全文获取类型
收费全文 | 910篇 |
免费 | 70篇 |
国内免费 | 13篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 34篇 |
妇产科学 | 11篇 |
基础医学 | 72篇 |
口腔科学 | 17篇 |
临床医学 | 153篇 |
内科学 | 159篇 |
皮肤病学 | 12篇 |
神经病学 | 45篇 |
特种医学 | 188篇 |
外科学 | 63篇 |
综合类 | 51篇 |
预防医学 | 66篇 |
眼科学 | 9篇 |
药学 | 30篇 |
1篇 | |
中国医学 | 1篇 |
肿瘤学 | 75篇 |
出版年
2022年 | 7篇 |
2021年 | 20篇 |
2020年 | 10篇 |
2019年 | 9篇 |
2018年 | 16篇 |
2017年 | 7篇 |
2016年 | 15篇 |
2015年 | 19篇 |
2014年 | 14篇 |
2013年 | 15篇 |
2012年 | 28篇 |
2011年 | 31篇 |
2010年 | 18篇 |
2009年 | 23篇 |
2008年 | 21篇 |
2007年 | 36篇 |
2006年 | 27篇 |
2005年 | 39篇 |
2004年 | 24篇 |
2003年 | 32篇 |
2002年 | 34篇 |
2001年 | 20篇 |
2000年 | 19篇 |
1999年 | 25篇 |
1998年 | 32篇 |
1997年 | 28篇 |
1996年 | 22篇 |
1995年 | 27篇 |
1994年 | 22篇 |
1993年 | 34篇 |
1992年 | 12篇 |
1991年 | 16篇 |
1990年 | 17篇 |
1989年 | 27篇 |
1988年 | 24篇 |
1987年 | 42篇 |
1986年 | 22篇 |
1985年 | 25篇 |
1984年 | 10篇 |
1983年 | 15篇 |
1982年 | 8篇 |
1981年 | 17篇 |
1980年 | 14篇 |
1978年 | 10篇 |
1977年 | 7篇 |
1976年 | 7篇 |
1975年 | 7篇 |
1973年 | 6篇 |
1970年 | 4篇 |
1967年 | 5篇 |
排序方式: 共有993条查询结果,搜索用时 15 毫秒
71.
M T Rizzo E Regazzi D Garau L Akard M Dugan H S Boswell V Rizzoli C Carlo-Stella 《Cancer research》1999,59(19):5047-5053
The hallmark of chronic myeloid leukemia (CML) is the presence of the bcr-abl oncogene, which is associated with transforming ability and an intrinsic resistance to induction of apoptosis by genotoxic agents. Arachidonic acid (AA), a biologically active fatty acid, plays a crucial role as a mediator of signaling pathways involved in cell proliferation and survival. In this study, we investigated the potential role of AA as a proapoptotic agent in CML. Pretreatment of human CML isolated progenitor cells with AA (100 microM for 18 h) induced 71-75% inhibition of in vitro colony formation of granulocyte-macrophage colony-forming units, multilineage colony-forming units, and erythroid burst-forming units. This inhibition was significantly greater than the effect on normal progenitor cells (19-39% growth inhibition of erythroid burst-forming units, multilineage colony-forming units, and granulocyte-macrophage colony-forming units). AA also inhibited growth of the bcr-abl-transformed cell line H7.bcr-abl A54. In contrast, a minimal effect of AA on inhibition of cell growth was observed in the parental nontransformed NSF/N1.H7 cell line. The antiproliferative effect of AA was associated with apoptosis. Gamma-linolenic acid, a precursor of AA, also inhibited cell growth, whereas other unsaturated and saturated fatty acids had no effect. Pharmacological inhibition of cyclooxygenase, lipooxygenase, and cytochrome P450 monooxygenase enzymes prior to exposure to AA did not rescue cells from the inhibitory effect of AA. Moreover, 5,8,11,14-eicosatetraynoic acid, a nonmetabolizable arachidonate analogue, also inhibited cell growth, suggesting that the effect of AA did not require further metabolism. Treatment with antioxidants prior to stimulation with AA was also ineffective in preventing its antiproliferative effect. Thus, AA inhibited proliferation of CML cells by inducing apoptotic cell death. The signaling mechanisms of AA-induced inhibition of cell growth appeared to be independent of its conversion into eicosanoids or free radical generation. 相似文献
72.
Passik SD Donaghy KB Theobald DE Lundberg JC Holtsclaw E Dugan WM 《Journal of pain and symptom management》2000,19(5):329-338
We examined oncologists' and nurses' ability to recognize depressive symptoms in two cancer patients who were interviewed on videotape. The study was conducted in a rural community, hospital-based outreach network. Staff were given a one-hour in-service on the use of the Mini International Neuropsychiatric Interview (MINI)-a brief diagnostic interview-to provide a differential diagnosis (no psychiatric diagnosis, major depressive disorder, or adjustment disorder with depressed mood). Next, the staff viewed a videotape of an investigator (S.P.) utilizing the MINI to interview two depressed breast cancer patients. Staff subsequently rated depressive symptoms on the MINI and made a diagnosis. Findings indicated a high concordance among staff regarding symptom ratings on a straightforward example of major depressive disorder. Concordance on diagnosis, severity level, and specific symptoms declined slightly on a more difficult case involving primarily cognitive symptoms and a diagnosis of adjustment disorder. Following brief didactic training on depressive disorders, oncologists and nurses were able to identify depressive symptoms in cancer patients on videotape. Learning to use a semistructured interview can increase oncologists' awareness of depressive symptoms and may be a good training model. 相似文献
73.
为探讨体外循环(CPB)导致心脏植物神经系统(CAS)损伤的机理,了解温血心停跳液能否防止CPB后心率变异性(HRV)的降低,采用对照方法观察了温血心停跳液与冷晶体心停跳液对狗HRV的影响。结果显示:CPB后温血心停跳液组(WB组)和冷晶体心停跳液组(CC组)的全频谱(TP)、低频(LF)和高频(HF)均较术前明显降低(P<0.05),而且CC组比WB组降低更明显(P<0.05),但LF/HF在组内及组间均无明显变化(P>0.05)。CPB后24小时平均心率(MHR)明显增加(P<0.05),且CC组高于WB组(P<0.05)。本研究表明:采用温血心停跳液或冷晶体心停跳液的CPB不会干扰CAS平衡,但均能使HRV降低,温血心停跳液不能防止HRV损害。 相似文献
74.
Perforated colorectal neoplasms: correlation of clinical, contrast enema, and CT examinations 总被引:2,自引:0,他引:2
Hulnick DH; Megibow AJ; Balthazar EJ; Gordon RB; Surapenini R; Bosniak MA 《Radiology》1987,164(3):611-615
Results of clinical, contrast enema (CE), and computed tomographic (CT) examinations in 39 patients with perforated colorectal neoplasms were retrospectively reviewed. Twenty patients were toxemic at initial presentation, but in only four patients was the diagnosis of perforated colorectal neoplasm initially suspected clinically. CE study was performed in 22 patients and enabled the diagnosis of perforated neoplasm in 11 cases, neoplasm alone in eight, and neither neoplasm nor perforation in three. CT was performed in 38 patients and enabled the diagnosis of perforated neoplasm in 36; pericolic phlegmon but no mass lesion was evident in two. In 16 patients, CT also demonstrated metastatic disease. Because of its reliability in establishing the diagnosis and staging the extent of the inflammatory and neoplastic disease, CT is indicated in cases of suspected or proved perforated colorectal neoplasm and in cases in which CE study findings are indeterminate or suggestive of perforated neoplasm. 相似文献
75.
76.
We report the successful long-term engraftment of normal male donor bone marrow (BM) transfused into noncytoablated female mice, challenging the assumption that "niches" need to be created for marrow to engraft. We have used chromosomal banding and Southern blot analysis to identify transplanted male marrow cells, and shown the long-term stability of the chimeric marrows. Balb/C, BDF1, or CBA-J female hosts (no irradiation) received for 5 consecutive days 40 x 10(6) male cells (per day) of the same strain, and repopulation patterns were observed. Parallel studies were performed using tibia/femur equivalents of normal marrow or marrow from Balb/C mice pretreated 6 days previously with 150 mg/kg 5-fluorouracil (5-FU). Chromosome banding techniques showed that 5% to 46% of marrow cells were male 3 to 9 months posttransplant with normal donor marrow. Southern blot analysis, using the pY2 probe, showed continued engraftment at 21 to 25 months posttransplant, ranging from 15% to 42% male engrafted cells in marrow. Normal donor male marrow engrafted significantly better than 5-FU-pretreated male marrow as shown 1 to 12 months posttransplant in non-cytoablated female recipients. Percentages of male engrafted cells in BM ranged from 23% to 78% for recipients of normal donor marrow and from 0.1% to 39% for recipients of 5-FU marrow. Mean engraftment for 6 mice receiving normal marrow was 38%, whereas that for 6 mice receiving post-5-FU marrow was 8%, as assayed 1 to 3 months posttransplant. At 10 to 12 months, mean engraftment for the normal donor group was 46%, compared with 16% for the 5-FU group. The patterns of engraftment with normal and 5-FU marrow were similar for spleen and thymus. These results show that long-term chimerism can be established after transplantation of normal donor marrow to normal nonirradiated host mice and indicate that marrow spaces do not have to be created for successful engraftment. They suggest that transplanted marrow competes equally with host marrow for marrow space. Finally, these data show that post-5-FU Balb/C male marrow is markedly inferior in the repopulation of Balb/C female host marrow, spleen, and thymus, and suggest that this population of cells may not be the ideal population for gene transfer studies. 相似文献
77.
78.
79.
Left ventricular volumes measured by MR imaging 总被引:9,自引:0,他引:9
We assessed the potential of proton magnetic resonance (MR) imaging for accurately measuring left ventricular volumes using 15 latex casts of excised human left ventricles. The casts were submerged in water to stimulate the endocardial left ventricular cavity interface in in vivo imaging conditions. Tomographic image sections perpendicular to the long axis of the cast were obtained, spanning each cast from apex to base. Simpson's rule was used to calculate the cast volumes. Correlation between the actual cast volumes (as measured by the displacement method) and the calculated volumes using MR imaging for the 15 casts was excellent. Our data demonstrate that MR imaging accurately measures cardiac chamber volumes in this in vitro model. 相似文献
80.
Ulka N. Vaishampayan Anwar N. Mohamed Michael C. Dugan Robert E. Bloom Margarita Palutke 《British journal of haematology》2001,115(1):66-68
Two elderly men with stage IV mantle cell lymphoma (MCL) rapidly developed a leukaemic phase with unusually high blast counts that proved fatal. One lymph node biopsy showed diffuse MCL, the other blastic morphology. In addition to t(11;14), there were t(8;14) and t(1;19) in case 1 and dup(8)(q24q13) in case 2. Fluorescence in situ hybridization revealed genomic fusion of IgH/MYC genes in case 1 and an extra copy of C-MYC gene in case 2. The genomic alteration of C-MYC oncogene is probably implicated in the blastic transformation and aggressive behaviour of the disease. 相似文献