Phase II Clinical Study of Three-Dimensional Printed Coplanar Template Combined with CT-Guided Percutaneous Core Needle Biopsy of Pulmonary Nodules in Elderly Patients

Background: As the population age structure gradually ages, more and more elderly people were found to have pulmonary nodules during physical examinations. Most elderly people had underlying diseases such as heart, lung, brain and blood vessels and cannot tolerate surgery. Computed tomography (CT)-guided percutaneous core needle biopsy (CNB) was the first choice for pathological diagnosis and subsequent targeted drugs, immune drugs or ablation treatment. CT-guided percutaneous CNB requires clinicians with rich CNB experience to ensure high CNB accuracy, but it was easy to cause complications such as pneumothorax and hemorrhage. Three-dimensional (3D) printing coplanar template (PCT) combined with CT-guided percutaneous pulmonary CNB biopsy has been used in clinical practice, but there was no prospective, randomized controlled study. Methods: Elderly patients with lung nodules admitted to the Department of Oncology of our hospital from January 2019 to January 2023 were selected. A total of 225 elderly patients were screened, and 30 patients were included after screening. They were randomly divided into experimental group (Group A: 30 cases) and control group (Group B: 30 cases). Group A was given 3D-PCT combined with CT-guided percutaneous pulmonary CNB biopsy, Group B underwent CT-guided percutaneous pulmonary CNB. The primary outcome measure of this study was the accuracy of diagnostic CNB, and the secondary outcome measures were CNB time, number of CNB needles, number of pathological tissues and complications. Results: The diagnostic accuracy of group A and group B was 96.67% and 76.67%, respectively (P = 0.026). There were statistical differences between group A and group B in average CNB time (P = 0.001), number of CNB (1 vs more than 1, P = 0.029), and pathological tissue obtained by CNB (3 vs 1, P = 0.040). There was no statistical difference in the incidence of pneumothorax and hemorrhage between the two groups (P > 0.05). Conclusions: 3D-PCT combined with CT-guided percutaneous CNB can improve the puncture accuracy of elderly patients, shorten the puncture time, reduce the number of punctures, and increase the amount of puncture pathological tissue, without increasing pneumothorax and hemorrhage complications. We look forward to verifying this in a phase III randomized controlled clinical study. .

Flexible bidirectional pulse charging regulation achieving long-life lithium-ion batteries

Typical application scenarios,such as vehicle to grid(V2G)and frequency regulation,have imposed significant long-life demands on lithium-ion batteries.Herein,we propose an advanced battery life-extension method employing bidirectional pulse charging(BPC)strategy.Unlike traditional constant current charging methods,BPC strategy not only achieves comparable charging speeds but also facilitates V2G frequency regulation simultaneously.It significantly enhances battery cycle ampere-hour throughput and demonstrates remarkable life extension capabilities.For this interesting conclusion,adopting model identification and postmortem characterization to reveal the life regulation mechanism of BPC:it mitigates battery capacity loss attributed to loss of lithium-ion inventory(LLI)in graphite anodes by intermittently regulating the overall battery voltage and anode potential using a negative charging current.Then,from the perspective of internal side reaction,the life extension mechanism is further revealed as inhibition of solid electrolyte interphase(SEI)and lithium dendrite growth by regulating voltage with a bidirectional pulse current,and a semi-empirical life degradation model combining SEI and lithium dendrite growth is developed for BPC scenarios health management,the model parameters are identified by genetic algorithm with the life simulation exhibiting an accuracy exceeding 99%.This finding indicates that under typical rate conditions,adaptable BPC strategies can extend the service life of LFP battery by approximately 123%.Consequently,the developed advanced BPC strategy offers innovative perspectives and insights for the development of long-life battery applications in the future.

西藏昂仁县树龄超过300年和1000年的古树树木年轮学论证

西藏西部地区由于生境严酷,很难发现树龄特大的古树。笔者在2023年对昂仁县的古树资源调查中,发现了两棵树龄特大的大果圆柏(Juiperus tibetica Kom.)古树。一棵古树位于达局乡甘丹塔空寺内,采集到的树芯样本接近树干髓心,通过树木年轮学方法鉴定其树龄约为306年(起始于1716年)。另一棵古树位于多白乡谢村,其胸围高达8.5米,仅采集到12厘米的树芯样本上有216个年轮,推算这棵古树的树龄超过了千年。两株古树的树木年轮数据既反映了区域气候变化信号,也反映了局地小生境和人们对古树的保护信号,同时显示了古树目前生长处于健康状态。研究结果丰富了昂仁县古树本底资源信息,对认识西藏西部地区古树文化、生态、气候、科研和社会价值具有重要意义。

A new horizon for neuroscience:terahertz biotechnology in brain research

Terahertz biotechnology has been increasingly applied in various biomedical fields and has especially shown great potential for application in brain sciences.In this article,we review the development of terahertz biotechnology and its applications in the field of neuropsychiatry.Available evidence indicates promising prospects for the use of terahertz spectroscopy and terahertz imaging techniques in the diagnosis of amyloid disease,cerebrovascular disease,glioma,psychiatric disease,traumatic brain injury,and myelin deficit.In vitro and animal experiments have also demonstrated the potential therapeutic value of terahertz technology in some neuropsychiatric diseases.Although the precise underlying mechanism of the interactions between terahertz electromagnetic waves and the biosystem is not yet fully understood,the research progress in this field shows great potential for biomedical noninvasive diagnostic and therapeutic applications.However,the biosafety of terahertz radiation requires further exploration regarding its two-sided efficacy in practical applications.This review demonstrates that terahertz biotechnology has the potential to be a promising method in the field of neuropsychiatry based on its unique advantages.

Flotation separation of scheelite from calcite using luteolin as a novel depressant

This paper proposes luteolin(LUT)as a novel depressant for the flotation-based separation of scheelite and calcite in a sodium oleate(NaOL)system.The suitability of LUT as a calcite depressant is confirmed through micro-flotation testing.At pH=9,with LUT concentration of 50 mg·L^(-1) and NaOL concentration of 50 mg·L^(-1),scheelite recovery reaches 80.3%.Calcite,on the other hand,exhibits a recovery rate of 17.6%,indicating a significant difference in floatability between the two minerals.Subsequently,the surface modifica-tions of scheelite and calcite following LUT treatment are characterized using adsorption capacity testing,Zeta potential analysis,Fourier transform infrared spectroscopy(FT-IR),X-ray photoelectron spectroscopy(XPS),and atomic force microscopy(AFM).The study in-vestigates the selective depressant mechanism of LUT on calcite.Adsorption capacity testing and Zeta potential analysis demonstrate sub-stantial absorption of LUT on the surface of calcite,impeding the further adsorption of sodium oleate,while its impact on scheelite is min-imal.FT-IR and XPS analyses reveal the selective adsorption of LUT onto the surface of calcite,forming strong chemisorption bonds between the hydroxyl group and calcium ions present.AFM directly illustrates the distinct adsorption densities of LUT on the two miner-al types.Consequently,LUT can effectively serve as a depressant for calcite,enabling the successful separation of scheelite and calcite.

Reference values of carotid intima-media thickness and arterial stiffness in Chinese adults based on ultrasound radio frequency signal:A nationwide,multicenter study

Background:Carotid intima-media thickness(IMT)and diameter,stiffness,and wave reflections,are independent and important clinical biomarkers and risk predictors for cardiovascular diseases.The purpose of the present study was to establish nationwide reference values of carotid properties for healthy Chinese adults and to explore potential clinical determinants.Methods:A total of 3053 healthy Han Chinese adults(1922 women)aged 18-79 years were enrolled at 28 collaborating tertiary centers throughout China between April 2021 and July 2022.The real-time tracking of common carotid artery walls was achieved by the radio frequency(RF)ultrasound system.The IMT,diameter,compliance coefficient,βstiffness,local pulse wave velocity(PWV),local systolic blood pressure,augmented pressure(AP),and augmentation index(AIx)were then automatically measured and reported.Data were stratified by age groups and sex.The relationships between age and carotid property parameters were analyzed by Jonckheere-Terpstra test and simple linear regressions.The major clinical determinants of carotid properties were identified by Pearson’s correlation,multiple linear regression,and analyses of covariance.Results:All the parameters of carotid properties demonstrated significantly age-related trajectories.Women showed thinner IMT,smaller carotid diameter,larger AP,and AIx than men.Theβstiffness and PWV were significantly higher in men than women before forties,but the differences reversed after that.The increase rate of carotid IMT(5.5µm/year in women and 5.8µm/year in men)and diameter(0.03 mm/year in both men and women)were similar between men and women.For the stiffness and wave reflections,women showed significantly larger age-related variations than men as demonstrated by steeper regression slopes(all P for age by sex interaction<0.05).The blood pressures,body mass index(BMI),and triglyceride levels were identified as major clinical determinants of carotid properties with adjustment of age and sex.Conclusions:The age-and sex-specific reference values of carotid properties measured by RF ultrasound for healthy Chinese adults were established.The blood pressures,BMI,and triglyceride levels should be considered for clinical application of corresponding reference values.

NbN quantum dots anchored hollow carbon nanorods as efficient polysulfide immobilizer and lithium stabilizer for Li-S full batteries

The shuttle effect of lithium polysulfides(LiPSs)and uncontrollable lithium dendrite growth seriously hinder the practical application of lithium-sulfur(Li-S)batteries.To simultaneously address such issues,monodispersed Nb N quantum dots anchored on nitrogen-doped hollow carbon nanorods(NbN@NHCR)are elaborately developed as efficient Li PSs immobilizer and Li stabilizer for high-performance Li-S full batteries.Density functional theory(DFT)calculations and experimental characterizations demonstrate that the sulfiphilic and lithiophilic NbN@NHCR hybrid can not only efficiently immobilize the soluble Li PSs and facilitate diffusion-conversion kinetics for alleviating the shuttling effect,but also homogenize the distribution of Li+ions and regulate uniform Li deposition for suppressing Li-dendrite growth.As a result,the assembled Li-S full batteries(NbN@NHCR-S||Nb N@NHCR-Li)deliver excellent long-term cycling stability with a low decay rate of 0.031%per cycle over 1000 cycles at high rate of 2 C.Even at a high S loading of 5.8 mg cm^(-2)and a low electrolyte/sulfur ratio of 5.2μL mg^(-1),a large areal capacity of 6.2 mA h cm^(-2)can be achieved in Li-S pouch cell at 0.1 C.This study provides a new perspective via designing a dual-functional sulfiphilic and lithiophilic hybrid to address serious issues of the shuttle effect of S cathode and dendrite growth of Li anode.

Sinensetin protects against periodontitis through binding to Bach1 enhancing its ubiquitination degradation and improving oxidative stress

Periodontitis is a chronic inflammatory and immune reactive disease induced by the subgingival biofilm.The therapeutic effect for susceptible patients is often unsatisfactory due to excessive inflammatory response and oxidative stress.Sinensetin(Sin)is a nature polymethoxylated flavonoid with anti-inflammatory and antioxidant activities.Our study aimed to explore the beneficial effect of Sin on periodontitis and the specific molecular mechanisms.We found that Sin attenuated oxidative stress and inflammatory levels of periodontal ligament cells(PDLCs)under inflammatory conditions.Administered Sin to rats with ligation-induced periodontitis models exhibited a protective effect against periodontitis in vivo.By molecular docking,we identified Bach1 as a strong binding target of Sin,and this binding was further verified by cellular thermal displacement assay and immunofluorescence assays.Chromatin immunoprecipitation-quantitative polymerase chain reaction results also revealed that Sin obstructed the binding of Bach1 to the HMOX1 promoter,subsequently upregulating the expression of the key antioxidant factor HO-1.Further functional experiments with Bach1 knocked down and overexpressed verified Bach1 as a key target for Sin to exert its antioxidant effects.Additionally,we demonstrated that Sin prompted the reduction of Bach1 by potentiating the ubiquitination degradation of Bach1,thereby inducing HO-1 expression and inhibiting oxidative stress.Overall,Sin could be a promising drug candidate for the treatment of periodontitis by targeting binding to Bach1.

Laryngeal leiomyoma:A case report and review of literature

BACKGROUND Leiomyomas(LMs)are mesenchymal tumors that arise from smooth muscle cells.LMs most commonly arise in organs with an abundance of smooth muscle such as the uterus and gastrointestinal tract.Conversely,LMs are rarely detected in the head and neck region.In this study,we report a rare case of laryngeal LM(LLM)and summarized the clinical characteristics of reported LLMs to help clinicians better understand this rare disease and improve its diagnosis,treatment,and postoperative course.CASE SUMMARY A 49-year-old man was admitted to our ENT outpatient clinic with a chief complaint of pharynx discomfort for 2 months.Laryngoscopy performed under topical anesthesia revealed a solitary,pink mass at the tubercle of epiglottis.Surgery via laryngeal endoscopy was performed under general anesthesia,and the lesion was excised easily.Positive immunohistochemical staining for desmin and smooth-muscle actin indicated a smooth muscle origin and the diagnosis was laryngeal leiomyoma.After surgery,the patient’s condition was stable,and he was discharged 2 d after surgery.During the 1-year postoperative period,the patient’s condition remained stable without evidence of recurrence.CONCLUSION Surgical resection is the preferred treatment for LLMs,its early diagnosis and differential diagnosis have important clinical significance.

Construction of prognostic markers for gastric cancer and comprehensive analysis of pyroptosis-related long non-coding RNAs

BACKGROUND China's most frequent malignancy is gastric cancer(GC),which has a very poor survival rate,and the survival rate for patients with advanced GC is dismal.Pyroptosis has been connected to the genesis and development of cancer.The function of pyroptosis-related long non-coding RNAs(PRLs)in GC,on the other hand,remains uncertain.AIM To explore the construction and comprehensive analysis of the prognostic characteristics of long non-coding RNA(lncRNA)related to pyroptosis in GC patients.METHODS The TCGA database provided us with 352 stomach adenocarcinoma samples,and we obtained 28 pyroptotic genes from the Reactome database.We examined the correlation between lncRNAs and pyroptosis using the Pearson correlation coefficient.Prognosis-related PRLs were identified through univariate Cox analysis.A predictive signature was constructed using stepwise Cox regression analysis,and its reliability and independence were assessed.To facilitate clinical application,a nomogram was created based on this signature.we analyzed differences in immune cell infiltration,immune function,and checkpoints between the high-risk group(HRG)and low-risk group(LRG).RESULTS Five hundred and twenty-three PRLs were screened from all lncRNAs(absolute correlation coefficient>0.4,P<0.05).Nine PRLs were included in the risk prediction signature that was created through stepwise Cox regression analysis.We determined the risk score for GC patients and employed the median value as the dividing line between HRG and LRG.The ability of the risk signature to predict the overall survival(OS)of GC is demonstrated by the Kaplan-Meier analysis,risk curve,receiver operating characteristic curve,and decision curve analysis curve.The risk signature was shown to be an independent prognostic factor for OS in both univariate and multivariate Cox regression analyses.HRG showed a more efficient local immune response or modulation compared to LRG,as indicated by the predicted signal pathway analysis and examination of immune cell infiltration,function,and checkpoints(P<0.05).CONCLUSION In general,we have created a brand-new prognostic signature using PRLs,which may provide ideas for immunotherapy in patients with GC.

西格列汀对局灶性脑缺血再灌注小鼠血-脑脊液屏障通透性的影响及抗凋亡作用

目的研究西格列汀(SIT)在非糖尿病的小鼠脑缺血再灌注(I/R)时的神经保护作用。方法采用大脑中动脉栓塞(MCAO)模型,脑缺血60 min后实施再灌注。SIT按低剂量(40 mg·kg^(-1))、高剂量(80 mg·kg^(-1))在手术前口服给药3d,术后再次给药。术后24 h检测小鼠神经功能、梗死体积和脑水肿,通过Western blot评估Bcl-2和Akt的蛋白表达,RT-qPCR评估Bax和Bcl-2的转录水平。SIT对血-脑脊液屏障(BCFB)通透性的影响通过伊文思蓝渗出和Claudin-5的蛋白表达来测量。结果本研究结果表明,SIT可减轻CD-1小鼠大脑中动脉栓塞再灌注24h后的肢体功能障碍,减少脑梗死体积,减轻脑水肿。SIT显著增加Bcl-2和磷酸化Akt的蛋白表达水平,下调Bax、上调Bcl-2的基因表达。减少小鼠脑组织伊文思蓝渗出并增加Claudin-5的蛋白表达水平(~均P<0.05)。结论SIT在非糖尿病小鼠的脑I/R急性期,降低神经功能缺损评分、减少脑梗死体积、保护BCFB,具有脑保护作用,机制可能与抗凋亡有关。这些发现为急性缺血性脑血管病的治疗提供新的策略。

Research on PolSAR Image Classification Method Based on Vision Transformer Considering Local Information

In response to the problem of inadequate utilization of local information in PolSAR image classification using Vision Transformer in existing studies, this paper proposes a Vision Transformer method considering local information, LIViT. The method replaces image patch sequence with polarimetric feature sequence in the feature embedding, and uses convolution for mapping to preserve image spatial detail information. On the other hand, the addition of the wavelet transform branch enables the network to pay more attention to the shape and edge information of the feature target and improves the extraction of local edge information. The results in Wuhan, China and Flevoland, Netherlands show that considering local information when using Vision Transformer for PolSAR image classification effectively improves the image classification accuracy and shows better advantages in PolSAR image classification.

西藏尼洋河流域河谷地带土壤可蚀性K值空间分布特征

【目的】研究西藏尼洋河流域河谷地带土壤可蚀性K值的空间分布特征,为降低该区域土壤侵蚀风险提供参考。【方法】以位于藏东南尼洋河流域的冻融侵蚀区(海拔>4200 m)、冻融水力侵蚀交错区(海拔3800~4200 m)和水力侵蚀区(海拔<3800 m)为研究对象,共布设122个样地,测定流域内表层土壤的基本理化性质,在此基础上运用EPIC模型计算土壤可蚀性K值,采用普通克里金插值法获取尼洋河流域河谷地带土壤可蚀性K值的空间分布图,并分析土壤可蚀性K值与海拔和土壤理化性质的相关性。【结果】(1)尼洋河流域冻融侵蚀区、冻融水力侵蚀交错区和水力侵蚀区的土壤理化性质存在明显差异,其中冻融侵蚀区土壤体积质量最小,土壤孔隙度、含水率和有机质、粉粒、黏粒含量均最高。(2)冻融侵蚀区、冻融水力侵蚀交错区和水力侵蚀区的土壤可蚀性K值分别为0.263~0.431,0.218~0.374,0.104~0.409 t·hm^(2)·h/(MJ·mm·hm^(2)),3个研究区土壤可蚀性K值的平均值分别为0.349,0.310,0.292 t·hm^(2)·h/(MJ·mm·hm^(2)),变异系数分别为11.7%,12.7%和21.5%,属于中等变异。尼洋河流域土壤可蚀性K值总体上由西北向东南呈降低趋势。在尼洋河流域,较低可蚀性、中可蚀性、较高可蚀性和高可蚀性土壤均有分布,但是主要土壤侵蚀类型在3个研究区的分布存在一定差异,其中高可蚀性土壤主要分布在冻融侵蚀区,而较低可蚀性和中可蚀性土壤主要分布在水力侵蚀区和冻融水力侵蚀交错区。(3)土壤可蚀性K值与海拔和土壤理化性质的相关性均达极显著水平(P<0.01),其中与砂粒、粉粒、黏粒含量的相关系数均较高,分别为-0.98,0.99和0.62。【结论】探明了西藏尼洋河流域河谷地带土壤可蚀性K值的空间分布特征,土壤机械组成是该流域可蚀性K值的主要影响因素。

生物专业大学生人格特征及对专业认同的分析

目的探讨生物专业的大学生的人格特征及对专业的认同,以期达到促进心理健康的目的。方法采取整群抽样的方法,2021年6月抽取衡水学院在校生中生物专业8个班级,包括大一至大四4个年级共540名进行艾森克人格问卷简式量表中国版及专业认同问卷调查。人格问卷分为精神质(P)、内外向(E)、神经质(N)和掩饰性(L)4个人格维度。专业认同问卷包括23个问题,调查大学生对专业认同的总分及大学生对专业认同的四因子,认知性、情感性、行为性及适切性,并探讨专业认同与人格特征的关系。结果问卷全部收回,有效问卷537份,有效率99.44%。艾森克人格问卷调查显示在精神质(P)、内外向(E)、神经质(N)和掩饰性(L)四个人格维度在大一至大四年级,差异无统计学意义(P>0.05)。在专业认同方面显示大一至大四年级对专业的认同情况明显不同,与大一年级相比,大二、大四学生的认知性及适切性明显提升,高年级学生的学生行为性均有所增加,但大四的情感性较大一有所降低,差异有统计学意义(P<0.05),进一步探讨发现不同人格特征学生在专业认同方面差异明显,外向学生对本专业的认知性、行为性及适切性均高于内向及中间型性格的学生,但性格中间型学生的情感性是最高的,差异有统计学意义(P<0.05)。结论生物专业大学生各年级并无明显的性格差异,但不同的人格对专业认同情况有差异。

绞股蓝总苷对急性期缺血性脑卒中小鼠NF-κB及TNF-α表达的影响

目的探讨绞股蓝总苷对急性期缺血性脑卒中小鼠核因子-κB(NF-κB)及肿瘤坏死因子-α(TNF-α)表达的影响。方法将24只健康雄性C57小鼠随机分为假手术组、缺血性脑卒中组、绞股蓝总苷低剂量组、绞股蓝总苷高剂量组,每组6只。除假手术组外,其余组小鼠采用Longa线栓法阻塞大脑中动脉建立缺血性脑卒中模型。术后2 h,绞股蓝总苷低、高剂量组分别给予绞股蓝总苷100 mg/kg、200 mg/kg腹腔注射,假手术组和缺血性脑卒中组均给予等量生理盐水腹腔注射。术后24 h对各组小鼠进行神经功能缺损评分,使用TTC染色测定各组小鼠脑梗死体积,分别使用Western blot法和qRT-PCR法检测手术组、缺血性脑卒中组、绞股蓝总苷高剂量组小鼠脑组织中NF-κB、TNF-α蛋白及mRNA表达情况。结果绞股蓝总苷低剂量组小鼠的神经功能缺损评分与缺血性脑卒中组比较差异无统计学意义(P>0.05),脑梗死体积占比明显低于缺血性脑卒中组(P<0.05);绞股蓝总苷高剂量组小鼠的神经功能缺损评分和脑梗死体积占比均明显低于缺血性脑卒中组和绞股蓝总苷低剂量组(P均<0.05)。缺血性脑卒中组小鼠脑组织中NF-κB、TNF-α蛋白及mRNA表达量均明显高于假手术组(P均<0.05),绞股蓝总苷高剂量组小鼠脑组织中NF-κB、TNF-α蛋白及mRNA表达量均明显低于缺血性脑卒中组(P均<0.05)。结论在缺血性脑卒中急性期,绞股蓝总苷可通过下调NF-κB、TNF-α表达,减轻炎症反应,减小脑梗死体积,保护脑组织。

青藏高原色季拉山流石滩表层土壤有机碳的空间变化特征及影响因素

[目的]分析青藏高原不同海拔下表层土壤可溶性有机碳(DOC),易氧化有机碳(ROC)、碳库稳定性及碳储量变化特征研究及土壤有机碳(SOC),DOC的影响因素,为后续复杂地形寒区SOC的稳定性研究提供科学依据。[方法]以色季拉山流石滩为研究区,以单因素方差分析法分析了4300~4700 m之间不同海拔土壤物理性质,DOC,ROC以及SOC的含量特征,结合Pearson相关分析与冗余分析探讨了DOC,ROC与各因子之间的相互关系。[结果]①土壤容重、密度与海拔呈负相关,其最大值分别为1.56,1.12 g/cm^(3),土壤含水率和孔隙度与海拔呈正相关,其最大值分别为74.22%,58.70%;②SOC含量随海拔升高呈现先升高后降低趋势,DOC,ROC随海拔升高而呈现出波动变化趋势;③海拔4400 m时DOC/SOC,ROC/SOC达到最大值,可溶性有机碳储量(DOCS)和有机碳储量(SOCS)均值分别为40.779 g/m^(2),8.105 kg/m^(2),流石滩土壤碳库稳定性较好;④DOC与土壤物理性质不相关,但与SOCS有一定相关性;ROC则与物理性质和SOC及其相关因子均有一定的相关性;各因子对色季拉山流石滩土壤DOC和ROC变化的解释贡献率排序大小为:DOCS>土壤孔隙度>ROC/SOC>土壤含水率>SOC>SOCS>DOC/SOC>土壤密度。[结论]不同海拔流石滩表层土壤DOC,ROC与海拔有一定相关性,且DOCS、土壤孔隙度与ROC/SOC均是影响DOC,ROC含量的重要因子,同时各因子间存在密切的关系。

Numerical modeling on strain energy evolution in rock system interaction with energy-absorbing prop and rock bolt

The interaction mechanism between coal and rock masses with supporting materials is significant in roadway control, especially in deep underground mining situations where dynamic hazards frequently happened due to high geo-stress and strong disturbed effects. This paper is to investigate the strain energy evolution in the interaction between coal and rock masses with self-designed energy-absorbing props and rock bolts by numerical modeling with the finite difference method. The interaction between rock and rock bolt/prop is accomplished by the cables element and the interface between the inner and outer props. Roadway excavation and coal extraction conditions in deep mining are numerically employed to investigate deformation, plastic zone ranges, strain energy input, accumulation, dissipation,and release. The effect on strain energy input, accumulation, dissipation, and release with rock deformation, and the plastic zone is addressed. A ratio of strain energy accumulation, dissipation, and release with energy input a, β, γ is to assess the dynamic hazards. The effects on roadway excavation and coal extraction steps of a, β, γ are discussed. The results show that:(1) In deep high geo-stress roadways, the energyabsorbing support system plays a dual role in resisting deformation and reducing the scope of plastic zones in surrounding rock, as well as absorbing energy release in the surrounding rock, especially in the coal extraction state to mitigate disturbed effects.(2) The strain energy input, accumulation is dependent on roadway deformation, the strain energy dissipation is relied on plastic zone area and disturbed effects, and strain energy release density is the difference among the three. The function of energyabsorbing rock bolts and props play a key role to mitigate strain energy release density and amount, especially in coal extraction condition, with a peak density value from 4×10^(4) to 1×10^(4)J/m^(3), and amount value from 3.57×10^(8) to 1.90×10^(6)J.(3) When mining is advanced in small steps, the strain energy accumulation is dominated. While in a large step, the released energy is dominant, thus a more dynamic hazards proneness. The energy-absorbing rock bolt and prop can reduce three times strain energy release amount, thus reducing the dynamic hazards. The results suggest that energy-absorbing props and rock bolts can effectively reduce the strain energy in the coal and rock masses, and prevent rock bursts and other hazards.The numerical model developed in this study can also be used to optimize the design of energyabsorbing props and rock bolts for specific mining conditions.

金属Pd催化NO还原形成NH_(3),N_(2)O和N_(2)的原子机制

工业污染物NO是对环境和人类健康的潜在威胁.因此,将NO选择性地催化还原成无害的N_(2)、NH_(3)或N_(2)O气体是非常有意义的.在许多催化剂中,金属钯已被证明在将NO还原为N_(2)的选择性方面是最有效的.然而,NO在Pd上的还原机制,特别是N-N键的形成途径仍然不清楚,阻碍了新型催化剂的开发.本文基于密度泛函理论的量子力学计算,报道了还原NO形成NH_(3)、N_(2)O和N_(2)的反应路径中的所有基本反应步骤.结果表明,N_(2)O的形成是通过Eley-Rideal反应机制进行的.即在较高的NO^(*)表面覆盖率时,通过将一个吸附的NO^(*)与一个来自溶剂或气相的非吸附的NO结合,形成dimer-(NO)_(2)^(*)中间物,其N-N耦合势垒较低(0.58 eV).发现了dimer-(NO)_(2)^(*)将继续与溶剂中的NO反应,形成N_(2)O,这一点本文发现之前没有报道过.随着NO的消耗和溶剂中N_(2)O^(*)的形成,Langmuir-Hinshelwood(L-H)机制将占主导地位,N_(2)O^(*)将在低化学势垒(0.42 eV)下被还原,从而形成N_(2).相比之下,NH_(3)完全由L-H反应形成,它具有较高的化学势垒(0.87 eV).此外,本文报道了通过在NO^(*)吸附位点掺入另一个金属原子(M)以形成M/Pd,通过考察其对N-N键形成能和N_(2)^(*)结合能的影响,从而实现对产物选择性的调控.

绞股蓝总苷对小鼠缺血性脑卒中的脑保护作用及细胞凋亡影响

目的探讨绞股蓝总苷对小鼠缺血性脑卒中(CIS)的影响。方法健康雄性C57小鼠,随机分为假手术组,溶剂组,用药组,每组6只,采用线栓法建立小鼠大脑中动脉阻塞动物模型,用药组:小鼠大脑中动脉闭塞后2h绞股蓝总苷200mg·kg^(-1)腹腔注射,假手术组:小鼠假手术后2h生理盐水腹腔注射;溶剂组:小鼠大脑中动脉闭塞后2h生理盐水腹腔注射。术后24h,对小鼠进行神经功能评分,脑梗死体积测定,脑组织含水量测定及伊文思蓝染色,检测Bax、Bcl-2在小鼠脑组织中表达。结果应用绞股蓝总苷的小鼠与溶剂组小鼠相比,神经功能评分明显降低(P<0.05);脑梗死体积明显减小(P<0.05);与假手术组小鼠相比,溶剂组小鼠脑组织的含水量明显增高,而应用绞股蓝总苷的小鼠脑组织的含水量在24h明显降低(P<0.05);溶剂组小鼠血-脑脊液屏障(BCFB)完整性严重破坏,用药组小鼠脑组织伊文思蓝渗出明显减少(P<0.05)。与假手术组相比,溶剂组小鼠Bax及Bcl-2的mRNA及蛋白水平明显升高,应用绞股蓝总苷后可下调Bax及上调Bcl-2的表达。结论绞股蓝总苷在CIS急性期降低神经功能缺损评分,减少脑梗死体积,减轻伊文思蓝渗出,具有脑保护作用,机制可能与抗凋亡有关。

Realization of T_(e0)>10 keV long pulse operation over 100 s on EAST

In 2021,EAST realized a steady-state long pulse with a duration over 100 s and a core electron temperature over 10 keV.This is an integrated operation that resolves several key issues,including active control of wall conditioning,long-lasting fully noninductive current and divertor heat/particle flux.The fully noninductive current is driven by pure radio frequency(RF)waves with a lower hybrid current drive power of 2.5 MW and electron cyclotron resonance heating of 1.4 MW.This is an excellent experimental platform on the timescale of hundreds of seconds for studying multiscale instabilities,electron-dominant transport and particle recycling(plasma-wall interactions)under weak collisionality.