全文获取类型
收费全文 | 10853篇 |
免费 | 691篇 |
国内免费 | 65篇 |
专业分类
耳鼻咽喉 | 63篇 |
儿科学 | 244篇 |
妇产科学 | 283篇 |
基础医学 | 1539篇 |
口腔科学 | 399篇 |
临床医学 | 1001篇 |
内科学 | 2210篇 |
皮肤病学 | 192篇 |
神经病学 | 1334篇 |
特种医学 | 322篇 |
外科学 | 1262篇 |
综合类 | 24篇 |
现状与发展 | 1篇 |
一般理论 | 8篇 |
预防医学 | 982篇 |
眼科学 | 121篇 |
药学 | 690篇 |
中国医学 | 49篇 |
肿瘤学 | 885篇 |
出版年
2024年 | 17篇 |
2023年 | 122篇 |
2022年 | 250篇 |
2021年 | 426篇 |
2020年 | 259篇 |
2019年 | 393篇 |
2018年 | 433篇 |
2017年 | 343篇 |
2016年 | 394篇 |
2015年 | 371篇 |
2014年 | 468篇 |
2013年 | 607篇 |
2012年 | 872篇 |
2011年 | 848篇 |
2010年 | 453篇 |
2009年 | 425篇 |
2008年 | 671篇 |
2007年 | 642篇 |
2006年 | 629篇 |
2005年 | 571篇 |
2004年 | 534篇 |
2003年 | 473篇 |
2002年 | 383篇 |
2001年 | 115篇 |
2000年 | 82篇 |
1999年 | 110篇 |
1998年 | 59篇 |
1997年 | 69篇 |
1996年 | 39篇 |
1995年 | 34篇 |
1994年 | 32篇 |
1993年 | 24篇 |
1992年 | 51篇 |
1991年 | 65篇 |
1990年 | 34篇 |
1989年 | 41篇 |
1988年 | 32篇 |
1987年 | 33篇 |
1986年 | 27篇 |
1985年 | 25篇 |
1984年 | 26篇 |
1983年 | 8篇 |
1982年 | 15篇 |
1981年 | 9篇 |
1980年 | 8篇 |
1979年 | 11篇 |
1977年 | 11篇 |
1974年 | 12篇 |
1973年 | 8篇 |
1971年 | 8篇 |
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
91.
92.
Mitch Dowsett Steve R Ebbs J Michael Dixon Anthony Skene Clive Griffith Irene Boeddinghaus Janine Salter Simone Detre Margaret Hills Susan Ashley Stephen Francis Geraldine Walsh Ian E Smith 《Journal of clinical oncology》2005,23(11):2477-2492
PURPOSE: To investigate the relationships between biomarker changes in breast cancer during neoadjuvant (preoperative) endocrine therapy. PATIENTS AND METHODS: The IMPACT trial compared the preoperative use of tamoxifen with anastrozole alone or in combination in postmenopausal women (n = 330) with primary breast cancer. Biomarkers were measured in tumor biopsy specimens taken at baseline, and after 2 and 12 weeks of treatment. RESULTS: 52 (93%) of 56, 46 (85%) of 54, and 37 (84%) of 44 patients in the anastrozole, tamoxifen, and combination groups, respectively. There was a significantly greater suppression of Ki67 in the anastrozole-treated group than in the tamoxifen- or combination-treated groups, which is parallel to the greater efficacy seen for anastrozole over these two treatments in the Arimidex, Tamoxifen, Alone or in Combination adjuvant trial. A positive relationship was noted between estrogen-receptor level and Ki67 suppression in all patients. Ki67 was reduced to a greater extent in progesterone receptor-positive tumors compared with progesterone receptor-negative tumors. HER-2-negative tumors tended to show a greater reduction in Ki67 compared with HER-2-positive tumors, but the difference was only significant in the tamoxifen group after 2 weeks, and in the anastrozole group after 12 weeks. CONCLUSION: These results confirm the value of Ki67 as a molecular marker, and provide information regarding the relationships between treatment-induced changes in Ki67 and other important biomarkers. Studies such as this should help integrate agents targeted at growth factor signaling with endocrine agents in breast cancer. 相似文献
93.
Luisa Di Marzio Alfredo Di Leo Benedetta Cinque Donatella Fanini Alessio Agnifili Pasquale Berloco Michele Linsalata Dionigi Lorusso Michele Barone Claudio De Simone Maria Grazia Cifone 《Cancer epidemiology, biomarkers & prevention》2005,14(4):856-862
OBJECTIVES: Intestinal alkaline sphingomyelinase, by exerting a major role in dietary sphingomyelin digestion, is responsible for the generation of messengers able to trigger the rapid turnover and apoptosis in intestinal epithelial cells. Markedly reduced mucosal alkaline sphingomyelinase activity has been associated with human colorectal neoplasms. The aim of this study was to analyze the alkaline sphingomyelinase activity in feces from healthy subjects and colorectal adenocarcinoma patients and to correlate it with the enzyme activity in intestinal tissues. MATERIALS AND METHODS: The enzyme activity was measured both in the intestinal samples from 12 healthy controls and 51 patients with colorectal adenocarcinoma (tumoral and paratumoral tissue) and in the fecal samples of 34 healthy subjects and 29 patients with adenocarcinoma. The relation between sphingomyelinase activity and Dukes' stage, cell differentiation degree, age, and gender was also analyzed. RESULTS: Alkaline sphingomyelinase was significantly decreased (P < 0.001; mean reduction >90%) in tumoral intestinal mucosa of patients compared with controls independently of Dukes' stage and tumor differentiation grade. Interestingly, the enzyme activity in histologically normal paratumoral tissues was statistically lower than control samples (P < 0.001). As occurs in neoplastic tissues, a relevant mean reduction (P < 0.0001; almost 90%) of alkaline sphingomyelinase was revealed in stool samples from tumor patients when compared with controls. CONCLUSION: These findings may have implications for cancer biology and perhaps also for the design of clinical test, thus suggesting that the fecal sphingomyelinase activity could really reflect the human intestinal mucosa enzyme level and could represent a new marker for human colorectal adenocarcinoma, mainly taking into account its early appearance in intestinal neoplasms. 相似文献
94.
Simone Bagel Bernd Wiedemann 《European journal of pharmaceutics and biopharmaceutics》2004,57(2):353-358
Nasal drops and nasal sprays are commonly supplied in multi-dose containers that usually include suitable levels of an appropriate preservative in order to kill or prevent growth of any microorganisms which might enter the dispensing system. Preservatives should both protect the patient from infection and prevent spoilage of the product. Unfortunately, preservatives often cause unwanted side effects; in particular, the nasal mucosa is irritated frequently. Consequently, the use of preservatives in nasal preparations should be avoided. The technical design of the 3K system, a new multi-dose container, combines several microbiological safety features and therefore allows use without preservatives. Earlier tests have shown its safety for 6 weeks after the first opening. In order to test the microbiological safety of this multi-dose system over longer time periods, an in-use stability test was designed. The results revealed that the first dose as well as the contents complied with the requirements of the European Pharmacopoeia. Therefore, from a microbiological point of view for the tested nasalia in the 3K system, the stability after opening could be extended from 6 weeks up to several months without loss of microbiological quality. 相似文献
95.
96.
Simone Ribero John R. Davies Celia Requena Cristina Carrera Daniel Glass Ramon Rull Sergi Vidal‐Sicart Antonio Vilalta Lucia Alos Virtudes Soriano Pietro Quaglino Victor Traves Julia A. Newton‐Bishop Eduardo Nagore Josep Malvehy Susana Puig Veronique Bataille 《International journal of cancer. Journal international du cancer》2015,137(7):1691-1698
A high number of nevi is the most significant phenotypic risk factor for melanoma and is in part genetically determined. The number of nevi decreases from middle age onward but this senescence can be delayed in patients with melanoma. We investigated the effects of nevus number count on sentinel node status and melanoma survival in a large cohort of melanoma cases. Out of 2,184 melanoma cases, 684 (31.3%) had a high nevus count (>50). High nevus counts were associated with favorable prognostic factors such as lower Breslow thickness, less ulceration and lower mitotic rate, despite adjustment for age. Nevus count was not predictive of sentinel node status. The crude 5‐ and 10‐year melanoma‐specific survival rate was higher in melanomas cases with a high nevus count compared to those with a low nevus count (91.2 vs. 86.4% and 87.2 vs. 79%, respectively). The difference in survival remained significant after adjusting for all known melanoma prognostic factors (hazard ratio [HR] = 0.43, confidence interval [CI] = 0.21–0.89). The favorable prognostic value of a high nevus count was also seen within the positive sentinel node subgroup of patients (HR = 0.22, CI = 0.08–0.60). High nevus count is associated with a better melanoma survival, even in the subgroup of patients with positive sentinel lymph node. This suggests a different biological behavior of melanoma tumors in patients with an excess of nevi. 相似文献
97.
Fiorentini G Rossi S Bonechi F Vaira M De Simone M Dentico P Bernardeschi P Cantore M Guadagni S 《Journal of chemotherapy (Florence, Italy)》2004,16(3):293-297
Neuroendocrine tumors, particularly those of gastrointestinal tract origin, have a predisposition for metastasizing to the liver, causing parenchymal substitution and paraneoplastic syndrome. Lipiodol embolization combined with anticancer drugs is a recent tool in regional therapy. It has been proven that chemoembolization reduces tumor bulk and hormone levels, and that it palliates the symptoms of many patients with liver-dominant neuroendocrine metastases. Beginning in December 1988, ten patients with unresectable and chemotherapy-refractory liver metastatic neuroendocrine tumors were treated with chemoembolization based on a mixture of lipiodol, mitomycin, cisplatin, epirubicin, followed by gelfoam powder and contrast media. Toxicity encountered included: upper right quadrant pain requiring narcotics, elevation of lactate dehydrogenase, alkaline phosphatase, and transaminases. One patient had liver abscess and persistent fever for 2 weeks. We obtained two complete remissions lasting 12 and 34 months and 5 partial remissions. The median survival was 22 months. Four patients had urinary elevation of 5-hydroxyindolacetic acid (5-HIAA). They showed more than a 75% decrease in urinary secretion after treatment. In a patient with transplanted liver we noticed a partial response lasting 7 months. We conclude that chemoembolization will improve the clinical condition of a significant percentage of patients with liver metastases, that future therapy of carcinoid tumors will be based on specific tumor biology and that treatment will be customized for each individual patient combining the use of cytoreductive procedures including radiofrequency ablation, laser treatment and chemoembolization. 相似文献
98.
Simone Murchio Matteo Benedetti Anastasia Berto Francesca Agostinacchio Gianluca Zappini Devid Maniglio 《Materials》2022,15(17)
Despite the tremendous technological advances that metal additive manufacturing (AM) has made in the last decades, there are still some major concerns guaranteeing its massive industrial application in the biomedical field. Indeed, some main limitations arise in dealing with their biological properties, specifically in terms of osseointegration. Morphological accuracy of sub-unital elements along with the printing resolution are major constraints in the design workspace of a lattice, hindering the possibility of manufacturing structures optimized for proper osteointegration. To overcome these issues, the authors developed a new hybrid multifunctional composite scaffold consisting of an AM Ti6Al4V lattice structure and a silk fibroin/gelatin foam. The composite was realized by combining laser powder bed fusion (L-PBF) of simple cubic lattice structures with foaming techniques. A combined process of foaming and electrodeposition has been also evaluated. The multifunctional scaffolds were characterized to evaluate their pore size, morphology, and distribution as well as their adhesion and behavior at the metal–polymer interface. Pull-out tests in dry and hydrated conditions were employed for the mechanical characterization. Additionally, a cytotoxicity assessment was performed to preliminarily evaluate their potential application in the biomedical field as load-bearing next-generation medical devices. 相似文献
99.
Federica Ursi Simone Virga Gonzalo Garcìa-Espejo Norberto Masciocchi Antonino Martorana Francesco Giannici 《Materials》2022,15(23)
Layered TiS2 intercalated with linear alkylamines has recently attracted significant interest as a model compound for flexible n-type thermoelectric applications, showing remarkably high power factors at room temperature. The thermal and, particularly, environmental stability of such materials is, however, a still an open challenge. In this paper, we show that amine-intercalated TiS2 prepared by a simple mechanochemical process is prone to chemical decomposition through sulfur exsolution, and that the presence of molecular oxygen is likely to mediate the decomposition reaction. Through computational analysis of the possible reaction pathways, we propose that Ti-N adducts are formed as a consequence of amine groups substituting for S vacancies on the internal surfaces of the S-Ti-S layers. These findings provide insights for possible future applications of similar hybrid compounds as devices operating in ambient conditions, and suggest isolating them from atmospheric oxygen. 相似文献
100.
Leonardo De Luca Paolo Calabr Fabio Chirillo Cristina Rolfo Alberto Menozzi Piera Capranzano Maurizio Menichelli Elisa Nicolini Ciro Mauro Carlo Trani Francesco Versaci Fabrizio Tomai Giuseppe Musumeci Carlo Di Mario Martino Pepe Sergio Berti Carlo Cernetti Plinio Cirillo Diego Maffeo Giuseppe Talanas Marco Ferlini Marco Contarini Valerio Lanzilotti Marino Scherillo Giuseppe Tarantini Simone Muraglia Roberta Rossini Leonardo Bolognese ARCANGELO study group 《Clinical cardiology》2022,45(9):913
BackgroundThe itAlian pRospective Study on CANGrELOr (ARCANGELO) was aimed to assess the safety of using cangrelor during percutaneous coronary intervention (PCI) in patients with acute coronary syndromes (ACS) in the daily practice.HypothesisThe safety of cangrelor after the transition to oral P2Y12 inhibitors was evaluated as the incidence of bleeding outcomes in the 30 days following PCI according to postauthorization safety study guidelines.MethodsAdults with ACS who were treated with cangrelor in one of the 28 centers involved in the study. Patients who consented to participate were followed in the 30 days following their PCI. Bleedings (Bleeding Academic Research Consortium [BARC] classification), major adverse cardiac events (MACEs), and adverse events were recorded. The interim results at two‐thirds of the enrollment period are presented.ResultsA total of 17 bleedings were observed in the 320 patients who completed the study at this stage. All bleedings were classified as BARC Type 1–2, except for one case of Type 3a (vessel puncture site hematoma). Four patients experienced MACEs (2 acute myocardial infarctions, 1 sudden cardiac death, 1 noncardiovascular death due to respiratory distress, and multiorgan failure). None of the bleedings was rated as related to cangrelor.ConclusionsThe interim results of the ARCANGELO study provide a preliminary confirmation that the use of cangrelor on patients with ACS undergoing PCI is not associated with severe bleedings. 相似文献