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Solid polymer electrolytes have attracted considerable attention, owing to their flexibility and safety. At present, poly(ethylene oxide) is the most widely studied polymer electrolyte matrix. It exhibits higher safety than the polyolefin diaphragm used in traditional lithium-ion batteries. However, it readily crystallizes at room temperature, resulting in low ionic conductivity, and the preparation process involves organic solvents. In this study, from the perspective of molecular design, solvent-free polyaspartate polyurea (PAEPU) and the cheap and easily available polypropylene (PP) nonwoven fabric were used as support materials for the PAEPU/PP composite solid polymer electrolyte (PAEPU/PP m -CPE). This CPE has good thermal stability, dimensional stability, flexibility, and mechanical properties. Among the different CPEs that were analyzed, PAEPU/PP10-CPE@20 had the highest ionic conductivity, which was reinforced with 10 g/m2 PP nonwoven fabric and the content of lithium salt was 20 wt %. Furthermore, PAEPU/PP10-CPE@20 exhibited the highest electrochemical stability with an electrochemical window value of 5.53 V. Moreover, the capacity retention rate of the Li//PAEPU/PP10-CPE@20//LiFePO4 half-cell was 96.82% after 150 cycles at 0.05 C and 60 °C, and the capacity recovery rate in the rate test reached 98.81%.
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PM2.5 is a main atmospheric pollutant with various sources and complex chemical compositions, which are influenced by various factors, such as anthropogenic emissions (AE) and meteorological conditions (MC). MC have a significant impacts on variations in atmospheric pollutant; therefore, emission reduction policies and ambient air quality are non-linearly correlated, which hinders the accurate assessment of the effectiveness of control measures. In this study, we conducted online observations of PM2.5 and its chemical composition in Hohhot, China, from December 1, 2019, to February 29, 2020, to investigate how the chemical compositions of PM2.5 respond to the variations in AE and MC. Moreover, the random forest (RF) model was used to quantify the contributions of AE and MC to PM2.5 and its chemical composition during severe hazes and the COVID-19 pandemic lockdown period. During the clean period, MC reduced PM2.5 concentrations by 124%, while MC incresed PM2.5 concentrations by 49% during severe pollution episode. Inorganic aerosols (SO42-, NO3-, and NH4+) showed the strongest response to MC. MC significantly contributed to PM2.5 (36%), SO42- (32%), NO3- (29%), NH4+ (28%), OC (22%), and SOC (17%) levels during pollution episodes. From the pre-lockdown to lockdown period, AE (MC) contributed 52% (48%), 81% (19%), 48% (52%), 68% (32%), 59% (41%), and 288% (-188%) to the PM2.5, SO42-, NO3-, NH4+, OC, and SOC reductions, respectively. The variations in MC (especially the increase in relative humidity) rapidly generated meteorologically sensitive species (SO42-, NO3-, and NH4+), which led to severe winter pollution. This study provides a reference for assessing the net benefits of emission reduction measures for PM2.5 and its chemical compositions.
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Poluentes Atmosféricos , Poluição do Ar , COVID-19 , Monitoramento Ambiental , Material Particulado , Material Particulado/análise , COVID-19/epidemiologia , COVID-19/prevenção & controle , Poluentes Atmosféricos/análise , China , Poluição do Ar/estatística & dados numéricos , Poluição do Ar/análise , Monitoramento Ambiental/métodos , Humanos , Aerossóis/análise , SARS-CoV-2 , Pandemias , Conceitos MeteorológicosRESUMO
Organophosphate esters (OPEs) are frequently used as flame retardants and plasticizers in various commercial products. While initially considered as substitutes for brominated flame retardants, they have faced restrictions in some countries due to their toxic effects on organisms. We collected 37 soil and crop samples in 20 cities along the coast of South China, and OPEs were detected in all of them. Meanwhile, we studied the contamination and potential human health risks of OPEs. In soil samples, the combined concentrations of eight OPEs varied between 74.7 and 410 ng/g, averaging at 255 ng/g. Meanwhile, in plant samples, the collective concentrations of eight OPEs ranged from 202 to 751 ng/g, with an average concentration of 381 ng/g. TDCIPP, TCPP, TCEP, and ToCP were the main OPE compounds in both plant and soil samples. Within the study area, the contaminants showed different spatial distributions. Notably, higher OPEs were found in coastal agricultural soils in Guangdong Province and crops in the Guangxi Zhuang Autonomous Region. The results of an ecological risk assessment show that the farmland soil along the southern coast of China is at high or medium ecological risk. The average non-carcinogenic risk and the carcinogenic risk of OPEs in soil through ingestion and dermal exposure routes are within acceptable levels. Meanwhile, this study found that the dietary intake of OPEs through food is relatively low, but twice as high as other studies, requiring serious attention. The research findings suggest that the human risk assessment indicates potential adverse effects on human health due to OPEs in the soil-plant system along the coast of South China. This study provides a crucial foundation for managing safety risks in agricultural operations involving OPEs.
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Silver/polymeric vesicle composite nanoparticles with good antibacterial properties were fabricated in this study. Silver nanoparticles (AgNPs) were prepared inâ situ on cross-linked vesicle membranes through the reduction of silver nitrate (AgNO3) using polyvinylpyrrolidone (PVP) via coordination bonding between the Ag+ ions and the nitrogen atoms on the vesicles. X-ray diffraction (XRD), ultraviolet-visible spectroscopy (UV-vis), and transmission electron microscopy (TEM) analyses confirmed the formation of AgNPs on the vesicles. The antibacterial test demonstrated good antibacterial activity against both Gram-negative bacteria (Escherichia coli) and Gram-positive bacteria (Staphylococcus aureus) for the produced AgNP-decorated vesicles. The minimum inhibitory concentration (MIC) values of the AgNP-decorated vesicles for E.â coli and S.â aureus were 8.4 and 9.6â µg/mL, respectively. Cell viability analysis on the A549 cells indicated that the toxicity was low when the AgNP concentrations did not exceed the MIC values, and the wound healing test confirmed the good antibacterial properties of the AgNP-decorated vesicles.
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Antibacterianos , Escherichia coli , Nanopartículas Metálicas , Testes de Sensibilidade Microbiana , Prata , Staphylococcus aureus , Antibacterianos/farmacologia , Antibacterianos/química , Antibacterianos/toxicidade , Prata/química , Prata/farmacologia , Nanopartículas Metálicas/química , Nanopartículas Metálicas/toxicidade , Staphylococcus aureus/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Humanos , Sobrevivência Celular/efeitos dos fármacos , Células A549 , Polímeros/química , Polímeros/farmacologiaRESUMO
INTRODUCTION: Atypical glandular cells (AGC) represent less than 1% of Pap test cases and include a variety of lesions in both the cervix and endometrium. The study aimed to investigate the cytology-histology correlation in AGC patients and to evaluate the clinical utility of hrHPV testing in this diagnostic context. MATERIALS AND METHODS: We identified 491 atypical glandular cells (AGC) cases in our quality analysis (QA) database of 336,064 Pap tests interpreted between March 1, 2013 and July 12, 2016. Of these, 251 cases had follow-up biopsies with hrHPV tests in 148 cases. RESULTS: The most common histologic diagnosis associated with AGC was normal/benign or low-grade lesions, comprising 55% of cervical biopsies and 24% of endometrial biopsies. High-grade lesions were identified in 21% of follow-up biopsies. In patients with AGC cytology, a positive hrHPV test significantly increased the likelihood of cervical HSIL or above lesions on biopsy by 26.4 times (OR = 26.4, 95% CI: 5.8-119.4, P < 0.0001). A positive genotyping result for HPV 16 dramatically increased the likelihood of cervical HSIL or above lesions on biopsy (OR = 84, 95% CI: 12.0-590.5, P < 0.0001). The HPV test had a negative predictive value of 97% (CI: 85%-100%). CONCLUSIONS: Our study confirms that AGC is a significant diagnosis with an overall risk for high-grade cervical or endometrial lesions as high as 21%. hrHPV testing with genotyping is an effective tool for identifying high-risk individuals within the AGC population, with excellent positive and negative predictive values. This approach is valuable for clinical risk stratification and differential diagnosis in patients with AGC cytology.
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Teste de Papanicolaou , Infecções por Papillomavirus , Neoplasias do Colo do Útero , Esfregaço Vaginal , Adulto , Idoso , Feminino , Humanos , Pessoa de Meia-Idade , Adulto Jovem , Biópsia , Colo do Útero/patologia , Colo do Útero/virologia , Neoplasias do Endométrio/patologia , Neoplasias do Endométrio/diagnóstico , Neoplasias do Endométrio/virologia , Endométrio/patologia , Endométrio/virologia , Teste de Papanicolaou/métodos , Papillomaviridae/isolamento & purificação , Papillomaviridae/genética , Infecções por Papillomavirus/diagnóstico , Infecções por Papillomavirus/patologia , Infecções por Papillomavirus/virologia , Medição de Risco , Displasia do Colo do Útero/diagnóstico , Displasia do Colo do Útero/patologia , Displasia do Colo do Útero/virologia , Neoplasias do Colo do Útero/diagnóstico , Neoplasias do Colo do Útero/patologia , Neoplasias do Colo do Útero/virologia , Esfregaço Vaginal/métodosRESUMO
Sulfonamide antibiotics, extensively used in human and veterinary therapy, accumulate in agroecosystem soils through livestock manure and sewage irrigation. However, the interaction between sulfonamides and rice plants remains unclear. This study investigated the transformation behavior and toxicity of sulfamethoxazole (SMX) and its main metabolite, N4-acetyl-sulfamethoxazole (NASMX) in rice. SMX and NASMX were rapidly taken up by roots and translocated acropetally. NASMX showed higher accumulating capacity, with NASMX concentrations up to 20.36 ± 1.98 µg/g (roots) and 5.62 ± 1.17 µg/g (shoots), and with SMX concentrations up to 15.97 ± 2.53 µg/g (roots) and 3.22 ± 0.789 µg/g (shoots). A total of 18 intermediate transformation products of SMX were identified by nontarget screening using Orbitrap-HRMS, revealing pathways such as deamination, hydroxylation, acetylation, formylation, and glycosylation. Notably, NASMX transformed back into SMX in rice, a novel finding. Transcriptomic analysis highlights the involvements of cytochrome P450 (CYP450), acetyltransferase (ACEs) and glycosyltransferases (GTs) in these biotransformation pathways. Moreover, exposure to SMX and NASMX disrupts TCA cycle, amino acid, linoleic acid, nucleotide metabolism, and phenylpropanoid biosynthesis pathways of rice, with NASMX exerting a stronger impact on metabolic networks. These findings elucidate the sulfonamides' metabolism, phytotoxicity mechanisms, and contribute to assessing food safety and human exposure risk amid antibiotic pollution.
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Oryza , Sulfametoxazol , Humanos , Sulfametoxazol/toxicidade , Sulfametoxazol/química , Oryza/metabolismo , Antibacterianos/química , Sulfonamidas , Solo/química , SulfanilamidaRESUMO
Tetracycline is frequently found in various environments and poses significant ecological risks. Calcium hydroxide-modified biochar has shown potential as a material for removing multiple classes of pollutants from wastewater streams. The tetracycline-adsorption performance and mechanism of alkali-modified biochars derived from nine wastes (corn straw, rice straw, swine manure, cypress powder, wheat straw, peanut shell, walnut shell powder, soybean straw, and corncobs) were investigated in the study. Among the four alkalis tested, calcium hydroxide exhibited the most effective modification effects at a pyrolysis temperature of 500 °C. Straw biomass was most suitable to be modified by calcium hydroxide, and calcium hydroxide-modified biochar showed the highest adsorption performance for tetracycline. The maximum adsorption capacities were 8.22 mg g-1 for pristine corn straw biochar and 93.46 mg g-1 for calcium hydroxide-modified corn straw biochar. The tetracycline adsorption mechanism by calcium hydroxide-modified corn straw biochar involved hydrogen bonding, oxygen-containing functional groups, Ca2+ metal complexation, and electrostatic attraction. Consequently, calcium hydroxide-modified corn straw biochar emerges as an environment-friendly, cost-effective, and efficient tetracycline adsorbent.
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The criticality of the jamming transition responsible for amorphous solidification has been theoretically linked to the marginal stability of a thermodynamic Gardner phase. While the critical exponents of jamming appear independent of the preparation history, the pertinence of Gardner physics far from equilibrium is an open question. To fill this gap, we numerically study the nonequilibrium dynamics of hard disks compressed toward the jamming transition using a broad variety of protocols. We show that dynamic signatures of Gardner physics can be disentangled from the aging relaxation dynamics. We thus define a generic dynamic Gardner cross-over regardless of the history. Our results show that the jamming transition is always accessed by exploring increasingly complex landscape, resulting in anomalous microscopic relaxation dynamics that remains to be understood theoretically.
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Carbonaceous aerosols have great adverse impacts on air quality, human health, and climate. However, there is a limited understanding of carbonaceous aerosols in semi-arid areas. The correlation between carbonaceous aerosols and control measures is still unclear owing to the insufficient information regarding meteorological contribution. To reveal the complex relationship between control measures and carbonaceous aerosols, offline and online observations of carbonaceous aerosols were conducted from October 8, 2019 to October 7, 2020 in Hohhot, a semi-arid city. The characteristics and sources of carbonaceous aerosols and impacts of anthropogenic emissions and meteorological conditions were studied. The annual mean concentrations (± standard deviation) of fine particulate matter (PM2.5), organic carbon (OC), and elemental carbon (EC) were 42.81 (±40.13), 7.57 (±6.43), and 2.25 (±1.39) µg m-3, respectively. The highest PM2.5 and carbonaceous aerosol concentrations were observed in winter, whereas the lowest was observed in summer. The result indicated that coal combustion for heating had a critical role in air quality degradation in Hohhot. A boost regression tree model was applied to quantify the impacts of anthropogenic emissions and meteorological conditions on carbonaceous aerosols. The results suggested that the anthropogenic contributions of PM2.5, OC, and EC during the COVID-19 lockdown period were 53.0, 15.0, and 2.36 µg m-3, respectively, while the meteorological contributions were 5.38, 2.49, and -0.62 µg m-3, respectively. Secondary formation caused by unfavorable meteorological conditions offset the emission reduction during the COVID-19 lockdown period. Coal combustion (46.4% for OC and 35.4% for EC) and vehicular emissions (32.0% for OC and 50.4% for EC) were the predominant contributors of carbonaceous aerosols. The result indicated that Hohhot must regulate coal use and vehicle emissions to reduce carbonaceous aerosol pollution. This study provides new insights and a comprehensive understanding of the complex relationships between control strategies, meteorological conditions, and air quality.
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Poluentes Atmosféricos , COVID-19 , Humanos , Poluentes Atmosféricos/análise , Monitoramento Ambiental , Controle de Doenças Transmissíveis , Aerossóis e Gotículas Respiratórios , Material Particulado/análise , Emissões de Veículos/análise , Carvão Mineral/análise , Estações do Ano , Carbono/análise , ChinaRESUMO
BACKGROUND: The association between pulmonary involvement and microscopic polyangiitis (MPA) has been increasingly recognized in recent years. Whether interstitial lung disease (ILD) and bronchiectasis (BE) are disease manifestations of MPA, preexisting comorbidities or important complications remains unclear. The purpose of this study was to determine the clinical characteristics and prognosis of MPA with pulmonary involvement to further guide clinical management. METHODS: The data for 97 patients with a definitive diagnosis of MPA were retrospectively reviewed. The MPA diagnosis was based on the 2012 revised Chapel Hill Consensus Conference (CHCC) criteria. The baseline clinical information and laboratory parameters were collected and analysed at each patient's initial diagnosis. RESULTS: Forty-seven out of the 97 (48.5%) patients who were diagnosed with MPA presented with pulmonary involvement, including 37 patients with ILD, 12 patients with BE and two patients with diffuse alveolar haemorrhage (DAH). ILD and BE antedated MPA in 56.76% and 75.00% of the patients, respectively. Compared with that in the MPA-BE group, the serum LDH level (222.86 ± 68.19 vs. 171.58 ± 31.43, p = .016) in the MPA-ILD group was significantly higher. In the multivariate Cox analysis, elevated serum creatinine (HR 4.08, confidence interval (CI) 1.38-12.05, p = .011) was an independent risk factor for shorter survival in MPA patients with pulmonary involvement, and treatment with glucocorticoid pulse cyclophosphamide therapy (HR 0.095, 95% CI 0.019-0.47, p = .004) was independently associated with prolonged survival. Among the patients in the MPA-ILD group, acute exacerbations of ILD (HR 4.55 CI 1.16-17.86, p = .029) and elevated serum creatinine (HR 4.95, CI 1.39-17.54, p = .014) were independently associated with a poor prognosis, and treatment with glucocorticoids (HR 0.057, 95% CI 0.012-0.28, p < .001) was independently associated with significant prolongation of survival. CONCLUSIONS: Patients with MPA have a high prevalence of pulmonary involvement, and ILD is the most common subtype of MPA. ILD and BE can be considered preexisting comorbidities of MPA. Elevated serum creatinine was associated with shorter survival. However, remission induction regimens with glucocorticoids and/or immunosuppressants may improve this outcome.
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Bronquiectasia , Doenças Pulmonares Intersticiais , Poliangiite Microscópica , Humanos , Poliangiite Microscópica/complicações , Poliangiite Microscópica/diagnóstico , Poliangiite Microscópica/tratamento farmacológico , Estudos Retrospectivos , Relevância Clínica , Glucocorticoides/uso terapêutico , Creatinina , Prognóstico , Probabilidade , Bronquiectasia/complicaçõesRESUMO
As vaccine adjuvants, polyacrylate materials can induce a specific immune response in the body and have been widely studied in recent years due to their advantages, such as their safety, effectiveness, and low required dosage. In this study, a series of polyacrylates with hydrophobic physical crosslinking and chemical crosslinking were prepared using precipitation polymerization, and their structures were characterized by nuclear magnetic resonance spectroscopy and Fourier-transform infrared spectroscopy. The optimal reaction conditions were determined according to the effect of reaction time, azodiisobutyronitrile, Span 60, allyl pentaerythritol, and octadecyl methacrylate (OMA) contents on the viscosity of the polyacrylate microgel, combined with the effects of allyl pentaerythritol and OMA contents on the subcutaneous immune safety of the polyacrylate microgel in BALB/c mice. The polyacrylate microgels with different OMA contents showed good biological safety. In addition, inâ vivo immunity experiments were carried out in mice to analyze the adjuvant properties of ovalbumin as a model antigen. Based on the titer results of the IgG1 and IgG2a antibodies, with 1â wt % OMA content, the polyacrylate microgel vaccine could optimally induce the body to produce an immune response type dominated by Th2-type humoral immune response and supplemented by Th1-type cellular immune response.
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Microgéis , Animais , Camundongos , Ovalbumina/farmacologia , Células Th1 , Células Th2 , Adjuvantes Imunológicos/química , Adjuvantes Imunológicos/farmacologia , Antígenos/farmacologia , Adjuvantes Farmacêuticos/farmacologiaRESUMO
Post-encapsulation and release of the anticancer drug doxorubicin hydrochloride (DOX·HCl) through cell-like transmission functions of polymeric vesicles were studied using cross-linked pH-responsive polymeric vesicles. The vesicles were fabricated for the first time via the redox-initiated reversible addition-fragmentation chain transfer dispersion polymerization in ethanol-water mixture, using 2-(diisopropylamino)ethyl methacrylate and glycidyl methacrylate, and the vesicle membrane was modified post-cross-linking by using ethylenediamine. A phase diagram was constructed for reproducible fabrication of the polymeric vesicles, and well-shaped vesicles were formed when the target degree of polymerization of the hydrophobic polymer chains was equal to or higher than 50 with solid content in the range of 10-30 wt%. The cross-linked vesicle membrane served as a gate enabling "open" and "closed" states in response to pH stimulation. Up to 50% drug loading efficiency and 39% drug loading content could be achieved, and in vitro release of the DOX-loaded vesicles in aqueous buffer solutions showed a much faster DOX release rate at pH 5.0 than at pH 6.5. The polymeric vesicles were of very low cytotoxicity to A549 cells up to the concentration of 2 mg/mL, and the IC50 of DOX-loaded vesicles were higher than that of the free DOX. The intracellular DOX release study indicated higher cellular uptake capability for DOX-loaded vesicles than that of free DOX.
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Antineoplásicos , Antineoplásicos/farmacologia , Antineoplásicos/química , Doxorrubicina/farmacologia , Doxorrubicina/química , Polímeros/química , Concentração de Íons de Hidrogênio , Portadores de Fármacos/química , Liberação Controlada de FármacosRESUMO
BACKGROUND: This study retrospectively analyzed the laboratory data and chest images of patients with amyopathic dermatomyositis associated with interstitial lung disease (ADM-ILD) and patients with other connective tissue disease-related ILDs (CTD-ILDs) to find a characteristic index for the early recognition of ADM-ILD and help clinicians consider the possibility of ADM-ILD as soon as possible. METHODS: In our cohort study, the records of 128 Chinese patients with CTD-ILD, including 33 ADM-ILD patients, 37 rheumatoid arthritis (RA)-ILD patients, 33 primary Sjogren's syndrome (pSS)-ILD patients, 14 systemic sclerosis (SSc)-ILD patients and 11 systemic lupus erythematosus (SLE)-ILD patients. The patients' clinical features, laboratory parameters, and chest HRCT findings were analyzed. RESULTS: ADM-ILD patients generally had significantly higher LDH (333.52±160.21 U/L), AST (66.21±83.66 U/L), and CK-MB (18.23±8.28 U/L) levels than other CTD-ILD patients. A total of 90.91% (30/33) of ADM-ILD patients had elevated LDH. Patients with ADM-ILD were more prone to organizing pneumonia radiologic patterns on chest HRCT scans than patients with other CTD-ILDs (χ2=37.39, p < 0.001) and were found in 18 of 33 ADM-ILD patients. Anti-MDA5 (45.45%) was the most commonly detected autoantibody in ADM-ILD patients, followed by anti-PL-7 (21.21%), anti-Jo-1 (12.12%), and anti-PL-12 (9.09%), and levels of ALT (96.93±119.79 vs. 17.50±6.218 U/L), AST (113.00±106.13 vs. 23.56±6.91 U/L), LDH (415.00±198.51 vs. 261.94±67.75 U/L) and CK-MB (22.57±5.91 vs. 14.61±8.36 U/L) were significantly higher in anti-MDA5-positive patients, but these patients had significantly lower WBC counts (4.82±2.61 vs. 7.14±3.00 × 109/L), lymphocyte counts (0.72±0.20 vs. 1.23±0.53 × 109/L), and ALB levels (31.90±4.76 vs. 35.49±4.71 g/L). CONCLUSIONS: ADM-ILD patients have higher serum LDH, AST and CK-MB levels, especially serum LDH levels, and are more prone to organizing pneumonia radiologic patterns on chest HRCT scans than other CTD-ILD patients. A high level of serum LDH with ILD may be a useful characteristic index for recognizing ADM-ILD.
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Doenças do Tecido Conjuntivo , Doenças Pulmonares Intersticiais , Humanos , Estudos Retrospectivos , Estudos de Coortes , Doenças Pulmonares Intersticiais/complicações , Doenças Pulmonares Intersticiais/diagnóstico por imagem , Doenças do Tecido Conjuntivo/complicações , Doenças do Tecido Conjuntivo/diagnóstico por imagem , PrognósticoRESUMO
Objective: The aim of our study was to investigate the role of three-dimensional arterial spin labeling (3D-ASL) perfusion in the diagnosis and follow-up of children with viral encephalitis. Methods: Twenty-five consecutive children with viral encephalitis and 25 healthy children of similar age were recruited for the study between 2017 and 2020. Conventional magnetic resonance imaging and 3D-ASL were performed for all subjects, and a color map of cerebral blood flow (CBF) was generated. The images were classified into three groups depending on the time points at which the magnetic resonance examinations were conducted, including the initial admission scan, inpatient review, and follow-up review. Clinical, neuroradiologic, and follow-up features were studied.The CBF values of the lesion area in the diseased brain group and the bilateral temporal cortex in the control group were measured and the differences between the two groups were compared. Results: Perfusion was significantly increased in the acute cerebral disease group, and CBF and normalized cerebral blood flow(nCBF) were significantly higher than in the control group (124.5 vs 70.3 mL/100 g/min, 2.85 vs 1.36). Follow-up revealed that brain tissue perfusion in the lesion area of nine children decreased gradually after treatment, as their condition improved. Conclusion: Brain tissue perfusion in children with viral encephalitis increases during the acute stage and decreases when the condition improves. 3D-ASL provides a reference for diagnosis and follow-up of viral encephalitis in children.
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To reveal the pollution status of agricultural soils along with rapid urbanization and economic growth, a large regional survey of organochlorine pesticides (OCPs) in agricultural soils was conducted in the Pearl River Delta (PRD) of China. The results showed that the total residues of 23 OCPs were in the range of ND-946 ng/g dry weight. OCP residues showed distinct spatial distribution characteristics within the PRD. OCPs were mainly found in areas with high agricultural production and industrial activities. Higher OCP concentrations were observed in the top layer of soil, while the concentration decreases to marginal levels when the soil depth is greater than 50 cm. OCPs are mainly derived from historical use. Hexachlorocyclohexanes (HCHs) in the top soil of the study area are mainly from the use of lindane. Soil pH was negatively and significantly correlated with total OCP concentration. The human health risk assessment showed no health risk for children, while for adults, there is a non-carcinogenic risk, which needs to be noticed. Agricultural activities and industrial production have made the region a pollution hotspot and should arouse more stringent regulation to protect the environment and food safety.
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Hidrocarbonetos Clorados , Praguicidas , Poluentes do Solo , Criança , Humanos , Solo/química , Rios/química , Hexaclorocicloexano/análise , Poluentes do Solo/análise , Monitoramento Ambiental/métodos , Hidrocarbonetos Clorados/análise , Praguicidas/análise , Medição de Risco , ChinaRESUMO
To explain the phenomenon of all-optical modulation of quantum cascade laser (QCL), and explore the physics in QCL's gain medium which consists of multiple of dielectric nanostructures with high refractive index under light injection, we modified the 1½-period model to calculate values of electron population and lifetime in each subband which is separated by the nanostructures, optical gain, current and number of photons in the cavity of a mid-infrared QCL modulated with near-infrared optical injection. The results were consistent with an experiment, where the injected light increases the electron population and lifetime, but does not affect the optical gain obviously. Our study can be helpful for optimizing its use and dielectric nanostructure design.
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Water availability is the main factor affecting the forage productivity of artificial grasslands, particularly in semi-arid regions. Generally, intercropping of gramineous grass and leguminous grass can achieve high productivity. However, how different water availability levels affect the productivity of intercropping system remains unclear. Here, we conducted a 3-year (2015-2017) study by manipulating the water conditions (CK equivalent to the annual precipitation, +50% treatment equivalent to 50% increase over the average precipitation, and -50% treatment equivalent to 50% decrease over the average precipitation) to explore the responses of plant traits, nitrogen use efficiency, and biomass of the monoculture of Medicago sativa (a leguminous grass, M.s), monoculture of Elymus nutans (a gramineous grass, E.n), and intercropping of M.s and E.n in a semi-arid region in Inner Mongolia, China. The results showed that the biomass obtained by intercropping of M.s and E.n decreased by 24.4% in -50% treatment compared to the CK treatment, while that of the monoculture of M.s decreased by 34.4% under the -50% treatment compared to the CK treatment. However, there was no significant difference in the biomass between intercropping artificial grassland and monoculture M. sativa under +50% treatment. Compared to monoculture, M.s can obtain more nitrogen by biological nitrogen fixation and decrease the proportion of nitrogen absorbed from soils under intercropping in the same water conditions. Under the intercropping system, the proportions of nitrogen absorbed from soils by M.s were 87.4%, 85.1, and 76.9% in -50%, CK, and +50% treatments, respectively. Under monoculture, these proportions were 91.9, 89.3, and 82.3% in -50%, CK, and +50% treatments, respectively. Plant trait, but not soil nitrogen content, was the main regulator for the productivity responses to water level changes. Our results highlight that intercropping can achieve higher productivity in both dry and wet conditions. Therefore, considering the fluctuating rainfall events in the future, it might be useful to alter the proportions of intercropped forage species in an artificial grassland to obtain optimal productivity by reducing the limitations of nitrogen availability. However, the economic viability of intercropping M. sativa and E. nutans should be evaluated in the future.
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To enable that the new generation of entrepreneurs can effectively use their own qualities and abilities to improve the level of entrepreneurial performance, and to successfully pass through the entrepreneurial period of the enterprise and achieve longer-term development, the new generation of entrepreneurs is taken as the research object, and firstly, the definition and interaction of psychological capital and entrepreneurial performance are pointed out. Secondly, the questionnaires are designed with reference to the relevant maturity scales, and the reliability, validity analysis, correlation analysis, and multiple linear regression analysis of the collected effective questionnaires are carried out through SPSS and AMOS software. Thirdly, on this basis, it verifies the influence of psychological capital of the new generation entrepreneurs on entrepreneurial performance and the moderating effect of entrepreneurial environment perception. The results show that there is a significant positive correlation between the dimensions of psychological capital and entrepreneurial performance. Gender, age, educational background, marital status, the establishment time of enterprises, and the number of employees all have a significant impact on the psychological capital of the new generation of entrepreneurs. Among them, the psychological capital of the new generation of entrepreneurs aged 31-35 is the best, followed by aged 26-30, 21-25, and the worst is 20 years old and below, which is logical. The correlation coefficient between psychological capital and entrepreneurial performance, social capital and entrepreneurial performance shows a significant positive correlation. The research on the relationship between psychological capital, social capital, and entrepreneurial performance of new generation entrepreneurs systematically explains why some enterprises created by the new generation of entrepreneurs can achieve rapid growth and deepen the research in related fields.