全文获取类型
收费全文 | 225篇 |
免费 | 6篇 |
出版年
2020年 | 3篇 |
2017年 | 2篇 |
2016年 | 4篇 |
2015年 | 5篇 |
2014年 | 5篇 |
2013年 | 13篇 |
2012年 | 4篇 |
2011年 | 8篇 |
2010年 | 5篇 |
2009年 | 8篇 |
2008年 | 7篇 |
2007年 | 4篇 |
2006年 | 5篇 |
2005年 | 3篇 |
2004年 | 4篇 |
2003年 | 2篇 |
2001年 | 3篇 |
2000年 | 3篇 |
1999年 | 2篇 |
1998年 | 2篇 |
1997年 | 3篇 |
1996年 | 5篇 |
1995年 | 3篇 |
1994年 | 4篇 |
1993年 | 4篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1989年 | 4篇 |
1987年 | 4篇 |
1986年 | 2篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1980年 | 3篇 |
1979年 | 3篇 |
1978年 | 2篇 |
1976年 | 2篇 |
1971年 | 3篇 |
1961年 | 3篇 |
1960年 | 2篇 |
1953年 | 2篇 |
1950年 | 3篇 |
1942年 | 2篇 |
1940年 | 4篇 |
1936年 | 18篇 |
1933年 | 13篇 |
1932年 | 8篇 |
1931年 | 11篇 |
1929年 | 4篇 |
1924年 | 1篇 |
1915年 | 1篇 |
排序方式: 共有231条查询结果,搜索用时 15 毫秒
211.
212.
213.
ZONE LINES IN PLANT TISSUES 总被引:2,自引:0,他引:2
The black lines of Polyporus squamosus have been found in the wood of elms. Isolations were made from these lines and an account of the development of P. squamosus in artificial culture is given. Particular mention is made of the formation of black plates, or lines as they appear in section, in culture media and of the appearance of abnormal fructifications. Pure cultures of the fungus on sterilized wood blocks have produced black lines in the wood, similar to those occurring in nature.
From a consideration of the structure and formation of the black plates, the suggestion is made that they form the limiting layer or rind of sclerotium-like bodies buried in the attacked wood.
A review is given of sclerotium formation and structure in several species of Polyporus, and analogies are made between these sclerotia and the sclerotium-like body of P. squamosus. It is decided to distinguish the P. squamosus body from these sclerotia by naming it a pseudo-sclerotium, on the criteria previously advanced for Armillaria mellea (8). 相似文献
From a consideration of the structure and formation of the black plates, the suggestion is made that they form the limiting layer or rind of sclerotium-like bodies buried in the attacked wood.
A review is given of sclerotium formation and structure in several species of Polyporus, and analogies are made between these sclerotia and the sclerotium-like body of P. squamosus. It is decided to distinguish the P. squamosus body from these sclerotia by naming it a pseudo-sclerotium, on the criteria previously advanced for Armillaria mellea (8). 相似文献
214.
Eric Scott Sills Adam C Brady Ahmed B Omar David J Walsh Umme Salma Anthony PH Walsh 《Reproductive biology and endocrinology : RB&E》2010,8(1):31
Background
Premature ovarian failure (POF) remains a clinically challenging entity because in vitro fertilisation (IVF) with donor oocytes is currently the only treatment known to be effective. 相似文献215.
216.
We propose a rigorous definition for the termtemporal encoding as it is applied to schemes for the representation of information withinpatterns of neuronal action potentials, and distinguish temporal encoding schemes from those based on window-averagedmean rate encoding. The definition relies on the identification of anencoding time window, defined as the duration of a neuron's spike train assumed to correspond to a single symbol in the neural code. The duration of the encoding time window is dictated by the time scale of the information being encoded. We distinguish between the concepts of theencoding time window and theintegration time window, the latter of which is defined as the duration of a stimulus signal that affects the response of the neuron. We note that the duration of the encoding and integration windows might be significantly different. We also present objective, experimentally assessable criteria for identifying neurons and neuronal ensembles that utilize temporal encoding to any significant extent. The definitions and criteria are made rigorous within the contexts of several commonly used analytical approaches, including thestimulus reconstruction analysis technique. Several examples are presented to illustrate the distinctions between and relative capabilities of rate encoding and temporal encoding schemes. We also distinguish our usage oftemporal encoding from the termtemporal coding, which is commonly used in reference to the representation of information about thetiming of events by rate encoding schemes. 相似文献
217.
218.
219.
Leonardus W.J.E. Beurskens Robert de Jonge Ernst M. Schoonderwaldt Dick Tibboel Régine P.M. Steegers‐Theunissen 《Birth defects research. Part A, Clinical and molecular teratology》2012,94(7):557-560
Homocysteine is an intermediate of the one‐carbon (1‐C) pathway and increased concentrations have been related to neural crest‐related congenital anomalies. The neural crest and the 1‐C pathway might be involved also in the etiology of Congenital Diaphragmatic Hernia (CDH). In 22 CDH and 28 control newborns and their mothers, general characteristics were obtained by standardized questionnaires. The 1‐C pathway intermediates total homocysteine (tHcy), S‐adenosylmethionine (SAM), and S‐adenosylhomocysteine (SAH) were determined in cord blood. Correlations between maternal and newborn factors and risk estimates were investigated by univariate and multivariable logistic regression analyses. Birth weight (2962 vs. 3418 gram; p < 0.001) was lower and gestational age (270 vs. 277 days; p = 0.006) was shorter in case children. Control mothers were slightly older (32 vs. 35 year; p = 0.05). Other characteristics were comparable between case and control children and mothers. The concentrations of homocysteine, SAM and SAH, and the SAM/SAH ratio were comparable (tHcy: 8.57 vs. 8.56 μmol/l, p = 0.99; SAM: 152.7 vs. 157.3 nmol/l, p = 0.76; SAH: 43.5 vs. 48.9, p = 0.26; ratio: 3.8 vs. 3.5, p = 0.50). Maternal and newborn characteristics were not correlated to the biomarker concentrations. In conclusion, the biomarkers of methylation determined in cord blood are not associated with CDH risk. Maternal and child characteristics could not predict newborn biomarker concentrations of the 1‐C pathway. Birth Defects Research (Part A) 2012. © 2012 Wiley Periodicals, Inc. 相似文献
220.
Kirstin A Carswell Kasim A Behranwala Ashutosh Nerurkar A Gerald PH Gui 《International Seminars in Surgical Oncology : ISSO》2006,3(1):32
A 58 year old lady presented with a right breast cancer and a prior history of malignant melanoma excised from the right chest wall eight years previously. An abnormal axillary lymph node resected contained features of both metastatic breast carcinoma and malignant melanoma. Following oncologic breast cancer management, the patient is well with no evidence of recurrence at three years. 相似文献