摘要：癌症作为全球主要的致死原因之一,对公共卫生构成了巨大的挑战。癌症的防控策略不仅需要治疗技术的进步,也同样需要诊断技术的发展。肿瘤的发生和发展伴随着细胞结构和功能的多种变化,以及肿瘤微环境的显著改变。在这些变化过程中,特定分子的表达水平会出现异常,这些异常表达的分子可以作为肿瘤诊断的生物标志物。近年来,正电子发射断层扫描(Positron Emission Tomography,简称PET)作为一种重要的分子成像技术,已被广泛应用于检测肿瘤的结构和功能变化。PET技术的核心在于放射性示踪剂的开发与应用,这些示踪剂的设计和合成一般基于化学原理的深入理解和创新应用。本文旨在综述PET中几种典型的放射性示踪剂,并探讨核素标记过程中涉及的化学原理,增进对PET在肿瘤诊断中应用的理解,并提升对化学在生物医学领域中作用的认识。此外,PET放射性示踪剂的设计和合成过程是化学教育的宝贵资源,对化学在生命科学相关学科的教学具有重要意义。

摘要：AIM： To examine the underlying mechanisms of erlotinib-induced growth inhibition in hepatocellular carcinoma （HCC）. METHODS： Erlotinib-induced alterations in gene expression were evaluated using cDNA array technology; changes in protein expression and/or protein activation due to erlotinib treatment as well as IGF-1-induced EGFR transactivation were investigated using Western blotting. RESULTS： Erlotinib treatment inhibited the mitogen activated protein （MAP）-kinase pathway and signal transducer of activation and transcription （STAT）- mediated signaling which led to an altered expression of apoptosis and cell cycle regulating genes as demonstrated by cDNA array technology. Overexpression of proapoptotic factors like caspases and gadds associated with a down-regulation of antiapoptotic factors like Bcl-2, Bcl-XL or jun D accounted for erlotinib＇s potency to induce apoptosis. Downregulation of cell cycle regulators promoting the G1/S-transition and overexpression of cyclin-dependent kinase inhibitors and gadds contributed to the induction of a G1/G0-arrest in response to erlotinib. Furthermore, we displayed the transactivation of EGFR-mediated signaling by the IGF-1-receptor and showed erlotinib＇s inhibitory effects on the receptor-receptor cross talk. CONCLUSION： Our study sheds light on the understanding of the mechanisms of action of EGFR-TK- inhibition in HCC-cells and thus might facilitate the design of combination therapies that act additively or synergistically. Moreover, our data on the pathways responding to erlotinib treatment could be helpful in predicting the responsiveness of tumors to EGFR-TKIs in the future.

摘要：The immune response after implantation of a biomaterial may shorten the functional life of the implant,depending on the degree of the *** this study,we used a polyacrylamide-alginate(PAAm-Alg)hydrogel,which has been previously characterized as a biocompatible material and shown to enhance regeneration of cartilage in vivo,along with a graphiteenhanced hydrogel(PAAm-Alg-G)as a non-biocompatible counterpart,to evaluate macrophage attachment and polarization to pro-or anti-inflammatory *** performance of each biomaterial in the presence of fibroblasts and chondrocytes was validated by an in vitro model which demonstrated modulation of the foreign-body response.A blend of 5%gelatin methacryloyl and 0.1%methacrylated hyaluronic acid was optimized to mimic the extracellular matrix(ECM)and support cell viability,proliferation,migration,and functionality at an initial concentration of 3.25×10^(5) cells/*** PAAm-Alg-G hydrogel localized in the simulated ECM showed cytotoxic and genotoxic effects for both fibroblasts and chondrocytes,while exhibiting a proliferative effect on macrophages with elevated immune *** M1/M2 ratio was 0.73 for PAAm-Alg hydrogel but 2.64 for PAAm-Alg-G,leading to significant M1 dominance(p0.05).The interleukin-6(IL-6)concentration secreted in the presence of PAAm-Alg hydrogel(4.58 pg/mL)significantly decreased(p<0.0001)on day 13,while the increase(p<0.0001)in interleukin-10(IL-10)concentration(120.73 pg/mL)confirmed the switch from a pro-inflammatory to an anti-inflammatory *** immune responses by developing a simplistic yet powerful three-dimensional in vitro model provides advantages in preparing for clinical use of biomaterials.

摘要：In the era of burgeoning breakthroughs around medical and biomedical technologies,personalizing our medicine still sounds like a dream yet to be *** cancer as an example,while the pool of anti-cancer therapeutic agents is tremendously large,pinpointing a drug or a combination of drugs that would always work out well for a given patient,remains quite impossible—in fact,we are not even close to this ideal *** an incapability,of course,originates primarily from the overly complex,volumetrically structured and dynamic microenvironments in a patient’s tumor,meaning that the same tumor as seen on Day 1 might be entirely different than when seen again a month later.

摘要：We report the development of a metastasis-on-a-chip platform to model and track hepatocellular carcinoma(HCC)-bone metastasis and to analyze the inhibitory effect of an herb-based compound,thymoquinone(TQ),in hindering the migration of liver cancer cells into the bone *** bioreactor consisted of two chambers,one accommodating encapsulated HepG2 cells and one bone-mimetic niche containing hydroxyapatite(HAp).Above these chambers,amicroporous membrane was placed to resemble the vascular barrier,where medium was circulated over the *** was observed that the liver cancer cells proliferated inside the tumor microtissue and disseminated from the HCC chamber to the circulatory flow and eventually entered the bone *** number of metastatic HepG2 cells to the bone compartment was remarkably higher in the presence of HAp in the *** was then used as ametastasis-controlling agent in both free form and encapsulated nanoparticles,to analyze its suppressing effect on HCC *** indicated that the nanoparticle-encapsulated TQ provided a longer period of inhibitory *** summary,HCC-bone metastasis-on-a-chip platform was demonstrated to model certain key aspects of the cancer metastasis process,hence corroborating the potential of enabling investigations on metastasis-associated biology as well as improved anti-metastatic drug screening.

摘要：Amidst the rapidly expanding integration of large language models(LLMs)across various sectors(ranging from everyday applications to specialized fields demanding stringent regulatory adherence),our investigation seeks to determine how well these models can support medical device software *** device classification functions to systematically categorize devices according to their designated use,associated risk levels,and requisite regulatory oversight,thereby providing a structured framework for ensuring safety and efficacy as mandated by regulatory authorities.

摘要：The three-dimensional (3D)bioprinting technology has progressed tremendously over the past *** controlling the size, shape,and architecture of the bioprinted constructs,3D bioprinting allows for the fabrication of tissue/organ-like constructs with strong structural-functional similarity with their in vivo counterparts at high *** bioink,a blend of biomaterials and living cells possessing both high biocompatibility and printability,is a critical component of *** particular, gelatin methacryloyl (GelMA)has shown its potential as a viable bioink material due to its suitable biocompatibility and readily tunable physicochemical *** GelMA-based bioinks and relevant bioprinting strategies for GelMA bioprinting are briefly reviewed.

摘要：mRNA疫苗因其免疫原性强、无基因整合风险和低成本制造等天然优势,已在传染病的预防以及癌症治疗等领域展示出巨大的潜力.目前,针对mRNA疫苗面临的稳定性差和蛋白表达效率不高等挑战,研究人员开展了广泛的mRNA设计和优化工作.传统的mRNA疫苗设计依赖于经验和实验结果的反复迭代,而随着人工智能技术的发展, mRNA疫苗设计正向更加理性和高效的方向转变.本文首先系统介绍了各种疫苗的特性,并概述了多款已上市和临床评估阶段的mRNA疫苗.同时,针对mRNA疫苗的优化问题,根据mRNA的五个不同结构区域,分别详细介绍了经验设计和人工智能设计在mRNA疫苗理性设计中的应用和优缺点.最后,讨论了人工智能模型在mRNA疫苗优化中的局限性和未来发展方向.

摘要：The human gut microbiota is widely considered to be a metabolic organ hidden within our bodies,playing a crucial role in the host’s *** factors affect its composition,so a wide variety of microbes residing in the gut are present in the world *** excessive imbalances in microbial composition are often associated with human disorders and pathologies,and new investigative strategies to gain insight into these pathologies and define pharmaceutical therapies for their treatment are *** vitro models of the human gut microbiota are commonly used to study microbial fermentation patterns,community composition,and host-microbe *** and microfluidic devices have been designed to culture microorganisms from the human gut microbiota in a dynamic environment in the presence or absence of eukaryotic cells to interact *** this review,we will describe the overall elements required to create a functioning,reproducible,and accurate in vitro culture of the human gut *** addition,we will analyze some of the devices currently used to study fermentation processes and relationships between the human gut microbiota and host eukaryotic cells.

摘要：波士顿人工角膜是全世界应用范围最广,最成功的人工角膜之一,它适用于严重角膜疾病和多次角膜移植失败的病例.它的长期预后因病种不同而不同,自身免疫性疾病,如瘢痕性类天疱疮和Stevens-Johnson综合征、中毒性表皮坏死溶解症,以及严重化学烧伤等疾病的预后较非感染性角膜病的预后差.在适应证的扩展方面,儿童遗传性角膜混浊病早期植入人工角膜可以有效地减少弱视的发生.波士顿人工角膜采用“领扣”式设计,使用聚甲基丙烯酸甲酯的生物材料.波士顿人工角膜使用供体角膜,也可使用患者自体角膜作为载体.针对我国角膜供体材料匮乏的特点,采用自体角膜为载体为角膜盲患者复明提供了一种选择.波士顿人工角膜经过多次改进,减少了严重并发症的发生,其中包括后盘的多孔设计,使角膜植片能够从房水中获得充足的营养,减少了角膜溶解的发生率,持续性佩戴角膜接触镜有效地防止了眼表水分的蒸发,有效地减少角膜组织的坏死和溶解,人工角膜的在位率明显提高.术后预防性地使用抗生素有效地预防了感染的发生,从而降低了眼内炎的发生率.