全文获取类型
收费全文 | 2051篇 |
免费 | 115篇 |
出版年
2023年 | 24篇 |
2022年 | 39篇 |
2021年 | 74篇 |
2020年 | 45篇 |
2019年 | 63篇 |
2018年 | 61篇 |
2017年 | 68篇 |
2016年 | 99篇 |
2015年 | 111篇 |
2014年 | 123篇 |
2013年 | 151篇 |
2012年 | 168篇 |
2011年 | 153篇 |
2010年 | 109篇 |
2009年 | 80篇 |
2008年 | 116篇 |
2007年 | 106篇 |
2006年 | 71篇 |
2005年 | 76篇 |
2004年 | 75篇 |
2003年 | 56篇 |
2002年 | 45篇 |
2001年 | 28篇 |
2000年 | 35篇 |
1999年 | 25篇 |
1998年 | 16篇 |
1997年 | 17篇 |
1996年 | 11篇 |
1995年 | 9篇 |
1994年 | 3篇 |
1993年 | 10篇 |
1992年 | 9篇 |
1991年 | 14篇 |
1990年 | 6篇 |
1989年 | 7篇 |
1988年 | 6篇 |
1987年 | 4篇 |
1986年 | 3篇 |
1985年 | 5篇 |
1984年 | 9篇 |
1983年 | 4篇 |
1981年 | 3篇 |
1979年 | 2篇 |
1978年 | 4篇 |
1975年 | 3篇 |
1974年 | 3篇 |
1973年 | 3篇 |
1967年 | 3篇 |
1966年 | 2篇 |
1955年 | 1篇 |
排序方式: 共有2166条查询结果,搜索用时 15 毫秒
941.
942.
943.
Cristiane Aparecida Pereira Anna Carolina Borges Pereira da Costa Ana Karina Silva Machado Miltom Beltrame Júnior Maria Stella Amorin Costa Zöllner Juliana Campos Junqueira Antonio Olavo Cardoso Jorge 《Mycopathologia》2011,171(2):103-109
Candida strains can cause oral candidosis, as well as nipples candidosis and lead to premature weaning or yeast transmission. The
aim of this study was to evaluate 51 Candida isolates obtained from the oral cavities of infants during breastfeeding and mothers’ oral cavities and nipples, their enzymatic
activity and their sensitivity to amphotericin B, fluconazole and Baccharis dracunculifolia essential oil. Among the studied strains, 96.1% produced phospholipase and 78.4% produced proteinase. The antifungal resistance
was only observed among isolates of C. albicans, for which three strains showed a resistant activity to fluconazole and one showed a resistant activity to amphotericin B.
All strains were sensitive to B. dracunculifolia essential oil with MIC between 0.2 and 6.25 mg/ml. It was concluded that most of the strains showed significant enzymatic
activity and were sensitive to amphotericin B and fluconazole. B. dracunculifolia essential oil inhibited the growth of all strains, including the ones resistant to commercial antifungal agents. 相似文献
944.
945.
946.
Fernanda Laroza Paganelli Eliana Gertrudes de Macedo Lemos Lúcia Maria Carareto Alves 《World journal of microbiology & biotechnology》2011,27(4):773-778
Polyhydroxyalkanoates (PHAs) are hydroxyalkanoate polymers that are produced and accumulate by many kinds of bacteria. These
polymers act as an energy store for bacteria. Polyhydroxybutyrate (PHB) is the most studied polymer in the PHA family. These
polymers have awakened interest in the environmental and industrial research areas because they are biodegradable and have
thermoplastic qualities, like polypropylene. In this work, we analyzed the PHB production in Bradyrhizobium sp., Rhizobium leguminosarum bv. phaseoli, and Rhizobium huautlense cultured with two different carbon sources. We did biochemical quantification of PHB production during the three phases of
growth. Moreover, these samples were used for RNA extraction and phbC gene expression analysis via real-time PCR. The bacteria showed different manner of growth, PHB accumulation and phbC gene expression when different quantity and quality of carbon sources were used. These results showed that under different
growth media conditions, the growth and metabolism of different species of bacteria were influenced. These differences reflect
the increase or decrease in PHB accumulation. 相似文献
947.
Michael B. Toffolo Alexander Fantalkin Irene S. Lemos Rainer C. S. Felsch Wolf-Dietrich Niemeier Guy D. R. Sanders Israel Finkelstein Elisabetta Boaretto 《PloS one》2013,8(12)
The relative chronology of the Aegean Iron Age is robust. It is based on minute stylistic changes in the Submycenaean, Protogeometric and Geometric styles and their sub-phases. Yet, the absolute chronology of the time-span between the final stages of Late Helladic IIIC in the late second millennium BCE and the archaic colonization of Italy and Sicily toward the end of the 8th century BCE lacks archaeological contexts that can be directly related to events carrying absolute dates mentioned in Egyptian/Near Eastern historical sources, or to well-dated Egyptian/Near Eastern rulers. The small number of radiocarbon dates available for this time span is not sufficient to establish an absolute chronological sequence. Here we present a new set of short-lived radiocarbon dates from the sites of Lefkandi, Kalapodi and Corinth in Greece. We focus on the crucial transition from the Submycenaean to the Protogeometric periods. This transition is placed in the late 11th century BCE according to the Conventional Aegean Chronology and in the late 12th century BCE according to the High Aegean Chronology. Our results place it in the second half of the 11th century BCE. 相似文献
948.
Carlos Araujo da Costa Karen Cristini Yumi Ogawa Furtado Louise de Souza Canto Ferreira Danilo de Souza Almeida Alexandre da Costa Linhares Ricardo Ishak Antonio Carlos Rosário Vallinoto José Alexandre Rodrigues de Lemos Luisa Caricio Martins Edna Aoba Yassui Ishikawa Rita Catarina Medeiros de Sousa Maísa Silva de Sousa 《PLoS neglected tropical diseases》2013,7(6)
Background
HTLV-1 is a retrovirus that causes lymphoproliferative disorders and inflammatory and degenerative diseases of the central nervous system in humans. The prevalence of this infection is high in parts of Brazil and there is a general lack of public health care programs. As a consequence, official data on the transmission routes of this virus are scarce.Objective
To demonstrate familial aggregation of HTLV infections in the metropolitan region of Belém, Pará, Brazil.Method
A cross-sectional study involving 85 HTLV carriers treated at an outpatient clinic and other family members. The subjects were tested by ELISA and molecular methods between February 2007 and December 2010.Results
The prevalence of HTLV was 43.5% (37/85) for families and 25.6% (58/227) for the family members tested (95% CI: 1.33 to 3.79, P = 0.0033). Sexual and vertical transmission was likely in 38.3% (23/60) and 20.4% (29/142) of pairs, respectively (95% CI: 1.25 to 4.69, P = 0.0130). Positivity was 51.3% (20/39) and 14.3% (3/21) in wives and husbands, respectively (95% CI: 0.04 to 0.63, P = 0.0057). By age group, seropositivity was 8.0% (7/88) in subjects <30 years of age and 36.7% (51/139) in those of over 30 years (95% CI: 0.06 to 0.34, P<0.0001). Positivity was 24.1% (7/29) in the children of patients infected with HTLV-2, as against only 5.8% (4/69) of those infected with HTLV-1 (95% CI: 0.05 to 0.72, P = 0.0143).Conclusion
The results of this study indicate the existence of familial aggregations of HTLV characterized by a higher prevalence of infection among wives and subjects older than 30 years. Horizontal transmission between spouses was more frequent than vertical transmission. The higher rate of infection in children of HTLV-2 carriers suggests an increase in the prevalence of this virus type in the metropolitan region of Belém. 相似文献949.
Silva Maria Cláudia Cardozo Bonfim Carbone Débora Diniz Pedro Fernando Freitas Fernandes Fabrício Fuzo Carlos Alessandro Santos Pereira Cardoso Trindade Carolina Rodrigues Chang Marilene Silva João Santana 《Mycopathologia》2020,185(4):675-684
Mycopathologia - Candida tropicalis is a non-albicans Candida specie that causes candidosis in several countries, including Brazil. However, little is known about the mechanisms of drug resistance... 相似文献
950.
Glauberto da Silva Quirino Gerlânia de Oliveira Leite Luciana Magalhães Rebelo Adriana da Rocha Tomé José Galberto Martins da Costa André Herzog Cardoso Adriana Rolim Campos 《Phytochemistry letters》2009,2(4):179-183
Caryocar coriaceum Wittm. (Caryocaraceae), popularly known as Pequi, is a common tree frequently used in folk medicine to treat many types of afflictions, such as wound lesions, gastric and inflammatory diseases. The present study was undertaken to evaluate the healing potential of the pulp oil from C. coriaceum (OCC) in rats and mice. OCC was tested by monitoring wound contraction in incised wounds and topical application of OCC accelerated wound contraction in open wounds. The mean values of wound contraction in pulp oil treated rats on day 16 were 6.25 ± 0.51% as against 4.17 ± 0.28% seen in control and the difference was statistically significant (p < 0.01). Gastric lesions induced by ethanol and aspirin were significantly reduced by OCC (200 and 400 mg/kg, p < 0.05). Pretreatment of mice with yohimbine, indomethacin, l-NAME or glibenclamide greatly suppressed the gastroprotective effect of OCC. Thus we provide the first evidence that OCC reduces gastric damage induced by ethanol, at least in part, by mechanisms that involve α2-receptors, endogenous prostaglandins, nitric oxide and K+ATP channels. These results indicate the beneficial effect of C. coriaceum on wound and gastric healing and justify its traditional use for the treatment of wounds and gastric ulcers. 相似文献