全文获取类型
收费全文 | 32576篇 |
免费 | 1411篇 |
国内免费 | 157篇 |
专业分类
耳鼻咽喉 | 260篇 |
儿科学 | 551篇 |
妇产科学 | 316篇 |
基础医学 | 3862篇 |
口腔科学 | 881篇 |
临床医学 | 1928篇 |
内科学 | 7810篇 |
皮肤病学 | 472篇 |
神经病学 | 2646篇 |
特种医学 | 1501篇 |
外科学 | 5732篇 |
综合类 | 180篇 |
一般理论 | 1篇 |
预防医学 | 1092篇 |
眼科学 | 943篇 |
药学 | 2452篇 |
中国医学 | 96篇 |
肿瘤学 | 3421篇 |
出版年
2023年 | 117篇 |
2022年 | 263篇 |
2021年 | 469篇 |
2020年 | 289篇 |
2019年 | 375篇 |
2018年 | 478篇 |
2017年 | 373篇 |
2016年 | 500篇 |
2015年 | 508篇 |
2014年 | 651篇 |
2013年 | 940篇 |
2012年 | 1522篇 |
2011年 | 1705篇 |
2010年 | 938篇 |
2009年 | 805篇 |
2008年 | 1561篇 |
2007年 | 1790篇 |
2006年 | 1848篇 |
2005年 | 1842篇 |
2004年 | 1864篇 |
2003年 | 1694篇 |
2002年 | 1757篇 |
2001年 | 1031篇 |
2000年 | 1016篇 |
1999年 | 921篇 |
1998年 | 512篇 |
1997年 | 419篇 |
1996年 | 399篇 |
1995年 | 300篇 |
1994年 | 310篇 |
1993年 | 258篇 |
1992年 | 623篇 |
1991年 | 586篇 |
1990年 | 562篇 |
1989年 | 537篇 |
1988年 | 475篇 |
1987年 | 464篇 |
1986年 | 459篇 |
1985年 | 443篇 |
1984年 | 294篇 |
1983年 | 230篇 |
1982年 | 148篇 |
1981年 | 131篇 |
1980年 | 120篇 |
1979年 | 210篇 |
1978年 | 147篇 |
1977年 | 131篇 |
1975年 | 109篇 |
1973年 | 109篇 |
1970年 | 115篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
81.
Change in apoptosis in the gastric surface epithelium and glands after eradication of Helicobacter pylori 总被引:4,自引:0,他引:4
K. Satoh H. Kawata K. Tokumaru Y. Kumakura Y. Ishino S. Kawakami K. Inoue T. Kojima Y. Satoh H. Mutoh K. Kihira K. Sugano 《Digestive and liver disease》2003,35(2):78-84
BACKGROUND: Change in apoptosis in gastric glands after eradication of Helicobacter pylori has never been reported. AIMS: The purpose of this paper is to investigate the change in apoptosis in gastric glands after eradication of Heliobacter pylori. PATIENTS AND METHODS: We studied 23 Heliobacter pylori-positive patients with duodenal and gastric ulcers, who were monitored for 6-12 months after eradication, and eight controls. Biopsies were taken from the antrum and body. Apoptosis was evaluated immunohistochemically using anti-single stranded DNA antibody. Apoptotic index was calculated by counting immunostained cells in surface epithelial and glandular cells. RESULTS: In the surface epithelium, Apoptotic indexes were significantly higher in patients than in controls. In the upper portion of fundic glands, apoptotic indexes were significantly higher in patients with gastric ulcers (14.2% (9.3, 17.8)) (median (1st quartile, 3rd quartile)) than in controls (8.0% (2.0, 9.0), p < 0.01) and decreased significantly after eradication (3.4% (2.0, 5.3)), p < 0.01). In pyloric glands, apoptotic indexes were no different between patients and controls. In the lower portion of fundic glands, apoptotic indexes were very low, both in patients and in controls. CONCLUSIONS: Our results showed that apoptosis, not only of surface epithelial cells but also of glandular cells in the upper portion of fundic glands, increased in Heliobacter pylori-positive patients with gastric ulcers and decreased to normal levels after eradication of Heliobacter pylori. 相似文献
82.
M Inoue T Honma T Saitoh T Suyama H Aoki K Matsuki S Hasegawa 《Nihon Kyōbu Shikkan Gakkai zasshi》1991,29(8):978-983
In order to investigate the influence of respiratory frequency in the measurement of specific airway conductance (sGaw) during non-panting breathing, we examined specific airway conductance using a body plethysmograph (BX-82, Minato) in 20 stable pulmonary emphysema patients and 19 normal control subjects. Our body plethysmograph device can measure sGaw automatically without panting by making various corrections using a 16-bit microcomputer. We measured sGaw first at a flow of 0.5 L/sec during both inspiratory and expiratory ventilatory phases, then the respiratory frequency was changed from 0.5 to 1.0, 1.5 and 2.0 Hz. In normal control subjects sGaw, tidal volume and mouth flow significantly changed by increasing respiratory frequency, and there was a significant correlation between sGaw and mouth flow. In pulmonary emphysema patients, tidal volume decreased significantly by increasing respiratory frequency, and there was a significant correlation between sGaw and tidal volume, but sGaw and mouth flow did not change significantly by increasing respiratory frequency. These results suggest that specific airway conductance is influenced by respiratory frequency, possibly due to the change in tidal volume and mouth flow. It is necessary to standardize respiratory frequencies and mouth flows in the measurement of specific airway conductance during non-panting breathing. 相似文献
83.
Five latissimus dorsi musculocutaneous flaps (LD flap) were used for reconstruction with prostheses after resection of tumors between 1984 and 1991 in our hospital. Bony structures were reconstructed with prostheses and in three cases autoclaved autobone grafts were also needed. The prostheses and adjacent grafts were then wrapped by the LD flaps. Tumor sites included one humerus, two thighs, and two knees. All but one case healed primarily. The sole case of infection was successfully treated with debridement and irrigation. Due to the LD flaps' plentiful blood supply, we believe infection of the prosthetics can be avoided and good clinical results can be achieved using the flap with autoclaved autograft prosthetic composite reconstruction. © 1994 Wiley-Liss, Inc. 相似文献
84.
85.
S Nanto K Kodama Y Kimura T Masuyama M Mishima Y Hamanaka M Hori M Inoue 《Japanese circulation journal》1988,52(2):155-161
We examined the effects of a new inotrope, OPC-8212 (OPC: 2(1H)-quinolinone), on coronary sinus flow (CSF), myocardial oxygen consumption, myocardial lactate extraction ratio (LER), cardiac index (CI) and pulmonary arterial diastolic pressure (PADP) in eleven patients with prior myocardial infarction. Measurements were taken before (control) and 8 hours after administration of OPC (480 mg, p.o.). A cardiac function curve was obtained in each stage with rapid intravenous administration of 500 ml of saline (loaded state) after baseline measurements. There was a significant increase in the cardiac index and decrease in the pulmonary arterial diastolic pressure in the loaded state after OPC. Thus the ventricular function curve was shifted to the left and showed a steep incline, indicating an increased inotropic state. On the other hand, myocardial oxygen consumption and myocardial lactate extraction ratio were unchanged. Thus we concluded that OPC improved cardiac performance without increasing myocardial oxygen consumption. 相似文献
86.
Shigeru Fukuzawa Shun Ozawa Masayuki Inagaki Toshihiro Inoue Shigeru Morooka Juji Sugioka 《Annals of nuclear medicine》1996,10(2):231-235
Tc-99m tetrofosmin is a lipophilic, cationic perfusion imaging agent that changes to Tl-201 in detecting coronary artery disease during exercise testing. The purpose of this study is to evaluate the usefulness of Tc-99m tetrofosmin dipyridamole stress imaging combined with low level exercise for the detection of coronary artery disease. We examined 42 patients and 10 normal volunteers who also underwent coronary angiography. A one-day protocol was used: in the stress study, 296 MBq of tetrofosmin was injected and in the rest study 888 MBq was injected. After intravenous administration of dipyridamole (0.142 mg/kg/min for 4 minutes), the patient was exercised on a bicycle ergometer for 3 min (25 Watts). Tetrofosmin was injected 2 minutes after dipyridamole infusion during the exercise. Single photon emission computed tomographic images were obtained 30 minutes after the tracer injection. Images were interpreted as abnormal in 36 of 42 patients with coronary artery disease, and normal in all of 10 normal volunteers. The overall sensitivity of detection of coronary artery disease was 83.3% and the normalcy rate was 100%. The diagnostic values for the detection of significant stenosis in the three major arteries were: LAD sensitivity 83%, specificity 92%; LCX sensitivity 47%, specificity 91%; RCA sensitivity 75%, specificity 83%. Of the 66 arteries with more than 50% stenosis, 48 arteries were correctly identified. Of the 36 with more than 70% stenosis, 31 were identified. Scintigraphic evidence of multivessel disease was found in only 9 patients (50%). A protocol of Tc-99m tetrofosmin SPECT combined with low level exercise after dipyridamole is therefore useful for the detection of the coronary artery disease. 相似文献
87.
Difference between substance P- and acetylcholine-induced currents in mammalian smooth muscle cells.
The effects of substance P (SP) and acetylcholine (ACh) on membrane currents were compared using freshly isolated smooth muscle cells from guinea-pig ileum. Both SP (100 nM) and ACh (10 microM) induced inward currents at negative holding potentials. The ACh-induced current, but not the SP-induced current, showed relaxation upon voltage-stepping. The SP-induced current was increased by hyperpolarization more negative than -50 mV whereas the ACh-induced current was decreased by hyperpolarization. The results suggest that the SP-induced inward current is elicited via an ionic pathway different from that involved with ACh-activated channels. 相似文献
88.
89.
Kazuo Okura Takafumi Kato Jacques Y Montplaisir Barry J Sessle Gilles J Lavigne 《Clinical neurophysiology》2006,117(2):269-278
OBJECTIVE: The aim of this study was to make a quantitative analysis of the changes in cranial and limb muscle activity from wakefulness to light and deep sleep stages and during rapid eye movement (REM) sleep of normal subjects. METHODS: Polysomnographic recordings were made of the sleep of 9 healthy human subjects, including electromyograms of the suprahyoid, temporalis and masseter cranial muscles and the anterior tibialis limb muscle. Quantitative assessments of EMG activity were carried out with root mean square (RMS) and frequency-spectral analysis (FSA) methods. RESULTS: From wakefulness to sleep, a significant reduction (-25.2 to -71.2%; P < 0.01) was observed in EMG activity (for both RMS and FSA) of the 3 cranial muscles using both methods of analysis. The EMG activity of suprahyoid muscle further decreased from non-REM to REM sleep (-17.8 to -43.0%; P < 0.01). In contrast, the EMG activity of the anterior tibialis muscle was only slightly reduced across sleep stages and did not further reduce during REM sleep. During REM sleep, all the 4 muscles maintained minimal activity. CONCLUSIONS: The maintenance of muscle activity during REM sleep suggests that a minimal level of activity is required to preserve physiological functions (e.g. airway patency, posture) related to homeostasis and bodily protection. SIGNIFICANCE: This study suggests that quantitative sleep EMG analysis is important for understanding the mechanisms of sleep-related movement disorders or when objective assessment of changes in EMG activity are needed for diagnostic purposes or for the assessment of drug efficiency. 相似文献
90.
Tsunao Imamura Rie Takeshita Rikako Koyama Chikao Okuda Kazuo Takeuchi Masamichi Matsuda Masashi Hashimoto Goro Watanabe Hitoshi Yoshida Michio Imawari 《Digestive endoscopy》2006,18(4):303-307
Background: Pancreatic carcinoma is one of the most lethal cancers. Because pancreatic carcinoma is still very difficult to diagnose in its early stage, many of these patients will be considered unsuitable for surgery. If a cytological diagnosis is obtained at initial endoscopic retrograde cholangiopancreatography (ERCP), suitable treatment will be initiated without delay. Methods: To increase the number of exfoliated cells from the pancreatic duct, we devised a new technique, pancreatic duct lavage fluid (PDLF), following bronchoalveolar lavage fluid. The present paper reports the effectiveness of cytological examination using PDLF in the diagnosis of pancreatic carcinoma. We examined 18 pancreatic carcinoma cases. After the endoscopic retrograde pancreatography (ERP), PDLF was collected from a double‐lumen catheter inserted into the main pancreatic duct. Saline injected from the lumen for the injection, and PDLF was aspirated from the other lumen for the guidewire at the same time. The cytological examination was performed using PDLF. Results: Exfoliated cells were more frequently found in PDLF from all patients. In 15 cases (83%), cytological examination of PDLF revealed positive cytological results as the diagnosis of pancreatic carcinoma. Conclusion: Cytological examination using PDLF has a high sensitivity for detection of pancreatic carcinoma. The new examination, PDLF, is simple, safe and effective, so we expect PDLF to become widely popular. 相似文献