全文获取类型
收费全文 | 5025篇 |
免费 | 151篇 |
国内免费 | 18篇 |
专业分类
耳鼻咽喉 | 167篇 |
儿科学 | 218篇 |
妇产科学 | 337篇 |
基础医学 | 723篇 |
口腔科学 | 49篇 |
临床医学 | 217篇 |
内科学 | 1020篇 |
皮肤病学 | 77篇 |
神经病学 | 433篇 |
特种医学 | 110篇 |
外科学 | 333篇 |
综合类 | 18篇 |
一般理论 | 1篇 |
预防医学 | 372篇 |
眼科学 | 236篇 |
药学 | 664篇 |
中国医学 | 5篇 |
肿瘤学 | 214篇 |
出版年
2023年 | 26篇 |
2022年 | 91篇 |
2021年 | 132篇 |
2020年 | 52篇 |
2019年 | 87篇 |
2018年 | 142篇 |
2017年 | 104篇 |
2016年 | 112篇 |
2015年 | 126篇 |
2014年 | 186篇 |
2013年 | 238篇 |
2012年 | 387篇 |
2011年 | 408篇 |
2010年 | 188篇 |
2009年 | 128篇 |
2008年 | 280篇 |
2007年 | 277篇 |
2006年 | 350篇 |
2005年 | 306篇 |
2004年 | 371篇 |
2003年 | 304篇 |
2002年 | 274篇 |
2001年 | 125篇 |
2000年 | 133篇 |
1999年 | 87篇 |
1998年 | 25篇 |
1997年 | 12篇 |
1996年 | 7篇 |
1995年 | 8篇 |
1994年 | 9篇 |
1992年 | 5篇 |
1991年 | 7篇 |
1990年 | 8篇 |
1988年 | 9篇 |
1987年 | 5篇 |
1986年 | 8篇 |
1985年 | 13篇 |
1984年 | 6篇 |
1982年 | 10篇 |
1981年 | 7篇 |
1980年 | 9篇 |
1979年 | 9篇 |
1978年 | 7篇 |
1977年 | 13篇 |
1976年 | 8篇 |
1975年 | 25篇 |
1974年 | 13篇 |
1973年 | 10篇 |
1971年 | 5篇 |
1966年 | 4篇 |
排序方式: 共有5194条查询结果,搜索用时 15 毫秒
71.
Maciej Banach Pawe Burchardt Krzysztof Chlebus Piotr Dobrowolski Dariusz Dudek Krzysztof Dyrbu Mariusz Gsior Piotr Jankowski Jacek J
wiak Longina Kosiewicz-Latoszek Irina Kowalska Maciej Maecki Aleksander Prejbisz Micha Rakowski Jacek Rysz Bogdan Solnica Dariusz Sitkiewicz Grayna Sygitowicz Grayna Sypniewska Tomasz Tomasik Adam Windak Dorota Zozuliska-Zikiewicz Barbara Cybulska 《Archives of Medical Science》2021,17(6):1447
72.
Proteinases are known to be capable of prolonging the survival of endoparasites in a host. We were therefore interested in
knowing whether immunization of lambs against a proteasome (multisubunit proteinases) preparation obtained from Trichostrongylus colubriformis infective third-stage larvae (L3) would have any effect on the immune response to a single challenge infection with the same
organism. A total of 21 penned lambs aged 8 months were divided into 3 equal groups. Group 1 was immunized on three occasions
with increasing amounts of a proteasome-enriched fraction obtained from infective L3. Group 2 was given a similar amount of
protein from the initial supernatant of homogenized larvae. Group 3 (controls) received adjuvant plus saline solution only.
All groups were challenged with 60,000 infective T. colubriformis larvae at 28 days after the last immunization. Significant protection was obtained only when the initial supernatant extract
was used to immunize lambs. The proteasome preparation seemed to have immunosuppressive effects through the stimulation of
nonspecific IgE production. Significantly lower levels of specific IgE were observed in lambs immunized with the proteasome-enriched
fraction, and levels of specific IgG antibodies were increased. We suggest that proteasome fractions of T. colubriformis may serve as useful preparations for the study of mechanisms of IgE production in parasitized sheep.
Received: 26 September 1999 / Accepted: 22 October 1999 相似文献
73.
Zielonka TM Marchel A Pogorzelski R Górska K Safianowska A Byśkiniewicz K Chazan R 《Pneumonologia i alergologia polska》2004,72(9-10):429-432
The authors describe the case of survival for the period of 10 years after brain metastasis surgery and removal of the left lung upper lobe due to adeno-squamous cells carcinoma. Surgery did not generate any complications. Within 8 years after the surgery the radiological examination showed infiltrations resembling changes typical for tuberculosis. Microbiological analysis showed a culture of Mycobacterium kansasi leading to diagnosis of mycobacteriosis. Hence the antituberculous treatment was extended to 12 months to be interrupted due to liver damage. Two years later the patient experienced incident of haemoptysis. Detailed examination and assessment of the respiratory tract condition revealed COPD without features of renewal of the neoplastic process or infection by Mycobacterium tuberculosis or mycobacterium other than tuberculosis. This case demonstrates that aggressive surgical approaches to lung cancer with solitary cerebral metastasis significantly improve patient survival and justifies its widespread use. 相似文献
74.
Jaroslaw Wozniak Mateusz Petrus Tomasz Cygan Artur Lachowski Bogusawa Adamczyk-Cielak Dorota Moszczyska Agnieszka Jastrzbska Tomasz Wojciechowski Wanda Ziemkowska Andrzej Olszyna 《Materials》2020,13(22)
This paper discusses the influence of Ti3C2 (MXene) addition on silicon nitride and its impact on the microstructure and mechanical properties of the latter. Composites were prepared through powder processing and sintered using the spark plasma sintering (SPS) technic. Relative density, hardness and fracture toughness, were analyzed. The highest fracture toughness at 5.3 MPa·m1/2 and the highest hardness at HV5 2217 were achieved for 0.7 and 2 wt.% Ti3C2, respectively. Moreover, the formation of the Si2N2O phase was observed as a result of both the MXene addition and the preservation of the α-Si3N4→β-Si3N4 phase transformation during the sintering process. 相似文献
75.
76.
Saccharomyces boulardii interferes with enterohemorrhagic Escherichia coli-induced signaling pathways in T84 cells 下载免费PDF全文
Dahan S Dalmasso G Imbert V Peyron JF Rampal P Czerucka D 《Infection and immunity》2003,71(2):766-773
Enterohemorrhagic Escherichia coli (EHEC) infections are associated with the modification of tight-junction permeability and synthesis of proinflammatory cytokine interleukin-8 (IL-8). In a previous study, it was demonstrated that EHEC-induced IL-8 secretion is due to the involvement of the mitogen-activated protein kinase (MAPK), AP-1, and NF-kappaB pathways. In this study, we investigated the effect of the yeast Saccharomyces boulardii on EHEC infection in T84 cells. For this purpose, cells were (i) incubated with bacteria and yeast at the same time or (ii) incubated overnight with yeast cells that were maintained during infection or eliminated by several washes before infection. Coincubation is sufficient to maintain the transmonolayer electrical resistance (TER) of EHEC-infected cells, whereas the preincubation of cells with the yeast without elimination of the yeast during infection is necessary to significantly decrease IL-8 secretion. We thus analyzed the mechanisms of S. boulardii action. We showed that S. boulardii has no effect on EHEC growth or on EHEC adhesion. Kinetics studies revealed that EHEC-induced myosin light chain (MLC) phosphorylation precedes the decrease of TER. ML-7, an MLC kinase inhibitor, abolishes the EHEC-induced MLC phosphorylation and decrease of TER. Studies show that S. boulardii also abolishes EHEC-induced MLC phosphorylation. We demonstrated that the preincubation of cells with S. boulardii without washes before EHEC infection inhibits NF-kappaB DNA binding activity, phosphorylation and degradation of IkappaB-alpha, and activation of the three members of a MAPK group (extracellular signal-regulated protein kinases 1 and 2, p38, and c-jun N-terminal kinase). These findings demonstrate that S. boulardii exerts a preventive effect on EHEC infection by (i) interfering with one of the transduction pathways implicated in the control of tight-junction structure and (ii) decreasing IL-8 proinflammatory secretion via inhibition of the NF-kappaB and MAPK signaling pathways in infected T84 cells. 相似文献
77.
Kowalczyk JR Gaworczyk A Winnicka D Lejman M Babicz M 《Cancer Genetics and Cytogenetics》2003,142(1):51-55
Fluorescence in situ hybridization (FISH) using chromosome-specific DNA probes is rapidly becoming a part of clinical laboratory practice. However, as a relatively new clinical test, it is not yet standardized and for practical reasons each laboratory must establish its own criteria. For this purpose we have evaluated the specificity of a dual-color BCR/ABL translocation probe by establishing the range of BCR/ABL fusion-positive scores in a healthy donor group. The false positive rate (FPR), determined by the percent of FISH BCR/ABL fusion-positive cells found in the specimens of healthy donors, was estimated at 2.3% (mean = 1%-4%). Thus the cut-off value for false positive nuclei was set at 5%. 相似文献
78.
Malgorzata Wegner Aleksandra Araszkiewicz Maria Piorunska-Stolzmann Bogna Wierusz-Wysocka Dorota Zozulinska-Ziolkiewicz 《Inflammation》2013,36(3):723-728
Interleukin 6 (IL-6) plays an important role in the initiation and acceleration of chronic inflammation and could contribute to development of microvascular complications in patients with type 1 diabetes (DM1). Therefore, this study was aimed to investigate the association between concentration of IL-6 in relation to glucose control, lipid profile, and body mass index (BMI) in 69 DM1 patients subdivided according to the absence or presence of microvascular complications. BMI, level of fasting plasma glucose (FPG), and concentrations of total cholesterol (TCH), LDL cholesterol (LDL-C), and IL-6 were higher in DM1 patients compared to the control group. In DM1 patients, IL-6 concentration was positively correlated with level of FPG, LDL-C, TCH concentrations, and BMI. These correlations were stronger in the subgroup of patients with microvascular complications. In addition, BMI independently influences IL-6 concentration in DM1 patients. In conclusion, elevated IL-6 concentration is associated with diabetes-related variables which could accelerate progression of microvascular complications in DM1 patients. 相似文献
79.
RB Kostogrys M Franczyk-Żarów E Maślak M Gajda L Mateuszuk CL Jackson S Chłopicki 《Atherosclerosis》2012,223(2):327-331
Although in apoE/LDLR(-/-) mice atherosclerotic plaques develop spontaneously, various atherogenic diets (e.g. Western diet) are frequently used to accelerate the disease in this model. The objective of this study was to compare the effects on atherosclerosis of Western diet and other types of high-fat, high cholesterol, hypertriglyceridemic diets with the effects of the low carbohydrate, high protein (LCHP) diet. 16-18 week old mice with pre-established atherosclerosis were assigned to experimental groups and fed for the next 10 weeks with control diet, margarine diet (margarine 7%), hypertrigliceridemic diet (fructose 62%), high-fat diet (Western diet), high cholesterol diet (egg yolk diet) or with LCHP diet. No differences in body weight were observed among experimental groups. Plasma cholesterol concentration was significantly increased in egg yolk diet- and LCHP diet-fed apoE/LDLR(-/-) mice as compared to other types of diets. Plasma concentration of triacylglycerols was significantly elevated in egg yolk diet- and LCHP diet-fed apoE/LDLR(-/-) mice. The area of atherosclerotic plaques in the aortic root was substantially increased in LCHP diet-fed mice as compared to other types of diets. Furthermore, in brachiocephalic arteries of LCHP diet-fed mice there was evidence of plaque rupture. In conclusion, the LCHP diet promoted atherosclerosis in apoE/LDLR(-/-) mice more intensively than classical Western diet and favored the development of unstable lesions. 相似文献
80.
Nan Zhong Krystyna E. Wisniewski Jaana Hartikainen Weina Ju Dorota N. Moroziewicz Lucille McLendon Susan Sklower Brooks W Ted Brown 《Clinical genetics》1998,54(3):234-238
Zhong N, Wisniewski KE, Hartikainen J, Ju W, Moroziewicz DN, McLendon L, Sklower Brooks S, Brown WT. Two common mutations in the CLN2 gene underlie late infantile neuronal ceroid lipofuscinosis
Late infantile neuronal ceroid lipofuscinosis (LINCL) is one of the most common pediatric neuronal degenerative disorders. A candidate gene underlying this disease, designated CLN2, was recently cloned and the gene product was characterized as a lysosomal pepstatin-insensitive carboxypeptidase (LPIC). Four mutations were identified in CLN2 from three unrelated LINCL individuals. To investigate further the mutation frequency in LINCL, we screened 16 LINCL probands for these four mutations. The previously reported intronic mutation, T523–1 G°C, was found in 56% (9/16) of the cases, of which two were homozygous and accounted for 34% (11/32) of LINCL chromosomes. The previously reported nonsense mutation, 636 C→T leading to R208stop, was found in 31% (5/16) of the cases, including one ho-mozygote and accounted for 19% (6/32) of LINCL chromosomes. Two previously described missense mutations, 1107 T°C and 1108 G→A, were not detected in any of these 16 probands. In total, the two observed mutations, T523–1 G°C and 636 C→T, accounted for 53% (17/32) of LINCL alleles. Thus, one or both mutations were seen in 11 (69%) cases and no mutation has yet been identified in five. Our finding that these two mutations are common in LINCL cases adds further evidence in support of the idea that dysfunction of LPIC underlies LINCL. Positive molecular testing can now complement clinical diagnosis of LPIC and will allow for pre-natal diagnosis for subsequent pregnancies. 相似文献
Late infantile neuronal ceroid lipofuscinosis (LINCL) is one of the most common pediatric neuronal degenerative disorders. A candidate gene underlying this disease, designated CLN2, was recently cloned and the gene product was characterized as a lysosomal pepstatin-insensitive carboxypeptidase (LPIC). Four mutations were identified in CLN2 from three unrelated LINCL individuals. To investigate further the mutation frequency in LINCL, we screened 16 LINCL probands for these four mutations. The previously reported intronic mutation, T523–1 G°C, was found in 56% (9/16) of the cases, of which two were homozygous and accounted for 34% (11/32) of LINCL chromosomes. The previously reported nonsense mutation, 636 C→T leading to R208stop, was found in 31% (5/16) of the cases, including one ho-mozygote and accounted for 19% (6/32) of LINCL chromosomes. Two previously described missense mutations, 1107 T°C and 1108 G→A, were not detected in any of these 16 probands. In total, the two observed mutations, T523–1 G°C and 636 C→T, accounted for 53% (17/32) of LINCL alleles. Thus, one or both mutations were seen in 11 (69%) cases and no mutation has yet been identified in five. Our finding that these two mutations are common in LINCL cases adds further evidence in support of the idea that dysfunction of LPIC underlies LINCL. Positive molecular testing can now complement clinical diagnosis of LPIC and will allow for pre-natal diagnosis for subsequent pregnancies. 相似文献