全文获取类型
收费全文 | 19058篇 |
免费 | 1103篇 |
国内免费 | 162篇 |
专业分类
耳鼻咽喉 | 168篇 |
儿科学 | 310篇 |
妇产科学 | 299篇 |
基础医学 | 2334篇 |
口腔科学 | 370篇 |
临床医学 | 1211篇 |
内科学 | 5267篇 |
皮肤病学 | 472篇 |
神经病学 | 1131篇 |
特种医学 | 702篇 |
外科学 | 3570篇 |
综合类 | 126篇 |
预防医学 | 626篇 |
眼科学 | 193篇 |
药学 | 1074篇 |
中国医学 | 34篇 |
肿瘤学 | 2436篇 |
出版年
2023年 | 146篇 |
2022年 | 303篇 |
2021年 | 534篇 |
2020年 | 297篇 |
2019年 | 373篇 |
2018年 | 464篇 |
2017年 | 400篇 |
2016年 | 467篇 |
2015年 | 524篇 |
2014年 | 669篇 |
2013年 | 768篇 |
2012年 | 1187篇 |
2011年 | 1299篇 |
2010年 | 719篇 |
2009年 | 631篇 |
2008年 | 1076篇 |
2007年 | 1196篇 |
2006年 | 1195篇 |
2005年 | 1148篇 |
2004年 | 1134篇 |
2003年 | 1045篇 |
2002年 | 959篇 |
2001年 | 351篇 |
2000年 | 355篇 |
1999年 | 376篇 |
1998年 | 230篇 |
1997年 | 185篇 |
1996年 | 176篇 |
1995年 | 131篇 |
1994年 | 108篇 |
1993年 | 111篇 |
1992年 | 218篇 |
1991年 | 169篇 |
1990年 | 189篇 |
1989年 | 164篇 |
1988年 | 126篇 |
1987年 | 94篇 |
1986年 | 74篇 |
1985年 | 81篇 |
1984年 | 67篇 |
1983年 | 48篇 |
1982年 | 39篇 |
1981年 | 34篇 |
1980年 | 31篇 |
1979年 | 45篇 |
1978年 | 39篇 |
1977年 | 31篇 |
1972年 | 35篇 |
1970年 | 30篇 |
1969年 | 33篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
11.
12.
Mamoru Uemura MD Masahiko Higashiyama MD Jiro Okami MD Kazuyuki Oda MD Koji Takami MD Ken Kodama MD 《General thoracic and cardiovascular surgery》2006,54(2):289-292
We present a case of intrapulmonary metastasis developing 18 years after complete resection of thymoma. An 8 mm nodule in the lower lobe of the left lung was noted on chest X-ray in a 76-year-old woman who had undergone complete resection of Masaoka’s stage II thymoma 18 years earlier. Since the nodule grew to 17 mm during a 2-year follow-up, wedge resection was performed. The lesion was histologically diagnosed as an intrapulmonary metastasis from thymoma. Extremely late recurrence after complete resection of thymoma is discussed. 相似文献
13.
Nobuaki Yanagisawa Shinichi Abe Hiroko Agematsu Koji Sakiyama Akinobu Usami Yuichi Tamatsu Yoshinobu Ide 《Annals of anatomy》2006,188(4):329-336
To elucidate the effects of teeth on muscle fibers in the tongue during the developmental process, we examined the expression of muscle contractile proteins and the genes for those proteins in normal mice and microphthalmic (mi/mi) mice with impaired tooth eruption. The mice were observed during the growth period, including weaning, which is when feeding movements undergo major changes. Expression of the myosin heavy chain (MyHC)-2a protein, whose contraction speed is relatively slow, disappeared after weaning in normal mice, while it remained in high concentrations even after weaning in mi/mi mice. The presence of MyHC-2a after weaning in mice with no tooth eruption was attributed to a compensation for lack of proper masticatory function and sucking-like movements, as MyHC-2a is necessary for these movements. 相似文献
14.
15.
Scott E Strome Elizabeth Martin Dallas Flies Dianne Khurana Diva Salomao Koji Tamada Andrei I Chapoval Jan L Kasperbauer Kerry D Olsen Lieping Chen 《Otolaryngology--head and neck surgery》2002,126(2):180-187
OBJECTIVES: CD62L was evaluated as a determinant of human pre-effector T cells. STUDY DESIGN AND SETTING: Phenotype and cytokine secretion profiles of CD62L cells were determined based on activation status. RESULTS: CD62L(Low) T cells demonstrated significantly higher secretion of interleukin (IL)-10 and interferon (IFN)-gamma than did CD62L(High) T cells. After activation, the majority of cells expressed high levels of the CD62L surface marker. Postactivation levels of IL-10 production remained elevated or unchanged. In a murine B16 melanoma model, freshly isolated CD62L(Low) tumor draining lymph nodes (TDLN) T cells showed increased secretion of IL-2 and IL-4 but not of IL-10 or IFN-gamma. The surface expression of CD62L and cytokine secretion patterns were maintained after activation with concomitant increases in IL-10. CONCLUSION: Our results provide evidence that CD62L(Low) T cells in TDLNs of progressively growing squamous cell carcinoma of the head and neck differ phenotypically and functionally from those of mouse origin. SIGNIFICANCE: Characterization of this human CD62L(Low) T cell population provides initial insight regarding novel surface markers in TDLN T cells that might correlate with antitumor reactivity. 相似文献
16.
17.
18.
Marijuana components suppress induction and cytolytic function of murine cytotoxic T cells in vitro and in vivo. 总被引:3,自引:0,他引:3
T W Klein Y Kawakami C Newton H Friedman 《Journal of toxicology and environmental health》1991,32(4):465-477
Killer lymphocytes play a major role in host defense against tumors and infectious diseases. Previously, we reported that delta-9-tetrahydrocannabinol (THC) and II-hydroxy-delta-9-tetrahydrocannabinol (II-hydroxy-THC) suppressed the cytolytic activity of cultured natural killer (NK) cells. Also, we showed that the drugs appeared to be affecting a stage in the killing process subsequent to the binding of the killer cell to the target cell. In the present report, we have extended these studies to an examination of the effect of cannabinoids on the activity of cytotoxic T lymphocytes (CTLs). The cytolytic activity of CTLs generated by cocultivation with either allospecific stimulators or TNP-modified-self stimulators were suppressed by both THC and II-hydroxy-THC treatment. Allospecific CTLs generated in vivo were also inhibited by an in vitro exposure to either THC or II-hydroxy-THC, and the sensitivity of these cells to drug effects appeared to be greater than the sensitivity of the in vitro generated CTLs. Suppression of cytolytic function by THC and II-hydroxy-THC was maximal after a 4-h drug treatment, suggesting that the drug effects were inducible and therefore required a finite period of time to develop maximally. As seen in previous studies involving NK cells, drug treatment of mature CTLs appears to have little effect on the binding capacity of these cells for the target. However, the maximal killing capacity of the cells and the frequency of CTLs were significantly reduced by drug treatment. In addition to suppressing the cytolytic activity of mature effector CTLs, we also show that drug treatment inhibits both the proliferation of lymphocytes responding to an allogeneic stimulus and the maturation of these lymphocytes to mature CTLs. Similarly, CTL activity developing in vivo could be inhibited by THC injection. These results suggest that CTLs are inhibited by cannabinoids by at least two mechanisms. First, the cytolytic activity of mature killers is suppressed at some point beyond the binding to the target cell. Second, the cannabinoids appear to suppress the normal development of these mature effector cells from less mature precursor cells. 相似文献
19.
Treatment strategy for synchronous metastases of colorectal cancer: is hepatic resection after an observation interval appropriate? 总被引:1,自引:1,他引:0
Yasuhiro Shimizu Kenzo Yasui Tsuyoshi Sano Takashi Hirai Yukihide Kanemitsu Koji Komori Tomoyuki Kato 《Langenbeck's archives of surgery / Deutsche Gesellschaft fur Chirurgie》2007,392(5):535-538
Background In cases of synchronous colorectal hepatic metastases, the primary colorectal cancer strongly influences on the metastases.
Our treatment policy has been to conduct hepatic resection for the metastases at an interval of 3 months after colorectal
resection. We examined the appropriateness of interval hepatic resection for synchronous hepatic metastasis.
Materials and methods The subjects were 164 patients who underwent resection of hepatic metastasis of colorectal cancer (synchronous, 70 patients;
metachronous, 94 patients). Background factors for hepatic metastasis and postoperative results were compared for synchronous
and metachronous cases.
Results The cumulative survival rate for 164 patients at 3, 5, and 10 years postoperatively was 71.9%, 51.8%, and 36.6%, and the post-resection
recurrence rate in remnant livers was 26.8%. Interval resection for synchronous hepatic metastases was conducted in 49 cases
after a mean interval of 131 days. No difference was seen in postoperative outcome between synchronous and metachronous cases.
Conclusion The outcome was similarly favorable in cases of synchronous hepatic metastasis and in cases of metachronous metastasis. Delaying
resection allows accurate understanding of the number and location of hepatic metastases, and is beneficial in determining
candidates for surgery and in selecting surgical procedure. 相似文献
20.
Kiyohito Yamamoto Koji Onoda Yasuhiro Sawada Kazuya Fujinaga Kyoko Imanaka-Yoshida Toshimichi Yoshida Hideto Shimpo 《Annals of thoracic and cardiovascular surgery》2007,13(5):322-330
BACKGROUND: Pathological changes in vein grafts begin immediately after arterial circulation is applied to the grafts. Chemical mediator stimulation and mechanical strain induce neointimal hyperplasia and medial thickening of the vein grafts, resulting in their failure. We investigated the inhibitory effect of locally applied cilostazol, an inhibitor of cyclic adenosine monophosphate phosphodiesterase III, on neointimal hyperplasia and medial thickening of the grafts. METHODS AND RESULTS: We established a distal anastomotic stricture model of femoral vein-abdominal aorta interposition grafting in rats. In this model, neointimal hyperplasia was observed not only at the distal anastomotic sites, but also in the graft body at postoperative day 14 and was markedly progressed at day 28. A strong expression of tenascin-C was found in the media and neointima of the graft body. In the grafts around which cilostazol was administered locally using Pluronic gel, neointimal hyperplasia was significantly suppressed compared with control grafts treated with the gel alone, with the mean neointimal cross-sectional area reduced by 87.1% for the graft body and by 78.9% for the distal anastomotic sites and mean medial cross-sectional area of the graft body reduced by 54.2% at day 28 versus the control. Cilostazol treatment decreased cell proliferation and the number of tenascin-C-producing cells seen by in situ hybridization, but the expression of tenascin-C protein was not suppressed. CONCLUSION: We concluded that a single perivascular application of cilostazol inhibits neointimal hyperplasia and medial thickening of vein grafts in a rat model. 相似文献