RP-HPLC法测定克乳痛胶囊中丹皮酚和芍药甙的含量

建立了ＲＰ－ＨＰＬＣ法测定克乳痛胶囊中丹皮酚和芍药甙的含量,均用十八烷基硅烷键合硅胶为固定相;前者以甲醇－醋酸－水（５８２４０）为流动相,检测波长为２７４ｎｍ;后者以乙腈－水（２０８０）为流动相,检测波长为２４３ｎｍ。本法简便、快速、重现性好。     

应用PCR产物直接测序技术测定乙型肝炎病毒前C区基因序列

目的 :测定乙型重型肝炎和慢性乙型肝炎患者血清中乙型肝炎病毒前C区基因序列 ,探讨乙型肝炎病毒前C区基因变异的意义。方法 :采用PCR产物直接测序技术 ,测定 13例乙型重型肝炎和 10例慢性乙型肝炎患者血清中乙型肝炎病毒前C区基因序列 ,并与基因库中来自世界各地的不同基因型的毒株进行比较。结果 :患者血清中乙型肝炎病毒前C区基因序列 ,除发现乙型肝炎病毒前C区基因 1896位存在点变异外 ,还可见 184 6位点变异 ,且乙型重型肝炎患者发生病毒变异的频率明显高于慢性乙型肝炎 (P <0 .0 5 ) ,而 186 2位未检出变异。 1838位核苷酸全部为腺嘌呤核苷酸 (A) ,184 6位核苷酸大多为胸腺嘧啶核苷酸 (T) ,仅 4例发生了G→A点突变。经与不同基因型的毒株进行比较 ,提示沈阳地区流行的乙型肝炎病毒毒株接近美国株。结论 :乙型重型肝炎患者发生病毒变异的频率明显高于慢性乙型肝炎 ;沈阳地区流行的乙型肝炎病毒毒株接近美国株     

The Antibacterial and Cytotoxic Effects of Silver Nanoparticles Coated Titanium Implants: A Narrative Review

Nanotechnology has become an emerging research field with numerous biomedical scientific applications. Silver possesses bactericidal activities that have been harnessed for centuries; however, there is a concern about the toxic effects of silver nanoparticles. This paper aims to provide an overview of silver-treated dental implants and discuss their potential to reduce the prevalence of peri-implant diseases. An electronic search was performed using PubMed. After screening, data extraction was performed on the 45 remaining articles using inclusion and exclusion criteria. Most of the articles demonstrated that silver nanoparticles embedded in a coating layer and/or on surface-treated titanium exhibit sound antibacterial effects and biocompatibility. Most of the reviewed studies revealed that silver nanoparticles on dental implant surfaces reduced cytotoxicity but provided a prolonged antibacterial effect. The cytotoxicity and antibacterial effect are closely linked to how the silver nanoparticles are released from the titanium surfaces, where a slower release increases cell viability and proliferation. However, to improve the clinical translation, there is still a need for more studies, especially evaluating the long-term systemic effects and studies recreating the conditions in the oral cavity.     

Retinal phototoxicity from the operating microscope. The role of inspired oxygen

The effect of the inspired oxygen concentration (FIO2) on the production of retinal phototoxicity by the operating microscope was studied in phakic rhesus monkeys. One eye of each monkey was exposed to light under conditions of 99% FIO2, and the other eye was exposed under 21% oxygen (O2). Three of four locations on each retina were exposed to light for durations varying from 1 1/2 to 20 minutes per exposure. Fundus photographs and fluorescein angiograms were obtained 24 to 72 hours after exposure. Animals were euthanatized for analysis of retinal histopathology at intervals from 2 weeks to 8 months after light exposure. Retinal phototoxic lesions were produced after an average of 5 minutes of light exposure under both 21 and 99% O2. O2 potentiated the light damage both clinically and histologically. Under both conditions, lesion size was directly related to the duration of light exposure (P less than 0.005). Lesions near threshold produced with 99% FIO2 were 1.6 to 6.9 (mean, 2.9) times larger than the corresponding lesions formed with 21% FIO2. Histologic damage was likewise more severe in lesions produced under high O2 conditions. Retinal repair occurred in lesions produced under high and low O2 conditions. Photoreceptor regeneration was nearly complete by 18 weeks, whereas retinal pigment epithelial (RPE) recovery lagged up to 1 1/2 months. The results of this study have important implications for clinical practice: the operating microscope can produce retinal phototoxicity rapidly, and O2 administered during ophthalmic procedures may potentiate the damage if appropriate precautions are not taken.     

Real-Time Standard View Classification in Transthoracic Echocardiography Using Convolutional Neural Networks

Transthoracic echocardiography examinations are usually performed according to a protocol comprising different probe postures providing standard views of the heart. These are used as a basis when assessing cardiac function, and it is essential that the morphophysiological representations are correct. Clinical analysis is often initialized with the current view, and automatic classification can thus be useful in improving today's workflow. In this article, convolutional neural networks (CNNs) are used to create classification models predicting up to seven different cardiac views. Data sets of 2-D ultrasound acquired from studies totaling more than 500 patients and 7000 videos were included. State-of-the-art accuracies of 98.3% ± 0.6% and 98.9% ± 0.6% on single frames and sequences, respectively, and real-time performance with 4.4 ± 0.3 ms per frame were achieved. Further, it was found that CNNs have the potential for use in automatic multiplanar reformatting and orientation guidance. Using 3-D data to train models applicable for 2-D classification, we achieved a median deviation of 4° ± 3° from the optimal orientations.     

Design,synthesis and biological evaluation of 6‐substituted quinolines derived from cabozantinib as c‐Met inhibitors

Based on the cabozantinib scaffold, novel c‐Met inhibitors were rationalized from the limited knowledge of structure‐activity relationships for the quinoline 6‐position. Emphasis was given to modifications capable of engaging in additional polar interactions with the c‐Met active site. In addition, ortho‐fluorinations of the terminal benzene ring were explored. Fifteen new molecules were synthesized and evaluated in a c‐Met enzymatic binding assay. A wide range of substituents were tolerated in the quinoline 6‐position, while the ortho‐fluorinations performed were shown to give considerable reductions in the c‐Met binding affinity. The antiproliferative effects of the compounds were evaluated in the NCI60 cancer cell line panel. Most notably, compounds 15b and 18b were able to inhibit cell proliferation more efficiently than cabozantinib in leukemia, CNS, and breast cancer cell lines. The in vitro data agreed well with the in silico docking results, where additional hydrogen bonding was identified in the enzymatic pocket for the para‐amino substituted 15b and 18b .     

Enhanced X-ray absorption for micro-CT analysis of low density polymers

X-ray microtomography (micro-CT), one of the most resourceful instruments for high resolution 3D analysis, can provide qualitative and quantitative accurate structural and compositional information for a broad range of materials. Yet its contribution to the field of biopolymeric materials science is often limited by low imaging contrast due to scarce X-ray attenuation features, particularly for sponges and foam-like structures. This limitation can be overcome to some extent by adjusting the working parameters of micro-CT equipment. However, such approach also facilitates noise and artefacts, and solving the signal-to-noise trade-off has been always problematic. Searching for alternatives turns one’s attention towards the improvement of X-ray attenuation features. While several studies report the use of contrast agents for biological materials, studies to integrate multiple micro-CT approaches for biopolymers were not conducted so far. This method paper is thus aimed to serve as a platform for micro-CT analysis of low X-ray absorptive polymers. Here, several contrast enhancing artifices were developed and trialled on gelatin and poly(vinyl alcohol) biopolymer composites (GP). Accordingly, GP were modified with iodine, barium, silver-based chemicals and hexa(methyl disilazane) by two different methods, i.e. addition of high atomic number chemicals during materials synthesis and post-synthesis staining, respectively. Consequently, cross-sectional scanning electron microscopy emerged as complementary characterization, aimed to confirm the reproducibility of samples morphological features. The most versatile methods were barium chloride additive incorporation and iodine staining coupled with hexa(methyl disilazane) chemical drying. Both methods significantly improved the X-ray absorbance of our polymeric samples, providing better contrast of micro-CT tomograms.     

Inflammation in the pleural cavity following injection of multi-walled carbon nanotubes is dependent on their characteristics and the presence of IL-1 genes

Upon inhalation, multi-walled carbon nanotubes (MWCNTs) may reach the subpleura and pleural spaces, and induce pleural inflammation and/or mesothelioma in humans. However, the mechanisms of MWCNT-induced pathology after direct intrapleural injections are still only partly elucidated. In particular, a role of the proinflammatory interleukin-1 (IL-1) cytokines in pleural inflammation has so far not been published. We examined the MWCNT-induced pleural inflammation, gene expression abnormalities, and the modifying role of IL-1α and β cytokines following intrapleural injection of two types of MWCNTs (CNT-1 and CNT-2) compared with crocidolite asbestos in IL-1 wild-type (WT) and IL-1α/β KO (IL1-KO) mice. Histopathological examination of the pleura 28?days post-exposure revealed mesothelial cell hyperplasia, leukocyte infiltration, and fibrosis occurring in the CNT-1 (Mitsui-7)-exposed group. The pleura of these mice also showed the greatest changes in mRNA and miRNA expression levels, closely followed by CNT-2. In addition, the CNT-1-exposed group also presented the greatest infiltrations of leukocytes and proliferation of fibrous tissue. WT mice were more prone to development of sustained inflammation and fibrosis than IL1-KO mice. Prominent differences in genetic and epigenetic changes were also observed between the two genotypes. In conclusion, the fibrotic response to MWCNTs in the pleura depends on the particles’ physico-chemical properties and on the presence or absence of the IL-1 genes. Furthermore, we found that CNT-1 was the most potent inducer of inflammatory responses, followed by CNT-2 and crocidolite asbestos.