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排序方式: 共有730条查询结果,搜索用时 15 毫秒
721.
722.
Ana Freitas Ribeiro Ciléa Tengan Helena Keico Sato Roberta Spinola Melissa Mascheretti Ana Cecilia Costa Fran?a Marcio Port-Carvalho Mariza Pereira Renato Pereira de Souza Marcos Amaku Marcelo Nascimento Burattini Francisco Antonio Bezerra Coutinho Luis Fernandez Lopez Eduardo Massad 《Memórias do Instituto Oswaldo Cruz》2015,110(2):230-234
We propose a method to analyse the 2009 outbreak in the region of Botucatu in the
state of São Paulo (SP), Brazil, when 28 yellow fever (YF) cases were confirmed,
including 11 deaths. At the time of the outbreak, the Secretary of Health of the
State of São Paulo vaccinated one million people, causing the death of five
individuals, an unprecedented number of YF vaccine-induced fatalities. We apply a
mathematical model described previously to optimise the proportion of people who
should be vaccinated to minimise the total number of deaths. The model was used to
calculate the optimum proportion that should be vaccinated in the remaining,
vaccine-free regions of SP, considering the risk of vaccine-induced fatalities and
the risk of YF outbreaks in these regions. 相似文献
723.
724.
Elisangela Gomes Fidelis de Morais Marcelo Coutinho Picanço Robert Weingart Barreto Nilson Rodrigues Silva Mateus Ribeiro Campos 《Biocontrol Science and Technology》2010,20(1):107-116
Diclidophlebia smithi Burckhardt, Morais and Picanço (Hemiptera: Psyllidae) is a promising biological control agent of Miconia calvescens DC. (Melastomataceae), a neotropical invasive weed in forest ecosystems in French Polynesia and Hawaii and a threat in Australia, where it was also introduced. A study on the reproductive performance of D. smithi under laboratory conditions through life expectancy and fertility tables is presented. Results indicated that this psyllid has a high reproductive capacity (R 0>1 and r m >0) and a short life cycle (46–47 days) and can have up to nine generations per year. The critical period of its life cycle is during the nymphal stage which is clearly inadequate for field introductions. The best age for introducing D. smithi against M. calvescens is the 4th day of the adult stage. D. smithi is easily mass-reared and has a short life cycle and a high reproductive capacity, which are desirable characteristics for a biological control agent. 相似文献
725.
Julia Penna Coutinho Anna Caroline Campos Aguiar Pierre Alexandre dos Santos Joaquim Corsino Lima Maria Gabrielle Lima Rocha Carlos Leomar Zani Tania Maria Almeida Alves Ant?nio Euzébio Goulart Santana Maria de Meneses Pereira Antoniana Ursine Krettli 《Memórias do Instituto Oswaldo Cruz》2013,108(8):974-982
Infusions of Aspidosperma nitidum (Apocynaceae) wood bark are used
to treat fever and malaria in the Amazon Region. Several species of this family are
known to possess indole alkaloids and other classes of secondary metabolites, whereas
terpenoids, an inositol and the indole alkaloids harmane-3 acid and braznitidumine
have been described in A. nitidum . In the present study, extracts
from the wood bark, leaves and branches of this species were prepared for assays
against malaria parasites and cytotoxicity testing using human hepatoma and normal
monkey kidney cells. The wood bark extracts were active against Plasmodium
falciparum and showed a low cytotoxicity in vitro, whereas the leaf and
branch extracts and the pure alkaloid braznitidumine were inactive. A crude methanol
extract was subjected to acid-base fractionation aimed at obtaining alkaloid-rich
fractions, which were active at low concentrations against P.
falciparum and in mice infected with and sensitive Plasmodium
berghei parasites. Our data validate the antimalarial usefulness of
A. nitidum wood bark, a remedy that can most likely help to
control malaria. However, the molecules responsible for this antimalarial activity
have not yet been identified. Considering their high selectivity index, the
alkaloid-rich fractions from the plant bark might be useful in the development of new
antimalarials. 相似文献
726.
Veneroni-Gouveia G Meirelles SL Grossi DA Santiago AC Sonstegard TS Yamagishi ME Matukumalli LK Coutinho LL Alencar MM Oliveira HN Regitano LC 《Animal genetics》2012,43(5):518-524
Backfat thickness affects the preservation of the beef carcass after slaughter and confers organoleptic characteristics assessed by the consumer. One of the breeding goals for Canchim, a tropically adapted breed, is to comprehensively increase fat thickness. Our goals were to identify genomic regions associated with backfat in Canchim populations and validate the association of single nucleotide polymorphisms (SNPs) overlapping previously identified QTL regions known to affect fat deposition. Fifteen animals with lower and 15 animals with higher residues for backfat, according to a linear model using the SAS GLM procedure, were selected from a population of 1171 animals and genotyped using the BovineSNP50 BeadChip. Initial analysis revealed more than 100 SNPs that discriminated the tails of phenotypic distribution. One extended region of association included the centromeric region of chromosome (Chr) 14. Because this region overlapped with QTL from previous reports, we developed SNP assays to interrogate two linkage disequilibrium blocks, one in the centromeric region and another in the middle region of Chr 14 to confirm the association. The analysis validated the presence of specific haplotypes affecting fat thickness. 相似文献
727.
The effect of colony age on PCR fingerprinting 总被引:3,自引:1,他引:2
H. L. C. Coutinho B. A. Handley H. E. Kay L. Stevenson J. E. Beringer 《Letters in applied microbiology》1993,17(6):282-284
The pattern of DNA fragments produced by the polymerase chain reaction using arbitrary primers is strongly influenced by the age of the colonies sampled. We show that the number, clarity and reproducibility of the bands produced is optimal when very young colonies are sampled.
This work was supported by European Community grants (EEC CI1* 0545-UK, JEB and HC; BIOT-CT91-0283, JEB and HK), the AFRC (PG7 586, JEB and BH) and the SERC Biotechnology Directorate and Zeneca Ltd through a CASE studentship to LS. 相似文献
This work was supported by European Community grants (EEC CI1* 0545-UK, JEB and HC; BIOT-CT91-0283, JEB and HK), the AFRC (PG7 586, JEB and BH) and the SERC Biotechnology Directorate and Zeneca Ltd through a CASE studentship to LS. 相似文献
728.
F. A. B. Coutinho L. F. Lopez M. N. Burattini E. Massad 《Bulletin of mathematical biology》2001,63(6):1041-1062
The variation of viraemia in the natural course of HIV infection is expected to have major influence on the probability of
transmission and, consequently, on the epidemiology of HIV/AIDS.
In this paper we propose a model which takes into account the time evolution of HIV viraemia (measured as HIV-RNA copies per
ml of blood) in an infected individual and its impact on the threshold for the establishment of an endemic level, and mainly
on the relative contribution of each of the clinical phases of the infection to the total transmission of HIV per infected
individual.
We consider that an infected individual passes through three phases of viraemia. The first phase, which lasts for 6–7 weeks,
is characterized by very high viraemia. In the second phase, which lasts about 10 years, the viraemia is much lower, increasing
again in the last phase, which lasts up to two years, and ends in full-blown AIDS.
We show that the relative contribution of each phase to the total transmission of HIV is very sensitive to the model we assume
for the dependence of the transmissibility of HIV on the viral load. For instance, if we assume that transmissibility is proportional
to the decimal logarithm of viraemia, then the second phase predominates always. Due to the epidemiological importance of
this fact, it is clear that further improvement on virological research to better understand the dependence of HIV transmissibility
on the viral concentration in biological fluids is necessary. 相似文献
729.
J. B. Coutinho B. Moser D. G. Kilburn R. A. J. Warren R. C. Miller Jr 《Molecular microbiology》1991,5(5):1221-1233
The cenC gene of Cellulomonas fimi, encoding endoglucanase CenC, has an open reading frame of 1101 codons closely followed by a 9 bp inverted repeat. The predicted amino acid sequence of mature CenC, which is 1069 amino acids long, is very unusual in that it has a 150-amino-acid tandem repeat at the N-terminus and an unrelated 100-amino-acid tandem repeat at the C-terminus. CenC belongs to subfamily E1 of the beta-1,4-glycanases. High-level expression in Escherichia coli of cenC from a 3.6 kbp fragment of C. fimi DNA leads to levels of CenC which exceed 10% of total cell protein. Most of the CenC is in the cytoplasm in an inactive form. About 60% of the active fraction of CenC is in the periplasm. The catalytic properties of the active CenC are indistinguishable from those of native CenC from C. fimi. The Mr of CenC from E. coli and C. fimi is approximately 130 kDa. E. coli and C. fimi also produce an endoglucanase, CenC', of approximate Mr 120kDa and with the same N-terminal amino acid sequence and catalytic properties as CenC. CenC' appears to be a proteolytic product of CenC. CenC and CenC' can bind to cellulose and to Sephadex. CenC is the most active component of the C. fimi cellulase system isolated to date. 相似文献
730.
V beta 17 gene polymorphism in wild-derived mouse strains: two amino acid substitutions in the V beta 17 region greatly alter T cell receptor specificity 总被引:16,自引:0,他引:16
P A Cazenave P N Marche E Jouvin-Marche D Voegtlé F Bonhomme A Bandeira A Coutinho 《Cell》1990,63(4):717-728
Of 41 wild-derived mouse strains analyzed, 14 contained T cells bearing V beta 17 receptors in spite of the concomitant expression of I-E antigens. Reciprocal F1 and F2 hybrids of one of these strains, PWK, with laboratory strains revealed different patterns of V beta 17 T cell deletions from those observed with V beta 17 T cells from SJL, implying that the two V beta 17 regions are associated with recognition of distinct superantigens. The structures of the V beta 17 alleles differ by two amino acid substitutions, which lie together in an area distant from the predicted site of T cell receptor interaction with peptide-MHC complexes but overlapping with that implicated in V beta 8.2 recognition of Mls-1 superantigen. This demonstrates that the self-superantigen leading to V beta 17 T cell deletion varies with the allele of the receptor gene and confirms that T cell deletions by such ligands involve interactions with a region of the V beta domain that is distinct from the conventional combining site. 相似文献