全文获取类型
收费全文 | 668篇 |
免费 | 35篇 |
专业分类
703篇 |
出版年
2023年 | 1篇 |
2022年 | 10篇 |
2021年 | 17篇 |
2020年 | 7篇 |
2019年 | 8篇 |
2018年 | 20篇 |
2017年 | 13篇 |
2016年 | 23篇 |
2015年 | 30篇 |
2014年 | 41篇 |
2013年 | 30篇 |
2012年 | 57篇 |
2011年 | 65篇 |
2010年 | 36篇 |
2009年 | 39篇 |
2008年 | 41篇 |
2007年 | 48篇 |
2006年 | 37篇 |
2005年 | 32篇 |
2004年 | 41篇 |
2003年 | 33篇 |
2002年 | 28篇 |
2001年 | 9篇 |
2000年 | 3篇 |
1999年 | 4篇 |
1998年 | 2篇 |
1997年 | 1篇 |
1996年 | 4篇 |
1995年 | 3篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1984年 | 3篇 |
1982年 | 1篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1972年 | 2篇 |
1971年 | 1篇 |
排序方式: 共有703条查询结果,搜索用时 0 毫秒
71.
72.
Marcin Łoś Piotr Golec Joanna M Łoś Anna Węglewska-Jurkiewicz Agata Czyż Alicja Węgrzyn Grzegorz Węgrzyn Peter Neubauer 《BMC biotechnology》2007,7(1):13
Background
Bacteriophage infections of bacterial cultures cause serious problems in genetic engineering and biotechnology. They are dangerous not only because of direct effects on the currently infected cultures, i.e. their devastation, but also due to a high probability of spreading the phage progeny throughout a whole laboratory or plant, which causes a real danger for further cultivations. Therefore, a simple method for quick inhibition of phage development after detection of bacterial culture infection should be very useful. 相似文献73.
Leptospirosis vaccines 总被引:1,自引:0,他引:1
Leptospirosis is a serious infection disease caused by pathogenic strains of the Leptospira spirochetes, which affects not only humans but also animals. It has long been expected to find an effective vaccine to prevent
leptospirosis through immunization of high risk humans or animals. Although some leptospirosis vaccines have been obtained,
the vaccination is relatively unsuccessful in clinical application despite decades of research and millions of dollars spent.
In this review, the recent advancements of recombinant outer membrane protein (OMP) vaccines, lipopolysaccharide (LPS) vaccines,
inactivated vaccines, attenuated vaccines and DNA vaccines against leptospirosis are reviewed. A comparison of these vaccines
may lead to development of new potential methods to combat leptospirosis and facilitate the leptospirosis vaccine research.
Moreover, a vaccine ontology database was built for the scientists working on the leptospirosis vaccines as a starting tool. 相似文献
74.
Ewa Jankowska-Steifer Gayane Martirosian Alicja Ekiel Aldona Komar Barbara Wiechuła Jarosław Jóźwiak Paweł Cieślik Stanisław Moskalewski 《World journal of microbiology & biotechnology》2011,27(7):1689-1694
We have previously demonstrated that C. histolyticum reference strain ATCC 19401 produces not only lethal factor but also hitherto unrecognized vacuolating toxin. The aim of
this study was to compare vacuolating and lethal activities of six reference C. histolyticum strains (ATCC 6282, 8034, 17859, 17860, 19401 and 25770) and to determine whether production of vacuolating toxin is strain-dependent
and how the amounts of both toxins produced by the same strain are related to each other and also to protease, collagenase
and clostripain activities. All strains produced vacuolating and lethal toxins as well as collagenase, clostripain and proteases,
but with different yield. Strain ATCC 19401 demonstrated considerable vacuolating and lethal activities and low activity of
collagenase, clostripain and proteases. In other strains such relationship was not evident. Positive correlations were observed
in collagenase and clostripain activities of all studied C. histolyticum strains (r = 0.71). Positive correlations were detected also in vacuolating activities of studied strains and clostripain (r = 0.62) and collagenase (r = 0.87) production, and this effect was statistically significant (P < 0.05). Negative non-significant correlations were detected: (a) in lethal activities of studied strains and clostripain,
or collagenase activities, (b) in vacuolating activities and protease production. 相似文献
75.
Katarzyna Kapczyńska Piotr Stefanowicz Łukasz Jaremko Mariusz Jaremko Alicja Kluczyk Zbigniew Szewczuk 《Amino acids》2011,40(3):923-932
Protein glycation is often a cause of diabetes-associated complications. The isotopically labeled peptide-derived Amadori
products may serve as standards for quantitative determination of the glycated proteins. In this paper, we discussed various
approaches to the synthesis of Amadori products labeled selectively with stable isotopes 2H, 13C and 18O. 相似文献
76.
Nica AC Parts L Glass D Nisbet J Barrett A Sekowska M Travers M Potter S Grundberg E Small K Hedman AK Bataille V Tzenova Bell J Surdulescu G Dimas AS Ingle C Nestle FO di Meglio P Min JL Wilk A Hammond CJ Hassanali N Yang TP Montgomery SB O'Rahilly S Lindgren CM Zondervan KT Soranzo N Barroso I Durbin R Ahmadi K Deloukas P McCarthy MI Dermitzakis ET Spector TD;MuTHER Consortium 《PLoS genetics》2011,7(2):e1002003
While there have been studies exploring regulatory variation in one or more tissues, the complexity of tissue-specificity in multiple primary tissues is not yet well understood. We explore in depth the role of cis-regulatory variation in three human tissues: lymphoblastoid cell lines (LCL), skin, and fat. The samples (156 LCL, 160 skin, 166 fat) were derived simultaneously from a subset of well-phenotyped healthy female twins of the MuTHER resource. We discover an abundance of cis-eQTLs in each tissue similar to previous estimates (858 or 4.7% of genes). In addition, we apply factor analysis (FA) to remove effects of latent variables, thus more than doubling the number of our discoveries (1,822 eQTL genes). The unique study design (Matched Co-Twin Analysis--MCTA) permits immediate replication of eQTLs using co-twins (93%-98%) and validation of the considerable gain in eQTL discovery after FA correction. We highlight the challenges of comparing eQTLs between tissues. After verifying previous significance threshold-based estimates of tissue-specificity, we show their limitations given their dependency on statistical power. We propose that continuous estimates of the proportion of tissue-shared signals and direct comparison of the magnitude of effect on the fold change in expression are essential properties that jointly provide a biologically realistic view of tissue-specificity. Under this framework we demonstrate that 30% of eQTLs are shared among the three tissues studied, while another 29% appear exclusively tissue-specific. However, even among the shared eQTLs, a substantial proportion (10%-20%) have significant differences in the magnitude of fold change between genotypic classes across tissues. Our results underline the need to account for the complexity of eQTL tissue-specificity in an effort to assess consequences of such variants for complex traits. 相似文献
77.
Anna Junkiert-Czarnecka Maria Pilarska-Deltow Aneta Bk Marta Heise Anna Latos-Bieleska Jacek Zaremba Alicja Bartoszewska-Kubiak Olga Haus 《Current issues in molecular biology》2022,44(4):1472
Background: Ehlers-Danlos syndrome (EDS) is a common non-inflammatory, congenital connective tissue disorder. Classical type (cEDS) EDS is one of the more common forms, typically caused by mutations in the COL5A1 and COL5A2 genes, though causative mutations in the COL1A1 gene have also been described. Material and methods: The study group included 59 patients of Polish origin, diagnosed with cEDS. The analysis was performed on genomic DNA (gDNA) with NGS technology, using an Illumina sequencer. Thirty-five genes related to connective tissue were investigated. The pathogenicity of the detected variants was assessed by VarSome. Results: The NGS of 35 genes revealed variants within the COL5A1, COL5A2, COL1A1, and COL1A2 genes for 30 of the 59 patients investigated. Our panel detected no sequence variations for the remaining 29 patients. Discussion: Next-generation sequencing, with an appropriate multigene panel, showed great potential to assist in the diagnosis of EDS and other connective tissue disorders. Our data also show that not all causative genes giving rise to cEDS have been elucidated yet. 相似文献
78.
Olszanecka-Glinianowicz M Banaś M Zahorska-Markiewicz B Kuglin D Mokrzycka J Mentel A 《Endokrynologia Polska》2005,56(6):921-926
THE AIM: of the present study was to evaluate serum concentrations of adrenal and ovarian androgens and sex hormone-binding globulin in obese women without additional diseases and in obese women with polycystic ovary syndrome with and without insulin resistance. MATERIAL AND METHODS: The study group involved 73 obese women (39 with PCOS--A and 34 obese without additional diseases--B). The serum concentration of glucose and insulin were measured and the study group was divided on the basis of HOMA index into two subgroups: A I-PCO without insulin resistance (n=18, mean age 27.2+/-5.9 yr; BMI 33.2+/-3.5 kg/m2); AII-PCO with insulin resistance (n=21, mean age 27.5+/-7.1 yr; BMI 37.6+/-6.5 kg/m2); B I-obese without insulin resistance (n=8, age 33.5+/-7.5 yr; BMI 35.2+/-4.8 kg/m2); B II-obese with insulin resistance (n=24, age 30.3+/-5.2 yr; BMI 36.4+/-5.8 kg/m2). Body mass and height were measured and body mass index was calculated with formula. Body composition was measured using bioimpedance method. The serum concentrations of FSH, LH, total and free testosterone, androstendione, DHEAS, SHBG and insulin were determined by RIA method and glucose was determined by enzymatic procedure. RESULTS: We observed significantly higher body mass, fat mass and BMI in AII subgroup when compared to AI, BI and BII subgroups. Only serum concentration of free testosterone was significantly higher in AII subgroup when compared to AI subgroup. We observed a positive correlation between serum concentrations of insulin and free testosterone in both groups A and B, moreover we observed positive correlations between serum concentrations of insulin and both DHEAS and LH in group B. CONCLUSIONS: It seems that insulin resistance plays a key role in the development of hyperandrogenism in obese women. However mechanisms leading to hyperandrogenism in PCOS are still unrevealed and seem to be more complex. 相似文献
79.
Lazińska B Rokosz A Sawicka-Grzelak A Luczak M 《Medycyna do?wiadczalna i mikrobiologia》2005,57(3):287-294
Every year in Poland from tens to more than hundred bacteriologically verified extraintestinal infections caused by Salmonella species have been registered. These unusually located infections have substantially heavy course and in many cases hospitalisation and antibiotic therapy have to be involved. Cases of extraintestinal infections with these Gram-negative rods, which were described in the literature, concerned: pneumonias, lung abscesses and thoracic empyemas, and infections of: blood, bones and joints, wounds, fistulas and urinary tract. The aim of this study was to set extraintestinal Salmonella infections and to analyze a susceptibility of isolated strains to antimicrobial agents. Between 01.07.2002 and 31.12.2004 (30 months) 13 strains of Salmonella genus have been isolated, including 11 S. enteritidis and 2 S. Hadar. In general, with one exception, isolated strains were susceptible to tested antibiotics/chemotherapeutics. ESBL - positive strains were not detected. The tendency of Salmonella strains to cause extraintestinal infections has been noticed. The problem is still escalating, especially in group of patients chronically treated, with immunodeficiency and immunosuppression, after complicated medical procedures, also in the group of small children and aged persons. Therefore, it is necessary to evaluate a susceptibility to antibiotics/chemotherapeutics of every strain from confirmed case of Salmonella extraintestinal infection and it is important to apply a guided therapy. 相似文献
80.
Miller AL Webb MS Copik AJ Wang Y Johnson BH Kumar R Thompson EB 《Molecular endocrinology (Baltimore, Md.)》2005,19(6):1569-1583