Objective To study mutagenic effects of spaceflight on physiological and biochemical parameters of Rhodobacter sphaeroides and select high-yield mutants in co-enzyme Q10(CoQ10) production for providing the experimental and theoretical basis for industrial production through mutagenic effects of spaceflight.Methods Variations in stress resistance and CoQ10 production of isolated strains were studied,the strain Rhodobacter sphaeroides was taken back by a recoverable satellite after 15 d flight in space.Results Compared to the control,the strain was characterized by highter NaCl tolerance and higher stress resistance,as well as with broader scope in growth temperature and pH value after spaceflight.The mutant colonies appeared white or pink which was different from their original red.The CoQ10 production of mutant 10 strain was increased by 73.13% much higher than that of control.Conclusion Spaceflight mutagenic effects on Rhodobacter sphaeroides shows to be multi-factor compared to the traditional single-factor mutagenesis methods.It can enhance stress resistance and increase CoQ10 production of isolated strains,and can be utilized in industrial microbial mutagenesis and breeding in the future.

AIM: To investigate whether celecoxib induces gastric cancer cell apoptosis in a COX-2 non-expression cell line.METHODS: The COX-2 protein was examined by western blotting.Fluorescence microscopy,DNA agarose gel electrophoresis and flow cytometry analysis were used to test apoptosis.RESULTS: COX-2 was expressed in AGS but not MGC-803 gastric cancer cell line;Selective COX-2 inhibitor celecoxib induced MGC-803 cell line apoptosis in a concentration and time-dependent manner.CONCLUSION: Celecoxib induces apoptosis in COX-2 non-expression gastric cancer cells.

AIM:This study aimed to observe the analgesic effects of Hegu acupoint catgut embedding in a rat model of labor and investigate its influence on biomarkers such as calcitonin gene-related peptide(CGRP)signals at the Hegu acupoint.METHODS:Thirty-six pregnant rats were randomly divided into three groups:control group,Hegu acu-puncture group,and Hegu catgut embedding group.Pain threshold changes were assessed using the tail immersion test and paw withdrawal thermal latency at four time points:pre-induction,before the onset of labor,at the onset of labor,and at the mid-stage of labor.Tissue samples from the Hegu acupoint were collected at the mid-stage of labor to detect the ex-pression of CGRP,substance P(SP),and mast cells using immunofluorescence.The concentrations of ATP and ade-nosine were measured using ELISA.RESULTS:Before labor induction,there was no significant difference in tail immer-sion test and paw withdrawal thermal latency among the three groups(P>0.05).Before the onset of labor,both the acu-puncture and catgut embedding groups exhibited significantly higher tail-flick times and paw withdrawal latencies com-pared to the control group(P<0.05).At labor initiation and mid-labor,the catgut embedding group had significantly higher tail-flick times and paw withdrawal latencies compared to both the control and acupuncture groups(P<0.05).During mid-labor,the expression of CGRP,SP,mast cells,ATP,and adenosine concentrations in the catgut embedding group was significantly higher than that in the control and acupuncture groups(P<0.05),with co-expression of CGRP,SP,and mast cells observed.CONCLUSION:Hegu acupoint catgut embedding effectively alleviates labor pain,and its mechanism may involve increased local expression of CGRP and SP,promoting mast cell degranulation,and increasing ATP release and its conversion to adenosine.

OBJECTIVE: To investigate the effect of orthodontic traction on the microstructure of dental enamel. METHODS: Forty-eight isolated premolars were randomly divided into 6 groups (=8), including Group A (blank control group), in which the teeth were bonded with the orthodontic brackets without any loading force; Groups B1, B2, and B3 where the teeth were bonded with the orthodontic brackets using clinical adhesives and loaded with 50 g force for 6 months, 200 g force for 6 months, and 200 g force for 1 month, respectively; and Groups C1 and C2, where the teeth were bonded with straight wire brackets using light curing bonding and chemical curing bonding techniques, respectively. All the teeth were embedded with non-decalcified epoxy resin. Scanning electron microscope (SEM), atomic force microscope (AFM), and energy spectrometer (EDS) were used to analyze interface morphology and elemental composition of the teeth sliced with a hard tissue microtome. RESULTS: Compared with those in Group A, the teeth in the other 5 groups showed increased adhesive residue index with microcracks and void structures on the enamel surface under SEM; AFM revealed microcracks on the enamel surface with angles to the grinding direction. A larger loading force on the bracket resulted in more microcracks on the enamel interface. The interface roughness differed significantly between Groups A and C2, and the peak-to-valley distance differed significantly between Groups A, C, and C2. CONCLUSIONS Orthodontic traction can cause changes in the microstructure of normal dental enamel.
Dental Enamel ; Materials Testing ; Orthodontic Brackets ; Resin Cements ; Surface Properties ; Traction

Deconvolution of potential drug targets of the central nervous system (CNS) is particularly challenging because of the complicated structure and function of the brain. Here, a spatiotemporally resolved metabolomics and isotope tracing strategy was proposed and demonstrated to be powerful for deconvoluting and localizing potential targets of CNS drugs by using ambient mass spectrometry imaging. This strategy can map various substances including exogenous drugs, isotopically labeled metabolites, and various types of endogenous metabolites in the brain tissue sections to illustrate their microregional distribution pattern in the brain and locate drug action-related metabolic nodes and pathways. The strategy revealed that the sedative-hypnotic drug candidate YZG-331 was prominently distributed in the pineal gland and entered the thalamus and hypothalamus in relatively small amounts, and can increase glutamate decarboxylase activity to elevate γ-aminobutyric acid (GABA) levels in the hypothalamus, agonize organic cation transporter 3 to release extracellular histamine into peripheral circulation. These findings emphasize the promising capability of spatiotemporally resolved metabolomics and isotope tracing to help elucidate the multiple targets and the mechanisms of action of CNS drugs.