Distribution of cardiorespiratory fitness in children and adolescents at different latitudes.

OBJECTIVE: To explore the differences and characteristics of cardiorespiratory fitness (CRF) among children and adolescents in regions with different latitudes in China. METHODS: A total of 9892 children and adolescents aged 7-22 years were selected from seven administrative regions in China by the stratified cluster random sampling method. CRF was measured by performance on the 20 m shuttle run test (20mSRT) and estimated maximal oxygen consumption (VO2max ). One-way ANOVA, one-way ANCOVA, and the Lambda Mu and Sigma methods were used to analyze the data. RESULTS: Overall, the VO2max of children and adolescents at high latitudes was significantly lower than that of children at low and middle latitudes. The P10 , P50 , and P90 20mSRT values for children and adolescents of most age groups in high latitudes were less than those in low and middle latitudes. The 20mSRT-Z and VO2max -Z scores among children and adolescents aged 7-22 in high latitudes were lower than those in middle and low latitudes after adjusting for age, per capita gross domestic product (GDP), and per capita disposable income. CONCLUSION: In general, the CRF of children and adolescents at high latitudes was less than that at low and middle latitudes. Effective measures should be taken to improve CRF in children and adolescents at high latitudes.

Characterization of the vaginal microbiome during cytolytic vaginosis using high-throughput sequencing.

BACKGROUND: Cytolytic vaginosis (CV) is a common disease that results in pruritus, dyspareunia, and vulvar dysuria. However, the pathological mechanisms of the disease are still unclear. Compared to traditional methods, high-throughput sequencing can obtain more accurate qualitative and quantitative information on the microbiome. METHODS: We collected 75 samples from 32 healthy women (average age 44 ± 8) and 43 patients with CV (average age 38 ± 8). We used high-throughput sequencing of the 16S rRNA V3-V4 region to characterize and compare the vaginal microbiota of patients with CV and healthy women and to identify potential biomarkers for CV. RESULTS: The vaginal pH of patients with CV was ≤3.8, and the vaginal concentration of H2 O2 was ≥2 µmol/L. Colony densities of Lactobacillus spp. in patients with CV ranged from +++ (5-30) to ++++ (>30) and were significantly higher than those in healthy women. High-throughput sequencing showed that Lactobacillus was the most prominent genus both in patients with CV and in healthy women, with abundances of 83.8% and 97.2%, respectively (P < 0.001). Lactobacillus crispatus was more abundant in patients with CV, whereas Lactobacillus sp. L-YJ was more abundant in healthy women, with area under the curve (AUC) values of 0.9375 and 0.8379, respectively. CONCLUSION: The abundance of Lactobacillus spp. in CV patients was significantly different from that of healthy patients. Two suitable biomarkers, L. crispatus and Lactobacillus sp. L-YJ, were identified. These results will be useful for the identification of women at risk of serious illness before they develop obvious symptoms.

High-resolution ghost imaging experiments with cosh-Gaussian modulated incoherent sources.

We experimentally demonstrate that ghost imaging (GI) quality can be significantly improved by modulating the incoherent Gaussian sources with hyperbolic cosine functions. In our experiments, a source with desired cosh-Gaussian intensity distribution can be generated by a programmable spatial light modulator, and is used in the GI setup to obtain high quality ghost images. The influences of the hyperbolic cosine parameter on the point-spread function and the GI quality have been investigated experimentally and interpreted theoretically. Our experimental results show that the resolution of ghost images can be obviously enhanced with cosh-Gaussian modulated incoherent sources. The kind of source-shaping technique proposed in this paper is a high-efficiency method to improve the GI quality and may be very useful for the GI applications.

Re-emerging magnetic order in correlated van der Waals antiferromagnet NiPS3.

Van der Waals (vdW) gap is a significant feature that distinguishes vdW magnets from traditional magnets. Manipulating the magnetic properties by changing the vdW gap has been hot topic in condensed matter research. Here we report a re-emerging magnetic order induced by pressure in a correlated vdW antiferromagnetic insulator NiPS3. It is found that the interlayer magnetoresistance (MR) nearly vanishes at the critical pressure where the crystal structure transforms fromC2/mphase to the slidingC2/mphase. On further compression within the slidingC2/mphase, a substantially enhanced MR emerges from low temperature associated with an insulator-to-metal transition, indicating a metallic antiferromagnetic phase. The enhanced re-emerging MR in slidingC2/mphase can be ascribed to the increasing magnetic interaction between neighboring layers due to the vdW gap narrowing. Our results provide important experimental clues for understanding the pressure effects on magnetism in correlated layered materials.

Assessment of stress levels and reproductive condition in giant pandas: insights from hair, faecal and saliva samples.

Concerted conservation efforts have brought the giant panda (Ailuropoda melanoleuca) back from the brink of extinction, but pandas continue to face anthropogenic threats in the wild and breeding success in captivity remains low. Because stress can have detrimental impacts on reproduction, monitoring stress- and sex-steroid levels would help assess the effectiveness of conservation mitigation measures in panda populations as well as monitor the welfare and reproductive health of captive animals. In this proof-of-concept study, we used faecal sex steroid and cortisol concentrations (n = 867 samples collected from five males and five females at Beijing Zoo every 4 days over the course of 12 months) as a reference to investigate if testosterone, estradiol, progesterone and cortisol can be meaningfully measured in panda hair (n = 10) using radio-immuno-assays. Additionally, we calculated the ratio of testosterone to cortisol (T:C ratio) for each male, which can provide a biomarker of stress and physical performance. Our findings revealed distinct monthly variations in faecal sex-steroid and cortisol concentrations, reflecting reproductive seasonality and visitor-related stress among individual pandas. Notably, the oldest male had a significantly lower T:C ratio than other males. Our results confirm that the level of sex steroids and cortisol can be assayed by panda hair, and the hair cortisol concentrations correlate significantly with that in faeces with one month lag behind (r = 0.68, P = 0.03). However, the concentrations of hormones detected in saliva are lower than those in faeces by two orders of magnitude, making it difficult to ensure accuracy. By assessing the applicability of hair, faecal and salivary sampling, we can infer their utility in monitoring the reproductive status and acute and chronic stress levels of giant pandas, thereby providing a means to gauge the success of ongoing habitat restoration efforts and to discuss the feasibility of sample collection from wild populations.

Effects of Age and Season on Blood Parameters of Captive Giant Pandas: A Pilot Study.

The giant panda, Ailuropoda melanoleuca, serves as a flagship species for biodiversity conservation, embodying the intersection of ecological, evolutionary, and anthropogenic forces shaping the natural world. Hematological parameters serve as crucial indicators for assessing the physiological status of animals. However, our understanding of blood parameters and hemorheology in captive giant pandas under non-anesthetic conditions is limited. In this study, from September 2018 to August 2020, we collected blood samples from captive giant pandas under non-anesthetic conditions. Twelve captive giant pandas, ranging in age from 2 to 28 years, were divided into three groups based on their age, and the variations in basic blood parameters and hemorheological parameters across four seasons were analyzed. This provided baseline data for future blood sample comparisons in non-anesthetized captive giant pandas. Additionally, we observed seasonal changes in hematological morphology, hemorheology, and serum enzymes. Moreover, seasonality had a regulatory effect on hemorheological parameters and negatively impacted blood viscosity. Age influenced changes in serum enzymes, serum protein content, and serum metabolites, indicating differences in overall metabolic processes among giant pandas of different age groups. Whether factors such as season and climate contribute to environmental stress in captive giant pandas requires further investigation. The findings of this study may help to protect the stability of the giant panda population better and provide a reference for the medical care of captive giant pandas.

Sol-gel-derived hydroxyapatite-carbon nanotube/titania coatings on titanium substrates.

In this paper, hydroxyapatite-carbon nanotube/titania (HA-CNT/TiO(2)) double layer coatings were successfully developed on titanium (Ti) substrates intended for biomedical applications. A TiO(2) coating was firstly developed by anodization to improve bonding between HA and Ti, and then the layer of HA and CNTs was coated on the surface by the sol-gel process to improve the biocompatibility and mechanical properties of Ti. The surfaces of double layer coatings were uniform and crack-free with a thickness of about 7 µm. The bonding strength of the HA-CNT/TiO(2) coating was higher than that of the pure HA and HA-CNT coatings. Additionally, in vitro cell experiments showed that CNTs promoted the adhesion of preosteoblasts on the HA-CNT/TiO(2) double layer coatings. These unique surfaces combined with the osteoconductive properties of HA exhibited the excellent mechanical properties of CNTs. Therefore, the developed HA-CNT/TiO(2) coatings on Ti substrates might be a promising material for bone replacement.

Combined toxicity characteristics and regulation of residual quinolone antibiotics in water environment.

In this study, the mixture toxicity index method was used to evaluate the combined toxicity of residual Quinolones (QNs) on algae in twelve groups of water environment reported in the literature. The selected three sets of data (II, Ⅺ, and Ⅻ) combined with full factorial design method were used to analyze the significance of the combined toxicity. Subsequently, molecular docking was used to reveal the significant mechanism of the primary effect of the combined toxicity. Finally, based on the sensitivity analysis method, the acid-base conditions affecting the combined toxicity were screened, and molecular dynamics simulation was used to control the combined toxicity in the water environment. The results of the mixture toxicity index method showed that the combined toxicity in all the twelve groups of water environments was synergistic. The full factorial design method revealed that ciprofloxacin, norfloxacin, enrofloxacin, lomefloxacin, and their binary combinations from the combined toxicity system of QNs, were the significant factors that caused the synergistic toxicity of QNS on algae. Molecular docking confirmed that the total number of amino acids, the number of significant amino acids, and hydrogen bonds of QNs toxic targets were significantly related to the synergistic effect of the combined toxicity. In addition, the molecular dynamics simulation showed that the binding energy of residual QNs and toxic targets changes with the acid-base conditions of the water environment. Thus, the combined toxicity can be slowed down or reduced by adequately adjusting the acid-base condition of the water.

Efficient parallelization of tensor network contraction for simulating quantum computation.

We develop an algorithmic framework for contracting tensor networks and demonstrate its power by classically simulating quantum computation of sizes previously deemed out of reach. Our main contribution, index slicing, is a method that efficiently parallelizes the contraction by breaking it down into much smaller and identically structured subtasks, which can then be executed in parallel without dependencies. We benchmark our algorithm on a class of random quantum circuits, achieving greater than 105 times acceleration over the original estimate of the simulation cost. We then demonstrate applications of the simulation framework for aiding the development of quantum algorithms and quantum error correction. As tensor networks are widely used in computational science, our simulation framework may find further applications.

Protein molecularly imprinted polyacrylamide membrane: for hemoglobin sensing.

A hemoglobin sensor based on a molecularly imprinted polymer-modified electrode has been fabricated by electrochemically induced redox polymerization of acrylamide in the presence of hemoglobin.

Fuzzy Comprehensive Evaluation Assistant 3D-QSAR of Environmentally Friendly FQs to Reduce ADRs.

Most studies on adverse drug reactions (ADRs) of fluoroquinolones (FQs) have focused on the mechanisms of single ADRs, and no quantitative structure-activity relationship (QSAR) method studies have been carried out that combine several ADRs of FQs. In this study, an improved three-dimensional (3D) QSAR method was established using fuzzy comprehensive evaluation. This method could simultaneously consider three common ADRs of FQs using molecular parameters. The improved method could comprehensively predict three ADRs of FQs and provide direction for the development of new drugs with lower ADRs than the originals. According to the improved method, 48 derivatives with lower ADRs (decreased by 4.86% to 50.92%) were designed from pazufloxacin. Three derivatives with a higher genotoxicity, higher photodegradation, and lower bioconcentration than pazufloxacin were selected using the constructed QSAR methods of the FQs. Finally, three traditional 3D-QSAR methods of single ADR were constructed to validate the improved method. The improved method was reasonable, with a relative error range of 0.96% to 4.30%. This study provides valuable reference data and will be useful for the development of strategies to produce new drugs with few ADRs. In the absence of complementary biological studies of these adverse drug reactions, the results reported here may be quite divergent from those found in humans or experimental animals in vivo. One major reason for this is that many adverse drug reactions are dependent upon enzyme-catalyzed metabolic activation (toxication) or on non-enzymatic conversion to toxic products and are not due to the parent drug moiety.

Prospective Study on the Excretion of Mucous Stools and its Association with Age, Gender, and Feces Output in Captive Giant Pandas.

The giant panda (Ailuropoda melanoleuca) has evolved a large number of mucous glands in the intestinal lining to adapt to the digestion of high-fiber foods. However, in captive pandas, excessive mucus might form a mass and then be eliminated, which is often accompanied by discomfort and decreased activity. This event is called 'mucous excretion'. The causes of mucus excretions in captive pandas, however, remain unknown. The aims of this study were to document the occurrence of mucus excretion and to investigate its possible associations with pandas' age, gender, and feces output. Eighteen giant pandas were studied at the Beijing Zoo from April 2003 to June 2017, and a total of 900 occurrences of mucous excretion and 32,856 daily defecation outputs in weight were recorded. The likelihood of mucous excretion occurrence decreased by 11.34% for each 1 kg of fecal output (Z = -4.12, p < 0.0001), while it increased by 5.89% per year of age (Z = 4.02, p < 0.0001). However, individual differences in gender had no significant effect on the mucous occurrence (Z = -0.75, p = 0.4508). A monthly change in mucus occurrence was also found. The mean frequency of mucus occurrence was significantly higher in October. In August, time (month) change showed the biggest negative influence on feces output but the biggest positive influence on mucus excretion (seasonal factors were -2.261 and 0.0126, respectively). Our results documented the occurrence of mucous excretions and confirmed their possible associations with the pandas' age and fecal output based on a 15-year prospective study. This study not only adds to our knowledge of panda physiology but also suggests the need for further studies examining the causes of the excretion of mucous stools in captive pandas. Reducing the incidence of mucous excretion would promote ex situ conservation and enhance panda welfare.

Selective detection of uric acid in the presence of ascorbic acid at physiological pH by using a beta-cyclodextrin modified copolymer of sulfanilic acid and N-acetylaniline.

A beta-cyclodextrin (CD) modified copolymer membrane of sulfanilic acid (p-ASA) and N-acetylaniline (SPNAANI) on glassy carbon electrode (GCE) was prepared and used to determine uric acid (UA) in the presence of a large excess of ascorbic acid (AA) by differential pulse voltammetry (DPV). The properties of the copolymer were characterized by X-ray photoelectron spectra (XPS) and Raman spectroscopy. The oxidation peaks of AA and UA were well separated at the composite membrane modified electrode in phosphate buffer solution (PBS, pH 7.4). A linear relationship between the peak current and the concentration of UA was obtained in the range from 1.0 x 10(-5) to 3.5 x 10(-4)mol L(-1), and the detection limit was 2.7 x 10(-6)mol L(-1) at a signal-to-noise ratio of 3. Two hundred and fifty-fold excess of AA did not interfere with the determination of UA. The application of the prepared electrode was demonstrated by measuring UA in human serum samples without any pretreatment, and the results were comparatively in agreement with the spectrometric clinical assay method.

Simultaneous determination of 5-hydroxyindoleacetic acid and 5-hydroxytryptamine in urine samples from patients with acute appendicitis by liquid chromatography using poly(bromophenol blue) film modified electrode.

The fabrication and application of a novel electrochemical detection (ED) system with a poly(bromophenol blue) (PBPB) film chemically modified electrode (CME) for high performance liquid chromatography (HPLC) were described. The electrochemical behaviors of 5-hydroxytryptamine (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) at this CME were investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). It was found that the PBPB CME efficiently exhibited electrocatalytic effect on the current responses of 5-HT and 5-HIAA with relatively high sensitivity, stability and long life of activity. In HPLC-ED, the two analytes had good and stable current responses at the CME and their linear ranges were over four orders of magnitude (R> or =0.9992) with the detection limits being 0.25 nmol L(-1) for 5-HT and 0.50 nmol L(-1) for 5-HIAA. The application of this method for the determination of 5-HT and 5-HIAA in urine samples from patients with acute appendicitis (AA) was satisfactory.

Determination of glutathione and glutathione disulfide in hepatocytes by liquid chromatography with an electrode modified with functionalized carbon nanotubes.

Glutathione (GSH) and glutathione disulfide (GSSG) are important thiols, which provide defence against oxidative stress by scavenging free radicals or causing the reduction of hydrogen peroxide. The ratio GSH/GSSG is often used as a sensitive index of oxidative stress in vivo. In this paper, a direct electrochemical method using an electrode modified with functionalized carbon nanotubes as electrochemical detector (ED) for liquid chromatography (LC) was described. The electrochemical behaviors of GSH and GSSG on this modified electrode were investigated by cyclic voltammetry and it was found that the functionalized carbon nanotubes exhibited efficiently electrocatalysis on the current responses of GSH and GSSG. In LC-ED, both of the analytes showed good and stable current responses. The detection limit of GSH was 0.2 pmol on column and that of GSSG was 1.2 pmol on column, which were low enough for the analysis of real small samples. The method was sensitive enough to detect difference in concentration of GSH and GSSG in hepatocytes from animals with and without introduction of oxidation stress by glucose or hydrogenperoxide.

Establishment of a novel one-step reverse transcription loop-mediated isothermal amplification assay for rapid identification of RNA from the severe fever with thrombocytopenia syndrome virus.

As an emerging infectious disease, severe fever with thrombocytopenia syndrome virus (SFTSV) infection has been found in many areas of China. Suitable laboratory diagnostic method is urgently needed in clinical detections and epidemiological investigations. In this study, a modified, low-cost and rapid visualized one-step reverse transcription loop-mediated isothermal amplification (RT-LAMP) method for the detection of RNA from the SFTSV has been established. In order to avoid the risk of aerosol contamination and facilitate the naked eye to observe, a microcrystalline wax-dye capsule wrapping the highly sensitive DNA fluorescence dye SYBR Green I was added to the RT-LAMP reaction tube before the initiation of the assay. The detection limit of the established RT-LAMP assay was 10 fg template RNA per reaction mixture. The RT-LAMP assay was confirmed to be high specific to SFTSV, and no cross-reaction was found with the detection of the Chikungunya fever virus, Hemorrhagic Fever with Renal Syndrome virus (HFRSV), and Dengue fever virus. The assay was then applied for the detection of SFTSV RNA in 32 clinical serum samples and showed 94.4% consistence with the detection results of the real-time RT-PCR. The whole process, from sample preparation to result reporting, can be completed within 2h. This adapted, cost efficient and quick visualized RT-LAMP method is feasible for SFTSV field diagnosis in resource-limited field settings.

A high-sensitive and fast-fabricated glucose biosensor based on Prussian blue/topological insulator Bi2Se3 hybrid film.

A novel and fast-fabricated Prussian blue (PB)/topological insulator Bi(2)Se(3) hybrid film has been prepared by coelectrodeposition technique. Taking advantages of topological insulator in possessing exotic metallic surface states with bulk insulating gap, Prussian blue nanoparticles in the hybrid film have smaller size as well as more compact structure, showing excellent pH stability even in the alkalescent solution of pH 8.0. Based on the Laviron theory, the electron transfer rate constant of PB/Bi(2)Se(3) hybrid film modified electrode was calculated to be 4.05 ± 0.49 s(-1), a relatively big value which may be in favor of establishing a high-sensitive biosensor. An amperometric glucose biosensor was then fabricated by immobilizing glucose oxidase (GOD) on the hybrid film. Under the optimal conditions, a wide linear range extending over 3 orders of magnitude of glucose concentrations (1.0 × 10(-5)-1.1 × 10(-2)M) was obtained with a high sensitivity of 24.55 µA mM(-1) cm(-2). The detection limit was estimated for 3.8 µM defined from a signal/noise of 3. Furthermore, the resulting biosensor was applied to detect the blood sugar in human serum samples without any pretreatment, and the results were comparatively in agreement with the clinical assay.

Preparation and characterization of cationic curcumin nanoparticles for improvement of cellular uptake.

In the present paper, cationic nanoparticles of curcumin, chitosan and poly(ɛ-caprolactone) were developed by a simple nano-precipitation method. The developed curcumin loaded chitosan/poly(ɛ-caprolactone) (chitosan/PCL) nanoparticle showed almost spherical shape and its diameter was varied between 220 nm and 360 nm and zeta potential was varied between +30 mV and 0 mV as a function with pH value. The encapsulation of curcumin into nanoparticles was confirmed by fluorescence spectral analysis. In vitro release study showed the sustained release behavior of curcumin from nanoparticles during the period of 5 days study. In vitro cytotoxicity test revealed the drug concentration dependent on the cell viability against Hela cells and OCM-1 cells after 48 h co-incubation. Furthermore, in vitro cell uptake study revealed that the cell uptake of curcumin was greatly enhanced by encapsulated curcumin into cationic chitosan/PCL nanoparticles. Therefore, the developed cationic chitosan/PCL nanoparticles might be a promising candidate for curcumin delivery to cancer cells.

In vivo evaluation of in situ polysaccharide based hydrogel for prevention of postoperative adhesion.

In this paper, the carboxymethyl chitosan/oxidized dextran hydrogel was developed and its potency application in the prevention of postoperative adhesion was investigated. The developed hydrogel showed porous and interconnected interior structure with pore size about 250 µm, which was sensitive to lysozymic solution (1.5 µg/ml) with almost complete degradation after 4 weeks of in vitro incubation. In vivo study suggested that the developed hydrogel showed the great capacity on the prevention of postoperative adhesions in rat model. According to the result of histopathological examination, it clearly showed that the mesothelial cell layer of abdominal wall and cecum were completely recovered after 7 days of surgery in 3% carboxymethyl chitosan/oxidized dextran hydrogel group, while obvious adhesion between abdominal wall and cecum was observed as treatment with saline solution or 3% carboxymethyl chitosan solution after 1 day of surgery. All these results suggested that the developed biodegradable hydrogel might have potential application in the prevention of postoperative adhesion.