Self-Rolled-Up WSe2 One-Dimensional/Two-Dimensional Homojunctions: Enabling High-Performance Self-Powered Polarization-Sensitive Photodetectors.

Mixed-dimensional heterostructures integrate materials of diverse dimensions with unique electronic functionalities, providing a new platform for research in electron transport and optoelectronic detection. Here, we report a novel covalently bonded one-dimensional/two-dimensional (1D/2D) homojunction structure with robust junction contacts, which exhibits wide-spectrum (from the visible to near-infrared regions), self-driven photodetection, and polarization-sensitive photodetection capabilities. Benefiting from the ultralow dark current at zero bias voltage, the on/off ratio and detectivity of the device reach 1.5 × 103 and 3.24 × 109 Jones, respectively. Furthermore, the pronounced anisotropy of the WSe2 1D/2D homojunction is attributed to its low symmetry, enabling polarization-sensitive detection. In the absence of any external bias voltage, the device exhibits strong linear dichroism for wavelengths of 638 and 808 nm, with anisotropy ratios of 2.06 and 1.96, respectively. These results indicate that such mixed-dimensional structures can serve as attractive building blocks for novel optoelectronic detectors.

Gut microbiota regulation of T lymphocyte subsets during systemic lupus erythematosus.

BACKGROUND: Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by disturbance of pro-inflammatory and anti-inflammatory lymphocytes. Growing evidence shown that gut microbiota participated in the occurrence and development of SLE by affecting the differentiation and function of intestinal immune cells. The purpose of this study was to investigate the changes of gut microbiota in SLE and judge its associations with peripheral T lymphocytes. METHODS: A total of 19 SLE patients and 16 HCs were enrolled in this study. Flow cytometry was used to detect the number of peripheral T lymphocyte subsets, and 16 s rRNA was used to detect the relative abundance of gut microbiota. Analyzed the correlation between gut microbiota with SLEDAI, ESR, ds-DNA and complement. SPSS26.0 software was used to analyze the experimental data. Mann-Whitney U test was applied to compare T lymphocyte subsets. Spearman analysis was used for calculating correlation. RESULTS: Compared with HCs, the proportions of Tregs (P = 0.001), Tfh cells (P = 0.018) and Naïve CD4 + T cells (P = 0.004) significantly decreased in SLE patients, and proportions of Th17 cells (P = 0.020) and γδT cells (P = 0.018) increased in SLE. The diversity of SLE patients were significantly decreased. Addition, there were 11 species of flora were discovered to be distinctly different in SLE group (P < 0.05). In the correlation analysis of SLE, Tregs were positively correlated with Ruminococcus2 (P = 0.042), Th17 cells were positively correlated with Megamonas (P = 0.009), γδT cells were positively correlated with Megamonas (P = 0.003) and Streptococcus (P = 0.004), Tfh cells were positively correlated with Bacteroides (P = 0.040), and Th1 cells were negatively correlated with Bifidobacterium (P = 0.005). As for clinical indicators, the level of Tregs was negatively correlated with ESR (P = 0.031), but not with C3 and C4, and the remaining cells were not significantly correlated with ESR, C3 and C4. CONCLUSION: Gut microbiota and T lymphocyte subsets of SLE changed and related to each other, which may break the immune balance and affect the occurrence and development of SLE. Therefore, it is necessary to pay attention to the changes of gut microbiota and provide new ideas for the treatment of SLE.

Directed Assembly of Ordered Mixed-Spacer Quasi-2D Halide Perovskites through Homomeric Chains of Intermolecular Bonds.

Two-dimensional (2D) halide perovskites (HPs) are of significant interest to researchers because of their natural structural frameworks and intriguing optoelectronic properties. However, the direct fabrication of ordered mixed-spacer quasi-2D HPs remains challenging. Herein, a synthetic strategy inspired by the principle of supramolecular synthons is employed for the self-assembly of a series of ordered mixed-spacer bilayered HPs. The key innovation involves the introduction of intermolecular hydrogen bonds using a bifunctional 3-aminopropionitrile cation. Three homogeneous n = 2 structures are obtained, with a subtly ordered perovskite connected by two distinct types of organic cation layers, resulting in a recurrent ABAB' stacking sequence. These three compounds exhibit attractive semiconducting properties. Moderate bandgaps in the range of 2.70 to 2.76 eV with an absorption wavelength range of 448-459 nm exhibit excellent photoelectric response. Moreover, the ordered structures facilitate excellent polarization-sensitive photodetection, with an impressive on/off ratio of 103. The response speed ranged from 298 to 381 µs, and the out-of-plane polarization-related dichroism ratio is determined to be 1.19. Such ordered mixed-spacer bilayered perovskites have not been reported. These results enrich the HPs system and play a significant role in the direct assembly of novel perovskites with ordered structures.

Rolling up 2D WSe2 Nanosheets to 1D Anisotropic Nanoscrolls for Polarization-Sensitive Photodetectors.

The intrinsic low-symmetry crystal structures or external geometries of low-dimensional materials are crucial for polarization-sensitive photodetection. However, these inherently anisotropic materials are limited in variety, and their anisotropy is confined to specific crystal directions. Transforming 2D semiconductors, such as WSe2, from isotropic 2D nanosheets into anisotropic 1D nanoscrolls expands their application in polarization photodetection. Despite this considerable potential, research on polarization photodetection based on nanoscrolls remains scarce. Here, the uniform crystalline orientation of WSe2 nanoscrolls is achieved conveniently and efficiently by applying ethanol droplets to vapor deposition-grown bilayer WSe2 nanosheets. Angle-resolved polarized Raman spectroscopy of WSe2 nanoscrolls demonstrates vibrational anisotropy. Photodetectors based on these nanoscrolls show competitive overall performance with a broadband detection range from 405 to 808 nm, a competitive on/off ratio of ≈900, a high detectivity of 3.4 × 108 Jones, and a fast response speed of ≈30 ms. Additionally, WSe2 nanoscroll-based photodetectors exhibit strong polarization-sensitive detection with a maximum dichroic ratio of 1.5. More interestingly, due to high photosensitivity, the WSe2 nanoscroll detectors can easily record sequential puppy images. This work reveals the potential of WSe2 nanoscrolls as excellent polarization-sensitive photodetectors and provides new insights into the development of high-performance optoelectronic devices.

Nonlinear Optical Switching in a Tin-Based Multilayered Halide Perovskite Activated by Stereoactive Lone Pairs and Confined Rotators.

In recent years, there has been a surge in research enthusiasm on searching for solid-state nonlinear optical (NLO) switching materials in halide perovskites owing to their exceptional structural flexibility, compositional diversity, and broad property tenability. However, the majority of reported halide perovskite NLO switching materials contain toxic elements (e.g., Pb), which raise significant environmental concerns. Herein, we present a novel lead-free multilayered halide perovskite NLO switching material, (BA)2(EA)2Sn3Br10 (1, where BA is butylammonium and EA is ethylammonium). Driven by the stereochemically active lone-pair electrons of the Sn2+ cation and the cage-confined effect of EA rotators, 1 undergoes a phase transition with symmetry breaking from P4/mnc to Cmc21, which gives rise to a highly efficient modulation of the quadratic NLO property (0.7 times that of KH2PO4) at a high temperature of 353 K. Furthermore, crystallographic investigation combined with theoretical calculations reveals that the efficient modulation of NLO properties in 1 stems from the synergistic effects between stereochemically active lone pair-induced octahedral distortions and order/disorder transformation of organic cations. This study opens up an instructive avenue for designing and advancing environmentally friendly solid-state NLO switches in halide perovskites.

Longitudinal dynamic single-cell mass cytometry analysis of peripheral blood mononuclear cells in COVID-19 patients within 6 months after viral RNA clearance.

This study investigates the longitudinal dynamic changes in immune cells in COVID-19 patients over an extended period after recovery, as well as the interplay between immune cells and antibodies. Leveraging single-cell mass spectrometry, we selected six COVID-19 patients and four healthy controls, dissecting the evolving landscape within six months post-viral RNA clearance, alongside the levels of anti-spike protein antibodies. The T cell immunophenotype ascertained via single-cell mass spectrometry underwent validation through flow cytometry in 37 samples. Our findings illuminate that CD8 + T cells, gamma-delta (gd) T cells, and NK cells witnessed an increase, in contrast to the reduction observed in monocytes, B cells, and double-negative T (DNT) cells over time. The proportion of monocytes remained significantly elevated in COVID-19 patients compared to controls even after six-month. Subpopulation-wise, an upsurge manifested within various T effector memory subsets, CD45RA + T effector memory, gdT, and NK cells, whereas declines marked the populations of DNT, naive and memory B cells, and classical as well as non-classical monocytes. Noteworthy associations surfaced between DNT, gdT, CD4 + T, NK cells, and the anti-S antibody titer. This study reveals the changes in peripheral blood mononuclear cells of COVID-19 patients within 6 months after viral RNA clearance and sheds light on the interactions between immune cells and antibodies. The findings from this research contribute to a better understanding of immune transformations during the recovery from COVID-19 and offer guidance for protective measures against reinfection in the context of viral variants.

Response of tree growth to drought variability in arid areas: Local hydroclimate and large-scale precipitation.

The impact of drought on terrestrial ecosystems is increasing, and the spatiotemporal heterogeneity of drought changes exacerbates the difficulty of determining ecosystem responses, especially in arid regions far from oceans. Tree rings have been widely used to understand how forest ecosystems respond to drought. However, the link between local hydroclimate variations related to tree rings and large-scale climate changes is not clear in the Qilian Mountains. Here, we used the tree ring width index to analyze the trend of Picea crassifolia growth and its relationship with climate in the middle Qilian Mountains. The results showed that the radial growth trend of Picea crassifolia is synchronized in the middle Qilian Mountains by calculating the Gleichläufigkeit index (GLK). Our analyses indicated that tree radial growth is positively correlated with drought during the growing season. Tree growth responds stably to drought (scPDSI and SPEI) and precipitation but unstably to temperature during 1950-2019. We further traced the meteorological factors that cause regional drought changes associated with radial growth. An increased total precipitation and decreased evaporation contribute to drought alleviation, favoring an increased tree radial growth. The increased total precipitation is mainly due to increased large-scale precipitation, which is related to water vapor transport changes. This study attempts to explore the influence of large-scale meteorology on regional drought change and its related tree radial growth response, which helps us to better understand the changes in forest ecosystems under climate change.

Transcriptome Analysis Reveals the Mechanism by Which Exogenous Melatonin Treatment Delays Leaf Senescence of Postharvest Chinese Kale (Brassica oleracea var. alboglabra).

Melatonin, a pleiotropic small molecule, is employed in horticultural crops to delay senescence and preserve postharvest quality. In this study, 100 µM melatonin treatment delayed a decline in the color difference index h* and a*, maintaining the content of chlorophyll and carotenoids, thereby delaying the yellowing and senescence of Chinese kale. Transcriptome analysis unequivocally validates melatonin's efficacy in delaying leaf senescence in postharvest Chinese kale stored at 20 °C. Following a three-day storage period, the melatonin treatment group exhibited 1637 differentially expressed genes (DEGs) compared to the control group. DEG analysis elucidated that melatonin-induced antisenescence primarily governs phenylpropanoid biosynthesis, lipid metabolism, plant signal transduction, and calcium signal transduction. Melatonin treatment up-regulated core enzyme genes associated with general phenylpropanoid biosynthesis, flavonoid biosynthesis, and the α-linolenic acid biosynthesis pathway. It influenced the redirection of lignin metabolic flux, suppressed jasmonic acid and abscisic acid signal transduction, and concurrently stimulated auxin signal transduction. Additionally, melatonin treatment down-regulated RBOH expression and up-regulated genes encoding CaM, thereby influencing calcium signal transduction. This study underscores melatonin as a promising approach for delaying leaf senescence and provides insights into the mechanism of melatonin-mediated antisenescence in postharvest Chinese kale.

Transcriptome Analysis Reveals the Mechanism of Exogenous Selenium in Alleviating Cadmium Stress in Purple Flowering Stalks (Brassica campestris var. purpuraria).

In China, cadmium (Cd) stress has a significant role in limiting the development and productivity of purple flowering stalks (Brassica campestris var. purpuraria). Exogenous selenium supplementation has been demonstrated in earlier research to mitigate the effects of Cd stress in a range of plant species; nevertheless, the physiological and molecular processes by which exogenous selenium increases vegetable shoots' resistance to Cd stress remain unclear. Purple flowering stalks (Brassica campestris var. purpuraria) were chosen as the study subject to examine the effects of treatment with sodium selenite (Na2SeO3) on the physiology and transcriptome alterations of cadmium stress. Purple flowering stalk leaves treated with exogenous selenium had higher glutathione content, photosynthetic capacity, and antioxidant enzyme activities compared to the leaves treated with Cd stress alone. Conversely, the contents of proline, soluble proteins, soluble sugars, malondialdehyde, and intercellular CO2 concentration tended to decrease. Transcriptome analysis revealed that 2643 differentially expressed genes (DEGs) were implicated in the response of exogenous selenium treatment to Cd stress. The metabolic pathways associated with flavonoid production, carotenoid synthesis, glutathione metabolism, and glucosinolate biosynthesis were among those enriched in these differentially expressed genes. Furthermore, we discovered DEGs connected to the production route of glucosinolates. This work sheds fresh light on how purple flowering stalks' tolerance to cadmium stress is improved by exogenous selenium.

Boosting Visible-Light Photocatalytic Activity of BiOCl Nanosheets via Synergetic Effect of Oxygen Vacancy Engineering and Graphene Quantum Dots-Sensitization.

In recent years, oxygen vacancy (VO) engineering has become a research hotspot in the field of photocatalysis. Herein, an efficient GQDs/BiOCl-VO heterojunction photocatalyst was fabricated by loading graphene quantum dots (GQDs) onto BiOCl nanosheets containing oxygen vacancies. ESR and XPS characterizations confirmed the formation of oxygen vacancy. Combining experimental analysis and DFT calculations, it was found that oxygen vacancy promoted the chemical adsorption of O2, while GQDs accelerated electron transfer. Benefiting from the synergistic effect of oxygen vacancy, GQDs, and dye sensitization, the as-prepared GQDs/BiOCl-VO sample exhibited improved efficiency for RhB degradation under visible-light irradiation. A 2 wt% GQDs/BiOCl-VO composite effectively degraded 98% of RhB within 20 min. The main active species were proven to be hole (h+) and superoxide radical (·O2-) via ESR analysis and radical trapping experiments. This study provided new insights into the effective removal of organic pollutants from water by combining defect engineering and quantum dot doping techniques in heterojunction catalysts.

Effects of glycated serum protein, homocysteine, and cystatin-C levels on pregnancy outcomes in patients with gestational diabetes mellitus.

Objective: To explore the effects of serum glycated serum protein (GSP), homocysteine (Hcy) and cystatin-C (Cys-C) levels on pregnancy outcomes in patients with gestational diabetes mellitus (GDM). Methods: Retrospective selection of 247 pregnant women who underwent normal prenatal examinations in The Yan'an People's Hospital from January 2020 to May 2022 were included in this retrospective study. Among them, 119 were pregnant women with diabetes (GDM-group) and 128 were pregnant women with normal blood glucose (Normal-group). The levels of serum GSP, HCY, CYS-C, and incidence of adverse pregnancy outcomes were compared between the two groups. The clinical value of levels of serum GSP, Hcy, and Cys-C in predicting adverse pregnancy outcomes were analyzed. Results: Compared with the Normal-group, the overall incidence of adverse pregnancy outcomes, serum GSP, Hcy, and Cys-C levels in the GDM-group were significantly higher (p<0.05). Logistic regression analysis showed that the levels of GSP, Hcy, and Cys-C were independent risk factors for adverse pregnancy outcomes in the GDM-group (p<0.05). Receiver operating characteristic (ROC) curve showed that the area under the curve (AUC) for diagnosing adverse pregnancy outcomes in pregnant women with GDM using serum GSP, Hcy, and CysC levels alone were 0.817, 0.843, and 0.775, respectively. The AUC of the three indicators combined was 0.921, indicating that this combination has a good predictive value for diagnosing adverse outcomes in GDM-complicated pregnancies. Conclusions: GDM is associated with a high risk of adverse pregnancy outcomes. Levels of serum GSP, Hcy, and Cys-C are higher in patients with GDM. The higher the levels of GSP, Hcy, and Cys-C, the greater the risk of adverse pregnancy outcomes. Combining these three indicators can effectively predict maternal pregnancy outcomes.

Impact of health shocks on household consumption structure.

Introduction: In the aftermath of the pandemic, the impact of health shocks on household expenditure patterns has become a critical area of focus due to the heightened uncertainty surrounding consumers' expectations. Household medical expenditures have emerged as a key factor in the evolving consumption structure. Method: This research developed a practical framework to assess the influence of health shocks on family spending patterns, focusing on health shortfalls. Health emergencies were measured through randomized medical spending. Data was sourced from the 2010-2018 Wave 5 Statistical Report of the China Family Panel Studies (CFPS), which included a total of 25,809 participants. Results: The findings revealed that health shocks significantly increased the proportion of household spending on medical expenses. Concurrently, sub-expenditures such as food and education were reduced to varying degrees as households adjusted their consumption patterns to mitigate the impact of health shocks. The effects of these shocks were more pronounced in low-income households and those with health insurance. Discussions: The government should take steps to promote public health, reduce the burden of medical expenses resulting from health shocks, and unlock the consumption potential. Additionally, efforts should be made to boost economic growth and systematically upgrade household consumption patterns to effectively cushion the impact of health shocks.

Adult rhabdomyosarcoma combined with acute myeloid leukemia: A case report.

BACKGROUND: Rhabdomyosarcoma is a tumor of mesenchymal origin. Secondary leukemia is a complication of previous transformation to other hematologic disorders or is a treatment-related acute myeloid leukemia secondary to cytotoxic chemotherapy or radiation therapy for other malignancies. CASE SUMMARY: We present the case of a 36-year-old female patient who was diagnosed with rhabdomyosarcoma and acute myeloid leukemia. Further disease progression was observed after multiline chemotherapy. Eventually, the patient suffered cerebral hemorrhage, which resulted in death. CONCLUSION: The incidence of rhabdomyosarcoma in adults is extremely low, and secondary leukemia caused by rhabdomyosarcoma is even rarer. Secondary leukemia has a very poor prognosis and a low overall survival rate.

Monomorphic epitheliotropic intestinal T-cell lymphoma with bone marrow involved: A case report.

BACKGROUND: Monomorphic epithelial intestinal T-cell lymphoma (MEITL) is a rare type of peripheral T-cell lymphoma. The clinical manifestations are diarrhea, abdominal pain, perforation and an abdominal mass. CASE SUMMARY: We present a 52-year-old female patient who was diagnosed with MEITL. Further disease progression was observed after multiline chemotherapy. Eventually, the patient died of a severe infection. CONCLUSION: MEITL is a rare intestinal primary T-cell lymphoma with aggressive behavior, a high risk of severe life-threatening complications, and a poor prognosis.

Case report: Mutation evolution in a patient with TdT positive high grade B cell lymphoma with MYC and BCL2 rearrangements following the treatment of concurrent follicular lymphoma and diffuse large B-cell lymphoma.

BACKGROUND: Concurrent follicular lymphoma (FL) and diffuse large B-cell lymphoma (DLBCL)was reported in some studies, while the diagnosis of TdT (terminal deoxynucleotydil transferase) positive high grade B cell lymphoma (HGBL) with MYC and BCL2 rearrangements ("double hit") transformed from FL/DLBCL has been rarely reported. Herein, we described the clinical features and mutation profiles of a case diagnosed with TdT positive "double hit" HGBL following the treatment of FL/DLBCL. CASE PRESENTATION: This is a 43-year-old Chinese man who was diagnosed with low grade FL (account for 80%) combined with DLBCL (20%) at a stage of IVB. The patient presented with BCL2/IGH translocation without MYC rearrangement, as well as the expressions of CD20, CD19, CD10 and BCL2 at the initial diagnosis of FL/DLBCL. MYC rearrangement and TdT expression occurred after the treatment. The targeted sequencing revealed mutations in KMT2D, FOXO1, CREBBP, ATM, STAT6, BCL7A, DDX3X, MUC4, FGFR3, ARID5B, DDX11 and PRKCSH genes were the co-mutations shared by the FL/DLBCL and TdT positive "double hit" HGBL, while CCND3, BIRC6, ROBO1 and CHEK2 mutations specifically occurred after the treatment. The overall survival time was 37.8 and 17.8 months after the initial diagnosis of FL/DLBCL and TdT positive "double hit" HGBL, respectively. CONCLUSION: This study reports a rare case of TdT positive "double hit" HGBL following the treatment of concurrent FL/DLBCL and highlights the mutation characteristics. Collectively, this study will help enrich the knowledge of TdT positive "double hit" HGBL transformed from FL/DLBCL.

Preparation of a novel polypyrrole/dolomite composite adsorbent for efficient removal of Cr(VI) from aqueous solution.

A novel adsorbent, deposited PPy on the DMI (PPy/DMI) composite, was successfully synthesized for Cr(VI) removal from aqueous solution. PPy/DMI composite was characterized by BET, SEM, TEM, XRD, and XPS. The SEM and TEM analyses revealed that DMI can greatly reduce the aggregation of PPy and significantly enhance its adsorption performance. The Cr(VI) removal was highly pH dependent. The high selectivity of PPy/DMI composite for Cr(VI) removal was found even in the presence of co-existing ions. The adsorption kinetic process followed the pseudo-second-order equation, demonstrating that the Cr(VI) adsorption behavior onto PPy/DMI is chemisorption. Furthermore, the intra-particle diffusion model implied that the adsorption was controlled by both liquid membrane diffusion and internal diffusion. The adsorption isotherm data fitted well with the Langmuir model with the maximum adsorption capacity (406.50 mg/g at 323 K) which was considerably higher than that of other PPy-based adsorbents. The Cr(VI) adsorption onto PPy/DMI composite was endothermic. The main mechanisms of Cr(VI) removal are involved in adsorption through electrostatic attractions, ion exchange, and in situ reduction. The results suggested that PPy/DMI composite could be a promising candidate for efficient Cr(VI) removal from aqueous solution.

Clinical nurses' work procrastination and smartphone addiction: a potential profile study.

Background: In the medical field, effective time management by clinical nurses is crucial for enhancing the quality of patient care. However, in recent years, with increasing work pressure for clinical nurses, procrastination has become a prevalent issue. Many nurses use smartphones as a way to alleviate stress and manage emotions, but excessive smartphone use could exacerbate procrastination, thereby jeopardizing patient safety and healthcare quality. Therefore, understanding the current state of work procrastination among clinical nurses, its heterogeneity, and exploring the impact of smartphone addiction and demographic factors on different aspects of nurse procrastination hold significant importance for improving patient care quality. Objective: This study aims to explore the current state of work procrastination among clinical nurses and identify potential profile categories. It further analyzes the impact of mobile phone addiction and demographic factors on work procrastination among clinical nurses. Methods: Convenience sampling was employed to recruit participants from three tertiary hospitals in central China from October to November 2023. Surveys measuring nurses' work procrastination and smartphone addiction were distributed and collected through online platforms. A total of 1,536 nurses participated in this study. Mplus 8.3 statistical software was used for latent profile analysis of clinical nurses' work procrastination, and SPSS 26.0 software was utilized for chi-square tests, rank-sum tests, and multi-classification logistic regression analyses. Results: The median total score for clinical nurses' work procrastination was 21.00 (17.00, 28.00), and three subgroups were identified: low procrastination (66.93%), medium-low procrastination (20.66%), and medium-high procrastination (12.41%). Additionally, logistic regression analysis revealed that smartphone addiction and department atmosphere were common influencing factors for medium-low and medium-high work procrastination. Hospitals with stricter management and nurses holding the position of head nurse were more likely to belong to the low work procrastination group. Nurses with higher incomes or those holding intermediate titles were more prone to medium-low work procrastination, while those experiencing career advancement difficulties were more likely to exhibit medium-high work procrastination (p < 0.05). Conclusion: Clinical nurses' work procrastination is generally at a medium-to-low level, with three subgroups identified: low procrastination, medium-low procrastination, and medium-high procrastination. Additionally, clinical nurses in surgical departments or those with intermediate titles exhibit higher levels of procrastination. Factors such as smartphone addiction, higher monthly income, tense departmental atmosphere, and unsuccessful career advancement are more likely to lead to work procrastination. Conversely, nurses in hospitals with strict management or those holding the position of head nurse exhibit lower levels of work procrastination. Therefore, nursing managers should pay close attention to the work procrastination behaviors of clinical nurses, actively monitor predictive factors among different groups, and provide psychological counseling and relevant training based on individual nurse circumstances. Additionally, it is also essential to focus on and improve departmental atmosphere and nurse smartphone addiction to enhance clinical nurses' work efficiency and reduce work procrastination.

Prediction of potential suitable habitats in the 21st century and GAP analysis of priority conservation areas of Chionanthus retusus based on the MaxEnt and Marxan models.

Chionanthus retusus (C. retusus) has a high economic and medicinal value, but in recent years it has been included in the list of China's major protected plants and China's Red List of Biodiversity due to the serious destruction of its wild germplasm resources. Based on 131 sample points of C. retusus, this study simulated potential habitats and spatial changes of C. retusus in the 21st century using the Maxent model combined with the geographic information system ArcGIS, predicted prioritized protected areas by the Marxan model, and assessed current conservation status through GAP analysis. The results showed that (1) when the regularization multiplier was 1.5 and the feature combinations were linear, quadratic, and fragmented, the area under the curve of the subjects in the training and test sets were both above 0.9, the true skill statistic value was 0.80, and the maximum Kappa value was 0.62, meaning that the model had high accuracy; (2) Temperature seasonality, annual precipitation, min temperature for coldest month, and precipitation of wettest month had relatively strong influences on species' ranges. (3) The moderately and optimally suitable habitats of C. retusus were primly located in the areas of southwestern Shanxi, central Hebei, western Henan, Shandong, Shaanxi, Anhui and Hubei; (4) Under different future climate scenarios, the area of each class of suitable habitat will increase for varied amounts compared to the current period, with a general trend of expansion to the south; (5) The C. retusus priority protected areas were mainly located in most of Shandong, southern Liaoning, southwestern Shanxi, western Henan, and central Hebei, and its conservation vacancy area was relatively large compared to its protected area. These results will provide scientific strategies for implementing long-term conservation of C. retusus in China and similar regions under warming conditions in the 21st century.

Potential habitat areas and priority protected areas of Tilia amurensis Rupr in China under the context of climate change.

Introduction: Tilia amurensis Rupr (T. amurensis) is one endangered and national class II key protected wild plant in China. It has ornamental, material, economic, edible and medicinal values. At present, the resources of T. amurensis are decreasing, and the prediction of the distribution of its potential habitat in China can provide a theoretical basis for the cultivation and rational management of this species. Methods: In this study, the R language was used to evaluate 358 distribution records and 38 environment variables. The MaxEnt model was used to predict the potential distribution areas of T. amurensis under the current and future climate scenarios. The dominant environmental factors affecting the distribution of T. amurensis were analyzed and the Marxan model was used to plan the priority protected areas of this species. Results: The results showed that Bio18, Slope, Elev, Bio1, Bio9 and Bio2 were the dominant environmental factors affecting the distribution of T. amurensis. Under the future climatic scenarios, the potential suitable areas for T. amurensis will mainly distribute in the Northeast China, the total suitable area will reduce compared with the current climate scenarios, and the general trend of the centroid of suitable habitat will be towards higher latitudes. The SPF value of the best plan obtained from the priority conservation area planning was 1.1, the BLM value was 127,616, and the priority conservation area was about 57.61×104 km2. The results suggested that climate, soil and topographic factors jointly affected the potential geographical distribution of T. amurensis, and climate and topographic factors had greater influence than soil factors. Discussion: The total suitable area of T. amurensis in China under different climate scenarios in the future will decrease, so more effective protection should be actively adopted.

In vitro and in vivo degradation, biocompatibility and bone repair performance of strontium-doped montmorillonite coating on Mg-Ca alloy.

Poor bone growth remains a challenge for degradable bone implants. Montmorillonite and strontium were selected as the carrier and bone growth promoting elements to prepare strontium-doped montmorillonite coating on Mg-Ca alloy. The surface morphology and composition were characterized by SEM, EDS, XPS, FT-IR and XRD. The hydrogen evolution experiment and electrochemical test results showed that the Mg-Ca alloy coated with Sr-MMT coating possessed optimal corrosion resistance performance. Furthermore, in vitro studies on cell activity, ALP activity, and cell morphology confirmed that Sr-MMT coating had satisfactory biocompatibility, which can significantly avail the proliferation, differentiation, and adhesion of osteoblasts. Moreover, the results of the 90-day implantation experiment in rats indicated that, the preparation of Sr-MMT coating effectively advanced the biocompatibility and bone repair performance of Mg-Ca alloy. In addition, The Osteogenic ability of Sr-MMT coating may be due to the combined effect of the precipitation of Si4+ and Sr2+ in Sr-MMT coating and the dissolution of Mg2+ and Ca2+ during the degradation of Mg-Ca alloy. By using coating technology, this study provides a late-model strategy for biodegradable Mg alloys with good corrosion resistance, biocompatibility. This new material will bring more possibilities in bone repair.