探查阶段旅游地居民支持度的影响因素分析与实证研究——以海口市北港村为例

选择处于探查阶段的海口市北港村为案例地,以决策行为理论为分析框架,构建了一个居民视角下由理性层面的旅游发展潜力认知、积极影响感知、消极影响感知和非理性层面的地方感组成的概念模型,使用AMOSS和SPSS软件量化探究上述因素对探查阶段旅游地居民旅游支持度的影响路径。结果表明:1)在旅游发展探查阶段,旅游发展潜力认知、积极影响感知、消极影响感知和地方感对居民支持度产生显著影响,其中旅游发展潜力认知不仅通过直接和中介作用对居民支持度产生影响,还对积极、消极影响感知和地方感产生不同程度作用;2)地方感强的居民对旅游积极影响的感知较易受旅游发展潜力认知调节,而居民对旅游消极影响的感知不易受其他因素调节;3)在居民的主观选择决策中,理性与非理性的因素共同发挥作用。在同构关系下,理性与非理性因素之间各自独立又彼此交融。

儿童肝囊型包虫病诊治进展

肝包虫病是一种全世界广泛分布的由棘球蚴感染引起的人畜共患寄生虫病.儿童处于特殊的年龄阶段,不仅是棘球蚴病的重点防治人群,也是大规模防治中的重点监测对象.儿童肝囊性包虫病症状不典型,易误诊,治疗不规范易导致复发甚至死亡,因此本文从儿童肝囊型包虫病的诊断和治疗方式作一综述.

腹腔镜治疗儿童肝囊型包虫病的研究进展

肝囊型包虫病是一种流行于畜牧业区的人兽共患性寄生虫疾病,目前该疾病仍以手术治疗为主;相对于传统开腹手术,近年来随着微创手术及精准手术理念的发展,腹腔镜手术治疗肝囊型包虫病已在临床广泛应用;目前成人应用腹腔镜技术治疗肝囊型包虫病已得到临床肯定,但儿童肝囊型包虫病由于其腹腔空间小、囊壁薄、易破裂等因素目前临床尚未普及,故本文根据国内外相关文献归纳并着重阐述腹腔镜下治疗儿童肝囊型包虫病的不同手术方式在临床中的应用情况,为儿童肝囊型包虫病的微创手术治疗提供一定的参考.

Cast-rolling force model in solid-liquid cast-rolling bonding(SLCRB) process for fabricating bimetal clad strips

Based on twin-roll casting, a cast-rolling force model was proposed to predict the rolling force in the bimetal solid-liquid cast-rolling bonding(SLCRB) process. The solid-liquid bonding zone was assumed to be below the kiss point(KP). The deformation resistance of the liquid zone was ignored. Then, the calculation model was derived. A 2D thermal-flow coupled simulation was established to provide a basis for the parameters in the model, and then the rolling forces of the Cu/Al clad strip at different rolling speeds were calculated. Meanwhile, through measurement experiments, the accuracy of the model was verified. The influence of the rolling speed, the substrate strip thickness, and the material on the rolling force was obtained. The results indicate that the rolling force decreases with the increase of the rolling speed and increases with the increase of the thickness and thermal conductivity of the substrate strip. The rolling force is closely related to the KP height. Therefore, the formulation of reasonable process parameters to control the KP height is of great significance to the stability of cast-rolling forming.

乡村旅游地“公地悲剧”有效治理的路径与机制研究——以河南省重渡沟村为例

乡村旅游地发展过程中的“公地悲剧”呈现出周期性变化特征,一种固定的治理模式在旅游发展的不同阶段未必能长期有效。为探究有效治理的机制,运用观察、访谈等质性研究方法,选取河南省重渡沟村为案例地,对其旅游发展历程和“公地悲剧”的治理路径进行研究,结果发现:(1)乡村旅游地“公地悲剧”治理存在基于“结构—功能—保障”圈层关系的治理机制。(2)“公地悲剧”能够通过主导性治理主体的灵活转换、治理主体间的长期协作、制度规则的安排与应时调整进行治理。(3)在“公地悲剧”治理过程中,各主体应将重心更多地放在合理的制度安排和应时调整上,而非治理主体的判断和选择上。

Expression of FOXG1 is associated with the malignancy of human glioma

Objective： Recent evidence indicates that the increased expression of FOXG1 is associated with tumor genesis. This study was designed to explore the expression and role which FOXG1 plays in human glioma. Methods： We detected the expression of FOXG1 by immunohistochemistry in glioma tissue samples. Following the down-regulation of FOXG1 in glioma cell lines by a specific short hairpin RNA, the function of FOXG1 in proliferation and apoptosis was assessed. Results： Glioma tissues exhibited notably higher expression of FOXG1 compared with control brain tissues and was positively corre- lated with histological malignancy. The down-regulation of FOXG1 in glioma cells led to a cell apoptosis in vitro. Cenclusion： The overexpression of FOXG1 is a novel glioma malignancy marker, and FOXG1 may be used as a new target in therapeutic strategies for human glioma.

Simulation and preparation of novel medium convex artificial blood vessel for reducing compliance mismatch

Compliance mismatch between artificial blood vessel and host vessel can cause abnormal hemodynamics and is the main mechanical trigger of intimal hyperplasia(IH)after transplantation.To explore the specific effects of the degree of compliance mismatch on hemodynamics,the concept of“compliance mismatch degree”was defined in this paper.Numerical results showed that when the compliance mismatch degree was less than-22.21%or more than 3.16%,the minimum WSS in the anastomotic site was less than the safety threshold of 0.5 Pa,which is easy to induce IH.In addition,the compliance mismatch caused different radial displacements first,which in turn affected the hemodynamics.Inspired by this,a novel medium convex artificial blood vessel was proposed,and the simulation results theoretically validated its desired effect on reducing the compliance mismatch.An increase of 0.22 mm in the diameter of the artificial blood vessel corresponded to a decrease of 0.88%in compliance mismatch degree.The feasibility of preparing real medium convex artificial blood vessel was also investigated.The PLCL medium convex artificial blood vessel with good mechanical properties was prepared by dip-coating and electrospinning composite method.These findings are valuable for the design and preparation of novel artificial blood vessel which can make up for the mismatch of compliance.

Effects of Duhuojisheng Tang and combined therapies on prolapse of lumbar intervertebral disc:a systematic review of randomized control trails

OBJECTIVE： A systematic review of the literature was conducted to evaluate the curative effect and safety of Duhuojisheng Tang on prolapse of the lumbar intervertebral disc. METHODS： The databases of PubMed, China Na- tional Knowledge Infrastructure （CNKI）, Chinese Sci- entific Journals Database （VlP）, Chinese Biomedical Literature Database （CBM） and Chinese Medical Ci- tation Index （CMCl） were searched up to January 30, 2012. Randomized controlled trials were select- ed to compare Duhuojisheng Tang with one ormore of the following treatments： traction, acu- puncture, massage, cupping and Western medical treatment. The quality-evaluating standard and the software RevMan 5.1 in Cochrane coordinative net were used to analyze the data. The effective index- es of the results were clinical curative rate, effective- ness of alleviating clinical symptoms and adverse reaction. RESULTS： Thirty-one randomized controlled trials of low quality, involving 3915 patients were system- atically evaluated. Statistical analyses showed that good curative effect was achieved in both the group using Duhuojisheng Tang alone and with combined therapies. CONCLUSION： Using Duhuojisheng Tang alone or combined with other therapies can effectively im- prove pain, leg-raising height and other clinical symptoms of patients with prolapse of lumbar in- tervertebral disc. Due to low methodological quali- ty of the articles, no exact recommendations can be made.

卵泡液中细胞外囊泡及其携带的microRNA对卵泡发育的作用

细胞外囊泡(Extracellular vesicles,EVs)是指细胞分泌的双层膜转运囊泡。EVs能从细胞中摄取大分子物质,并将其转移至受体细胞。在这些大分子物质中,研究最多的就是microRNA (miRNA)。miRNA是一种参与基因表达调控的非编码RNA,已证实在哺乳动物卵泡液EVs中有不同的非编码RNA存在,EVs携带miRNA可以作为自分泌和旁分泌的替代机制,影响卵泡发育。文中系统介绍了EVs的种类、特征和分离鉴定方法,重点综述了EVs及携带的miRNA对卵泡发育的作用,包括早期卵泡发育、卵母细胞成熟、卵泡优势化以及对颗粒细胞功能的影响。同时对卵泡液中EVs及其携带的miRNA的未来研究进行了展望,为卵泡液中EVs及携带的miRNA功能的研究及应用提供了思路和方向。

MSSSA:a multi-strategy enhanced sparrow search algorithm for global optimization

The sparrow search algorithm(SSA) is a recent meta-heuristic optimization approach with the advantages of simplicity and flexibility. However, SSA still faces challenges of premature convergence and imbalance between exploration and exploitation, especially when tackling multimodal optimization problems. Aiming to deal with the above problems, we propose an enhanced variant of SSA called the multi-strategy enhanced sparrow search algorithm(MSSSA) in this paper. First, a chaotic map is introduced to obtain a high-quality initial population for SSA, and the opposition-based learning strategy is employed to increase the population diversity. Then, an adaptive parameter control strategy is designed to accommodate an adequate balance between exploration and exploitation. Finally, a hybrid disturbance mechanism is embedded in the individual update stage to avoid falling into local optima. To validate the effectiveness of the proposed MSSSA, a large number of experiments are implemented, including 40 complex functions from the IEEE CEC2014 and IEEE CEC2019 test suites and 10 classical functions with different dimensions. Experimental results show that the MSSSA achieves competitive performance compared with several state-of-the-art optimization algorithms. The proposed MSSSA is also successfully applied to solve two engineering optimization problems. The results demonstrate the superiority of the MSSSA in addressing practical problems.

Numerical simulation to study the impact of compliance mismatch between artificial and host blood vessel on hemodynamics

Small-diameter artificial blood vessels are prone to cause intimal hyperplasia(IH)after transplantation,which leads to restenosis and low long-term patency rates.The main biomechanical factor for IH formation is the compliance mismatch between the artificial and host blood vessels which can cause abnormal hemodynamics.Although there have been many studies on vascular compliance mismatches,however,little attention has been paid to the effect of the degree of compliance mismatch between graft and the host vessel on hemodynamics.At present,the research on compliance mismatch between the artificial and host blood vessels is still very limited,especially with regard to the specific impact of the compliance mismatch degree on hemodynamics.Therefore,three end-to-end anastomosis models(the compliance of the artificial blood vessel is lower than,similar to,and higher than that of the host blood vessel,called model 1,model 2,model 3,respectively)were constructed and simulated in this study.Simulation results showed that the radial displacement difference between the artificial and host blood vessels were 0.281 mm,0.183 mm and 0.485 mm in model 1,model 2 and model 3,respectively.A low-velocity recirculation zone near the distal anastomosis was formed in model 1 which resulted in excessively low TAWSS(9.261 E-5Pa)and high OSI(0.497).Similarly,a low-velocity recirculation zone near the proximal anastomosis was formed in model 3 and lead to low TAWSS(6.007 E-4Pa)and high OSI(0.480).However,there was no low-velocity recirculation zone near the anastomosis stoma in model 2.The results are instructive for the design and preparation of artificial blood vessels.