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51.
Meining Li Huahua Li Hong Yang Rina Cheng Pengdou Zheng Rui Guo 《Biomedical chromatography : BMC》2020,34(4):e4799
Spermiogenesis in mammals is an exclusive process during which haploid round spermatids mature into spermatozoa in the testis. Any abnormality in the process of spermiogenesis may result in male infertility. The aim of the present study was to characterize the differentially expressed proteins between round and elongated spermatids in mice using label-free quantitative mass spectrometry. Of the 2411 proteins identified in this study, 333 were differentially expressed with a ≥10-fold change, including 208 upregulated proteins and 125 downregulated proteins in round spermatids relative to elongated spermatids. Gene Ontology analysis showed that these differentially expressed proteins were categorized into 10 types of subcellular localizations, 9 molecular functions, and were involved in 9 biological processes. All the identified proteins participated in 268 different pathways. In addition, ubiquitin-mediated proteolysis and the proteasome pathway, autophagy, lysosome, and apoptosis pathways were involved in the mechanism of spermiogenesis. Our data may provide valuable information for a better understanding of spermiogenesis and help improve the diagnosis and treatment of male factor infertility. 相似文献
52.
Jia Yang Xingang Li Wenjun Li Xin Xi Qian Du Feng Pan Songqing Liu 《Biomedical chromatography : BMC》2020,34(8):e4857
Because of its unpredictable side effects and efficacy, the anticancer drug docetaxel (DTX) requires improved characterisation of its pharmacokinetic profiles through population pharmacokinetic studies. A sensitive and rugged LC–MS/MS method for the detection of DTX in human plasma was developed and optimised using paclitaxel as an internal standard (IS). The plasma samples underwent rapid extraction using hybrid solid-phase extraction-protein precipitation. The analyte and IS were separated with an isocratic system on a Zorbax Eclipse Plus C18 column using water containing 0.05% acetic acid along with 20 μM of sodium acetate and methanol (30/70, v/v) as the mobile phase. Quantification was performed using a triple quadrupole mass spectrometer through multiple reaction monitoring in positive mode, using the m/z 830.3 → 548.8 and m/z 876.3 → 307.7 transitions for DTX and paclitaxel, respectively. The range of the calibration curve was 1–500 ng/mL for DTX, and the linear correlation coefficient was >0.99. The accuracies ranged from −4.6 to 4.2%, and the precision was no higher than 7.0% for the analytes. No significant matrix effect was observed. Both DTX and the IS showed considerable recovery. This method was finally applied to the establishment of a population pharmacokinetic model to optimise the clinical use of DTX. 相似文献
53.
Jun Xu Victor V. Terskikh Yueying Chu Anmin Zheng Yining Huang 《Magnetic resonance in chemistry : MRC》2020,58(11):1082-1090
Metal–organic frameworks (MOFs) are a class of important porous materials with many current and potential applications. Their applications almost always involve the interaction between host framework and guest species. Therefore, understanding of host–guest interaction in MOF systems is fundamentally important. Solid-state NMR spectroscopy is an excellent technique for investigating host–guest interaction as it provides information complementary to that obtained from X-ray diffraction. In this work, using MOF α-Mg3(HCOO)6 as an example, we demonstrated that 13C chemical shift tensor of organic linker can be utilized to probe the host–guest interaction in MOFs. Obtaining 13C chemical shift tensor components (δ11, δ22, and δ33, where δ11 ≥ δ22 ≥ δ33) in this MOF is particularly challenging as there are six coordinatively equivalent but crystallographically non-equivalent carbons in the unit cell with very similar local coordination environment. Two-dimensional magic-angle-turning experiments were employed to measure the 13C chemical shift tensors of each individual crystallographically non-equivalent carbon in three microporous α-Mg3(HCOO)6 samples with different guest species. The results indicate that the δ22 component (with its direction approximately being co-planar with the formate anion and perpendicular to the C−H bond) is more sensitive to the adsorbate molecules inside the MOF channel due to the weak C−H···O hydrogen bonding or the ring current effect of benzene. The 13C isotropic chemical shift, on the other hand, seems much less sensitive to the subtle changes in the local environment around formate linker induced by adsorption. The approach described in this study may be used in future studies on host–guest interaction within MOFs. 相似文献
54.
Can Li Dr. Zheng Yang Lei Wang Prof. Dr. Yinlong Guo Prof. Dr. Zheng Huang Prof. Dr. Shengming Ma 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(15):6337-6342
An efficient pincer-ligand-based cobalt-complex-catalyzed allene hydroboration affording Z-allylic boronates is described. The reaction demonstrates an excellent regio- as well as Z-stereoselectivity and a wide substrate scope that tolerates many functional groups. Based on solvent-assisted electrospray ionization mass spectrometry (SAESI-MS) studies, a rationale for the cobalt-catalyzed hydroboration involving the highly selective insertion of an allene into the Co−H bond to form Z-allylic cobalt intermediates is proposed. 相似文献
55.
Dr. Haixiang Han Jesse C. Carozza Audra P. Colliton Yuxuan Zhang Dr. Zheng Wei Dr. Alexander S. Filatov Prof. Dr. Yu-Sheng Chen Melisa Alkan Prof. Dr. Andrey Yu. Rogachev Prof. Dr. Evgeny V. Dikarev 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(24):9711-9717
A known trinuclear structure was used to design the heterobimetallic mixed-valent, mixed-ligand molecule [CoII(hfac)3−Na−CoIII(acac)3] ( 1 ). This was used as a template structure to develop heterotrimetallic molecules [CoII(hfac)3−Na−FeIII(acac)3] ( 2 ) and [NiII(hfac)3−Na−CoIII(acac)3] ( 3 ) via isovalent site-specific substitution at either of the cobalt positions. Diffraction methods, synchrotron resonant diffraction, and multiple-wavelength anomalous diffraction were applied beyond simple structural investigation to provide an unambiguous assignment of the positions and oxidation states for the periodic table neighbors in the heterometallic assemblies. Molecules of 2 and 3 are true heterotrimetallic rather than a statistical mixture of two heterobimetallic counterparts. Trinuclear platform 1 exhibits flexibility in accommodating a variety of di- and trivalent metals, which can be further utilized in the design of molecular precursors for the NaMM′O4 functional oxide materials. 相似文献
56.
Semiconductors grown by the solution-processed method have shown low-cost,facile fabrication process and comparable performance.However,there are many reasons why it is difficult to achieve high quality films.For example,lattice constant mismatch is one of the problems when photovoltaic devices made of organ metallic perovskites.In this work,MAPbBrMA=CH3NH3^+perovskites single crystals grown on the surface of MAPbBr2.5 CI0.5 perovskites single crystals via liquid epitaxial growth method is demonstrated.It is found that when the lattice constants of the two perovskite single crystals are matched,another crystal can be grown on the surface of one crystal by epitaxial growth.The whole epitaxy growth process does not require high heating temperature and long heating time.X-ray diffraction method is used to prove the lattice plane of the substrate and the epitaxial grown layer.A scanning electron microscope is used to measure the thickness of the epitaxial layer.Compared with perovskite-based photodetectors without epitaxial growth layer,perovskite-based photodetectors with epitaxial growth layer have lower dark current density and higher optical responsibility. 相似文献
57.
本文利用红外光解离光谱研究了第三族金属氧化物离子对二氧化碳分子的转化机制. 研究表明,对于[ScO(CO2)n]+体系,在n≤4时,形成了溶剂化结构;在n=5时,形成了碳酸盐结构,实现了二氧化碳的转化. 对于[YO(CO2)n]+体系,需要4个二氧化碳分子就可以实现二氧化碳的转化. 而在[YO(CO2)n]+体系中,只发现了溶剂化结构,没有观察到碳酸盐结构. 理论计算表明,[YO(CO2)n]+体系拥有最小的溶剂化结构向碳酸盐结构转化能垒,[LaO(CO2)n]+体系拥有最大的溶剂化结构向碳酸盐结构转化能垒. 本文从分子水平揭示了不同金属氧化物离子对二氧化碳分子转化的影响规律. 相似文献
58.
60.
在溶液法制备有机电致发光器件(OLEDs)的研究中, PEDOT∶PSS由于具有较好的成膜性与高透光性而常被用作器件的空穴注入层。但相关研究表明, PEDOT∶PSS本身稳定性较差以及功函数较低,这使得溶液法制备OLEDs的性能差且不稳定。蓝色作为全彩色的三基色之一,制备高效的蓝光器件对于实现高质量显示器件和固态照明装置必不可少。而目前溶液法制备蓝光OLEDs的器件效率普遍较差,针对此问题,本文利用传统的蓝光热激活延迟荧光发光(TADF)材料DMAC-DPS作为发光层,用溶液法制备了蓝光TADF OLEDs,通过在PEDOT∶PSS中掺杂PSS-Na制备混合空穴注入层(mix-HIL)来提高空穴注入层的功函数,研究其对于蓝光TADF OLEDs器件性能的影响。首先在PEDOT∶PSS水溶液中掺入不同体积的PSS-Na溶液,在相同条件下旋涂制膜,进行器件制备。通过观测各个实验组器件的电致发光(EL)光谱,发现掺入PSS-Na后器件EL谱存在光谱蓝移的现象,这是由于掺入PSS-Na水溶液后, mix-HIL层的厚度有所降低,使得在微腔效应作用下, EL光谱发生蓝移。通过对比各组器件的电流密度-电压-亮度(J-V-L)曲线及其计算所得器件的电流效率,结果显示随着PSS-Na的掺入,器件的亮度和电流都有所增大,器件的电流效率也得到了提升,当掺杂比例为0.5∶0.5(PEDOT∶PSS/PSS-Na)时提升幅度最大(亮度提升86.7%,电流效率提升34.3%)。通过在瞬态电致发光测试过程中施加或撤去驱动电压观测了器件EL强度的变化,分析了在混合空穴注入层/发光层(mix-HIL/EML)界面处的电荷积累情况。实验证明,通过在PEDOT∶PSS中掺杂PSS-Na制备mix-HIL获得了蓝光TADF OLEDs器件性能的提升,这是一个获得高效率溶液法制备OLEDs的可行方法。 相似文献