ABSTRACT
To assess the Siberian crane (Grus leucogeranus)'s response to changing water levels and habitat quality at Poyang Lake, we analyzed the lake's hydrological trends over the past two decades with the Mann-Kendall and Sen slope methods. Additionally, we explored the link between the crane population size and hydrological conditions at the lake from 2011 to 2019. Meanwhile, five environmental factors, including habitat type, distance from shallow lakes, human footprint index, elevation and normalized vegetation index were selected, and the distribution patterns of suitable habitats for the Siberian crane under 10 water level gradients with intervals of about 1 m (5.3-14.2 m) were simulated by using an improved habitat suitability index model that determines the weights of evaluating factors based on the MaxEnt model. The results showed that the overall trend of the inundated area in Poyang Lake was shrinking in the last 20 years, with a significant increase in the area of exposed floodland during the early wintering period (Z = -2.26). The prolonged drought resulting from this will force vegetation succession, thereby diminishing the food resources for cranes in their natural habitat. The mean inundated area in June demonstrated a significant negative correlation with the population of Siberian cranes in natural habitats (r = -0.75, p = 0.02). Shortage of the Siberian crane-preferred Vallisneria tuber due to June flooding was the primary driver of the crane's altered foraging strategy and habitat shift. In years with relatively normal June inundation, indicating abundant Vallisneria resources, the relationship between the inundated area during the dry season and the crane population fit well, with a quadratic curve (R2 = 0.92, p = 0.02). The dry season's inundated area primarily affected the crane population and distribution pattern by influencing the availability of food resources, and both excessive and insufficient inundation areas were unfavorable for crane survival. The modeling results for habitat suitability indicated that as the water level decreased, the trend of the area of good habitat for the Siberian crane showed an inverted bell shape, peaking at a water level of 8.8 m, with optimal conditions occurring between 8 and 10 m. The combined effects of climate and human activities have made the shortage of food resources in Poyang Lake the new normal. The degradation of natural habitats has led to a decline in the quality of Siberian crane habitats, and artificial habitats can only be used as refuges to a certain extent. Thus, formulating strategies to restore natural habitats and enhance the management of artificial habitats is crucial for the conservation efforts of Siberian cranes.
ABSTRACT
Cytokinesis block micronucleus (CBMN) assay is a widely used radiation biological dose estimation method. However, the subjectivity and the time-consuming nature of manual detection limits CBMN for rapid standard assay. The CBMN analysis is combined with a convolutional neural network to create a software for rapid standard automated detection of micronuclei in Giemsa stained binucleated lymphocytes images in this study. Cell acquisition, adhesive cell mass segmentation, cell type identification, and micronucleus counting are the four steps of the software's analysis workflow. Even when the cytoplasm is hazy, several micronuclei are joined to each other, or micronuclei are attached to the nucleus, this algorithm can swiftly and efficiently detect binucleated cells and micronuclei in a verification of 2000 images. In a test of 20 slides, the software reached a detection rate of 99.4% of manual detection in terms of binucleated cells, with a false positive rate of 14.7%. In terms of micronuclei detection, the software reached a detection rate of 115.1% of manual detection, with a 26.2% false positive rate. Each image analysis takes roughly 0.3 s, which is an order of magnitude faster than manual detection.
Subject(s)
Image Processing, Computer-Assisted , Lymphocytes , Algorithms , Cytokinesis , Humans , Image Processing, Computer-Assisted/methods , Micronuclei, Chromosome-Defective , Micronucleus Tests/methodsABSTRACT
In photocatalysis, the most efficient way to separate photogenerated electron-hole pairs has been extensively studied. However, the methods to increase the quantities of free electrons are neglected. Herein, we used a self-assembly method to fabricate MTCPP/TiO2 composite materials with a series of metalloporphyrins (MTCPPs, M = Fe, Co, Zn) as sensitizers to modify TiO2 nanosheets. First, abundant carboxyl and hydroxyl on porphyrin were adsorbed by metal ions. Then, the remaining carboxyl and hydroxyl on porphyrin were anchored on the surface of TiO2 nanosheets. Finally, MTCPP/TiO2 was obtained by a layer-by-layer self-assembly process. MTCPP broadens the light response of TiO2 from ultraviolet light to visible light and enhances the CO2 adsorption ability. Moreover, metal ions coordinating with porphyrin regulate the electron density of the porphyrin ring and provide a stronger π feedback bond, which promote charge separation. Consequently, by optimizing the type of metal ion, the yield of ZnTCPP/TiO2 composites reached 109.33 µmol/(g h) of CO and 9.94 µmol/(g h) of CH4, which was more than 50 times that of pure TiO2. This study proposes a possible visible-light-induced CO2 reduction mechanism of metal-ion-based photocatalysis, which provides great insights into optimizing the designation of efficient photocatalysis.
ABSTRACT
Thallium (TI) is one of the most toxic heavy metals and priority pollutant metals. The emerging TI environmental pollution worldwide has posed a great threat to human health. However, based on the World Health Organization (WHO), the risk and severity of adverse health effects of TI in the range of 5-500 µg/L are uncertain. Moreover, evidence regarding the adverse impacts of TI on children's health is still insufficient. Herein, we aim to investigate the early adverse effects of TI on children's health and provide references for the WHO to establish stricter safety limits of TI. From 2015 to 2019, urinary TI and many clinical laboratory parameters related to blood routine, hepatic, renal, myocardial, coagulation function and serum electrolyte were measured in six children aged 1-9 years. The urinary TI concentration ranged from 13.4 µg/L to 60.1 µg/L with a mean of 36.1 µg/L and a median of 34.8 µg/L in six children in 2015. Although only four children felt a little poor appetite, several laboratory abnormalities indicated early damage in liver, renal, and myocardial functions in all children in 2015. After treatment and following up for four years, although the children's TI concentration decreased below 5 µg/L, their liver and renal functions did not completely recover, and their myocardial function worsened. Results indicated that impaired liver, renal, and myocardial functions were closely associated with elevated urinary TI concentration in children. Considering the increasing use of TI in high-technology industries and emerging TI environmental-contamination zones worldwide, establishing stricter safety limits of TI and paying more attention to the adverse health effects of TI on children are urgently required. SUMMARY: We found that a relatively low concentration of thallium (13.4 µg/L to 60.1 µg/L) impaired liver, renal, and myocardial function in six children. After treatment and following up these children for four years, although their urinary TI concentration decreased below 5 µg/L, their liver and renal functions did not completely recover, and their myocardial function worsened.
Subject(s)
Environmental Pollutants/urine , Heart/physiopathology , Kidney/physiopathology , Liver/physiopathology , Metals, Heavy/urine , Thallium/adverse effects , Thallium/urine , Water Pollutants, Chemical/urine , Child , Child, Preschool , Environmental Exposure , Female , Humans , Infant , Male , Metals, Heavy/toxicity , Myocardial Infarction , Water Pollutants, Chemical/toxicityABSTRACT
Rhizobia induce root nodules and fix atmospheric N2 for most legume species in exchange for carbon. However, the diverse endophytic non-rhizobial bacteria in legume nodules that co-exist with rhizobia are often ignored because they are difficult to cultivate using routine cultivation approaches. To enhance our understanding of the incidence and diversity of legume-bacteria associations, a high-throughput sequencing analysis of bacterial 16S rRNA genes was used to examine the bacterial community in the rhizospheres and root nodules of Dalbergia odorifera seedlings that were uninoculated or inoculated with Bradyrhizobium elkanii H255, Rhizobium multihospitium-like HT221, or Burkholderia pyrrocinia-like H022238, in two growth media (nitrogen [N]-supplied soil or N-omitted potting mix). Seedlings inoculated with Bradyrhizobium had significantly more nodules than seedlings in the other inoculation conditions, regardless of growth media. Using the 15N natural abundance method, it was shown that the inoculated plants had significantly higher N2 fixation efficiency (48-57%) and specific nodule activity [269-313 µg N mg-1 of dry weight (dwt) nodule] compared to the uninoculated plants (203 µg N mg-1 dwt nodule). The 16S rRNA gene analysis showed that there was generally a higher bacterial diversity in the rhizosphere than in the nodules in the corresponding condition. Both rhizobial inoculation and media status significantly altered the bacterial communities in the rhizospheres and nodules (P < 0.05), with the exception of the inoculated soil rhizospheres. Regarding non-rhizobial bacteria, three genera, i.e., Lactococcus, Bacillus, and Pseudomonas, were consistently enriched in the rhizosphere and Bradyrhizobium, Chloroplast norank (which belongs to Cyanobacteria), and Lactococcus were commonly found in the nodules. In contrast, common rhizobial genera (including Rhizobium, Mesorhizobium, and Burkholderia) were only present in the nodules at low relative abundances (0.01-3.41%). Regarding non-rhizobial bacteria, 32 genera were found in the nodules, with non-rhizobial bacteria being predominant in the N omitted potting mix (with a relative abundance of 56-87%). This study suggests that legume nodules are inhabited by a high diversity of non-rhizobial bacteria, which may play a vital role in nodulation and N2 fixation in the host plants.
ABSTRACT
OBJECTIVE: To evaluate the clinical efficacy of open supracondylar osteotomy of the femoral condyle for the treatment of valgus knee osteoarthritis. METHODS: From April 2008 to June 2015, 21 patients with valgus knee osteoarthritis underwent an open wedge femoral supracondylar osteotomy using the distal femur dissection plates combined with autologous iliac bone graft for the bone defect. There were 8 males (8 knees) and 13 females (15 knees), ranging in age from 30 to 54 years old, with a mean age of 41.2 years old. All the patients had valgus deformity and knee joint pain in the lateral compartment. The average tibiofemoral angle was (162.0±2.6)° which was measured on the image of preoperative lower extremity weight-bearing X-ray. Clinical outcomes were comprehensively assessed according to the bone healing time, postoperative complications, progress of knee osteoarthritis after operation, the Hospital for Special Surgery rating system (HSS), and tibiofemoral angle before and after operation. RESULTS: All 21 patients were followed up, the valgus deformity of knee joint was corrected in all patients after operation. No obvious delayed union or nonunion were found, and no serious complications were found. The HSS knee score was improved from the preoperative 57.3±3.1 to the final follow-up time 88.6±2.7. Tibiofemoral angle was improved to the postoperative(176.0±1.4)°. CONCLUSIONS: Open wedge femoral supracondylar osteotomy has a clear surgical approach, and it is easy to control the bone mass of osteotomy and can effectively correct the valgus deformity and improve the function of knee joint using this method. It is an effective method for the treatment of valgus knee osteoarthritis in young and middle-aged patients.