ANALYSIS OF DYNAMIC STABILITY WHILE TEXTING DURING STAIR DESCENT

The purpose of this study was to explore the modifications in saggital and frontal dynamic stability during stair descent while texting to provide a database for guidelines of fall prevention. Participants (n=26; 13 male, 13 female) performed three stair descent trials under texting and No texting task conditions at self-selected speed, respectively. Synchronous kinematics and kinetics were collected by an eight-camera Vicon infrared motion capture system and two force platforms. A paired sample t-test was used to analyze the differences between two task conditions. With the interference of texting, anterior–posterior margin of stability (MOSap) increased in the initiation of double-support phase (DSP), while decreased in the initiation of single-support phase (SSP), medial–lateral MOS (MOSml) decreased in the initiation of SSP. Posterior instability was induced in the initiation of DSP. The initiation of DSP was the most unstable moment and should alert texters, particularly young adults, to potential risk of falling backward during stair descent

Correlative study on retinal microvascular changes and sex hormones in male patients with central serous chorioretinopathy

Central serous chorioretinopathy (CSC) is a disease in which the outer retinal barrier is damaged with high incidence in young adult males. We aimed to analyze the correlations between retinal microvascular changes and sex hormone levels. The vascular density of the superficial retinal capillary plexus (SCP), deep retinal capillary plexus (DCP), foveal avascular zone (FAZ) area, choriocapillary blood flow area, and the subfoveal choroidal thickness (SCT) were investigated by optical coherence tomography angiography (OCTA). We also determined the levels of sex hormones (adrenaline (AD), norepinephrine (NE), dopamine (DA), corticosteroids (Cor), aldosterone (ALD), estradiol (E2) and total testosterone (TT)). The relationship between sex hormone levels and OCTA parameters was then determined. We detected significantly higher levels of NE, Cor and TT in serum from the observation group than in the control group (p < 0.05). Significant correlations were identified between SCT and choriocapillary blood flow area in the affected eyes, contralateral eyes and healthy eyes in the control group (p < 0.05). SCT levels of both eyes in the observation group were higher and the choriocapillary blood flow area was smaller than in the control group. The SCT in affected eyes from the observation group were higher than the contralateral eyes (p < 0.05). The choriocapillary blood flow area was significantly smaller than in the contralateral eyes (p < 0.05). Correlation analysis unveiled that NE, Cor and TT levels were positively correlated with SCT in CSC patients and negatively correlated with choriocapillary blood flow area (p < 0.05). The serum levels of sex hormone levels in male CSC patients were different from those in healthy men of the same age. Our findings suggest that the serum levels of NE, Cor and TT levels may influence the pathogenesis of CSC by affecting SCT thickness and choriocapillary blood flow

Colonic mucosal biopsy location can not affect the results of mucosal metabolomics and mucosal microbiota analysis in IBS

ObjectiveTo compare and analyze the mucosal metabolites and mucosal microbiota of different parts of colon in patients with IBS.MethodsA total of 10 patients with IBS-D and six healthy controls (HC) were enrolled. All enrolled participants underwent two biopsies of the ileocecal and sigmoid colon during colonoscopy. Metabolomic profiling of one piece of tissue was conducted using desorption electrospray ionization-mass spectrometry (DESI-MS), and the gut flora of the other piece was examined using 16S rRNA sequencing. The metabolic profiles and flora of the ileocecal and sigmoid colonic mucosa in each group were further analyzed in this study.Results(1) Principal components analysis (PCA) indicated that mucosal metabolites did not differ in different parts of the colon in either the IBS-D or HC groups. (2) In the mucosal microbiome analyses, no differences between the microbiota of the two parts of the colon were found by using Principal Co-ordinates Analysis (PCoA). In IBS group, comparing with sigmoid mucosa, the chao1 richness indice was higher and the Shannon index was lower in the ileocecal mucosa (p = 0.40, p = 0.22). However, in the HC group, microbiome analysis of the ileocecal mucosa showed lower values for Chao 1 and Shannon indices than those of the sigmoid colon mucosa (p = 0.06, p = 0.86). (3) Compared with the HC group, 1,113 metabolic signal peaks were upregulated, whereas 594 metabolites were downregulated in the IBS-D samples. Moreover, the PCA of the metabolites showed significant separation between the IBS-D and HC groups. (4) Chao1 expression was significantly higher in the mucosal microbiota with IBS-D than in the HC (p = 0.03). The Shannon index was lower in IBS-D, but the difference was not statistically significant (p = 0.53). PCoA revealed a significant difference in the microflora structure between the IBS-D and HC groups.ConclusionThe mucosal metabolic profile and mucosal flora structure of the colon were similar, despite different locations in IBS and healthy subjects. IBS had abnormal colonic mucosal metabolism and flora disturbances

Nitrogen addition regulates soil nematode community composition through ammonium suppression

Nitrogen (N) enrichment resulting from anthropogenic activities has greatly changed the composition and functioning of soil communities. Nematodes are one of the most abundant and diverse groups of soil organisms, and they occupy key trophic positions in the soil detritus food web. Nematodes have therefore been proposed as useful indicators for shifts in soil ecosystem functioning under N enrichment. Here, we monitored temporal dynamics of the soil nematode community using a multi-level N addition experiment in an Inner Mongolia grassland. Measurements were made three years after the start of the experiment. We used structural equation modeling (SEM) to explore the mechanisms regulating nematode responses to N enrichment. Across the N enrichment gradient, significant reductions in total nematode abundance, diversity (H' and taxonomic richness), maturity index (MI), and the abundance of root herbivores, fungivores and omnivores-predators were found in August. Root herbivores recovered in September, contributing to the temporal variation of total nematode abundance across the N gradient. Bacterivores showed a hump-shaped relationship with N addition rate, both in August and September. Ammonium concentration was negatively correlated with the abundance of total and herbivorous nematodes in August, but not in September. Ammonium suppression explained 61% of the variation in nematode richness and 43% of the variation in nematode trophic group composition. Ammonium toxicity may occur when herbivorous nematodes feed on root fluid, providing a possible explanation for the negative relationship between herbivorous nematodes and ammonium concentration in August. We found a significantly positive relationship between fungivores and fungal phospholipid fatty acids (PLFA), suggesting bottom-up control of fungivores. No such relationship was found between bacterivorous nematodes and bacterial PLFA. Our findings contribute to the understanding of effects of N enrichment in semiarid grassland on soil nematode trophic groups, and the cascading effects in the detrital soil food web

Simulation of charge transport in polypropylene-based nano-composites

Polypropylene (PP)-based polymers are environmentally friendly and degradable materials thatmake them attractive alternatives to polyethylene for the electrical insulation systems of powercables in the future. To enhance the insulation performance of PP and to impede leakagecurrents through the material, different admixtures are utilized. In this paper, the effect ofnano-fillers on charge transport characteristics in PP composites under DC electric fields isinvestigated by using a bipolar charge transport model accounting for mobile and trappedelectrons and holes as well as ionic species. The model was validated by comparing thenumerical results with the experimental data. The dynamic distributions of space chargedensities and electric field in PP with and without nano-fillers are analyzed and compared. Thenumerical results confirmed that 0.5 phr ZnO nano-fillers can significantly improve the electricfield distribution in PP nanocomposites and suppress the bulk current by reducing the chargegeneration rate and mobilities of charge carriers, thus resulting in a decrease in the volumeconductivity. The obtained results provide a theoretical background for tailoring PP-basedcomposites for specific applications by controlling nano-fillers

Comparison of two functional kappa light‐chain transcripts amplified from a hybridoma

Three heavy‐chain and three kappa (κ)‐chain transcripts were amplified from hybridoma cells secreting a monoclonal antibody (m A b) against transferrin receptor. Sequence analysis via IMGT / V ‐ QUEST yielded the functional/aberrant prediction. Two functional κ‐chain transcripts, V κ2 and V κ3, and one functional V H 1 were revealed. Comprehensive bioinformatics analyses including sequence alignment, phylogenetic tree, somatic hypermutation prediction, and three‐dimensional‐molecular structure modeling were used to predict the origin of the two κ‐chain transcripts. The results of bioinformatics analysis suggest that V κ3 is derived from the myeloma partner of the hybridoma; V κ2 is derived from B‐cell. Functional transcripts V H 1 and V κ2 and V κ3 were then used to construct two chimeric antibodies chi‐ C 2 ( V κ2– V H 1) and chi‐ C 3 ( V κ3–V H 1), respectively. Antigen‐binding experiments showed that only chi‐ C 2 remained the same affinity as its parental mAb. Possible explanations for the coexistence of two functional κ‐chain transcripts and the different affinity of the two chimeric antibodies are discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98790/1/bab1080.pd

Towards Establishing Empirical Rainfall Thresholds for Shallow Landslides in Guangzhou, Guangdong Province, China

Empirical rainfall thresholds for predicting rainfall-triggered shallow landslides are proposed for Guangzhou city, which is prone to widespread geological hazards during the annual flood season due to the subtropical monsoon climate and frequent tropical storms and typhoons. In this study, the cumulated event rainfall (E, in mm), the duration of rainfall event (D, in day) (E–D) thresholds, normalized cumulated event rainfall, and the duration of rainfall event (EMAP–D) thresholds were defined. Thresholds based on five lithological units were obtained at 5%, 20%, and 50% probability levels using quantile regression methods. More than two-thirds of the landslides occurred within units of intrusive rock. The 20-day cumulative rainfall of 97 mm integrating cumulative event rainfall and the duration of rainfall events (CED) is introduced into the three-dimensional spatial threshold. The areas under the receiver operating characteristic curves for the CED threshold and E–D threshold were 0.944 and 0.914, respectively, and the true-positive rate of the CED threshold with the same probability level was slightly lower than that of the E–D threshold, but the CED threshold false-positive rate was much better than the E–D threshold, which can significantly reduce false alarm rate since many non-triggering rainfalls were filtered out

Light-Emitting Diode-Based Illumination System for In Vitro Photodynamic Therapy

The aim of this study is to develop a light-emitting diode- (LED-) based illumination system that can be used as an alternative light source for in vitro photodynamic therapy (PDT). This illumination system includes a red LED array composed of 70 LEDs centered at 643 nm, an air-cooling unit, and a specific-designed case. The irradiance as a function of the irradiation distance between the LED array and the sample, the homogeneity and stability of irradiation, and the effect of long-time irradiation on culture medium temperature were characterized. Furthermore, the survival rate of the CNE1 cells that sensitized with 5-aminolevulinic acid after PDT treatment was evaluated to demonstrate the efficiency of the new LED-based illumination system. The obtained results show that the LED-based illumination system is a promising light source for in vitro PDT that performed in standard multiwell plate

Bidirectional Anions Gathering Strategy Afford Efficient Mixed Pb-Sn Perovskite Solar Cells

Abstract Mixed lead-tin (Pb-Sn) perovskite solar cells (PSCs) possess low toxicity and adjustable bandgap for both single-junction and all-perovskite tandem solar cells. However, the performance of mixed Pb-Sn PSCs still lags behind the theoretical efficiency. The uncontrollable crystallization and the resulting structural defect are important reasons. Here, the bidirectional anions gathering strategy (BAG) is reported by using Methylammonium acetate (MAAc) and Methylammonium thiocyanate (MASCN) as perovskite bulk additives, which Ac− escapes from the perovskite film top surface while SCN− gathers at the perovskite film bottom in the crystallization process. After the optoelectronic techniques, the bidirectional anions movement caused by the top-down gradient crystallization is demonstrated. The layer-by-layer crystallization can collect anions in the next layer and gather at the broader, enabling a controllable crystallization process, thus getting a high-quality perovskite film with better phase crystallinity and lower defect concentration. As a result, PSCs treated by the BAG strategy exhibit outstanding photovoltaic and electroluminescent performance with a champion efficiency of 22.14%. Additionally, it demonstrates excellent long-term stability, which retains ≈92.8% of its initial efficiency after 4000 h aging test in the N2 glove box

The effect of text-based math task on dynamic stability control during stair descent (ID: BM-D-20-00079R3)

© 2020 Elsevier Ltd Stair descent imposes a significant challenge for dynamic stability among young adults. The effect of a concurrent text-based math task on dynamic stability control remains unclear during stair descent when considering the influence of gait velocity. Twenty-six participants performed three successful stair descent trials under TEXTING or NO-TEXTING conditions at their preferred speed. Synchronous kinematics and kinetics were collected by an eight-camera Vicon infrared motion capture system and two force platforms. Repeated measures analysis of covariance and Wilcoxon signed rank test were used to analyze the differences between the two different task conditions with gait velocity as a covariate. The outcomes indicated that under TEXTING condition, sagittal margin of stability increased at right-foot-landing; step cadence, double-support percentage, sagittal and frontal joint moment decreased; and sagittal and frontal joint angles were also modified. It is concluded that concurrent TEXTING impaired sagittal and frontal stability control during stair descent despite slowing down the step cadence. Knee and ankle joint adjustment strategies were mainly adopted in response to stability control in the sagittal plane with the interference of TEXTING, whereas the hip joint adjustment strategy was adopted in the frontal plane. In conclusion, texting behaviors on mobile phones should be minimized during stair descent