全文获取类型
收费全文 | 287篇 |
免费 | 17篇 |
国内免费 | 1篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2021年 | 4篇 |
2020年 | 6篇 |
2019年 | 7篇 |
2018年 | 9篇 |
2017年 | 11篇 |
2016年 | 20篇 |
2015年 | 12篇 |
2014年 | 19篇 |
2013年 | 23篇 |
2012年 | 23篇 |
2011年 | 30篇 |
2010年 | 14篇 |
2009年 | 10篇 |
2008年 | 12篇 |
2007年 | 24篇 |
2006年 | 9篇 |
2005年 | 12篇 |
2004年 | 9篇 |
2003年 | 5篇 |
2002年 | 6篇 |
2001年 | 5篇 |
2000年 | 2篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 4篇 |
1990年 | 4篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1980年 | 1篇 |
1977年 | 1篇 |
1975年 | 2篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1968年 | 2篇 |
1965年 | 1篇 |
1960年 | 1篇 |
排序方式: 共有305条查询结果,搜索用时 203 毫秒
81.
Neurochemical Research - This study investigated the efficacy of quercetin (QCT) in combination with sodium butyrate (NaB) in enhancing apoptosis in rat C6 and human T98G glioblastoma cells though... 相似文献
82.
Talukdar P Sakai N Sordé N Gerard D Cardona VM Matile S 《Bioorganic & medicinal chemistry》2004,12(6):1325-1336
The characteristics of pores formed by p-octiphenyl beta-barrels with LWV triads at the outer surface are reported in comparison with the conventional rigid-rod beta-barrels with all-L outer surface. Maintained multifunctionality of tetrameric pores with external LWV triads (inversion of ion selectivity, molecular recognition and transformation) is implicative for intact barrel interior. Increased pore activity supports dominance of high bilayer affinity for W over low affinity for V. Transmembrane p-octiphenyl orientation (from fluorescence depth quenching) supports barrel-stave (rather than toroidal) pores and dominance of transmembrane preference of rigid rods over interfacial preference of W. Destabilization of beta-barrel pores in membranes (from short single-channel lifetimes) and in the media (from 4th-power dependence on monomer concentration) by LWV triads supports dominance of low beta-propensity for W over high beta-propensity for V. The relation between the stability of supramolecular (pre)pores and dependence of activity on monomer concentration is discussed in a more general context. 相似文献
83.
Phytochemical investigation of the heartwood of Myristica malabarica has led to the isolation of the new 7,4'-dimethoxy-5-hydroxyisoflavone together with two other isoflavones, biochanin A and prunetin, and a 1,3-diarylpropanol and a rare alpha-hydroxydihydrochalcone. 相似文献
84.
Samanta SK Kylänlahti I Yli-Kauhaluoma J 《Bioorganic & medicinal chemistry letters》2005,15(16):3717-3719
A convenient method for the synthesis of 1,5-disubstituted imidazoles has been developed on a polymeric support using base-promoted 1,3-dipolar cycloaddition reaction of p-toluenesulfonylmethyl isocyanide (TOSMIC) with immobilized imines under microwave irradiation. The immobilized imines were synthesized by the reaction of various primary benzyl amines with 4-formyl-3-methoxyphenoxymethyl polystyrene in the presence of trimethyl orthoformate at room temperature. Cleavage from the polymeric support using trifluoroacetic acid gave the desired 1,5-disubstituted imidazoles with excellent yield and high purity. 相似文献
85.
86.
Justa Priyanka Kumar R. Suresh Talukdar Gautam Sinha Anindya 《International journal of primatology》2019,40(3):356-373
International Journal of Primatology - Comparative studies of closely related species with similar ecological requirements are essential to understand the behavioral adaptations that allow them to... 相似文献
87.
Swapan K. De Ranajit K. Banerjee 《Biochimica et Biophysica Acta (BBA)/General Subjects》1984,800(3):233-241
The peroxidase activity in rat gastric mucosa is inhibited after administration of glucocorticoids. The synthetic steroid dexamethasone is more potent than the naturally occurring steroids, such as cortisone or corticosterone. Almost complete inhibition of the enzyme occurs after 24 h with a single dose of 100 μg dexamethasone/120 g body weight. Other mitochondrial enzyme activities, like monoamine oxidase, succinic dehydrogenase and Mg2+-ATPase, remain unaltered under the same experimental condition. Submaxillary peroxidase and thyroid peroxidase activity are not inhibited by dexamethasone. Gastric peroxidase activity is increased 200–250% on the 6th day after adrenalectomy. This effect is blocked by the administration of dexamethasone. In fact, the enzyme becomes more sensitive to dexamethasone after adrenalectomy, since it is inhibited by more than 90% at the dose of 25 μg/120 g body weight. The inhibition by dexamethasone in normal animals is reversible. The enzyme is also inhibited after the administration of a single dose of ACTH. The apparent Km of the enzyme for H2O2 is not altered after dexamethasone treatment or after adrenalectomy. The increase in enzyme activity following adrenalectomy is not blocked by actinomycin D or by α-amanitin, but is prevented by puromycin or cycloheximide. After administration of dexamethasone, the iodide concentration process in the gastric mucosa is not affected, but the organification of iodide is significantly diminished. 相似文献
88.
Lars Fehren-Schmitz Bastien Llamas Susanne Lindauer Elsa Tomasto-Cagigao Susan Kuzminsky Nadin Rohland Fabrício R. Santos Peter Kaulicke Guido Valverde Stephen M. Richards Susanne Nordenfelt Verena Seidenberg Swapan Mallick Alan Cooper David Reich Wolfgang Haak 《PloS one》2015,10(6)
The discovery of human remains from the Lauricocha cave in the Central Andean highlands in the 1960’s provided the first direct evidence for human presence in the high altitude Andes. The skeletons found at this site were ascribed to the Early to Middle Holocene and represented the oldest known population of Western South America, and thus were used in several studies addressing the early population history of the continent. However, later excavations at Lauricocha led to doubts regarding the antiquity of the site. Here, we provide new dating, craniometric, and genetic evidence for this iconic site. We obtained new radiocarbon dates, generated complete mitochondrial genomes and nuclear SNP data from five individuals, and re-analyzed the human remains of Lauricocha to revise the initial morphological and craniometric analysis conducted in the 1960’s. We show that Lauricocha was indeed occupied in the Early to Middle Holocene but the temporal spread of dates we obtained from the human remains show that they do not qualify as a single contemporaneous population. However, the genetic results from five of the individuals fall within the spectrum of genetic diversity observed in pre-Columbian and modern Native Central American populations. 相似文献
89.
90.
Udayan Borthakur Rumi Dev Barman Chatrapati Das Ajit Basumatary Anjan Talukdar M. Firoz Ahmed Bibhab Kumar Talukdar Rupjyoti Bharali 《European Journal of Wildlife Research》2011,57(3):603-613
The Brahmaputra Valley of Assam, India, is one of the prime habitats for the endangered Royal Bengal tiger Panthera tigris tigris. With dwindling global population, estimation of the minimum number of tigers has always been a curiosity to wildlife researchers
as well as to protected area managers. In the present study, DNA-based techniques were used for identifying individual tigers
present in Orang National Park of Assam, from 57 faecal samples collected during February 2009. Orang National Park stands
as an island of a single forest patch along the north bank of river Brahmaputra. The present study confirms the presence of
17 individual tigers in Orang National Park, with five male and 12 female. DNA-based capture–recapture analysis yielded minimum
range estimate of 18 and 19 individuals, with possible overestimates of population size following two models of capture probability
in CAPWIRE. The results of our genetic counting of tigers are compared with the estimates of 19 tigers based on pugmark analysis
by the state Forest Department in 2000 and an independent capture–recapture estimate of 14 (±3.6) individuals based on photographic
identity study in 2009. Looking at high mortality of tigers in the area, with 19 reported deaths during 2000 to 2009, our
results indicate high individual turnover in the area. This study shows that Orang National Park harbours a healthy breeding
population of tigers. However, the possibility of a source-sink dynamics operating in the landscape could not be ruled out,
with possible immigration from nearby Kaziranga National Park on the south bank of Brahmaputra, which has the highest reported
density of the species in the world. 相似文献