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81.
82.
When the distillable oil from adult pecan weevils, Curculio caryae, of both sexes was investigated separately with an integrated gas chromatographymass spectrometry system, evidence was obtained for a number of di- and trisubstituted aromatic hydrocarbons, seven phenolic and carbonyl aromatic compounds, and at least three alcohols. The major compounds were a series of alkanes and alkenes, four esters and four heterocyclic compounds. Among these, eleven compounds were unique to males and four were unique to females. The volatiles were also bioassayed in the field and each attracted the opposite sex. This investigation was part of a study made to identify the possible rôle of these compounds as a pheromone produced by the pecan weevil.  相似文献   
83.
These studies were undertaken to determine the molecular events by which estradiol and follicle-stimulating hormone (FSH) stimulate in ovarian granulosa cells the increase in the content of one of the regulatory subunits of cAMP-dependent protein kinase type II, RII51 (Mr = 51,000), and its electrophoretic variants RII51.5 (Mr = 51,500) and RII52 (Mr = 52,000). To analyze the de novo synthesis of RII51/52, granulosa cells were cultured (10(6) cells/ml) for 0, 12, 24, or 48 h with estradiol (10 nM) +/- FSH (12.5, 25, and 50 ng/ml), 8-bromo-cAMP (0.25-3 mM), or forskolin (0.5-100 microM) and then pulse-labeled with [35S]methionine (300 microCi/ml; 4 h). Labeled RII51, present either in urea extracts of total cellular protein or after partial purification from a soluble cell extract by cAMP-Sepharose chromatography, was quantitated by autoradiography of two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis gels and by excision of the silver-stained spots of the RII51 variants from the gels and counting. Synthesis of RII51 and its electrophoretic variants was low in cells cultured with estradiol alone for 48 h, whereas it was increased 4-5-fold in cells cultured with estradiol and FSH. Changes in the synthesis of actin were minor throughout the culture period regardless of hormone treatment. Pulse-chase experiments using [35S]methionine provided evidence that the isoelectric variants RII51.5 and RII52 may be derived from RII51 by post-translation modification, such as phosphorylation. Labelling with [32P]orthophosphate showed that RII52 contained more radioactivity than RII51.5 and RII51. Northern and filter hybridization assays demonstrated a 6-10-fold dose- and time-dependent increase in the amount of RII51 mRNA in granulosa cells exposed to estradiol and FSH or estradiol and forskolin compared to those cultured with estradiol alone. In vitro translation of poly(A)+ mRNA of granulosa cells from estradiol- and FSH-treated hypophysectomized rats also demonstrated an increase in the content of translatable RII51 mRNA. These studies indicate that in cultured rat granulosa cells the synthesis of RII51 and the content of its mRNA are selectively increased by estradiol and cAMP in a time- and dose-dependent manner. Based on these observations, RII51 appears to be a useful marker to determine the molecular (genomic?) sites of estradiol and FSH action in differentiating rat granulosa cells.  相似文献   
84.
Plasma fibronectin promotes modulation of rat arterial smooth muscle cells from a contractile to a synthetic phenotype during the first few days in primary culture. This process includes cell adhesion and spreading, loss of myofilaments, and formation of a widespread rough endoplasmic reticulum and a prominent Golgi complex. The structural reorganization is accompanied by activation of overall RNA and protein synthesis. Moreover, the cells gain the ability to replicate their DNA and divide in response to platelet-derived growth factor. Here, it is demonstrated that the power of fibronectin to bring about this change in the differentiated properties of the smooth muscle cells resides in a 105-kD cell-binding fragment, whereas a 70-kD collagen-binding fragment and a 31-kD heparin-binding fragment are inactive in this respect. Laminin, another adhesive glycoprotein and a component of the basement membrane that normally surrounds arterial smooth muscle, was contrarily found to maintain the cells in a contractile phenotype. However, with increasing time more and more cells went through the modulation into a synthetic phenotype. This "catch-up" was counteracted by a peptide that contained the cell-attachment sequence of fibronectin (Arg-Gly-Asp-Ser). Hence, it is possible that the delayed modulation on laminin was due to production of fibronectin by the cells themselves. In support of this notion, fibronectin isolated from smooth muscle cultures was found to be as effective as plasma fibronectin in stimulating the phenotypic modulation. Moreover, using a combination of chemical, immunochemical, and immunocytochemical methods, it was demonstrated that the cells secreted fibronectin as well as laminin at an increasing rate during the first 4 d in primary culture and, notably, cells cultured on laminin produced more fibronectin than cells cultured on fibronectin. Newly synthesized fibronectin was incorporated into a network of pericellular and intercellular fibrils, whereas laminin formed a more diffuse layer covering the cells in a basement membrane-like manner. Taken together, the findings suggest diverse roles for fibronectin and laminin in the control of the differentiated properties of arterial smooth muscle cells. They further indicate that the ability of arterial smooth muscle cells to produce fibronectin and laminin early in primary culture is not directly related to the phenotypic state as determined morphologically and by measurement of overall rates of RNA and protein synthesis. This may be due to the cells being able to sense the macromolecular composition of the pericellular matrix and to modify their secretory activity accordingly.(ABSTRACT TRUNCATED AT 400 WORDS)  相似文献   
85.
One isoform of the regulatory subunit of type II cAMP-dependent protein kinase (R-II51; Mr = 51,000) and its electrophoretic variants (R-II51.5 and R-II52; Mr = 51,500 and 52,000, respectively) are selectively induced by estradiol and follicle-stimulating hormone (cAMP) in rat ovarian granulosa cells. To ascertain the amino acid sequence of R-II51 and to gain insight into the molecular events regulating the intracellular content of ovarian follicular R-II51, we constructed a lambda gt11 cDNA expression library from poly(A)+ RNA of hormone-primed rat granulosa cells. A 1.5-kilobase (kb) cDNA insert, isolated from a plaque-purified R-II antibody positive bacteriophage clone, selectively bound R-II51 mRNA as demonstrated by analysis of the hybrid-selected translation product. Restriction maps and sequence analyses of the 1.5-kb cDNA insert and of the 1.8- and 2.2-kb cDNA inserts from two additional clones showed overlapping sequences which span a region of 3065 nucleotides in size. The 1.5- and 1.8-kb cDNA inserts each contained poly(A) addition signals (1508 and 1761 nucleotides, respectively), terminal poly(A) sequences, and the entire coding region for R-II51 (1204 nucleotides) except for a small number of nucleotides at the 5' end. The 2.2-kb cDNA insert contained 394 nucleotides of the coding region a long 3' untranslated region and two more poly(A) addition signals (3041 and 3059 nucleotides). An amino acid microsequence surrounding the autophosphorylation site of pure rat ovarian R-II51 agreed with the amino acid sequence deduced from the nucleotide sequence of the cDNA. Northern blot analyses demonstrated two major mRNA species (1.8 and 3.2 kb in size) in hormone-primed rat ovaries which were approximately 10- and 50-fold greater than the R-II mRNA content in rat brain and rat heart, respectively. Southern blot analysis of rat liver DNA indicated that a single gene codes for R-II51 mRNA. Structural differences among rat ovarian R-II51, rat heart R-II54, and the known amino acid sequences of bovine R-II and R-I subunits also indicate that the rat ovarian R-II51 subunit is the product of a distinct gene.  相似文献   
86.
The monotypic genus Cryptomaster Briggs, 1969 was described based on individuals from a single locality in southwestern Oregon. The described species Cryptomaster leviathan Briggs, 1969 was named for its large body size compared to most travunioid Laniatores. However, as the generic name suggests, Cryptomaster are notoriously difficult to find, and few subsequent collections have been recorded for this genus. Here, we increase sampling of Cryptomaster to 15 localities, extending their known range from the Coast Range northeast to the western Cascade Mountains of southern Oregon. Phylogenetic analyses of mitochondrial and nuclear DNA sequence data reveal deep phylogenetic breaks consistent with independently evolving lineages. We use discovery and validation species delimitation approaches to generate and test species hypotheses, including a coalescent species delimitation method to test multi-species hypotheses. For delimited species, we use light microscopy and SEM to discover diagnostic morphological characters. Although Cryptomaster has a small geographic distribution, this taxon is consistent with other short-range endemics in having deep phylogenetic breaks indicative of species level divergences. Herein we describe Cryptomaster behemoth sp. n., and provide morphological diagnostic characters for identifying Cryptomaster leviathan and Cryptomaster behemoth.  相似文献   
87.
88.
Alpha taxonomy, and specifically the delimitation of species, is becoming increasingly objective and integrative. The use of coalescent-based methods applied to genetic data is providing new tools for the discovery and delimitation of species. Here, we use an integrative approach via a combination of discovery-based multivariate morphological analyses to detect potential new species. These potential species are then used as a priori species in hypothesis-driven validation analyses with genetic data. This research focuses on the harvestmen genus Sclerobunus found throughout the mountainous regions of western North America. Based on our analyses, we conduct a revision of Sclerobunus resulting in synonymy of Cyptobunus with Sclerobunus including transfer of S. cavicolens comb. nov. and elevation of both subspecies of S. ungulatus: S. ungulatus comb. nov. and S. madhousensis comb. nov., stat. nov. The three subspecies of S. robustus are elevated, S. robustus, S. glorietus stat. nov., and S. idahoensis stat. nov. Additionally, five new species of Sclerobunus are described from New Mexico and Colorado, including S. jemez sp. nov., S. klomax sp. nov., S. skywalkeri sp. nov., S. speoventus sp. nov., and S. steinmanni sp. nov. Several of the newly described species are single-cave endemics, and our findings suggest that further exploration of western North American cave habitats will likely yield additional new species.  相似文献   
89.
Comparative phylogenetic and phylogeographic analyses have revealed a pervasive midpeninsular divergence in the mitochondrial genealogies of numerous vertebrate taxa distributed on the Baja California Peninsula. In this study, we extend the investigation of regional vicariance in Baja California to an arthropod taxon by examining patterns of phylogenetic and morphological divergence in the spider genus Homalonychus (Araneae, Homalonychidae). We analyzed data from two mtDNA genes (16S rRNA and NADH dehydrogenase subunit (1) and a nuclear gene (28S rRNA) using maximum parsimony and Bayesian phylogenetic analyses, and also conducted geometric morphometric analyses employing landmark data on male and female genitalia. Genes and morphology both reveal a deep split across the Colorado River and Gulf of California, separating Homalonychus selenopoides on the east side of river from its congener Homalonychus theologus on the west side of the river, including the Baja California Peninsula. Along the north-south axis of the Baja Peninsula, an apparently more recent midpeninsular phylogenetic break is evident within H. theologus in the mitochondrial genome and in female genitalia. However, there is no measurable divergence between northern and southern populations in either nuclear DNA or male genitalia. We suggest that this discordance between datasets reflects either a difference in rates of evolution between male versus female systems, or that male-based nuclear gene flow is obscuring a phylogenetic split that is fixed in the female-based systems. Our findings provide additional support for a midpeninsular Baja divergence event, although the timing and geological evidence for such an event remain elusive.  相似文献   
90.
Detailed knowledge on habitat requirements is a key to successful conservation actions. The marbled jewel beetle Poecilonota variolosa (Buprestidae) has a wide global distribution but populations are often scarce and typically fragmented. In Sweden it is monophagous on aspen Populus tremula and is classified as near threatened on the Swedish Red List due to its rapid population decline. This study aimed to investigate habitat preferences and regional-scale distribution patterns of P. variolosa in southern Sweden in order to suggest conservation measures. Aspen trees in four study areas in the province of Småland were surveyed for exit holes during late summer 2011. The occurrence and number of exit holes (both new and old ones) per tree were compared between study areas and habitat types, and were related to the sun exposure and bark thickness of individual trees. Further, the occurrence of new and older exit holes was related to tree sun exposure and bark thickness. The most preferred habitat types were aspens on clear-cuts, followed by roadside aspens, aspens in pastures, and aspens in closed forest. Thick bark and high sun exposure were consistently significant as predictors for both occurrence and number of new exit holes per tree. The majority of exit holes were located towards south. Our results indicate several useful management measures: to retain aspen on clear-cuts, to cut alongside roads and around some selected coarse aspens in closed forests and in pastures.  相似文献   
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