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1.
RNA binding protein with multiple splicing (RBPMS) is expressed exclusively in retinal ganglion cells (RGCs) in the retina and can label all RGCs in normal retinas of mice, rats, guinea pigs, rabbits, cats, and monkeys, but its function in these cells is not known. As a result of the limited knowledge regarding RBPMS, we analyzed the expression of RBPMS in the retina of different mammalian species (humans, pigs, and rats), in various stages of development (neonatal and adult) and with different levels of injury (control, hypoxia, and organotypic culture or explants). In control conditions, RBPMS was localized in the RGCs somas in the ganglion cell layer, whereas in hypoxic conditions, it was localized in the RGCs dendrites in the inner plexiform layer. Such differential distributions of RBPMS occurred in all analyzed species, and in adult and neonatal retinas. Furthermore, we demonstrate RBPMS localization in the degenerating RGCs axons in the nerve fiber layer of retinal explants. This is the first evidence regarding the possible transport of RBPMS in response to physiological damage in a mammalian retina. Therefore, RBPMS should be further investigated in relation to its role in axonal and dendritic degeneration.  相似文献   

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王彦  左宁  姜媛媛  陈芳媛 《化工进展》2020,39(4):1539-1549
污泥生物炭中氮硫元素含量高,其氮硫行为和环境效应对全球气候变化的影响不容忽视。以往的研究中,研究者往往以富碳生物炭作为主要研究对象,关注碳对全球气候变化的行为和功效,而对氮硫元素的作用关注不够。本文从原始污泥基本性质到其热解过程,再到生物炭的老化,逐步对污泥生物炭整个生命周期内氮硫的行为及其环境效应研究进行综述,并对未来应注重开展的研究方向进行展望,为生物炭中氮硫元素固定、释放及与之关联的环境效应和温室气体排放控制研究提供理论基础。分析表明,污泥中氮元素含量普遍高于硫元素,且热解过程中氮比硫更容易转移至气相产物。氮硫元素随热解温度的增加,在三相产物中的分配都是炭中持续减少,油中先增后减,气中一直增加。高温(>800℃)条件下,气相中的氮含量高于固相,而硫元素则仍然主要存在于固相中。污泥生物炭老化及其环境效应研究表明,污泥生物炭氮硫元素与土壤的相互作用及其温室效应问题在今后的研究中应引起重视。  相似文献   

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In rats with hyperlipemia induced by Triton WR-1339, changes in tocopherol concentrations in plasma and RBC were compared with those in the liver and its subcellular fractions, microsomes and mitochondria. After daily injection with Triton, plssma total lipids at 3 days and 7 days, respectively, showed elevation 6.5 times and 15 times as high as those in the control rats, and triglycerides showed the most predominant elevation. With the hyperlipemia, the concentrations of tocopherol in RBC and the subcellular fractions decreased, as plasma lipids and plasma tocopherol increased, while no change occurred in tocopherol concentrations in liver homogenates. The changes in the ratio of tocopherol to total lipids in plasma coincided with changes in tocopherol concentrations in the RBC and subcellular fractions.  相似文献   

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Mean intakes of dietary fiber (DF) were estimated in the population of Central America and Panama, using the results of dietary surveys conducted in 1969 and 1986 both in rural and urban areas, as well as data on the DF content of foods as consumed in the region. Data on preschool children were also estimated. The results indicated that DF intake in urban areas is lower than that of rural areas, particularly in Costa Rica and Panama. In 1969, intake varied from 32g in El Salvador to 15g in Panama in urban areas, while in rural areas intake was from 45g in El Salvador to 13g in Panama. The foods which contributed most to the total intake in Guatemala, El Salvador and Honduras were tortillas and beans, while in Costa Rica and Panama, beans provided the largest intake. In preeschool children, intake was 12.5g in El Salvador and 5.4g in Costa Rica in 1969, which is the same tendency as that found for adults. From more recent data on food intake, it was found that DF intake had decreased in the rural areas of El Salvador, Honduras and Costa Rica, being between 4 and 9% in the first two countries and 12% in Costa Rica. In the urban area of the latter, from 1969 to 1986 a decrease in DF intake of around 20% has taken place.  相似文献   

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The profile of sphingomyelin and its metabolites shows changes in the plasma, organs, and tissues of patients with cardiovascular, renal, and metabolic diseases. The objective of this study was to investigate the effect of empagliflozin on the levels of sphingomyelin and its metabolites, as well as on the activity of acid and neutral sphingomyelinase (aSMase and nSMase) and neutral ceramidase (nCDase) in the plasma, kidney, heart, and liver of streptozotocin-induced diabetic and Angiotensin II (Ang II)-induced hypertension rats. Empagliflozin treatment decreased hyperglycemia in diabetic rats whereas blood pressure remained elevated in hypertensive rats. In diabetic rats, empagliflozin treatment decreased sphingomyelin in the plasma and liver, ceramide in the heart, sphingosine-1-phosphate (S1P) in the kidney, and nCDase activity in the plasma, heart, and liver. In hypertensive rats, empagliflozin treatment decreased sphingomyelin in the plasma, kidney, and liver; S1P in the plasma and kidney; aSMase in the heart, and nCDase activity in the plasma, kidney, and heart. Our results suggest that empagliflozin downregulates the interaction of the de novo pathway and the catabolic pathway of sphingolipid metabolism in the diabetes, whereas in Ang II-dependent hypertension, it only downregulates the sphingolipid catabolic pathway.  相似文献   

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To evaluate the effects of strain, gender and fasting in the regulation of lipoprotein lipase (LPL) and hepatic lipase (HL) activities were measured in tissues of male and female Wistar and Sprague-Dawley rats after feeding or a 24-h starvation period. It is noteworthy that an effect of gender on LPL activity was observed in Wistar, but not in Sprague-Dawley rats, not in the basal (fed) activity in several tissues, such as white and brown adipose tissues, heart, and brain, but also in response to fasting which affected LPL activity in brown adipose tissue, heat and lung of female but not of male Wistar rats. By contrast, HL activity in liver, plasma and adrenals of Sprague-Dawley rats was higher in females than in males. No effect of gender on HL activity was observed in Wistar rats. Our results indicate that differences exist between Wistar and Sprague-Dawley rats in the regulation of both LPL and HL. Some of the contradictory results found in the literature may be explained by the differences between rat strains and gender, as well as differences in the nutritional status of the animals.  相似文献   

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Histone deacetylases (HDACs) are conserved enzymes that remove acetyl groups from lysine side chains in histones and other proteins and play a crucial role in epigenetic regulation. Previously, we showed that histone acetylation is implicated in ultraviolet (UV)-induced inflammation and matrix impairment. To elucidate the histone acetylation status and specific HDACs involved in skin aging, we examined the changes in histone acetylation, global HDAC activity, and the expression of HDACs and sirtuins (SIRTs) in intrinsically aged and photoaged human skin as well as in UV-irradiated human skin in vivo. Following acute UV irradiation, the acetylated histone H3 (AcH3) level was increased, but HDAC activity and the expression levels of HDAC4, HDAC11, and SIRT4 were significantly decreased. In intrinsically aged skin, AcH3 levels were increased, but HDAC activity and the expression levels of HDAC4, HDAC5, HDAC10, HDAC11, SIRT6, and SIRT7 were significantly decreased. However, histone acetylation and HDAC expression in photoaged skin were not significantly different from those in intrinsically aged skin. Collectively, HDAC4 and HDAC11 were decreased in both UV-irradiated and intrinsically aged skin, suggesting that they may play a universal role in increased histone acetylation associated with skin aging.  相似文献   

9.
Pyrolysis of melamine–formaldehyde and urea–formaldehyde resins in helium and air was investigated by means of TG and gravimetry with isothermal heating, as well as elemental and HCN analyses. Weight loss curves suggest three kinds of reactions involved in the pyrolysis, namely, initiation reactions, reactions splitting off volatile fragments, and reactions forming stabilized structures. In TG, in both helium and air atmospheres, the active weight loss of the melamine resin was completed in two steps, and that of the urea resin was completed in one step, which, however, consisted of a few small successive steps. The isothermal heating weight losses progressed through a few stages of first- and zeroth-order reactions. Arrhenius parameters were obtained for the weight losses in TG and with isothermal heating. The residue from the melamine resin is rich in carbon and nitrogen, and poor in oxygen and hydrogen, while that from the urea resin is rich in carbon, and poor in nitrogen, oxygen, and hydrogen. The effects of temperature on HCN yield changed, depending on the amount of air fed. The melamine resin evolved much more HCN than the urea resin because of the more stable C—N linkages in the resin.  相似文献   

10.
任平  赵洁  居莹  王玉  沈康俊  刘曙 《中国塑料》2022,36(2):139-146
汇总了国内外法规、标准、技术指南和文献中与食品接触材料相关的41种初级芳香胺(PAAs),分析了食品接触材料中PAAs的来源和迁移风险,对比了2021年以前中国、欧盟、韩国等国家及地区PAAs相关技术法规的差异.研究发现,食品接触材料中PAAs主要来源于偶氮着色剂、芳香族异氰酸酯以及其他助剂;聚酰胺餐厨具、有色塑料制品...  相似文献   

11.
The use of surfactants in polymerization reactions is particularly important, mainly in emulsion polymerizations. Further, micelles from biocompatible surfactants find use in pharmaceutical dosage forms. This paper reviews recent developments in the synthesis of novel gemini and bicephalous surfactants, micelle formation, and their applications in polymer and nanoparticle synthesis, oil recovery, catalysis, corrosion, protein binding, and biomedical area, particularly in drug delivery.  相似文献   

12.
廖玮婷  解新安  李璐  李雁  樊荻  孙娇  王鑫 《化工进展》2019,38(5):2205-2211
通过研究木质素分别在超临界甲醇和乙醇溶剂中的液化过程,分析反应温度(260~340℃)及反应时间(0~120min)对木质素在两种溶剂中的转化率、生物油收率及其组分差异的影响。实验表明,木质素在超临界乙醇中的转化率及产物收率均高于甲醇。当反应温度340℃,反应时间60min,木质素在超临界乙醇中的转化率和生物油收率比在甲醇中分别提高了16.23%和11.54%,残渣收率降低了16.23%。通过GC-MS和FTIR对生物油和残渣分析,发现生物油组分中芳香族化合物相对含量较高,在甲醇和乙醇溶剂中分别达到66.13%和58.84%;随着反应时间的延长,甲醇溶剂中残渣的醚键官能团逐渐增强,而在乙醇溶剂中则先增强后减弱。分析认为在木质素降解过程中,超临界乙醇和甲醇均可产生氢自由基作为供氢体,攻击木质素及其大分子片段中的官能团,同时使液化产物中的活性片段减活,减弱重聚合反应,从而更利于芳烃产物的生成。而甲醇在液化过程中容易与木质素断键产生的苯酚中间体发生脱氢缩合反应,通过醚键聚合产生长链芳香族化合物,形成残渣,降低生物油收率。  相似文献   

13.
To investigate the effect of eupatilin in asthma treatment, we evaluated its therapeutic effect and related signal transduction in OVA-induced asthmatic mice and LPS-stimulated RAW264.7 cells. The BALF was tested for changes in lung inflammatory cells. Th2 cytokines in the BALF and OVA-IgE in the serum were measured by ELISA. H&E and PAS staining were used to evaluate histopathological changes in mouse lungs. The key proteins NF-κB, MAPK, and Nrf2 in lung tissues were quantitatively analyzed by Western blotting. Finally, we evaluated the effect of eupatilin on cytokines and related protein expression in LPS-stimulated RAW 264.7 cells in vitro. In OVA-induced asthmatic mice, eupatilin reduced the numbers of inflammatory cells, especially neutrophils and eosinophils. Eupatilin also decreased the levels of IL-5, IL-13 in the BALF and OVA-IgE in the serum. Furthermore, eupatilin inhibited the activation of NF-κB and MAPK pathways and increased the expression of Nrf2 in OVA-induced asthmatic mice. In vitro, eupatilin significantly reduced LPS-stimulated NO, IL-6, and ROS production. Additionally, the NF-κB, MAPK, and Nrf2 protein expression in LPS-stimulated RAW264.7 cells was consistent with that in OVA-induced asthmatic lung tissues. In summary, eupatilin attenuated OVA-induced asthma by regulating NF-κB, MAPK, and Nrf2 signaling pathways. These results suggest the utility of eupatilin as an anti-inflammatory drug for asthma treatment.  相似文献   

14.
This study aimed to describe glutathione peroxidase 4 (GPx4) in rat oocytes, preimplantation embryos, and female genital organs. After copulation, Sprague Dawley female rats were euthanized with anesthetic on the first (D1), third (D3), and fifth days of pregnancy (D5). Ovaries, oviducts, and uterine horns were removed, and oocytes and preimplantation embryos were obtained. Immunohistochemical, immunofluorescent, and Western blot methods were employed. Using immunofluorescence, we detected GPx4 in both the oocytes and preimplantation embryos. Whereas in the oocytes, GPx4 was homogeneously diffused, in the blastomeres, granules were formed, and in the blastocysts, even clusters were present mainly around the cell nuclei. Employing immunohistochemistry, we detected GPx4 inside the ovary in the corpus luteum, stroma, follicles, and blood vessels. In the oviduct, the enzyme was present in the epithelium, stroma, blood vessels, and smooth muscles. In the uterus, GPx4 was found in the endometrium, myometrium, blood vessels, and stroma. Moreover, we observed GPx4 positive granules in the uterine gland epithelium on D1 and D3 and cytoplasm of fibroblasts forming in the decidua on D5. Western blot showed the highest GPx4 levels in the uterus and the lowest levels in the ovary. Our results show that the GPx4 is necessary as early as in the preimplantation development of a new individual because we detected it in an unfertilized oocyte in a blastocyst and not only after implantation, as was previously thought.  相似文献   

15.
The orientation, spatial displacement and interaction of solid particles, in vacua and in liquid media, polarised in electrical and in magnetic fields, are computed. The separation effect in mixtures of particulate solids in the superimposed electromagnetic and gravitational fields is then analysed and the simple graphico-analytical method of positioning particles in superimposed fields is developed, with examples of such separations.  相似文献   

16.
简要介绍纤维素酶的酶学性质、降解机制、生产工程菌的选育、纤维素酶的应用情况,以及对纤维素酶生产与应用方面存在的问题和未来发展趋势进行了分析与探讨。纤维素酶在食品、酿造行业、农副产品深加工、饲料、医药、环境保护和化工等领域有着非常广阔的应用前景和应用潜力。我国纤维素酶的生产及应用研究近年来取得了很大进展,今后必将在应用深度和广度上进一步扩展。  相似文献   

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The non-selective cation channel TRPA1 is best known as a broadly-tuned sensor expressed in nociceptive neurons, where it plays key functions in chemo-, thermo-, and mechano-sensing. However, in this review we illustrate how this channel is expressed also in cells of the immune system. TRPA1 has been detected, mainly with biochemical techniques, in eosinophils, mast cells, macrophages, dendritic cells, T cells, and B cells, but not in neutrophils. Functional measurements, in contrast, remain very scarce. No studies have been reported in basophils and NK cells. TRPA1 in immune cells has been linked to arthritis (neutrophils), anaphylaxis and atopic dermatitis (mast cells), atherosclerosis, renal injury, cardiac hypertrophy and inflammatory bowel disease (macrophages), and colitis (T cells). The contribution of TRPA1 to immunity is dual: as detector of cell stress, tissue injury, and exogenous noxious stimuli it leads to defensive responses, but in conditions of aberrant regulation it contributes to the exacerbation of inflammatory conditions. Future studies should aim at characterizing the functional properties of TRPA1 in immune cells, an essential step in understanding its roles in inflammation and its potential as therapeutic target.  相似文献   

19.
目的观察去上皮羊膜及其浸提液体外诱导骨髓间充质干细胞(Bone marrow mesenchymal stem cells,BMSCs)向上皮细胞的分化,并探讨其机制。方法从胎儿四肢长骨分离BMSCs,扩增后采用流式细胞术分析第3代(P3)细胞表面抗原(CD29、CD34、CD71和HLA-DR)的表达,并用4,6-乙酰基-2-苯基吲哚(DAPI)标记第4代BMSCs(P4-BMSCs)。机械法去除正常胎盘羊膜上皮,制成去上皮羊膜,并制备去上皮羊膜浸提液。将DAPI标记的BMSCs接种于羊膜上,设加或不加表皮细胞生长因子(Epidermal growth factor,EGF)、类胰岛素1号生长因子(Insulin-like growth factor 1,IGF-1)、羊膜浸提液诱导组及细胞爬片对照组,体外诱导培养后,采用免疫荧光组织(细胞)化学染色学法检测各组细胞角蛋白(Cytokeratin,CK)、EGF-R和IGF-1-R的表达,并于诱导后第10天计算CK阳性细胞率。结果原代BMSCs呈典型旋涡状生长,P3细胞表达CD29和CD71,不表达CD34和HLA-DR。羊膜组和细胞爬片组BMSCs在加入EGF或IGF-1诱导后,表达EGF-R和IGF-1-R的时间较未加生长因子的对照组提前2~4 d,表达CK的时间提前2~6 d,单用羊膜组或羊膜浸提液组的表达时间差异无统计学意义(P>0.05);诱导第10天,单用羊膜或羊膜浸提液诱导组的CK阳性细胞表达率明显高于细胞爬片对照组(P<0.05);羊膜与EGF、IGF-1联合诱导组高于单用羊膜组(P<0.05);EGF诱导组高于IGF-1诱导组(P<0.05)。结论羊膜及羊膜浸提液、外源性EGF和IGF-1在体外均可诱导BMSCs向上皮细胞分化,羊膜可能主要通过其所含的细胞因子诱导BMSCs向上皮分化。  相似文献   

20.
Changes in starch characteristics caused by alkaline-cooking in two corn genotypes (hard and soft) were studied in the present work. Color, pH, pasting properties (Brabender viscoamylograph), water sorption, solubility, swelling power and thermal analysis (Differential scanning calorimetry) were determined in starches previously extracted, from raw and alkaline-cooked hard and soft corns. A reduction in maximum viscosity peak, temperature at the endothermic peak and swelling power at 90 degrees C, and an increase in solubility was observed in starches obtained from both hard and soft corn after alkaline-cooking. Starch from hard corn showed an increment in initial pasting temperature after alkaline-cooking. Alkaline-cooking induced higher modifications in hard than in soft corn starch, probably as a result of its endosperm type and grain hardness, although optimum cooking times were used for each corn genotype.  相似文献   

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