全文获取类型
收费全文 | 435篇 |
免费 | 34篇 |
国内免费 | 26篇 |
出版年
2023年 | 13篇 |
2022年 | 11篇 |
2021年 | 16篇 |
2020年 | 13篇 |
2019年 | 17篇 |
2018年 | 17篇 |
2017年 | 14篇 |
2016年 | 17篇 |
2015年 | 21篇 |
2014年 | 37篇 |
2013年 | 34篇 |
2012年 | 25篇 |
2011年 | 23篇 |
2010年 | 9篇 |
2009年 | 19篇 |
2008年 | 12篇 |
2007年 | 20篇 |
2006年 | 26篇 |
2005年 | 15篇 |
2004年 | 17篇 |
2003年 | 15篇 |
2002年 | 14篇 |
2001年 | 6篇 |
2000年 | 6篇 |
1999年 | 9篇 |
1998年 | 3篇 |
1997年 | 8篇 |
1996年 | 4篇 |
1995年 | 2篇 |
1994年 | 5篇 |
1993年 | 1篇 |
1992年 | 5篇 |
1991年 | 1篇 |
1990年 | 4篇 |
1989年 | 3篇 |
1988年 | 4篇 |
1987年 | 5篇 |
1986年 | 1篇 |
1985年 | 3篇 |
1984年 | 3篇 |
1982年 | 6篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1979年 | 4篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1976年 | 1篇 |
排序方式: 共有495条查询结果,搜索用时 15 毫秒
401.
Tasuku Konno Toshihiro Kurahashi Saori Suzuki Jaeyong Lee Futoshi Okada 《Free radical research》2016,50(7):793-800
Oxidative stress due to a superoxide dismutase 1 (SOD1) deficiency causes anemia and autoimmune responses, which are phenotypically similar to autoimmune hemolytic anemia (AIHA) and systemic lupus erythematosus (SLE) in C57BL/6 mice and aggravates AIHA pathogenesis in New Zealand black (NZB) mice. We report herein on an evaluation of the role of reactive oxygen species (ROS) in a model mouse with inherited SLE, that is, F1 mice of the NZB?×?New Zealand white (NZW) strain. The ROS levels within red blood cells (RBCs) of the F1 mice were similar to the NZW mice but lower compared to the NZB mice throughout adult period. Regarding SLE pathogenesis, we examined the effects of an SOD1 deficiency or the overexpression of human SOD1 in erythroid cells by establishing corresponding congenic F1 mice. A SOD1 deficiency caused an elevation in ROS production, methemoglobin content, and hyperoxidation of peroxiredoxin in RBC of the F1 mice, which were all consistent with elevated oxidative stress. However, while the overexpression of human SOD1 in erythroid cells extended the life span of the congenic F1 mice, the SOD1 deficiency had no effect on life span compared to wild-type F1 mice. It is generally recognized that NZW mice possess a larval defect in the immune system and that NZB mice trigger an autoimmune reaction in the F1 mice. Our results suggest that the oxidative insult originated from the NZB mouse background has a functional role in triggering an aberrant immune reaction, leading to fatal responses in F1 mice. 相似文献
402.
目的观察不同给药方案对治疗肾性贫血的疗效及安全性。方法将我院收治的198例肾性贫血患者依据治疗方案差异进行分组,于每次血透后给予rHuEPO治疗的98例患者为对照组,于每次血透后应用左卡尼汀联合rHuEPO治疗的100例患者为观察组,比较两组疗效及不良反应情况。结果治疗后,两组患者的Hb、Hct水平变化与治疗前比较,差异均有统计学意义(P0.05)。两组的rHuEPO用量比较,差异无统计学意义(P0.05)。观察组治疗总有效率为93.00%明显高于对照组的82.65%,不良反应发生率为10.00%明显低于对照组的21.43%,组间比较差异均有统计学意义(均P0.05)。结论肾性贫血患者给予左卡尼汀联合rHuEPO治疗的疗效确切,且不良反应低,具有临床推广价值。 相似文献
403.
Thirty aqueous and ethanolic extracts from 13 congolese plants were evaluated for their antidrepanocytary activity. Twelve of these plants, Alchornea cordifolia, Afromomum albo violaceum, Annona senegalensis, Cymbopogon densiflorus, Bridelia ferruginea, Ceiba pentandra, Morinda lucida, Hymenocardia acida, Coleus kilimandcharis, Dacryodes edulis, Caloncoba welwithsii, and Vinga unguiculata exhibited significant activities, thus, supporting the claims of the traditional healers and suggesting a possible correlation between the chemical composition of these plants and their uses in traditional medicine. 相似文献
404.
David Sibon Tereza Coman Julien Rossignol Mathilde Lamarque Olivier Kosmider Elisa Bayard Guillemette Fouquet Rachel Rignault Selin Topçu Pierre Bonneau Florence Bernex Michael Dussiot Kathy Deroy Laetitia Laurent Jacques Callebert Jean-Marie Launay Sophie Georgin-Lavialle Geneviève Courtois Francine Côté 《Cell reports》2019,26(12):3246-3256.e4
405.
Background: The relationship between H. pylori infection and anemia in childhood is still unclear. The aim of the study was to examine the association between H. pylori infection and anemia or iron deficiency in school‐age children and in infants. Materials and Methods: Six‐ to 9‐ year‐old Israeli Arab children (N = 202) and infants (N = 197) were examined for hemoglobin and ferritin levels. ELISA was used to detect H. pylori antigens in stool specimens collected from the participants. Household characteristics were obtained through personal interviews with the mothers. Results: The prevalence of anemia was 15.5 versus 5.5% in H. pylori‐positive and ‐negative school‐age children, respectively and 34.5 versus 29.8% in H. pylori‐positive and ‐negative infants, respectively. The Mantel–Haenszel age‐adjusted prevalence ratio (PR) and 95% confidence intervals (CIs) were 1.6 (95%CI 1.0, 2.6). In multivariate analysis controlling for socioeconomic variables, H. pylori infection was associated with 2.8 higher prevalence of anemia only in school‐age children: adjusted PR 2.8 (95% CI 0.9, 9.3). The adjusted mean difference in hemoglobin levels between H. pylori infected school‐age children and uninfected ones was ?0.372 gr/dL (95% CI ?0.704, ?0.039) (p = .04). The respective mean ferritin difference was ?6.74 μg/L (95% CI ?13.38, ?.011) (p = .04). Such differences were not found in infants. Conclusions: H. pylori infection is associated with higher prevalence of anemia in school‐age children independently of socioeconomic variables. Such association was not observed in infants. These findings are of clinical and public health importance. 相似文献
406.
Gürgöze MK Olçücü A Aygün AD Taskin E Kiliç M 《Biological trace element research》2006,111(1-3):23-29
In the present study, the serum and hair levels of zinc, selenium, and copper were determined in children with iron-deficiency
anemia (IDA). A total of 52 anemic children aged 1–4 yr constituted the study group. Fortysix healthy children acted as controls.
The copper and zinc levels were measured with an atomic absorption spectrophometer. Serum and hair selenium was determined
by a spectroflourometric method. The serum zinc and selenium concentrations in the IDA group were found to be significantly
lower and serum copper significantly higher than those in the controls (p<0.05). Lower iron, zinc, and selenium concentrations (p<0.001) but not copper were found in hair (p>0.05). 相似文献
407.
Various aspects of the responses of cotton rats to intraperitoneal infections with Echinococcus multilocularis were examined to determine if they could be related to the progress of the infection. At 14 weeks post-infection, infected animals had enlarged spleens; there was a slight decrease in packed cell volume, but no reticulocytosis. The number of all four types of leukocytes in the peripheral blood (lymphocytes, monocytes, neutrophils and eosinophils) increased during the course of the infection. In the peritoneal fluid, the numbers of neutrophils increased, monocytes and basophils decreased, and lymphocytes and eosinophils remained unchanged. Antibodies to E. multilocularis were detected in the serum of infected cotton rats as early as 2 weeks post-infection. The mean levels of transaminases (SGOT and SGPT) in the serum of infected animals were higher than in controls, and 5'-nucleotidase levels were elevated in heavily infected animals. There were no differences in responses between male and female animals. Comparison with results previously obtained suggest that both the outcome of the infection, and responses to it, may be under host control. 相似文献
408.
Volume-stimulated,Cl−-dependent K+ efflux is highly expressed in young human red cells containing normal hemoglobin or HbS 总被引:8,自引:0,他引:8
Mitzy Canessa Mary E. Fabry Nadia Blumenfeld Ronald L. Nagel 《The Journal of membrane biology》1987,97(2):97-105
Summary We report here that a Cl–-dependent K– (KCl) efflux, which is stimulated by N-ethylmaleimide, (NEM) and by increased red cell volume, exists in young red cells of individuals with normal hemoglobin A (AA) and in those homozygous for hemoglobin S (SS). We have investigated this KCl efflux in several density-defined red cell fractions obtained from Percoll-Stractan continuous density gradients. We found high activity of the NEM-stimulated KCl transport in reticulocytes and young red cells from nine sickle cell (SS) patients (43±27 mean±sd mmol K+/liter of cells/hr=flux units (FU)) and in the young cell fraction of three AA individuals with high reticulocytosis recuperating from nutritional anemias (41.7±10 FU). In addition, we observed significant interindividual variation of this KCl efflux in the discocyte fraction of SS blood. Cell swelling markedly stimulated the KCl efflux, in SS whole blood (9.8±7.4 FU, in SS young cells (13±13 FU), and in AA young cells (21.4±11 FU). The activity of the Na–K–Cl cotransport, as estimated by the bumetanide sensitive K+ efflux was not found to be cell-age dependent in either AA or SS cells.Measurements of red cell density by isopycnic gradients indicated that 27% of the young cells reduce their volume by a Cl–-dependent process in hypotonic or low pH-induced swelling.The large volume-stimulated KCl efflux in AA young cells raises the possibility that these fluxes may be involved in the maturation of erythropoietic precursors. The high activity in the red cells of sickle cell anemia patients and its interindividual variation may have pathophysiological consequences since it reverses the decrease in the intracellular concentration of hemoglobin which occurs in response to low pH or osmolarity, an unwelcome pro-sickling event. 相似文献
409.
Christopher D. Hillyer Sherry A. Klumpp Jacquelynn M. Hall Dixon A. Lackey III Aftab A. Ansari Harold M. McClure 《Journal of medical primatology》1993,22(4):253-256
We attempted to define the etiology of anemia in SIV-infected rhesus macaques. Bone marrow culture showed significantly decreased (75% reduction) burst forming unit-erythroid (BFU-E) growth in end-stage SIV+ “sick” animals. Direct antiglobulin tests (DAT) were positive in nine of 35 SIV+ “well” and 14 of 14 SIV+ “sick” monkeys (0 of 25 control animals had positive DATs). In animals with a positive DAT, moderate to severe anemia was observed, as was increased LDH and spherocytosis. Erythropoietin was measured in four control, eight SIV+ “well” and five SIV+ “sick” animals with mean levels of 4.0, 15.4, and 1176 mU/mL (r = .94) in the three groups. These data suggest that the cause of anemia in the SIV-infected rhesus macaque is multifactorial, that there may be a defect in erythropoiesis, and that, serologically, an IgG mediated autoimmune hemolytic anemia is also present. 相似文献
410.
Stimulation of root Fe(III) reductase activity by iron additions to iron-deficient growth media may be the result of iron activation of 1-aminocyclopropane-1-carboxylic acid (ACC) oxidase required for ethylene biosynthesis. Two different ethylene inhibitors, aminooxyacetic acid (AOA) (20
m; ACC synthase inhibitor) and cobalt (3
m CoCl2; ACC oxidase inhibitor), were used to study the effects of iron supply and cobalt inhibition on ethylene action in controlling the activity of Fe(III)-chelate reductase in pea (Pisum sativum L.) roots. Supplying 20 gm
m Fe(III)-N,N-ethylenebis[2-(2-hydroxypheyl)-glycine [Fe(III)-EDDHA] to either cobalt-treated, iron-deficient Sparkle (normal parent) or E107 (brz mutant genotype) pea seedlings reversed the negative effects of cobalt on root Fe(III)-reductase activity. Re-supplying 20
m Fe(III)-EDDHA to iron-deficient, AOA-treated seedlings did not enhance root Fe(III)-reductase. Apparently, cobalt competes with iron for the active site in ACC oxidase during ethylene synthesis. Inhibition of root reductase activity by cobalt treatment lowered manganese, zinc, magnesium and potassium content of mutant E107 pea seedlings. In contrast, iron enhancement of root reductase activity in iron-deficient, cobalt-treated E107 seedlings resulted in higher seedling accumulations of manganese, zinc, magnesium and potassium. These results support the hypothesis that root cell plasma membrane reductase activity plays a role in cation uptake by root cells. 相似文献