全文获取类型
收费全文 | 524篇 |
免费 | 41篇 |
出版年
2023年 | 3篇 |
2022年 | 5篇 |
2021年 | 19篇 |
2020年 | 5篇 |
2019年 | 9篇 |
2018年 | 10篇 |
2017年 | 9篇 |
2016年 | 16篇 |
2015年 | 39篇 |
2014年 | 34篇 |
2013年 | 31篇 |
2012年 | 37篇 |
2011年 | 54篇 |
2010年 | 35篇 |
2009年 | 29篇 |
2008年 | 32篇 |
2007年 | 19篇 |
2006年 | 17篇 |
2005年 | 13篇 |
2004年 | 28篇 |
2003年 | 19篇 |
2002年 | 18篇 |
2001年 | 6篇 |
2000年 | 14篇 |
1999年 | 11篇 |
1998年 | 10篇 |
1997年 | 8篇 |
1996年 | 2篇 |
1995年 | 3篇 |
1994年 | 3篇 |
1993年 | 1篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 6篇 |
1987年 | 2篇 |
1985年 | 4篇 |
1983年 | 1篇 |
1981年 | 1篇 |
1977年 | 3篇 |
1976年 | 1篇 |
1962年 | 1篇 |
1955年 | 1篇 |
1952年 | 1篇 |
1948年 | 1篇 |
1947年 | 1篇 |
排序方式: 共有565条查询结果,搜索用时 15 毫秒
1.
Boudreau James C.; Do Ly Thi; Sivakumar Latha; Oravec Joseph; Rodriguez Carlos A. 《Chemical senses》1987,12(3):437-458
Single unit recordings were taken from sensory ganglion cellsin the petrosal ganglion (PG) of the glossopharyngeal nerveof the rat. These taste units were examined with respect tospontaneous and evoked discharge patterns and responsivenessto a wide variety of chemical compounds, most of natural occurrence.Spontaneous activity patterns, with few exceptions, tended tobe extremely irregular with both bursting (clusters of 23spikes) and grouping (large groups of spikes as in evoked discharges).Most interspike interval histograms of spontaneous activitywere multimodal, similar to rat geniculate ganglion (GG) units.Evoked discharges usually displayed grouping of spikes, andlong latencies of onset and persistence of discharge after rinsewere sometimes seen. Little response was shown to nucleotidesor salts. Units responsive to amino acids tended to show largedischarge to only one or two amino acids; and the most responsiveamino acid usually varied from cell to cell. Units responsiveto alkaloids only responded to a few alkaloids with atropineand quinine being the most stimulatory. Units responsive toacids only discharged to a few of the acids tested and oftenacids of low pH elicited no discharge. Saccharin activated unitsresponsive to both sugar and alkaloids. A few units highly responsiveto both sugar and alkaloids were seen. The units were placedinto four clusters on the basis of chemicals activating themand certain neurophysiological characteristics: PG salt units,PG acid units and, tentatively, amino acid (sugar) units andX (alkaloid and alkaloid plus) units. The PG salt units didnot show the exclusive sensitivity to sodium and lithium compoundsas did the GG salt units. The PG acid units could also be differentiatedfrom the GG acid units. The petrosal amino acid and X units,on the other hand, could not be differentiated from similarunits in the rat GG. 相似文献
2.
This paper describes a computer modeling study of the generation of 10 Hz oscillations in the electrical activity of guinea pig thalamic neurons in vitro. The computer model was based on experimental evidence suggesting that single thalamic neurons in guinea pig have a set of voltage- and calcium-dependent ionic conductances that is capable of generating self-sustained rhythmic oscillations. Simulation results are consistent with this hypothesis, and indicate that a model that contains dendritic calcium and calcium-dependent potassium conductances, as well as a voltage-dependent, slow sodium conductance, can indeed generate self-sustained oscillations like those seen in thalamic neurons. Moreover, simulations indicate that the occurrence of such oscillatory activity is strongly dependent on the location of the slow sodium conductance. Results predict that this slow sodium conductance is located in the dendrites.The authors express their appreciation to R. J. MacGregor for providing equations and computer programs for simulating a two-point neuronal model with active calcium-related conductances 相似文献
3.
The present study evaluates in osteosarcoma cells, the effects of a calcium channel inhibitor nicardipine in 24-hydroxylase activity and 45Ca desaturation curve in presence of 1,25-dihydroxycholecalciferol (1,25(OH)2D3). This sterol induced an increase in 24-OHase activity and 45Ca fluxes. Nicardipine reversed the effect of 1,25(OH)2D3 on 45Ca fluxes but reinforced the enhancement of the 24-OHase activity. The fact that the effects of 1,25(OH)2D3 were reduced by cycloheximide support the hypothesis of a de novo protein synthesis. Our study has allowed us to dissociate the effects of 1,25(OH)2D3 on 24-OHase enhancement from those on Ca2+ transport. 相似文献
4.
5.
Neurophysiology of geniculate ganglion (facial nerve) taste systems: species comparisons 总被引:2,自引:2,他引:0
Boudreau James C.; Sivakumar Latha; Do Ly Thi; White Thomas D.; Oravec Joseph; Hoang Nga Kieu 《Chemical senses》1985,10(1):89-127
On the basis of various measures taken from geniculate gangliontaste neurons in four species, it was concluded that withineach species the neurons could be subdivided into distinct functionalgroups. In this report, the neural groups of different specieswere directly compared. Units from all four species were studiedwith a common test series of solutions in addition to otherstimuli. Since these stimuli were presented at the same concentrationsto all species, direct quantitative comparisons across specieswere possible for a wide range of chemical compounds. In addition,the neural groups were compared with respect to spontaneousand evoked activity measures, latency to electrical stimulation,and receptive field characteristics. These neurophysiologicaldata suggest a basic model of four distinct subgroups: acidunits, salt units, amino acid units, and X units. 相似文献
6.
Xuan Cuong Mai Chia-Rui Shen Chao-Lin Liu Dang Mau Trinh Minh Ly Nguyen 《Journal of phycology》2023,59(4):775-784
Species identification of Scenedesmus-like microalgae, comprising Desmodesmus, Tetradesmus, and Scenedesmus, has been challenging due to their high morphological and genetic similarity. After developing a DNA signaturing tool for Desmodesmus identification, we built a DNA signaturing database for Tetradesmus. The DNA signaturing tool contained species-specific nucleotide sequences of Tetradesmus species or strain groups with high similarity in ITS2 sequences. To construct DNA signaturing, we collected data on ITS2 sequences, aligned the sequences, organized the data by ITS2 sequence homology, and determined signature sequences according to hemi-compensatory base changes (hCBC)/CBC data from previous studies. Four Tetradesmus species and 11 strain groups had DNA signatures. The signature sequence of the genus Tetradesmus, TTA GAG GCT TAA GCA AGG ACCC, recognized 86% (157/183) of the collected Tetradesmus strains. Phylogenetic analysis of Scenedesmus-like species revealed that the Tetradesmus species were monophyletic and closely related to each other based on branch lengths. Desmodesmus was suggested to split into two subgenera due to their genetic and morphological distinction. Scenedesmus must be analyzed along with other genera of the Scenedesmaceae family to determine their genetic relationships. Importantly, DNA signaturing was integrated into a database for identifying Scenedesmus-like species through BLAST. 相似文献
7.
A specific and sensitive assay for the detection of human blood was developed using polyester cloth coated with goat anti-human IgG antibody to capture human IgG, an abundant and stable protein in blood. The captured IgG was detected by the reaction between goat anti-human IgG antibody-peroxidase conjugate and a chromogenic peroxidase substrate. Because the assay is simple and rapid, and permits simultaneous analysis of multiple samples, it has the potential to be used as a forensic test for human blood. 相似文献
8.
Ly Diane Dongol Anjila Cuthbertson Peter Guy Thomas V. Geraghty Nicholas J. Sophocleous Reece A. Sin Lucia Turner Bradley J. Watson Debbie Yerbury Justin J. Sluyter Ronald 《Purinergic signalling》2020,16(1):109-122
Purinergic Signalling - The ATP-gated P2X7 ion channel has emerging roles in amyotrophic lateral sclerosis (ALS) progression. Pharmacological blockade of P2X7 with Brilliant Blue G can ameliorate... 相似文献
9.
Pedro Barbosa Liudmila Zhaunova Simona Debilio Verdiana Steccanella Van Kelly Tony Ly Hiroyuki Ohkura 《The Journal of cell biology》2021,220(2)
Meiosis creates genetic diversity by recombination and segregation of chromosomes. The synaptonemal complex assembles during meiotic prophase I and assists faithful exchanges between homologous chromosomes, but how its assembly/disassembly is regulated remains to be understood. Here, we report how two major posttranslational modifications, phosphorylation and ubiquitination, cooperate to promote synaptonemal complex assembly. We found that the ubiquitin ligase complex SCF is important for assembly and maintenance of the synaptonemal complex in Drosophila female meiosis. This function of SCF is mediated by two substrate-recognizing F-box proteins, Slmb/βTrcp and Fbxo42. SCF-Fbxo42 down-regulates the phosphatase subunit PP2A-B56, which is important for synaptonemal complex assembly and maintenance. 相似文献
10.
Uche V. Amazigo Stephen G. A. Leak Honorat G. M. Zoure Chukwu Okoronkwo Maimouna Diop Ly Sunday Isiyaku Andy Crump Joseph C. Okeibunor Boakye Boatin 《PLoS neglected tropical diseases》2021,15(3)
The neglected tropical diseases (NTDs) affect hundreds of millions of people, predominantly in rural, often difficult-to-access areas, poorly served by national health services. Here, we review the contributions of 4.8 million community-directed distributors (CDDs) of medicines over 2 decades in 146,000 communities in 27 sub-Saharan African countries to control or eliminate onchocerciasis and lymphatic filariasis (LF). We examine their role in the control of other NTDs, malaria, HIV/AIDS interventions, immunisation campaigns, and support to overstretched health service personnel. We are of the opinion that CDDs as community selected, trained, and experienced “foot soldiers,” some of whom were involved in the Ebola outbreak responses at the community level in Liberia, if retrained, can assist community leaders and support health workers (HWs) in the ongoing Coronavirus Disease 2019 (COVID-19) crisis. The review highlights the improved treatment coverage where there are women CDDs, the benefits and lessons from the work of CDDs, their long-term engagement, and the challenges they face in healthcare delivery. It underscores the value of utilising the CDD model for strong community engagement and recommends the model, with some review, to hasten the achievement of the NTD 2030 goal and assist the health system cope with evolving epidemics and other challenges. We propose that, based on the unprecedented progress made in the control of NTDs directly linked to community engagement and contributions of CDDs “foot soldiers,” they deserve regional and global recognition. We also suggest that the World Health Organization (WHO) and other international stakeholders promote policy and guidance for countries to adapt this model for the elimination of NTDs and to strengthen national health services. This will enhance the accomplishment of some Sustainable Development Goals (SDGs) by 2030 in sub-Saharan Africa. 相似文献