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1.
Stem Cell Res Ther ; 11(1): 100, 2020 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-32127035

RESUMO

BACKGROUND: In mammals, specification of primordial germ cells (PGCs) is established in the early post-implantation embryo. The bone morphogenetic protein (BMP)-SMAD and WNT3-ß-catenin signaling initiate the gene regulatory network for PGC specification. The activation of SOX17-BLIMP1 axis is critical for human PGC program. Moreover, EpCAM and INTEGRINα6 were identified as surface markers of human PGC-like cells (PGCLCs) recently. However, the signaling mechanism for PGC specification in non-rodent mammals remains to be clarified. METHODS: We differentiated human induced pluripotent stem cells (hiPSCs) into PGCLCs in vitro in response to Activin A and BMP4. The percentage of EpCAM/INTEGRINα6 double-positive cells (PGCLCs) was analyzed by flow cytometry. The expression of PGC genes was evaluated by qRT-PCR and immunofluorescence. The expression dynamic of multi-lineage genes during the differentiation process was evaluated by qRT-PCR. RESULTS: Under the stimulation for PGCLC induction, the embryoids derived from hiPSCs initiated significant upregulation of the early PGC genes (BLIMP1, TFAP2C, and NANOS3), but maintained low or no levels of DPPA3 and late PGC genes (DAZL and DDX4). The percentage of EpCAM/INTEGRINα6 double-positive PGCLCs reached the highest at day 6 of induction. After pre-induction, the incipient mesoderm-like cells (iMeLCs) upregulated most of the mesoderm genes (EOMES, T, MSXI, RUNX2, and MIXL1). The differentiating embryoids showed high levels of key pluripotency genes, OCT4 and NANOG, but became negative for SOX2. In contrast to iMeLCs, the differentiating embryoids downregulated mesoderm genes RUNX2 and EOMES, and ectoderm gene PAX6, but increased the expression of endoderm gene SOX17. CONCLUSIONS: During PGCLC induction process in vitro, the differentiating embryoids not only activated the PGC-related genes, but also displayed complex regulation of pluripotency genes and multi-lineage genes. These results would be meaningful for future research investigating the regulation of human early germ line development.

2.
J Am Chem Soc ; 2020 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-32125832

RESUMO

Crystalline SnSe has been revealed as an efficient thermoelectric candidate with outstanding performance. Herein, record-high thermoelectric performance is achieved among SnSe crystals via simply introducing a small amount of SnSe2 as a kind of extrinsic defect dopant. This excellent performance mainly arises from the largely enhanced power factor by increasing the carrier concentration high as 6.55 × 1019 cm-3, which was surprisingly promoted by introducing extrinsic SnSe2 even though pristine SnSe2 is an n-type conductor. The optimized carrier concentration promotes a deeper Fermi level and activates more valence bands, leading to an extraordinary room-temperature power factor ∼54 µW cm-1 K-2 through enlarging the band effective mass and Seebeck coefficient. As a result, on the basis of simultaneously depressed thermal conductivity induced from both Sn vacancies and SnSe2 microdomains, maximum ZT values ∼0.9-2.2 and excellent average ZT > 1.7 among the working temperature range are achieved in Na doped SnSe crystals with 2% extrinsic SnSe2. Our investigation illustrates new approaches on improving thermoelectric performance through introducing defect dopants, which might be well-implemented in other thermoelectric systems.

3.
Int J Mol Sci ; 21(5)2020 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-32156008

RESUMO

Melanoma is the deadliest form of skin cancer, and its incidence has continuously increased over the past 20 years. Therefore, the discovery of a novel targeted therapeutic strategy for melanoma is urgently needed. In our study, MTT-based cell proliferation assay, cell cycle, and apoptosis assays through flow cytometry, protein immunoblotting, protein immunoprecipitation, designing of melanoma xenograft models, and immunohistochemical/immunofluorescent assays were carried out to determine the detailed molecular mechanisms of a novel HSP90-PI3K dual inhibitor. Our compound, named DHP1808, was found to suppress A375 cell proliferation through apoptosis induction by activating the Fas/FasL signaling pathway; it also induced cell-cycle arrest and inhibited the cell migration and invasion of A375 cells by interfering with Hsp90-EGFR interactions and downstream signaling pathways. Our results indicate that DHP1808 could be a promising lead compound for the Hsp90/PI3K dual inhibitor.

4.
R Soc Open Sci ; 7(1): 191124, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32218943

RESUMO

Based on an electrochemical multiphysical simulation, a method for analysing electrolysis efficiency has been presented that considers the energy consumption required to produce a single kilogram of lithium and for the production of lithium, rather than the voltage in various parts. By adopting them as the criteria for analysing electrolysis efficiency in the lithium cell, several structural parameters have been optimized, such as the anode radius and anode-cathode distance. These parameters strongly affect the cell voltage and the velocity field distribution, which has a significant impact on the concentration distribution. By integrating the concentration distribution, the lithium production and energy consumption per kilogram, lithium is computed. By appointing the minimum of the chlorine and lithium concentration as the secondary reaction intensity, it is clear where the secondary reaction intensity is strong in the cell. The structure of a lithium electrolysis cell has been optimized by applying an orthogonal design approach, with the energy consumption notably decreasing from 35.0 to 28.3 kWh (kg Li)-1 and the lithium production successfully increasing by 0.17 mol.

5.
Clin Sci (Lond) ; 2020 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-32219337

RESUMO

The molecular mechanisms governing the secretion of the non-coding genome are poorly understood. We show herein that cyclin D1, the regulatory subunit of the cyclin-dependent kinase that drives cell-cycle progression, governs the secretion and relative proportion of secreted non-coding RNA subtypes (miRNA, rRNA, tRNA, CDBox, scRNA, HAcaBox. scaRNA, piRNA) in human breast cancer. Cyclin D1 induced the secretion of miRNA governing the tumor immune response and oncogenic miRNAs. miR-21 and miR-93, which bind Toll-Like Receptor 8 to trigger a pro-metastatic inflammatory response, represented >85% of the cyclin D1-induced secreted miRNA transcripts. Furthermore, cyclin D1 increased secretion of the P-element Induced WImpy testis (PIWI)-interacting RNAs (piRNAs) including piR-016658 and piR-016975 which governed stem cell expansion, and increased the abundance of the PIWI member of the Argonaute family, piwil2 in ERα positive breast cancer. The cyclin D1-mediated secretion of pro-tumorigenic immuno-miRs and piRNAs may contribute to tumor initiation and progression.

6.
Artigo em Inglês | MEDLINE | ID: mdl-32223070

RESUMO

Postpartum depression is a serious mental illnessdisorder that occurs after delivery and is one of the most common post-partum complications. With the increasing popularity and extensive use of smartphones worldwide and the fact that China has become the country with the largest number of smartphone users, it is necessary to have a deep understanding of the use and influence of smartphones and discuss the role of smartphone applications in postpartum depression. This study evaluated and analysed the contents of all postpartum depression applications available in China, applying the US Preventive Services Task Force Recommendation Statement (Interventions to Prevent Perinatal Depression) and expert consensus on the guidelines for the prevention and treatment of postpartum depression. We used the keywords 'postpartum depression; and 'PPD' to search Android, iOS, and WeChat in the Chinese application market. Two reviewers agreed on the coding guidelines and coded the content and functionality of the application through content analysis to determine its intervention and adherence to the guidelines. In addition, we used the Mobile App Rating Scale (MARS) to evaluate the application for engagement, functionality, aesthetics, and information domains and recorded the features of the postpartum depression application. The current findings suggest that despite the recent expansion of smartphone platforms and increased availability of applications, existing Chinese apps for postpartum depression have low levels of adherence to clinical practice-based guidelines. New apps need to be developed, and existing apps need to be revised following evidence-based principles.

7.
Biomed Pharmacother ; 126: 110057, 2020 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-32145590

RESUMO

Platinum-based chemotherapy remains the cornerstone of treatment for many malignancies. However, although therapeutic efficiency varies greatly among individuals, there is a lack of pharmacogenomic biomarkers that can be used in clinical settings to identify chemosensitive patients and allow stratification. With the development of high-throughput screening techniques and systems biology approaches, a growing body of evidence has shown that platinum resistance is a multifactorial, multi-dimensional, dynamic process incorporating genetic background, tumor evolution and gut microbes. This review critically summarizes potential pharmacogenomic biomarkers for predicting the efficacy of platinum drugs and provides a comprehensive, time-varying perspective that integrates multiple markers.

8.
ChemSusChem ; 2020 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-32196953

RESUMO

It remains a challenge to rational design of a new metal organic framework (MOF) as highly efficient direct catalysts for the oxygen evolution reaction (OER). Herein, we developed a simple and effective method to explore a new pillared-layered MOF with syringic acid as a promising OER catalyst. The isostructural mono, heterobimetallic MOF and N, S co-doped MOF by mixing thiourea  were quickly synthesized in a high yield under solvothermal condition. Moreover, the optimized N,S co-doped MOF exhibits the lowest overpotential of 254 mV at 10 mA cm-2 on a glass carbon electrode and a small Tafel slope of 50 mV dec-1, especially, this catalyst also possesses long-term electrochemical durability for at least 16 hrs. According to the characterization, the incorporation of N and S atoms into this heterobimetallic CoFe-MOF could modify its pore structure, tune the electronic structure, accordingly, improve the mass and electron transportation, and facilitate the formation of active species, as a consequence, the improved activity of this new N, S co-doped MOF for OER might mainly be ascribed to higher electrochemical activation to lead to the active species via the in-situ surface modification during OER process.

9.
BMC Neurol ; 20(1): 78, 2020 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-32138678

RESUMO

BACKGROUND: Subtle cognitive decline (SCD) may represent a very early stage of objective cognitive impairment before mild cognitive impairment (MCI), with less neuronal damage and more functional reservation. Detecting individuals with SCD is imperative for dementia prevention and treatment. In this study, we aimed to compare the validations of three cognitive screening tests, Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment-Chinese Version (MoCA-CV), and Memory and Executive Screening (MES), in identifying subtle cognitive decline. METHODS: A total of 407 individuals were recruited, including 147 cognitively normal controls (NC), 102 individuals with subtle cognitive decline (SCD) and 158 individuals with mild cognitive impairment (MCI) according to the operational neuropsychological criteria proposed by Jak and Bondi's. All participants underwent standardized comprehensive neuropsychological tests and the three cognitive screening tests. Chi-square analysis was used to compare the cognitive performance among the groups of NC, SCD and MCI. Receiver operating characteristic (ROC) curves were used to evaluate the abilities of MMSE, MoCA-CV and MES in discriminating NC, SCD and MCI. RESULTS: Compared with NC, SCD showed a significant decline only in the tests of memory, such as Auditory Verbal Learning Test (AVLT), Rey-Osterrieth Complex Figure Test (CFT) and Prospective Memory Test (PrM) (P < 0.01). However, MCI showed significant decline in all cognitive performances (P < 0.01). The scores of MMSE, MoCA-CV and MES all showed a progressive downward trend within the groups of NC, SCD and MCI (P < 0.001). In ROC Analyses for discriminating individuals with SCD from NC, the most appropriate MES cutoff was 84, with a sensitivity of 74.3%, a specificity of 60.8% and 0.738 for AUC (95%CI, 0.675-0.801). By contrast, MMSE and MOCA-CV had poor sensitivity (67.4 and 70.8%, respectively) and specificity (51.0 and 52.9%, respectively), and smaller AUCs (0.643 and 0.644, respectively) than the MES. CONCLUSION: As a screening test, MES is more efficacious in identifying SCD from normal controls than MMSE and MoCA-CV.

10.
J Pharm Biomed Anal ; 185: 113225, 2020 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-32163850

RESUMO

Stephania tetrandra S. Moore, a widely used traditional antirheumatic herbal medicine (HM), is a rich source of isoquinoline alkaloids. With the exception of the two recognized isoquinolines, viz. tetrandrine and fangchinoline, the other isoquinoline alkaloids present in S. tetrandra have not been clearly clarified. In addition, due to their similar names and morphological similarities, S. tetrandra is often mistakenly substituted and adulterated with the nephrotoxic Aristolochia fangchi. In this study, ultra-high-performance liquid chromatography-triple time-of-flight mass spectrometry (UHPLC-Q-TOF-MS) was initially employed to comprehensively profile the isoquinolines from S. tetrandra. To overcome the complexities arising due to the similar mass behaviors of the isoquinolines, a stepwise diagnostic fragment ion (DFI) and neutral loss (NL)-dependent structure annotation algorithm was proposed, and this accelerated the identification of 393 isoquinolines distributed over twenty classes. Consequently, liquid microjunction surface sampling-high-resolution mass spectrometry (LMJ-HRMS) was deployed in an attempt to directly authenticate S. tetrandra by the chemical profiling of its crude slice. By matching the 393 isoquinolines, the 87 peaks detected by LMJ-HRMS were assigned to 270 isoquinolines, including the recognized tetrandrine and fangchinoline. The absence of aristolochic acid-related mass signals confirmed the authentication of S. tetrandra. In summary, LMJ-HRMS can be considered a direct, nondestructive, high-throughput, and environment-friendly analytical method for the authentication of HMs. Moreover, the stepwise DFI- and NL-dependent structure annotation algorithm-based UHPLC-Q-TOF-MS method allowed high-coverage detection and high-quality data processing of the inherent structural similarity and complexity of isoquinolines or other phytochemical compounds.

11.
Chem Commun (Camb) ; 2020 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-32211708

RESUMO

The synthesis of vinyl sulfones via silver-promoted cross-coupling of vinyl bromides with sulfonyl hydrazides was realized. Water was used as the sole solvent. Multisubstituted vinyl sulfones were easily prepared with excellent alkyl group tolerance. A mechanism involving nucleophilic attack of a sulfinate anion was proposed.

12.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 28(1): 130-135, 2020 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-32027265

RESUMO

OBJECTIVE: To study the expression level of TGFß1 and VEGF gene in patients with acute myeloid leukemia (AML) and its clinical prognostic value. METHODS: Seventy-eight AML patients treated in our hospital from July 2016 to September 2018 were selected. After isolation of bone marrow mononuclear cells from the patients, the levels of TGFß1 and VEGF genes were detected by RT-PCR, and the correlation of TGFß1 with VEGF genes and clinical characteristics of AML patients was analyzed. OS and EFS of the patients were evaluated by Kaplan-Meier, and Cox risk ratio model was used to analyze the prognostic risk factors of AML patients. RESULTS: The relative expression level of TGFß1 gene in AML patients was 0.32±0.04, which was significantly lower than that in control group (P<005). The relative expression level of vascular endothelial growth factor(VEGF) gene in the patients was 2.65±0.15, which was significantly higher than that in the control group (P<0.05). The levels of TGFß1 and VEGF genes significantly correlated with leukocyte count, hemoglobin, platelet and peripheral blast levels in AML patients (P<0.05). The level of TGFß1 in AML patients with complete remission was higher than that in patients with partial remission or non-remission (P<0.05). The level of TGFß1 in AML patients with partial remission was significantly higher than that in patients with non-remission (P<0.05). The level of VEGF in AML patients with complete remission was lower than at in patients with partial remission or non-remission (P<0.05). The level of VEGF in AML patients with partial remission was significantly lower than that in patients with non-remission (P<0.05). Kaplan-Meier survival analysis showed that OS and DFS in AML patients with high expression of TGFß1 were better than those in patients with low expression of TGFß1 (P<0.05), OS and DFS in AML patients with low expression of VEGF were better than those in patients with high expression of VEGF (P<0.05). Multivariate Cox regression analysis showed that platelet, TGFß1 and VEGF gene were independent influencing factors of OS (P<0.05). Leukocyte, TGFß1 and VEGF gene were independent influencing factors of DFS (P<0.05). CONCLUSION: Decreased expression of TGFß1 and increased expression of VEGF gene in AML patients closely relate to the poor prognosis of AML patients, which can provide reference for improving clinical efficacy of AML patients.


Assuntos
Leucemia Mieloide Aguda , Fator de Crescimento Transformador beta1/genética , Fator A de Crescimento do Endotélio Vascular/genética , Humanos , Estimativa de Kaplan-Meier , Leucemia Mieloide Aguda/genética , Prognóstico , Indução de Remissão
13.
Artif Cells Nanomed Biotechnol ; 48(1): 533-541, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32041436

RESUMO

Hypoxia is an important cause of myocardial cell loss, further inducing various heart illnesses, including acute myocardial infraction (AMI). Long non-coding RNA (LncRNA) discrimination antagonising non-protein coding RNA (DANCR) was firstly identified as epidermal cell differentiation suppressor. Here, we aimed to explore the effects and mechanism of DNACR in hypoxia-induced H9c2 cells. Hypoxic cells were made through 94% N2, 5% CO2, and 1% O2 environment for 24 h. Cell viability and apoptosis were detected via methyl thiazolyl tetrazolium (MTT) method and flow cytometry analysis, respectively. The expression of DANCR and HIF-1α was examined via qRT-PCR. The expression of proteins related to cell apoptosis and PI3K/AKT/mTOR and ERK1/2 signal pathways was examined through western blot analysis. We found that hypoxia induced obvious cell activity inhibition and apoptosis increasing in H9c2 cells. DANCR was negatively regulated under hypoxia condition. Overexpression of DANCR rescued activity and attenuated apoptosis. Moreover, the overexpression of DANCR elevated the activation of PI3K/AKT/mTOR and ERK1/2 pathways. Further study indicated that DANCR could up-regulate the expression of HIF-1α. Si-HIF-1α transfection could remove the beneficial effects of DANCR overexpression in hypoxia-caused H9c2 cells damage. In conclusion, DANCR alleviated hypoxia-caused H9c2 cells damage through positive regulation of HIF-1α.

14.
J Neurosurg Sci ; 2020 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-32043849

RESUMO

BACKGROUND: To explore the effect and mechanism of miR-16-5p on neuron apoptosis and inflammatory response induced by spinal cord injury (SCI). METHODS: Allen's weight-drop method and Basso Bcattie Bresnahan (BBB) rating scale were used to establish SCI rat model and assess locomotor function, respectively. Histopathology of SCI rats and Sham-operated rats was validated by hematoxylin and eosin (H&E) staining. After intravenous injection of miR-16-5p agomir, miR-16-5p antagomir, pcDNA3.1-Apelin-13 or negative controls into SCI rat tails, neuron apoptosis and the expression of miR-16-5p, Apelin-13, apoptotic proteins, inflammatory response-related proteins and ERK1/2 pathway-related protein were detected. Dual luciferase reporter gene assay was applied for identifying the binding between miR-16-5p and Apelin-13. RESULTS: SCI rats had locomotor impairment with markedly edema and hemorrhage. Upregulated miR-16-5p expression and downregulated Apelin-13 expression were presented in SCI rats. Intravenous injection of miR-16-5p antagomir or/and pcDNA3.1-Apelin-13 could increase the expression of anti-apoptotic proteins (Bcl-2 and Mcl-1) and p-ERK1/2 expression while decrease the expression of pro-apoptotic proteins (cleaved caspase-3 and Bax) and inflammatory response-related proteins (TNF-α, IL-1ß and IL-6). The reverse pattern was shown in rats injected with miR-16-5p agomir. MiR-16-5p targeted Apelin-13. Promotion of miR-16-5p agomir on SCI was attenuated by injection of agomir + pcDNA3.1-Apelin-13. CONCLUSIONS: Downregulation of miR-16-5p could upregulate Apelin-13 expression to activate ERK1/2 pathway, thus alleviating SCI-induced neuron apoptosis and inflammatory response.

15.
BMJ Open ; 10(2): e031227, 2020 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-32075822

RESUMO

OBJECTIVES: A combined equation based on white cell count (WCC) and total bilirubin (TB) was assessed for its ability to predict adverse clinical outcomes in patients with acute ST-segment elevation myocardial infarction (STEMI) with primary percutaneous coronary intervention (PCI). DESIGN: A single-centre, prospective cohort study. SETTING: The First Affiliated Hospital of Xinjiang Medical University. METHOD: A total of 615 patients with STEMI postprimary PCI were enrolled. WCC and TB were collected at admission. Logistic regression was used to determine the combined equation. The primary endpoints were in-hospital mortality and major adverse cardiovascular events (MACE), which composed of cardiac death, cardiac shock, malignant arrhythmia (ventricular tachycardia, ventricular fibrillation), severe cardiac insufficiency, non-fatal myocardial infarction, angina pectoris readmission, severe cardiac insufficiency (cardiac III-IV level), stent restenosis and target vessels revascularisation during the hospitalisation and 36 months follow-up period. RESULT: 77 patients occurred in MACE during the hospitalisation (17 in-hospital mortality). WCC and TB were taken as an independent variables to make a category of logistic regression analysis of in-hospital MACE, the logistic regression model was: logit (P)=-8.00+0.265 WCC+0.077 TB, the combination of WCC and TB was more valuable on evaluating the in-hospital mortality (area under the curve 0.804, 95% CI 0.678 to 0.929, p<0.001). Multivariate logistic regression analysis showed that combined detection was an independent risk factor for in-hospital MACE (OR 5.85, 95% CI 3.425 to 9.990, p=0.032). During the follow-up period, 172 patients (29.5%) developed MACE. But the combined detection did not predict the long-term clinical outcome. CONCLUSION: The combination of WCC and TB is an independent predictor for in-hospital outcomes in patients with STEMI than single detection.

16.
J Bacteriol ; 202(8)2020 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-32015147

RESUMO

The (p)ppGpp-mediated stringent response (SR) is a highly conserved regulatory mechanism in bacterial pathogens, enabling adaptation to adverse environments, and is linked to pathogenesis. Actinobacillus pleuropneumoniae can cause damage to the lungs of pigs, its only known natural host. Pig lungs are known to have a low concentration of free branched-chain amino acids (BCAAs) compared to the level in plasma. We had investigated the role for (p)ppGpp in viability and biofilm formation of A. pleuropneumoniae Now, we sought to determine whether (p)ppGpp was a trigger signal for the SR in A. pleuropneumoniae in the absence of BCAAs. Combining transcriptome and phenotypic analyses of the wild type (WT) and an relA spoT double mutant [which does not produce (p)ppGpp], we found that (p)ppGpp could repress de novo purine biosynthesis and activate antioxidant pathways. There was a positive correlation between GTP and endogenous hydrogen peroxide content. Furthermore, the growth, viability, morphology, and virulence were altered by the inability to produce (p)ppGpp. Genes involved in the biosynthesis of BCAAs were constitutively upregulated, regardless of the existence of BCAAs, without accumulation of (p)ppGpp beyond a basal level. Collectively, our study shows that the absence of BCAAs was not a sufficient signal to trigger the SR in A. pleuropneumoniae (p)ppGpp-mediated regulation in A. pleuropneumoniae is different from that described for the model organism Escherichia coli Further work will establish whether the (p)ppGpp-dependent SR mechanism in A. pleuropneumoniae is conserved among other veterinary pathogens, especially those in the Pasteurellaceae family.IMPORTANCE (p)ppGpp is a key player in reprogramming transcriptomes to respond to nutritional challenges. Here, we present transcriptional and phenotypic differences of A. pleuropneumoniae grown in different chemically defined media in the absence of (p)ppGpp. We show that the deprivation of branched-chain amino acids (BCAAs) does not elicit a change in the basal-level (p)ppGpp, but this level is sufficient to regulate the expression of BCAA biosynthesis. The mechanism found in A. pleuropneumoniae is different from that of the model organism Escherichia coli but similar to that found in some Gram-positive bacteria. This study not only broadens the research scope of (p)ppGpp but also further validates the complexity and multiplicity of (p)ppGpp regulation in microorganisms that occupy different biological niches.

17.
Chemosphere ; 244: 125532, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32050334

RESUMO

Hierarchical Co3O4@MnOx material has been synthesized by in-suit growth of MnOx on the Co3O4 and applied in catalytic oxidation of volatile organic compounds (VOCs). Results revealed that T90 of acetone on the Co3O4@MnOx was 195 °C, which was 36 °C and 32 °C lower than that on the Co3O4 and MnOx/Co3O4, respectively. The universality experiments demonstrated that T90 of ethyl acetate and toluene on the Co3O4@MnOx were 200 °C and 222 °C, respectively. The above results indicated that Co3O4@MnOx catalyst presented a robust catalytic performance. Characterization results showed that high catalytic activity of the Co3O4@MnOx catalyst could be attributed to the improvement of low temperature reducibility, the enhancement of Co3+ and adsorbed oxygen species resulted from the sufficient reaction between MnO4- and Co2+ during secondary hydrothermal process. Furthermore, stability and water-resistance experiments showed the Co3O4@MnOx catalyst with high cycle and long-term stability, satisfied endurability to 5.5-10 vol. % water vapor at 210 °C.


Assuntos
Modelos Químicos , Nanofios/química , Compostos Orgânicos Voláteis/química , Adsorção , Catálise , Oxirredução , Óxidos , Oxigênio , Tolueno
18.
Fitoterapia ; 142: 104491, 2020 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-32032634

RESUMO

Two new monoterpenoid indole alkaloids, bousangines A (1) and B (2), were isolated from the twigs and leaves of Bousigonia angustifolia. Their structures including absolute configurations were elucidated by a combination of MS, NMR, ECD calculation, and single-crystal X-ray diffraction analysis. Bousangine A (1) possessed a rearrangement pentacyclic skeleton derived from aspidosperma-type alkaloids with C-17 degradation. Their antiproliferative activity against several human cancer cell lines were evaluated.

19.
Biomed Pharmacother ; 125: 109875, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32036211

RESUMO

Efficient DNA repair is critical for cell survival following exposure to DNA topoisomerase I (Top1) inhibitors camptothecin, a nature product from which the common chemotherapeutic drugs irinotecan and topotecan are derived. The camptothecin-derived agents exert their antitumor activities by specifically stabilizing the Top1-DNA covalent complexes (Top1cc) and blocking the DNA religation step. When exposed to these DNA damage agents, tumor cells quickly activate DNA damage response. This allows sufficient time to remove the Top1ccs and prevent tumor cells from apoptosis. Several repair pathways have been implicated in this process. One of the most relevant repair modes is DNA single strand break repair (SSBR) pathway. The expression level or mutagenesis of specific repair factors involved in SSBR pathway may play an indispensable role in individual's capacity of repairing camptothecin induced DNA damage. Therefore, understanding of the tolerance pathways counteracted to camptothecin cytotoxicity is crucial in alleviating chemotherapy resistance. This review focus on the SSBR pathway in repair camptothecin induced DNA damage, aiming to provide insights into the potential molecular determinants of camptothecin chemosensitivity.

20.
Sci Rep ; 10(1): 3017, 2020 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-32080303

RESUMO

Oxytocin possesses several physiological and social functions, among which an important analgesic effect. For this purpose, oxytocin binds mainly to its unique receptor, both in the central nervous system and in the peripheral nociceptive terminal axon in the skin. However, despite its interesting analgesic properties and its current use in clinics to facilitate labor, oxytocin is not used in pain treatment. Indeed, it is rapidly metabolized, with a half-life in the blood circulation estimated at five minutes and in cerebrospinal fluid around twenty minutes in humans and rats. Moreover, oxytocin itself suffers from several additional drawbacks: a lack of specificity, an extremely poor oral absorption and distribution, and finally, a lack of patentability. Recently, a first non-peptide full agonist of oxytocin receptor (LIT-001) of low molecular weight has been synthesized with reported beneficial effect for social interactions after peripheral administration. In the present study, we report that a single intraperitoneal administration of LIT-001 in a rat model induces a long-lasting reduction in inflammatory pain-induced hyperalgesia symptoms, paving the way to an original drug development strategy for pain treatment.

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