[Occurrence Characteristics of Microplastics in Multi-environmental Media and Bellamya aeruginosa of Manao River].

Microplastic pollution poses threats to aquatic ecosystems and human health. In this study, in order to investigate the characteristics of microplastic occurrence in different environmental media, the abundance, particle size, shape, color, and composition types of microplastics in the water column, sediment, riparian zone soil, and the benthic snail Bellamya aeruginosa of the Manao River were analyzed using field sampling, microscopic observation, and Fourier infrared spectroscopy. The results showed that the average abundance of microplastics in the surface water of the Manao River was (5.9±0.26) n·L-1; the abundance of microplastics in the upper sediment (by dry weight) was (1.35±0.1) n·g-1, and that in the lower sediment (by dry weight) was (0.93±0.12) n·g-1. The abundance of microplastics in the near riparian zone soil (by dry weight) was (0.68±0.16) n·g-1, and that in the far riparian zone soil (by dry weight) was (0.69±0.14) n·g-1, and the abundance of microplastics in the B. aeruginosa was (2.06±0.25) n·g-1. The analysis results showed that the abundance of microplastics in the upper and lower sediments were positively correlated; the abundance of microplastics in B. aeruginosa was positively correlated with the abundance of microplastics in the upper and lower sediments, respectively; and the abundance of microplastics in the near and far riparian zone soils were also correlated. Most of the microplastics within each environmental medium and B. aeruginosa were <0.1 mm in size, mainly in the form of fibers and fragments, mainly blue and black in color, and mainly composed of polypropylene (PP) and polyethylene (PE). It was found that microplastics in riparian zone soils mainly originated from the fragmentation and decomposition of agricultural plastic films. The results of this study shed light on the accumulation of microplastics in macrobenthic organisms through the investigation of microplastics in multi-environmental media and in the B. aeruginosa, which helps us to understand the potential ecological risk of microplastics in a comprehensive manner.

[Assessment of Microplastic Pollution and Estimation of Annual Emission Volume in the Dongshan Canal of Yichang City].

Microplastics, as an emerging pollutant, have garnered global attention. Urban areas are key hotspots for the generation of microplastic pollution, whereas urban water bodies act as vital conduits for the dissemination of microplastics to other freshwater environments. In this study, the Dongshan Canal in the urban area of Yichang City was selected as the research subject. Through field sampling, microscopic observation, and Fourier infrared spectroscopy analysis conducted in July and October 2022, the occurrence characteristics and potential pollution sources of microplastics in the water body of the Dongshan Canal were identified and analyzed. The ecological risk and annual emission volume of microplastics in the water body were quantitatively assessed using the risk index (H), pollution load index (PLI) model, and proportional flow method. The results indicated that the average abundances of microplastics in the surface water of the Dongshan Canal were (7 295±1 051) n·m-3 (July) and (5 145±762.6) n·m-3 (October). Fibrous microplastics (27.63%-63.23%), microplastics with a size of <0.5 mm (75.68%-96.2%), and colored microplastics (22.73%-61.83%) dominated the samples, with PE (30.1%) and PET (26.33%) being the predominant materials. The assessment results from the two models classified the ecological risk index of the Dongshan Canal as class Ⅲ, whereas the overall pollution load fell into class I, with certain sampling points reaching class Ⅱ. Estimates revealed that the Dongshan Canal transports approximately 3.37 t of microplastics to the Yangtze River annually. Overall, the microplastic pollution level in the Dongshan Canal of Yichang City could be considered moderate, with potential sources of pollution including laundry wastewater, personal care products, and plastic waste.

Structurally diverse terpenoids from Elephantopus scaber L. and their acetylcholinesterase inhibitory activities.

Three undescribed compounds elephantopuscabers A-C, along with one previously reported compound spirowallichiione, were isolated from Elephantopus scaber L. Their structures were determined via extensive NMR spectroscopic analysis, quantum chemical calculations, and single-crystal X-ray diffraction crystallography. A plausible biosynthetic pathway for spirowallichiione was proposed. All the isolated compounds were tested for their acetylcholinesterase inhibitory activities. Among them, elephantopuscaber B and C displayed promising inhibitory activities against AChE, and the binding sites were predicted by molecular docking.

Integration of cross-scale milli/microlenses by ion beam etching and femtosecond laser modification.

Integrated cross-scale milli/microlenses offer irreplaceable functions in modern integrated optics with the advantage of reducing the size of the optical system to millimeters or microns. However, the technologies for fabricating millimeter-scale lenses and microlenses are always incompatible, which makes the successful fabrication of cross-scale milli/microlenses with a controlled morphology challenging. Here, ion beam etching is proposed as a means to fabricate smooth millimeter-scale lenses on various hard materials. In addition, by combining femtosecond laser modification and ion beam etching, an integrated cross-scale concave milli/microlens (27,000 microlenses on a lens with a diameter of 2.5 mm) is demonstrated on fused silica, and can be used as the template for a compound eye. The results provide a new, to the best of our knowledge, route for the flexible fabrication of cross-scale optical components for modern integrated optical systems.

Causal relationship between insulin resistance and sarcopenia.

Sarcopenia is a multifactorial disease characterized by reduced muscle mass and function, leading to disability, death, and other diseases. Recently, the prevalence of sarcopenia increased considerably, posing a serious threat to health worldwide. However, no clear international consensus has been reached regarding the etiology of sarcopenia. Several studies have shown that insulin resistance may be an important mechanism in the pathogenesis of induced muscle attenuation and that, conversely, sarcopenia can lead to insulin resistance. However, the causal relationship between the two is not clear. In this paper, the pathogenesis of sarcopenia is analyzed, the possible intrinsic causal relationship between sarcopenia and insulin resistance examined, and research progress expounded to provide a basis for the clinical diagnosis, treatment, and study of the mechanism of sarcopenia.

Catalyst-Controlled Nickel-Catalyzed Intramolecular endo-Selective C-H Cyclization of Benzimidazoles with Alkenes.

Compared with the widely explored exo-selective C-H cyclization, transition metal-catalyzed endo-selective C-H cyclization of benzimidazoles with alkenes has been a formidable challenge. Previous efforts mainly rely on substrate-controlled methods, rendering the product complexity restricted. Herein we report a catalyst-controlled method to facilitate endo-cyclization, in which a bulky N-heterocyclic carbene ligand and tBuOK base-enabled Ni-Al bimetallic catalyst prove critical to the endo selectivity.

[Distribution Characteristics of Microplastics and Their Migration Patterns in Xiangxi River Basin].

Microplastics as a prevalent pollutant in water bodies have recently attracted widespread attention. To investigate the spatial and temporal distribution characteristics of microplastics in freshwater rivers and their migration patterns, the surface water, sediments, and subsidence zone of the Xiangxi River, a tributary of the Yangtze River, were sampled and analyzed in November 2020 and April 2021, respectively. The results showed that the average abundance of microplastics in the surface water of Xiangxi River was (6.64±1.32) n·L-1 in flat water and (5.00±1.07) n·L-1 in dry water, the average abundance of microplastics in sediments was (0.56±0.13) n·g-1 in flat water and (0.41±0.09) n·g-1 in dry water, and the average abundance of microplastics in the subsidence zone was (0.53±0.15) n·g-1 in flat water and (0.68±0.18) n·g-1in dry water. There were significant differences in the abundance distribution of microplastics in the surface water, sediments, and subsidence zone (P<0.05). In the surface water and sediments, the particle size of microplastics was mainly distributed in the range of 0.1-0.5 mm, and in the subsidence zone, it mainly ranged from 1-5 mm. The color of microplastics was mainly transparent in the surface water and subsidence zone and blue in sediments. The morphology of microplastics in the Xiangxi River basin was mainly fiber, and the materials were mainly polyethylene (PE) and polypropylene (PP). There were many factors affecting the distribution of microplastics. The analysis results showed that the abundance of microplastics in the surface water was negatively correlated with the flow rate of the water body. The abundance of microplastics in the sediment was related to the substrate type of the riverbed and negatively correlated with the substrate particle size. Combined with the microplastic abundance data of each sampling site, it was found that there was a significant migration process of microplastics in the spatial distribution of the Xiangxi River in the watershed. Along the river longitudinal direction, the longitudinal migration of microplastics in the surface water was along the river direction, and in the vertical direction, it showed the mutual migration between the water body and the subsidence zone and the water body and sediments.

Mass drug administration in response to vivax malaria resurgence in Anhui Province of Huanghuai Plain, China.

This article summarizes the background, specific conditions, main measures, steps and effects of the implementation of Mass Drug Administration (MDA) to control the local P. vivax malaria epidemic in Anhui Province in central China. Distributing medicines to the designated population quickly controlled the local epidemic of P. vivax. Implementing MDA to control P. vivax ensured the correct selection of medicines, clarification of the targeted population for receipt of medicines, and assurance of a high rate of compliance through government support and health education. These results provide a reference for countries and regions experiencing similar events and planning to implement MDA in malaria control.

Expert Recommendations for Prevention, Treatment and Care of Oral Ulcers and Other Mucosal Diseases during the Coronavirus Outbreak.

In December 2019, some new and unexplained cases of pneumonia were found in Wuhan, Hubei province, China, and were later named as coronavirus disease 2019 by the World Health Organisation. The number of cases increased rapidly, and the virus spread continuously. Tens of thousands of medical staff throughout the country have since rushed to Wuhan to provide intensive medical treatment. Due to high levels of stress and work intensity, insufficient sleep and a lack of access to water after entering the isolation ward, staff may suffer from oral mucosal ulcers and other oral mucosal diseases. Police officers, community workers, family members in quarantine and even patients with mild coronavirus 2019, as well as those who have previously had oral mucosal disease, have also reported experiencing discomfort as a result of stress-induced oral mucosal disorders, such as recurrent aphthous ulcers, chronic cheilitis and oral lichen planus. This article will offer some suggestions for the prevention, treatment and care of the above-mentioned oral mucosal diseases during the fight against coronavirus 2019, focusing on measures to deal with the oral mucosal damage caused in response to stress.

Asymmetric synthesis of l-phosphinothricin using thermostable alpha-transaminase mined from Citrobacter koseri.

α-Transaminase (α-TA) responsible for catalyzing the reversible transfer of amino groups between amine donors and amine acceptors, is applicable to enzymatic route for asymmetric synthesis of herbicide l-phosphinothricin (l-PPT). In the search for α-TAs with better catalysis performance, three α-TAs were discovered by genome mining approach using a known sequence encoding Escherichia coli tyrosine TA (TyrB) as probe. Through detailed comparison of their expression amount, activities and characteristics, Citrobacter koseri TA (CkTA) exhibited better activity and thermostability, which retain 65.9% of initial activity after incubation at 57 °C for 4 h. The Km and kcat/Km values of CkTA were 36.75 mM and 34.29 mM-1 min-1, respectively. In addition, recombinant CkTA cells were immobilized onto Celite 545 using tris(hydroxymethyl)phosphine as crosslinker. During five repetitive asymmetric synthesis of l-PPT from 20 g/L prostereogenic ketone using l-Glu as amine donor, all the yields of l-PPT reached up to 91.2% (＞99% ee). These characteristics made CkTA a valuable addition to the currently scarce α-TA library for stereospecific synthesis of l-PPT.

Hepatitis B Virus X Protein Upregulates Intracellular Calcium Signaling by Binding C-terminal of Orail Protein.

Hepatitis B virus X (HBx) protein plays a pivotal role in the development of hepatitis B virus (HBV)-associated hepatocellular carcinoma. Although regulation of cytosolic calcium is essential for HBV replication and is mediated by HBx protein, the mechanism of HBx protein regulating intracellular calcium level remains poorly understood. The present study examined whether HBx protein elevated the intracellular calcium through interacting with storeoperated calcium entry (SOCE) components, Orail and stromal interaction molecule 1, and then identified the targets of HBx protein, with an attempt to understand the mechanism of HBx protein upsetting intracellular calcium homeostasis. By employing co-immunoprecipitation and GST-pull-down assay, we found that Orail protein interacted with HBx protein, and the C-terminus of Orail was implicated in the interaction. Confocal microscopy also revealed that HBx protein could co-localize with full-length Orail protein in HEK293 cells. Moreover, live cell calcium imaging exhibited that HBx protein elevated intracellular calcium, possibly by binding to SOCE components. Our results suggest that HBx protein binds to STIM1-Orail complexes to positively regulate the activity of plasma membrane store-operated calcium channels.

Whole cell immobilization of refractory glucose isomerase using tris(hydroxymethyl)phosphine as crosslinker for preparation of high fructose corn syrup at elevated temperature.

Glucose isomerase (GI) responsible for catalyzing the isomerization from d-glucose to d-fructose, was an important enzyme for producing high fructose corn syrup (HFCS). In a quest to prepare HFCS at elevated temperature and facilitate enzymatic recovery, an effective procedure for whole cell immobilization of refractory Thermus oshimai glucose isomerase (ToGI) onto Celite 545 using tris(hydroxymethyl)phosphine (THP) as crosslinker was established. The immobilized biocatalyst showed an activity of approximate 127.3 U/(g·immobilized product) via optimization in terms of cells loading, crosslinker concentration and crosslinking time. The pH optimum of the immobilized biocatalyst was displaced from pH 8.0 of native enzyme to neutral pH 7.0. Compared with conventional glutaraldehyde (GLU)-immobilized cells, it possessed the enhanced thermostability with 70.1% residual activity retaining after incubation at 90°C for 72 h. Moreover, the THP-immobilized biocatalyst exhibited superior operational stability, in which it retained 85.8% of initial activity after 15 batches of bioconversion at 85°C. This study paved a way for reducing catalysis cost for upscale preparation of HFCS with higher d-fructose concentration.

Lipoxin A4 Activates Nrf2 Pathway and Ameliorates Cell Damage in Cultured Cortical Astrocytes Exposed to Oxygen-Glucose Deprivation/Reperfusion Insults.

Lipoxin A4 (LXA4), a potent antioxidant and anti-inflammation mediator, protects brains against cerebral ischemia/reperfusion (I/R) injury in vivo. However, few reports concern its function on astrocytes during cerebral I/R injury. The pathogenesis of cerebral I/R injury involves oxidative stress caused by reactive oxygen species (ROS). Upregulation of nuclear factor erythroid 2-related factor 2 (Nrf2) is generally considered to reduce oxidative stress. Nrf2 can induce heme oxygenase-1 (HO-1) expression and glutathione (GSH) release to combat increased oxidative stress. We investigated the effects of LXA4 on astrocytic cell damage, the production of ROS, and Nrf2 pathway, especially on HO-1 expression and GSH release in cultured cortical astrocytes exposed to oxygen-glucose deprivation (OGD)/recovery (OGDR) insults. Primary astrocytes were subjected to a 4-h OGD, followed by 8-h recovery. Cell viability, the production of ROS, and GSH release were measured. Furthermore, Nrf2, HO-1, and p62 expression levels were determined by Western blot. Moreover, Nrf2 location was studied by immunofluorescence staining. Treatment of LXA4 attenuates OGDR-induced cell damage and the production of ROS in a concentration-related manner. LXA4 induced Nrf2 expression and its nuclear translocation, as well as HO-1 expression and GSH release. Moreover, LXA4 induced the excess p62 accumulation. These results indicate that LXA4 can effectively protect against OGDR-induced cell damage in astrocytes, and activation of Nrf2 pathway to reduce oxidative stress may be involved in its protective effects. p62 accumulation induced by LXA4 may be closely related to Nrf2 activation.

Lipoxin A4 ameliorates cerebral ischaemia/reperfusion injury through upregulation of nuclear factor erythroid 2-related factor 2.

OBJECTIVES: Lipoxin A4 (LXA4) is a potent anti-inflammatory mediator that exerts a neuroprotective effect following cerebral ischaemia/reperfusion (I/R) injury. However, little is known about the underlying mechanisms. Upregulation of nuclear factor erythroid 2-related factor 2 (Nrf2) is generally considered to reduce cerebral I/R injury. Nuclear factor erythroid 2-related factor 2 can induce haeme oxygenase-1 (HO-1) and glutathione (GSH) expression to combat increased oxidative stress. The present study aimed to investigate the effects of Nrf2 signalling on LXA4-mediated neuroprotection. METHODS: Adult male Sprague Dawley rats were subjected to 2-hour middle cerebral artery occlusion followed by 24-hour reperfusion. Rats were randomly divided into four groups: Sham, I/R, LXA4, and LXA4+butoxycarbonyl-Phe-Leu-Phe-Leu-Phe (Boc2) (all n = 24). Brain infarction was detected by 2,3,5-triphenyltetrazolium chloride staining. After 24 hours of reperfusion, Nrf2, HO-1, and p62 expression levels were determined by western blot, and GSH synthesis was assessed. RESULTS: Lipoxin A4 effectively reduced infarct volumes and improved neurological scores. These effects were partially blocked by Boc2, a specific antagonist of the LXA4 receptor (ALXR). Lipoxin A4 induced Nrf2 expression and its nuclear translocation, as well as HO-1 expression and GSH synthesis; Boc2 did not block these effects. The excess p62 accumulation induced by LXA4 might be closely related to Nrf2 activation. DISCUSSION: Overall, our data suggest that Nrf2 upregulation is involved in the neuroprotective effects of LXA4 and may be ALXR independent.