Scene 3-D Reconstruction System in Scattering Medium

Research on neural radiance fields for novel view synthesis has experienced explosive growth with the development of new models and extensions.The NeRF(Neural Radiance Fields)algorithm,suitable for underwater scenes or scattering media,is also evolving.Existing underwater 3D reconstruction systems still face challenges such as long training times and low rendering efficiency.This paper proposes an improved underwater 3D reconstruction system to achieve rapid and high-quality 3D reconstruction.First,we enhance underwater videos captured by a monocular camera to correct the image quality degradation caused by the physical properties of the water medium and ensure consistency in enhancement across frames.Then,we perform keyframe selection to optimize resource usage and reduce the impact of dynamic objects on the reconstruction results.After pose estimation using COLMAP,the selected keyframes undergo 3D reconstruction using neural radiance fields(NeRF)based on multi-resolution hash encoding for model construction and rendering.In terms of image enhancement,our method has been optimized in certain scenarios,demonstrating effectiveness in image enhancement and better continuity between consecutive frames of the same data.In terms of 3D reconstruction,our method achieved a peak signal-to-noise ratio(PSNR)of 18.40 dB and a structural similarity(SSIM)of 0.6677,indicating a good balance between operational efficiency and reconstruction quality.

便携式可穿戴设备结合运动管理对糖尿病患者糖脂代谢影响的Meta分析

目的系统评价可穿戴设备结合运动管理对糖尿病患者糖脂代谢的影响。方法检索中国知网、万方、维普、中国生物医学数据库、美国国立医学图书馆数据库(PubMed)、荷兰医学文摘数据库(Embase)、科学引文数据库(Web of Science)、循证医学数据库(the Cochrane Library)、CINAHL数据库自建库起至2023年4月关于糖尿病患者使用可穿戴设备结合运动控制血糖的随机对照试验,筛选和评估文献质量后提取有效信息。试验组患者使用基于便携式可穿戴设备结合运动的管理方案;对照组患者未使用便携式可穿戴设备,采用常规或其他血糖管理方案。主要结局指标为糖化血红蛋白(HbA1c);次要结局指标为空腹血糖(FPG)、总胆固醇(TC)、甘油三酯(TG)、低密度脂蛋白胆固醇(LDL-C)和高密度脂蛋白胆固醇(HDL-C)。使用Review Manager 5.4软件对提取数据进行Meta分析,采用标准化均数差(SMD)作为效应指标,各效应指标均进行显著性分析并提供其95%CI。结果共纳入10篇文献,包含1260例患者。Meta分析结果显示,与对照组相比,试验组HbA1c(SMD=-0.49%,95%CI-0.62%~-0.36%,P<0.01)、FPG(SMD=-0.87 mmol/L,95%CI-1.04~-0.70 mmol/L,P<0.001)、TG(SMD=-0.28 mmol/L,95%CI-0.42~-0.15 mmol/L,P<0.001)、HDL-C(SMD=0.07 mmol/L,95%CI 0.01~0.13 mmol/L,P=0.02)均有显著改善,差异均有统计学意义。而两组TC(SMD=-0.25 mmol/L,95%CI-0.37~0.12 mmol/L,P=0.27)、LDL-C(SMD=-0.12 mmol/L,95%CI-0.19~-0.06 mmol/L,P=0.22)比较差异无统计学意义。结论可穿戴设备结合运动管理有助于改善糖尿病患者的HbA1c、FPG、TG和HDL-C水平,但对于TC、LDL-C无明显影响。

甘蔗鞭黑粉菌侵染甘蔗的早期可视化观察

【目的】甘蔗鞭黑粉菌(Sporisorium scitamineum)引起的甘蔗黑穗病是我国甘蔗生产重要的病害。示踪甘蔗鞭黑粉菌侵染甘蔗的过程将有助于揭示其致病性和甘蔗抗黑穗病机制,为抗病品种的选育以及黑穗病的防治奠定基础。【方法】利用农杆菌介导的遗传转化技术对甘蔗鞭黑粉菌进行黄色荧光标记,对转化子进行配合及致病力检测,将标记菌株接种甘蔗感病品种ROC22及抗病品种中蔗1号、中蔗6号和中蔗9号并进行早期可视化观察。【结果】组成型表达的eYFP不影响标记菌株的配合及致病能力,而且黄色荧光性状能通过冬孢子稳定遗传。激光共聚焦显微观察表明,注射接种病原菌第5天,在感病品种ROC22的生长点已可见荧光菌丝及少量聚集状菌丝体,在抗病品种中蔗1号、中蔗6号和中蔗9号中可见少量单一丝状菌丝,无聚集状菌丝体。接种后35 d,在ROC22中可见大量聚集状菌丝体,但在中蔗品种中的聚集状菌丝体明显较少,而以中蔗1号最少。【结论】成功构建了甘蔗鞭黑粉菌侵染甘蔗的荧光示踪系统,并发现中蔗系列品种存在抑制甘蔗鞭黑粉菌菌丝体在细胞间扩展的机制。

From the microspheres to scaffolds:advances in polymer microsphere scaffolds for bone regeneration applications

The treatment and repair of bone tissue damage and loss due to infection,tumours,and trauma are major challenges in clinical practice.Artificial bone scaffolds offer a safer,simpler,and more feasible alternative to bone transplantation,serving to fill bone defects and promote bone tissue regeneration.Ideally,these scaffolds should possess osteoconductive,osteoinductive,and osseointegrative properties.However,the current first-generation implants,represented by titanium alloys,have shown poor bone-implant integration performance and cannot meet the requirements for bone tissue repair.This has led to increased research on second and third generation artificial bone scaffolds,which focus on loading bioactive molecules and cells.Polymer microspheres,known for their high specific surface areas at the micro-and nanoscale,exhibit excellent cell and drug delivery behaviours.Additionally,with their unique rigid structure,microsphere scaffolds can be constructed using methods such as thermal sintering,injection,and microsphere encapsulation.These scaffolds not only ensure the excellent cell drug loading performance of microspheres but also exhibit spatial modulation behaviour,aiding in bone repair within a three-dimensional network structure.This article provides a summary and discussion of the use of polymer microsphere scaffolds for bone repair,focusing on the mechanisms of bone tissue repair and the current status of clinical bone grafts,aimed at advancing research in bone repair.