全文获取类型
收费全文 | 15463篇 |
免费 | 1303篇 |
国内免费 | 58篇 |
专业分类
耳鼻咽喉 | 126篇 |
儿科学 | 529篇 |
妇产科学 | 256篇 |
基础医学 | 2066篇 |
口腔科学 | 328篇 |
临床医学 | 1607篇 |
内科学 | 3288篇 |
皮肤病学 | 269篇 |
神经病学 | 1849篇 |
特种医学 | 855篇 |
外国民族医学 | 1篇 |
外科学 | 2693篇 |
综合类 | 83篇 |
一般理论 | 8篇 |
预防医学 | 837篇 |
眼科学 | 296篇 |
药学 | 712篇 |
1篇 | |
中国医学 | 12篇 |
肿瘤学 | 1008篇 |
出版年
2023年 | 132篇 |
2022年 | 251篇 |
2021年 | 470篇 |
2020年 | 310篇 |
2019年 | 369篇 |
2018年 | 434篇 |
2017年 | 366篇 |
2016年 | 481篇 |
2015年 | 447篇 |
2014年 | 616篇 |
2013年 | 725篇 |
2012年 | 1132篇 |
2011年 | 1136篇 |
2010年 | 642篇 |
2009年 | 565篇 |
2008年 | 871篇 |
2007年 | 889篇 |
2006年 | 777篇 |
2005年 | 693篇 |
2004年 | 648篇 |
2003年 | 605篇 |
2002年 | 577篇 |
2001年 | 337篇 |
2000年 | 320篇 |
1999年 | 285篇 |
1998年 | 137篇 |
1997年 | 110篇 |
1996年 | 96篇 |
1995年 | 110篇 |
1994年 | 76篇 |
1993年 | 67篇 |
1992年 | 160篇 |
1991年 | 148篇 |
1990年 | 141篇 |
1989年 | 150篇 |
1988年 | 112篇 |
1987年 | 112篇 |
1986年 | 112篇 |
1985年 | 94篇 |
1984年 | 91篇 |
1983年 | 72篇 |
1982年 | 50篇 |
1981年 | 39篇 |
1979年 | 77篇 |
1978年 | 63篇 |
1976年 | 47篇 |
1975年 | 43篇 |
1974年 | 48篇 |
1973年 | 39篇 |
1972年 | 52篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Wolfgang H Oertel Tobias W?chter Niall P Quinn Gudrun Ulm Dirk Brandst?dter 《Movement disorders》2003,18(4):430-432
According to the consensus statement on the diagnosis of multiple system atrophy (MSA), erectile dysfunction is required for male patients to fulfil the urinary incontinence criterion. However, there is no equivalent item for female patients. We questioned 19 female patients with MSA of the parkinsonian type (MSA-P), 28 female patients with Parkinson's disease (PD), and 27 healthy controls on their genital sensitivity. A total of 47% of the MSA patients but only 4% of the PD patients and 4% of the control group admitted to reduced genital sensitivity, a highly significant difference (P < 0.001). Moreover, the appearance of reduced genital sensitivity in female MSA patients showed a close temporal relation to the onset of the disease. If these preliminary results can be confirmed and further specified in a larger sample, a historical item of reduced genital sensitivity in female patients might become a diagnostic feature for MSA, comparable to erectile dysfunction in male patients. 相似文献
62.
Three-dimensional reconstruction of magnetic resonance images of the temporomandibular joint by I-DEAS. 总被引:1,自引:0,他引:1
Evaluation of the temporomandibular joint has been limited by the inability of current technology to image complex morphology and motion in three dimensions. An engineering design program, I-DEAS, has been used to construct solid models from magnetic resonance images. A dried skull with an acrylic resin temporomandibular disc replica, immersed in water, provided sagittal and coronal MR images. Linear dimensions and disc volumes obtained from the models were compared with the original and found to be consistent, within the limits imposed by the slice thickness. We have applied the method to the living joint in an asymptomatic volunteer, and report our initial experience in demonstrating the spatial relationships and motion of the joint components. 相似文献
63.
The Boston AIDS Survival Score (BASS): a multidimensional AIDS severity instrument. 总被引:2,自引:1,他引:1
下载免费PDF全文
![点击此处可从《American journal of public health》网站下载免费的PDF全文](/ch/ext_images/free.gif)
G R Seage rd C Gatsonis J S Weissman J S Haas P D Cleary F J Fowler M P Massagli V E Stone D E Craven H Makadon J Goldberg K Coltin K S Levin A M Epstein 《American journal of public health》1997,87(4):567-573
OBJECTIVES: This study developed a new acquired immunodeficiency syndrome (AIDS) severity system by including diagnostic, physiological, functional, and sociodemographic factors predictive of survival. METHODS: Three-hundred five persons with AIDS in Boston were interviewed; their medical records were reviewed and vital status ascertained. RESULTS: Overall median (+/- SD) survival for the cohort from the first interview until death was 560 +/- 14.4 days. The best model for predicting survival, the Boston AIDS Survival Score, included the Justice score (stage 2 relative hazard [RH] = 1.25, 95% confidence interval [CI] = 0.80, 1.96; stage 3 RH = 1.76, 95% CI = 1.15, 2.70), a newly developed opportunistic disease score (Boston Opportunistic Disease Survival Score; stage 2 RH = 1.35, 95% CI = 0.90, 2.02; stage 3 RH = 2.10, 95% CI = 1.38, 3.18), and measures of activities of daily living (any intermediate limitations, RH = 1.84, 95% CI = 1.05, 3.21; any basic limitations, RH = 2.60, 95% CI = 1.44, 4.69). This model had substantially greater predictive power (R2 = .17, C statistic = .68) than the Justice score alone (R2 = .09, C statistic = .61). CONCLUSIONS: Incorporating data on clinically important events and functional status into a physiologically based system can improve the prediction of survival with AIDS. 相似文献
64.
65.
Jan Stulik Tobias Rainer Pitzen Jan Chrobok Sabine Ruffing Jörg Drumm Laurentius Sova Ravel Kucera Tomas Vyskocil Wolf Ingo Steudel 《European spine journal》2007,16(10):1689-1694
Anterior cervical plate fixation is an approved surgical technique for cervical spine stabilization in the presence of anterior
cervical instability. Rigid plate design with screws rigidly locked to the plate is widely used and is thought to provide
a better fixation for the treated spinal segment than a dynamic design in which the screws may slide when the graft is settling.
Recent biomechanical studies showed that dynamic anterior plates provide a better graft loading possibly leading to accelerated
spinal fusion with a lower incidence of implant complications. This, however, was investigated in vitro and does not necessarily
mean to be the case in vivo, as well. Thus, the two major aspects of this study were to compare the speed of bone fusion and
the rate of implant complications using either rigid- or dynamic plates. The study design is prospective, randomized, controlled,
and multi-centric, having been approved by respective ethic committees of all participating sites. One hundred and thirty-two
patients were included in this study and randomly assigned to one of the two groups, both undergoing routine level-1- or level-2
anterior cervical discectomy with autograft fusion receiving either a dynamic plate with screws being locked in ap - position
(ABC, Aesculap, Germany), or a rigid plate (CSLP, Synthes, Switzerland). Segmental mobility and implant complications were
compared after 3- and 6 months, respectively. All measurements were performed by an independent radiologist. Mobility results
after 6 months were available for 77 patients (43 ABC/34 CSLP). Mean segmental mobility for the ABC group was 1.7 mm at the
time of discharge, 1.4 mm after 3 months, and 0.8 mm after 6 months. For the CSLP- group the measurements were 1.0, 1.8, and
1.7 mm, respectively. The differences of mean segmental mobility were statistically significant between both groups after
6 months (P = 0.02). Four patients of the CSLP-group demonstrated surgical hardware complications, whereas no implant complications were
observed within the ABC-group (P = 0.0375). Dynamic plate designs provided a faster fusion of the cervical spine compared with rigid plate designs after prior
spinal surgery. Moreover, the rate of implant complications was lower within the group of patients receiving a dynamic plate.
These interim results refer to a follow-up period of 6 months after prior spinal surgery. Further investigations will be performed
2 years postoperatively. 相似文献
66.
Physicians may have the opportunity to prevent suicide. An awareness of suicide risk factors, such as depression, alcoholism, drug abuse, schizophrenia, and chronic pain or disease, may facilitate suicide prevention. Recognition of acute and chronic suicidal vulnerability occurs through direct questioning. Psychiatric consultation is indicated for patients exhibiting clear self-injury risk, as exemplified by expressed suicide intent, an overt plan for death, or a "gesture." Hospitalization is usually recommended for socially isolated patients presenting with overt suicidal ideation, complicated by injurious self-harm, encephalopathy, or substance abuse. Family involvement and a "no-suicide" contract with the patient, coupled with close outpatient follow-up appointments, should suffice for those exhibiting milder or transient thoughts of suicide without manifest intent to die. 相似文献
67.
J D Klausner J A Sweeney M D Deck G L Haas A B Kelly 《The Journal of nervous and mental disease》1992,180(7):407-412
Numerous studies have shown evidence of cerebral ventricular enlargement in schizophrenia and its relationship to severity of clinical symptoms and psychosocial dysfunction. In this large prospective study, 88 noninstitutionalized DSM-III-R schizophrenic patients were administered a CT scan and rated for positive and negative symptomatology and premorbid adjustment. The CT scans from 14 healthy controls were used for comparison of cerebral ventricular measures. Patients had an enlarged ventricle to brain ratio of the anterior portion of the lateral ventricles, the frontal horns, compared with controls. Patients with larger frontal horns had more severe negative symptoms and poorer premorbid childhood adjustment. The area of the main body of the cerebral lateral ventricles, though not elevated in patients, was correlated with the total number of prior hospitalizations. These results support the hypothesis of a structural and functional "frontal" deficit in schizophrenia. 相似文献
68.
The fresh brain weights of 79 infants with sudden infant death syndrome (SIDS) were tabulated and compared with expected "normal" brain weights. The series included 47 males and 32 females. Their ages ranged from 8 days to 16 months with a median of 2.5 months. The weights of all these brains were above the 50th percentile for age, and 64 of 79 brains (81%) were above the 95th percentile, including 15 (19%) at or above the 99.9th percentile. The ratio of the brain stem plus cerebellum weight to the whole brain weight of 93 formalin-fixed brains from victims of SIDS showed that the cerebrum was disproportionately heavier in most cases. No gross or microscopic evidence of cerebral edema was noted to account for the heavier weight. The significance of these findings is debatable. The increase in brain weight was less obvious in infants younger than 1 month of age but accelerated after that age. The brain weights of infants with SIDS may represent the really "normal" weights, since these patients were not known to be ill prior to death. If the brain weights of SIDS infants are really heavier than "normal," the possibility must be considered that disproportionately rapid growth of the brain during early infancy may be detrimental to the neural control of the cardiorespiratory system. 相似文献
69.
Ensuring data quality in a multicenter clinical trial: remote site data entry, central coordination and feedback 总被引:1,自引:0,他引:1
J B Severe N R Schooler J H Lee G Haas K T Mueser P Rosen D Shortell M Shumway 《Psychopharmacology bulletin》1989,25(3):488-490
In an ongoing multicenter clinical trial, "Treatment Strategies in Schizophrenia," the five participating sites have the capacity to perform a variety of tasks or study functions independently. These tasks include (a) verification of diagnostic eligibility through the use of computerized decision algorithms; (b) assignment of patients to treatment based on prognostic indicators using a computerized randomization algorithm; (c) entry of data into a microcomputer using a clinical trial data management system that performs simple range and missing data item checks; and (d) regular transfer of all data to the central coordinating team. The clinical trial data management system employed allows for both independent site functioning and assurance of consistency across sites. The integration of a variety of software outside the main data management system provides the central coordinators with the tools to monitor critical data as it is collected, as well as the capacity to assess the flow, quality, and uniformity of the ongoing trial. 相似文献
70.
Functional analysis of the cag pathogenicity island in Helicobacter pylori isolates from patients with gastritis, peptic ulcer, and gastric cancer 总被引:9,自引:0,他引:9
下载免费PDF全文
![点击此处可从《Infection and immunity》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Backert S Schwarz T Miehlke S Kirsch C Sommer C Kwok T Gerhard M Goebel UB Lehn N Koenig W Meyer TF 《Infection and immunity》2004,72(2):1043-1056
Helicobacter pylori is the causative agent of a variety of gastric diseases, but the clinical relevance of bacterial virulence factors is still controversial. Virulent strains carrying the cag pathogenicity island (cagPAI) are thought to be key players in disease development. Here, we have compared cagPAI-dependent in vitro responses in H. pylori isolates obtained from 75 patients with gastritis, peptic ulcer, and gastric cancer (n = 25 in each group). AGS gastric epithelial cells were infected with each strain and assayed for (i) CagA expression, (ii) translocation and tyrosine phosphorylation of CagA, (iii) c-Src inactivation, (iv) cortactin dephosphorylation, (v) induction of actin cytoskeletal rearrangements associated with cell elongation, (vi) induction of cellular motility, and (vii) secretion of interleukin-8. Interestingly, we found high but similar prevalences of all of these cagPAI-dependent host cell responses (ranging from 56 to 80%) among the various groups of patients. This study revealed CagA proteins with unique features, CagA subspecies of various sizes, and new functional properties for the phenotypic outcomes. We further showed that induction of AGS cell motility and elongation are two independent processes. Our data corroborate epidemiological studies, which indicate a significant association of cagPAI presence and functionality with histopathological findings in gastritis, peptic ulcer, and gastric cancer patients, thus emphasizing the importance of the cagPAI for the pathogenicity of H. pylori. Nevertheless, we found no significant association of the specific H. pylori-induced responses with any particular patient group. This may indicate that the determination of disease development is highly complex and involves multiple bacterial and/or host factors. 相似文献