全文获取类型
收费全文 | 7374篇 |
免费 | 522篇 |
国内免费 | 38篇 |
专业分类
耳鼻咽喉 | 65篇 |
儿科学 | 223篇 |
妇产科学 | 266篇 |
基础医学 | 1189篇 |
口腔科学 | 90篇 |
临床医学 | 686篇 |
内科学 | 1538篇 |
皮肤病学 | 172篇 |
神经病学 | 974篇 |
特种医学 | 146篇 |
外科学 | 773篇 |
综合类 | 17篇 |
一般理论 | 4篇 |
预防医学 | 476篇 |
眼科学 | 150篇 |
药学 | 522篇 |
中国医学 | 11篇 |
肿瘤学 | 632篇 |
出版年
2023年 | 59篇 |
2022年 | 141篇 |
2021年 | 218篇 |
2020年 | 110篇 |
2019年 | 175篇 |
2018年 | 201篇 |
2017年 | 178篇 |
2016年 | 228篇 |
2015年 | 257篇 |
2014年 | 277篇 |
2013年 | 388篇 |
2012年 | 581篇 |
2011年 | 599篇 |
2010年 | 336篇 |
2009年 | 298篇 |
2008年 | 491篇 |
2007年 | 454篇 |
2006年 | 432篇 |
2005年 | 443篇 |
2004年 | 392篇 |
2003年 | 369篇 |
2002年 | 285篇 |
2001年 | 83篇 |
2000年 | 105篇 |
1999年 | 101篇 |
1998年 | 61篇 |
1997年 | 52篇 |
1996年 | 44篇 |
1995年 | 35篇 |
1994年 | 31篇 |
1993年 | 35篇 |
1992年 | 44篇 |
1991年 | 50篇 |
1990年 | 40篇 |
1989年 | 34篇 |
1988年 | 40篇 |
1987年 | 34篇 |
1986年 | 14篇 |
1985年 | 27篇 |
1984年 | 20篇 |
1983年 | 13篇 |
1982年 | 13篇 |
1981年 | 8篇 |
1979年 | 9篇 |
1974年 | 8篇 |
1973年 | 11篇 |
1972年 | 8篇 |
1970年 | 15篇 |
1969年 | 14篇 |
1968年 | 8篇 |
排序方式: 共有7934条查询结果,搜索用时 15 毫秒
91.
A Harden G Pampiglione A Battaglia 《Journal of neurology, neurosurgery, and psychiatry》1982,45(7):627-632
Neurophysiological investigations (EEG, ERG, VEP) were carried out in 13 patients with proven "mitochondrial myopathy". There were nine girls and four boys. Varied abnormalities were seen in the EEGs of all cases, and in one patient unusual repetitive bursts of irregular slow waves and spikes were observed. The ERG was abnormal in five of the 12 cases tested, while the VEP (flash) was definitely abnormal in six out of these 12 cases. These neurophysiological findings suggest some involvement of both the brain and the visual system. It seem therefore appropriate that this condition be considered a "mitochondrial disease" affecting many systems rather than only muscles. 相似文献
92.
Lori E Shapiro Sandra R Knowles Elizabeth Weber Manuela G Neuman Neil H Shear 《Drug safety》2003,26(3):187-195
OBJECTIVE: To evaluate cross reactivity between sulfonamide antimicrobials and celecoxib in patients with histories of allergies to sulfonamide antimicrobials. METHODS: Immunocompetent patients with a history of sulfonamide antimicrobial allergy who were being considered for therapy with celecoxib were prospectively enrolled. Sulfamethoxazole and trimethoprim skin prick and intradermal testing and/or an in vitro lymphocyte toxicity assay were performed. If skin testing was negative, an oral challenge with sulfamethoxazole and trimethoprim was performed. Oral challenges with celecoxib were administered to all patients. RESULTS: Twenty-eight immunocompetent patients (26 female; mean age 60 years) were evaluated. History of sulfonamide antimicrobial allergy included urticaria (n = 7), cutaneous eruptions (n = 9), and other (n = 12). Four of the 28 patients who were skin prick tested were positive to sulfamethoxazole and two of the ten patients who underwent in vitro testing were positive to sulfamethoxazole. All 28 patients were administered celecoxib and tolerated the medication. Phone call follow up in 25 patients disclosed that 15 patients continued to take celecoxib, while five patients did not take celecoxib following the oral challenge, and five discontinued celecoxib due to adverse effects, lack of drug efficacy or physician preference. CONCLUSIONS: Confusion exists regarding the potential for cross reactivity between sulfonamide antimicrobials and other sulfonamide-containing compounds. The six sulfonamide-allergic patients tolerated celecoxib uneventfully. This pilot study supports the hypothesis that the potential for cross-reactivity between celecoxib and sulfonamide antimicrobials appears to be low. However, further investigations are required to confirm this. 相似文献
93.
Expression profiling of T-cell lymphomas differentiates peripheral and lymphoblastic lymphomas and defines survival related genes. 总被引:1,自引:0,他引:1
Beatriz Martinez-Delgado Barbara Meléndez Marta Cuadros Javier Alvarez Jose Maria Castrillo Ana Ruiz De La Parte Manuela Mollejo Carmen Bellas Ramon Diaz Luis Lombardía Fatima Al-Shahrour Orlando Domínguez Alberto Cascon Mercedes Robledo Carmen Rivas Javier Benitez 《Clinical cancer research》2004,10(15):4971-4982
PURPOSE: T-Cell lymphomas constitute heterogeneous and aggressive tumors in which pathogenic alterations remain largely unknown. Expression profiling has demonstrated to be a useful tool for molecular classification of tumors. EXPERIMENTAL DESIGN: Using DNA microarrays (CNIO-OncoChip) containing 6386 cancer-related genes, we established the expression profiling of T-cell lymphomas and compared them to normal lymphocytes and lymph nodes. RESULTS: We found significant differences between the peripheral and lymphoblastic T-cell lymphomas, which include a deregulation of nuclear factor-kappaB signaling pathway. We also identify differentially expressed genes between peripheral T-cell lymphoma tumors and normal T lymphocytes or reactive lymph nodes, which could represent candidate tumor markers of these lymphomas. Additionally, a close relationship between genes associated to survival and those that differentiate among the stages of disease and responses to therapy was found. CONCLUSIONS: Our results reflect the value of gene expression profiling to gain insight about the molecular alterations involved in the pathogenesis of T-cell lymphomas. 相似文献
94.
Aldo Becciolini Manuela Balzi Paola Faraoni Elena Tisti Giorgia Zappoli Thyrion Valentino Giach Luca Bandettini Christopher S. Potten 《Acta oncologica (Stockholm, Sweden)》1998,37(1):65-71
Cell kinetics parameters have been analysed in colonic mucosa at different distances from a tumour in patients with colon carcinoma. Total cell number (TCN), H thymidine labelling index (TLI), mitotic index (MI), Goblet cell index (GCI) and the distribution of labelled cells along the crypt column (cell position frequency plot) were determined in well-aligned crypts. Total cell number, GCI and the labelled cell position frequency plots were similar in different samples from the same individual. A negative linear correlation between TCN and TLI was observed. The analysis of the cell position plots showed two patterns 1) with a high concentration in the bottom fifth of the crypt and 2) with frequent labelled cells at high positions. Whereas a negative correlation between overall TLI and the percent contribution to the TLI of the lowermost fifth was seen, the correlation was positive for the next 3 fifths and labelling was absent in the last part of the crypt. 相似文献
95.
F Boccardo A Rubagotti M Battaglia P Di Tonno F P Selvaggi G Conti G Comeri A Bertaccini G Martorana P Galassi F Zattoni A Macchiarella A Siragusa G Muscas F Durand D Potenzoni A Manganelli V Ferraris F Montefiore 《Journal of clinical oncology》2005,23(4):808-815
PURPOSE: To determine whether tamoxifen or anastrozole prevents gynecomastia and breast pain caused by bicalutamide (150 mg) without compromising efficacy, safety, or sexual functioning. PATIENTS AND METHODS: A double-blind, placebo-controlled trial was performed in patients with localized, locally advanced, or biochemically recurrent prostate cancer. Patients (N = 114) were randomly assigned to either bicalutamide (150 mg/d) plus placebo or in combination with tamoxifen (20 mg/d) or anastrozole (1 mg/d) for 48 weeks. Gynecomastia, breast pain, prostate-specific antigen (PSA), sexual functioning, and serum levels of hormones were assessed. RESULTS: Gynecomastia developed in 73% of patients in the bicalutamide group, 10% of patients in the bicalutamide-tamoxifen group, and 51% of patients in the bicalutamide-anastrozole group (P < .001); breast pain developed in 39%, 6%, and 27% of patients, respectively (P = .006). Baseline PSA level decreased by > or = 50% in 97%, 97%, and 83% of patients in the bicalutamide, bicalutamide-tamoxifen, and bicalutamide-anastrozole groups, respectively (P = .07); and adverse events were reported in 37%, 35%, and 69% of patients, respectively (P = .004). There were no major differences among treatments in sexual functioning parameters from baseline to month 6. Elevated testosterone levels occurred in each group; however, free testosterone levels remained unchanged in the bicalutamide-tamoxifen group because of increased sex hormone-binding globulin levels. CONCLUSION: Anastrozole did not significantly reduce the incidence of bicalutamide-induced gynecomastia and breast pain. In contrast, tamoxifen was effective, without increasing adverse events, at least in the short-term follow-up. These data support the need for a larger study to determine any effect on mortality. 相似文献
96.
Kirsti A Bocskay Deliang Tang Manuela A Orjuela Xinhua Liu Dorothy P Warburton Frederica P Perera 《Cancer epidemiology, biomarkers & prevention》2005,14(2):506-511
Molecular and traditional epidemiology studies have indicated a possible relationship between in utero environmental exposures and increased risk for childhood cancers, especially acute leukemias. Chromosomal aberrations have been associated with environmental exposures and cancer risk in adults. In order to more clearly define the association between prenatal exposures to carcinogenic polycyclic aromatic hydrocarbons (PAH) and chromosomal aberrations, chromosomal aberration frequencies were measured in a subset of 60 newborns from the Columbia Center for Children's Environmental Health (CCCEH) Prospective Cohort Study. The subset was composed of African American and Dominican, nonsmoking mother-newborn pairs residing in low-income neighborhoods of New York City, who were exposed to varying levels of airborne PAHs. Prenatal exposure was assessed by questionnaire, personal air monitoring during the third trimester, and PAH-DNA adducts in umbilical cord blood. Chromosomal aberrations were measured in cord blood lymphocytes by fluorescence in situ hybridization. PAH-DNA adducts were not associated with chromosomal aberrations. However, airborne PAHs were significantly associated with stable aberration frequencies in cord blood (P < 0.01). Moreover, stable aberration frequencies were significantly higher among African American newborns compared with Dominican, despite no significant differences in PAH exposure. These results show for the first time an association between prenatal exposure to airborne carcinogenic PAHs and chromosomal aberrations in cord blood, suggesting that such prenatal exposures have the potential to cause cytogenetic damage that has been related to increased cancer risk in other populations. If confirmed, this finding may open new avenues for prevention. 相似文献
97.
Luigi Quintieri Cristina Geroni Marianna Fantin Rosangela Battaglia Antonio Rosato William Speed Paola Zanovello Maura Floreani 《Clinical cancer research》2005,11(4):1608-1617
PURPOSE: Nemorubicin (3'-deamino-3'-[2'(S)-methoxy-4'-morpholinyl]doxorubicin; MMDX) is an investigational drug currently in phase II/III clinical testing in hepatocellular carcinoma. A bioactivation product of MMDX, 3'-deamino-3',4'-anhydro-[2'(S)-methoxy-3'(R)-oxy-4'-morpholinyl]doxorubicin (PNU-159682), has been recently identified in an incubate of the drug with NADPH-supplemented rat liver microsomes. The aims of this study were to obtain information about MMDX biotransformation to PNU-159682 in humans, and to explore the antitumor activity of PNU-159682. EXPERIMENTAL DESIGN: Human liver microsomes (HLM) and microsomes from genetically engineered cell lines expressing individual human cytochrome P450s (CYP) were used to study MMDX biotransformation. We also examined the cytotoxicity and antitumor activity of PNU-159682 using a panel of in vitro-cultured human tumor cell lines and tumor-bearing mice, respectively. RESULTS: HLMs converted MMDX to a major metabolite, whose retention time in liquid chromatography and ion fragmentation in tandem mass spectrometry were identical to those of synthetic PNU-159682. In a bank of HLMs from 10 donors, rates of PNU-159682 formation correlated significantly with three distinct CYP3A-mediated activities. Troleandomycin and ketoconazole, both inhibitors of CYP3A, markedly reduced PNU-159682 formation by HLMs; the reaction was also concentration-dependently inhibited by a monoclonal antibody to CYP3A4/5. Of the 10 cDNA-expressed CYPs examined, only CYP3A4 formed PNU-159682. In addition, PNU-159682 was remarkably more cytotoxic than MMDX and doxorubicin in vitro, and was effective in the two in vivo tumor models tested, i.e., disseminated murine L1210 leukemia and MX-1 human mammary carcinoma xenografts. CONCLUSIONS: CYP3A4, the major CYP in human liver, converts MMDX to a more cytotoxic metabolite, PNU-159682, which retains antitumor activity in vivo. 相似文献
98.
AIM: The authors aim to evaluate the sensitivity and specificity of abdominal ultrasonography in 183 in-patients (113 females--70 males), aged between 3 and 78 years old, in the General Surgery department of Pugliese Hospital in Catanzaro, for abdominal pain and possible acute appendicitis, using a retrospective study. All patients underwent ultrasonography at the Division of Radiology in the same hospital. METHODS: The technique used was graded-compression US (useful to eliminate gas artifacts and to reduce the distance from the appendix) using a linear transducer between 3.5 and 7.5 MHz. The method lasted an average of 15 minutes and was performed by specially trained radiologists. The transducer was held between the forefinger and thumb and pushed into the abdomen using both palms, as if palpating the abdomen. When compression is applied slowly and gently, the pain is surprisingly well tolerated by the patient. The radiologist records whether the inflamed appendix is visualised ultrasonographically and with what degree of certainty, and whether perforations or the formation of abscesses and other pathological processes can be seen. In this case, clinical diagnosis was confirmed by radiological imaging and eventually by surgical evidence. RESULTS: Of the 183 patients examined, 135 showed positive US findings, 11 refused surgery and pain was resolved by pharmacological treatment, and 9 presented other pathologies (3 gastric ulcers, 4 acute cholecystitis and 2 extrauterine pregnancies). Therefore, 115 patients were effectively positive. Of the 183 patients, 48 were negative but of these, only 39 were effectively negative because 3 were false negatives and 6 revealed other pathologies when examined using other methods of diagnosis. Even if the diagnosis of appendicitis was confirmed by clinical examination in most cases, US is of value both to confirm the clinical diagnosis and to rule out any complications. In this particular case it was also useful for the surgeon as a means of locating the position of the appendix. Even if this method is partly conditioned by the patient's clinical conditions, the results were excellent. CONCLUSIONS: The authors conclude that US of the appendix is a valuable aid in the diagnosis of appendicitis, especially in the case of acute or subacute forms in which other radiological imaging might worsen the pathology and lead to the onset of further complications. US offers undeniable advantages using a non-invasive, low cost technique with a specificity of around 80% and sensitivity between 85 and 93%. It also provides a means of identifying other sources of low abdominal pain. However, we still regard clinical examination as being essential for diagnosis. 相似文献
99.
Stefan Pleus Andreas Stuhr Manuela Link Cornelia Haug Guido Freckmann 《Journal of diabetes science and technology》2022,16(3):649
Background:There is an increasing use of continuous glucose monitoring (CGM) by people with diabetes. Measurement performance is often characterized by the mean absolute relative difference (MARD). However, MARD is influenced by a number of factors and little is known about whether MARD is stable throughout the day.Material and Methods:A total of 24 participants with type 1 diabetes were enrolled in the study. The study was performed for seven in-patient days. Participants wore two CGM systems in parallel and performed additional frequent blood glucose (BG) measurements. On two days, glucose excursions were induced.MARD was calculated between pairs of CGM and BG values, with BG values serving as reference values. ARD values calculated from CGM-BG pairs were grouped by hour of the day. Results were analyzed separately for glucose excursion days and for regular days.Results:Total MARDs for the complete study duration were 12.5% ± 3.6% and 13.2% ± 2.4% (n = 24). Throughout the day marked variability of MARD was observed (8.0% ± 1.3%-16.3% ± 2.9% (G5); 9.1% ± 1.4%-16.3% ± 5.3% (FL), up to n = 157 each). Low(est) MARD values were observed before breakfast and dinner, when subjects were in or near a fasting state. Especially after breakfast and lunch, MARD values were higher than average.Conclusions:Analytical performance of the two CGM systems, assessed by MARD, was found to vary markedly throughout the day. Activities of daily life likely triggered these variations. An increasing number of CGM users base therapeutic decisions on CGM values, and they should be aware of these variations of performance throughout the day. 相似文献
100.