全文获取类型
收费全文 | 2371482篇 |
免费 | 198182篇 |
国内免费 | 4204篇 |
专业分类
耳鼻咽喉 | 34265篇 |
儿科学 | 72746篇 |
妇产科学 | 62929篇 |
基础医学 | 334866篇 |
口腔科学 | 67520篇 |
临床医学 | 215512篇 |
内科学 | 468581篇 |
皮肤病学 | 47929篇 |
神经病学 | 200769篇 |
特种医学 | 95960篇 |
外国民族医学 | 886篇 |
外科学 | 360385篇 |
综合类 | 56217篇 |
现状与发展 | 1篇 |
一般理论 | 977篇 |
预防医学 | 190600篇 |
眼科学 | 55464篇 |
药学 | 177519篇 |
4篇 | |
中国医学 | 4365篇 |
肿瘤学 | 126373篇 |
出版年
2018年 | 24206篇 |
2016年 | 20576篇 |
2015年 | 23281篇 |
2014年 | 33533篇 |
2013年 | 50829篇 |
2012年 | 68735篇 |
2011年 | 72274篇 |
2010年 | 42471篇 |
2009年 | 40861篇 |
2008年 | 68755篇 |
2007年 | 73093篇 |
2006年 | 73995篇 |
2005年 | 72033篇 |
2004年 | 69331篇 |
2003年 | 67010篇 |
2002年 | 66258篇 |
2001年 | 112449篇 |
2000年 | 116525篇 |
1999年 | 98334篇 |
1998年 | 27858篇 |
1997年 | 25522篇 |
1996年 | 25447篇 |
1995年 | 24609篇 |
1994年 | 23161篇 |
1993年 | 21552篇 |
1992年 | 79386篇 |
1991年 | 76393篇 |
1990年 | 73575篇 |
1989年 | 70841篇 |
1988年 | 65846篇 |
1987年 | 64800篇 |
1986年 | 61334篇 |
1985年 | 58399篇 |
1984年 | 44222篇 |
1983年 | 37657篇 |
1982年 | 22886篇 |
1981年 | 20332篇 |
1980年 | 19034篇 |
1979年 | 41299篇 |
1978年 | 28985篇 |
1977年 | 24346篇 |
1976年 | 22832篇 |
1975年 | 23964篇 |
1974年 | 29638篇 |
1973年 | 28042篇 |
1972年 | 26226篇 |
1971年 | 24151篇 |
1970年 | 22752篇 |
1969年 | 21087篇 |
1968年 | 19135篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
971.
Clinical characteristics and surgical treatment of sporadic primary hyperparathyroidism with emphasis on chief cell hyperplasia 总被引:4,自引:0,他引:4
In 570 patients with sporadic primary hyperparathyroidism, the age, sex, symptoms, and preoperative serum calcium values were related to the histopathologic diagnoses, operative findings, and the extent and outcome of parathyroid surgery. Renal stone formation was especially prevalent in younger patients with slight hypercalcemia and parathyroid chief cell hyperplasia, whereas neuromuscular and psychiatric disturbances were overrepresented among older women with higher serum calcium values. Serum calcium concentration was inversely correlated to the proportional incidence of chief cell hyperplasia and positively correlated to the glandular weight of both adenomas and hyperplasias. Glandular size was markedly irregular in chief cell hyperplasia, with increased gland weights of no more than two glands in 78% of patients. During follow-up, for as long as 27 years, normocalcemia was obtained in 91% of patients with adenomas, with failures mainly depending on difficulties in identifying the parathyroid glands. The rate of normocalcemia was lower (80%) among patients with hyperplasia, but an inability to visualize the glands was not a major cause of failure. In patients with hyperplasia with asymmetric and more markedly enlarged glands, it appeared sufficient to remove only the enlarged glands, whereas the findings advocated a subtotal 3- to 3.5-gland resection in patients with more symmetrically or less enlarged hyperplastic glands. 相似文献
972.
J Somerville 《British journal of hospital medicine》1990,43(2):132-136
'Grown-up' congenital cardiac patients are an increasing medical community, not at present being properly cared for in any country. Information on over 2000 patients aged 15-65 years with congenital heart disease who have been treated in the National Heart Hospital provides the data for this report. 相似文献
973.
A novel method for culturing sweat gland epithelia: comparison of normal and cystic fibrosis tissues.
下载免费PDF全文
![点击此处可从《British journal of clinical pharmacology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
A new method is described to produce epithelial sheets by direct explantation of human sweat glands onto matrigel-coated millipore filters. The method is applicable to whole glands, separated coils or ducts and to normal and CF tissues. Electrogenic transport studies show that epithelia develop sodium transporting capability, even when explants are derived from secretory coils. 相似文献
974.
Acute and chronic renal failure in liver transplantation 总被引:9,自引:0,他引:9
We have performed a retrospective review of the incidence and etiologies of acute renal failure (ARF) in 105 adult patients receiving liver transplants. The prevalence of chronic renal failure was also determined. ARF occurred in 94.2% of these patients. Acute tubular necrosis was the leading cause of ARF and was associated with the highest mortality. Factors associated with increased mortality included: (1) peak serum creatinine greater than 3 mg/dl, (2) multiple liver transplants and (3) the need for dialysis. Pretransplant renal failure did not increase mortality. Chronic renal failure developed in 83% of patients at latest follow-up (mean: 30.5 +/- 7.9 months). 相似文献
975.
K Y Mumcuoglu J Miller R Gofin B Adler F Ben-Ishai R Almog D Kafka S Klaus 《Public health reviews》1990,18(4):335-344
BACKGROUND: The aim was to determine the influence of the socioeconomic status of the family and the hygienic practices in the home on the prevalence of head lice infestation in children. METHODS: The study was carried out by analyzing the answers to a standardized epidemiological questionnaire given to parents of school children aged 4-17 in Bet Shemesh, a medium-sized urban town 25 km from Jerusalem. RESULTS: Of 3,000 questionnaires distributed, 958 (31.9%) were completed and returned. The majority of the children (72.4%) had been previously infested with lice. Half of them had other family members, mainly brothers and sisters, who had been infested in the past with lice. In 97.5% of the families the mother was responsible for examining the children for lice, and for carrying out treatment when infestation was present. An association was found between presence of lice infestation and mother's education, age of child, and frequency of shampooing, combing, and examination for lice. There was no association between infestation rates and mother's country of origin, crowding in the home, and the sharing of combs, brushes, hats, scarves, towels, and clothes. CONCLUSIONS: There is evidence that the incidence of lice infestation depends on the hygienic practices in the home rather than on the socioeconomic status of the family or sharing of personal articles among family members. 相似文献
976.
Abnormal magnetic-resonance scans of the lumbar spine in asymptomatic subjects. A prospective investigation 总被引:36,自引:0,他引:36
S D Boden D O Davis T S Dina N J Patronas S W Wiesel 《The Journal of bone and joint surgery. American volume》1990,72(3):403-408
We performed magnetic resonance imaging on sixty-seven individuals who had never had low-back pain, sciatica, or neurogenic claudication. The scans were interpreted independently by three neuro-radiologists who had no knowledge about the presence or absence of clinical symptoms in the subjects. About one-third of the subjects were found to have a substantial abnormality. Of those who were less than sixty years old, 20 per cent had a herniated nucleus pulposus and one had spinal stenosis. In the group that was sixty years old or older, the findings were abnormal on about 57 per cent of the scans: 36 per cent of the subjects had a herniated nucleus pulposus and 21 per cent had spinal stenosis. There was degeneration or bulging of a disc at at least one lumbar level in 35 per cent of the subjects between twenty and thirty-nine years old and in all but one of the sixty to eighty-year-old subjects. In view of these findings in asymptomatic subjects, we concluded that abnormalities on magnetic resonance images must be strictly correlated with age and any clinical signs and symptoms before operative treatment is contemplated. 相似文献
977.
R D Perrone T I Steinman G J Beck C I Skibinski H D Royal M Lawlor L G Hunsicker 《American journal of kidney diseases》1990,16(3):224-235
Assessment of glomerular filtration rate (GFR) with inulin is cumbersome and time-consuming. Radioisotopic filtration markers have been studied as filtration markers because they can be used without continuous intravenous (IV) infusion and because analysis is relatively simple. Although the clearances of 99mTc-diethylenetriamine-pentaacetic acid (DTPA), 169Yb-DTPA, and 125I-iothalamate have each been compared with inulin, rarely has the comparability of radioisotopic filtration markers been directly evaluated in the same subject. To this purpose, we determined the renal clearance of inulin administered by continuous infusion and the above radioisotopic filtration markers administered as bolus injections, simultaneously in four subjects with normal renal function and 16 subjects with renal insufficiency. Subjects were studied twice in order to assess within-study and between-study variability. Unlabeled iothalamate was infused during the second half of each study to assess its effect on clearances. We found that renal clearance of 125I-iothalamate and 169Yb-DTPA significantly exceeded clearance of inulin in patients with renal insufficiency, but only by several mL.min-1.1.73m-2. Overestimation of inulin clearance by radioisotopic filtration markers was found in all normal subjects. No differences between markers were found in the coefficient of variation of clearances either between periods on a given study day (within-day variability) or between the two study days (between-day variability). The true test variability between days did not correlate with within-test variability. We conclude that the renal clearance of 99mTc-DTPA, 169Yb-DTPA, or 125I-iothalamate administered as a single IV or subcutaneous injection can be used to accurately measure GFR in subjects with renal insufficiency; use of the single injection technique may overestimate GFR in normal subjects. 相似文献
978.
Altered serum immunoglobulin response to model intestinal antigens during dietary exposure to vomitoxin (deoxynivalenol) 总被引:1,自引:0,他引:1
The effect of dietary vomitoxin on the serum IgA and IgG responses to two model intestinal antigens, casein and cholera toxin (CT), were assessed in 4 experimental groups: (1) mice fed casein-based diet, (2) mice fed casein-based diet containing 25 ppm vomitoxin, (3) mice fed casein-based diet and immunized with CT, and (4) mice fed casein-based diet containing 25 ppm vomitoxin and immunized with CT. Unimmunized and CT-immunized mice that were fed vomitoxin exhibited increased levels of total serum IgA relative to matched control animals fed the standard diet. Relative concentrations of casein-specific IgA were greater in both unimmunized mice and CT-immunized mice fed standard diet with vomitoxin than in matched controls fed standard diet only. CT-specific serum IgA in CT-immunized mice was not affected by vomitoxin feeding, but relative levels of CT-specific IgA were higher in unimmunized mice fed vomitoxin than in unimmunized mice fed standard diet. Both casein- and CT-specific serum IgG were depressed in mice fed vomitoxin. Significant differences in total, casein-specific and CT-specific IgA within the intestinal contents were not observed between CT-immunized mice fed vomitoxin and those fed the control diet. The results suggest that vomitoxin altered regulation of the normal immunoglobulin response to intestinal antigens and that this was manifested in the systemic compartment. 相似文献
979.
Frances J. Mather Richard M. Simon Gary M. Clark Daniel D. 《Statistics in medicine》1990,9(9):1118-1118
980.
W J Scott C A Duggan C M Schreiner M D Collins 《Toxicology and applied pharmacology》1990,103(2):238-254
The effects of acetazolamide on the developing rodent limb bud were postulated to result from a reduction of intracellular pH (pHi). Embryonic intracellular pH was calculated from transplacental distribution of the weak acid, 5,5'-dimethyloxazolidine-2,4-dione, in teratogenically sensitive (C57BL/6) and resistant (SWV) inbred mice. pHi was reduced by acetazolamide treatment in C57 embryos and limb buds but not in SWV samples. Acetazolamide teratogenesis can be exacerbated by coadministration of amiloride, presumably through inhibition of Na+/H+ exchange attributable to the latter agent. pHi reduction after such treatment was more profound than after acetazolamide alone, providing further support for the central hypothesis. pH was also reduced in other embryonic (embryo plasma) and extraembryonic compartments (exocoelomic fluid, amniotic fluid). pH changes in these compartments could also lead or contribute to abnormal development. 相似文献