全文获取类型
收费全文 | 13976篇 |
免费 | 655篇 |
国内免费 | 119篇 |
专业分类
耳鼻咽喉 | 95篇 |
儿科学 | 273篇 |
妇产科学 | 409篇 |
基础医学 | 1733篇 |
口腔科学 | 355篇 |
临床医学 | 959篇 |
内科学 | 3957篇 |
皮肤病学 | 217篇 |
神经病学 | 1316篇 |
特种医学 | 589篇 |
外科学 | 2097篇 |
综合类 | 34篇 |
一般理论 | 1篇 |
预防医学 | 499篇 |
眼科学 | 156篇 |
药学 | 695篇 |
中国医学 | 23篇 |
肿瘤学 | 1342篇 |
出版年
2024年 | 12篇 |
2023年 | 89篇 |
2022年 | 200篇 |
2021年 | 409篇 |
2020年 | 207篇 |
2019年 | 298篇 |
2018年 | 390篇 |
2017年 | 289篇 |
2016年 | 323篇 |
2015年 | 362篇 |
2014年 | 553篇 |
2013年 | 701篇 |
2012年 | 970篇 |
2011年 | 989篇 |
2010年 | 643篇 |
2009年 | 587篇 |
2008年 | 1000篇 |
2007年 | 1002篇 |
2006年 | 908篇 |
2005年 | 954篇 |
2004年 | 849篇 |
2003年 | 783篇 |
2002年 | 695篇 |
2001年 | 79篇 |
2000年 | 69篇 |
1999年 | 100篇 |
1998年 | 148篇 |
1997年 | 108篇 |
1996年 | 128篇 |
1995年 | 86篇 |
1994年 | 98篇 |
1993年 | 79篇 |
1992年 | 70篇 |
1991年 | 55篇 |
1990年 | 50篇 |
1989年 | 40篇 |
1988年 | 30篇 |
1987年 | 20篇 |
1986年 | 34篇 |
1985年 | 32篇 |
1984年 | 30篇 |
1983年 | 24篇 |
1982年 | 32篇 |
1981年 | 33篇 |
1980年 | 31篇 |
1979年 | 20篇 |
1976年 | 10篇 |
1975年 | 8篇 |
1974年 | 8篇 |
1964年 | 8篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
Yuri A. Zarate Luigi Boccuto Sujata Srikanth Rini Pauly Eylem Ocal Tonya Balmakund Kevin Hinkle Vikki Stefans Gerald B. Schaefer Ronnie Thomas Collins II 《American journal of medical genetics. Part A》2019,179(6):1047-1052
Kosaki overgrowth syndrome is a recently described syndrome characterized by distinctive facial features, brain white matter lesions, and developmental delay. Germline activating heterozygous PDGFRB mutations have been reported in this condition. Systemic connective tissue‐type findings have been described in some individuals. We describe a 19‐year‐old Caucasian female with a history of hydrocephalus, Dandy–Walker malformation, cervical spine arachnoid cyst, progressive scoliosis, and overgrowth. Her physical exam included distinctive craniofacial dysmorphism, as well as soft and hyperextensible skin. Cardiovascular imaging during adolescence revealed saccular aneurysms in both coronary artery systems and subtle tortuosity of the cervical vertebral arteries. Exome sequencing trio analysis identified a de novo previously reported pathogenic variant in PDGFRB, c.1696T>C (p.[Trp566Arg]). Further functional studies included platelet‐derived growth factor cellular metabolic pathway activity that confirmed the variant causes a constitutive activation of the PI3K‐AKT pathway. This is the first report to characterize the activating nature of this PDGFRB variant. We also highlight the connective tissue findings seen in Kosaki overgrowth syndrome and recommend baseline echocardiographic evaluation in all individuals with this condition with particular emphasis on coronary arteries. 相似文献
72.
Buonaguro L Tagliamonte M Tornesello ML Pilotti E Casoli C Lazzarin A Tambussi G Ciccozzi M Rezza G Buonaguro FM;Italian Concerted Action on PHI Treatment 《Journal of acquired immune deficiency syndromes (1999)》2004,37(2):1295-1306
OBJECTIVE: The increasing prevalence of HIV-1 transmission through heterosexual contacts and the growing number of immigrants from non-Western countries, where non-B subtypes and recombinant forms are prevalent, suggest the possible emergence in Italy of a new epidemic wave of HIV-1 non-B subtypes as well as recombinant forms. METHODS: The distribution of HIV-1 subtypes has been evaluated in 63 seropositive individuals residing in Italy, most of whom were infected through a sexual route during the last 5 years. A modified heteroduplex mobility assay (HMA) strategy, reverse HMA (rHMA), has been developed in our laboratory, allowing rapid identification of divergent-from-B-subtype isolates, which have been subsequently characterized by detailed molecular and phylogenetic analyses. RESULTS: Five samples show, on rHMA, an electrophoretic pattern compatible with a non-B subtype classification. Their phylogenetic analysis, performed on both env and gag regions, confirms the rHMA subtyping prediction, given that 3 samples fall into the "A-family" subtype and 2 into the G subtype. The 5 non-B-subtype HIV-1 isolates have been identified among 23 variants (prevalence, 21.74%) isolated during the 2000 to 2001 period in heterosexuals. In parallel, B-subtype isolates show high levels of intrasubtype nucleotide divergence, compatible with a constant HIV-1 molecular diversification. CONCLUSION: The Italian HIV-1 epidemic is still mostly attributable to the B subtype, which shows an increasing nucleotide heterogeneity. Heterosexual transmission and the interracial blending, however, are slowly introducing novel HIV-1 subtypes, and the data indicate that rHMA represents a powerful tool for HIV-1 biomolecular screening in epidemics characterized by a mono-/dual-subtype predominance. 相似文献
73.
Pnina Fishman Emily Falach-Vaknin Benjamin Sredni Piere Luigi Meroni Angela Tincani Dror Dicker Yehuda Shoenfeld 《American journal of reproductive immunology (New York, N.Y. : 1989)》1996,35(2):80-84
PROBLEM: Previously we reported on the generation of experimental anti-phospholipid syndrome (APS) in mice. These models were employed to evaluate the efficacy of various novel therapeutic modalities including interleukin-3 (IL-3) and low dose aspirin. The efficacy of the latter was found to be interrelated. Low dose aspirin is capable of inhibiting the activity of the enzyme cyclooxygenase which is responsible for the metabolism of arachidonic acid towards the production of prostaglandins. This shifts the metabolism of arachidonic acid to the other pathway and leads to an overproduction of leukotrienes. The leukotrienes act as stimulators of IL-3 production, a positive cytokine in pregnancy which enhances placental and fetal development. In the current study we evaluated the IL-3 levels in pregnant women with APS and expanded our knowledge on the interrelationships between aspirin, arachidonic acid metabolites and IL-3 in the human system. METHODS: IL-3 levels were recorded in the serum of pregnant women with APS and compared to a control pregnant group. In addition peripheral blood mononuclear cells from healthy subjects were incubated with different concentrations of aspirin or with arachidonic acid metabolites (Leukotriene B4, C4 or PGE2), and IL-3 production in the culture fluids was evaluated. RESULTS: Serum level of IL-3 in pregnant patients with primary APS, APS secondary to SLE and SLE was lower in comparison to the control group. The in vitro studies revealed that only low dose aspirin (10 mg/μl) stimulated IL-3 production while higher doses of the drug failed to induce the cytokine generation. Leukotriene B4 and C4 were stimulatory whereas PGE2 acted as inhibitor of IL-3 production. CONCLUSIONS: The serum level of IL-3 is decreased to pregnant women with primary or secondary APS. Low dose aspirin is capable of stimulating EL-3 production in vitro most probably through an elevation of leukotriene production, which may explain its beneficial activity in preventing the manifestations of APS. 相似文献
74.
Daniela Vitucci Angela Amoresano Marcella Nunziato Simona Muoio Andreina Alfieri Giovannangelo Oriani Luca Scalfi Luigi Frusciante Maria Manuela Rigano Piero Pucci Luigi Fontana Pasqualina Buono Francesco Salvatore 《Nutrients》2021,13(4)
The isoforms of lycopene, carotenoids, and their derivatives including precursors of vitamin A are compounds relevant for preventing chronic degenerative diseases such as cardiovascular diseases and cancer. Tomatoes are a major source of these compounds. However, cooking and successive metabolic processes determine the bioavailability of tomatoes in human nutrition. To evaluate the effect of acute/chronic cooking procedures on the bioavailability of lycopene and carotene isoforms in human plasma, we measured the blood levels of these compounds and of the serum antioxidant potential in volunteers after a meal containing two different types of tomato sauce (rustic or strained). Using a randomized cross-over administration design, healthy volunteers were studied, and the above indicated compounds were determined by HPLC. The results indicate an increased bioavailability of the estimated compounds and of the serum antioxidant potential with both types of tomato purée and the subsequently derived sauces (the increase was greater with strained purée). This study sheds light on the content of nutrient precursors of vitamin A and other antioxidant compounds derived from tomatoes cooked with different strategies. Lastly, our study indicates that strained purée should be preferred over rustic purée. 相似文献
75.
Luigi Barrea Giovanna Muscogiuri Gabriella Pugliese Chiara Graziadio Maria Maisto Francesca Pivari Andrea Falco Gian Carlo Tenore Annamaria Colao Silvia Savastano 《Nutrients》2021,13(5)
Individual differences in the chronotype, an attitude that best expresses the individual circadian preference in behavioral and biological rhythms, have been associated with cardiometabolic risk and gut dysbiosis. Up to now, there are no studies evaluating the association between chronotypes and circulating TMAO concentrations, a predictor of cardiometabolic risk and a useful marker of gut dysbiosis. In this study population (147 females and 100 males), subjects with the morning chronotype had the lowest BMI and waist circumference (p < 0.001), and a better metabolic profile compared to the other chronotypes. In addition, the morning chronotype had the highest adherence to the Mediterranean diet (p < 0.001) and the lowest circulating TMAO concentrations (p < 0.001). After adjusting for BMI and adherence to the Mediterranean diet, the correlation between circulating TMAO concentrations and chronotype score was still kept (r = −0.627, p < 0.001). Using a linear regression analysis, higher chronotype scores were mostly associated with lower circulating TMAO concentrations (β = −0.479, t = −12.08, and p < 0.001). Using a restricted cubic spline analysis, we found that a chronotype score ≥59 (p < 0.001, R2 = −0.824) demonstrated a more significant inverse linear relationship with circulating TMAO concentrations compared with knots <59 (neither chronotype) and <41 (evening chronotype). The current study reported the first evidence that higher circulating TMAO concentrations were associated with the evening chronotype that, in turn, is usually linked to an unhealthy lifestyle mostly characterized by low adherence to the MD. 相似文献
76.
Barbara Colitti Luigi Bertolotti Alessandro Mannelli Gianmarco Ferrara Andrea Vercelli Andrea Grassi Claudio Trentin Saverio Paltrinieri Chiara Nogarol Nicola Decaro Emiliana Brocchi Sergio Rosati 《Emerging infectious diseases》2021,27(7):1919
We conducted a serologic survey among dogs and cats in Italy to detect antibodies against severe acute respiratory syndrome virus 2 (SARS-CoV-2). We found that SARS-CoV-2 seroprevalence was higher among cats (16.2%) than dogs (2.3%). In addition, seroprevalence was higher among animals living in close contact with SARS-CoV-2–positive owners. 相似文献
77.
Luca Boeri Federico Belladelli Paolo Capogrosso Walter Cazzaniga Luigi Candela Edoardo Pozzi Luca Valsecchi Enrico Papaleo Paola Viganò Costantino Abbate Filippo Pederzoli Massimo Alfano Francesco Montorsi Andrea Salonia 《Andrologia》2021,53(1):e13861
A proportion of men are infertile despite having normal medical history/physical examination and normal semen analysis. We aimed to assess whether normal sperm parameters per se account for male factor fertility. 1,957 infertile men were compared with 103 age-comparable fertile controls. Semen analysis was based on 2010 World Health Organization reference criteria. Of all, 12.1% of infertile men and 40.8% of fertile men presented with normal sperm parameters. Among fertile men, 36.9% had isolated sperm abnormalities and 22.3% men showed two or more concomitant sperm abnormalities. Serum total testosterone was higher in infertile men with normal sperm parameters compared to those with ≥2 sperm abnormalities or azoospermia, but similar to those with isolated sperm abnormalities (p ≤ .001). Circulating hormones were similar among sperm parameters groups in fertile men. At multivariable analyses, testicular volume (OR 1.12, p ≤ .001) and FSH (OR 0.8, p ≤ .001) were associated with normal sperm parameters. Overall, the longer the infertility period, the greater the number of sperm parameters abnormalities (p < .01). In conclusion, we found that 12% of infertile men and only 41% of fertile men present with normal sperm parameters. Normal sperm parameters per se do not reliably account for fertility in the real-life setting. 相似文献
78.
Santoro Giorgio Piccirilli Manolo Chiarella Vito Greco Nicoletta Berra Luigi Valentino Santoro Antonio 《Neurosurgical review》2021,44(4):1977-1985
Neurosurgical Review - Capillary hemangiomas (CHs) of the central nervous system represent a rare diagnosed pathology. CHs are benign vascular tumors whose most common manifestations are dermal and... 相似文献
79.
Vural Alperen Carobbio Andrea Luigi Camillo Ferrari Marco Rampinelli Vittorio Schreiber Alberto Mattavelli Davide Doglietto Francesco Buffoli Barbara Rodella Luigi Fabrizio Taboni Stefano Tomasoni Michele Gualtieri Tommaso Deganello Alberto Hirtler Lena Nicolai Piero 《Neurosurgical review》2021,44(5):2857-2878
Neurosurgical Review - Transorbital endoscopic approaches are increasing in popularity as they provide corridors to reach various areas of the ventral skull base through the orbit. They can be used... 相似文献
80.
Luca M. Sconfienza Domenico Albano Carmelo Messina Rocco D’Apolito Elena De Vecchi Luigi Zagra 《The Journal of arthroplasty》2021,36(8):2962-2967
BackgroundTo diagnose periprosthetic joint infection (PJI) preoperatively, ultrasound-guided joint aspiration (US-JA) may not be performed when effusion is minimal or absent. We aimed to report and investigate the diagnostic performance of ultrasound-guided periprosthetic biopsy (US-PB) of synovial tissue to obtain joint samples in patients without fluid around the implants.MethodsOne-hundred nine patients (55 men; mean age: 68 ± 13 years) with failed total hip arthroplasty (THA) who underwent revision surgery performed preoperative US-JA or US-PB to rule out PJI.ResultsSixty-nine of 109 patients had joint effusion and underwent US-JA, while the remaining 40 with dry joint required US-PB. Thirty-five of 109 patients (32.1%) had PJI, while 74/109 (67.9%) had aseptic THA failure. No immediate complications were observed in both groups. Technical success of US-PB was 100%, as the procedure was carried on as planned in all cases. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of US-JA were 52.2%, 97.8%, 92.3%, 80.3%, and 82.6%, while for US-PB, they were 41.7%, 100%, 100%, 80%, and 82.5%, respectively, with no significant difference (P = .779). Using the final diagnosis as reference standard, we observed a moderate agreement with both US-JA (k = 0.56) and US-PB (k = 0.50).ConclusionWe present a novel US-guided technique to biopsy periprosthetic synovial tissue of failed THA to rule out PJI. We found similar diagnostic performance as compared with traditional US-JA. This supports future larger studies on this procedure that might be applied in patients without joint effusion. 相似文献