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91.
Ashley J. Basson Dr. Nathan R. Halcovitch Dr. Mark G. McLaughlin 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(48):e202201107
A range of highly functionalized polycyclic fragments have been synthesized, employing a catalytic dehydrative cyclization. A range of nucleophiles are shown to be successful, with the reaction producing numerous high value motifs. 相似文献
92.
Kwang-Woo Jung Moon-Soo Chung Hyoung-Woo Bai Byung-Yeoup Chung Sungbeom Lee 《Molecules (Basel, Switzerland)》2021,26(11)
Due to lifespan extension and changes in global climate, the increase in mycoses caused by primary and opportunistic fungal pathogens is now a global concern. Despite increasing attention, limited options are available for the treatment of systematic and invasive mycoses, owing to the evolutionary similarity between humans and fungi. Although plants produce a diversity of chemicals to protect themselves from pathogens, the molecular targets and modes of action of these plant-derived chemicals have not been well characterized. Using a reverse genetics approach, the present study revealed that thymol, a monoterpene alcohol from Thymus vulgaris L., (Lamiaceae), exhibits antifungal activity against Cryptococcus neoformans by regulating multiple signaling pathways including calcineurin, unfolded protein response, and HOG (high-osmolarity glycerol) MAPK (mitogen-activated protein kinase) pathways. Thymol treatment reduced the intracellular concentration of Ca2+ by controlling the expression levels of calcium transporter genes in a calcineurin-dependent manner. We demonstrated that thymol decreased N-glycosylation by regulating the expression levels of genes involved in glycan-mediated post-translational modifications. Furthermore, thymol treatment reduced endogenous ergosterol content by decreasing the expression of ergosterol biosynthesis genes in a HOG MAPK pathway-dependent manner. Collectively, this study sheds light on the antifungal mechanisms of thymol against C. neoformans. 相似文献
93.
Microwave (MW) heating was proven to efficiently solid-synthesize calcium carbide at 1750 °C, which was about 400 °C lower than electric heating. This study focused on the investigation of the diffusion behaviors of graphite and calcium oxide during the solid-state synthesis of calcium carbide by microwave heating and compared them with these heated by the conventional method. The phase compositions and morphologies of CaO and C pellets before and after heating were carefully characterized by inductively coupled plasma spectrograph (ICP), thermo gravimetric (TG) analyses, X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The experimental results showed that in both thermal fields, Ca and C inter-diffused at a lower temperature, but at a higher temperature, the formed calcium carbide crystals would have a negative effect on Ca diffusion to carbon. The significant enhancement of MW heating on carbon diffusion, thus on the more efficient synthesis of calcium carbide, manifested that MW heating would be a promising way for calcium carbide production, and that a sufficient enough carbon material, instead of CaO, was beneficial for calcium carbide formation in MW reactors. 相似文献
94.
Dr. Bhupendra Goswami Dr. Thomas J. Feuerstein Dr. Ravi Yadav Dr. Ralf Köppe Dr. Sergei Lebedkin Prof. Dr. Manfred M. Kappes Prof. Dr. Peter W. Roesky 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(13):4401-4411
The synthesis of calcium complexes ligated by three different chiral iminophosphonamide ligands, L- H ( L =[Ph2P{N(R)CH(CH3)Ph}2]), L′ -H ( L′ =[Ph2P{NDipp}{N(R)CH(CH3)Ph}]), (Dipp=2,6-iPr2C6H3), and L′′ -H ( L′′ =[Ph2P{N(R)CH(CH3)naph}2]), (naph=naphthyl) is presented. The resulting structures [ L 2Ca], [ L′ 2Ca], and [ L′′ 2Ca] represent the first examples of enantiopure homoleptic calcium complexes based on this type of ligands. The calcium complexes show blue–green photoluminescence (PL) in the solid state, which is especially bright at low temperatures. Whereas the emission of [ L′′ 2Ca] is assigned to the fluorescence of naphthyl groups, the PL of [ L 2Ca] and [ L′ 2Ca] is contributed by long-lived phosphorescence and thermally activated delayed fluorescence (TADF), with a strong variation of the PL lifetimes over the temperature range of 5–295 K. Furthermore, an excellent catalytic activity was found for these complexes in hydroboration of ketones at room temperature, although no enantioselectivity was achieved. 相似文献
95.
96.
目的 了解温州地区维持性血液透析患者矿物质代谢紊乱情况及相关影响因素。方法 收集2013 年在温州地区长期维持性血液透析患者血钙、血磷、全段甲状旁腺激素(iPTH)的资料,并根据美国肾脏病协会指南(KDOQI)及中华医学会肾脏病学分会(CSN)制订的《慢性肾脏病矿物质和骨异常诊治指导》计算患者的血钙、血磷、iPTH 的达标率,并对相关影响因素进行分析。结果 共收集2 227 例2013 年在温州地区各家透析中心维持性血液透析患者的资料。按KDOQI 指南标准,患者血钙、血磷、iPTH 的达标率分别为44.90%、46.30%、27.64%,3 项均达标者占6.29%;按《慢性肾脏病矿物质和骨异常诊治指导》建议,患者血钙、血磷、iPTH 的达标率分别为57.66%、46.30%、61.14%,3 项均达标者占16.97%。此外,三级医院维持性血液透析患者的平均血磷水平为(1.67±0.51)mmol/L,血磷达标率49.10%,二级医院患者的平均血磷水平为(1.79±0.53)mmol/L,达标率为43.22%,三级医院维持性血液透析患者的血磷达标率情况优于二级医院。血白蛋白、含钙磷结合剂的使用及透析频率是影响血钙达标的独立相关因素。患者的性别、年龄、活性维生素D 的使用、透析龄及透析频率是影响血磷达标的独立相关因素。患者活性维生素D的使用是影响iPTH 达标的独立相关因素。结论 温州地区维持性血液透析患者矿物质代谢紊乱纠正情况与有关指南的要求仍然存在较大差距;患者性别、营养状态、透析频率、含钙磷结合剂的服用、活性维生素D 的使用等是影响维持性血液透析患者矿物质代谢紊乱纠正的主要相关因素。 相似文献
97.
The evolution of amorphous calcium carbonate (ACC) into crystals in ethanol/water binary solvents under ambient temperature was investigated, and it was found to depend on the volume ratio of ethanol to water (R). Calcite remained dominant when the amount of water was high (R = 1/3). A slight change in the amount of ethanol (R = 3/1) could lead to a dramatic change in the polymorph from calcite to aragonite. However, when poly (allylamine hydrochloride) (PAH) was added at R = 3/1, almost pure vaterite could be obtained, which has a specific morphological variation (from hollow microspheres to cloud‐like). This study provides an alternative polymorphic route for the CaCO3 mineral by using the evolution of ACC in different solvent environments, which provides some useful clues for understanding the importance of kinetic control of the morphologies and polymorphs of a wide range of inorganic materials. In addition, this simple mild phase‐controlled synthetic method could be scaled up as a green chemistry route for the industrial production of different polymorphs of CaCO3. 相似文献
98.
Dr. Jérémie Topin Claire A. de March Dr. Landry Charlier Prof. Dr. Catherine Ronin Prof. Dr. Serge Antonczak Dr. Jérôme Golebiowski 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(33):10227-10230
A joint approach combining free‐energy calculations and calcium‐imaging assays on the broadly tuned human 1G1 olfactory receptor is reported. The free energy of binding of ten odorants was computed by means of molecular‐dynamics simulations. This state function allows separating the experimentally determined eight agonists from the two non‐agonists. This study constitutes a proof‐of‐principle for the computational deorphanization of olfactory receptors. 相似文献
99.
Calcite Microneedle Arrays Produced by Inorganic Ion‐Assisted Anisotropic Dissolution of Bulk Calcite Crystal 下载免费PDF全文
Xia Long Ruijie Meng Weike Wu Prof. Yurong Ma Prof. Dong Yang Prof. Limin Qi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(15):4264-4272
Besides studies on the mineralization process, research on the demineralization of minerals provides another way to understand the crystallization mechanism of biominerals and fabricate crystals with complicated morphologies. The formation of ordered arrays of c‐axis‐oriented calcite microneedles with a tri‐symmetric structure and lengths of more than 20 μm was realized on a large scale for the first time through anisotropic dissolution of calcite substrates in undersaturated aqueous solution in the presence of ammonium salts. The lengths and the aspect ratios of the calcite microneedles can be tuned by simply changing the concentrations of the ammonium salts and the dissolution time. The shape of the transverse cross sections of the calcite microneedles obtained in the presence of NH4Cl and NH4Ac is almost regularly triangular. The tri‐symmetric transverse cross‐section geometry of the calcite microneedles could be attributed to the tri‐symmetric feature of rhombohedral calcite atomic structures, the synergetic interactions between electrostatic interaction of ammonium ions and dangling surface carbonate groups, and the ion incorporation of halide ions. 相似文献
100.
Solvothermal Transformation of a Calcium Oleate Precursor into Large‐Sized Highly Ordered Arrays of Ultralong Hydroxyapatite Microtubes 下载免费PDF全文
Dr. Bing‐Qiang Lu Prof. Dr. Ying‐Jie Zhu Feng Chen Chao Qi Xin‐Yu Zhao Jing Zhao 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(23):7116-7121
Hydroxyapatite (HAP), a well‐known member of the calcium phosphate family, is the major inorganic component of bones and teeth in vertebrates. The highly ordered arrays of HAP structures are of great significance for hard tissue repair and for understanding the formation mechanisms of bones and teeth. However, the synthesis of highly ordered HAP structure arrays remains a great challenge. In this work, inspired by the ordered structure of tooth enamel, we have successfully synthesized three‐dimensional bulk materials with large sizes (millimeter scale) that are made of highly ordered arrays of ultralong HAP microtubes (HOAUHMs) by solvothermal transformation of calcium oleate precursor. The core–shell‐structured oblate sphere consists of a core that is composed of HAP nanorods and a shell that consists of highly ordered HAP microtube arrays. The prepared HOAUHMs are large: 6.0 mm in diameter and up to 1.4 mm in thickness. With increasing solvothermal reaction time, the HOAUHMs grow larger; the microtubes become more uniform and more ordered. This work provides a new synthetic method for synthesizing highly ordered arrays of uniform HAP ultralong microtubes that are promising for biomedical applications. 相似文献