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41.
Based on lithium aluminosilicate glass, the composition of glass was optimized by replacing SiO2 with B2O3, and the influence of glass composition on structure and performance was studied. With the increase in B2O3 concentrations from 0 to 6.5 mol%, Al2O3 always existed in the form of four-coordinated [AlO4] in the network structure, and B2O3 mainly entered the network in the form of four-coordinated [BO4]. The content of Si-O-Si linkages (Q4(0Al)) was always dominant. The incorporation of boron oxide improved the overall degree of polymerization and connectivity of the lithium aluminosilicate glass network structure. An increase in the degree of network polymerization led to a decrease in the thermal expansion coefficient of the glass and an increase in Vickers hardness and density. The durability of the glass in hydrofluoric acid and NaOH and KOH solutions was enhanced overall.  相似文献   
42.
目的:确定复方丙谷胺西昧替丁片溶出度测定的方法。方法:采用转篮法,以磷酸盐缓冲液(pH7.2)为溶出介质,转速100r·min^-1,高效液相法检测。结果:45分钟的溶出量不少于70%,三种主要成分丙谷胺、西咪替丁、尿囊素分别在120~280μg/ml;58.4~136.4μg/ml;65.3~153.7μg/ml范围内呈现良好的线性关系。结论:本方法操作简单,准确可靠,能满足质量控制的要求。  相似文献   
43.
分散片的处方和工艺   总被引:75,自引:1,他引:75  
分析了分散片的处方和工艺特点,及其在药物溶出度和生物利用度方面的优越性。  相似文献   
44.
目的综述龙胆苦苷的药学进展及临床配伍应用。方法查阅近20年的文献资料,总结龙胆苦苷的成分、结构、理化性质、药理作用、药代动力学研究及其临床应用情况。结果龙胆苦苷具有良好的抗炎、镇痛,保肝利胆和健胃养胃等作用;在体内分布较快,消除、排泄也较快。结论龙胆苦苷在临床上具有较高的应用价值,为开发新药及临床应用提供一定的参考。  相似文献   
45.
桂利嗪分散片溶出度测定的研究   总被引:1,自引:0,他引:1  
采用紫外分光光度法对桂利嗉分散片溶出度进行了测定。结果显示 ,本品 3批 3 min平均溶出量均超过标示量的 80 % ,提示该方法用于桂利嗪分散片的溶出度的测定快速简便、结果满意。  相似文献   
46.
齐红艺  李莉  余洁 《中国中药杂志》2013,38(19):3388-3394
Xenohormesis解释了为何植物受环境胁迫后产生的次生代谢产物能提高取食动物的胁迫耐受性与生存机会,认为在自然选择压力下动物保留着感知这些胁迫信号分子的能力,从而激活进化保守性的细胞应激响应机制,提高逆境适应力.该文在介绍Xenohormesis效应概念与机制,分析总结植物与昆虫及人类的Xenohormesis效应关系的基础上,以人参为例阐述了中药Xenohormesis效应,认为借鉴Xenohormesis理论能从进化与生态角度理解中药生物效应的本质,对中药现代化研究具重要价值.  相似文献   
47.
白藜芦醇的制备方法研究进展   总被引:2,自引:0,他引:2  
白藜芦醇是一种含有芪类结构的非黄酮类多酚化合物,在医药和食品工业中应用广泛,需求量大幅增加。本文综述了白藜芦醇的制备方法研究进展,包括天然植物提取法、化学合成法、生物工程技术法等,为进一步开发利用白藜芦醇提供依据。  相似文献   
48.
The conventional processing route of TNM (Ti-Nb-Mo) alloys combines casting and Hot Isostatic Pressing (HIP) followed by forging and multiple heat treatments to establish optimum properties. This is a time-consuming and costly process. In this study we present an advanced alternative TNM alloy processing route combining HIP and heat treatments into a single process, which we refer to as IHT (integrated HIP heat treatment), applied to a modified TNM alloy with 1.5B. A Quintus HIP lab unit with a quenching module was used, achieving fast and controlled cooling, which differs from the slow cooling rates of conventional HIP units. A Ti-42.5Al-3.5Nb-1Mo-1.5B (at.%) was subjected to an integrated two HIP steps at 200 MPa, one at 1250 °C for 3 h and another at 1260 °C for 1 h, both under a protective Ar atmosphere and followed by cooling at 30 K/min down to room temperature. The results were compared against the Ti-43.5Al-3.5Nb-1Mo-0.8B (at.%) thermomechanically processed in a conventional way. Applying IHT processing to the 1.5B alloy does indeed achieve good creep strength, and the secondary creep rate of the IHT processed materials is similar to that of conventionally forged TNM alloys. Thus, the proposed advanced IHT processing route could manufacture more cost-effective TiAl components.  相似文献   
49.
One of the biggest challenges in microbiome research in environmental and medical samples is to better understand functional properties of microbial community members at a single-cell level. Single-cell isotope probing has become a key tool for this purpose, but the current detection methods for determination of isotope incorporation into single cells do not allow high-throughput analyses. Here, we report on the development of an imaging-based approach termed stimulated Raman scattering–two-photon fluorescence in situ hybridization (SRS-FISH) for high-throughput metabolism and identity analyses of microbial communities with single-cell resolution. SRS-FISH offers an imaging speed of 10 to 100 ms per cell, which is two to three orders of magnitude faster than achievable by state-of-the-art methods. Using this technique, we delineated metabolic responses of 30,000 individual cells to various mucosal sugars in the human gut microbiome via incorporation of deuterium from heavy water as an activity marker. Application of SRS-FISH to investigate the utilization of host-derived nutrients by two major human gut microbiome taxa revealed that response to mucosal sugars tends to be dominated by Bacteroidales, with an unexpected finding that Clostridia can outperform Bacteroidales at foraging fucose. With high sensitivity and speed, SRS-FISH will enable researchers to probe the fine-scale temporal, spatial, and individual activity patterns of microbial cells in complex communities with unprecedented detail.

With the rapid advances in both genotyping and phenotyping of single cells, bridging genotype and phenotype at the single-cell level is becoming a new frontier of science (1). Methods have been developed to shed light on the genotype–metabolism relationship of individual cells in a complex environment (2, 3), which is especially relevant for an in-depth understanding of complex microbial communities in the environment and host-associated microbiomes. For functional analyses of microbial communities, single-cell isotope probing is often performed in combination with nanoscale secondary ion mass spectrometry (NanoSIMS) (47), microautoradiography (MAR) (8, 9), or spontaneous Raman microspectroscopy (1012) to visualize and quantify the incorporation of isotopes from labeled substrates. These methods can be combined with fluorescence in situ hybridization (FISH) using ribosomal ribonucleic acid (rRNA)-targeted probes (13), enabling a direct link between metabolism and identity of the organisms. In addition, Raman-activated cell sorting has been recently developed using either optical tweezers or cell ejection for downstream sequencing of the sorted cells (1416). While these approaches have expanded the possibilities for functional analyses of microbiome members (17), all of the aforementioned methods suffer from extremely limited throughput. Consequently, only relatively few samples and cells per sample are typically analyzed in single-cell stable isotope probing studies, hampering a comprehensive understanding of the function of microbes in their natural environment.To overcome the limited throughput of Raman spectroscopy, coherent Raman scattering microscopy based on coherent anti-Stokes Raman scattering (CARS) or stimulated Raman scattering (SRS) has been developed (18, 19). Compared with CARS, the SRS signal is free of the electronic resonance response (20) and is linear to molecular concentration, thus permitting quantitative mapping of biomolecules (21, 22). Both CARS and SRS microscopy have successfully been applied for studying single-cell metabolism in eukaryotes (2326). In a label-free manner, SRS imaging has led to the discovery of an aberrant cholesteryl ester storage in aggressive cancers (27, 28), lipid-rich protrusions in cancer cells under starvation (29), and fatty acid unsaturation in ovarian cancer stem cells (30) and more recently, in melanoma (31, 32). CARS and SRS have also been harnessed to explore lipid metabolism in live Caenorhabditis elegans (3336). Combined with stable isotope probing, SRS microscopy has allowed the tracing of glucose metabolism in eukaryotic cells (37, 38) and the visualization of metabolic dynamics in living animals (25). Recently, SRS was successfully applied to infer antibiotic resistance patterns of bacterial pure cultures and heavy water (D2O) metabolism (39). Yet, SRS microscopy has not been adapted for studying functional properties of members of microbiomes as SRS itself lacks the capability of identifying cells in a complex community.Here, we present an integrative platform that exploits the advantages of SRS for single-cell stable isotope probing together with two-photon FISH for the identification of cells in a high-throughput manner. To deal with the challenges in detecting low concentrations of metabolites inside small cells with diameters around 1 µm, we have developed a protocol that maximizes the isotope label content in cells and exploits the intense SRS signal from the Raman band used for isotope detection.Conventionally, FISH is performed separately by one-photon excited fluorescence microscopy (40). To enhance efficiency, we developed a system that implements highly sensitive SRS metabolic imaging with two-photon FISH using the same laser source. These efforts collectively led to a high-throughput platform that enables correlative imaging of cell identity and metabolism at a speed of 10 to 100 ms per cell. In comparison, it takes about 20 s to record a Raman spectrum from a single cell in a conventional spontaneous Raman FISH experiment (41, 42).Our technology enabled high-throughput analysis of single-cell metabolism in the human gut microbiome. In the human body, microbes have been shown to modulate the host’s health (43, 44). Analytical techniques looking into their activities and specific physiologies (i.e., phenotype) as a result of both genotype and the environment provide key information on how microbes function, interact with, and shape their host. As a proof of principle, we used stimulated Raman scattering–two-photon fluorescence in situ hybridization (SRS-FISH) to track the incorporation of deuterium (D) from D2O into a mixture of two distinct gut microbiota taxa. Incorporation of D from D2O into newly synthesized cellular components of active cells, such as lipids and proteins, occurs analogously to incorporation of hydrogen from water during the reductive steps of biosynthesis of various cellular molecules (10, 45, 46). Importantly, D incorporation from D2O has been shown to be reliable to track metabolic activity of individual cells within complex microbial communities in response to the addition of external substrates (10, 17, 47). When microbial communities are incubated in the presence of D2O under nutrient-limiting conditions, individual cells display only minimal activity and only minor D incorporation (11, 17, 47). In contrary, when cells are stimulated by the addition of an external nutrient, cells that can metabolize this compound become active and incorporate D into macromolecules, which lead to the presence of C-D bonds into the cell’s biomass. Consequently, D incorporation from D2O can be combined with techniques able to detect C-D signals, such as Raman-based approaches, and to track metabolic activity at the single-cell level in response to a variety of compounds. Here, we show that SRS-FISH enables fast and sensitive determination of the D content of individual cells while simultaneously unveiling their phylogenetic identity. We applied this technique to complex microbial communities by tracking in situ the metabolic responses of two major phylogenetic groups of microbes in the human gut (Bacteroidales and Clostridia spp.) and of a particular species within each group to supplemented host-derived nutrients. Our study revealed that 1) Clostridia spp. can actually outperform Bacteroidales spp. at foraging on the mucosal sugar fucose and shows 2) a significant interindividual variability of responses of these major microbiome taxa toward mucosal sugars. Together, our results demonstrate the capability of SRS-FISH to unveil the metabolism of particular microbes in complex communities at a throughput that is two to three orders of magnitude higher than other metabolism identity bridging tools, therefore providing a valuable multimodal platform to the field of single-cell analysis.  相似文献   
50.
Eicosapentaenoic acid (EPA), an omega-3 (ω-3) polyunsaturated fatty acid, is an essential nutrient that exhibits antiinflammatory, neuroprotective, and cardiovascular-protective activities. Although EPA is used as a nutrient-based pharmaceutical agent or dietary supplement, its molecular target(s) is debatable. Here, we showed that EPA and its metabolites strongly and reversibly inhibit vesicular nucleotide transporter (VNUT), a key molecule for vesicular storage and release of adenosine triphosphate (ATP) in purinergic chemical transmission. In vitro analysis showed that EPA inhibits human VNUT-mediated ATP uptake at a half-maximal inhibitory concentration (IC50) of 67 nM, acting as an allosteric modulator through competition with Cl. EPA impaired vesicular ATP release from neurons without affecting the vesicular release of other neurotransmitters. In vivo, VNUT−/− mice showed a delay in the onset of neuropathic pain and resistance to both neuropathic and inflammatory pain. EPA potently attenuated neuropathic and inflammatory pain in wild-type mice but not in VNUT−/− mice without affecting the basal nociception. The analgesic effect of EPA was canceled by the intrathecal injection of purinoceptor agonists and was stronger than that of existing drugs used for neuropathic pain treatment, with few side effects. Neuropathic pain impaired insulin sensitivity in previous studies, which was improved by EPA in the wild-type mice but not in the VNUT−/− mice. Our results showed that VNUT is a molecular target of EPA that attenuates neuropathic and inflammatory pain and insulin resistance. EPA may represent a unique nutrient-based treatment and prevention strategy for neurological, immunological, and metabolic diseases by targeting purinergic chemical transmission.

Omega-3 (ω-3) polyunsaturated fatty acids (PUFAs) are essential nutrients that contain multiple double bonds. PUFAs can be classified into ω-3 and ω-6 depending on the position of the bonds. As humans cannot produce PUFAs, they must be acquired from the diet to maintain homeostasis. Omega-3 PUFAs, such as eicosapentaenoic acid (EPA), are abundantly present in fish and linseed oil and exhibit antiinflammatory, neuroprotective, and cardiovascular-protective activities via the competitive inhibition of cyclooxygenase (COX)-2 in eicosanoid production (13). Danish and Greenland Inuit epidemiological studies have reported that EPA reduces the risk of death after myocardial infarction (4, 5), and other studies have reported its influence on analgesia, neuroinflammatory disease (Parkinson’s disease, Alzheimer’s disease, and depression) improvement, platelet aggregation inhibition, decrease in blood triglyceride and glucose levels, and improved insulin resistance (1, 611). Omega-3 fatty acid supplementation in COVID-19 patients showed a beneficial effect in managing the cytokine storm (12). Conversely, omega-6 fatty acids, such as arachidonic acid, produce inflammatory eicosanoids and play central roles in the initial stage of inflammatory responses (13). Although arachidonic acid has also been reported to produce antiinflammatory metabolites, omega-6 PUFA-derived linoleate diols have a harmful effect and are biomarkers for severe COVID-19 infection (14). An omega-6 PUFA-enriched Western-style diet, which abundantly contains linoleate, causes neuropathy and chronic pain, but an omega-3 PUFA-enriched diet attenuates these pathological conditions (15).All therapeutic effects of EPA cannot be explained by COX-2 inhibition alone (16). Typically, COX-2 inhibitors (nonsteroidal antiinflammatory druga [NSAIDs]) are effective for inflammatory pain but ineffective for neuropathic pain (16). However, EPA significantly attenuates both inflammatory and neuropathic pain, which strongly suggests another important molecular target of EPA related to neuropathy (7, 8). Although chronic pain is coincidentally caused by inflammation and neuropathy, there is no therapeutic drug with few side effects to attenuate both inflammatory and neuropathic pain (1720). In this situation, EPA may affect the key signaling molecule(s) in neurological, metabolic, and immunological functions.Purinergic chemical transmission is involved in neurological, metabolic, and immunological disruptions and functions, including neuropathic and inflammatory pain, depression, inflammation, increase in blood triglyceride and glucose levels, insulin resistance, and blood coagulation (21, 22). The released adenosine triphosphate (ATP) and degraded adenosine diphosphate (ADP) or adenosine binds to many types of purinoceptors that are intricately involved in biological and pathological processes. In pain perception, ATP and ADP bind to P2X and P2Y receptors and thereby exacerbate neuropathic and inflammatory pain (23). Adenosine binds to P1 receptors and thereby attenuates neuropathic and inflammatory pain (24). However, a vesicular nucleotide transporter (VNUT/SLC17A9) is localized in the secretory vesicles of neuronal, endocrine, and immune cells. It plays an essential role in vesicular ATP storage in a Δψ- and Cl-dependent manner in the purinergic chemical transmission, which leads to vesicular ATP release (25, 26). Thus, VNUT is a key molecule in the initiation of purinergic signaling for neurological, metabolic, and immunological disruptions and functions. Interestingly, the observed effects of the VNUT inhibitor and phenotypes of VNUT−/− mice were consistent with the above-mentioned therapeutic effects of EPA (2731). Therefore, we hypothesized that VNUT serves as a molecular target of EPA to attenuate neuropathic and inflammatory pain.Here, we demonstrated that a low concentration of EPA and its metabolites, but not docosahexaenoic acid (DHA), are potent and selective physiological inhibitors of vesicular ATP release via the blockade of purinergic chemical transmission, which improved neuropathic and inflammatory pain and insulin resistance. Furthermore, EPA is more effective for neuropathic and inflammatory pain and has fewer side effects than existing drugs.  相似文献   
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