601 research outputs found

    Bis[bis­(1-ethyl­benzimidazol-2-ylmeth­yl) ether]cobalt(II) dipicrate dimethyl­formamide disolvate

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    In the title complex, [Co(C20H22N4O)2](C6H2N3O7)2·2C3H7NO, the CoII ion is coordinated by two sets of two N atoms and an O atom from two independent tridendate ligands in a distorted octa­hedral coordination environment. There are significant differences between chemically equivalent coordination bond lengths. The crystal structure is stabilized by weak inter­molecular C—H⋯O hydrogen bonds and weak π–π stacking inter­actions [centroid–centroid distance 3.495 (1) Å]. In one of the anions one nitro group is rotationally disordered about the C—N bond with refined occupancies of 0.524 (8) and 0.476 (8)

    Effect of Prunella vulgaris L extract on hyperplasia of mammary gland in rats

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    Purpose: To explore the effects of Prunella vulgaris L extract (PVE) on hyperplasia of mammary gland (HMG) in rats.Methods: Forty virgin female Wistar rats were randomly divided into normal group, control group (HMG model), positive control group (Rupixiao Capsule, RPXC), and low-, medium- and high-dose (150, 300 and 600 mg/kg) of PVE groups. Injections of estrogen and progestogen were given at the same time to prepare rat. Changes in nipple height were measured, while serum estradiol (E2), progesterone (P), prolactin (PRL), follicle stimulating hormone (FSH) and luteinizing hormone (LH) levels were evaluated by ELISA; Uterus and ovary indices were determined.Results: Compared with control group, PVE reduced elevated nipple height to 2.25 ± 0.09 mm (p < 0.01) and uterus index to 2.29 ± 0.41 mg/g (p < 0.01), as well as reduced the number of mammary gland lobules and secretion in HMG rats. Compared with control group, serum E2 (2.81 ± 0.17 pmol/L), PRL (269.38 ± 8.28 pg/mL) and FSH (0.13 ± 0.03 IU/L) levels (p < 0.01) were lowered, but serum P (1.31 ± 0.13 ng/mL) and LH (1.73 ± 0.08 mIU/mL) levels were higher (p < 0.01) in rats treated with highdose PVE.Conclusion: These results suggest that PVE exerts anti-HMG effect in rats induced by estrogen and progestogen.Keywords: Prunella vulgaris L; Anti-inflammatory; Anti-hyperplasia of mammary glan

    An Exotic Species Is the Favorite Prey of a Native Enemy

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    An Exotic Species Is the Favorite Prey of a Native Enemy

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    Although native enemies in an exotic species' new range are considered to affect its ability to invade, few studies have evaluated predation pressures from native enemies on exotic species in their new range. The exotic prey naiveté hypothesis (EPNH) states that exotic species may be at a disadvantage because of its naïveté towards native enemies and, therefore, may suffer higher predation pressures from the enemy than native prey species. Corollaries of this hypothesis include the native enemy preferring exotic species over native species and the diet of the enemy being influenced by the abundance of the exotic species. We comprehensively tested this hypothesis using introduced North American bullfrogs (Lithobates catesbeianus, referred to as bullfrog), a native red-banded snake (Dinodon rufozonatum, the enemy) and four native anuran species in permanent still water bodies as a model system in Daishan, China. We investigated reciprocal recognition between snakes and anuran species (bullfrogs and three common native species) and the diet preference of the snakes for bullfrogs and the three species in laboratory experiments, and the diet preference and bullfrog density in the wild. Bullfrogs are naive to the snakes, but the native anurans are not. However, the snakes can identify bullfrogs as prey, and in fact, prefer bullfrogs over the native anurans in manipulative experiments with and without a control for body size and in the wild, indicating that bullfrogs are subjected to higher predation pressures from the snakes than the native species. The proportion of bullfrogs in the snakes' diet is positively correlated with the abundance of bullfrogs in the wild. Our results provide strong evidence for the EPNH. The results highlight the biological resistance of native enemies to naïve exotic species

    Design and Testing of an Online Fertilizing Amount Detection Device Based on the Moment Balance Principle

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    Based on the principle of moment balance, this paper designs a fertilizer application amount online detection device, which is mainly composed of two major parts: the fertilizer guide mechanism and the fertilizer metering and discharging mechanism.Under the electromagnetic reversing and buffering of the fertilizer guide mechanism, the fertilizer discharged into the device falls alternately into the storage box of the two metering units of the metering and discharging mechanism. Once the gravity of the fertilizer in the storage box is greater than the suction of the electromagnetic sucker, the fertilizer discharging board is automatically opened for fertilizer discharge, and the metering pulse signal is accumulated once. Meanwhile, the fertilizer guide plate is driven by the electromagnetic commutator to reverse the material, and then another storage box is started for fertilizer storage and metering. In this approach, online detection of fertilizer flow can be realized by repeatedly guiding and reversing and metering the incoming fertilizer. According to the single metering fertilizer quality and the number of metering pulse signals, the fertilization amount can be calculated in real-time.The performance of the device was verified by bench test. The test results indicated that: The established fertilizer application detection model is a quadratic function (R2>0.98), and the verification error was less than 3.73% in the detection of alternating cycle fertilizer discharge; the coefficient of determination (R2) and the root mean square error (RMSE) reached 0.992 and 9.858 respectively, indicating high detection accuracy of the device is

    Toksičnost aromatskih ketona za stanice kvasca i ubrzanje njihove redukcije primjenom adsorpcijskih smola

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    Asymmetric reduction of the prochiral aromatic ketone catalyzed by yeast cells is one of the most promising routes to produce its corresponding enantiopure aromatic alcohol, but the space-time yield does not meet people’s expectations. Therefore, the toxicity of aromatic ketone and aromatic alcohol to the yeast cell is investigated in this work. It has been found that the aromatic compounds are poisonous to the yeast cell. The activity of yeast cell decreases steeply when the concentration of acetophenone (ACP) is higher than 30.0 mmol/L. Asymmetric reduction of acetophenone to chiral S-α-phenylethyl alcohol (PEA) catalyzed by the yeast cell was chosen as the model reaction to study in detail the promotion effect of the introduction of the resin adsorption on the asymmetric reduction reaction. The resin acts as the substrate reservoir and product extraction agent in situ. It has been shown that this reaction could be remarkably improved with this technique when the appropriate kind of resin is applied. The enantioselectivity and yield are acceptable even though the initial ACP concentration reaches 72.2 mmol/L.Asimetrična redukcija prokiralnih aromatskih ketona, katalizirana stanicama kvasca, obećavajuća je metoda proizvodnje enantiomerno čistih aromatskih alkohola, no iskorištenje reakcije ne zadovoljava današnje potrebe. U radu je utvrđena toksičnost aromatskih ketona i alkohola za stanice kvasca. Aktivnost stanica kvasca naglo se smanjila pri koncentracijama acetofenona većim od 30 mmol/L. Kao model reakcije za detaljno ispitivanje pozitivnog učinka uvođenja adsorpcijskih smola odabrana je asimetrična redukcija acetofenona u kiralni S-α-feniletilni alkohol, katalizirana stanicama kvasca. Utvrđeno je da smola djeluje kao rezervoar supstrata i agens za ekstrakciju proizvoda in situ. Tako se odvijanje reakcije može znatno poboljšati uvođenjem prikladne smole. Enantioselektivnost i prinos su zadovoljavajući iako je početna koncentracija acetofenona dosegla čak 72,2 mmol/L

    Wavelet multiresolution complex network for analyzing multivariate nonlinear time series

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    Z. K. Gao was supported by National Natural Science Foundation of China under Grant No. 61473203, and the Natural Science Foundation of Tianjin, China under Grant No. 16JCYBJC18200Peer reviewedPostprin

    Regulating Cytoplasmic Calcium Homeostasis Can Reduce Aluminum Toxicity in Yeast

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    Our previous study suggested that increased cytoplasmic calcium (Ca) signals may mediate aluminum (Al) toxicity in yeast (Saccharomyces cerevisiae). In this report, we found that a yeast mutant, pmc1, lacking the vacuolar calcium ion (Ca2+) pump Ca2+-ATPase (Pmc1p), was more sensitive to Al treatment than the wild-type strain. Overexpression of either PMC1 or an anti-apoptotic factor, such as Bcl-2, Ced-9 or PpBI-1, decreased cytoplasmic Ca2+ levels and rescued yeast from Al sensitivity in both the wild-type and pmc1 mutant. Moreover, pretreatment with the Ca2+ chelator BAPTA-AM sustained cytoplasmic Ca2+ at low levels in the presence of Al, effectively making the cells more tolerant to Al exposure. Quantitative RT-PCR revealed that the expression of calmodulin (CaM) and phospholipase C (PLC), which are in the Ca2+ signaling pathway, was down-regulated under Al stress. This effect was largely counteracted when cells overexpressed anti-apoptotic Ced-9 or were pretreated with BAPTA-AM. Taken together, our results suggest that the negative regulation of Al-induced cytoplasmic Ca signaling is a novel mechanism underlying internal resistance to Al toxicity
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