稀土上转光剂掺杂纳米TiO2催化可见光降解甲基紫

合成了一种新型含有稀土金属Er的上转光剂,此上转光剂在488nm可见光的激发下,可产生5个波长均小于387nm的上转换紫外发射峰。采用超声波分散的方法制备出了上转光剂掺杂的纳米TiO2,可见光光催化剂。实验结果表明,作为掺杂成分的上转光剂可有效地将可见光转化为紫外光并被纳米TiO2粉末吸收利用, 紫外光谱和离子色谱分析表明,在可见光照射16小时后甲基紫分解产物为Cl-和NO3-等,其降解率达92．2%, 大大高于未掺杂纳米TiO2的降解率71．2％。     

高效液相色谱法同时测定红景天中维生素D和E研究

用高效液相色谱法首次测定了红景天中维生素D和E的含量。在NOVA -PakC1 8柱上 ,甲醇作流动相 ,紫外检测。实验回收率大于 92 .5 % ,变异系数小于 2 .0 % ,维生素D和E的检出限分别为 1 .0ng ,7.1ng。特征波长的应用 ,使分析方法更为简便、准确。     

紫外分光光度法快速测定哌嗪

哌嗪紫外吸收弱，最强峰对应波长处吸光度线性范围窄，因此紫外分光光度法在呱嗪检测中的应用受到了限制。根据哌嗪紫外吸收特点．探讨了对哌嗪水溶液进行紫外分光光波法快速测定的方法．该方法不采用哌嗪紫外吸收最强蜂对应波长作为测定波长，而采用了基线干噪和波段积分等手段对哌嗪紫外吸收光潜进行了数据处理，因此该方法的准确度和精确度得到了保证，回收率实验和精密度实验的结果表明．该方法的准确和精确度良好．     

含受阻胺结构的苯并三唑光稳定性和热稳定性研究

测试了4种2-[2’-羟基-3’-叔丁基-5’-（3-丙酸-4-哌啶酯基）苯基]-2H-苯并三唑结构类光稳定剂紫外吸收光谱、光稳定性及热稳定性。4种化合物在270～400nm均有较强的吸收峰,与引入受阻胺结构前苯并三唑光稳定剂相比．紫外吸收波长和摩尔消光系数不变。4种化合物的光稳定性和热稳定性明显高于引入受阻胺结构前的苯并三唑光稳定剂。光老化12h后,4种化合物仅分解3．2％～6．9％,引入受阻胺结构前苯并三唑则分解35．0％～36．3％。热稳定性测试表明。4种化合物失重1％时的温度为264～272℃．而引入受阻胺结构前苯并三唑失重1％时的温度分别为227℃和235℃。该类化合物分子内同时具有紫外吸收剂和自由基捕获剂两种功能,为高效光稳定剂。     

固相敏化剂光敏异构化速甾醇为预维生素D3的研究

光敏异构化速甾醇为预维生素D3是高产率合成维生素D3的重要反应.目前专利和文献报道的应用于这个反应的多为有机小分子敏化剂和可溶高分子敏化剂.由于存在分离困难和漂白等问题,限制了它们在实际生产中的应用.研究开发具有高敏化效率并且易于体系分离的新型敏化剂是将速甾醇光敏异构化为预维生素D3反应应用于工业化生产的重要工作.     

HPLC法测定维生素D3粉中有关物质

目的:建立HPLC测定维生素D3粉中有关物质的方法。方法:艾杰尔,Venusil XBP Silica C18色谱柱(4.6 mm×250 mm,3μm);流动相:正己烷∶正戊醇(996.5∶3.5);柱温:30℃;流速:2.0 mL/min;检测波长:265 nm、281 nm双波长检测;外标法定量。结果:维生素D3色谱峰与其相邻杂质峰能完全分离,各已知杂质峰能完全分离,各杂质具有良好的检测限。结论:该法简便,灵敏,专属性强,适用于维生素D3粉原料质量控制要求,亦可用于含维生素D3的制剂的维生素D3有关物质测定。     

感光科学与光化学(学报)2003年第21卷总目次

特约综述　基于羧酸银的光敏热成像技术进展 DavidR .Whitcomb( 1 19)…………………………………研究快讯　硅胶固载光敏剂的合成及其在反式维生素D3 光敏异构化为顺式维生素D3 中的　　应用 高云燕 ,游长江 ,陈金平 ,李　 ( 1 2 4 )……………………………………………………研究论文　咪碳菁类染料在溶液中的聚集行为 闫文 ,钱惠红 ,黄德音 ( 1 2 5)……………………………　二苯胺 4 偶氮磺酸盐及其树脂的制备和光、热分解性质 罗　? ,曹维孝 ( 1 30 )…………　紫外线对BaFCl:Eu光激励发光的增强效应 李　捷 ,韩　莉 ,薛敏…     

无溶剂干法固相合成1,3,4-噁二唑衍生物

以对称二酰基肼和P2O5为原料用无溶剂干法固相合成了一系列1,3,4-噁二唑衍生物,研究了取代基的种类和取代位置对产物收率的影响,并采用荧光发射光谱和紫外-可见吸收光谱测定了其光物理化学性能。结果表明,在所合成的衍生物中,氟原子在对位取代时产率最高;强吸电性的硝基,使荧光发射波长和紫外-可见吸收波长发生明显的红移。此法避免使用大量有机溶剂,节约资源、减少了环境污染。     

云南松树皮提取物的性能研究

以乙酸乙酯-水为溶剂对云南松树皮进行提取。对提取产物的溶解性、紫外吸收光谱、热稳定性、光稳定性和抗氧化性进行了研究。结果表明,云南松树皮提取物具有较好的水溶性,最大吸收波长为 280 nm,当温度≤60℃时,对热稳定,具有一定的耐光性;对食用油脂具有良好的抗氧化作用。     

壳聚糖支载菁染料荧光探针及荧光特性

壳聚糖支载有机荧光染料可在生理条件下改变其荧光特性,本文采用壳聚糖(CTS)支载有机荧光染料Cy3,利用红外光谱和热分析对产物进行了表征,研究了壳聚糖支载的荧光染料紫外吸收光谱和荧光光谱特性,结果表明,壳聚糖支载的荧光染料Cy3的紫外吸收特征峰的波长无明显变化,荧光强度明显增强,支载后的荧光染料光稳定性良好,初步细胞标记实验显示,壳聚糖支载后的Cy3染料对脑胶质瘤细胞具有良好的亲和性,并能穿透细胞膜且发出明显荧光。     

维生素D2生产新工艺

经预处理、萃取、浓缩、结晶等过程从富含麦角固醇的菌丝体中提取麦角固醇,并用自制紫外光源和反应器将其转化为维生素D_2。此新工艺成本低,麦角固醇转化率高,具有良好的经济效益,得到的麦角固醇和维生素D_2分别符合SIGMA公司试剂标准和国家药典标准。     

Vitamin D-Bestimmung in Margarine

Determination of Vitamin D in Margarine The very low Vitamin D content of margarine necessitates for its quantitative determination a very elaborate working up of the sample. After cold saponification and extraction of the unsaponifiables a preliminary purification is carried out on an Aluminium-oxide-Digitonin/Celite column. The other impurities are eliminated by HPLC on an adsorption column and by collecting the Vitamin D fraction. The final analysis is done by HPLC on a reversed phase system which allows a separation of Vitamin D₂ and D₃. Whichever D-Vitamin is not contained in the sample is used as an internal standard.     

Antitumor Effects of Vitamin D Analogs on Hamster and Mouse Melanoma Cell Lines in Relation to Melanin Pigmentation

Deregulated melanogenesis is involved in melanomagenesis and melanoma progression and resistance to therapy. Vitamin D analogs have anti-melanoma activity. While the hypercalcaemic effect of the active form of Vitamin D (1,25(OH)₂D₃) limits its therapeutic use, novel Vitamin D analogs with a modified side chain demonstrate low calcaemic activity. We therefore examined the effect of secosteroidal analogs, both classic (1,25(OH)₂D₃ and 25(OH)D₃), and novel relatively non-calcemic ones (20(OH)D₃, calcipotriol, 21(OH)pD, pD and 20(OH)pL), on proliferation, colony formation in monolayer and soft-agar, and mRNA and protein expression by melanoma cells. Murine B16-F10 and hamster Bomirski Ab cell lines were shown to be effective models to study how melanogenesis affects anti-melanoma treatment. Novel Vitamin D analogs with a short side-chain and lumisterol-like 20(OH)pL efficiently inhibited rodent melanoma growth. Moderate pigmentation sensitized rodent melanoma cells towards Vitamin D analogs, and altered expression of key genes involved in Vitamin D signaling, which was opposite to the effect on heavily pigmented cells. Interestingly, melanogenesis inhibited ligand-induced Vitamin D receptor translocation and ligand-induced expression of VDR and CYP24A1 genes. These findings indicate that melanogenesis can affect the anti-melanoma activity of Vitamin D analogs in a complex manner.     

The Role of Vitamin D and Vitamin D Binding Protein in Chronic Liver Diseases

Vitamin D (calciferol) is a fat-soluble vitamin that has a significant role in phospho-calcium metabolism, maintaining normal calcium levels and bone health development. The most important compounds of vitamin D are cholecalciferol (vitamin D3, or VD3) and ergocalciferol (vitamin D2, or VD2). Besides its major role in maintaining an adequate level of calcium and phosphate concentrations, vitamin D is involved in cell growth and differentiation and immune function. Recently, the association between vitamin D deficiency and the progression of fibrosis in chronic liver disease (CLD) was confirmed, given the hepatic activation process and high prevalence of vitamin D deficiency in these diseases. There are reports of vitamin D deficiency in CLD regardless of the etiology (chronic viral hepatitis, alcoholic cirrhosis, non-alcoholic fatty liver disease, primary biliary cirrhosis, or autoimmune hepatitis). Vitamin D binding protein (VDBP) is synthesized by the liver and has the role of binding and transporting vitamin D and its metabolites to the target organs. VDBP also plays an important role in inflammatory response secondary to tissue damage, being involved in the degradation of actin. As intense research during the last decades revealed the possible role of vitamin D in liver diseases, a deeper understanding of the vitamin D, vitamin D receptors (VDRs), and VDBP involvement in liver inflammation and fibrogenesis could represent the basis for the development of new strategies for diagnosis, prognosis, and treatment of liver diseases. This narrative review presents an overview of the evidence of the role of vitamin D and VDBP in CLD, both at the experimental and clinical levels.     

Vitamin D-Bestimmung in Lebertran

Determination of Vitamin D in Fish-Liver Oil The relative high content of vitamin D in fish-liver oil compared to margarine can be determined by HPLC without problems. Many accompanying substances which influence the determination are removed by the purification steps on an Aluminium-oxide-Digitonin/Celite column and subsequently by HPLC on an adsorption column. The final analysis is carried out on a reversed phase column. Vitamin D₂ is used as an internal standard.     

Effects of Vitamin D Supplementation on Adipose Tissue Inflammation and NF-κB/AMPK Activation in Obese Mice Fed a High-Fat Diet

Adipose tissue expansion is strongly associated with increased adipose macrophage infiltration and adipocyte-derived pro-inflammatory cytokines, contributing to obesity-associated low-grade inflammation. Individuals with vitamin D deficiency have an increased prevalence of obesity and increased circulating inflammatory cytokines. However, the effect of vitamin D supplementation on obesity-induced inflammation remains controversial. Male C57BL/6J mice received a low-fat (10% fat) or high-fat (HF, 60% fat diet) containing 1000 IU vitamin D/kg diet, or HF supplemented with 10,000 IU vitamin D/kg diet for 16 weeks (n = 9/group). Vitamin D supplementation did not decrease HF-increased body weight but attenuated obesity-induced adipose hypertrophy and macrophage recruitment as demonstrated by the number of crown-like structures. Vitamin D supplementation significantly reduced the mRNA expression of CD11c, CD68, and iNOS, specific for inflammatory M1-like macrophages, and decreased serum levels of NO. In addition, significant reductions in pro-inflammatory gene expression of IL-6, MCP-1, and TNFα and mRNA levels of ASC-1, CASP1, and IL-1β involved in NLRP3 inflammasome were found in obese mice supplemented with vitamin D. Vitamin D supplementation significantly increased obesity-decreased AMPK activity and suppressed HF-increased NF-κB phosphorylation in adipose tissue from obese mice. These observed beneficial effects of vitamin D supplementation on adipose tissue expansion, macrophage recruitment, and inflammation might be related to AMPK/NF-κB signaling.     

Effect of High-Dose Vitamin D3 Intake on Ambulation, Muscular Pain and Bone Mineral Density in a Woman with Multiple Sclerosis: A 10-Year Longitudinal Case Report

Mounting evidence correlate vitamin D3 (cholecalciferol) supplementation or higher serum levels of vitamin D (25(OH)D) with a lower risk of developing multiple sclerosis (MS), reduced relapse rate, slower progression or fewer new brain lesions. We present here the case of a woman who was diagnosed with MS in 1990. From 1980 to 2000, her ability to walk decreased from ~20 to 1 km per day. Since January 2001, a vitamin D3 supplement was ingested daily. The starting dose was 20 mcg (800 IU)/day and escalated to 100 mcg (4000 IU)/day in September 2004 and then to 150 mcg (6000 IU)/day in December 2005. Vitamin D3 intake reduced muscular pain and improved ambulation from 1 (February 2000) to 14 km/day (February 2008). Vitamin D intake over 10 years caused no adverse effects: no hypercalcaemia, nephrolithiasis or hypercalciuria were observed. Bowel problems in MS may need to be addressed as they can cause malabsorption including calcium, which may increase serum PTH and 1,25(OH)2D levels, as well as bone loss. We suggest that periodic assessment of vitamin D3, calcium and magnesium intake, bowel problems and the measurement of serum 25(OH)D, PTH, Ca levels, UCa/Cr and bone health become part of the integral management of persons with MS.     

Spezielle Probleme bei der Vitamin D-Analytik in Futtermitteln mit HPLC

Special Problems of the Vitamin D-Analysis in Feedstuff by HPLC The protection of vitamin D by new coatings requires the saponification of the sample. The advantages of digestion at room temperature fail, for example the separation of unchanged vitamin A-esters. Saponification involves additional difficulties: the displacement of equilibrium vitamin D/previtamin D to more previtamin, the separation vitamin D from vitamin A-alcohols and the separation from citranaxanthin and canthaxanthin in poultry feedstuff. These substances interfere in HPLC by absorption at 265 nm, the absorption maximum of vitamin D. A special method for poultry feedstuff is described: 1. saponification and extraction, 2. Al₂O₃ column chromatography, 3. thin-layer chromatography, 4. reversed phase-HPLC, 5. straight phase-HPLC.     

The Perspective of Vitamin D on suPAR-Related AKI in COVID-19

The coronavirus disease 2019 (COVID-19) pandemic has claimed the lives of millions of people around the world. Severe vitamin D deficiency can increase the risk of death in people with COVID-19. There is growing evidence that acute kidney injury (AKI) is common in COVID-19 patients and is associated with poorer clinical outcomes. The kidney effects of SARS-CoV-2 are directly mediated by angiotensin 2-converting enzyme (ACE2) receptors. AKI is also caused by indirect causes such as the hypercoagulable state and microvascular thrombosis. The increased release of soluble urokinase-type plasminogen activator receptor (suPAR) from immature myeloid cells reduces plasminogen activation by the competitive inhibition of urokinase-type plasminogen activator, which results in low plasmin levels and a fibrinolytic state in COVID-19. Frequent hypercoagulability in critically ill patients with COVID-19 may exacerbate the severity of thrombosis. Versican expression in proximal tubular cells leads to the proliferation of interstitial fibroblasts through the C3a and suPAR pathways. Vitamin D attenuates the local expression of podocyte uPAR and decreases elevated circulating suPAR levels caused by systemic inflammation. This decrease preserves the function and structure of the glomerular barrier, thereby maintaining renal function. The attenuated hyperinflammatory state reduces complement activation, resulting in lower serum C3a levels. Vitamin D can also protect against COVID-19 by modulating innate and adaptive immunity, increasing ACE2 expression, and inhibiting the renin–angiotensin–aldosterone system. We hypothesized that by reducing suPAR levels, appropriate vitamin D supplementation could prevent the progression and reduce the severity of AKI in COVID-19 patients, although the data available require further elucidation.