组织工程小血管摩擦力测量方法的研究与应用

目的设计一套用于组织工程小血管内壁摩擦力测量的装置并对组织工程血管的材料进行初步的测量,以验证装置的可靠性和相关结论。方法根据血液动力学的原理,对血管的力学模型进行分析,确定组织工程血管内皮细胞摩擦力的测量方法,从而设计完成整套装置并对弹性元件进行测量,并进行组织工程降解材料聚羟基乙酸PGA构成的管状支架进行摩擦力的测量。结果设计完成了测量组织工程血管内壁摩擦力的实验装置,弹性元件的牵拉力与位移的关系呈良好的线性关系。聚羟基乙酸PGA管状支架的摩擦力随流速的增加而增加。结论测量组织工程血管内壁摩擦力的实验装置是可行的,聚羟基乙酸PGA管状支架的摩擦力与流速基本呈现线性关系。     

Some notes on uncertainty; Federal policy and innovation

The legislative background and current responsibilities of the new National Center for Health Care Technology (NCHCT) are discussed. The NCHCT's charge is to consider the stage of development, the actual or potential risks, costs and rate of use of health care technology. The role of Government in supporting new technologies, stimulating innovation and encouraging application of research products is considered. These issues are discussed in the context of the uncertainty inherent in planning and the formulation of public policy.     

Biomedical waste in laboratory medicine: audit and management

Pathology, microbiology, blood bank and other diagnostic laboratories generate sizable amount of biomedical waste (BMW). The audit of the BMW is required for planning proper strategies. The audit in our laboratory revealed 8 kgs anatomical waste, 600 kgs microbiology waste, 220 kgs waste sharps, 15 kgs soiled waste, 111 kgs solid waste, 480 litres liquid waste along with 33,000 litres per month liquid waste generated from labware washing and laboratory cleaning and 162 litres of chemical waste per month. Section wise details are described in the text. Needle sharps are collected in puncture proof containers and the needles autoclaved before sending to needle pit. The glass forms the major sharp category and is disinfected with hypochlorite before washing/recycling. All microbiology waste along with containers/plates/tubes are autoclaved before recycling/disposal. The problem of formalin fixed anatomical waste as histology specimens is pointed out. The formalin containing tissues cannot be sent for incineration for the fear of toxic gas release and the guidelines by the Biomedical waste rule makers need to be amended for the issue. The discarded/infected blood units in blood bank need to be autoclaved before disposal since chemical treatments are difficult or inefficient. The liquid waste management needs more attention and effluent treatment facility needs to be viewed seriously for hospital in general. The segregation of waste at source is the key step and reduction, reuse and recycling should be considered in proper perspectives.     

Direct prenatal chromosome diagnosis of a malignancy

A fetal tumor was suspected at 31 weeks of gestation. The occurrence of polyhydramnios led to an ultrasound examination, which revealed deformation of the fetal head, face, eye, and neck. This was confirmed by computerized tomography. Amniocentesis yielded cells with an inverted duplication of chromosome #1. This abnormality of chromosome #1 marked the malignant teratoma cells in the amniotic fluid. Cytogenetic analysis of tumor tissue and of normal tissue obtained postnatally confirmed that the abnormality of chromosome #1 observed in amniotic fluid cells was confined to the tumor. The constitutional karyotype was normal. To our knowledge, this is the first report of the direct chromosomal detection of malignancy before birth.     

生物医学科技论文存在的利益冲突问题及其应对措施

【目的】 探讨生物医学科技论文存在的主要利益冲突(Conflict of Interest, COI)问题及其应对措施。【方法】 通过检索Retraction Watch 数据库,收集2016—2021年生物医学期刊中因COI相关问题被撤销、更正或关注的95篇论文为研究对象。回顾性调查论文及其处理(撤稿、更正或关注)声明的主要特征、存在的COI问题及处理措施。【结果】 本研究纳入的95篇论文中,72篇被撤销,23篇被更正或关注。论文存在的主要COI问题包括COI披露不完整(46.3%)、确实存在COI(18.9%)、对已披露COI的完整性存在质疑(12.6%)、潜在的COI披露不完整(12.6%)、COI披露错误(5.3%)等;具体COI表现为作者与企业(42.1%)、其他研究者(9.7%)、其他作者(7.0%)、研究机构(6.1%),以及期刊编辑或审稿人(5.3%)等之间存在的潜在COI或COI。【结论】 生物医学期刊论文发表过程中存在多种COI问题,并且表现形式多样。建立并完善COI相关编辑政策,可预防COI相关问题的发生,从而减少发表偏倚。     

“双一流”高校工科学报校内发文量与学术影响力统计分析

【目的】 研究“双一流”高校工科学报校内发文量与学术影响力间的关系,探讨学报发挥自身优势,提升期刊学术质量,继续推动高校和学科建设的策略。【方法】 依据中国知网期刊数据库及《中国科技期刊引证报告(核心版)》统计24种“双一流”高校工科学报2012年、2014年、2016年和2018年的校内发文量、影响因子、被引频次、基金论文比、综合排名,辅以EI收录期刊、“中国科技期刊卓越行动计划”入选期刊的情况。【结果】 有18种高校学报的校内发文比例较高,具有较强的内向性;大部分学报的校内发文比例呈下降或波动稳定趋势,开放办刊的同时也流失了部分校内优质稿件;基金论文比普遍较高;23种学报的影响因子在0.5上下波动,特色优势不明显。由此可见,校内发文比例不直接决定学报的学术影响力,更为重要的是要积极拓展稿源,提升论文质量。【结论】 “双一流”高校工科学报需要依托高校优势学科,设定特色栏目吸引特色论文;挖掘本校学者资源,提升校内发文质量;坚持科学评价导向,让高校涌现的高水平成果落地生根,推进大学各学科发展,共创一流。     

Iterative reconstruction algorithms

In this paper a survey of recent results on iterative reconstruction algorithms is given. These results, many of which have not yet appeared elsewhere, are applicable to a very general formulation of the reconstruction problem based on the series expansion approach. A set of optimization criteria and a number of iterative reconstruction algorithms are stated, together with theorems on the convergence of the algorithms to optimum images. The efficacy of the algorithms is compared to that of the convolution method. In particular, the falseness of the claim that ART and the backprojection method are the same is demonstrated.     

Committing to genomic answers for all kids: Evaluating inequity in genomic research enrollment

PurposePersistent inequities in genomic medicine and research contribute to health disparities. This analysis uses a context-specific and equity-focused strategy to evaluate enrollment patterns for Genomic Answers for Kids (GA4K), a large, metropolitan-wide genomic study on children.MethodsElectronic health records for 2247 GA4K study participants were used to evaluate the distribution of individuals by demographics (race, ethnicity, and payor type) and location (residential address). Addresses were geocoded to produce point density and 3-digit zip code maps showing local and regional enrollment patterns. Health system reports and census data were used to compare participant characteristics with reference populations at different spatial scales.ResultsRacial and ethnic minoritized and populations with low-income were underrepresented in the GA4K study cohort. Geographic variation demonstrates inequity in enrollment and participation among children from historically segregated and socially disadvantaged communities.ConclusionOur findings illustrate inequity in enrollment related to both GA4K study design and structural inequalities, which we suspect may exist for similar US-based studies. Our methods provide a scalable framework for continually evaluating and improving study design to ensure equitable participation in and benefits from genomic research and medicine. The use of high-resolution, place-based data represents a novel and practical means of identifying and characterizing inequities and targeting community engagement.     

皮肤角质形成细胞的无血清培养方法

目的探索建立少量成年自体皮肤角质形成细胞体外无血清培养体系,为自体组织工程皮肤的构建与移植奠定物质基础。方法:无菌条件下,取2cm×2cm 兔耳皮肤组织块,Dispase 消化,分离真表皮,表皮以胰蛋白酶+EDTA 消化获得角质形成细胞,以含钙和不含钙的角质形成细胞培养液(K-SFM),按不同细胞密度接种于24孔板,观察细胞生长状况;免疫组化鉴定,MTT 法测定不同血清浓度对角质形成细胞增殖分化的影响。结果:在适当的 Ca~(2+)浓度下,少量自体角质形成细胞能够在无血清培养液 k-SFM 中培养扩增,最多可传4～6代。添加血清后可明显加速细胞分化。结论:无血清培养体系适用于少量成年自体角质形成细胞的体外连续培养扩增,培养的细胞可用于自体组织工程皮肤的构建。     

自制NECM修复兔耳廓软骨缺损的试验研究

目的本研究的目的在于评价自制同种异体天然细胞外基质(Nature Extracellular Matrix,NECM)在修复兔耳廓软骨缺损中的价值,从而在体外研究的基础上进一步证实我们采用的去污剂-酶四步法制作的NECM在组织工程学中的可行性.方法选用10只新西兰大白兔,于其双耳廓制造1.0×.0cm大小的软骨缺损后,分别作以下研究:①灰兔NECM修复兔耳廓缺损.②灰兔NECM复合软骨膜修复兔耳廓缺损;③不植任何材料的空白对照.术后4、6、12、24周取材并行组织学检查.结果NECM植入后4、6周有轻重不一的炎症反应,第12周炎症反应消失,NECM周边无包裹现象.第12周时NECM复合软骨膜组有软骨膜细胞长入NECM,此时的软骨膜细胞多处于增殖期,24周时软骨膜细胞继续增殖分化细胞逐渐长入NECM深部,且部分软骨膜细胞发育成熟.单纯NECM修复组,第6周出现纤维结缔组织长入NECM,12、24周纤维结缔组织逐渐长入NECM深部,并逐渐取代NECM.结论①NECM可诱导软骨膜细胞增殖分化生长,修复软骨缺损:②NECM具有较好的组织亲和性和相容性;③软骨膜细胞可以作为NECM再生软骨的种子细胞的来源;④软骨膜可以阻止纤维结缔组织侵入修复区NECM.