全文获取类型
收费全文 | 9078篇 |
免费 | 434篇 |
国内免费 | 99篇 |
专业分类
耳鼻咽喉 | 179篇 |
儿科学 | 145篇 |
妇产科学 | 92篇 |
基础医学 | 1702篇 |
口腔科学 | 127篇 |
临床医学 | 823篇 |
内科学 | 1755篇 |
皮肤病学 | 244篇 |
神经病学 | 564篇 |
特种医学 | 504篇 |
外科学 | 1118篇 |
综合类 | 22篇 |
一般理论 | 2篇 |
预防医学 | 336篇 |
眼科学 | 254篇 |
药学 | 877篇 |
中国医学 | 93篇 |
肿瘤学 | 774篇 |
出版年
2024年 | 3篇 |
2023年 | 63篇 |
2022年 | 242篇 |
2021年 | 360篇 |
2020年 | 182篇 |
2019年 | 206篇 |
2018年 | 271篇 |
2017年 | 210篇 |
2016年 | 266篇 |
2015年 | 412篇 |
2014年 | 525篇 |
2013年 | 567篇 |
2012年 | 800篇 |
2011年 | 768篇 |
2010年 | 456篇 |
2009年 | 396篇 |
2008年 | 546篇 |
2007年 | 576篇 |
2006年 | 504篇 |
2005年 | 442篇 |
2004年 | 317篇 |
2003年 | 289篇 |
2002年 | 233篇 |
2001年 | 201篇 |
2000年 | 199篇 |
1999年 | 172篇 |
1998年 | 46篇 |
1997年 | 38篇 |
1996年 | 25篇 |
1995年 | 18篇 |
1994年 | 19篇 |
1993年 | 27篇 |
1992年 | 34篇 |
1991年 | 28篇 |
1990年 | 26篇 |
1989年 | 22篇 |
1988年 | 16篇 |
1987年 | 22篇 |
1986年 | 15篇 |
1985年 | 12篇 |
1984年 | 4篇 |
1983年 | 6篇 |
1982年 | 5篇 |
1979年 | 6篇 |
1978年 | 6篇 |
1977年 | 4篇 |
1976年 | 3篇 |
1975年 | 3篇 |
1970年 | 3篇 |
1968年 | 4篇 |
排序方式: 共有9611条查询结果,搜索用时 0 毫秒
71.
Arellano R Gan BS Salpeter MJ Yeo E McCluskey S Pinto R Irish J Ross DC Doyle DJ Parkin J Brown D Rotstein L Witterick I Matthews W Yoo J Neligan PC Gullane P Lampe H 《Anesthesia and analgesia》2005,100(6):1846-1853
In Canada, hydroxyethyl starch 264/0.45 (HES 264/0.45; molar weight 264 kDa, molar substitution 0.45) has largely replaced albumin as the colloidal fluid of choice for perioperative intravascular volume expansion. The maximum recommended dose of HES 264/0.45 is 28 mL/kg; however, there are no clinical data supporting this limit. In this study we compared the hemostatic effects of HES 264/0.45 versus 5% albumin in doses up to 45 mL/kg over 24 h during major reconstructive head and neck surgery. Fifty patients were randomized to receive HES 264/0.45 or 5% human albumin from the induction of anesthesia until 24 h thereafter. Both albumin and HES 264/0.45 effectively maintained physiologic variables in the perioperative and postoperative periods. The partial thromboplastin time and international normalized ratio were significantly increased in the HES 264/0.45 group compared with the albumin group after infusion of 30 mL/kg and 45 mL/kg (P < 0.05). Factor VIII activity and von Willebrand factor level were significantly reduced in the HES 264/0.45 group compared with the albumin group after infusion of 15 mL/kg, 30 mL/kg, and 45 mL/kg (P < 0.05). Significantly more subjects in the HES 264/0.45 group received allogeneic red blood cell transfusions (P < 0.02). We conclude that HES 264/0.45 infusions >30 mL/kg over 24 h impair coagulation to a greater extent than albumin, possibly leading to more allogeneic transfusions. 相似文献
72.
BACKGROUND: The effect of haemodynamic derangement during coronary artery anastomosis in off-pump coronary artery bypass surgery on cerebral blood flow has not been elucidated. Jugular bulb oxygen saturation is a useful indicator of cerebral blood flow provided that the cerebral metabolic rate is constant. This study was designed to evaluate the changes in jugular bulb oxygen saturation during off-pump coronary artery bypass surgery. METHODS: With IRB approval, 48 patients were included. After anaesthesia, an 18-G catheter was introduced into the jugular bulb. Haemodynamic variables and oxygen profiles from gas analysis of jugular bulb blood and arterial blood were obtained: after sternotomy (baseline); at 5 min after the beginning of the anastomosis of the left anterior descending artery, obtuse marginal artery, and right coronary artery; and after sternal closure. RESULTS: Cardiac index and mixed venous oxygen saturation decreased significantly during anastomosis of all three arteries compared to the baseline value. Although the changes in jugular bulb oxygen saturation during anastomosis were statistically significant compared to its baseline value, jugular bulb oxygen saturation remained within normal limit throughout the study. CONCLUSIONS: Jugular bulb oxygen saturation, which represents the global cerebral oxygenation, was well maintained during the anastomosis of all coronary arteries despite significant haemodynamic changes during off-pump coronary artery bypass (OPCAB). 相似文献
73.
Jiwon An Youn-Woo Lee Woo Young Park Sungchul Park Hyungbae Park Ji Won Yoo Jong Bum Choi 《Journal of anesthesia》2016,30(6):999-1002
Purpose
Anatomic variations complicate surface landmark-guided needle placement, thereby increasing nerve blockade failure rate. However, little is understood about how anatomic distances change under different clinical conditions. As the cricoid cartilage is an easy and accurate landmark, we investigated changes in distance between the sixth or seventh cervical transverse processes (C6TP or C7TP) and the cricoid cartilage in neutral and extended supine positions.Methods
Forty-two patients (16 men, 26 women) were included in this study. Distances between the cricoid cartilage and C6TP/C7TP were measured using ultrasonography with the patient in neutral and extended supine positions.Results
C6TP and C7TP were caudally located at 6.0 ± 8.1 and 15.1 ± 7.2 mm, respectively, from the cricoid cartilage in the neutral supine position, and at 15.2 ± 8.0 and 25.3 ± 8.0 mm, respectively, in the extended supine position. In the extended supine position, the cricoid cartilage was more cephalad than C6TP and C7TP in all patients. The distance from the cricoid cartilage to C6TP was 12.1 ± 7.6 mm in men and 17.2 ± 7.7 mm in women.Conclusion
C6TP and C7TP are located approximately 15 and 25 mm, respectively, caudal to the cricoid cartilage in the extended supine position. Our results highlight the fact that there can be significant anatomic variation between the extended and neutral supine positions used in stellate ganglion block, which should be kept in mind when devising easily identifiable and palpable surface landmarks.74.
75.
R.-E. Yoo S.H. Choi T.M. Kim S.-H. Lee C.-K. Park S.-H. Park I.H. Kim T.J. Yun J.-H. Kim C.H. Sohn 《AJNR. American journal of neuroradiology》2015,36(10):1846
BACKGROUND AND PURPOSE:Subependymal enhancement and DWI have been reported to be useful MR imaging markers for identifying true progression. Our aim was to determine whether the subependymal enhancement pattern and ADC can differentiate true progression from pseudoprogression in patients with glioblastoma multiforme treated with concurrent chemoradiotherapy by using temozolomide.MATERIALS AND METHODS:Forty-two patients with glioblastoma multiforme with newly developed or enlarged enhancing lesions on the first follow-up MR images obtained within 2 months of concurrent chemoradiotherapy completion were included. Subependymal enhancement was analyzed for the presence, location, and pattern (local or distant relative to enhancing lesions). The mean ADC value and the fifth percentile of the cumulative ADC histogram were determined. A multiple logistic regression analysis was performed to identify independent factors associated with true progression.RESULTS:Distant subependymal enhancement (ie, extending >1 cm or isolated from the enhancing lesion) was significantly more common in true progression (n = 24) than in pseudoprogression (n = 18) (P = .042). The fifth percentile of the cumulative ADC histogram was significantly lower in true progression than in pseudoprogression (P = .014). Both the distant subependymal enhancement and the fifth percentile of the cumulative ADC histogram were independent factors associated with true progression (P = .041 and P = .033, respectively). Sensitivity and specificity for the diagnosis of true progression were 83% and 67%, respectively, by using both factors.CONCLUSIONS:Both the distant subependymal enhancement and the fifth percentile of the cumulative ADC histogram were significant independent factors predictive of true progression.Glioblastoma multiforme (GBM) is the most common form of malignant primary brain tumor in adults,1 which is notorious for its intrinsic aggressiveness and a dismal prognosis.2,3 The current standard treatment for GBM is maximal safe tumor resection followed by radiation therapy with concurrent temozolomide (TMZ) and adjuvant TMZ.4Recently, the criteria for assessing therapeutic responses in high-grade gliomas have been updated by the Response Assessment in Neuro-Oncology (RANO) Working Group to address the limitations of the previous guideline.5 For instance, contrast enhancement, which has been regarded as a surrogate marker for tumor progression, has been reassessed as a nonspecific finding merely reflecting the passage of contrast material across a disrupted blood-tumor barrier.6–11 In particular, radiologists and clinicians have increasingly recognized the occurrence of progressive MR imaging lesions immediately after completion of concurrent chemoradiotherapy (CCRT) with TMZ, which spontaneously improved without further treatment other than the adjuvant TMZ.12–14 The treatment-related reaction is termed pseudoprogression and has received attention as a potential pitfall in the response evaluation. At present, owing to the lack of established findings in conventional contrast-enhanced MR imaging for the differential diagnosis of true progression from pseudoprogression,9,10 RANO stresses that the diagnosis of true progression can be made within the first 12 weeks after completion of radiation therapy only if most of the new enhancement is located outside the radiation field or if there is pathologic confirmation of progressive disease.5During the past few decades, there has been extensive effort to identify imaging biomarkers for tumor progression. Among the many parameters derived from advanced MR imaging techniques, DWI has been consistently reported to be helpful in differentiating tumor progression from treatment-related changes or necrosis.15–22 Meanwhile, most previous studies pertaining to the role of conventional MR imaging have not shown promising results.9,23 Nevertheless, a recent study focusing on the conventional MR imaging findings has proposed subependymal enhancement as a useful MR imaging marker for differentiating true progression from pseudoprogression.24 To our knowledge, however, no previous studies have conducted in-depth analysis of the subependymal enhancement, and its potential as an independent predictor for true progression remains elusive.The purpose of the present study was to determine whether the subependymal enhancement pattern and ADC can differentiate true progression from pseudoprogression in patients with GBM treated with radiation therapy and concomitant TMZ. 相似文献
76.
Background The purpose of this study was to identify any differences in the activity patterns of lower extremity muscles with and without
heel contact during stair ascent by women in their twenties wearing high-heeled shoes.
Methods Twenty healthy female subjects wearing high-heeled shoes walked up a step with a height of 20 cm with and without heel contact,
during which the activities of the vastus medialis oblique, vastus lateralis, and gastrocnemius were recorded using surface
electromyography.
Results During stair ascent the activities of the vastus lateralis and vastus medialis oblique were significantly higher and that
of the gastrocnemius significantly lower with high-heel contact than without high-heel contact.
Conclusion We suggest that young women wearing high-heeled shoes should step up with heel contact on the stair surface during stair ascent
to activate the quadriceps muscle. 相似文献
77.
Phil Hyun Song Young Don Kim Hyun Tae Kim Hwa Su Lim Chang Ho Hyun Joon Hyung Seo Eun Sang Yoo Choal Hee Park Hee Chang Jung 《BJU international》2009,104(8):1113-1117
OBJECTIVE
To evaluate the long‐term results and predictive risk factors for efficacy after the tension‐free vaginal tape (TVT) procedure for treating female stress urinary incontinence (SUI).PATIENTS AND METHODS
Inall, 306 women (mean age 50.7 years, sd 8.7) who had a TVT procedure for SUI were selected and followed ≥7 years (mean 92.3 months, range 84–110) after surgery. We analysed the long‐term results, the variables predictive of cure rates, and patient satisfaction.RESULTS
The overall 7‐year cure rate was 84.6%, with a satisfaction rate of 69.3%. The cure rates were lower in patients with high‐grade SUI (50% in grade III, 82.8% in grade II and 90.7% in grade I; P < 0.001). On multivariate analysis, there were no independent risk factors related to cure rate, and urgency was the only factor independently associated with patient satisfaction (P = 0.008; odds ratio 2.47). Seventy‐one patients (23.2%) had complications at the 1‐month follow‐up after surgery, but only eight (2.6%) had complications at the 7‐year follow‐up, including mesh exposure in six and de novo urgency in two.CONCLUSION
The absence of long‐term adverse events associated with the TVT procedure, and high subjective and objective 7‐year success rates with no independent predictive factors affecting the long‐term cure rate, make the TVT procedure a recommendable surgical treatment for female SUI. 相似文献78.
Seung Hwan Lee Joon Chul Kim Ji-Youl Lee Jang Hwan Kim Cheol Young Oh Seung Wook Lee Se Jeong Yoo Byung Ha Chung 《Asian journal of andrology》2009,11(6):663-668
We analyzed the effects of obesity on lower urinary tract symptoms (LUTSs) in Korean benign prostatic hyperplasia (BPH) patients. This is a multicenter, cross-sectional, prospective study conducted in four centers in Korea. A total of 602 men with LUTSs secondary to BPH were included. BPH/LUTSs cases were men aged ≥ 40 years with intemational prostate symptom scores (IPSS) ≥ 8 points. Height, weight and waist circumference were measured. Among the 602 patients, 156 patients had a waist circumference above 90 cm, representing central obesity, and 215 patients had a body mass index above 25 kg m2. Waist circumference was positively correlated with prostate volume (P = 0.034). Men with waist circumference 〉 90 cm experienced a 1.36-fold increased risk of severe LUTSs (95% CI 0.82-2.41) compared with men with waist circumference ≤ 90 cm. Prostate volume was positively correlated with urgency and nocturia in men with central obesity. In this population of Korean men diagnosed with BPH, central obesity rather than overall obesity seems to be the more important predictor of LUTSs correlated with BPH. 相似文献
79.
Ji-Hoon Ok Yang-Soo Kim Jung-Man Kim Tae-Wook Yoo 《Knee surgery, sports traumatology, arthroscopy》2013,21(7):1593-1597
Purpose
To compare the accuracy of ultrasonography and MR arthrography (MRA) imaging in detecting of rotator cuff tears with arthroscopic finding used as the reference standard.Methods
The ultrasonography and MRA findings of 51 shoulders that underwent the arthroscopic surgery were prospectively analysed. Two orthopaedic doctors independently performed ultrasonography and interpreted the findings at the office. The tear size measured at ultrasonography and MRA was compared with the size measured at surgery using Pearson correlation coefficients (r). The sensitivity, specificity, accuracy, positive predictive value, negative predictive value and false-positive rate were calculated for a diagnosis of partial-and full-thickness rotator cuff tears. The kappa coefficient was calculated to verify the inter-observer agreement.Results
The sensitivity of ultrasonography and MRA for detecting partial-thickness tears was 45.5 and 72.7 %, and that for full-thickness tears was 80.0 and 100 %, respectively. The accuracy of ultrasonograpy and MRA for detecting partial-thickness tears was 45.1 and 88.2 %, and that for full-thickness tears was 82.4 and 98 %, respectively. Tear size measured based on ultrasonography examination showed a poor correlation with the size measured at arthroscopic surgery (r = 0.21; p < 0.05). However, tear size estimated by MRA showed a strong correlation (r = 0.75; p < 0.05). The kappa coefficient was 0.47 between the two independent examiners.Conclusions
The accuracy of office-based ultrasonography for beginner orthopaedic surgeons to detect full-thickness rotator cuff tears was comparable to that of MRA but was less accurate for detecting partial-thickness tears and torn size measurement. Inter-observer agreement on the interpretation was fair. These results highlight the importance of the correct technique and experience in operation of ultrasonography in shoulder joint.Level of evidence
Diagnostic study, Level II. 相似文献80.
Hongyoon Choi Min Young Yoo Gi Jeong Cheon Keon Wook Kang June-Key Chung Dong Soo Lee 《Nuclear Medicine and Molecular Imaging》2013,47(3):188-195