全文获取类型
收费全文 | 222篇 |
免费 | 19篇 |
国内免费 | 1篇 |
出版年
2021年 | 2篇 |
2020年 | 2篇 |
2018年 | 3篇 |
2017年 | 6篇 |
2016年 | 7篇 |
2015年 | 8篇 |
2014年 | 14篇 |
2013年 | 13篇 |
2012年 | 7篇 |
2011年 | 11篇 |
2010年 | 6篇 |
2009年 | 7篇 |
2008年 | 4篇 |
2007年 | 9篇 |
2006年 | 13篇 |
2005年 | 11篇 |
2004年 | 7篇 |
2003年 | 6篇 |
2002年 | 4篇 |
2001年 | 7篇 |
1999年 | 7篇 |
1998年 | 5篇 |
1997年 | 4篇 |
1996年 | 5篇 |
1994年 | 3篇 |
1993年 | 3篇 |
1992年 | 3篇 |
1991年 | 3篇 |
1989年 | 3篇 |
1987年 | 4篇 |
1986年 | 5篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1983年 | 3篇 |
1981年 | 3篇 |
1980年 | 3篇 |
1978年 | 3篇 |
1977年 | 5篇 |
1976年 | 1篇 |
1975年 | 2篇 |
1974年 | 4篇 |
1973年 | 2篇 |
1972年 | 3篇 |
1971年 | 2篇 |
1966年 | 1篇 |
1965年 | 1篇 |
1947年 | 3篇 |
1944年 | 1篇 |
1942年 | 1篇 |
1941年 | 2篇 |
排序方式: 共有242条查询结果,搜索用时 15 毫秒
11.
12.
Danilo ML Prado Fabiana B Benatti Ana L de Sá-Pinto Ana P Hayashi Bruno Gualano Rosa MR Pereira Adriana ME Sallum Eloisa Bonfá Clovis A Silva Hamilton Roschel 《Arthritis research & therapy》2013,15(2):R46
Introduction
Exercise training has emerged as a promising therapeutic strategy to counteract physical dysfunction in adult systemic lupus erythematosus. However, no longitudinal studies have evaluated the effects of an exercise training program in childhood-onset systemic lupus erythematosus (C-SLE) patients. The objective was to evaluate the safety and the efficacy of a supervised aerobic training program in improving the cardiorespiratory capacity in C-SLE patients.Methods
Nineteen physically inactive C-SLE patients were randomly assigned into two groups: trained (TR, n = 10, supervised moderate-intensity aerobic exercise program) and non-trained (NT, n = 9). Gender-, body mass index (BMI)- and age-matched healthy children were recruited as controls (C, n = 10) for baseline (PRE) measurements only. C-SLE patients were assessed at PRE and after 12 weeks of training (POST). Main measurements included exercise tolerance and cardiorespiratory measurements in response to a maximal exercise (that is, peak VO2, chronotropic reserve (CR), and the heart rate recovery (ΔHRR) (that is, the difference between HR at peak exercise and at both the first (ΔHRR1) and second (ΔHRR2) minutes of recovery after exercise).Results
The C-SLE NT patients did not present changes in any of the cardiorespiratory parameters at POST (P > 0.05). In contrast, the exercise training program was effective in promoting significant increases in time-to-exhaustion (P = 0.01; ES = 1.07), peak speed (P = 0.01; ES = 1.08), peak VO2 (P = 0.04; ES = 0.86), CR (P = 0.06; ES = 0.83), and in ΔHRR1 and ΔHRR2 (P = 0.003; ES = 1.29 and P = 0.0008; ES = 1.36, respectively) in the C-SLE TR when compared with the NT group. Moreover, cardiorespiratory parameters were comparable between C-SLE TR patients and C subjects after the exercise training intervention, as evidenced by the ANOVA analysis (P > 0.05, TR vs. C). SLEDAI-2K scores remained stable throughout the study.Conclusion
A 3-month aerobic exercise training was safe and capable of ameliorating the cardiorespiratory capacity and the autonomic function in C-SLE patients.Trial registration
NCT01515163. 相似文献13.
14.
The analgesic properties of the tropane analogue (+/-)-SM 21 have been attributed to the antagonism of presynaptic m2 receptors resulting in a potentiation of acetylcholine release. However, drugs targeting a number of other neurotransmitter receptors have been shown to enhance acetylcholine release. In the current study, in vitro studies were conducted in order to determine the affinity of (+/-)-SM 21 for serotonin 5-HT3, 5-HT4, and sigma receptors. Our results indicate that (+/-)-SM 21, and its structural congeners, have a relatively high affinity for sigma2 receptors relative to their reported affinity for muscarinic receptors. The higher affinity for sigma2 versus sigma1 receptors indicates that (+/-)-SM 21 may be a suitable lead compound for developing sigma2-selective ligands. 相似文献
15.
Rodrigues JC Kitajima EW Childers CC Chagas CM 《Experimental & applied acarology》2003,30(1-3):161-179
Citrus leprosis is caused by Citrus leprosis virus (CiLV) that is transmitted by mites in the genus Brevipalpus (Acari: Tenuipalpidae). This disease directly reduces production and the life span of the citrus plant. The main symptoms of the disease include lesions on fruits, leaves, and twigs or small branches, causing premature fruit drop, defoliation, and death of the twigs or branches leading to serious tree decline. Leprosis is a highly destructive disease of citrus, wherever it occurs. The Brazilian citrus industry spends over 100 million US dollars annually on acaricides to control the vector, Brevipalpus phoenicis (Geijskes). This review contains information about the history of the etiology of citrus leprosis, its geographical distribution, host range, the role of the mite vectors, viral morphology and relationships with the infected cell, and transmissibility of the virus by the mite. In addition, data on the mite-virus-plant relationship, disease damage, and strategies for controlling disease spread are presented. 相似文献
16.
Childers CC Rodrigues JC Derrick KS Achor DS French JV Welbourn WC Ochoa R Kitajima EW 《Experimental & applied acarology》2003,30(1-3):181-202
According to published reports from 1906 to 1968, leprosis nearly destroyed the Florida citrus industry prior to 1925. This was supported with photographs showing typical leprosis symptoms on citrus leaves, fruit, and twigs. Support for the past occurrence of citrus leprosis in Florida includes: (1) presence of twig lesions in affected orange blocks in addition to lesions on fruits and leaves and corresponding absence of similar lesions on grapefruit; (2) yield reduction and die-back on infected trees; and (3) spread of the disease between 1906 and 1925. Transmission electron microscopy (TEM) examination of tissue samples from leprosis-like injuries to orange and grapefruit leaves from Florida in 1997, and fruits from grapefruit and sweet orange varieties from Texas in 1999 and 2000 did not contain leprosis-like viral particles or viroplasm inclusions. In contrast, leprosis viroplasm inclusions were readily identified by TEM within green non-senescent tissues surrounding leprosis lesions in two of every three orange leaf samples and half of the fruit samples obtained from Piracicaba, Brazil. Symptoms of leprosis were not seen in any of the 24,555 orange trees examined across Florida during 2001 and 2002. The authors conclude that citrus leprosis no longer exists in Florida nor occurs in Texas citrus based on: (1) lack of leprosis symptoms on leaves, fruit, and twigs of sweet orange citrus varieties surveyed in Florida: (2) failure to find virus particles or viroplasm inclusion bodies in suspect samples from both Florida and Texas examined by TEM; (3) absence of documented reports by others on the presence of characteristic leprosis symptoms in Florida; (4) lack of its documented occurrence in dooryard trees or abandoned or minimal pesticide citrus orchard sites in Florida. In view of the serious threat to citrus in the U.S., every effort must be taken to quarantine the importation of both citrus and woody ornamental plants that serve as hosts for Brevipalpus phoenicis (Geijskes), B. californicus (Banks), and B. obovatus Donnadieu (Acari: Tenuipalpidae) from countries where citrus leprosis occurs. 相似文献
17.
The ability of two strains of Lactobacillus acidophilus, CRL 640 and CRL 800, to survive and retain their biological activities under frozen storage was determined. Freezing and thawing, as well as frozen storage, damaged the cell membrane, rendering the microorganisms sensitive to sodium chloride and bile salts. Both lactic acid production and proteolytic activity were depressed after 21 days at -20 degreesC, whereas beta-galactosidase activity per cell unit was increased. Cell injury was partially overcome after repair in a salt-rich medium. Copyright 1998 Academic Press. 相似文献
18.
19.
The purpose of this study was to determine the seasonal water use patterns of dominant macrophytes coexisting in the coastal
Everglades ecotone. We measured the stable isotope signatures in plant xylem water of Rhizophora mangle, Cladium jamaicense, and Sesuvium portulacastrum during the dry (DS) and wet (WS) seasons in the estuarine ecotone along Taylor River in Everglades National Park, FL, USA.
Shallow soilwater and deeper groundwater salinity was also measured to extrapolate the salinity encountered by plants at their
rooting zone. Average soil water oxygen isotope ratios (δ
18O) was enriched (4.8 ± 0.2‰) in the DS relative to the WS (0.0 ± 0.1‰), but groundwater δ
18O remained constant between seasons (DS: 2.2 ± 0.4‰; WS: 2.1 ± 0.1‰). There was an inversion in interstitial salinity patterns
across the soil profile between seasons. In the DS, shallow water was euhaline [i.e., 43 practical salinity units (PSU)] while
groundwater was less saline (18 PSU). In the WS, however, shallow water was fresh (i.e., 0 PSU) but groundwater remained brackish
(14 PSU). All plants utilized 100% (shallow) freshwater during the WS, but in the DS R. mangle switched to a soil–groundwater mix (δ 55% groundwater) while C. jamaicense and S. portulacastrum continued to use euhaline shallow water. In the DS, based on δ
18O data, the roots of R. mangle roots were exposed to salinities of 25.4 ± 1.4 PSU, less saline than either C. jamaicense (39.1 ± 2.2 PSU) or S. portulacastrum (38.6 ± 2.5 PSU). Although the salinity tolerance of C. jamaicense is not known, it is unlikely that long-term exposure to high salinity is conducive to the persistence of this freshwater
marsh sedge. This study increases our ecological understanding of how water uptake patterns of individual plants can contribute
to ecosystem levels changes, not only in the southeast saline Everglades, but also in estuaries in general in response to
global sea level rise and human-induced changes in freshwater flows. 相似文献
20.