全文获取类型
收费全文 | 700篇 |
免费 | 35篇 |
专业分类
735篇 |
出版年
2023年 | 1篇 |
2022年 | 10篇 |
2021年 | 17篇 |
2020年 | 7篇 |
2019年 | 8篇 |
2018年 | 20篇 |
2017年 | 14篇 |
2016年 | 23篇 |
2015年 | 31篇 |
2014年 | 42篇 |
2013年 | 33篇 |
2012年 | 57篇 |
2011年 | 65篇 |
2010年 | 38篇 |
2009年 | 41篇 |
2008年 | 44篇 |
2007年 | 51篇 |
2006年 | 39篇 |
2005年 | 32篇 |
2004年 | 42篇 |
2003年 | 36篇 |
2002年 | 29篇 |
2001年 | 10篇 |
2000年 | 6篇 |
1999年 | 5篇 |
1998年 | 3篇 |
1997年 | 2篇 |
1996年 | 4篇 |
1995年 | 3篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1985年 | 1篇 |
1984年 | 3篇 |
1982年 | 1篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1972年 | 2篇 |
1971年 | 1篇 |
排序方式: 共有735条查询结果,搜索用时 15 毫秒
1.
Summary Familial occurrence of 1/21 translocation in connection with trisomy 21 was described. The possibilities of inheritance of further chromosome rearrangements arising during the gametogenesis of persons with this translocation were considered. 相似文献
2.
3.
Marianna Małek Bożena Bogusz Paulina Mrowiec Mariusz Szuta Maciej Opach Iwona Skiba-Kurek Paweł Nowak Karolina Klesiewicz Alicja Budak Elżbieta Karczewska 《Revista iberoamericana de micología》2018,35(3):140-146
Background
Fungal rhinosinusitis has become an increasingly recognized disease, being Aspergillus species responsible for most of the cases. Its diagnosis is quite difficult because of the non-specific symptoms and low sensitivity of the current diagnostic methods.Aims
An Aspergillus-specific nested polymerase chain reaction (PCR) assay using biopsy specimens taken from the maxillary sinuses was performed in order to assess its usefulness. Conventional diagnostic methods (histology and culture) were also carried out.Methods
A case–control study was performed in the Institute of Stomatology, Jagiellonian University in Kraków, between 2011 and 2014. The case group consisted of 21 patients with suspected rhinosinusal mycetoma while the control group included 46 patients with no suspicion of fungal rhinosinusitis. The two-step PCR assay amplified an Aspergillus specific portion of the 18S rRNA gene. Interval estimation of sensitivity, specificity, positive (PPV) and negative (NPV) predictive values were calculated to assess the diagnostic test performance. The agreement between the PCR and the other tests was evaluated using the Kappa coefficient (k).Results
Ninety percent of the samples obtained from patients diagnosed with mycetoma yielded positive PCR results. The PCR showed almost perfect concordance with histology (k = 0.88). Sensitivity, specificity, PPV and NPV estimates were 90%; 95% CI: (55.5–99.7%), 98.3%; 95% CI: (90.9–100%), 90%; 95% CI: (55.5–99.7%) and 98.3%; 95% CI: (90.9–100%), respectively. One clinical sample showed growth of Aspergillus fumigatus and positive PCR despite the negative histological examination.Conclusions
Nested PCR assay is a promising diagnostic tool to evaluate the presence of Aspergillus in the tissue of maxillary sinus from patients with suspicion of sinus aspergillosis. 相似文献4.
Anna Adamska‐Bartłomiejczyk Attila Borics Csaba Tömböly Szabolcs Dvorácskó Marek Lisowski Alicja Kluczyk Grzegorz Wołczański Justyna Piekielna‐Ciesielska Anna Janecka 《Journal of peptide science》2017,23(12):864-870
Three novel morphiceptin analogs, in which Pro in position 2 and/or 4 was replaced by cis‐4‐aminoproline connected with the preceding amino acid through the primary amino group, were synthesized. The opioid receptor affinities, functional assay results, enzymatic degradation studies and experimental and in silico structural analysis of such analogs are presented. Copyright © 2017 European Peptide Society and John Wiley & Sons, Ltd. 相似文献
5.
6.
7.
Studies have been made on the activity of two mitochondrial enzymes, Mg2+ ATPase (E.C.3.6.1.3.) and cytochrome c-oxidase (E.C.I.9.3.2.) in microsporocytes and somatic cells of anther in larch.
The material for study were homogeneous fractions of microsporocytes from 15 stages of meiosis and the attendant anther somatic
cells. The results have demonstrated that cells undergoing meiosis exhibit considerable mitochondrial metabolic activity.
It is characterized by considerable variations in the activity level of both enzymes studied. The level and dynamics of variations
of Mg2+-ATPase and cytochrome c-oxidase activity in microsporocytes are clearly different from those in the anther somatic cells.
The cytochrome c-oxidase activity in microsporocytes throughout microsporogenesis is higher compared with that in the anther
wall cells, whereas the Mg2+-ATPase activity in microsporocytes averagesca. one half that in the anther somatic cells
The dynamics of activity variations of the enzymes under study suggests enhanced mitochondrial metabolism in the period of
middle diplotene and young dyad. This result supports the thesis following from our earlier studies that the middle diplotene
and young dyad constitute specific metabolic switches in microsporogenesis in larch. 相似文献
8.
Danuta Stępalska Krystyna Harmata Idalia Kasprzyk Dorota Myszkowska Alicja Stach 《Aerobiologia》1999,15(1):39-47
The concentration of airborne spores of Cladosporium and Alternaria has been investigated at five monitoring stations situated in cities from the foot of the Tatra Mountains to central Poland along a south-north transect (Zakopane, Kraków, Ostrowiec witokrzyski, Warszawa, Pozna) i.e. from a height of 900 m to 80 m above sea level. The aerobiological monitoring of fungal spores was performed by means of five Burkard volumetric spore traps.Cladosporium spores were dominant at all the stations. The highest Cladosporium and Alternaria spore concentrations were observed at all the sites in July and August, except at Warszawa in both years and at Pozna in 1995 where the maximum of Cladosporium spores occurred in June and July, and at Ostrowiec witokrzyski in 1995 where the maximum was found in July, August and September.Fungal spore concentrations in Zakopane and Kraków were significantly lower than those in Ostrowiec witokrzyski, Warszawa and Pozna and periods of abundant Cladosporium spore occurrence were different in these two groups of monitoring stations. 相似文献
9.
Admixture mapping of an allele affecting interleukin 6 soluble receptor and interleukin 6 levels 下载免费PDF全文
Reich D Patterson N Ramesh V De Jager PL McDonald GJ Tandon A Choy E Hu D Tamraz B Pawlikowska L Wassel-Fyr C Huntsman S Waliszewska A Rossin E Li R Garcia M Reiner A Ferrell R Cummings S Kwok PY Harris T Zmuda JM Ziv E;Health Aging Body Composition 《American journal of human genetics》2007,80(4):716-726
Circulating levels of inflammatory markers can predict cardiovascular disease risk. To identify genes influencing the levels of these markers, we genotyped 1,343 single-nucleotide polymorphisms (SNPs) in 1,184 African Americans from the Health, Aging and Body Composition (Health ABC) Study. Using admixture mapping, we found a significant association of interleukin 6 soluble receptor (IL-6 SR) with European ancestry on chromosome 1 (LOD 4.59), in a region that includes the gene for this receptor (IL-6R). Genotyping 19 SNPs showed that the effect is largely explained by an allele at 4% frequency in West Africans and at 35% frequency in European Americans, first described as associated with IL-6 SR in a Japanese cohort. We replicate this association (P<1.0x10-12) and also demonstrate a new association with circulating levels of a different molecule, IL-6 (P<3.4x10-5). After replication in 1,674 European Americans from Health ABC, the combined result is even more significant: P<1.0x10-12 for IL-6 SR, and P<2.0x10-9 for IL-6. These results also serve as an important proof of principle, showing that admixture mapping can not only coarsely localize but can also fine map a phenotypically important variant. 相似文献
10.
Jinbo Pang Alicja Bachmatiuk Yin Yin Barbara Trzebicka Liang Zhao Lei Fu Rafael G. Mendes Thomas Gemming Zhongfan Liu Mark H. Rummeli 《Liver Transplantation》2018,8(8)
The successful isolation of phosphorene (atomic layer thick black phosphorus) in 2014 has currently aroused the interest of 2D material researchers. In this review, first, the fundamentals of phosphorus allotropes, phosphorene, and black phosphorus, are briefly introduced, along with their structures, properties, and synthesis methods. Second, the readers are presented with an overview of their energy applications. Particularly in electrochemical energy storage, the large interlayer spacing (0.53 nm) in phosphorene allows the intercalation/deintercalation of larger ions as compared to its graphene counterpart. Therefore, phosphorene may possess greater potential for high electrochemical performance. In addition, the status of lithium ion batteries as well as secondary sodium ion batteries is reviewed. Next, each application for energy generation, conversion, and storage is described in detail with milestones as well as the challenges. These emerging applications include supercapacitors, photovoltaic devices, water splitting, photocatalytic hydrogenation, oxygen evolution, and thermoelectric generators. Finally the fast‐growing dynamic field of phosphorene research is summarized and perspectives on future possibilities are presented calling on the efforts of chemists, physicists, and material scientists 相似文献