[Advances in the Effects of Microplastics on Soil N2O Emissions and Nitrogen Transformation].

Research on microplastics (MPs) is gaining more attention in the soil environment, but their impact on soil microbiota and related nitrogen processes remains poorly understood. Nitrous oxide (N2O) is one of the important greenhouse gases of the nitrogen cycle in agricultural soil, which mainly originates from microbial-mediated nitrogen (N) transformation processes. Microplastics can influence soil nitrogen transformation, as well as nitrogen-related functional enzymes and genes, and its enrichment may profoundly affect the N2O emissions in soil. However, because of the complexity of the properties of MPs, variations in experimental conditions, and spatial-temporal scales, the results on the effects of MPs on soil N2O emissions, nitrogen content, enzymes activities, and nitrogen functional genes remain inconsistent. Additionally, there is a lack of research conducted at broader experimental scales (e.g., pot scale), from diverse perspectives (e.g., denitrification or DNRA), and using advanced techniques (e.g., stable isotope approaches) to elucidate the underlying mechanisms. Therefore, to comprehend the environmental risk of MPs on soil from multiple perspectives, this review summarized the impact of MPs on soil N cycling from previous published research to provide a knowledge basis and gain holistic insights into the potential impact of soil microplastic enrichment on N2O emission patterns in agricultural soils under climate change conditions.

Streptococcus dysgalactiae subsp. dysgalactiae presents with progressive weakness in limbs: a case report and literature review.

BACKGROUND: Streptococcus dysgalactiae subsp. dysgalactiae has been identified as an animal pathogen that is thought to occur only in animal populations. Between 2009 and 2022, humans infected with SDSD were reported rarely. There is a lack of details on the natural history, clinical features, and management of disease caused by this pathogen. This case outlines a human SDSD with muscle aches and progressive loss of muscle strength leading to immobility and multi-organ dysfunction syndrome. CASE PRESENTATION: She presented with muscle pain and weakness, and later developed a sore throat, headache and fever with a maximum temperature of 40.5 °C. The muscle strength of the extremities gradually decreased to grade 1 and the patient was unable to move on his own. Next-generation blood sequencing and multi-culture confirmed the presence of Streptococcus dysgalactiae and Streptococcus dysgalactiae subsp. Dysgalactiae, respectively. A Sequential Organ Failure Assessment score of 6 indicated septicemia, and therapeutic antibiotics were prescribed empirically. After 19 days of inpatient treatment, the patient's condition greatly improved and completely recovered within a month. CONCLUSION: Symptoms of Streptococcus dysgalactiae subsp. dysgalactiae presenting with progressive limb weakness resemble polymyositis, so a precise differential diagnosis is essential. Multidisciplinary consultation is helpful when polymyositis cannot be ruled out and facilitates the choice of an optimal treatment protocol. In the context of this case, penicillin is an effective antibiotic for Streptococcus dysgalactiae subsp. dysgalactiae infection.

[Pollution Characteristics of PM2.5 Chemical Composition in Zhejiang Province].

To investigate the seasonal and regional pollution characteristics of PM2.5 chemical composition in Zhejiang province, this study was based on manual sampling monitoring data from 11 sampling sites of four regions in Zhejiang province from October 1, 2019 to September 30, 2020. The results showed that during the observation period, the average ρ(PM2.5) of the four regions ranged from 34.3 µg·m-3 to 46.4 µg·m-3. The PM2.5 mass concentrations in the hinterland areas of western Zhejiang and northern Zhejiang were relatively high, 15.1% and 13.2% higher than the mean value, respectively. The PM2.5 mass concentrations in the coastal areas of eastern Zhejiang and southern Zhejiang were relatively low, 8.4% and 14.9% lower than the average, respectively. The seasonal characteristics showed a higher concentration in autumn and winter and lowest concentration in summer. The seasonal variation in PM2.5 mass concentration from autumn to spring was not obvious in southern Zhejiang, whereas in western Zhejiang, the PM2.5 mass concentration followed a descending sequence of autumn>winter>spring>summer. In northern Zhejiang and eastern Zhejiang, the trend was winter>autumn>spring>summer. During the observation period in the inland area, the ρ(PM2.5) of the scenic area, administrative area, residential area, and mixed area of commercial traffic and residents were (40.2±10.2), (46.3±9.6), (50.1±10.6), and (46.7±10.2) µg·m-3, respectively. The highest value of ρ(PM2.5) was in the residential area. During the sampling period in coastal areas, the ρ(PM2.5) of the cultural and entertainment area and mixed area of commercial traffic and residents were (27.4±5.8) µg·m-3and (37.2±5.6) µg·m-3, respectively. The contribution rates of organic matter (OM), NO3-, SO42-, NH4+, trace elements, and crustal matter in PM2.5were 26.4%, 15.4%, 12.4%, 9.0%, 7.1%, and 5.7%, respectively. The SNA, including SO42-, NO3-, and NH4+, contributed 36.8% in PM2.5. In terms of seasons, the contribution of OM to PM2.5 in autumn, spring, and summer was higher than that of other compositions, which accounted for 28.3%, 27.7%, and 26.3%, respectively. The contribution rate of NO3- in PM2.5 was the largest in winter, reaching 24.3%. In terms of spatial distribution, SNA contributed the most to PM2.5 in all regions, ranging from 32.8% to 39.7%, with the highest in northern Zhejiang and the lowest in southern Zhejiang. The SNA of all regions presented NO3->SO42->NH4+. Based on the backward trajectory clustering analysis, the main air sources of northern Zhejiang were the Yellow Sea-southern Jiangsu (autumn), northern Anhui (winter), East China Sea (spring), and western Jiangsu (summer) areas, with contribution rates of 38.11%, 35.28%, 37.46%, and 27.87%, respectively. The main air sources of western Zhejiang were the Yellow Sea-southern Jiangsu (autumn), southern Anhui (winter), eastern Zhejiang (spring), and northern Zhejiang (summer), with contribution rates of 38.11%, 37.50%, 46.55%, and 32.58%, respectively. The air of autumn, winter, spring, and summer in eastern Zhejiang were influenced by air masses from northern Hebei (36.07%), eastern Shandong (38.06%), East China Sea (30.17%), and southern Guangdong (34.43%), respectively. In autumn, winter, spring, and summer, southern Zhejiang was affected by air masses from the Yellow Sea (35.66%), northeast Anhui (34.44%), East China Sea (26.72%), and southern Fujian coast (35.00%), respectively. The regions in Zhejiang province showed large seasonal differences. The difference value between the maximum value of ρ(PM2.5) in the northwest and the lowest value in the southeast was 21.0 µg·m-3 and 20.5 µg·m-3 in autumn and winter, respectively; the difference values in spring and summer were 10.4 µg·m-3 and 6.1 µg·m-3. Thus, the northern air mass had a certain exogenous contribution to PM2.5 in autumn and winter in Zhejiang province. However, with the weakening of the northern air mass trajectory in spring and summer and the increasing contribution of the southern and east China Sea air mass to the air flow in Zhejiang province, PM2.5 pollution showed a trend of improvement.

Leptospira infection complicated by demyelinating disease: A case report.

Leptospirosis is a zoonotic disease, found worldwide, that is caused by bacteria of the genus Leptospira. People can be infected with Leptospira if they come in direct contact with the urine of an infected animal. Leptospirosis may be associated with demyelinating lesions of the central nervous system. This case report describes a 66-year-old female patient who presented with fever and generalized aches and progressed to unconsciousness within a few hours of admission. Laboratory tests showed Leptospira infection, and brain magnetic resonance imaging revealed acute demyelinating lesions. The patient responded well to penicillin and intravenous methylprednisolone therapy. Leptospirosis presenting with acute disseminated encephalomyelitis is rare. In this patient, an interdisciplinary collaboration involving the neurologist, radiologist, and pathologist was crucial for diagnosis and management. Further studies are warranted to investigate whether there is a correlation between demyelinating lesions and leptospiral infection.

[Object-oriented segmentation and classification of forest gap based on QuickBird remote sensing image.] / 基于面向对象的QuickBird遥感影像林隙分割与分类.

Traditional field investigation and artificial interpretation could not satisfy the need of forest gaps extraction at regional scale. High spatial resolution remote sensing image provides the possibility for regional forest gaps extraction. In this study, we used object-oriented classification method to segment and classify forest gaps based on QuickBird high resolution optical remote sensing image in Jiangle National Forestry Farm of Fujian Province. In the process of object-oriented classification, 10 scales (10-100, with a step length of 10) were adopted to segment QuickBird remote sensing image; and the intersection area of reference object (RAor) and intersection area of segmented object (RAos) were adopted to evaluate the segmentation result at each scale. For segmentation result at each scale, 16 spectral characteristics and support vector machine classifier (SVM) were further used to classify forest gaps, non-forest gaps and others. The results showed that the optimal segmentation scale was 40 when RAor was equal to RAos. The accuracy difference between the maximum and minimum at different segmentation scales was 22%. At optimal scale, the overall classification accuracy was 88% (Kappa=0.82) based on SVM classifier. Combining high resolution remote sensing image data with object-oriented classification method could replace the traditional field investigation and artificial interpretation method to identify and classify forest gaps at regional scale.

[Changes of CD8+CD28- T cell percentage in patients with multiple injuries and their clinical significance].

OBJECTIVE: To investigate the correlation of the changes in CD8(+)CD28(-) T cell percentage with platelet (PLT) and D-dimer (D-D) levels in patients with multiple injuries (MI). METHODS: Twenty-six patients with MI, 31 with a single injury (SI group) and 26 healthy individuals were examined for peripheral blood CD8(+)CD28(-) T cells and intracellular transformation growth factor-ß1 (TGF-ß1) and interleukin 10 (IL-10) contents using flow cytometry at 24, 48, and 72 h after the injuries. PLT and D-dimer levels were compared among the 3 groups. RESULTS: CD8(+)CD28(-) T cells, TGF-ß1 and IL-10 were significantly higher in MI group than in SI group and healthy control group (P<0.05) without significant differences between the latter 2 groups. The levels of PLT and D-D differed significantly among the 3 groups, the highest in MI group and the lowest in the control group. In MI group, CD8(+)CD28(-) T cells, TGF-ß1 and IL-10 significantly increased at 48 h after the injury (P<0.05) but decreased significantly at 72 h (P<0.05) compared with the measurements at 24 h. The levels of PLT and D-D trended to decrease with time after the injuries and showed significant differences among the 3 groups at any of the 3 time points (P<0.05). CD8(+)CD28(-) T cells, TGF-ß1 and IL-10 were all positively correlated with the levels of PLT and D-D in MI patients (r>0.70, P<0.05 for all comparisons). CONCLUSION: In MI patients, CD8(+)CD28(-) T cell percentage and their cytokines tend to increase early after the injury but decrease significantly at 72 h in close relation with the changes of the coagulation function following the injuries.

Preparation and characterization of a novel aspirin derivative with anti-thrombotic and gastric mucosal protection properties.

The use of acetylsalicylic acid (ASP) is limited by its adverse effects, especially the effect on the gastric mucosa. To address this problem, we synthesized a derivative form of ASP, prepared by modification of ASP with nano-hydroxyapatite (a kind of inorganic particle containing Ca(2+)). The derivative was named Ca-ASP. Structural study showed that Ca-ASP was a kind of carboxylate containing intramolecular hydrogen bonds. Rats given a high dose of Ca-ASP (5 mmol per kg body weight) showed similar anti-thrombotic activity as those given the same dose of ASP, but had much lower gastric mucosal damage than ASP (UI: 2 versus UI: 12.5). These rats also showed reduced expression of COX-2, but their COX-1 expression was similar to that of control rats, but significantly higher than that of ASP-administered rats. Furthermore, the level of prostaglandin E2 (PGE2) was up-regulated in Ca-ASP-administered rats compared to ASP-administered rats. Taken together, the results showed that Ca-ASP possessed similar antithrombotic activity as ASP but without the side effect associated with ASP, and the underlying mechanism may center on inhibiting COX-2 without inhibiting COX-1, and thus favouring the production of PGE2, the prostaglandin that plays a vital role in the suppression of platelet aggregation and thrombosis, as well as in the repair of gastric damage.