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31.
Mitochondrial gene order is not conserved in arthropods: prostriate and metastriate tick mitochondrial genomes 总被引:25,自引:15,他引:10
The entire mitochondrial genome was sequenced in a prostriate tick, Ixodes
hexagonus, and a metastriate tick, Rhipicephalus sanguineus. Both genomes
encode 22 tRNAs, 13 proteins, and two ribosomal RNAs. Prostriate ticks are
basal members of Ixodidae and have the same gene order as Limulus
polyphemus. In contrast, in R. sanguineus, a block of genes encoding NADH
dehydrogenase subunit 1 (ND1), tRNA(Leu)(UUR), tRNA(Leu)(CUN), 16S rDNA,
tRNA(Val), 12S rDNA, the control region, and the tRNA(Ile) and tRNA(Gln)
have translocated to a position between the tRNA(Glu) and tRNA(Phe) genes.
The tRNA(Cys) gene has translocated between the control region and the
tRNA(Met) gene, and the tRNA(Leu)(CUN) gene has translocated between the
tRNA(Ser)(UCN) gene and the control region. Furthermore, the control region
is duplicated, and both copies undergo concerted evolution. Primers that
flank these rearrangements confirm that this gene order is conserved in all
metastriate ticks examined. Correspondence analysis of amino acid and codon
use in the two ticks and in nine other arthropod mitochondrial genomes
indicate a strong bias in R. sanguineus towards amino acids encoded by
AT-rich codons.
相似文献
32.
33.
McCarter FD Nierman SR James JH Wang L King JK Friend LA Fischer JE 《Life sciences》2002,70(16):1875-1888
Bacterial sepsis is frequently accompanied by increased blood concentration of lactic acid, which traditionally is attributed to poor tissue perfusion, hypoxia and anaerobic glycolysis. Therapy aimed at improving oxygen delivery to tissues often does not correct the hyperlactatemia, suggesting that high blood lactate in sepsis is not due to hypoxia. Various tissues, including skeletal muscle, demonstrate increased lactate production under well-oxygenated conditions when the activity of the Na+-K+ ATPase is stimulated. Although both muscle Na+-K+ ATPase activity and muscle plasma membrane content of Na+, K+-ATPase subunits are increased in sepsis, no studies in vivo have demonstrated correlation between lactate production and changes in intracellular Na+ and K+ resulting from increased Na+-K+ pump activity in sepsis. Plasma concentrations of lactate and epinephrine, a known stimulator of the Na+-K+ pump, were increased in rats made septic by E. coli injection. Muscle lactate content was significantly increased in septic rats, although muscle ATP and phosphocreatine remained normal, suggesting oxygen delivery remained adequate for mitochondrial energy metabolism. In septic rats, muscle intracellular ratio of Na+:K+ was significantly reduced, indicating increased Na+-K+ pump activity. These data thus demonstrate that increased muscle lactate during sepsis correlates with evidence of elevated muscle Na+-K+ ATPase activity, but not with evidence of impaired oxidative metabolism. This study also further supports a role for epinephrine in this process. 相似文献
34.
Lee M. Kaplan John A. Fallon Edward C. Mun Alan M. Harvey William V. Kastrinakis Elvira Q. Johnson Robert S. Nierman Christopher R. Keroack 《Obesity (Silver Spring, Md.)》2005,13(2):290-300
Objective: To review the use and usefulness of billing codes for services related to weight loss surgery (WLS) and to examine third party reimbursement policies for these services. Research Methods and Procedures: The Task Group carried out a systematic search of MEDLINE, the Internet, and the trade press for publications on WLS, coding, reimbursement, and coding and reimbursement policy. Twenty‐eight articles were each reviewed and graded using a system based on established evidence‐based models. The Massachusetts Dietetics Association provided reimbursement data for nutrition services. Three suppliers of laparoscopic WLS equipment provided summaries of coding and reimbursement information. WLS program directors were surveyed for information on use of procedure codes related to WLS. Results: Recommendations focused on correcting or improving on the current lack of congruity among coding practices, reimbursement policies, and accepted clinical practice; lack of uniform coding and reimbursement data across institutions; inconsistent and/or inaccurate diagnostic and billing codes; inconsistent insurance reimbursement criteria; and inability to leverage reimbursement and coding data to track outcomes, identify best practices, and perform accurate risk‐benefit analyses. Discussion: Rapid changes in the prevalence of obesity, our understanding of its clinical impact, and the technologies for surgical treatment have yet to be adequately reflected in coding, coverage, and reimbursement policies. Issues identified as key to effective change include improved characterization of the risks, benefits, and costs of WLS; anticipation and monitoring of technological advances; encouragement of consistent patterns of insurance coverage; and promotion of billing codes for WLS procedures that facilitate accurate tracking of clinical use and outcomes. 相似文献
35.
Fabrice N. Gravelat Anne Beauvais Hong Liu Mark J. Lee Brendan D. Snarr Dan Chen Wenjie Xu Ilia Kravtsov Christopher M. Q. Hoareau Ghyslaine Vanier Mirjam Urb Paolo Campoli Qusai Al Abdallah Melanie Lehoux Josée C. Chabot Marie-Claude Ouimet Stefanie D. Baptista J?rg H. Fritz William C. Nierman Jean Paul Latgé Aaron P. Mitchell Scott G. Filler Thierry Fontaine Donald C. Sheppard 《PLoS pathogens》2013,9(8)
36.
Qing Kong Chen Chi Jiujiang Yu Shihua Shan Qiyu Li Qianting Li Bin Guan William C. Nierman Joan W. Bennett 《Applied microbiology and biotechnology》2014,98(11):5161-5172
Aspergillus flavus is one of the major moulds that colonize peanut in the field and during storage. The impact to human and animal health, and to the economy in agriculture and commerce, is significant since this mold produces the most potent known natural toxins, aflatoxins, which are carcinogenic, mutagenic, immunosuppressive, and teratogenic. A strain of marine Bacillus megaterium isolated from the Yellow Sea of East China was evaluated for its effect in inhibiting aflatoxin formation in A. flavus through down-regulating aflatoxin pathway gene expression as demonstrated by gene chip analysis. Aflatoxin accumulation in potato dextrose broth liquid medium and liquid minimal medium was almost totally (more than 98 %) inhibited by co-cultivation with B. megaterium. Growth was also reduced. Using expression studies, we identified the fungal genes down-regulated by co-cultivation with B. megaterium across the entire fungal genome and specifically within the aflatoxin pathway gene cluster (aflF, aflT, aflS, aflJ, aflL, aflX). Modulating the expression of these genes could be used for controlling aflatoxin contamination in crops such as corn, cotton, and peanut. Importantly, the expression of the regulatory gene aflS was significantly down-regulated during co-cultivation. We present a model showing a hypothesis of the regulatory mechanism of aflatoxin production suppression by AflS and AflR through B. megaterium co-cultivation. 相似文献
37.
Fedorova ND Khaldi N Joardar VS Maiti R Amedeo P Anderson MJ Crabtree J Silva JC Badger JH Albarraq A Angiuoli S Bussey H Bowyer P Cotty PJ Dyer PS Egan A Galens K Fraser-Liggett CM Haas BJ Inman JM Kent R Lemieux S Malavazi I Orvis J Roemer T Ronning CM Sundaram JP Sutton G Turner G Venter JC White OR Whitty BR Youngman P Wolfe KH Goldman GH Wortman JR Jiang B Denning DW Nierman WC 《PLoS genetics》2008,4(4):e1000046
We present the genome sequences of a new clinical isolate of the important human pathogen, Aspergillus fumigatus, A1163, and two closely related but rarely pathogenic species, Neosartorya fischeri NRRL181 and Aspergillus clavatus NRRL1. Comparative genomic analysis of A1163 with the recently sequenced A. fumigatus isolate Af293 has identified core, variable and up to 2% unique genes in each genome. While the core genes are 99.8% identical at the nucleotide level, identity for variable genes can be as low 40%. The most divergent loci appear to contain heterokaryon incompatibility (het) genes associated with fungal programmed cell death such as developmental regulator rosA. Cross-species comparison has revealed that 8.5%, 13.5% and 12.6%, respectively, of A. fumigatus, N. fischeri and A. clavatus genes are species-specific. These genes are significantly smaller in size than core genes, contain fewer exons and exhibit a subtelomeric bias. Most of them cluster together in 13 chromosomal islands, which are enriched for pseudogenes, transposons and other repetitive elements. At least 20% of A. fumigatus-specific genes appear to be functional and involved in carbohydrate and chitin catabolism, transport, detoxification, secondary metabolism and other functions that may facilitate the adaptation to heterogeneous environments such as soil or a mammalian host. Contrary to what was suggested previously, their origin cannot be attributed to horizontal gene transfer (HGT), but instead is likely to involve duplication, diversification and differential gene loss (DDL). The role of duplication in the origin of lineage-specific genes is further underlined by the discovery of genomic islands that seem to function as designated "gene dumps" and, perhaps, simultaneously, as "gene factories". 相似文献
38.
Mutual independence of alkaline‐ and calcium‐mediated signalling in Aspergillus fumigatus refutes the existence of a conserved druggable signalling nexus 下载免费PDF全文
39.
The extent of productive RNA chain initiation in vitro by Escherichia coli RNA polymerase holoenzyme from the bacteriophage T7 A1 and A2 promoters on purified T7 DNA templates has been investigated at very low concentrations of the ribonucleoside triphosphate substrates. As the concentration of ribonucleoside triphosphates in the reaction is decreased from 10 to 1 micro M, the extent of productive RNA chain initiation at these promoter sites drops precipitously at about 3 micro M. At 1 micro M substrate concentration, productive chain initiation from the A1 promoter does not occur even after extended incubation although the dinucleoside tetraphosphate pppApU is produced at a significant rate under these conditions. The reason for the inability of RNA polymerase to carry out productive RNA chain initiation at 1 micro M substrate concentration is not yet understood. The phenomenon is not due to substrate consumption, enzyme inactivation, or a requirement for a nucleoside triphosphatase activity in the reaction. The possibility is raised that there are additional nucleoside triphosphate binding sites on E. coli RNA polymerase which play some role in the process of productive RNA chain initiation. 相似文献
40.
Nelson KE Fouts DE Mongodin EF Ravel J DeBoy RT Kolonay JF Rasko DA Angiuoli SV Gill SR Paulsen IT Peterson J White O Nelson WC Nierman W Beanan MJ Brinkac LM Daugherty SC Dodson RJ Durkin AS Madupu R Haft DH Selengut J Van Aken S Khouri H Fedorova N Forberger H Tran B Kathariou S Wonderling LD Uhlich GA Bayles DO Luchansky JB Fraser CM 《Nucleic acids research》2004,32(8):2386-2395
The genomes of three strains of Listeria monocytogenes that have been associated with food-borne illness in the USA were subjected to whole genome comparative analysis. A total of 51, 97 and 69 strain-specific genes were identified in L.monocytogenes strains F2365 (serotype 4b, cheese isolate), F6854 (serotype 1/2a, frankfurter isolate) and H7858 (serotype 4b, meat isolate), respectively. Eighty-three genes were restricted to serotype 1/2a and 51 to serotype 4b strains. These strain- and serotype-specific genes probably contribute to observed differences in pathogenicity, and the ability of the organisms to survive and grow in their respective environmental niches. The serotype 1/2a-specific genes include an operon that encodes the rhamnose biosynthetic pathway that is associated with teichoic acid biosynthesis, as well as operons for five glycosyl transferases and an adenine-specific DNA methyltransferase. A total of 8603 and 105 050 high quality single nucleotide polymorphisms (SNPs) were found on the draft genome sequences of strain H7858 and strain F6854, respectively, when compared with strain F2365. Whole genome comparative analyses revealed that the L.monocytogenes genomes are essentially syntenic, with the majority of genomic differences consisting of phage insertions, transposable elements and SNPs. 相似文献