全文获取类型
收费全文 | 1531篇 |
免费 | 93篇 |
专业分类
1624篇 |
出版年
2022年 | 4篇 |
2021年 | 19篇 |
2020年 | 7篇 |
2019年 | 13篇 |
2018年 | 24篇 |
2017年 | 11篇 |
2016年 | 27篇 |
2015年 | 46篇 |
2014年 | 44篇 |
2013年 | 141篇 |
2012年 | 89篇 |
2011年 | 92篇 |
2010年 | 47篇 |
2009年 | 54篇 |
2008年 | 96篇 |
2007年 | 85篇 |
2006年 | 96篇 |
2005年 | 86篇 |
2004年 | 74篇 |
2003年 | 96篇 |
2002年 | 85篇 |
2001年 | 33篇 |
2000年 | 28篇 |
1999年 | 30篇 |
1998年 | 18篇 |
1997年 | 23篇 |
1996年 | 20篇 |
1995年 | 16篇 |
1994年 | 16篇 |
1993年 | 18篇 |
1992年 | 20篇 |
1991年 | 15篇 |
1990年 | 17篇 |
1989年 | 21篇 |
1988年 | 14篇 |
1987年 | 9篇 |
1986年 | 9篇 |
1985年 | 8篇 |
1984年 | 13篇 |
1983年 | 8篇 |
1982年 | 8篇 |
1981年 | 3篇 |
1979年 | 3篇 |
1978年 | 4篇 |
1977年 | 3篇 |
1976年 | 3篇 |
1975年 | 5篇 |
1974年 | 3篇 |
1963年 | 2篇 |
1959年 | 4篇 |
排序方式: 共有1624条查询结果,搜索用时 0 毫秒
961.
Hiroshi Furukawa Shomi Oka Kota Shimada Shoji Sugii Atsushi Hashimoto Akiko Komiya Naoshi Fukui Tatsuo Nagai Shunsei Hirohata Keigo Setoguchi Akira Okamoto Noriyuki Chiba Eiichi Suematsu Taiichiro Miyashita Kiyoshi Migita Akiko Suda Shouhei Nagaoka Naoyuki Tsuchiya Shigeto Tohma 《PloS one》2013,8(1)
Introduction
Autoantibodies to ribonucleoprotein are associated with a variety of autoimmune diseases, including rheumatoid arthritis (RA). Many studies on associations between human leukocyte antigen (HLA) alleles and RA have been reported, but few have been validated in RA subpopulations with anti-La/SS-B or anti-Ro/SS-A antibodies. Here, we investigated associations of HLA class II alleles with the presence of anti-Ro/SS-A or anti-La/SS-B antibodies in RA.Methods
An association study was conducted for HLA-DRB1, DQB1, and DPB1 in Japanese RA and systemic lupus erythematosus (SLE) patients that were positive or negative for anti-Ro/SS-A and/or anti-La/SS-B antibodies.Results
An increased prevalence of certain class II alleles was associated with the presence of anti-Ro/SS-A antibodies as follows: DRB1*08∶03 (Pc = 3.79×10−5, odds ratio [OR] 3.06, 95% confidence interval [CI] 1.98–4.73), DQB1*06∶01 (Pc = 0.0106, OR 1.70, 95%CI 1.26–2.31), and DPB1*05∶01 (Pc = 0.0040, OR 1.55, 95%CI 1.23–1.96). On the other hand, DRB1*15∶01 (Pc = 0.0470, OR 3.14, 95%CI 1.63–6.05), DQB1*06∶02 (Pc = 0.0252, OR 3.14, 95%CI 1.63–6.05), and DPB1*05∶01 (Pc = 0.0069, OR 2.27, 95% CI 1.44–3.57) were associated with anti-La/SS-B antibodies. The DPB1*05∶01 allele was associated with anti-Ro/SS-A (Pc = 0.0408, OR 1.69, 95% CI 1.19–2.41) and anti-La/SS-B antibodies (Pc = 2.48×10−5, OR 3.31, 95%CI 2.02–5.43) in SLE patients.Conclusion
HLA-DPB1*05∶01 was the only allele associated with the presence of both anti-Ro/SS-A and anti-La/SS-B antibodies in Japanese RA and SLE patients. 相似文献962.
Ryoji Shinya Hironobu Morisaka Taisei Kikuchi Yuko Takeuchi Mitsuyoshi Ueda Kazuyoshi Futai 《PloS one》2013,8(6)
Since it was first introduced into Asia from North America in the early 20th century, the pine wood nematode Bursaphelenchus xylophilus has caused the devastating forest disease called pine wilt. The emerging pathogen spread to parts of Europe and has since been found as the causal agent of pine wilt disease in Portugal and Spain. In 2011, the entire genome sequence of B. xylophilus was determined, and it allowed us to perform a more detailed analysis of B. xylophilus parasitism. Here, we identified 1,515 proteins secreted by B. xylophilus using a highly sensitive proteomics method combined with the available genomic sequence. The catalogue of secreted proteins contained proteins involved in nutrient uptake, migration, and evasion from host defenses. A comparative functional analysis of the secretome profiles among parasitic nematodes revealed a marked expansion of secreted peptidases and peptidase inhibitors in B. xylophilus via gene duplication and horizontal gene transfer from fungi and bacteria. Furthermore, we showed that B. xylophilus secreted the potential host mimicry proteins that closely resemble the host pine’s proteins. These proteins could have been acquired by host–parasite co-evolution and might mimic the host defense systems in susceptible pine trees during infection. This study contributes to an understanding of their unique parasitism and its tangled roots, and provides new perspectives on the evolution of plant parasitism among nematodes. 相似文献
963.
Satoshi Hirose Hiroko M. Kimura Koji Jimura Akira Kunimatsu Osamu Abe Kuni Ohtomo Yasushi Miyashita Seiki Konishi 《PloS one》2013,8(8)
Episodic memory retrieval most often recruits multiple separate processes that are thought to involve different temporal regions. Previous studies suggest dissociable regions in the left lateral parietal cortex that are associated with the retrieval processes. Moreover, studies using resting-state functional connectivity (RSFC) have provided evidence for the temporo-parietal memory networks that may support the retrieval processes. In this functional MRI study, we tested functional significance of the memory networks by examining functional connectivity of brain activity during episodic retrieval in the temporal and parietal regions of the memory networks. Recency judgments, judgments of the temporal order of past events, can be achieved by at least two retrieval processes, relational and item-based. Neuroimaging results revealed several temporal and parietal activations associated with relational/item-based recency judgments. Significant RSFC was observed between one parahippocampal region and one left lateral parietal region associated with relational recency judgments, and between four lateral temporal regions and another left lateral parietal region associated with item-based recency judgments. Functional connectivity during task was found to be significant between the parahippocampal region and the parietal region in the RSFC network associated with relational recency judgments. However, out of the four tempo-parietal RSFC networks associated with item-based recency judgments, only one of them (between the left posterior lateral temporal region and the left lateral parietal region) showed significant functional connectivity during task. These results highlight the contrasting roles of the parahippocampal and the lateral temporal regions in recency judgments, and suggest that only a part of the tempo-parietal RSFC networks are recruited to support particular retrieval processes. 相似文献
964.
Manabu Kume Junjiro N. Negishi Shiro Sagawa Tetsuya Miyashita Shigeyuki Aoki Tetsuji Ohmori Seiji Sanada Yuichi Kayaba 《Limnology》2014,15(2):109-115
We examined fish community structures in floodplain backwaters in the Kiso River, Central Japan, in an uncommon drought year. Nine floodplain backwaters with varying levels of flood inundation frequency were surveyed for winter fish communities, and measured for local environmental variables in summer and winter periods. The winter fish community was better represented, with less diverse and physiologically tolerant species in backwaters with a decreasing flood pulse frequency. The temporal frequency of hypoxic conditions (dissolved oxygen of <2 mg l?1) and chlorophyll a in summer explained the heterogeneity of the fish community along the gradient of inundation frequency, while no variables measured in winter had an explanatory power. These results suggest that drought-induced, infrequent flood pulses in the autumn–winter period limited the dispersal opportunity of fishes, and thus maintained community structures selected by summer limiting factors until the survey took place in winter. Future comparisons of our data with those in non-drought years would provide important implications to the sustainable management of floodplains for wintering fishes against the increasing probability of future flow regime changes. 相似文献
965.
Takayuki Katsuyama Kazuyoshi Saito Satoshi Kubo Masao Nawata Yoshiya Tanaka 《Arthritis research & therapy》2014,16(1):R43
Introduction
Pneumocystis pneumonia (PCP) is one of the most prevalent opportunistic infections in patients undergoing immunosuppressive therapy. In this article, we discuss risk factors for PCP development in patients with rheumatoid arthritis (RA) during the course of biologic therapy and describe a prophylactic treatment for PCP with trimethoprim/sulfamethoxazole (TMP/SMX). We also evaluate the effectiveness and safety of the treatment.Methods
We retrospectively analyzed 702 RA patients who received biologic therapy and compared the characteristics of patients with vs. without PCP to identify the risk factors for PCP. Accordingly, we analyzed 214 patients who received the TMP/SMX biologic agents as prophylaxis against PCP at the start of treatment to evaluate their effectiveness and safety.Results
We identified the following as risk factors for PCP: age at least 65 years (hazard ratio (HR) = 4.37, 95% confidence interval (CI) = 1.04 to 18.2), coexisting pulmonary disease (HR = 8.13, 95% CI = 1.63 to 40.0), and use of glucocorticoids (HR = 11.4, 95% CI = 1.38 to 90.9). We employed a protocol whereby patients with two or three risk factors for PCP would receive prophylactic treatment. In the study with 214 patients, there were no cases of PCP, and the incidence of PCP was reduced to 0.00 per 100 person-years compared with that before the procedure (0.93 per 100 person-years). There were no severe adverse events induced by the TMP/SMX treatment.Conclusions
RA patients with two or three risk factors for PCP who are receiving biologic therapy can benefit from safe primary prophylaxis. 相似文献966.
Takahiro Hayashi Masato Murakami Shohei Yokota Takashi Yamada Yuka Mashimo Hirokazu Miyashita Hiroaki Yokoyama Tomoki Ochiai Takashi Nishimoto Masashi Yamaguchi Noriaki Moriyama Tamiharu Yamagishi Kazuki Tobita Koki Shishido Shingo Mizuno Futoshi Yamanaka Yutaka Tanaka Saeko Takahashi Shigeru Saito 《Indian pacing and electrophysiology journal》2021,21(2):67-72
967.
968.
Piao JH Hasegawa M Heissig B Hattori K Takeda K Iwakura Y Okumura K Inohara N Nakano H 《The Journal of biological chemistry》2011,286(20):17879-17888
Fine-tuning of host cell responses to commensal bacteria plays a crucial role in maintaining homeostasis of the gut. Here, we show that tumor necrosis factor receptor-associated factor (Traf)2(-/-) mice spontaneously developed severe colitis and succumbed within 3 weeks after birth. Histological analysis revealed that apoptosis of colonic epithelial cells was enhanced, and B cells diffusely infiltrated into the submucosal layer of the colon of Traf2(-/-) mice. Expression of proinflammatory cytokines, including Tnfa, Il17a, and Ifng, was up-regulated, whereas expression of antimicrobial peptides was down-regulated in the colon of Traf2(-/-) mice. Moreover, a number of IL-17-producing helper T cells were increased in the colonic lamina propria of Traf2(-/-) mice. These cellular alterations resulted in drastic changes in the colonic microbiota of Traf2(-/-) mice compared with Traf2(+/+) mice. Treatment of Traf2(-/-) mice with antibiotics ameliorated colitis along with down-regulation of proinflammatory cytokines and prolonged survival, suggesting that the altered colonic microbiota might contribute to exacerbation of colitis. Finally, deletion of Tnfr1, but not Il17a, dramatically ameliorated colitis in Traf2(-/-) mice by preventing apoptosis of colonic epithelial cells, down-regulation of proinflammatory cytokines, and restoration of wild-type commensal bacteria. Together, TRAF2 plays a crucial role in controlling homeostasis of the colon. 相似文献
969.
970.
Kazuyoshi Kuwano Naoko Abe Yukari Nishi Hiromi Seno Gregory N. Nishihara Masafumi Iima Vilém Zachleder 《Journal of phycology》2014,50(4):744-752
The cell‐cycle progression of Ulva compressa is diurnally gated at the G1 phase in accordance with light–dark cycles. The present study was designed to examine the spectral sensitivity of the G1 gating system. When blue, red, and green light‐emitting diodes (LEDs) were used for illumination either alone or in combination, the cells divided under all illumination conditions, suggesting that all colors of light were able to open the G1 gate. Although blue light was most effective to open the G1 gate, red light alone or green light alone was also able to open the G1 gate even at irradiance levels lower than the light compensation point of each color. Occurrence of a period of no cell division in the course of a day suggested that the G1 gating system normally functioned as under ordinary illumination by cool‐white fluorescent lamps. The rise of the proportion of blue light to green light resulted in increased growth rate. On the other hand, the growth rates did not vary regardless of the proportion of blue light to red light. These results indicate that the difference in growth rate due to light color resulted from the difference in photosynthetic efficiency of the colors of light. However, the growth rates significantly decreased under conditions without blue light. This result suggests that blue light mediates cell elongation and because the spectral sensitivity of the cell elongation regulating system was different from that of the G1 gating system, distinct photoreceptors are likely to mediate the two systems. 相似文献