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排序方式: 共有242条查询结果,搜索用时 15 毫秒
51.
本项研究工作表明,塔式生物滤池在处理模拟洗涤剂工业废水时,能够适应和克服一般好氧生化法所不能解决的泡沫问题,并对废水中的LAS和COD具有一定的去除效果。根据实验结果,初步认为塔滤可应用于洗涤剂工业废水的生化处理,并向洗涤剂行业首次推荐这种废水生物学净化方法。从塔滤的生物膜中分离出了优势菌,经鉴定为一种气单胞菌(Aeromonas sp. D-4)。 相似文献
52.
Kimiyuki Satoh 《Physiologia plantarum》1988,72(1):209-212
Until recently nearly all available experimental evidence seemed to indicate that the largest subunit of about 50 kDa in the photosystem II core complex ( psb B gene product) is the site of primary photochemistry, and thus the name "P-680 apoprotcin" has been given to this subunit. The notion, however, has also been challenged on the basis of deduced amino acid sequence homology between the proteins in the photosystem II and those of the purple bacterial reaction center. The actual preparation of a functionally active photosystem II reaction center completely devoid of the psb B gene product, but consisting of D-1 and D-2 proteins and cytochrome b -559, has now been achieved. 相似文献
53.
Complete nucleotide sequence of the hexokinase PI gene (HXK1) of Saccharomyces cerevisiae 总被引:9,自引:0,他引:9
The nucleotide sequence of the yeast glycolytic hexokinase isoenzyme PI-gene, HXK1, has been determined by sequencing the yeast DNA insert of the previously isolated plasmid HXK1 clone [Entian et al., Mol. Gen. Genet. 198 (1984) 50-54]. The structural gene sequence included 1452 bp coding for 484 amino acid (aa) residues corresponding to the Mr of 153 605 for the HXK1 monomer. Several initiation regions and termination points were located using nuclease S1 mapping. The HXK1 sequence was 76% homologous with that of HXK2, which is responsible for triggering glucose repression in yeasts. Since HXK1 is not involved in this regulatory system, the regulatory function of HXK2 must correspond to one or more of the differences between both isoenzymes. Most changes in the amino acid sequence were statistically distributed; however, four clustered regions with more than five altered aa residues were identified. 相似文献
54.
Torsten Kessler Ariane Baumeier Caroline Brand Michael Grau Linus Angenendt Saliha Harrach Ursula Stalmann Lars Henning Schmidt Georg Gosheger Jendrik Hardes Dimosthenis Andreou Johannes Dreischalück Georg Lenz Eva Wardelmann Rolf M. Mesters Christian Schwöppe Wolfgang E. Berdel Wolfgang Hartmann Christoph Schliemann 《Translational oncology》2018,11(6):1271-1282
Aminopeptidase N (CD13) is expressed on tumor vasculature and tumor cells. It represents a candidate for targeted therapy, e.g., by truncated tissue factor (tTF)-NGR, binding to CD13, and causing tumor vascular thrombosis. We analyzed CD13 expression by immunohistochemistry in 97 patients with STS who were treated by wide resection and uniform chemo-radio-chemotherapy. Using a semiquantitative score with four intensity levels, CD13 was expressed by tumor vasculature, or tumor cells, or both (composite value, intensity scores 1-3) in 93.9% of the STS. In 49.5% tumor cells, in 48.5% vascular/perivascular cells, and in 58.8%, composite value showed strong intensity score 3 staining. Leiomyosarcoma and synovial sarcoma showed low expression; fibrosarcoma and undifferentiated pleomorphic sarcoma showed high expression. We found a significant prognostic impact of CD13, as high expression in tumor cells or vascular/perivascular cells correlated with better relapse-free survival and overall survival. CD13 retained prognostic significance in multivariable analyses. Systemic tTF-NGR resulted in significant growth reduction of CD13-positive human HT1080 sarcoma cell line xenografts. Our results recommend further investigation of tTF-NGR in STS patients. CD13 might be a suitable predictive biomarker for patient selection. 相似文献
55.
Michael Rother Vivien Quitzke 《Biochimica et Biophysica Acta (BBA)/General Subjects》2018,1862(11):2451-2462
Background
The major biological form of selenium is that of the co-translationally inserted amino acid selenocysteine (Sec). In Archaea, the majority of proteins containing Sec, selenoproteins, are involved in methanogenesis. However, the function of this residue is often not known because selenium-independent homologs of the selenoproteins can be employed, sometimes even in one organism.Scope of review
This review summarizes current knowledge about the selenoproteins of Archaea, the metabolic pathways where they are involved, and discusses the (potential) function of individual Sec residues. Also, what is known about the “archaeal” way of selenoprotein synthesis, and the regulatory mechanism leading to the replacement of the selenoproteins with selenium-independent homologs, will be presented. Where appropriate, similarities with (and differences to) the respective steps employed in the other two domains, Bacteria and Eukarya, will be emphasized.Major conclusions
Genetic and biochemical studies guided by analysis of genome sequences of Sec-encoding archaea has revealed that the pathway of Sec synthesis in Archaea and Eukarya are principally identical and that Sec insertion in Eukarya probably evolved from an archaeal mechanism employed prior to the separation of the archaeal and eukaryal lines of decent.General significance
In light of the emerging close phylogenetic relationship of Eukarya and Archaea, archaeal models may be highly valuable tools for unraveling “eukaryotic” principles in molecular and cell biology. 相似文献56.
Many marine Alphaproteobacteria of the Roseobacter group show a characteristic swim-or-stick lifestyle, for which motility is a crucial trait. Three phylogenetically distinct flagellar gene clusters (FGCs) have been identified in Rhodobacteraceae that have been named fla1, fla2 and fla3 according to their relative abundance. In addition to the flagellar-dependent swimming and swarming motility, pilus-dependent twitching mediates bacterial locomotion. Furthermore, filament independent modes of motility, namely gliding and sliding, have been described for various microorganisms. However, no mode of motility other than swimming has so far been described for roseobacters. In the present study, we investigated motility, distribution of flagellar systems and the phylogeny of 120 genome-sequenced Rhodobacteraceae. The phylogenetically broad taxon sampling that included 114 type strains revealed the presence of at least ten distinct clades that were statistically well supported. The investigation of the actual physiological capacity for swimming motility on soft agar plates showed that only about half of the 120 tested strains were motile under the tested conditions. Seven strains developed a conspicuous dendritic motility phenotype that was reminiscent of the swarming motility in Pseudomonas aeruginosa. The observed dendritic motility in two strains (i.e. Sulfitobacter pseudonitzschiae DSM 26842 and Roseovarius pacificus DSM 29589) was particularly surprising because they did not harbor any genes of the FGC. Accordingly, it was concluded that this form of dendritic motility was independent of a flagellum. A comparative genomics approach allowed a remarkable number of pilus-related candidate genes to be identified for this novel type of motility in Rhodobacteraceae. 相似文献
57.
Fangxia Zou Stefan Pusch Jie Hua Tianfang Ma Lijun Yang Qihua Zhu Yungen Xu Yueqing Gu Andreas von Deimling Xiaoming Zha 《Bioorganic & medicinal chemistry letters》2018,28(3):388-393
IDH1 mutation (mIDH1) occurs in 20–30% of gliomas and is a promising target for the cancer therapy. In this article, a cross docking-based virtual screening was employed to identify seven small molecules for the allosteric site of mIDH1. Compounds ZX01, ZX05 and ZX06 exhibited the potent inhibitory activity and the high selectivity against WT-IDH1, providing a good starting point for the further development of highly selective mIDH1 inhibitors. Importantly, the parallel artificial membrane permeation assay of the blood-brain barrier (PAMPA-BBB) identified ZX06 with a good ability to penetrate BBB. These findings indicate that ZX06 deserves further optimization as a lead compound for the treatment of patients with IDH1 mutated brain cancers. 相似文献
58.
59.
Toshio Matsumoto Yumiko Kawanobe Etsuro Ogata 《Biochimica et Biophysica Acta (BBA)/Molecular Cell Research》1985,845(3):358-365
Regulation of 25-hydroxyvitamin D-3 24-hydroxylase by 1,25-dihydroxyvitamin D-3 and synthetic human parathyroid hormone fragment 1–34 (PTH1–34) was investigated using a cloned monkey kidney cell line, JTC-12. Treatment of the cells with 1,25-dihydroxyvitamin D-3 markedly enhanced the conversion of [3H]-25-hydroxyvitamin D-3 into a more polar metabolite. The metabolite was identified as 24,25-dihydroxyvitamin D-3 by normal phase and reverse phase high-performance liquid chromatography and periodate oxidation. The 24-hydroxylae activity appeared to follow Michaelis-Menten kintics, and 1,25-dihydroxyvitamin D-3 treatment increased the of 24-hydroxylase from 33 to 95 pmol/h per 106 cells without affecting the apparent value of the enzyme (220 nM in control vs. 205 nM in 1,25-dihydroxyvitamin D-3 treated cells). The enzyme activity reached a maximum between 4 and 8 h of treatment with 1,25-dihydroxyvitamin D-3. The dose of 1,25-dihydroxyvitamin D-3 required to cause a half-maximal stimulation was about 3 · 10?10 M. The 1,25-dihydroxyvitamin D-3-induced increase in 24-hydroxylase was almost completely inhibited by the presence of 1 μM cycloheximide. Treatment of the cells with PTH1–34 caused a dose-dependent increase in cyclic AMP production. Half-maximal stimulation of cyclic AMP production was obtained at about 5 · 10?9 M PTH1–34. When 2.4 · 10?9 M PTH1–34 was added after 1,25-dihydroxyvitamin D-3 treatment, the 1,25-dihydroxyvitamin D-3-stimulated 24-hydroxylase was inhibited to of control. Higher concentrations of PTH1–34 caused less inhibition of the enzyme activity. When cyclic AMP was added instead of PTH1–34, the enzyme activity was also suppressed significantly. These results indicate that, in JTC-12 cells, 1,25-dihydroxyvitamin D-3 stimulates 24-hydroxylase in a dose- and time-dependent manner by increasing the of the enzyme through a mechanism dependent upon new protein synthesis, and suggest that PTH1–34 inhibits the 1,25-dihydroxyvitamin D-3-induced stimulation of 24-hydroxylase through its effect on cyclic AMP production. 相似文献
60.
The ability of different receptors to mediate inhibition of cyclic AMP accumulation due to a variety of agonists was examined in rat striatal slices. In the presence of 1 mM 3-isobutyl-1-methylxanthine, dopamine D-2, muscarinic cholinergic, and opiate receptor stimulation by RU 24926, carbachol, and morphine (all at 10(-8)-10(-5) M), respectively, inhibited the increase in cyclic AMP accumulation in slices of rat striatum due to dopamine D-1 receptor stimulation by 1 microM SKF 38393. In contrast, these inhibitory agents were unable to reduce the ability of a number of other agonists, including isoprenaline, prostaglandin E1, 2-chloroadenosine, vasoactive intestinal polypeptide, and cholera toxin, to increase cyclic AMP levels in striatal slices. These results suggest that in rat striatum either dopamine D-2, muscarinic cholinergic, and opiate receptors are only functionally linked to dopamine D-1 receptors or that the D-1 and D-2 receptors linked to adenylate cyclase lie on the cells, distinct from other receptors capable of elevating striatal cyclic AMP levels. 相似文献