全文获取类型
收费全文 | 19199篇 |
免费 | 1301篇 |
国内免费 | 71篇 |
专业分类
耳鼻咽喉 | 342篇 |
儿科学 | 520篇 |
妇产科学 | 341篇 |
基础医学 | 2280篇 |
口腔科学 | 238篇 |
临床医学 | 1941篇 |
内科学 | 4287篇 |
皮肤病学 | 466篇 |
神经病学 | 1713篇 |
特种医学 | 676篇 |
外科学 | 2825篇 |
综合类 | 236篇 |
现状与发展 | 1篇 |
一般理论 | 18篇 |
预防医学 | 1781篇 |
眼科学 | 503篇 |
药学 | 1257篇 |
中国医学 | 23篇 |
肿瘤学 | 1123篇 |
出版年
2023年 | 95篇 |
2022年 | 193篇 |
2021年 | 440篇 |
2020年 | 269篇 |
2019年 | 409篇 |
2018年 | 519篇 |
2017年 | 354篇 |
2016年 | 420篇 |
2015年 | 463篇 |
2014年 | 670篇 |
2013年 | 954篇 |
2012年 | 1373篇 |
2011年 | 1440篇 |
2010年 | 789篇 |
2009年 | 754篇 |
2008年 | 1210篇 |
2007年 | 1314篇 |
2006年 | 1268篇 |
2005年 | 1234篇 |
2004年 | 1251篇 |
2003年 | 1083篇 |
2002年 | 958篇 |
2001年 | 169篇 |
2000年 | 146篇 |
1999年 | 188篇 |
1998年 | 253篇 |
1997年 | 168篇 |
1996年 | 143篇 |
1995年 | 149篇 |
1994年 | 133篇 |
1993年 | 109篇 |
1992年 | 101篇 |
1991年 | 89篇 |
1990年 | 68篇 |
1989年 | 75篇 |
1988年 | 70篇 |
1987年 | 77篇 |
1986年 | 72篇 |
1985年 | 78篇 |
1984年 | 89篇 |
1983年 | 66篇 |
1982年 | 86篇 |
1981年 | 108篇 |
1980年 | 78篇 |
1979年 | 62篇 |
1978年 | 51篇 |
1977年 | 64篇 |
1976年 | 43篇 |
1975年 | 37篇 |
1974年 | 36篇 |
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
931.
Chronic lymphocytic leukemia (CLL) is truly a heterogenous disease, in which individual outcomes range from no need for therapeutic
intervention to very aggressive, nonresponding disease. The ability to develop clear, sound prognostic information that permits
reliable counsel must be our goal. A combination of easily obtainable, traditional prognostic parameters (bone marrow infiltration
patterns, β-2 microglobulin) along with the clinical Rai stage is still frequently used in the initial risk stratification
of patients with CLL. However, novel parameters such as defects detectable on fluorescence in situ hybridization (FISH), expression
levels of CD38 and ZAP-70, and immunoglobulin heavy-chain variable region status can add significant prognostic information
about a given patient with CLL. How to incorporate these newer tests within the context of the more traditional parameters
for a patient with a new diagnosis is the focus of significant continuing research. The outcome of this research has implications
for predicting clinical progression rates and the response and duration of response to therapy, as well as for highlighting
high-risk patients who will need earlier or more specific treatment approaches. 相似文献
932.
Objective As retailers of complementary medicines (CMs), pharmacists are well placed to advise consumers on the safe and effective use of these products; where CMs are available in pharmacies, pharmacists should be well informed about such products. This study explored the extent to which CMs are available in community pharmacies in England, and examined pharmacists' experiences, professional practices and training with regard to these products. Method A cross‐sectional study was conducted, involving a structured questionnaire posted to community pharmacists. Coded follow‐up mailings were sent to non‐responders after 2 and 4 months, and a reminder telephone call made after 3 months. Setting All community pharmacists in six areas (Devon, Cornwall, Bradford, Leeds, Manchester, Stockport) of England (total n = 1337). Key findings The response rate was 66.5%. Overall, 92% of respondents reported that CMs (excluding vitamins/minerals) are sold in the pharmacy in which they practise, 81% had received requests from patients/consumers for specific CMs in the previous year, and 58% had recommended CMs. Around 70% of respondents rarely/never asks about CMs use when counter‐prescribing conventional medicines or when receiving reports of suspected adverse drug reactions (ADRs) associated with conventional medicines. In total, 40% of respondents had undertaken training in complementary/alternative medicine (CAM). Pharmacists who had undertaken training were more likely to ask patients/consumers specifically about use of CMs when counter‐prescribing conventional over‐the‐counter (OTC) medicines (37.0% versus 23.4%, respectively; χ2 = 17.4; P = 0.0003) and when receiving reports from patients/customers of suspected ADRs associated with conventional (prescribed or OTC) medicines (35.6% versus 23.8%, respectively; χ2 = 13.0; P = 0.0003). Conclusion CMs are widely available in pharmacies in England, and pharmacists interact with users of these products. An opportunity exists for pharmacists to embrace a professional role as expert advisors on CMs. However, pharmacists' training, professional practices and competence with respect to CMs first need to improve. 相似文献
933.
Nicola E Wilsher Will J Court Ruth Ruddle Yvette M Newbatt Wynne Aherne Peter W Sheldrake Neil P Jones Matilda Katan Suzanne A Eccles Florence I Raynaud 《Drug metabolism and disposition》2007,35(7):1017-1022
Phosphoinositide-specific phospholipase C (PLC) is a key enzyme in the regulation of Ca(2+) release from inositol 1,4,5-triphosphate-sensitive stores. U73122 (1-(6-((17beta-3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione) has been extensively used as a pharmacological inhibitor of PLC to elucidate the importance of this enzyme family in signal transduction pathways. U73122 has an electrophilic maleimide group, which readily reacts with nucleophiles such as thiols and amines. In the current study the conjugation of U73122 to common components of cell culture medium, namely l-glutamine, glutathione, and bovine serum albumin (BSA), was demonstrated. The half-life of U73122 on incubation with phosphate-buffered saline (PBS), Hanks' buffered saline solution (with 2 mM glutamine), optimized basal nutrient medium (MCDB131, without BSA), complete medium, Dulbecco's modified Eagle's medium (with 2 mM l-glutamine) was approximately 150, 60, 32, 30, and 18 min, respectively. However, U73122 was not recoverable from medium supplemented with 0.5% BSA. U73122 underwent hydrolysis of the maleimide group when incubated with PBS. Glutamine conjugates of U73122 were identified in cell culture medium. Furthermore, the inhibition of epidermal growth factor-stimulated Ca(2+) release in a human epidermoid carcinoma cell line (A431) by U73122 was substantially reduced by the presence of BSA in a time-dependent manner. In complex cellular assays, the availability of U73122 to inhibit PLC may be limited by its chemical reactivity and lead to the misinterpretation of results in pharmacological assays. 相似文献
934.
Neil M Richtand Jeffrey A Welge Aaron D Logue Paul E Keck Stephen M Strakowski Robert K McNamara 《Neuropsychopharmacology》2007,32(8):1715-1726
The relationship between clinically effective antipsychotic drug dosage and binding affinity to cloned dopamine (DA) and serotonin receptor subtypes was analyzed in an effort to elucidate the contribution of individual receptor subtypes to medication response. Clinically effective dose and binding affinity to D(2) DA receptor were modestly correlated for typical antipsychotic medications (r=0.54, p=0.046), but surprisingly were not correlated for atypical antipsychotics (r=0.41, p=0.31). For typical antipsychotics, a more robust inverse relationship was observed between medication dose and 5-HT(2C) affinity (r=-0.68, p=0.021). The strongest correlation for typical antipsychotics was observed between drug dosage and 5-HT(2C)/D(2) binding affinity ratio (r=-0.81, p=0.003). For atypical antipsychotics, no significant correlations were identified between medication dosage and 5-HT(2C), 5-HT(2A), 5-HT(2C)/D(2), or 5-HT(2A)/D(2) receptor-binding affinities. In contrast, atypical antipsychotic medication dosage was highly correlated with the ratios of D(2) (5-HT(2A)/5-HT(1A)) (r=0.80, p=0.031), and D(2) (5-HT(2C)/5-HT(1A)) (r=0.78, p=0.038) binding affinities. These observations demonstrate an interaction between D(2) and 5-HT(2C) receptor effects contributing to positive symptom response for typical antipsychotic medications, suggesting that signaling through 5-HT(2C) receptors interacts with and improves antipsychotic effects achieved via D(2) receptor blockade. This analysis also demonstrates that, in contrast to typical antipsychotics, therapeutic effects of atypical antipsychotic medications are determined by opposing interactions among three different domains: (1) increasing D(2) DA receptor-binding affinity enhances antipsychotic potency. (2) Increasing 5-HT(2C) and 5-HT(2A) receptor-binding affinities also facilitate antipsychotic efficacy. (3) Increasing 5-HT(1A) receptor-binding affinity, in contrast, reduces antipsychotic efficacy. 相似文献
935.
936.
Kathryn R Starr Gary W Price Jeannette M Watson Peter J Atkinson Roberto Arban Sergio Melotto Lee A Dawson Jim J Hagan Neil Upton Mark S Duxon 《Neuropsychopharmacology》2007,32(10):2163-2172
Preclinically, the combination of an SSRI and 5-HT autoreceptor antagonist has been shown to reduce the time to onset of anxiolytic activity compared to an SSRI alone. In accordance with this, clinical data suggest the coadministration of an SSRI and (+/-) pindolol can decrease the time to onset of anxiolytic/antidepressant activity. Thus, the dual-acting novel SSRI and 5-HT(1A/B) receptor antagonist, SB-649915-B, has been assessed in acute and chronic preclinical models of anxiolysis. SB-649915-B (0.1-1.0 mg/kg, i.p.) significantly reduced ultrasonic vocalization in male rat pups separated from their mothers (ED(50) of 0.17 mg/kg). In the marmoset human threat test SB-649915-B (3.0 and 10 mg/kg, s.c.) significantly reduced the number of postures with no effect on locomotion. In the rat high light social interaction (SI), SB-649915-B (1.0-7.5 mg/kg, t.i.d.) and paroxetine (3.0 mg/kg, once daily) were orally administered for 4, 7, and 21 days. Ex vivo inhibition of [(3)H]5-HT uptake was also measured following SI. SB-649915-B and paroxetine had no effect on SI after 4 days. In contrast to paroxetine, SB-649915-B (1.0 and 3.0 mg/kg, p.o., t.i.d.) significantly (p<0.05) increased SI time with no effect on locomotion, indicative of an anxiolytic-like profile on day 7. Anxiolysis was maintained after chronic (21 days) administration by which time paroxetine also increased SI significantly. 5-HT uptake was inhibited by SB-649915-B at all time points to a similar magnitude as that seen with paroxetine. In conclusion, SB-649915-B is acutely anxiolytic and reduces the latency to onset of anxiolytic behavior compared to paroxetine in the SI model. 相似文献
937.
Stephane Supiot Shubber Shubbar Neil Fleshner Padraig Warde Karen Hersey Kris Wallace Heather Cole Joan Sweet John Tsihlias Michael A.S. Jewett Laurence Klotz Robert G. Bristow 《Radiotherapy and oncology》2008,88(1):53-60
BACKGROUND AND PURPOSE: Selected patients undergoing radical prostatectomy for localized prostate cancer can be at high-risk for pT3 disease and require subsequent radiotherapy. In a phase I trial, we investigated the feasibility of pre-operative radiotherapy for this patient subset. MATERIALS AND METHODS: Eligibility criteria were: T1/T2N0M0 tumors plus (i) Gleason >or=7, PSA>10 ng/ml and <35 ng/ml, or (ii), PSA >15 ng/ml and less <35 ng/ml (any Gleason). Patients received 25 Gy in five fractions of radiotherapy followed by radical prostatectomy. Trial endpoints included intra-operative morbidity and late toxicity following combined treatment. We also stained pre- and post-radiotherapy prostate samples for DNA damage response proteins. RESULTS: Between 2001 and 2004, 15 patients were entered on trial. Thirteen patients completed combined-modality treatment. Only one patient had signs of intra-operative inflammation. No patient had post-operative complication. There was no severe late gastrointestinal toxicity. Late genitourinary toxicity consisted of severe urinary incontinence in 2 of 13 patients. From a translational standpoint, irradiated prostate tumor tissues had long-term activation of the CDK-inhibitor p21(WAF) associated with reduced cell proliferation. CONCLUSION: Intra-operative morbidity is low following short-course, pre-operative radiotherapy. A phase II trial is planned to fully document biochemical response with this combined-modality approach. 相似文献
938.
An initial report of a radiation dose-escalation trial in patients with one to five sites of metastatic disease 总被引:1,自引:0,他引:1
Joseph K Salama Steven J Chmura Neil Mehta Kamil M Yenice Walter M Stadler Everett E Vokes Daniel J Haraf Samuel Hellman Ralph R Weichselbaum 《Clinical cancer research》2008,14(16):5255-5259
PURPOSE: Previous investigations have suggested that a subset of patients with metastatic cancer in a limited number of organs may benefit from local treatment. We investigated whether cancer patients with limited sites of metastatic disease (oligometastasis) who failed standard therapies could be identified and safely treated at one to five known sites of low-volume disease with radiotherapy. EXPERIMENTAL DESIGN: Patients with one to five sites of metastatic cancer with a life expectancy of >3 months and good performance status received escalating doses of radiation to all known sites of cancer with hypofractionated radiation therapy. Patients were followed radiographically with computed tomography scans of the chest, abdomen, and pelvis and metabolically with [18F]fluorodeoxyglucose-positron emission tomography 1 month following treatment and then every 3 months. Acute toxicities were scored using the National Cancer Institute Common Terminology Criteria for Adverse Events version 3.0 and late toxicities were scored using the Radiation Therapy Oncology Group late toxicity scoring system. RESULTS: Twenty-nine patients with 56 metastatic lesions were enrolled from November 2004 to March 2007, with a median follow-up of 14.9 months. Two patients experienced acute (radiation pneumonitis and nausea) and one experienced chronic (gastrointestinal hemorrhage) grade > or =3 toxicity. Fifty-nine percent of patients responded to protocol therapy. Twenty-one percent of patients have not progressed following protocol treatment. Fifty-seven percent of treated lesions have not progressed at last follow-up. Progression was amenable to further local therapy in 48% of patients. CONCLUSIONS: Patients with low-volume metastatic cancer can be identified, safely treated, and may benefit from radiotherapy. 相似文献
939.
Lymphangiomas are uncommon, benign developmental tumours of the lymphatic system. Though usually symptomless, lymphangiomas can cause problems through pressure effects and may sometimes be life-threatening, especially in newborn infants with massive lesions involving the neck and mediastinum. The literature is reviewed with 33 additional cases presented. Despite the advent of more recent and innovative treatments, surgical excision is associated with the least number of complicatons and is still the most widely used and successful method of treatment. 相似文献
940.
Neil O''Connor Beate Hermelin 《Journal of child psychology and psychiatry, and allied disciplines》1990,31(2):203-215
Three groups of subjects, an idiot-savant group, a group of mentally handicapped subjects matched for IQ, and normal artistically gifted children, were compared for their recognition and graphic reproduction abilities. It was found that, independent of input modality, level of intelligence determined recognition performance, while graphic ability independent of IQ was the determining factor in reproduction accuracy. 相似文献