高导电性和催化活性的Janus-TiNbCO_(2)析氢反应催化材料

探寻具有高导电性和高催化活性的析氢反应(HER)催化材料一直是可持续能源发展研究中的热点。Ti_(2)C具有表面活性位点多和优良的力学稳定性、导电性等,已成为潜在的制氢催化剂。然而,终端O修饰Ti_(2)C表面,会降低该材料的导电性,进而限制了电子在价带与导带间的输运。本研究通过Nb掺杂,构建双电层Janus-TiNbCO_(2),并借助VASP软件研究了Janus-TiNbCO_(2)的能带结构、HER性能和HER反应路径过渡态。结果表明,Janus-TiNb-CO_(2)为导体材料,其在应力、氧空位缺陷和H^(*)覆盖度的影响下,均表现出极优异的催化活性,计算获得的最优△G_(H^(*))值为0.02 eV。H^(*)在Janus-TiNbCO_(2)上可能以Heyrovsky路径进行反应,该路径的迁移能势垒为0.23 eV。Janus-TiNbCO_(2)是一种具有HER应用前景的催化材料。

Safety of different acupuncture manipulations for posterior circulation ischemia with vertigo

Acupuncture at Fengchi（GB20） in the posterior neck improves vertigo.However,subarachnoid hemorrhage and spinal epidural hematoma have been reported to occur after acupuncture in the posterior neck.Therefore,in the present study,we assessed the safety of acupuncture at Fengchi.Laboratory tests and adverse event reports were used to evaluate the safety of different acupuncture manipulations for the treatment of posterior circulation ischemia with vertigo.A total of 136 patients were randomly assigned to four groups.Verum acupuncture was conducted with different needle insertion directions（contralateral paropia or prominentia laryngea） and different needle twisting frequencies（60 or 120 times/minute） at Fengchi and matching acupoints（for example,Zhongwan [CV12],Qihai [CV6],Zusanli [ST36],and Fenglong [ST40]）.The patients received 14 treatments over 3–4 weeks.Routine blood analysis,hepatic and renal function tests,urine and feces tests and electrocardiography were performed before the first treatment session and after the final session.Adverse events were recorded after every session.Of the 136 patients,120 completed the study.There were no significant differences between pretreatment and posttreatment test results in any of the groups.Only five patients suffered from minor adverse events（needling pain,slight hematoma and transient chest tightness）.No serious adverse events were found.Our results indicate that a 14-session course of needling at Fengchi is relatively safe for treating posterior circulation ischemia with vertigo.

Protection of the liver against CCl_4-induced injury by intramuscular electrotransfer of a kallistatin-encoding plasmid

AIM:To investigate the effect of transgenic expression of kallistatin(Kal) on carbon tetrachloride(CCl 4)induced liver injury by intramuscular(im) electrotransfer of a Kal-encoding plasmid formulated with poly-Lglutamate(PLG).METHODS:The pKal plasmid encoding Kal gene was formulated with PLG and electrotransferred into mice skeletal muscle before the administration of CCl 4.The expression level of Kal was measured.The serum biomarker levels of alanine aminotransferase(ALT),aspartate aminotransferase(AST),malonyldialdehyde(MDA),and tumor necrosis factor(TNF)-α were monitored.The extent of CCl 4-induced liver injury was analyzed histopathologically.RESULTS:The transgene of Kal was sufficiently expressed after an im injection of plasmid formulated with PLG followed by electroporation.In the Kal gene-transferred mice,protection against CCl 4-induced liver injury was reflected by significantly decreased serum ALT,AST,MDA and TNF-α levels compared to those in control mice(P < 0.01 to 0.05 in a dose-dependent manner).Histological observations also revealed that hepatocyte necrosis,hemorrhage,vacuolar change and hydropic degeneration were apparent in mice after CCl 4 administration.In contrast,the damage was markedly attenuated in the Kal gene-transferred mice.The expression of hepatic fibrogenesis marker transforming growth factor-β1 was also reduced in the pKal transferred mice.CONCLUSION:Intramuscular electrotransfer of plasmid pKal which was formulated with PLG significantly alleviated the CCl 4-induced oxidative stress and inflammatory response,and reduced the liver damage in a mouse model.

Electroacupuncture induces acute changes in cerebral cortical mi RNA profile, improves cerebral blood flow and alleviates neurological deficits in a rat model of stroke

Electroacupuncture has been shown to improve cerebral blood flow in animal models of stroke. However, it is unclear whether electroacupuncture alters mi RNA expression in the cortex. In this study, we examined changes in the cerebral cortical mi RNA profile, cerebral blood flow and neurological function induced by electroacupuncture in a rat model of stroke. Electroacupuncture was performed at Renzhong（GV26） and Neiguan（PC6）, with a frequency of 2 Hz, continuous wave, current intensity of 3.0 m A, and stimulation time of 1 minute. Electroacupuncture increased cerebral blood flow and alleviated neurological impairment in the rats. mi RNA microarray profiling revealed that the vascular endothelial growth factor signaling pathway, which links cell proliferation with stroke, was most significantly affected by electroacupuncture. Electroacupuncture induced changes in expression of rno-mi R-206-3p, rno-mi R-3473, rno-mi R-6216 and rno-mi R-494-3p, and these changes were confirmed by quantitative real-time polymerase chain reaction. Our findings suggest that changes in cell proliferation-associated mi RNA expression induced by electroacupuncture might be associated with the improved cerebral blood supply and functional recovery following stroke.

Tetramethylpyrazine inhibits proliferation of colon cancer cells in vitro

BACKGROUND Colon cancer is one of the most common malignancies worldwide,and chemotherapy is a widely used strategy in colon cancer clinical therapy.However,chemotherapy resistance is a major cause of disease recurrence and progression in colon cancer,and thus novel drugs for treatment are urgently needed.Tetramethylpyrazine(TMP),a component of the traditional Chinese medicine Chuanxiong Hort,has been proven to exhibit a beneficial effect in tumors.AIM To investigate the potential anticancer activity of TMP in colon cancer and its underlying mechanisms.METHODS Colon cancer cells were incubated with different concentrations of TMP.Cell viability was evaluated by crystal violet staining assay and cell counting kit-8 assay,and cell apoptosis and cell cycle were assessed by flow cytometry.RESULTS TMP significantly inhibited the proliferation of colon cancer cells in a dose-and time-dependent manner.In addition,flow cytometry revealed that TMP induced cell cycle arrest at the G0/G1 phase.TMP treatment caused early stage apoptosis in SW480 cells,whereas it caused late stage apoptosis in HCT116 cells.CONCLUSION Our studies demonstrated that TMP inhibits the proliferation of colon cancer cells in a dose-and time-dependent manner by inducing apoptosis and arresting the cell cycle at the G0/G1 phase.Our findings suggest that TMP might serve as a potential novel therapeutic drug in the treatment of human colon cancer.

Retrorectal mucinous adenocarcinoma arising from a tailgut cyst:A case report and review of literature

BACKGROUND Tailgut cysts are defined as congenital cysts that develop in the rectosacral space from the residue of the primitive tail.As a congenital disease,caudal cysts are very rare,and their canceration is even rarer,which makes the disease prone to misdiagnosis and delayed treatment.We describe a case of caudal cyst with adenocarcinogenesis and summarize in detail the characteristics of cases with analytical value reported since 1990.CASE SUMMARY A 35-year-old woman found a mass in her lower abdomen 2 mo ago.She was asymptomatic at that time and was not treated because of the coronavirus disease 2019 pandemic.Two weeks ago,the patient developed abdominal distension and right waist discomfort and came to our hospital.Except for the high level of serum carcinoembryonic antigen,the medical history and laboratory tests were not remarkable.Magnetic resonance imaging showed a well-defined,slightly lobulated cystic-solid mass with a straight diameter of approximately 10 cm×9 cm in the presacral space,slightly high signal intensity on T2-weighted imaging,and moderate signal intensity on T1-weighted imaging.The mass was completely removed by laparoscopic surgery.Histopathological examination showed that the lesion was an intestinal mucinous adenocarcinoma,and the multidisciplinary team decided to implement postoperative chemotherapy.The patient recovered well,the tumor marker levels returned to normal,and tumor-free survival has been achieved thus far.CONCLUSION The case and literature summary can help clinicians and researchers develop appropriate examination and therapeutic methods for diagnosis and treatment of this rare disease.

Theoretical framework for geoacoustic inversion by adjoint method

Traditional geoacoustic inversions are generally solved by matched-field processing in combination with metaheuristic global searching algorithms which usually need massive computations. This paper proposes a new physical framework for geoacoustic retrievals. A parabolic approximation of wave equation with non-local boundary condition is used as the forward propagation model. The expressions of the corresponding tangent linear model and the adjoint operator are derived, respectively, by variational method. The analytical expressions for the gradient of the cost function with respect to the control variables can be formulated by the adjoint operator, which in turn can be used for optimization by the gradient-based method.

Wear and corrosion resistance of CoCrNi composite coatings by laser cladding

Two kinds of CoCrNi composite coatings,CoCrNiMo and CoCrNiMoBC,were prepared by laser cladding on the base metal of 304 stainless steel.The wear and corrosion properties of the coatings were studied by wear tests and electrochemical tests.Results show that the addition of B_(4)C promotes the generation of the ceramic phase,and therefore improving the microhardness of the coating and enhancing its wear resistance,while simutaneously keeps its excellent corrosion resistance.Energy dispersive X-ray spectrometry analysis shows that the chromium distribution in the two coatings is relatively uniform,which is beneficial for corrosion resistance.Scanning Kelvin probe microscopy results reveal that the potential difference between dendrites and interdendrites is only 20 mV,which leads to a relatively low driving force for galvanic corrosion.Observation through the atomic-scale high-resolution transmission electron microscopy shows that the fundamental reason for the high wear and corrosion resistance of the coating is the excellent coherent interface between the two phases,which reduces the interface energy and potential difference and thus improving its corrosion resistance.

Development and prospects of cervical laminoplasty

Cervical laminoplasty surgery is an alternative to laminectomy. It can increase the space of the spinal cord available by raising the lamina, and achieve the indirect decompression effect to treat cervical spondylosis. Various techniques of laminoplasty have since been developed after two prototype techniques: Hirabayashi's open-door laminoplasty and Kurokawa's double-door laminoplasty. Several studies report superior biomechanical stability of the cervical spine after laminoplasty compared with laminectomy. Recent development in laminoplasty is preservation of muscle attachment, which enabled dynamic and static stabilization of the cervical spine by neck extensor muscles. After treatment with new laminoplasty techniques with active postoperative neck muscle exercises, postoperative instability, kyphosis, axial neck pain, and loss of ROM become minimal. The development,complications and future trends of cervical laminoplasty are summarized below.

Efficacy of acupuncture as an adjuvant to speech and language therapy for aphasia after ischemic stroke:a protocol of systematic review and meta-analysis

Background:Aphasia is one of the common complications of stroke.Speech and language therapy is a conventional treatment for aphasia following stroke.However,rehabilitation often remains unsatisfactory after speech and language therapy alone.Acupuncture may be effective for aphasia after stroke.We designed this systematic review to assess the efficacy and safety of acupuncture as an adjunct to speech and language therapy for aphasia following ischemic stroke.Methods:An extensive search will be performed in databases including Cochrane Central Register of Controlled Trials,PubMed,Web of Science,EMBASE,China National Knowledge Infrastructure,Sinomed,Wei Pu Date and Wan Fang Data.No limitation will be set in language,publication date or status of the study.The primary outcomes include scores of Western Aphasia Battery and Aphasia Quotient.The secondary outcomes include Scales of Clinical Rehabilitation Research Center Aphasia Examination,Communicative Abilities in Daily Living,Aphasia Battery of Chinese,Chinese Functional Communication Profile,adverse reactions,etc.Results:All of the data will be processed with Review Manager software.Cochrane‘risk of bias’tool will be used to assess the risk of bias.Conclusion:This study will contribute to the selection of appropriate therapies for aphasia after ischemic stroke and the development of clinical guidelines on this topic.

Efficacy and safety of electroacupuncture for insomnia:A systematic review and meta-analysis

Background:Electroacupuncture is often used to treat insomnia.Objective:To evaluate the efficacy and safety of electroacupuncture for insomnia.Search strategy:Databases including PubMed,Cochrane Library,Embase,Web of Science,Chinese Biomedical Literature Database,China National Knowledge Infrastructure,Wanfang Data and VIP Fulltext e-Journals Database were searched up to January 15,2023.Inclusion criteria:Randomized clinical trials were included if they compared the clinical efficacy and safety of electroacupuncture with sham acupuncture,no treatment or usual care (UC) and general acupuncture.Data extraction and analysis:The full texts of the studies were reviewed to remove ineligible literature.The extracted data included authors,publication year,diagnostic criteria,sample size,population characteristics,interventions and outcomes.The above steps were performed independently by two reviewers and the data were cross checked.Stata15.0 software was used to analyze the extracted outcome data.For continuous data (Pittsburgh Sleep Quality Index[PSQI]score and Insomnia Severity Index score),weighted mean difference (WMD) was calculated and 95% confidence interval (CI) was reported when the same scale was applied.For dichotomous variables (clinical response rate and adverse events),a meta-analysis was performed using risk ratio (RR) as the effect indicator.Results:Thirty-one trials with 2226 subjects were included.The meta-analysis suggested that electroacupuncture was more effective in improving insomnia compared with the control group (sham acupuncture,no treatment,UC and general acupuncture)(RR=1.21;95 CI:[1.16,1.27]),significantly reducing the PSQI score in insomnia patients after treatment and at follow-up (WMD=-3.23;95%CI:[-4.29,-2.17];P<0.001).There was no significant difference in the incidence of adverse events between the EA and control groups (sham acupuncture and no treatment or UC.RR=1.48;95%CI:[0.91,2.40];P=0.117).In addition,the regression results revealed that receiving electroacupuncture for seven to nine weeks provided the best efficacy (P<0.05). Conclusion:Electroacupuncture can significantly promote better sleep quality in insomnia patients and is suitable for the treatment of various types of insomnia.However,the articles included were single-center trials with small sample sizes,and some articles were of poor quality.Therefore,further research is still needed to confirm these findings.

Morphology,structure and corrosion resistance of Mg-Al LDH films fabricated in different Al^(3+)concentration solutions

In situ-grown Mg-Al layered double hydroxide(LDH)films were obtained on an anodized AZ31 substrate,with the immersion of sample in different concentrations of Al^(3+)solution.The structure,composition and morphology of LDH films were investigated by X-ray diffraction(XRD),Fourier transform infrared(FTIR)and scanning electronic microscopy(SEM),and the corrosion behavior of LDH films was further studied by electrochemical impedance spectroscopy(EIS).The influence of Al^(3+)concentration on the growth behavior of LDH was also discussed.The results indicated that the nest-like structure of MgAl-LDH film was composed of interconnected MgAl-LDH nanosheets.Besides,the LDH obtained in0.032 mol·L^(-1)Al^(3+)solution,possessing dense laminated structure,could effectively seal the porous surface of anodic oxide film.EIS results revealed that the samples coated with LDH films showed a higher electrochemical impedance,and thus,the corrosion resistance of samples coated with LDH films was signally improved compared with the anodized alloy.

Progress in ceramic materials and structure design toward advanced thermal barrier coatings

Thermal barrier coatings(TBCs)can effectively protect the alloy substrate of hot components in aeroengines or land-based gas turbines by the thermal insulation and corrosion/erosion resistance of the ceramic top coat.However,the continuous pursuit of a higher operating temperature leads to degradation,delamination,and premature failure of the top coat.Both new ceramic materials and new coating structures must be developed to meet the demand for future advanced TBC systems.In this paper,the latest progress of some new ceramic materials is first reviewed.Then,a comprehensive spalling mechanism of the ceramic top coat is summarized to understand the dependence of lifetime on various factors such as oxidation scale growth,ceramic sintering,erosion,and calcium–magnesium–aluminium–silicate(CMAS)molten salt corrosion.Finally,new structural design methods for high-performance TBCs are discussed from the perspectives of lamellar,columnar,and nanostructure inclusions.The latest developments of ceramic top coat will be presented in terms of material selection,structural design,and failure mechanism,and the comprehensive guidance will be provided for the development of next-generation advanced TBCs with higher temperature resistance,better thermal insulation,and longer lifetime.

Regulation of the timing of oligodendrocyte differentiation:mechanisms and perspectives

Axonal myelination is an essential process for normal functioning of the vertebrate central nervous system. Proper formation of myelin sheaths around axons depends on the timely differentiation of oligodendrocytes. This differentiation occurs on a predictable schedule both in culture and during development. However, the timing mechanisms for oligodendrocyte differentiation during normal development have not been fully uncovered. Recent studies have identified a large number of regulatory factors, including cell-intrinsic factors and extracel- lular signals, that could control the timing of oligodendrocyte differentiation. Here we provide a mechanistic and critical review of the timing control of oligodendrocyte differentiation.