基因组编辑技术(Genomeeditingtechnology)是一种通过人工手段在基因组水平对DNA序列进行改造的遗传操作技术,包括特定DNA片段的插入、敲除、替换和点突变。其中,依赖核酸酶的基因组编辑技术的基本原理是在基因组的特定位置产生双链DNA...基因组编辑技术(Genomeeditingtechnology)是一种通过人工手段在基因组水平对DNA序列进行改造的遗传操作技术,包括特定DNA片段的插入、敲除、替换和点突变。其中,依赖核酸酶的基因组编辑技术的基本原理是在基因组的特定位置产生双链DNA断裂(Double-strandedbreak,DSB)后通过非同源末端连接(Non-homologous end joining,NHEJ)或同源重组(Homologous recombination,HR)的方式进行修复。随着对核酸酶更深入的研究,基因组编辑技术也得到了快速发展,其中最常使用的核酸酶主要包括巨型核酸酶、锌指核酸酶、转录激活因子样效应物核酸酶以及成簇的规律间隔的短回文重复序列相关蛋白(Clusteredregularly interspaced short palindromic repeats(CRISPR)-associated proteins(Cas)。文中在介绍上述基因组编辑技术的发展及作用原理的基础上,主要综述了CRISPR/Cas9系统在基因功能鉴定、疾病模型建立、基因治疗和免疫治疗等应用领域的研究进展,并对其未来发展进行了展望。展开更多
目的:比较远端胃癌根治术毕Ⅱ式吻合应用圆形吻合器与直线吻合器实施消化道重建的近期安全性、有效性及术后生存质量。方法:回顾性分析2013年1月至2017年7月北京大学肿瘤医院胃肠肿瘤中心四病区行根治性远端胃大部切除术的132例胃腺癌...目的:比较远端胃癌根治术毕Ⅱ式吻合应用圆形吻合器与直线吻合器实施消化道重建的近期安全性、有效性及术后生存质量。方法:回顾性分析2013年1月至2017年7月北京大学肿瘤医院胃肠肿瘤中心四病区行根治性远端胃大部切除术的132例胃腺癌患者的临床资料。根据消化道重建采用吻合器形状的不同,分为圆形吻合器组64例(48.5%)和直线吻合器组68例(51.5%)。比较两组患者术中情况、术后恢复情况、并发症发生率以及术后1年残胃情况。结果:两组手术时间、手术方式、术中出血量、淋巴结清扫数目以及阳性淋巴结数目的差异均无统计学意义(均P>0.05)。直线吻合器组患者较圆形吻合器组患者术后首次排气时间(中位数:3.0 d vs.4.0 d)、首次进食时间(中位数:7.0 d vs.8.0 d)、首次拔除腹腔引流管时间(中位数:7.0 d vs.9.0 d)及术后住院时间(中位数:8.0 d vs.10.0 d)均较短,差异具有统计学意义(均P<0.05);两组患者术后并发症发生率分别为10.9%和1.5%,差异无统计学意义(P=0.056)。术后1年胃镜检查结果显示,两组患者的食物潴留、残胃黏膜炎及胆汁反流发生率,差异均无统计学意义(P>0.05)。结论:在远端胃癌根治术毕Ⅱ式吻合中,直线吻合器组患者术后胃肠道功能恢复更快,患者住院时间更短,更具优势。展开更多
Objective: By observing the treatment and nursing care of a patient with Grade IV capsular contracture following breast cancer expander implantation and subsequent Stage II reconstruction, we aim to analyze the reason...Objective: By observing the treatment and nursing care of a patient with Grade IV capsular contracture following breast cancer expander implantation and subsequent Stage II reconstruction, we aim to analyze the reasons for the formation of capsular contracture after Stage I expander implantation and prevent its recurrence following Stage II reconstruction. Methods: In May 2020, the patient noticed an increase in the size of a breast mass. In August, she underwent AC-THP neoadjuvant chemotherapy, followed by a “right breast-conserving nipple-areolar subglandular excision + right axillary lymph node dissection + expander implantation” surgery in November 2020. Radiation therapy began in January 2021. During radiation therapy, the patient experienced severe breast hardening, distortion, tenderness, and was diagnosed with Grade IV capsular contracture. To relieve the capsular contracture, the patient underwent a “contracted capsule incision and release procedure + removal of the right breast expander + right breast implantation” surgery in July 2021. Postoperatively, measures were taken to prevent incision infection, emphasizing aseptic techniques, ensuring smooth negative pressure drainage, reducing skin flap tension, monitoring skin flap blood supply, actively preventing subcutaneous effusion and hematoma, and applying appropriate compression dressings. Results: The patient was discharged after the removal of the drainage tube. During the postoperative follow-up at 3 and 6 months, there was no recurrence of capsular contracture, and the breast appeared full, upright, and relatively soft. There were no complications such as hematoma, infection, breast implant rupture, breast sagging, or displacement. The patient had a good outcome without additional financial or surgical burdens. Conclusion: The occurrence of Grade IV capsular contracture in the patient is generally related to infection after Stage I expander implantation, improper compression dressing, excessive saline injection causing content infiltration展开更多
Despite their excellent environmental stability,low defect density,and high carrier mobility,large-n quasi-two-dimensional halide perovskites(quasi-2DHPs)feature a limited application scope because of the formation of...Despite their excellent environmental stability,low defect density,and high carrier mobility,large-n quasi-two-dimensional halide perovskites(quasi-2DHPs)feature a limited application scope because of the formation of self-assembled multiple quantum wells(QWs)due to the similar thermal stabilities of large-n phases.However,large-n quasi-phase-pure 2DHPs(quasi-PP-2DHPs)can solve this problem perfectly.This review discusses the structures,formation mechanisms,and photoelectronic and physical properties of quasi-PP-2DHPs,summarises the corresponding single crystals,thin films,and heterojunction preparation methods,and presents the related advances.Moreover,we focus on applications of large-n quasi-PP-2DHPs in solar cells,photodetectors,lasers,light-emitting diodes,and field-effect transistors,discuss the challenges and prospects of these emerging photoelectronic materials,and review the potential technological developments in this area.展开更多
Lake is an important part of the natural ecosystem, and its morphological characteristics reflect the capacity of lake regulation and storage, the strength of material migration, and the characteristics of shoreline d...Lake is an important part of the natural ecosystem, and its morphological characteristics reflect the capacity of lake regulation and storage, the strength of material migration, and the characteristics of shoreline development. In most existing studies, remote sensing images are used to quantify the morphological characteristics of lakes. However, the extraction accuracy of lake water is greatly affected by cloud cover and vegetation cover, and the inversion accuracy of lake elevation data is poor, which cannot accurately describe the response relationship of lake landscape morphology with water level change. Therefore, this paper takes Tonle Sap Lake as the research object, which is the largest natural freshwater lake in Southeast Asia. DEM is constructed based on high-resolution measured topographic data, and morphological indicators such as lake area, lake shoreline length, perimeter area ratio, longest axis length, maximum width, shoreline development index, lake shape complexity, compactness ratio and form ratio are adopted to researching the evolution law of high water overflows and low water outbursts quantitatively, and clarifying the variation characteristics of landscape morphology with water level gradient in Tonle Sap Lake. The research results have important theoretical significance for the scientific utilization of Tonle Sap Lake water resources and the protection of the lake ecosystem.展开更多
文摘基因组编辑技术(Genomeeditingtechnology)是一种通过人工手段在基因组水平对DNA序列进行改造的遗传操作技术,包括特定DNA片段的插入、敲除、替换和点突变。其中,依赖核酸酶的基因组编辑技术的基本原理是在基因组的特定位置产生双链DNA断裂(Double-strandedbreak,DSB)后通过非同源末端连接(Non-homologous end joining,NHEJ)或同源重组(Homologous recombination,HR)的方式进行修复。随着对核酸酶更深入的研究,基因组编辑技术也得到了快速发展,其中最常使用的核酸酶主要包括巨型核酸酶、锌指核酸酶、转录激活因子样效应物核酸酶以及成簇的规律间隔的短回文重复序列相关蛋白(Clusteredregularly interspaced short palindromic repeats(CRISPR)-associated proteins(Cas)。文中在介绍上述基因组编辑技术的发展及作用原理的基础上,主要综述了CRISPR/Cas9系统在基因功能鉴定、疾病模型建立、基因治疗和免疫治疗等应用领域的研究进展,并对其未来发展进行了展望。
文摘目的:比较远端胃癌根治术毕Ⅱ式吻合应用圆形吻合器与直线吻合器实施消化道重建的近期安全性、有效性及术后生存质量。方法:回顾性分析2013年1月至2017年7月北京大学肿瘤医院胃肠肿瘤中心四病区行根治性远端胃大部切除术的132例胃腺癌患者的临床资料。根据消化道重建采用吻合器形状的不同,分为圆形吻合器组64例(48.5%)和直线吻合器组68例(51.5%)。比较两组患者术中情况、术后恢复情况、并发症发生率以及术后1年残胃情况。结果:两组手术时间、手术方式、术中出血量、淋巴结清扫数目以及阳性淋巴结数目的差异均无统计学意义(均P>0.05)。直线吻合器组患者较圆形吻合器组患者术后首次排气时间(中位数:3.0 d vs.4.0 d)、首次进食时间(中位数:7.0 d vs.8.0 d)、首次拔除腹腔引流管时间(中位数:7.0 d vs.9.0 d)及术后住院时间(中位数:8.0 d vs.10.0 d)均较短,差异具有统计学意义(均P<0.05);两组患者术后并发症发生率分别为10.9%和1.5%,差异无统计学意义(P=0.056)。术后1年胃镜检查结果显示,两组患者的食物潴留、残胃黏膜炎及胆汁反流发生率,差异均无统计学意义(P>0.05)。结论:在远端胃癌根治术毕Ⅱ式吻合中,直线吻合器组患者术后胃肠道功能恢复更快,患者住院时间更短,更具优势。
文摘Objective: By observing the treatment and nursing care of a patient with Grade IV capsular contracture following breast cancer expander implantation and subsequent Stage II reconstruction, we aim to analyze the reasons for the formation of capsular contracture after Stage I expander implantation and prevent its recurrence following Stage II reconstruction. Methods: In May 2020, the patient noticed an increase in the size of a breast mass. In August, she underwent AC-THP neoadjuvant chemotherapy, followed by a “right breast-conserving nipple-areolar subglandular excision + right axillary lymph node dissection + expander implantation” surgery in November 2020. Radiation therapy began in January 2021. During radiation therapy, the patient experienced severe breast hardening, distortion, tenderness, and was diagnosed with Grade IV capsular contracture. To relieve the capsular contracture, the patient underwent a “contracted capsule incision and release procedure + removal of the right breast expander + right breast implantation” surgery in July 2021. Postoperatively, measures were taken to prevent incision infection, emphasizing aseptic techniques, ensuring smooth negative pressure drainage, reducing skin flap tension, monitoring skin flap blood supply, actively preventing subcutaneous effusion and hematoma, and applying appropriate compression dressings. Results: The patient was discharged after the removal of the drainage tube. During the postoperative follow-up at 3 and 6 months, there was no recurrence of capsular contracture, and the breast appeared full, upright, and relatively soft. There were no complications such as hematoma, infection, breast implant rupture, breast sagging, or displacement. The patient had a good outcome without additional financial or surgical burdens. Conclusion: The occurrence of Grade IV capsular contracture in the patient is generally related to infection after Stage I expander implantation, improper compression dressing, excessive saline injection causing content infiltration
基金supported by the National Natural Science Foundation of China(62105292,61935017,and 62175268)Shaanxi Fundamental Science Research Project for Mathematics and Physics(22JSY015)+7 种基金Young Talent Fund of Xi’an Association for Science and Technology(959202313020)the Natural Science Foundation of Shaanxi Province(2021GXLH-Z-0 and 2020JZ-02)the Project of Innovative Team of Shaanxi Province(2020TD-001)the China Fundamental Research Funds for the Central Universitiesthe Science and Technology Development Fund,Macao SAR(FDCT-0044/2020/A1,006/2022/ALC)UM’s research fund(MYRG2022-00241-IAPME,MYRG-CRG2022-00009-FHS)the research fund from Wuyi University(EF38/IAPME-XGC/2022/WYU)Shenzhen-Hong Kong-Macao Science and Technology Innovation Project(Category C)(SGDX2020110309360100)。
文摘Despite their excellent environmental stability,low defect density,and high carrier mobility,large-n quasi-two-dimensional halide perovskites(quasi-2DHPs)feature a limited application scope because of the formation of self-assembled multiple quantum wells(QWs)due to the similar thermal stabilities of large-n phases.However,large-n quasi-phase-pure 2DHPs(quasi-PP-2DHPs)can solve this problem perfectly.This review discusses the structures,formation mechanisms,and photoelectronic and physical properties of quasi-PP-2DHPs,summarises the corresponding single crystals,thin films,and heterojunction preparation methods,and presents the related advances.Moreover,we focus on applications of large-n quasi-PP-2DHPs in solar cells,photodetectors,lasers,light-emitting diodes,and field-effect transistors,discuss the challenges and prospects of these emerging photoelectronic materials,and review the potential technological developments in this area.
文摘Lake is an important part of the natural ecosystem, and its morphological characteristics reflect the capacity of lake regulation and storage, the strength of material migration, and the characteristics of shoreline development. In most existing studies, remote sensing images are used to quantify the morphological characteristics of lakes. However, the extraction accuracy of lake water is greatly affected by cloud cover and vegetation cover, and the inversion accuracy of lake elevation data is poor, which cannot accurately describe the response relationship of lake landscape morphology with water level change. Therefore, this paper takes Tonle Sap Lake as the research object, which is the largest natural freshwater lake in Southeast Asia. DEM is constructed based on high-resolution measured topographic data, and morphological indicators such as lake area, lake shoreline length, perimeter area ratio, longest axis length, maximum width, shoreline development index, lake shape complexity, compactness ratio and form ratio are adopted to researching the evolution law of high water overflows and low water outbursts quantitatively, and clarifying the variation characteristics of landscape morphology with water level gradient in Tonle Sap Lake. The research results have important theoretical significance for the scientific utilization of Tonle Sap Lake water resources and the protection of the lake ecosystem.
