Objective To screen a thermostable urate oxidase-producing strain, optimize the fermentation conditions and study the enzymatic properties.Methods A urate oxidase-producing strain was screened from high temperature starter based on transparent circle method.Its 16S rDNA sequence was then amplified and analyzed.Meanwhile, the phylogenetic trees were built.Optimization of the fermentation conditions from this strain was carried out.The enzymatic properties of urate oxidase were studied.Results A urate oxidase-producing strain, named Bacillus subtilis ZX-6 by molecular identification, was obtained.The production of urate oxidase under the optimized conditons (135.9 U/L) was 133.7%higher than before.The optimum reaction temperature and pH were 45℃ and 7.6 respectively.The residual activity of urate oxidase at 37℃ for 48 h was still 17.2%.Conclusion The successful screening of a thermostable urate oxidase-producing strain and optimization of the fermentation conditions will lay a foundation for the further research.

AIM: To study the effect of proliferating cell nucler antigen antisense oligonucleotide on ex vivo expansion of cord blood CD34~+ hematopoietic stem/progenitor cells.METHODS: CD34~+ cells were purified from fresh cord blood by immunomagnetic beads.CD34~+ cells were incubated in liquid culture system with different concentrations of(PCNA-ASODN).Using flow cytometry,the number of different kinds of stem/progenitor cells and PCNA expression were measured after CD34~+ cell incubation.RESULTS: PCNA was lowly expressed in low experiential group,with a positive rate of(27.2?3.6)% and(19.0?1.5)%,the positive rate of control group was(53.8?8.3)%(P

Objective:To explore the protective effect of vagus nerve stimulation (VNS) on the prognosis of rats suffering from cardiac arrest/cardiopulmonary resuscitation (CA/CPR) under different treatment timings.Methods:The method of percutaneous epicardial electrical stimulation was used to establish CA model of rat. Fifty-three male SD rats were randomly (random number) divided into the sham group ( n=5), CPR group ( n=12), PRE group ( n=12), POST5 group ( n=12) and POST30 group ( n=12). The sham group did not experience CA/CPR. VNS treatment was started at 30 min before CA (PRE group, n=12), 5 min after recovery of spontaneous circulation (ROSC) (POST5 group, n=12), and 30 min after ROSC (POST30 group, n=12) in different VNS-treated group, respectively. The electrical stimulation was applied to the vagus nerve for 30 min with a unified parameter. The neurological deficit scores at 24, 48, and 72 h after ROSC were recorded, and the survival rate in each group was observed. TUNEL staining was used to detect the apoptosis of cortical area and the expression of α7 nicotinic acetylcholine receptor (α7nAChR) in brain tissue was measured by immunofluorescence at 72 h after ROSC. Variables were compared with one-way analysis of variance, and survival for Kaplan-Meier curves were tested with the log-rank test. A P value less than 0.05 was considered statistically significant. Results:Compared with the CPR group (survival rate 33.33%), both pre-treatment (survival rate 75%) and post-treatment of VNS (POST5 group survival rate 75% and POST30 group survival rate 83.33%) significantly improved the 72 h survival rate after CPR ( P<0.05), mitigated neurological deficits after ROSC, reduced the positive rate of apoptosis neurons, and up-regulated the expression of α7nAChR in cerebral cortex. There was no significant difference among the VNS-treated groups (all P>0.05). Conclusions:Both pre-treatment and post-treatment of VNS can play a protective role in rats after CA/CPR, which may be related to the activation of α7nAChR-mediated anti-inflammatory and anti-apoptosis effects.

Objective:To observe the effects of acupuncture and moxibustion on ubiquitin-like containing PHD and RING finger domains 1(UHRF1)and DNA methyltransferase 1(DNMT1)in ectopic endometrium of rats with endometriosis(EMS). Methods:Forty Sprague-Dawley rats were randomly divided into a sham operation group with 10 rats and a model-building group with 30 rats according to body mass.EMS rat models were established in the model-building group and then were divided into a model group,an acupuncture and moxibustion group,and a progesterone group,with 10 rats in each group.All rats were fixed by a fixator.The sham operation group and the model group were given normal saline by gavage.The acupuncture and moxibustion group received acupuncture at Xuehai(SP10)and Sanyinjiao(SP6),moxibustion at Guanyuan(CV4),and gavage of normal saline.The progesterone group was given the mixed liquid made of dydrogesterone and normal saline by gavage.After 28 d of treatments,the three diameters(length,width,and height)of EMS rats'ectopic cysts were measured,the cyst volumes were calculated,the volumes before intervention were subtracted,and the difference values were used to evaluate the growth of ectopic cysts.UHRF1 and DNMT1 mRNA and protein levels in normal endometrium,eutopic endometrium,and ectopic endometrium were detected by real-time polymerase chain reaction and immunohistochemistry. Results:There was no significant difference in the ectopic cyst volume difference between the acupuncture and moxibustion group and the progesterone group(P>0.05),but they were smaller than that of the model group(P<0.05).The levels of UHRF1 and DNMT1 mRNA and protein in the ectopic endometrium of the model group were lower than those in the normal endometrium(P<0.05).The levels of DNMT1 mRNA and UHRF1 protein in the eutopic endometrium of the model group were lower than those in the normal endometrium(P<0.05).The levels of UHRF1 mRNA and protein and the level of DNMT1 protein in the ectopic endometrium of the acupuncture and moxibustion group were higher than those in the model group(P<0.05),and the level of UHRF1 mRNA was higher than that in the progesterone group(P<0.05).The level of DNMT1 mRNA in the eutopic endometrium of the acupuncture and moxibustion group was higher than that in the model group(P<0.05).The levels of UHRF1 and DNMT1 mRNA and protein in the acupuncture and moxibustion group were insignificantly different from those in the normal endometrium(P>0.05). Conclusion:Acupuncture and moxibustion may up-regulate the levels of UHRF1 mRNA and UHRF1 and DNMT1 proteins in the ectopic endometrium to the normal level so as to reduce the volume of ectopic cysts and cure EMS in rats.

There is a certain relationship between chemotherapy and stroke in cancer patients. Its mechanism may be associated with the increase of the prevalence of traditional vascular factors, the promotion of coagulation dysfunction, the induction of anemia, the impairment of cardiac function, and vascular inflammation. The pathophysiological mechanism of chemotherapy-associated stroke is still in the exploratory stage. This article reviews the pathophysiological mechanism, monitoring indicators, and diagnosis and treatment progress of stroke in cancer patients during chemotherapy.

Objective: To understand the relationship between childhood abuse and social anxiety and its influencing factors,so as to provide a theoretical basis for the intervention targeting social anxiety in adolescents. Methods: The Metaanalysis was conducted on the 30 selected articles using randomeffects models, comprising 93 independent effect sizes and a total sample of 19 354. Odds ratio (OR) was used to integrate the relationship between childhood abuse and social anxiety. Results: There was a significant positive correlation between childhood abuse and social anxiety (r=0.22), and its subtypes (emotional abuse, emotional neglect, emotional maltreatment, physical abuse, physical neglect, sexual abuse) could also positively predict social anxiety (OR=3.14,1.97,2.42,1.78,1.68,1.54)(P<0.01). The moderating effect showed that cultural background could significantly moderate the relationship between emotional neglect and the composite index and social anxiety (Qb=3.95,3.93), and the relationship between emotional abuse and composite index and social anxiety were significantly moderated by age (Qb=7.65,8.72)(P<0.05). Conclusions Childhood abuse is a positive predictor of social anxiety. Cultural background and age have a significant moderating effect on the relationship between childhood abuse and social anxiety, but gender has no significant moderating effect.

The wide use of ZnO and CuO nanoparticles in research, medicine, industry, and other fields has raised concerns about their biosafety. It is therefore unavoidable to be discharged into the sewage treatment system. Due to the unique physical and chemical properties of ZnO NPs and CuO NPs, it may be toxic to the members of the microbial community and their growth and metabolism, which in turn affects the stable operation of sewage nitrogen removal. This study summarizes the toxicity mechanism of two typical metal oxide nanoparticles (ZnO NPs and CuO NPs) to nitrogen removal microorganisms in sewage treatment systems. Furthermore, the factors affecting the cytotoxicity of metal oxide nanoparticles (MONPs) are summarized. This review aims to provide a theoretical basis and support for the future mitigating and emergent treatment of the adverse effects of nanoparticles on sewage treatment systems.
Wastewater/toxicity* ; Sewage/chemistry* ; Zinc Oxide/chemistry* ; Waste Disposal, Fluid ; Nanoparticles/chemistry* ; Metal Nanoparticles/chemistry* ; Nitrogen/metabolism* ; Water Purification

Resource utilization is an effective way to cope with the rapid increase of kitchen waste and excess sludge, and volatile fatty acids produced by anaerobic fermentation is an important way of recycling organic waste. However, the single substrate limits the efficient production of volatile fatty acids. In recent years, volatile fatty acids produced by anaerobic co-fermentation using different substrates has been widely studied and applied. In this paper, we analyze the characteristics of fermentation to produce acid using kitchen waste and excess sludge alone or mixture. Influences of environmental factors and microbial community structure on the type and yield of volatile fatty acids in the anaerobic fermentation system are discussed in detail. Moreover, we propose future research directions, to provide a reference for recycling kitchen waste and excess sludge.
Anaerobiosis ; Bioreactors ; Fatty Acids, Volatile ; Fermentation ; Hydrogen-Ion Concentration ; Microbiota ; Organic Chemicals ; Sewage

RAS, a member of the small GTPase family, functions as a binary switch by shifting between inactive GDP-loaded and active GTP-loaded state. RAS gain-of-function mutations are one of the leading causes in human oncogenesis, accounting for ∼19% of the global cancer burden. As a well-recognized target in malignancy, RAS has been intensively studied in the past decades. Despite the sustained efforts, many failures occurred in the earlier exploration and resulted in an 'undruggable' feature of RAS proteins. Phosphorylation at several residues has been recently determined as regulators for wild-type and mutated RAS proteins. Therefore, the development of RAS inhibitors directly targeting the RAS mutants or towards upstream regulatory kinases supplies a novel direction for tackling the anti-RAS difficulties. A better understanding of RAS phosphorylation can contribute to future therapeutic strategies. In this review, we comprehensively summarized the current advances in RAS phosphorylation and provided mechanistic insights into the signaling transduction of associated pathways. Importantly, the preclinical and clinical success in developing anti-RAS drugs targeting the upstream kinases and potential directions of harnessing allostery to target RAS phosphorylation sites were also discussed.

SIRT6 belongs to the conserved NAD⁺-dependent deacetylase superfamily and mediates multiple biological and pathological processes. Targeting SIRT6 by allosteric modulators represents a novel direction for therapeutics, which can overcome the selectivity problem caused by the structural similarity of orthosteric sites among deacetylases. Here, developing a reversed allosteric strategy AlloReverse, we identified a cryptic allosteric site, Pocket Z, which was only induced by the bi-directional allosteric signal triggered upon orthosteric binding of NAD⁺. Based on Pocket Z, we discovered an SIRT6 allosteric inhibitor named JYQ-42. JYQ-42 selectively targets SIRT6 among other histone deacetylases and effectively inhibits SIRT6 deacetylation, with an IC₅₀ of 2.33 μmol/L. JYQ-42 significantly suppresses SIRT6-mediated cancer cell migration and pro-inflammatory cytokine production. JYQ-42, to our knowledge, is the most potent and selective allosteric SIRT6 inhibitor. This study provides a novel strategy for allosteric drug design and will help in the challenging development of therapeutic agents that can selectively bind SIRT6.