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51.
Macrophage migration inhibitory factor (MIF) is a unique cytokine that reportedly overrides the anti-inflammatory effect of endogenous glucocorticoids. MIF has been demonstrated to be involved in a variety of inflammatory diseases. In this study, we examined the role of MIF in bleomycin (BLM)-induced lung injury and fibrosis. The levels of MIF in lung tissues and bronchoalveolar lavage fluids were significantly increased in the period 5-10 days after intratracheal administration of BLM. Treatment with the anti-MIF antibody significantly reduced the mortality at 14 days and the histopathological lung injury score at 10 days. These effects were accompanied with significant suppression of the accumulation of inflammatory cells in the alveolar space and tumor necrosis factor-alpha in the lungs at 7 days. However, the anti-MIF antibody did not affect either the content of lung hydroxyproline or the histopathological lung fibrosis score at 21 days after BLM. These data provide further evidence for the crucial role of MIF in acute lung inflammation but do not support the involvement of MIF in lung fibrosis induced by BLM in mice.  相似文献   
52.
The effects of pot size, timing of the application of paclobutrazol (PTZ) and gibberellic acid (GA3), and the counteractive effect of these two compounds on growth and tuber yield of greenhouse-grown Norland and Russet Burbank potatoes were investigated. Plants were grown either in 1.5-liter pots (15 cm deep) or 3.0-liter pots (18 cm deep) and received a foliar application of either 1.5 mm PTZ or 9 × 10−3 mm GA3 at early or late stolon initiation. Some plants that had been foliar treated with 1.5 mm PTZ at early stolon initiation were foliar treated with 9 × 10−3 mm GA3 at late stolon initiation. PTZ reduced haulm length in both cultivars significantly, particularly when the treatment was applied at early stolon initiation, but the late treatment reduced haulm length only when growing in 3.0-liter pots. Irrespective of the timing of treatment, GA3 increased haulm length in Norland growing in both pot sizes, but the treatment increased haulm length in Russet Burbank only when applied at late stolon initiation. GA3 applied after PTZ did not overcome the growth-inhibiting effect of the PTZ treatment. The PTZ treatment effectively increased usable tuber number/plant (UTN) in Norland, but PTZ had no effect on UTN in Russet Burbank. PTZ reduced usable tuber weight/plant (UTW) only in Norland growing in 1.5-liter pots. By contrast, GA3 increased UTN only when treated at late stolon initiation of 1.5-liter pot-grown Norland, whereas the same treatment was effective when applied only at early stolon initiation for Russet Burbank. For Norland, the increase in UTN by early applied PTZ was reduced by the subsequent application of GA3. The use of 3.0-liter pots for minituber production in both Norland and Russet Burbank appears to have no advantage over growing in 1.5-liter pots, particularly when PTZ or GA3 is used to enhance tuberization. Received May 30, 1997; accepted February 3, 1998  相似文献   
53.
Wheat (Triticum aestivum L.) is the largest cereal crop grown in Western Canada where drought during late vegetative and seed filling stages affects plant development and yield. To identify new physiochemical markers associated with drought tolerance, epidermal characteristics of the flag leaf of two wheat cultivars with contrasting drought tolerance were investigated. The drought resistant ‘Stettler’ had a lower drought susceptibility index, greater harvest index and water‐use efficiency than the susceptible ‘Superb’. Furthermore, flag leaf width, relative water content and leaf roll were significantly greater in Stettler than in Superb at moderate drought stress (MdS). Visible differences in epicuticular wax density on the adaxial flag leaf surfaces and larger bulliform cells were identified in Stettler as opposed to Superb. Mid‐infrared attenuated total internal reflectance spectra revealed that Stettler flag leaves had increased asymmetric and symmetric CH2 but reduced carbonyl esters on its adaxial leaf surface compared to Superb under MdS. X‐ray fluorescence spectra revealed a significant increase in total flag leaf Zn concentrations in Stettler in response to MdS. Such information on the microstructural and chemical features of flag leaf may have potential as markers for drought tolerance and thereby accelerate the selection and release of more drought‐resistant cultivars.  相似文献   
54.
用单克隆抗体LCA,UCHL1,MT1,MB1,MB2,LN1和LN2对65例非何杰金氏淋巴瘤常规福尔马林固定石蜡包埋组织切片作免疫表型研究。证实B细胞性淋巴瘤50例(77%)。T细胞性淋巴瘤11例(17%)(4例染色不良,未能分型)。根据国际工作分类,本组T细胞淋巴瘤所占比例分别是11%,27%和13%。全部病例中LCA阳性率97%。T细胞抗体UCHL;阳性率(91%)明显高于MT1(73%),且与B淋巴细胞无交叉反应。4种B细胞抗体阳性率分别为LN。(96%),MB2(94%),LN1(86%),MB1(84%)。LN2和LN1对源于滤泡中心细胞淋巴瘤有更强的反应。研究结果表明上述单克隆抗体可有效用于非何杰金氏淋巴瘤石蜡切片的免疫组织化学标记,合理选用单克隆抗体有助于进行免疫学分型。  相似文献   
55.
To prepare a whole-cell biocatalyst of a stable lipase at a low price, mutated Candida antarctica lipase B (mCALB) constructed on the basis of the primary sequences of CALBs from C. antarctica CBS 6678 strain and from C. antarctica LF 058 strain was displayed on a yeast cell surface by α-agglutinin as the anchor protein for easy handling and stability of the enzyme. When mCALB was displayed on the yeast cell surface, it showed a preference for short chain fatty acids, an advantage for producing flavors; although when Rhizopus oryzae lipase (ROL) was displayed, the substrate specificity was for middle chain lengths. When the thermal stability of mCALB on the cell surface was compared with that of ROL on a cell surface, T 1/2, the temperature required to give a residual activity of 50% for heat treatment of 30 min, was 60°C for mCALB and 44°C for ROL indicating that mCALB displayed on cell surface has a higher thermal stability. Furthermore, the activity of the displayed mCALB against p-nitrophenyl butyrate was 25-fold higher than that of soluble CALB, as reported previously. These findings suggest that mCALB-displaying yeast is more practical for industrial use as the whole-cell biocatalyst.  相似文献   
56.
Signaling adaptor protein Crk has been shown to be involved in pathogenesis of human cancers including brain tumor where Crk was reported to be overexpressed. In this study, we addressed whether Crk is indispensable for malignant phenotype of brain tumor. In 20 surgical specimens of glioma, mRNA of both CrkI and CrkII was found to be elevated in malignant tumor. To define a precise role of Crk, we have established Crk-knockdown cell lines of glioblastoma KMG4 by siRNA, and early phase of cell adhesion to laminin was found to be suppressed. Wound healing assay revealed the decreased cell motility in Crk knockdown cells, and suppression of both anchorage-dependent and -independent growth were demonstrated in these cells. Furthermore, in vivo tumor forming potential was also markedly suppressed. These results suggest that Crk is required for early attachment to laminin, cell motility, and growth of glioblastoma cell line KMG4.  相似文献   
57.
Meaningful improvements in winter cereal cold hardiness requires a complete model of freezing behaviour in the critical crown organ. Magnetic resonance microimaging diffusion‐weighted experiments provided evidence that cold acclimation decreased water content and mobility in the vascular transition zone (VTZ) and the intermediate zone in rye (Secale cereale L. Hazlet) compared with wheat (Triticum aestivum L. Norstar). Differential thermal analysis, ice nucleation, and localization studies identified three distinct exothermic events. A high‐temperature exotherm (?3°C to ?5°C) corresponded with ice formation and high ice‐nucleating activity in the leaf sheath encapsulating the crown. A midtemperature exotherm (?6°C and ?8°C) corresponded with cavity ice formation in the VTZ but an absence of ice in the shoot apical meristem (SAM). A low‐temperature exotherm corresponded with SAM injury and the killing temperature in wheat (?21°C) and rye (?27°C). The SAM had lower ice‐nucleating activity and freezing survival compared with the VTZ when frozen in vitro. The intermediate zone was hypothesized to act as a barrier to ice growth into the SAM. Higher cold hardiness of rye compared with wheat was associated with higher VTZ and intermediate zone desiccation resulting in the formation of ice barriers surrounding the SAM.  相似文献   
58.
59.
Abstract Among 40 short rod-shaped mutants of Pseudomonas aeruginosa PAO isolated after nitrosoguanidine mutagenesis, a stable clone designated KG1034 was obtained and studied for its cellular and genetical features. Cells of the parent strain, PAO2302 had a mean cell length of 1.9 μm, whereas that of KG1034 was 1.3 μm. The doubling time of KG1034 was less than that of the parent strain, although both strains elongated at the same rate and exhibited the same relative amounts and pattern of penicillin-binding proteins. These results suggested that the phenotype of KG1034 was due to the initiation of septation at an earlier stage. The new gene responsible for this phenotype was named srs (abbreviation for short r od shape) and mapped by conjugation between cys -54 and puuC .  相似文献   
60.
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