Nanoscale mass sensing based on vibration of single-layered graphene sheet in thermal environments

Based on vibration analysis, single-layered graphene sheet （SLGS） with multiple attached nanoparticles is developed as nanoscale mass sensor in thermal environments. Graphene sensors are assumed to be in simplysupported configuration. Based on the nonlocal plate the- ory which incorporates size effects into the classical theory, closed-form expressions lot the frequencies and relative fre- quency shills of SLGS-based mass sensor are derived using the Galerkin method. The suggested model is justified by a good agreement between the results given by the present model and available data in literature. The effects of tem- perature difference, nonlocal parameter, the location of the nanoparticle and the number of nanoparticles on the relative frequency shift of the mass sensor are also elucidated. The obtained results show that the sensitivity of the SLGS- based mass sensor increases with increasing temperature difference.

剖宫产术皮内缝合切口愈合不良分析

目的:探讨剖宫产术皮内缝合切口愈合不良的原因、治疗和预防措施。方法:对960例采用皮内缝合剖宫产患者的临床资料进行回顾性分析,分析切口愈合不良的原因,并进一步探索预防措施和治疗方法。结果:剖宫产术皮内缝合切口愈合不良与肥胖、糖尿病、水肿、贫血、滞产、缝合方式及技术、术后咳嗽、妊娠期高血压疾病、切口张力增加、术前是否使用抗生素密切相关。结论:选择剖宫产术皮肤切口缝合方式、加强剖宫产术后腹部切口护理、合理预防性应用抗生素,可有效预防切口愈合不良并使切口早期愈合。