Search

AbstractThe impact of land use on water quality is spatially scale-dependent. Exploring the relationship between land use pattern and river water quality provides an important basis for water quality safety and land planning. This study explores the effect of land use patterns on surface water quality using land use data and water quality data of 16 sampling points in the middle reach of the Huai River. It investigates the water quality status of the middle reach of the Huai River and the relationship between land use patterns and water quality indices at 100, 500, and 1000 m and watershed scales utilising Spearman correlation, redundancy analysis (RDA), and multiple linear regression analysis. Multiple linear regression analysis showed that the water pollutants in the middle reach of the Huai River are mainly total nitrogen (TN) and total phosphorus (TP). Redundancy analysis (RDA) indicated that the impact of land use patterns on water quality is significant on watershed scales. Spearman correlation indicated that water quality and land use showed significant correlation differences, the building land was positively correlated with TP, TN and NH3-N, the cultivated land was positively correlated with TN, and the grassland was negatively correlated with TP and NH3-N. This studies have revealed that building land acts as a 'source’ of pollutants, grassland purifies the load of TP and NH3-N, and forest land has the effect of interception and deposition of pollutants. The results can provide important information for land use planning and water quality protection measures at multiple spatial scales.

Free trial is a widely used business strategy that takes advantage of information asymmetry. However, evidence on what we can learn and how rapidly we can learn from a free trial of health care is limited. This study evaluates the effect of a free trial of eyeglasses on children’s 8 items of perception related to eyeglasses use. An evaluation was conducted alongside a cluster-randomized controlled trial involved 832 myopic children from northwest rural China. A total of 428 myopic children from 42 schools were randomized to receive free eyeglasses, and 404 myopic children from 42 schools were randomized as control group. We find that the perceived costs and benefits of eyeglasses use and the perceived timing of wearing eyeglasses at the appropriate time can be learned from a free trial of eyeglasses. Compared with the control group in the long run, 5.6 percentage points more children in treatment group agreed that wearing eyeglasses was attractive, 16.5 percentage points more children agreed that wearing eyeglasses is helpful to academic performance, and 7.9 percentage points more children agreed that children with vision problems should wear eyeglasses. Due to the effects of a free product and the time to learning from experience, the magnitude of the impact of a free trial changed over time. We also find that the indirect experience, such as a vision protection course, cannot change children’ perceptions about the cost or benefits of eyeglasses use. The findings imply that children can learn significantly from the experience of a free trial of eyeglasses. A free trial is an effective strategy to solve the information asymmetry problem for health care. The first pair of eyeglasses of children can be one-off subsidized to trigger demand for eyeglasses use.

Abstract Calf Spleen Extractive Injection (CSEI), extracted from the spleen of healthy cows (within 24 hours of birth), is a small-peptide-enriched extraction and often used as an ancillary agent in cancer therapy. This study evaluated the hematopoietic function of CSEI and its underlying mechanisms, principally in CHRF, K562 cells, BMNCs and a mouse model of cyclophosphamide (CTX)-induced hematopoietic suppression. CSEI promoted the proliferation and differentiation of CHRF and K562 cells, activated hematopoietic- and proliferation-related factors RSK1p90, ELK1 and c-Myc, and facilitated the expression of differentiation- and maturation-related transcription factors GATA-1, GATA-2. In the mice with hematopoietic suppression, 3 weeks of CSEI administration enhanced the bodyweights and thymus indices, suppressed the spleen indices and strongly elevated the production of HSPCs, neutrophils and B cells in bone marrow, ameliorated bone marrow cellularity, and regulated the ratio of peripheral blood cells. Proteome profiling combined with ELISA revealed that CSEI regulated the levels of cytokines, especially G-CSF and its related factors, in the spleen and plasma. Additional data revealed that CSEI promoted phosphorylation of STAT3, which was stimulated by G-CSF in both mice spleen and cultured BMNCs. Taken together, CSEI has the potential to improve hematopoietic function via the G-CSF-mediated JAK2/STAT3 signaling pathway.

The expansion of intercultural interaction between countries and cultures requires the training of modern specialists who know both foreign languages and intercultural communication. However, in the training of translators, there is a lack of authentic material offered by the native speakers of the corresponding language and culture. The purpose of the article is to suggest strategies for teaching the translation of advertising texts and anthroponyms in the Russian-Chinese discourse. The methodological basis of the research is the theory of skopos considering translation as a practical type of activity, as well as a comparative analysis of anthroponyms. As a result of the research, there proposed strategies for translating advertising texts (working with linguistic forms, cultural content, adding and omitting information, combining these strategies) and anthroponyms (using transliteration from Russian into Chinese, it is necessary not only to choose suitable Chinese hieroglyphs but also take into account their meanings, special cases). Comparing Russian and Chinese names, an important difference is found: transliterating Russian names, a person’s gender information can be expressed through Chinese hieroglyphs but this effect cannot be achieved when transliterating Chinese names. Russian-Chinese discourse has a strong cultural connotation, reflecting the unique way of people’s life. The task of the translator is to reproduce not only the formal but also the cultural information of the original text. The novelty of the work is determined by the need to research the Sino-Tibetan language group in order to improve the methodology of teaching translation and intercultural communication as a practical activity.

BACKGROUND: Dihydroartemisinin (DHA), a semi-synthetic derivative of artemisinin, has recently shown antitumor activity in various cancer cells. Apo2 ligand or tumor necrosis factor-related apoptosis-inducing ligand (Apo2L/TRAIL) is regarded as a promising anticancer agent, but chemoresistance affects its efficacy as a treatment strategy. Apoptosis induced by the combination of DHA and Apo2L/TRAIL has not been well documented, and the mechanisms involved remain unclear. METHODOLOGY/PRINCIPAL FINDINGS: Here, we report that DHA enhances the efficacy of Apo2L/TRAIL for the treatment of pancreatic cancer. We found that combined therapy using DHA and Apo2L/TRAIL significantly enhanced apoptosis in BxPC-3 and PANC-1 cells compared with single-agent treatment in vitro. The effect of DHA was mediated through the generation of reactive oxygen species, the induction of death receptor 5 (DR5) and the modulation of apoptosis-related proteins. However, N-acetyl cysteine significantly reduced the enhanced apoptosis observed with the combination of DHA and Apo2L/TRAIL. In addition, knockdown of DR5 by small interfering RNA also significantly reduced the amount of apoptosis induced by DHA and Apo2L/TRAIL. CONCLUSIONS/SIGNIFICANCE: These results suggest that DHA enhances Apo2L/TRAIL-mediated apoptosis in human pancreatic cancer cells through reactive oxygen species-mediated up-regulation of DR5.

This study developed a facile, highly sensitive technique for extracting and quantifying barbiturates in serum samples. This method combined ultrasound and surfactant‐assisted dispersive liquid–liquid microextraction with poly(ethylene oxide)‐mediated stacking in capillary electrophoresis. Factors influencing the extraction and stacking performance, such as the type and volume of extraction solvents, the type and concentration of surfactant, extraction time, salt additives, sample matrix, solution pH, and composition of the background electrolyte, were carefully studied and optimized to achieve the optimal detection sensitivity. Under the optimized extraction (injecting 140 μL C2H4Cl2 into 1 mL of sample with pH 4 (5 mM sodium phosphate containing 0.05 mM Tween 20 and sonication for 1 min) and separation conditions (150 mM tris(hydroxymethyl)aminomethane‐borate with pH 8.5 containing 0.5% (m/v) poly(ethylene oxide)), the limits of detection (signal‐to‐noise ratio = 3) of five barbiturates ranged from 0.20 to 0.33 ng/mL, and the calculated sensitivity improvement ranged from 868‐ to 1700‐fold. The experimental results revealed excellent linearity (R2 > 0.99), with relative standard deviations of 2.1%–3.4% for the migration time and 4.3%–5.7% for the peak area. The recoveries of the spiked serum samples were 97.1% –110.3%. Our proposed approach offers a rapid and practical method for quantifying barbiturates in biological fluids. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the characteristics and contribution of dissolved organic matter (DOM) components released from agricultural waste to water and to control the exogenous input of DOM in the water environment. The EEMs-PARAFAC (three-dimensional fluorescence-parallel factor) method was used to analyse the grass surrounding Anfeng Pond. The extracts of stems, rice straws, and fallen leaves were used to extract DOM in the agricultural waste for analysis. The results showed that three components were separated from the grass stems, rice straws, and leaves, which were C1-type tryptophan, C2 visible-light region (fulvic acid-like), and C3-like humic acid (humic acid-like) components. Among them, the DOM of the leaf leachate mainly contributed the C2 visible light region (fulvic acid-like) components to the water body, and the DOM of the leaching solution of the grass stems and rice straw mainly contributed the C1-like tryptophan and C3-like humic acid components to the water body. Through principal component analysis, the DOM components of the grass stem and rice straw extracts showed similar characteristics; C1 and FI showed a significant (p<0.05) positive correlation, while C2 and C3 showed a very significant (p<0.01) positive correlation with FI and HIX index, respectively. The three components were significantly positively correlated with NO3-N. C3 was significantly positively correlated with NH4+-N. The management measures of agricultural wastes should be strengthened to reduce the transport of DOM produced by agricultural wastes to the water environment way. [ABSTRACT FROM AUTHOR]

Introduction and Objectives: Hepatitis B surface antigen (HBsAg) clearance, indicating functional cure or resolved chronic hepatitis B (CHB), remains difficult to achieve via nucleos(t)ide analogue monotherapy. We investigated whether metformin add-on therapy could help achieve this goal in entecavir-treated patients with hepatitis B e antigen (HBeAg)-negative CHB. Patients and Methods: Patients with HBeAg-negative CHB who met eligibility criteria (entecavir treatment for > 12 months, HBsAg < 1000 IU/mL) were randomly assigned (1:1) to receive 24 weeks of either metformin (1000 mg, oral, once a day) or placebo (oral, once a day) add-on therapy. The group allocation was blinded for both patients and investigators. Efficacy and safety analyses were based on the intention-to-treat set. The primary outcome, serum HBsAg level (IU/mL) at weeks 24 and 36, was analysed using mixed models. Results: Sixty eligible patients were randomly assigned to the metformin (n = 29) and placebo (n = 31) groups. There was no substantial between-group difference in the HBsAg level at week 24 (adjusted mean difference 0.05, 95% confidence interval -0.04 to 0.13, p = 0.278) or week 36 (0.06, -0.03 to 0.15, p = 0.187), and no significant effect of group-by-time interaction on the HBsAg level throughout the trial (p = 0.814). The occurrence of total adverse events between the two groups was comparable (9 [31.0%] of 29 vs. 5 [16.1%] of 31, p = 0.227) and no patient experienced serious adverse events during the study. Conclusion: Although it was safe, metformin add-on therapy did not accelerate HBsAg clearance in entecavirtreated patients with HBeAg-negative CHB. [ABSTRACT FROM AUTHOR]

This work proposed a straightforward synthesis of copper nanoclusters (CuNCs) with an emission wavelength of 496 nm and a quantum yield of 2.2% by directly using pepsin as a template with low toxicity NaBH4 and ascorbic acid as reducing agents. The chemical composition and optical properties of the pepsin‐stabilized CuNCs (pepsin‐CuNCs) were well‐characterized by spectroscopy‐related techniques. The pepsin‐CuNCs retained the fluorescence intensity at neutral pH, at 37°C, and in high salinity, proving their suitability in biological systems. Although the pepsin‐CuNCs remained only half of the initial fluorescence intensity after 24 days due to air oxidation, their storage stability was comparable to that of CuNCs reported in the literature. Given that the absorption peaks of hemoglobin overlap the excitation and emission wavelengths of pepsin‐CuNCs, this feature allowed pepsin‐CuNCs to serve as a luminescence turn‐off sensor for sensing hemoglobin through the inner‐filter effect process. The pepsin‐CuNC probe provided a fast (within 1 min) platform for hemoglobin detection with a dynamic quantitative range of 0.1–10 μM and a detection limit of 70 nM. Importantly, the proposed probe was well‐suited to detect hemoglobin in nearly undiluted human urine, demonstrating its great potential for the clinical diagnosis of trace hemoglobin in urine. [ABSTRACT FROM AUTHOR]

We developed a triple-readout probe for colorimetric, fluorescent, and fluorescence-lifetime sensing of alkaline phosphatase (ALP) through the hydrolyzed ascorbic acid phosphate (AAP)–mediated formation of silver nanoparticles (AgNPs) on Ag+-deposited MoS2 quantum dots (QDs). Ag+ ions were self-assembled on a monolayer MoS2 QD surface through the formation of Ag–S bonds. When ALP hydrolyzed AAP in an alkaline buffer, the resultant ascorbic acid (AA) triggered the reduction of the bound Ag+ ions into AgNPs on the MoS2 QD surface. The resultant AgNPs induced an efficient fluorescence quenching of the MoS2 QDs through simultaneous static and dynamic quenching processes, generated an intense surface plasmon resonance peak, and triggered a reduction in the fluorescence lifetime of the MoS2 QDs. Electron microscopy and spectroscopic techniques revealed the successful fabrication of Ag+-deposited MoS2 QDs and the ALP-mediated formation of AgNPs on the MoS2 QD surface. The linear quantification ranges for ALP were 0.05–2.5, 0.1–4, and 1–4 units L−1 in the fluorescent, colorimetric, and fluorescence-lifetime detection modes, respectively. In addition, the proposed probe integrated with an ALP-linked sandwich immunoassay exhibited high sensitivity and selectivity for the fluorescence sensing of rabbit immunoglobulin G with a detection limit of 8 pg mL−1 and linear range of 25–1000 pg mL−1. The sensitivity of the probe is comparable to those of previously reported immunoassays involving ultrasensitive electrochemical detection, hydrogen evolution reactions, or electron spin resonance. The probe integrated with the sandwich assay serves as a promising platform for the detection of target proteins in clinical samples. [ABSTRACT FROM AUTHOR]

The multiquantum well infrared photodetector's performance is studied theoretically. The current response is calculated first and dark current is determined as a function of bias voltage and temperature within the sequential tunneling approach. The noise characteristics of such detectors are also discussed in detail with the consideration of the background radiation.

Pesticides are a family of non-biodegradable chemical compounds which widely used in agriculture to control pests and increase yield production. However, overuse or abuse of pesticides and their metabolites may cause potential toxicity for the environment as well as human health and all other living organisms, even at deficient concentrations. Consequently, the development of sensors for monitoring these compounds is significant. Recently, nanoparticles-based sensors have been extensively employed as a potential alternative or complementary analytical tool to conventional detection methods for pesticides. Among them, gold nanoparticles (AuNPs) owing to their unique optical properties have been developed as smart sensors with high selectivity, sensitivity, simplicity, and portability. These comprehensive reviews have summarized various studies performed based on different detection strategies, i.e., colorimetric, fluorescence, surface-enhanced Raman scattering, and electrochemical, using AuNPs as sensing probes for pesticide analysis in various matrices. Additionally, the current challenges and future trends for developing novel AuNPs-based sensors for the detection of pesticides are also discussed. [ABSTRACT FROM AUTHOR]

A rapid, simple, and sensitive technique for the quantitative detection of fluoxetine and norfluoxetine enantiomers in biological fluids was developed based on the combination of field-amplified sample stacking (FASS)–related capillary electrophoresis (CE) with ultrasound-assisted dispersive liquid–liquid microextraction (UA-DLLME). The extraction efficiency of UA-DLLME was strongly related to extraction time, salt concentration, type of extraction and dispersion solvents, and volume of extraction and dispersion solvents. The extracted fluoxetine and norfluoxetine enantiomers in a mixture of 50% methanol and 50% deionized water were efficiently stacked using FASS and then separated using cyclodextrin-modified CE. Under optimal conditions of FASS (chiral selector, 3 mM trimethyl-β-cyclodextrin; and background electrolyte, 100 mM phosphate buffer) and UA-DLLME (extraction solvent, 200 μL of acetone; and dispersed solvent, 50 μL of C2H2Cl4 in 1 mL of the sample solution), the obtained enrichment factors of fluoxetine and norfluoxetine enantiomers reached approximately 2000. The linear ranges for the quantification of fluoxetine and norfluoxetine enantiomers were 0.3–150 and 0.6–150 nM, respectively. The relative standard deviations in peak areas and migration time for four analytes were less than 3.3% and 6.3%, respectively. The proposed system provided limits of detection (signal-to-noise ratio of 3) for four analytes corresponding to 0.1 nM. The precision and accuracy for urine and serum samples were less than 6.8 and 8.3%, respectively. These findings suggested that the proposed system exhibited a high potential for the reliable determination of fluoxetine and norfluoxetine enantiomers in clinical samples. [ABSTRACT FROM AUTHOR]

Elastic quantum ballistic electron transport from source to drain through a conducting channel explains the observed transconductance oscillations for upper and lower gate voltages in dual-gate Si transistors. Solutions to the three-dimensional Poisson and Schrodinger equations provide the geometry of conducting channel. They also negate the possibility of quantum dot formation in dual-gate Si transistors. The decrease in the oscillation period in the conductance as functions of the lower gate bias corresponds to decrease in the upper gate bias.

The validity of an eight-band k·p method with the axial approximation for modeling the band structures and optical properties of type-II interband cascade lasers is assessed by comparing its results with those from the standard eight-band k·p method. Explicit expressions for anisotropic k·p interaction terms, which are neglected by the axial approximation, are obtained. Then the band structures and optical properties of practical type-II interband cascade lasers are calculated using both eight-band k·p methods and the numerical results are discussed in detail. It is found that the axial approximation may be problematical for the simulation of type-II interband cascade lasers. [ABSTRACT FROM AUTHOR]

This study developed a sensitive method involving capillary electrophoresis (CE) coupled with ultraviolet absorption for the simultaneous separation of chiral phenothiazine drugs at nanomolar concentration levels. The method consists of hydroxypropyl-γ-cyclodextrin (Hp-γ-CD) as a chiral selector and poly (diallyldimethylammonium chloride) (PDDAC)-based CE. Five pairs of d,l-phenothiazines were baseline separated using a background electrolyte containing 0.9% PDDAC, 5 mM Hp-γ-CD, and 100 mM tris(hydroxymethyl)aminomethane (Tris)-formate (pH 3.0). The five pairs were successfully stacked on the basis of the difference in viscosity between the PDDAC-containing background electrolyte and the sample solution, with almost no loss of resolution. The combination of a solid-phase extraction and PDDAC-mediated CE can efficiently improve the sensitivity of the phenothiazine enantiomers. Under optimal conditions, calibration graphs displayed the linear range between 6 and 1500 nM, with relative standard deviation values lower than 3.5% (n = 5). Detection limit ranged from 2.1 to 6.3 nM for target analytes, and 607- to 1555-fold enhancement was achieved. The practicality of using the proposed method to determine five pairs of d,l-phenothiazines in urine is also validated, in which recoveries between recoveries of all phenothiazines from urine ranged from 89% to 101%. [ABSTRACT FROM AUTHOR]

Integrated modular avionics (IMA) architecture is widely adopted for the design of modern aircraft. It simplifies the system development process and improves the system security and reliability. In IMA systems, avionics applications are packed into various partitions and integrated into a standard computing platform. How to determine the schedulability of systems is one of the key problems. In this paper, using the characters of avionics systems, a partition model with a strict period is built and constraints in space, time, and communication are analyzed. Based on the mixed integer linear programming formulation, a solution to determine the schedulability of IMA systems is presented. Experience reveals that this solution not only determines the system schedulability, but also achieves the required minimum number of modules and guides the design of IMA systems. [ABSTRACT FROM AUTHOR]