全文获取类型
收费全文 | 718篇 |
免费 | 12篇 |
国内免费 | 3篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 38篇 |
妇产科学 | 24篇 |
基础医学 | 63篇 |
口腔科学 | 27篇 |
临床医学 | 38篇 |
内科学 | 141篇 |
皮肤病学 | 21篇 |
神经病学 | 55篇 |
特种医学 | 19篇 |
外科学 | 118篇 |
综合类 | 8篇 |
预防医学 | 76篇 |
眼科学 | 7篇 |
药学 | 64篇 |
中国医学 | 12篇 |
肿瘤学 | 19篇 |
出版年
2023年 | 3篇 |
2022年 | 3篇 |
2021年 | 21篇 |
2020年 | 6篇 |
2019年 | 92篇 |
2018年 | 63篇 |
2017年 | 36篇 |
2016年 | 5篇 |
2015年 | 3篇 |
2014年 | 14篇 |
2013年 | 13篇 |
2012年 | 7篇 |
2011年 | 5篇 |
2010年 | 2篇 |
2009年 | 3篇 |
2008年 | 6篇 |
2007年 | 3篇 |
2006年 | 8篇 |
2005年 | 5篇 |
2004年 | 9篇 |
2003年 | 3篇 |
2002年 | 4篇 |
2001年 | 4篇 |
1999年 | 3篇 |
1998年 | 5篇 |
1997年 | 2篇 |
1996年 | 4篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1985年 | 45篇 |
1984年 | 53篇 |
1983年 | 33篇 |
1982年 | 43篇 |
1981年 | 30篇 |
1980年 | 36篇 |
1979年 | 34篇 |
1978年 | 18篇 |
1977年 | 28篇 |
1976年 | 19篇 |
1975年 | 19篇 |
1974年 | 17篇 |
1973年 | 13篇 |
1972年 | 1篇 |
排序方式: 共有733条查询结果,搜索用时 0 毫秒
71.
J M Johnson L Lemberger M Novotny R B Forney W S Dalton M P Maskarinec 《Toxicology and applied pharmacology》1984,72(3):440-448
This basic fraction (BF) of marihuana whole smoke condensate was subjected to pharmacological testing in males, Swiss-Webster mice. In a general pharmacological activity screen looking at behavioral, neurologic, and autonomic parameters, BF, at iv doses of 5, 10, and 20 mg/kg, caused impairment of visual placing, increase in tail pinch response, decrease in tail elevation, and induction of piloerection. These effects, although statistically significant, were slight and not consistently dose dependent. In a second study with doses ranging from 10 to 29 mg/kg, BF caused a decrease in spatial locomotion, rearing behavior, and urination incidence. In a third study, body temperatures of mice were measured periodically for 2 hr following administration of BF (1.2, 2.4, and 4.8 mg/kg) alone or in combination with 1.0 mg/kg delta-9-tetrahydrocannabinol (THC). BF did not alter body temperature, nor did it affect THC-induced hypothermia. These results, although suggesting that the basic fraction of marihuana whole smoke condensate has pharmacological activity in mice, offers little evidence for the presence of highly active compounds. 相似文献
72.
Robert Rutledge Robert E. Applebaum Justin B. Kim Mary B. Engler Marguerite M. Engler 《American journal of surgery》1984,148(3):357-361
One thousand five hundred ninety-eight patients who underwent cardiac valve replacement were reviewed. One hundred fifty-two patients (10 percent) required a second valve replacement. The indications for repeat valve replacement were prosthetic valve dysfunction in 53 patients (35 percent), development of a new valvular lesion in 46 patients (30 percent), simple closure of a perivalvular leak in 14 patients (9 percent), change of the valve poppet in 13 patients (8 percent), severe hemolysis or emboli in 21 patients (14 percent), and prosthetic valve endocarditis in 5 patients (3 percent). The mean preoperative New York Health Association functional class improved from 3 to 1.5 in the nonreoperated patients and from 2.9 to 1.8 in patients who underwent a second valve replacement. Similarly, the mean cardiac index improved from 2.5 to 2.9 and from 2.5 to 2.8 in nonreoperated and reoperated patients, respectively. The operative mortality rate was 14 percent in the nonreoperated patients and 16 percent at second operation in the reoperated patients. Using actuarial techniques, the risk of repeat valve replacement was 1 to 4 percent per year. Long-term survival was compared between groups. Using actuarial techniques, the estimated survival rates at 1, 5, and 10 years were 89 percent, 69 percent, and 52 percent, respectively in nonreoperated patients and 87 percent, 60 percent, and 37 percent in reoperated patients.This study has documented the excellent improvement in functional and hemodynamic state after second cardiac valve replacement. The operative mortality and long-term survival rates were similar to those of the nonreoperated patients. Patients having repeat cardiac valve replacement can expect good improvement in length and quality of life. 相似文献
73.
The incomplete anterior interosseous nerve syndrome 总被引:1,自引:0,他引:1
The anterior interosseous nerve syndrome involves paralysis of the flexor pollicis longus, flexor digitorum profundus of the index and long fingers, and the pronator quadratus. We have encountered 33 cases of an incomplete syndrome in which only the flexor pollicis longus or the flexor digitorum profundus of the index finger is either paretic or paralyzed. This entity must be distinguished from flexor tendon rupture, flexor tendon adherence or adhesion, and stenosing tenosynovitis. The nerve is usually compressed by fibrous bands that most commonly originate from the deep head of the pronator teres and to the brachialis fascia. Less common causes of compression are: fibrous bands from the superficial head of the pronator teres; bands from the superficialis arcade; the nerve running deep to both heads of the pronator; and compression by a double lacertus fibrosus. Patients presenting with paresis should be observed. Most will improve spontaneously without surgery. We recommend exploration and neurolysis of the anterior interosseous nerve in patients who present with complete paralysis of either muscle-tendon unit and who have shown no improvement as determined by physical examination or repeat electromyography after 12 weeks of observation. Recovery after neurolysis is often rapid and complete. 相似文献
74.
J A Hill J T O'Brien E Scott C R Conti C J Pepine 《The American journal of cardiology》1984,53(6):679-683
Bepridil, a calcium antagonist with a half-life of approximately 42 hours, was compared with placebo in a double-blind, randomized, crossover trial. Thirteen men (average age 62 years) with exercise-related angina pectoris and a positive exercise test (modified Bruce protocol) were studied. In the group as a whole, bepridil (400 mg once a day) caused an increased total exercise time (2.6 +/- 1.8 minutes, mean +/- standard deviation), time to onset of angina (3.3 +/- 1.6 minutes), time to 1 mm of ST-segment depression (2.2 +/- 2.3 minutes), time to 2 mm of ST-segment depression (2.4 +/- 1.4 minutes) and total work load achieved (1.8 +/- 1.4 kpm) compared with the preceding placebo phase (all p less than 0.05). Frequency of angina and nitroglycerin consumption were low and did not change significantly during bepridil therapy. Comparison of the 3 placebo periods (run-in, double-blind and washout) did not reveal a change in any measurement except time to onset of angina, suggesting no training effect or change in patient status. Adverse effects were common in patients taking both placebo and bepridil, but only 2 patients had adverse effects (dizziness) with bepridil that necessitated discontinuation of therapy. Similarity of the double product (systolic blood pressure X heart rate) at the end of exercise suggests a decrease in myocardial oxygen demand as the primary mode of action. This study suggests that bepridil is a promising agent for the treatment of exercise-induced myocardial ischemia. 相似文献
75.
Y-Organs and control tissues from intact (intermolt) and 48-hr de-eyestalked Cancer antennarius donors were cultured for 12 and 24 hr in crustacean saline supplemented 10% with crab serum and containing [14C]cholesterol. Under these conditions, Y-organs took up significantly more [14C]cholesterol than ovary or muscle, and Y-organs from 48-hr de-eyestalked crabs took up threefold more than Y-organs from intact crabs. The labeled cholesterol of the culture medium was observed to bind rapidly to the lipoproteins of the serum supplement; subcellular fractionation of the activated Y-organs after incubation showed 59% of the label localized in the cytosolic fraction. The increase in cholesterol uptake did not result from a change in extracellular volume, and was not accompanied by a change in Y-organ total cholesterol. It was, however, accompanied by a greater than threefold increase in ecdysone secretion. 相似文献
76.
John W. Seeds Robert C. Cefalo Herbert J. Proctor Frans F. Jobsis-van der Vliet 《American journal of obstetrics and gynecology》1984,149(6):679-684
Current clinical methods for assessing fetal oxygenation in labor are indirect and remain somewhat imperfect. Since infrared light passes through the cranium and infrared light absorbance by tissues has been shown in adult animals to vary with oxygenation, monitoring of intracranial infrared light absorbance may serve as the basis for a new, more direct technique for the assessment of fetal condition. Described here is the application of infrared reflectance spectrophotometry to a fetal sheep model and the precision of the relationship between fetal arterial or venous PO2 and infrared light absorbance at selected wavelengths. A very strong, linear correlation () was found between fetal arterial PO2 and intracranial infrared light absorbance according to an algorithm developed for selective monitoring of the state of hemoglobin oxygenation in tissue. With further development, this method holds promise for a more direct, noninvasive assessment of fetal condition in labor than is currently available. 相似文献
77.
Serum creatine kinase and CK-MB isoenzyme responses to acute and prolonged swimming in trained athletes 总被引:2,自引:0,他引:2
J D Symanski R G McMurray L M Silverman B W Smith A J Siegel 《Clinica chimica acta; international journal of clinical chemistry》1983,129(2):181-187
Six highly-trained male swimmers completed a maximum work capacity tethered swim and a 1-h continuous tethered swim at approximately 70% VO2max in order to evaluate total serum creatine kinase and CK-MB isoenzyme changes. Venous blood obtained before, 5 min post-, 6 h post-, and 24 h post-exercise was analyzed for total serum CK (kinetic UV method, normal = less than 100 U/l) and CK-MB isoenzyme (quantitative electrophoretic technique, normal = less than 5 U/l). VO2max averaged 4.59 +/- 0.28 l/min, with a mean total work time of 24.5 min to achieve maximum capacity. Mean resting total CK was 100.5 +/- 15.8 U/l. Compared to rest, neither swim bout produced a significant (p greater than 0.05) elevation in mean total creatine kinase. No CK-MB isoenzyme was observed in any post-exercise blood sample. Swimming, performed by highly-trained swimmers at high levels of intensity or for prolonged durations, may not impose sufficient degrees of trauma producing muscular stress. Therefore, the structural integrity of the cell membrane is maintained and the loss of intracellular creatine kinase to the bloodstream prevented. 相似文献
78.
Although somatizing patients may be aided by psychotherapy, they usually are very resistant to any therapeutic engagement. We have found a biopsychosocial integrative interview to be helpful for involving severely somatizing inpatients in psychotherapy. Two case examples clarify four elements central to successful use of the interview: (1) the psychiatrist becomes involved early; (2) the interview occurs in the context of an inpatient medical work-up, at the conclusion of diagnostic testing, and after the psychiatrist has spent some time with the patient; (3) a multifactorial, integrated perspective is discussed with the patient; and (4) substantial empathy is achieved. 相似文献
79.
80.
Although premature closure of the foramen ovale has been proposed as a possible cause of hypoplastic left heart syndrome, very few such cases have been described. We have seen two examples of the combination and no associated malformations. In both the foramen was firmly closed on its left atrial aspect and the dimensions of the left sided structures were well below normal values. 相似文献