全文获取类型
收费全文 | 2739篇 |
免费 | 216篇 |
国内免费 | 4篇 |
专业分类
耳鼻咽喉 | 8篇 |
儿科学 | 180篇 |
妇产科学 | 34篇 |
基础医学 | 329篇 |
口腔科学 | 47篇 |
临床医学 | 220篇 |
内科学 | 588篇 |
皮肤病学 | 37篇 |
神经病学 | 378篇 |
特种医学 | 303篇 |
外科学 | 238篇 |
综合类 | 34篇 |
预防医学 | 179篇 |
眼科学 | 62篇 |
药学 | 93篇 |
中国医学 | 1篇 |
肿瘤学 | 228篇 |
出版年
2021年 | 21篇 |
2020年 | 23篇 |
2019年 | 23篇 |
2018年 | 38篇 |
2017年 | 24篇 |
2016年 | 31篇 |
2015年 | 29篇 |
2014年 | 41篇 |
2013年 | 61篇 |
2012年 | 70篇 |
2011年 | 80篇 |
2010年 | 60篇 |
2009年 | 69篇 |
2008年 | 82篇 |
2007年 | 85篇 |
2006年 | 105篇 |
2005年 | 94篇 |
2004年 | 90篇 |
2003年 | 84篇 |
2002年 | 80篇 |
2001年 | 81篇 |
2000年 | 54篇 |
1999年 | 67篇 |
1998年 | 72篇 |
1997年 | 85篇 |
1996年 | 72篇 |
1995年 | 69篇 |
1994年 | 69篇 |
1993年 | 69篇 |
1992年 | 51篇 |
1991年 | 46篇 |
1990年 | 46篇 |
1989年 | 73篇 |
1988年 | 81篇 |
1987年 | 60篇 |
1986年 | 78篇 |
1985年 | 51篇 |
1984年 | 36篇 |
1983年 | 48篇 |
1982年 | 35篇 |
1981年 | 42篇 |
1980年 | 43篇 |
1979年 | 31篇 |
1978年 | 36篇 |
1977年 | 33篇 |
1976年 | 22篇 |
1975年 | 35篇 |
1974年 | 20篇 |
1969年 | 19篇 |
1967年 | 19篇 |
排序方式: 共有2959条查询结果,搜索用时 15 毫秒
61.
Hyman SE 《Archives of general psychiatry》2000,57(1):88-89
Psychiatry enters the new millennium poised to answer many of its central questions. Given the complexity of the human brain and its interactions with our world, these questions are among the most difficult ever addressed by human science. How is the human brain built? How does it change over the life span? What are the precise genetic and environmental risk factors for mental illnesses? What are the pathophysiologic processes that produce the symptoms and disabilities? How do our treatments, including psychotherapy, work? What objective markers can we discover to monitor the progression of the pathogenic processes and the effects of treatment? How will we discover preventive measures and cures that will be effective in diverse populations and settings? Parallel to the pursuit of its public health agenda, psychiatry will grow closer to neuroscience, behavioral science, and neurology. In so doing, those who practice these disciplines will be better positioned to ask meaningful questions about the relationship among mind, brain, and behavior, and to finally overcome the pervasive Cartesianism that continues to incubate stigma and ignorance about mental illness. 相似文献
62.
Chin JY Knowles RB Schneider A Drewes G Mandelkow EM Hyman BT 《Journal of neuropathology and experimental neurology》2000,59(11):966-971
Paired helical filaments, the main structural components of the neurofibrillary tangles in Alzheimer disease, consist of phosphorylated tau protein. Because the levels and degree of phosphorylation are significantly higher in paired helical filament (PHF)-derived tau than in normal adult tau, and because phosphorylation of tau severely disrupts microtubule stability, it is postulated that tau phosphorylation is an important step in PHF formation. The kinases and/or phosphatases that act in vivo to help induce such a pathological state of tau, however, are not yet known. In this study we implicate the non-proline directed kinase MARK in PHF-tau phosphorylation, by virtue of its close intermolecular association with the phosphorylated Ser262 epitope on PHF-tau as assessed by fluorescence resonance energy transfer. Moreover, because this tight enzyme-substrate association is observed in neurofibrillary tangles in Alzheimer tissue, we suggest that PHF-tau phosphorylation may occur to some extent on assembled PHF filaments. 相似文献
63.
JE McMICHAEL 《Journal of paediatrics and child health》1997,33(1):1-3
An understanding of the neurodevelopmental outcome of long-term survivors of neonatal intensive care is essential for the informed management of preterm or high risk infants. This annotation looks at the current status of neonatal follow-up services in Australasia and highlights problems in the collection and interpretation of data. It suggests that we should work towards achieving a consensus on standard definitions and test regimes and on national data collection. 相似文献
64.
L Patel PE Clayton ME Jenney JE Ferguson TJ David 《Archives of disease in childhood》1997,76(6):505-508
Cross sectional studies have reported impaired growth in children with atopic dermatitis. If this growth impairment is irreversible, it would be expected to adversely influence final height attainment. The standing heights and other anthropometric parameters were assessed in 35 adults with onset of atopic dermatitis before 5 years of age and a control group of 35 adults with adult onset contact dermatitis or psoriasis. There was no significant difference in the standing height SD score, mid-parental height SD score, sitting height SD score, subischial leg length SD score, nor body mass index between the atopic dermatitis and control groups. The standing height SD score was not significantly different among: (a) patients with atopic dermatitis affecting less than 50% of their body surface area and those with greater than 50% affected; (b) patients using the four different potency topical corticosteroids; and (c) patients with atopic dermatitis without asthma and those with coexisting asthma. It is concluded that short stature is not a feature of our group of adult patients with onset of atopic dermatitis before 5 years of age, continuing into adulthood, and severe enough to require specialist care. This suggests that if growth impairment occurs in childhood, it is likely to be temporary and reversible. 相似文献
65.
Hydrogen peroxide inhibits gap junctional intercellular communication in glutathione sufficient but not glutathione deficient cells 总被引:7,自引:5,他引:7
Cell to cell communication via gap junctions is essential in the
maintenance of the homeostatic balance of multicellular organisms. Aberrant
intercellular gap junctional communication (GJIC) has been implicated in
tumor promotion, neuropathy and teratogenesis. Oxidative stress has also
been implicated in similar pathologies such as cancer. We report a
potential link between oxidative stress and GJIC. Hydrogen peroxide, a
known tumor promoter, inhibited GJIC in WB-F344 rat liver epithelial cells
with an I50 value of 200 microM. Inhibition of GJIC by H2O2 was reversible
as indicated by the complete recovery of GJIC with the removal of H2O2 via
a change of fresh media. Free radical scavengers, such as t-butyl alcohol,
propylgallate, and Trolox, did not prevent the inhibition of GJIC by H2O2,
which indicated that the effects of H2O2 on GJIC was probably not a
consequence of aqueous free radical damage. The depletion of intracellular
GSH reversed the inhibitory effect of H2O2 on GJIC. The treatment of
glutathione- sufficient cells with H2O2 resulted in the
hyperphosphorylation of connexin43, which is the basic subunit of the
hexameric gap junction protein, as determined by Western blot analysis.
TPA, a well-known tumor promoter, also inhibits GJIC via
hyperphosphorylation of GJIC, which is a result of protein kinase-C
activation. However, H2O2 also induced hyperphosphorylation in
GSH-deficient cells that had normal rates of GJIC. Therefore, the mechanism
of GJIC inhibition must be different from the TPA-pathway and involves GSH.
相似文献
66.
Dietary polyamines promote the growth of azoxymethane-induced aberrant crypt foci in rat colon 总被引:1,自引:1,他引:1
We have examined whether dietary polyamines influence the formation and
initial growth of azoxymethane (AOM)-induced aberrant crypt foci (ACF) in
rat colon. Effects of a combination of dietary polyamines at three dose
levels (putrescine: 50, 280, 740 nmol/g; spermidine: 10, 261, 763 nmol/g;
spermine: 1, 31, 91 nmol/g) in the polyamine-poor AIN-76A diet were studied
in animals in two different experimental situations: animals treated with
AOM alone and animals treated with AOM + difluoromethylornithine (DFMO), a
specific inhibitor of endogenous polyamine synthesis. In both experimental
situations, dietary polyamines enhanced the growth of ACF, expressed as the
number of large ACF (foci with three or more aberrant crypts, ACF > or =
3), whereas the formation of ACF, expressed as the number of ACF, was
apparently not altered. In animals treated with AOM alone, maximal growth
enhancing effect on ACF was nearly obtained with the median level of
dietary polyamine. In rats fed a low polyamine diet, basic AIN-76A, DFMO
reduced the growth of AOM-induced ACF by 83%. This inhibitory effect of
DFMO was counteracted by dietary polyamines in a dose- dependent manner,
and it was abolished at the highest level of polyamines. In conclusion, it
was demonstrated that dietary polyamines are able to enhance the growth of
AOM-induced ACF. Further, dietary polyamines reversed the DFMO-caused
inhibition of ACF growth, probably by compensating for the DFMO-reduced
endogenous polyamine synthesis.
相似文献
67.
Hansen LA; Malarkey DE; Wilkinson JE; Rosenberg M; Woychik RE; Tennant RW 《Carcinogenesis》1998,19(10):1837-1845
We previously reported that papillomas can arise from the follicular
epithelium of v-Ha-ras transgenic TGxAC mice. Since the viable-yellow
mutation (A(vy)) of the mouse agouti gene which regulates coat color
pigmentation by acting within the micro-environment of the hair follicle
has been shown to function as a tumor promoter in the liver, we
hypothesized that it may also play a role in TGxAC skin tumorigenesis.
Endogenous agouti protein product was detected in the outer root sheath of
anagen hair follicles following plucking of the hair shaft, but not in the
interfollicular epithelium, in TGxAC mice on an FVB/N genetic background.
It was also detected in papillomas from these mice produced by
12-O-tetradecanoylphorbol-13-acetate (TPA) treatment or plucking.
Expression of the A(vy) allele in the v-Ha-ras transgenic TGxAC mouse line
results in an approximately 2-fold increase in papilloma development
compared with controls which did not carry the A(vy) allele following
twice-weekly treatment with 1.25, 2.5 or 5.0 microg TPA. In addition,
TPA-treated, papilloma-bearing F1 mice which carried the A(vy) allele, but
not F1 mice which did not carry the A(vy) allele, exhibited a syndrome of
humoral hypercalcemia mediated by parathyroid hormone-related protein
(PTHrP) that led to weight loss, hypercalcemia and hypophosphatemia. Thus,
we conclude that the A(vy) allele can influence the development of skin
tumors and PTHrP-mediated humoral hypercalcemia in v-Ha-ras transgenic
TGxAC mice.
相似文献
68.
Social support and its implications in older,early‐stage breast cancer patients in CALGB 49907 (Alliance A171301) 下载免费PDF全文
69.
G. J. Hyman 《Addictive behaviors》1986,11(4):355-365
Studies in smoking cessation have generally failed to adequately control for active treatment effects and have assumed that measures of smoking behaviour (i.e., estimated smoking rate, self-monitoring and chemical analysis) are equally reliable measures. Sixty smokers were randomly assigned to one of four different smoking cessation treatment groups: hypnosis, focussed smoking, attention placebo and a waiting list control. Subjects were asked to estimate and monitor their own smoking behaviour. Blood samples were also taken for thiocyanate analysis before treatment. Smoking rates were similarly measured directly, at 3 months and 6 months after treatment. The results indicate that the three measures of smoking behaviour were all highly correlated. No significant differences were found between treatments, directly after treatment or at the 3- and 6-month follow-ups. These results suggest that active treatment effects may not be responsible for behavioural change in a smoking cessation program. The implications of these findings are discussed. 相似文献
70.
Don V. Jackson Julia M. Cruz Douglas R. White Hyman B. Muss Allen R. Chauvenet 《Investigational new drugs》1990,8(Z1):S59-S64
Following the identification of a synergistic antitumor effect in a murine model, the combination of etoposide and vincristine has been explored in the clinic. Etoposide was given at 4 dose levels (250, 500, 750 or 1,000 mg/m2) with each dose given in 3 equal fractions daily for 3 days. The dose of vincristine was fixed (two 0.75 mg infusions over 22 hours each between doses of etoposide). A total of 26 patients were entered into study and 7, 11, 10 and 5 patients were treated at the 250, 500, 750, and 1,000 mg/m2 dose levels, respectively. Myelosuppressioh was the principle side effect and Grade 4 WBC toxicity (<>3) developed in 14%, 27%, 40% and 40%, respectively, of the patients treated at each of these respective dose levels. Life-threatening infections occurred in 0%, 9%, 30% and 60% of the patients at these levels, respectively. Reversal of marrow toxicity was rapid with repeat courses given at 3-week intervals. Non-hematologic toxicity, including neurotoxicity, nausea, vomiting, and mucositis was generally mild when present. Objective responses were observed in 1 patient each with refractory Hodgkin's disease and immunoblastic lymphoma. Prolonged periods of stable disease occurred in 2 patients with adenocarcinoma of the lung and one patient with Hodgkin's disease. The starting dose of etoposide recommended for further trials of this agent in combination with infusion of vincristine is 500 mg/m2 given in fractionated doses; dose escalation should be possible in many patients. 相似文献