Antimicrobial second skin using copper nanomesh

The functional support and advancement of our body while preserving inherent naturalness is one of the ultimate goals of bioengineering. Skin protection against infectious pathogens is an application that requires common and long-term wear without discomfort or distortion of the skin functions. However, no antimicrobial method has been introduced to prevent cross-infection while preserving intrinsic skin conditions. Here, we propose an antimicrobial skin protection platform copper nanomesh, which prevents cross-infectionmorphology, temperature change rate, and skin humidity. Copper nanomesh exhibited an inactivation rate of 99.99% for Escherichia coli bacteria and influenza virus A within 1 and 10 min, respectively. The thin and porous nanomesh allows for conformal coating on the fingertips, without significant interference with the rate of skin temperature change and humidity. Efficient cross-infection prevention and thermal transfer of copper nanomesh were demonstrated using direct on-hand experiments.

The functional support and advancement of our body while preserving the inherent naturalness is one of the ultimate goals of bioengineering (1–4). A functional layer is placed on the skin to complement the intrinsic biological and interactive functions (5, 6) and to add functions that do not yet exist (7–9). During use, the second skin layer should completely exploit its function and underlay skin functions without deforming the skin or interfering with the skin’s external interaction. Materials and structures need to be conformal and mechanically similar to the skin to minimize the distortion of natural sensations and movements. In addition, the air and heat transfer on the skin must be unimpeded to obtain a natural and comfortable wear fit (10).Body protection that requires common and long-term wear is an application in which both functionality and naturalness are important. As the outermost layer connecting our body to the environment, the skin is exposed to physical damage, hazardous chemicals, and infectious pathogens (11, 12). Therefore, we add a protective layer on the skin that blocks or filters out external contaminants. This entails the isolation and accumulation of biochemical compounds, which can lead to self-contamination and the subsequent cross-contamination/infection by interacting with other objects. In contrast to chemical contamination, which is not self-reproductive, the biological contamination of infectious microbes, such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a considerable issue to be addressed.By containing an antimicrobial material on the surface of the skin protective layer, cross-infection can be prevented in the long term. Unlike temporary rinsing or disinfection, the use of antibacterial or antiviral substances such as chemical or natural disinfectants and metal nanomaterials inhibits the growth of microorganisms on the surface (13–17). These materials are embedded in a complete covering polymer layer, such as gloves (18, 19), to isolate and protect both the inner and outer surfaces from the infection. To add breathability to the textile especially for the mask (13, 20, 21), many antibacterial fibers have been developed based on these materials. Moreover, various skin-attachable platforms with antimicrobial properties have been developed for convenient usage in daily lives. Antimicrobial nanofibers with conformal attachment to the skin have been developed for drug delivery, wound healing (22, 23), and electrophysiology (24, 25). In addition, stretchable and antibacterial hydrogels have been developed to allow more natural skin movement in wound-healing applications (26–28).However, there has been no practical skin protective solution to prevent cross-infection while preserving intrinsic skin conditions such as surface morphology, thermal transfer, and skin humidity. The thickening of the additional skin layer frequently results in a significant modification of the surface morphology, heat transfer, and the corresponding sensation. Thin layers have limited performance in terms of antimicrobial duration and speed. The skin coverage of polymer or hydrogel film blocks the transfer of air, moisture, and heat. In addition, the antimicrobial performance is focused on the skin side rather than the external side that affects cross-infection. Voids owing to the stiffness of the film or fiber and morphological differences compared to the skin further limit conformality, heat transfer, and water/air permeability (29).Here, we propose an antimicrobial skin protection platform copper nanomesh, which prevents cross-infection while minimizing modification of intrinsic skin properties such as interfacial morphology, temperature change rate, and skin humidity. The thin thickness and porous structure of the nanomesh allow conformal attachment to the fingertips, regardless of the mechanical and structural variations of the fingerprints, nails, and interfaces. To impart antimicrobial properties, copper, one of the most well-known antimicrobial (nano)materials (30–33), was coated with maintaining the nanomesh structure (copper nanomesh, from here onward). The measured inactivation rates of copper nanomesh against Escherichia coli bacteria and influenza virus A (H1N1) were 99.99% within 1 min and 10 min, respectively. It was found that the nanomesh structure contributed to the acceleration of bacterial inactivation compared to the copper film. Furthermore, it exhibited high biocompatibility with the skin cells and stable antibacterial performance even after long-term use (more than 6 h), including water immersion (more than 1 h).In addition, we investigated the naturalness of the copper nanomesh compared to that of the copper film and conventional gloves. As confirmed using the artificial skin and fingerprint recognition, the proposed copper nanomesh exhibited a higher conformability compared to that of the copper film. The copper nanomesh showed a high hydrophobicity to block external contaminants in solution while having high gas permeability and maintaining the skin humidity in a safe range. Additionally, the insertion of copper nanomesh did not affect the temperature change rate, which is important to maintain the sensation and comfort fit of the skin. Finally, the copper nanomesh was compared to the glove by wearing on our hands and interacting with various real-life objects. Using the proposed copper nanomesh, we successfully achieved an effective prevention of cross-infection and less-hindered thermal recognition of objects.     

干细胞技术在血管组织工程中的应用

随着冠状动脉粥样硬化性心脏病发病率和冠状动脉旁路移植手术数量的逐年增加,自体桥血管和人造血管已不能满足临床治疗的需求,组织工程为此带来了希望。干细胞的定向分化能力和超强的扩增能力,有望成为组织工程中理想的种子细胞。文章概述了目前干细胞技术在血管组织工程中的应用情况。     

儿童脑动静脉畸形出血早期诊断和显微外科治疗

目的 探讨儿童脑动静脉畸形(AVM)破裂出血急性期的诊断方法和显微外科治疗的时机与手术技术.方法 对2002年6月至2011年6月间收治的32例儿童AVM出血患者进行回顾性分析.除CTA和MRA检查外,本组行早期全脑DSA检查24例,另外入院时因出血量大发生脑疝者8例,立即行血肿清除术,其中3例病情稳定后再行DSA检查.明确诊断后根据Spetzler-Martin分级选择治疗方案.24例Spetzler-Martin分级Ⅰ～Ⅲ级AVM患者行急性期(3d内)显微外科治疗,其中栓塞后再手术2例.结果 8例急诊行显微手术血肿清除术者,术后死亡2例,镜下AVM完全切除2例,部分切除1例.病情稳定后行DSA检查证实AVM者3例,继而再行显微手术切除.24例急性期显微手术AVM切除者,术中显微镜下AVM血管团和颅内血肿完全清除.术后获DSA或CTA复查18例,均未见病灶残留.随访3-12个月.根据GOS评定:24例Sptetzler-Martin分级Ⅰ～Ⅲ级AVM患者恢复良好者21例,轻残2例,重残1例,无死亡病例.结论 DSA是儿童AVM出血早期诊断主要的检查手段.急性期显微手术可降低出血病死率和改善预后.     

5-羟色胺2A受体基因多态性与抑郁症的关联

目的：探讨中国汉族人群难治性抑郁症患者与5-羟色胺2A(5-HT2A)受体基因的T102C多态性之间的关系。方法：抽取79例难治性抑郁症患者作研究，以102名正常人作对照。应用聚合酶链式反应(PCR)扩增技术及限制性片段长度多态性(RFLP)分别测定所有研究对象的5-HT2A受体基因的基因型和等位基因。结果：5-HT2A受体基因的3种基因型(A1／A1，A1／A2和A2／A2)在难治性抑郁症组的分布分别为31．6％、54．4％和13．9％，在对照组分别为29．4％、45．1％和25．5％，两组间差异无显著性。结论：5-HB。受体基因的T102C多态性与难治性抑郁症之间无显著关联。     

直接数字化摄影在尘肺病检查及诊断中的应用研究

目的：探讨直接数字化摄影（DR）技术在尘肺病检查和诊断方面的应用价值。方法选择来我院欲提交诊断的20世纪60～80年代参加国防施工的复退军人及部分经职业健康查体筛选的企业工人共计811例,同时拍摄高千伏（HkV）胸片及DR胸片,部分加照CT扫描胸片,并对二组胸片进行质量及尘肺病诊断一致性等方面的比较。结果二组胸片的质量对比发现：DR胸片总体质量优于高千伏胸片,尤其DR胸片的一级片率明显高于 HkV胸片,DR胸片的三级片率明显低于HkV胸片,且差异有统计学意义（ P ＜0．05）;DR胸片在图像清晰度及肺部微细结构显示方面较好,两组胸片的诊断结果基本一致,尘肺患者胸片在小阴影形态、总体密集度、分布范围方面无明显差别。结论 DR胸片质量好于HkV胸片,三级片率明显低于HkV胸片;DR摄影可用于尘肺病检查与分期诊断。     

高速三角破片致猪坐骨神经损伤的特点

目的 探讨高速三角破片致猪坐骨神经损伤的伤情特点. 方法 长白猪14只,体重(34.3±5.2)kg.采用随机数字表法分为A、B两组各7只,用初速为(773.1±12.4)m/s的0.37 g三角破片致伤,分别瞄准猪右后肢外侧坐骨神经体表投影线中点和旁开2 cm射击.观察伤道入口和出口大小、长度,神经与伤道位置关系,伤后48 h观察神经大体及光电镜改变. 结果 破片在伤道内存在不同程度的偏离原射入方向.A、B组分别有5只和1只坐骨神经位于原发伤道内,其中4例出现不间程度断裂;光镜下见神经严重出血水肿、炎细胞浸润,大量神经纤维、轴索断裂,髓鞘着色浅;电镜下见髓鞘严重溃变、轴索变形.A、B组分别有1只和5只位于震荡区内,距原发伤道(2.07±0.45)cm,光镜见神经轻度出血、充血,部分神经纤维、轴索断裂;电镜下可见髓鞘部分分层.A、B组各有1只位于挫伤区内,神经受损程度介于二者之间. 结论 高速三角破片在组织内走行不稳定;其原发伤道内的猪坐骨神经断裂发牛率高,损伤严重,范围广,华勒变性早;位于原发伤道旁的神经亦发生形态学改变,其损害程度与神经和原发伤道距离有关.     

舒肝安乐宁浸膏对肝纤维化大鼠肝组织TGF-β1表达和细胞外胶原沉积的影响

目的通过研究舒肝安乐宁浸膏对实验性肝纤维化大鼠肝脏组织TGF-β1mRNA表达和细胞外胶原沉积的影响,探讨舒肝安乐宁复方抗肝纤维化作用机理。方法以皮下注射CCl4花生油溶液建立大鼠肝纤维化模型,观测舒肝安乐宁浸膏不同剂量组对肝纤维化大鼠肝脏Ⅰ、Ⅲ型胶原的含量以及肝组织TGF-β1mRNA表达的影响。结果舒肝安乐宁浸膏能抑制肝组织中COLⅠ和COLⅢ的含量和TGF-β1mRNA的表达。结论舒肝安乐宁浸膏对CCl4造成的实验性肝纤维化大鼠具有一定的抗肝纤维化作用,其机制与抑制胶原蛋白的形成以及抑制TGF-β1的基因表达有关。     

宫颈癌的介入化疗与栓塞

目的：评价超选择介入化疗与栓塞在宫颈癌中的作用。方法：1997-2000年15例宫颈癌患者行介入治疗,12例于介入术1-4个疗程后再行肿瘤切除术。结果：（1）宫颈癌介入治疗有效率为80%：（2）介入术后宫颈癌切除术率为80%;（3）副作用主要为胃肠道反应和骨髓抑制反应。结论：超选择髂内动脉插管化疗与栓塞可使宫颈癌缩小,为手术治疗创造条件,是治疗宫颈癌的一种新的有效辅助疗法。     

中国四川一个系统性红斑狼疮家系蛋白指纹图谱的表达研究

目的 研究系统性红斑狼疮(SLE)家系蛋白质指纹图谱的表达,寻找与SLE家族遗传相关的蛋白质标志物.方法 采用弱阳离子纳米磁性微球捕获血清蛋白,ProteinChip PBSⅡ-C型蛋白质芯片阅读仪检测7例中国四川地区SLE家系成员(包括3例确诊SLE患者)、63例散发SLE及83例健康体检者血清蛋白指纹图谱,所有蛋白指纹图谱采用Biomarker Wizard 3.10软件分析.结果 在SLE家系筛选出4个与散发SLE患者和健康对照者有明显差异的蛋白峰,其中质荷比(m/z)为9342.23的蛋白峰在SLE家系高于散发SLE患者和健康对照组(P<0.05),散发SLE患者又高于健康对照组(P<0.05);而m/z为4094.03、5905.35和 7973.53的3个蛋白峰在SLE家系低于散发SLE患者和健康对照组(P<0.05),散发SLE患者又低于健康对照组(P<0.05).结论 m/z为9342.23、4094.03、5905.35和7973.53的蛋白多肽在SLE家族成员致病中可能起重要作用,m/z为9342.23的蛋白表达越高,4094.03、 5905.35和 7973.53蛋白质表达越低,患SLE的危险度越大.这些蛋白可能成为SLE特异标志物,从而预测SLE的患病危险度,同时为SLE的生物治疗提供理论依据.