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971.
The effects of lateral shade and wind on stem allometry, whole-plant biomass allocation, and mechanical stability were examined for Abutilon theophrasti in a fully factorial glasshouse experiment. Lateral shade from neighboring plants increased stem height by 33% relative to control plants grown individually, despite a decrease in plant dry mass. Intermittent wind decreased stem height by 18% in unshaded plants, but by only 3% in shaded plants. Surprisingly, both lateral shade and wind caused decreases in stem diameter, even with diameter controlled for height, resulting in low diameter?:?height ratios in wind-treated plants relative to untreated plants. Under shade, wind-treated plants had higher root allocation than untreated plants, which allowed wind-treated shade plants to compensate for a low diameter?:?height ratio. This did not occur in the absence of shade, where stem tissue density and root allocation of wind-treated plants did not exceed that of untreated plants. Nevertheless, wind-treated plants experienced low drag relative to untreated plants due to a lower leaf area. Consequently, stem deflections of wind-treated plants did not exceed those of untreated plants at any given windspeed. Our results document a complex interaction between shade and wind on plant morphology and suggest that the nature of this interaction is generally that lateral shade acts to reduce or eliminate thigmomorphogenic responses. 相似文献
972.
The lily PR-10 belongs to a family of intracellular pathogenesis-related (IPR) proteins. Genomic Southern analysis indicates that the PR-10 is encoded by a family of multiple genes. Seven heterogeneous cDNA clones encoding lily PR-10 from Lilium longiflorum are divided into two subclasses based on sequence comparison and Southern hybridization. A 82% overall sequence similarity was found between the two subclasses (represented by PR-10c and d). The two cDNAs include an open reading frame of 474 bp encoding 157 amino acids. 5'- and 3'-untranslated regions exhibit low similarity, but similarity is high in the coding region. The lily PR-10 genes are induced by abscisic acid (ABA) and methyl jasmonate (MeJA) in the anther and various other organs of lily plants. The induction of PR-10 genes by ABA and MeJA in lily anthers occurs by two separate signal transduction pathways. The protein phosphatase inhibitor okadaic acid inhibits the MeJA-induced expression of PR-10 genes downstream of MeJA. In addition, the protein kinase inhibitor staurosporine inhibits the MeJA-induced expression of PR-10 genes, implying that an activity of staurosporine-sensitive protein kinases exists downstream of MeJA in the anther. However, okadaic acid does not inhibit the ABA-induced expression of PR-10 genes whereas staurosporine does. These observations suggest that, in addition to the known pathway that ABA induces gene expression by activating JA or MeJA, a MeJA-independent pathway of ABA induction exists in the anther. The alternative pathway of ABA induction involves a staurosporine-sensitive protein kinase activity downstream of ABA. 相似文献
973.
Shuai Liu Zepeng Liu Xi Shen Xuelong Wang Sheng‐Chieh Liao Richeng Yu Zhaoxiang Wang Zhiwei Hu Chien‐Te Chen Xiqian Yu Xiaoqing Yang Liquan Chen 《Liver Transplantation》2019,9(32)
Li‐rich layered metal oxides are one type of the most promising cathode materials in lithium‐ion batteries but suffer from severe voltage decay during cycling because of the continuous transition metal (TM) migration into the Li layers. A Li‐rich layered metal oxide Li1.2Ti0.26Ni0.18Co0.18Mn0.18O2 (LTR) is hereby designed, in which some of the Ti4+ cations are intrinsically present in the Li layers. The native Li–Ti cation mixing structure enhances the tolerance for structural distortion and inhibits the migration of the TM ions in the TMO2 slabs during (de)lithiation. Consequently, LTR exhibits a remarkable cycling stability of 97% capacity retention after 182 cycles, and the average discharge potential drops only 90 mV in 100 cycles. In‐depth studies by electron energy loss spectroscopy and aberration‐corrected scanning transmission electron microscopy demonstrate the Li–Ti mixing structure. The charge compensation mechanism is uncovered with X‐ray absorption spectroscopy and explained with the density function theory calculations. These results show the superiority of introducing transition metal ions into the Li layers in reinforcing the structural stability of the Li‐rich layered metal oxides. These findings shed light on a possible path to the development of Li‐rich materials with better potential retention and a longer lifespan. 相似文献
974.
Two experiments were conducted to study effects of cloprostenol sodium (cloprostenol) and clenbuterol HCl (clenbuterol) during postpartum anestrus on subsequent reproductive performance in cows. In Experiment I, 96 cows received either 0.5 mg cloprostenol (PGF, n = 25), 364 mg clenbuterol (CLEN, n = 24), 0.5 mg cloprostenol and 364 mg clenbuterol (CLEN+PGF, n = 21) or no treatment (Control, n = 26) on Day 20 post partum. Treatments failed to influence postpartum interval, pregnancy rate or the incidence of short estrous cycles preceding the first normal estrous cycle. In Experiment II, anestrous cows were administered cloprostenol (0.5 mg) on either Day 20 (PGF20, n = 27) or Day 35 post partum (PGF35, n = 25), or served as untreated controls (Control, n = 26). Neither postpartum interval nor pregnancy rate were affected by cloprostenol treatment. In conclusion, treatment of postpartum cows with PGF did not alter the resumption of normal estrous cycles following parturition. 相似文献
975.
976.
Kelem Kassahun Pei Hu Mark P. Grillo Margaret R. Davis Lixia Jin Thomas A. Baillie 《Chemico-biological interactions》1994,90(3):253-275
The ability of 2-n-propyl-4-pentenoic acid (Δ4-VPA) and 2-n-propyl-2(E)-pentenoic acid ([E]-Δ2-VPA), two unsaturated metabolites of valproic acid (VPA), to form reactive intermediates, deplete hepatic glutathione (GSH) and cause accumulation of liver triglycerides was investigated in the rat. With the aid of ionspray liquid chromatography-tandem mass spectrometry (LC-MS/MS), three GSH adducts were detected in the bile of Δ4-VPA-treated animals and were identified as 4-hydroxy-5-glutathion-S-yl-VPA-γ-lactone, 5-glutathion-S-yl-(E)-Δ3-VPA and 3-oxo-5-glutathion-S-yl-VPA. A fourth conjugate was identified tentatively as 4-glutathion-S-yl-5-hydroxy-VPA. Quantitative analysis of the corresponding N-acetylcysteine (NAC) conjugates in urine indicated that metabolism of Δ4-VPA via the GSH-dependent pathways accounted for approximately 20% of an acute dose (100 mg kg−1 i.p.). In contrast, when rats were given an equivalent dose of (E)-Δ2-VPA, only one GSH adduct (5-glutathion-S-yl-(E)-Δ3-VPA) was detected at low concentrations in bile. In vitro experiments with rat liver mitochondria demonstrated that Δ4-VPA undergoes coenzyme A- and ATP-dependent metabolic activation in this organelle via the β-oxidation pathway to intermediates which bind covalently to proteins. When liver homogenates and hepatic mitochondria from rats injected with Δ4-VPA, (E)-Δ2-VPA or VPA were analyzed for GSH content, it was found that only Δ4-VPA depleted GSH pools significantly. Treatment of rats with Δ4-VPA and (to a lesser extent) VPA led to an accumulation of liver triglycerides, whereas (E)-Δ2-VPA had no measurable effect. It is concluded that Δ4-VPA undergoes metabolic activation by both microsomal cytochrome P-450-dependent and mitochondrial coenzyme A-dependent processes, and that the resulting electrophilic intermediates, which are trapped in part by GSH, may mediate the hepatotoxic effects of this compound. In contrast, (E)-Δ2-VPA is not transformed to any appreciable extent to reactive metabolites, which thus accounts for the apparent lack of hepatotoxicity of this positional isomer in the rat. 相似文献
977.
曾子申;胡峻;利容千 《武汉植物学研究》1985,3(4):439-442
本文对我国栽培辣椒Capsicum annuum L.的四个品种即汉川椒、华椒一号、牛角椒和二金条进行了核型分析,其染色体数目均为2n=2x=24,核型公式均为2n=24=20m+2sm+2st,但汉川椒和华椒一号具一对随体,牛角椒和二金条具两对随体。本文还对它们的进化关系进行了讨论。 相似文献
978.
Hongmei Zhao Xiaomin Song Li Yan Meng Ren Xingxing Cui Yao Li Ran Gao Wei Zhang Marobian Liu Bin Liu Yi Hu Jing Wang 《生物化学与生物物理学报:疾病的分子基础》2018,1864(1):189-196
Immunoglobulin E (IgE) has been suggested as a risk factor for allergy-induced low blood pressure, which has not been well explained in molecular details. Our current study shows a novel mechanism involving IgE, Fc?R1, miRNA-212-5p (miR-212-5p), and sodium/calcium exchanger protein 1(NCX1) for asthma to induce hypotension. In arterial smooth muscle cells, IgE up-regulated miR212-5p via its receptor Fc?R1, which resulted in down-regulation of NCX1 that is a regulating factor for blood pressure. In mice, asthma induced hypotension by interfering vasoconstrictive function; knockout of Fc?R1 kept the asthmatic mice from developing hypotension; knock-down of miR-212-5p in asthmatic mice resulted in a significant restoration of blood pressure. In human, asthma and IgE were positively correlated with hypotension in cohort study on NIH epidemiological data. This study suggests a novel therapeutic target (miR-212-5p) for treatment of asthma-induced hypotension. 相似文献
979.
Songsong Zhang Beibei Qiu Weiping Hu Fanyi Ma M. Z. H. Khan 《Journal of enzyme inhibition and medicinal chemistry》2018,33(1):1335-1342
Present study aimed to immobilise the α-glucosidase on suitable supports to construct enzymatic microreactors and their subsequent applicability in efficient inhibitor screening from the Chinese Yam (Dioscorea opposita Thunb.) peel. A type of lamellar and porous composites (rGO@Fe3O4) were synthesised with a facile one-step solvothermal method and employed as carriers to construct enzymatic microreactors for screening α-glucosidase ligand from the Chinese Yam peel in league with the high performance liquid chromatography and mass spectrometry (HPLC-MS). The immobilisation amount of α-glucosidase on rGO@Fe3O4 under the optimised conditions was about 40?μg α-glucosidase/mg carriers. Furthermore, the binding capacities of screened inhibitors, 2,4-dimethoxy-6,7-dihydroxyphenanthrene and batatasin I, were 35.6 and 68.2%, respectively. Hence, considering their high screening efficiency and excellent magnetic separation ability, these as-prepared nanocomposite consisting of rGO and Fe3O4 may be potential supports for the enzyme (such as α-glucosidase) immobilisation for rapid α-glucosidase inhibitors screening from the diverse nature resources. 相似文献
980.