浅谈青羊峡铅锌矿中矿石矿物的组成及组构特征

青羊峡铅锌矿床是位于秦岭造山带西成矿田西南部的和碳酸岩、碎屑岩沉积建造相关的层控型铅锌矿床,矿床成因类型属热水沉积—改造型矿床,矿床的产出及其分布基本受层位控制。矿区矿体表现出同生沉积成岩以及后期改造成矿的特点。本文以青羊峡铅锌矿床为例,剖析矿体的矿石矿物组成以及矿石组构特征,总结了区域变质作用对岩矿石结构、构造的影响。通过对其矿石组构特征的分析与总结,以期为该区矿床地质成因研究以及勘查找矿工作提供一定的参考。

Tailoring spatiotemporal dynamics of plasmonic vortices

Plasmonic vortices confining orbital angular momentums to surface have aroused wide research interest in the last decade.Recent advances of near-field microscopes have enabled the study on the spatiotemporal dynamics of plasmonic vortices,providing a better understanding of optical orbital angular momentums in the evanescent wave regime.However,these works only focused on the objective characterization of plasmonic vortex and have not achieved subjectively tailoring of its spatiotemporal dynamics for specific applications.Herein,it is demonstrated that the plasmonic vortices with the same topological charge can be endowed with distinct spatiotemporal dynamics by simply changing the coupler design.Based on a near-field scanning terahertz microscopy,the surface plasmon fields are directly obtained with ultrahigh spatiotemporal resolution,experimentally exhibiting the generation and evolution divergences during the whole lifetime of plasmonic vortices.The proposed strategy is straightforward and universal,which can be readily applied into visible or infrared frequencies,facilitating the development of plasmonic vortex related researches and applications.

Regulating single-atom Mn sites by precisely axial pyridinic-nitrogen coordination to stabilize the oxygen reduction

Designing single-atom catalysts for oxygen reduction reaction(ORR)are fashionable but challenging to boost the zinc-air battery performance.Significantly enhanced ORR activity by manganese(Mn)singleatom catalysts can be achieved by accurately regulating the coordination number of isolated Mn atoms.Theoretical calculations indicate that the single Mn-N5sites possess lower free energy barrier and higher oxygen adsorption performance than single Mn-N4sites to accelerate the ORR kinetics.Target to it,here we synthesize an atomically dispersed Mn-N5catalyst by precisely axial coordination of pyridinic-N doped into two-dimensional(2D)porous nanocarbon sheets(~3.56 nm thickness),which reveals outstanding catalytic activity and ultrahigh stability for the ORR in zinc-air battery owing to the inhomogeneous charge distribution of Mn-N5sites compared to the conventional single-site Mn-N4catalyst and Pt/C.This work gives a new strategy for in situ regulating the electronic structure of metal single-atoms and further promoting the overall ORR performance in energy systems.

Thermal conductive proppant with self-suspension ability

The in situ mining technology is applied to the exploitation of medium-and low-maturity shale oil,which can use heaters to warm up the oil shale formations and pyrolyze the kerogen.Due to the low thermal conductivity of oil shale,electric heaters need extra equipment to improve heat transfer efficiency.In this study,a thermally conductive proppant is fabricated by coating epoxy-resin and graphite on ceramic proppants for the first time,which could support the fracturing crack and transfer heat.The thermal conduction property of epoxy-resin and graphite coated proppants(EGPs)is 245%higher than that of uncoated proppants,which can transfer more heat to the oil shale formation and accelerate the conversion of kerogen.The adhesive property of EGPs is improved by 47.9%under the load force of 1500 nN,which prolongs the time for the fracture to close.In summary,this novel proppant is expected to assist in-situ mining technology in the production of medium and low-maturity shale oil.

一个具有共存吸引子的四阶混沌系统动力学分析及FPGA实现

为进一步探索共存吸引子中复杂的动力学行为,构建了一个具有4种类型共存吸引子的四阶混沌系统,该系统具有4个不稳定的平衡点.采用相轨迹图、时域波形图、庞加莱映射、Lyapunov指数谱和分岔图等方法对新系统的动力学行为进行分析.实验结果表明:随着参数的变化,系统表现出稳定点、倍周期分岔、共存分岔模式、混沌危机等丰富的动力学行为.当改变系统参数和忆阻参数时,发现系统具有不同类型的共存吸引子,例如:两个周期吸引子共存、两个单涡卷混沌吸引子共存、两个双涡卷混沌吸引子共存、两个点吸引子共存.特别地,该系统还存在共存吸引子的旋转现象.最后设计了一个非线性反馈控制器,可使新系统在短时间内实现混沌同步.采用现场可编程门阵列(field-programmable gate array,FPGA)硬件平台捕捉到的相图与数值仿真结果保持一致,证明了该系统的可实现性.

Modified stomach-partitioning gastrojejunostomy for initially unresectable advanced gastric cancer with outlet obstruction: A case report

BACKGROUND Chemotherapy followed by gastrojejunostomy remains the main treatment for unresectable gastric cancer(GC)in the middle-or lower-third regions with gastric outlet obstruction(GOO).Radical surgery is performed as part of a multimodal treatment strategy for selected patients who respond well to chemotherapy.This study describes a case of successful radical resection with completely laparoscopic subtotal gastrectomy after a modified stomach-partitioning gastrojejunostomy(SPGJ)for obstruction relief,in a patient with GOO.CASE SUMMARY During the initial esophagogastroduodenoscopy,an advanced growth was detected in the lower part of the stomach,which caused an obstruction in the pyloric ring.Following this,a computed tomography(CT)scan revealed the presence of lymph node metastases and tumor invasion in the duodenum,but no evidence of distant metastasis was found.Consequently,we performed a modified SPGJ,a complete laparoscopic SPGJ combined with No.4sb lymph node dissection,for obstruction relief.Seven courses of adjuvant capecitabine plus oxaliplatin combined with Toripalimab(programmed death ligand-1 inhibitor)were administered thereafter.A preoperative CT showed partial response;therefore,completely laparoscopic radical subtotal gastrectomy with D2 lymphadenectomy was performed after conversion therapy,and pathological complete remission was achieved.CONCLUSION Laparoscopic SPGJ combined with No.4sb lymph node dissection was an effective surgical technique for initially unresectable GC with GOO.

Bi-doped carbon quantum dots functionalized liposomes with fluorescence visualization imaging for tumor diagnosis and treatment

Liposomes are one of the significant classes of antitumor nanomaterials and the most successful nanomedicine drugs in clinical translation. However, it is difficult to accurately reveal liposome delivery modes and drug release rates at different p H values to assess the biodistribution and drug delivery pathways in vivo. Here, we established a strategy to integrate Bi-doped carbon quantum dots(CQDs)with liposomes to produce fluorescence visualization and therapeutic effects, namely lipo/Bi-doped CQDs.Lipo/Bi-doped CQDs show good water solubility and physicochemical properties, which can be used for in vitro labeling of colon cancer(CT26) cells and in vivo imaging localization tracking tumors for monitoring. Simultaneously, thanks to the excellent p H sensitivity and ion doping characteristic of Bi-doped CQDs, lipo/Bi-doped CQDs can be used to reveal the drug release rate of liposomes at different p H values and exhibit potential effects in vivo antitumor therapy.

D-组氨酸抑制变异链球菌生物膜作用的研究

目的:研究D-组氨酸对变异链球菌生物膜的抑制作用。方法:通过生长曲线实验评估D-组氨酸对变异链球菌细菌活性的影响。通过结晶紫染色实验评估变异链球菌形成生物膜的量;采用胞外多糖实验检测D-组氨酸对变异链球菌生物膜胞外多糖含量的影响;经扫描电镜观察经D-组氨酸处理后变异链球菌生物膜的结构。结果:经生长曲线实验评估发现D-组氨酸在浓度≥20%时抑制变异链球菌的生物活性且呈浓度依赖性。通过结晶紫染色实验和生物膜胞外多糖实验评估发现,D-组氨酸浓度≥40%时抑制变异链球菌生物膜的形成并影响生物膜胞外多糖的含量。经扫描电镜观察,40%的D-组氨酸即可影响变异链球菌生物膜的形成,同时细菌的粘附量有所下降。结论:D-组氨酸具有良好的抑制变异链球生物膜的作用,并影响变异链球菌的细菌活性。

西罗莫司治疗儿童蓝色橡皮疱痣综合征2例并文献复习

为探讨口服西罗莫司治疗儿童胃肠道蓝色橡皮疱痣综合征(BRBNS)的疗效,该文回顾性分析了2例BRBNS患儿的临床资料和使用西罗莫司治疗的随访结果。2例伴有消化道出血和贫血的BRBNS患儿,给予口服西罗莫司(初始剂量为1 mg/d)作为治疗方案的一部分,维持血药浓度在2.5~12.0 ng/mL之间,患儿消化道出血消失,贫血和凝血功能改善,治疗期间可停止输血且无明显药物不良反应。在PubMed、万方数据库、中国知网搜索西罗莫司治疗BRBNS的相关文献进行总结。检索文献结果显示,年龄为0~18岁的BRBNS儿童病例共检索出26例,加上该研究中报道的2例,共28例使用西罗莫司治疗均取得满意疗效。西罗莫司在儿童BRBNS患者的治疗中可能是有效和安全的,有待进一步的前瞻性研究来评估这种药物的长期疗效。

凋亡信号调节激酶-1抑制剂在非酒精性脂肪性肝炎中的研究进展

非酒精性脂肪性肝炎(non-alcoholic steatohepatitis,NASH)是最常见的慢性肝病,当前未见有效疗法。凋亡信号调节激酶-1(apoptosis signal regulating kinases 1,ASK-1)是细胞丝裂原活化蛋白激酶激酶激酶(mitogen-activated protein kinase kinase kinases,MAPKKKs)家族成员之一,当机体受到细胞内活性氧簇应激、内质网应激、钙内流和细胞外炎症等信号刺激时,ASK-1激活c-Jun氨基末端激酶(c-Jun amino terminal kinasec,JNK)和p38 MAPK通路,从而促进细胞增殖、分化、凋亡以及炎症因子的产生,诱发NASH、纤维化等疾病,因此可通过抑制ASK-1的活性来治疗NASH。本文对当前NASH的治疗手段、ASK-1结构和作用机制以及近年ASK-1抑制剂治疗NASH的研究进展进行综述,旨在为该类抑制剂的设计与开发提供参考。

美学区多颗牙连续缺失种植修复1例

种植修复越来越多的应用于牙列缺损和牙列缺失,但美学区多颗牙连续缺失的种植修复依然是难点,通过本病例探讨恢复上颌前牙连续缺失的美学与功能的方法。

蛋白精氨酸甲基转移酶5抑制剂研究进展

蛋白精氨酸甲基转移酶(PRMTs)对组蛋白和非组蛋白的翻译后修饰在生物学过程中起到了非常重要的作用。PRMT5是精氨酸残基对称双甲基化的主要酶,已被视为肿瘤治疗的潜在靶点。在过去10年中,发现和开发PRMT5抑制剂已经成为科研人员关注的热点。本文介绍了PRMT5的结构、生化功能以及其与肿瘤的相关性,同时就目前在研的PRMT5抑制剂与其结合方式以及生物活性进行综述,并讨论了PRMT5抑制剂在肿瘤治疗中的应用潜力。

Additional laparoscopic gastrectomy after noncurative endoscopic submucosal dissection for early gastric cancer: A single-center experience

BACKGROUND The necessity of additional gastrectomy for early gastric cancer (EGC) patients who do not meet curative criteria after endoscopic submucosal dissection (ESD) is controversial. AIM To examine the clinicopathologic characteristics of patients who underwent additional laparoscopic gastrectomy after ESD and to determine the appropriate strategy for treating those after noncurative ESD. METHODS We retrospectively studied 45 patients with EGC who underwent additional laparoscopic gastrectomy after noncurative ESD from January 2013 to January 2019 at the Cancer Hospital of the Chinese Academy of Medical Sciences. We analyzed the patients’ clinicopathological data and identified the predictors of residual cancer (RC) and lymph node metastasis (LNM). RESULTS Surgical specimens showed RC in ten (22.2%) patients and LNM in five (11.1%).Multivariate analysis revealed that positive horizontal margin [odds ratio (OR)=13.393, 95% confidence interval (CI): 1.435-125, P=0.023] and neural invasion (OR=14.714, 95%CI: 1.087-199, P=0.043) were independent risk factors for RC. Undifferentiated type was an independent risk factor for LNM (OR=12.000, 95%CI: 1.197-120, P=0.035). Tumors in all patients with LNM showed submucosal invasion more than 500 μm. Postoperative complications after additional laparoscopic gastrectomy occurred in five (11.1%) patients, and no deaths occurred among patients with complications. CONCLUSION Gastrectomy is necessary not only for patients who have a positive margin after ESD, but also for cases with neural invasion, undifferentiated type, and submucosal invasion more than 500 μm. Laparoscopic gastrectomy is a safe, minimally invasive, and feasible procedure for additional surgery after noncurative ESD. However, further studies are needed to apply these results to clinical practice.

Malignant extra-gastrointestinal stromal tumor of the pancreas:Report of two cases and review of the literature

Gastrointestinal stromal tumors(GISTs)are mesenchymal tumors that arise from the gastrointestinal tract.In rare cases,these tumors are found in intra-abdominal sites unrelated to the gastrointestinal tract,such as the mesentery,omentum and retroperitoneum.However,pancreatic extra-gastrointestinal stromal tumors are extremely rare,with only 14 previous cases reported.A 61-year-old man with no clinical symptoms had a routine check-up,during which an abdominal mass located in the pancreas tail was detected.Abdominal surgery was performed with resection of the pancreas tail and the spleen,and he was diagnosed with lowrisk GISTs.Another 60-year-old man with no clinical symptoms underwent Computed tomography which revealed a well-demarcated tumor,6 cm in diameter,in the head of the pancreas.He was diagnosed with pancreatic GISTs.Here,we describe two rare cases of pancreatic GISTs and review the cases previously reported in the literature.

一个具有超级多稳定性的忆阻混沌系统的分析与FPGA实现

为了进一步提高混沌系统的复杂性,用磁控忆阻器代替基于Sprott-B的四维混沌系统中的耦合参数,构建了一个五维忆阻混沌系统.通过分岔图、李雅普诺夫指数谱、相轨图、庞加莱映射等常规手段分析了系统的动力学行为.分析表明新系统具有丰富的动力学行为:不仅存在依赖于系统参数变化的周期极限环和混沌吸引子,还存在依赖于忆阻初始条件变化的无限多共存吸引子的超级多稳定现象.最后,基于现场可编程门阵列(FPGA)技术实现了忆阻混沌系统的数字电路,在示波器上捕捉到的相图与数值仿真一致,验证了忆阻系统的正确性与可实现性.

Effect of hot-dip galvanizing processes on the microstructure and mechanical properties of 600-MPa hot-dip galvanized dual-phase steel

A C–Mn dual-phase steel was soaked at 800°C for 90 s and then either rapidly cooled to 450°C and held for 30 s(process A) or rapidly cooled to 350°C and then reheated to 450°C(process B) to simulate the hot-dip galvanizing process. The influence of the hot-dip galvanizing process on the microstructure and mechanical properties of 600-MPa hot-dip galvanized dual-phase steel(DP600) was investigated using optical microscopy, scanning electron microscopy(SEM), transmission electron microscopy(TEM), and tensile tests. The results showed that, in the case of process A, the microstructure of DP600 was composed of ferrite, martensite, and a small amount of bainite. The granular bainite was formed in the hot-dip galvanizing stage, and martensite islands were formed in the final cooling stage after hot-dip galvanizing. By contrast, in the case of process B, the microstructure of the DP600 was composed of ferrite, martensite, bainite, and cementite. In addition, compared with the yield strength(YS) of the DP600 annealed by process A, that for the DP600 annealed by process B increased by approximately 50 MPa because of the tempering of the martensite formed during rapid cooling. The work-hardening coefficient(n value) of the DP600 steel annealed by process B clearly decreased because the increase of the YS affected the computation result for the n value. However, the ultimate tensile strength(UTS) and elongation(A80) of the DP600 annealed by process B exhibited less variation compared with those of the DP600 annealed by process A. Therefore, DP600 with excellent comprehensive mechanical properties(YS = 362 MPa, UTS = 638 MPa, A_(80) = 24.3%, n = 0.17) was obtained via process A.

Surgical resection of gastric stump cancer following proximal gastrectomy for adenocarcinoma of the esophagogastric junction

BACKGROUND Proximal gastrectomy(PG) is performed widely as a function-preserving operation for early gastric cancer located in the upper third of the stomach and is an important function-preserving approach for esophagogastric junction(EGJ)adenocarcinoma. The incidence of gastric stump cancer(GSC) after PG is increasing. However, little is known about the GSC following PG because very few studies have been conducted on the disease.AIM To clarify clinicopathologic features, perioperative complications, and long-term survival rates after the resection of GSC following PG.METHODS Data for patients with GSC following PG for adenocarcinoma of the EGJ diagnosed between January 1998 and December 2016 were retrospectively reviewed. Multivariate analysis was performed to identify factors associated with overall survival(OS). GSC was defined in accordance with the Japanese Gastric Cancer Association.RESULTS A total of 35 patients were identified. The median interval between the initial PGand resection of GSC was 4.9(range 0.7-12) years. In 21 of the 35 patients, the tumor was located in a nonanastomotic site of the gastric stump. Total gastrectomy was performed in 27 patients; the other 8 underwent partial gastrectomy. Postoperative complications occurred in 6 patients(17.1%). The tumor stage according to the depth of tumor invasion was T1 in 6 patients, T2 in3 patients, T3 in 9 patients, and T4 in 17 patients. Lymph node metastasis was observed in 18 patients. Calculated 1-, 3-, and 5-year OS rates were 86.5%, 62.3%,and 54.2%, respectively. Multivariate analysis showed advanced T stage to be associated with OS.CONCLUSION This study reveals the characteristics of GSC following PG for adenocarcinoma of the EGJ and suggests that a surgical approach can lead to a satisfactory outcome.

Non-concomitant cortical structural and functional alterations in sensorimotor areas following incomplete spinal cord injury

Brain plasticity, including anatomical changes and functional reorganization, is the physiological basis of functional recovery after spinal cord injury（SCI）. The correlation between brain anatomical changes and functional reorganization after SCI is unclear. This study aimed to explore whether alterations of cortical structure and network function are concomitant in sensorimotor areas after incomplete SCI. Eighteen patients with incomplete SCI（mean age 40.94 ± 14.10 years old; male：female, 7：11） and 18 healthy subjects（37.33 ± 11.79 years old; male：female, 7：11） were studied by resting state functional magnetic resonance imaging. Gray matter volume（GMV） and functional connectivity were used to evaluate cortical structure and network function, respectively. There was no significant alteration of GMV in sensorimotor areas in patients with incomplete SCI compared with healthy subjects. Intra-hemispheric functional connectivity between left primary somatosensory cortex（BA1） and left primary motor cortex（BA4）, and left BA1 and left somatosensory association cortex（BA5） was decreased, as well as inter-hemispheric functional connectivity between left BA1 and right BA4, left BA1 and right BA5, and left BA4 and right BA5 in patients with SCI. Functional connectivity between both BA4 areas was also decreased. The decreased functional connectivity between the left BA1 and the right BA4 positively correlated with American Spinal Injury Association sensory score in SCI patients. The results indicate that alterations of cortical anatomical structure and network functional connectivity in sensorimotor areas were non-concomitant in patients with incomplete SCI, indicating the network functional changes in sensorimotor areas may not be dependent on anatomic structure. The strength of functional connectivity within sensorimotor areas could serve as a potential imaging biomarker for assessment and prediction of sensory function in patients with incomplete SCI. This trial was registered with the Chinese Clinical Trial Registry（registration number： Chi CTR-ROC-17013566）.

Decentralized Adaptive Strategies for Synchronization of Fractional-order Complex Networks

This paper focuses on synchronization of fractionalorder complex dynamical networks with decentralized adaptive coupling.Based on local information among neighboring nodes,two fractional-order decentralized adaptive strategies are designed to tune all or only a small fraction of the coupling gains respectively.By constructing quadratic Lyapunov functions and utilizing fractional inequality techniques,Mittag-Leffler function,and Laplace transform,two sufficient conditions are derived for reaching network synchronization by using the proposed adaptive laws.Finally,two numerical examples are given to verify the theoretical results.

Clinical observations on the treatment of infantile hemangiomas with topical imiquimod 5% cream

Objective： To observe the efficacy and safety of topical imiquimod 5% cream in the treatment of uncomplicated infantile hemangiomas （IHs）. Methods： A total of 68 IHs were treated with topical imiquimod 5% cream. Among them, 36 were superficial, 22 were mixed, and 10 were deep. The size of IHs ranged from 1.0 cm × 1.5 cm to an area of a whole forearm. All the hemangiomas were in a proliferative stage. Imiquimod was applied 3 times weekly in 44 patients and 5 times weekly in 24 patients for up to 36 weeks. Results： All superficial IHs improved, and 18 achieved complete clinical resolution, 10 had excellent improvement, 5 showed moderate improvements, and 3 patients displayed minimal improvement. Two mixed IHs showed excellent improvement, 3 showed moderate improvement and 5 manifested minimal improvements. The remaining 12 mixed IHs and all deep IHs did not respond to the therapy. The total incidence of local adverse events was 58.82%（40/68）, which included erythema or edema, local itching, incrustation or peeling, erosion or ulceration, although most of these were mild to moderate reactions and did not affect the treatment. Scarring occurred in 2 mixed IHs. No systemic side effects developed. Conclusion： Imiquimod 5% cream may be a safe and effective alternative for the treatment of superficial IHs and some mixed IHs in which the superficial component predominates. An appropriate treatment duration for proliferative IHs treated with this therapy may be 24 weeks. Some local adverse events, such as crusting and erosion with possible scarfing potential may occur and should be addressed by prompt, but temporary, discontinuation of the imiquimod. Topical imiquimod 5% cream can be prudently used in the treatment of IHs larger than 5.0 cm × 5.0 cm in newborns and infants less than 6 months of age. To our knowledge, this is the largest IH group treated with imiquimod that has been reported in the literature to date.