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991.
We employed a standardized investigative approach to evaluate four cases of "idiopathic neutropenia" in very low birthweight infants. The evaluation included maternal anti-neutrophil antibodies, a marrow aspiration, and a three-day trial of recombinant granulocyte colony-stimulating factor (rG-CSF). All patients had neutropenia at or shortly following delivery, and remained neutropenic (generally <500/microl) for 1-9 weeks until rG-CSF was administered. Blood and bone marrow studies in all 4 indicated that the neutropenia was: (i) the kinetic result of diminished neutrophil production; (ii) not alloimmune; (iii) not cyclic; and (iv) not associated with recognized inborn errors, bacterial or viral infections, or medications. All responded to rG-CSF by transiently increasing their blood neutrophils to normal, and the neutropenia resolved in all cases with time. It is likely that "idiopathic neutropenia" in this population represents a common phenotype of several different causes, rather than a single entity. Some cases, perhaps the majority, will respond to a short course of rG-CSF administration. 相似文献
992.
FJ Ramos BS Kaplan RD Bellah EH Zackai P Kaplan 《Canadian Metallurgical Quarterly》1998,78(5):474-481
The Hajdu-Cheney syndrome (HCS) is a rare autosomal dominant disorder. It comprises a coarse face, short neck, hirsutism, joint laxity, and normal intelligence. Bone dysplasias, include acro-osteolysis, bathrocephaly, and vertebral anomalies. In 1988, Exner [1988: Eur J Pediatr 147:544-546] coined the term "serpentine fibula-polycystic kidney syndrome" (SFPKS) when he reported on a girl with short stature, unusual facial appearance, polycystic kidneys, and elongated curved fibulae. He postulated that it was a new entity different from the Melnick-Needles syndrome. Since his report, five similar cases have been published. Similarities between both HCS and SFPKS were noticed first by us and then by other authors. In this report we show that many clinical and radiological characteristics are shared by the HCS and the SFPKS and hypothesize that they represent a single entity with a variable degree of expression. 相似文献
993.
A bubble surfactometer was used to measure the surface tension of an aqueous suspension of surfactant TA as a function of bubble area over a range of cycling rates and surfactant bulk concentrations. Results of the surface tension-interfacial area loops exhibited a rich variety of phenomena, the character of which varied systematically with frequency and bulk concentration. A model was developed to interpret and explain these data and for use in describing the dynamics of surface layers under more general circumstances. Surfactant was modeled as a single component with surface tension taken to depend on only the interfacial surfactant concentration. Two distinct mechanisms were considered for the exchange of surfactant between the bulk phase and interface. The first is described by a simple kinetic relationship for adsorption and desorption that pertains only when the interfacial concentration is below its maximum equilibrium value. The second mechanism is "squeeze-out" by which surfactant molecules are expelled from an interface compressed past a maximum packing state. The model provided good agreement with experimental measurements for cycling rates from 1 to 100 cycles/min and for bulk concentrations between 0.0073 and 7.3 mg/ml. 相似文献
994.
Jitendra Kumar Samriya Mohit Kumar Sukhpal Singh Gill 《International Journal of Network Management》2023,33(5):e2243
Mobile Internet services are developing rapidly for several applications based on computational ability such as augmented/virtual reality, vehicular networks, etc. The mobile terminals are enabled using mobile edge computing (MEC) for offloading the task at the edge of the cellular networks, but offloading is still a challenging issue due to the dynamism, and uncertainty of upcoming IoT requests and wireless channel state. Moreover, securing the offloading data enhanced the challenges of computational complexities and required a secure and efficient offloading technique. To tackle the mentioned issues, a reinforcement learning-based Markov decision process offloading model is proposed that optimized energy efficiency, and mobile users' time by considering the constrained computation of IoT devices, moreover guarantees efficient resource sharing among multiple users. An advanced encryption standard is employed in this work to fulfil the requirements of data security. The simulation outputs reveal that the proposed approach surpasses the existing baseline models for offloading overhead and service cost QoS parameters ensuring secure data offloading. 相似文献
995.
Livers incubated at 30°C in closed tubs developed floras dominated by Enterobacteriaceae. At chiller temperatures, floras were ultimately dominated by psychrotrophic lactobacilli. Tub-packed livers can have an extended shelf life similar to that reported for vacuum-packed liver. 相似文献
996.
WL Clark HL Alpern WS Breall RM Hyman A Markovitz JB O'Brien RD Starke 《Canadian Metallurgical Quarterly》1993,158(3):263-267
Cardiac disability ratings in workers' compensation cases currently lack any consistent scientific basis, with varying medical evidence used by different examiners in the same case. Opinions about the extent of disability may differ with the same patient, delaying resolution and the delivery of benefits. We describe guidelines for determining cardiac impairment and suggest a schedule for rating disability based on evidence. Our experience is in California, but arriving at equitable ratings for disability purposes is a nationwide challenge. Exercise stress testing provides the best reproducible data to test the heart's ability to do work. When exercise stress testing is not possible or adequate, alternative or supplemental testing is necessary. Certain conditions, such as hypertension, arrhythmias, coronary artery spasm, and a history of coronary artery operations or myocardial infarction, may affect "cardiac disability" but may not necessarily be reflected in exercise testing. 相似文献
997.
Adaptive neuro-fuzzy inference system modeling of cryogenically treated AISI M2 HSS turning tool for estimation of flank wear 总被引:1,自引:0,他引:1
Simranpreet Singh Gill Rupinder SinghJagdev Singh Harpreet Singh 《Expert systems with applications》2012,39(4):4171-4180
This study deals with modeling the flank wear of cryogenically treated AISI M2 high speed steel (HSS) tool by means of adaptive neuro-fuzzy inference system (ANFIS) approach. Cryogenic treatment has recently been found to be an innovative technique to improve wear resistance of AISI M2 HSS tools but precise modelling approach which also incorporates the cryogenic soaking temperature to simulate the tool flank wear is still not reported in any open literature. In order to obtain data for developing the ANFIS model, turning of hot rolled annealed steel stock (C-45) by cryogenically treated tools treated at various cryogenic soaking temperatures was performed in steady state conditions while varying the cutting speed and cutting time. The model combined modeling function of fuzzy inference with the learning ability of artificial neural network; and a set of rules has been generated directly from experimental data. It was determined that the predictions usually agreed well with the experimental data with correlation coefficients of 0.994 and mean errors of 2.47%. The proposed model can also be used for estimating tool flank wear on-line but the accuracy of the model depends upon the proper training and selection of data points. 相似文献
998.
CO(2) has been shown to have a number of effects on biological systems, but it is uncertain which of these are important in its inhibition of Gram-negative spoilage bacteria. The effects of CO(2) on intracellular pH, in vitro enzyme actities and substrate transport were examined to see if any changes in these functions could be correlated with the observed patterns of growth inhibition, which varied with the composition of the growth medium. CO(2) inhibition of growth could not be explained by postulating inhibition of intracellular enzymes, but inhibition of substrate uptake appears to correlate with-and offer a satisfactory explanation for-growth inhibition. However, the data do not allow the inhibition of substrate transport to be ascribed to a particular mode of action of CO(2). 相似文献
999.
1000.
Rational design of Rhizopus oryzae lipase with modified stereoselectivity toward triradylglycerols 总被引:1,自引:0,他引:1
Scheib H; Pleiss J; Stadler P; Kovac A; Potthoff AP; Haalck L; Spener F; Paltauf F; Schmid RD 《Protein engineering, design & selection : PEDS》1998,11(8):675-682
The binding site of sn-1(3)-regioselective Rhizopus oryzae lipase (ROL) has
been engineered to change the stereoselectivity of hydrolysis of
triacylglycerol substrates and analogs. Two types of prochiral
triradylglycerols were considered: 'flexible' substrates with ether,
benzylether or ester groups, and 'rigid' substrates with amide or phenyl
groups, respectively, in the sn-2 position. The molecular basis of sn-1(3)
stereoselectivity of ROL was investigated by modeling the interactions
between substrates and ROL, and the model was confirmed by experimental
determination of the stereoselectivity of wild-type and mutated ROL. For
the substrates, the following rules were derived: (i) stereopreference of
ROL toward triradylglycerols depends on the substrate structure. Substrates
with 'flexible' sn-2 substituents are preferably hydrolyzed at sn-1,
'rigid' substrates at sn-3. (ii) Stereopreference of ROL toward
triradylglycerols can be predicted by analyzing the geometry of the
substrate docked to ROL: if the torsion angle phiO3-C3 of glycerol is more
than 150 degrees, the substrate will preferably be hydrolyzed in sn-1,
otherwise in sn-3. For ROL, the following rules were derived: (i) residue
258 affects stereoselectivity by steric interactions with the sn-2
substituent rather than polar interactions. To a lower extent,
stereoselectivity is influenced by mutations further apart (L254) from
residue 258. (ii) With 'rigid' substrates, increasing the size of the
binding site (mutations L258A and L258S) shifts stereoselectivity of
hydrolysis toward sn-1, decreasing its size (L258F and L258F/L254F) toward
sn-3.
相似文献