首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   47593篇
  免费   1944篇
  国内免费   46篇
耳鼻咽喉   715篇
儿科学   1386篇
妇产科学   1082篇
基础医学   6945篇
口腔科学   1751篇
临床医学   4366篇
内科学   8385篇
皮肤病学   1186篇
神经病学   4908篇
特种医学   2198篇
外科学   6631篇
综合类   198篇
现状与发展   1篇
一般理论   30篇
预防医学   3105篇
眼科学   922篇
药学   3194篇
  1篇
中国医学   69篇
肿瘤学   2510篇
  2024年   161篇
  2023年   280篇
  2022年   200篇
  2021年   414篇
  2020年   482篇
  2019年   512篇
  2018年   1048篇
  2017年   870篇
  2016年   1159篇
  2015年   932篇
  2014年   1081篇
  2013年   1943篇
  2012年   2453篇
  2011年   2817篇
  2010年   1497篇
  2009年   963篇
  2008年   2810篇
  2007年   2982篇
  2006年   2837篇
  2005年   2668篇
  2004年   2580篇
  2003年   2626篇
  2002年   2572篇
  2001年   2031篇
  2000年   2568篇
  1999年   1363篇
  1998年   431篇
  1997年   385篇
  1996年   284篇
  1995年   246篇
  1994年   262篇
  1993年   243篇
  1992年   209篇
  1991年   167篇
  1990年   176篇
  1989年   225篇
  1988年   170篇
  1987年   175篇
  1986年   180篇
  1985年   218篇
  1984年   252篇
  1983年   193篇
  1982年   199篇
  1981年   165篇
  1980年   162篇
  1979年   187篇
  1978年   135篇
  1977年   152篇
  1976年   152篇
  1975年   131篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
Objective

To determine frequencies, interlaboratory reproducibility, clinical ratings, and prognostic implications of neural antibodies in a routine laboratory setting in patients with suspected neuropsychiatric autoimmune conditions.

Methods

Earliest available samples from 10,919 patients were tested for a broad panel of neural antibodies. Sera that reacted with leucine-rich glioma-inactivated protein 1 (LGI1), contactin-associated protein-2 (CASPR2), or the voltage-gated potassium channel (VGKC) complex were retested for LGI1 and CASPR2 antibodies by another laboratory. Physicians in charge of patients with positive antibody results retrospectively reported on clinical, treatment, and outcome parameters.

Results

Positive results were obtained for 576 patients (5.3%). Median disease duration was 6 months (interquartile range 0.6–46 months). In most patients, antibodies were detected both in CSF and serum. However, in 16 (28%) patients with N-methyl-d-aspartate receptor (NMDAR) antibodies, this diagnosis could be made only in cerebrospinal fluid (CSF). The two laboratories agreed largely on LGI1 and CASPR2 antibody diagnoses (κ = 0.95). The clinicians (413 responses, 71.7%) rated two-thirds of the antibody-positive patients as autoimmune. Antibodies against the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR), NMDAR (CSF or high serum titer), γ-aminobutyric acid-B receptor (GABABR), and LGI1 had ≥ 90% positive ratings, whereas antibodies against the glycine receptor, VGKC complex, or otherwise unspecified neuropil had ≤ 40% positive ratings. Of the patients with surface antibodies, 64% improved after ≥ 3 months, mostly with ≥ 1 immunotherapy intervention.

Conclusions

This novel approach starting from routine diagnostics in a dedicated laboratory provides reliable and useful results with therapeutic implications. Counseling should consider clinical presentation, demographic features, and antibody titers of the individual patient.

  相似文献   
3.

Aim

We herein describe the establishment of the Helsinki Vascularized Composite Allotransplantation (VCA) program and its execution in the first two face transplant cases.

Methods & patients

The Helsinki VCA program initially required the fulfillment of legal, hospital, financial, and ethical requirements. Thereafter, the assembling of a multidisciplinary team commenced. A team of Plastic, maxillofacial and ENT surgeons comprise the facial VCA team. The protocol involves collaboration with the Solid Organ Transplant (SOT) team, transplant immunology, immunosuppression, microbiology, psychiatric evaluation, well-defined VCA indications and informed consent. Between 2011 and 2017 two patients were selected for transplantation. Both patients had a severe composite facial deformity involving the maxilla and mandible following earlier ballistic injury.

Results

Patient 1 was a 35 year-old male who underwent successful near total face transplantation in February 2016 and at 30 months he has a good aesthetic outcome with symmetrical restoration of the central face and good sensory and symmetrical motor functional outcomes. Patient 2 was a 58 year-old male who underwent full face transplantation in March 2018 and at 5 months he has recovered without major problems.

Conclusion

A successful facial VCA program requires a well-prepared research protocol, experts from multiple specialties and careful patient selection. The establishment of the Helsinki VCA program required long and thorough planning and resulted in the first two Nordic face transplantation cases. This protocol now forms the platform (as a proof of concept) for other types of vascularized composite allotransplantations.  相似文献   
4.
5.
The spread of antimicrobial resistance challenges the empirical treatment of urinary tract infections (UTIs). Among others, nitrofurantoin is recommended for first-line treatment, but acceptance among clinicians is limited due to chronic nitrofurantoin-induced lung toxicity and insufficient coverage of Enterobacteriaceae other than Escherichia coli. Nitroxoline appears to be an alternative to nitrofurantoin owing to its favourable safety profile, however data on its current in vitro susceptibility are sparse. In this study, susceptibility to nitroxoline was tested against 3012 urinary clinical isolates (including multidrug-resistant bacteria and Candida spp.) by disk diffusion test and/or broth microdilution. At least 91% of all Gram-negatives (n?=?2000), Gram-positives (n?=?403) and yeasts (n?=?132) had inhibition zone diameters for nitroxoline ≥18?mm. Except for Pseudomonas aeruginosa, nitroxoline MIC90 values were ≤16?mg/L and were 2- to >16-fold lower compared with nitrofurantoin. In extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae and methicillin-resistant Staphylococcus aureus (MRSA), MIC90 values of nitroxoline were two-fold higher compared with non-ESBL-producing enterobacteria and methicillin-susceptible S. aureus (MSSA). The in vitro efficacies of nitroxoline and nitrofurantoin against ATCC strains of E. coli, Enterococcus faecalis and Proteus mirabilis were compared by time–kill curves in Mueller–Hinton broth and artificial urine. Nitroxoline was non-inferior against E. coli, P. mirabilis and E. faecalis in artificial urine. In conclusion, nitroxoline showed a broad antimicrobial spectrum, with inhibition zone diameters and MICs of nitroxoline well below the EUCAST breakpoint for E. coli for most organisms, and thus may also be a target for therapy of uncomplicated UTIs.  相似文献   
6.
7.
8.
There is little objective data about whether surgical technique or mandibular anatomy are a risk for inferior alveolar nerve (IAN) injury during bilateral sagittal split osteotomy (BSSO). Orthodromic sensory nerve action potentials (SNAPs) of the IAN were continuously recorded on both sides in 20 patients with mandibular retrognathia during BSSO operation. Changes in latency, amplitude, and sensory nerve conduction velocity (SNCV) at baseline and at different stages of the operation were analyzed. The SNAP latencies prolonged, the amplitudes diminished, and the SNCVs slowed down during BSSO (P = 0.0000 for all parameters). The most obvious changes occurred during surgical procedures on the medial side of the mandibular ramus. There was a clear tendency towards more disturbed IAN conduction with longer duration of these procedures (right side R = -0.529. P = 0.02; left side R = -0.605, P = 0.006). Exposure or manipulation of the IAN usually had no effect on nerve function, but the IAN conduction tended to be more disturbed in cases with nerve laceration. Low corpus height (R = 0.802, P = 0.001) and the location of the mandibular canal near the inferior border of the mandible (R = 0.52, P = 0.02) may increase the risk of IAN injury. There was no correlation between the age of the patients and the electrophysiological grade of nerve damage.  相似文献   
9.
BACKGROUND: Papillon Lefèvre syndrome (PLS) is a rare entity and, as such, it is almost impossible to evaluate an effective therapy in a randomized controlled study. The amount of success reported after therapy for prepubertal periodontitis (PP) in PLS is highly variable from case to case. The goal of this case report is to evaluate the effects of a combined mechanical and antibiotic periodontal therapy regimen in the management of PLS. METHODS: A male patient was diagnosed as suffering from PP associated with PLS at the age of 7 years. He showed hyperkeratosis of the palms and soles, as well as advanced periodontal disease already affecting permanent teeth with maximal probing depth and vertical attachment loss of 12 mm and 11 mm, respectively. Subgingival debridement was performed with simultaneous administration of oral 250 mg amoxicillin 3 times daily and 250 mg metronidazole twice daily for one week. Clinical parameters were assessed and subgingival plaque was collected from all teeth prior to therapy and 7 and 26 months after treatment. Selective cultures for A. actinomycetemcomitans were incubated for each individual tooth and DNA probe analysis was performed for various periodontal pathogens. RESULTS: Prior to combined mechanical and antibiotic treatment, all teeth but one harbored Actinobacillus actinomycetemcomitans subgingivally. However, at 7 and 26 months after therapy A. actinomycetemcomitans could be detected neither by culture nor by DNA probes. Clinical parameters improved markedly and teeth erupting after therapy did not exhibit attachment loss of more than 1.5 mm during the observation period. CONCLUSIONS: Eradication (suppression beneath detection levels) of A. actinomycetemcomitans seems to play a significant role in the successful treatment of localized prepubertal periodontitis in PLS.  相似文献   
10.
Accuracy of the Third Molar Eruption Predictor in predicting eruption   总被引:1,自引:0,他引:1  
OBJECTIVE: To evaluate the possibility of applying the Third Molar Eruption Predictor to all panoramic radiographs. STUDY DESIGN: Panoramic radiographs were retrospectively analyzed from a 4-year follow-up study of third molars carried out at the University of Copenhagen, Denmark. The radiographs, taken at a mean age of 20.6 years, included 45 unerupted or partially erupted mandibular third molars in 28 subjects. Because the device was calibrated both with simple proportions and by use of the methods of Bayes' Decision Theory, the separation point of the device was therefore adjusted at 12 mm from the distal surface of the second molar. RESULTS: The predictions of future eruption or impaction made with the calibrated device and the actual clinical outcome 4 years later were in conformity for 80% of the mandibular third molars. CONCLUSION: The Third Molar Eruption Predictor may be applied to all panoramic radiographs, but it seems to require calibration before use.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号