炭黑在不同并用橡胶中的分布

利用裂解气相色谱研究在不同比例的天然/丁苯(NR/SBR),丁苯/顺丁(SBR/BR)并用胶中炭黑N234的分布情况,及白炭黑在异戊/丁苯(IR/SBR)和丁苯/顺丁(SBR/BR)胶中的分布情况。不同种类的混炼胶所制备的结合胶的裂解气相结果显示:N234在NR/SBR并用胶中优先选择分布在NR中,而在SBR/BR并用胶中优先分布在BR中;而白炭黑在IR/SBR和SBR/BR中均优先选择分布在SBR中。     

Moz—氨基酸在肽合成中的应用

简述并对比了 Moz-氨基酸及 Boc-氨基酸在肽合成中的作用。认为脱除 Moz 的温和条件(10%TFA/CH_2Cl_2)可使目标肽的纯度及收率明显提高。Moz-氨基酸的另一特点是制备成本较低、方法简便。因此实现其商品化对我国肽合成化学的发展是有益的。     

丁苯胶乳合成中的粒径及其分布

用动态激光光散射法测定了丁二烯－苯乙烯乳液聚合的乳胶料粒子的粒径及其分布,结果表明,在反应初期平均粒径较大,粒径分布最宽,当单体转化率为６０％左右时,乳胶粒子分散度最低,说明粒径较大的液滴逐渐消失,继续聚合,乳胶粒子发生合并聚结,其平均粒径略有增长,粒径分布下降,加入电解质ＫＣｌ是增大乳胶平均粒径的有效方法。     

锆基色料在不同粒度分布熔块釉中的对比试验

本文研究了低温透明熔块釉不同粒度分布对锆基色料发色的影响,通过对比试验得出了适合锆基色料发色的粒度范围,并简要考察了影响锆基色料在熔块釉中发色的因素。     

合成甲醇等温化剂颗粒内各组份的浓度分布和反应速率分布—2考虑扩散影响

本文探讨了用电子计算机数值计算方法研究在Ｃｕ／Ｚｎ／Ａｌ２Ｏ３催化剂颗粒内进行低压合成甲醇反应时，外扩散对催化剂颗粒内浓度分布，反应速率分布和内表面利用率的影响。     

催化剂层温度分布对甲醇合成的影响

本文针对目前国内甲醇生产中存在的甲醇催化剂寿命短、生产能力低的突出问题,以新开发成功的均温型甲醇塔的工厂实际使用结果,从催化剂热表和中毒失活速度诸方面来分析甲醇合成塔催化剂层温度分布对甲醇合成的影响。     

F—T合成产物分布的数理统计处理

F-T合成是一结构敏感的表面聚合反应,其产物分布比较复杂,许多模型只能近似地描述F-T合成反应的产物分布规律。本文系统总结了近几年用数理统计法对F-T合成产物分布的处理结果,这些方法的共同假设是F-T合成的三类主要产物——烷烃、烯烃和含氧有机物——是经由同一中间体形成的,只是链终止的方式不同。详细介绍了T-W模型和Basini模型,以及对ASF分布的深入分析。     

低能量红光在不同细胞指标中的有效剂量筛选

通过实验筛选在不同细胞指标上产生积极响应的低能量红光辐照剂量。选择成纤维细胞进行检测,筛选对线粒体膜电位、ATP释放量、细胞迁移率和胶原合成量4个指标产生积极响应的低能量红光辐照剂量。实验结果表明,2 J/cm²的辐照剂量对成纤维细胞中的上述4个指标均可产生积极响应。将成纤维细胞上的测试模型迁移到毛乳头细胞中进行实验验证,结果表明2 J/cm²的辐照剂量在毛乳头细胞的线粒体膜电位、ATP释放量、细胞增殖率和胶原合成量4个指标上有积极响应。由此证明,2 J/cm²的辐照剂量可以提高成纤维细胞和毛乳头细胞的线粒体功能、细胞迁移率和胶原合成量,从而为细胞活动提供能量、提高细胞修复能力和细胞抗衰能力。     

合成肽在不对称催化反应中的应用

综述了合成肽作为催化剂在不对称催化反应中的应用,总结了各种合成肽催化剂的结构及其在催化不同类型反应如氰醇化反应、Strecker反应、Aldol反应、Michael加成反应、Morita-Baylis-Hillman反应和Stetter反应等中的催化活性及影响因素.     

磁性灰粒在不同粒级气化灰渣中的分布特性

以气流床煤气化粗渣和细灰为原料,采用筛分和磁选的方法研究了磁性灰粒在不同粒级气化灰渣中的分布特性。结果表明：随着灰渣粒径的减小,在粗渣和细灰中,磁性灰粒的含量均呈现先升高后降低的趋势,磁性灰粒在粗渣中的含量高于细灰。粗渣中,磁性灰粒在0.5~0.25mm粒级中分布最多,该粒级神宁炉和GSP气化炉粗渣在粒度组成中的占比也最高,质量分数分别为38.42%和37.16%,各个粒级中磁性灰粒产率随粒径减小呈递增趋势;细灰中,磁性灰粒在0.074~0.045mm粒级中分布最多,而细灰粒度组成中的占比最高的却是大于0.25mm粒级,磁性灰粒产率在各个粒级都不高,呈现随粒径减小而升高的规律。气化过程中,磁铁矿会更多地富集在凝结团聚且高度玻璃化的大粒径粗渣中,粗渣和细灰中仍有相当量的含铁物相不显磁性。不同粒级煤气化灰渣中磁性灰粒的分布特性可为气化渣分级分质及高值化利用提供基础数据支撑和应用思路。     

Review of Dendritic Cells,Their Role in Clinical Immunology,and Distribution in Various Animal Species

Dendritic cells (DCs) are cells derived from the hematopoietic stem cells (HSCs) of the bone marrow and form a widely distributed cellular system throughout the body. They are the most efficient, potent, and professional antigen-presenting cells (APCs) of the immune system, inducing and dispersing a primary immune response by the activation of naïve T-cells, and playing an important role in the induction and maintenance of immune tolerance under homeostatic conditions. Thus, this review has elucidated the general aspects of DCs as well as the current dynamic perspectives and distribution of DCs in humans and in various species of animals that includes mouse, rat, birds, dog, cat, horse, cattle, sheep, pig, and non-human primates. Besides the role that DCs play in immune response, they also play a pathogenic role in many diseases, thus becoming a target in disease prevention and treatment. In addition, its roles in clinical immunology have also been addressed, which include its involvement in transplantation, autoimmune disease, viral infections, cancer, and as a vaccine target. Therefore, based on the current knowledge and understanding of the important roles they play, DCs can be used in the future as a powerful tool for manipulating the immune system.     

抽提工艺中明胶不同组分的分布

本文采用高效液相色谱仪(HPLC),对明胶抽提工艺中不同道次明胶的分子量分布进行了分离和表征,测定了其不同组分的分布,并对图谱进行了解析。结果表明:随着抽提道次的增加,明胶的分子量分布变宽,α组分明显减少。     

Phosphosite Mapping of HIP-55 Protein in Mammalian Cells

In the present study, hematopoietic progenitor kinase 1 (HPK1)-interacting protein of 55 kDa (HIP-55) protein was over-expressed in HEK293 cells, which was genetically attached with 6x His tag. The protein was purified by nickel-charged resin and was then subjected to tryptic digestion. The phosphorylated peptides within the HIP-55 protein were enriched by TiO₂ affinity chromatography, followed by mass spectrometry analysis. Fourteen phosphorylation sites along the primary structure of HIP-55 protein were identified, most of which had not been previously reported. Our results indicate that bio-mass spectrometry coupled with manual interpretation can be used to successfully identify the phosphorylation modification in HIP-55 protein in HEK293 cells.     

不同诱导剂对工程菌发酵及重组蛋白表达的影响

目的观察不同诱导剂对工程菌发酵及HSP-MUC1重组蛋白表达的影响,从而选取最佳诱导表达条件。方法分别用IPTG和乳糖作为诱导剂,发酵表达HSP-MUCI重组蛋白质,并对重组蛋白质表达量和性状进行分析。结果用IPTG诱导发酵的菌体经普通匀浆法即可将细菌破碎;而用乳糖发酵的菌体经普通匀浆法不能破菌,通过延长发酵时间也能达到与IPTG诱导相同的表达量。结论乳糖可以作为基因工程重组蛋白的理想诱导剂。     

Hydrogen Peroxide-Inducible PROTACs for Targeted Protein Degradation in Cancer Cells

Proteolysis-targeting chimeras (PROTACs) provide a powerful technique to degrade targeted proteins utilizing the cellular ubiquitin-proteasome system. The major concern is the host toxicity resulting from their poor selectivity. Inducible PROTACs responding to exogenous stimulus, such as light, improve their specificity, but it is difficult for photo-activation in deep tissues. Herein, we develop H₂O₂-inducible PROTAC precursors 2 / 5 , which can be activated by endogenous H₂O₂ in cancer cells to release the active PROTACs 1 / 4 to effectively degrade targeted proteins. This results in the intended cytotoxicity towards cancer cells while targeted protein in normal cells remains almost unaffected. The higher Bromodomain-containing protein 4 (BRD4) degradation activity and cytotoxicity of 2 towards cancer cells is mainly due to the higher endogenous concentration of H₂O₂ in cancer cells (A549 and H1299), characterized by H₂O₂-responsive fluorescence probe 3 . Western blot assays and cytotoxicity experiments demonstrate that 2 degrades BRD4 more effectively and is more cytotoxic in H₂O₂-rich cancer cells than in H₂O₂-deficient normal cells. This method is also extended to estrogen receptor (ER)-PROTAC precursor 5 , showing H₂O₂-dependent ER degradation ability. Thus, we establish a novel strategy to induce targeted protein degradation in a H₂O₂-dependent way, which has the potential to improve the selectivity of PROTACs.     

Chemical Biology Toolbox to Visualize Protein Aggregation in Live Cells

Protein misfolding and aggregation is a complex biochemical process and has been associated with numerous human degenerative diseases. Developing novel chemical and biological tools and approaches to visualize aggregated proteins in live cells is in high demand for mechanistic studies, diagnostics, and therapeutics. In this review, we summarize the recent developments in the chemical biology toolbox applied to protein aggregation studies in live cells. These methods exploited fluorescent protein tags, fluorescent chemical tags, and small-molecule probes to visualize the protein-aggregation process, detect proteome stresses, and quantify the protein homeostasis network capacity. Inspired by these seminal works, we have generalized design principles for the development of new detection methods and probes in the future that will illuminate this important biological process.     

Metastatic Voyage of Ovarian Cancer Cells in Ascites with the Assistance of Various Cellular Components

Epithelial ovarian cancer (EOC) is the most lethal gynecologic malignancy and has a unique metastatic route using ascites, known as the transcoelomic root. However, studies on ascites and contained cellular components have not yet been sufficiently clarified. In this review, we focus on the significance of accumulating ascites, contained EOC cells in the form of spheroids, and interaction with non-malignant host cells. To become resistant against anoikis, EOC cells form spheroids in ascites, where epithelial-to-mesenchymal transition stimulated by transforming growth factor-β can be a key pathway. As spheroids form, EOC cells are also gaining the ability to attach and invade the peritoneum to induce intraperitoneal metastasis, as well as resistance to conventional chemotherapy. Recently, accumulating evidence suggests that EOC spheroids in ascites are composed of not only cancer cells, but also non-malignant cells existing with higher abundance than EOC cells in ascites, including macrophages, mesothelial cells, and lymphocytes. Moreover, hetero-cellular spheroids are demonstrated to form more aggregated spheroids and have higher adhesion ability for the mesothelial layer. To improve the poor prognosis, we need to elucidate the mechanisms of spheroid formation and interactions with non-malignant cells in ascites that are a unique tumor microenvironment for EOC.     

Nanoscopic Characterisation of Individual Endogenous Protein Aggregates in Human Neuronal Cells

The aberrant misfolding and subsequent conversion of monomeric protein into amyloid aggregates characterises many neurodegenerative disorders, including Parkinson's and Alzheimer's diseases. These aggregates are highly heterogeneous in structure, generally of low abundance and typically smaller than the diffraction limit of light (≈250 nm). To overcome the challenges these characteristics pose to the study of endogenous aggregates formed in cells, we have developed a method to characterise them at the nanometre scale without the need for a conjugated fluorophore. Using a combination of DNA PAINT and an amyloid‐specific aptamer, we demonstrate that this technique is able to detect and super‐resolve a range of aggregated species, including those formed by α‐synuclein and amyloid‐β. Additionally, this method enables endogenous protein aggregates within cells to be characterised. We found that neuronal cells derived from patients with Parkinson's disease contain a larger number of protein aggregates than those from healthy controls.     

Microsphere‐Mediated Protein Delivery into Cells

Delivering the goods : By coupling proteins to varyingly sized polymeric microspheres, it is possible to deliver them to cells in an easy and effective way. For this study a fluorescent protein (EGFP) and a functional enzyme (β‐galactosidase) were coupled to these particles. Evaluation of the cellular uptake after “beadfection” shows that the functionality and activity of these proteins were not adversely affected through coupling to the carrier system; this shows that their functional structure is retained.