Objective: Emotional disturbance is a common complication of stroke significantly affecting functional recovery and quality of life. Identifying relevant neurophysiologic markers associated with post-stroke emotional disturbance may lead to a better understanding of this disabling condition, guiding the diagnosis, development of new interventions and the assessments of treatment response.Methods: Thirty-five subjects with chronic stroke were enrolled in this study. The emotion sub-domain of Stroke Impact Scale (SIS-Emotion) was used to assess post-stroke mood and emotional control. The relation between SIS-Emotion and neurophysiologic measures was assessed by using covariance mapping and univariate linear regression. Multivariate analyses were conducted to identify and adjust for potential confounders. Neurophysiologic measures included power asymmetry and coherence assessed by electroencephalography (EEG); and motor threshold, intracortical inhibition (ICI) and intracortical facilitation (ICF) measured by transcranial magnetic stimulation (TMS).Results: Lower scores on SIS-Emotion was associated with (1) frontal EEG power asymmetry in alpha and beta bands, (2) central EEG power asymmetry in alpha and theta bands, and (3) lower inter-hemispheric coherence over frontal and central areas in alpha band. SIS-Emotion also correlated with higher ICF and MT in the unlesioned hemisphere as measured by TMS.Conclusions: To our knowledge, this is the first study using EEG and TMS to index neurophysiologic changes associated with post-stroke mood and emotional control. Our results suggest that inter-hemispheric imbalance measured by EEG power and coherence, as well as an increased ICF in the unlesioned hemisphere measured by TMS might be relevant markers associated with post-stroke mood and emotional control which can guide future studies investigating new diagnostic and treatment modalities in stroke rehabilitation. Emotional disturbance is a common complication of stroke  are still unknown. Different mechanisms including direct effects of ischemia to mood regulating neural networks  is a safe, cost-effective technique used to assess cortical activity and has been valuable in assessing emotion related networks. Among the qEEG parameters, frontal alpha power asymmetry has been especially of interest given its relation to emotional processes and pathological conditions such as major depressive disorder (MDD) and anxiety  is another technique that is useful in assessing cortical activity in both MDD and stroke. TMS studies assessing changes in cortical activity in patients with MDD have shown decreased excitability in the left hemisphere  and several neurophysiologic measures obtained by EEG and TMS when adjusted for potential confounders such as age and time since stroke. Given that hemispheric asymmetry plays an important role in both stroke and mood disorders, we hypothesized that post-stroke changes in mood and emotional control is associated with inter-hemispheric imbalance that can be indexed by EEG and TMS.This study analyzes the secondary data from 35 participants with chronic stroke who were initially enrolled in a larger clinical trial that compares different rehabilitation techniques. All subjects were over the age of 18 years, clinically stable and had clinical and neuro-imaging based diagnosis of stroke within 6–36 months prior to enrollment. The exclusion criteria were: (1) Mini-Mental Examination score lower than 24 or, for aphasic patients, inability to understand the rehabilitation tasks, (2) more than 1 stroke event, (3) psychoaffective disorders that prevented adherence to treatment and (4) joint damage and pain or deformities that makes the implementation of the therapy infeasible. Since the subjects were enrolled to participate in a trial assessing the effectiveness of rehabilitation techniques, some of these criteria were related to application of rehabilitation techniques. The study was approved by the Local Ethics Committee and a written consent was obtained from each subject.The Brazilian version of SIS 3.0 was used to measure quality of life and impact of stroke. For the purpose of this study we only analyzed the “emotion” sub-domain of SIS as a measure of mood and emotional control. SIS-Emotion consists of nine-items and has shown good criterion validity when compared to SF-36 Mental Health and Geriatric Depression Scale for SIS 2.0  assessment to test the association between motor impairment and SIS-Emotion. We also used FM to show that EEG and TMS findings of this study are specific to mood and emotional control.TMS assessments included both single pulse and paired-pulse TMS protocols. We measured motor threshold (MT), intracortical inhibition (ICI), and intracortical facilitation (ICF) for both lesioned and unlesioned hemispheres. Motor threshold was defined as the minimum stimulus intensity necessary to elicit a motor-evoked potential (MEP) with the amplitude of at least a 50 μV in %50 of the trials. MEPs were recorded from first dorsal interosseous muscle (FDI). In the absence of MEPs, a maximum value of 100% was accepted as the MT. Paired-pulse protocol was used to measure ICI  and facilitation . In this protocol the conditioning pulse was set to 80% of MT while the test pulse was determined as the intensity eliciting an MEP of at least 1 mV. ICI and ICF were calculated as the ratio between the amplitude of MEP elicited during single pulse and during inhibition or facilitation.EEG was recorded by using a 128-channel EEG cap with active electrodes  and linked-ear reference for 20 min. During recordings, subjects were asked to close their eyes in a resting position and instructed not to fall asleep. EEG sessions were monitored online for the effects of drowsiness and potential movements. The EEG data was analyzed offline with EEGLab and MATLAB . To ensure EEG data was not contaminated by the effects of drowsiness only the first 6 min of EEG recordings were included in the analyses. The data was filtered automatically (high-pass at 1 Hz and low-pass at 35 Hz) and then cleaned from artifacts manually by an evaluator blinded to assessments.alpha − Ralpha) for 40 pairs of electrodes representing different cortical localizations: frontal (20 pairs), central (11 pairs), and parietal (9 pairs)  and averaged for the following EEG bands: theta (4–8 Hz), alpha 8–13 Hz) [including the sub-bands low-alpha (8–10 Hz) and high-alpha (1–13 Hz)], and beta [low-beta (13–20 Hz) and high-beta (21–30 Hz)]. Power asymmetry was determined by calculating the difference in power between the left hemisphere (LH) and right hemisphere  and MATLAB.In order to explore the correlation between SIS-Emotion and EEG data, we used a method introduced by Koening et al. which combines covariance analysis and resampling methods (“TANCOVA”) to overcome the issue of multiple testing across EEG electrodes , and each neurophysiologic, demographic, and clinical variable (as an independent variable). Neurophysiologic variables included EEG  and TMS data . Demographic and clinical variables were age, gender, time since stroke, medication use, lesioned side, and Fugl-Meyer.P < 0.05 was accepted as significant.In order to assess and adjust for possible confounders for EEG and TMS models , we added each demographic and clinical variable as an independent variable in multivariate regression models where SIS-Emotion was the dependent variable and each EEG and TMS variable is the main predictor. Each possible confounding variable was tested one at a time and when led to a more than 10% change in the β-coefficient of the main predictor, the variable was kept in the model. Finally, we performed multivariate regression analyses by forcing all significant confounders into final EEG and TMS models. In order to assess the specificity of our findings we also tested whether the significant EEG and TMS variables (independent variables) are also predictors of motor (Fugl-Meyer) function (dependent variable). The aim was o show that these variables are not associated with motor disability.In order to control and check whether individual values were driving our final results, we excluded outliers and repeated the analysis for the univariate and multivariate models. For each variable values that were above or below three inter-quartile range (Q1− 3IQR or Q3+ 3IQR) were defined as outliers and excluded.In addition to the above analysis we compared patients with left and right hemisphere damage with regards to neurophysiological and clinical parameters using linear regression in order to further explore the effect of lesion side on these parameters.Demographics and baseline characteristics of subjects are described in Table We divided our results into three sections in order to facilitate easy reading: A. Initial analyses of covariance mapping, univariate models and confounders as prerequirements of multivariate analyses; B. Multivariate models; C. Sensitivity Analysis ; D. Summary of the final multivariate models as also discussed in discussion; E. Other exploratory analyses.With regards to results of covariance mapping Table , SIS-EmoSimilar results were also found for the univariate linear regression models which showed significant associations between the dependent variable SIS-Emotion, and (1) alpha power asymmetry, (2) alpha coherence, and (3) MT in the unlesioned hemisphere.We also found that age is a significant predictor for SIS-Emotion Table  and is ap = 0.005, β = 180.52, Adj-R2 = 0.30) in frontal regions and alpha power asymmetry  in parietal regions when adjusted for age and time since stroke .We found that SIS-Emotion was significantly associated with beta power asymmetry , central  and parietal areas  as well as in beta band over parietal areas . These results were adjusted for age, side of lesion , time since stroke , and gender . No other significant association was found for power and coherence in other frequency bands and locations (p > 0.05).In addition to power asymmetry, SIS-Emotion was significantly associated with lower functional connectivity measured by inter-hemispheric EEG coherence in p = 0.003, β = −0.73, Adj-R2 = 0.32) when adjusted for age and gender. ICF in the unlesioned hemisphere (adjusted for age) was also significantly associated with SIS-Emotion . There was no association between SIS-Emotion and other TMS variables.A significant association was found between MT in the unlesioned hemisphere and SIS-Emotion  and central  regions, as well as theta asymmetry in central areas  became significant for the dependent variable SIS-Emotion when adjusted for age. In beta band, the main effect of power asymmetry in the sub-band low-beta remained significant  became not significant when outliers were excluded. The models for frontal and central regions remained same as there were no outliers for these regions Figure . MultivaThe results of the sensitivity analysis suggest that the association between SIS-Emotion and EEG variables is more robust for frontal and central areas as compared to parietal areas which seemed to be driven by outliers. Therefore, in our discussion we focused on the results without outliers.In summary, subjects with right greater than left hemisphere EEG power in beta and alpha band over frontal areas as well as in theta band over central areas were found to have more difficulty in post-stroke mood and emotional control (lower SIS-Emotion scores). Interestingly, this relation seems to be inverted for alpha power asymmetry over central areas. The relation between SIS-Emotion and EEG coherence was in line with the results for power asymmetry, and suggests that reduced functional connectivity in alpha band over frontal and central areas is also associated with difficulty in post-stroke mood and emotional control. In addition to EEG variables, the multivariate models with TMS variables showed that MT and ICF in the unlesioned hemisphere could be relevant markers for mood and emotional control after stroke.We tested whether the significant EEG and TMS variables from this study are also correlated with motor function outcomes (Fugl-Meyer). In these models Fugl-Meyer was the dependent variable and each EEG and TMS variable was an independent variable. None of the EEG and TMS variables that were significant for SIS-Emotion were associated with Fugl-Meyer , (2) parietal inter-hemispheric alpha coherence , and (3) left centro-parietal  and fronto-parietal  intra-hemispheric alpha coherence.There was a main effect of the lesion side for the following dependent EEG variables: (1) frontal beta power asymmetry  higher inter-hemispheric imbalance in cortical activity as measured by EEG power and coherence and (2) higher intracortical excitability and motor threshold in the unlesioned hemisphere as measured by TMS when adjusted for confounders. Furthermore, to our knowledge this is the first study that emphasizes the potential use of EEG and TMS to index neurophysiologic changes associated with post-stroke mood and emotional control.With regards to the EEG findings in beta band, we found that post-stroke mood and emotional control is associated with greater frontal beta power asymmetry. The direction of the asymmetry index indicates that subjects with relatively greater right than left hemisphere beta power have more difficulties in mood and emotional control. This finding is consistent with previous studies showing higher EEG beta power in the right frontal regions in depressive disorders , but also our findings regarding frontal beta asymmetry . However, it is possible that greater activity in the left frontal cortex as measured by reduced alpha power represents different neural interactions and has other implications. For example several authors suggested that greater left prefrontal hyperactivity is involved in anxious apprehension while right sided hyperactivity is related to anxious arousal  experiencing more difficulty in mood and emotional control. In depression, posterior hyperactivation in right parieto-temporal cortex has been associated with the presence of co-morbid anxiety  in the unlesioned hemisphere are associated with lower (worse) SIS-Emotion scores. TMS is advantageous over EEG considering that it can evaluate the cortical activity within each hemisphere, whereas EEG indices such as power asymmetry and coherence are difficult to interpret regarding which hemisphere mostly contributes to the asymmetry or reduced connectivity. Given that both ICF and EEG beta oscillations reflect interactions between glutamergic excitatory and GABAergic inhibitory neurons  frontal power asymmetry in high-beta band, (2) parietal power asymmetry in low-alpha band, and (3) intra-hemispheric coherence in alpha band within the left hemisphere. These results suggest that patients have relatively greater frontal high-beta power in the lesioned side. Also patients with left sided injuries have reduced connectivity within the left hemisphere as well as in between the two hemispheres over parietal areas as compared to patients with right sided injuries. Even though there was no direct relation between SIS-Emotion and these variables, it seems that the lesion side might have certain effects on brain activity regardless of the change in mood and emotional control.Altogether, our results support our initial hypothesis suggesting the association between inter-hemispheric imbalance and post-stroke mood and emotional control. Even though inter-hemispheric imbalance is a common finding in stroke and is associated with motor recovery  interpreted the results and contributed to the final manuscript.This article was produced as part of the activities of FAPESP Center for Neuromathematics . The authors gratefully acknowledge NIH support (Support to FF—NIH grant 5 R21 HD079048-02).The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The reviewer RP and handling Editor declared their shared affiliation, and the handling Editor states that the process nevertheless met the standards of a fair and objective review.


The East Asian summer monsoon (EASM) experienced decadal transitions over the past few decades, and the associated "wetter-South-drier-North" shifts in rainfall patterns in China significantly affected the social and economic development in China. Two viewpoints stand out to explain these decadal shifts, regarding the shifts either a result of internal variability of climate system or that of external forcings (e.g. greenhouse gases (GHGs) and anthropogenic aerosols). However, most climate models, for example, the Atmospheric Model Intercomparison Project (AMIP)-type simulations and the Coupled Model Intercomparison Project (CMIP)-type simulations, fail to simulate the variation patterns, leaving the mechanisms responsible for these shifts still open to dispute. In this study, we conducted a successful simulation of these decadal transitions in a coupled model where we applied ocean data assimilation in the model free of explicit aerosols and GHGs forcing. The associated decadal shifts of the three-dimensional spatial structure in the 1990s, including the eastward retreat, the northward shift of the western Pacific subtropical high (WPSH), and the south-cool-north-warm pattern of the upper-level tropospheric temperature, were all well captured. Our simulation supports the argument that the variations of the oceanic fields are the dominant factor responsible for the EASM decadal transitions. The East Asian summer monsoon (EASM) is a crucial climate system in Indo-China, the Philippines, China, the Korean Peninsula and Japan456From the internal variability view of point, slow variations in a coupled atmosphere-ocean system tend to be controlled by the slowly evolving ocean field, thus the intrinsic oscillation in the ocean is usually regarded as a dominant cause for the decadal variations of the EASM. Observational evidences showed that in the positive (negative) Pacific Decadal Oscillation (PDO) phase, with the warming (cooling) in the central and eastern tropical Pacific, summer precipitation in North China decreases (increases)811With respect to external forcings, some suggest that greenhouse gases (GHGs)-induce global warming, especially the Indian Ocean and western Pacific warm pool warming, may lead to monsoonal precipitation increase in East Asia19A realistic simulation of the EASM decadal change is indispensable to enhance our understanding. In this study, we developed a weakly-coupled data assimilation system in which ocean observations are employed to constrain ocean fields of a coupled climate model CAS-ESM-C; MethodsIt is a more complex situation turning to the simulation of precipitation . From thThen the spatial patterns of the anomalous precipitation in the three separate decadal periods are shown in both observation and simulation . It seemBecause the precipitation anomaly in East China usually shows a south-north dipole pattern, separated by 31°N from our above analysis, we further provide the time series of precipitation anomaly in north (31°–38°N) and south (23°–31°N) part of East China, respectively . AlthougIt should be acknowledged that the model indeed has difficulty in simulating the EASM-related precipitation. The same issue is suffered by almost all state-of-the-art climate models. The reason for simulated precipitation bias may be resulted from many factors  which cannot be improved through assimilating the SST. We further examined the results of all forcing run and AMIP run in 9 latest CMIP5 models Methods; . Neitherω) is well simulated by SST_Assim, the meridional circulation is badly reproduced, even worse than AMIP . Through data assimilation techniques, our system can input the signal of internal variability in the model. Conventionally, it is impossible for a CGCM to reproduce the actual climate fluctuations without inputting observed information. Bad simulations of SST decadal oscillations  is the third factor that counts. Due to the fact that the random synoptic process of atmosphere, on its own, cannot last for more than two weeksThe model used in this study is a fully coupled climate system model (CAS-ESM-C) developed in the Institute of Atmospheric Physics (IAP), Chinese Academy of Science (CAS)383940Two types of numerical experiments are designed as follow: 1) SST_Assim: The observed SST is assimilated into the ocean component of CAS-ESM-C once every 7 days during the free coupled integration. Coupling is performed without any adjustment of SST and fluxes. 2) AMIP: The atmospheric component is forced with observed monthly SST as the oceanic boundary condition. The gridded daily SST data used for assimilation are infrared satellite data from Advanced Very High Resolution Radiometer (AVHRR)42Four sets of observational monthly data are used: 1) a high resolution gridded precipitation data across China produced by National Climate Centre China of China Meteorological Administration45The outputs of AMIP and all forcing runs from 9 CMIP5 models are analyzed in this study , temperature (T), salinity (S), zonal and meridional current (u and v); R denotes the observation error covariance matrix; H is the observation operator that interpolates from the model space to observation space; A′, consisting of n ensemble members which are taken from the model state anomalies. The stationary ensemble of model states adopted in EnOI is usually sampled during a long-term control run to estimate the structure of the background error covarianceThe subscripts a, b and o denote the analysis, background and observation, respectively; And the superscript T denotes matrixes transpose; In this study, the EnOI scheme is adopted to assimilate observed SST data into the ocean component of CAS-ESM-C. Actually, the same assimilation scheme has been adopted in establishing the global ocean data assimilation system (ZFL_GODAS)How to cite this article: Lin, R. et al. Decadal shifts of East Asian summer monsoon in a climate model free of explicit GHGs and aerosols. Sci. Rep.6, 38546; doi: 10.1038/srep38546 (2016).Publisher's note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.


Prodrug approach deals with chemical biotransformation or enzymatic conversion or involves inactive or less active bio-reversible derivatives of active drug molecules. They have to pass through enzymatic or chemical biotransformation before eliciting their pharmacological action.The two different pharmacophores combine to give synergistic activity or may help in targeting the active drug to its target. Prodrug super seeds the problems of prodrug designing, for example solubility enhancement, bioavailability enhancement, chemical stability improvement, presystemic metabolism, site specific delivery, toxicity masking, improving patient acceptance, or eradicating undesirable adverse effects.As an outcome the search for a prodrug or mutual prodrug with reduced toxicity has continued during recent years. This present review emphasizes the common help to revamp physiochemical, pharmaceutical and therapeutic effectiveness of drugs.This gives the researcher a common platform where they can find prodrugs of commonly used NSAIDs to overcome the gastrointestinal toxicity . ThFig. 11) . For exasol Fig. , its pholin Fig.  showed gxen Fig.  produced622) linked through ester linkage -4-acetic acid and flurbiprofen  were synthesized. All the prodrugs were screened for hydrolytic stability and found significant result. The compounds were found to possess less ulcerogenic potency with slight higher anti-inflammatory activity.The five different etorolac  were synl-proline, trans-4-hydroxy-l-proline or dl pipecolinic acid   , were quantified for ulcerogenic, anti-inflammatory, analgesic and antipyretic activity [An nitrate containing compound [3-nitrooxyphenyl acetylsalicylate ]  [A new mutual prodrug was prepared that had 4-biphenylacetic acid and quercetin tetramethyl ether  . Its pha89) with heteroaromatic amines and judged in vivo for their analgesic activity [A series of ibuprofen amide prodrugs were prepared .The prodrug of ibuprofen with various sulfa drugs was prepared. The prodrug was synthesized with the aim that it could be used for infection as well as for inflammation   having a benzofuroxan heterocyclic moiety [2. The prodrug elicited good gastric tolerance.The prodrug was prepared with 1-Oxy-benzo , 5oxadiac moiety . The pha92a; b; c; d) were synthesized and assessed for their analgesic and anti-inflammatory activity [The ester and amide derivatives of ibuprofen, ketoprofen and mefenamic acid -naproxen and ibuprofen. It used a two-carbon ethyl spacer and a sulfohydroxamic acid component (CH2CH2SO2NHOH) to equip a group of hybrid ester prodrugs  that released nitric oxide (NO) and nitroxyl (HNO) moiety [S)-naproxen and ibuprofen were influential and relatively more active than parent drugs. The prodrug of indomethacin was found to be less ulcerogenic than indomethacin itself. It was presumed that the synthesized prodrug acts like selective COX-2 inhibitor with retain anti-inflammatory activity.The prodrug was conjugated with the carboxylic acid group of indomethacin,  moiety . All com94) with the aim to mask the possible side effects of nicotinic acid. This is done by making the ester of these. This blocks the synthesis of prostaglandin and released ibuprofen [in vitro enzymatic hydrolysis than chemical hydrolysis.The prodrug was synthesized with nicotinic acid and ibuprofen . The synthesized prodrugs were selective regulator of cyclooxygenase-2 (COX-2) with NO releasing properties and reduced related adverse side effects.A novel series of pyrrole-derived nitrooxy esters were synthesized. They were designed in such a way that they were exhibiting cyclooxygenase (COX) inhibition and maintain the release of nitric oxide (NO). This would lead to develop safer drug for the gastric and cardio related troubles . . It used glycol spacers to reduce the gastric adverse effects and getting synergistic analgesic effects [The prodrug of some NSIADs with gabapentin was prepared via ester bonds  and aminobutyl esters  of ketorolac were prepared. They had 1-methylpiperazine, N-acetylpiperazine or morpholine substituents. Its hydrolysis kinetics study was done [The aminoethyl  of compounds consisting of mefenamic acid, glycine and organic nitrates  [The prodrug was synthesized with two derivatives  . The Nit99a) and 4-((4-substituted benzylidene) amino) phenyl 2-amino)benzoate  analogs were synthesized by fusion with the respective acids via use dicyclohexyl carbodiimmide [in vivo and correlated with that of parent drug.The esters of ibuprofenic acid and mefenamic acid, named as 4-((4-substituted benzylidene)amino)phenyl 2-(4-isobutylphenyl) propanoate  [The mutual prodrug of ibuprofen was synthesized with naturally existing components bearing phenol and alcohol groups like menthol, thymol and eugenol and evaluated for pharmacological activities  . Here, n101) having ester and amide linkage [The prodrugs of dexibuprofen were synthesized  through glycol esters that showed significant anti-inflammatory activity and possessed less degree of ulcerogenic potential [The rhein-NSAIDs prodrugs were synthesized  designed and synthesized with diacerein and antioxidant thymol [The prodrug  with NSAIDs using (O-(Benzotriazol-1-yl)-N, N, N′, N′-tetramethyluronium tetrafluoroborate) in good yield [in vitro anti-inflammatory activity.The prodrug was synthesized with a series of nicotinic acid conjugates  glucosamine [In vitro hydrolytic studies of prodrug showed good rate of hydrolysis in blood plasma and simulated intestinal fluid whereas it was stable in gastric simulated fluid. In vivo pharmacological studies were done on animals, elicited good analgesic, antiinflammatory and antiarthritic activity. The data showed better action of prodrug as compared to ketorolac and showed less gastrointestinal side effects. The prodrug was evaluated by ulcerogenic and histopathologic analysis. Histopathological study showed less ulceration in the gastric region.The amide prodrug of ketorolac was synthesized with  of diclofenac and paracetamol was prepared and carried out there in vitro hydrolysis studies [1H NMR spectroscopy. The physiochemical parameters were determined and the results showed that they were more lipophilic than the parent drug. The compound was also evaluated for anti-inflammatory and ulcerogenicity.The mutual prodrug  [108) and carried out their in vitro hydrolysis studies [The prodrug synthesized N-ethoxycarbonylmorpholine ester of diclofenac  . The sta studies . The phy109) with acidic NSAIDs such as ketoprofen, ibuprofen, and diclofenac produced mutual prodrug with synergistic effects [In Vitro and In Vivo and it also showed minimal GI irritation. The prodrug is synthesized with a total of six amide based prodrugs (Ia-f)  of aceclofenac, diclofenac, fenbufen, indomethacin, mefenamic acid and 4-biphenyl acetic acid through one-pot method (single step method) [The prodrug is coupling of propyphenazone  . HydrolyThis review is based on literature of prodrugs that protects gastric toxicity. This opens the field of research towards design of drugs through prodrug approach. It develops the idea that a lot many researchers are involved in developing safer NSAIDs. This literature would help the scientist to get the preliminary idea of the research done in the field of prodrugs as NSAIDs. This helps to generate the view that development of NSAIDs as prodrug is required due to the side effects they have. This paper would lead to generate the idea how the safer NSAIDs can be developed which may be fruitful for the society.


The shorter SiNWs (maximum length ≈300 nm) were generally found to possess a nanoparticle at their tip. STEM energy dispersive X-ray (EDX) spectroscopy combined with electron tomography performed on these nanostructures revealed that they contain iron, clearly demonstrating that the short ICP-synthesized SiNWs grew via an iron-catalyzed vapor–liquid–solid (VLS) mechanism within the plasma reactor. Both the STEM tomography and STEM-EDX analysis contributed to gain further insight into the self-assembly process. In the long-term, this approach might be used to optimize the synthesis of VLS-grown SiNWs via ICP as a competitive technique to the well-established bottom-up approaches used for the production of thin SiNWs.Scanning transmission electron microscopy (STEM) was successfully applied to the analysis of silicon nanowires (SiNWs) that were self-assembled during an inductively coupled plasma (ICP) process. The ICP-synthesized SiNWs were found to present a Si–SiO In this context, electron tomography (ET) together with TEM arises as a remarkable technique to study a larger range of volumes, while still offering reasonable spatial resolution from ≈1 nm3 [As the scaling down of the feature size of devices proceeds , new synm ≈1 nm3  down to m ≈1 nm3 –8. Electm ≈1 nm3 . It is wm ≈1 nm3 . By combIn the present work, ET combined with STEM-EDX and energy-filtered TEM (EFTEM) enabled the structural characteristics of SiNWs spontaneously assembled during an inductively coupled plasma (ICP) process to be elucidated as finely as possible. The ICP technique has been conventionally exploited for the synthesis of micrometer-structured Si spheres . In this2 plasmon loss (23 eV), display a common core–shell Si–SiO2 internal structure for both the NSs and the NWs (see Preliminary examinations of the ICP sample were performed by means of scanning electron microscopy (SEM). In the typical SEM image, as reported in  NWs see . FurtherElectron tomography and STEM-EDX analyses were conducted on these short SiNWs in order to better elucidate their structural and chemical characteristics. 3D tomography was performed on the nanostructures shown in Nevertheless, from the inspection of The identification of these elements was accomplished by performing the same reconstruction four times and separating the four different areas of interest. Thus, it is possible to distinguish the SiNS in yellow, the two SiNWs in green, the two nanoparticles in darkish red and the carbon support layer in blue in Statistical STEM-EDX analyses were carried out using a sub-nanometer electron probe in order to corroborate the structural analysis with further chemical information. Typical EDX spectra were acquired in two different regions over the SiNWs, namely (i) at the dark particle  under conditions of an abundance of Si content, as established by the Fe–Si binary phase diagram [Calculations based on the ZAF method  applied orted in , where w diagram .It is well known that metal-containing particles located at the top of SiNWs are a distinctive feature of VLS-grown SiNWs, which occurs on crystalline Si substrates –15. HencIn conclusion, the combination of EFTEM, HAAD-STEM tomography and STEM-EDX spectroscopy was essential to confirm the growth mechanism of short SiNWs grown via the above-described ICP process. Indeed, by revealing the 3D structure of our ICP-produced Si nanostructures, it was possible to pinpoint the presence of small iron-containing nanoparticles at the top of the SiNWs. Moreover, EFTEM images revealed that the Si core of the SiNSs acted as a substrate from which the SiNWs grow. Metal-containing nanoparticles at the top of the SiNWs are an evident feature of VLS-grown SiNWs, where the growth is expected to start from the crystalline Si substrate. Hence, we conclude that the VLS mechanism is responsible for the growth of short SiNWs in the above-described ICP process, provided that a small amount of Fe is present during the spheroidization process. In this way, the ICP technique can be seen as a prospect for the synthesis of SiNWs via the VLS mechanism after suitable optimization of the process.2 plasma is maintained at extremely high temperature . The Si particles partially melt in-flight and, while being carried down in the first collector of the ICP machine, re-condensate as silicon spheres due to the surface-energy minimization principle. During the formation of the microspheres, a fraction of the Si feedstock sublimates and the molecules in the vapor phase aggregate in the form of lighter Si nanostructures. These are transported downstream in the reactor towards a second collector where they accumulate in the form of Si nanopowder. To perform our studies, this Si nanopowder was collected, dispersed into isopropyl alcohol, and sonicated for 5 min. By dropcasting this solution on Si substrates and on lacey carbon Cu or Au grids, both scanning electron microscope (SEM) imaging and TEM-based analyses were performed, respectively.The inductively coupled plasma process  is conve2) EDX silicon drift detector with an energy resolution of 127 eV. The former was used to realise the EFTEM analysis on individual SiNWs, while the latter was used to accomplish the STEM-EDX analysis with a sub-nanometer probe and ET in STEM mode by using a HAADF detector. Electron tomography was conducted by using a single-tilt Fischione tomography sample holder (±60° range). Finally, the Composer Kai software was used for the reconstruction based on the filtered back projection (FBP) alghoritm, while the Visualiser Kai software was used for visualization.The SEM characterizations were carried out using a field emission gun (FEG) Zeiss Supra25. TEM analyses were performed with a JEOL JEM 2010F operating at 200 kV and with a spherical aberration probe corrected cold FEG ARM JEOL (0.27 eV energy spread) operating at 100 keV and equipped with a large area (100 mmFile 1A video showing the 3D reconstructed volume of a SiNS and VLS-grown SiNWs with an Fe nanoparticle on top. The image presented in


Drosophila cells by metabolic labeling in combination with cellular fractionation. By mathematical modeling of these data we determined rates of transcription, export and cytoplasmic decay for 5420 genes. We characterized these kinetic rates and investigated links with mRNA features, RNA-binding proteins (RBPs) and chromatin states. We found prominent correlations between mRNA decay rate and transcript size, while nuclear export rates are linked to the size of the 3'UTR. Transcription, export and decay rates are each associated with distinct spectra of RBPs. Specific classes of genes, such as those encoding cytoplasmic ribosomal proteins, exhibit characteristic combinations of rate constants, suggesting modular control. Binding of splicing factors is associated with faster rates of export, and our data suggest coordinated regulation of nuclear export of specific functional classes of genes. Finally, correlations between rate constants suggest global coordination between the three processes. Our approach provides insights into the genome-wide nucleocytoplasmic kinetics of mRNA and should be generally applicable to other cell systems.Eukaryotic mRNAs undergo a cycle of transcription, nuclear export, and degradation. A major challenge is to obtain a global, quantitative view of these processes. Here we measured the genome-wide nucleocytoplasmic dynamics of mRNA in  All mRNAs start from production in the nucleus, undergo exportation through nuclear pores and finally are degraded in the cytoplasm. A comprehensive characterization of the kinetic rates of all mRNAs is an important prerequisite for a global understanding of the regulation of the transcriptome and the cell. By conducting a time-series experiment and building a mathematical model, we trace the dynamics of mRNAs from the nucleus to the cytoplasm and determine the rates at each kinetic step at transcriptome-wide level. This information allows us to associate mRNA kinetic rates with a wealth of biological features and made some intriguing discoveries. We show mRNA decay is positively linked to transcript length while mRNA export is negatively linked to the length of the 3' UTR. We show binding of splicing factors is associated with faster rates of mRNA export. We provide evidence for global coordination between nuclear export an decay of mRNA. We show genes sharing specific functions tend to have similar nucleoplasmic kinetics, in which ribosomal proteins possessing special kinetic features exclusively stand out. Altogether, our integrated approach to quantitatively determine the rates of kinetic steps on a gene-by-gene basis provides a blueprint to obtain the global understanding of RNA regulation. The production, nuclear export and degradation of mRNA are key steps in the control of cytoplasmic mRNA levels. Steady-state levels of transcripts in the cytoplasm are determined by the rates of these three processes. Hence, our understanding of gene regulatory systems requires quantitative knowledge of the relative contributions of each of these steps. Comparison of the kinetic rate constants for these steps across genes may provide insights into mechanisms of differential gene regulation.Recent technological advances have enabled genome-wide measurements of mRNA dynamics , 2 and sThese studies of mRNA kinetics have taken the total cellular mRNA as a single entity to calculate the overall turnover rate, overlooking nucleocytoplasmic transportation, which is thought to be a key aspect of mRNA dynamics and has been shown to be regulated by a variety of evolutionarily conserved mechanisms , 13. HerDrosophila Kc167 cells as a representative model for metazoan cells, because of their ease to perform experiment and the availability of a wealth of genome-wide information. We report kinetic rate constants for 5420 genes and determine the relative contributions of each of transcription, nuclear export and decay to overall cytoplasmic abundance. Moreover, we uncover links between the three kinetic steps and transcript features, interactions of specific RNA-binding proteins and specific gene classes.We chose Drosophila Kc167 cells using 4-thiouridine (4sU). We then isolated nuclear and cytoplasmic fractions from cells at each time point, and determined the relative abundance of “old” (unlabeled) mRNA for thousands of genes by high-throughput sequencing, as a function of time in both fractions. We then fed these measurements into a computational model that describes the process of sequential mRNA transcription, export and decay as a set of differential equations. Parameter fitting of the model to the measurements yielded kinetic rate constants for each of these three steps. Below we describe each step of the approach in more detail.To obtain genome-wide measurements of the nucleocytoplasmic dynamics of mRNA we followed a strategy as outlined in Drosophila . In. InDrosoChromatin is well-known for its role in regulating transcription, but there is also evidence that it may control the downstream fate of RNA. For example, specific histone modifications can influence alternative splicing , 44 and As expected, the modeled transcription rates differ widely among chromatin states, both at TSSs and TTSs . BLUE chS. pombe  [80 [80k′f, And for every hour the nuclear RNA that diffuses into the cytoplasm at the beginning of M phase isTo obtain the kinetic rates of nucleocytoplasmic dynamics, we considered four attributes that ought to be satisfied,mRNA dynamics of the nuclear compartment.mRNA dynamics of the cytoplasmic compartment.quasi-steady-state of the cytoplasmic compartment,The relationship between cytoplasmic decay rate and overall turnover rate,RNA-seq experiments render an over-dispersed non-Gaussian distribution for technical noise . To adjuThus, taking differential dispersions at individual time points into account we compute the difference on logarithmic scale, and minimized the corresponding four-component fitting gradient by least square.We used the Levenberg—Marquardt algorithm to fit experimental data using the ModFit function in the package of FME in R.r2 > 0.8. The consistency of the modeled rates was very high between the original and the down-sampled data, indicating that the performance of modeling is quite resilient to the reduction of sequencing depth  for Drosophila melanogaster genome BDGP5 were used for these analyses.Annotations from BioMart , and calculated the ratio of Pol II signal within 200 bp around TSS and Pol II signal from 201bp to the end of the gene, similar to previous studies [To compute the pausing index of Pol II, we used Pol II Chip-seq data of  studies . To inveChromatin states data were from Filion et al  and Kharhttp://cbl-gorilla.cs.technion.ac.il/). Corresponding p values were retrieved and gene ontology processes with p < 10−11 for at least one kinetic processes were displayed in a heatmap generated by the ‘pheatmap’ R package.GO analysis was performed using the single ranked list method on the Gorilla server Click here for additional data file.S2 FigA) Scatter plot showing the log10 transformed FPKM value of gene expression for Drosophila Kc167 cells unlabeled versus labelled for 480 minutes. (B) Scatter plot showing the log10 transformed FPKM value of gene expression for unfractionated Drosophila Kc167 cells versus the sum of the nuclear and cytoplasmic fractions. Red dots in (A) and (B) mark genes that were excluded from computation of kinetic rate constants; red lines indicate the cutoff functions Click here for additional data file.S3 Fig(A-D) Consistency between two independent biological replicates (rep1 and rep2) of the relative abundance of pre-existing RNA for both nuclear  and cytoplasmic  fractions at 0 min  and 450 min  of labeling. (E) Time series of the relative abundance of cytoplasmic and nuclear pre-existing RNA relative to the yeast RNA spike-in. Error bars depict standard deviation between two biological replicates. (F) Total mRNA abundance (nuclear and cytoplasmic combined) normalized to yeast spike-in as a function of time. Model fitting was used to determine the plateau level (dotted red line) that is eventually reached.  log2 of exon over intron ratio of two genes, Lam and Fmo-2, in both nuclear and cytoplasmic fractions of two biological replicates. (I) Time series of the remaining ribosomal RNA after polyA selection on linear scale. Error bars show standard deviation between two biological replicates.(EPS)Click here for additional data file.S4 Fig(A-C) show the consistency between rate constants determined from the down-sampled and full datasets.Sequence reads were randomly down-sampled to 25 percent and modeling was repeated. (EPS)Click here for additional data file.S5 Fig(A) and intron lengths (B) of genes that are modeled well and not modeled well, using r2 = 0.8 as cutoff.Comparison of transcription rates (EPS)Click here for additional data file.S6 Fig(A-F) Same analysis as in (A-C) and 50% longest (D-F) genes. (G) Boxplot showing log2 transformed export rates of intron-less and intron-containing genes. Central horizontal lines represent median values; box margins represent 25th and 75th percentiles, and whiskers represent the 5th percentile and the 95th percentile. (H) Boxplot showing 3’UTR length of intron-less and intron-containing genes. (I) Log2 transformed ratio between the number intron-less genes and the number of intron-containing genes, for mRNAs bound by the indicated RBPs according to Stoiber et al [(J) Heatmap showing pairwise overlap of mRNA binding by RBPs, sorted by hierarchical clustering. Overlap was calculated as the ratio between the number of the overlapping mRNAs and the number of all mRNAs bound by a particular RBP.er et al . (J) Hea(EPS)Click here for additional data file.S7 Fig(A) transcription rates of genes divided by their chromatin states at their transcription start sites (TSS). Whiskers represent the 5th percentile and the 95th percentile; (B) Between each pair of chromatin states at TSS, a line is drawn if there is statistical difference ;  same as , but for chromatin states at transcription termination sites (TTS). Similar analyses are displayed for nuclear export (E-H) and cytoplasmic decay (I-L).(EPS)Click here for additional data file.S1 Tabler2), for both nuclear and cytoplasmic fractions.Excel spreadsheet. As indicated by the header, for two biological replicates, the table contains the rate of transcription (FPKM/min), export (1/min) and cytoplasmic decay (1/min) for each gene, as well as the goodness of fit which is measured by the coefficient of determination ((XLSX)Click here for additional data file.S2 TableThe layout of the table is identical to that of (XLSX)Click here for additional data file.


Organic/inorganic nanohybrid materials have attracted particular scientific and technological interest because they combine the properties of the organic and the inorganic component. Inorganic nanoparticles exhibit interesting electrical, optical, magnetic and/or catalytic properties, which are related with their nano-scale dimensions. However, their high surface-to-volume ratio often induces agglomeration and leads to the loss of their attractive properties. Surface modification of the inorganic nano-objects with physically or chemically end-tethered polymer chains has been employed to overcome this problem. Covalent tethered polymer chains are realized by three different approaches: the “grafting to”, the “grafting from” and the “grafting through” method. This article reviews the synthesis of end-grafted polymer chains onto inorganic nanoparticles using “controlled/living” polymerization techniques, which allow control over the polymer characteristics and the grafting density of the end-tethered polymer chains. The synthesis of core-shell nano-objects comprising of an inorganic core and a polymer shell has recently gathered great scientific interest with a view towards new opportunities for constructing functional nanostructured materials ,2. Inorgvia weak interactions  and the second the permanent attachment of the macromolecular chains onto the nanoparticles surface via chemisorption. The covalent binding of the polymeric modifiers onto the curved surface can be achieved either by the “grafting to” method, upon which pre-prepared macromolecules are grafted onto the nanomaterials surface using the affinity of the polymer end-group for the functionalities present on the surface of the particles dioctylphosphine oxide were used to covalently bind long vinyl-terminated poly(3-hexylthiophene) (P3HT) chains r matrix . para-methyl triphenylamine-b-cysteamine acrylamide) coated CdSe-ZnS quantum dots prepared by the “grafting to” method using thiol chemistry showed improved performance in light-emitting diodes attributed to the uniform film deposition of the hybrid layer as well as the facilitated hole injection into the quantum dots by the directly linked polymer [Poly degrade the nanoparticles and quench their photoluminescence. One of the first attempts for the surface modification of quantum dots came from Patten and Farmer who encapsulated CdS quantum dots in a silica shell and polymerized PMMA chains from the silica surface by ATRP . These hco-PMMA copolymer chains from the surface of CdSe nanoparticles pre-functionalized with initiating molecules bearing phosphine oxide derivatives as the anchor groups [“Unprotected” quantum dots without the intermediate silica layer have been used lately as substrates for the development of core-shell hybrids providing an intimate connection of the polymer to the nanoparticle core. Sill and Emrick reported the NMP synthesis of PS homopolymer and PS-r groups . The PS-r groups . Upon suAnother approach used activators generated by electron transfer (AGET) ATRP in a miniemulsion system to synthesize well-defined polymer chains from the surface of pre-functionalized CdS nanoparticles . The hybp-vinylbenzyl-di-n-octylphosphine oxide [Polyolefin-coated CdSe nanoparticles have been prepared by ruthenium-catalyzed ROMP from particles pre-modified with ne oxide . This apvia coordination-insertion ROP from the surface of CdS particles bearing hydroxyl-groups. In the first step, the reaction of mercaptoethanol and thioglycerol with cadmium acetate and thiourea afforded the hydroxy-coated CdS nanoparticles. The surface hydroxyl groups were next activated into aluminum alkoxide species, by reaction with AlEt3, which selectively initiated the ROP of (ε-caprolactone) from the nanoparticles surface. The covalent grafting of the hydrophobic polyester chains onto the semiconducting nanoparticles modified the surface properties of the nanoparticles and facilitated their dispersion in organic solvents such as toluene [Moreover, an interesting approach was used to synthesize PCL  toluene . via ATRP. The original nanoclusters retain their photophysics upon altering the termination group which is consistent with a stable nanocluster surface [Hydroxyl-terminated germanium nanoclusters have been also appropriately functionalized to yield polymer-coated nanoclusters  surface . in situ anionic ROP from the surface of CdTe nanoparticles. Their good dispersion in water along with the strong fluorescence signal supported their use in cytotoxicity studies, which revealed the low toxicity of the hybrids in human lung cancer cells [Hyperbranched polyglycerol-modified quantum dots which are attractive for use in biomedical applications due to the reactivity of the hydroxyls towards functional biomolecules have been prepared by er cells . Finally, thermo-responsive quantum dots with PDMAEMA-grafted polymer chains, grown by surface-initiated oxyanionic vinyl polymerization, were shown to self-assemble into large spheres above the LCST of the grafted polymer and are attractive for use as “smart” materials in biological applications .i.e., semiconducting metal oxides, magnetic and quantum dots, which are still prone to aggregation and colloidal or chemical instabilities at various stages of their synthesis. Moreover, the grafting of inert polymer chains has been adequately described in most cases, whereas stimuli-responsive polymer brushes and their potential to control the designed morphology of the nanocomposite have not been fully explored. The controlled synthesis of end-grafted macromolecules with pre-defined molecular weight, composition, functionality and grafting density onto the surface of active nanocolloids will open up new avenues for their use in many high-value applications. Furthermore, much can be gained by understanding the structure-properties relationship of the nanohybrids for the retro-design of materials with the desired macroscopic properties.This review has given an overview of the range of hybrid core-shell nanostructures that can be prepared by end-grafting polymer chains onto the surface of inorganic nanocolloids using the direct covalent “grafting to”/“grafting from” strategies. CRP techniques have allowed the synthesis of well-defined advanced functional materials. It was shown that different mechanisms are possible and have been successfully applied for a variety of nanoparticles. However, although the surface functionalization of some types of nanoparticles such as silica and gold, have been extensively studied and, to a great extend, understood, more research is required for the successful dispersion and functionalization of other nanoparticulate objects,


More than forty years after the first open heart surgery in Nigeria, all open heart surgeries were carried out in government-owned hospitals before the introduction of such surgeries in 2013 at Biket Medical Centre, a privately owned hospital in Osogbo, South-western Nigeria. The aim of this paper is to review our initial experience with open heart surgery in this private hospital.All patients who underwent open heart surgery between August 2013 and January 2014 were included in this prospective study. The medical records of the patients were examined and data on age, sex, diagnosis, type of surgery, cardiopulmonary bypass details, complications and length of hospital stay were extracted and the data was analysed using SPSS version 16.Eighteen patients comprising of 12 males and 6 females with ages ranging between 8 months and 52 years (mean= of 15.7 +/- 15 years) were studied. Pericardial patch closure of isolated ventricular septal defect was done in 7 patients (38.9%) while total correction of isolated tetralogy of Fallot was carried out in 5 patients (27.8%). Two patients had mitral valve repair for rheumatic mitral regurgitation. Sixty day mortality was 0%.Safe conduct of open heart surgery in the private hospital setting is feasible in Nigeria. It may be our only guarantee of hitch free and sustainable cardiac surgery. In mary 1974 .rd of August 2013 and the aim of this paper is to review our initial 16-month experience of open heart surgeries at this facility.Also there has been a paradigm shift from the training of the cardiothoracic surgeon to the training of cardiac surgical teams  to incluSetting: The BMC is a 48-bedded multispecialty hospital with a three-bed intensive care unit and a three-bed high dependency unit. It has 4 echocardiography machines with two trans-oesophageal probes (one adult and one paediatric), a Sarns 8000TM cardiopulmonary bypass machine and heat exchanger, a cardiac catheterization laboratory, mobile x-ray facility and relevant consumables.Personnel: There is one cardiologist, a cardiac surgeon, two cardiac anaesthesiologists, one intensivist, two cardiopulmonary perfusionists and peri-operative and ward nurses which comprise the local team. The BMC has strategic partnerships with two foreign hospitals  that visit with their complement of staff during cardiac surgeries. This partnership helps with further training of the local team and confidence boosting of the population. This however necessitates the need to pool patients together so that the local and foreign teams can work together at mutually agreed times. We have had three cardiac missions within the period under review and this report includes all patients who underwent open heart surgeries.Statistical methods: Records of all patients who underwent open heart surgery using a median sternotomy and cardiopulmonary bypass were prospectively collected to include the patient's age, sex, diagnosis, type of surgery, cardiopulmonary bypass details, post-operative complications and length of hospital stay and the data was analysed using SPSS version 16. Continuous variables were summarized using means and standard deviations or medians and inter-quartile ranges for highly skewed variables. Discrete variables were summarized as counts and percentages and P-values less than 0.05 were considered statistically significant.2. Most of the patients had mild clinical cardiac decompensation with 9 patients (50.0%) in New York Heart Association (NYHA) class 2 while 7 patients (38.9%) were in NYHA class 3 and only two patients (11.1%), were in NYHA class 4. Sixteen patients (88.9%) had congenital heart disease mainly of ventricular septal defect  patients were operated upon in the 16-month period. The patients had a median age of 5.25 years (age range=8 months-52 years) with 9 patients (50.0%) aged less than 5 years, . There wl defect . Glutaral defect .One child (5.6%) with double outlet right ventricle, subpulmonic hypertrophied muscle bands, sub aortic VSD and a sub aortic membrane was managed by tunnelled pericardial patch closure, resection of both hypertrophied muscle bands and the sub aortic membrane. The two females (11.1%) with rheumatic mitral regurgitation aged 15 and 31 years had mitral valve repair consisting of chordal shortening and annuloplasty ring implantation . All pat® 638R  while the 30-year-old only had implantation of a 28mm semi-rigid mitral ring annuloplasty (CG future® 638R). Adequacy of the repair with only trivial regurgitation in both patients was confirmed by intra-operative trans-oesophageal echocardiography. Mitral valve repair in these patients with favourable mitral valve apparatus is recommended [The median age of patients (5.25 years) reflects our focus on congenital heart disease and would have been much lower but for one 52-year-old man with symptomatic ventricular septal defect and mild pulmonary hypertension. It is essential to operate children with congenital heart disease as quickly as possible and feasible before the onset of severe pulmonary hypertension and severe cardiac decompensation which are time dependent so, most of our patients were highly selected with few co-morbidities. This decision is well supported by other previous pioneers  in open ommended  as it prommended –14.®  and re-suturing over the suture line on the right atrium. Several researchers have previously discussed the defective coagulation in patients with cyanotic heart diseases, highlighting inferior clot formation occasioned by defects in both the intrinsic and extrinsic coagulation pathways [The two patients were symptom-free at the 6-month follow-up clinic visit and trans-thoracic echocardiography done then did not show any deterioration in the degree of mitral valve regurgitation. Long term follow-up is being done on these patients. All cases were done using bicaval cannulation and antegrade cold blood cardioplegia and the aortic cross-clamp and cardiopulmonary bypass periods were noted to be slightly longer in patients with tetralogy of Fallot (TOF) compared with patients with non-cyanotic heart disease though the difference was not statistically significant. This is not unexpected since the complexity of repair in TOF is greater than for the non-cyanotic surgeries that were carried out in our series. Post-operatively, the patients were transferred to the intensive care unit and most had early extubation and weaning from mechanical ventilation after adequate recovery from anaesthesia using a fast-tracking approach which is recommended even in the paediatric population by various authors –17. Thispathways –20. ThisThe safe conduct of open heart surgery is feasible in the completely private hospital setting in Nigeria with an initial blend of local and foreign teams which with time can lead to less dependency on foreign missions. The lessons from these will no doubt assist government-funded hospitals to stem the bureaucratic impediments that hinder the growth of this important contribution to heart care in the developing world.In the West African sub-region, all open heart surgeries are carried out in government-funded hospitals;Inefficiencies and bureaucratic impediments hinder the growth of open heart surgery in Nigeria.It is possible to perform open heart surgery in the completely privately funded hospital in West Africa;Repair of complex intra-cardiac defects are possible in the private hospital in West Africa with very low morbidity and mortality.The authors declare no competing interests.


Whole genome sequence of evolved strains showed that daptomycin resistance in MRSA is associated with a high fitness cost mediated by mutations in mprF gene, revealed as a key element of the biological cost. Moreover, we determined that daptomycin resistance-associated fitness cost was independent of vancomycin intermediate resistance phenotype, as demonstrated in additional clinical MRSA vancomycin susceptible strains. This study highlights important observations as, despite daptomycin offers a useful treatment option for the patients with persistent infections, it has to be carefully monitored. The high fitness cost associated to daptomycin resistance may explain the reduced dissemination of daptomycin resistance and the absence of daptomycin reported outbreaks.Daptomycin remains as one of the main treatment options for Methicillin-Resistant Staphylococcus aureus (MRSA). Sporadic resistance cases reported in patients treated with either daptomycin or glycopeptides are a growing concern. In a previous study, we described a clinical case of a patient with a community-acquired MRSA infection resistant to daptomycin and with intermediate resistance to vancomycin who developed a recurrent infection with a susceptible isogenic strain. In the present work, we further investigated the sequential events to determine whether the switch from a daptomycin resistance to a susceptible phenotype was due to a phenomenon of resistance reversion or recurrent infection with a susceptible strain. Pairwise competition experiments showed that the susceptible clinical recurrent SA6850 strain had increased fitness when compared to the resistant counterpart SA6820 strain. In fact, although we have demonstrated that reversion of daptomycin resistance to daptomycin susceptible can occur  Staphylococcus aureus is one of the most common human pathogens isolated from both community-acquired (CA) and hospital-acquired (HA) infections. Antibiotic management of those infections has become complex over the last decades due to large spreads of multiresistant strains, notably methicillin resistant S. aureus (MRSA) and vancomycin intermediate S. aureus (VISA)  ≤ 1 mg/L are classified as DAP susceptible (DAP-S) according to Clinical and Standard Laboratory Institute (s (VISA) . Daptomys (VISA) , is the s (VISA) . The mecs (VISA) . S. aurenstitute . As no rS. aureus is a stepwise and multifactorial process that includes cell membrane and probably cell wall perturbations (mprF), cell wall , and RNA polymerase subunits (rpoC and rpoB), both in clinical isolates and laboratory derivatives  and resistance to DAP who developed a recurrence with a susceptible isogenic strain . A similmprF gene, and that in vivo conversion of DAP resistance to a susceptible phenotype was in fact a recurrent infection rather than reversion.In the present investigation, by using competition and phylogenetic analyses of the successive isolates originated from the same patient, we show that DAP resistance in MRSA is associated with a high fitness cost mediated by mutations in mec type IV-PVL+) were recovered from blood cultures from a patient with chronic kidney failure under dialysis with a history of fracture osteosynthesis: SA6819 (h-VISA/S-DAP), SA6820 (VISA/R-DAP), and SA6850 (VSSA/S-DAP) /CB-1634(R) and CB-5013(S)/CB-5014(R) (Table 1 were used as representative strains displaying DAP-R and vancomycin susceptible phenotype (VSSA) for studies of DAP resistance fitness cost in vancomycin susceptible isolates.Consecutive CA-MRSA clinical isolates (ST5-SCCA/S-DAP) . The SA6-5014(R)  describeE-test . Antimicrobial susceptibility testing was performed by Kirby–Bauer method and according to the guidelines of the Clinical and Laboratory Standards with antimicrobial Sensi-disks . The antimicrobial susceptible testing was used to complement genetic approaches to evaluate the antibiotic susceptible phenotype related to the occurrence of specific mutations and to follow up the identity of the strains during long-term passages experiments. The antibiotics tested were rifampicin (RIF), vancomycin (VAN), ciprofloxacin (CIP), and chloramphenicol (CM).Daptomycin was provided by former Cubist/Merck Pharmaceuticals. Susceptibilities to vancomycin and DAP were performed by Genomic DNA of all strains was extracted from an overnight culture grown in BHI at 37°C using the DNeasy Blood and Tissue Kit . Libraries were prepared from purified DNA using Nextera XT DNA Library Preparation Kit  and sequenced (50 nucleotide reads) with HiSeq 2000 instruments at the Epigenetics and Genomic Laboratory at Weill Cornell University, New York, NY, United States.BA000018) and the SNPs identified using the Lasergene 13 Suite Software .Templated assemblies of the short reads were performed versus N315  were downloaded from PATRIC in April, 2017. Genes were aligned using MAFFT and a tree was built using FastTree. Trees were rendered using the iTOL website  and containing or not DAP 2 mg/L. The mutational genetic events of the resulting strain obtained after 35 days (SA6820-revertant) were determined by whole genome sequencing and its fitness was compared against its parental SA6820 strain.To access the ability of DAP resistance to revert, the resistant strain SA6820 was serially passaged daily in drug-free BHI broth. Every 5 days, enumeration of the DAP-resistant population was performed by plating the culture and its serial dilutions on BHI agar supplemented with calcium . The mixed 24-h culture was then diluted 1:1000 in fresh BHI broth and repeated daily during 10 days. Enumeration of the DAP resistant population was performed every 2 days followed by plating the culture and its serial dilutions on BHI agar supplemented with calcium  and containing or not DAP 2 mg/L. The final level of DAP resistance of the population was also evaluated after the 10 days of competition by E-test  with a 0.5 McF inoculum and directly from the whole population cells. Single cultures of the resistant strain SA6820 were conducted in parallel of the competition assay by daily passage in drug-free BHI broth to assess their stability during the competition experiment. The susceptible strain SA6850 was also plated on BHI containing DAP to evaluate the spontaneous mutation frequency. For the competitive culture between SA6850 and SA6820ΔmprF that are both DAP-S, respectively; CIP 2 mg/L and CM 10 mg/L were used as antimicrobial markers to identify SA6850 (CIP-R) and for SA6820ΔmprF (CM-R).Pairwise competition experiments between isogenic strains were conducted to compare their fitness . This meFigure 1). DAP resistance in SA6820 developed concomitantly with the acquisition of a full VISA resistance phenotype  after DAP treatment of a heterogeneous-vancomycin intermediate resistant (h-VISA: 2 μg/ml) isolate (SA6819) . Whole genome sequencing analysis revealed that SA6820 carried the L826F mprF mutation, one of the most commonly found in DAP resistant isolates . After treatment was switched to LNZ (linezolid), CIP and SXT (trimethoprim/sulfamethoxazole) and following a 3-month period of clinical improvement, the patient developed a recurrent infection due to a DAP susceptible isolate (SA6850).The patient described in our previous study presented multiple comorbidities , and was treated for a persistent bacteremia by various combination of antibiotics including VAN and DAP  it could be a recurrence of a previous version of the strain that the patient carried before acquisition of the DAP resistance. In both proposed hypotheses, the underlying condition was that the resistant SA6820 strain had a fitness disadvantage compared to SA6850, which allowed the replacement of the resistant strain by a susceptible one.However, sequence analysis of SA6850 displayed a mutation in the and MLST  correspoin vitro competitive cultures between DAP resistant SA6820 and its susceptible counterpart SA6850. After 10 days of subculture, the DAP susceptible strain SA6850 had completely outgrown the DAP resistant SA6820 . MIC determination performed by E-test after 10 days of culture with inoculum from whole population (SA6820 + SA6850) revealed a susceptible phenotype with a DAP MIC at 0.38 μg/mL. Residual population growing on BHI containing 2 mg/L DAP was shown to be spontaneous mutants of SA6850, as indicated by their characteristic resistance to CIP which was not carried by SA6820. In parallel, SA6820 resistant strain in single culture was shown to be stable during the 10 days of the experiment with a decrease of resistance of only 1 log10  and an MIC by E-test of 3 μg/mL. The results of in vitro competition experiments are in agreement with the observation that the DAP susceptible SA6850 strain had an increased fitness compared to its DAP resistant counterpart SA6820 strain.To test the fitness difference, we performed in vitro serial passages of SA6820 in drug-free BHI broth to determine the ability of the DAP resistance to revert. We observed a progressive decrease of the DAP resistant population  showing the slow reversion of the resistance. After 35 days, a fully susceptible strain with a DAP MIC at 0.5 μg/mL, named SA6820-revertant, was recovered. A residual population growing on BHI+Ca2+ containing 2 mg/L of DAP was present in similar proportion (1.77 × 10-7) than the spontaneous DAP resistance frequency previously described in S. aureus  in position 346 leading to a reading frameshift (Y116fs) and an early stop codon in position 126 of MprF, suggesting a direct role of mprF in the conversion process and thus in the fitness modification. Additional de novo mutations were also found in genes previously described to be associated with vancomycin intermediate resistance (Table 2), both of which may be also linked to its reversion.To determine the sistance  includinin vitro revertant that showed a rapid decrease of the resistant population . The difference of fitness was similar to the one observed between the clinical strains SA6820 and the in vivo DAP susceptible recurrent SA6850 strain . Since VAN phenotype appears to be directly affected during the process of reversion and may confound our results, the independent role of DAP resistance was confirmed in additional strains which were DAP resistant but VAN susceptible (these data are shown in separate section of this manuscript).Previous studies have shown that a resistant strain can rapidly acquire compensatory mutations to improve its fitness or adapt its metabolism to its culture media . Howeverin vivo revertant or a recurrence of a susceptible strain previously carried by the patient, deeper analysis taking into account all the SNPs identified versus the S. aureus N315 reference strain was performed, with the goal of determining the proximity between SA6819, SA6820, SA6850, and the in vitro obtained SA6820-revertant strain. The phylogenetic tree revealed that the recurrent susceptible SA6850 strain was closer to the DAP susceptible h-VISA isolate SA6819 than to the VISA DAP resistant SA6820 . The high homology between these strains was confirmed by the phylogenetic tree based on rpoC  strain. As expected, this inactivation restored the DAP susceptibility and, of note, also decreased slightly the VAN intermediate resistance (Table 1). The mprF influence on VAN resistance had been previously suggested by different studies , confirming the impact of mprF on the strain fitness. Competition between the two DAP susceptible strains SA6820ΔmprF and SA6850 showed no major difference of fitness; as shown in Figure 5B, after 10 days both remained in culture in similar proportion as confirmed by their resistance to both ciprofloxacin, characteristic of SA6850, and to chloramphenicol, marker of SA6820ΔmprF.The competition experiment between the SA6820 and SA6850 confirmed that the resistant strain had a lower fitness. This observation together with the spontaneous inactivation of MprF during serial passages of the resistant strain suggested that MprF, the major determinant of DAP resistance, may have a key role in the fitness cost of the resistance. To test this hypothesis,  studies ; howeverIn vitro studies proved the ability of DAP resistance to revert within a month , a mechanism mediated by the inactivation of mprF, the key gene responsible for the resistance. This modification improved the fitness of mprF-inactivated population which progressively outcompeted the resistant population. However, we cannot exclude the possibility that the in vivo process may differ from the in vitro one due to the potential complexity of its environment.rpoB SNPs carried by SA6820 have been previously associated with a high fitness cost . These results strengthened our hypothesis showing the mprF-mediated DAP resistance fitness cost, and demonstrated that it was independent of the presence of rpoB mutations and VAN intermediate resistance.The vancomycin intermediate resistance and ess cost , and couess cost . To test CB-5014 . By perfS. aureus and the role of mprF in this phenomenon. Therefore, due to the loss of fitness, DAP resistance conversion to DAP susceptibility can occur in patients when antibiotic pressure is removed. Our study demonstrate the possibility that a patient can carry strains with different resistance phenotypes, which can compete with each other and have different selective advantage in different contexts (presence or absence of antibiotics) in this particular case DAP. In fact, although we have demonstrated that reversion of DAP-R to DAP-S can occur in vitro, our results revealed that that in vivo conversion of DAP resistance to a susceptible phenotype was in fact a recurrent infection rather than reversion as also observed in additional reported cases (In summary, our study demonstrates for the first time the fitness cost of DAP resistance in clinical ed cases These findings are in support of one of our initial hypotheses in where the resistant SA6820 strain had a fitness disadvantage compared to SA6850, therefore favoring the replacement of the resistant strain by a susceptible one. In fact, MICs should be carefully monitored during the course of persistent infections or recurrence in where DAP may offer a useful treatment option for the patient , althougMR: conceived and designed experiments. JD: performed genome and phylogeny analysis. PG: performed data analysis. MR, PG, and AR: drafted the manuscript. LE, PC, and AC: provided clinical strains and performed data analysis. AR, MR, and JD edited the manuscript and did final preparation.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


P<.05) stratified by participants’ self-reported human immunodeficiency virus (HIV) status. The AMIS-2015 round of data collection resulted in 10,217 completed surveys from MSM representing every US state and Puerto Rico. Participants were mainly non-Hispanic white, older than 40 years, living in the US South, living in urban areas, and recruited from general social networking websites. Self-reported HIV prevalence was 9.35% . Compared to HIV-negative/unknown status participants, HIV-positive participants were more likely to have had anal sex without a condom with any male partner in the past 12 months  and more likely to have had anal sex without a condom with a serodiscordant or unknown status partner . The reported use of marijuana and other illicit substances in the past 12 months was higher among HIV-positive participants than HIV-negative/unknown status participants . Most HIV-negative/unknown status participants  reported ever having a previous HIV test, and 55.69% (5158/9262) reported HIV testing in the past 12 months. HIV-positive participants were more likely to report sexually transmitted infection (STI) testing and diagnosis compared to HIV-negative/unknown status participants .The American Men’s Internet Survey (AMIS) is an annual Web-based behavioral survey of men who have sex with men (MSM) living in the United States. This Rapid Surveillance Report describes the third cycle of data collection . The key indicators are the same as previously reported for AMIS . The AMIS survey methodology has not substantively changed since AMIS-2014. MSM were recruited from a variety of websites using banner advertisements and email blasts. Additionally, participants from AMIS-2014 who agreed to be recontacted for future research were emailed a link to the AMIS-2015 survey. Men were eligible to participate if they were age 15 years and older, resided in the United States, provided a valid US ZIP code, and reported ever having sex with a man. We examined demographic and recruitment characteristics using multivariable regression modeling ( The American Men’s Internet Survey (AMIS) is an annual online behavioral survey of men who have sex with men (MSM) who live in the United States. The methods have been previously published ,2. This As in the prior year, AMIS participants were recruited through convenience sampling from a variety of websites using banner advertisements or email blasts to website members . The survey was not incentivized. Data on the number of clicks on all banner ads were obtained directly from the websites. In AMIS-2014, data on the number of clicks on geospatial social networking banner ads were instead obtained by counting the number of clicks on the survey landing page. Men who clicked on the ads were taken directly to the survey website hosted on a secure server administered by SurveyGizmo . Participants were also recruited by emailing participants from the previous cycle of AMIS (AMIS-2014) who consented to be recontacted for future studies. To be eligible for the survey, participants had to be 15 years of age or older, consider themselves to be male, and report that they had oral or anal sex with a man at least once in the past (hereafter referred to as MSM). Persons who reported being younger than 15 years of age or refused to provide their age were not asked any other screening questions. Those MSM who met the eligibility criteria and consented to participate in the study started the online survey immediately. The full questionnaire for AMIS-2015 is presented in AMIS-2015 ran from September 2015 through April 2016, and resulted in 137,608 persons clicking on the ads and landing on the study’s recruitment page . Most peAlmost all these surveys  provided a valid US ZIP code. ZIP codes provided by participants were validated by merging them with the 2015 ZIP code-to-county crosswalk files created by the US Department of Housing and Urban Development . ZIP codFor AMIS-2015 analyses, participants were categorized as either being AMIS-2014 participants who took the survey again or new participants from website/app types based on target audience and purpose: gay social networking (n=1), gay general interest (n=2), general social networking (n=4), and geospatial social networking (n=2). Recruitment outcomes and demographic characteristics for the AMIS-2014 participants are presented and for all behavioral outcomes, they are recategorized according to their original recruitment source. We do not provide the names of the websites/apps to preserve operator and client privacy, particularly where a category has only one operator. The participants who were eligible, consented, unduplicated, successful, reported male-male sex in the past 12 months, and provided a valid US ZIP code were included in analyses of participant characteristics and behavior.For AMIS-2015, we created a more refined population density variable for each participant’s county of residence as determined by their ZIP code. The levels of the population density variable are from the National Center for Health Statistics (NCHS) Rural-Urban classification scheme [P values to denote an independently significant difference in the behavior for each subgroup compared to a referent group. Statistical significance was determined at P<.05.The analysis methods for AMIS-2015 did not substantively differ from those previously published but are repeated in this report for clarity . HIV tesApproximately seven in 10  participants included in this report were white and non-Hispanic, less than half were 40 years of age or older , and their most common region of residence was the South followed by the West . ParticiMost participants reported having anal sex without a condom with another man within the past 12 months . CompareAlmost one-quarter  of HIV-positive participants reported using marijuana in the past 12 months . CompareHIV testing behaviors were examined among those who did not report being HIV-positive . Most paCompared to HIV-negative/unknown status participants, HIV-positive participants were significantly more likely to report sexually transmitted infection (STI) testing  and STI diagnosis  in the past 12 months . The mos