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1.
Artigo em Inglês | MEDLINE | ID: mdl-33067683

RESUMO

L-Tyrosine is an aromatic, polar, non-essential amino acid that contains a highly reactive α-amino, α-carboxyl, and phenolic hydroxyl group. Derivatization of these functional groups can produce chemicals, such as L-3,4-dihydroxyphenylalanine, tyramine, 4-hydroxyphenylpyruvic acid, and benzylisoquinoline alkaloids, which are widely employed in the pharmaceutical, food, and cosmetics industries. In this review, we summarize typical L-tyrosine derivatizations catalyzed by enzymatic biocatalysts, as well as the strategies and challenges associated with their production processes. Finally, we discuss future perspectives pertaining to the enzymatic production of L-tyrosine derivatives.Key points• Summary of recent advances in enzyme-catalyzed L-tyrosine derivatization.• Highlights of relevant strategies involved in L-tyrosine derivatives biosynthesis.• Future perspectives on industrial applications of L-tyrosine derivatization.

2.
Curr Microbiol ; 2020 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-33011835

RESUMO

Many organisms secrete xylanase, an import group of proteins hydrolyzing xylan, and thus are able to use xylan as their carbon source. In this study, we sequenced the whole genome of a bacterial strain, YD01, which was isolated from the sludge near the sewage discharge outlet of a papermill and showed high alkalic xylanase activity. Its genome consists of a chromosome and two plasmids. Six rRNA genes, 46 tRNA genes, 3136 CDSs as well as 955 repetitive sequences were predicted. 3046 CDSs were functionally annotated. Phylogenetic analysis on 16S rRNA shows that YD01 is a new species in Microbacterium genus and is taxonomically close to M. jejuense THG-C31T and M. kyungheense THG-C26T. A comparative study on phylogenetic trees of 16S rRNA and xylanase genes suggests that xylanase genes in YD01 may originate from horizontal gene transfer instead of ancestral gene duplication.

3.
Diabetes Res Clin Pract ; : 108493, 2020 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-33039489

RESUMO

AIMS: To investigate the association of severe hypoglycemia (SH) with all-cause mortality and complication risks among Chinese patients with type 2 diabetes mellitus (T2DM). METHODS: Cohort study and nested case-control studies were conducted based on medical insurance database 2008-2015. The incidence of outcomes or the exposure of previous SH was compared among matched patients, respectively. The association between SH and outcomes was investigated and validated by difference models. RESULTS: Among cohort study participants (mean age of 59.0 ± 11.2 years), SH was associated with higher risk of all-cause mortality (HR=1.80, P<0.001) and transient ischemic attacks (TIA, HR=1.51, P<0.001), while no association was observed between SH and complications including myocardial infarction (MI), angina, arrhythmia and stroke. Similarly, SH was associated with about doubled all-cause mortality (OR=1.76, P<0.001) and TIA (OR=2.00, P<0.001), but not associated with risk of MI or stroke in nested case-control studies. CONCLUSIONS: In Chinese patients with T2DM, SH is associated with increased risk of all-cause mortality and TIA, but no significant differences were found regard to the other examined complication risks, which need to be further explored in future studies.

4.
PLoS Negl Trop Dis ; 14(10): e0008643, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33044969

RESUMO

BACKGROUND: Clonorchis sinensis, a fluke dwelling in the intrahepatic bile ducts causes clonorchiasis, which affect about 15 million people wide-distributed in eastern Asia. During C. sinensis infection, worm-host interaction results in activation of patterns recognition receptors (PRRs) such as Toll-like receptors (TLRs) and further triggers immune responses, which determines the outcome of the infection. However, the mechanisms by which pathogen-associated molecules patterns from C. sinensis interact with TLRs were poorly understood. In the present study, we assumed that the molecules from C. sinensis may regulate host immune responses via TLR2 signaling pathway. METHODOLOGY/PRINCIPAL FINDINGS: In the present study, we have identified a ~34 kDa CsHscB from C. sinensis which physically bound with TLR2 as demonstrated by molecular docking and pull-down assay. We also found that recombinant CsHscB (rCsHscB) potently activates macrophage to express various proteins including TLR2, CD80, MHCII, and cytokines like IL-6, TNF-α, and IL-10, but rCsHscB failed to induce IL-10 in macrophages from Tlr2-/- mice. Moreover, ERK1/2 activation was required for rCsHscB-induced IL-10 production in macrophages. In vivo study revealed that rCsHscB triggered a high production of IL-10 in the wild-type (WT) but not in Tlr2-/- mice. Consistently, the phosphorylation of ERK1/2 was also attenuated in Tlr2-/- mice compared to the WT mice, after the treatment with rCsHscB. CONCLUSIONS/SIGNIFICANCE: Our data thus demonstrate that rCsHscB from C. sinensis interacts with TLR2 to be endowed with immune regulatory activities, and may have some therapeutic implications in future beyond parasitology.

5.
Value Health ; 23(10): 1391-1399, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33032784

RESUMO

OBJECTIVES: To explore the acceptability, consistency, and accuracy of eliciting health state utility values using discrete choice experiment (DCE) and DCE with life duration dimension (DCETTO) as compared with conventional time trade-off (TTO) by using the SF-6Dv2. METHODS: During face-to-face interviews, a representative sample of the general population in Tianjin, China, completed 8 TTO tasks and 10 DCE/DCETTO tasks, with the order of TTO and DCE/DCETTO being randomized. The fixed-effect model and conditional logit models were used for TTO and DCEs data estimation, respectively. Acceptability was assessed by self-reported difficulties in understanding/answering. Consistency was observed by the monotonicity of model coefficients. Accuracy was evaluated by investigating differences between observed and predicted TTO values using intraclass correlation coefficient, mean absolute difference, and root mean square difference. RESULTS: A total of 503 respondents (53.7% male; range, 18-86 years) were included, with comparable characteristics between respondents who completed DCE (N = 252) and DCETTO (N = 251). No significant difference was observed in self-reported difficulties among 3 approaches. The monotonicity of coefficients could not be achieved for 2 DCE approaches, even when combining the inconsistent levels. The health state utility values generated by DCE were generally higher than those generated by TTO, whereas DCETTO was lower than TTO. The TTO had a better prediction accuracy than the DCEs. CONCLUSIONS: Two DCE approaches are feasible for eliciting health state utility values; however, they are not considered to be easier to understand/answer than TTO. There are systematic differences in the health state utility values generated by 3 approaches. The issue of non-monotonicity from 2 DCE approaches remains a concern.

6.
Biomed Chromatogr ; : e4998, 2020 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-33037660

RESUMO

Isoliquiritigenin and isoliquiritin, two kinds of major flavonoids in licorice, are biological active substances with antioxidant, anti-inflammatory and tumor-suppressive effects. However, their in vivo metabolites, possible material basis of this two licorice chalcones for the diseases treatment, have not been fully studied. To clarify the metabolism of isoliquiritigenin and isoliquiritin, the metabolites of this two licorice chalcones in mice plasma, urine, feces and bile after oral administration of 100 mg/kg/d for consecutive 8 days were determined using liquid chromatography coupled with quadrupole/time-of-flight mass spectrometry in this study. The structures of those metabolites were tentatively identified according to their fragment pathways, accurate masses, characteristic product ions, metabolism law and reference standards-matching. As a result, a total of 25 o 29 metabolites of isoliquiritigenin or isoliquiritin were respectively identified. Seven main metabolic pathways, including oxidation and reduction, deglycosylation and glycosylation, dehydroxylation and hydroxylation, demethoxylation and methoxylation, acetylation, glucuronidation and sulfation were summarized to tentatively explain how the metabolites were biologically transformed. These results provide the important information on the metabolism of isoliquiritigenin and isoliquiritin, which may be helpful for the further research of their pharmacological mechanism.

7.
Medicine (Baltimore) ; 99(40): e22292, 2020 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-33019404

RESUMO

This study aims to assess the survival status of patients with Primary gallbladder cancer (PGC) and analyze the prognosis factors to facilitate the exploration of the prevention and therapeutic strategies of PGC.Data from 2433 PGC patients collected from 2010 to 2015 were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. The SEER*Stat, SPSS 23.0 and GraphPad Prism 8 were used for statistical analyses. Kaplan Meier analysis was performed for the survival curve, log-rank test analyses were used to compare the survival rate difference and Cox regression analyses were performed to determine the prognosis factors.A total of 2433 PGC cases were reported from 2010 to 2015. The median age was 64.2 ±â€Š10.4 years old and the percentages of the white patients were 73.7% (1794/2433). The percentage of patients who received surgery treatment was 82.1% (1998/2433). The overall median survival time of all patients was 19 months and the 5-year survival rate was 28.8%. The 5-year survival rate of PGC patients in pN2 stage dropped to 0% and the 5-year survival rate for PGC patients with distant metastasis was only 2.7%. Age, tumor size, grade, pT stage, pM stage were risk factors for prognosis, surgery or not and radiation or not were protective factors for prognosis.Survival analysis of PGC patients based on the SEER database have provided an opportunity for understanding PGC prognosis and the basis for the exploration of viable PGC prevention and therapeutic strategies.

8.
J Recept Signal Transduct Res ; : 1-6, 2020 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-33019890

RESUMO

Matrine has been found to affect cell viability and function. In the present study, we explored the cardioprotective role of matrine in cardiomyocyte damage under hypoxia/reoxygenation. In vitro, cardiomyocyte hypoxia/reoxygenation was used to mimic ischemia/reperfusion injury in the presence of matrine. After exposure to hypoxia/reoxygenation, cardiomyocyte viability was reduced and cell apoptosis was increased; this alteration was inhibited by matrine. At the molecular levels, Sirt3 and AMPK were significantly downregulated by hypoxia/reoxygenation injury whereas matrine administration was able to upregulate Sirt3 and AMPK expression and activity in the presence of hypoxia/reoxygenation. Interestingly, inhibition of Sirt3/AMPK pathway abolished the cardioprotective action of matrine on cardiomyocyte in the presence of hypoxia/reoxygenation injury, resulting into cardiomyocyte viability reduction and cell death augmentation. Altogether, our results demonstrated a novel role played by matrine in regulating cardiomyocyte viability and death in the presence of hypoxia/reoxygenation, with a potential application in the clinical practice for the treatment of patients with myocardial infarction.

9.
Biomolecules ; 10(10)2020 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-33020402

RESUMO

Neovascular retinal degeneration is a leading cause of blindness in advanced countries. Anti-vascular endothelial growth factor (VEGF) drugs have been used for neovascular retinal diseases; however, anti-VEGF drugs may cause the development of chorioretinal atrophy in chronic therapy as they affect the physiological amount of VEGF needed for retinal homeostasis. Hypoxia-inducible factor (HIF) is a transcription factor inducing VEGF expression under hypoxic and other stress conditions. Previously, we demonstrated that HIF was involved with pathological retinal angiogenesis in murine models of oxygen-induced retinopathy (OIR), and pharmacological HIF inhibition prevented retinal neovascularization by reducing an ectopic amount of VEGF. Along with this, we attempted to find novel effective HIF inhibitors. Compounds originally isolated from mushroom-forming fungi were screened for prospective HIF inhibitors utilizing cell lines of 3T3, ARPE-19 and 661W. A murine OIR model was used to examine the anti-angiogenic effects of the compounds. As a result, 2-azahypoxanthine (AHX) showed an inhibitory effect on HIF activation and suppressed Vegf mRNA upregulation under CoCl2-induced pseudo-hypoxic conditions. Oral administration of AHX significantly suppressed retinal neovascular tufts in the OIR model. These data suggest that AHX could be a promising anti-angiogenic agent in retinal neovascularization by inhibiting HIF activation.

10.
Dalton Trans ; 2020 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-33025992

RESUMO

An aqua-coordinated lamellar net [Zn(5-NH2-1,3-bdc)(H2O)] (1, 5-NH2-1,3-H2bdc = 5-amino-1,3-benzenedicarboxylic acid) has been found to undergo a reversible stimuli-responsive 2D-to-2D crystal-to-crystal transformation with a water-free bilayered-lamellar net [Zn(5-NH2-1,3-bdc)] (1') upon removal and rebinding of aqua ligands, whereas a 2D porous pillared-bilayer [Zn2(5-NH2-1,3-bdc)2(NI-bpy-44)]·DMF (2, NI-bpy-44 = N-(pyridin-4-yl)-4-(pyridin-4-yl)-1,8-naphthalimide) has been tailored by introducing NI-bpy-44 to replace the coordinated aqua ligands. Pillared-bilayer 2 displayed a moderate CO2 uptake of 79.1 cm3 g-1 STP at P/P0 = 1 and 195 K with an isosteric heat of CO2 adsorption (Qst) of 37.0 kJ mol-1 at zero-loading. It is noteworthy that the water suspensions of 1 and 2 both displayed good fluorescence performances, which were effectively quenched by Fe3+, MnO4-, and Cr2O72- ions and shifted to long wavelengths by Fe3+, Al3+, and Cr3+, even with the coexistence of equal amounts of most other interfering ions. Taking the Stern-Volmer quenching constant, limit of detection, quenching efficiency, anti-interference ability, and visual observation into consideration, it is clear that both 1 and 2 are promising and excellent fluorescent sensors for highly sensitive detection of Fe3+, MnO4-, and Cr2O72-.

11.
Ann Hum Genet ; 2020 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-33026665

RESUMO

OBJECTIVE: To assess the experience on prenatal diagnosis of Miller-Dieker syndrome (MDS) to further delineate the fetal presentation of this syndrome. METHODS: This was a retrospective study. Fetal MDS was diagnosed prenatally by chromosomal microarray (CMA). Clinical data were reviewed for these cases, including maternal characteristics, indications for prenatal diagnosis, sonographic findings, CMA results, and pregnancy outcomes. RESULTS: Four cases were diagnosis as MDS by CMA. The most common sonographic features were ventriculomegaly (3/4) and polyhydramnios (2/4). Deletion sizes ranged from 1.5 to 5.4 Mb. All microdeletions were located at the MDS critical region and showed haploinsufficiency of the YWHAE, CRK, and PAFAH1B1. All patients chose to terminate the pregnancy. Parental chromosome analysis were preformed in three cases and demonstrated that two cases were de novo and one case was caused by inherited derivative chromosomes from parental balanced translocations. CONCLUSION: The most common prenatal ultrasound findings of MDS were ventriculomegaly and polyhydramnios. CMA can improve diagnostic precision for detecting MDS.

12.
Food Funct ; 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-33001073

RESUMO

Previous researches have indicated that sleep plays a vital role in cognitive functions. Sleep deprivation (SD) causes learning and memory damage, which is associated with oxidative stress. This study was performed to investigate the neuroprotective effects of an extract of Abelmoschus manihot flower (EAM) against memory deficit induced by SD in mice. The SD model was evoked by multiple platform method for 5 days, successively. The learning and memory-improving effects of EAM were assessed by behavioral trials and the underlying mechanism was investigated by measuring the oxidative stress alteration. Our findings indicated that the SD-induced memory deficit and the EAM treatment improved the cognitive functions of mice in the object location recognition test and passive avoidance task. In addition, EAM effectively improved the activities of the antioxidant enzyme, decreased the content of malondialdehyde (MDA), and restored the protein expression of the brain-derived neurotrophic factor (BDNF), tyrosine kinase B (TrkB) and glutamate receptor 1 (GluR1) in brain tissues. In conclusion, EAM could improve the SD-evoked learning and memory impairments. The possible underlying mechanisms of EAM may be related to its antioxidant capacity and enhanced BDNF/TrkB/GluR1 levels in the hippocampal memory.

13.
Eur J Radiol ; 132: 109286, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-33007519

RESUMO

PURPOSE: This study aims to compare pelvic incidence (PI), a skeletal angle formed by the first sacral vertebrae and femoral heads, in women with and without pelvic organ prolapse (POP) and to explore the correlation of PI with the progression of POP, through 3D reconstruction of MRI scans. METHOD: The case-control study enrolled 48 prolapse patients and 48 paired subjects by collecting and screening clinical information including age, BMI, vaginal deliveries, and levator ani defect scores. PI values were measured in 3D reconstruction models based on MRI scans, and the mean and standard deviation values of PI in both groups were calculated. Receiver operating characteristic (ROC) analysis and logistic regression were used to quantify relationships between PI and prolapse. Additionally, by performing a cross-section study of 69 patients with POP, correlations between PI values and descending vaginal locations were assessed by multivariate linear regression models. RESULTS: Compared with the control group, the patient group has a significantly larger average PI (48.68 ±â€¯10.77˚ vs 42.20 ±â€¯8.55˚, P=0.002). ROC analysis for the classification of prolapse based on PI has an area under the curve of 70.1 % (P < 0.001). Logistic regression identified a larger PI value as a risk factor of prolapse with an odds ratio of 2.90 (95 %CI: 1.46-5.74, P = 0.002) for PI per increasing 10˚. Point Ba and Bp represent the most distal positions of any part of the upper anterior and posterior vaginal walls, respectively. In the patient group, internally, Ba and Bp would descend 0.62 (95 %CI: 0.24-1.00, P=0.002) cm and 0.74 (95 %CI 0.22-1.26, P=0.006) cm for every 10° increase in PI, respectively. The coefficients of the partial correlation of PI for Ba and Bp are 0.381 (P = 0.002) and 0.336 (P = 0.006). CONCLUSIONS: PI is significantly related to morbidity and progression of POP, especially for the anterior and posterior pelvic compartments. As an individual constant value of the spinopelvic skeletal shape, a larger PI value is a risk factor and should be evaluated carefully in medical imaging of POP.

14.
Global Health ; 16(1): 96, 2020 10 09.
Artigo em Inglês | MEDLINE | ID: mdl-33036622

RESUMO

BACKGROUND: The outbreak of Coronavirus Disease is causing considerable acute risk to public health and might also have an unanticipated impact on the mental health of children and adolescents in the long run. This study collected data during the national lockdown period in China and aims to understand whether there is a clinically significant difference in anxiety, depression, and parental rearing style when comparing adolescents from Wuhan and other cities in China. This study also intends to examine whether gender, grade in school, single child status, online learning participation, parents' involvement in COVID-19 related work, and parents being quarantined or infected due to the disease would lead to clinically significant differences in anxiety and depression. Beyond that, this study explored the pathways among the different variables in order to better understand how these factors play a part in impacting adolescents' mental health condition. RESULTS: Results showed that there was a statistically significant difference in anxiety symptoms between participants who were from Wuhan compared to other urban areas, but not in depressive symptoms. In addition, participants' grade level, gender, relative being infected, and study online have direct positive predictive value for depressive and anxiety symptoms, whereas location and sibling status have indirect predictive value. Having relatives who participated in COVID-19 related work only had positive direct predictive value toward depression, but not anxiety. CONCLUSIONS: This study discovered several risk factors for adolescents' depression and anxiety during the pandemic. It also called for a greater awareness of Wuhan parents' mental wellbeing and recommended a systematic approach for mental health prevention and intervention.

15.
Eur Radiol ; 2020 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-33052463

RESUMO

OBJECTIVES: There currently lacks a noninvasive and accurate method to distinguish benign and malignant ovarian lesion prior to treatment. This study developed a deep learning algorithm that distinguishes benign from malignant ovarian lesion by applying a convolutional neural network on routine MR imaging. METHODS: Five hundred forty-five lesions (379 benign and 166 malignant) from 451 patients from a single institution were divided into training, validation, and testing set in a 7:2:1 ratio. Model performance was compared with four junior and three senior radiologists on the test set. RESULTS: Compared with junior radiologists averaged, the final ensemble model combining MR imaging and clinical variables had a higher test accuracy (0.87 vs 0.64, p < 0.001) and specificity (0.92 vs 0.64, p < 0.001) with comparable sensitivity (0.75 vs 0.63, p = 0.407). Against the senior radiologists averaged, the final ensemble model also had a higher test accuracy (0.87 vs 0.74, p = 0.033) and specificity (0.92 vs 0.70, p < 0.001) with comparable sensitivity (0.75 vs 0.83, p = 0.557). Assisted by the model's probabilities, the junior radiologists achieved a higher average test accuracy (0.77 vs 0.64, Δ = 0.13, p < 0.001) and specificity (0.81 vs 0.64, Δ = 0.17, p < 0.001) with unchanged sensitivity (0.69 vs 0.63, Δ = 0.06, p = 0.302). With the AI probabilities, the junior radiologists had higher specificity (0.81 vs 0.70, Δ = 0.11, p = 0.005) but similar accuracy (0.77 vs 0.74, Δ = 0.03, p = 0.409) and sensitivity (0.69 vs 0.83, Δ = -0.146, p = 0.097) when compared with the senior radiologists. CONCLUSIONS: These results demonstrate that artificial intelligence based on deep learning can assist radiologists in assessing the nature of ovarian lesions and improve their performance. KEY POINTS: • Artificial Intelligence based on deep learning can assess the nature of ovarian lesions on routine MRI with higher accuracy and specificity than radiologists. • Assisted by the deep learning model's probabilities, junior radiologists achieved better performance that matched those of senior radiologists.

16.
Ageing Res Rev ; : 101174, 2020 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-32971255

RESUMO

One of the key issues facing public healthcare is the global trend of an increasingly ageing society which continues to present policy makers and caregivers with formidable healthcare and socio-economic challenges. Ageing is the primary contributor to a broad spectrum of chronic disorders all associated with a lower quality of life in the elderly. In 2019, the Chinese population constituted 18 % of the world population, with 164.5 million Chinese citizens aged 65 and above (65+), and 26 million aged 80 or above (80+). China has become an ageing society, and as it continues to age it will continue to exacerbate the burden borne by current family and public healthcare systems. Major healthcare challenges involved with caring for the elderly in China include the management of chronic non-communicable diseases (CNCDs), physical frailty, neurodegenerative diseases, cardiovascular diseases, with emerging challenges such as providing sufficient dental care, combating the rising prevalence of sexually transmitted diseases among nursing home communities, providing support for increased incidences of immune diseases, and the growing necessity to provide palliative care for the elderly. At the governmental level, it is necessary to make long-term strategic plans to respond to the pressures of an ageing society, especially to establish a nationwide, affordable, annual health check system to facilitate early diagnosis and provide access to affordable treatments. China has begun work on several activities to address these issues including the recent completion of the of the Ten-year Health-Care Reform project, the implementation of the Healthy China 2030 Action Plan, and the opening of the National Clinical Research Center for Geriatric Disorders. There are also societal challenges, namely the shift from an extended family system in which the younger provide home care for their elderly family members, to the current trend in which young people are increasingly migrating towards major cities for work, increasing reliance on nursing homes to compensate, especially following the outcomes of the 'one child policy' and the 'empty-nest elderly' phenomenon. At the individual level, it is important to provide avenues for people to seek and improve their own knowledge of health and disease, to encourage them to seek medical check-ups to prevent/manage illness, and to find ways to promote modifiable health-related behaviors (social activity, exercise, healthy diets, reasonable diet supplements) to enable healthier, happier, longer, and more productive lives in the elderly. Finally, at the technological or treatment level, there is a focus on modern technologies to counteract the negative effects of ageing. Researchers are striving to produce drugs that can mimic the effects of 'exercising more, eating less', while other anti-ageing molecules from molecular gerontologists could help to improve 'healthspan' in the elderly. Machine learning, 'Big Data', and other novel technologies can also be used to monitor disease patterns at the population level and may be used to inform policy design in the future. Collectively, synergies across disciplines on policies, geriatric care, drug development, personal awareness, the use of big data, machine learning and personalized medicine will transform China into a country that enables the most for its elderly, maximizing and celebrating their longevity in the coming decades. This is the 2nd edition of the review paper (Fang EF et al., Ageing Re. Rev. 2015).

17.
Carbohydr Polym ; 248: 116753, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32919556

RESUMO

As an indispensable component, separator is close related to electrochemical performance and safety of lithium-ion batteries (LIBs). However, the current widely applied polyolefin microporous separator impedes the development of high power LIBs due to poorer electrolyte wettability and inferior thermal stability. Herein, heat-resistant polyphenylene sulfide (PPS) fibers and cellulose fibers (CFs) are adopted to fabricate a novel composite separator (CFs/PPS) via a facile papermaking process. The as-prepared CFs/PPS separator exhibits higher porosity, improved electrolyte uptake and superior wettability. These boost its ionic conductivity and decrease interfacial resistance between CFs/PPS separator and electrode, which further endow battery with good rate capability. Moreover, in comparison to commercial polypropylene separator, CFs/PPS separator gives superior thermal stability, satisfactory mechanical strength, broader electrochemical window and more stable cycle performance. Accordingly, CFs/PPS composite separator is very promising for application in high power LIBs.

19.
Bioorg Chem ; 103: 104192, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32889382

RESUMO

Structural modification of natural products by biotransformation with fungi is an attractive tool to obtain novel bioactive derivatives. In the present study, cryptotanshinone (1), a quinoid abietane diterpene from traditional Chinese medicine Salvia miltiorrhiza (Danshen), was transformed by two marine-derived fungi. By using Cochliobolus lunatus TA26-46, one new oxygenated and rearranged product (2), containing a 5,6-dihydropyrano[4,3-b]chromene moiety, together with one known metabolite (10), were obtained from the converted broth of cryptotanshinone (1) with the isolated yields of 1.0% and 2.1%, respectively. While, under the action of Aspergillus terreus RA2905, seven new transformation products (3-9) as well as 10 with the fragments of 2-methylpropan-1-ol and oxygenated p-benzoquinone were produced and obtained with the isolated yields of 0.1%-1.3%. The structures of the new compounds were elucidated by comprehensive spectroscopic analysis including High Resolution Electrospray Ionization Mass Spectroscopy (HRESIMS), Nuclear Magnetic Resonance (NMR) and Electronic Circular Dichroism (ECD). The metabolic pathways of cryptotanshinone by these two fungi were presumed to be the opening and rearrangement of furan ring, and/or oxygenation of cyclohexane ring. Cryptotanshinone (1) and its metabolites displayed anti-inflammatory activities against NO production in LPS-stimulated BV-2 cells and antibacterial activities towards methicillin-resistant Staphylococcus aureus. These findings revealed the potential of marine fungi to transform the structures of natural products by biotransformation.

20.
Int J Mol Med ; 46(4): 1409-1422, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32945349

RESUMO

The present study aimed to examine the effects of FcγRIIB on systemic lupus erythematosus (SLE) and to investigate the underlying mechanisms. For this purpose, lentiviral vector carrying the membrane­bound type FcγRIIB gene (mFcγRIIB lentivirus) and soluble FcγRIIB (sFcγRIIB) protein were used to treat B cells from patients with SLE. The B cells were treated with calf thymus DNA (ctDNA) and anti­calf thymus DNA­immune complexes (anti­ctDNA­IC). mFcγRIIB lentivirus and sFcγRIIB protein were also injected into MRL/lpr SLE mice. The results revealed that anti­ctDNA­IC treatment significantly downregulated the IgG antibody secretion of B cells treated with mFcγRIIB lentivirus. mFcγRIIB and sFcγRIIB decreased the phosphorylation level of Bruton's tyrosine kinase (BTK) in B cells, and increased the phosphorylation level of Lyn proto­oncogene (Lyn), docking protein 1 (DOK1) and inositol polyphosphate­5­phosphatase D (SHIP). mFcγRIIB promoted the apoptosis of B cells. Following the treatment of MRL/lpr SLE mice with mFcγRIIB lentivirus, the levels of urinary protein, serum anti­nuclear and anti­dsDNA antibodies were decreased, while the levels of mFcγRIIB in B cells were increased. mFcγRIIB ameliorated the pathologies of the kidneys, liver and lymph node tissues of the MRL/lpr SLE mice. Following treatment of the MRL/lpr SLE mice with sFcγRIIB, the levels of urinary protein, serum anti­dsDNA antibody and BTK and SHIP phosphorylation levels in B cells were decreased, while the serum sFcγRIIB and sFcγRIIB­IgG levels were increased. On the whole, the findings of the present study demonstrate that recombinant FcγRIIB inhibits the secretion of IgG antibody by B cells from patients with SLE, ameliorates the symptoms of SLE in mice, and alters the phosphorylation levels of downstream proteins of the FcγRIIB signaling pathway in B cells. These results suggest that FcγRIIB may play preventive and therapeutic roles in SLE by inhibiting B cell activation via the FcγRIIB signaling pathway, which provides a novel theory and strategy for the prevention and treatment of SLE.

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