Headwater streams contain amounts of heavy metal in an alpine forest in the upper reaches of the Yangtze River

Headwater streams are an essential link in the source and sink dynamics of heavy metals between terrestrial and aquatic ecosystems and are also critically important for downstream ecosystem processes and water quality. However, there is little available information about headwater streams. Therefore, the stream storage and distribution patterns of Cd, Pb, Ni, Cr, Cu, Mn and Zn were investigated in ten headwater streams of an Alpine forest located in the upper Yangtze River during the rainy season. The results indicated that the heavy metal storage per unit area of the investigated streams was as follows: 0.95 mg·m-2 for Cd, 8.36 mg m-2 for Pb, 1.98 mg m-2 for Ni, 136.98 mg m-2 for Cr, 9.29 mg m-2 for Cu, 433.39 mg m-2 for Mn and 29.07 mg m-2 for Zn; while the heavy metal storage per unit area of the catchment was as follows: 1.19 mg hm-2 for Cd, 10.47 mg hm-2 for Pb, 2.48 mg hm-2 for Ni, 171.62 mg hm-2 for Cr, 11.64 mg hm-2 for Cu, 542.99 mg hm-2 for Mn and 36.42 mg hm-2 for Zn. Headwater streams present remarkable potential for contamination, and plant debris from riparian forests may be the most important source of heavy metals, while the stream sediment acts as a significant sink for heavy metals. These results provide new perspectives and data for understanding the ecological links between alpine forests and watersheds

Construction of PAN-based activated carbon nanofibers for hydrogen storage under ambient pressure

Adsorption agents are an important class of solid hydrogen storage materials. Attributed to their high specific surface area and adjustable nanopore structure, activated carbon nanofibers have attracted extensive attention in the application of solid hydrogen storage. The research in this field mostly focuses on applications with a hydrogen pressure condition of 30 to 300 bar, while there have been few systematic studies on the hydrogen storage performance of these materials under ambient pressure. In this study, polyacrylonitrile-based activated carbon nanofibers were constructed by electrospinning technology and ultrasonic-assisted activation technology for the application of atmospheric hydrogen storage. Their nanopore structure was revealed to be mainly composed of micropores, and the relative contents of micropore volume and ultramicropore volume were 77.92% to 88.3% and 22.34% to 24.68%, respectively. Attributed to the synergy of rich microporous structure and surface chemical structure, the atmospheric hydrogen storage density of activated carbon nanofibers could reach 2.64 wt% at 77 K and 1 bar. After the optimization analysis of adsorption isotherm models, the Multisite-Langmuir model was found as more suitable for accurately describing the atmospheric hydrogen adsorption process of activated carbon nanofibers.Cited as: Yu, J., Lin, T., Li, J., Zhang, W., Bao, W., Zhu, B. Construction of PAN-based activated carbon nanofibers for hydrogen storage under ambient pressure. Capillarity, 2023, 6(3): 49-56. https://doi.org/10.46690/capi.2023.03.0

In-situ secondary growth of nanocube-based Prussian-blue film as an ultrasensitive biosensor

A regular nanostructure has been widely confirmed to result ina marked improvement in material performance in biosensing applications. In the present study, a regular nanostructured Prussian blue (PB) film with two heterogeneous crystal layers was synthesized in-situ using a secondary growth method. A PB seed layer was first controlled to form uniform cube-like crystal nuclei through an ultrasonic reaction with a single reactant. Then, well-defined 100 nm PB nanocubes were further crystallized on this seed layer using a self-assembly approach. In order to accelerate the electron transfer rate during the enzyme reaction for glucose detection, the graphene was used as the main cross-linker to immobilize glucose oxidase on the PB film. The as-prepared biosensor exhibited high electrocatalysis and electron conductivity for the detection of trace glucose with a sensitivity of 141.5 µA mM-1 cm-2, as well as excellent anti-interference ability in the presence of ascorbic acid and uric acid under a low operation potential of -0.05 V

The efficacy and prognosis analysis after stereotactic body radiotherapy for multiple primary early-stage lung cancer

Background and purpose: More and more patients with multiple primary early-stage lung cancer are choosing to receive stereotactic body radiation therapy (SBRT), and this study aimed to retrospectively analyze the efficacy and prognostic factors of SBRT. Methods: In this study, patients who underwent SBRT at Shanghai Chest Hospital, Shanghai Jiao Tong University School of Medicine from August 2014 to December 2020 and who met the inclusion criteria were included. Patients with multiple primary early-stage lung cancer were examined for efficacy and prognostic factors. After using propensity score matching (PSM), the difference in efficacy of SBRT between single and multiple primary early-stage lung cancer was observed. Results: This study included 241 early-stage lung cancer patients with SBRT, including 94 patients with multiple primary early-stage lung cancer. The 3- and 5-year local control rate (LC), progression-free survival (PFS) and overall survival (OS) were 87.1% and 71.3%, 84.0% and 66.9%, 93.3% and 79.3% in multiple primary early-stage lung cancer, respectively. Patients with multiple primary early-stage lung cancer did not experience any grade 3 or higher pulmonary toxicity with an overall toxicity incidence of 54.3%, and grade 2 toxicity occurred in 24 patients (25.5%). There was a total of 18 (19.1%) recurrences, and there were 3 (3.2%), 1 (1.1%), 12 (12.7%) and 2 (2.1%) patients with multiple primary early-stage lung cancers who experienced local recurrence, regional recurrence, distant metastasis and uncertain death, respectively. Patients with multiple primary early-stage lung cancer and those with single primary early-stage lung cancer had significant differences in clinical features prior to PSM. After PSM, there were 56 patients with multiple primary early-stage lung cancer and 56 patients with single primary early-stage lung cancer, and there was no statistically significant difference in LC (P = 0.291), PFS (P = 0.954) and OS (P = 0.880). Age≥70 years was an independent risk factor for OS of multiple primary early-stage lung cancer, according to an analysis of the prognostic variables of SBRT in 94 patients with multiple primary early-stage lung cancer. Regarding synchronous (≤180 d) and metachronous (>180 d) multiple primary early-stage lung cancer, there was no discernible difference between the two groups (P = 0.440). There was no significant difference in the total number of treatments for multiple primary early-stage lung cancer (P = 0.232) and no significant difference in the type of treatment for multiple primary early-stage lung cancer (P = 0.225) among 59 patients with synchronous multiple primary early-stage lung cancer within 5 years of the first-to-last treatment interval. Conclusion: SBRT has a strong and comparable efficacy for multiple primary early-stage lung cancer compared with single primary early-stage lung cancer, making it a viable treatment choice. Based on age and tumor biological behavior of the lesion, future strategies and procedures for local intervention of multiple primary early-stage lung cancer need to be investigated

Genomic monitoring of SARS-CoV-2 uncovers an Nsp1 deletion variant that modulates type I interferon response

The SARS-CoV-2 virus, the causative agent of COVID-19, is undergoing constant mutation. Here, we utilized an integrative approach combining epidemiology, virus genome sequencing, clinical phenotyping, and experimental validation to locate mutations of clinical importance. We identified 35 recurrent variants, some of which are associated with clinical phenotypes related to severity. One variant, containing a deletion in the Nsp1-coding region (D500-532), was found in more than 20% of our sequenced samples and associates with higher RT-PCR cycle thresholds and lower serum IFN-beta levels of infected patients. Deletion variants in this locus were found in 37 countries worldwide, and viruses isolated from clinical samples or engineered by reverse genetics with related deletions in Nsp1 also induce lower IFN-beta responses in infected Calu-3 cells. Taken together, our virologic surveillance characterizes recurrent genetic diversity and identified mutations in Nsp1 of biological and clinical importance, which collectively may aid molecular diagnostics and drug design.Peer reviewe

Climate, plant organs and species control dissolved nitrogen and phosphorus in fresh litter in a subalpine forest on the eastern Tibetan Plateau

International audienceAbstractKey messageFresh litter contains a higher concentration of dissolved phosphorus (DP) than dissolved nitrogen (DN), which implies a more efficient DN transformation or reabsorption in the subalpine forest on the eastern Tibetan Plateau. Both DN and DP concentrations increased with the increase of mean monthly temperature, although the concentrations were also regulated by plant organs and species.ContextThe dissolved nitrogen (DN) and dissolved phosphorus (DP) released from fresh litter are important pathways by which total nitrogen and phosphorus are transferred from the vegetation to soil in forest ecosystems. However, few studies have paid attention to the DN and DP in fresh litter, which affects our understanding of the nitrogen and phosphorus cycles.AimsThe objectives of this study were to elucidate the dynamic characteristics of the concentrations and storage of DN and DP, and to analyze how DN and DP are affected by different plant species and organs, and climate factors.MethodsFresh litter was collected in three plots in a spruce-fir forest and classified by different plant species and organs. Concentration and storage of DN and DP in fresh litter were determined and related to the climatic variables that were monthly recorded.ResultsThe concentration of DP was higher than that of DN in fresh litter, and the concentrations of both elements were determined by plant organs and species. Moreover, The DN and DP concentration was positively related to mean monthly temperature, while DN and DP storage was negatively correlated with mean monthly temperature and monthly precipitation. The storage of DN and DP was determined by litter biomass, which the order in litter from different plant organs was leaves>twigs>miscellaneous>flowers and fruits. The storage of DN and DP in leaves showed two peaks in April and October, but that in twigs and the miscellaneous showed only one peak in October.ConclusionOur results indicated that dissolved nitrogen (DN) is transferred and reabsorbed more than dissolved phosphorus (DP) before plant leaf senescence and other organs fall. Furthermore, DN and DP were associated with climate, plant organs and species in a subalpine forest on the eastern Tibetan Plateau

The waaL gene mutation compromised the inhabitation of Enterobacter sp. Ag1 in the mosquito gut environment

Abstract Background The mosquito gut harbors a variety of bacteria that are dynamically associated with mosquitoes in various contexts. However, little is known about bacterial factors that affect bacterial inhabitation in the gut microbial community. Enterobacter sp. Ag1 is a predominant Gram negative bacterium in the mosquito midgut. Methods In a mutant library that was generated using transposon Tn5-mediated mutagenesis, a mutant was identified, in which the gene waaL was disrupted by the Tn5 insertion. The waaL encodes O antigen ligase, which is required for the attachment of O antigen to the outer core oligosaccharide of the lipopolysaccharide (LPS). Results The waaL − mutation caused the O antigen repeat missing in the LPS. The normal LPS structure was restored when the mutant was complemented with a plasmid containing waaL gene. The waaL − mutation did not affect bacterial proliferation in LB culture, the mutant cells grew at a rate the same as the wildtype (wt) cells. However, when waaL − strain were co-cultured with the wt strain or complemented strain, the mutant cells proliferated with a slower rate, indicating that the mutants were less competitive than wt cells in a community setting. Similarly, in a co-feeding assay, when fluorescently tagged wt strain and waaL − strain were orally co-introduced into the gut of Anopheles stephensi mosquitoes, the mutant cells were less prevalent in both sugar-fed and blood-fed guts. The data suggest that the mutation compromised the bacterial inhabitation in the gut community. Besides, the mutant was more sensitive to oxidative stress, demonstrated by lower survival rate upon exposure to 20 mM H2O2. Conclusion Lack of the O antigen structure in LPS of Enterobacter compromised the effective growth in co-culture and co-feeding assays. In addition, O-antigen was involved in protection against oxidative stress. The findings suggest that intact LPS is crucial for the bacteria to steadily stay in the gut microbial community

Incidence of Perimenopausal Syndrome in Chinese Women Aged 40 to 65 Years: a Meta-analysis

Background With the rapid development of economy and society in China, the living standards and health care awareness have been improved significantly, the average life expectancy of our population is gradually prolonged, causing increasing population of perimenopausal women, therefore, the health management of perimenopausal women has become more important. Perimenopausal syndrome can be seen in women aged 40-65 years, which can seriously affect the physical and mental health and quality of life of patients. Objective To systematically review the incidence of perimenopausal syndrome in Chinese women aged 40-65 years. Methods PubMed, Embase, Web of Science, CNKI, Wanfang Data, CBM and VIP were searched by computer to collect cross-sectional studies on the occurrence of perimenopausal syndrome in Chinese women aged 40-65 years from inception to February 1, 2023. Two investigators independently screened the literature, extracted data and evaluated the quality of included literature. Meta-analysis was performed using Stata 17.0 software. Results A total of 62 cross-sectional studies were included, with a total sample size of 82 340 cases. Meta-analysis showed that the incidence of perimenopausal syndrome in Chinese women aged 40-65 years was 61.0%. The results of subgroup analysis showed that the incidence of perimenopausal syndrome in women aged 40-45 years, >45-50 years, >50-55 years, >55-60 years and >60 years was 42.6%, 53.8%, 64.6%, 59.7% and 56.1%, respectively. The incidence of perimenopausal syndrome in women aged 40-65 years with normal, disordered and postmenopausal menstrual status was 43.6%, 56.9% and 61.3%, respectively. The incidence of perimenopausal syndrome in women aged 40-65 years with and without chronic diseases was 85.9% and 68.3%, respectively. The incidence of perimenopausal syndrome was highest in women aged 40-65 years in Southwest China at 71.3%, and at 57.4%, 57.9%, 50.5%, 59.2%, 69.5%, and 68.6% in North, East, South, Northwest, Northeast, and Central China, respectively. The incidence of perimenopausal syndrome in women aged 40-65 years with education level of junior high school and below, high school or technical secondary school, university and above was 54.1%, 55.7% and 49.6%, respectively. The incidence of perimenopausal syndrome in Han Chinese and ethnic minority women aged 40-65 years was 62.1% and 64.7%, respectively. Conclusion The incidence of perimenopausal syndrome is high in women aged 40 to 65 years in China. Among them, women aged >50-55 years, menopausal, suffering from chronic diseases, living in southwest region, with education level of high school or below, and ethnic minorities are at high risk of perimenopausal syndrome. We should pay attention to the prevention, screening and intervention of perimenopausal syndrome in relevant population to lay the foundation of elderly health in women