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   694篇
  免费   16篇
耳鼻咽喉   5篇
儿科学   47篇
妇产科学   17篇
基础医学   77篇
口腔科学   10篇
临床医学   81篇
内科学   152篇
皮肤病学   23篇
神经病学   41篇
外科学   123篇
综合类   9篇
预防医学   14篇
眼科学   3篇
药学   50篇
中国医学   3篇
肿瘤学   55篇
  2022年   5篇
  2021年   9篇
  2017年   3篇
  2016年   3篇
  2015年   12篇
  2014年   13篇
  2013年   10篇
  2012年   10篇
  2011年   4篇
  2010年   15篇
  2009年   22篇
  2008年   9篇
  2007年   7篇
  2006年   33篇
  2005年   23篇
  2004年   14篇
  2003年   16篇
  2002年   12篇
  2001年   10篇
  2000年   5篇
  1999年   11篇
  1998年   41篇
  1997年   40篇
  1996年   30篇
  1995年   41篇
  1994年   30篇
  1993年   21篇
  1992年   16篇
  1991年   14篇
  1990年   3篇
  1989年   11篇
  1988年   7篇
  1987年   3篇
  1986年   9篇
  1985年   8篇
  1984年   11篇
  1982年   2篇
  1981年   5篇
  1980年   3篇
  1979年   3篇
  1978年   2篇
  1977年   4篇
  1976年   3篇
  1959年   7篇
  1958年   21篇
  1957年   30篇
  1956年   38篇
  1955年   30篇
  1954年   22篇
  1948年   4篇
排序方式: 共有710条查询结果,搜索用时 312 毫秒
131.
summary Periodontal jaw reflex, duration of percussion sounds, tooth mobility, and time-moment analysis of occlusal contacts by the T-scan system was recorded in nine periodontally healthy volunteers. The results showed that (i) reflex responses to the pressure applied to the uppercentageral incisors in the lingolabial direction varied, depending on the background jaw-clenching force (BCF) of the same-sided first molars. The BCF levels to elicit excitatory reflexes were 6–8Kgf, and inhibitory reflexes were clearly elicited with a BCF of l0Kgf and beyond. (ii) Duration of percussion sounds via an occlusal sound analyser (4.73–4.84mS: upper first molars. 4.89–5.00mS: uppercentageral incisors) and tooth mobility using a 'Periotest' (3.3–3.5: upper first molars, 5.5–5.6: uppercentageral incisors) showed a normal value. (iii) The time moments of occlusal contacts were symmetrical toward the midsagittal axis of the occlusal plane. The centre of the anterioposteriol occlusal contacts was located in the first molar regions.  相似文献   
132.
AIM: There is increasing evidence that non-steroidal anti-inflammatory drugs are effective for the treatment of nocturia. In this study, we attempted to investigate the role of loxoprofen sodium (loxoprofen) in the therapeutic management of patients with nocturia. METHODS: Fifteen benign protastatic hyperplasia and/or overactive bladder patients (13 males and 2 females, 71.1 +/- 1.5 years old) with three or more voids per night were involved. These patients had received standard drug therapy. Although these patients had received standard drug therapy for more than half a year, they had still three or more episodes of nocturia. The patients took a single dose of 60 mg of loxoprofen at night prior to sleep. Before and 1 week after the initiation of this therapy, the effects of this treatment were assessed by frequency volume chart and a questionnaire. RESULTS: In the questionnaire, seven patients answered as excellent, six patients demonstrated improvement of their symptoms, two patients did not show a significant change in their symptoms and no patients demonstrated a deterioration in the symptoms. In frequency volume chart, total void per day, total void per night, total urine volume per day, total night urine volume per day and single voided volume in the night before and after this treatment were 9.97 +/- 0.81 and 8.99 +/- 0.74 per day, 3.82 +/- 0.25 and 1.82 +/- 0.27 per night, 1349 +/- 81 and 1258 +/- 91 mL per day, 567 +/- 46 and 325 +/- 51 mL per night, and 143 +/- 13 and 149 +/- 10 mL, respectively. CONCLUSION: Loxoprofen can be effective and useful for patients with nocturia. Our data suggest that the main mechanism of this effect is to decrease urine production during a night's sleep.  相似文献   
133.
Anterograde concealed conduction into the concealed accessory atrioventricular (AV) pathway has been postulated to be one of the factors preventing the reciprocating process via the accessory pathway in patients with the concealed Wolff-Parkinson-White(WPW) syndrome but its presence has not been documented. To demonstrate the occurrence of anterograde concealment, 12 patients with the concealed WPW syndrome were selected for study. A pacing protocol was designed in which the retrograde conduction of the ventricular extrastimulus over the accessory pathway was assessed during ventricular pacing aione (conventional method) and during the AV simultaneous pacing (simultaneous method); the results were then compared. When the high right atrium was simultaneously paced, the effective refractory period of the concealed accessory pathway shortened as compared with the conventional method in five of 12 patients (from 341.7 ± 110.8 to 312.5 ± 108.2 msec, n = 12), whereas, it decreased in all patients studied when the coronary sinus near the accessory pathway was simultaneously paced (from 375.7 ± 135.0 to 287. ± 116.1 msec, n = 7). These results demonstrate that the AV simultaneous pacing frequently shortens the refractoriness of the concealed accessory AV pathway and such facilitation seems to he well explained by the probable anterograde concealment in it and peeling back of the refractory barrier.  相似文献   
134.
Abstract: Laser application in gastrointestinal endoscopy started with the development of flexible optical fibers in about 1970. Originally, non-contact irradiation with high power Nd: YAG lasers of 100 watts (W) was used for gastrointestinal hemostasis. It was difficult to achieve safe and reliable irradiation with this method, the quarts fiber tips were susceptible to coagulation damage, and the cost was high. As a result local injections were recognized as an inexpensive and excellent method of producing hemostasis, and became the treatment of first choice. Therefore, the endoscopic use of lasers shifted from hemostasis to the topical treatment of tumors. In 1984 low-power Nd: YAG laser irradiation at 1 to 30W became possible using a ceramic contact probe co-developed by the authors and the Surgical Laser Technology Japan Co. This made photocoagulation, vaporization, cutting and local hyperthermia (Laserthermia) feasible. Improvements in laser irradiation efficiency led to the development of inexpensive equipment, costing less than one-third of the price of conventional equipment. The application of low-power contact lasers significantly improved the clinical efficacy of the treatment of minute cancers, but the technique has the same limitations as other endoscopic methods. Furthermore, because laserthermia is still being developed, the best technique has not yet been fully defined. In the future, treatments that can be used effectively in association with low-power contact laser therapy need to be identified. Low-power contact laserthermia, local hyperthermia with microwaves, and photodynamic therapy with excimer dye lasers all need to be studied further. This will contribute to the development of a minimum invasive therapy for gastrointestinal lesions.  相似文献   
135.
PURPOSE: Thirty-nine renal cell carcinoma patients with bony metastasis were intensively treated, primarily with immunotherapy using natural type interferon-alpha (IFN-alpha) continuous subcutaneous injection in combination with surgical resection and radiation therapy. Long-term survival was achieved, including three patients with complete response. The results of this study are presented. METHODS: The mode of administration of IFN-alpha was as follows: natural-type IFN-alpha (25,000,000 IU) was dissolved in 60 mL of distilled water and administered via continuous subcutaneous injection (0.5 mL/h) as 'one course of the treatment'. Two courses of IFN-alpha therapy were given 2 weeks preoperatively, while 13 courses of IFN-alpha therapy were given postoperatively (one course per week). Thus, 15 courses of IFN-alpha therapy were administered during the trial period. Thereafter, IFN-alpha therapy was repeated either every week or every other week depending on the condition of the patient. Additionally, blood levels of IFN-alpha were monitored for four patients following initiation of IFN-alpha continuous subcutaneous injection therapy. RESULTS: Immediately after injection of IFN-alpha, blood levels of IFN-alpha started to rise, reaching 40.5 IU/mL on average at 24 h after initiation of IFN-alpha therapy. Thereafter, blood levels of IFN-alpha remained high and measurable blood levels of IFN-alpha were maintained for up to 24 h after completion of IFN-alpha injection. As a whole, IFN-alpha was detectable for 6-8 days and Cmax (maximum blood concentration of IFN) was 167 IU/mL. Thirty-nine patients with bony metastases were treated as follows: IFN mono-therapy (19 patients), IFN and radiation therapy (15 patients) and IFN and surgical resection of bony metastases (five patients). Fourteen patients survived and the details of these 14 patients are as follows: complete response in three cases, partial response in two, no change in six and progressive disease in three. Twenty-five patients died of renal cell carcinoma. The overall 5-year survival rate was 35.0%. CONCLUSIONS: These findings indicate that IFN-alpha continuous subcutaneous injection therapy is a useful modality for renal cell carcinoma patients with bony metastasis if administered in combination of radical nephrectomy and radiation therapy.  相似文献   
136.
We evaluated the clinical usefulness of a protein induced by vitamin K absence, antagonist-prothrombin (PIVKA-II), in detecting hepatocellular carcinoma (HCC) specifically in patients with liver cirrhosis, and the possible correlation between levels of PIVKA-II and pathological features of HCC. Plasma levels of PIVKA-II and alpha-fetoprotein (AFP) were measured in 628 patients with various diseases, including 253 with liver cirrhosis and 116 with HCC. PIVKA-II was detected (greater than or equal to 0.1 arbitrary unit/mL) in 54.3% of HCC and the concentration showed a positive correlation with the tumour size. As a screening test for the detection of HCC, PIVKA-II produced values comparable with those of AFP with a sensitivity, specificity and validity of 52.8, 98.8 and 51.6% respectively. Sixteen of 45 patients (37%) with HCC who had low AFP (less than 100 ng/mL) levels were positive for PIVKA-II. No apparent relationship, however, could be found between the levels of PIVKA-II and the aetiology or pathological findings of HCC. These results suggest that PIVKA-II can be a reliable marker for detecting HCC in patients with liver cirrhosis.  相似文献   
137.
Abstract The rat with congenital osteochondrodysplasia with systemic subcutaneous edema (ocd/ocd) dies shortly after parturition. The cause of death has not been fully understood in the similar lethal disorders in other species. The present study describes the morphological abnormalities in the respiratory tract in relation to the cause of death in ocd/ocd. Mid saggital section of the respiratory tract of the ocd/ocd neonate revealed that the air flow from nose to lung is disturbed by occlusion of the pharynx and larynx area with the cleft palate and relatively large tongue. Smaller thoracic volume was also noted in the ocd/ocd neonate. Of intra-thoracic organs, only the lung showed significantly smaller weight in the ocd/ocd neonate than that of phenotypically normal (+/quest;). Histology of the fetal and neonatal lung showed atelectasis and many small alveolar cavities with abundant lung surfactants in the ocd/ocd. Disarrangement of the cells composing the alveolar wall was also revealed in the ocd/ocd. Electron microscopy of the fetal lung demonstrates the lamella bodies in the alveolar cavities and the pneumocyte type II cells in both genotypes. Insufficiency of the surfactant was excluded for the cause of death in the ocd/ocd.  相似文献   
138.
Abstract: Phlebosclerosis of the mesenteric vein is a rare cause of ischemic colitis. The current report includes two patients with segmental ischemic colitis associated with marked calcifications of the mesenteric vessels. No evidence of systemic vasculitis, tuberculosis nor amyloidosis was observed. The patients were previously healthy and had no history of drug use of any kind. Clinical findings included abdominal pain in the right upper quadrant and diarrhea alternating with constipation, and colonic narrowing were discoverd by barium enema. An abdominal X-ray examination revealed some patchy calcifications in the right and left upper quadrants. An angiography of the superior mesenteric artery revealed sclerosis of the artery, disturbance of colonic blood flow, and calcifications of the mesenteric vessels. The patients were treated with an anticoagulant. In follow-up studies, barium enema and colonoscopy revealed a gradual progression of the disease over the last five years. Treatment with an anticoagulant may have prevented rapid advancement of the disease and thereby eliminated the need for emergency operations. These unusual venous lesions have been rarely reported, and their etiology and pathogenesis remain unknown.  相似文献   
139.
Abstract All night polysomnographic evaluation (PSG) soon after admission and at the late period of admission revealed an atypically high sleep efficiency and a prolonged total sleep time. Sleep onset latency and distribution of REM and NREM sleep stages were like those of normal sleepers. On REM latency, while it was remarkably reduced (25.0 min) soon after admission and sleep onset REM period (SOREMP) was found, at the late period of admission it was prolonged and SOREMP was not found. Giving multiple sleep latency test with polysomnography, soon after admission subjective excessive daytime sleepiness had already improved and mean sleep latency (13.2 min) was within normal range. However, SOREMP appeared twice in five tests. We considered that the appearance at the early period of admission was the result of REM pressure growing.  相似文献   
140.
Laparoscopic adrenalectomy in patients with large adrenal tumors   总被引:4,自引:0,他引:4  
OBJECTIVES: The maximum size of adrenal tumors that should be removed by laparoscopic adrenalectomy is controversial. We conducted a retrospective comparison of the results of laparoscopic adrenalectomy between patients with adrenal tumors > or =6 cm ('large tumors') and patients with adrenal tumors <6 cm ('small tumors'). METHODS: The participants in the study were 16 patients with large tumors and 111 patients with small tumors. The patients comprised 59 men and 68 women (mean age, 49.0 years; age range, 23-79) with varying diagnoses. Of the 16 patients with large tumors, five had Cushing's syndrome, four had pheochromocytomas, six had a non-functional tumor and one had malignant lymphoma. Adrenal tumors were confirmed by hormonal assays, biochemical tests and computed tomography. Of the 16 large tumors, five tumors were on the right and 11 were on the left. RESULTS: We found no significant differences in general demographic parameters between patients with large and small tumors. The mean duration of surgery was not significantly different between two groups. (large tumors, 210 min; small tumors,175 min). The mean volume of blood loss was 212 mL for large tumors and 30 mL for small tumors (P < 0.001, significant difference). There was no significant difference in time until walking, duration of hospitalization or number of using analgesics used. The time to first oral intake of group 1 (<6 cm) was significantly shorter than group 2 (> or =6 cm). Tumor size (> or =7.5 cm) was an independent predictor of a longer operation and greater blood loss in large tumors. CONCLUSIONS: Laparoscopic adrenalectomy for large tumors was safe and minimally invasive.  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