Cycloaddition and Skeleton Rearrangement of Heterocyclic Ketene Aminals (HKAs) with 1-Diazonaphthalen-2(1H)-ones for the Synthesis of Functionalized 1,2,3-Triazoles.

We developed a protocol for the synthesis of highly functionalized 5,6-dihydro-imidazo[1,2-c][1,2,3]triazole derivatives 4-5 (DHITs) from 1-diazonaphthalen-2(1H)-one derivatives with heterocyclic ketene aminals (HKAs). This strategy involved cycloaddition and skeletal rearrangement entailing the heating of a mixture of substrates 1 with HKAs 2-3 and THF without any catalyst. As a result, a series of DHITs 4-5 were produced by cleaving one bond (1 C═N bond) and forming three bonds (1 N-N and 2 C-N bonds) in a single step. This protocol achieved the dual functionalization of diazo building blocks involving both the aromatic nitrogen alkylation reaction to form an ArC-N bond without any metal catalyst and the intermolecular cycloaddition of the N═N bond. These strategies can be used to synthesize functionalized DHITs for combinatorial and parallel syntheses via one-pot reactions without any catalyst.

FAM134B deletion exacerbates apoptosis and epithelial-to-mesenchymal transition in rat lungs exposed to hyperoxia.

Oxygen therapy is widely used in clinical practice; however, prolonged hyperoxia exposure may result in hyperoxic acute lung injury (HALI). In this study, we investigated the role of FAM134B in hyperoxia-induced apoptosis, cell proliferation, and epithelial-to-mesenchymal transition (EMT) using RLE-6TN cells and rat lungs. We also studied the effect of CeO2-NPs on RLE-6TN cells and lungs following hyperoxia exposure. FAM134B was inhibited in RLE-6TN cells and rat lungs following hyperoxia exposure. Overexpressing FAM134B promoted cell proliferation, and reduced EMT and apoptosis following hyperoxia exposure. FAM134B activation increased ER-phagy, decreased apoptosis, improved lung structure damage, and decreased collagen fiber deposition to limit lung injury. These effects could be reversed by PI3K/AKT pathway inhibitor LY294002. Additionally, CeO2-NPs protected RLE-6TN cells and lung damage following hyperoxia exposure by ameliorating impaired ER-phagy. Therefore, FAM134B restoration is a potential therapeutic target for the HALI. Moreover, CeO2-NPs can be used for the treatment of HALI.

Comparison of the accuracy of hematological parameters in the diagnosis of neonatal sepsis: a network meta-analysis.

BACKGROUND: Currently, there are hundreds of hematological parameters used for rapid diagnosis of neonatal sepsis, but there is no network meta-analysis to compare the diagnostic efficacy of these parameters. METHODS: We searched for literature on the diagnostic neonatal sepsis and selected 20 of the most common parameters to compare their diagnostic efficacy. We used Bayesian network meta-analysis, Frequentist network meta-analysis, and individual traditional diagnostic meta-analysis to analyze the data and verify the stability of the results. Based on the above analysis, we ranked the diagnostic efficacy of 20 parameters and searched for the optimal indicator. We also conducted subgroup analysis based on different designs. GRADE was used to evaluate the quality of evidence. RESULTS: 311 articles were included in the analysis, of which 206 articles were included in the network meta-analysis. Bayesian models fond the top three of the advantage index were P-SEP, SAA, and CD64. In Individual model, P-SEP, SAA, and CD64 had the best sensitivity; ABC, SAA, and P-SEP had the best specificity. Frequentist model showed that CD64, P-SEP, and IL-10 ranked in the top three for sensitivity, while P-SEP, ABC, and I/M in specificity. Overall, P-SEP, SAA, CD64, and PCT have good sensitivity and specificity among all the three methods. The results of subgroup analysis were consistent with the overall analysis. All evidence was mostly of moderate or low quality. CONCLUSIONS: P-SEP, SAA, CD64, and PCT have good diagnostic efficacy for neonatal sepsis. However, further studies are required to confirm these findings.

Research Progress on Ferroptosis and Nanotechnology-Based Treatment in Triple-Negative Breast Cancer.

In recent years, more and more researches on cell death mode in breast cancer, including apoptosis, ferroptosis, etc. Ferroptosisis a regulated form of cell death characterized by iron-dependent accumulation of lipid peroxidation to lethal levels, and numerous studies have shown that ferroptosis is closely associated with tumor cells. Breast cancer is one of the malignant tumors with the highest incidence in women, and TNBC accounts for about 15-20% of all types of breast cancer. Due to the poor prognosis, strong aggressiveness, high drug resistance and lack of molecular targeting characteristics of TNBC, the treatment of TNBC faces many difficulties and great challenges. A large number of studies have shown that ferroptosis plays an important role in the occurrence and development of TNBC, tumor diagnosis, treatment and prognosis, among which the main mechanisms inducing ferroptosis include oxidative stress pathway, iron metabolism pathway and lipid metabolism pathway. Since TNBC is highly sensitive to oxidative stress pathways, intracellular GSH reduces reactive oxygen species under the action of GSH peroxidase (GPX), and when intracellular lipid peroxidase (LPO) accumulates to a certain level, ferroptosis will be induced, thus achieving the purpose of killing TNBC cells. In addition, lipid metabolism is highly consistent with the high lipid level of TNBC tumor cells. As a new therapeutic method, nanotechnology has added security to the treatment of cancer with its high safety and excellent biocompatibility. Therefore, the combination of nanotechnology with iron-based radiotherapy, chemotherapy, targeting and immunization has great research value for the treatment of TNBC In addition, the novel idea of treating TNBC with ethnopharmacology combined with ferroptosis is also involved. This article reviews the mechanism of ferroptosis and the recent research on the treatment prospects of TNBC based on ferroptosis and nanotechnology, hoping to provide references for the treatment of diseases based on ferroptosis.

Ultrasound-Activatable In Situ Vaccine for Enhanced Antigen Self- and Cross-Presentation to Overcome Cancer Immunotherapy Resistance.

Insufficient antigen self-presentation of tumor cells and ineffective antigen cross-presentation by dendritic cells (DCs) contribute to diminished immune recognition and activation, which cause resistance to immunotherapies. Herein, we present an ultrasound-activatable in situ vaccine by utilizing a hybrid nanovesicle composed of a thylakoid (TK)/platelet (PLT) membrane and a liposome encapsulating DNA methyltransferase inhibitor zebularine (Zeb) and sonosensitizer hematoporphyrin monomethyl ether (HMME). Upon local exposure to ultrasound, reactive oxygen species (ROS) are generated and induce the sequential release of the payloads. Zeb can efficiently inhibit tumor DNA hypermethylation, promoting major histocompatibility complex class I (MHC-I) molecules-mediated antigen self-presentation to improve immune recognition. Meanwhile, the catalase on the TK membrane can decompose the tumoral overexpressed H2O2 into O2, which boosts the generation of ROS and the destruction of tumor cells, resulting in the in situ antigen release and cross-presentation of tumor antigens by DCs. This in situ vaccine simultaneously promotes antigen self-presentation and cross-presentation, resulting in heightened antitumor immunity to overcome resistance.

Development and optimization of the Glabridin-loaded dissolving microneedle for enhanced treatment of keloid.

Glabridin (Gla) has been reported to have significant effects in scar treatment, and however, the water insolubility of Gla leads to its poor transdermal absorption ability, which affects its bioactivities. Therefore, we attempted to prepare the Gla dissolving microneedles (Gla-MN) to improve the absorbtion of Gla. After investigation of the 3 factors including the needle tip matrix concentration, the prescription concentration of backing material, and the dissolution method of Gla, we finally determined the process parameters of 10% hyaluronic acid (HA) as the needle tip and 5% polyvinyl alcohol (PVA) as the backing, according to which the Gla-MN was prepared with the good characteristics of high hardness, complete appearance and good in vitro dissolution ability. We then loaded Gla onto the microneedles and measured that the average drug loading of Gla-MN was 2.26 ± 0.11 µg/mg and the cumulative transdermal release of Gla-MN was up to 76.9% after 24 h. In addition, Gla-MN had good skin penetration properties, with Gla-MN penetrating at least 4 to 5 layers of parafilm. And the skin basically could return to normal after 4 h of piercing. Importantly, our results showed that Gla-MN had higher transdermal delivery and therapeutic effects against keloid than that of Gla at the same dosage.

Extraction methods, chemical compositions, molecular structure, health functions, and potential applications of tea polysaccharides as a promising biomaterial: A review.

Tea polysaccharides (TPS) have attracted much attention due to their multiple biological activities, excellent biocompatibility and good biodegradability, creating a wide range of potential applications in the food and pharmaceutical industries. However, the high molecular weight and complexity of TPS components have restricted its purification and bioactivity, limiting its potential applications. In this review, the effects of various extraction methods, tea processing, and degree of fermentation on the composition and structure of TPS were thoroughly investigated to overcome this dilemma. Through a comprehensive analysis of in vivo and in vitro studies, the health benefits of TPS are discussed in detail, including antioxidant, anti-obesity, modulation of gut microbial communities, and anticancer bioactivities. Typical structural characterization techniques of TPS are also summarized, and interactions with common food components are discussed in depth, providing a deeper perspective on the overall knowledge of TPS. Finally, this review offers an extensive overview of the wide range of applications of TPS, including its strong emulsifying properties and bio-accessibility, in various fields such as food nutrition, drug delivery, encapsulation films, and emulsifiers. This review aims to provide a theoretical basis for the profound development of TPS for productive utilization.

Platelet-rich Fibrin Membrane Transplantation for the Treatment of Highly Myopic Macular Hole Retinal Detachment.

INTRODUCTION: Highly myopic macular hole retinal detachment (MHRD) is often associated with a poor prognosis, and there is currently no optimal treatment. Platelet-rich fibrin (PRF), an autologous blood product, has been shown to promote tissue regeneration. This prospective, randomized, controlled study investigated the efficacy of conventional internal limiting membrane (ILM) peeling versus PRF membrane transplantation in highly myopic MHRD. METHODS: Eyes with highly myopic MHRD were randomly assigned to either a conventional ILM peeling group (IP group, n = 19) or a PRF membrane transplantation group (PMT group, n = 21). The study followed participants for a period of 6 months. The primary outcome measure was macular hole (MH) closure assessed using optical coherence tomography. Secondary outcomes included best-corrected visual acuity (BCVA), central retinal thickness (CRT), superficial vascular density (SVD), deep vascular density (DVD), rate of retinal reattachment, and any complications encountered. RESULTS: MH closure was achieved in a significantly greater proportion of eyes in the PMT group (21/21, 100.00%) compared to the IP group (15/19, 78.95%) (P = 0.042). Retinal reattachment was accomplished in all patients (100.00%) within both groups. Except for an insignificant difference in BCVA observed at 1 week post-surgery in the IP group, significant improvements in BCVA and CRT were documented in both groups across all other post-operative time points. Final BCVA (P = 0.040), CRT (P = 0.002), SVD (P = 0.002), and DVD (P = 0.013) were all significantly higher in the PMT group compared to the IP group. No serious complications were identified in either group. CONCLUSIONS: This study demonstrated the superiority of PRF membrane transplantation compared to conventional ILM peeling in promoting MH closure and enhancing retinal vascular density in patients with highly myopic MHRD. Additionally, PRF membrane transplantation effectively restores retinal reattachment, improves visual function, and increases retinal thickness without introducing additional complications. TRIAL REGISTRATION NUMBER: www. CLINICALTRIALS: gov , NCT06200727.

Stimuli-Responsive Hydrogels Potentiating Photothermal Therapy against Cancer Stem Cell-Induced Breast Cancer Metastasis.

The self-renewal and differentiation properties of cancer stem cells (CSCs) result in chemoresistance in breast cancer. Even though numerous drugs have been developed to target CSCs, they have suffered from inefficient delivery and accumulation at the focal site. Here, a thermoresponsive hydrogel is developed by coencapsulating aggregation-induced emission (AIE)-active photothermal agent and thioridazine (THZ), demonstrating a controllable delivery system triggered by the AIE agent to augment THZ-mediated CSC ablation. Upon near-infrared laser stimuli, the photothermal effect from the AIE agent induces hydrogel deformation for burst drug release. The precise in situ tumor administration of the hydrogel accelerates drug diffusion and accumulation in deep breast cancer lesions. Thus, THZ can invade tumors and provoke massive CSC apoptosis via dopamine receptor blockage and oxidative stress induction. Consequently, effective CSC inhibition and significant suppression of tumor recurrence and metastasis are demonstrated in mice with breast cancer. We believe that this intelligent hydrogel-based delivery system represents a promising treatment strategy for metastatic breast cancer with clinical potential.

Abnormalities in copper status associated with diminished ovarian reserve: A case-control and cross-sectional study.

OBJECTIVE: This study aimed to illustrate the copper status of diminished ovarian reserve in Chinese women, especially the effects of copper, ceruloplasmin, non-ceruloplasmin-bound copper (NCC) and CuZn superoxide dismutase (SOD1). METHODS: This case-control, cross-sectional investigation included women with diminished ovarian reserve (DOR group, n = 35) and matched normal ovarian reserve (NOR group, n = 35). The serum levels of copper, ceruloplasmin, NCC, SOD1, follicle-stimulating hormone, luteinizing hormone, estradiol, testosterone, and anti-Müllerian hormone were tested and analyzed. RESULTS: The serum copper concentrations (60.88%), NCC (54.75%) and SOD1 (54.75%) in the DOR group were significantly higher than those in the NOR group (all P < 0.001), and the concentrations of the three markers were higher in most subgroups (P < 0.001). The correlation analysis verified the correlation between copper status and impaired ovarian function. Additionally, linear regression analysis showed that NCC and SOD1 levels were negatively correlated with anti-Müllerian hormone (P < 0.05 or 0.001). CONCLUSION: Our exploration found significant increases in copper, NCC and SOD1 levels in DOR and suggests a possible link. Copper status is expected to serve as the predictive marker for DOR.

Cytochrome P450 Enzyme Design by Constraining the Catalytic Pocket in a Diffusion Model.

Although cytochrome P450 enzymes are the most versatile biocatalysts in nature, there is insufficient comprehension of the molecular mechanism underlying their functional innovation process. Here, by combining ancestral sequence reconstruction, reverse mutation assay, and progressive forward accumulation, we identified 5 founder residues in the catalytic pocket of flavone 6-hydroxylase (F6H) and proposed a "3-point fixation" model to elucidate the functional innovation mechanisms of P450s in nature. According to this design principle of catalytic pocket, we further developed a de novo diffusion model (P450Diffusion) to generate artificial P450s. Ultimately, among the 17 non-natural P450s we generated, 10 designs exhibited significant F6H activity and 6 exhibited a 1.3- to 3.5-fold increase in catalytic capacity compared to the natural CYP706X1. This work not only explores the design principle of catalytic pockets of P450s, but also provides an insight into the artificial design of P450 enzymes with desired functions.

Correlation between serum trimethylamine-N-oxide and body fat distribution in middle-aged and older adults: a prospective cohort study.

BACKGROUND: Trimethylamine-N-oxide (TMAO) is linked with obesity, while limited evidence on its relationship with body fat distribution. Herein, we investigated the associations between serum TMAO and longitudinal change of fat distribution in this prospective cohort study. METHODS: Data of 1964 participants (40-75y old) from Guangzhou Nutrition and Health Study (GNHS) during 2008-2014 was analyzed. Serum TMAO concentration was quantified by HPLC-MS/MS at baseline. The body composition was assessed by dual-energy X-ray absorptiometry at each 3-y follow-up. Fat distribution parameters were fat-to-lean mass ratio (FLR) and trunk-to-leg fat ratio (TLR). Fat distribution changes were derived from the coefficient of linear regression between their parameters and follow-up duration. RESULTS: After an average of 6.2-y follow-up, analysis of covariance (ANCOVA) and linear regression displayed women with higher serum TMAO level had greater increments in trunk FLR (mean ± SD: 1.47 ± 4.39, P-trend = 0.006) and TLR (mean ± SD: 0.06 ± 0.24, P-trend = 0.011). Meanwhile, for women in the highest TMAO tertile, linear mixed-effects model (LMEM) analysis demonstrated the annual estimated increments (95% CI) were 0.03 (95% CI: 0.003 - 0.06, P = 0.032) in trunk FLR and 1.28 (95% CI: -0.17 - 2.73, P = 0.083) in TLR, respectively. In men, there were no similar significant observations. Sensitivity analysis yielded consistent results. CONCLUSION: Serum TMAO displayed a more profound correlation with increment of FLR and TLR in middle-aged and older community-dwelling women in current study. More and further studies are still warranted in the future. TRIAL REGISTRATION: NCT03179657.

The Impact of Health Status on Health Care Utilization of Children in Foster Care.

OBJECTIVES: This study sought to understand the health status of children in foster care; the relationship between their health status and health care utilization; and demographic and placement factors associated with health care utilization. METHODS: To estimate relationships between health status and health care utilization, this study used electronic health records from 4976 children in foster care seen at a children's hospital in the southwestern United States, 2017 to 2020. An algorithm classified patients' health status as nonchronic, noncomplex chronic, or complex chronic. Descriptive statistics were used to describe patients and utilization. The χ2, Kruskal-Wallis, and pairwise comparison post hoc tests were used to examine relationships between health status and health care utilization. Zero-inflated negative binomial (ZINB) regression further estimated relationships between health status and health care utilization while factoring in demographic and placement characteristics. RESULTS: Within the sample, 35.6% had complex chronic health status. Significant differences were found among health status groups in age, gender, ethnicity, and maltreatment exposure. Both nonparametric pairwise comparisons and the ZINB regression model showed that having complex chronic health was associated with higher utilization of all hospital resources: emergency, admission, primary and specialty care, and various therapies, relative to having noncomplex chronic and nonchronic health. CONCLUSION: A high percentage of children in foster care had complex chronic health, and these patients used significantly more resources. This study suggests that hospital-based health clinics focused on children in foster care and care coordination may be warranted.

Preparation of Sn-Doped Ga2O3 Thin Films and MSM Ultraviolet Detectors Using Magnetron Co-Sputtering.

Sn-doped Ga2O3 thin films and metal-semiconductor-metal (MSM) ultraviolet detectors were prepared using the co-sputtering method to enhance their photoelectric performance. The results revealed that Sn doping can effectively change the optical and electrical properties of thin films, greatly improving the photoelectric responsiveness of the devices. Through microstructure testing results, all of the thin film structures were determined to be monoclinic beta phase gallium oxide. At a DC power of 30 W, the thickness of the Sn-doped thin film was 430 nm, the surface roughness of the thin film was 4.94 nm, and the carrier concentration, resistivity, and mobility reached 9.72 × 1018 cm-3, 1.60 × 10-4 Ω·cm, and 45.05 cm3/Vs, respectively. The optical results show that Sn doping clearly decreases the transmission of thin films and that the bandgap can decrease to 3.91 eV. Under 30 W DC power, the photo dark current ratio of the detector can reach 101, time responses of tr = 31 s and tf = 22.83 s were obtained, and the spectral responsivity reached 19.25 A/W.

Vitamin A influences the incretin hormone profiles by activating the retinoic acid receptor ß.

BACKGROUND: This study aimed to investigate the impact of Vitamin A (VA) on intestinal glucose metabolic phenotypes. METHODS: Male C57BL/6 mice were randomized assigned to a VA-normal diet (VAN) or a VA-deficient diet (VAD) for 12 weeks. After12 weeks, the VAD mice were given 30 IU/g/d retinol for 10 days and VAN diet (VADN) for 10 weeks. By using glucose tolerance tests, immunofluorescence staining, quantitative polymerase chain reaction, siRNA transduction, and enzyme-linked immunosorbent assay, the glucose metabolic phenotypes as well as secretory function and intracellular hormone changes of STC-1 were assessed. RESULTS: VAD mice showed a decrease of glucose-stimulated insulin secretion and a loss of intestinal glucagon-like peptide-1 (GLP-1) expression. Through reintroducing dietary VA to VAD mice, the intestinal VA levels, GLP-1 expression and normal glucose can be restored. The incubation with retinol increased VA signaling factors expression within STC-1 cells, especially retinoic acid receptor ß (RARß). The activation of RARß restored intracellular incretin hormone synthesis and secretory function. CONCLUSIONS: VA deficiency leads to an imbalance of intestinal glucose metabolic phenotypes through a mechanism involving RARß signaling pathway, suggesting a new method to achieve the treatment for VAD induced glucose metabolism impairment.

Identification and characterization of a potential strain for the production of polyhydroxyalkanoate from glycerol.

While poly (3-hydroxybutyrate) (PHB) holds promise as a bioplastic, its commercial utilization has been hampered by the high cost of raw materials. However, glycerol emerges as a viable feedstock for PHB production, offering a sustainable production approach and substantial cost reduction potential. Glycerol stands out as a promising feedstock for PHB production, offering a pathway toward sustainable manufacturing and considerable cost savings. The identification and characterization of strains capable of converting glycerol into PHB represent a pivotal strategy in advancing PHB production research. In this study, we isolated a strain, Ralstonia sp. RRA (RRA). The strain exhibits remarkable proficiency in synthesizing PHB from glycerol. With glycerol as the carbon source, RRA achieved a specific growth rate of 0.19 h-1, attaining a PHB content of approximately 50% within 30 h. Through third-generation genome and transcriptome sequencing, we elucidated the genome composition and identified a total of eight genes (glpR, glpD, glpS, glpT, glpP, glpQ, glpV, and glpK) involved in the glycerol metabolism pathway. Leveraging these findings, the strain RRA demonstrates significant promise in producing PHB from low-cost renewable carbon sources.

The characterization of cell traction force on nonflat surfaces with different curvature by elastic hydrogel microspheres.

It is of great importance to study the detachment/attachment behaviors of cells (cancer cell, immune cell, and epithelial cell), as they are closely related with tumor metastasis, immunoreaction, and tissue development at variety scales. To characterize the detachment/attachment during the interaction between cells and substrate, some researchers proposed using cell traction force (CTF) as the indicator. To date, various strategies have been developed to measure the CTF. However, these methods only realize the measurements of cell passive forces on flat cases. To quantify the active CTF on nonflat surfaces, which can better mimic the in vivo case, we employed elastic hydrogel microspheres as a force sensor. The microspheres were fabricated by microfluidic chips with controllable size and mechanical properties to mimic substrate. Cells were cultured on microsphere and the CTF led to the deformation of microsphere. By detecting the morphology information, the CTF exerted by attached cells can be calculated by the in-house numerical code. Using these microspheres, the CTF of various cells (including tumor cell, immunological cell, and epithelium cell) were successfully obtained on nonflat surfaces with different curvature radii. The proposed method provides a versatile platform to measure the CTF with high precision and to understand the detachment/attachment behaviors during physiology processes.

An origami microfluidic paper device based on core-shell Cu@Cu2S@N-doped carbon hollow nanocubes.

BACKGROUD: The global prevalence of diabetes mellitus, a serious chronic disease with fatal consequences for millions annually, is of utmost concern. The development of efficient and simple devices for monitoring glucose levels is of utmost significance in managing diabetes. The advancement of nanotechnology has resulted in the indispensable utilization of advanced nanomaterials in high-performance glucose sensors. Modulating the morphology and intricate composition of transition metals represents a viable approach to exploit their structure/function correlation, thereby achieving optimal electrocatalytic performance of the synthesized catalysts. RESULTS: Herein, a sensitive and rapid Cu-encapsulated Cu2S@nitrogen-doped carbon (Cu@Cu2S@N-C) hollow nanocubes-functionalized microfluidic paper-based analytical device (µ-PAD) was fabricated. Through a delicate sacrificial template/interface technique and thermal decomposition, inter-connected hollow networks were formed to boost the active sites, and the carbon shell was coated to protect Cu from being oxidation. For application, the constructed µ-PAD is used for glucose sensing utilizing an origami automated sample pretreatment system enabled by a simple application of strong alkaline solution on wax paper. Under optimal circumstances, the Cu@Cu2S@N-C electrochemical biosensor exhibits broad detection range of 2-7500 µM (R2 = 0.996) with low detection limit of 0.16 µM (S/N = 3) and high sensitivity of 1996 µA mM-1 cm-2. Additionally, the constructed µ-PAD also exhibited excellent selectivity, stability, and reproducibility. SIGNIFICANCE: By rationally designing the double-shell hollow nanostructure and introducing Cu-encapsulated inner layer, the synthesized Cu@Cu2S@N-C hollow nanocubes show large specific surface area, short diffusion channels, and high stability. The proposed origami µ-PAD has been successfully applied to serum samples without any additional sample preparation steps for glucose determination, offering a new perspective for early nonenzymatic glucose diagnosis.

Root-soil-microbiome interaction in the rhizosphere of Masson pine (Pinus massoniana) under different levels of heavy metal pollution.

Heavy metal pollution of the soil affects the environment and human health. Masson pine is a good candidate for phytoremediation of heavy metal in mining areas. Microorganisms in the rhizosphere can help with the accumulation of heavy metal in host plants. However, studies on its rhizosphere bacterial communities under heavy metal pollution are still limited. Therefore, in this study, the chemical and bacterial characteristics of Masson pine rhizosphere under four different levels of heavy metal pollution were investigated using 16 S rRNA gene sequencing, soil chemistry and analysis of plant enzyme activities. The results showed that soil heavy metal content, plant oxidative stress and microbial diversity damage were lower the farther they were from the mine dump. The co-occurrence network relationship of slightly polluted soils (C1 and C2) was more complicated than that of highly polluted soils (C3 and C4). Relative abundance analysis indicated Sphingomonas and Pseudolabrys were more abundant in slightly polluted soils (C1 and C2), while Gaiella and Haliangium were more abundant in highly polluted soils (C3 and C4). LEfSe analysis indicated Burkholderiaceae, Xanthobacteraceae, Gemmatimonadaceae, Gaiellaceae were significantly enriched in C1 to C4 site, respectively. Mantel analysis showed that available cadmium (Cd) contents of soil was the most important factor influencing the bacterial community assembly. Correlation analysis showed that eight bacterial genus were significantly positively associated with soil available Cd content. To the best of our knowledge, this is the first study to investigate the rhizospheric bacterial community of Masson pine trees under different degrees of heavy metal contamination, which lays the foundation for beneficial bacteria-based phytoremediation using Masson pines in the future.

College students with depression symptom are more sensitive to task difficulty in reinforcement learning.

BACKGROUND: Depression is usually characterized by impairments in reward function, and shows altered motivation to reward in reinforcement learning. This study further explored whether task difficulty affects reinforcement learning in college students with and without depression symptom. METHODS: The depression symptom group (20) and the no depression symptom group (26) completed a probabilistic reward learning task with low, medium, and high difficulty levels, in which task the response bias to reward and the discriminability of reward were analyzed. Additionally, electrophysiological responses to reward and loss feedback were recorded and analyzed while they performed a simple gambling task. RESULTS: The depression symptom group showed more response bias to reward than the no depression symptom group when the task was easy and then exhibited more quickly decrease in response bias to reward as task difficulty increased. The no depression symptom group showed a decrease in response bias only in the high-difficulty condition. Further regression analyses showed that, the Feedback-related negativity (FRN) and theta oscillation could predict response bias change in the low-difficulty condition, the FRN and oscillations of theta and delta could predict response bias change in the medium and high-difficulty conditions. LIMITATIONS: The electrophysiological responses to loss and reward were not recorded in the same task as the reinforcement learning behaviors. CONCLUSIONS: College students with depression symptom are more sensitive to task difficulty during reinforcement learning. The FRN, and oscillations of theta and delta could predict reward leaning behavior.