全文获取类型
收费全文 | 10755篇 |
免费 | 1081篇 |
国内免费 | 32篇 |
专业分类
耳鼻咽喉 | 89篇 |
儿科学 | 383篇 |
妇产科学 | 325篇 |
基础医学 | 1629篇 |
口腔科学 | 184篇 |
临床医学 | 1215篇 |
内科学 | 1946篇 |
皮肤病学 | 128篇 |
神经病学 | 1114篇 |
特种医学 | 390篇 |
外国民族医学 | 1篇 |
外科学 | 1342篇 |
综合类 | 202篇 |
一般理论 | 8篇 |
预防医学 | 1215篇 |
眼科学 | 193篇 |
药学 | 895篇 |
中国医学 | 10篇 |
肿瘤学 | 599篇 |
出版年
2022年 | 66篇 |
2021年 | 180篇 |
2020年 | 104篇 |
2019年 | 183篇 |
2018年 | 234篇 |
2017年 | 165篇 |
2016年 | 140篇 |
2015年 | 163篇 |
2014年 | 272篇 |
2013年 | 409篇 |
2012年 | 522篇 |
2011年 | 553篇 |
2010年 | 282篇 |
2009年 | 235篇 |
2008年 | 478篇 |
2007年 | 549篇 |
2006年 | 529篇 |
2005年 | 549篇 |
2004年 | 477篇 |
2003年 | 475篇 |
2002年 | 415篇 |
2001年 | 294篇 |
2000年 | 278篇 |
1999年 | 278篇 |
1998年 | 154篇 |
1997年 | 130篇 |
1996年 | 116篇 |
1995年 | 106篇 |
1994年 | 114篇 |
1993年 | 109篇 |
1992年 | 228篇 |
1991年 | 213篇 |
1990年 | 230篇 |
1989年 | 195篇 |
1988年 | 172篇 |
1987年 | 175篇 |
1986年 | 145篇 |
1985年 | 151篇 |
1984年 | 133篇 |
1983年 | 126篇 |
1982年 | 69篇 |
1981年 | 71篇 |
1979年 | 116篇 |
1978年 | 91篇 |
1977年 | 76篇 |
1976年 | 101篇 |
1975年 | 88篇 |
1974年 | 85篇 |
1973年 | 90篇 |
1972年 | 89篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
71.
Leukotriene B4 (LTB4) and the protein kinase C activator, 4-beta-phorbol dibutyrate (PDBu), both induced a pronounced and concentration-dependent stimulation of hydrogen peroxide (H2O2) generation by purified guinea pig peritoneal eosinophils in the concentration range 1 nM-1 microM. The LTB4 response was inhibited competitively by the specific LTB4 receptor antagonist, U-75302, with a KB of 25 nM, while the concentration-response curves for both stimuli were shifted rightwards (3.8-fold and 2.8-fold for LTB4 and PDBu, respectively) by the competitive protein kinase C inhibitor, 1-O-hexadecyl-2-O-methylglycerol at a concentration of 300 microM. LTB4 appears, therefore, to induce respiratory burst in eosinophils via a receptor-mediated mechanism involving protein kinase C. 相似文献
72.
73.
74.
In order to determine the frequency and natural history of benign extracerebral fluid collections, computed tomography reports from a period of 26 months at Oklahoma Children's Memorial Hospital were reviewed (total scans: 3,411). Bilateral frontal extracerebral fluid collections were found in 94 infants under 1 year of age. Eighty-two infants had computed tomography scans as part of the evaluation for macrocrania. Thirteen patients had the typical findings of benign extracerebral fluid collections but otherwise were completely asymptomatic. Longitudinal observation for up to 30 months failed to reveal any changes in neurologic status of these patients. Benign extracerebral fluid collections are a relatively common cause of macrocrania in infants. The presence of these fluid collections is not of immediate concern, providing that clinical evaluations fail to identify either neurologic or developmental abnormalities. 相似文献
75.
Critchley Hilary O.D.; Bailey Deborah A.; Au Chak L.; Affandi Biran; Rogers Peter A.W. 《Human reproduction (Oxford, England)》1993,8(10):1632-1639
The bleeding problems experienced by users of subdermal levonorgestrelimplants (Norplant) remain unexplained. The aim of the presentstudy was to investigate the oestrogen (ER) and progesteronereceptor (PR) distribution in levonorgestrel-treated endometrialbiopsies from 31 subjects recruited in Jakarta, Indonesia, andto compare the sex steroid receptor immunostaining with thatof endometrium from 58 normally cycling women from Melbourne,Australia. Sex steroid receptor immunoreactivity was additionallycompared with days of exposure to subdermal levonorgestrel,serum oestradiol and progesterone levels and days of bleedingduring a 90-day reference period. An immunohistochemical techniquewith an alkaline phosphatase anti-alkaline phosphatase (APAAP)detection system for use in formalin-fixed paraffin wax embeddedendometrial tissue was employed. Significantly greater meanimmunostaining scores of stromal PR were observed in Norplantcompared with control endometrium at all stages across the cycle.No significant correlations were demonstrated between sex steroidreceptor immunostaining and days of exposure to subdermal levonorgestrel,serum oestradiol or progesterone concentrations or days of bleedingduring a 90-day reference period. Whether the elevated stromalPR immunostaining in Norplant-treated endometrium is a consequenceof increased synthesis or reduced turnover of receptor remainsunclear. As yet it is undetermined whether increased PR immunoreactivitycorresponds to an increase in number of functional PR. 相似文献
76.
Helen Herrman Bruce Singh Hilary Schofield Robin Eastwood Philip Burgess Virginia Lewis Richard Scotton 《Australian and New Zealand journal of public health》1993,17(3):261-266
Abstract: Informal caregivers are the families and other unpaid caregivers in the home who support people of all ages with severe and chronic mental or physical disabilities. Home care of this sort has been increasing over the past 30 years because of the reduced number of beds in hospitals and nursing homes and increased outpatient and community care. Moreover, with an aging population and increasing rates of disability, the demand for family caregiving will continue to rise. This has important implications for the development of health, community service and social policy. At the same time, however, very little is known about the impact such changes are having on the caregivers of various ages and in various circumstances. The Victorian Health Promotion Foundation is funding a research and intervention program in Melbourne to promote wellbeing and prevent ill-health in caregivers. 相似文献
77.
Mitchell Koolpe Juan J. Rodrigo Hilary P. Benton 《Journal of orthopaedic research》1998,16(2):217-226
Small calcium-mobilizing inflammatory mediators have been implicated in joint pathology. Here we demonstrate that bradykinin, adenosine 5′-triphosphate, uridine 5′-triphosphate, and lysophosphatidic acid raise the intracellular calcium concentration ([Ca2+]i) in human articular chondrocytes. Heterologous cross-desensitization experiments showed that the uridine 5′-triphosphate response was abolished by prior treatment with adenosine 5′-triphosphate and conversely, that the adenosine 5′-triphosphate response was abolished by prior treatment with uridine 5′-triphosphate: this indicated competition for the same receptor site, whereas bradykinin and lysophosphatidic acid did not compete with other ligands. Pretreatment with thapsigargin abolished ligand-mediated Ca2+ responses but not vice versa: this confirmed that Ca2+ release occurred from intracellular stores. Single-cell analysis of Fura-2 acetoxymethyl ester loaded chondrocytes showed mediator-dependent patterns of oscillatory Ca2+ changes in a subset of cells when challenged with submaximal concentrations of bradykinin, adenosine 5′-triphosphate, or uridine 5′-triphosphate in the presence of extracellular Ca2+. However, no oscillatory responses were seen after a challenge with lysophosphatidic acid. Therefore, although a number of different Ca2+-mobilizing ligands activate chondrocytes, the differences that occur in the temporal patterning of Ca2+ responses may result in unique mediator-dependent changes in cellular activity. 相似文献
78.
Martin A. Graham David R. Newell Brenda J. Foster A. Hilary Calvert 《Cancer chemotherapy and pharmacology》1989,23(1):8-14
Summary CI-941 is a new synthetic DNA-binding agent selected for phase I clinical evaluation. The drug has broad-spectrum antitumour activity against a number of murine tumours and, in contrast to doxorubicin, is unlikely to induce cardiotoxicity by a free-radical-mediated mechanism. In this study the toxicity and pharmacokinetics of CI-941 were studied in the mouse to enable the implementation of a pharmacokinetically guided dose-escalation strategy in patients. Following a single i.v. bolus injection in mice, CI-941 induced dose-dependent leukopenia. The white blood cell counts were suppressed on day 3 by 18%, 50% and 65% of control, at doses of 10, 15 and 20 mg/kg CI-941, respectively. Other toxicities such as weight loss, alopecia, diarrhoea and convulsions were observed at doses >20 mg/kg. Lethality studies in female Balb-c mice resulted in an LD10 value of 20 mg/kg (95% confidence limits; range, 19–21 mg/kg) and an LD50 value of 22 mg/kg (95% confidence limits; range, 21–23 mg/kg). The pharmacokinetics of CI-941 were studied at four dose levels from 1/10 of the LD10 to the LD10 (20 mg/kg). The drug was rapidly cleared from the plasma (250–400 ml/min per kg) at a rate approaching the cardiac output of mice, displaying triphasic plasma pharmacokinetics. The area under the plasma CI-941 concentration vs time curve (AUC) was linear with respect to the dose, up to and including 15 mg/kg (AUC=110 M x min at 15 mg/kg), but became non-linear at 20 mg/kg (AUC=277 M x min). Despite 80%–84% plasma protein binding, CI-941 was rapidly and extensively distributed into tissues, especially the kidney. Following i.v. bolus injections at doses of 1.5 and 15 mg/kg, elimination of the parent compound by urinary excretion accounted for 12%–18% of the delivered dose. A phase-I starting dose (based on that equivalent to 1/10 of the LD10 in the mouse) of 5 mg/m2 CI-941 is recommended for single administration schedules. In addition, a pharmacokinetically guided dose-escalation strategy, based on achieving a target AUC of 110 M x min, is proposed. 相似文献
79.
Loss of heterozygosity mutations of tumor suppressor genes in cytologically atypical areas in chronic lymphocytic thyroiditis 总被引:1,自引:0,他引:1
Hunt JL Baloch ZW Barnes L Swalsky PA Trusky CL Sesatomi E Finkelstein S LiVolsi VA 《Endocrine pathology》2002,13(4):321-330
The relationship between chronic lymphocytic thyroiditis (CLT) and papillary thyroid carcinoma (PTC) is a subject of controversy. Some investigators suggest a causal relationship, whereas others regard the two as only a coincidental occurrence. An additional complicating factor is the presence of atypical nuclei frequently found within lymphoid infiltrates in CLT, which resemble those in PTC. The finding of the RET-PTC translocations in CLT has been reported by two independent groups of investigators, suggesting that the areas of nuclear atypia in CLT are neoplastic rather than reactive. In the present study, we report additional molecular findings that support the hypothesis that the atypical nuclear changes in CLT may be preneoplastic or neoplastic. We microdissected small areas with atypical nuclei in glands with CLT and observed loss-of-heterozygosity mutations of tumor suppressor genes. These genetic mutations are evidence of clonal preneoplastic or neoplastic changes in the follicular cells of CLT. The clinical malignant potential of these minute foci is likely to be very small but remains to be determined. 相似文献
80.