全文获取类型
收费全文 | 510篇 |
免费 | 24篇 |
出版年
2023年 | 2篇 |
2022年 | 16篇 |
2021年 | 15篇 |
2020年 | 6篇 |
2019年 | 15篇 |
2018年 | 13篇 |
2017年 | 14篇 |
2016年 | 8篇 |
2015年 | 19篇 |
2014年 | 13篇 |
2013年 | 30篇 |
2012年 | 24篇 |
2011年 | 27篇 |
2010年 | 16篇 |
2009年 | 18篇 |
2008年 | 34篇 |
2007年 | 19篇 |
2006年 | 18篇 |
2005年 | 22篇 |
2004年 | 18篇 |
2003年 | 16篇 |
2002年 | 23篇 |
2001年 | 16篇 |
2000年 | 19篇 |
1999年 | 11篇 |
1998年 | 9篇 |
1997年 | 9篇 |
1996年 | 8篇 |
1995年 | 12篇 |
1994年 | 3篇 |
1993年 | 6篇 |
1992年 | 9篇 |
1991年 | 6篇 |
1990年 | 5篇 |
1989年 | 3篇 |
1988年 | 10篇 |
1987年 | 4篇 |
1986年 | 5篇 |
1985年 | 5篇 |
1984年 | 1篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1978年 | 1篇 |
1975年 | 2篇 |
排序方式: 共有534条查询结果,搜索用时 78 毫秒
531.
Tsubasa Bito Yuto Tashiro Yusuke Suzuki Yuu Kajiwara Hala Zeidan Mirei Kawagoe 《Electromagnetic biology and medicine》2019,38(1):48-54
This study aimed to investigate the acute effects of capacitive and resistive electric transfer (CRet) on Achilles tendon elongation during muscle contraction, as well as the circulation in the peritendinous region. Sixteen healthy men participated in this study. All 16 participants underwent 2 interventions: (1) CRet trial and (2) CRet without power (sham trial). Tendon elongation was measured four times. Using near-infrared spectroscopy, the blood circulation (volume of total-hemoglobin (Hb), oxygenated hemoglobin (oxy-Hb), and deoxygenated hemoglobin (deoxy-Hb)) was measured for 5 min before the intervention and for 30 min after the intervention. The differences between the measurements obtained before and after intervention were compared between the two interventions. The changes in tendon elongation and deoxy-Hb were not significantly different between the interventions. Total- and oxy-Hb were significantly increased in the CRet trial compared with the sham trial. In addition, the increases in total-Hb and oxy-Hb lasted for 30 min after the CRet intervention (CRet vs. sham: oxy-Hb: F = 8.063, p = 0.001, total-Hb: F = 4.564, p = 0.011). In conclusion, CRet significantly improved blood circulation in the peritendinous region. 相似文献
532.
Facultative Second Oviposition as an Adaptation to Egg Loss in a Semelparous Crab Spider 总被引:1,自引:0,他引:1
Kyoko Futami & Shin-ichi Akimoto 《Ethology : formerly Zeitschrift fur Tierpsychologie》2005,111(12):1126-1138
Semelparity is prevalent in arthropod species that exhibit maternal care. Previous hypotheses postulated that long‐term maternal care constrains future reproduction in females, leading to the evolution of semelparity. Nevertheless, females may occasionally lose all or part of their offspring because of predation or other causes. Where females lose the first egg mass for any reason, the potential for females to produce an additional egg mass could be adaptive. This potential may be found widely among semelparous arthropods as a conditional strategy. We tested this hypothesis using the crab spider Lysiteles coronatus whose females guard their egg mass against predators. L. coronatus females did not consume food during the 40‐d guarding period; this resulted in a 30.2% loss in their weight. When the females were separated from their eggs immediately after oviposition and were provided with food, they resumed feeding and their ovaries redeveloped. Dissection of guarding females indicated that their ovaries developed temporarily during egg guarding and that the developed ovaries were subsequently reabsorbed. These results suggest that the females maintain the potential to produce a second egg mass in case of egg loss, but that this potential declines towards the end of the guarding period. Field observations showed that a small fraction of the females oviposited in late July, when most females had completed egg guarding. The size of the late broods was similar to the oocyte numbers that we found in the females fed in the laboratory. This result suggests that a few females produced a second egg mass after they had lost the first one. Thus, we suggest that facultative second oviposition in L. coronatus females has evolved as an adaptation to egg loss, and that the development of ovaries during the guarding period is intrinsically programmed for compensatory oviposition. 相似文献
533.
Tetraneura nigriabdominalis (Sasaki, 1899) is a galling aphid that is distributed widely in Eurasia. In the present study, a diagnostic multiplex polymerase chain reaction (PCR) protocol was developed to discriminate two types of the cytochrome oxidase subunit I (COI) sequences in this species, and its usefulness was examined from 25 samples of T. nigriabdominalis. Multiplex PCR and electrophoresis revealed that 10 and 15 samples had one band of 133 bp (type A) and 426 bp (type B), respectively. This discrimination was identical to the division of the 25 samples based on the alignments of COI sequences (511 bp), indicating high accuracy of this protocol in distinguishing the two types. This protocol is useful for studying microgeographic distributions of the two types and genetic diversities in T. nigriabdominalis. 相似文献
534.
Y Kuchino Y Kimura H Akimoto H Nomura N Kamei S Nishimura 《Nucleic acids symposium series》1985,(16):221-223
Monoclonal antibodies specific for queuine have been prepared. Synthetic 9-(5-carboxypentyl)queuine (cp9Q) was conjugated with bovine serum albumin (BSA) or keyhole limpet hemocyanin (KLH), and the conjugate was used to immunize BALB/c mice by intraperitoneal and subcutaneous injection. Monoclonal antibodies were subsequently obtained by fusion of spleen cells and the mouse myeloma cell line X63Ag8U1. An enzyme-linked immunoabsorbent assay (ELISA) using o-phenylenediamine as peroxidase substrate was used for screening of clones and characterization of antibodies. Inhibition experiments with various homologous nucleosides revealed that the monoclonal antibody designated as 2D8E6 has no cross-reactivity with guanosine, adenosine or 7-methylguanosine. 相似文献