Ralstonia solanacearum is a serious disease and causes severe yield losses in chili peppers worldwide. Resistant cultivar breeding is the most effective in controlling BW. Thus, a simple and reliable evaluation method is required to assess disease severity and to investigate the inheritance of resistance for further breeding programs. Here, we developed a reliable leaf-to-whole plant spread bioassay for evaluating BW disease and then, using this, determined the inheritance of resistance to R. solanacearum in peppers. Capsicum annuum ‘MC4′ displayed a completely resistant response with fewer disease symptoms, a low level of bacterial cell growth, and significant up-regulations of defense genes in infected leaves compared to those in susceptible ‘Subicho’. We also observed the spreading of wilt symptoms from the leaves to the whole susceptible plant, which denotes the normal BW wilt symptoms, similar to the drenching method. Through this, we optimized the evaluation method of the resistance to BW. Additionally, we performed genetic analysis for resistance inheritance. The parents, F1 and 90 F2 progenies, were evaluated, and the two major complementary genes involved in the BW resistance trait were confirmed. These could provide an accurate evaluation to improve resistant pepper breeding efficiency against BW.Bacterial wilt (BW) disease from  Capsicum spp.) is an important economic crop that belongs to the Solanaceae family alongside potatoes, tomatoes, and eggplants. Pepper is widely consumed as fresh, dried, or processed products and provides many essential vitamins, and capsaicin is used as a major spicy source in most global cuisines [Ralstonia solanacearum is the causal agent of bacterial wilt (BW), one of the most destructive soil-borne bacterial pathogens in tropical and subtropical areas, with a wide host range of more than 400 plant species, especially the Solanaceae family including peppers [R. solanacearum is widely prevalent in peppers across much of Asia [Chili pepper , R. solanacearum (phylotype II), and R. syzygii (phylotype IV) [R. solanacearum species complex includes phenotypically diverse and heterogeneous strains causing BW in a variable host range. This is one of the constraint factors of resistance studies on R. solanacearum. The pathogen can invade the plant through root wounds and subsequently resides in the xylem vessels to block water transport and ultimately kills the plant host [alcohols . R. solandonesia . Recentltype IV) ,13. Thusant host ,14.R. solanacearum in plants used two screening methods of R. solanacearum, i.e., root cut (soil)-drench and root-dipping inoculation [R. solanacearum was already optimized and has been reported in several studies [R. solanacearum studies in peppers. This assay can infiltrate a relatively equal quantity of R. solanacearum into infected leaves and evaluate the quantification of pathogen growth in a plant. Additionally, leaf infiltration can recognize the inoculated leaves and non-inoculated systemic organs and establish disease scoring according to disease transmission in the whole plant.Most studies on resistance to culation ,16,17,18culation . The lea studies ,21. But R. solanacearum are not sufficiently effective because chemical and biological controls are limited and ineffective in preventing the spread of R. solanacearum to the host plant [Capsicum spp. Several pepper accessions were reported among them, C. annuum ‘MC4′, C. annuum ‘MC5′, C. annuum ‘LS2341′, C. annuum ‘PBC473′, C. annuum ‘PBC 1347′, and C. annuum ‘PBC631′ are well known as the most strong BW resistant cultivars in various pathogens [C. annuum ‘Mie-Midori’ [C. annuum ‘PM687′ reported additive effects with two to five genes to control the BW resistance [C. annuum ‘LS2341′ is reportedly polygenic and linked to a major quantitative trait loci (QTL) named Bw1 on chromosome 1 [qRRs-10.1 in chromosome 10 was revealed as a resistance pepper line C. annuum ‘BVRC1′ [To date, developed management programs of st plant ,23. One athogens ,25,26. B-Midori’ . Additiosistance . The pepmosome 1 . Recentl ‘BVRC1′ .C. annuum ‘MC4′ is a well-known accession with a strong level of resistance to various R. solanacearum strains [C. annuum ‘MC4′ resistance to BW, genetic inheritance analysis of BW resistance in C. annuum ‘MC4′ has not been determined yet because of pathogen strain complexity and a lack of an efficient bioassay of R. solanacearum in peppers. Here, we developed a fast and reliable bioassay for phenotype evaluation against R. solanacearum in pepper germplasms. Using this method, BW resistance and susceptible symptoms were distinctly confirmed, and we successfully detected disease symptoms through whole plant wilting and validation for pepper cultivars. Through this, a genetic inheritance analysis of BW resistance was investigated in the parents, F1 and F2 progeny populations. The BW resistance trait in ‘MC4′ confirmed to be affected with at least two major complementary genes.Among them,  strains ,24,31,32R. solanacearum, we performed an infiltration of R. solanacearum SL1931 (hereafter SL1931) with 10 6 CFU/mL in resistant ‘MC4′ and susceptible ‘Subicho’ to BW. We observed phenotypes of the infiltrated area for both cultivars from day 1 to day 4 after inoculation. Disease symptoms, leaf wilting, and yellowing with necrosis were observed in ‘Subicho’ at 3 days after inoculation (dai), whereas ‘MC4′ displayed less disease symptoms within 4 dai , and the CaCDM gene was also significant at 6 and 24 hai. We confirmed the transcript expression levels of the CaHsr203J gene was significantly increased in ‘MC4′ than in ‘Subicho’ at all three-time points  from 0 to 4 using LWB, which demonstrated identical BW symptoms with other methods A–E 30,3,330,37. R. solanacearum that inhabits tropical and subtropical areas. Appropriate temperature conditions (28–32 °C) of screening for bacterial wilt were identified in several studies on various crops and R. solanacearum strains [3 CFU/mL to 10 6 CFU/mL at 10-fold intervals  and 3:1 ratio (p > 0.1). It appeared more closely at an 11:5 ratio than 3:1, which demonstrated that BW resistance was predominantly controlled by at least one major factor and/or two major alleles around two weeks after inoculation. At 20 dai, resistant plants in the F2 prevailed with 61 resistant plants versus 29 susceptible, which nearly matched a 9:7 ratio (p > 0.5) and 11:5 ratio (p > 0.1). Lastly, the segregation was represented as a 9:7 ratio (p > 0.05) with 42 resistant plants versus 48 susceptible at 30 dai  that demonstrated more aggregation of the pathogen in susceptible cultivar (BVRC 1) then resistance (BVRC 25) [R. solanacearum and displayed a higher expression level of cell-death related genes compared with ‘Subicho’. The cell-death markers used in this study were related to the resistant response and defense-related pathway [In this study, we confirmed the different symptoms in leaves after inoculation to discover if the method is suitable for resistant ‘MC4′ and susceptible ‘Subicho’. Additionally, the transcript levels of defense-related genes and bacterial cell growth were significantly different in the resistant or susceptible cultivars following BVRC 25) . Likewis pathway ,45. As au et al. 19 that du et al. 19 that d pathway ,46. In cR. solanacearum affects crops [6 CFU/mL indicating that it was sufficiently able to confirm the phenotypic difference between two control cultivars with a lower concentration and less volume than the drenching method.The temperature was the main environmental factor in which ts crops ,48. An ets crops ,38. TherR. solanacearum strains in Lee et al. (2018) [R. solanacearum is exceptionally difficult. An accurate and reliable bioassay (LWB) can identify the exact BW phenotype in pepper through the equal inoculate without any wound of the root.We executed the LWB in eleven commercial pepper cultivars with BW phenotype information and one commercial pepper cultivar with no information. As a result, five and two cultivars represented R-phenotype and S-phenotype, respectively, and the others were the MR-phenotype. Among them, the cultivars of ‘Muhanjilju’, ‘PR-Jangwongeubje’, and ‘PR-Gukgadeapyo’ demonstrated susceptibility in Hwang et al. (2017), but our results demonstrated the resistance of BW phenotypes, which is an opposite result. These results could affect the metabolic activity of the host due to artificial wounds in the root, making it difficult to identify the accurate BW phenotype. In case of ‘Muhanjilju’, it represented R, MR, or S-phenotypes according to inoculation with various . (2018) . Additio. (2018) , in whicCapsicum spp. including C. annuum ‘MC4′, ‘MC5′, ‘LS2341′, and ‘PBC631′ [qRRs-10.1) in ‘BVRC1′ accession and one major (Bw1) in ‘LS2341′ accession were identified at different chromosome 10 and 1 for each resource, respectively [One of the most effective control managements is developing a resistance cultivar in the crops by integrating a resistance gene. Until now, a few sources of BW resistance have been reported in ‘PBC631′ ,25,26. Iectively ,30. Despectively ,50.R. solanacearum complex [2 population with ‘Subicho’ (susceptible) and performed an analysis of the inheritance of BW resistance through the LWB. We identified BW resistance as dominant and over susceptible, and at least two pairs of genes appeared to control the trait in a complementary manner. Matsunaga et al. (1998) studied the mode of inheritance of BW resistance by crossing the resistant sweet pepper cultivar ‘Mie-Midori’ with the susceptible ‘AC2258′ and found that bacterial wilt resistance demonstrated incomplete dominance, and at least two genes were involved in resistance [R. solanacearum using six resistant pepper lines and five susceptible pepper lines [2 plants (n = 440), in which the wilting pattern of segregation was similar to our result [1 and F2 generation, and which indicated to appear epistasis dominant like our result. These studies indicated that the inheritance of BW resistance is complicated, and a minimum of two genes interact to express resistance traits in the pepper germplasm. Our data suggest that the LWB method may determine a more exact BW resistance phenotype of pepper germplasms and reveal the interaction of plant-pathogens at the molecular level. Further investigations of inheritance factors could provide insights into QTL analysis and the development of BW resistance-related molecular markers.‘MC4′ is well-known to have high-level resistance to the species of the  complex ,26,31, bsistance . This reer lines . Recentlr result . EspeciaCapsicum annuum ‘MC4′ with resistance to R. solanacearum and C. annuum ‘Subicho’ with susceptibility to R. solanacearum, were provided by Dr. Seon-Woo Lee . The 12 commercial pepper cultivars  was obtained from Dr. Seon-Woo Lee . Bacterial cells were streaked and grown on Kelman’s tetrazolium chloride gar medium and maintained at 28 °C for 48 h. A single fluidal colony of R. solanacearum was grown on CPG broth and shaken at 250 rpm at 28 °C for 24 h. A bacterial culture suspension was diluted with distilled water to adjust the concentration to 10 8 CFU/mL (OD600 = 0.3) [3 CFU/mL to 10 6 CFU/mL per leaf were used for inoculation. Seedlings of fully expanded four-leaf-stage were inoculated with 0.1 mL bacteria/leaf using a needleless syringe. Disease symptoms were observed under controlled conditions of 29 ± 1 °C under 16 h of light a day with 50% humidity for 20 days. The leaf-inoculation assay was performed with three independent tests, and each consisted of at least 8 plants per cultivar. Inoculum concentration was performed with 10 6 CFU/mL per leaf for the inheritance analysis of the F2 population.The strain 0 = 0.3) . Ten-folC. annuum ‘MC4′ and ‘Subicho’) were leaf-inoculated with bacterial suspensions (1 × 10 4 CFU/mL). Inoculated leaves were harvested at various time points for further analysis. Two independent assays were performed, which consisted of 6–8 samples for each time point in an experiment. Bacterial growth was measured by grinding inoculated samples in distilled water, plating serially diluted tissue samples with two replicates on CPG agar with 0.1% gentamicin (v/v), and counting colony-forming units.Bacterial quantification was performed like below with modification described by Yi et al. (2009) . To deteR. solanacearum as described below. The disease severity index (DSI) of individual inoculated plants was rated on a scale of 0 to 4 as five phases in which 0 is no wilt disease symptoms observed; 1 is minor symptoms with less than 25% wilted leaves; 2 is moderate symptoms with 25%–50% wilted leaves; 3 is severe symptoms with 50%–75% wilted leaves; 4 is 75%–100% wilted leaves or dead plant. The area under the disease progress curve (AUDPC) was calculated during the disease observation (0 to 15 dai) with a DSI value. [p < 0.05 was considered a significant difference. Statistical analysis used SAS .Disease evaluations were assessed daily after inoculation with I value. . WiltingR. solanacearum infection, quantitative RT-PCR was performed using the defense-related genes (CaACT) was used as an endogenous control to normalize the expression levels. Expression levels were reported as three replicates as mean values with standard errors.Total RNA was extracted from pepper leaves inoculated with the pathogen using the Trizol reagent , and 2 ug of total RNA were reverse transcribed using Superscript IV . To confirm the plant response against ed genes  [34,36,52 population. The BW resistance response of ‘MC4′ represents lower disease symptoms in leaves than susceptible ‘Subicho’, and we observed the spreading of wilt symptoms from leaves to a whole susceptible plant, similar to the drenching method. As a result, we optimized the evaluation method of resistance to BW with 12 commercial pepper cultivars. Using LWB, we confirmed the two major complementary genes related to the BW resistance trait through the analyzed genetic inheritance in 90 F2 progenies. This bioassay could promote an accurate evaluation of BW disease phenotype, and the two inheritance factors of ‘MC4′ could provide useful information for further QTL analysis in pepper breeding.Breeding a resistant cultivar is most effective in controlling bacterial wilt that causes serious yield losses in peppers worldwide. An accurate and reliable evaluation method is necessary to evaluate disease severity and reveal the genetic inheritance for BW resistance. We established a simple LWB to evaluate BW disease and then, using this, analyzed the inheritance of BW resistance through a ‘Subicho’ × ‘MC4′ F


Scientific Reports 10.1038/s41598-019-46484-2, published online 10 July 2019Correction to: The original version of this Article contained errors in the Reference list. Reference 26 was incorrectly listed as reference 48, and reference 27 was incorrectly listed as reference 31. As a result, the original references 26–30 are now listed as references 28–32, and references 32–47 are now listed as references 33–48. This has been corrected in both the HTML and PDF versions of this Article.


While numerous factors have been recognized in affecting suicidal thoughts and behaviors (STB), the associated environmental risks have been poorly understood. Foremost among the various environment risks were air pollution, in particular, the PM2.5. The present study attempted to examine the relationship between PM− 3) and the index of suicidal ideation (Mean = 49.9).Using Internet search query volumes in Baidu (2017), the largest internet search engine in China, we constructed a prefectural panel data  and employed dynamic panel GMM system estimation to analyze the relationship between weekly concentration of PM2.5 (Mean = 87 μg·m− 3 increase in the prior week’s PM2.5 in a Chinese city is significantly associated with 0.020 increase in ISI in spring and a 0.007 increase in ISI in winter, after taking account other co-pollutants and meteorological conditions.The results indicate that in the spring and winter, a 10 μg·m2.5 level.We innovatively proposed the measure of suicidal ideation and provided suggestive evidence of a positive association between suicidal ideation and PM Suicide has long been one of the most prominent and published public health problems, accounting for 800,000 deaths worldwide each year, according to the World Health Organization . Far mor10 and PM2.5 (particles less than 10 or 2.5 μm in diameter). As a mixture of fine particles and liquid droplets, PM2.5 is a particular danger because it is easily sucked into the lungs, where it can have a devastating impact on an individual’s health.While numerous factors have been recognized in affecting suicidal thoughts and behaviors (STB), such as, life stresses, chronic pain and illness, conflict, disaster, violence, losses, et al. , the env2.5 and PM10 also have detrimental impact on mental health. For instance, depression has been reported by a bulk of literature to be closely correlated with PM2.5 [2.5 and PM10 might also influence suicidal ideation. However, results of studies on the link between particulate matter and suicidal behaviors are mixed and mostly from western developed countries [Previous studies also indicate that PMth PM2.5 –34. Impoth PM2.5 –38. Therountries –42.Since suicidal ideation is an independent and important risk factor for suicidal behavior , quantif2.5 concentration data collected from the air quality monitoring station in more than 300 cities indicated that the majority of cities fail to meet air quality standards set by WHO [2.5). Drastic actions have been taken to improve air quality in recent years including shutting down local coal-fired power plants, reducing the production of steel, and limiting driving. Still, the environmental hazard persists and makes China an ideal lab for looking into the potential link between suicidal ideation and ambient air particulates, especially PM2.5.Therefore, we chose China as the case for study. In the past two decades, China has experienced unprecedented economic growth accompanied by rapidly increasing mental health problems  as well t by WHO . Of noteTo quantify the aggregate level of suicidal ideation, we extract from Baidu (the largest online search engine in China) the local volumes of online search queries indicating suicidal thoughts manifested by the presence of plans to commit suicide. In fact, online searches indicating suicidal thoughts are used to quantify suicidal ideation in a recent study published in JAMA . BesidesUsing this method to measure suicidal ideation, we proceed to examine whether and how local PM2.5 levels are associated with local suicidal ideation in China, based on nationally representative panel data collected from 278 Chinese prefectures in 52 weeks in 2017.2.5 exposure and suicidal ideation.Using Internet search query volumes in China’s largest search engine Baidu and other online environmental data in 2017, we constructed a panel dataset at prefecture-level . In Baidu archives, most frequently searched items (words or short sentences) and the relevant IP locations from these searches were launched. Daily frequencies are computed as the Baidu Index. This allows us to access daily/weekly/monthly volumes of suicidal-ideation-related search queries at the prefecture level. We used Python 2.7.11 software to gather data on all chosen terms, and chose ‘week’ as the analytic time-frame unit over the course of 2017 because weekly time series are not affected by noise in daily time series and can be used to better identify seasonal and long-term trends of PMsuicide) and 11) Death ends all trouble (一了百了). The five direct and eleven indirect signal phrases/words together constitute the list of suicide-related words, based on which, we conduct principle component analysis (PCA). we choose the number of components based on the number of larger than one eigenvalue criteria. The PCA result shows that there is only one component whose eigenvalue is larger than one, in this regard, one principal component can capture most of variation of primary variables. By using regression method, we construct index of suicidal ideation ISI-1.Prefecture-level suicidal ideation, the dependent variable, is gauged by the index of suicidal ideation (ISI) computed using suicide-related search data extracted from Baidu. As for the items signaling suicidal thoughts, we chose most commonly used phrases or short sentences clearly stating an intent to commit suicide. Specifically, we extracted the search volumes for five short sentences: 1) I want suicide (我想自杀); 2) I would like to commit suicide (我要自杀); 3) How to commit suicide (如何自杀); 4) suicidal methods (自杀方法); and 5) methods of suicide (自杀的方法); together with 11 Chinese words that can be seen as indirect signals of suicidal thoughts, such as various methods of committing suicide, the word suicide itself, and several synonyms. Specifically, these words are: 1) suicide (自杀), 2) wrist cutting (割腕), 3) hang oneself (上吊), 4) charcoal-burning (烧炭), 5) self-burning (自焚), 6) jump to death (跳楼), 7) cutting one’s own throat (自刎), 8) lay on the railway (卧轨), 9) attempt suicide (寻死), 10) suicide . We also collected the information of weekly average PM10, SO2, and NO2 from the same source, as various research has shown that these co-pollutants are associated with elevated risk of adverse health outcomes.The key explanatory variable is a prefecture’s weekly average PM2.5 and suicidal ideation searches is likely to be confounded by time-variant factors. Previous studies that examined the effect PM2.5 on mental disorders and results such as suicide pointed out that confounding meteorological conditions including sunlight, temperature [2.5 concentration. We controlled for weekly day mean temperature (Temp), weekly ratio of rainy days (Rain), and adjusted weekly sunlight (Sunlight) measured by the average length of a day in a given week multiplied by the weekly ratio of sunny days in each city over the course of the year. This information was collected from the Chinese website Historical Weather (http://www.tianqihoubao.com/lishi) and Sunrise and Sunset on the website of Convenience Inquiry (https://mtop.chinaz.com/site_richurimo.51240.com.html).Additionally, the relationship between PMperature , 54, andperature –57 becauperature , 58–63 aWebportal). They are 百度 (Baidu), 微信 (We-chat), QQ (qq), 淘宝 (Taobao), 支付宝 (Alipay), 新浪 (Sina), 搜狐 (Sohu), 网易 (Netease), 腾讯 (Tencent), 中央电视台 , and 高铁 (Bulliet Strain). To reduce the dimensionality of the data, we conducted principal component analysis and extracted one factor from these items. Moreover, we also controlled for the air pollution search to take into account the regional concern about air pollution. This measure not only reflected the regional population’s environmental awareness, but also reflected the media effect on air pollution. The descriptive statistics of key variables are shown in Table Given that the imbalanced internet development across regions may potentially influence individuals’ search behaviors, we further controlled for city-level frequency of surfing 11 of the most popular and widely-used web portals in China (t – 1) of ISI to specify the path dependence condition. In order to deal with the reversed causality problem, we imposed the temporal order in the models by using the lagged values (t – 1) of all explanatory variables. The model can be written as:In this analysis, we take advantage of the panel to control for regional heterogeneity. To capture the dynamic structure of suicide-related searches, we adopted dynamic panel models by introducing the one-week lagged value  is its one-week lagged value. PM2.5i _ (t − 1) is the key independent variable, representing the level of weekly average PM2.5 in city i week t − 1. Considering the potential confounding from other co-pollutants and meteorological variables, we include one-week lag of PM10, SO2, NO2, temperature (Temp), rainy day ratio (Rain), weekly sunlight (Daylength) in city i. Moreover, to adjust for the different level of internet development and pollution concern across cities, one-week lag of frequency of searching air pollution related items  and frequency of searching air pollution related items (PollutionSearch) are also included in the Eq. ; and (3) the Henson/Sargan over-identification test to examine the validity of these instruments (p > 0.05). Overall, the results of these tests suggest that SGMM is a valid estimator in this study.We employed System Generalized Method of Moments (SGMM) estimator to examine the association between PMd levels , 65, we d levels . We have2.5 level of all 278 cities over the course of the year was around 86.2 μg·m− 3. To show the distribution of PM2.5 and ISI across cities, we draw Fig. 2.5 and ISI, and both varied seasonally as well. There is an elevated PM2.5 concentration in central China and some parts of northeast and northwest China where heavy industry abounds. However, in western, south and some parts of northeast and China where service industries prevail, PM2.5 concentration is relatively low. In terms of changes in PM2.5 concentration throughout the year, we observed a higher level of PM2.5 in winter than in other seasons. We also observed a larger variation in PM2.5 in northwest China relative to the rest of China, where a continental rather than a monsoon climate is dominant.Table 2.5.Table 2.5 does not seem to significantly predict ISI. Given that the mixture of particulate matter varies by season, we further look into the effects across seasons.In Table 2 and NO2 do not exert significant impacts on ISI throughout the year. PM2.5 can positively predict ISI in spring and winter, even when taking account co-pollutants, and other weather conditions , regional internet usage, and pollution concerns. A 10 μg·m − 3 increase in PM2.5 is associated with a 0.020 increase of ISI in spring and a 0.007 increase in winter. Though PM10 also shows significant positive effect in spring, the effect is much smaller, merely 1/7 of PM2.5.The by-season results clearly show that, SOAs a robustness check, we follow the same model-building strategy and take ISI-2, the measure of suicidal ideation, using more extended search items relevant to suicide as the dependent variable in Table Suicide is a global public health threat. Despite its importance, much remains unknown about the risk factors behind suicidal thoughts and behaviors. Some researchers blamed this to a lack of reliable STB indicators, leading to the slow progress and low effectiveness of suicide interventions , 43, 67.2.5, is a factor in depression. Suicidal ideation, a symptom of major depression is thus likely to be influenced by PM2.5. To explore such correlates, this research examines the potential link between PM2.5 and suicide ideation based on the context of China. The country has experienced rapid industrialization and modernization accompanied by an increase in mental health problems as well as environmental problems, where air pollution continues to pose a serious and sustained threat to residents physical and mental health.In the past decades, numerous attempts have been made to establish risk factors of suicidal thoughts and behaviors, encompassing biological, psychological, and sociological factors –70, whet2.5 on suicidal ideation varies by season. A higher concentration of PM2.5 predicted a higher level of suicidal ideation in spring and winter, with ISI increasing for 0.020 in spring and 0.007 in winter for every 10 μg·m − 3 increase in PM2.5, holding constant of other co-pollutants and meteorological variables. For the rest of the year, PM2.5 did not show a significant effect. This result, to some degree, echoes the findings of depressive symptoms [We constructed a weekly index of suicidal ideation (ISI) in 278 major cities in China using internet searches that indicated suicide thoughts on Baidu, the most widely used search engine in China. The internet-based method of quantifying suicidal ideation allowed us to proxy the local level of thinking about suicide, which is often concealed, fleeting, and not easy to identify using traditional means. The SGMM estimators revealed that the effect of PMsymptoms , where tsymptoms –77 or spsymptoms .2.5 and suicidal ideation, contributing to the literature not only by shedding more light on our understanding of the pollution-suicide link but also by providing a scientific method to quantify suicidal ideation using online big data.Overall, our study shows a significant and substantial positive relation between PM2.5. In this vein, assuming no short-term change of social, economic, and political conditions is plausible. Third, due to the lack of relevant clinical data, we cannot the identify the mechanism to establish the PM2.5-suicidal ideation link across seasons. However, as documented in various other research, the larger effect of PM2.5 in winter and spring is likely to be attributed to inflammation and oxidative stress [Our research has several limitations. First, due to stigmatization, individuals who are thinking of committing suicide incline to hide their true feelings, and often, they may express such inclination in a subtler and less straightforward way. In this vein, we may overlook some relevant searches that can signal suicidal thinking and behaviors. However, there are a wide range of thoughts and behaviors in suicidal thoughts and behaviors: thinking about suicide, developing a plan, obtaining the relevant tools. Only the last stage reflects a serious intention that may turn to physical action. In this vein, the search items we designed for this analysis captured intention to a large degree. Second, due to weekly changes in social, economic, and political conditions in each city, we may have ignored economic crisis, social conflict, or political hurdles that influenced suicide ideation. However, our analysis is based on weekly information in only 1 year, meaning that we focus on the short-term, rather than long-term impact of PMe stress –83, frome stress –88, for 2.5 and suicidal ideation. Our study shows a significant positive relationship between PM2.5 and ISI, contributing to the literature not only by shedding more light on our understanding of the pollution-suicide link but also by providing a new method to quantify suicide ideation using big data. The present environmental degradation and pollution is a product of rapid, unbridled industrialization. Amid public outcry over record-high pollution levels, researchers face a pressing urgency to understand how these pollutants are associated with physical and mental health risks.Despite these drawbacks, our research is an innovative attempt to quantify suicide ideation and reveal the potential linkage between PM2.5 and ISI, and showed how such association would vary by season. Although future studies are still needed to explore specific mechanisms. Our findings might be taken as a reference for suicide prevention.There is heavy stigma associated with suicide, making suicidal ideation a hidden pain. To reveal suicidal ideation as accurately as we can, we resort internet search data to construct a prefecture-level weekly index of suicidal ideation (ISI). By using this innovative measure, the present study examined the association between PM


Background: This study aimed to explore the effects of sodium-glucose co-transporter 2 (SGLT2) on hemoglobin levels in patients with type 2 diabetes mellitus (T2DM) and chronic kidney disease.Methods: PubMed, EMBASE, the Cochrane Central Register of Controlled Trials, the China National Knowledge Infrastructure database, Wanfang Digital Periodicals Database (WFDP) and the Chinese Biological and Medical database (CBM) were searched for randomized trials of SGLT2 inhibitors in patients with T2DM and chronic kidney disease up to July 25, 2020. A total of four studies that included 19,259 patients were identified.Results: Compared to control patients, SGLT2 inhibitors were shown to increase hemoglobin levels in patients with T2DM and chronic kidney disease .Conclusion: SGLT2 inhibitors may bring additional benefits to patients with T2DM and chronic kidney disease. In the past ten years, the incidence of type 2 diabetes mellitus (T2DM) has been increasing  which inSodium-glucose co-transporter 2 (SGLT2) inhibitors are a newly approved class of oral hypoglycemic agents that increase the excretion of glucose in the urine by inhibiting the reabsorption of urine glucose in the proximal tubules of the kidney, thereby reducing blood glucose levels, weight and blood pressure . In addiIn this study, we aimed to ascertain the effects of SGLT2 inhibitors on the hemoglobin levels in patients with T2DM and chronic kidney disease.The PubMed, EMBASE, the Cochrane Central Register of Controlled Trials, the China National Knowledge Infrastructure (CNKI) database, Wanfang Digital Periodicals database (WFDP), the Chinese Biological and Medical database (CBM) were searched. The following Medical Subject Headings (MeSH) terms and free-text terms were applied: “Sodium-Glucose Transporter 2 Inhibitors”, “Sodium Glucose Transporter 2 Inhibitors”, “SGLT2 Inhibitors”, “SGLT-2 Inhibitors”, “SGLT 2 Inhibitors”, “Gliflozins”, “Renal Insufficiency, Chronic”, “Chronic Renal Insufficiencies”, “Renal Insufficiencies, Chronic”, “Chronic Renal Insufficiency”, “Kidney Insufficiency, Chronic”, “Chronic Kidney Insufficiency”, “Chronic Kidney Insufficiencies”, “Kidney Insufficiencies, Chronic”, “Chronic Kidney Diseases”, “Chronic Kidney Disease”, “Disease, Chronic Kidney”, “Diseases, Chronic Kidney”, “Kidney Disease, Chronic”, “Kidney Diseases, Chronic”, “Chronic Renal Diseases”, “Chronic Renal Disease”, “Disease, Chronic Renal”, “Diseases, Chronic Renal”, “Renal Disease, Chronic”, “Renal Diseases, Chronic”. All publications up to July 25, 2020 were selected without the restriction of origins, countries, languages or article types.Published articles that were included in the analysis were required to meet the following criteria: 1) the eligible subjects were men and women with T2DM and chronic kidney disease; 2) interventions involved treatment with SGLT2 inhibitors alone or with other hypoglycemic agents; 3) studies compared placebo control or standard of care; 4) outcomes reported changes in hemoglobin levels from baseline; 5) studies that were randomized controlled trials (RCTs); 6) studies with follow-up times of 12 weeks or longer. Observational studies, non-randomized trials and uncontrolled trials were excluded from the analysis.Two investigators extracted the following data independently from eligible publications: first author, publication year, study design, inclusion criteria, sample size, patient characteristics, interventions (types and doses of SGLT2 inhibitors), comparison (placebo control or standard care), follow-up duration and outcomes (changes in hemoglobin levels from baseline). The unit of hemoglobin levels was uniformly converted into g/l. Discrepancies were resolved by the discussion between two investigators. The Cochrane risk-of-bias tool was adopted to assess randomization, masking of treatment allocation, blinding, adherence and withdrawals for each of the RCTs .p values (<0.05) were considered to represent statistically significant publication bias.Data analysis was performed using Stata version 12.0 software. The effect sizes on scores were presented as the standard mean difference (SMD) and 95% confidence intervals (CIs). The Chi-squared test based on Q-statistic and I2 statistics was used to estimate the heterogeneity  . A fixedA total of 579 references were retrieved and finally, four studies  met the With the exception of one open-label study, the other three studies on random sequence generation were fully considered. The studies were all double-blind trials but there was no further explanation on the details of allocation concealment. There were no incomplete outcomes and selective reporting in the four studies. Based on the characteristics, we believe that the included studies had a low risk of bias.p < 0.0001) and so the random-effects model was used. The pooled effect size showed significant differences in hemoglobin levels  in favor of the experimental groups compared to the control groups (Four studies (Four publications) investigated a total of 19,259 participants  and reported hemoglobin levels. There was high heterogeneity ; thus, the fixed-effects model was used. The pooled effect size showed a significant difference in Hematocrit  in favor of experimental group, compared with the control group  reported Hematocrit. There was no heterogeneity . Subgroups were divided as to eGFR based on 30 ≤ eGFR <60 ml/min/1.73 mA sensitivity analysis was conducted by sequentially removing one study to observe the influence of each of the included studies on the overall pooled SMD. No single study was found to significantly influence the overall pooled SMD indicating that the results were stable.p = 0.161 (>0.05)) and Egger’s linear regression test ).In assessing publication bias, a funnel plot for the four studies analyzed was constructed. The shape of the funnel plot was symmetrical indicating the absence of publication bias. No significant bias was observed using the Begg’s rank correlation test , the differences were statistically significant.This article conducted a meta-analysis of four randomized controlled studies to explore the effects of SGLT2 inhibitors on hemoglobin levels in diabetic patients with chronic kidney disease. The results showed that the hemoglobin levels of patients after treatment with SGLT2 inhibitors increased from baseline and the differences were statistically significant. The hematocrit levels of patients after treatment with SGLT2 inhibitors increased from baseline and the differences were statistically significant. Whether it was different type and dosage of the drug , or different eGFR (30 ≤ eGFR <60 ml/min/1.73 mMost of the observations from previous reports in the literature and meta-analysis demonstrate the effects of SGLT2 on blood sugar levels, cardiovascular events and renal outcomes. There are very few studies that have analyzed the effects of SGLT2 inhibitors on hemoglobin levels or have performed meta-analyses of these effects across multiple RCTs.SGLT2 inhibitors protect patients with T2DM and chronic kidney disease through several different mechanisms. First, in diabetic patients, upregulation of SGLT2 increases the reabsorption of sodium and glucose by the proximal tubules, SGLT2 inhibitors lower blood sugar by blocking the glucose reabsorption of SGLT2 in the proximal renal tubules. Second, SGLT2 inhibitors also have a certain effect on renal hemodynamics. SGLT2 inhibitors block the reabsorption of glucose and sodium in the proximal tubules and increase the transport of sodium to the macula densa, thereby restoring impaired tubuloglomerular feedback. Thus, SGLT2 inhibitors can alleviate glomerular filtration in the early stage of diabetic nephropathy, reduce albuminuria, and delay the decline of renal function for a long time . BesidesThe mechanisms by which SGLT2 inhibitors improve hemoglobin levels in patients with diabetes and chronic kidney disease are not fully understood. It has been reported that SGLT2 inhibitors have diuretic-like effects and reduce plasma volume . It has 2. This meant that a small number of patients with normal renal function may have been included. In addition, the population included in the study did not have obvious renal anemia before SGLT2 inhibitors treatment. Therefore, for patients with significant renal anemia, the benefits of SGLT2 inhibitors need to be further investigated.Several limitations of this study should be noted. Firstly, a total of four articles were included in the analysis which is a small sample size, however, the total number of patients included was nor large. Secondly, the majority of the subjects were Caucasian and so the applicability of the data to other races including Asians requires further investigation. Thirdly, although we concluded that hemoglobin levels increased after treatment with SGLT2 inhibitors, we did not observe differences in the effects of different types of SGLT2 inhibitors on hemoglobin levels, the relationship between the increase in hemoglobin level and the duration of medication. Fourthly, among the populations included in the study, some had eGFR ≥ 60 ml/min/1.73 mIn summary, patients with T2DM and chronic kidney disease have increased hemoglobin and hematocrit levels after treatment with SGLT2 inhibitors. SGLT2 inhibitors may bring additional benefits to patients with T2DM and chronic kidney disease.


Our results confirmed that paretic knee extensor strength, gait velocity, and fat mass were major determinants of peak aerobic capacity in subacute stroke. Therefore, therapeutic approaches should focus on improving gait velocity and paretic knee extensor strength in the early stages of recovery from stroke.The purpose of this study is to investigate major determinants of peak aerobic capacity in subacute stroke patients among body composition, balance function, walking capacity, and lower limb muscular strength. This was a retrospective observational cohort study. Eighty-three subacute stroke patients were enrolled and their medical records were retrospectively reviewed in the study . Gait capacity was assessed by gait velocity  and gait endurance . Balance function was evaluated with Berg Balance Scale (BBS). The isometric muscular strengths of bilateral knee extensors were measured with an isokinetic dynamometer. Cardiovascular fitness was evaluated with an expired gas analyzer. In backward linear regression analyses, paretic isometric extensor strength (p < 0.001), fat mass (p = 0.005) and 10MWV (p < 0.001) are significantly correlated with peak aerobic capacity (adjusted R Thus, the goals of stroke rehabilitation therapy at the subacute stage is to enhance locomotion and basic ADL skills2. While 60–70% of subacute stroke patients can walk independently at discharge3, only 7% of stroke patients have sufficient capacity to maintain an independent gait in the community3. The barriers to community ambulation are related to persistent functional deficits such as muscle weakness, poor balance, and reduced mobility, which result in decreased physical activity and cardiorespiratory fitness1. Because cardiorespiratory fitness is significantly associated with baseline status and recovery of functional outcomes at the subacute stage, the reduced aerobic capacity might contribute to poor rehabilitation outcomes and exacerbate metabolic risk factors for recurrence of stroke, such as hypertension, obesity, and diabetes4. In addition, several studies have reported an association between body composition and cardiorespiratory fitness5. However, few studies in subacute stroke patients have comprehensively examined body composition and clinical functional outcome including gait performance, muscle strength, balance function, and cardiorespiratory fitness.Stroke is one of the most common causes of death and, in survivors, often induces chronic residual deficits that impair walking ability and the basic activities of daily living (ADL)Therefore, the objectives of this study were to determine the major predictors of peak aerobic capacity in subacute stroke patients among body composition, balance function, walking capacity, and lower limb muscular strength.This study was a retrospective observational cohort study. Eighty-three subacute stoke patients were recruited from October 2014 to July 2016 in department of rehabilitation medicine.The inclusion criteria were described as; (1) A first-onset ischemic or hemorrhagic stroke patient that is confirmed by magnetic resonance imaging (MRI) or computed tomography (CT); (2) Disease duration within 3 months after onset;(3) Mild to moderate hemiparesis that is cable of walking at least 3 m, irrespective of a gait aid.6.The exclusion criteria composed as below: (1) Severe deficits in communication, memory, or comprehension that cannot follow instructions or communicate with the investigators; (2) Cerebellar or brainstem lesions that demonstrates balance dysfunction; (3) Any additional neurological or orthopedic disease such as peripheral neuropathy, fractures, degenerative arthritis, or joint instability of hip or knee; (4) Psychiatric or cardiorespiratory problems; (5) Contraindication of maximal exercise testing, as proposed by the American College of Sports Medicine (ACSM)All patients received conventional rehabilitation therapy composed of a 30-min of physical therapy and a 30-min of occupational therapy, twice per day, five times per week for 4 weeks. Retrospective chart review was performed to all patients according to medical history, physical and neurological examinations, and body composition. Given the retrospective study design, the need for informed consent was waived. Thus, the informed consent from patients in this research was waived by the institutional review board of Jeju National University Hospital .7. The body mass index (BMI) was then taken from (weight/height2) (kg/m2).Body composition data including body weight, fat mass, and muscle mass were measured using a bioelectrical impedance analysis (BIA) device  on standing and gripping an eight-point tactile electrode system. 15 impedance values in five body segments were obtained by three distinct frequencies Participants conducted a symptom-limited exercise tolerance test (ETT) by a treadmill  or a cycle ergomety , with supervision of a physiatrist and a physical therapist.8, forty nine patients started to walk as fast as possible but safely on the treadmill at zero incline for the initial 2 min. After then, the workload was changed to a 4% incline for 2 min and increased by a 2% incline every 2 min. For thirty four patients that could not run on a treadmill, the cycle ergometry was alternatively used at a rate of 50–60 revolutions per minute (rpm) with a workload of 10 W for the first 2 min and the workload was raised by 5 W every 2 min. The test was terminated according to guidelines of ACSM6, if the patient asked or there was gait instability or signs of cardiovascular decompensation.After sitting for 15 min2max) by portable metabolic anaysis system  were obtained if at least two of the following five criteria for maximal effort were satisfied: (1) a respiratory exchange ratio (RER) ≥ 1.0;(2) a steady VO2 (< 150 mL/min) with increasing in exercise intensity;(3) no increase in heart rate (HR) despite workload increase;(4) % PHR > 95% of age-predicted maximal HR; or (5) volitional fatigue (a drop of cycling rate to < 30 rpm)6.Peak exercise cardiovascular responses and maximal oxygen consumption (VO2peak), resting/peak heart rate (RHR/PHR), resting/peak blood pressure (RBP/PBP), ETT duration, RERpeak, and peak rate pressure product (RPPpeak). RPPpeak was calculated as PHR × systolic PBP/100, and %PHR was converted from the percentage (%) of the age-predicted maximal HR [PHR /(220 – age)] × 1006.The parameters measured were peak oxygen consumption  of their knee extensor bilaterally using an isokinetic dynamometer  on sitting with 85°-hip angles until the variation in torque was less than 5% for three successive trials10.Gait performance was assessed by gait velocity  and gait endurance . For 10MWV, subjects were instructed to walk 14 m (including both 2-m acceleration and deceleration phases) at a comfortable but fastest possible safe pace without verbal encouragement. Time was recorded in the use of a stopwatch and self-selected and fastest gait velocities (m/s) were calculated from the time taken to walk the middle 10 m track11.For 6MWD, subjects were guided to walk as far as possible during 6 min, while walking through a 50 m hallway indicated with lines12 and reveals high level of the inter-rater reliability  and the intra- rater reliability in both physiatrist group (0.95) and physical therapist group (0.97)13.The BBS is a typical measurement of a subject’s balance and risk of fall which is composed of functional tasks common in everyday life15.The tasks progress from standing-up from a sitting position to tandem standing, and standing on one leg. Static and dynamic balance are evaluated by tasks such as reaching, standing position, and transference with a maximal score of 56 indicating good balance2 tests were used for categorical variables. Pearson’s and spearmann correlation analysis was used to assess the relationships among clinical parameters with VO2peak, respectively. Pearson's and Spearmann’s correlation coefficients were categorized as below; weak < 0.3, 0.3 ≤ moderate < 0.7, strong ≥ 0.717.Descriptive analysis was used to characterize the samples and the distribution of variables. Average data are indicated as mean ± standard deviation (SD) for continuous variables including age, fat mass, muscle mass, BMI, and stroke duration, and all parameters of clinical outcome and cardiopulmonary fitness. χ16.Multivariate linear regression analysis using backward selection linear regression model was employed to determine a significant predictor of cardiovascular fitness. All statistical analysis were performed using the SP statistical package ver. 20.0 . A statistically significant difference was considered with a p-value of less than 0.05. Estimation of minimal sample size and statistical power was determined by G* Power programAll procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee (JNUH-IRB 2016–09) and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.2peak (18.62 ± 5.94 mL/kg/min); K-BBS score (39.87 ± 11.96); 10MWV (0.7 ± 0.39 m/s); 6MWD (200.95 ± 131.80 m); paretic and non-paretic knee extensor strength (56.93 ± 35.06 and 77.53 ± 35.6 Nm); paretic and non-paretic knee flexor strength (30.95 ± 20.93 and 44.46 ± 20.87 Nm).Baseline demographic and stroke-related data are presented in Table 2 = 0.35, was estimated as 57 and the range of critical r in the correlation analysis with an alpha = 0.05, a statistical power of 80% and an assumed moderate effect of H1 = 0.3, was calculated from − 0.214 to 0.214.Using a priori determination of G* Power program, a minimal sample size of the backward multiple linear regression analysis with numbers of predictors, an α = 0.05, a statistical power of 80% and an assumed large effect of fr = 0.281, p = 0.011), fat mass , paretic knee extensor strength , non-paretic knee extensor strength , paretic knee flexor strength , non-paretic knee flexor strength , 6MWD , 10MWV , and BBS  .Peak aerobic capacity correlated significantly with muscle mass (p < 0.001), fat mass (p = 0.005), and 10MWV (p < 0.001) were independent predictors of peak aerobic capacity (adjusted R2 = 0.499) in all patients  (10.5 mL/kg/min) of oxygen consumption and more intense ADLs require about 5 METs (17.5 mL/kg/min)4. Thus, the aerobic capacity of our patients was insufficient to perform various activities in the community. In addition, peak aerobic capacity was closely related to gait performance and lower limb muscle strength, also in agreement with previous finding21.Decreased aerobic fitness is common in stroke patients21 previously showed that gait function influences cardiorespiratory fitness, and Baert et al. reported a relationship between VO2peak and 6MWD in mild stroke patients22. However, our data indicate that gait velocity rather than gait endurance predicts cardiovascular fitness. Walking speed can be considered an easy and accessible indicator of independent walking in the community and Perry et al. found that gait velocity was highly related to different levels of ambulation23: household ambulation refers to a severe gait disorder with a walking velocity of less than 0.4 m/s; limited community and full community ambulation indicate moderate to mild gait disorders with walking speeds greater than 0.4 m/s and 0.8 m/s, respectively. Another study reported that a significant correlation between walking speed and community ambulation, and gait speed (> 0.66 m/s), could differentiate between community and non-community ambulators in stroke patients24. Because reduced gait speed may increase the energy cost of walking25, gait speed may be a key determinant of peak exercise capacity in stroke patients, especially those who are independent ambulators.Our novel finding was that paretic knee extensor strength, gait speed, and fat mass were independent predictors of peak aerobic capacity in patients with subacute stroke. Patterson et al.26. Our previous results revealed that hemiparetic knee extensor strength is a predictor of gait endurance and that balance function is also a major determinant of gait speed and endurance in subacute stroke patients. During the stance phase of gait, the knee extensors support knee stability, thereby enabling the non-paretic limb to proceed in a swing phase during long-distance walking20. Furthermore, knee extensor weakness in stroke patients is caused by a reduction in recruitable motor units and a diminished capacity for oxidative metabolism27. Paretic lower limb strength is a strong predictor of gait function28, and Suzuki et al29. reported that knee muscle strength is significantly related to walking performance in stroke patients. Our findings also indicate that the peak torque of knee extensor strength is an independent predictor of cardiorespiratory fitness. Therefore, improving gait velocity and paretic leg extensor strength should be emphasized in patients with subacute stroke.Lower limb weakness occurs frequently in stroke survivors, especially in the quadriceps and hamstring, which induces several kinematic gait problems30. Our anthropometric analysis revealed that body-fat mass was inversely related to maximal aerobic capacity, whereas muscle mass and BMI were positively correlated with peak aerobic capacity. Individuals with abnormally high body-fat levels or a body weight exceeding the standard measure are defined as overweight (BMI ≥ 23) or obese (BMI ≥ 25)31. Of our participants, 71.1% (N = 53) were classed as overweight. Several studies have demonstrated a significant relationship between cardiorespiratory fitness and being overweight. Buchan et al. reported an independent association between cardiorespiratory fitness, waist circumference, BMI32 and Ortega et al. noted that cardiorespiratory fitness might have an effect on the association between being overweight and the level of physical activity33. The findings of these studies are consistent with the results of the present study; that is, there is a close relationship between body composition and aerobic capacity.Exercise capacity is dependent on the severity of disease and body compositionMost previous studies have assessed gait function using gait speed or short-distance walking only, but in this study we measured gait endurance and velocity, balance, body composition, and knee extensor strength in detail in a relatively large population of patients with subacute stroke.However, this study had several limitations. First, we focused on knee muscle strength rather than hip and ankle muscle strength. We selected knee muscle strength because it is recovered early after stroke and is strongly correlated with gait function in patients with subacute stroke. The effect of muscle strength in different muscles may be researched in future studies. Second, the study was a cross-sectional study that focused on physical performance and we did not confirm the long-term effect on clinical or cardiorespiratory parameters. Third, in this study, cerebellum or brainstem infarction patients were not included. Because of, it is difficult to generalize to all stroke patients. Further studies should be conducted them. Finally, this study could not include patients with severe motor deficits who could not perform the ETT or gait tests. It is therefore difficult to generalize this result to all stroke patients.In conclusion, this study presents scientific evidence for a significant association between cardiovascular fitness and body composition, gait performance, knee muscle strength, and balance function. Our results also show that gait speed, fat mass, and paretic knee extensor strength are major contributors to cardiovascular fitness in subacute stroke patients. Therefore, further studies focused on increasing muscle strength and gait speed and on managing fat mass might be warranted to improve cardiovascular fitness in subacute stroke rehabilitation therapy.


Smokers discount delayed rewards steeper than non-smokers or ex-smokers, possibly due to neuropharmacological effects of tobacco on brain circuitry, or lower abstinence rates in smokers with steep discounting. To delineate both theories from each other, we tested if temporal discounting, choice inconsistency, and related brain activity in treatment-seeking smokers (1) are higher compared to non-smokers, (2) decrease after smoking cessation, and (3) predict relapse.k and inconsistency var(k) were estimated with Bayesian analysis.At T1, 44 dependent smokers, 29 non-smokers, and 30 occasional smokers underwent fMRI while performing an intertemporal choice task. Smokers were measured before and 21 days after cessation if abstinent from nicotine. In total, 27 smokers, 28 non-smokers, and 29 occasional smokers were scanned again at T2. Discounting rate k and var(k) in smokers in treatment were not higher than in non-smokers or occasional smokers. Second, neither k nor var(k) changed after smoking cessation. Third, k did not predict relapse, but high var(k) was associated with relapse during treatment and over 6 months. Brain activity in valuation and decision networks did not significantly differ between groups and conditions.First, Our data from treatment-seeking smokers do not support the pharmacological hypothesis of pronounced reversible changes in discounting behavior and brain activity, possibly due to limited power. Behavioral data rather suggest that differences between current and ex-smokers might be due to selection. The association of choice consistency and treatment outcome possibly links consistent intertemporal decisions to remaining abstinent.The online version contains supplementary material available at 10.1007/s00213-020-05688-5. The concept that a reward’s value decreases when being delivered with delay is described as temporal or delay discounting Mischel, . EconomiA preference towards immediate rewards has been reported in a number of pathological conditions. Especially substance use disorders (SUDs) are associated with elevated temporal discounting. Smoking  and the respective neural correlates were assessed twice during fMRI in a group of smokers enrolled in behavioral treatment and two control groups . For smokers in treatment, the second assessment was scheduled 3 weeks after cessation. Differences in discounting behavior and its neural underpinnings between smokers before cessation and controls would be in line with predictions from both competing hypotheses. The pharmacological hypothesis would predict that these readouts changed after smoking cessation. We would expect to see changes in smoker’s behavior or activation patterns. Contrariwise, the selection hypothesis would predict that discounting behavio, and neural correlates before cessation were associated with increased risk for relapse but did not change after cessation.The aim of this study was to test whether the difference between current smokers and non-/ex-smokers can be better explained by the pharmacological or the selection hypothesis. For this purpose, intertemporal choice behavior  and had no history of schizophrenia, bipolar disorder, SUD except cigarette smoking (lifetime), or other neurological or mental disorders . The assessment included the Fagerström Test for Nicotine Dependence (FTND) , and 30 occasional smokers  to a baseline assessment T1). The latter two groups served as control groups . The delay level changed after 10 decisions. At all five delay levels, the size of the first amount presented was 40 €. The pre-scan test included an adaptive staircase algorithm: offered amounts of money were raised or reduced depending on the previously made decision. If the delayed amount was chosen, the next trial included a delayed amount, which was reduced by half the difference between immediate and delayed reward, and vice versa. The indifference points were estimated as the mean of the maximum delayed amount rejected and the minimum delayed amount chosen. After finding the indifference amount for each delay, these points were fit to a hyperbolic function using ordinary least squares. Thereby, we characterized the subjective value V of a reward across the range of delays.All participants underwent two fMRI sessions (T1 and T2) performing an intertemporal choice task which we optimized for fMRI application  and MATLAB R2015a  to perform the paradigm.Here, k value in a way that (1) subjects were expected to choose the immediate reward in half of the trials, (2) the mean value of all delayed rewards would be the same (30 €) for each subject, and (3) the maximal value of all rewards was twentyfold the minimum value . The offers were adapted to the previously assessed Vd) lower than the immediate reward the respective delayed amounts were higher than the immediate ones, we included the parameter c and set it to 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45 and 0.5 respectively. The maximum value (V) for each delay was exactly twentyfold the lowest value for the minimum value for each subject, i.e., the 180 days (D) condition. The difference between immediate reward and maximum reward value was divided into 9 equidistant value categories above the immediate reward. The mean of all computed values (V) was standardized to 30 € and the immediate amount was adapted for each participant so that rewards were presented with the same mean over all trials for each subject. Finally, all respective amounts (A) were computed using the formula:To ensure that for all values  was adjusted for every trial. Thereby, we calculated the decision probabilities for each trial based on our informative model which included the hyperbolic discounting function  is known at every trial. However, we were interested in estimating k and β given the observed choices P. In order to connect the two probabilities, we used the Bayes’ rule  for the Bayesian framework.Thereby, the posterior distribution on parameter values is proportional to the product of the likelihood of the observation and the prior belief on the parameters. We discretize the parameter space  Lovric, . The indk and β together with the variance of k and β. The variance of k at the end of the task, var(k), can be understood as the width of the posterior likelihood distribution of the estimated k. During the task, the variability will increase after an unexpected choice, but it should decrease over the course of the experiment following consistent choices. Using the final estimate of this parameter, we can assess how consistently a participant acts across consecutive choices.Given our Bayesian framework, we are provided with the estimation of β and var(k). However, the two parameters are complementary and based on different theoretical perspectives: β is an estimated parameter in the softmax function indicating how strongly a subject’s decision is determined by increasing or decreasing the offer’s subjective value. In contrast, var(k) is derived from the dynamic Bayesian estimation over the course of the task. It captures an incongruence of a decision with the current expected discount rate and increases whenever incongruent decisions are made and k has to be adjusted accordingly. In other words, when incongruent decisions are observed, it becomes more difficult from a computational perspective to capture all decisions with one discount rate, which is reflected in an increased uncertainty of the “true” value. Thus, var(k) represents the “fickleness” of intertemporal choice across trials. Intriguingly, low β values can both occur with relatively low and high var(k), but high β values preclude high var(k). To normalize the distributions, we refer to k and β following natural log-transformation.Within our behavioral model, two parameters are directly related to the consistency of choices, namely 3 voxel size. For structural abnormality checking, a T1-weighted anatomical 3D magnetization–prepared rapid gradient echo (MPRAGE) dataset was acquired .Image registration was performed using a 3-T whole-body MRI scanner  with a standard 12-channel head coil. Head stabilization was attained using additional tomograph equipment pillows. For functional data registration, gradient echo-planar imaging (EPI) with 2.41 s of repetition time (TR), 25 ms of echo time (TE), and a flip angle of 80° was employed. A total of 642 whole brain scans were acquired from 42 transversal slices , aligned axially with 30° to the anterior commissure–posterior commissure line, with a 192-mm field of view (FOV), 64 × 64 pixels matrix size, and a 3 × 3 × 2 mm3). Smoothing was performed using an isotropic Gaussian kernel (8 mm FWHM). We excluded data sets from 5 participants at T1 (and consequently at T2) due to excessive head movement (2-mm threshold) and one participant because normalization failed.SPM12  in MATLAB R2015a was used for preprocessing and statistical analyses. The acquired images followed slice-time correction, spatial realignment, and normalization to the standard MNI  EPI template and resampled , we included five first-level regressors of the task: offer presentation onset, offered subjective value (as a parametric modulator), motor response left, motor response right, and missing responses. Therefore, we assessed both value-independent (first regressor) and value-dependent (second regressor) processing of offers. In line with previous studies, the subjective value of each offer was computed according to pre-scan p = 0.001 uncorrected.At the group level, we then tested for value-independent (at offer presentation) and value-dependent main effects during intertemporal choice. To identify possible differences between our participant groups, we included first-level contrast maps of non-smokers, occasional smokers, abstinent smokers (if abstinence > 30 days), and early relapsers into two second-level factorial designs . To test whether smokers differ from controls, we computed contrasts between smokers, non-smokers, and occasional smokers (question 1). To test whether brain responses are associated with risk for relapse, we compared abstaining and relapsing smokers (question 3). To identify changes after cessation, we set up second-level contrasts with first-level images (follow-up—baseline) for both contrasts  and compared abstaining smokers with controls (question 2). Primarily, thresholds for all statistical analyses at the group level were set at k and var(k) were tested for normality using Shapiro-Wilk test. Groups were compared using Student’s t tests (k) or Mann–Whitney U tests for var(k) which was not normally distributed. We used ANOVA to test for longitudinal changes of k and Cox regression to test if k predicted relapse. As var(k) was not normally distributed, we performed Wilcoxon signed-rank test to compare T1 and T2 values.Our above-mentioned behavioral variables were tested as follows: The temporal discounting rate k in treatment-seeking smokers and controls. Contrary to the pharmacological and the selection hypotheses, discounting was not significantly higher in smokers in treatment  compared to non-smokers ; t(71) = 1.27, p = 0.209, and also occasional smokers ; t(57) = − 0.86, p = 0.392 at T1  at T2 was not lower than ex-smokers’ k ; t(53) = − 1.33, p = 0.189 or occasional smokers’ k ; t(55) = − 1.27, p = 0.208.First, we compared the temporal discounting rate F = 2.651, p = 0.107) and no interaction of time and group on discounting  = 0.193, p = 0.825), i.e., smoking cessation did not lead to changes in discounting.Second, there was no main effect of time  Fig. 1Third, discounting rate k) as estimated from Bayesian trial-by-trial analysis. First, the distributions differed from normal distribution (Shapiro-Wilk p < 0.05); therefore, nonparametric tests were applied. There were no differences between var(k) in non-smokers  and treatment-seeking smokers , U = 576.0, Z = − 0.699, p = 0.485) or in occasional smokers ; U = 335.0, Z = − 1.516, p = 0.129 at T1  and treatment-seeking smokers , t(71) = − 0.79, p = 0.432, or occasional smokers , t(57) = − 1.58, p = 0.120.Next, we assessed choice consistency var generally was lower at T2 than at T1 , indicating less inconsistency, which matched with lower β values t(83) = − 3.68, p = 0.001, as var(k) and β are inversely correlated. However, at T2, there was no significant difference between the non-smokers’ var(k)  compared with ex-smokers’ var(k)  .Second, var(k) at T1 in smokers relapsing within 30 days was higher compared to those smokers who abstained . Yet as mentioned above, k did not predict time to relapse in our sample of smokers. Again, we found that var(k) predicted time to relapse, in addition to the FTND  HR = 2.18, CI = 1.23–3.82, p = 0.007), cf. Fig. k) is associated with both early and mid-term tobacco abstinence.Third, notably, var(k and var(k), boxplots of all groups at T1 and T2 are provided in the supporting information.For further illustration of both p > 0. 001 at T1 .As reported in previous studies .The subjective value of the delayed offers was tracked in the “valuation network”: high subjective value corresponded to an increased BOLD signal in the ventral striatum/nucleus accumbens, and perigenual anterior cingulate cortex  differ between smokers in treatment and controls, (2) change after smoking cessation, and (3) predict time to relapse. Contrary to previous studies, we did not find steeper discounting in our group of treatment-seeking smokers. Furthermore, the discounting rate In line with the behavioral results, the imaging results supported the absence of cross-sectional differences between treatment-seeking smokers and controls. We found similar activation patterns of value-independent and value-dependent networks during intertemporal choice as in earlier studies , there might be different factors which facilitate early relapse. In line with the current understanding of the development of compulsive behavior in addiction


Mixed connective tissue disease was first described as a new autoimmune rheumatic disease in 1972 based on the claim of a distinct clinical picture associated with anti-RNP antibody positivity. Subsequently, this new entity has divided opinions in the rheumatology community. We have reviewed recent cohort studies with more than 100 patients, comparing the clinical and immunological features, treatment, prognosis and evolution to well-defined autoimmune rheumatic diseases. We also reviewed clinical features of undifferentiated autoimmune rheumatic diseases based on the most recent studies. After gathering and reviewing these data, we discuss whether the designation “mixed connective tissue disease” should be maintained. In 1972, Sharp et al. –9.Many studies have explored the subject, but no really large-scale prospective studies have been undertaken, and the results of later studies have been just as contradictory –9.Since it was first described, the clinical picture of “MCTD” has changed. Four different classification and diagnostic criteria have been developed  and a follow-up period time of more than 5 years in an attempt to draw more tangible conclusions. Four studies were identified and compared. Studies with more than 100 patients are uncommon, though a study that analyses anti-RNP positive patients, with 50 MCTD patients, was also included. Cohort studies of Gunnarson et al. were not reviewed as they only address pulmonary disease in “MCTD”.We have reviewed cohort studies with a significant number of patients  and revaluated for the study (t2). At t1, the mean disease duration was 10(± 8), and at t2, it was 17 (± 9) years. More than 90% of the 118 patients had disease duration > 8 years and were observed for > 5 years. Disease conversion was defined as change of antibody profile together with concordant clinical features of another ARD. In those patients in whom more than one specific autoantibody was identified, the dominant antibody specificity was determined together with the clinical features. It is not clear whether “MCTD” classified patients also fulfilled criteria for other ARD. Remission was considered and was evaluated using a combination of SLE and SSc validated activity criteria, though neither is validated for use in “MCTD”. Remission was defined as a Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) equal to zero and a European Scleroderma Trials and Research group score (EUSTAR) inferior to 2.5. The main goal of this study was to compare the characteristics at t1 of “MCTD” stable patients and disease converters.In the Reiseter et al.  cohort sHajas et al.  recruiteUngprasert et al.  used theSzodoray et al.  evaluateFrandsen et al.  evaluateTable Comparing the most striking features of patients with “MCTD”, at diagnosis and cumulative frequency after around 10 years of follow-up, it is noticeable that they often differ substantially across the various studies. Puffy hands vary between 53 and 72% at presentation and 46% and 92% after follow-up. Raynaud’s phenomenon was present in between 50.3 and 93.2% at presentation and 57.5% to 99% after follow-up. Arthritis at presentation occurred between 65.3 and 86%, 49.7 and 89.6% after follow-up. Oesophageal hypomobility or dilation occurred in 34.8% to 38.9% at presentation and 45.3 to 49.6% during follow-up. Evolution to ILD and/or PHA is reported in some, but not all, studies. Some believe it to be a characteristic of patients with “MCTD” –32, but It is generally assumed that a positive anti-U1RNP antibody is necessary for a diagnosis of “MCTD” to be made. However, it is not exclusive to this condition. In our own group of Systemic Lupus Erythematosus (SLE) patients, anti-RNP antibodies were present in 35% . UngprasSeveral smaller studies have reported that “MCTD” patients have a high anti-RNP titre , 19, 32.Other antibodies  have been reported in patients with MCTD with variable frequencies. Several studies have attempted to link different antibody profiles to clinical features and evolution to well-defined ARD , 28. HowA cornerstone in the advocacy of the existence of “MCTD” is the association between antibody production and HLA haplotypes. Different studies have demonstrated an association between the presence of anti-U1RNP antibody and an HLA-DR4-specific haplotype –22, 34. Disease stability is a core argument in favour of the existence of “MCTD” as an independent ARD. The aforementioned studies address this issue but report conflicting results Table . CappellIn the Reiseter et al. study, the conversion frequency was 11.9% after a follow-up of 17 ± 9 years. As above, considering that conversion definition is not strict, it is not clear whether “MCTD-stable” patients also fulfilled other ARD criteria. It also considered remission on treatment  or not . The absence of the anti-RNP antibody was considered a remission marker. Therefore, patients who once fitted the criteria for “MCTD” but no longer did, due to absent disease activity, were considered to have “MCTD”, regardless of their anti-RNP antibody status. Furthermore, the most common symptoms in patients with active “MCTD” disease were arthritis, rash and alopecia. Conversion to SLE occurred in 5 of 118 patients (4.3%) that developed high anti-dsDNA titres and low complement. RA was diagnosed in 4 of 118 patients (3.4%) with positive anti-CCP and bone erosions on X-ray, and they concluded that bone erosions are not common in “MCTD” and should raise suspicion about differentiation to other ARD. These results raise several questions, namely whether: anti-RNP antibodies were an intermittent finding and had no relation to therapy; therapy was concealing clinical manifestations that would otherwise occur and enable evolution into a well-defined ARD; if the “MCTD-stable” patients fulfilled other ARD criteria and, in fact, had an well-defined ARD.Hajas et al. described an “no disease conversion” over a period of 13.1(± 7.5) years. It is not clear which criteria were used to evaluate disease conversion. As described below, 78.2% patients were treated with high-dose steroids, 74.6% with cytotoxic agents and 15% with anti-TNF agents. In this cohort, 11 patients had renal disease with a biopsy showing thrombocytopenic thrombotic purpura/haemolytic-uremic syndrome (TTP/HUS) in 3 patients, ISN class II (5 patients) or class V glomerulonephritis (3 patients). Anti-dsDNA antibodies were present in 3.2% and anti-Sm antibodies in 6.7%, but complement levels were not measured. An association with anti-phospholipid syndrome (APS) was also described in 72 of 280 patients (25.7%), in contrast to previous reports  that described patients with positive APS antibodies without clinical APS criteria. In contrast to Reiseter et al., erosive arthritis was diagnosed in 17.5% of patients, after 5 to 10 years of the “MCTD” diagnosis. An anti-CCP antibody was positive in 18.9% at the end of the follow-up. Analysing this study, although the data are scattered, it is debatable whether some of these “MCTD” patients would not have fulfilled other ARD criteria.Ungprasert et al. reported a 10% conversion rates, but again no description of the criteria used to determine whether other ARD had developed, nor which treatment was given.The treatment of “MCTD” is relatively little discussed. In Hajas et al., 219 of 280 (78.2%) patients were treated with high-dose steroid (≥ 1 mg/kg/day methylprednisolone), 209 (74.6%) with cytotoxic agent  and 42 (15%) with anti-TNF. Cappelli et al. reported 58% patients treated with immunosuppressants , 82% requiring glucocorticoids (no dose reported) and 45% of patients treated with antimalarial drugs. Thus, in these studies, most patients needed immunosuppressive treatment. Treatment varied with organ evolvement, in accordance with current well-defined ARD guidelines.Ungprasert et al. reported 10% deaths, but the overall mortality rate was not different from the general population. Reiseter et al. also reported 11.9% deaths in their group, although these patients had an older mean age and higher prevalence of pericarditis and ILD. Hajas et al. described 7.9% deaths in their study. The major cause of death was PAH, followed by cardiovascular events and TTP/HUS. Overall, the prognosis appears to be connected to the presence of pulmonary disease.Overall, it is hard to escape the conclusion that there is no current evidence or agreement about the optimal criteria for diagnosis, follow-up or treatment strategies. It may be argued that larger studies are needed to allow these conclusions. It is evident that these patients might require careful periodic lung involvement evaluation.Hajas et al. used one set of diagnostic criteria, whereas all the other studies used several different diagnostic criteria sets. No agreement on which one is the most sensitive criteria set was achieved, when comparing the studies analysed.UARD is a term used to capture those patients with clinical features and antibodies compatible with an ARD, but who do not fulfil the criteria for any well-defined individual ARD. Currently, there are no globally accepted diagnostic criteria , 36.Symptom frequency described in several cohort studies are scattered, as in “MCTD”, although most studies have 5-year follow-up time or less . ArthritAnti-RNP antibodies are reported in the UCTD cohorts, with no consistent clinical significance , 41, 42.As with “MCTD”, patients are treated similarly to those with the well-established ARD , 41, 42.Following the original claims about the existence of a new entity, “MCTD” rapidly became very popular. Perhaps this was because rheumatologists sought to “accentuate the positive”, when explaining to their patients that while they had a disease of their immune system, its symptoms were relatively mild, the corticosteroid requirement was low, the symptoms annoying but not serious and, most importantly, prognosis was good. Sadly, it is very clear, from this and earlier reviews –9, that Although no direct comparison has been made, reviewing the “MCTD” and UARD literature, there are no striking differences regarding clinical presentation, evolution, treatment, and prognosis. It would be interesting to compare all the undifferentiated patients (“MCTD” and UARD) anti-RNP positive and negative.While we do not pretend that there are no patients who may have high levels of antibodies to RNP and whose clinical features fall within the “MCTD” description, many of these patients, as clearly indicated by long-term follow-up studies, “evolve” into other more specific ARDs. We take the view that the patients, whose clinical features remain stable, would best be described as having an undifferentiated ARD. The term MCTD seems to us thoroughly discredited and does not better define these patients.Further and larger studies are still needed to assess the significance of anti-U1RNP antibodies in ARD. Further long-term cohort studies encompassing all undifferentiated patients are also needed to ascertain diagnostic criteria, optimal follow-up, treatment and prognosis.


Research suggests that neuromuscular function decreased and hormonal responses increased up to 24 h after the match. Considering anthropometric characteristics, players present low percentage of body fat, which seems commonplace among athletes from different on-court positions and competition levels. Elite players display greater values and at VO2max with respect to sub-elite competitors. Little is known regarding elite and sub-elite futsal players' neuromuscular abilities . However, it appears that elite players present better sprinting abilities compared to lower-level athletes. Futsal players aiming to compete at the highest level should focus on developing maximal speed, lower-body power and strength, aerobic capacity, and lean muscle mass.Futsal, also known as five-a-side indoor soccer, is a team-sport that is becoming increasingly popular. In fact, the number of futsal-related investigations is growing in recent years. This review aimed to summarize the scientific literature addressing the match-play demands from the following four dimensions: time-motion/external load analysis and physiological, neuromuscular, and biochemical responses to competition. Additionally, it aimed to describe the anthropometric, physiological, and neuromuscular characteristics of elite and sub-elite male futsal players, contemplating the differences between competition levels. The literature indicates that elite futsal players cover greater total distance with higher intensities and perform a greater number of sprints during match-play when compared to sub-elite players. The physiological demands during competition are high (average intensity of ≥85% maximal heart rate and ~80% maximum oxygen uptake [VO Futsal, also known as five-a-side indoor soccer, is a team-sport officially authorized by FIFA and is becoming increasingly popular all over the world. It is characterized as a high-intensity intermittent sport that imposes high physical, technical, tactical, and psychological demands on players  at different levels of competition in futsal. The review was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement . All titles and abstracts from the search were cross-referenced to identify duplicates and any missing studies and then screened for a subsequent full-text review. The search was performed independently by two authors , and any disagreement was resolved by a third party (TF).The review included cross-sectional and longitudinal studies published in English considering professional futsal players. The studies were included if they comprised (1) elite male futsal players; (2) sub-elite players, but only when compared to superior competition levels; (3) players ≥20 years old; and (4) variables related to the physical and physiological match-play demands and player characteristics  were reported. Importantly, in the context of the current review, players were classified as elite if they competed in the National Team or 1st Division of their respective countries or in the 2nd Division of Spain, Portugal, Italy, or Russia. All the players that did not meet this standard were considered to be sub-elite.Studies were excluded if (1) participants were ≤ 19 years old; (2) were female; (3) only sub-elite/state-level players participated in the study; (4) the division in which players competed was not detailed in the study ; (5) non-English language; (6) the methodological quality assessment score was ≤ 8; and (7) the study consisted on a review or a conference paper.The initial search was conducted by two researchers . After the removal of duplicates, an intensive review of all the titles and abstracts obtained was completed and the ones not related to the review's topic were discarded. Following the systematic screening process, the full version of the remaining articles was read. All studies not meeting the inclusion criteria were then excluded.http://getdata-graph-digitizer.com) was used to extract the outcome values from the articles' figures or graphs.Two reviewers  extracted the following data from the included studies: number and competitive level of the participants; match-play time-motion and physiological data; players' physiological and neuromuscular characteristics, the tests performed, measurement tools used, and outcome units. As the aim of the present review was not to investigate or determine the effects of different training programs on futsal players' physical qualities, in the studies in which interventions were used, the baseline values  were extracted and reported in the respective tables in the Results section. In case the manuscript did not present numerical description of the data, the software GetData Graph Digitizer 2.26  using the modified scale of Downs and Black  distance corresponded to 135 ± 54 m. Moreover, the authors reported that futsal players performed a great number of high-intensity ACC (87 ± 49) and DEC (80 ± 32), when compared to the total number of jumps (9 ± 4). Utilizing a different approach , Castagna et al. (−1) and sprinting (≥18.3 km·h−1) accounted for 12 and 5% of the whole match duration, respectively. Furthermore, players performed a sprint every 79 s with an average distance of 10.5 m, a duration of 1.95 s, and a recovery between sprints of <40 s  and jogging (3.7–10.8 km·h−1) were 397 m and 1,792 m, respectively, which represent 9 and 40% of the total mean distance covered. The mean distance in medium intensity activity (10.9–18 km·h−1) was 1,232 m , high-intensity running (18.1–25 km·h−1) 571 m (13.7%), and sprinting (≥25.1 km·h−1) 348 m (8.9%)  to analyze match-play demands  Dograma. Most rea et al.  had preva et al. , which cExamining the number of sprints performed during futsal competition, Caetano et al.  observed−1; 2nd half: 96.4 ± 7.5 m·min−1) decreased significantly from the 1st to the 2nd half but found no meaningful differences regarding the number of sprints or total sprinting time. Despite these inconsistencies, it appears that intensity tends to decrease as the match approaches the final minutes, which may be due not only to increased fatigue levels but also to tactical decisions  that “slow down” the game.Comparing the 1st and 2nd halves, a study with Brazilian elite players , or blood lactate concentration ([La]) , oxygen uptake (VOmean was 174 ± 7 b·min−1 (range: 164–181), which represented 90 ± 2% (range 86–93) of HRmax. With HR being classified based on the percentage of time spent in different zones, players spent 0.3, 16, and 83% at intensities ≤ 65, 85–65, and ≥85% of HRmax, respectively. Other data from official matches, however, displayed slightly lower HR values (86.4 ± 3.8% HRmax)  and HRmean  ; however, more research is needed to clarify the differences between the 1st and 2nd halves.Barbero-Alvarez et al.  monitore2, a study reported that the mean game values  were 48.6 ml·kg−1·min−1  and that players spent 46% of the playing time (during a simulated match) at intensities higher than 80% of VO2max  mmol·L−1 was reported after the previously mentioned simulated match investigated by Castagna et al. (2max), this value was higher than official games, in which [La]mean  of 4.8 ± 2.3 mmol·L−1  and 4.2 ± 2.2 mmol·L−1  were found  as the assessment was performed throughout the match, when the player was taken out.Regarding VOa et al. . Interesmax) with an important decrement of high-intensity efforts between the two halves.The knowledge about the physiological demands of futsal is of paramount importance since it offers information concerning the stress imposed upon the players during competition. The average intensity of effort during the matches is high  play a significant role in team-sports. Several studies indicate that stronger and more powerful players  of different sports are prone to accelerate faster, jump higher, and change direction more rapidly  are important components of physical fitness as it is well-accepted that, for example, excessive body fat can potentially impair performance in team-sports  of 44.4 ± 4.6 ml·kg−1·min−1 while sub-elite displayed 39.1 ± 4.0 ml·kg−1·min−1  but reported that the speed at VT2 (Svt2) and speed at VO2max (SVo2max) were significantly higher in elite players when compared to their sub-elite counterparts   and that fitness field tests may be useful to evaluate the aerobic capacity on elite players  was assessed in the preferred and non-preferred limbs of 40 players, significant contralateral differences were found on knee flexors' eccentric contractions and in the H/Q ratio in favor of the preferred limb  than the non-dominant leg. Based on this information, strength and conditioning specialists should be aware that unilateral strength testing may be necessary to allow preparing specialized and tailored training plans to maximize lower-body strength and attenuate the likelihood of injuries. However, given that isokinetic testing is extremely time-consuming, expensive, and not practical to use in real-world scenarios, other exercises  should be implemented when assessing lower-body strength.−1, respectively  , 5.68 ± 0.19 m·s−1 (10 m), and 6.61 ± 0.22 m·s−1 (20 m) in elite futsal players. Regarding acceleration ability , the same study reported values of 4.64 ± 0.50 m·s−2 for 0–5 m, 1.22 ± 0.22 m·s−2 for 5–10 m, and 0.74 ± 0.09 m·s−2 for 10–20 m. Gorostiaga et al.  , physical , and technical aspects   given the importance of COD maneuvers in futsal.Some limitations should be addressed when considering the present research. Firstly, the number of studies assessing each variable is quite different, which means that the evidence level is dissimilar among variables. For example, there are more studies describing the match-play demands via time–motion analysis than describing the strength or COD capacities of futsal players. Secondly, the instruments, tests, or data collection procedures differed among studies, which precluded a direct comparison and interpretation of the data in some occasions. Further studies are still necessary to have a clearer picture of the futsal match-play demands, particularly, using new technologies . In addition, more research into the athletes' physical characteristics and performance outcomes (and how they fluctuate across a competitive season) would bring further understanding on the neuromuscular profile of futsal players.2max values of around 62 ml·kg−1·min−1. Elite futsal players possess higher VO2max, when compared to their sub-elite counterparts. From the present review, it can be concluded that further investigation on the neuromuscular capabilities  of futsal players is warranted. Still, it appears that elite futsal players present better sprinting abilities when compared to lower-level players but that jumping capacity seems not to differentiate between competition levels. Futsal players aiming to compete at the highest level should focus on developing maximal speed, lower-body power and strength, aerobic capacity, and lean muscle mass.This systematic review provides useful information for strength and conditioning coaches and sport scientists regarding the match demands, anthropometric characteristics, and physical qualities of elite and sub-elite male futsal players. The results indicated that futsal is characterized by intermittent high-intensity activities with a great number of ACC, DEC, and sprints; short recovery times between them; and multiple COD actions during match-play. The abundance of these types of efforts produces important decrements in physiological and neuromuscular responses between the two halves and immediately following match-play. Moreover, biochemical responses appear to be affected up to 24 h after the match. Comparing competition level, differences were observed in match demands, with elite players covering higher distance, performing more high-intensity actions, and presenting lower standing time when compared to sub-elite players. An analysis of the anthropometric characteristics of futsal players showed low percentages of body fat with no differences between on-court players of different positions or level of competition. However, goalkeepers were found to present higher body fat. Regarding the physiological characteristics of futsal players, these display VOKS, TF, and PA designed this study. Research literature was conducted by KS and EM-C. KS drafted the manuscript. All authors revised the manuscript and approved the final version to be published.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.