全文获取类型
收费全文 | 24874篇 |
免费 | 1810篇 |
国内免费 | 56篇 |
专业分类
耳鼻咽喉 | 319篇 |
儿科学 | 523篇 |
妇产科学 | 529篇 |
基础医学 | 3212篇 |
口腔科学 | 385篇 |
临床医学 | 2972篇 |
内科学 | 5004篇 |
皮肤病学 | 345篇 |
神经病学 | 2162篇 |
特种医学 | 918篇 |
外科学 | 4320篇 |
综合类 | 192篇 |
一般理论 | 51篇 |
预防医学 | 1891篇 |
眼科学 | 607篇 |
药学 | 1605篇 |
中国医学 | 22篇 |
肿瘤学 | 1683篇 |
出版年
2023年 | 224篇 |
2022年 | 367篇 |
2021年 | 1024篇 |
2020年 | 521篇 |
2019年 | 884篇 |
2018年 | 954篇 |
2017年 | 687篇 |
2016年 | 742篇 |
2015年 | 847篇 |
2014年 | 1240篇 |
2013年 | 1403篇 |
2012年 | 2280篇 |
2011年 | 2297篇 |
2010年 | 1187篇 |
2009年 | 1092篇 |
2008年 | 1668篇 |
2007年 | 1642篇 |
2006年 | 1498篇 |
2005年 | 1380篇 |
2004年 | 1195篇 |
2003年 | 1042篇 |
2002年 | 873篇 |
2001年 | 162篇 |
2000年 | 136篇 |
1999年 | 101篇 |
1998年 | 129篇 |
1997年 | 94篇 |
1996年 | 63篇 |
1995年 | 38篇 |
1994年 | 52篇 |
1993年 | 43篇 |
1992年 | 59篇 |
1991年 | 56篇 |
1990年 | 54篇 |
1989年 | 54篇 |
1988年 | 63篇 |
1987年 | 55篇 |
1986年 | 54篇 |
1985年 | 49篇 |
1984年 | 37篇 |
1983年 | 30篇 |
1982年 | 19篇 |
1981年 | 20篇 |
1980年 | 20篇 |
1979年 | 32篇 |
1978年 | 22篇 |
1976年 | 25篇 |
1974年 | 24篇 |
1973年 | 22篇 |
1972年 | 19篇 |
排序方式: 共有10000条查询结果,搜索用时 234 毫秒
31.
There is no universally accepted method to determine effective therapy for central sleep apnea (CSA). Continuous positive
airway pressure (CPAP) applied acutely most often does not eliminate apneas and hypopneas. We hypothesized that the application
of two or more therapeutic modalities after the diagnostic phase of polysomnography, a multi-modality titration study (MMTS),
would identify a successful CSA treatment more often than a standard split-night study (SNS) and obviate the need for additional
polysomnograms to determine a successful therapy. We retrospectively analyzed polysomnograms of patients diagnosed with CSA
at our Sleep Disorders Center. We defined a therapy trial that resulted in an apnea–hypopnea index < 10 with at least one
treatment modality as a therapeutic success. One hundred fifteen patients with CSA were studied. Sixty-six patients (57.4%)
underwent a SNS, and 49 patients (42.6%) underwent a MMTS. SNS yielded only 8/66 (12.1%) successes on the first night, whereas
a MMTS yielded 19/49 (38.8%) successes (p = 0.001, two-tailed Fishers exact). Patients who underwent a SNS eventually had similar rate of success as patients studied
with MMTS (60.6 vs 63.3%, NS), but required more testing. Adaptive servo-ventilation was the most successful modality tested,
yielding 36/46 (78.3%) successes. Trials of additional modalities following a failed trial of CPAP often produce a successful
option that may guide therapy in patients with CSA. This approach may lead to establishing the diagnosis and treatment plans
faster, while reducing unnecessary testing. 相似文献
32.
33.
34.
Jason P. Glover DPM Christopher F. Hyer DPM Gregory C. Berlet MD Thomas H. Lee MD 《The Journal of foot and ankle surgery》2008,47(3):237-242
In our retrospective study, we report the objective results of the Mau osteotomy in the treatment of hallux valgus. We reviewed the results of 24 cases of moderate to severe hallux valgus deformities corrected with the Mau osteotomy of the first metatarsal combined with a distal soft-tissue procedure. Follow-up was possible in 24 cases. Preoperatively the mean hallux valgus and first intermetatarsal angles were 31.3 degrees and 16.6 degrees respectively, and were corrected postoperatively to an average of 13.00 degrees+/-7.15 degrees and 9.80 degrees+/-2.43 degrees respectively (P< .001). In the sagittal plane, the first metatarsal was shortened by an average of 2.00 mm. Two (8.3%) cases had dorsal elevation of the osteotomy fragment. Complications included 3 recurrences of the deformity, 1 frank nonunion, 8 dorsal cortical nonunions, 5 cases of undercorrection, and 1 case of broken hardware that was present in the nonunion that went on to revision. There were no superficial or deep infections, and no cases of transfer metatarsalgia were noted. In this series, the use of an oblique first metatarsal osteotomy with a dorsal shelf resulted in reliable and powerful correction of the first intermetatarsal angle in patients with moderate to severe hallux valgus. Particular attention should be paid to severe IM angles and the possibility of undercorrections. Despite ambulation postoperatively, the Mau osteotomy minimized dorsal malunion and the incidence of transfer metatarsalgia. LEVEL OF CLINICAL EVIDENCE: 4. 相似文献
35.
36.
37.
PURPOSE: The pharmacology of methamphetamine is reviewed, and the effects of methamphetamine use on oral health are described. SUMMARY: Methamphetamine is a highly addictive amphetamine analogue, initially synthesized in 1919. Illicit methamphetamine use leads to devastating effects on health, particularly the dentition. Illegal production of methamphetamine has skyrocketed in recent years, as have the number of users. The chief complaint of methamphetamine users is xerostomia. Without the protective effects of saliva, caries development in these patients is rampant. The typical pattern of decay involves the facial and cervical areas of both the maxillary and mandibular teeth, with eventual progression to frank coronal involvement. The acidic substances used to manufacture this drug have also been implicated as a cause of tooth decay and wear in users, as has bruxism as a result of drug-induced hyperactivity. When possible, these patients should be referred to a dentist to improve their oral health status and minimize the potential for adverse cardiovascular sequelae. Other preventive measures for methamphetamine users include stimulating saliva flow and increasing fluoride supplementation. Pharmacists should also counsel users to avoid carbohydrate-rich soft drinks in favor of water. Oral moisturizers may also be effective. CONCLUSION: Methamphetamine use causes xerostomia secondary to sympathetic central nervous system activation, rampant caries caused by high-sugar intake in the absence of protective saliva, and bruxism as a result of hyperactivity. Practitioners should know how to recognize the signs of and manage the oral health of patients with a history of methamphetamine use. 相似文献
38.
39.
Ganapathy A Prasad Kenneth K Wang Lori S Lutzke Jason T Lewis Schuyler O Sanderson Navtej S Buttar Louis M Wong Kee Song Lynn S Borkenhagen Lawrence J Burgart 《Clinical gastroenterology and hepatology》2006,4(2):173-178
BACKGROUND & AIMS: The aim of this study was to assess the validity of frozen section analysis of endoscopic mucosal resection (EMR) specimens from Barrett's esophagus as compared with permanent sections for the detection of neoplasia. Frozen sections help to give immediate feedback for surgical procedures. It has not been determined whether EMR can be adequately interpreted by using frozen sections to aid endoscopists in completely resecting neoplastic lesions. METHODS: EMR specimens from Barrett's esophagus with high-grade dysplasia (HGD) and/or carcinoma were tested by frozen section. Pathologists evaluated EMR specimens for the depth of invasion as well as the appearance of clear margins of resection. The kappa statistic was calculated to assess the degree of agreement between the frozen section and permanent section diagnoses. RESULTS: Twenty-three consecutive patients underwent 30 EMRs with frozen section diagnosis. Frozen section revealed a carcinoma in 7 specimens (23%) and dysplasia in 20 (66%). Permanent sections found carcinoma in 8 specimens (26%), dysplasia in 19 specimens (63%), and normal or nondysplastic Barrett's esophagus in the remainder. The kappa statistic for the depth of invasion of EMR specimens was 0.93 (near perfect agreement). The kappa statistic for the margins of the EMR specimens was 0.80 (excellent agreement). CONCLUSIONS: This study indicated that frozen section analysis of esophageal EMR specimens is valid as compared with permanent section. This technique might allow rapid evaluation about the degree and depth of involvement of cancers. This allows physicians to make decisions regarding further therapy if margins are involved or decrease the use of EMR for histologically benign-appearing lesions. 相似文献
40.
Mark G Stokes Christopher D Chambers Ian C Gould Therese English Elizabeth McNaught Odette McDonald Jason B Mattingley 《Clinical neurophysiology》2007,118(7):1617-1625
OBJECTIVE: To examine the relationship between coil-cortex distance and effective cortical stimulation using transcranial magnetic stimulation (TMS) in the left and right motor cortex. We also compare the effect of coil-cortex distance using 50 and 70 mm figure-eight stimulating coils. METHODS: Coil-cortex distance was manipulated within each participant using 5 and 10 mm acrylic separators placed between the coil and scalp surface. The effect of cortical stimulation was indexed by resting motor threshold (MT). RESULTS: Increasing distance between the coil and underlying cortex was associated with a steep linear increase in MT. For each additional millimetre separating the stimulating coil from the scalp surface, an additional approximately 2.8% of absolute stimulator output (approximately 0.062 T) was required to reach MT. The gradient of the observed distance effect did not differ between hemispheres, and no differences were observed between the 50 and 70 mm TMS coils. CONCLUSIONS: Coil-cortex distance directly influences the magnitude of cortical stimulation in TMS. The relationship between TMS efficacy and coil-cortex distance is well characterised by a linear function, providing a simple and effective method for scaling stimulator output to a distance adjusted MT. SIGNIFICANCE: MT measured at the scalp-surface is dependent on the underlying scalp-cortex distance, and therefore does not provide an accurate index of cortical excitability. Distance-adjusted MT provides a more accurate index of cortical excitability, and improves the safety and efficacy of MT-calibrated TMS. 相似文献