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1.
ACS Nano ; 2021 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-34726393

RESUMO

Aqueous potassium-ion batteries are long-term pursued, due to their excellent performance and intrinsic superiority in safe, low-cost storage for portable and grid-scale applications. However, the notorious issues of K-ion battery chemistry are the inferior cycling stability and poor rate performance, due to the inevitably destabilization of the crystal structure caused by K-ions with pronouncedly large ionic radius. Here, we resolve such issues by reconstructing commercial vanadium oxide (α-V2O5) into the bronze form, i.e., δ-K0.5V2O5 (KVO) nanobelts, as cathode materials with layered structure of enlarged space and anisotropic pathways for K-ion storage. Specifically, it can deliver a high capacity as 116 mAh g-1 at the 1 C-rate, an outstanding rate capacity of 65 mAh g-1 at 50 C, and a robust cyclic stability with 88.2% capacity retention after 1,000 cycles at 1 C. When coupled with organic anode in a full-cell configuration, the KVO electrodes can output 95 mAh g-1 at 1 C and cyclic stability with 77.3% capacity retention after 20,000 cycles at 10 C. According to experimental and calculational results, the ultradurable cyclic performance is assigned to the robust structural reversibility of the KVO electrode, and the ultrahigh-rate capability is attributed to the anisotropic pathways with improved electrical conductivity in KVO nanobelts. In addition, applying a 22 M KCF3SO3 water-in-salt electrolyte can impede the dissolving issues of the KVO electrode and further stabilize the battery cyclic performance. Lastly, the as-designed AKIBs can operate with superior low-temperature adaptivity even at -30 °C. Overall, the KVO electrode can serve as a paradigm toward developing more suitable electrode materials for high-performance AKIBs.

2.
World J Clin Cases ; 9(29): 8729-8739, 2021 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-34734051

RESUMO

BACKGROUND: Hypotension after the induction of anesthesia is known to be associated with various adverse events. The involvement of a series of factors makes the prediction of hypotension during anesthesia quite challenging. AIM: To explore the ability and effectiveness of a random forest (RF) model in the prediction of post-induction hypotension (PIH) in patients undergoing cardiac surgery. METHODS: Patient information was obtained from the electronic health records of the Second Affiliated Hospital of Hainan Medical University. The study included patients, ≥ 18 years of age, who underwent cardiac surgery from December 2007 to January 2018. An RF algorithm, which is a supervised machine learning technique, was employed to predict PIH. Model performance was assessed by the area under the curve (AUC) of the receiver operating characteristic. Mean decrease in the Gini index was used to rank various features based on their importance. RESULTS: Of the 3030 patients included in the study, 1578 (52.1%) experienced hypotension after the induction of anesthesia. The RF model performed effectively, with an AUC of 0.843 (0.808-0.877) and identified mean blood pressure as the most important predictor of PIH after anesthesia. Age and body mass index also had a significant impact. CONCLUSION: The generated RF model had high discrimination ability for the identification of individuals at high risk for a hypotensive event during cardiac surgery. The study results highlighted that machine learning tools confer unique advantages for the prediction of adverse post-anesthesia events.

3.
J Agric Food Chem ; 2021 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-34797063

RESUMO

As one of the major polymethoxyflavones in citrus peels, sinensetin (Sin) has been reported to possess numerous bioactivities. However, its detailed in vivo metabolic fate has not been uncovered yet. In the present study, the possible metabolites of Sin were synthesized, and all five mono-demethylated metabolites were successfully identified via ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) analysis in rats fed with 100 mg/(kg·bw) Sin. The excretion and pharmacokinetic studies were then carried out to quantitatively investigate their variation in content with time in urine, feces, and plasma samples. Results showed that 4'-demethylsinensetin, 6-demethylsinensetin, and 3'-demethylsinensetin were the three most abundant metabolites generated in the above-mentioned biological samples. In addition, the total amount of Sin with its metabolites showed a significantly higher content in urine than in feces, indicating that Sin may be easily absorbed in the small intestine.

4.
Opt Express ; 29(24): 40161-40176, 2021 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-34809363

RESUMO

In this paper, a self-adaptable anti-interference scheme in a hybrid wireless fidelity (WiFi) and visible light communication (VLC) network is firstly proposed by light-path blocking. By human behavior characteristics, a user-device position relationship model is constructed to determine users' orientations. By the model, a strategy of choosing access points (AP) is present. By the strategy, communicating APs can be self-adaptively selected to match them with users' orientations. In the scheme, interference signals can be effectively blocked through the user's body to ensure normal communication. Finally,the effectiveness of the scheme has been demonstrated with simulations. Also, the scheme has its comparative advantages of not only saving energy, increasing SINR and lifting the availability of the hybrid WiFi-VLC network but also having faster response speed of network, higher efficiency of user access, easier implementation and lower cost.

5.
Acad Radiol ; 28 Suppl 1: S148-S156, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34756818

RESUMO

RATIONAL AND OBJECTIVES: To prospectively evaluate the clinical feasibility of the magnetic resonance cholangiopancreatography (MRCP) protocol using both contact-free physiological monitoring (CFPM) and compressed sensing (CS) (CS-CFPM-MRCP) and to compare its performance with that of the standard navigator-triggered (NT) CS-NT-MRCP and NT-MRCP. MATERIALS AND METHODS: A total of 63 patients (36 males, 27 females, age range: 18-83 years, mean age: 52.30 ± 15.70 years) suspected with duct-related pathologies were prospectively enrolled and performed the three MRCP protocols randomly. The acquisition time was compared. The pancreaticobiliary system was divided into 12 segments and evaluated based on a five-point Likert scale and compared by the Friedman test with a post hoc test. The diagnostic performance of the 3 MRCP was evaluated by the AUC value and compared by Delong's test. The interobserver agreement was evaluated by Kendall's W test. RESULTS: Compared to NT-MRCP, the acquisition time of CS-NT-MRCP and CS-CFPM-MRCP was significantly decreased (both p < 0.001). There is no significant difference in the overall imaging quality (p > 0.05) between the NT-MRCP and CS-CFPM-MRCP protocols. CS-CFPM-MRCP depicted pancreatic duct and intrahepatic ducts better than CS-NT-MRCP (all p < 0.05) and was comparable with that of the NT-MRCP (all p > 0.05). For identification of abnormalities and diseases associated with MPD anatomy, the mean AUC value for NT-MRCP and CS-CFPM-MRCP were 0.896 (95%CI: 0.834, 0.958) and 0.905 (95%CI: 0.846, 0.964), which were significantly higher when compared to that for CS-NT-MRCP (0.713 [95%CI:0.622, 0.805]) (p = 0.001 and < 0.001). All evaluations showed good to excellent agreement (0.619-0.897). CONCLUSION: The combination of CS and CFPM is considered feasible for shortening the scan time of 3D free breath MRCP without impairing the imaging quality and CS-CFPM-MRCP is considered feasible for patients suspected with pancreaticobiliary diseases.


Assuntos
Colangiopancreatografia por Ressonância Magnética , Pancreatopatias , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Imageamento Tridimensional , Masculino , Pessoa de Meia-Idade , Monitorização Fisiológica , Pancreatopatias/diagnóstico por imagem , Estudos Prospectivos , Adulto Jovem
6.
Brain Imaging Behav ; 2021 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-34743296

RESUMO

Subjective cognitive decline (SCD)-related worries are indicative of an increased risk for developing Alzheimer's disease (AD) dementia. However, the influence of SCD-related worries on the relationship between amyloid and gray matter (GM) atrophy remains unknown. A total of 93 SCD participants underwent 18F-florbetapir PET and T1-weighted MRI scans. SCD individuals were classified into amyloid-positive or amyloid-negative groups based on global amyloid uptake. Three-step statistical analyses were performed: (1) partial correlation analysis was conducted to determine whether global amyloid relates to GM volume in amyloid-positive and amyloid-negative groups; (2) linear regression analysis was conducted to determine whether the interaction term (worries × global amyloid) predicts GM volume; and (3) post hoc subgroup linear regression analysis was conducted to determine the association between amyloid and GM volume in the subgroups with and without worries. Age, sex, education and total intracranial volume were adjusted in all models. We found a negative relationship between global amyloid load and GM volume in the right hemisphere (r = 0.441, p = 0.012) and right temporal cortex (r = 0.506, p = 0.003) in the amyloid-positive group. Moreover, in the amyloid-positive group, a significant worries × amyloid interaction effect on GM volume was found in the bilateral hemisphere (right: pinteraction=0.037; left: pinteraction=0.036), left temporal cortex (pinteraction=0.044) and bilateral frontal cortex (right: pinteraction=0.010; left: pinteraction=0.011). Subsequent post hoc analysis revealed a significant amyloid-GM association only in the subgroup with worries but not in the subgroup without worries. In preclinical AD cases, SCD-related worries may occur as a symptom in those cases where amyloid affects GM to a greater extent and may thus represent a high-risk population for future cognitive decline.

7.
Pharmacol Res ; 175: 105983, 2021 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-34822972

RESUMO

Angiogenesis plays an important role in the growth and metastasis of solid tumors including melanoma. Inhibiting tumor-associated angiogenesis is a tactic in treating melanoma. Dioscin restrains angiogenesis in colon tumor and has anti-melanoma effects in cell and animal models. In a previous study, we found that dioscin inhibits Src/STAT3 signaling in melanoma cells. Activation of the Src/STAT3 pathway has been shown to promote tumor angiogenesis. This study aimed to determine whether dioscin's anti-melanoma effects is related to inhibiting Src/STAT3 signaling-mediated angiogenesis. In a B16F10 allograft mouse model, we found that dioscin inhibited melanoma growth and angiogenesis. To exclude the impact of tumor growth on angiogenesis, a chicken chorioallantoic membrane (CAM) model was used to verify the anti-angiogenic effect of dioscin. Results showed that dioscin suppressed vessel formation in CAM. To determine if tumor secreted pro-angiogenic cytokines are involved in the anti-angiogenic effect of dioscin, conditioned media from dioscin-treated A375 melanoma cells were used to culture human umbilical vein endothelial cells (HUVECs), and tube formation was monitored. It was observed that the tube formation of HUVECs was inhibited. Mechanistic studies revealed that dioscin inhibited the activation of Src and STAT3, and lowered mRNA and protein levels of STAT3 transcriptionally-regulated genes, in B16F10 melanomas. ELISA assays showed that dioscin decreased the secretion of MMP-2, MMP-9 and VEGF from A375 cells. Over-activation of STAT3 lessened the effects of dioscin in decreasing the secretion of pro-angiogenic cytokines from melanoma cells, and in inhibiting tube formation of HUVECs cultured with conditioned media from melanoma cell cultures. In summary, we for the first time demonstrated that inhibiting Src/STAT3 signaling-mediated angiogenesis is involved in the anti-melanoma effects of dioscin. This study provides further pharmacological groundwork for developing dioscin as an anti-melanoma agent.

8.
Biomed Pharmacother ; 145: 112367, 2021 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-34740097

RESUMO

Cardiovascular comorbidities are pervasive in chronic obstructive pulmonary disease (COPD) and often result in serious adverse cardiovascular events. Tongxinluo (TXL) has been clinically verified to treat atherosclerosis (AS), improve lung function and alleviate dyspnoea. The present study aimed to explore the effect of lung microvascular barrier dysfunction on AS in COPD and the potential pulmonary protective mechanisms of TXL in COPD complicated with AS. COPD complicated with AS was induced in mice by cigarette smoke (CS) exposure and high-fat diet (HFD) feeding. The mice were treated with atorvastatin (ATO), TXL or combination therapy (ATO+TXL) for 20 weeks. Pulmonary function, lung pathology, serum lipid levels, atherosclerotic plaque area and indicators of barrier function, oxidative stress and ferroptosis in lung tissue were evaluated. In vitro, human pulmonary microvascular endothelial cells (HPMECs) were pretreated with TXL for 4 h and then incubated with cigarette smoke extract (CSE) and homocysteine (Hcy) for 36 h to induce barrier dysfunction. Then the indicators of barrier function, oxidative stress and ferroptosis were measured. The results demonstrate that CS aggravated dyslipidaemia, atherosclerotic plaque formation, pulmonary function decline, pathological injury, barrier dysfunction, oxidative stress and ferroptosis in the HFD-fed mice. However, these abnormalities were partially reversed by ATO and TXL. Similar results were observed in vitro. In conclusion, pulmonary microvascular barrier dysfunction plays an important role by which COPD affects the progression of AS, and ferroptosis may be involved. Moreover, TXL delays the progression of AS and reduces cardiovascular events by protecting the pulmonary microvascular barrier and inhibiting ferroptosis.

9.
Sci Total Environ ; : 151134, 2021 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-34695460

RESUMO

To effectively reduce the compound pollution of fine particulate matter (PM2.5) and ozone (O3), volatile organic compound (VOC) emission sources are being extensively studied. Studies on VOC emission characteristics have mainly focused on solvent-using and technological sources, while research on the combustion processes of high-energy-consuming industries remains limited. Here, we investigate the emission characteristics of 102 VOC species emitted from eight sources (sintering, pelletizing, steel smelting, a coke oven chimney, the topside of a coke oven, thermal power, and two types of cement kilns) used in four types of high-energy-consuming industries. Our results show significant differences among these sources. The average VOC mass concentrations varied from 0.14 to 7.08 mg/m3. Alkanes had the highest percentage contribution to VOCs from sintering (45.9%) and thermal power (44.6%), while aromatics had the highest percentage contribution from steel smelting (47.8%) and the topside of the coke oven (52.9%). Alkenes were abundant in the coke oven chimney (49.1%), and oxygenated VOCs accounted for 65.3% of the total VOCs from pelletizing. We also observed notable differences between the two types of cement kilns. In general, ethane, ethene, benzene, propane, acetaldehyde, and chloromethane were the dominant VOC species in all sources. The differences between the sources were due to factors such as the applied raw materials, calcination temperature, and end-of-pipe treatment. By reviewing studies from the past 20 years, we found that differences in the number of VOC species and the implementation of ultra-low emissions affect VOC emission characteristics. The coke oven chimney and cement kiln chimney-1 had the highest ozone formation potential and secondary organic aerosol potential, respectively. The VOC emissions from coking, iron and steel, thermal power, and cement industries were 1162.1, 289.9, 311.0, and 470.2 Gg, respectively. Our results highlight the need for more effective control measures to minimize VOC emissions from high-energy-consuming industries.

10.
Artigo em Inglês | MEDLINE | ID: mdl-34639471

RESUMO

During the post-COVID-19 era, preventive practices, such as washing hands and wearing a mask, remain key measures for controlling the spread of infection for older adults. This study investigated the status of preventive practices among older adults and identified the related influencing factors. Participants who were ≥60 years old were recruited nationwide. Data were collected through self-designed questionnaires, including demographic variables, knowledge, perceived vulnerability, response efficacy, anxiety and preventive practices. Descriptive statistics and chi-square tests were performed. Hierarchical logistic regression was conducted to determine the predictors. A total of 2996 participants completed this study. Of them, 2358 (78.7%) participants reported washing hands regularly in the last two weeks, and 1699 (56.7%) always wore masks outside this year. Knowledge (hand washing: OR = 1.09, p < 0.01; mask wearing: OR = 1.17, p < 0.01) and response efficacy (hand washing: OR = 1.61, p < 0.01; mask wearing: OR = 1.70, p < 0.01) were positively associated with preventive practices, whereas perceived vulnerability had a negative effect (hand washing: OR = 0.54, p < 0.01; mask wearing: OR = 0.72, p < 0.01). Knowledge, response efficacy and perceived vulnerability were found to be significant predictors of the preventive practice among older adults in the post-COVID-19 era. This study provides new insights into preventive suggestions after the peak of the pandemic and also has significant implications in improving the life quality of older adults.


Assuntos
COVID-19 , Idoso , China , Estudos Transversais , Humanos , Pessoa de Meia-Idade , Pandemias , SARS-CoV-2 , Inquéritos e Questionários
11.
J Alzheimers Dis ; 84(3): 1279-1289, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34657889

RESUMO

BACKGROUND: Evidence suggests that subjective cognitive decline (SCD) individuals with worry have a higher risk of cognitive decline. However, how SCD-related worry influences the functional brain network is still unknown. OBJECTIVE: In this study, we aimed to explore the differences in functional brain networks between SCD subjects with and without worry. METHODS: A total of 228 participants were enrolled from the Sino Longitudinal Study on Cognitive Decline (SILCODE), including 39 normal control (NC) subjects, 117 SCD subjects with worry, and 72 SCD subjects without worry. All subjects completed neuropsychological assessments, APOE genotyping, and resting-state functional magnetic resonance imaging (rs-fMRI). Graph theory was applied for functional brain network analysis based on both the whole brain and default mode network (DMN). Parameters including the clustering coefficient, shortest path length, local efficiency, and global efficiency were calculated. Two-sample T-tests and chi-square tests were used to analyze differences between two groups. In addition, a false discovery rate-corrected post hoc test was applied. RESULTS: Our analysis showed that compared to the SCD without worry group, SCD with worry group had significantly increased functional connectivity and shortest path length (p = 0.002) and a decreased clustering coefficient (p = 0.013), global efficiency (p = 0.001), and local efficiency (p < 0.001). The above results appeared in both the whole brain and DMN. CONCLUSION: There were significant differences in functional brain networks between SCD individuals with and without worry. We speculated that worry might result in alterations of the functional brain network for SCD individuals and then result in a higher risk of cognitive decline.

12.
Am J Transl Res ; 13(8): 8670-8682, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34539986

RESUMO

OBJECTIVE: Nuclear technology has been widely used in military and civilian fields, and radiotherapy is an effective and common form of treatment for cancer. However, acute radiation disease caused by high doses of radiation is a serious complication. The aim of this study was to investigate the chance of mitigating radiation-triggered hematopoiesis failure using human umbilical cord mesenchymal stem cell (HUCMSC) transplantation. METHODS: Umbilical cords were obtained from three full-term female neonatus through cesarean section at Xinqiao Hospital. Bone marrow mesenchymal stem cells (BMSCs) were cultivated as depicted before. Briefly, monocytes were collected from bone marrow blood by means of density separation columns. An acute radiation disease mouse model was established to compare the restoration effect of HUCMSCs and BMSCs transplanted via the tail vein. The hematopoietic stem cell transplantation (HSCT) mouse model was obtained through bone marrow cell transplantation (BMCT) from C57BL/6 mice (H-2b, donor) to female CB6F1 mice (H-2b×d, recipient) after irradiation. The mice were divided into five groups, including control (saline), irradiated (radiation), bone marrow (HSCT, transplanted 1×106 BM cells), HUCMSC (transplanted a mixture of 1×106 HUCMSCs and 1×106 BM cells), and BMSC group (transplanted a mixture of 1×106 BMSCs and 1×106 BM cells). The blood condition results were used to test the radiation-induced inflammatory reaction, and bone marrow pathological staining (H&E) was used to determine the radiation-induced bone marrow hematopoiesis failure. RESULTS: After radiation, HUCMSC transplantation significantly improved the survival rate. By analyzing the blood condition test, colony formation, and bone marrow pathology, it was found that the HUCMSC group demonstrated significant functional improvements in terms of the recovery from hematopoiesis failure and reduction of inflammatory reaction. CONCLUSIONS: HUCMSCs have more advantages over BMSCs in restoring and promoting the recovery of radiation-induced hematopoietic damage, thus having a new therapeutic potential for patients with acute radiation disease.

13.
J Sci Food Agric ; 2021 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-34498275

RESUMO

BACKGROUND: The high cost of controlled-release urea (CRU) has prompted this study to explore whether the amount of CRU can be reduced by adding biostimulants while maintaining or increasing rice yield. A 2 year field experiment was conducted with CRU at three levels (60%, 80%, and 100% of the recommended nitrogen (N) fertilizer) and a novel biostimulant Paecilomyces variotii extract (ZNC), to investigate their synergistic effects on yield, nitrogen use efficiency (NUE), and net profitability of rice. RESULTS: Controlled-release urea achieved a significantly higher gain yield and NUE than conventional urea with the same N level, which could be attributed to its N supply. Even if the N level of CRU was reduced by 40%, both rice yield and net profit were still significantly higher than for the full amount of urea. Paecilomyces variotii extract sprayed on the surface of CRU at a dose of only 87.5 mL ha-1 exhibited ultra-high effectiveness by increasing the panicles, the N accumulation, and the rice yield. Controlled-release urea enriched by ZNC achieved significantly higher gain yield than CRU alone, increasing the yield by 9.2% and 8.7%, respectively, in 2 years under the full recommended N rate. The combination of 80% CRU and ZNC showed no significant difference in rice yield from treatment with 100% CRU, indicating that the rate of CRU could be reduced by ZNC. The application of ZNC further increased NUE, N partial factor productivity, and net profit. CONCLUSION: The CRU and ZNC combination provided a feasible approach for reducing N input while maintaining rice yield and agricultural sustainability. © 2021 Society of Chemical Industry.

14.
ACS Omega ; 6(37): 24027-24038, 2021 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-34568681

RESUMO

In this study, the potential regulatory effects of fulvic acid extracted from paper mill effluent (PFA) in apple replant disease (ARD) were investigated through a comprehensive experimental evaluation of the effects of PFA on soil properties, growth inhibition of apple replant pathogens, and growth of replanted Malus hupehensis Rehd. seedlings. PFA with a relatively lower molecular weight was mainly composed of carbohydrates, lignin derivatives, and polysaccharides and was rich in functional groups such as carboxyl and phenolic hydroxyl groups. Treatment with PFA dosages ranging from 2 to 3 g/pot significantly increased available phosphorus (P) in soil by 47.5 to 57.5% when compared with the control without PFA, indicating that PFA had a positive effect in activating P. In addition, PFA stimulated the growth of replanted seedlings by promoting root elongation, enhancing leaf photosynthesis, and increasing the activity of root antioxidant enzymes including superoxide dismutase, peroxidase, and catalase. However, no convincing evidence was found that application of different dosages of PFA had remarkable effects on soil pH, inorganic nitrogen, available potassium, organic matter, and the numbers of bacteria and fungi. Notably, PFA had no effect on the copy number of the main pathogenic fungi causing ARD, including Fusarium oxysporum, Fusarium solani, Fusarium proliferatum, and Fusarium moniliforme. Overall, PFA can alleviate ARD to a certain extent mainly through its effects on improving the resilience of replanted young seedlings rather than by affecting soil microorganisms or providing nutrients.

15.
Cytotherapy ; 23(11): 996-1006, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34465514

RESUMO

BACKGROUND AIMS: Human mesenchymal stem cells (MSCs) from various tissues have emerged as attractive candidates for the prevention and treatment of graft-versus-host disease (GVHD). However, the molecular machinery that defines and channels the behavior of these cells remains poorly understood. METHODS: In this study, the authors compared the efficacy of four tissue-derived MSC types in controlling GVHD in a murine model and investigated their immunomodulatory effects. RESULTS: Human umbilical cord-derived mesenchymal stem cells (hUCMSCs) effectively decreased the incidence and severity of GVHD, which was mediated by the enrichment of myeloid-derived suppressor cells in GVHD target tissues. RNA sequencing results showed that hUCMSCs highly expressed CXCL1. CONCLUSIONS: These results suggest a novel prophylactic application of hUCMSCs for controlling GVHD after allogeneic hematopoietic stem cell transplantation.


Assuntos
Doença Enxerto-Hospedeiro , Transplante de Células-Tronco Hematopoéticas , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais , Células Supressoras Mieloides , Animais , Quimiocina CXCL1 , Doença Enxerto-Hospedeiro/prevenção & controle , Humanos , Camundongos , Cordão Umbilical
16.
Front Microbiol ; 12: 694847, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34335524

RESUMO

Lipo-tridecapeptides, a class of bacterial non-ribosomally produced peptides, show strong antimicrobial activity against Gram-positive pathogens, including antibiotic-resistant Staphylococcus aureus and Enterococcus spp. However, many of these lipo-tridecapeptides have shown high hemolytic activity and cytotoxicity, which has limited their potential to be developed into antibiotics. Recently, we reported a novel antimicrobial lipo-tridecapeptide, brevibacillin 2V, which showed no hemolytic activity against human red blood cells at a high concentration of 128 mg/L, opposite to other brevibacillins and lipo-tridecapeptides. In addition, brevibacillin 2V showed much lower cytotoxicity than the other members of the brevibacillin family. In this study, we set out to elucidate the antimicrobial mode of action of brevibacillin 2V. The results show that brevibacillin 2V acts as bactericidal antimicrobial agent against S. aureus (MRSA). Further studies show that brevibacillin 2V exerts its bactericidal activity by binding to the bacterial cell wall synthesis precursor Lipid II and permeabilizing the bacterial membrane. Combined solid-state NMR, circular dichroism, and isothermal titration calorimetry assays indicate that brevibacillin 2V binds to the GlcNAc-MurNAc moiety and/or the pentapeptide of Lipid II. This study provides an insight into the antimicrobial mode of action of brevibacillin 2V. As brevibacillin 2V is a novel and promising antibiotic candidate with low hemolytic activity and cytotoxicity, the here-elucidated mode of action will help further studies to develop it as an alternative antimicrobial agent.

17.
Biology (Basel) ; 10(8)2021 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-34440001

RESUMO

Three sampling strategies with a 16s rRNA high-throughput sequencing and gene expression assay (by RT-PCR) were designed, to better understand the host and probiotics effect on gut microbiota in sheep. Sampling: (1) colon contents and back-fat tissues from small-tailed Han sheep (SHS), big-tailed Hulun Buir sheep (BHBS), and short-tailed Steppe sheep (SHBS) (n = 12, 14, 12); (2) jejunum, cecum and colon contents, and feces from Tan sheep (TS, n = 6); (3) feces from TS at 4 time points (nonfeeding, 30 and 60 feeding days, and stop feeding 30 days) with probiotics supplementation (n = 7). The results indicated SHS had the highest Firmicutes abundance, the thinnest back-fat, and the lowest expression of C/EBPß, C/EBPδ, ATGL, CFD, and SREBP1. Some bacteria orders and families could be potential biomarkers for sheep breeds with a distinct distribution of bacterial abundance, implying the host genotype is predominant in shaping unique microbiota under a shared environment. The microbiota diversity and Bifidobacterial populations significantly changed after 60 days of feeding but restored to its initial state, with mostly colonies, after 30 days ceased. The microbiota composition was greatly different between the small and large intestines, but somewhat different between the large intestine and feces; feces may be reliable for studying large intestinal microbiota in ruminants.

18.
Huan Jing Ke Xue ; 42(9): 4095-4103, 2021 Sep 08.
Artigo em Chinês | MEDLINE | ID: mdl-34414708

RESUMO

This study used sampling analysis and a CAMx-PSAT coupling model to analyze the components, transmission, and source apportionment of PM2.5 in Beijing and Tangshan in January 2018. The results showed that in January 2018, water-soluble inorganic ions (WSⅡs) accounted for 49.59% and 39.13% of PM2.5 mass concentrations in Beijing and Tangshan, respectively. The ratios of NO3- to SO42- were 2.02 and 1.51, respectively, indicating that pollution in both cities was dominated by mobile sources. In Beijing and Tangshan, PM2.5 accounted for 48.74% and 30.67% of transmission, respectively. Regional transmissions were mainly contributed by neighboring areas, northwest masses, and southwest masses. However, the contribution of the southwest passage to pollution in the respective cities increased by 9.65% and 15.02% during pollution periods. The principal sources contributing to PM2.5 pollution in Beijing were mobile and dust sources. Secondary ions were more obviously affected by regional contributions, mobile and industrial sources had the most significant effect in Tangshan, and most particulate matter and sulfate were contributed by local emissions. From 2013 to 2018, the dominant component of WSⅡs changed from sulfate to nitrate while the main pollution sources changed from coal-fired and industrial sources to mobile and dust sources. Meanwhile, in January 2018, the meteorological factors were more favorable for pollution mitigation than in 2013. The meteorological impact of secondary ions is closely related to the lower relative humidity in 2018, compared to 2013.


Assuntos
Poluentes Atmosféricos , Poluentes Atmosféricos/análise , Pequim , Cidades , Monitoramento Ambiental , Nitratos , Material Particulado/análise
19.
ACS Omega ; 6(32): 20758-20767, 2021 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-34423184

RESUMO

CO2 fracturing is a promising technology for oil field development in tight, continental deposits, with potential advantages of enhanced oil recovery (EOR), CO2 sequestration, and water conservation. Compared with CO2-EOR techniques, such as CO2 huff and puff and CO2 flooding, CO2 can interact with reservoir rock and fluid under higher pressure conditions during fracturing, resulting in CO2 stimulation and sequestration effects that differ from those that occur during conventional CO2-EOR. In this paper, the CO2 interactions between CO2 and reservoirs in continental tight oil reservoirs under fracturing conditions are systematically studied through laboratory experiments. The results show that under high pressure, CO2 effectively changes the pore structure through the extraction of hydrocarbons, dissolution of the rock matrix, and migration of minerals. CO2 dissolution of the rock matrix can significantly increase the number and complexity of fractures. Furthermore, CO2 has a higher solubility in formation fluid under high-pressure conditions. Given the higher pressures, CO2 forms a miscible phase with crude oil, diffuses more deeply into the formation, and reacts fully with the reservoir minerals and fluid during CO2 fracturing. Accordingly, CO2 can improve the permeability of the reservoir and flowability of crude oil significantly. Hence, CO2 fracturing can enhance oil recovery and CO2 sequestration more effectively. Core displacement experiments indicate that oil recovery of CO2 soaking process after CO2 fracturing is 36%, which is 12% and 9% higher than those of CO2 huff and puff and CO2 flooding with 5 pore volume, respectively. Field tests show that average oil production after CO2 fracturing is 1.42 times higher than that after CO2 flooding, which further validates the advantage of CO2 fracturing and demonstrates its huge application potential.

20.
Pestic Biochem Physiol ; 178: 104925, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34446201

RESUMO

The codling moth, Cydia pomonella (Lepidoptera: Tortricidae) is a major pest of pome fruit and walnuts worldwide. Although environmentally compatible integrated control strategies, such as mating disruption, attract-kill strategy, and sterile insect technique have been conducted for management of this notorious pest, effects to control of codling moth have mainly relied on insecticides. In consequence, different levels of insecticide resistance towards organophosphates, neonicotinoids, hydrazines, benzoylureas, pyrethroids, diamides, spinosyns, avermectins, JH mimics, carbamates, oxadiazines and C. pomonella granulovirus (CpGVs) have developed in codling moth in different countries and areas. Both metabolic and target-site mechanisms conferring resistance have been revealed in the codling moth. In this review, we summarize the current global status of insecticide resistance, the biochemical and molecular mechanisms involved, and the implications for resistance management.


Assuntos
Inseticidas , Mariposas , Piretrinas , Animais , Resistência a Inseticidas , Inseticidas/farmacologia , Neonicotinoides
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