全文获取类型
收费全文 | 12531篇 |
免费 | 949篇 |
国内免费 | 451篇 |
专业分类
耳鼻咽喉 | 57篇 |
儿科学 | 218篇 |
妇产科学 | 381篇 |
基础医学 | 439篇 |
口腔科学 | 73篇 |
临床医学 | 4752篇 |
内科学 | 1890篇 |
皮肤病学 | 81篇 |
神经病学 | 358篇 |
特种医学 | 774篇 |
外国民族医学 | 3篇 |
外科学 | 1463篇 |
综合类 | 2075篇 |
预防医学 | 319篇 |
眼科学 | 164篇 |
药学 | 384篇 |
4篇 | |
中国医学 | 61篇 |
肿瘤学 | 435篇 |
出版年
2024年 | 92篇 |
2023年 | 321篇 |
2022年 | 405篇 |
2021年 | 536篇 |
2020年 | 545篇 |
2019年 | 585篇 |
2018年 | 379篇 |
2017年 | 398篇 |
2016年 | 355篇 |
2015年 | 398篇 |
2014年 | 647篇 |
2013年 | 622篇 |
2012年 | 534篇 |
2011年 | 760篇 |
2010年 | 640篇 |
2009年 | 562篇 |
2008年 | 596篇 |
2007年 | 639篇 |
2006年 | 751篇 |
2005年 | 612篇 |
2004年 | 546篇 |
2003年 | 508篇 |
2002年 | 452篇 |
2001年 | 379篇 |
2000年 | 225篇 |
1999年 | 221篇 |
1998年 | 282篇 |
1997年 | 170篇 |
1996年 | 143篇 |
1995年 | 126篇 |
1994年 | 98篇 |
1993年 | 62篇 |
1992年 | 63篇 |
1991年 | 55篇 |
1990年 | 55篇 |
1989年 | 34篇 |
1988年 | 27篇 |
1987年 | 16篇 |
1986年 | 15篇 |
1985年 | 6篇 |
1984年 | 15篇 |
1983年 | 11篇 |
1982年 | 10篇 |
1981年 | 7篇 |
1980年 | 6篇 |
1979年 | 4篇 |
1978年 | 6篇 |
1977年 | 5篇 |
1975年 | 4篇 |
1973年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
The common ultrasonographic features of pilomatricoma. 总被引:3,自引:0,他引:3
OBJECTIVES: The purpose of this series was to describe typical ultrasonographic features of 20 cases of pilomatricoma and to improve its diagnostic rate with the use of an ultrasonographic approach. METHODS: For 20 pilomatricomas in 19 patients with preoperative ultrasonography from 1995 to 2004, we reviewed age, sex, symptoms, duration, referring clinician, and tumor sites. The ultrasonographic findings were retrospectively analyzed for tumor location, shape, size, margin, echo texture, echogenicity, presence, amount, and shape of calcification, presence of a hypoechoic rim, and Doppler flow pattern. RESULTS: The mean age of the 19 patients was 6.9 years (range, 1-21 years), and the female-male ratio was 1.1:1. Patients had a painful palpable mass in 10 cases (50%). Nine lesions occurred in the neck, 5 in the cheek, 2 in the preauricular region, and 4 in the extremity. All tumors were located in the subcutaneous layer. The mean size of the tumors was 13.4 mm. Fourteen pilomatricomas (70%) appeared as well-defined oval masses. Tumors were heterogeneously hyperechoic in 80% of cases. All tumors had internal echogenic foci. A hypoechoic rim was seen in 17 cases (85%). Doppler flow signals were observed in the peripheral region in 14 cases (70%). A correct preoperative diagnosis was made in 33% on the basis of clinical findings and in 76% by ultrasonography. CONCLUSIONS: Diagnosis of pilomatricoma should be considered when a well-defined mass with inner echogenic foci and a peripheral hypoechoic rim or a completely echogenic mass with strong posterior acoustic shadowing in the subcutaneous layer of the head, neck, or extremity is found on ultrasonography. 相似文献
62.
Kenji Yamao Atsushi Irisawa Hiroyuki Inoue Koji Matsuda Mitsuhiro Kida Shomei Ryozawa Yoshiki Hirooka Teruo Kozu 《Digestive endoscopy》2007,19(Z1):S180-S205
Standard imaging techniques using a curved linear array echoendocope are summarized to facilitate the attainment of expertise in endoscopic ultrasonography and endoscopic ultrasound‐guided fine needle aspiration, and to promote the widespread use of this diagnostic and therapeutic tool. Typical images of the mediastinal organs, the bilio‐pancreatic systems and neighboring organs by scanning from the esophagus, stomach, duodenal bulb, and descending portion of the duodenum, are shown in a sequential manner. The basic techniques of endoscopic ultrasound‐guided fine needle aspiration are also presented. 相似文献
63.
O. John Ma MD Michael P. Kefer MD James R. Mateer MD RDMS Beth Thoma MD 《Academic emergency medicine》1995,2(7):581-586
Objective: To compare the sensitivities, specificities, and accuracies between a single-view ultrasonography (US) technique and a multiple-view technique for identifying hemoperitoneum in multiple-trauma patients.
Methods: Data from a prior prospective study of US for trauma diagnosis at a level I trauma center were retrospectively analyzed. A convenience sample of adult patients (≥ 18 years of age) who had presented with major blunt or penetrating torso trauma and had undergone rapid trauma US examinations to detect hemoperitoneum were reviewed. The US interpretations by emergency physicians had been recorded prior to obtaining other diagnostic tests. Five views were evaluated, including the right intercostal oblique view examining Morison's pouch. Evidence of free intraperitoneal fluid by exploratory laparotomy, CT, or diagnostic peritoneal lavage (DPL) was used as the criterion standard.
Results: Of the 245 patients entered into the study, 37 had free intraperitoneal fluid, confirmed by CT, DPL, or exploratory laparotomy. With the multiple-view technique, US was 87% (95% CI = 71%, 96%) sensitive, 100% (95% CI = 97%, 100%) specific, and 98% (95% CI = 95%, 100%) accurate. The single-view technique, evaluating only Morison's pouch, was 51% (95% CI = 34%, 68%) sensitive, 100% (95% CI = 98%, 100%) specific, and 93% (95%. CI = 89%, 96%) accurate.
Conclusions: An initial trauma US examination using a multiple-view technique is more sensitive than that using a single-view technique for detecting hemoperitoneum in trauma patients. 相似文献
Methods: Data from a prior prospective study of US for trauma diagnosis at a level I trauma center were retrospectively analyzed. A convenience sample of adult patients (≥ 18 years of age) who had presented with major blunt or penetrating torso trauma and had undergone rapid trauma US examinations to detect hemoperitoneum were reviewed. The US interpretations by emergency physicians had been recorded prior to obtaining other diagnostic tests. Five views were evaluated, including the right intercostal oblique view examining Morison's pouch. Evidence of free intraperitoneal fluid by exploratory laparotomy, CT, or diagnostic peritoneal lavage (DPL) was used as the criterion standard.
Results: Of the 245 patients entered into the study, 37 had free intraperitoneal fluid, confirmed by CT, DPL, or exploratory laparotomy. With the multiple-view technique, US was 87% (95% CI = 71%, 96%) sensitive, 100% (95% CI = 97%, 100%) specific, and 98% (95% CI = 95%, 100%) accurate. The single-view technique, evaluating only Morison's pouch, was 51% (95% CI = 34%, 68%) sensitive, 100% (95% CI = 98%, 100%) specific, and 93% (95%. CI = 89%, 96%) accurate.
Conclusions: An initial trauma US examination using a multiple-view technique is more sensitive than that using a single-view technique for detecting hemoperitoneum in trauma patients. 相似文献
64.
本文报道15例经病理证实的肝脏良性实质性肿瘤,其声像图特征包括;(1)边界清晰;(2)外形不规则;(3)内回声不均质;(4)周围血管无浸润及栓塞症像.本组B型超声术前确诊10例,定位错误2例,定性错误3例.文中认为正确识别声像图上的特征有利于肝肿瘤的鉴别诊断. 相似文献
65.
66.
Effects of cholestyramine on gallbladder and gastric emptying in obese and lean subjects 总被引:3,自引:0,他引:3
P. PORTINCASA † A. DI CIAULA V. PALMIERI G. P. VAN BERGE-HENEGOUWEN† G. PALASCIANO 《European journal of clinical investigation》1995,25(10):746-753
Abstract. Gallbladder stasis is frequent in obese subjects and may contribute to their increased risk for gallstone formation. The bile salt sequestrant cholestyramine acutely enhances postprandial gallbladder emptying in lean subjects, through dis-inhibition of a negative feedback between intraluminal bile salts and CCK release. In this study the effect of cholestyramine on both gallbladder and gastric antrum dynamics were studied by realtime ultrasonography in 12 obese and 15 lean subjects. For the acute study, on different days, subjects ingested a liquid meal (two egg yolks plus water 200 mL, 50 kJ) or a meal with 4g cholestyramine. Gallbladder emptying was impaired in obese patients who had significantly larger fasting gallbladder volume (39.4 ± 6.9 vs. 21.6 ± l.7mL, P <0.02), larger residual volume (12.3 ± 1.8 vs. 4.0 ± 0.5ml, P < 0.0006) and slower emptying time ( T /2: 33 ± 2 vs. 21 ± 2 min, P < 0.05) than lean subjects. Integrated antral emptying was also less in obese than lean subjects (5521 ± 578 vs. 7908 ± 491 % 120min-1 , P <0.02). Cholestyramine enhanced postprandial gallbladder emptying in both obese and lean subjects. Gastric emptying was delayed with cholestyramine in lean but not obese subjects. For the chronic study, after 1 month therapy with cholestyramine (4 g every 2 days), the motility tests were repeated in nine obese subjects. Gallbladder and gastric responses to a test meal, with or without cholestyramine, were preserved. We conclude that both gallbladder and antral emptying of a liquid test meal are impaired in obese subjects. Gallbladder emptying improves after acute administration of a low dose cholestyramine with test meal. This effect is sustained after 1 month treatment with a low dose of cholestyramine and does not interfere with gastric emptying of obese patients. Cholestyramine may improve gallbladder hypomotility in obese people. 相似文献
67.
高频彩超对颈部淋巴结囊性病变的诊断价值 总被引:2,自引:2,他引:0
①目的探讨高频彩超对颈部淋巴结囊性病变的诊断价值。②方法回顾性分析25例颈部淋巴结囊性病变的高频彩超表现。③结果颈部淋巴结囊性病变见于颈淋巴结囊性转移瘤、化脓性淋巴结炎及淋巴结结核。其中13例为颈部淋巴结囊性转移瘤,其特征性超声表现为颈部淋巴结囊性肿大,伴囊壁实性结节;较大囊壁结节内常可探及动脉血流信号,部分囊壁结节可见微钙化。7例为颈部急性化脓性淋巴结炎,其主要超声表现为上颈部淋巴结呈单发、圆形囊性肿大;囊壁略厚,且较均匀;囊液呈细密点状回声。5例为颈部淋巴结干酪脓肿型结核,其主要超声表现为单侧或双侧中下颈部淋巴结呈多发、椭圆形囊性肿大,部分可融合成团;内壁毛糙,囊液内散在分布点状高回声。④结论高频彩超检查对颈部淋巴结囊性病变的诊断和鉴别诊断具有重要价值。 相似文献
68.
目的 探讨阴茎折断伤的病因和诊治。方法 对2l例阴茎折断伤的临床资料进行回顾性分析。结果 致伤原因以粗暴性交13例,手淫5例,跌伤、撞击伤各l例,拒绝说明原因l例。B超确诊12例,阴茎海绵体造影确诊l例。12h内手术13例,超过12h手术3例,保守治疗5例。12h内手术组有2例发生阴茎白膜硬结,术后性功能正常;超过12h手术组和保守治疗组各有l例和2例并发阴茎硬结、阴茎成角畸形和勃起功能障碍。结论 阴茎折断致伤原因以粗暴性交和手淫为主;B超检查是诊断阴茎折断首选方法;早期手术能减少其并发症的发生;术中采用纵行小切口容易准确找到白膜破裂位置,且创伤小,适于临床应用。 相似文献
69.
Objective To obtain a general overview of gallstone disease in Shanghai. Methods 3415citizens aged >20 in the community of Shanghai were randomly selected to undergo a clinical epidemiological study and an ultrasound examination to screen for cholelithiasis. Results Overall prevalence rate of gallstones was 6.5% (8.6% in women and 5.1% in men). Among the 3415 persons investigated, 65 had already undergone cholecystectomy. The percentage of asymptomatic gallstone was 70 .5% . Prevalence of gallstone diseases (gallstones plus cholecystectomy) increased with age significantly. Conclusion Compared to the research in Shanghai ten years ago, especially for the persons older than 50 years, the gallstone disease has become more frequent. The proportion of asymptomatic gallstones and the awareness is increasing. 相似文献
70.