全文获取类型
收费全文 | 8450篇 |
免费 | 575篇 |
国内免费 | 93篇 |
专业分类
耳鼻咽喉 | 69篇 |
儿科学 | 206篇 |
妇产科学 | 396篇 |
基础医学 | 931篇 |
口腔科学 | 189篇 |
临床医学 | 1041篇 |
内科学 | 1726篇 |
皮肤病学 | 75篇 |
神经病学 | 711篇 |
特种医学 | 270篇 |
外科学 | 1093篇 |
综合类 | 229篇 |
一般理论 | 4篇 |
预防医学 | 472篇 |
眼科学 | 184篇 |
药学 | 706篇 |
中国医学 | 83篇 |
肿瘤学 | 733篇 |
出版年
2023年 | 46篇 |
2022年 | 107篇 |
2021年 | 183篇 |
2020年 | 105篇 |
2019年 | 177篇 |
2018年 | 213篇 |
2017年 | 178篇 |
2016年 | 176篇 |
2015年 | 245篇 |
2014年 | 288篇 |
2013年 | 378篇 |
2012年 | 552篇 |
2011年 | 628篇 |
2010年 | 418篇 |
2009年 | 348篇 |
2008年 | 508篇 |
2007年 | 500篇 |
2006年 | 519篇 |
2005年 | 460篇 |
2004年 | 401篇 |
2003年 | 335篇 |
2002年 | 300篇 |
2001年 | 270篇 |
2000年 | 226篇 |
1999年 | 192篇 |
1998年 | 72篇 |
1997年 | 69篇 |
1996年 | 66篇 |
1995年 | 49篇 |
1994年 | 37篇 |
1993年 | 39篇 |
1992年 | 112篇 |
1991年 | 117篇 |
1990年 | 96篇 |
1989年 | 72篇 |
1988年 | 71篇 |
1987年 | 73篇 |
1986年 | 47篇 |
1985年 | 41篇 |
1984年 | 33篇 |
1983年 | 35篇 |
1981年 | 24篇 |
1980年 | 18篇 |
1979年 | 27篇 |
1978年 | 33篇 |
1977年 | 18篇 |
1975年 | 18篇 |
1974年 | 26篇 |
1973年 | 17篇 |
1968年 | 18篇 |
排序方式: 共有9118条查询结果,搜索用时 15 毫秒
991.
Tadpoles from a single clutch of Rana pipiens eggs were cultured at different temperatures in order to achieve at a single time a broad span of developmental stages (I+ through XII) and sizes (20–60 mm). They were placed in dl-thyroxine solutions at concentrations of 50 μg/liter, and maintained at 23°C, until death ensued (approximately 14 days for the largest, and 22 days for the smallest, animals). Initially all animals grew, the larger animals less than the smaller. Tail shortening occurred in all, with latent periods being least in the large and greatest in the small tadpoles. Also, changes in limb characteristics (a measure of metamorphic progress) were much greater in the small than in the large animals, before tail shortening began. After tail shortening began, changes in limb form and rate of tail loss were much alike for tadpoles of all sizes. The differences in latent period correlate inversely with stage and size, and thus compel the conclusion that capacity (i.e., sensitivity) of the tail to respond to thyroid hormone stimulation increases with developmental stage. 相似文献
992.
Shyung LR Chang WH Lin SC Shih SC Kao CR Chou SY 《World journal of gastroenterology : WJG》2005,11(8):1248-1249
We report on a case of gossypiboma. A 78-year-old man was admitted to our hospital with acute abdomen. He had undergone an operation for colon cancer 4 mo previously. Abdominal ultrasonography revealed an echogenic lesion with a hypoechoic rim and strong posterior acoustic shadowing in the lower abdomen. Diagnosis of gossypiboma can be made by ultrasonography to avoid loss-of-chance of survival. We reviewed the English literature briefly of gossypiboma from the medical and juridical view. According to the theory of loss-of-chance, the damage of plaintiff is the loss of the chance of survival or recovery, rather than the final harm. The victim would allow recovery for the loss of the chance from the defendant. But the plaintiff would show by a preponderance that he was deprived of a betterchance of a cure. Under the proposed rule, the compensable value of the victim would be the plaintiff's compensation for the loss of the victim's chance of survival. 相似文献
993.
Chi-Ming Liu Tao-Hsin Tung Shih-Tzer Tsai Jorn-Hon Liu Yeh-Kuang Tsai Victor Tze-Kai Chen Tseng-Nip Tam Hsu-Feng Lu Kuang-Kuo Wang Chung-Te Hsu Hui-Chuan Shih De-Chuan Chan Pesus Chou 《World journal of gastroenterology : WJG》2005,11(45)
AIM: To explore the association of serum insulin, insulin resistance, and β-cell dysfunction with gallstone disease (GSD) in type 2 diabetics.METHODS: We used a community-based study conducted between 1991 and 1993 in Kinmen, Taiwan to identify type 2 diabetics. A screening program for GSD was performed in 2001 by a panel of specialists who employed real-time ultrasound sonography to examine the abdominal region after the patient had fasted for at least 8 h. Screening was conducted in 2001 on 848patients diagnosed with type 2 diabetes. The HOMA method was used to compare the profile differences for insulin resistance (HOMA IR) and β-cell dysfunction (HOMA β-cell).RESULTS: We studied 440 type 2 diabetics who attended sonography check-ups. After excluding eight insulin-treated diabetics, the prevalence of GSD among the remaining 432 was 13.9% (26/187) among males and 14.7% (36/245) among females. After adjustment for other GSD-associated risk factors in addition to age and obesity, GSD risk increased among females with levels of serum insulin [4th vs 1st quartile odds ratios (OR)= 4.46 (95%CI: 1.71-11.66)] and HOMA IR [4th vs 1st quartile OR = 4.46 (95% CI: 1.71-11.66)]. Better HOMA β-cell function was significantly related to decreased risk of GSD [4th vs 1st quartile OR = 0.16 (95% CI: 0.03-1.70)].Among males, age and central obesity were the most significant risk factors for GSD. No association of GSD with serum insulin, HOMA IR, and HOMA β-cell was observed among males.CONCLUSION: Serum insulin, insulin resistance, and β-cell dysfunction are risk factors for GSD in females, but not males with type 2 diabetes. 相似文献
994.
Synergistic cytotoxic effect of azidothymidine and recombinant interferon alpha on normal human bone marrow progenitor cells 总被引:4,自引:0,他引:4
Berman E; Duigou-Osterndorf R; Krown SE; Fanucchi MP; Chou J; Hirsch MS; Clarkson BD; Chou TC 《Blood》1989,74(4):1281-1286
Azidothymidine (AZT) and interferon alpha (IFN-alpha) are among the drugs showing strong in vitro activity against the human immunodeficiency virus type-1 (HIV-1). Each drug, however, has significant toxicity against normal marrow progenitor cells that frequently proves dose-limiting in patients. In this study, AZT and recombinant IFN-alpha 2a (rIFN-alpha 2a) were tested as single agents and in combination against normal myeloid (CFU-GM) and erythroid (BFU- E) colony forming cells in a standard methylcellulose culture assay. The data were analyzed using a quantitative computerized analysis based on the median-effect principle and the isobologram equation as described by Chou and Talalay (Adv Enz Regul 22:27, 1984). The ED90 for BFU-E and CFU-GM inhibition was then compared with previously measured in vivo plasma levels of each drug and the ED90 for the anti-HIV-1 effect in vitro. We demonstrate that (a) the drugs are strongly synergistic in inhibiting marrow progenitor cell growth and that this synergism occurs at drug levels that are within the range of measured plasma levels in phase I clinical trials, (b) BFU-E are more sensitive than CFU-GM to the inhibiting effects of AZT, rIFN-alpha 2a or both drugs in combination, (c) the drug concentrations in combination that synergistically inhibit bone marrow progenitors are much higher than those required to inhibit HIV-1 replication in vitro, and (d) the anti- HIV-1 effect for the combination of AZT and rIFN-alpha 2a was clearly superior to the effect of AZT or rIFN-alpha 2a alone as indicated by the combination index and the dose-reduction index. These data suggest that substantially lower doses of AZT and rIFN-alpha than those currently being tested in clinical trials might not only maintain a strong synergistic anti-HIV-1 effect but might also avoid significant hematologic toxicity. 相似文献
995.
We reviewed the clinical, radiographic, and pathologic findings of ureteral transitional cell carcinoma (TCC) in a blackfoot disease (BFD) endemic area in southern Taiwan to increase understanding of tumor behavior in this area, which has a high incidence of urothelium carcinoma. From August 1995 to February 2002, 28 histologically proven ureteral TCCs from this area were eligible for study. There was an unusual female predominance (male:female ratio, 1:1.333). The urographic filling defects in the 28 ureteral TCCs were classified into four categories. An ovoid filling defect was significantly associated with non-invasive tumors (p = 0.003) and a trend toward low tumor grades (p = 0.073). The risk of ureteral TCC in this BFD endemic area of southern Taiwan remained high between August 1995 and February 2002. Urographic surveillance provides a simple, clear, inexpensive method to study the extent, location, and morphology of the ureteral mass. Detailed assessment of the image could be useful for preoperative planning and predicting prognosis. Large-scale, randomized, prospective clinical trials are needed to validate our results. 相似文献
996.
Termination of paroxysmal supraventricular tachycardia with a single oral dose of diltiazem and propranolol 总被引:1,自引:0,他引:1
The efficacy of a single oral dose combination of 120 mg diltiazem and 160 mg propranolol in terminating paroxysmal supraventricular tachycardia (PSVT) was evaluated in 15 patients. All 15 patients underwent electrical induction of PSVT that lasted longer than 15 min, and all underwent randomized crossover placebo and diltiazem and propranolol studies on 2 consecutive days. On each day PSVT was induced and placebo or diltiazem and propranolol was administered 15 min later. Electrical conversion of PSVT was performed when severe symptoms occurred or at the end of 240 min. With placebo PSVT lasted 164 +/- 89 (mean +/- SD) min; four patients had spontaneous conversion. With diltiazem and propranolol PSVT lasted 39 +/- 49 min (p less than .001); 14 patients had spontaneous conversion in an average of 27 +/- 15 min. None of the 14 patients had electrical reinduction of sustained PSVT after conversion. The sinus nodal recovery time during spontaneous or electrical conversion of PSVT was 911 +/- 459 msec with placebo and 1076 +/- 270 msec with diltiazem and propranolol (NS). Two patients developed transient second-degree atrioventricular block and junctional rhythm while on diltiazem and propranolol. Serum diltiazem and propranolol levels (ng/ml) after diltiazem and propranolol in five patients were, respectively, 49 +/- 26 and 108 +/- 101 at 15 min, 232 +/- 147 and 228 +/- 148 at 30 min, 254 +/- 169 and 370 +/- 393 at 45 min, 280 +/- 115 and 209 +/- 189 at 60 min, 188 +/- 72 and 268 +/- 264 at 120 min, and 118 +/- 57 and 265 +/- 148 at 240 min.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
997.
Chou YH Li CC Wang HJ Chen CC Huang CH 《The Kaohsiung journal of medical sciences》2001,17(7):385-389
A 62-year-old female patient with chronic medical history of DM and hypertension was admitted due to traffic accident. She was asymptomatic until 5 days before admission. She was referred to our medical center with an abdominal CT revealing left renal tumor. The diameter of the renal mass was 50 mm. On ultrasonographic examination, a heterogenous lesion over the left kidney was noted. Renal scanning showed a cold nodule in the left kidney. Hand-assisted laparoscopic transperitoneal radical nephrectomy was performed smoothly. The kidney was removed from the hand port in the supraumbilical skin incision with a volume of 14 x 7 x 6 cm3 and weight of 570 gm. The operation time was 5 hours, blood loss was 200 cc, and no significant change of blood pressure was noted during the surgery. The patient's postoperative course was uneventful. The pathological report of this mass was renal cell carcinoma. 相似文献
998.
We conducted this experiment to assess the effect of saline injection in electrochemical therapy. Platinum electrodes using direct current were inserted into egg white or liver parenchyma. Pure water or 0.9%, 3%, or 26% sodium chloride were injected into various objects to compare with the control group (no injection). Power was set at 10 V. In the egg-white experiment, gas bubbles and coagulated protein developed around the electrodes. In ex vivo liver, frothy reddish debris developed around the cathodes, while a hardening and shrunken surface occurred around the anodes. The pH was 14 around the cathodes, 0 around the anodes. The electric current, the amount of coagulated protein, and the severity of tissue damage were all in proportion to the concentrations of the injected saline. The volume destroyed in the 26% saline group was 8.1 times larger than that of the control group. Therefore, injected saline, especially saturated saline, can enhance the effect of electrochemical therapy. 相似文献
999.
1000.