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排序方式: 共有440条查询结果,搜索用时 9 毫秒
1.
Knut Brockow Katarzyna Plata-Nazar Magdalena Lange Bogusaw Nedoszytko Marek Niedoszytko Peter Valent 《International journal of molecular sciences》2021,22(5)
Mastocytosis is characterized by the pathological accumulation of mast cells (MC) in various organs. In these patients, MC may degranulate and thereby contribute to clinical symptoms, especially when a concomitant allergy is present. However, MC activation can not only be induced by high-affinity receptors for IgE, but also by anaphylatoxins, neuropeptides, IgG immune complexes, complement-components, drugs, products of bacteria or parasites, as well as physical factors such as heat, cold, vibration, stress, sun, or physical effort. Symptoms due to mediators released by activated MC may develop in adults suffering from systemic mastocytosis, but also evolve in children who usually have cutaneous mastocytosis (CM). Clinically, CM is otherwise characterized by typical brown, maculopapular skin lesions or mastocytoma associated with a positive Darier’s sign. Pruritus and flushing are common and blistering may also be recorded, especially in diffuse CM (DCM). Pediatric patients with mastocytosis may also have gastrointestinal, respiratory, and neurologic complaints. Although anaphylaxis is not a typical finding, pediatric patients with massive skin involvement and high tryptase levels have a relatively high risk to develop anaphylaxis. This paper reviews MC mediator-related symptoms and anaphylaxis in children with mastocytosis, with special emphasis on risk factors, triggers, and management. 相似文献
2.
Oscar Ljungkrantz Knut Åkesson Martin Fabian Amir Hossein Ebrahimi 《Empirical Software Engineering》2014,19(3):655-677
This paper presents an empirical study of control logic specifications used to document industrial control logic code in manufacturing applications. More than one hundred input/output related property specifications from ten different reusable function blocks were investigated. The main purpose of the study was to provide understanding of how the specifications are expressed by industrial practitioners, in order to develop new tools and methods for specifying control logic software, as well as for evaluating existing ones. In this paper, the studied specifications are used to evaluate linear temporal logic in general and the specification language ST-LTL, tailored for functions blocks, in particular. The study shows that most specifications are expressed as implications, that should always be fulfilled, between input and output conditions. Many of these implications are complex since the input and output conditions may be mixed and involve sequences, timer issues and non-boolean variables. Using ST-LTL it was possible to represent all implications of this study. The few non-implication specifications could be specified in ST-LTL as well after being altered to suit the specification language. The paper demonstrates some advantages of ST-LTL compared to standard linear temporal logic and discusses possible improvements such as support for automatic rewrite of complex specifications. 相似文献
3.
We here present a method for estimating the accessible volume surrounding each atom of a ligand when bound to a receptor. The accessible volumes are calculated as the volume of a sphere with fixed radius, centered on each ligand atom, not simultaneously occupied by the volume of the receptor. The method is capable of describing the packing of the ligand in the binding pocket. Moreover, where structural models of several receptors in complex with the same ligand are available, a comparative study discriminating on accessible volumes can be performed. For these cases, a relatively large accessible volume in a particular receptor might indicate that this receptor has a unique cavity that might be exploited to develop a selective ligand analog. The ligand atoms showing variation in surrounding volume accessibility when bound to different receptors constitute attractive anchor points where one might want to attach substituents that modify the selectivity of the ligand. We have applied the described method to two different enzyme-ligand systems that bind tetrahydrobiopterin, i.e. the aromatic amino acid hydroxylases and nitric oxygen synthases. Our results yield new insights into the specificity of cofactor binding to these protein families. 相似文献
4.
Practice-based perspectives have established the situated nature of how technology is appropriated, enacted, and improvised in organisations. Empirical studies demonstrate how the same technology produces different results in different contexts of use. However, practice-based research has, to date, less to offer in terms of accounting for the relationship between instances of situated use (i.e., work practices) that are separated in space and/or time. The term trans-situated use is intended to highlight this blind spot. We focus on one type of relationship, viz., significant degrees of similarities between technologically mediated, geographically dispersed work practices. This degree of similarity is achieved through a process of commensurability consisting of (i) standardisation (addressing interdependencies between multiple instances of the ‘same’ work practice at geographically dispersed sites); and (ii) heterogeneity (addressing the entanglement of one work practice with apparently unrelated work practices and modules). Empirically, we report on a longitudinal, interpretative case study (1998–2004) of a company strategically targeting an integrated information system as a principal vehicle to establish similar services globally. 相似文献
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Electrical characterization of individual metal‐coated polymer spheres used in isotropic conductive adhesives 下载免费PDF全文
Hoang‐Vu Nguyen Jianying He Tore Helland Helge Kristiansen Knut E. Aasmundtveit 《应用聚合物科学杂志》2016,133(31)
Isotropic conductive adhesives (ICAs) filled with metal‐coated polymer spheres (MPS) have been proposed to improve the mechanical reliability compared to conventional ICAs filled with silver flakes. The electrical properties of MPS play an important role in the electrical performance of macroscopic MPS‐based ICAs. This article deals with the electrical characterization of individual MPS using a nanoindentation‐based flat punch method, in which the resistance and the deformation of single MPS were monitored simultaneously. Four groups of silver‐coated polymer spheres (AgPS) with identical polymer cores but different silver coating thicknesses were tested. The resistance of AgPS decreases gradually with increasing deformation degree of particles, and increases when the deformation of particles is reduced. In addition, the resistance of individual AgPS is dependent on the physical properties of the silver coating, such as thickness, uniformity, and porosity. The thicker the silver coating is, the lower and more stable the resistance of AgPS is. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43764. 相似文献
8.
Grundwasser - Chloridazon ist ein Herbizidwirkstoff, der in Deutschland seit 1964 für den Einsatz in der Landwirtschaft zugelassen ist. Er wird hauptsächlich beim Anbau von Rüben,... 相似文献
9.
Comminuted sausages formulated with mechanically deboned poultry meat-MDPM (turkey or chicken, frame or neck) treated in different ways before production (vacuum packed MDPM or air packed skeletons deboned at production) and stored frozen for 6 or 18 weeks have been studied using a full-factorial design and chemical, physical and sensory analysis. MDPM was obtained from a Beehive separator. Comminuted sausages with MDPM from turkey frames, stored at -25?°C as skeletons, packed in air for 18 weeks developed marked rancid odour and flavour which could also be detected by thiobarbituric acid reactive substances (TBARS) and the concentration of volatile compounds. Vacuum packed mechanically deboned meat irrespective of species and carcass part could be stored for up to 18 weeks and used in formulation of sausages without any serious changes in their sensory profiles. Instrumental colour differences between sausages were mainly due to species. Turkey sausages were darker, redder and less yellow than chicken sausages. Moisture and fat contents were influenced by carcass part and to a lesser extent depended on species and storage time. Principal least squares regression (PLS2) showed close relationships between instrumental parameters and sensory attributes. TBARS, hexanal and volatile compounds were highly correlated with rancid flavour while redness (a(?)) was strongly related to sensory colour hue and colour strength. 相似文献
10.
Two different extrusion‐coating qualities of polyethylene, namely LDPE and HDPE, were coated on high‐density papers. Differences were observed with respect to their response to storage and low temperature heat treatment. HDPE does not respond to storage at ambient temperature and heat treatment in the same way as LDPE. The LDPE‐coating exhibits an increase in the monoclinic crystalline fraction at the paper surface as a result of heat treatment. The nature of this response appears to be a result of adhesion to a paper surface, the properties of this surface, orientation of polymer chains, and chain mobility differences. The increase of the monoclinic fraction is shown to relate to an increase of the mean crystallite thickness and initiation of new crystallites at the paper surface. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 235–241, 2004 相似文献