Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 748
Filtrar
1.
Vaccine ; 2020 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-33199077

RESUMO

BACKGROUND: Community-acquired pneumonia (CAP) is one of the major global health problems worldwide. However, the epidemiological information of CAP is limited in China. This study aimed to estimate the incidence rate of CAP and describe the epidemiologic characteristics among the Chinese population. METHODS: We conducted a retrospective analysis of CAP incidence using the Chinese Urban Basic Medical Insurance database of 23 provinces in 2016, which covered 427.52 million urban beneficiaries of all age groups in Mainland China. CAP episodes were identified using a diagnosis-term-derived algorithm, and multiple CAP records of one single person within 90 continuous days were considered as one single episode. The incidence rates were calculated and described by sex, age, region, and season. RESULTS: A total of 1.42 million patients were identified as having one or more CAP episodes, and finally a sum of 1.48 million CAP episodes were counted. The overall incidence of CAP was 7.13 (95% CI: 6.11-8.15) per 1000 person-years, in males 7.32 (95% CI: 6.28-8.35) and females 6.93 (95% CI: 5.92-7.94) per 1000 person-years, respectively. The incidence varied by age with a U-shaped curve peaking in children aged < 5 years old [65.80 (95% CI: 62.52-69.08)] and elderly population aged ≥ 80 years old [14.98 (95% CI: 13.63-16.34)]. The incidence varied markedly by regions. Furthermore, the rate showed a clear seasonal trend, which peaked in spring, decreased in summer and autumn, and re-ascended in winter. CONCLUSION: This study reveals a relatively high level of CAP incidence in China. These findings provide baseline data for establishing effective prevention strategies, targeted at susceptible populations, regions, and seasons in China.

2.
Artigo em Inglês | MEDLINE | ID: mdl-33199630

RESUMO

Schaftoside and isoschaftoside are bioactive natural products widely distributed in higher plants including cereal crops and medicinal herbs. Their biosynthesis may be related with plant defense. However, little is known on the glycosylation biosynthetic pathway of these flavonoid di-C-glycosides with different sugar residues. Herein, we report that the biosynthesis of (iso)schaftosides is sequentially catalyzed by two C-glycosyltransferases (CGTs), i.e., CGTa for C-glucosylation of the 2-hydroxyflavanone aglycone and CGTb for C-arabinosylation of the mono-C-glucoside. The two enzymes of the same plant exhibit high homology but remarkably different sugar acceptor and donor selectivities. A total of 14 CGTa and CGTb enzymes were cloned and characterized from seven dicot and monocot plants, including Scutellaria baicalensis, Glycyrrhiza uralensis, Oryza sativa ssp. japonica, and Zea mays, and the in vivo functions for three enzymes were verified by RNA interference and overexpression. Through transcriptome analysis, we found homologous genes in 119 other plants, indicating this pathway is general for the biosynthesis of (iso)schaftosides. Furthermore, we resolved the crystal structures of five CGTs and realized the functional switch of SbCGTb to SbCGTa by structural analysis and mutagenesis of key amino acids. The CGT enzymes discovered in this paper allow efficient synthesis of (iso)schaftosides, and the general glycosylation pathway presents a platform to study the chemical defense mechanisms of higher plants.

3.
Medicine (Baltimore) ; 99(47): e23286, 2020 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-33217858

RESUMO

BACKGROUND: Allergic rhinitis is an allergic disease of the nasal mucosa mediated by IgE after the body is exposed to allergens. Acupuncture of sphenoid ganglion is a new technique developed by Professor Li Xinwu in the 1860 s to treat allergic rhinitis the efficacy of acupuncture on the sphenopalatine ganglion in the treatment of AR has been clinically verified, but a systematic review and meta-analysis of them is lacking. Our purpose is to evaluate the efficacy and safety of acupuncture on the sphenopalatine ganglion in the treatment of AR. METHODS: We will search 8 electronic databases, including: Web of Science, PubMed, Cochrane Library, Embase, CNKI, CBM, Wanfang, VIP, WHO ICTRP, ChiCTR, Clinical Trials, Grey Literature Database. The literature search, screening and extraction will be carried out independently by 2 researchers. When the opinions are not uniform, it depends on the opinion of the third researcher. We will use RevmanV.5.3 to perform a fixed-effect meta-analysis on the date of clinical homogeneity studies, and the level of evidence will pass GRADE method. RESULTS: This systematic review and meta-analysis will put a high-quality synthesis of the efficacy and safety of acupuncture of sphenoid ganglion treatment in AR. CONCLUSION: The review will provide a comprehensive basis for the treatment of AR patients with acupuncture on the sphenopalatine ganglion. ETHICS AND DISSEMINATION: Since this article does not involve patient privacy, ethical approval is not required. TRIAL REGISTRATION NUMBER: INPLASY2020100067.

4.
Artigo em Inglês | MEDLINE | ID: mdl-33168192

RESUMO

Hepatocellular carcinoma (HCC) is a severe global health problem. There is increasing evidence for the important roles of long noncoding RNAs in tumorigenesis and metastasis in HCC. In this study, we identified and characterized a novel long noncoding RNA, LINC02580, involved in HCC. LINC02580 was highly downregulated in HCC cohorts and was identified as a tumor suppressor. Low LINC02580 expression in patients with HCC was correlated with poor prognosis. Functional assays indicated that LINC02580-deficient cells show enhanced colony formation, migration, and invasion in vitro and promote subcutaneous tumor formation and distant lung metastasis in vivo. With respect to the underlying mechanism, we found that LINC02580 modulates the epithelial-mesenchymal transition (EMT) associated pathway in HCC cells by specifically binding to serine and arginine-rich splicing factor 1 (SRSF1). In summary, our findings illustrated that LINC02580 is a metastasis-suppressing lncRNA in HCC, and provided vital clues of how LINC02580 performs its biological functions. Further, this lncRNA may be a potential target in the prognosis and treatment of HCC.

5.
Med Sci Monit ; 26: e925401, 2020 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-33132382

RESUMO

BACKGROUND Although mutations and dysfunction of mitochondrial DNA (mtDNA) are related to a variety of diseases, few studies have focused on the relationship between mtDNA and coronary artery disease (CAD), especially the relationship between rare variants and CAD. MATERIAL AND METHODS Two-stage high-throughput sequencing was performed to detect mtDNA variants or heteroplasmy and the relationship between them and CAD phenotypes. In the discovery stage, mtDNA was analyzed by high-throughput sequencing of long-range PCR products generated from the peripheral blood of 85 CAD patients and 80 demographically matched controls. In the validation stage, high-throughput sequencing for mtDNA target regions captured by GenCap Kit was performed on 100 CAD samples and 100 controls. Finally, tRNA fine mapping was performed between our study and the reported Chinese CAD study. RESULTS Among the tRNA genes, we confirmed a highly conserved rare variant, A5592G, previously reported in the Chinese CAD study, and 2 novel rare mutations that reached Bonferroni's correction significance in the combined analysis were found (P=7.39×10-4 for T5628C in tRNAAla and P=1.01×10-5 for T681C in 12S rRNA) in the CAD study. Both of them were predicted to be pathological, with T5628C disrupting an extremely conservative base-pairing at the AC stem of tRNAAla. Furthermore, we confirmed the controversial issue that the number of non-synonymous heteroplasmic sites per sample was significantly higher in CAD patients. CONCLUSIONS In conclusion, our study confirmed the contribution of rare variants in CAD and showed that CAD patients had more non-synonymous heterogeneity mutations, which may be helpful in identifying the genetic and molecular basis of CAD.

6.
Sci Total Environ ; : 143222, 2020 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-33203555

RESUMO

The interaction between flocs and bubbles is crucial to achieve separation efficiency in the separation zone of the dissolved air flotation process. In this study, a micro-scale observation system was established to investigate the interaction between flocs and bubbles in the separation zone of the system. Four periodic interactions were observed-collision, adhesion, coalescence, and desorption (CACD). Small flocs achieved higher unit buoyancy (buoyancy per surface area) than that of large flocs. High collision probability can be obtained between bubbles and small flocs according to Stokes' law and Reynolds experiments. Simulation using Fluent indicated that low-pressure drag acting on small flocs resulted in a high probability of collision. Therefore, small flocs can capture bubbles and accumulate high enough buoyancy in a short time due to the high collision probability and low buoyancy required for small flocs to float. Moreover, the small flocs have a limited number of bubbles on the surface within such a short time, leading to a low probability of desorption and coalescence. The practical verification also show that small flocs are favorable for the high separation efficiency of the flotation process.

7.
Artigo em Inglês | MEDLINE | ID: mdl-33148152

RESUMO

BACKGROUND: Influenza is a contagious respiratory illness caused by acute infection of influenza viruses, among which influenza A virus causes epidemic seasonal infection nearly every year. Along with unpredictability of evolving influenza A virus and time-consuming vaccine development cycles, novel universal influenza vaccine designed to induce broadly cross-reactive immune responses against frequently mutant influenza A virus strains are greatly urgent. OBJECTIVE: The aim of this study was to synthesize a novel vaccine through the dual-site specific conjugation of the constant epitope of 23 amino acids (M2e) of influenza A virus with highly immunogenic carrier protein of cross-reacting material (CRM197) under denaturation, and evaluate its primary immunogenicity in mice. METHODS: The antigen (M2e) and the carrier protein (CRM197) were linked with different type of hetero-functionalized linkers, α-maleimide-ε-hydrazide polyethylene glycol 2k (MAL-PEG-HZ) and N-ß-maleimidopropionic acid hydrazide (BMPH) separately. The immunogenicity of the M2e-CRM197 conjugates with different type of linkers was evaluated in mice, and the M2e-specific total IgG and IgG-isotypes were determined by ELSIA. RESULTS: Immunogenicity study revealed that anti-M2e antibody could be induced by the conjugate products, M2e-PEGCRM197 and M2e-BMPH-CRM197, were approximately 30 and 90-fold higher than that of M2e group. In addition, the antiM2e antibody level induced by M2e-PEG-CRM197 conjugate was three times higher than that of M2e-BMPH-CRM197 conjugate, and the former could simultaneously activate both cellar and humoral immune responses. CONCLUSIONS: The M2e-CRM197 conjugated vaccines we synthesized in this study are highly immunogenic compared with M2e alone. Besides, evidences were presented here indicated that the hydrophilic, non-immunogenic and biocompatible chain of the cross-linker might be a better choice for development of conjugate vaccine.

8.
BMC Cancer ; 20(1): 1021, 2020 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-33087103

RESUMO

BACKGROUND: Both intermittent intravenous (IIV) infusion and continuous intravenous (CIV) infusion of Endostar are widely used for NSCLC in China. We aimed to compare the efficacy and safety of CIV of Endostar versus IIV in combination with first-line chemotherapy for patients with advanced NSCLC. METHODS: RCTs, NRCTs and cohort studies which compared CIV of Endostar with IIV in advanced NSCLC patients and reported efficacy or safety outcomes were eligible. Two reviewers independently screened records, extracted data and assessed risk of bias. Pooled risk ratios (RRs) with 95% confidence intervals were calculated using random effects meta-analysis for short-term efficacy and safety outcomes, and hazard ratios (HRs) for survival outcomes. RESULTS: Finally nine studies involving 597 patients were included, containing two RCTs, three NRCTs and four cohort studies. For short-term efficacy, moderate quality of evidence showed that there were no significant differences between CIV of Endostar and IIV in objective response rate (ORR; RR 1.34, 95% CI 0.91-1.98, P = 0.14) and disease control rate (DCR; RR 1.11, 95% CI 0.94-1.30, P = 0.21). Very low quality of evidence indicated that CIV of Endostar significantly improved both overall survival (OS; HR 0.69, 95% CI 0.48-0.99, P = 0.046) and progression-free survival (PFS; HR 0.71, 95% CI 0.55-0.93, P = 0.01) compared with IIV. As for safety outcomes, moderate quality of evidence found that CIV of Endostar significantly reduced the risk of myelosuppression (RR 0.55, 95% CI 0.32-0.96, P = 0.03) and cardiovascular toxicity (RR 0.21, 95% CI 0.06-0.78, P = 0.02) compared with IIV. CONCLUSIONS: In advanced NSCLC, compared with IIV, CIV of Endostar had similar short-term efficacy, and substantially lower risk of myelosuppression and cardiovascular toxicity. Although very low quality of evidence supported the survival benefit of CIV compared with IIV, large RCTs with long-term follow-up are needed to demonstrate survival benefits. Caution should be given for off-label use of CIV of Endostar.

9.
J Sci Food Agric ; 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-33063338

RESUMO

BACKGROUND: The quality of tea is influenced by numerous factors, especially l-theanine, which is one of the important markers used to evaluate the sweetness and freshness of tea. Sensitive, rapid, and accurate detection of l-theanine is therefore useful to identify the grade and quality of tea. RESULTS: A high-sensitivity, paper-based fluorescent sensor combined with chemometrics was established to detect l-theanine in tea water based on CdTe quantum dots / corn carbon dots and nano tetra pyridel-porphine zinc (ZnTPyP). To verify the reliability of this method, fluorescence spectra and fluorescence-visualized paper-based sensors were compared. The fluorescence spectrum method demonstrated a linear range of 1 to 10 000 nmol L-1 and a limit of detection (LOD) of 0.19 nmol L-1 . In the fluorescence-visualized paper-based sensors there was a linear range of 10-1000 nmol L-1 , and the LOD was 10 nmol L-1 . Partial least squares discriminant analysis (PLSDA) and partial least squares regression analysis (PLSR) were used successfully to determine l-theanine accurately in tea water with this approach. The accuracy of the PLSDA model was 100% both in the training set and the predicting set, and the correlation coefficient between the actual concentration and the predicted concentration was greater than 0.9997 in the PLSR model. CONCLUSION: This fluorescence-visualized paper-based sensor, combined with chemometrics, could be applied efficiently to the practical analysis of tea water samples, which provides a new idea to ensure the flavor and quality of tea. © 2020 Society of Chemical Industry.

10.
Oncol Rep ; 44(6): 2443-2454, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33125141

RESUMO

Flap endonuclease­1 (FEN1), a structure­specific nuclease participating in DNA replication and repair processes, has been confirmed to promote the proliferation and drug resistance of tumor cells. However, the biological functions of FEN1 in cancer cell migration and invasion have not been defined. In the present study, using online database analysis and immunohistochemistry of the specimens, it was found that FEN1 expression was associated with a highly invasive triple­negative breast cancer (TNBC) subtype in both breast cancer samples from the Oncomine database and from patients recruited into the study. Furthermore, FEN1 was an important biomarker of lymph node metastasis and poor prognosis in patients with TNBC. FEN1 promoted migration of TNBC cell lines and FEN1 knockdown reduced the number of spontaneous lung metastasis in vivo. Ingenuity Pathway Analysis of FEN1­related transcripts in 198 patients with TNBC demonstrated that the polo­like kinase family may be the downstream target of FEN1. PLK4 was further identified as a critical target of FEN1 mediating TNBC cell migration, by regulating actin cytoskeleton rearrangement. The results of the present study validate FEN1 as a therapeutic target in patients with TNBC and revealed a new role for FEN1 in regulating TNBC invasion and metastasis.

11.
Aging (Albany NY) ; 12(20): 20658-20683, 2020 10 24.
Artigo em Inglês | MEDLINE | ID: mdl-33098638

RESUMO

Hormone receptor-positive breast cancer accounts for around 75% of breast cancers. The estrogen receptor pathway promotes tumor progression and endocrine resistance. Recently, the cross-talk between the ER signaling pathway and cell cycle regulation has been identified. It is necessary to determine the underlying molecular mechanisms involved in the ER signaling pathway and find new target genes for prognosis and drug resistance in ER+ breast cancer. In this study, lncRNA MAFG-AS1 was shown to be up-regulated and associated with poor prognosis in ER+ breast cancer. Functionally, down-regulation of MAFG-AS1 could inhibit cell proliferation and promote apoptosis. In addition, MAFG-AS1 which contained an estrogen-responsive element could promote CDK2 expression by sponging miR-339-5p. Subsequently, MAFG-AS1 and CDK2 were found to be up-regulated in tamoxifen-resistant MCF-7 cells. Cross-talk between the ER signaling pathway and cell cycle conducted by MAFG-AS1 and CDK2 could promote tamoxifen resistance. In conclusion, our study indicated that estrogen-responsive lncRNA MAFG-AS1 up-regulated CDK2 by sponging miR-339-5p, which promoted ER+ breast cancer proliferation. Cross-talk between the ER signaling pathway and cell cycle suggested that lncRNA MAFG-AS1 is a potential biomarker and therapeutic target in ER+ breast cancer. CDK2 inhibitors may be applied to endocrine resistance therapy.

12.
Br J Clin Pharmacol ; 2020 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-33080064

RESUMO

OBJECTIVE: The purpose of this study is to examine the safety and efficacy of eltrombopag as first-line treatment for thrombocytopenia among pediatric patients after HSCT. METHODS: Forty-three childhood patients with thrombocytopenia after HSCT who received eltrombopag were retrospectively analyzed. RESULT: Eltrombopag was began at the median of 27 days after HSCT and lasted for 24 days. Thirty-five children responded to eltrombopag therapy, and the cumulative platelet recovery rate was 88.9%. Obviously, the cumulative incidence of PLT recovery was lower (83.9% vs 100%; P=0.035) in patients with decreased numbers of megakaryocytes before starting eltrombopag than in those with normal. Factors associated with a significantly elevated response to eltrobopag from univariate analysis were donor tpye. Results from the multiple regression analysis found that weight (HR=0.7, 95%CI 0.5-0.9, P=0.022), platelet engraftment time (HR=1.0, 95%CI 1.0-1.0,P=0.012) and BM megakaryocytes (HR=8.0, 95%CI 1.5-43.3, P=0.016) before starting eltrombopag were the independent risk factors. Based on Youden's index algorithm in the ROC curve, the optimal cut-off value of the Maintenance dose of eltrombopag in predicting nonresponders was 4mg/kg, The AUC was 0.923 with sensitivity of 97.8%, specificity of 87.9%, PPV of 72.3%, and NPV of 92%. None of the pediatric patients stoped using eltrombopag due to side effect or intolerability. CONCLUSION: Eltrombopag is effective and safe in pediatric patients with thrombocytopenia after HSCT. The number of megakaryocytes in bone marrow before eltrombopag treatment may serve as a predictor of the response to eltrombopag. We recommend that the maintenance dose of eltrombopag should not exceed 4mg/kg per day.

13.
Mol Cells ; 43(10): 856-869, 2020 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-33115978

RESUMO

To elucidate the mechanism of action of HOXA11-AS in modulating the cisplatin resistance of nasopharyngeal carcinoma (NPC) cells. HOXA11-AS and miR-454-3p expression in NPC tissue and cisplatin-resistant NPC cells were measured via quantitative reverse transcriptase polymerase chain reaction. NPC parental cells (C666-1 and HNE1) and cisplatin-resistant cells (C666-1/DDP and HNE1/DDP) were transfected and divided into different groups, after which the MTT method was used to determine the inhibitory concentration 50 (IC50) of cells treated with different concentrations of cisplatin. Additionally, a clone formation assay, flow cytometry and Western blotting were used to detect DDP-induced changes. Thereafter, xenograft mouse models were constructed to verify the in vitro results. Obviously elevated HOXA11-AS and reduced miR-454-3p were found in NPC tissue and cisplatin-resistant NPC cells. Compared to the control cells, cells in the si-HOXA11-AS group showed sharp decreases in cell viability and IC50, and these results were reversed in the miR-454-3p inhibitor group. Furthermore, HOXA11-AS targeted miR-454-3p, which further targeted c-Met. In comparison with cells in the control group, HNE1/DDP and C666-1/DDP cells in the si-HOXA11-AS group demonstrated fewer colonies, with an increase in the apoptotic rate, while the expression levels of c-Met, p-Akt/Akt and p-mTOR/mTOR decreased. Moreover, the si-HOXA11-AS-induced enhancement in sensitivity to cisplatin was abolished by miR-454-3p inhibitor transfection. The in vivo experiment showed that DDP in combination with si-HOXA11-AS treatment could inhibit the growth of xenograft tumors. Silencing HOXA11-AS can inhibit the c-Met/AKT/mTOR pathway by specifically upregulating miR-454-3p, thus promoting cell apoptosis and enhancing the sensitivity of cisplatin-resistant NPC cells to cisplatin.

14.
Huan Jing Ke Xue ; 41(8): 3637-3645, 2020 Aug 08.
Artigo em Chinês | MEDLINE | ID: mdl-33124337

RESUMO

Due to the vulnerability of karst hydrological systems, nitrate pollution in karst groundwater has become a global common and serious environmental problem. In order to ensure drinking water safety, it is very important to accurately identify groundwater nitrate sources. The groundwater hydrochemistry and δ15N-NO3- and δ18O-NO3- isotopes were analyzed in samples taken from a suburb of Chongqing:the Longfeng karst trough-valley, which is mainly affected by agricultural activities, and the Longche karst trough-valley, which is primarily affected by urbanization. The IsoSource model was then used to quantify the groundwater nitrate sources. The results showed that:① The NO3- concentration in groundwater ranged from 19.31 mg·L-1 to 37.01 mg·L-1(mean of 28.21 mg·L-1) in the Longfeng karst trough-valley, and from 2.15 mg·L-1 to 27.69 mg·L-1(mean of 10.31 mg·L-1) in the Longche karst trough-valley. The groundwater NO3- concentration exhibited an obvious seasonal variation in both valleys. ② The δ15N-NO3- and δ18O-NO3- isotopes in groundwater in the Longfeng karst trough-valley ranged from 3.29‰ to 11.03‰ (mean of 6.74‰) and 0.88‰ to 7.51‰ (mean of 3.18‰), respectively. In contrast, groundwater in the Longche karst trough-valley presented higher δ15N-NO3- and δ18O-NO3- values that ranged from 5.25‰ to 11.40‰ (mean of 7.95‰) and 2.90‰ to 19.94‰ (mean of 11.18‰), respectively. The lower values of δ15N-NO3- and δ18O-NO3- in groundwater in the Longfeng karst trough-valley suggest that groundwater NO3- was mainly sourced from agricultural N fertilizer, while the higher values of δ15N-NO3- and δ18O-NO3- in groundwater in the Longche karst trough-valley indicate that groundwater NO3- was primarily sourced from domestic sewage. Moreover, such δ15N-NO3- and δ18O-NO3- values in groundwater indicate that nitrification was the primary process for nitrogen conversion in both valleys. Meanwhile, significant seasonal differences in groundwater δ15N-NO3- and δ18O-NO3- were observed in both valleys; the δ15N-NO3- and δ18O-NO3- values were higher during the dry season (means of 8.83‰ and 2.79‰, respectively) than during the rainy season (means of 4.64‰ and 3.58‰, respectively) in the Longfeng karst trough-valley, whereas the δ15N-NO3- and δ18O-NO3- values were lower during the dry season (means of 9.79‰ and 14.56‰, respectively) than during the rainy season (means of 5.12‰ and 7.8‰, respectively) in the Longche trough-valley. This suggests that there were differences in the seasonal NO3- sources to groundwater in both valleys. During the rainy season, the groundwater NO3- concentration in the Longfeng karst trough-valley was mainly due to the nitrification of NH4+ in precipitation and fertilizer as well as organic nitrogen in soil, whereas during the dry season, the groundwater NO3- concentration primarily originated from domestic sewage. In contrast, the groundwater NO3- concentration in the Longche karst trough-valley primarily originated from domestic sewage in both seasons. ③ The results of the IsoSource model indicated that the nitrification of NH4+ from fertilizer and rainwater was the primary NO3- source to groundwater (44.63% of the total) in the Longfeng trough valley, and was followed by domestic sewage (29.5%), soil organic nitrogen (22.38%), and NO3- from rainwater and fertilizer (<10%). During the rainy season, the groundwater NO3- concentration was mainly due to the nitrification of NH4+ from fertilizer and rainwater (52.25% of the total) in Longfeng trough-valley, while groundwater NO3- concentration primarily originated from domestic sewage during the dry season (41% of the total). In contrast, the groundwater NO3- concentration was mainly from domestic sewage (36.17%) in Longche karst trough-valley, and was followed by the nitrification of NH4+ from fertilizer and rainwater (23.5%), soil organic nitrogen (22.5%), and NO3- from rainwater and fertilizer (<10%). The groundwater NO3- concentration in the Longche karst trough-valley primarily originated from domestic sewage in both seasons, and accounted for 47% and 25% during the rainy season and dry season, respectively.


Assuntos
Água Subterrânea , Poluentes Químicos da Água , Monitoramento Ambiental , Nitratos/análise , Isótopos de Nitrogênio/análise , Poluentes Químicos da Água/análise
15.
Environ Sci Technol ; 54(21): 13467-13477, 2020 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-33084314

RESUMO

Emissions of aromatic compounds cause air pollution and detrimental health effects. Here, we explore the reaction kinetics and products of key radicals in benzene photo-oxidation. After initial OH addition and reaction with O2, the effective production rates of phenol and bicyclic peroxy radical (BCP-peroxy) are experimentally constrained at 295 K to be 420 ± 80 and 370 ± 70 s-1, respectively. These rates lead to approximately 53% yield for phenol and 47% yield for BCP-peroxy under atmospheric conditions. The reaction of BCP-peroxy with NO produces bicyclic hydroxy nitrate with a branching ratio <0.2%, indicating efficient NOx recycling. Similarly, the reaction of BCP-peroxy with HO2 largely recycles HOx, producing the corresponding bicyclic alkoxy radical (BCP-oxy). Because of the presence of C-C double bonds and multiple functional groups, the chemistry of BCP-oxy and other alkoxy radicals in the system is diverse. Experimental results suggest the aldehydic H-shift and ring-closure to produce an epoxide functionality could be competitive with classic decomposition of alkoxy radicals. These reactions are potential sources of highly oxygenated molecules. Finally, despite the large number of compounds observed in our study, we are unable to account for ∼20% of the carbon flow.

16.
J Cell Mol Med ; 2020 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-33063955

RESUMO

This study aims to determine the efficacy of Zinc finger protein ZBTB20 in treatment of post-infarction cardiac remodelling. For this purpose, left anterior descending (LAD) ligation was operated on mice to induce myocardial infarction (MI) with sham control group as contrast and adeno-associated virus (AAV9) system was used to deliver ZBTB20 to mouse heart by myocardial injection with vehicle-injected control group as contrast two weeks before MI surgery. Then four weeks after MI, vehicle-treated mice with left ventricular (LV) remodelling underwent deterioration of cardiac function, with symptoms of hypertrophy, interstitial fibrosis, inflammation and apoptosis. The vehicle-injected mice also showed increase of infarct size and decrease of survival rate. Meanwhile, the ZBTB20-overexpressed mice displayed improvement after MI. Moreover, the anti-apoptosis effect of ZBTB20 was further confirmed in H9c2 cells subjected to hypoxia in vitro. Further study suggested that ZBTB20 exerts cardioprotection by inhibiting tumour necrosis factor α/apoptosis signal-regulating kinase 1 (ASK1)/c-Jun N-terminal kinase 1/2 (JNK1/2) signalling, which was confirmed by shRNA-JNK adenoviruses transfection or a JNK activator in vitro as well as ASK1 overexpression in vivo. In summary, our data suggest that ZBTB20 could alleviate cardiac remodelling post-MI. Thus, administration of ZBTB20 can be considered as a promising treatment strategy for heart failure post-MI. Significance Statement: ZBTB20 could alleviate cardiac remodelling post-MI via inhibition of ASK1/JNK1/2 signalling.

17.
Ecotoxicol Environ Saf ; 203: 111021, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32888607

RESUMO

Volatile iodine released from nuclear power plant reactors is radiological hazard to environment and human's health because of their high fission yield and environmental mobility. The complexity of nuclear waste management motivated the development of solid-phase adsorbents. Herein, co-radiation induced graft polymerization (CRIGP) was employed in the graft polymerization of N-vinyl-2-pyrrolidone (NVP) onto polyethylene-coated polypropylene skin-core (PE/PP) fibers using electron beam (EB) irradiation. This work provides a one-step green synthetic approach to prepare iodine fibrous adsorbents without any chemical initiators or large amount of organic solvent. The original and modified PE/PP fibers were characterized by fourier transform infrared spectrometry (FTIR), X-ray photoelectron spectroscopy (XPS), thermogravimetric (TG) and scanning electron microscopy (SEM) to demonstrate the grafting of NVP onto the PE/PP fibers. The capacity of iodine absorbed by the PE/PP-g-PNVP fibers was 1237.8 mg/g after 180 min. Meanwhile, absorbents can be regenerated efficiently by two different means of ethanol elution and heating at 120 °C, respectively. Within 10 min, 94.17% and 90.12% of the iodine can be released from the PE/PP-g-PNVP fibers with these two methods, respectively. The adsorbent exhibited a long service life of at least ten adsorption-desorption cycles, suggesting that PE/PP-g-PNVP fibers might be a promising adsorbent for volatile iodine adsorption from fission products in nuclear power plant reactors.


Assuntos
Poluentes Radioativos do Ar/análise , Raios gama , Química Verde/métodos , Iodo/análise , Polipropilenos/química , Pirrolidinonas/química , Adsorção , Humanos , Cinética , Polimerização , Polipropilenos/efeitos da radiação , Pirrolidinonas/efeitos da radiação , Propriedades de Superfície
18.
Sci Rep ; 10(1): 15730, 2020 09 25.
Artigo em Inglês | MEDLINE | ID: mdl-32978480

RESUMO

Prunella vulgaris L, a perennial herb widely used in Asia in the treatment of various diseases including cancer. In vitro studies have demonstrated the therapeutic effect of Prunella vulgaris L. against breast cancer through multiple pathways. However, the nature of the biological mechanisms remains unclear. In this study, a Network pharmacology based approach was used to explore active constituents and potential molecular mechanisms of Prunella vulgaris L. for the treatment of breast cancer. The methods adopted included active constituents prescreening, target prediction, GO and KEGG pathway enrichment analysis. Molecular docking experiments were used to further validate network pharmacology results. The predicted results showed that there were 19 active ingredients in Prunella vulgaris L. and 31 potential gene targets including AKT1, EGFR, MYC, and VEGFA. Further, analysis of the potential biological mechanisms of Prunella vulgaris L. against breast cancer was performed by investigating the relationship between the active constituents, target genes and pathways. Network analysis showed that Prunella vulgaris L. exerted a promising preventive effect on breast cancer by acting on tumor-associated signaling pathways. This provides a basis to understand the mechanism of the anti-breast cancer activity of Prunella vulgaris L.

19.
Soft Matter ; 2020 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-32909581

RESUMO

Lignin nanospheres (LNPs) are an emerging high-value material platform to realize lignin valorization. The modification or introduction of new functions to LNPs is of great significance to expand its downstream applications. This work evaluated the technical feasibility of preparing lignin-xylan hybrid nanospheres (LXNPs) through a simple solution-based self-assembly process, with the goal of achieving the application as pesticide carriers for enzyme-mediated controlled release. Hybrid LXNPs with various weigh ratios (lignin to xylan, 3 : 1, 1 : 1, 1 : 3) were obtained using deep eutectic solvent-extracted condensed lignin and water-insoluble xylan fragments, which exhibited a nanosphere size of about 166-210 nm with considerable stability in the pH range of 4-10. LXNPs with lignin to xylan ratios of 3 : 1 and 1 : 1 showed well-defined core-shell structures with enriched hydroxyl groups on the surface. It was proposed that lignin could anchor xylan fragments through van der Waals force and hydrophobic interactions between lignin phenylpropanes and xylan molecular backbones, thus facilitating the self-assembly process for the formation of this specific spherical structure. The resulting hydrophobic LXNPs core enabled the facile encapsulation of the biological pesticide avermectin (AVM) with 57.9-67.0% efficiency using one-pot synthesis. When these AVM-encapsulated LXNPs were subjected to enzymatic hydrolysis using xylanase, considerable AVM release of 44.8-55.1% was achieved after 16 h, in comparison to the 4.1% release only for those without xylanase. This work showed the high promise of fabricating hybrid LXNPs through the self-assembly process and also provided a universal nanosphere carrier for drug encapsulation and subsequent enzyme-mediated controlled release.

20.
Talanta ; 219: 121370, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32887087

RESUMO

Biomarker selection has played an increasingly important part in modern medicine with advances of omics techniques. Kohonen self-organizing map is a well-established variable reduction algorithm in identifying significant biomarkers based on variable clustering. However, high dimensionality but small sample size of omics data makes self-organizing map-based model problematic in terms of selection stability and reproducibility. A novel feature screening system is presented in this study by coupling bootstrap with synergy self-organizing map-based orthogonal partial least squares discriminant analysis for stable and biologically meaningful metabolic biomarker selection. In the proposed feature screening system, particle swarm optimization algorithm is utilized to configure synergy self-organizing map-based orthogonal partial least squares discriminant analysis to perform the combination of clusters in a heuristic learning manner, enabling flexible selection of more informative features cost-effectively. Based on the paradigm of ensemble feature selection, bootstrap is adopted to explore significant variables consistently identified across multiple feature selectors rather than a single one. The feasibility of the novel feature screening system is evaluated by two most common inherited metabolic diseases, methylmalonic academia and propionic academia, using urinary metabolomics data. With the desirable classification performance, the proposed feature screening system outperforms simpler techniques in the identification of more features closely correlated with the metabolic mechanisms and the stability of selected candidate biomarkers against sample variations. Besides, the novel feature screening system greatly degrades the sensitivity of identified candidate biomarkers to the network size of self-organizing map, benefiting the identification of a suitable and stable final candidate biomarker list.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA