全文获取类型
收费全文 | 409篇 |
免费 | 30篇 |
出版年
2023年 | 4篇 |
2022年 | 4篇 |
2021年 | 20篇 |
2020年 | 5篇 |
2019年 | 11篇 |
2018年 | 9篇 |
2017年 | 10篇 |
2016年 | 11篇 |
2015年 | 24篇 |
2014年 | 30篇 |
2013年 | 30篇 |
2012年 | 40篇 |
2011年 | 31篇 |
2010年 | 18篇 |
2009年 | 19篇 |
2008年 | 21篇 |
2007年 | 9篇 |
2006年 | 24篇 |
2005年 | 14篇 |
2004年 | 23篇 |
2003年 | 9篇 |
2002年 | 9篇 |
2001年 | 6篇 |
2000年 | 3篇 |
1999年 | 7篇 |
1997年 | 2篇 |
1996年 | 3篇 |
1995年 | 6篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1980年 | 1篇 |
1979年 | 3篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1974年 | 4篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1970年 | 2篇 |
1966年 | 1篇 |
1961年 | 1篇 |
1960年 | 1篇 |
排序方式: 共有439条查询结果,搜索用时 296 毫秒
411.
Yanan Guo Pierre-Yves Dupont Carl H. Mesarich Bo Yang Rebecca L. McDougal Preeti Panda Paul Dijkwel David J. Studholme Christine Sambles Joe Win Yuanchao Wang Nari M. Williams Rosie E. Bradshaw 《Molecular Plant Pathology》2020,21(9):1131-1148
New Zealand kauri is an ancient, iconic, gymnosperm tree species that is under threat from a lethal dieback disease caused by the oomycete Phytophthora agathidicida. To gain insight into this pathogen, we determined whether proteinaceous effectors of P. agathidicida interact with the immune system of a model angiosperm, Nicotiana, as previously shown for Phytophthora pathogens of angiosperms. From the P. agathidicida genome, we defined and analysed a set of RXLR effectors, a class of proteins that typically have important roles in suppressing or activating the plant immune system. RXLRs were screened for their ability to activate or suppress the Nicotiana plant immune system using Agrobacterium tumefaciens transient transformation assays. Nine P. agathidicida RXLRs triggered cell death or suppressed plant immunity in Nicotiana, of which three were expressed in kauri. For the most highly expressed, P. agathidicida (Pa) RXLR24, candidate cognate immune receptors associated with cell death were identified in Nicotiana benthamiana using RNA silencing-based approaches. Our results show that RXLRs of a pathogen of gymnosperms can interact with the immune system of an angiosperm species. This study provides an important foundation for studying the molecular basis of plant–pathogen interactions in gymnosperm forest trees, including kauri. 相似文献
412.
Nishida Hanna Shimoda Yoshikazu Win Khin Thuzar Imaizumi-Anraku Haruko 《Journal of plant research》2023,136(5):769-780
Journal of Plant Research - Most plants interact with various soil microorganisms as they grow through the soil. Root nodule symbiosis by legumes and rhizobia is a well-known phenomenon of... 相似文献
413.
A Alfahad EM Thet F Radwan J Sudhakar K Nini P Tachtatzis 《Journal of medical case reports》2012,6(1):272
ABSTRACT: INTRODUCTION: Osteoporosis is an asymptomatic disease characterized by bone weakening and predisposition to fragility (insufficiency) fractures and can have devastating effects on individual life and great financial impact on the economy. Bisphosphonates are used worldwide for the primary and secondary prevention of osteoporotic fractures. However, increasing evidence raises concern that bisphosphonates can be associated with atypical fractures. CASE PRESENTATION: A 65-year-old Caucasian woman on long-term steroid treatment for polymyalgia rheumatica was admitted with severe and constant pain in the right hip, radiating to the right knee. She had a history of steroid-induced osteoporosis, for which she was started on risedronate four years earlier. She had no history of trauma. Her blood results were unremarkable. Her X-rays confirmed that she had an incomplete right subtrochanteric femoral fracture. A bone scan confirmed the diagnosis and also ruled out any other associated fractures. Our patient successfully underwent internal nail fixation of the fracture. She was reviewed by a rheumatology team, which stopped the risedronate. She was started on treatment with denosumab injection. CONCLUSIONS: Previous case series have reported that long-term bisphosphonate use is associated with atypical fractures of the femur, and certain criteria have been established to help identify such rare fractures. Delayed union or non-union is expected in such fractures following definitive orthopedic treatment because of the long half life of bisphosphonates. In this case report, we try to raise questions related to this important subject, like the duration and safety of bisphosphonate use and the alternative medications used in osteoporosis in this rare condition. We consider this case report not only interesting but also important and unusual because it is about a patient who developed a potentially rare and serious side effect of long-term bisphosphonate use, estimated to affect 2.3 in every 10,000 patients, and who presented with a pelvic X-ray that showed the characteristic features of atypical fractures secondary to risedronate use. In addition, most of the documented cases have been associated with many years of bisphosphonate use whereas our patient had been on risedronate for only four years. 相似文献
414.
D Halder A S Dharap M Than 《Anthropologischer Anzeiger; Bericht über die biologisch-anthropologische Literatur》1999,57(1):69-75
Early identification of a syndrome at birth is of paramount importance for genetic counselling and possible prevention. Often malformation of the hands and fingers are cardinal manifestations of recognizable syndromes. As there are no published standards for hand and finger size for Malay newborn infants, this study was undertaken to establish normal values for hand, middle finger and palmar lengths, and their indices. A cross-sectional study was done on 509 consecutive newborn Malay babies between 34 and 42 weeks of gestation. Measurements were made on the right hand according to the recommended guidelines of Bergsma & Feingold (1975). The mean values for the measurements did not differ significantly between boys and girls, or change with gestation. For the whole group the mean value for total hand length was 64.4 +/- 3.42 mm, middle finger length 37.1 +/- 2.91 mm, palmar length 27.4 +/- 2.15 mm, finger index 0.425 +/- 0.03 and palmar index 0.58 +/- 0.03. A comparison with published measurements for newborns of different racial origin shows significant differences for the total hand length, middle finger length and palm length from Indian and Jewish infants, but not from Japanese infants. The indices were similar in Malay, Indian, Jewish and Japanese newborn infants. 相似文献
415.
416.
Aaydha Chidambara Vinayaka Than Linh Quyen Van Ngoc Huynh Mogens Madsen Dang Duong Bang Anders Wolff 《Microbial biotechnology》2023,16(11):2105-2113
Sensitive detection of pathogens in livestock farms is an integral part of the One Health Action Plan of the European Union (EU). Ensuring this requires on-site testing devices that are compatible with complex matrices such as primary production samples. Among all, faeces are considered the most challenging matrix type that makes it difficult to identify pathogens because of complexity in sample preparation for molecular testing. We have developed a loop-mediated isothermal amplification (LAMP) based veterinary point-of-care (POC) device (VETPOD) and adapted it to detect Salmonella enterica in primary production samples. Three different sampling methods (semi-wet chicken faeces, boot socks collection and dust samples from poultry shed) were iteratively tested to assess their nature of complexity and possibility for adapting them as suitable sampling methods for on-site testing. During the study, the sample preparation method that included a two-step centrifugation combined with washing of the enriched Salmonella cells was found crucial in eliminating amplification inhibitors originating from the faecal matrices. A total of 90 samples were tested that included 60 samples for sensitivity study and 30 samples for relative level of detection (RLOD, a level of detection in comparison to ISO 6579:1 reference method). Overall, the VETPOD had a sensitivity of 90%, 84.62% and 81.82% for boot sock, faecal and dust samples, respectively. The RLOD was 2.23 CFU/25 g which was found to be 1.33 times higher than the ISO 6579:1. Performing with an excellent agreement with ISO 6579:1, the VETPOD proved as a promising alternative to detect Salmonella spp. in primary production and animal husbandry samples. 相似文献
417.
Objective To determine the diagnostic accuracy of two verbally asked questions for screening for depression.Design Cross sectional criterion standard validation study.Setting 15 general practices in New Zealand.Participants 421 consecutive patients not taking psychotropic drugs.Main outcome measures Sensitivity, specificity, and likelihood ratios of the two questions compared with the computerised composite international diagnostic interview.Results The two screening questions showed a sensitivity and specificity of 97% (95% confidence interval, 83% to 99%) and 67% (62% to 72%), respectively. The likelihood ratio for a positive test was 2.9 (2.5 to 3.4) and the likelihood ratio for a negative test was 0.05 (0.01 to 0.35). Overall, 37% (157/421) of the patients screened positive for depression.Conclusion Two verbally asked questions for screening for depression would detect most cases of depression in general practice. The questions have the advantage of brevity. As treatment is more likely when doctors make the diagnosis, these questions may have even greater utility. 相似文献
418.
Bo Wu Xinfeng Liu Than Zaw Oo Guichuan Xing Nripan Mathews Tze Chien Sum 《Plasmonics (Norwell, Mass.)》2012,7(4):677-684
A cost-effective approach to enhancing broadband light trapping in ultrathin bulk heterojunction organic photovoltaic (OPV) devices is proposed. This is achieved by simply inserting an array of Al nanodisks at the interface of the ITO anode and the organic active layer; forming circular plasmonic nanopatch cavities (between the nanodisks and the Al cathode) that sandwich the active layer. Through interactions between the surface plasmon polaritons localized at the nanodisk and the cathode, a tunable broadband resonance peak spanning 450?C700?nm in the scattering cross-section spectrum is formed, thereby enhancing the electromagnetic field in the active layer. Compared to an OPV device with a 60-nm-thick PCPDTBT/PC60BM layer, our numerical simulations reveal that integrated absorption enhancements of up to 40?% can be achieved in an equivalent device integrated with an array of nanodisks with a diameter of 100?nm and a periodicity of 250?nm. From the analysis of the structure?Cperformance relationships, implications for the design of these nanopatch cavities for light harvesting in ultrathin OPV devices are discussed. 相似文献
419.
420.