全文获取类型
收费全文 | 5296篇 |
免费 | 357篇 |
出版年
2024年 | 4篇 |
2023年 | 20篇 |
2022年 | 66篇 |
2021年 | 97篇 |
2020年 | 45篇 |
2019年 | 79篇 |
2018年 | 116篇 |
2017年 | 94篇 |
2016年 | 153篇 |
2015年 | 218篇 |
2014年 | 273篇 |
2013年 | 408篇 |
2012年 | 452篇 |
2011年 | 438篇 |
2010年 | 275篇 |
2009年 | 205篇 |
2008年 | 341篇 |
2007年 | 340篇 |
2006年 | 319篇 |
2005年 | 318篇 |
2004年 | 280篇 |
2003年 | 229篇 |
2002年 | 245篇 |
2001年 | 52篇 |
2000年 | 46篇 |
1999年 | 54篇 |
1998年 | 50篇 |
1997年 | 37篇 |
1996年 | 44篇 |
1995年 | 39篇 |
1994年 | 30篇 |
1993年 | 41篇 |
1992年 | 28篇 |
1991年 | 16篇 |
1990年 | 17篇 |
1989年 | 16篇 |
1988年 | 15篇 |
1987年 | 16篇 |
1986年 | 14篇 |
1985年 | 12篇 |
1984年 | 23篇 |
1983年 | 15篇 |
1982年 | 7篇 |
1981年 | 16篇 |
1980年 | 9篇 |
1979年 | 7篇 |
1978年 | 6篇 |
1977年 | 7篇 |
1976年 | 4篇 |
1965年 | 3篇 |
排序方式: 共有5653条查询结果,搜索用时 15 毫秒
61.
The binding of tritium-labelled 7,12-dimethylbenz[a]anthracene (DMBA), benzo[a]pyrene (BP) and 3-methylcholanthrene (MCA) to DNA or polynucleotides in vitro was re-examined both in the presence and in the absence of rat liver or human placental microsomes.A high level of non-enzymatic binding was evident when thymus DNA was used as acceptor. This non-enzymatic binding made it difficult to determine the effect of microsomes, except in the case of BP when induced rat microsomes were used. Better results were obtained using polynucleotides: a definite microsome-dependent binding occurred between all the polynucleotides and all the hydrocarbons tested.No clear evidence of binding catalysed by microsomes from human placenta was found except in polynucleotide-BP interactions: further studies are required to completely evaluate the ability of such nucleic acid-microsomal system for testing in vitro possible oncogenic substances in animals and humans. 相似文献
62.
Paola Ivancich-Gambaro 《BioControl》1975,20(2):171-177
The results of investigations onTyphlodromus italicus Chant in some peach orchards in the Verona district, where the predator is wide-spread, are described. Both field and laboratory studies have shown thatT. italicus grows rapidly (egg to adult 6 days at 25°C.) and has a long reproductive period, especially when prey is available. It speedily recovers in number and has a high prey-searching capacity. It is fast-moving, and its distribution over the tree corresponds to that of the phytophagous mites. It can live and reproduce on the tree in the absence of prey. A density of 50–60T. italicus/100 leaves is reached in August. FemaleT. italicus are found on leaves till November feeding whenever prey is available, and wintering in a mated condition in bark crevices. Many enter diapause in late autumn. Overwinter mortality is high. These characteristics enableT. italicus to play a very significant role in the control of peach mites and in orchards, which are unsprayed, it keeps their populations at a low density from spring to autumn. 相似文献
63.
64.
Giovanna Carr Paolo Nicoli Marcello Francesco Lingua Beatrice Maffeo Antonio Cartell Paola Circosta Mara Brancaccio Guido Parvis Valentina Gaidano Angelo Guerrasio Giuseppe Saglio Riccardo Taulli Alessandro Morotti 《Journal of cellular and molecular medicine》2020,24(2):1650-1657
The development of drugs able to target BTK, PI3k‐delta and BCL2 has dramatically improved chronic lymphocytic leukaemia (CLL) therapies. However, drug resistance to these therapies has already been reported due to non‐recurrent changes in oncogenic pathways and genes expression signatures. In this study, we investigated the cooperative role of the BCL2 inhibitor venetoclax and the BRD4 inhibitor JQ1. In particular, we found that JQ1 shows additional activity with venetoclax, in CLL cell lines and in ex vivo isolated primary CD19+ lymphocytes, arguing in favour of combination strategies. Lastly, JQ1 is also effective in venetoclax‐resistant CLL cell lines. Together, our findings indicated that the BET inhibitor JQ1 could be a promising therapy in CLL, both as first‐line therapy in combination with venetoclax and as second‐line therapy, after the emergence of venetoclax‐resistant clones. 相似文献
65.
Katarína Šoltys Matej Planý Paola Biocca Valentina Vianello Mária Bučková Andrea Puškárová Maria Carla Sclocchi Piero Colaizzi Marina Bicchieri Domenico Pangallo Flavia Pinzari 《Environmental microbiology》2020,22(4):1517-1534
A multidisciplinary approach was carried out in order to study the biodeterioration and the associated microbiome of a XVIII Century wax seal coloured with minium. A small wax seal fragment was observed by scanning electron microscopy combined with energy dispersive spectroscopy in non-destructive mode. The same object was analysed by Raman and Fourier-transform infrared spectroscopy. The identification of the microbiota growing on the seal was performed with both a culture-dependent strategy, combined with hydrolytic assays, and high-throughput sequencing using the MinION platform. The whole bacterial 16S rRNA gene and the fungal markers ITS and 28S rRNA were targeted. It was observed that the carnauba wax coloured with lead tetroxide (minium) was covered by a biofilm consisting of a network of filaments and other structures of microbial origin. The culture-dependent and culture-independent investigations showed the presence of a complex microbiota composed mainly by fungal members, which demonstrated interesting properties related to lipids and lead processing. The formation of lead soaps and secondary biogenic minerals was also described. 相似文献
66.
Walter De Simone Mattia Iannella Paola DAlessandro Maurizio Biondi 《Global Change Biology Bioenergy》2020,12(10):864-877
Climate change is currently affecting both biodiversity and human activities; land use change and greenhouse gas emissions are the main drivers. Many agricultural services are affected by the change, which in turn reflects on the basic provisioning services, which supply food, fibre and biofuels. Biofuels are getting increasing interest because of their sustainability potential. Jatropha curcas gained popularity as a biodiesel crop, due to its ease of cultivation even in harsh environmental conditions. Notwithstanding its high economic importance, few studies are available about its co‐occurrence with pests of the genus Aphthona in sub‐Saharan Africa, where these insects feed on J. curcas, leading to relevant economic losses. Using ecological niche modelling and GIS post‐modelling analyses, we infer the current and future suitable territories for both these taxa, delineating areas where J. curcas cultivations may occur without suffering the presence of Aphthona, in the context of future climate and land use changing. We introduce an area‐normalized index, the ‘Potential‐Actual Cultivation Index’, to better depict the ratio between the suitable areas shared both by the crop and its pest, and the number of actual cultivations, in a target country. Moreover, we find high economic losses (~?50%) both in terms of carbon sequestration and in biodiesel production when J. curcas co‐occur with the Aphthona cookei species group. 相似文献
67.
Xiangming Li Yujian Zhang Li Jing Zongming Fu Ou Ma Jishna Ganguly Nilesh Vaidya Richard Sisson Jennifer Naginskaya Avinash Chinthala Minggang Cui Ryan Yamagata Mark Wilson Matthew Sanders Zihao Wang Paola Lo Surdo Marcin Bugno 《Biotechnology progress》2020,36(2):e2914
Mammalian cell line generation typically includes stable pool generation, single cell cloning and several rounds of clone selection based on cell growth, productivity and product quality criteria. Individual clone expansion and phenotype-based ranking is performed initially for hundreds or thousands of mini-scale cultures, representing the major operational challenge during cell line development. Automated cell culture and analytics systems have been developed to enable high complexity clone selection workflows; while ensuring traceability, safety, and quality of cell lines intended for biopharmaceutical applications. Here we show that comprehensive and quantitative assessment of cell growth, productivity, and product quality attributes are feasible at the 200–1,200 cell colony stage, within 14 days of the single cell cloning in static 96-well plate culture. The early cell line characterization performed prior to the clone expansion in suspension culture can be used for a single-step, direct selection of high quality clones. Such clones were comparable, both in terms of productivity and critical quality attributes (CQAs), to the top-ranked clones identified using an established iterative clone screening approach. Using a complex, multi-subunit antigen as a model protein, we observed stable CQA profiles independently of the cell culture format during the clonal expansion as well as in the batch and fed-batch processes. In conclusion, we propose an accelerated clone selection approach that can be readily incorporated into various cell line development workstreams, leading to significant reduction of the project timelines and resource requirements. 相似文献
68.
Bonanomi Giuliano Zotti Maurizio Cesarano Gaspare Sarker Tushar C. Saulino Luigi Saracino Antonio Idbella Mohamed Agrelli Diana D’Ascoli Rosaria Rita Angelo Adamo Paola Allevato Emilia 《Plant and Soil》2021,460(1-2):263-280
Plant and Soil - Data about woody debris (WD) decomposition are very scarce for the Mediterranean basin. The specific aim of this work is to explore the relationships between WD traits with the... 相似文献
69.
Integrated requirement of non‐specific and sequence‐specific DNA binding in Myc‐driven transcription
70.
Ventura Luigi Gnetti Letizia Rossi Maurizio Tiseo Marcello Giordano Giovanna Corradi Massimo Silva Mario Milanese Gianluca Minari Roberta Leonetti Alessandro Cattadori Sara Ampollini Luca Carbognani Paolo Mozzoni Paola 《Molecular biology reports》2021,48(4):3485-3494
Molecular Biology Reports - Benign metastasizing leiomyoma (BML) is a rare disease characterized by extrauterine benign leiomyomatosis in patients with a previous or concomitant history of uterine... 相似文献