全文获取类型
收费全文 | 684篇 |
免费 | 39篇 |
国内免费 | 46篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 47篇 |
妇产科学 | 20篇 |
基础医学 | 73篇 |
口腔科学 | 37篇 |
临床医学 | 99篇 |
内科学 | 185篇 |
皮肤病学 | 10篇 |
神经病学 | 21篇 |
特种医学 | 120篇 |
外科学 | 26篇 |
综合类 | 10篇 |
预防医学 | 19篇 |
眼科学 | 13篇 |
药学 | 51篇 |
1篇 | |
肿瘤学 | 35篇 |
出版年
2023年 | 6篇 |
2022年 | 6篇 |
2021年 | 5篇 |
2019年 | 4篇 |
2018年 | 10篇 |
2017年 | 9篇 |
2016年 | 11篇 |
2015年 | 15篇 |
2014年 | 19篇 |
2013年 | 26篇 |
2012年 | 12篇 |
2011年 | 12篇 |
2010年 | 19篇 |
2009年 | 21篇 |
2008年 | 10篇 |
2007年 | 40篇 |
2006年 | 16篇 |
2005年 | 9篇 |
2004年 | 8篇 |
2003年 | 4篇 |
2002年 | 12篇 |
2001年 | 5篇 |
2000年 | 11篇 |
1999年 | 16篇 |
1998年 | 44篇 |
1997年 | 52篇 |
1996年 | 54篇 |
1995年 | 45篇 |
1994年 | 30篇 |
1993年 | 31篇 |
1992年 | 6篇 |
1991年 | 12篇 |
1990年 | 8篇 |
1989年 | 14篇 |
1988年 | 25篇 |
1987年 | 20篇 |
1986年 | 16篇 |
1985年 | 15篇 |
1984年 | 7篇 |
1983年 | 8篇 |
1982年 | 9篇 |
1981年 | 10篇 |
1980年 | 11篇 |
1979年 | 3篇 |
1978年 | 6篇 |
1977年 | 9篇 |
1975年 | 7篇 |
1974年 | 3篇 |
1973年 | 6篇 |
1967年 | 3篇 |
排序方式: 共有769条查询结果,搜索用时 15 毫秒
101.
102.
髋关节骨关节炎患者进行金属对超高分子量聚乙烯(ul tra-high molecular weight polyethylene,UHMWPE)的全髋关节置换是二十世纪最为成功的外科手术之一.据文献报道使用UHMWPE衬垫的骨水泥假体20年成功率达到75%以上[1]. 相似文献
103.
Radiology conferences enable participants the opportunity to ask experts questions through question and answer (Q and A) sessions
or individually. Given the time limitations and intimidating circumstances, we incorporated conference text messaging (confexting)
as a method of increasing interactivity between the audience and speakers. During a 5-day radiology conference, text messaging
was utilized for anonymous interactivity between the audience and speakers during Q and A sessions. There were 324 text messages;
76 of these were either follow-up statements or questions related to earlier text messages. Forty-two questions were submitted
via paper notes. There was a general trend of an increasing number of text messages and a decreasing number of paper notes.
The anonymous text messaging system was found to be an effective method for interactivity between the audience and the speakers.
The questions and answers could be presented in a PowerPoint format at the formal Q and A sessions. Questions texted to the
authors during their talks could be immediately answered or addressed in subsequent talks. Although difficult for some individuals
to embrace technology, confexting allows for interactivity and prompts discussion. Confexting is an effective method for interactivity
between the audience and speakers not previously utilized in a conference setting. The anonymity and asynchronous communication
enable conference participants to submit more questions than in the traditional setting. The speakers may be able to explain
more thoroughly difficult concepts more thoroughly with additional slides at Q and A sessions or may immediately answer texted
questions during their talks. 相似文献
104.
105.
High-dose therapy and autologous bone marrow transplantation in patients with follicular lymphoma during first remission 总被引:14,自引:9,他引:14
Freedman AS; Gribben JG; Neuberg D; Mauch P; Soiffer RJ; Anderson KC; Pandite L; Robertson MJ; Kroon M; Ritz J; Nadler LM 《Blood》1996,88(7):2780-2786
We report the results of a study in previously untreated advanced stage patients with follicular lymphoma (FL) who underwent uniform induction chemotherapy with cyclophosphamide, doxorubicin, vincristine, prednisone (CHOP) followed by myeloablative therapy and anti-B-cell monoclonal antibody purged autologous bone marrow transplantation (ABMT). Eighty-three patients with previously untreated, low-grade FL were enrolled. After CHOP induction, only 36% achieved complete remission (CR) and 77 patients underwent ABMT. Before BM harvest, 70 patients had a known t(14;18), as determined by polymerase chain reaction (PCR), and all remained PCR positive in the BM at harvest. After ABMT, the disease-free survival (DFS) and overall survival are estimated to be 63% and 89% at 3 years, respectively, with a median follow-up of 45 months. Patients whose BM was PCR negative after purging experienced significantly longer freedom from recurrence (FFR) than those whose BM remained PCR positive (P = .0006). Continued PCR negativity in follow-up BM samples was also strongly predictive of continued CR. This study suggests that a subset of patients with advanced FL may experience prolonged clinical and molecular remissions following high-dose ablative therapy, although longer follow-up will be necessary to determine potential impact on overall survival. 相似文献
106.
We investigated the ability of blood B cells, bone marrow (BM) plasma cells, and terminal leukemic plasma cells (T-PCL) from patients with multiple myeloma (MM) to migrate on extracellular matrix proteins. Hyaluronan (HA), but not collagen type I, collagen type IV, or laminin, promoted migration of MM blood B cells, as determined by time-lapse video microscopy. Between 13% and 20% of MM blood B cells migrated on HA with an average velocity of 19 micron/min, and greater than 75% of MM blood B cells exhibited vigorous cell movement and plasma membrane deformation, as did circulating T-PCL and extraskeletal plasma cells from patients with MM. In contrast, plasma cells obtained from BM of patients with MM lacked motility on all substrates tested and did not exhibit cell membrane protrusions or cellular deformation. MM blood B cells and MM plasma cells from all sources examined expressed the HA- binding receptors receptor for HA-mediated motility (RHAMM) and CD44. On circulating MM B cells, both RHAMM and CD44 participated in HA- binding, indicating their expression ex vivo in an activated conformation. In contrast, for the majority of BM plasma cells in the majority of patients with MM, expression of RHAMM or CD44 was not accompanied by HA binding. A minority of patients did have HA-binding BM plasma cells, involving both RHAMM and CD44, as evidenced by partial blocking with monoclonal antibodies (MoAbs) to RHAMM or to CD44. Despite HA binding by both RHAMM and CD44, migration of MM blood B cells on HA was inhibited by anti-RHAMM but not by anti-CD44 MoAbs, indicating that RHAMM but not CD44 mediates motility on HA. Thus, circulating B and plasma cells in MM exhibit RHAMM- and HA-dependent motile behavior indicative of migratory potential, while BM plasma cells are sessile. We speculate that a subset(s) of circulating B or plasma cells mediates malignant spread in myeloma. 相似文献
107.
Kersten MJ; Evers LM; Dellemijn PL; van den Berg H; Portegies P; Hintzen RQ; van Lier RA; von dem Borne AE; van Oers RH 《Blood》1996,87(5):1985-1989
Diagnosis of meningeal localization of lymphoid malignancies by means of cytologic examination of the cerebrospinal fluid (CSF) can be difficult. Thus far no reliable CSF tumor markers have been identified. CD27 is a transmembrane disulfide-linked 55-kD homodimer present on most peripheral blood T cells and on a subset of B cells. CD27 is also expressed on human malignant B cells and high levels of soluble CD27 can be present in the serum of patients with B-cell malignancies. The aim of this study is to determine prospectively the diagnostic value of CSF sCD27 as a tumor marker in patients with meningeal localization of lymphoid malignancies. CSF sCD27 levels were determined by sandwich enzyme-linked immunosorbent assay. The optimal cut-off value using receiver operator characteristics curves was found to be 10 U/mL. sCD27 levels were normal in all 50 control patients (lumbar disc protrusion) and in 39 of 40 samples obtained from patients with either solid tumors or acute myeloid leukemia. Of 104 CSF samples from 70 children with acute lymphoblastic leukemia (ALL) or non-Hodgkin's lymphoma (NHL) undergoing routine central nervous system (CNS) staging, sCD27 was false positive and false negative in only one sample each. In 70 samples from 45 patients suspected of meningeal localization of ALL or NHL, the sCD27 test had an excellent sensitivity (100%) and specificity (82%). In 7 patients with positive CSF studied longitudinally, sCD27 levels correlated very well with remission and relapse. sCD27 levels were not nonspecifically increased by the administration of cytostatic drugs. Finally, sCD27 was also elevated in the 4 patients studied with primary central nervous system lymphoma (PCNSL). CSF sCD27 is a promising tumor marker in patients with either meningeal localization of lymphoid malignancies or PCNSL, and can be useful in the differential diagnosis of CNS involvement by either lymphoid malignancies or solid tumors. 相似文献
108.
Cardoso AA; Schultze JL; Boussiotis VA; Freeman GJ; Seamon MJ; Laszlo S; Billet A; Sallan SE; Gribben JG; Nadler LM 《Blood》1996,88(1):41-48
Even if neoplastic cells express tumor associated antigens they still may fail to function as antigen presenting cells (APC) if they lack expression of one or more molecules critical for the induction of productive immunity. These cellular defects can be repaired by physiologic activation, transfection, or fusion of tumor cells with professional APC. Although such defects can be repaired, antitumor specific T cells may still fail to respond in vivo if they may have been tolerized. Here, human pre-B cell acute lymphoblastic leukemia (pre-B ALL) was used as a model to determine if primary human tumor cells can function as alloantigen presenting cells (alloAPC) or alternatively whether they induce anergy. In the present report, we show that pre-B cell ALL express alloantigen and adhesion molecules but uniformly lack B7-1 (CD80) and only a subset express B7-2 (CD86). Pre-B ALL cells are inefficient or ineffective alloAPC and those cases that lack expression of B7-1 and B7-2 also induce alloantigen specific T- cell unresponsiveness. Under these circumstances, T-cell unresponsiveness could be prevented by physiologic activation of tumor cells via CD40, cross-linking CD28, or signaling through the common gamma chain of the interleukin-2 receptor on T cells. Taken together, these results suggest that pre-B ALL may be incapable of inducing clinically significant T-cell-mediated antileukemia responses. This defect may be not only due to their inability to function as APC, but also due to their potential to induce tolerance. Attempts to induce clinically significant antitumor immune responses may then require not only mechanisms to repair the antigen presenting capacity of the tumor cells, but also reversal of tolerance. 相似文献
109.
Migraine-associated vertigo 总被引:2,自引:0,他引:2
PA Savundra JD Carroll RA Davies LM Luxon 《Cephalalgia : an international journal of headache》1997,17(4):505-510
A retrospective analysis was performed on consecutive series of 363 patients presenting with vertigo; 32% had migraine. Of the 224 patients with no pathology other than migraine or vestibular dysfunction, migraineurs had a significantly higher prevalence of normal, central, and combined central and peripheral vestibular dysfunction compared to non-migraineurs. The combination of central and peripheral vestibular signs was a feature of migraine with aura. The results support the hypothesis that migraine-associated vertigo is a diagnostic entity. 相似文献
110.
Thrombosis in inflammatory bowel disease: clinical setting, procoagulant profile and factor V Leiden 总被引:7,自引:0,他引:7
Jackson LM; O'Gorman PJ; O'Connell J; Cronin CC; Cotter KP; Shanahan F 《QJM : monthly journal of the Association of Physicians》1997,90(3):183-188
Patients with inflammatory bowel disease have an increased frequency of
thromboembolism, and microvascular thrombosis has been proposed as a
contributory pathogenic factor. The mechanism of enhanced procoagulant
activity is not understood. We examined the clinical setting of
thromboembolic events in 52 patients with Crohn's disease or ulcerative
colitis, and assessed the procoagulant laboratory profile, including Factor
V Leiden, in a subset of 20 patients to identify procoagulant risk factors.
Patients who developed thrombosis tended to be young; 60% of thrombotic
events occurred in patients under 50 years. Multiple thromboembolic
episodes occurred in 13% and unusual sites of thrombosis (e.g.
intracardiac, cerebral, inominate veins) in 11%. No risk factor was
identifiable in 52% of cases and two-thirds of thromboses occurred in an
out-patient setting. The mortality rate was 8%. Evidence for inflammatory
disease activity was found in only 45% of patients with ulcerative colitis
at the time of the thromboembolic event, in contrast to 89% of those with
Crohn's disease. Assays for specific coagulation defects were negative in
all cases tested (protein S, C were normal in 17/17; anti-thrombin III,
anti-phospholipid antibodies and activated protein C resistance were
negative in 20/20, and only 1/20 patients was found to be heterozygous for
Factor V leiden. Thrombosis in inflammatory bowel disease is important
because it occurs in a young population, often in unusual sites, and has a
high mortality. The development of thrombosis is related to active
inflammatory disease in most patients with Crohn's disease but apparently
not in those with ulcerative colitis. Since approximately half of the
patients had no other identifiable risk factor, there remains a substantial
group of patients with IBD who develop thrombosis for unknown reasons.
相似文献