Dissolvable temporary barrier:a novel paradigm for flexible hydrogel patterning in organ-on-a-chip models

A combination of hydrogels and microfluidics allows the construction of biomimetic three-dimensional(3D)tissue models in vitro,which are also known as organ-on-a-chipmodels.The hydrogel patterningwith awell-controlled spatial distribution is typically achieved by embedding sophisticated microstructures to act as a boundary.However,these physical barriers inevitably expose cells/tissues to a less physiologically relevant microenvironment than in vivo conditions.Herein,we present a novel dissolvable temporary barrier(DTB)strategy that allows robust and flexible hydrogel patterning with great freedom of design and desirable flow stimuli for cellular hydrogels.The key aspect of this approach is the patterning of a water-soluble rigid barrier as a guiding path for the hydrogel using stencil printing technology,followed by a barrier-free medium perfusion after the dissolution of the DTB.Single and multiple tissue compartments with different geometries can be established using either straight or curved DTB structures.The effectiveness of this strategy is further validated by generating a 3D vascular network through vasculogenesis and angiogenesis using a vascularized microtumor model.As a new proof-of-concept in vasculature-on-a-chip,DTB enables seamless contact between the hydrogel and the culture medium in closed microdevices,which is an improved protocol for the fabrication ofmultiorgan chips.Therefore,we expect it to serve as a promising paradigm for organ-on-a-chip devices for the development of tumor vascularization and drug evaluation in the future preclinical studies.

头皮转移作为肺鳞癌的首发表现:1例极其罕见的病例报告及文献回顾

原发性肺鳞癌远处转移中皮肤转移是一件罕有发生的事,而头皮转移作为患者首发的临床表现更加少见。头部皮肤转移灶很容易误诊为其他头部疾病,但它的出现提示着肺癌恶化与预后不良。这篇病例报告记录了1例以头部皮肤毛囊炎为首发表现就诊于皮肤科,通过影像学诊断为肺恶性肿瘤后转科至胸外科,头部病灶切除病理提示为肺癌的远处转移灶的女性患者,并对报道过类似病例的文章进行回顾总结。本文旨在增进对肺癌皮肤转移的了解和认识,提高对该类疾病的重视,加强早期识别、精准诊断,防止临床上对该疾病漏诊与误诊,最终达成推进后续的治疗、改善患者预后的目的。

利用磁场加速析氧反应

无需额外的能源消耗,利用永磁体有望克服电解水的瓶颈问题.尽管近年来研究者在该方向付出了很多努力,但磁场效应的潜在机制仍然不明确.本文通过浸涂超亲水性γ-Fe_(2)O_(3)层,使其沉积在不同的电极基底上,并改变它们的表面润湿性和磁性,从而成功地揭示了磁场效应的作用机制.结果表明,在高电流密度下,磁场主要由额外施加在氧气气泡上的洛伦兹力和开尔文力产生,前者决定外加磁场的几何构型,后者则与电极的磁性密切相关.同时,本文还提出了通过优化磁场效应从而提高水电解整体效率的策略.

Learning-Based Dynamic Connectivity Maintenance for UAV-Assisted D2D Multicast Communication

Unmanned aerial vehicles(UAVs) enable flexible networking functions in emergency scenarios.However,due to the movement characteristic of ground users(GUs),it is challenging to capture the interactions among GUs.Thus,we propose a learningbased dynamic connectivity maintenance architecture to reduce the delay for the UAV-assisted device-todevice(D2D) multicast communication.In this paper,each UAV transmits information to a selected GU,and then other GUs receive the information in a multi-hop manner.To minimize the total delay while ensuring that all GUs receive the information,we decouple it into three subproblems according to the time division on the topology:For the cluster-head selection,we adopt the Whale Optimization Algorithm(WOA) to imitate the hunting behavior of whales by abstracting the UAVs and cluster-heads into whales and preys,respectively;For the D2D multi-hop link establishment,we make the best of social relationships between GUs,and propose a node mapping algorithm based on the balanced spanning tree(BST) with reconfiguration to minimize the number of hops;For the dynamic connectivity maintenance,Restricted Q-learning(RQL) is utilized to learn the optimal multicast timeslot.Finally,the simulation results show that our proposed algorithms perfor better than other benchmark algorithms in the dynamic scenario.

A multiphysical-geochemical coupling model for caprock sealing efficiency in CO_(2) geosequestration

Precipitation or dissolution due to geochemical reactions has been observed in the caprocks for CO_(2) geosequestration.Geochemical reactions modify the caprock sealing efficiency with self-limiting or self-enhancement.However,the effect of this modification on the caprock sealing efficiency has not been fully investigated through multiphysical-geochemical coupling analysis.In this study,a multiphysical-geochemical coupling model was proposed to analyze caprock sealing efficiency.This coupling model considered the full couplings of caprock deformation,two-phase flow,CO_(2) concentration diffusion,geochemical reaction,and CO_(2) sorption.The two-phase flow only occurs in the fracture network and the CO_(2) may partially dissolve into water and diffuse through the concentration difference.The dissolved CO_(2) has geochemical reactions with some critical minerals,thus altering flow channels.The CO_(2) in the fracture network diffuses into matrix,causing the matrix swelling.This fully coupling model was validated with a penetration experiment on a cement cube and compared with two other models for CO_(2) storage plumes.Finally,the effects of geochemical reactions on penetration depth and pore pressure were studied through parametric study.The numerical simulations reveal that the coupling of geochemical reactions and matrix diffusion significantly affect the caprock sealing efficiency.Geochemical reactions occur at a short time after the arrival of CO_(2) concentration and modify the fracture porosity.The CO_(2) diffusion into the matrix requires a much longer time and mainly induces matrix swelling.These effects may produce selfenhancement or self-limiting depending on the flow rate in the fracture network,thus significantly modifying caprock sealing efficiency.

典型肺纤毛黏液结节性乳头状肿瘤1例临床病理分析

背景与目的肺纤毛黏液结节性乳头状肿瘤(ciliated muconodular papillary tumor of the lung,CMPT)的发病极其少见,在临床上与其他肺部病变亦难以区别,易造成误诊、漏诊;通过收集CMPT的资料,分析其临床病理特征,可以为广大医务工作者提供诊治思路,减少医疗差错。方法回顾性分析1例典型的CMPT患者的临床资料、病理特征、免疫表型并结合相关文献进行探讨。结果患者胸部计算机断层扫描(computed tomography,CT)提示右下肺近胸膜处可见混合密度结节影,直径约9 mm,肿瘤行肺楔形切除术,镜下见结节由增生的纤毛细胞、黏液细胞及基底样细胞混合组成,以乳头状、腺样结构为主,纤毛细胞衬覆于乳头状结构表面,基底样细胞位于外层,黏液细胞则位于两者之间,各种细胞异型不明显。免疫组化:上皮细胞CEA(+)、CK7(+)、CA125(+)、TTF-1(弱+)、CK20(-)、Ki67(1%+)、CK5/6(+);基底细胞P63(+)。结论CMPT是一种新近发现的罕见的肺部肿瘤,关于其良恶性目前尚无定论,但多数学者倾向于良性,其在影像学上可表现出诸多恶性肿瘤征象而常被误认为是肺腺癌,通过其典型的病理组织学特点及免疫组化表型可与其他肺部疾病进行鉴别,基因突变是否是其驱动因素目前尚不得知,该肿瘤行手术切除预后较好。

食管-胃结合部腺癌手术治疗的共识与争议

食管-胃结合部腺癌(adenocarcinoma of esophagogastric junction,AEG)在全球的发病率不断升高,因其特殊的解剖位置、独特的生物学行为被越来越多的临床工作者所重视。目前国内外虽然对AEG的发病、分型等已形成了一定共识,但在更多方面,尤其是外科治疗手段,诸如手术路径、胃的切除范围、淋巴结的清扫范围、消化道重建等方面仍存在较多争议。这些争议不仅限制了对AEG治疗的探索与发展,同时使得对AEG的规范化诊疗变得更加困难。本文结合近些年的相关文献,就目前AEG治疗的国内外相关共识与争议进行综述,以期为临床诊治提供更加合理、有效的方法。

MiR-182 is up-regulated and targeting Cebpa in hepatocellular carcinoma

MicroRNAs(miRNAs) are endogenous small non-coding RNAs that repress their targets at post transcriptional level.Existing studies have shown that miRNAs are important regulatory genes in hepatocellular carcinoma(HCC),as either tumor suppressors or oncogenes.MiR-122 is normally downregulated in HCC and regarded as a tumor suppressor.Recently miR-122 has been reported to be regulated by CEBPA,which is then involved in a novel pathway to influence proliferation of tumor cells.However it is unknown whether CEBPA is regulated by miRNAs in HCC.In this study,we find that miR-182 is upregulated in HCC model rat,and represses CEBPA in both rat and human.This further improves the current CEBPA/miR-122 pathway that controls the proliferation of tumor cells.These results suggest that miR-182 is a potential oncogene in HCC and could be used as a diagnostic marker and drug target of HCC.

Bronchial artery embolization for hemoptysis:A systematic review and meta-analysis

Objective:To assess the safety and efficacy of bronchial artery embolization(BAE)for hemoptysis.Methods and materials:Databases with articles published in English,including Pubmed,Embase,Web of science and Chochrane library,were comprehensively searched to get accurate,up-to-date and sufficient literature about BAE for hemoptysis until March 2020.The technical success rates,immediate control rates,recurrence rates,mortality rates,and total complication rates(minor and major complication rates)extracted from the articles were pooled to estimate and assess the efficacy and safety of BAE using random-effect and fixed-effect models.Results:21 articles published between 2008 and 2019,which include a total of 2511 patients,were studied to evaluate the safety and efficacy of BAE.The technical success and immediate control rates are 99.9%(95%CI:99%-100%)and 99.5%(95%CI:97.8%-99.2%),respectively.This study showed hemoptysis recurrence in 23.7%(95%CI:18.5%-28.9%)with a mortality rate of 2%(95%CI:0-3%).Additionally,the assessment of complications revealed a total complication rate of 13.4%(95%CI:7.6-19.2%),in which 0.2%(95%CI:0.2-0.4%)were major complications and 10%(95%CI:4.7-9.6%)were minor complications.Conclusion:BAE is an effective,safe,and feasible procedure with a low complication rate for hemoptysis patients.However,recurrence of hemoptysis is still at high risk after BAE due to different underlying diseases.

A thermoresponsive composite separator loaded with paraffin@SiO_(2) microparticles for safe and stable lithium batteries

Lithium-ion batteries (LIBs)-related accidents have been reported for years and safety issues are stumbling blocks for the practical applications of lithium metal batteries (LMBs) with higher energy density. More effective strategies to shut down the battery at the early stage of thermal runaway with less side effects on the electrochemical performance are greatly desired. In this work, the core–shell structural paraffin@SiO_(2) microparticles were synthesized by in situ emulsion interfacial hydrolysis and polycondensation and the paraffin@SiO_(2)-loaded separator (PSS) was prepared by a facile filtration method. The introduction of hydrophilic silica shells in paraffin@SiO_(2) enhanced the wettability of carbonate electrolyte with the composite separator and improved the processability of soft paraffin. As a result, when used in LMBs at room temperature, the cell with PSS inside had a more uniform deposition of lithium, a much lower overpotential and a more stable electrochemical performance than the cell with the blank separator or the conventional pure paraffin-loaded separator inside. More significantly, when a heating stimulation (i.e. 115 ℃) was subjected to the cell with PSS inside, the paraffin in the core of paraffin@SiO_(2) could be released, blocking the gaps between particles and the pores in the separator and efficiently stopping the transportation of Li+ between two electrodes, resulting in the thermally-induced shutdown of the cell below the melting temperature of PE (~135 ℃) in the Celgard2325 separator. The core–shell structure of paraffin@SiO_(2) enables the maintaining of each component’s benefits while avoiding each one’s drawbacks by elaborating microstructural design. Therefore, the conventional dilemma between the electrochemcial performance and safety of LMBs could be solved in the future.

Highly Efficient Photoelectrocatalytic Reduction of CO2 to Methanol by a p–n Heterojunction CeO2/CuO/Cu Catalyst

Photoelectrocatalytic reduction of CO2 to fuels has great potential for reducing anthropogenic CO2 emissions and also lessening our dependence on fossil fuel energy.Herein,we report the successful development of a novel photoelectrocatalytic catalyst for the selective reduction of CO2 to methanol,comprising a copper catalyst modified with flower-like cerium oxide nanoparticles(CeO2 NPs)(a n-type semiconductor)and copper oxide nanoparticles(CuO NPs)(a p-type semiconductor).At an applied potential of−1.0 V(vs SCE)under visible light irradiation,the CeO2 NPs/CuO NPs/Cu catalyst yielded methanol at a rate of 3.44μmol cm^−2 h^−1,which was approximately five times higher than that of a CuO NPs/Cu catalyst(0.67μmol cm^−2 h^−1).The carrier concentration increased by^108 times when the flower-like CeO2 NPs were deposited on the CuO NPs/Cu catalyst,due to synergistic transfer of photoexcited electrons from the conduction band of CuO to that of CeO2,which enhanced both photocatalytic and photoelectrocatalytic CO2 reduction on the CeO2 NPs.The facile migration of photoexcited electrons and holes across the p–n heterojunction that formed between the CeO2 and CuO components was thus critical to excellent light-induced CO2 reduction properties of the CeO2 NPs/CuO NPs/Cu catalyst.Results encourage the wider application of composite semiconductor electrodes in carbon dioxide reduction.

Percutaneous microwave ablation combined with simultaneous transarterial chemoembolization for hepatocellular carcinoma with macrovascular invasion or extrahepatic metastases

Objective:To evaluate the safety and efficacy of percutaneous microwave ablation(MWA)combined with simultaneous transarterial chemoembolization(TACE)in patients with hepatocellular carcinoma(HCC)patients with microvascular invasion(MVI)or extrahepatic metastases(EHM).Methods:Between August 2012 and April 2017,101 patients with MVI/EHM of HCC underwent percutaneous MWA combined with simultaneous TACE at our center.The clinical data were collected and analyzed for survival and prognostic factors.Results:The mean follow-up time was 23.6±14.7 months.One patient had grade 3 complications,and the median overall survival was 12.0 months(95%confidence interval 9.7-14.3).Multivariate analysis showed that ChildPugh class,serum alpha-fetoprotein level,and Eastern Cooperative Oncology Group performance status were independent factors of survival.Conclusion:Our results suggest that percutaneous MWA combined with simultaneous TACE is a safe and effective treatment for HCC with MVI/EHM.

卵巢成熟性畸胎瘤采用不同手术方式的疗效分析

目的探讨卵巢成熟性畸胎瘤采用不同手术方式的疗效。方法回顾性分析我院妇产科2013年6月~2020年6月7年间因卵巢畸胎瘤住院行手术治疗的患者53例。根据手术方式不同,分为开腹组(30例),腹腔镜组(23例),对二者在手术时间、术中出血量、住院时间及术后排气时间及并发症进行统计学对比。结果53例患者均成功完成手术,术后恢复良好。与开腹组相比,腹腔镜组的术中出血量、术后排气时间明显少于开腹组,差异有统计学意义(P<0.05),而手术时间及住院时间差异无统计学意义(P>0.05);并发症发生率:腹腔镜组13.04%(3/23),开腹组66.67%(20/30),两组差异具有统计学意义(P<0.05)。结论较开腹手术而言,腹腔镜手术能减少出血量及术后并发症。

Constructing retroviral vector carrying green fluorescent protein(GFP)and investigating the expression of GFP in primary rat myoblast

Objective:To construct green fluorescent protein(GFP)retroviral vector(pLgXSN),and to investigate the expression of GFP in primary rat myoblast.Methods:GFP cDNA was subcloned into the plasmid pLgXSN,and the recombinant vector was transfected into packaging cell PT67.G418 was used to select positive colony.Myoblasts were infected by a high-titer viral supernatant.The recombinant retroviral plasmid vector was identified by restriction endonuclease analysis and DNA sequence analysis.Confocal microscopy and flow cytometry were used to detect the expression of GFP.Results:The GFP cDNA sequence was identical to that of GenBank.Recombinant retroviral plasmid vector pLgGFPSN was constructed successfully.The titer of the packaged recombinant retrovirus was 1 × 106 cfu/ml.Bright green fluorescence of the transfected cells was observed under confocal microscope 48 h after transfection.The transfection rate was 33%.The effective expression of GFP in myoblast infected by recombinant retrovirus lasted for 6 weeks.Conclusion:GFP gene could be effectively and stably expressed in myoblast,which suggests that GFP could act as a marker for studies on myoblast.

Improvement in Nutritional Status of Protein-Malnutrition Elderly after Intervention Using a Casein-Based Balanced Liquid Nutrition Formula as Nutritional Support

A nutritional intervention for 8 weeks was conducted in the elderly (>65 y) living in nursing homes in Shanghai, who showed body weight within the normal range but albumin levels of <35 g/L. The intervened took 400 kcal/day of a balanced liquid nutrition formula containing casein as a major protein source (90% of total protein) in addition to their daily diets, while the non-intervened took only daily diets. Daily diet intakes during the trial were 1738 ± 240 kcal/day in the intervened and 1612 ± 187 kcal/day in the non-intervened. The energy intake in the intervened wascompensated for by reducing their daily diets, which resulted in a similar level to that in the non-intervened. This intervention resulted in intakes of protein and carbohydrate being significantly increased: P16.4%, F27.3%, C56.3% in the intervened;P13.0%, F36.3%, C50.7% in the non-intervened. Albumin level of the intervened increased from 32.7 ± 3.1 g/L to 37.3 ± 1.9 g/L, while it did not significantly change in the non-intervened: 30.0 ± 4.2 g/L to 31.3 ± 4.6 g/L. Using GNRI (geriatric nutritional risk index), nutritional risk levels were assessed;GNRI of the intervened significantly improved from 88.7 ± 6.3 (intermediate risk) to 95.7 ± 4.5 (low risk), while its status did not change in the non-intervened: 84.6 ± 7.7 (intermediate risk) to 86.5 ± 7.9 (intermediate risk). The intervention using a casein-based balanced liquid nutrition formula effectively improved protein-malnutrition in the elderly. This result suggests that a casein-based balanced liquid nutrition formula is an effective nutrition source that can be applied to a nutritional program to improve malnutrition of the elderly.

Microecological Prevention and Control Technology of Facility Strawberry Continuous Cropping Diseases and Its Application Effects

In order to actively develop green ecological strawberry, the authors have studied integrated microecological prevention and control technologies of strawberry continuous cropping diseases, including increasing soil biomass and solar high temperature disinfection during strawberry greenhouse leisure period in summer, biological fertilizer (agent) treatment before colonization, root irrigation treatment with biocontrol agent, as well as appropriate amount of fulvic acid and cytex after colonization, forming a supporting technical system for the microecological prevention and control of soil-borne diseases in facilities. The demonstration application in production shows that the technology has the functions of restoring and enhancing soil biological fertility, enriching beneficial microbial flora, antagonizing harmful bacteria, significantly promoting the growth and development of strawberry, reducing the incidence of soil-borne diseases, reducing the use of chemical fertilizers and pesticides, promoting the early ripening and high yield of strawberry, significantly improving the quality and flavor of strawberry, reducing the risk of pesticide residues, and boosting consumer confidence, which further improves the economic benefit, social benefit and ecological benefit, with good application prospect in production.

Traumatic Middle Meningeal Artery Pseudoaneurysms Presenting with Intractable Epistaxis: A Rare Case Report and Review of Literature

Middle meningeal artery (MMA) pseudoaneurysms are very rare and are most often traumatic. They may present as an epidural or intraparenchymal hematoma. This study reports a rare case in which a patient suffered from intractable epistaxis because of a pseudoaneurysm in middle meningeal artery and skull base fracture after craniocerebra trauma. Pseudoaneurysm and the feeding artery were embolized by using Onyx-18 liquid embolic system. Complete cessation of bleeding was achieved in this case immediately after the endovascular therapies. In this study, clinical manifestation, diagnostic imaging and endovascular treatment are described. Formation mechanisms and the treatment of traumatic pseudoaneurysm of middle meningeal artery are discussed.

A research on the Sports Tourism Special Project In Hainan International Tourism Island

At the background of the constrictions of international tourist island, this paper applies the methods of literature review, the interview, in-site investigation to analyze the current development of the sports tourism in Hainan with a benchmark of the construction plan of the Hainan international tourist island and the combination of the world's four famous tourism Islanders. It makes a planning assumption of the development of the sports tourism in accordance with the characteristics of sports tourism resources in Hainan. The tourism resources in Hainan are rich and unique. It aims to set up the development planning guidelines and objectives of sports tourism in Hainan, to clarify the spatial layout of resources, the distribution of different sports tourism zones and the tourism routes, to propose the project plans of the sports tourism in Hainan with a combination of the construction of international tourism island, to establish a sports tourism industry in cooperation with large enterprises in a new concept of society development. The sports tourism development project makes a combination among the tourism products, tourism program and tourist routes. It strengthens the cooperation in different bureaus in the sports and tourism management, to accelerate the construction and sport tourism personnel training, to standardized the management, other safeguards and construct the camp for self-driving tourists, the motel , the auto theater and launch the Hainan Card to increase the "migratory birds" economic and promote the development of the tourism in Xisha Island, Nansha Island.

A review of commercial development of continental shale oil in China

Continental shale oil is an important strategic supplement to the sustainable development of petroleum industry in China.Based on the thermal maturity of organic matter,most shale oil in China is mediumhigh or medium-low mature oil with relatively high density that is usually stored in thin layers and difficult to extract due to strong fluid flow resistance.Most petroliferous basins in China host shale oil but the abundance and distribution are not favorable for operators looking for a commercial exploitation.This study systematically investigates the recent progress of shale oil exploration and development in China.The result shows that the country is facing the following challenges while trying to explore its shale oil resources:complex geological conditions;a lack of established effective development mode;high development cost;and an absence of substantial breakthroughs in key technologies.Given these,the study suggests from research and policy-making perspectives to strengthen the research on basic theories and key technologies,establish demonstration zones for development of different types of shale oil,pursue breakthroughs in a stepwise approach,innovate the management mode to reduce the development cost,set shale oil as an independent mineral type,and give special policy incentives.

Survey of Data Value Evaluation Methods Based on Open Source Scientific and Technological Information

It is important to effectively identify the data value of open source scientific and technological information and to help intelligence analysts select high-value data from a large number of open-source scientific and technological information. The data value evaluation methods of scientific and technological information is proposed in the open source environment. According to the characteristics of the methods, the data value evaluation methods were divided into the following three aspects: research on data value evaluation methods based on information metrology, research on data value evaluation methods based on economic perspective and research on data value assessment methods based on text analysis. For each method, it indicated the main ideas, application scenarios, advantages and disadvantages.