Diaqua­bis­{5-carb­oxy-2-[(1H-1,2,4-triazol-1-yl)meth­yl]-1H-imidazole-4-carboxyl­ato}zinc

In the title compound, [Zn(C8H6N5O4)2(H2O)2], the six-coordinate ZnII ion, which is located on an inversion center, has a distorted octa­hedral configuration. Each 5-carb­oxy-2-[(1H-1,2,4-triazol-1-yl)meth­yl]-1H-imidazole-4-carboxyl­ate ligand chelates to the ZnII ion through a triazole N atom and a carboxyl­ate O atom in the equatorial plane. The coordination sphere is completed by two water mol­ecules in axial positions. There is an intra­molecular O—H⋯O hydrogen bond in the ligand. In the crystal, mol­ecules are linked via inter­molecular O—H⋯O, O—H⋯N and N—H⋯N hydrogen bonds, forming a three-dimensional structure

Scutellaria baicalensis decreases ritonavir-induced nausea

BACKGROUND: Protease inhibitors, particularly ritonavir, causes significant gastrointestinal disturbances such as nausea, even at low doses. This ritonavir-induced nausea could be related to its oxidative stress in the gut. Alleviation of drug-induced nausea is important in effectively increasing patients' compliance and improving their quality of life. Conventional anti-emetic drugs can only partially abate the symptoms in these patients, and their cost has also been a concern. Rats respond to nausea-producing emetic stimuli by increasing consumption of non-nutritive substances like kaolin or clay, a phenomenon known as pica. In this study, we used this rat pica model to evaluate the effects of Scutellaria baicalensis, a commonly used oriental herbal medicine, on ritonavir-induced nausea. RESULTS: Rats treated with 20 mg/kg ritonavir significant caused increases of kaolin consumption at 24 to 48 hr (P < 0.01). Pretreatment with 0.3 and 3 mg/kg Scutellaria baicalensis extract significantly decreased ritonavir-induced kaolin intake in a dose-related manner (P < 0.01). Compared to vehicle treatment, the extract completely prevented ritonavir-induced kaolin consumption at dose 3 mg/kg. The area under the curves (AUC) for kaolin intake from time 0 to 120 hr for vehicle only, ritonavir only, SbE 0.3 mg/kg plus ritonavir, and SbE 3 mg/kg plus ritonavir were 27.3 g•hr, 146.7 g•hr, 123.2 g•hr, and 32.7 g•hr, respectively. The reduction in area under the curves of kaolin intake from time 0 to 120 hr between ritonavir only and SbE 0.3 mg/kg plus ritonavir, ritonavir only and SbE 3 mg/kg plus ritonavir were 16.0% and 77.7%, respectively. CONCLUSION: Scutellaria baicalensis significantly attenuated ritonavir-induced pica, and demonstrated a potential in treating ritonavir-induced nausea

Histone H3 Threonine Phosphorylation Regulates Asymmetric Histone Inheritance in the Drosophila Male Germline

SummaryA long-standing question concerns how stem cells maintain their identity through multiple divisions. Previously, we reported that pre-existing and newly synthesized histone H3 are asymmetrically distributed during Drosophila male germline stem cell (GSC) asymmetric division. Here, we show that phosphorylation at threonine 3 of H3 (H3T3P) distinguishes pre-existing versus newly synthesized H3. Converting T3 to the unphosphorylatable residue alanine (H3T3A) or to the phosphomimetic aspartate (H3T3D) disrupts asymmetric H3 inheritance. Expression of H3T3A or H3T3D specifically in early-stage germline also leads to cellular defects, including GSC loss and germline tumors. Finally, compromising the activity of the H3T3 kinase Haspin enhances the H3T3A but suppresses the H3T3D phenotypes. These studies demonstrate that H3T3P distinguishes sister chromatids enriched with distinct pools of H3 in order to coordinate asymmetric segregation of “old” H3 into GSCs and that tight regulation of H3T3 phosphorylation is required for male germline activity

Pressure-induced coevolution of transport properties and lattice stability in CaK(Fe1-xNix)4As4 (x= 0.04 and 0) superconductors with and without spin-vortex crystal state

Here we report the first investigation on correlation between the transport properties and the corresponding stability of the lattice structure for CaK(Fe1-xNix)4As4 (x=0.04 and 0), a new type of putative topological superconductors, with and without a spin-vortex crystal (SVC) state in a wide pressure range involving superconducting to non-superconducting transition and the half- to full-collapse of tetragonal (h-cT and f-cT) phases, by the complementary measurements of high-pressure resistance, Hall coefficient and synchrotron X-ray diffraction. We identify the three critical pressures, P1 that is the turn-on critical pressure of the h-cT phase transition and it coincides with the critical pressure for the sign change of Hall coefficient from positive to negative, a manifestation of the Fermi surface reconstruction, P2 that is the turn-off pressures of the h-cT phase transition, and P3 that is the critical pressure of the f-cT phase transition. By comparing the high-pressure results measured from the two kinds of samples, we find a distinct left-shift of the P1 for the doped sample, at the pressure of which its SVC state is fully suppressed, however the P2 and the P3 remain the same as that of the undoped one. Our results not only provide a consistent understanding on the results reported before, but also demonstrate the importance of the Fe-As bonding in stabilizing the superconductivity of the iron pnictide superconductors through the pressure window

Rational synthesis of an atomically precise carboncone under mild conditions

在已知的碳的存在形态中，还有一种锥型的碳结构，早在50年前人们在热解碳时发现了这类结构，此前也常被人们称为碳纳米锥，虽然这类碳纳米锥有望作为扫描隧道显微镜的探针、场发射头等替代材料，但始终未能找到合适方法精准地合成它们。因此，这类锥型碳材料尚未得到人们足够重视和开发。功能团簇材料创新研究群体的谢素原、张前炎课题组与美国波士顿学院的Lawrence Scott教授合作，首次通过有机合成途径，在温和的条件下合成得到了首例结构明确的碳锥单元（碳锥子）C70H20及其可溶衍生物。他们通过实验、理论计算、结构分析，最终在他们合成的碳锥子结构中，仅有1个五元环在锥顶，而在锥顶和锥缘之间（围绕着中心五元环）有2圈由六元环组成的完整的稠圈层，谢素原等将这一碳锥子命名为carboncone[1,2]。通过这一典型的碳锥子（carboncone[1,2]），有望借助气相沉积等技术不断增加稠圈层数（m）来制备具有确定锥角的系列单壁纳米碳锥（carboncone[1,m>2]）。随着研究的深入，不久的将来人类有望合成出其它四种不同锥角的碳锥子（carboncone[n=2-5,m]），完整地研究探索和开发利用这类锥型结构的碳材料。 化学化工学院2015级硕士生朱正钟（主要负责合成）和2017级博士生陈佐长（主要负责理论计算）为该论文的共同第一作者。Carboncones, a special family of all-carbon allotropes, are predicted to have unique properties that distinguish them from fullerenes, carbon nanotubes, and graphenes. Owing to the absence of methods to synthesize atomically well-defined carboncones, however, experimental insight into the nature of pure carboncones has been inaccessible. Herein, we describe a facile synthesis of an atomically well-defined carboncone[1,2] (C70H20) and its soluble penta-mesityl derivative. Identified by x-ray crystallography, the carbon skeleton is a carboncone with the largest possible apex angle. Much of the structural strain is overcome in the final step of converting the bowl-shaped precursor into the rigid carboncone under mild reaction conditions. This work provides a research opportunity for investigations of atomically precise single-layered carboncones having even higher cone walls and/or smaller apex angles.This research was supported by the National Natural Science Foundation of China (21771152, 21721001, 21390390, 21827801, 51572231, 21571151, and 21701134), the 973 Program of China (2015CB932301), the Major Science and Technology Project between University-Industry Cooperation in Fujian Province (2016H6023), and the Fundamental Research Funds for the Central Universities (20720170028 and 20720160084). This research was also supported financially by the U.S. National Science Foundation (CHE-0809494 and CHE-1149096). 研究工作得到国家自然科学基金（21771152等）、科技部重大科学研究计划项目（2015CB932301）和福建省高校产学合作项目、中央高校基本科研业务费、美国国家科学基金等的资助