Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 46
Filter
1.
Front Psychiatry ; 15: 1352971, 2024.
Article in English | MEDLINE | ID: mdl-38563026

ABSTRACT

Background: No consistent conclusion has been reached regarding the attentional bias characteristics of adolescents with major depressive disorders (MDD), and unexamined co-occurring anxiety distress may contribute to this inconsistency. Methods: We enrolled 50 MDD adolescents with anxiety distress, 47 MDD adolescents without anxiety distress and 48 healthy adolescents. We measured attentional bias using a point-probe paradigm during a negative-neutral emotional face task. Reaction time, correct response rate and attentional bias value were measured. Results: MDD adolescents did not show a negative attentional bias; MDD adolescents with anxiety distress exhibited longer reaction time for negative and neutral stimuli, lower correct response rate for negative stimuli. Hamilton Anxiety Scale scores were positively correlated with reaction time, negatively correlated with correct response rate, and not significantly correlated with attentional bias value. Limitations: The cross-sectional design hinders causal attribution, and positive emotional faces were not included in our paradigm. Conclusion: Negative attentional bias is not a stable cognitive trait in adolescents with MDD, and avoidance or difficulty in disengaging attention from negative emotional stimuli may be the attentional bias characteristic of MDD adolescents with anxiety distress.

3.
Ying Yong Sheng Tai Xue Bao ; 35(2): 307-320, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38523087

ABSTRACT

The complex stand structure and high species diversity of natural forests pose great challenges for analyzing stand growth and formulating reasonable plans for forest management. The height-diameter relationship is of great significance for predicting stand growth and formulating forest management measures. Based on survey data of 48 broad-leaved mixed forest plots in Maoershan, we classified 23 tree species into four groups based on species structure, growth characteristics and bionomics. We established a generalized model including stand, tree competition, species mixing and species diversity variables by reparameterization method, and a two-level mixed effect model of plot and tree species group. We tested the prediction ability of the model by leave-one-out cross-validation method. The results showed that the Ratkowsky (1990) model was the optimal basic model. The introduction of dominant height, basal area of trees larger than the object tree, basal area proportion of each species, and Shannon index could better explain the height-diameter relationship of broad-leaved mixed forest in Maoershan. The introduction of the mixed effect model of plot and tree species group could significantly improve the prediction accuracy of the model, with a Ra2 of 0.83. Under the same gradient of environmental factors, intolerant tree species exhibited higher tree heights than shade-tolerant tree species. In this study, we used the constructed tree height-diameter model to analyze the effects of species mixing and tree functional traits on tree height, which provided a theoretical basis for accurately predicting height of different tree species and analyzing the growth relationships in broadleaved mixed forests.


Subject(s)
Pinus , China , Ecology
4.
ACS Appl Mater Interfaces ; 16(1): 957-965, 2024 Jan 10.
Article in English | MEDLINE | ID: mdl-38151466

ABSTRACT

Developing novel porous adsorbents for efficient wastewater treatment is significant to the environment protection. Herein, three porous polycalix[n]arenes (n = 4, 6, and 8) which had varying cavity sizes of the macrocycle (Azo-CX4P, Azo-CX6P, and Azo-CX8P) were prepared under mild conditions and tested for their potential application in water purification. Azo-CX8P with a larger cavity size of the macrocycle outperformed Azo-CX4P and Azo-CX6P in screening studies involving a range of organic micropollutants. It was proved that Azo-CX8P was especially efficient in the removal of cationic dyes because of its high negative surface charge. In terms of the adsorption of Rhodamine B with Azo-CX8P, the pseudo-second-order rate constant reaches 5.025 g·mg-1·min-1 with the maximum adsorption capacity being 1345 mg·g-1. These values are significantly higher compared with those recorded for most adsorbents. In addition, the easily prepared Azo-CX8P can be reused at least six times without a loss of the adsorption efficiency, demonstrating its potential use in water purification.

5.
J Thorac Dis ; 15(11): 6251-6264, 2023 Nov 30.
Article in English | MEDLINE | ID: mdl-38090296

ABSTRACT

Background: As a type of traditional Chinese medicine, Yanghepingchuan granules (YHPCG) are used to treat inflammatory diseases of the lungs, including asthma. However, the underlying molecular mechanism of the ability of YHPCG to reduce airway inflammation remains unknown. Methods: By sensitizing rats to aluminum hydroxide and ovalbumin, an asthma model was established. During the 14-day treatment period, the rats received YHPCG, TAK242 (TLR4 inhibitor), and a combination of the two treatments. Histopathology and goblet cell hyperplasia were observed in rats with ovalbumin-induced asthma by using hematoxylin-eosin (HE) and periodic acid-Schiff (PAS) staining. Immunohistochemical, autophagy-related immunofluorescence, and western blotting analyses were performed to determine autophagic activity. The effects of YHPCG on high mobility group box 1 (HMGB1)-mediated Toll-like receptor 4 (TLR4)/nuclear factor κB (NF-κB) pathway-related proteins and inflammatory factors in rats were evaluated via western blotting, PCR analysis, and enzyme-linked immunosorbent assay. A dual luciferase method was used to detect the interaction between miRNA328-3p and HMGB1. Results: YHPCG inhibit the HMGB1/TLR4/NF-κB pathway by upregulating miR-328-3p, reducing autophagosome production, inhibiting autophagy, and effectively preventing the progression of lung inflammation. Conclusions: Asthma airway inflammation can be treated with YHPCG by inhibiting autophagy via miRNA328-3p/HMGB1/TLR4/NF-κB signaling pathways.

6.
Front Pharmacol ; 13: 932686, 2022.
Article in English | MEDLINE | ID: mdl-35928262

ABSTRACT

Objective: We aimed to establish a population pharmacokinetic (PPK) model for isoniazid (INH) and its major metabolite Acetylisoniazid (AcINH) in healthy Chinese participants and tuberculosis patients and assess the role of the NAT2 genotype on the transformation of INH to AcINH. We also sought to estimate the INH exposure that would achieve a 90% effective concentration (EC90) efficiency for patients with various NAT2 genotypes. Method: A total of 45 healthy participants and 157 tuberculosis patients were recruited. For healthy subjects, blood samples were collected 0-14 h after administration of 300 mg or 320 mg of the oral dose of INH; for tuberculosis patients who received at least seven days therapy with INH, blood samples were collected two and/or six hours after administration. The plasma concentration of INH and AcINH was determined by the reverse-phase HPLC method. NAT2 genotypes were determined by allele-specific amplification. The integrated PPK model of INH and AcINH was established through nonlinear mixed-effect modeling (NONMEM). The effect of NAT2 genotype and other covariates on INH and AcINH disposition was evaluated. Monte Carlo simulation was performed for estimating EC90 of INH in patients with various NAT2 genotypes. Results: The estimated absorption rate constant (Ka), oral clearance (CL/F), and apparent volume of distribution (V2/F) for INH were 3.94 ± 0.44 h-1, 18.2 ± 2.45 L⋅h-1, and 56.8 ± 5.53 L, respectively. The constant of clearance (K30) and the volume of distribution (V3/F) of AcINH were 0.33 ± 0.11 h-1 and 25.7 ± 1.30 L, respectively. The fraction of AcINH formation (FM) was 0.81 ± 0.076. NAT2 genotypes had different effects on the CL/F and FM. In subjects with only one copy of NAT2 *5, *6, and *7 alleles, the CL/F values were approximately 46.3%, 54.9%, and 74.8% of *4/*4 subjects, respectively. The FM values were approximately 48.7%, 63.8%, and 86.9% of *4/*4 subjects, respectively. The probability of target attainment of INH EC90 in patients with various NAT2 genotypes was different. Conclusion: The integrated parent-metabolite PPK model accurately characterized the disposition of INH and AcINH in the Chinese population sampled, which may be useful in the individualized therapy of INH.

7.
Front Psychiatry ; 13: 798105, 2022.
Article in English | MEDLINE | ID: mdl-35222115

ABSTRACT

BACKGROUND: Cognitive impairment is a core feature of schizophrenia that is more serious in patients with early-onset schizophrenia (EOS). However, the neuroimaging basis of cognitive functions, including neurocognition and social cognition, remains unclear in patients with EOS. METHODS: Forty-three patients with EOS underwent structural and resting state functional magnetic resonance imaging scans. Brain structure and function were evaluated through the analysis of brain gray matter volume (GMV) and amplitude of low-frequency fluctuations (ALFF). They underwent comprehensive assessments for neurocognition (verbal memory, verbal expression, attention, and executive function) and social cognition (theory of mind and attributional bias). Correlation analyses were conducted to detect the potential link between cognitive function indices and brain imaging parameters. RESULTS: First, neurocognition was linked to brain structure characterized by higher immediate recall scores associated with increased GMV in the left temporal pole, higher verbal fluency scores associated with increased GMV in the left temporal pole: middle temporal gyrus, and higher Stroop-word scores associated with increased GMV in the right middle frontal gyrus. Second, social cognition was related to brain function characterized by lower sense of reality scores associated with increased ALFF in the left precentral gyrus, higher scores of accidental hostility bias associated with increased ALFF in the right middle temporal gyrus, and higher scores of accidental aggression bias associated with increased ALFF in the left precentral gyrus. CONCLUSION: These findings may add to the existing knowledge about the cognitive function-brain relationship. They may have clinical significance for studying the mechanism of neurocognitive and social cognitive impairment in patients with EOS and providing potential neural targets for their treatment and intervention.

8.
Zhonghua Nan Ke Xue ; 28(11): 963-969, 2022 Nov.
Article in Chinese | MEDLINE | ID: mdl-37846111

ABSTRACT

OBJECTIVE: To study the effect of cordycepin on the expression of connexin 43 (CX43) in the corpus cavernosum tissue of the ED rats with type II diabetic mellitus (DM). METHODS: Forty male SD rats were fed with high-fat diet and injected intraperitoneally with STZ solution to induce type II DM, and then divided into 4 groups of an equal number: DM model control, low-dose cordycepin (10.0 mg/kg/d), high-dose cordycepin (30.0 mg/kg/d) and sildenafil positive control (5.0 mg/kg/d). Another 10 male SD rats were taken as blank controls and fed with normal diet. After 6 weeks of intervention, the sexual behavior of the rats was observed, the ratio of intra-cavernous pressure to mean arterial pressure (ICP/MAP) measured, and the corpus cavernosal tissue harvested for observation of the morphology and determination of the expression level of CX43 in the corpus cavernosum by immunohistochemistry. RESULTS: Compared with the DM model controls, the rats in the high-dose cordycepin group showed significantly improved latency and frequency of captures (P < 0.01), increased ICP/MAP ratio (P < 0.05), and improved morphology of the corpus cavernosal tissue. The expression of CX43 was found mainly in the smooth muscle cells of the penile corpus cavernosum, and dramatically higher in the high-dose cordycepin group than in the DM model controls (P < 0.01). CONCLUSION: Cordycepin can effectively improve the erectile function of type Ⅱ diabetic rats by up-regulating the expression of CX43 in the penile corpus cavernosum.


Subject(s)
Diabetes Mellitus, Experimental , Diabetes Mellitus, Type 2 , Erectile Dysfunction , Humans , Rats , Male , Animals , Erectile Dysfunction/drug therapy , Erectile Dysfunction/etiology , Erectile Dysfunction/metabolism , Connexin 43/metabolism , Diabetes Mellitus, Experimental/metabolism , Diabetes Mellitus, Type 2/complications , Rats, Sprague-Dawley , Penis/metabolism , Penile Erection/physiology
9.
Andrologia ; 54(1): e14294, 2022 Feb.
Article in English | MEDLINE | ID: mdl-34811786

ABSTRACT

Diabetes-induced male dysfunction is considered as a worldwide challenge, and testicular damage mainly caused by oxidative stress is its most common manifestation. Cordycepin, a natural antioxidant, has been used in the treatment of diabetic complications. However, the protective action and underlying mechanism of cordycepin on hyperglycaemia-induced testicular damage are unclear. This study aimed to investigate the protective effects and molecular mechanisms of cordycepin against diabetes-induced testicular damage. The type 2 diabetes model was established in C57BL/6 male mice via high-fat diet for 4 weeks and injected intraperitoneally with 50 mg/kg/day streptozotocin for five consecutive days. Then mice were treated with cordycepin (10 and 20 mg/kg, respectively) for 8 weeks. At the end of experiment, biochemical indicators, microstructure of testicular tissue, sperm morphology, TUNEL staining and protein expressions were evaluated. In the present study, cordycepin alleviated the testicular damage, restored disruption of the blood-testis barrier, and improved spermatogenic function via the antiapoptotic and antioxidant capacity. Mechanistically, cordycepin significantly enhanced SIRT1 expression and triggered the activity of Foxo3a, further to induce the expression of its downstream antioxidant enzymes, including Mn-SOD and CAT. These findings indicated that cordycepin could improve hyperglycaemia-induced testicular damage by regulating downstream antioxidant enzymes activity through the SIRT1/Foxo3a signalling pathway.


Subject(s)
Cordyceps , Diabetes Mellitus, Type 2 , Animals , Cordyceps/metabolism , Deoxyadenosines , Male , Mice , Mice, Inbred C57BL , Oxidative Stress , Sirtuin 1/metabolism
10.
PLoS One ; 16(3): e0248102, 2021.
Article in English | MEDLINE | ID: mdl-33735257

ABSTRACT

Rattus tanezumi is a common domestic rat and host of the bubonic plague pathogen in China and Southeast Asia (SEA). The origin, genetic differentiation and dispersal of R. tanezumi have received increasing attention from researchers. The population genetics of R. tanezumi based on its mitochondrial cytochrome b gene have been studied to explain the origin, relationships and dispersal of populations. In this study, we captured a total of 229 rats; morphological and molecular biological identification cytochrome oxidase subunit I (COI) confirmed 131 R. tanezumi individuals collected from 6 provincial areas, and their Cytb gene sequences were analyzed. The results showed that the population in Mohan (MH), Yunnan, had the highest genetic diversity, while that in Ningde (ND), Fujian, had the lowest. Tajima's D statistic for all populations was negative and nonsignificant, indicating the possible expansion of R. tanezumi populations. Low gene flow occurred between the Zhangmu (ZM) R. tanezumi population and other populations, and the genetic differentiation among them was high. Furthermore, our analyses revealed the ZM lineage was the oldest lineage among the groups and diverged ~1.06 Mya, followed by the Luoyang (LY) lineages (~0.51 Mya) and Yunnan lineage (~0.33 Mya). In southeastern Yunnan, the Jinshuihe (JSH) and MH populations were more closely related to the populations in southeastern China (Fuzhou (FZ), ND, Quanzhou (QZ), Nanchang (NC)) and inland areas (Chongqing (CQ), LY) than to those in other areas of Yunnan (Jiegao (JG) and Qingshuihe (QSH)), indicating that R. tanezumi may have spread from southeastern Yunnan to the interior of China. In summary, R. tanezumi may have originated in ZM and adjacent areas, spread to Yunnan, and then spread from the southeast of Yunnan inland or directly eastward from ZM to inland China.


Subject(s)
Cytochromes b/genetics , Gene Flow , Genetic Drift , Mitochondria/genetics , Rats/genetics , Animals , Genes, Mitochondrial , Genetic Variation , Genetics, Population , Haplotypes
11.
ACS Appl Mater Interfaces ; 13(5): 6359-6366, 2021 Feb 10.
Article in English | MEDLINE | ID: mdl-33517654

ABSTRACT

Developing efficient adsorbents for the removal of water pollutants is of great significance for environmental protection. In this study, conjugated triaryl triazines (CTT), containing intramolecular hydrogen-bonding patterns, were recognized to be intriguing building blocks for the construction of porous organic polymer (POP) adsorbents. These planar monomers with multiple phenolic hydroxyl groups facilitated the formation of aza-linked polymers with hierarchical porous structures, sheet-like morphology, good surface wettability, and high degree of functionality. Such structural characteristics of the CTT-POP adsorbents provided superfast adsorption of various cationic dyes from water. For the adsorption of methylene blue dye, the pseudo-second-order rate constant of CTT-POP-1 is 12.9 g mg-1 min-1, superior to those reported in the existing literature. In addition, CTT-POP-1 can be regenerated at least seven times with no loss in performance, indicating its potential application in water treatment.

13.
Int Immunopharmacol ; 90: 107161, 2021 Jan.
Article in English | MEDLINE | ID: mdl-33168409

ABSTRACT

Inflammatory bowel disease (IBD) is a chronic gastrointestinal inflammation regulated by intricate mechanisms. Limonin, a natural tetracyclic triterpenoid compound, possesses multiple bioactivities including anti-inflammation, anti-cancer and so on. However, the therapeutic potential and the underlying mechanism of limonin on IBD remain unclear. Here, we probe into the effect of limonin on chronic colitis induced by dextran sulfate sodium (DSS) and illustrated the potential mechanisms. We found that limonin relieved the risk and severity of DSS-induced chronic colitis in mice through various aspects including increasing body weight and colon length, decreasing the mortality rate, inhibiting MPO activity and improving colon pathology. Limonin also decreased the production of proinflammatory cytokines TNF-α, IL-1ß, IL-6 and the expression of inflammatory proteins COX-2, iNOS in colon tissues from DSS-induced colitis mice. Moreover, limonin attenuated DSS-induced chronic colitis by inhibiting PERK-ATF4-CHOP pathway of endoplasmic reticulum (ER) stress and NF-κB signaling. In vitro, limonin not only decreased LPS-induced higher production of pro-inflammatory cytokines and inflammatory proteins mentioned above by inhibiting NF-κB signaling in macrophage cells RAW264.7, but also suppressed PERK-ATF4-CHOP pathway of ER stress. In summary, our study demonstrated that limonin mitigated DSS-induced chronic colitis via inhibiting PERK-ATF4-CHOP pathway of ER stress and NF-κB signaling. All of this study provides the possibility for limonin as an effective drug for chronic colitis of IBD in the future.


Subject(s)
Anti-Inflammatory Agents/therapeutic use , Colitis/drug therapy , Endoplasmic Reticulum Stress/drug effects , Inflammation/drug therapy , Limonins/therapeutic use , Signal Transduction/drug effects , Activating Transcription Factor 4/metabolism , Animals , Colitis/chemically induced , Cytokines/drug effects , Cytokines/metabolism , Dextran Sulfate/pharmacology , Inflammation/chemically induced , Lipopolysaccharides/pharmacology , Male , Mice , Mice, Inbred C57BL , NF-kappa B/metabolism , RAW 264.7 Cells , Transcription Factor CHOP/metabolism , eIF-2 Kinase/metabolism
14.
J Agric Food Chem ; 68(21): 5816-5824, 2020 May 27.
Article in English | MEDLINE | ID: mdl-32379448

ABSTRACT

Although the new dual model of the Bacillus thuringiensis insecticidal mechamism indicated that both Cry1A protoxin and activated toxin have the potency to kill insects, the difference in the toxic pathways elicited by the protoxin and activated toxin was less understood at the molecular level. Through utilizing the CF-203 cell line derived from the midgut of Choristoneura fumiferana, we found that there existed obvious differences in the binding sites and endocytosis pathways for the two forms of Cry1Ac. In addition, it was revealed that Cry1Ac protoxin existed predominantly in the midgut of Plutella xylostella at the early stage after ingesting Cry1Ac crystals, which brought about obvious damage to the midgut epithelium and exhibited different binding sites on the brush border membrane vesicle compared to the toxin. These findings supported the dual mode of action of B. thuringiensis Cry1A proteins and improved our understanding of the molecular features that contribute to the protoxin toxicity.


Subject(s)
Bacillus thuringiensis Toxins/toxicity , Endotoxins/toxicity , Hemolysin Proteins/toxicity , Insecticides/toxicity , Moths/drug effects , Animals , Bacillus thuringiensis/chemistry , Bacillus thuringiensis Toxins/metabolism , Digestive System/drug effects , Digestive System/metabolism , Endotoxins/metabolism , Hemolysin Proteins/metabolism , Insecticides/metabolism , Moths/metabolism
15.
Phytomedicine ; 69: 153211, 2020 Apr.
Article in English | MEDLINE | ID: mdl-32259676

ABSTRACT

BACKGROUND: Limonin, a bioactive compound from citrus plants, exerts antioxidant activities, however its therapeutic potential in acetaminophen (APAP)-induced hepatotoxicity remains unclear. PURPOSE: Our study aims to investigate the protective effect of limonin on APAP-induced hepatotoxicity and illuminate the underlying mechanisms. STUDY: design In vitro, we chose L-02 cells to establish in vitro APAP-induced liver injury model. L-02 cells were treated with APAP (7.5 mM) for 24 h after pre-incubation with limonin (10, 25, 50 µM) or NAC (250 µM) for 2 h. In vivo, we used C57BL/6 mice as an in vivo APAP-induced liver injury model. C57BL/6 mice with pre-treatment of limonin (40, 80 mg/kg) or NAC (150 mg/kg) for 1 h, were given with a single dose of APAP (300 mg/kg). METHODS: After pre-incubation with limonin (10, 25, 50 µM) for 2 h, L-02 cells were treated with APAP (7.5 mM) for 24 h.The experiments in vitro included MTT assay, Annexin V/PI staining, measurement of reactive oxygen species (ROS), quantitative real-time PCR analysis, Western blot analysis, immunofluorescence microscopy and analysis of LDH activity. Transfection of Nrf2 or Sirt1 siRNA was also conducted in vitro. In vivo, C57BL/6 mice with pre-treatment of limonin (40, 80 mg/kg) or NAC (150 mg/kg) for 1 h, were given with a single dose of APAP (300 mg/kg). Mice were sacrificed at 4, 12 h after APAP poisoning, and analysis of ALT and AST in serum, GSH level in liver tissues, liver histological observation and immunohistochemistry were performed. RESULTS: Limonin increased the cell viability and alleviated APAP-induced apoptosis in hepatocytes. Limonin also inhibited APAP-induced mitochondrial-mediated apoptosis by decreasing the ratio of Bax/Bcl-2, recovery of mitochondrial membrane potential (MMP), inhibiting ROS production and cleavage of caspase-3 in L-02 cells. Moreover, limonin induced activation of Nrf2 and increased protein expression and mRNA levels of its downstream targets, including HO-1, NQO1 and GCLC/GCLM. The inhibition of limonin on apoptosis and promotion on Nrf2 antioxidative pathway were lessened after the application of Nrf2 siRNA. In addition, limonin inhibited NF-κB transcriptional activation, NF-κB-regulated genes and protein expression of inflammatory related proteins iNOS and COX2. Furthermore, limonin increased the protein expression of Sirt1. Sirt1 siRNA transfection confirmed that limonin activated Nrf2 antioxidative pathway and inhibited NF-κB inflammatory response by upregulating Sirt1. Finally, we established APAP-induced liver injury in vivo and demonstrated that limonin alleviated APAP-induced hepatotoxicity by activating Nrf2 antioxidative signals and inhibiting NF-κB inflammatory response via upregulating Sirt1. CONCLUSION: In summary, this study documented that limonin mitigated APAP-induced hepatotoxicity by activating Nrf2 antioxidative pathway and inhibiting NF-κB inflammatory response via upregulating Sirt1, and demonstrated that limonin had therapeutic promise in APAP-induced liver injury.


Subject(s)
Acetaminophen/adverse effects , Antioxidants/metabolism , Chemical and Drug Induced Liver Injury/drug therapy , Limonins/pharmacology , NF-E2-Related Factor 2/metabolism , NF-kappa B/metabolism , Animals , Chemical and Drug Induced Liver Injury/metabolism , Liver/drug effects , Male , Mice , Mice, Inbred C57BL , Mitochondria/drug effects , Mitochondria/metabolism , Mitochondria/pathology , Reactive Oxygen Species/metabolism , Sirtuin 1/genetics , Sirtuin 1/metabolism , Transcriptional Activation/drug effects , Up-Regulation/drug effects
16.
J Phys Chem A ; 122(21): 4869-4881, 2018 May 31.
Article in English | MEDLINE | ID: mdl-29757648

ABSTRACT

The isodesmic reaction method is applied to calculate the potential energy surface (PES) along the reaction coordinates and the rate constants of the barrierless reactions for unimolecular dissociation reactions of alkanes to form two alkyl radicals and their reverse recombination reactions. The reaction class is divided into 10 subclasses depending upon the type of carbon atoms in the reaction centers. A correction scheme based on isodesmic reaction theory is proposed to correct the PESs at UB3LYP/6-31+G(d,p) level. To validate the accuracy of this scheme, a comparison of the PESs at B3LYP level and the corrected PESs with the PESs at CASPT2/aug-cc-pVTZ level is performed for 13 representative reactions, and it is found that the deviations of the PESs at B3LYP level are up to 35.18 kcal/mol and are reduced to within 2 kcal/mol after correction, indicating that the PESs for barrierless reactions in a subclass can be calculated meaningfully accurately at a low level of ab initio method using our correction scheme. High-pressure limit rate constants and pressure dependent rate constants of these reactions are calculated based on their corrected PESs and the results show the pressure dependence of the rate constants cannot be ignored, especially at high temperatures. Furthermore, the impact of molecular size on the pressure-dependent rate constants of decomposition reactions of alkanes and their reverse reactions has been studied. The present work provides an effective method to generate meaningfully accurate PESs for large molecular system.

17.
Appl Microbiol Biotechnol ; 102(2): 703-712, 2018 Jan.
Article in English | MEDLINE | ID: mdl-29184989

ABSTRACT

Avermectins, produced by Streptomyces avermitilis, are important antiparasitic agents. The use of traditional microbial breeding methods for this organism has been limited by the low-throughput shake flask-based screening process. The unique growth cycle of actinomycetes makes the establishment of a reliable high-throughput screening (HTS) process difficult. To enhance the efficiency of screening strains with high yields of avermectin, a HTS process aided by fluorescence-activated cell sorting (FACS) was established. Four different spore solutions were investigated for maintaining a relatively high viability of spores. Propidium iodide (PI) and fluorescein diacetate (FDA) were used to discriminate between dead and live spores using the FACS system. Spores stained with 7-µg/mL PI and 15-µg/mL FDA at 4 °C in the dark for 30 min resulted in optimum sorting. Spores were treated by atmospheric and room temperature plasma (ARTP). Single live spores were sorted and sprayed into 96-well microtiter plates containing 50 µL of solid agar culture medium. Solid-liquid combinatorial microculture was used for high-throughput avermectin culture. A high-titer avermectin producer (G9) was obtained from 5760 mutants after mutagenesis and HTS. Compared with the original strain, the titer was improved by 18.9% on flask culture and 20.6% on fermenter, respectively. The HTS process established in this study could easily be transferred to other similar target products produced by actinomycetes.


Subject(s)
Antiprotozoal Agents/metabolism , High-Throughput Screening Assays/methods , Ivermectin/analogs & derivatives , Streptomyces/metabolism , Bioreactors , Flow Cytometry , Fluorescent Dyes , Gene Expression Regulation, Bacterial , Ivermectin/metabolism , Mutagenesis , Spores , Streptomyces/genetics
18.
J Cell Mol Med ; 21(10): 2412-2425, 2017 10.
Article in English | MEDLINE | ID: mdl-28393453

ABSTRACT

Clinical pregnancies increasingly end in recurrent miscarriage (RM) during the first trimester, with genetic factors shouldering the main responsibility. MicroRNAs (miRNAs) regulate gene expression in a wide array of important biological processes. We examined the potential role of dysregulated miRNAs in RM pathogenesis and trophoblast development as an approach to elucidate the molecular mechanism behind RM. miRNA profiles from clinical specimens of RM and induced abortion (IA) were compared, and several miRNAs were found to be aberrantly expressed in RM samples. Among the miRNAs, miR-365 was significantly differentially expressed in RM decidual tissues. Furthermore, our results demonstrate that miR-365 functions as an upstream regulator of MDM2/p53 expression, cell cycle progression and apoptosis in trophoblasts. Bioinformatic prediction and experimental validation assays identified SGK1 as a direct target of miR-365; consistently, its protein levels were low in decidual tissues. Additionally, functional studies revealed that SGK1 silencing elicits cell cycle arrest and apoptosis in trophoblasts and that SGK1 overexpression attenuates the effects of miR-365 on apoptosis and MDM2/p53 expression. Collectively, our data provide evidence that the up-regulation of miR-365 may contribute to RM by decreasing SGK1 expression, which suggests its potential utility as a prognostic biomarker and therapeutic target for RM.


Subject(s)
Abortion, Habitual/genetics , Apoptosis/genetics , Gene Expression Regulation , MicroRNAs/genetics , Trophoblasts/metabolism , 3' Untranslated Regions/genetics , Abortion, Induced , Adult , Cell Cycle Checkpoints/genetics , Cell Line , Female , Gene Expression Profiling/methods , Humans , Immediate-Early Proteins/genetics , Immediate-Early Proteins/metabolism , Microscopy, Electron, Transmission , Pregnancy , Protein Serine-Threonine Kinases/genetics , Protein Serine-Threonine Kinases/metabolism , Proto-Oncogene Proteins c-mdm2/genetics , Proto-Oncogene Proteins c-mdm2/metabolism , RNA Interference , Trophoblasts/ultrastructure
19.
Int J Mol Med ; 37(4): 931-8, 2016 Apr.
Article in English | MEDLINE | ID: mdl-26936652

ABSTRACT

Intrauterine growth retardation (IUGR) induces metabolic syndrome, which is often characterized by insulin resistance (IR), in adults. Previous research has shown that microRNAs (miRNAs or miRs) play a role in the target genes involved in this process, but the mechanisms remain unclear. In the present study, we examined miRNA profiles using samples of skeletal muscles from both IUGR and control rat offspring whose mothers were fed either a protein-restricted diet or a diet which involved normal amounts of protein during pregnancy, respectively. miR­29a was found to be upregulated in the skeletal muscles of IUGR offspring. The luciferase reporter assay confirmed the direct interaction between miR­29a and peroxisome proliferator­activated receptor δ (PPARδ). Overexpression of miR­29a in the skeletal muscle cell line C2C12 suppressed the expression of its target gene PPARδ, which, in turn, influenced the expression of its coactivator, peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α). Thus, PPARδ/PGC-1α­dependent signals together reduced insulin-dependent glucose uptake and adenosine triphosphate (ATP) production. Overexpression of miR­29a also caused a decrease in levels of glucose transporter 4 (GLUT4), the most important glucose transporter in skeletal muscle, which partially induced a decrease insulin­dependent glucose uptake. These findings provide evidence for a novel micro-RNA­mediated mechanism of PPARδ regulation, and we also noted the IR-promoting actions of miR-29a in skeletal muscles of IUGR.


Subject(s)
Fetal Growth Retardation/genetics , Gene Expression Regulation , Insulin Resistance , MicroRNAs/genetics , Muscle, Skeletal/metabolism , PPAR delta/genetics , Animals , Cell Line , Female , Glucose/genetics , Glucose/metabolism , Glucose Transporter Type 4/genetics , Mice , Muscle, Skeletal/cytology , Myoblasts/cytology , Myoblasts/metabolism , Pregnancy , Rats , Rats, Sprague-Dawley
20.
Vector Borne Zoonotic Dis ; 15(12): 785-9, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26684526

ABSTRACT

To describe the prevalence of Rickettsia in ticks at the Sino-Russian and Sino-Mongolian borders, a total of 292 ticks were collected and tested by conventional PCR assays. The prevalence of Rickettsia was 53.4%, and phylogenetic analysis showed that they belonged to R. raoultii species after alignment for the ompA, ompB, and gltA genes, respectively. Coxiella burnetii DNA was detected for 14%, and no Ehrlichia, Borrelia burgdorferi, and Babesia species were found. Co-infection of two pathogens was 9.9%, and no co-infection with three or more pathogens was found. This study suggested Rickettsia was the most common pathogen in the ticks and co-infection was found. The findings might be helpful to provide advice on the prevention and control of tick-borne disease potential for tourists and residents.


Subject(s)
Rickettsia Infections/epidemiology , Rickettsia/isolation & purification , Tick-Borne Diseases/epidemiology , Ticks/microbiology , Animals , Babesia/genetics , Babesia/isolation & purification , Base Sequence , Borrelia burgdorferi/genetics , Borrelia burgdorferi/isolation & purification , China/epidemiology , Coinfection , Ehrlichia/genetics , Ehrlichia/isolation & purification , Geography , Molecular Sequence Data , Phylogeny , Polymerase Chain Reaction , Rickettsia/genetics , Rickettsia Infections/microbiology , Russia/epidemiology , Sequence Analysis, DNA , Tick-Borne Diseases/microbiology
SELECTION OF CITATIONS
SEARCH DETAIL
...