首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   68篇
  免费   3篇
化学工业   15篇
金属工艺   1篇
机械仪表   9篇
能源动力   1篇
轻工业   15篇
无线电   1篇
一般工业技术   10篇
冶金工业   13篇
原子能技术   1篇
自动化技术   5篇
  2022年   2篇
  2021年   3篇
  2020年   1篇
  2017年   4篇
  2014年   1篇
  2013年   2篇
  2012年   5篇
  2011年   6篇
  2010年   5篇
  2009年   8篇
  2008年   5篇
  2007年   4篇
  2006年   3篇
  2005年   2篇
  2004年   1篇
  2000年   1篇
  1999年   1篇
  1998年   2篇
  1997年   2篇
  1995年   2篇
  1993年   1篇
  1992年   1篇
  1987年   1篇
  1986年   1篇
  1982年   1篇
  1981年   1篇
  1977年   2篇
  1976年   3篇
排序方式: 共有71条查询结果,搜索用时 444 毫秒
61.
CALR mutations are a revolutionary discovery and represent an important hallmark of myeloproliferative neoplasms (MPN), especially essential thrombocythemia and primary myelofibrosis. To date, several CALR mutations were identified, with only frameshift mutations linked to the diseased phenotype. It is of diagnostic and prognostic importance to properly define the type of CALR mutation and subclassify it according to its structural similarities to the classical mutations, a 52-bp deletion (type 1 mutation) and a 5-bp insertion (type 2 mutation), using a statistical approximation algorithm (AGADIR). Today, the knowledge on the pathogenesis of CALR-positive MPN is expanding and several cellular mechanisms have been recognized that finally cause a clonal hematopoietic expansion. In this review, we discuss the current basis of the cellular effects of CALR mutants and the understanding of its implementation in the current diagnostic laboratorial and medical practice. Different methods of CALR detection are explained and a diagnostic algorithm is shown that aids in the approach to CALR-positive MPN. Finally, contemporary methods joining artificial intelligence in accordance with molecular-genetic biomarkers in the approach to MPN are presented.  相似文献   
62.
This narrative review summarises the evidence for considering physical exercise (PE) as a non-pharmacological intervention for delaying cognitive decline in patients with Alzheimer’s disease (AD) not only by improving cardiovascular fitness but also by attenuating neuroinflammation. Ageing is the most important risk factor for AD. A hallmark of the ageing process is a systemic low-grade chronic inflammation that also contributes to neuroinflammation. Neuroinflammation is associated with AD, Parkinson’s disease, late-onset epilepsy, amyotrophic lateral sclerosis and anxiety disorders. Pharmacological treatment of AD is currently limited to mitigating the symptoms and attenuating progression of the disease. AD animal model studies and human studies on patients with a clinical diagnosis of different stages of AD have concluded that PE attenuates cognitive decline not only by improving cardiovascular fitness but possibly also by attenuating neuroinflammation. Therefore, low-grade chronic inflammation and neuroinflammation should be considered potential modifiable risk factors for AD that can be attenuated by PE. This opens the possibility for personalised attenuation of neuroinflammation that could also have important health benefits for patients with other inflammation associated brain disorders (i.e., Parkinson’s disease, late-onset epilepsy, amyotrophic lateral sclerosis and anxiety disorders). In summary, life-long, regular, structured PE should be considered as a supplemental intervention for attenuating the progression of AD in human. Further studies in human are necessary to develop optimal, personalised protocols, adapted to the progression of AD and the individual’s mental and physical limitations, to take full advantage of the beneficial effects of PE that include improved cardiovascular fitness, attenuated systemic inflammation and neuroinflammation, stimulated brain Aβ peptides brain catabolism and brain clearance.  相似文献   
63.
Tartary buckwheat (Fagopyrum tataricum) seeds have a strong aroma that characteristically differs from the aroma of common buckwheat (Fagopyrum esculentum). Its phytochemical background has only been recently investigated. The aim of this study was to identify and quantify individual compounds responsible for tartary buckwheat aroma. Volatiles from different samples (whole seed, flour, and husks) were extracted with simultaneous extraction and distillation by Likens-Nickerson apparatus and analyzed by GC-MS. A total of 48 compounds were quantified and their odor activity values (OAV) were calculated. OAV of 26 compounds was higher than 10; therefore, they significantly contribute to the overall tartary buckwheat aroma. The compounds with OAV > 500 were: (E,E)-2,4-decadienal, (E)-2-nonenal, 2-phenylethanol, (E,E)-2,4-nonadienal, hexanal, decanal, and nonanal. The most important difference from the aroma of common buckwheat is the absence of salicylaldehyde and presence of naphthalene. Salicylaldehyde could be proposed as a marker to detect contamination/adulteration of tartary buckwheat with common buckwheat. PRACTICAL APPLICATION: Buckwheat is becoming one of important alternative crops. Its products which are rich in proteins, fiber, vitamins, and antioxidants have been associated with healthy nutrition. Although tartary buckwheat is similar to more familiar common buckwheat, their characteristic aromas differ notably. This study expands recent research on aroma of tartary buckwheat tea to seed, flour, and husks, and suggests how products from different species of buckwheat can be distinguished by analysis of aroma compounds.  相似文献   
64.
Kept under observation by the medical staff were 110 patients with mild or moderately severe generalized parodontitis in a sanatorium-preventorium setting. Depending on the severity of the process in the parodontium tissues the patients were given a differentiated treatment (mouth-baths with a chloridic-sodic mineral water, gum mud poultice applications, low frequency interference currents). Clinical, paraclinical, and laboratory methods were used to asses the studies results effectiveness. The greatest therapeutic benefit occurred in those patients who received a combined treatment with chloridic-sodic mineral water mouth-baths, gum mud poultice applications, and low frequency interference currents.  相似文献   
65.
The authors studied the action of lithium ions on the responses of rat dorsal root ganglion neurons and frog spinal motoneurons evoked by monoamine agonists using the microelectrode technique. Lithium ions reversibly inhibit the depolarizing responses of spinal sensory neurons and motoneurons evoked by activation of muscarinic choline-, alpha 1-adreno-, and 5-hydroxytryptamine2 receptors, but enhance the hyperpolarizing neuronal responses evoked by activation of 5-hidroxytryptamine1A receptors.  相似文献   
66.
This paper addresses the problem of discrete-time nonlinear predictive control of W iener systems. Wiener-model-based nonlinear predictive control combines the advantages of linear-model-based predictive control and gain scheduling while retaining a moderate level of computational complexity. A clear relation is shown between an iteration in the optimization of the nonlinear control problem and the control problem of the underlying linear-model-based method. This relation has a simple form of gain scheduling, thus the properties of the nonlinear control system can be analysed from the comprehensible linear control aspect. Several disturbance rejection techniques are proposed and compared. The method was tested on a simulated model of a pH neutralization process. The performance was excellent also in the case of a considerable plant-tomodel mismatch. The method can be applied as a first next step in cases where the performance of linear control is unsatisfactory owing to process nonlinearity.  相似文献   
67.
A thin, one-dimensional, gradient-index slab lens with a parabolic profile was designed and fabricated in fluorine-doped silica by use of plasma-enhanced chemical vapor deposition in a Helicon plasma reactor. The refractive-index profile of the fabricated lens was determined by the application of an inversion technique to the values of modal effective index measured with a prism coupler. The periodic refocusing property of the lens and the independence of the wavelength were measured with the fluorescence of a specially doped, thin polymer layer spin-coated onto the surface of the lens.  相似文献   
68.
Bismuth-powder modified carbon paste electrode (Bi-CPE) is presented as an attractive “mercury-free” sensor applicable in electrochemical striping analysis of selected heavy metals. The electrode paste was prepared as a mixture of finely powdered metallic bismuth together with graphite powder and silicon oil. The Bi-CPE was characterized in nondeaerated solutions containing Cd(II) and Pb(II) at the μg/L level in conjunction with square-wave anodic stripping voltammetry. The electrode exhibited well-defined and separated stripping signals for both metals accompanied with a low background contribution, and a reproducibility of 5.6 and 6.0% (n = 12) for 20 μg/L Cd(II) and Pb(II), respectively. The Bi-CPE exhibited superior performance in comparison to the bare carbon paste electrode (CPE) and the bismuth paste electrode (BiPE) and surprisingly, yielded a higher response than the in situ prepared bismuth-film carbon paste electrode. The electrode displayed excellent linear behavior in the examined concentration range from 10 to 100 μg/L Cd(II) + Pb(II) (R2 = 0.998 for both), with limits of detection of 1.2 μg/L for Cd(II) and 0.9 μg/L for Pb(II). The electroanalytical performance of Bi-CPE was successfully tested in a real sample of tap water spiked with Cd(II) and Pb(II).  相似文献   
69.
The results of pathomorphological research of internal organs of rats in hypoxical hypoxia and in the action of the antioxidant dihydroguersitine in acute hypoxia. Lt shows that DHQ causes favourable morphological changes in internal organs in acute hypoxia.  相似文献   
70.
Protein concentrates obtained from unconventional plant raw material, namely from the oil cake of tomato seeds, corn germs, flax and safflower hold promise as sources of biologically important components including mineral substances. The protein concentrates are marked by a high content of calcium, magnesium, phosphorus, copper, manganese and zinc. They are also rich in iron that occurs in the form of a protein complex of bivalent iron. The content of heavy metals and nitrates does not exceed quota permissible for foods.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号