全文获取类型
收费全文 | 3489篇 |
免费 | 173篇 |
国内免费 | 4篇 |
专业分类
3666篇 |
出版年
2024年 | 12篇 |
2023年 | 38篇 |
2022年 | 92篇 |
2021年 | 173篇 |
2020年 | 86篇 |
2019年 | 103篇 |
2018年 | 126篇 |
2017年 | 110篇 |
2016年 | 131篇 |
2015年 | 159篇 |
2014年 | 196篇 |
2013年 | 242篇 |
2012年 | 248篇 |
2011年 | 264篇 |
2010年 | 139篇 |
2009年 | 118篇 |
2008年 | 167篇 |
2007年 | 162篇 |
2006年 | 160篇 |
2005年 | 123篇 |
2004年 | 100篇 |
2003年 | 85篇 |
2002年 | 74篇 |
2001年 | 48篇 |
2000年 | 46篇 |
1999年 | 46篇 |
1998年 | 22篇 |
1997年 | 13篇 |
1996年 | 8篇 |
1994年 | 21篇 |
1993年 | 13篇 |
1992年 | 20篇 |
1991年 | 20篇 |
1990年 | 26篇 |
1989年 | 21篇 |
1988年 | 18篇 |
1987年 | 20篇 |
1986年 | 17篇 |
1985年 | 26篇 |
1984年 | 16篇 |
1983年 | 12篇 |
1982年 | 12篇 |
1981年 | 8篇 |
1979年 | 8篇 |
1977年 | 10篇 |
1974年 | 13篇 |
1973年 | 17篇 |
1972年 | 11篇 |
1971年 | 13篇 |
1970年 | 12篇 |
排序方式: 共有3666条查询结果,搜索用时 15 毫秒
51.
52.
53.
Mustafa A. Gassem 《Saudi Journal of Biological Sciences》2019,26(1):137-140
The Hout-Kasef is traditional salted fermented fish product of natural fermentation of salted mullet fish of coastal area of Jazan region of Saudi Arabia. The present study was carried out to investigate the microbiological and chemical characteristic of Hout-Kasef. A total of twenty-four salted fish samples were purchased from fish market in Jazan and Abu-Arish at different times of the year. The microbial studies of salted-fermented fish revealed a total bacterial count ranging from 2.81 to 4.72 Log10 CFU/g, yeast and mold counts ranging from 0.48 to 3.14 Log10 CFU/g, total staphylococci count 2.71–3.85 Log10 CFU/g, halophile bacteria count 3.26–5.14 Log10 CFU/g, and coliforms count <1 Log10 CFU/g. However, pathogenic bacteria such as Listeria monocytogenes, Vibrio spp., Campylobacter spp. and Yersinia species were not detected. The major bacteria species isolated and identified from the salted fermented fish were Bacillus Subtilus, Bacillus mycoides, Bacillus licheniformis, Bacillus pumilus, Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus hominis, Staphylococcus xylosus, Staphylococcus saprophticus and Staphylococcus cahnii subsp cahnii. The chemical analysis of salted fermented fish showed high content of moisture (47.96%), protein (25.71%), ash (19.6%) and salt (15.19%) but low contents of lipid (7.25%). The salted-fermented fish also showed high level of total volatile basic nitrogen (78.86 mg/100 gm sample) and thiobarbutric acid number (32.32 mg malonaldehyde/kg) with a pH value of pH 6.3. Finally, this study showed the presence of gram positive and gram negative bacteria in the fish product. The predominant microorganisms found were Bacillus and Staphylococcus spp. The fish product had high content of salt and TVB-N levels. 相似文献
54.
Sebahattin Özcan Cafer S. Sevimay Mustafa Yildiz Cengiz Sancak Murat Özgen 《Plant cell reports》1996,16(3-4):200-203
Summary Immature cotyledons and embryo axes of sainfoin were cultured on Murashige and Skoog (MS) media supplemented with various concentrations of 6-benzylaminopurine (BAP) and a-naphthaleneacetic acid (NAA) to induce adventitious shoot regeneration. The highest frequency of shoot regeneration occurred following an initial callus growth on a MS medium containing 0.5 mg/l BAP and 2 mg/l NAA. Immature embryo axes showed higher regeneration capacity than immature cotyledons, however, shoot elongation was best achieved on immature cotyledons. Regenerated shoots were excised and rooted in half strength MS medium with 1 mg/l indole-butyric acid (IBA) or 1 mg/l NAA. The rooted plantlets were finally transferred to compost. 相似文献
55.
Genome-wide fungal stress responsive miRNA expression in wheat 总被引:2,自引:0,他引:2
Behçet Inal Mine Türktaş Hakan Eren Emre Ilhan Sezer Okay Mehmet Atak Mustafa Erayman Turgay Unver 《Planta》2014,240(6):1287-1298
56.
57.
Farrukh Hussain Faisal Mobeen Bong-Seop Kil Sung Oh Yoo 《Journal of Plant Biology》1997,40(2):120-124
Laboratory studies were conducted to see the allelopathic suppression of wheat and mustard byRumex dentatus ssp.klotzschianus (Meissn) Rech. It was observed that aqueous extracts, rain leachates and litter from dried and fresh shoot and roots invariably inhibited the germination and seedling growth of both the crop species. Soil collected from beneathRumex dentatus also proved harmful for the germination and seedling growth. It is suggested thatRumex dentatus ssp.klotzschianus exhibits allelopathy against wheat and mustard. 相似文献
58.
Shahida Ibrahim G.M. Mir Abdul Rouf Abdul Rasheed War Barkat Hussain 《Journal of Asia》2018,21(1):367-373
The constitutive and induced resistance were studied in two varieties (Khanyari and Kawdari) of kale, Brassica oleracea var. acephala in response to cabbage butterfly, Pieris brassicae infestation and exogenous application of jasmonic acid (JA) and salicylic acid (SA). Phenols, condensed tannins, flavonoids and proteins were measured at six days after JA (1?mM) and SA (1?mM) application and/or insect infestation. Plant damage and larval weights were also recorded. Khanyari variety showed highest amounts of phenols (208.23?μg/g FW), condensed tannin (347.76?μg/g FW), flavonoids (175.61?μg/g FW) and proteins (0.71?mg/g FW) in plants pre-treated with JA and infested with insects. The PAL activity was high in response to JA application followed by insect infestation. Insects reared on Khanyari and Kawdari plants pre-treated with JA prior showed significantly reduced larval weights (97.88 and 102.46?mg, respectively). Damage was low in plants pre-treated with JA in Khanyari at 3, 6 and 9?days after treatment (10.52%, 8.52%, and 5.30%, respectively). Thus, JA can play an important role in plant defense in kale against P. brassicae. 相似文献
59.
60.
HUCB (human umbilical cord blood) has been frequently used in clinical allogeneic HSC (haemopoietic stem cell) transplant. However, HUCB is poorly recognized as a rich source of MSC (mesenchymal stem cell). The aim of this study has been to establish a new method for isolating large number of MSC from HUCB to recognize it as a good source of MSC. HUCB samples were collected from women following their elective caesarean section. The new method (Clot Spot method) was carried out by explanting HUCB samples in mesencult complete medium and maintained in 37°C, in a 5% CO2 and air incubator. MSC presence was established by quantitative and qualitative immunophenotyping of cells and using FITC attached to MSC phenotypic markers (CD29, CD73, CD44 and CD105). Haematopoietic antibodies (CD34 and CD45) were used as negative control. MSC differentiation was examined in neurogenic and adipogenic media. Immunocytochemistry was carried out for the embryonic markers: SOX2 (sex determining region Y-box 2), OLIG-4 (oligodendrocyte-4) and FABP-4 (fatty acid binding protein-4). The new method was compared with the conventional Rosset Sep method. MSC cultures using the Clot Spot method showed 3-fold increase in proliferation rate compared with conventional method. Also, the cells showed high expression of MSC markers CD29, CD73, CD44 and CD105, but lacked the expression of specific HSC markers (CD34 and CD45). The isolated MSC showed some differentiation by expressing the neurogenic (SOX2 and Olig4) and adipogenic (FABP-4) markers respectively. In conclusion, HUCB is a good source of MSC using this new technique. 相似文献