全文获取类型
收费全文 | 491篇 |
免费 | 34篇 |
专业分类
525篇 |
出版年
2022年 | 5篇 |
2021年 | 13篇 |
2020年 | 8篇 |
2019年 | 2篇 |
2018年 | 12篇 |
2017年 | 7篇 |
2016年 | 16篇 |
2015年 | 22篇 |
2014年 | 33篇 |
2013年 | 44篇 |
2012年 | 42篇 |
2011年 | 43篇 |
2010年 | 23篇 |
2009年 | 17篇 |
2008年 | 24篇 |
2007年 | 20篇 |
2006年 | 29篇 |
2005年 | 25篇 |
2004年 | 13篇 |
2003年 | 13篇 |
2002年 | 15篇 |
2001年 | 5篇 |
2000年 | 4篇 |
1999年 | 6篇 |
1998年 | 5篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1994年 | 4篇 |
1993年 | 4篇 |
1992年 | 6篇 |
1991年 | 6篇 |
1990年 | 6篇 |
1989年 | 5篇 |
1988年 | 1篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1985年 | 4篇 |
1984年 | 1篇 |
1982年 | 6篇 |
1981年 | 4篇 |
1980年 | 11篇 |
1979年 | 2篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1970年 | 1篇 |
1969年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有525条查询结果,搜索用时 15 毫秒
1.
In the present paper we discuss the properties of a recently developed preparation of isolated neurosecretory nerve endings obtained from the rate neurohypophysis. These nerve terminals release two neurohormones, oxytocin and vasopressin, which are easily assayed by radioimmunoassay. Depolarization-induced secretion is dependent on the same parameters as those regulating release from the whole neural lobe. The isolated nerve endings can be permeabilized by means of digitonin; a treatment which gives direct access to the cytoplasm allowing the study of the minimal requirements for inducing neuropeptide release. Furthermore, some nerve endings are large enough to allow the use of the patch-clamp technique. In the present paper we present evidences which show that the isolated neurohypophysial nerve terminals represent a protent tool for studying the mechanism of stimulus-secretion. 相似文献
2.
We show that the human glucocorticoid receptor (GR), isolated from the breast cancer cell line MCF-7, has an apparent molecular weight identical to that of rat liver GR (94 kDa) and reacts with antibodies raised against the latter. These antibodies were used to clone cDNA sequences corresponding to the human GR from a lambda gt11 expression library constructed using MCF-7 poly(A)+ RNA. Three non-homologous cDNA clones with inserts of 125, 220 and 350 bp, which express epitopes recognised by the rat liver GR antibodies, were isolated. Rat liver GR antibodies, immunopurified using the immobilised purified beta-galactosidase fusion proteins, detect partially purified rat liver and human GRs on Western blots. In addition, these antibodies immuno-adsorb rat liver and human GRs affinity-labelled with [3H] triamcinolone acetonide. Northern blot analysis, using all three cDNA probes, reveals the presence of a major MCF-7 poly(A)+ RNA species of approximately 7 kb. 相似文献
3.
Effect of soil solarization on nodulation,infection by mycorrhizal fungi and yield of cowpea 总被引:1,自引:1,他引:0
S. K. Nair C. K. Peethambaran D. Geetha Kamala Nayar K. I. Wilson 《Plant and Soil》1990,125(1):153-154
Solarization of soil was found beneficial for plant growth in cowpea under field conditions. Root nodulation, infection by
mycorrhizal fungi and yield were higher in plants grown in solarized soil. These increases were to the extent of 104.7, 20.0
and 23.7 per cent respectively when compared to control treatment without solarization. 相似文献
4.
The responses of the field mouse Mus booduga to shifts in schedules of LD cycles were monitored and the results were interpreted with the help of a PRC constructed for the same species. The results reveal that, M. booduga reentrained faster with a lesser number of transients after delay shifts than advance shifts, thus exhibiting “asymmetry effect.” A positive correlation was observed between the number of transients and the number of hours of shift. In most of the shifts, the sign of the transients (negative for delaying transients and positive for advancing transients) coincided with the direction of the shift. Interestingly, 11 and 12 h of advance shifting resulted in delaying transients. An 11-h advance shift can also be interpreted as a 13-h delay. Reentrainment through delaying transients is faster as compared to reentrainment through advancing transients. Thus, this animal might have taken a “shorter route,” as proved by the fact that an 11-h advance shift has evoked delaying transients. But a 13-h advance shift evoked only advancing transients. This prompts us to speculate that there may be a “phase jump” in M. booduga. Further, irrespective of whether L or D has been doubled in a 12-h shift, both evoked only delaying transients. 相似文献
5.
6.
Balagopalan Unni Punnee Barrera Malgorzata Muszynska-Pytel Govindan Bhaskaran Karl H. Dahm 《Archives of insect biochemistry and physiology》1993,24(4):173-185
During the last larval stage, corpora allata (CA) of Manduca sexta are inactivated by a factor from the brain. Apparently the same factor (allatinhibin, Al) is secreted by day 4 Vth instar brains kept overnight in Grace's medium. Al is rapidly inactivated by heat or acid but withstands exposure to alkali and can be recovered after freezing and lyophilization. Exposure to pronase, chymotrypsin, carboxypeptidases-A and-Y, as well as leucine aminopeptidase eliminated Al activity completely, whereas after exposure to trypsin and protease XVII-S, some residual activity remained. Inactivation by pyroglutamate aminopeptidase is interprefed as being due to prolinase activity of this enzyme. Incubation of CA with gentamicin, an aminoglycoside antibiotic, affects neither their ability to produce JH in vitro nor their viability in implantation assays. However, Al did not inactivate CA in the presence of low concentrations of gentamicin. This effect was used to guard against false positive assay results possibly produced by allatotoxic contamination. Al was purified by chromatography on Sephadex G-25. All activity recovered emerged from the columns in intermediate fractions with an apparent Mr of 1,000–2,000. © 1993 Wiley-Liss, Inc. 相似文献
7.
8.
The species of flies breeding in bovine manure, their parasites and predators as well as other associated arthropods in 3
localities in and near Bangalore are recoreded. The flies areMusca domestica L.,Musca pattoni
Austen,Stomoxys calcitrans L.,Physiphora aenea F.,Physiphora demandata F.,Sargus metallinus F.,Sepsis thoracica R.-D.,Sepsis nitens
Wiedemann,Sphaerocera scabricula
Hal, andLeptocera (Coproica) hirtula
Rondani. Four species of hymenopterous pupal parasites of these flies have been obtained:Spalangia cameroni
Perkins from pupae ofM. domestica, M. pattoni, S. calcitrans, P. aenea andP. demandata; Spalangia endius
Walker from pupae ofM. domestica, M. pattoni andS. calcitrans; Spalangia nigroaenea
Curtis from pupae ofM. domestica andS. calcitrans; andDirhinus trichiophthalmus
Masi from pupae ofSargus metallinus F. Percentage parasitism of fly puparia in field samples was noted. Four species ofHister andAleochara puberula
Klug feeding on various immature stages ofM. domestica, 2 species of scarabaeid beetles, 2 species of ants and a pseudoscorpion were also found in the manure. The importance of
biotic regulatory factors in the control of flies is discussed.
Paper presented at the seminar on utilization of farm wastes for rural industrial growth, National Dairy Research Institute, Bangalore, 31 st December, 1975.
This paper is published with the permission of the Director-General, Indian Council of Medical Research, New Delhi 相似文献
Résumé Dans 3 localités de Bangalore ou proches de cette ville, on a inventorié les espèces de mouches vivant dans le fumier de vache, leurs parasites et prédateurs ainsi que d'autres arthropodes associés. Les mouches récoltées sont:Musca domestica L.,Musca pattoni Austen,Stomoxys calcitrans L.,Physiphora aenea F.,Physiphora demandata F.,Sargus metallinus F.,Sepsis thoracica R-D.,Sepsis nitens Wiedemann,Sphaerocera scabricula Hal. etLeptocera (Coproica) hirtula Rondani. Quatre espèces d'hyménoptères parasites des pupes ont été obtenues de ces mouches:Spalangia cameroni Perkins deM. domestica, M. pattoni, S. calcitrans, P. aenea etP. demandata: Spalangia endius Walker deM. domestica, M. pattoni etS. calcitrans, P. aenea etP. demandata; Spalangia endius Walker trans; etDirhinus trichiophthalmus Masi deSargus metallinus F. On a noté le taux de parasitisme des nymphes dans les conditions naturelles. Quatre espèces deHister etAleochara puberula Klug s'attaquant aux divers stades non imaginaux deM. domestica, 2 espèces de scarabeides, 2 espèces de fourmis et un pseudoscorpion ont été également trouvés dans le fumier. L'importance de ces facteurs biotiques dans la régulation des populations de mouches est discutée.
Paper presented at the seminar on utilization of farm wastes for rural industrial growth, National Dairy Research Institute, Bangalore, 31 st December, 1975.
This paper is published with the permission of the Director-General, Indian Council of Medical Research, New Delhi 相似文献
9.
Kasthuri Kannayiram Vidhya Rekha Umapathy Y Chamundeswari JH Fathima Ramajayam Govindan Chella Perumal Palanisamy Vishnu Priya Veeraraghavan Selvaraj Jayaraman Ponnulakshmi Rajagopal 《Bioinformation》2022,18(3):80
Diabetes mellitus is a group of metabolic disorders that has risen to become the third most common cause in humans in recent years. The development of new bioactive substances from natural sources is a relatively new area. Flavonoids are believed to have a variety of beneficial properties in nature, including anti-inflammatory, antimicrobial, anticancer, antioxidant, neuroprotective, and anti-HIV properties. 15 naturally occurring flavonoids docked with the selected target aldose reductase. We report the optimal binding of Acumitin, Agathisflavone, Agehoustin B, and alpha-Toxicarol with aldose reductase for further consideration in drug discovery for T2DM. 相似文献
10.
Inhibition of hepatitis delta virus RNA editing by short inhibitory RNA-mediated knockdown of ADAR1 but not ADAR2 expression
下载免费PDF全文
![点击此处可从《Journal of virology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Hepatitis delta virus (HDV) requires host RNA editing at the viral RNA amber/W site. Of the two host genes responsible for RNA editing via deamination of adenosines in double-stranded RNAs, short inhibitory RNA-mediated knockdown of host ADAR1 expression but not that of ADAR2 led to decreased HDV amber/W editing and virus production. Despite substantial sequence and structural variation among the amber/W sites of the three HDV genotypes, ADAR1a was primarily responsible for editing all three. We conclude that ADAR1 is primarily responsible for editing HDV RNA at the amber/W site during HDV infection. 相似文献