Search

Background Dehydrocorydaline (DHC) and canadine (THB) are two active alkaloid compounds in Corydalis yanhusuo (Y.H. Chou & Chun C. Hsu) W.T. Wang ex Z.Y. Su & C.Y. Wu (Papaveraceae) (Rhizoma Corydalis). DHC and THC were previously shown to exert anti-platelet aggregation effect dose-dependently, but their exact mechanisms had not yet been addressed. Therefore, it is essential to study the mechanisms of DHC and THB affecting on platelet's function. Purpose To investigate the anti-platelet effects and corresponding signal cascades of DHC and THB on platelet aggregation. Methods Firstly, in vitro anti-platelet aggregation of DHC and THB induced by different agonists including thrombin (THR), adenosine diphosphate (ADP) and arachidonic acid (AA) were determined through turbidimetry method. Then the possible target-related platelet proteins after treated with DHC/THB were separated and identified by two dimensional gel electrophoresis (2-DE) and MALDI-TOF-MS/MS analysis, respectively. Finally, the signal cascades network induced by DHC/THB were predicted through functional analysis of these proteins along with the determination of platelet DAG concentration. Results The platelet aggregation stimulated by THR, ADP and AA were inhibited by DHC and THB dose-dependently to a certain degree. Meanwhile, DHC and THB had the strongest effect on ADP- and THR-induced platelet aggregation respectively. In addition, treatment of these two compounds caused regulations of about sixty proteins in platelet, including cytoskeleton proteins, cell signaling proteins, proteins related to material energy metabolism, etc. Conclusions Using proteomic analysis combined with platelet aggregation test and ELISA, this study was successful in exploring the possible mechanisms of DHC/THB on platelet aggregation. DHC might inhibit platelet aggregation by a mechanism involving the ADP receptors P2Y1 and P2Y12, and the effect of THB on platelet function may be related to its binding to THR receptor PAR1 for mediated Gi signaling pathway. These results provide fundamental information for the anti-thrombotic effect of RC.

In this study, an attempt was made to decipher the underlying differential response mechanism of Klebsiella sp. KL-1 induced by exposure to disparate categories of dyestuffs in xylose (Xyl) co-metabolic system. Here, representative reactive black 5 (RB5), remazol brilliant blue R (RBBR) and malachite green (MG) belonging to the azo, anthraquinone and triphenylmethane categories were employed as three model dyestuffs. Klebsiella sp. KL-1 enabled nearly 98%, 80% or 97% removal of contaminants in assays Xyl + RB5, Xyl + RBBR or Xyl + MG after 48 h, which was respectively 16%, 11% or 22% higher than those in the assays devoid of xylose. LC-QTOF-MS revealed an increased formation of smaller molecular weight intermediates in assay Xyl + RB5, whereas more metabolic pathways were deduced in assay Xyl + RBBR. Metaproteomics analysis displayed remarkable proteome alteration with regards to the structural difference effect of dyestuffs by Klebsiella sp. KL-1. Significant (p-value0.05) activation of pivotal candidate NADH-quinone oxidoreductase occurred after 48 h of disparate dyestuff exposure but with varying abundance. Dominant FMN-dependent NADH-azoreductase, Cytochrome d terminal oxidase or Thiol peroxidase were likewise deemed to be responsible for the catalytic cleavage of RB5, RBBR or MG, respectively. Further, the differential response mechanism towards the structurally discrepant dyestuffs was put forward. Elevated reducing force associated with the corresponding functional proteins/enzymes was transferred to the exterior of the cell to differentially decompose the target contaminants. Overall, this study was dedicated to provide in-depth insights into the molecular response mechanism of co-metabolic degradation of refractory and structurally discrepant dyestuffs by an indigenous isolated Klebsiella strain.

Aloe barbadensis, A. vera var. chinensis, A. ferox and A. arborescens are the most widely cultivated and used aloe species due to their potential and potent bioactivity. In this study, clot lysis and fibrin plate model were used to assess the in vitro thrombolytic and fibrinolysis activity of protein and phenolic extracts, as well as three pure compounds (aloin A, Aloin B and aloe emodin) from aloe. Meanwhile, the phenolic compounds in aloe were analyzed by high-performance liquid chromatography (HPLC) and LC–mass spectrometry (LC–MS). The in vitro thrombolytic and fibrinolytic activity assay results indicated that the protein and phenolic extracts of four aloe species had good clot lysis, fibrinolytic activity and enzyme activity, and aloin A and aloin B may be the main active ingredients. In addition, the chromatographic analysis shows obviously differences in components, such as aloenin A, isoaloeresin D and aloesin.

The strategy of ligand functionalization can be used to adjust and control the properties of Metal-Organic Frameworks (MOFs). Based on these considerations, we chose two similar ligands (bpta = 3,5-bis(4-pyridyl)-1,2,4-triazole, bpat = 3,5-bis (4-pyridyl)-4-amino-1,2,4-triazole) and synthesized two MOFs with similar structures, {Zn2(bpta)2(hpta)(H2O)2·6H2O}n (1), {Zn2(bpat)2(hpta)(H2O)4·4H2O}n (2), by introduction of Zn(NO3)2·6H2O and pyromellitic dianhydride (pmda) coligand. X-ray single-crystal diffraction reveals that two MOFs both crystallized in triclinic systems with NbO topology. We systematically studied their fluorescence sensing performance. The results reveal that they both show obvious fluorescence enhancement effect to high-valence metal ions (Fe3+, Al3+, Cr3+, In3+ and Zr4+) and some amino acids. Unlike compound 1, the change of fluorescence property is not only reflected in the intensity, but also in the emission peak position for compound 2 with amino group. In addition, 2-H2O has a high selectivity and sensitivity to tryptophan, and there is no shift of emission peak. We verified the mechanism for the difference in fluorescence response between compounds 1 and 2 by IR and X-ray photoelectron spectrum.

Danshensu [3-(3, 4-dihydroxyphenyl) lactic acid, DSS], one of the significant cardioprotective components, is extracted from the root of Salvia miltiorrhiza. In the present study, an ester prodrug of Danshensu (DSS), palmitoyl Danshensu (PDSS), was synthesized with the aim to improve its oral bioavailability and prolong its half-life. The in vitro experiments were carried out to evaluate the physicochemical properties and stability of PDSS. Although the solubility of PDSS in water was only 0.055 mg·mL-1, its solubility in FaSSIF and FeSSIF reached 4.68 and 9.08 mg·mL-1, respectively. Octanol-water partition coefficient (log P) was increased from -2.48 of DSS to 1.90 of PDSS. PDSS was relatively stable in the aqueous solution in pH range from 5.6 to 7.4. Furthermore, the pharmacokinetics in rats was evaluated after oral administration of PDSS and DSS. AUC and t1/2 of PDSS were enhanced up to 9.8-fold and 2.2-fold, respectively, compared to that of DSS. Cmax was 1.67 ± 0.11 μg·mL-1 for PDSS and 0.81 ± 0.06 μg·mL-1 for DSS. Thus, these results demonstrated that PDSS had much higher oral bioavailability and longer circulation time than its parent drug.

AlGaN/GaN metal-oxide-semiconductor (MOS) capacitor structures using atomic layer deposited high-dielectric-constant (High-k) Al2O3/La2O3 bilayer films as dielectric have been investigated using high-frequency capacitance-voltage measurement. The stable thickness and uniform surface morphology of the bilayer films with different La/Al deposition cycle ratio (La/Al ratio) were observed after rapid thermal annealing by spectroscopic ellipsometry and atomic force microscopy, respectively. We have found that with a decrease of the La/Al ratio, the dipole layer observed by X-ray photoelectron spectroscopy at Al2O3/La2O3 interfaces is close to the surface of semiconductor and the flat band voltage shifts to the negative direction. Furthermore, the dramatic drop in dielectric constant of the films as La/Al ratio decrease was caused by the formation of La(OH)3 in La2O3. Finally, the reason for the flat band voltage shifts, which is based on the dielectric constant of Al2O3 and La2O3 comprising the position of dipole layer in the dielectric films, is proposed.

Objective To investigate the factors significantly affecting the shoot buds regeneration of Carthamus tinctorius from Jimsar (CTJ). Methods Through tissue culture experiments, the influences of culture temperature, illuminance, relative humidity, explants type, seedlings age, and plant growth regulators added in culture media on in vitro regeneration of CTJ were investigated. Results The culture temperature was set at 24 °C in daytime and 16 °C at night, illuminance at 9000 lx, and 60% relative humidity were suitable for CTJ regeneration. Cotyledons excised from 6–8 d old seedlings were more responsive than even-aged euphyll, hypocotyl, and root explants because of inducing adventitious buds. The highest percentage of regenerated shoots (79.1%) with about five adventitious buds per responding explant was obtained from MS basal medium containing 12.0 mg/L TDZ, 2.5 mg/L IBA, and 1.5 mg/L 2-ip (No. 14 medium). Regenerated shoot buds (80%) could elongate successfully after 1–2 weeks transferred to shoot elongation medium. Conclusion Suitable factors of shoot buds regeneration for CTJ were determined. It may also make a useful reference for regeneration researches of other C. tinctorius varieties in China.

Introduction: Normal function of DNA repair system is essential for the removal of damage induced by many kinds of internal and environmental agents. Genetic polymorphisms in DNA repair genes associated with modified repair capacity may be related to the risk of developing esophageal cancer (EC). This article dealt whether single-nucleotide polymorphisms of DNA repair genes MSH2, WRN, and Ku70 potentially contributed to EC susceptibility. Methods: A hospital-based case-control study with 117 EC cases and 132 controls in a Chinese population was conducted. We genotyped three single-nucleotide polymorphisms MSH2 c.2063T>G, WRN c.4330T>C, and Ku70 c.-1310 C>G using polymerase chain reaction-based restriction fragment length polymorphism and then performed statistical analysis by calculating the adjusted odds ratios (OR) and 95% confidence intervals (95% CI). Results: Carriers of the MSH2 c.2063 G allele were at a higher risk of developing EC with the TT genotype as reference (OR = 4.53, 95% CI=1.92–10.64, 33p = 0.001). Also for WRN c.4330T>C, individuals with at least one C allele (T/C or C/C) had a 2.21-fold increased risk for EC development compared with those who bore the T/T wild-type genotype (OR = 2.21, 95% CI=1.06–4.59, 33p = 0.035). Moreover, statistically significant variant genotypic interaction was suggested between MSH2 and WRN as a result of a much increased predisposition to EC ( 33p = 0.016). No obvious correlation was observed between Ku70 c.-1310 CG and esophageal carcinogenesis ( 33p > 0.05). Conclusions: Our findings indicated that genetic variants in DNA repair pathways may be involved in esophageal tumorigenesis. MSH2 c.2063 G allele and WRN c.4330 C allele, not Ku70 c.-1310 CG, conferred risk for the process of developing EC.

Forty-eight possible isomers of N6H6 have been investigated at the B3LYP/6-311++G∗∗ and G3B3 levels. The results show that heats of formation of all isomers are positive and A2-3 is the lowest and C2 is the highest. In addition, the energies and the heats of formation of the ring-shaped isomers are higher than those of the chain-shaped isomers. Among the ring-shaped isomers, the four-membered ring isomers have the highest heat of formation and the five-membered ring isomers have the lowest. For six-membered ring isomers, only the chair-shaped isomers are stable. Among all those chain-shaped isomers, the ones which have N–N bond and its length is in the range of N N double bond can improve the stability of the compounds.

There exists abundant thermal water recourses in Guanzhong basin, Shaanxi province (northwestern China). With the deepening of exploitation for thermal aquifer nowadays, the information about the origin and movement of thermal water is limited by using traditional methods. This paper applies environmental isotope techniques to offer di-rect constraints on the recharge and movement of thermal water and improve the geological and hydrogeological data-base in Guanzhong Basin. The research on the environmental isotopes shows that the geothermal water of the area is mainly recharged by meteoric water. The temperature of meteoric water which replenishes geothermal water in the study area is −16 °C. The estimated age of recharging the geothermal water is 13.3–28.2 ka based on the isotope analysis, belonging to the last glacial period in Late Quaternary. The source of replenishment of the geothermal water is thought to have been derived from glacial snow-melt water with an elevation higher than 1 500 m (ASL) in the north side of Qinling Mountain. The isotopic analysis denotes that the geothermal water in the southern Guanzhong basin is the mixture of net thermal water and normal temperature groundwater. Based on calculating the percentage of the mix-ture, nearly half of cold groundwater had participated the circulating of the geothermal water. However, in the center part of the basin, some artificial factors such as mismanage of pumping are probably the reason for the mixturing. The temperature range of the geothermal reservoirs in the basin is estimated at about 80–121 °C based on calculation of both SiO2 geothermometer and thermal water saturation index, which are basically in accordance with the measured temperature of thermal water. Based on the replenishment time and mixture extent with cold water, the thermal water in the studied area can be classified into three parts: mixed thermal water replenished by modern meteoric water; mixed thermal water replenished by both modern and ancient meteoric water, and deep circulating thermal water replenished by ancient meteoric water without mixture.

Three tetraaryl imidazole derivatives 5a–5c bearing thiazole groups were synthesized in the presence of [Bmin]Br by one-pot reaction and their structures were fully characterized by the 1 H NMR, IR, MS and elemental analysis. The results of UV–vis spectra and fluorescent spectra upon metal ions complexation show that compound 5a displays high selectivity and sensitivity for Cr 3+ ions. The complexation ratio of compound 5a and Cr 3+ is 1:1.