has better short channel control and ease of manufacturability when compared to other conventional bulk devices. The radio frequency (RF) performance of FinFET is affected by gate-controlled parameters such as transconductance, output conductance, and total gate capacitance. In recent years, high-k spacer dielectric materials for manufacturing nanoscale devices are being widely explored because of their better electrostatic control and being less affected by short channel effects (SCEs). In this paper, we aim to explore the potential benefits of using different Dual-k spacers on source and drain, respectively: (AsymD-kk) trigate FinFET structure to improve the analog/RF figure of merit (FOM) for low-power operation at 14 nm gate length. It has been observed from the results that the AsymD-kk FinFET structure improves the coupling of the gate fringe field to the underlap region towards the source and drain side, improving the transconductance ( The introduction of FinFET technology has become an important milestone in the electronics industry. Commercially, Intel started using trigate FinFET technology at 14 nm ,3,4. AmoonI without any significant degradation in outer fringe capacitance. A detailed capacitive analysis of symmetric and asymmetric Dual-k FinFETs for improved circuit delay metrics can be found in [onI/offI) and cutoff frequency (Tf), with the disadvantages of parasitic capacitance increasing and slightly lower intrinsic gain (vA). A comprehensive study of optimal device parameters and RF/analog FOM due to permittivity spacers on circuit performances is still critically required.At device level, several researchers have focused on the integration of high-k materials as a gate-dielectric or spacers ,12,13,14finH), fin width (finW), aspect ratio (AR = finH/finW) and Source/Drain extension length (extL), studying its effect on RF/analog performance compared to conventional Dual-k spacer-based underlap SOI FinFETs. As these design parameters determine the FOM as well as other processing challenges, an analysis of the key parameters is crucial for achieving a reduction in device dimensions. The rest of the paper is arranged as follows. This paper investigates the effect of using high-k spacers and its length from the circuit perspective and optimizes the device architecture for better RF/analog performance. Meanwhile, we have focused on variation of fin height  and drain , and outer low-k spacer material  that contrasts with the different device structures, namely both side low-k spacers , both side Dual-k spacer , and source side only Dual-k spacer . The physical and electrical parameters are calibrated to meet the specifications according to ITRS projections for 14 nm physical gate length (gL) [finW), fin height (finH), and equivalent oxide thickness (EOT) are 6 nm, 20 nm, and 0.8 nm, respectively. The metal-gate work functions are tuned to 4.45 eV for p-type to achieve a requisite threshold (thV) at a supply voltage of 0.9 V. Source/Drain (S/D) extension region uses Gaussian-doping profiles followed by a later doping gradient of 3 nm/decade. The S/D extension length (extL) is taken as 20 nm . The channel and underlap regions are lightly doped with a boron concentration of 1 × 1016 cm−3 to reduce random dopant fluctuations (RDF) [The asymmetric Dual-kk trigate underlap FinFET under study is shown in rain Si3N,12 nm, ans (RDF) . The raigT) is nearly twice the gate length value [hkL) and outer low-k spacer length (lkL) are tuned to 12 nm and 8 nm, respectively, for an underlap length (extL) of 8 nm. The thickness of the buried-oxide (BOX) layer is 25 nm. maskT represents the hard mask thickness on top of a silicon fin. polyT is the geometrical thickness of the gate material on top of the hard mask layer. oxT is the thickness of the gate oxidation. The nominal device parameters are listed in Moreover, to consider the gate-to-source/drain (G-S/D) capacitance, metal contacts are taken into consideration. The gate-electrode thickness  active region, depend on the geometry of the transistor and bias conditions [nditions . The parnditions .Tf) and the maximum oscillation frequency (maxf), are evaluated using the following equation [ggC = ggeC + ggiC, mig and dig are the intrinsic transconductance and output conductance, respectively, and seR is the parasitic source resistance.Two RF figures of merit, namely, the current-gain cutoff frequency (equation :(1)fT=gmmaxf, thanks to the reduction of the total extrinsic gate capacitance as well as the source and gate parasitic resistances. Therefore, optimal geometric parameters adjustments can produce improvements in Tf and maxf.The optimization of the fin geometry will have also an impact on dsI = 10 μA/μm targeting weak/moderate inversion regime of operation. Cutoff frequency (Tf) is extracted from current gain (h21) through an extrapolation of the –20 dB/decade slope, whereas maximum oscillation frequency (maxf) is extracted from Mason’s unilateral gain (MUG) through an extrapolation of –20 dB/decade slope. The maximum oscillation frequency is a figure of merit related to the capability of the device to provide maximum available power gain at a large frequency [finH in accordance with the effective spacer formation step [Three-dimensional simulations of devices were carried out using a TCAD 3D Sentaurus device simulator activating modified local-density approximation (MLDA) quantization model, a Lombardi mobility model accounting for mobility degradation at the semiconductor–insulator interface, a doping dependence SRH recombination or generation for deep defect levels at the gaps, a band to band auger recombination, and old slot boom bandgap narrowing phenomenon . The RF/requency . Heavilynt gain h through mg and dsg [onI, offI, mg, dsg, ggC, Tf, output resistance (oR), and gain (vA) are evaluated and the sensitivity of said parameters with finH, finW, and extended length (extL) are systematically presented. Subsequently, we selected a fixed extL of 20 nm with HfO2 and Si3N4 on source and drain, respectively, as inner high-k spacer length (hkL) and other varied parameters to study the effects of gate electrostatic integrity (EI) and in turn its effect on variations of RF/analog FOM of FinFET. Relying on the analysis of the experimental data, the AsymD-kk FinFET optimum parameters are selected and determined.The use of high-k sidewall spacers can better screen the gate fringe field towards the source/drain side over the underlap region. This increases the fringe field coupling between the gate and underlap regions and lowers the barrier of the underlap region in the strong inversion region . For wea and gds . ConsequTf and maxf as traditional scaling of a FinFET is only achievable by choosing the optimal value of finH and finW. This phenomenon has been confirmed in [finH/finW), the height may concentrate larger internal stresses in their relatively narrow base, causing fracture and in turn operational failure [Taller fins are required for high-drive current and matching the current drivability, whereas narrow fins ensure better SCE immunity. It is important to forecast improvement in irmed in ,23. Howe failure .offI, and onI are increasing with the increase in finH. Hence, for higher current drivability and better SCE immunity, taller fins are required. When introducing the asymmetric Dual-kk spacer at source and drain side, the gate has more control over the channel, which results in a reduction in offI and improvement of onI. So it has been noticed that Dual-k structure shows a consistently higher onI/offI improvement (~1.6 times) in comparison with the conventional structure, followed by AsymD-kk and AsymD-kS structures. Moreover, AsymD-kk structure showed the highest improvement in mg by 50.39% with respect to the conventional structure, followed by AsymD-kS and Dual-k structures. Dual-k structure shows the lower value of dsg (~58.71%) in comparison to other structures. AsymD-kk and AsymD-kS structures show almost the same value of dsg at a height below 15 nm; subsequently, the AsymD-kk structure has a lower dsg and an improved finH. ggC and output resistance oR with respect to fin height. The Dual-k structure shows the maximum ggC followed by AsymD-kS, AsymD-kk, and conventional structures. Moreover, AsymD-kS and AsymD-kk structures show almost the same value of oR, which is lower than that obtained for a Dual-k structure. This shows that the AsymD-kk structure has the potential to reduce parasitic feedback capacitance and thereby improves the gate control over the channel region, resulting in the reduction of SCEs at short channel lengths.vA, followed by AsymD-kS, AsymD-kk, and conventional structures. However, the AsymD-kk structure shows a slight reduction (~14.49%) in vA in comparison with the Dual-k structure, but is higher than the AsymD-kS structure (about 8.48%). Compared to the increase in transconductance, the improvement of dsg is more obvious, resulting in a slight decrease. Meanwhile, as can be seen from the figure, the AsymD-kk structure has the best Tf (~29.69%) in comparison with the conventional structure, followed by AsymD-kS and Dual-k structures. As we know, maxf is inversely proportional to (dsg + 2π TCggf)1/2 [Tf is counteracted by the reduction in dsg for the AsymD-kk structure in comparison to other structures. Therefore, maxf is highest for the AsymD-kk structure with the variation of finH. Considering the manufacturing challenges and limited performance improvements of taller fins, it is desirable to aim for a AsymD-kk structure FinFET with suitable fins (~20 nm) that outperforms the other structures in all FOMs.As shown in TCgg)1/2 ; an incrfinW, the longitudinal electric field at the source end of the device can be easily screened out, which increases the EI. However, as the transistors are scaled down, variations in critical transistor attributes such as finW and extL are becoming major issues in transistor design. The variations become larger as the feature sizes approach the fundamental dimensions such as the size of atoms and the wavelength of usable light for patterning lithography masks [Due to the close proximity of multiple gates at smaller hy masks . Of partfinW. At the aforementioned technology node, we have varied the finW from 0.2 gL to 1.2 gL. By choosing a smaller finW, we are able to minimize the longitudinal electric field. However, as scaling approaches the fundamental dimensions such as atomic size range and the sensitivity of the device, the parameters have a greater impact on the device performance, particularly in the case of RF/analog performance. It is observed that narrow fins are preferred for achieving higher onI/offI compared to low-k FinFET. From highest to lowest, we have Dual-k, AsymD-kk, and AsymD-kS structures. Also, we notice that mg, dsg, and ggC increase almost linearly with increasing finW. The AsymD-kk structure has the highest improvement in mg (~51.38%) and the lowest value of ggC (~6.12%) in comparison to the conventional structure, followed by the AsymD-kS and Dual-k structures at a fin width of less than 10 nm. The Dual-k structure shows a lower value of dsg in comparison to other structures. However, the AsymD-kS and AsymD-kk structures show almost the same value of dsg. All designs show almost the same value of oR when varying finW.vA with respect to the fin width. It can be noticed that the AsymD-kk structure has the highest improvement in Tf (~25.11%) compared to the conventional structure, followed by the AsymD-kS and Dual-k structures. Meanwhile, despite the increase in mg, there is a large improvement in the dsg value for lower finW values. The AsymD-kk structure shows a lower vA (~18.06%) compared to the Dual-k structure, but outperforms traditional structures 1.11-fold. In addition, the percentage improvement in Tf of the AsymD-kk structure is limited below 0.5 gL. This may be attributed to the fact that the effective screening of gate fringing fields is improved with finW scaling, thereby increasing the gate capacitance. Therefore, designing AsymD-kk FinFET with AR ~3 and finW in the range 0.5–0.7 gL is a better option as compared to low-k FinFET.finH and extL. An increase in underlap extension length (extL) improved the gate controllability with reduced SCEs because of a shift in the lateral electric field from the gate edge toward the drain. Gate fringe-induced barrier lowering (GFIBL) has been observed in undoped underlap FinFET with an increase in the dielectric constant of the spacer region (extL) [A similar type of analysis as that employed in the previous section was systematically discussed for the variation of n (Lext) . The barextL). It is worth noting that the offI, onI, mg and dsg of both designs decrease linearly with an increase in extL due to a reduction in gate control over the increased effective channel region. Compared to the conventional structure, the Dual-k structure is preferred to achieve higher onI/offI, followed by AsymD-kk and AsymD-kS, but the percentage improvement in onI/offI is reduced at higher extL Additionally, AsymD-kk structures have the highest value of mg (~57.19%) and lowest value of dsg (~27.44%) with respect to the conventional structure. Simultaneously, AsymD-kk has a minimum value of ggC (~6.45%) and slightly larger oR compared to other structures. However, the total gate capacitance has a greater impact on the performance of the device than oR, and we can change other key device parameters to adjust the output resistance to the adaptive demand of the design.Tf of AsymD-kk FinFET is higher when varying extL compared to its counterparts. From the chart, the percentage reduction in ggC is less than that found for mg, with an increase in extL Therefore, AsymD-kk shows a slight reduction in Tf with extL, which is shown in vA compared to conventional structures, followed by AsymD-kS and AsymD-kk, but almost no variation with an increase in value of extL Therefore, the FOM improvement of the AsymD-kk design is enhanced at approximately extL ~20 nm, as shown in It can be noticed from hkL is varied from the gate to the source/drain edges for a fixed underlap length (unL) of 8 nm. Consequently, the same spacer extension length (extL = hkL + lkL) of 20 nm is selected for AsymD-kk FinFET, selecting optimized hkL from 0 nm to 20 nm for analysis.As the devices are scaled down to nano-scale regime formation, an ultra-shallow junction (USJ) can control the lateral electric field spread into the channel region . The lenoffI and onI increase linearly with increasing hkL. The parasitic resistance problem can be avoided by using higher hkL, which further increases the drain current and improves the SCE immunity. Meanwhile, by comparing the data in the figure, we can confirm that hkL ~12 nm represents the optimum predicted scenario. The AsymD-kk structure shows greater values of mg and dsg with respect to variation of hkL compared to the Dual-k and AsymD-kS structures. Furthermore, the AsymD-kk structure has a lower value of ggC and average oR compared with other structures. At this appropriate length (~12 nm), we can obtain the maximum Tf and vA, and a relatively smaller gate capacitance. When compared to the Dual-k structure, the AsymD-kk structure has a lower vA (~7.35%) because the improvement in mg is found to be less than that of dsg. However, the AsymD-kk structure shows the highest value of Tf (~18.79%). Also, the device acquires an appropriate threshold voltage (thV) and subthreshold slope (SS), which can better suppress the short channel effect and drain-induced barrier lowering (DIBL). Therefore, the FOM improvement of the AsymD-kk design is enhanced at approximately hkL ~12 nm, as shown in It can be observed from vA, all other analog parameters are better in the AsymD-kk structure than in the Dual-k structure. Simultaneously, it was found that the AsymD-kk structure outperforms the other two structures in terms of dsg, resulting in a slight reduction (~14.49%) of vA, despite having an increased value of mg. However, the AsymD-kk structure shows improvement in mg, Tf, and maxf and a reduction in ggC in comparison to the Dual-k and AsymD-kS structures. The main reason for the observed improvement of dsg compared with mg of the AsymD-kk structure is that there is less screening of the gate electric field towards the drain side since there is a lower high-k spacer towards the drain side in AsymD-kk structure, unlike in Dual-k structures. From the previous analysis of AsymD-kk spacer structures, it was found that, with the exception of DE  structure. This section describes the potential benefits of using AsymD-kkDE to further improving the analog/RF FOM. offI and onI with respect to the drain extension length (extDL) at a fixed source extension length (extSL) of 20 nm of the AsymD-kkDE structure. As we increase extDL from 20 nm to 40 nm, a reduction in offI (~27.67%) and onI (~30.81%) can be observed. Moreover, AsymD-kkDE shows a consistent onI/offI compared to the Dual-k structure. Additionally, it was shown to have a higher onI/offI improvement (~3.57%) in comparison with AsymD-kS. In addition, mg and dsg decrease from 10.131 μS/μm to 1.475 μS/μm (~85.25%) and 0.719 μS/μm to 0.084 μS/μm (~87.02%), respectively. To reduce the effect of the drain over the channel region and retain the Dual-k structure of the source and drain, we used an AsymD-kkDE structure has lower values of ggC and oR compared to other structures when extDL has a value of approximately 30 nm. An increase in extDL shifts the drain doping away from the gate edge towards the drain side, resulting in a reduction of gdC. However, increasing ggC is due to fewer SCEs in the AsymD-kkDE structure because of the increased extDL [gsC and gdC translates into a decrease in ggC by 38.57%, with an increase in extDL, as shown in The AsymD-kked LextD . The comdsg is more significant than for mg Therefore, vA from 23.77 to 30.13 dB with an increase in extDL from 20 nm to 30 nm. This is followed by a slight reduction to 24.88 dB until the length of extDL reaches 40 nm. Moreover, the AsymD-kkDE structure shows an improvement in Tf (~2.48%) and maxf with an increase in extDL from 20 nm to 30 nm. Subsequently, it goes slightly down as it approaches 40 nm. This shows that there is a range of values of extDL (~30 nm), which results in a better performance observed from simulating RF/analog devices.The reduction in DE structure, we also studied the Dual-k and AsymD-kS structures with asymmetric drain extension. As seen in the figure, the conventional structure with asymmetric drain extension has a better performance in almost all analog/RF FOM, except a slight reduction in mg and dsg in comparison to the conventional structure without drain extension. This occurs because of a significant reduction in inner fringe capacitance towards the drain side due to a shifting of the drain extension’s doping concentration away from the gate edge. It would not be appropriate to say that the improvement is produced by only an AsymD-kk spacer at the source or only by the asymmetric drain extension. However, observing the simulation results, the AsymD-kk structure shows more significant improvement in mg and dsg, and the asymmetric drain extension structure shows more significant improvement in Tf and a lower gain reduction. If we compare the AsymD-kk structure to other structures, it shows superior values of mg, dsg, Tf, and maxf, with a slightly reduced value of vA.To understand the contribution of asymmetric drain extension on the analog/RF performance of the AsymD-kkmg and dsg values of the device. Moreover, AsymD-kk structures show better performance in almost all analog/RF FOMs in comparison to the conventional structures for low-power operation with the exception of intrinsic gain, which was found to be lower. Therefore, further improvement in vA and Tf of the AsymD-kk structure can be obtained by introducing asymmetricity in drain extension regions (the AsymD-kkDE structure). From the simulations, it has also been observed that the AsymD-kkDE structure shows an improvement in mg by ~9.09%, in dsg by ~13.04%, in Tf by 12.91%, in vA by 19.47%, and also a reduction in ggC by 40.41% in comparison with the Dual-k structure at drain extension length extDL of 30 nm. Finally, from the reported results, it can be concluded that AsymD-kkDE FinFET is outperformed as compared to Dual-k FinFET for designing 14 nm low-power and high-frequency RF/analog circuits or robust SRAMs in FinFET technology, just selecting the optimal structural parameters. In future work, we will study the effect of various K values on RF/analog circuits and the improvement of delay performance.Asymmetric drain extension Dual-kk trigate underlap FinFET is an attractive option for designing circuitry for 14 nm low-power and high-frequency battery-operated portable devices given the improved RF/analog FOMs that they offer. It has been found that an asymmetric Dual-kk spacer strongly affects the


Considering the rate of growth of the older population in several countries, accidental falls in older cyclists are expected to increase. However, the prevalence and correlates of bicycle-related falls  are unknown. The aim of the present study was to explore the characteristics of BR-falls, focusing on the risk factors.Seven-hundred and ninety-one older adults participated in a comprehensive baseline assessment that included questions on bicycle use, BR-falls, lifestyle, and physical and cognitive evaluations. A cyclist was defined as a person who cycled at least a few times per month. The incidence of BR-falls in participants who did not report BR-falls at baseline was again ascertained 3 years later. Logistic regression analyses examined the predictors of BR-falls incidence.At baseline, 395 older adults were cyclists and 45 (11.4%) of them had experienced BR-falls. Adjusted regression analysis showed that slower gait velocity, shorter one-leg standing time, and experience of falls  were associated with BR-falls. Among the 214 cyclists who did not report BR-falls at baseline and who participated in both baseline and follow-up assessments, 35 (16.4%) cyclists experienced BR-falls during the 3-year follow-up. Adjusted regression analysis revealed that higher body mass index and non-BR-falls were predictors of future incidence of BR-falls, independent of physical function.Our results showed that experience of falls, irrespective of bicycling, is an independent correlate and risk factor of BR-falls. This suggests that experience of falls and BR-falls may share the same risk factors. This may result in the maintenance of physical and social functions.Bicycling is a convenient means of transportation and can help improve overall health. Considering that the population is aging in both developing and developed countries, particularly among Asian countries, the number of older cyclists will be expected to increase. A recent large-scale mail survey indicated that 63% of community-dwelling Japanese older adults in urban areas routinely ride bicycles.3 Bicycling-related falls  have high injury risks and thus may lead to adverse health outcomes, such as severe abrasion and fractures. Although the understanding of the prevalence of BR-falls and related risk factors among older adults may provide suggestive information to promote an age-friendly city, the prevalence and risk factors are poorly known.Although bicycling includes several expected health benefits for older adults, being an older cyclist may predispose cycling older adults to accidents, particularly falling during bicycling, due to impaired abilities of older cyclists compared to young cyclists.The purpose of this study was to investigate the prevalence of BR-falls and their risk factors among community-dwelling older adults, using longitudinal/observational data from the Tokyo Metropolitan Institute of Gerontology (TMIG) Longitudinal Study.2,4Data were collected from an ongoing longitudinal study, named “Otassha”, aimed to examine the physical and cognitive functions for daily activities among community-dwelling older adults. Design and logistics have been described in detail elsewhere.On the basis of the annual registration of local residents, recruitment letters for health checkup were mailed to older adults aged 65 years and over, who were dwelling in an urban area  from 2010. Participants were included in the analysis if they participated in the health checkup and answered a question regarding bicycle-related information, which was introduced in 2013 and 2016. In 2013, 2,022 older adults were recruited, and 2,497 participants were recruited in 2016. Participants who received additional assistance with their activities of daily living (ADL), had serious conditions or injuries , or did not complete all measurements, were excluded.The study was conducted in accordance with the ethical standards of the Declaration of Helsinki (1983). Ethics approval was obtained from the Tokyo Metropolitan Institute of Gerontology and participants’ signed informed consents, obtained at enrollment prior to study assessments.2 Regular cyclists were then included in the analysis.Experience of BR-falls was defined as an unexpected event in which participants came to rest on the ground while bicycling in the past year. For subjective confidence in bicycling, participants responded “yes/no” to the question: “Do you have confidence in your bicycling?”. Participants were also asked about the frequency of bicycling; responses were categorized as “every day”, “a few times a week”, “a few times a month”, “a few times a year”, or “very rarely”. The participants who responded “every day” to “a few times a month” and “a few times a year” or “very rarely” were categorized as regular and irregular cyclists, respectively.5 and Zung Self-Rating Depression Scale (SDS),6 respectively. Non-BR-falls were defined as any unintentional drops/falls to the ground or floor, excluding bicycle accidents, accidental contact with furniture, walls, or other environmental structures and sudden cardiovascular or central nervous system events .7All participants were interviewed by a nurse who assessed their health-related characteristics, including demographics, comorbidities, history of hospitalization, medication, and body mass index (BMI). The frequency of going outdoors, fall history in the previous year without bicycling , functional capacity , depression symptom, and fear of falling were also assessed by a trained interviewer. Functional capacity and depression symptoms were measured using TMIG Index of Competence (TMIG-IC)4,8 Cognitive function was assessed using both the Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment, which are widely used tools for assessing global cognition.9Physical ability was assessed using handgrip strength in the dominant hand, one-leg standing with eye opened, 5 m comfortable walking speed, and the timed up and go (TUG) test.2 test for categorical variables and t-tests for continuous variables. Logistic regression analyses were then performed to examine the correlated factors of previous BR-fall on the basis of all resultant significant differences. Regression analyses were adjusted for age, sex, BMI, comorbidities, number of medications , and frequency of riding a bicycle.Comparison between cyclists who experienced or did not experience BR-falls was made using the χFor cyclists who did not report BR-falls at baseline, differences in measurement items at baseline between participants who did not report BR-falls and those who reported new incidents of BR-falls at the follow-up assessment were compared in the same manner as the aforementioned analyses. Adjusted logistic regression analysis was also performed to elucidate the risk factors of incident of BR-falls on the basis of all resultant significant differences, similar to the cross-sectional analysis.P values less than 0.05 were considered statistically significant.All statistical analyses were performed using IBM SPSS Statistics, version 20.0 , and A total of 791 community-dwelling older adults participated in the baseline assessment in 2013. One hundred and three participants met the exclusion criteria, 55 participants had never ridden a bicycle, and 238 participants were irregular cyclists . In total, 395 older adults  with a mean age of 72.3  years were included in the cross-sectional analysis.At the baseline, 45 participants (11.4% of regular cyclists) had experience of BR-falls. These falls were mainly due to stumbling on uneven surfaces and the curb (31.1%), losing their balance due to an operational error (31.1%), or, being surprised by or avoiding pedestrians or cars (22.2%). Compared with cyclists who did not experience BR-falls, those who experienced BR-falls showed slower gait velocity, longer TUG time, shorter one-leg standing time, higher SDS score, more fear of falling, and more experience of non-BR-falls  reported BR-falls during the 3-year follow-up. In total, 214 participants were included in the longitudinal analysis.At the follow-up assessment, 35 participants had incident BR-falls . Among cyclists who experienced new BR-falls during the 3-year follow-up, 11 (31.4%) were treated at the hospital for their injury. Comparison analyses using baseline variables showed that cyclists who experienced new BR-falls showed higher BMI, shorter one-leg standing time, lower TMIG-IC score, and more non-BR-falls  is a risk factor of BR-falls. In other words, we found that even older adults who were likely to fall rode a bicycle regularly.In the cross-sectional analysis, slower gait velocity and shorter one-leg standing time, as well as non-BR-falls were associated with experience of BR-falls. This is a reasonable result since the ability to ride a bicycle requires sufficient physical abilities  to ride stably with appropriate body and limb control. Older cyclists with lower physical abilities may thus experience previous BR-falls.10 suggesting that this motor-control skill may be associated with increased BR-falls. Also, increased fall risk is associated with elevated co-contraction in the ankle during static balance challenges in older adults.11 These deficits in limb control may contribute to incidents of both BR-falls and non-BR-falls.The longitudinal association between non-BR-falls and BR-falls was independent of decreased physical functioning, such as slow gait and poor balance. This robust association suggests that these falls may share the same risk factors, other than the variables measured in this study. For example, a recent study showed that compared with young adults, the increased co-contraction of the upper limb among older cyclists is higher during perturbed cycling,12 Although we did not observe significant physical impairments, older adults with higher BMI could lack physical abilities required for bicycling.Our result also showed that increased BMI was an independent predictor of future incidents of BR-falls. This is somewhat reasonable because the overweight cyclist is thought to require sufficient physical abilities to ride a bicycle compared with non-overweight cyclists, due to the increased load. Furthermore, impaired gait and postural control and increased risk of falling have been reported in obese individuals.The practical implication of the present study is that, although bicycling can provide health benefits by expanding life space and by fostering the physical/social functions of older adult, caution should be taken when older adults who have experienced falls, independent of bicycling, attempt to use a bicycle. Since 65.4% of older cyclists reported recurrent BR-falling, cyclists who have experienced BR-falls should also be careful while bicycling. Although our study area, located in Itabashi Ward, Tokyo, has a relatively narrow footpath, bicycle riders generally use the footpath due to the heavy traffic congestion along the roads. Also, considering the result that the percentage of frequent bicycle riders tended to be higher in cyclists who experienced new BR-falls, bicycle lanes and other human-powered vehicles designed for fall prevention, such as tricycles, are important for the safety and comfort of such older cyclists.To our knowledge, this is the first study to provide information on the characteristics of BR-falls  among older adults, which can provide basis for the prevention of accidents among older cyclists. However, differences in the environmental factors and the traffic regulations between Japan and other countries , as well as the high-functionality of the participants in the present study may limit the generalizability of our results. Further multi-country research is needed to confirm the results of the present study in diverse populations.In conclusion, we found that about one in five older cyclists newly fell while bicycling over the 3-year follow-up. Our results also showed that experience of falls unrelated bicycling was a significant risk factor of BR-falls, which is independent of decreased physical functioning. This implies that motor and cognitive factors not measured in this study might have influenced both non-BR-falls and BR-falls.