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1.
Physiol Plant ; 176(5): e14501, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39256953

RESUMEN

Cold stress seriously affects plant development and secondary metabolism. The basic region/leucine zipper (bZIP) is one of the largest transcription factor (TFs) family and widely involved in plant cold stress response. However, the function of bZIP in Dendrobium catenatum has not been well-documented. Cold inhibited the growth of D. catenatum and increased total polysaccharide and alkaloid contents in stems. Here, 62 DcbZIP genes were identified in D. catenatum, which were divided into 13 subfamilies. Among them, 58 DcbZIPs responded to cold stress, which were selected based on the transcriptome database produced from cold-treated D. catenatum seedlings. Specifically, the expression of DcbZIP3/6/28 was highly induced by cold treatment in leaves or stems. Gene sequence analysis indicated that DcbZIP3/6/28 contains the bZIP conserved domain and is localized to the cell nucleus. Co-expression networks showed that DcbZIP6 was significantly negatively correlated with PAL2 (palmitoyl-CoA), which is involved in flavonoid metabolism. Moreover, DcbZIP28 has significant negative correlations with various metabolism-related genes in the polysaccharide metabolic pathway, including PFKA1 (6-phosphofructokinase), ALDO2 (aldose-6-phosphate reductase) and SCRK5 (fructokinase). These results implied that DcbZIP6 or DcbZIP28 are mainly involved in flavonoid or polysaccharide metabolism. Overall, these findings provide new insights into the roles of the DcbZIP gene family in secondary metabolism in D. catenatum under cold stress.


Asunto(s)
Respuesta al Choque por Frío , Dendrobium , Regulación de la Expresión Génica de las Plantas , Proteínas de Plantas , Metabolismo Secundario , Dendrobium/genética , Dendrobium/metabolismo , Dendrobium/fisiología , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Respuesta al Choque por Frío/genética , Respuesta al Choque por Frío/fisiología , Metabolismo Secundario/genética , Factores de Transcripción/metabolismo , Factores de Transcripción/genética , Frío , Filogenia
2.
Sci Rep ; 14(1): 9311, 2024 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-38654049

RESUMEN

Titanium alloy with high corrosion resistance, high strength-to-density ratio, and excellent biocompatibility has a wide range of applications in the field of biomedical implants. Polishing experiments of titanium alloy with a small size and complex shapes were investigated using an ultrasonic assisted magnetorheological finishing (UMRF) device excited by a three-pole magnetic field generator. The models of the normal force and the shear force were first proposed based on the Preston equation to analyze the mechanism of material removal in the UMRF process. Subsequently, the single-factor experiments using titanium alloy nuts (M3) and the MR polishing fluid with silicon carbide abrasives were carried out. Furthermore, to improve the surface roughness and the change rate of surface roughness of nuts, orthogonal tests with a standard L9(34) orthogonal array were designed and performed based on the optimized process parameters obtained from the single-factor experiment. The results indicated the effect on surface roughness and change rate of surface roughness as applied current > roller speed > ultrasonic amplitude > spindle speed and applied current > roller speed > spindle speed > ultrasonic amplitude, respectively. Moreover, the surface roughness was improved from an initial 1.247 µm to a final 0.104 µm after the polishing for 80 min under these optimal process parameters.

3.
J Ethnopharmacol ; 330: 118198, 2024 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-38621465

RESUMEN

ETHNOPHARMACOLOGICAL RELEVANCE: In recent years, Chinese herbal medicine has gained more and more recognition in disease prevention and control due to its low toxicity and comprehensive treatment. C. morifolium (Chrysanthemum morifolium Ramat.), as the medicine food homology plant with the bioactivity of anti-oxidation, anti-inflammatory, neuroprotection and cardiovascular protection, has important therapeutic effects and health benefits for colds, inflammation, cardiovascular diseases and various chronic diseases. AIM OF THE STUDY: By reviewing the historical development, classification and distribution of germplasm resources, phytochemistry, pharmacology, and modern application of C. morifolium, the paper provides a reliable basis for the further research and application of chrysanthemum as therapeutic agents and functional additives. MATERIALS AND METHODS: The literature and information about C. morifolium published in the last ten years were collected from various platforms, including Google Scholar, PubMed, ScienceDirect, Web of Science and China Knowledge Network. RESULTS: A comprehensive analysis confirmed that C. morifolium originated in China, and it went through the development process from food and tea to medicine for more than 3000 years. During this period, different cultivars emerged through several breeding techniques and were distributed throughout the world. Moreover, A variety of chemical components such as flavonoids, phenolic acids, volatile oils, and terpenes in chrysanthemum have been proven they possess various pharmacology of anti-inflammatory, anti-oxidant, and prevention of chronic diseases by regulating inflammatory cytokines, oxidative stress responses and signaling pathways, which are the essential conditions to play a role in TCM, nutraceuticals and diet. CONCLUSION: This paper provides a comprehensive review of historical development, classification, phytochemistry, pharmacology, and modern application of C. morifolium. However, future studies should continue to focus on the bioactive compounds and the synergistic mechanism of the "multi-component, multi-target, and multi-pathway" of chrysanthemum, and it is necessary to develop more innovative products with therapeutic effects.


Asunto(s)
Chrysanthemum , Medicina Tradicional China , Animales , Humanos , Chrysanthemum/química , Medicamentos Herbarios Chinos/farmacología , Medicamentos Herbarios Chinos/química , Medicamentos Herbarios Chinos/uso terapéutico , Etnofarmacología , Medicina Tradicional China/métodos , Fitoquímicos/farmacología , Fitoquímicos/química , Fitoterapia
4.
Environ Int ; 183: 108348, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38064924

RESUMEN

Few studies have delved into the effects of heatwaves on sleep duration loss among older adults. Our study examined correlations between heatwave exposure and sleep duration reductions in this demographic. Utilizing data of 7,240 older adults drawn from the China Health and Retirement Longitudinal Study (CHARLS) from 2015 to 2018, we assessed sleep duration differences between the baseline year (2015) and follow-up year (2018). Absolute reductions in sleep duration were defined as differences of ≥ 1, 1.5, or 2 h. Changes in sleep duration were categorized based on cut-offs of 5 and 8 h, including excessive decrease, moderate to short and persistent short sleep duration types. 12 heatwave definitions combining four thresholds (90th, 92.5th, 95th, and 97.5th percentiles of daily minimum temperature) and three durations (≥2, ≥3 and ≥ 4 days) were used. Heatwave exposure was determined by the difference in the number of 12 preceding months' heatwave days or events in 2015 and the number of 12 preceding months' heatwave days or events in 2018. The results showed that increased heatwave events (defined as ≥ P90th percentile & lasting three days) were associated with a higher likelihood of ≥ 1-hour sleep reduction and persistent short sleep duration. An increase in heatwave event (defined as ≥ P95th percentile & lasting three days) was linked to shifts from moderate to short sleep duration. For the association between an absolute reduction in sleep duration and heatwave exposure, while higher thresholds signified greater sleep reduction risks, the effect estimates of longer durations were not uniformly consistent. We observed that air pollution and green space modified the relationship between heatwaves and sleep duration. Females, urban residents, and individuals with chronic diseases were identified as vulnerable populations. This study found that increased heatwave exposure was associated with a higher risk of sleep duration loss in older adults.


Asunto(s)
Calor , Duración del Sueño , Femenino , Humanos , Anciano , Estudios Longitudinales , Factores de Riesgo , Rayos Infrarrojos
5.
Sci Total Environ ; 904: 166534, 2023 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-37647952

RESUMEN

The association between heatwaves and cognitive impairment in older adults, especially the joint effect of air pollution and green space on this association, remains unknown. The present cohort study used data from waves of the Chinese Longitudinal Healthy Longevity Survey (CLHLS) from 2008 to 2018. Heatwaves were defined as having daily maximum temperature ≥ 92.5th, 95th and 97.5th percentile that continued at least two, three and four days, measured as the one-year heatwave days prior to the participants' incident cognitive impairment. Data on the annual average air pollutant concentrations of fine particulate matter (PM2.5) and ozone (O3) as well as green space exposure (according to the Normalized Difference Vegetation Index (NDVI)) were collected. Time-varying Cox proportional hazards models were constructed to examine the independent effect of heatwaves on cognitive impairment and the combined effect of heatwaves, air pollution, and green space on cognitive impairment. Potential multiplicative interactions were examined by adding a product term of air pollutants and NDVI with heatwaves in the models. The relative excess risk due to interaction (RERI) was calculated to reflect additive interactions. We found that heatwave exposure was associated with higher risks of cognitive impairment, with hazard ratios (HRs) and 95 % confidence intervals (CIs) ranging from 1.035 (95 % CI: 1.016-1.055) to 1.058 (95 % CI: 1.040-1.075). We observed a positive interaction of PM2.5 concentrations, O3 concentrations, lack of green space, and heatwave exposure on a multiplicative scale (HRs for product terms >1). Furthermore, we found a synergistic interaction of PM2.5 concentrations, O3, lack of green space, and heatwave exposure on an additive scale, with RERIs >0. These results suggest that extreme heat exposure may be a potential risk factor for cognitive impairment in older adults. Additionally, coexposure to air pollution and lack of green space exacerbated the adverse effects of heatwaves on cognitive function.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , Disfunción Cognitiva , Humanos , Anciano , Estudios de Cohortes , Parques Recreativos , Contaminantes Atmosféricos/análisis , Material Particulado/análisis , Factores de Riesgo , Disfunción Cognitiva/inducido químicamente , Disfunción Cognitiva/epidemiología , Exposición a Riesgos Ambientales
6.
Materials (Basel) ; 16(8)2023 Apr 14.
Artículo en Inglés | MEDLINE | ID: mdl-37109946

RESUMEN

The compression tests under the unidirection for magnetorheological (MR) fluids have been studied at different compressive speeds. The results indicated that curves of compressive stress under different compression speeds at the applied magnetic field of 0.15 T overlapped well and were shown to be an exponent of about 1 of the initial gap distance in the elastic deformation region and accorded well with the description of continuous media theory. The difference in compressive stress curves increases significantly with an increasing magnetic field. At this time, the continuous media theory description could not be accounted for the effect of compressive speed on the compression of MR fluid, which seems to deviate from the Deborah number prediction under the lower compressive speeds. An explanation based on the two-phase flow due to aggregations of particle chains resulting in much longer relaxation times at a lower compressive speed was proposed to explain this deviation. The results have guiding significance for the theoretical design and process parameter optimization for the squeeze-assisted MR devices such as MR dampers and MR clutches based on the compressive resistance.

7.
IEEE J Biomed Health Inform ; 27(5): 2345-2352, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-37028060

RESUMEN

Physical activity (PA) quantification by estimating energy expenditure (EE) is essential to health. Reference methods for EE estimation often involve expensive and cumbersome systems to wear. To address these problems, light-weighted and cost-effective portable devices are developed. Respiratory magnetometer plethysmography (RMP) is among such devices, based on the measurements of thoraco-abdominal distances. The aim of this study was to conduct a comparative study on EE estimation with low to high PA intensity with portable devices including the RMP. Fifteen healthy subjects aged 23.84±4.36 years were equipped with an accelerometer, a heart rate (HR) monitor, a RMP device and a gas exchange system, while performing 9 sedentary and physical activities: sitting, standing, lying, walking at 4 and 6 km/h, running at 9 and 12 km/h, biking at 90 and 110 W. An artificial neural network (ANN) as well as a support vector regression algorithm were developed using features derived from each sensor separately and jointly. We compared also three validation approaches for the ANN model: leave one out subject, 10 fold cross-validation, and subject-specific. Results showed that 1. for portable devices the RMP provided better EE estimation compared to accelerometer and HR monitor alone; 2. combining the RMP and HR data further improved the EE estimation performances; and 3. the RMP device was also reliable in EE estimation for various PA intensities.


Asunto(s)
Actividad Motora , Caminata , Humanos , Caminata/fisiología , Actividad Motora/fisiología , Ejercicio Físico , Metabolismo Energético/fisiología , Pletismografía
8.
Sci Total Environ ; 867: 161560, 2023 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-36640878

RESUMEN

Extreme heat exposure has been associated with hypertension. However, its interactive influences with air pollution, green and blue spaces are unclear. This study aimed to explore the interaction between heatwaves, air pollution, green and blue spaces on hypertension. Cohort data enrolled 6448 Chinese older adults aged 65 years and over were derived from the Chinese Longitudinal Healthy Longevity Survey (CLHLS) between 2008 and 2018. Nine heatwave definitions, combining three heat thresholds (92.5th, 95th, and 97.5th percentiles of daily maximum temperature) and three durations (≥2, 3 and 4 days) were used as time-varying variables in the analysis and were the one-year exposure before survival events. Fine particulate matter (PM ≤2.5 µm in aerodynamic diameter (PM2.5)), the Normalized Difference Vegetation Index (NDVI) and the average proportion of open water bodies were used to reflect the air pollution, green and blue space exposures, respectively. PM2.5, green and blue space exposures were time-varying indicators and contemporaneous with heatwaves. Mixed Cox models with time-varying variables were fitted to assess the multiplicative and additive interaction of heatwaves, PM2.5, and green and blue spaces on hypertension, measured by a traditional product term with the ratio of hazard ratio (HR) and relative risk due to interaction (RERI), respectively. A positive multiplicative (HRs >1) and additive interaction (RERIs >0) between heatwaves and higher PM2.5 levels was observed. There was a synergistic effect between heatwaves and decreasing greenness levels on hypertension incidence on additive and multiplicative scales. No significant interaction between heatwaves and blue space was observed in the analysis. The combined effects of heatwaves, air pollution, green and blue space exposures on the risk of hypertension varied with age, gender, and educational attainment. This study's findings complemented the existing evidence and revealed synergistic harmful impacts for heatwaves with air pollution and lack of green space on hypertension incidence.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , Hipertensión , Humanos , Anciano , Estudios de Cohortes , Incidencia , Parques Recreativos , Material Particulado/análisis , Hipertensión/epidemiología , Contaminantes Atmosféricos/análisis , Exposición a Riesgos Ambientales/análisis
9.
Environ Res ; 217: 114854, 2023 01 15.
Artículo en Inglés | MEDLINE | ID: mdl-36403655

RESUMEN

BACKGROUND: Few studies have investigated the effects of greenness exposure, green land cover types and diversity and their interaction with particulate matter (PM) to adiposity. METHOD: Cohort data were collected from the Chinese Longitudinal Healthy Longevity Survey (CLHLS). Baseline data on greenness levels, green land cover types and diversity were assessed by the Normalized Difference Vegetation Index (NDVI), three greenery types (trees, shrublands and grassland) and Shannon's diversity index, respectively. Body mass index (BMI) and waist circumference (WC) were separately used as dependent variables and represented for peripheral overweight/obesity and central obesity, respectively. The mixed Cox model with random intercept was used to estimate the effects of greenness levels, types and diversity on overweight/obesity using single and multiple exposure models. We also examined the interaction of PM and the aforementioned indicators on overweight/obesity on both additive and multiplicative scales. RESULTS: Single exposure models showed that higher levels of residential greenness, tree coverage and ratio of trees to shrublands/grassland were inversely associated with peripheral overweight/obesity and central obesity. An increase in shrublands, grassland and diversity of green was related to lower odds of peripheral overweight/obesity. Multiple exposure models confirmed the association between greenness levels and peripheral overweight/obesity. Males, educated participants and elderly who lived in southern regions and areas with cleaner air environments acquired more benefits from greenspace exposure. Single and multiple exposure models indicated that an antagonistic effect of increasing PM and decreasing greenness levels on peripheral overweight/obesity and central obesity. Single exposure models showed the potential interaction of tree coverage, ratio of trees to grassland and PM2.5 exposures on the risk of peripheral overweight/obesity. CONCLUSION: Increasing residential greenness and diversity of green were associated with healthy weight status. The relationship between greenery and overweight/obesity varied, and the effects of greenspace exposure on overweight/obesity were associated with air pollution.


Asunto(s)
Contaminación del Aire , Sobrepeso , Masculino , Humanos , Anciano , Estudios de Cohortes , Sobrepeso/epidemiología , Obesidad Abdominal , Obesidad/epidemiología , Material Particulado/análisis , China/epidemiología
10.
Nutrients ; 14(19)2022 Oct 08.
Artículo en Inglés | MEDLINE | ID: mdl-36235842

RESUMEN

PURPOSE: Energy expenditure is a key parameter in quantifying physical activity. Traditional methods are limited because they are expensive and cumbersome. Additional portable and cheaper devices are developed to estimate energy expenditure to overcome this problem. It is essential to verify the accuracy of these devices. This study aims to validate the accuracy of energy expenditure estimation by a respiratory magnetometer plethysmography system in children, adolescents and adults using a deep learning model. METHODS: Twenty-three healthy subjects in three groups (nine adults (A), eight post-pubertal (PP) males and six pubertal (P) females) first sat or stood for six minutes and then performed a maximal graded test on a bicycle ergometer until exhaustion. We measured energy expenditure, oxygen uptake, ventilatory thresholds 1 and 2 and maximal oxygen uptake. The respiratory magnetometer plethysmography system measured four chest and abdomen distances using magnetometers sensors. We trained the models to predict energy expenditure based on the temporal convolutional networks model. RESULTS: The respiratory magnetometer plethysmography system provided accurate energy expenditure estimation in groups A (R2 = 0.98), PP (R2 = 0.98) and P (R2 = 0.97). The temporal convolutional networks model efficiently estimates energy expenditure under sitting, standing and high levels of exercise intensities. CONCLUSION: Our results proved the respiratory magnetometer plethysmography system's effectiveness in estimating energy expenditure for different age populations across various intensities of physical activity.


Asunto(s)
Aprendizaje Profundo , Adolescente , Adulto , Niño , Metabolismo Energético , Ejercicio Físico , Femenino , Humanos , Masculino , Oxígeno , Consumo de Oxígeno , Pletismografía
11.
Front Psychiatry ; 13: 967291, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36159950

RESUMEN

Background: The new-generation migrants born in 1980 and later are large and vulnerable internal migrants in China. Migration paths and social integration are important factors to explain for their mental health. However, they faced difficulties in social integration varying from migration paths. We aimed to explore the mediating role of social integration between migration paths and the mental health of new-generation migrants. Methods: The migration paths included urban-to-urban, urban-to-rural, rural-to-urban and rural-to-rural. Mental health was assessed by the Kessler Screening Scale for Psychological Distress (K6) and the Perceived Stress Scales (PSS-4). Social integration was measured by economic integration, life integration, maintenance of the local culture, acceptance of the host culture and psychological integration. Multiple linear regressions with bootstrapping were used to examine the mediating effect. Results: A total of 9,830 new-generation migrants were included in this study. The mean age was 26.92 (SD = 4.47) years and the proportion of rural-to-urban migrants was 63.7%. Compared with the new generation of rural-to-rural migrants, rural-to-urban migrants had higher psychological distress (ß = 0.305, 95% CI: 0.152-0.458) and perceived stress (ß = 0.328, 95% CI: 0.199-0.456). The bootstrapping test found that two dimensions ("life integration" and "acceptance of the host culture") of social integration as a mediator weakened the negative effect of the rural-to-urban migration path on the mental health of new-generation migrants. Conclusion: Rural-to-urban migrants had poorer mental health, and the association was mediated by their poorer social integration. The migration policies developed to enhance social integration could effectively improve the mental health of new-generation migrants.

12.
Environ Sci Pollut Res Int ; 29(50): 76091-76100, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-35665878

RESUMEN

China's household wastewater discharge has gradually increased, and its composition has become more complex, but the discharge treatment system is not perfect. At present, there is a lack of research on the impact of domestic wastewater on human health, especially on the frailty of the elderly. This study aimed to quantitatively assess the relationship between living wastewater and its main components and the frailty status of the elderly. The research data comes from the Chinese Longitudinal Healthy Longevity Survey (CLHLS), which consists of participants over 60 years old who participated in the three-wave survey in 2008, 2011, and 2014 and combined with domestic wastewater data in the statistical yearbook. A generalized estimating equation (GEE) model was used to assess the link between living wastewater and frailty status in the elderly. The single-pollutant model showed that there was a positive correlation between the discharge of household wastewater and the frailty of the elderly, OR (4.443), 95%CI (3.591, 5.498); ammonia nitrogen had a positive correlation with the frail state of the elderly, OR (4.527), 95%CI (3.587, 5.714); chemical oxygen demand (COD) had a negative association with whether the elderly are frail, OR (0.776), 95%CI (0.609, 0.988). After adjusting for covariates, there was still a positive correlation between household wastewater and the frailty of the elderly, OR (2.792), 95%CI (2.233, 3.492); a positive correlation between ammonia nitrogen and the frail state of the elderly, OR (2.894), 95%CI (2.284, 3.666). The association between COD and the frail state of the elderly, OR (0.823), 95%CI (0.640, 1.058), showed no correlation between the two. The results show that household wastewater may affect the health of the elderly, promote the occurrence of a frail state of the elderly, and increase the medical burden.


Asunto(s)
Contaminantes Ambientales , Fragilidad , Anciano , Amoníaco , China/epidemiología , Estudios de Cohortes , Anciano Frágil , Fragilidad/epidemiología , Humanos , Persona de Mediana Edad , Nitrógeno , Aguas Residuales
13.
Artículo en Inglés | MEDLINE | ID: mdl-35527011

RESUMEN

BACKGROUND: Research on the relationship between residential altitude and hypertension incidence has been inconclusive. Evidence at low altitudes (i.e., <1,500 m) is scarce, let alone in older adults, a population segment with the highest hypertension prevalence. Thus, the objective of this study is to determine whether hypertension risk may be affected by altitude in older adults living at low altitudes. METHODS: This prospective cohort study collected data from the Chinese Longitudinal Healthy Longevity Survey (CLHLS). We selected 6,548 older adults (≥65 years) without hypertension at baseline (2008) and assessed events by the follow-up surveys done in 2011, 2014, and 2018 waves. The mean altitude of 613 residential units (county or district) in which the participants resided was extracted from the Digital Elevation Model (DEM) of the National Aeronautics and Space Administration (NASA) and was accurate to within 30 m. The Cox regression model with penalized splines examined the linear or nonlinear link between altitude and hypertension. A random-effects Cox regression model was used to explore the linear association between altitude and hypertension. RESULTS: The overall rate of incident hypertension was 8.6 per 100-person years. The median altitude was 130.0 m (interquartile range [IQR] = 315.5 m). We observed that the exposure-response association between altitude and hypertension incidence was not linear. The shape of the exposure-response curve showed that three change points existed. Hypertension risk increased from the lowest to the first change point (247.1 m) and slightly fluctuated until the last change point (633.9 m). The risk decreased above the last change point. According to the categories stratified by the change points, altitude was only significantly associated with hypertension risk (hazard ratio [HR] = 1.003; 95% confidence interval [CI] = 1.002-1.005) under the first change point (247.1 m) after adjusting for related covariates. CONCLUSION: Our study found that the association between altitude and hypertension risk might not be linear. We hope the further study can be conducted to confirm the generality of our findings.


Asunto(s)
Altitud , Hipertensión , Anciano , Humanos , Hipertensión/epidemiología , Hipertensión/etiología , Incidencia , Prevalencia , Estudios Prospectivos
14.
Int J Antimicrob Agents ; 59(5): 106570, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-35296432

RESUMEN

Decreased effectiveness of metronidazole for the treatment of Clostridioides difficile infection has been documented. One reason for this is that levels of metronidazole in the colon are generally low; therefore, a modest increase in the minimum inhibitory concentration of metronidazole for C. difficile may result in an insufficient therapeutic concentration. Due to the lack of efficient genetic manipulation tools for C. difficile strains, the resistance mechanism is largely unknown. In this study, a metronidazole-resistant strain (SH182IR) was acquired by in-vitro induction with metronidazole from a clinical metronidazole-heteroresistant strain (SH182), and the genomic and transcriptional changes were investigated through whole-genome sequencing and RNA-seq. The morphology of the two strains was studied by transmission electron microscopy, and the roles of drug efflux pumps in metronidazole resistance were determined by inhibition assay. Genomic analysis showed that the ferrous iron transporter feoB3 was truncated in SH182IR, indicating that feoB3 contributed to the metronidazole resistance of C. difficile. RNA-seq analysis showed that genes involved in peptidoglycan synthesis, efflux pumps and metronidazole reductive action were expressed differentially between the two strains. Further cell imaging confirmed that cell wall thickness was significantly greater in SH182IR. The efflux pump inhibitor test showed that addition of reserpine or cyanide 3-chlorophenylhydrazone reduced metronidazole resistance in SH182IR, thus proving the role of efflux pumps in metronidazole resistance. These results found an association between genomic variation and metronidazole resistance in C. difficile, and show that metronidazole resistance in C. difficile is multi-factorial, involving metronidazole metabolism, cell wall thickness and efflux pumps. These findings will help improve knowledge and understanding of metronidazole resistance of C. difficile.


Asunto(s)
Clostridioides difficile , Infecciones por Clostridium , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Clostridioides , Clostridioides difficile/genética , Infecciones por Clostridium/tratamiento farmacológico , Genómica , Humanos , Metronidazol/farmacología , Metronidazol/uso terapéutico , Pruebas de Sensibilidad Microbiana , Transcriptoma
15.
Artículo en Inglés | MEDLINE | ID: mdl-36612832

RESUMEN

Frailty is an accumulation of deficits characterized by reduced resistance to stressors and increased vulnerability to adverse outcomes. However, there is little known about the effect of ambient temperature in winter on frailty among older adults, a population segment with the highest frailty prevalence. Thus, the objective of this study is to investigate the associations between frailty and ambient temperature in winter among older adults. This study was based on the Chinese Longitudinal Healthy Longevity Survey (CLHLS) of older adults aged ≥65 years from the 2005, 2008, 2011, and 2014 waves. The 39-item accumulation of frailty index (FI) was used to assess the frailty status of the participants. The FI was categorized into three groups as follows: robust (FI ≤ 0.10), prefrail (FI > 0.10 to <0.25), and frail (FI ≥ 0.25). Generalized linear mixed models (GLMMs) were conducted to explore the associations between frailty and ambient temperature in winter. A generalized estimating equation (GEE) modification was applied in the sensitivity analysis. A total of 9421 participants were included with a mean age of 82.81 (SD: 11.32) years. Compared with respondents living in the highest quartile (≥7.5 °C) of average temperature in January, those in the lowest quartile (<−1.9 °C) had higher odds of prefrailty (OR = 1.35, 95% CI 1.17−1.57) and frailty (OR = 1.61, 95%CI 1.32−1.95). The associations were stronger among the low-education groups, agricultural workers before retirement, and non-current exercisers. Additionally, results from the GEE model reported consistent findings. Lower levels of ambient temperature in winter were associated with higher likelihoods of prefrailty and frailty. The findings on vulnerability characteristics could help improve public health practices to tailor cold temperature health education and warning information.


Asunto(s)
Fragilidad , Anciano , Humanos , Anciano de 80 o más Años , Fragilidad/epidemiología , Temperatura , Evaluación Geriátrica/métodos , Longevidad , Estudios Longitudinales , Anciano Frágil
16.
Int J Mol Sci ; 22(24)2021 Dec 20.
Artículo en Inglés | MEDLINE | ID: mdl-34948420

RESUMEN

Recently, the atheroprotective role of endogenous GM3 and an atherogenesis-inhibiting effect of exogenous GM3 suggested a possibility of exogenous GM3 being recruited as an anti-atherosclerotic drug. This study seeks to endow exogenous GM3 with atherosclerotic targetability via reconstituted high-density lipoprotein (rHDL), an atherosclerotic targeting drug nanocarrier. Unloaded rHDL, rHDL loaded with exogenous GM3 at a low concentration (GM3L-rHDL), and rHDL carrying GM3 at a relatively high concentration (GM3H-rHDL) were prepared and characterized. The inhibitory effect of GM3-rHDL on lipid deposition in macrophages was confirmed, and GM3-rHDL did not affect the survival of red blood cells. In vivo experiments using ApoE-/- mice fed a high fat diet further confirmed the anti-atherosclerotic efficacy of exogenous GM3 and demonstrated that GM3 packed in HDL nanoparticles (GM3-rHDL) has an enhanced anti-atherosclerotic efficacy and a reduced effective dose of GM3. Then, the macrophage- and atherosclerotic plaque-targeting abilities of GM3-rHD, most likely via the interaction of ApoA-I on GM3-rHDL with its receptors (e.g., SR-B1) on cells, were certified via a microsphere-based method and an aortic fragment-based method, respectively. Moreover, we found that solution acidification enhanced GM3 release from GM3-rHDL nanoparticles, implying the pH-responsive GM3 release when GM3-rHDL enters the acidic atherosclerotic plaques from the neutral blood. The rHDL-mediated atherosclerotic targetability and pH-responsive GM3 release of GM3-rHDL enhanced the anti-atherosclerotic efficacy of exogenous GM3. The development of the GM3-rHDL nanoparticle may help with the application of exogenous GM3 as a clinical drug. Moreover, the data imply that the GM3-rHDL nanoparticle has the potential of being recruited as a drug nanocarrier with atherosclerotic targetability and enhanced anti-atherosclerotic efficacy.


Asunto(s)
Aterosclerosis/tratamiento farmacológico , Gangliósido G(M3)/farmacología , Lipoproteínas HDL , Macrófagos/efectos de los fármacos , Nanopartículas/química , Placa Aterosclerótica/tratamiento farmacológico , Animales , Aterosclerosis/inmunología , Aterosclerosis/metabolismo , Aterosclerosis/prevención & control , Sistemas de Liberación de Medicamentos , Gangliósido G(M3)/uso terapéutico , Humanos , Concentración de Iones de Hidrógeno , Metabolismo de los Lípidos , Macrófagos/metabolismo , Masculino , Ratones , Ratones Noqueados para ApoE , Células RAW 264.7
17.
Eur J Appl Physiol ; 121(11): 3211-3223, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34414476

RESUMEN

PURPOSE: To identify the changes of ventilation ([Formula: see text]E), tidal volume (VT) and respiratory frequency (fr) at different incremental step test intensities during maturation of children and adolescents. METHODS: A semi-longitudinal study was conducted on 68 healthy untrained boys and girls aged 11-17 years. The subjects were separated into three distinct age groups. [Formula: see text]E, VT and fr parameters were evaluated annually during 3 years by modifying incremental step test intensities according to ventilatory threshold (VTh) level (30, 60 and 90% of [Formula: see text]O2max). Absolute and relative values of ventilatory responses were analyzed and compared according to age and developmental phase. RESULTS: (1) Height, weight, lean body mass and vital capacity increased significantly from 11 to 17 years of age. (2) [Formula: see text]O2max, [Formula: see text]E, and VT increased during maturation even when exercise intensity changed, especially from 11 to 15 years of age. On the other hand, fr showed a decreasing trend. CONCLUSION: Increases of VT are the main reason for [Formula: see text]E increases during maturation of children. fr decreased independently of total body mass during maturation. [Formula: see text]E.kg-1 was stable despite intensity variations. VT.kg-1 increased significantly from 11 to 15 years then stabilized at 17 years. Lean body mass seems to explain the evolution of VT.kg-1 during maturation.


Asunto(s)
Crecimiento/fisiología , Consumo de Oxígeno/fisiología , Frecuencia Respiratoria/fisiología , Volumen de Ventilación Pulmonar/fisiología , Adolescente , Factores de Edad , Niño , Prueba de Esfuerzo , Femenino , Humanos , Estudios Longitudinales , Masculino
18.
Front Psychiatry ; 12: 652717, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33841214

RESUMEN

Background: Healthcare workers (HCWs) have been exposed to increased risks of insomnia and fatigue during the COVID-19 pandemic. In this study, we identify important risk factors associated with insomnia symptoms and fatigue among HCWs, and evaluate the effect of organizational support on insomnia and fatigue symptoms. Methods: This is an online cross-sectional survey of HCWs in China administered during the COVID-19 epidemic (from February 27, 2020 to March 12, 2020). We employed the AIS-8 scale for insomnia screening, and a self-reported ten-point scale to evaluate subjects' degrees of fatigue. We also designed a four-point scale to assess the degree of social support provided on an organizational level. Additionally, we conducted logistic regression analysis to identify risk factors. Results: This study included a total of 3,557 participants, 41% of which consisted of non-frontline HCWs and 59% of which was frontline HCWs. Of the non-frontline HCWs, 49% reported insomnia symptoms, and 53.8% reported a moderate to high degree of fatigue. Meanwhile, among the frontline HCWs, the percentages for insomnia and moderate to high fatigue were 63.4% and 72.2%, respectively. Additionally, frontline HCWs and HCWs employed at Centers for Disease Control and Prevention (CDCs) had elevated risks of insomnia and fatigue. However, with increased organizational support, insomnia symptoms decreased among frontline HCWs. Also, organizational support mitigated the positive correlation between daily working hours and degree of fatigue among HCWs. Conclusion: Frontline HCWs and staff in Chinese CDCs have been at a high risk of insomnia symptoms and fatigue during the fight against COVID-19. This study provides evidence for the positive effects of organizational support in relation to insomnia and fatigue among HCWs. This sheds light on government responses to the COVID-19 epidemic for other countries.

19.
Sci Rep ; 11(1): 8887, 2021 Apr 26.
Artículo en Inglés | MEDLINE | ID: mdl-33903684

RESUMEN

Compressions of magnetorheological (MR) fluids have been carried out under instantaneous magnetic fields. The yield strength of the MR fluid in compressive mode has been derived by assuming that it was a transformed shear flow in Bi-visous model. The compressive stresses have experimentally studied under different magnetic fields, different initial gap distances and different compressive velocities. The nominal yield shear stresses of the compressed MR fluid under different influential factors have been calculated. The compressive stress increased in a power law as the applied magnetic field increased, while it decreased as the initial gap distance and the compressive velocity increased. With the increase of magnetic field, the difference between the nominal yield shear stress curves increased, and the exponents of the power law increased with the increase of the magnetic field strengths. A larger initial gap distance and a lower compressive velocity resulted in a higher nominal yield shear stress under the same instantaneous magnetic field. The achieved results of the nominal yield shear stress with magnetic field seemed to deviate from the prediction of dipole model, and the chain structure aggregation effect, the sealing effect and the friction effect by compression should be considered.

20.
Clin Infect Dis ; 71(Suppl 4): S409-S415, 2020 12 23.
Artículo en Inglés | MEDLINE | ID: mdl-33367576

RESUMEN

BACKGROUND: Infectious disease is the leading cause of fever of unknown origin (FUO). Serum inflammatory markers historically used to diagnose bacterial infection have sufficient diagnostic sensitivity but low specificity. This study aimed to develop a simple scoring system for differentiating bacterial infections from other causes of early-stage FUO. METHODS: This study included a retrospective cohort of patients presenting with FUO at the Huashan Hospital (January 2014 to June 2017). The diagnostic utility of serum inflammatory markers for bacterial infection was evaluated using the receiver operating characteristic (ROC) curve analysis. Relevant markers were subsequently measured prospectively in a separate cohort of FUO patients (December 2017 to May 2019). A scoring system was based on inflammatory markers and other test results. RESULTS: Bacterial infection was identified in 34% of patients in the retrospective cohort. The area under the ROC curve (AUC) was 0.644 (95% confidence interval [CI], .595-.693) for C-reactive protein, 0.624 (95% CI, .573-.675) for procalcitonin, and 0.646 (95% CI, .595-.697) for serum ferritin (SF) in diagnosing bacterial infection. Bacterial infection was found in 29% of cases in the prospective cohort. A model based on serum amyloid A (SAA) and SF levels and neutrophil percentage yielded an AUC of 0.775 (95% CI, .695-.854). Validation analysis indicated lower probability (<15%) of bacterial infection for patients with a score <16.5 points. CONCLUSIONS: A scoring system based on SAA and SF levels and neutrophil percentage can help distinguish bacterial infection from other causes of FUO, potentially reducing antibiotic use.


Asunto(s)
Infecciones Bacterianas , Fiebre de Origen Desconocido , Infecciones Bacterianas/diagnóstico , Proteína C-Reactiva/análisis , Fiebre de Origen Desconocido/diagnóstico , Humanos , Estudios Prospectivos , Estudios Retrospectivos
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