全文获取类型
收费全文 | 7058篇 |
免费 | 271篇 |
国内免费 | 32篇 |
专业分类
耳鼻咽喉 | 42篇 |
儿科学 | 113篇 |
妇产科学 | 140篇 |
基础医学 | 757篇 |
口腔科学 | 130篇 |
临床医学 | 482篇 |
内科学 | 1746篇 |
皮肤病学 | 134篇 |
神经病学 | 560篇 |
特种医学 | 187篇 |
外科学 | 1334篇 |
综合类 | 23篇 |
预防医学 | 191篇 |
眼科学 | 134篇 |
药学 | 493篇 |
中国医学 | 15篇 |
肿瘤学 | 880篇 |
出版年
2023年 | 31篇 |
2022年 | 73篇 |
2021年 | 121篇 |
2020年 | 79篇 |
2019年 | 81篇 |
2018年 | 99篇 |
2017年 | 97篇 |
2016年 | 117篇 |
2015年 | 135篇 |
2014年 | 168篇 |
2013年 | 238篇 |
2012年 | 343篇 |
2011年 | 445篇 |
2010年 | 223篇 |
2009年 | 212篇 |
2008年 | 356篇 |
2007年 | 470篇 |
2006年 | 460篇 |
2005年 | 447篇 |
2004年 | 449篇 |
2003年 | 468篇 |
2002年 | 505篇 |
2001年 | 97篇 |
2000年 | 138篇 |
1999年 | 133篇 |
1998年 | 152篇 |
1997年 | 96篇 |
1996年 | 98篇 |
1995年 | 76篇 |
1994年 | 65篇 |
1993年 | 60篇 |
1992年 | 76篇 |
1991年 | 77篇 |
1990年 | 67篇 |
1989年 | 75篇 |
1988年 | 60篇 |
1987年 | 66篇 |
1986年 | 43篇 |
1985年 | 50篇 |
1984年 | 41篇 |
1983年 | 43篇 |
1982年 | 22篇 |
1981年 | 19篇 |
1980年 | 29篇 |
1979年 | 29篇 |
1978年 | 22篇 |
1977年 | 19篇 |
1976年 | 13篇 |
1975年 | 10篇 |
1971年 | 10篇 |
排序方式: 共有7361条查询结果,搜索用时 15 毫秒
101.
Sasaki M Nakamura H Tsuchiya S Horie S Kashiwayanagi M Saito T Murayama T 《Biological & pharmaceutical bulletin》2007,30(4):682-686
Flavonoids have been reported to be potent antioxidants and beneficial in oxidative stress related diseases. Quercetin, a major flavonoid in food, deserves much attention because of its antioxidative activity. However, the actions of flavonoids including quercetin are complex and paradoxical. Quercetin caused apoptosis and/or cell death in various cells including cancer cells and normal cells. In this study, we investigated the effects of quercetin with or without hydrogen peroxide (H2O2) on cell death of PC12 cells, a neuronal cell line. We showed that quercetin at 10-30 microM alone caused cell death accompanied by caspase-mediated DNA fragmentation in undifferentiated PC12 cells. Quercetin did not inhibit and rather enhanced 0.1 mM H2O2-induced cell death. The toxic effect of quercetin was not inhibited by antioxidants such as N-acetylcysteine and GSH, although H2O2-induced cell death was inhibited by the antioxidants. Quercetin-induced cell death was reduced by 2 h treatment with nerve growth factor and serum. In addition, quercetin caused cell death in differentiated PC12 cells that were cultured with nerve growth factor for 6 d. Genistein, a soy isoflavone that has the pro-apoptotic activity, also caused cell death with DNA fragmentation. Further evaluation of the potential of dietary flavonoids as neuroprotective reagents is needed. 相似文献
102.
Satoshi Gando Atsushi Shiraishi Takeshi Wada Kazuma Yamakawa Seitaro Fujishima Daizoh Saitoh Shigeki Kushimoto Hiroshi Ogura Toshikazu Abe Toshihiko Mayumi Junichi Sasaki Joji Kotani Naoshi Takeyama Ryosuke Tsuruta Kiyotsugu Takuma Shin-ichiro Shiraishi Yasukazu Shiino Taka-aki Nakada Kohji Okamoto Yuichiro Sakamoto Akiyoshi Hagiwara Satoshi Fujimi Yutaka Umemura Yasuhiro Otomo 《Medicine》2022,101(32)
Tranexamic acid (TXA) reduces the risk of bleeding trauma death without altering the need for blood transfusion. We examined the effects of TXA on coagulation and fibrinolysis dynamics and the volume of transfusion during the early stage of trauma. This subanalysis of a prospective multicenter study of severe trauma included 276 patients divided into propensity score–matched groups with and without TXA administration. The effects of TXA on coagulation and fibrinolysis markers immediately at (time point 0) and 3 hours after (time point 3) arrival at the emergency department were investigated. The transfusion volume was determined at 24 hours after admission. TXA was administered to the patients within 3 hours (median, 64 minutes) after injury. Significant reductions in fibrin/fibrinogen degradation products and D-dimer levels from time points 0 to 3 in the TXA group compared with the non-TXA group were confirmed, with no marked differences noted in the 24-hour transfusion volumes between the 2 groups. Continuously increased levels of soluble fibrin, a marker of thrombin generation, from time points 0 to 3 and high levels of plasminogen activator inhibitor-1, a marker of inhibition of fibrinolysis, at time point 3 were observed in both groups. TXA inhibited fibrin(ogen)olysis during the early stage of severe trauma, although this was not associated with a reduction in the transfusion volume. Other confounders affecting the dynamics of fibrinolysis and transfusion requirement need to be clarified. 相似文献
103.
104.
Toshihiko Sato Tsutomu Fukui Shinichi Kawata Kenta Nagahori Hidenobu Miyaso Zhonglian Li Takuya Omotehara Masahiro Itoh 《Journal of Physical Therapy Science》2023,35(3):199
[Purpose] To clarify the three-dimensional nature of foot mobility and its interrelationships within the foot due to bodyweight bearing. [Participants and Methods] Data regarding left foot mobility due to body weight bearing were collected from 31 healthy adults. Foot shape differences while sitting and standing, and their interrelationship were examined. The same examiner reapplied the landmark stickers when misaligned during measurement position changes. [Results] The foot length, heel width, forefoot width, hallux valgus angle, and calcaneus eversion angle were significantly larger in the standing than in sitting position. The digitus minimus varus angle was significantly smaller in the standing than in sitting position. The medial and lateral malleoli, navicular, and dorsum of the foot were displaced medially and inferiorly; the other indices, except for the midfoot, were displaced anteriorly. The interrelationships within the foot showed a positive correlation between the calcaneus eversion angle and the medial displacement of the medial and lateral malleoli, navicular, and dorsum of the foot points. There was a negative correlation between the calcaneus eversion angle and inferior displacement of the medial malleolus, navicular, and dorsum of the foot. [Conclusion] The intra-foot coordination relationship in response to bodyweight bearing was clarified. 相似文献
105.
Ryohei Yamamoto Hajime Yamazaki Seibi Kobara Hiromi Iizuka Yasukazu Hijikata Jun Miyashita Yuki Kataoka Nobuyuki Yajima Toshio Miyata Sugihiro Hamaguchi Takafumi Wakita Yosuke Yamamoto Shunichi Fukuhara 《Journal of general internal medicine》2023,38(5):1239
BackgroundThe burden of COVID-19 on healthcare workers (HCWs) is reported to be increasing, yet the psychometric scales now in use evaluate only single aspects; few measure the pandemic-specific burden on HCWs comprehensively.ObjectiveTo develop a scale to quantify the physical, mental, and socioeconomic burden of the COVID-19 pandemic on HCWs.DesignScale development and cross-sectional survey.ParticipantsConsenting HCWs aged ≥20.Main MeasuresDevelopment of an item-list based on literature reviews and HCW panel input, evaluation of content validity and item selection using the Delphi method, psychometric testing conducted on HCWs, validity assessment by factor analyses and hypothesis verification, internal consistency evaluation by Cronbach’s alpha, test-retest analysis, and interpretability assessment.Key ResultsThrough the Delphi process, a 29-item pilot scale was generated. In psychometric testing, data from 863 HCWs contributed to the development of the final version of this scale, called Pandemic Burden Index twenty for HCWs (PBI-20), a 20-item scale to measure six domains: fatigue, fear of infection, inadequacy as a medical professional, mental health concerns, prejudice or discrimination, and anxiety about one’s livelihood and daily life. Factor analysis showed each factor corresponded to the six domains of this scale. Hypothesis verification showed the PBI-20 total score to be moderately to highly correlated with the Short Form 36 vitality score and mental health score and with intention of turnover. The PBI-20 had good internal consistency (Cronbach’s alpha 0.92). Test-retest analysis showed the intraclass correlation coefficient to be 0.70 and the minimal important change to be −7.0.ConclusionsThe psychometrically sound questionnaire we developed to measure pandemic-specific burdens for HCWs provides an understanding of comprehensive burdens on HCWs and may serve to evaluate interventions to reduce the burdens.Supplementary InformationThe online version contains supplementary material available at 10.1007/s11606-023-08028-3.KEY WORDS: COVID-19, pandemic, burden, health personnel, psychometrics 相似文献
106.
Mari Maeda-Yamamoto Osamu Honmou Masanori Sasaki Akane Haseda Hiroyo Kagami-Katsuyama Toshihiko Shoji Ai Namioka Takahiro Namioka Hirotoshi Magota Shinichi Oka Yuko Kataoka-Sasaki Ryou Ukai Mitsuhiro Takemura Jun Nishihira 《Nutrients》2022,14(12)
The purple-flesh potato (Solanum tuberosum L.) cultivar “Shadow Queen” (SQ) naturally contains anthocyanins. This randomized, double-blind, placebo-controlled study determines whether ingesting purple potatoes increases the number of mesenchymal stem cells (MSC) and improves stress response, a minor health complaint in healthy adults (registration number: UMIN000038876). A total of 15 healthy subjects (ages: 50–70 years) with minor health complaints were randomly assigned to one of two groups. For 8 weeks, the placebo group received placebo potatoes cv. “Haruka” and the test group received test potato cv. SQ containing 45 mg anthocyanin. The MSC count and several stress responses were analyzed at weeks 0 and 8 of the intake periods. The ingestion of a SQ potato did not affect the MSC count but markedly improved psychological stress response, irritability, and depression as minor health complaints compared with “Haruka”. No adverse effects were noted. Hence, an 8-week intake of SQ could improve stress responses. 相似文献
107.
Yuki Yajima Akemi Kosaka Kei Ishibashi Shunsuke Yasuda Hiroki Komatsuda Toshihiro Nagato Kensuke Oikawa Masahiro Kitada Masanori Takekawa Takumi Kumai Kenzo Ohara Takayuki Ohkuri Hiroya Kobayashi 《Cancer science》2022,113(8):2526
Although neoantigens are one of the most favorable targets in cancer immunotherapy, it is less versatile and costly to apply neoantigen‐derived cancer vaccines to patients due to individual variation. It is, therefore, important to find highly immunogenic antigens between tumor‐specific or associated antigens that are shared among patients. Considering the cancer immunoediting theory, immunogenic tumor cells cannot survive in the early phase of tumor progression including two processes: elimination and equilibrium. We hypothesized that highly immunogenic molecules are allowed to be expressed in tumor cells after an immune suppressive tumor microenvironment was established, if these molecules contribute to tumor survival. In the current study, we focused on TWIST1 as a candidate for highly immunogenic antigens because it is upregulated in tumor cells under hypoxia and promotes tumor metastasis, which is observed in the late phase of tumor progression. We demonstrated that TWIST1 had an immunogenic peptide sequence TWIST1140–162, which effectively activated TWIST1‐specific CD4+ T‐cells. In a short‐term culture system, we detected more TWIST1‐specific responses in breast cancer patients compared with in healthy donors. Vaccination with the TWIST1 peptide also showed efficient expansion of TWIST1‐reactive HTLs in humanized mice. These findings indicate that TWIST1 is a highly immunogenic shared antigen and a favorable target for cancer immunotherapy. 相似文献
108.
109.
Pigmented poroma on the temporal region dermoscopically mimicking basal cell carcinoma: A report of two cases
下载免费PDF全文
![点击此处可从《The Journal of dermatology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
110.
Go Inokuchi Daisuke Yajima Mustumi Hayakawa Ayumi Motomura Fumiko Chiba Yohsuke Makino Hirotaro Iwase 《International journal of legal medicine》2013,127(1):263-266
The issue of proper use of postmortem computed tomography (PMCT) in forensic fields is currently being actively discussed. The PMCT image has specific findings that differ from the antemortem image, and it is essential to understand and interpret postmortem changes in order to utilize PMCT properly. In this article, we present two cases of acute subdural hematoma (ASDH) in which images were obtained both ante- and postmortem. These images showed marked reduction of hematoma and diminishing midline shift between the agonal and postmortem periods, without evacuation of the hematoma. Attention should be paid to this phenomenon because key findings in determining cause of death could disappear if investigating the cause of death takes too long in cases that prove to be ASDH. In other words, this phenomenon potentially becomes a risk for misdiagnosis when we decide the cause of death without knowing the details of the circumstances of death. 相似文献