Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 870
Filtrar
Filtros adicionais











Intervalo de ano
1.
Opt Express ; 27(16): 22645-22662, 2019 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-31510551

RESUMO

A comprehensive physically realizable space, namely, the overall purity index-components of purity (PI4D-CP) space is proposed for the characterization of the depolarization caused by random (or deterministic) media. The overall purity index (PI4D)is obtained via indices of polarimetric purity which are incurred by the eigenvalues of the covariance matrix, whereas the components of purity (CP) are the functions of the elements of a Mueller matrix. On the one hand, the proposed space is useful in studying the depolarization caused by material media and on the other hand, it provides information on the diattenuation-polarizance properties of a Mueller matrix. Thus, it gives a remarkable physical insight of the depolarization problem.

2.
J Biophotonics ; 2019 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-31465142

RESUMO

Recently, the incidence of inflammatory bowel diseases, especially the Crohn's disease (CD) and gastrointestinal luminal tuberculosis (ITB), has grown rapidly worldwide. Currently there is no general gold standard to distinguish between CD and ITB tissues, which both have tuberculosis and surrounding fibrous structures. Mueller matrix imaging technique is suitable for describing the location, density and distribution behavior of such fibrous structures. In this study, we apply the Mueller matrix microscopic imaging to the CD and ITB tissue samples. The 2D Mueller matrix images of the CD and ITB tissue slices are measured using the Mueller matrix microscope developed in our previous study, then the Mueller matrix polar decomposition and Mueller matrix transformation parameters are calculated. To evaluate the distribution features of the fibrous structures surrounding the tuberculosis areas more quantitatively and precisely, we analyze the retardance related Mueller matrix derived parameters, which show clear different distribution behaviors between the CD and ITB tissues, using the Tamura image processing method. It is demonstrated that the Mueller matrix derived parameters can reveal the structural features of tuberculosis areas and be used as quantitative indicators to distinguish between CD and ITB tissues, which may be useful for the clinical diagnosis. This article is protected by copyright. All rights reserved.

3.
Biomed Res Int ; 2019: 2141859, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31467872

RESUMO

Objectives: Hepatocellular carcinoma (HCC) with portal vein tumor thrombus (PVTT) remains a challenge in management. Transarterial chemoembolization (TACE) has been used for patients with PVTT but efficiency was limited with a median overall survival of 4 to 6.1 months. The aim of this study is to evaluate the efficiency of TACE combined with sorafenib in HBV background HCC with PVTT. Methods: A total of 498 patients were enrolled in the study including 69 patients who received TACE combined with sorafenib and 429 patients treated with TACE alone between January 1st, 2008, and April 30st, 2014. Using the 1:2 propensity score matching, 138 well-balanced patients were enrolled. Overall survival (OS) was compared between the two groups. The Kaplan-Meier method was used to evaluate the OS, and the differences between groups were analyzed with a log-rank test. Results: TACE combined with sorafenib improved the OS of the patients compared with TACE alone (13.0 vs 6.0 months, p<0.001). After propensity score matching, the median OS of combination therapy and TACE were 13.0 and 7.0 months, respectively (p=0.001). Subgroup analysis revealed that the patients younger than 60 years old, male patients, AFP more than 400ng/ml, tumor size more than 5cm, or type III/IV PVTT had OS benefits from TACE combined with sorafenib. Conclusions: Compared with TACE therapy alone, TACE combined with sorafenib could improve OS in HBV background HCC patients with PVTT. The patients who are younger, male, or with more tumor burden may benefit more from combination therapy.

4.
Nat Protoc ; 14(9): 2672-2690, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31391579

RESUMO

Understanding the photoinduced electron-transfer process is of paramount importance for realizing efficient solar energy conversion. It is rather difficult to clarify the link between the specific properties and the photoelectrochemical performance of an individual component in an ensemble system because data are usually presented as averages because of interplay of the heterogeneity of the bulk system. Here, we report a step-by-step protocol to fabricate an ultrasensitive photoelectrochemical platform for real-time detection of the intrinsic photoelectrochemical behaviors of a single entity with picoampere and sub-millisecond sensitivity. Using a micron-thickness nanoparticulate TiO2-filmed Au ultramicroelectrode (UME) as the electron-transport electrode, photocurrent transients can be observed for each individual dye-tagged oxide semiconductor nanoparticle collision associated with a single-entity photoelectrochemical reaction. This protocol allows researchers to obtain high-resolution photocurrent signals to quantify the photoinduced electron-transfer properties of an individual entity, as well as to precisely process the data obtained. We also include procedures for dynamic light scattering (DLS) analysis, transmission electron microscopy (TEM) imaging and collision frequency-concentration correlation to confirm that the photoelectrochemical collision events occur at an unambiguously single-entity level. The time required for the entire protocol is ~36 h, with a single-entity photoelectrochemical measurement taking <1 h to complete for each independent experiment. This protocol requires basic nanoelectrochemistry and nanotechnology skills, as well as an intermediate-level understanding of photoelectrochemistry.

5.
Dalton Trans ; 2019 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-31469147

RESUMO

Simultaneously involving abundant [NH2(CH3)2]+ cations and uncoordinated carboxylate oxygen atoms as dual active sites, two microporous CoII-MOFs (LCU-105 and LCU-106, LCU = Liaocheng University) both exhibit highly selective adsorption of CO2/CH4 and CO2/N2. GCMC theoretical simulations provide good verification of the experimental results.

6.
Int J Pharm ; 570: 118648, 2019 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-31465833

RESUMO

Skin is the first protection of human body. It is always challenged by a range of external factors, resulting in the wounds of skin. Hydrogel, as a dressing with multiple advantages, causes increasing interests or the applications in wound treatment. However, the function and importance of micro-environment of wound region are frequently neglected. In this study, we successfully developed a chemokine loaded biomimetic hydrogel as a functional reservoir to stimulate the rapid in situ recruitment of BMSCs for fast wound repair and regeneration. The biomimetic hydrogel was fabricated by using the Polyvinyl alcohol (PVA) combined with chitosan (CS) as the hybrid materials. The fabricated hydrogel possesses many features such as the porous structure, high swelling rate and moisture retention property. More importantly, the incorporated chemokine could be released with a sustained manner from the hydrogel and recruited the bone marrow mesenchymal stem cells (BMSCs) significantly both in vitro & in vivo. Moreover, the hydrogel was demonstrated to be highly biocompatible to the skin tissue without any side effect or irritation observed. Topical delivery of chemokine by the biomimetic PVA/CS hybrid material based hydrogel is demonstrated as a promising carrier to accelerate wound repair and regeneration without inducing scar formation and any other negative complications. The PVA/CS/SDF-1 hydrogel was shown a novel therapeutic system for wound therapy.

7.
Nanoscale ; 11(35): 16562-16570, 2019 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-31460546

RESUMO

The modulation of luminescence via external stimuli such as temperature, mechanical stress, hydrostatic pressure, as well as electric and/or magnetic fields, has witnessed great progress, enabled the disclosure of new principles and energy transfer pathways, and widened applications. However, investigations on the luminescence modulation of lanthanide ions doped in semiconductors via an applied electric field are still absent. Herein, for the first time, we have demonstrated the in situ, real-time, and reversible modulation of the luminescence of Eu3+ doped in SnO2 nanocrystals by manipulating the recombination rate of photo-generated electrons and holes, and the accompanied energy transfer mode in terms of linear and quasi-sinusoidal, from semiconductor to lanthanide ions. Following the same principle, the modulation of near infrared responsive Er3+ in SnO2 and the visible luminescence of perovskite nanocrystals is further realized. This study offers extra methodologies for luminescence modulation, in addition to those already reported for ferro- and/or piezoelectric-hosted luminescent materials.

8.
Int J Mol Sci ; 20(16)2019 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-31404956

RESUMO

(1) Background: Upland cotton (Gossypium hirsutum L.) is the most important natural fiber worldwide, and it is extensively planted and plentifully used in the textile industry. Major cotton planting regions are frequently affected by abiotic stress, especially drought stress. Drought resistance is a complex, quantitative trait. A genome-wide association study (GWAS) constitutes an efficient method for dissecting the genetic architecture of complex traits. In this study, the drought resistance of a population of 316 upland cotton accessions was studied via GWAS. (2) Methods: GWAS methodology was employed to identify relationships between molecular markers or candidate genes and phenotypes of interest. (3) Results: A total of 8, 3, and 6 SNPs were associated with the euphylla wilting score (EWS), cotyledon wilting score (CWS), and leaf temperature (LT), respectively, based on a general linear model and a factored spectrally transformed linear mixed model. For these traits, 7 QTLs were found, of which 2 each were located on chromosomes A05, A11, and D03, and of which 1 was located on chromosome A01. Importantly, in the candidate regions WRKY70, GhCIPK6, SnRK2.6, and NET1A, which are involved in the response to abscisic acid (ABA), the mitogen-activated protein kinase (MAPK) signaling pathway and the calcium transduction pathway were identified in upland cotton at the seedling stage under drought stress according to annotation information and linkage disequilibrium (LD) block analysis. Moreover, RNA sequencing analysis showed that WRKY70, GhCIPK6, SnRK2.6, and NET1A were induced by drought stress, and the expression of these genes was significantly different between normal and drought stress conditions. (4) Conclusions: The present study should provide some genomic resources for drought resistance in upland cotton. Moreover, the germplasm of the different phenotypes, the detected SNPs and, the potential candidate genes will be helpful for molecular marker-assisted breeding studies about increased drought resistance in upland cotton.

9.
Eur J Epidemiol ; 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31372866

RESUMO

To investigate the major causes and predictive factors of death in a middle-aged and elderly Chinese population. A total of 6591 residents aged ≥ 45 years from Shanghai Changfeng community were followed up for an average of 5.4 years. The causes of death were coded according to the 10th Revision of International Classification of Diseases. The mortality rate was calculated by person-years of follow up and age-standardized according to the 2010 Chinese census data. Multivariable-adjusted Cox proportional hazards model was performed to investigate the predictors of all-cause and cause-specific mortality. During the total follow-up of 35,739 person-years, 370 deaths were documented (157 from malignant neoplasms, 70 from heart diseases, 68 from cerebrovascular diseases, 75 from other causes). The age-standardized all-cause mortality rate was 798.2 per 100,000 person-years (927.9 among men and 716.7 among women). Results from multivariable analyses showed that aging, diabetes, and osteoporosis at baseline were independent predictors of all-cause mortality, with hazard ratios (HR) of 1.11 (95% CI 1.10-1.13), 1.91 (1.51-2.42), and 1.71 (1.24-2.35), respectively. The population attributable risk percent of diabetes and osteoporosis was 19.7% and 11.7%, respectively. Cigarette smoking was associated with a higher risk of all-cause mortality in men (HR and 95%CI 1.44, 1.01-2.06). In women, diabetes and osteoporosis were related to a higher risk of cardiovascular mortality (3.27, 1.82-5.88 and 1.89, 1.04-3.46, respectively). While in men, osteoporosis was related to a higher risk of malignant neoplasms mortality (2.39, 1.07-5.33). Malignant neoplasms, heart diseases, and cerebrovascular diseases are the leading causes of death. Aging, smoking, underweight, diabetes, and osteoporosis are independent predictors of premature death among middle-aged and elderly Chinese community population. Moreover, there may have been some differences in the causes and predictors of premature death between men and women.

10.
J Clin Neurosci ; 2019 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-31431402

RESUMO

In this study, the neuro-modulation effect of topical mesenchymal stem cells (MSCs) was tested in a rodent middle carotid artery occlusion (MCAO) model. Twenty-four hours after MCAO, craniotomy was made and 0.8 × 106 GFP-MSCs were topically applied to the exposed parietal cortex. The MSCs were fixed in position by a thin layer of fibrin glue (N = 30). In the control group, saline were topically applied to the ipsilateral parietal cortex (N = 30). Three days after topical application, few GFP-positive cells were found in the ischemic penumbra. They expressed GFAP and NeuN. Topical MSCs triggered microglial activation, astrocytosis and cellular proliferation at day 3. The recovery of neurological functions were significantly enhanced as determined in Rotarod test and Morris Water Maze test with smaller infarct volume. PCR array showed that expressions of ten genes of neurogenesis were altered in the penumbra region (fold change > 1.25, p < 0.05) in MSCs group: Apoe, Ascl1, Efnb1, Mef2c, Nog, A100a6 and B2m were up-regulated; Pax2, Pax3 and Th were down-regulated. In conclusion, topical application provided a direct and effective transplant method for the delivery of MSCs to the surface of ipsilateral cerebral cortex and the topical MSCs could improve the neurological function from cerebral ischemia resulting from a major cerebral artery occlusion in a rodent experimental model.

11.
Nat Commun ; 10(1): 3368, 2019 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-31358761

RESUMO

For seeking high enantiopurity, the previously reported thermal asymmetric catalysis is usually carried out at low temperature sometimes with limited yield, that is, the high enantiomeric excess (ee) usually at the cost of high yield. Thus, the achieving both high stereoselectivity and yield is an enormous challenge. We report herein two metal nanoparticle (M NP)-loaded and porphyrin-containing homochiral covalent organic framework (CCOF)-based composite catalysts, and their application in the thermally-driven asymmetric one-pot Henry and A3-coupling reactions. All the reactions are conducted at elevated temperatures with both excellent stereoselectivity and yield which resulted from the synergy of CCOF confinement effect and M NP catalytic activation. Notably, the needed thermal energy for the asymmetric reactions herein is derived from the photothermal conversion via porphyrin-based CCOF upon irradiation with visible light. Remarkably, the CCOF confinement effect can be effectively maintained up to 100 °C for the asymmetric one-pot Henry and A3-coupling reactions herein.

12.
Eye Contact Lens ; 2019 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-31361656

RESUMO

OBJECTIVE: This study aims to compare the increase in refractive error and axial length, variation of endothelium cells, and ratio of corneal staining between two regimens of high myopia-partial reduction orthokeratology (ortho-k) in children. METHODS: The present clinical prospective study recruited 102 high-myopia subjects (204 eyes). These subjects were randomly divided into three groups: (1) ortho-k group 1, subjects with a target myopia reduction of 6.00 D; (2) ortho-k group 2, subjects with a target myopia reduction of 4.00 D; and (3) control group, the refractive error of subjects was corrected using a pair of single-vision spectacles. Vision acuity, refractive error, and the cornea were examined at baseline, and at 2 days, 1 week, 1, 3, 6, and 12 months after commencing lens wear. The measurement of the axial length of the eyeball and a corneal endothelium examination were performed at baseline and at 12 months. RESULTS: The uncorrected vision acuities improved in subjects in these groups after treatment with ortho-k. Furthermore, the diopters of myopia and corneal curvature significantly decreased at 1 month, and the values continuously improved at 12 months, when compared with subjects at 1 month (P<0.05). Subjects in the control group had a significant increase in refractive error (0.565±0.313 D) and axial length (0.294±0.136 mm), when compared with subjects in the ortho-k-treated groups (P<0.05). However, there were no significant differences in changes in refractive error and axial length between ortho-k groups 1 (0.101±0.176 mm) and 2 (0.123±0.193 mm) at 12 months (P>0.05). Furthermore, subjects in group 1 (28.97%) had a higher rate of corneal staining, when compared with subjects in group 2 (13.06%) (P<0.05). CONCLUSION: The two ortho-k regimens, target reduction of 6.00 D and target of 4.00 D, had similar effects in controlling the increase in axial length and refractive error in high-myopia children. However, subjects with a target myopia reduction of 6.00 D had a higher rate of corneal staining than in subjects with a target myopia reduction of 4.00 D.

13.
J Biomed Opt ; 24(7): 1-9, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31347339

RESUMO

Mueller microscopy studies of fixed unstained histological cuts of human skin models were combined with an analysis of experimental data within the framework of differential Mueller matrix (MM) formalism. A custom-built Mueller polarimetric microscope was used in transmission configuration for the optical measurements of skin tissue model adjacent cuts of various nominal thicknesses (5 to 30 µm). The maps of both depolarization and polarization parameters were calculated from the corresponding microscopic MM images by applying a logarithmic Mueller matrix decomposition (LMMD) pixelwise. The parameters derived from LMMD of measured tissue cuts and the intensity of transmitted light were used for an automated segmentation of microscopy images to delineate dermal and epidermal layers. The quadratic dependence of depolarization parameters and linear dependence of polarization parameters on thickness, as predicted by the theory, was confirmed in our measurements. These findings pave the way toward digital histology with polarized light by presenting the combination of optimal optical markers, which allows mitigating the impact of tissue cut thickness fluctuations and increases the contrast of polarimetric images for tissue diagnostics.

.

14.
Opt Lett ; 44(13): 3302-3305, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31259945

RESUMO

A hybrid Tamm plasmonic system is proposed to investigate light manipulation at near-infrared frequency. The numerical results reveal that two remarkable absorption peaks are generated due to the different types of resonant modes excited in the structure, which can be well explained theoretically by guided-mode resonance (GMR) and Tamm plasmon polaritons. It is found that the electromagnetic energy can be easily trapped in different parts of the structure. More importantly, strong interaction between the two modes can be achieved by adjusting the structure period or incident angle, resulting in obvious mode hybridization and exhibiting unique energy-transfer characteristics. In addition, the active modulation of GMR-based absorption can be controlled in a continuous type by tuning the polarization angle or in a jump type by adjusting the chemical potential of graphene. This work should be useful for developing many high-performance optoelectronic devices, including sensors, modulators, detectors, etc.

15.
Int Health ; 2019 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-31343067

RESUMO

BACKGROUND: Occupational burnout in physicians is prevalent and can have many negative effects. The purposes of this study were to explore the prevalence of occupational burnout and to analyze the effects of social support and role stress on occupational burnout among Chinese physicians. METHODS: Using multistage-stratified cluster random sampling, physicians were selected to participate in the study and completed three questionnaires: the Chinese Maslach Burnout Inventory; the Cross-Cultural Role Conflict, Ambiguity and Overload Scale; and the Social Support Rating Scale. A path analysis was run to test the effects of role stress and social support on occupational burnout. RESULTS: Of 2530 physicians, 864 (34.2%) were experiencing moderate occupational burnout and 140 (5.5%) were experiencing severe occupational burnout. The path analysis results indicated that role conflict had direct positive effects on emotional exhaustion (EE) and depersonalization (DP), and role ambiguity had direct positive effects on DP and decreased personal accomplishment (DPA). Coworker support had direct negative effects on EE and positive effects on DP, family support had direct negative effects on DP and DPA. Coworker support mediated the effects of role ambiguity on EE and DP, and family support mediated the effects of role ambiguity on DP and DPA. CONCLUSIONS: These findings suggest that occupational burnout is common in Chinese physicians, and that role stress and social support play important roles in occupational burnout. Interventions that aim to reduce role stress and increase social support can be effective approaches to prevent occupational burnout among physicians.

16.
Aliment Pharmacol Ther ; 50(6): 684-695, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31250467

RESUMO

BACKGROUND: Age-related skeletal muscle loss and patatin-like phospholipase domain-containing 3 (PNPLA3) polymorphisms are both associated with increased liver steatosis and fibrosis in the absence of obesity. AIM: To investigate the influence of PNPLA3 polymorphism on the relationship between skeletal muscle loss and non-alcoholic fatty liver disease (NAFLD). METHODS: Liver fat content was measured using a quantitative ultrasound method, and liver fibrosis was assessed by NAFLD fibrosis, BARD and FIB-4 scores in 3969 Chinese adults. The degree of sarcopenia was measured by weight-adjusted appendicular skeletal muscle mass (ASM% = appendicular skeletal muscle mass(kg)/body weight(kg)  100%). RESULTS: The NAFLD proportion increased from 19.9% to 41.2% in men and 26.3% to 42.3% in women with decreasing ASM% quartiles (P < 0.001). Low ASM% was inversely associated with NAFLD in PNPLA3 CC (odds ratio [OR]: men, 0.735 [0.610-0.885] and women, 0.812 [0.718-0.918], both P = 0.001) and CG (OR: men, 0.673 [0.573-0.790] and women, 0.798 [0.713-0.893], both P < 0.001) but not GG genotype carriers. The association remained significant after adjustment for age, cigarette smoking, fat mass, interaction between fat mass and ASM%, obesity, diabetes and all components of metabolic syndrome. Subgroup analyses found that PNPLA3 GG gene variant did not increase the risk for NAFLD in individuals with low ASM% regardless of obesity status. Low ASM% also increased risk for liver fibrosis (all P < 0.05), which became insignificant after multiple adjustments. CONCLUSIONS: Low ASM% is associated with NAFLD and liver fibrosis. Dissociation of sarcopenia and NAFLD was found in PNPLA3 GG genotype carriers. A stratification based on PNPLA3 genotypes might facilitate personalised treatment for NAFLD.

17.
Int J Syst Evol Microbiol ; 69(8): 2445-2451, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31169491

RESUMO

A Gram-stain-negative, aerobic, non-motile, short-rod bacterium, strain MS2-2T, was isolated from mangrove sediment sampled at Jiulong River Estuary, Fujian province, PR China. 16S rRNA gene sequence similarity analysis showed that strain MS2-2T was most closely related to Defluviimonas indica 20V17T (97.41 %) and Defluviimonas pyrenivorans PrR001T (96.18 %). Phylogenetic trees based on 16S rRNA genes and genome sequences both revealed that strain MS2-2T formed a distinct cluster with D. indica 20V17T and D. pyrenivorans PrR001T within family Rhodobacteracea, quite separate from other type species in the genus Defluviimonas. The average nucleotide identity value between strain MS2-2T and D. indica 20V17T was 78.35 %. Growth of strain MS2-2T was observed at 16-41 °â€ŠC (optimum, 34 °â€ŠC), pH 3.6-7.5 (pH 6.0) and 0.5-10.0 % (w/v) NaCl (4.0 %). The major cellular fatty acids were summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c), C16 : 0 and C18 : 0. Ubiquinone 10 was the sole quinone. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The DNA G+C content was 67.9 mol%. The combined genotypic and phenotypic data show that strain MS2-2T represents a novel species of a novel genus in the family Rhodobacteraceae, for which the name Acidimangrovimonassediminis gen. nov., sp. nov. is proposed, with the type strain MS2-2T (=MCCC 1K02682T=NBRC 112978T). We also propose the reclassification of Defluviimonas indica as Acidimangrovimonas indica comb. nov. and Defluviimonas pyrenivorans as Acidimangrovimonas pyrenivorans comb. nov.


Assuntos
Avicennia/microbiologia , Sedimentos Geológicos/microbiologia , Filogenia , Rhodobacteraceae/classificação , Técnicas de Tipagem Bacteriana , Composição de Bases , China , DNA Bacteriano/genética , Estuários , Ácidos Graxos/química , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Rhodobacteraceae/isolamento & purificação , Análise de Sequência de DNA , Ubiquinona/química
18.
Cell Transplant ; 28(7): 874-884, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31185737

RESUMO

Traumatic brain injury is one of the leading causes of mortality and morbidity worldwide. At present there is no effective treatment. Previous studies have demonstrated that topical application of adipose tissue-derived mesenchymal stem cells can improve functional recovery in experimental traumatic brain injury. In this study, we evaluated whether hypoxic preconditioned mesenchymal stem cells could enhance the recovery from traumatic brain injury. Traumatic brain injury was induced with an electromagnetically controlled cortical impact device. Two million mesenchymal stem cells derived from the adipose tissue of transgenic green fluorescent protein Sprague-Dawley rats were cultured under either hypoxic (2.5% O2 for 18 hours) (N = 30) or normoxic (18% O2) (N = 30) conditions, then topically applied to the exposed cerebral cortex within 1 hour after traumatic brain injury. A thin layer of fibrin was used to fix the cells in position. No treatment was given to the animals with traumatic brain injury (N = 30). Animals that underwent craniectomy without traumatic brain injury were treated as the sham group (N = 15). Neurological functions were evaluated with water maze, Roto-rod and gait analysis. Animals were sacrificed at days 3, 7, and 14 for microscopic examinations and real-time polymerase chain reaction analysis. The rats treated with hypoxic mesenchymal stem cells showed the greatest improvement in neurological function recovery. More green fluorescent protein-positive cells were found in the injured brain parenchyma treated with hypoxic mesenchymal stem cells that co-expressed glial fibrillary acidic protein, Nestin, and NeuN. Moreover, there was early astrocytosis triggered by the infiltration of more glial fibrillary acidic protein-positive cells and microgliosis was suppressed with fewer ionized calcium binding adapter molecule 1-positive cells in the penumbra region of hypoxic mesenchymal stem cells group at day 3. Compared with normoxic mesenchymal stem cells and traumatic brain injury only groups, there was significantly (p < 0.05) less neuronal death in both the hippocampus and penumbral regions in sections treated with hypoxic mesenchymal stem cells as determined by Cresyl violet and terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling staining respectively. The expression of pro-inflammatory genes (interleukin 6, interleukin 1a, interleukin 1b, tumor necrosis factor α) was upregulated and apoptotic gene (Caspase-3) expression was suppressed at day 3. Anti-inflammatory (interleukin 10) and anti-apoptotic (BCL2 associated agonist of cell death) gene expression was upregulated at days 7 and 14. Our study showed that a hypoxic precondition enhanced the beneficial effects of mesenchymal stem cells on neurological recovery after traumatic brain injury.

19.
J Agric Food Chem ; 67(26): 7325-7335, 2019 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-31184120

RESUMO

Tea polyphenols (TP) possess the ability to regulate dyslipidemia and gut microbiota dysbiosis. However, the underlying mechanism is still elusive. The present study explored the intervention of TP on high fat diet induced metabolic disorders, gut microbiota dysbiosis in mice, and the underlying intestinal mechanism. As a result, TP significantly ameliorated hyperlipidemia, improved the expression levels of hepatic lipid metabolism genes, and modulated gut microbiota. The underlying mechanism was supposed to rely on the maintaining of intestinal redox state by TP. Intestinal redox related indicators were significantly correlated with the distribution of gut microbiota. An unidentified genus of Lachnospiraceae, Bacteroides, Alistipes, and Faecalibaculum were identified as the biomarkers for intestinal redox state. Importantly, different dosages of TP modulated intestinal redox state and gut microbiota in varied patterns, and an overdose intake attenuated the beneficial effects on gut health. Our findings offered novel insights into the mechanism of TP on intestinal homeostasis.


Assuntos
Camellia sinensis/química , Microbioma Gastrointestinal/efeitos dos fármacos , Hiperlipidemias/tratamento farmacológico , Intestinos/microbiologia , Estresse Oxidativo/efeitos dos fármacos , Extratos Vegetais/administração & dosagem , Polifenóis/administração & dosagem , Animais , Bactérias/classificação , Bactérias/efeitos dos fármacos , Bactérias/genética , Bactérias/isolamento & purificação , Dieta Hiperlipídica/efeitos adversos , Feminino , Humanos , Hiperlipidemias/genética , Hiperlipidemias/metabolismo , Hiperlipidemias/microbiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Chá
20.
Gene ; 711: 143925, 2019 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-31212048

RESUMO

More than 2300 genes have been reported to be involved in spermatogenesis but the functional roles of most genes in male fertility remain to be elucidated. In this study, we explored the function of dipeptidase 3 (Dpep3), a gene predicted to be testis-specific, in male fertility of mice. We showed that Dpep3 is evolutionarily conserved in human and mouse along with other eutherians. Its mRNA was exclusively detected in testicular tissue and expressed in testes from 7 days postpartum. To further explore its role in male fertility, we generated Dpep3 knockout mice (Dpep3-/-) using the CRISPR/Cas9 technology and found that the male Dpep3-/- mice are fertile despite a significant reduction in sperm count. Histology of testis and progression of meiotic prophase I showed no obvious difference between wild-type and Dpep3-/- mice. All these findings indicate that Dpep3 is not essential for male fertility in mice. These findings will help other researchers to avoid research duplication, save their time and resources to focus on the genes that are indispensable for male fertility.


Assuntos
Dipeptidases/genética , Dipeptidases/metabolismo , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Espermatogênese , Testículo/metabolismo , Animais , Sequência Conservada , Técnicas de Inativação de Genes , Humanos , Infertilidade Masculina/genética , Infertilidade Masculina/metabolismo , Masculino , Camundongos , Especificidade de Órgãos , Filogenia , Contagem de Espermatozoides , Motilidade Espermática
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA