Dynamic Evolution of S0_0∼\simS3_3 at the Oxygen Evolving Complex with the Spin Marker under the Photoelectric Polarization

Water oxidation in the oxygen evolving complex (OEC) of the photosystem II is catalyzed by the core cluster CaMn$_4$O$_5$ which was projected to experience five intermediate states S($\rm_i$) in the Kok's cycle since 1970's. However, the detailed dynamics of state evolutions still remains unclear, albeit with the general fact that the process is initiated by the transfer of photoelectrons with the steady electron donors of the water molecules. Based on density functional simulations, we find that the spin flips of Manganese atoms between the consecutive states in the electric polarization field can be used as a marker to uncover the intricate dynamic evolutions and the underlying dynamics. The dynamic electron and proton transfers and water insertion and dissociation are traced to reveal the evolution pathways of S$_0$$\sim$S$_3$ with commensurate spin flips towards the exact spin configuration of the next state. In particular, the various water insertions and dissociations at coordination sites of the S$_2$ open and closed cubane isomers are predicted with constraints on the necessary spin flips. Our study lays a solid ground for getting through the whole Kok's cycle via the pending S$_4$ state that is crucial for dioxygen generation.Comment: 8 pages, 5 figure

Effects of Mo on the Microstructure and Hydrogen Sorption Properties of Ti-Mo Getters

AbstractThe effects of Mo on the microstructure evolution, porosity and hydrogen sorption properties of Ti-Mo getters are investigated in this work. The results show that the addition of Mo prolongs the densification process of Ti-Mo getters and results in a significant amount of sintered pores. With the Mo content increasing, the porosity of getters firstly increases reaching the maximum value as it attains about 7.5wt.%, and then drops. At the room temperature, the hydrogen sorption property of getters increases progressively with the Mo content increasing, but the tendency is not very clear before its content lies below 2.5wt.%. When the Mo content achieves about 7.5wt.%, the hydrogen sorption property proves to be the best. The discussion is made about the above mentioned phenomena inclusive of hydrogen sorption properties of getters under different activation conditions (from 500–750 °C)

catena-Poly[[aqua­(dipyrido[3,2-a:2′,3′-c]phenazine-κ2 N 4,N 5)zinc(II)]-μ-pyrazine-2,3-dicarboxyl­ato-κ3 N 1,O 2:O 3]

In the title compound, [Zn(C6H2N2O4)(C18H10N4)(H2O)]n or [Zn(PZDC)(DPPZ)(H2O)]n (where DPPZ is dipyrido[3,2-a:2′,3′-c]phenazine and H2PZDC is pyrazine-2,3-dicarboxylic acid), the Zn atom is six-coordinated in a slightly distorted octa­hedral coordination geometry by three N atoms from one DPPZ ligand and one PZDC2− dianion, three O atoms from two different PZDC2− ligands and one water mol­ecule. Each PZDC2− dianion serves as a spacer, connecting adjacent metal atoms into a polymeric chain structure parallel to the b axis. The chain motif is consolidated into a three-dimensional supra­molecular network by O—H⋯O and O—H⋯N hydrogen bonds and π–π aromatic stacking inter­actions involving adjacent DPPZ ligands and PZDC2− dianions with centroid–centroid separations of 3.522 (6) and 3.732 (8) Å, respectively

Baicalein inhibits acinar-to-ductal metaplasia of pancreatic acinal cell AR42J via improving the inflammatory microenvironment

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive cancers. Recent research has demonstrated that chronic pancreatitis (CP) is associated with an increased risk of PDAC, partly due to acinar-to-ductal metaplasia (ADM). Baicalein has been shown to exert anti-inflammatory and anti-tumor effects for CP or PDAC, respectively. The aim of our study was to investigate the effect of baicalein, and the putative underlying mechanism, on inflammatory cytokines-induced ADM of rat pancreatic acinar cell line AR42J. To investigate ADM and baicalein effects in vitro, AR42J were treated with recombinant rat Tumor Necrosis Factor alpha (rTNFα) with or without baicalein for 5 days. Results showed that rTNFα-induced AR42J cells switched their phenotype from dominantly amylase-positive acinar cells to dominantly cytokeratin 19-positive ductal cells. Moreover, expression of the transcripts for TNFα or Hes-1, a Notch target, was up-regulated in these cells. Interestingly, baicalein reduced the population of ADM as well as cytokines gene expression but not Hes-1. Baicalein inhibited NF-κB activation induced by rTNFα in AR42J, but no effect on Notch 1activation. Moreover, baicalein suppressed the secretion of TNFα and Nitric Oxide (NO) in macrophages stimulated with LPS and further inhibited ADM of conditional medium-treated AR42J cells. Baicalein also suppressed the inflammatory response of LPS-activated macrophages, thereby inhibited ADM of AR42J by altering their microenvironment. Taken together, our study indicates that baicalein reduces rTNFα-induced ADM of AR42J cells by inhibiting NF-κB activation. It also sheds new light on Chinese material medica therapy of pancreatitis and thereby prevention of PDAC

Europium-doped amorphous calcium phosphate porous nanospheres: preparation and application as luminescent drug carriers

Calcium phosphate is the most important inorganic constituent of biological tissues, and synthetic calcium phosphate has been widely used as biomaterials. In this study, a facile method has been developed for the fabrication of amorphous calcium phosphate (ACP)/polylactide-block-monomethoxy(polyethyleneglycol) hybrid nanoparticles and ACP porous nanospheres. Europium-doping is performed to enable photoluminescence (PL) function of ACP porous nanospheres. A high specific surface area of the europium-doped ACP (Eu3+:ACP) porous nanospheres is achieved (126.7 m2/g). PL properties of Eu3+:ACP porous nanospheres are investigated, and the most intense peak at 612 nm is observed at 5 mol% Eu3+ doping. In vitro cytotoxicity experiments indicate that the as-prepared Eu3+:ACP porous nanospheres are biocompatible. In vitro drug release experiments indicate that the ibuprofen-loaded Eu3+:ACP porous nanospheres show a slow and sustained drug release in simulated body fluid. We have found that the cumulative amount of released drug has a linear relationship with the natural logarithm of release time (ln(t)). The Eu3+:ACP porous nanospheres are bioactive, and can transform to hydroxyapatite during drug release. The PL properties of drug-loaded nanocarriers before and after drug release are also investigated

Dichlorido(10,11,12,13-tetra­hydro-4,5,9,14-tetra­azabenzo[b]triphenyl­ene)cadmium(II) hemihydrate

In the title compound, [CdCl2(C18H14N4)2]·0.5H2O, the Cd atom assumes a distorted octa­hedral trans-CdCl2N4 geometry arising from its coordination by two N,N′-bidentate 10,11,12,13-tetra­hydro-4,5,9,14-tetra­azabenzo[b]triphenyl­ene (TBBT) mol­ecules and two chloride ions. In the crystal, π–π aromatic stacking inter­actions between adjacent TTBT rings are seen, with a centroid–centroid distance of 3.604 (3) Å. An O—H⋯Cl hydrogen bond between the half-occupied water molecule and one chloride ion also occurs

Spatial and temporal clustering analysis of tuberculosis in the mainland of China at the prefecture level, 2005-2015

BACKGROUND: Tuberculosis (TB) is still one of the most serious infectious diseases in the mainland of China. So it was urgent for the formulation of more effective measures to prevent and control it. METHODS: The data of reported TB cases in 340 prefectures from the mainland of China were extracted from the China Information System for Disease Control and Prevention (CISDCP) during January 2005 to December 2015. The Kulldorff\u27s retrospective space-time scan statistics was used to identify the temporal, spatial and spatio-temporal clusters of reported TB in the mainland of China by using the discrete Poisson probability model. Spatio-temporal clusters of sputum smear-positive (SS+) reported TB and sputum smear-negative (SS-) reported TB were also detected at the prefecture level. RESULTS: A total of 10 200 528 reported TB cases were collected from 2005 to 2015 in 340 prefectures, including 5 283 983 SS- TB cases and 4 631 734 SS + TB cases with specific sputum smear results, 284 811 cases without sputum smear test. Significantly TB clustering patterns in spatial, temporal and spatio-temporal were observed in this research. Results of the Kulldorff\u27s scan found twelve significant space-time clusters of reported TB. The most likely spatio-temporal cluster (RR = 3.27, P \u3c  0.001) was mainly located in Xinjiang Uygur Autonomous Region of western China, covering five prefectures and clustering in the time frame from September 2012 to November 2015. The spatio-temporal clustering results of SS+ TB and SS- TB also showed the most likely clusters distributed in the western China. However, the clustering time of SS+ TB was concentrated before 2010 while SS- TB was mainly concentrated after 2010. CONCLUSIONS: This study identified the time and region of TB, SS+ TB and SS- TB clustered easily in 340 prefectures in the mainland of China, which is helpful in prioritizing resource assignment in high-risk periods and high-risk areas, and to formulate powerful strategy to prevention and control TB

Puerarin Relieves Paclitaxel-Induced Neuropathic Pain: The Role of Nav1.8 β1 Subunit of Sensory Neurons

Currently there is no effective treatment available for clinical patients suffering from neuropathic pain induced by chemotherapy paclitaxel. Puerarin is a major isoflavonoid extracted from the Chinese medical herb kudzu root, which has been used for treatment of cardiovascular disorders and brain injury. Here, we found that puerarin dose-dependently alleviated paclitaxel-induced neuropathic pain. At the same time, puerarin preferentially reduced the excitability and blocked the voltage-gated sodium (Nav) channels of dorsal root ganglion (DRG) neurons from paclitaxel-induced neuropathic pain rats. Furthermore, puerarin was a more potent blocker of tetrodotoxin-resistant (TTX-R) Nav channels than of tetrodotoxin-sensitive (TTX-S) Nav channels in chronic pain rats’ DRG neurons. In addition, puerarin had a stronger blocking effect on Nav1.8 channels in DRG neurons of neuropathic pain rats and β1 subunit siRNA can abolish this selective blocking effect on Nav1.8. Together, these results suggested that puerarin may preferentially block β1 subunit of Nav1.8 in sensory neurons contributed to its anti-paclitaxel induced neuropathic pain effect

Effect of individualized diabetes education for type 2 diabetes mellitus: a single-center randomized clinical trial.

Background: To evaluate the effect of individualized education for patients with type 2 diabetes mellitus (T2DM). Methods: A total of 280 patients (158 males, mean age 63 \ub1 10 years) with T2DM were randomly divided into study and control group. Eysenck Personality questionnaire was used to assess the personality of the patients in the study group, which was provided us one-on-one counseling and individualized management plan. Group education was provided to the control group. Results: At the end of the study, the body mass index (21.5\ub12.5 vs 23.6\ub11.6 kg/m2, P =0.002), waist circumference (83.7\ub16.4 vs 85.7\ub17.7 cm, P =0.03), fasting blood glucose (6.0\ub10.8 vs 6.9\ub12.1 mmol/L, P =0.004), HbA1c (6.2\ub10.6% vs 6.9\ub13.1%, P =0.03), systolic blood pressure (130.1\ub18.8 vs 135.1\ub18.4 mmHg, P =0.003),triglyceride (1.21\ub10.66 vs 1.46\ub10.58 mmol/L) and low-density lipoprotein (2.36\ub10.44 vs 2.84\ub10.64 mmol/L, P =0.03) in the study group was lower than in the control group. Conclusion: Individualized diabetes education is more effective than group education in facilitating the control of type 2 diabetes