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31.
Intraosseous pressure was measured in the lunate of 10 patients undergoing surgery for Kienb?ck's disease. Using the styloid process of the radius and the capitate as reference points of bone pressure, I found a stasis rather than arterial insufficiency in the lunate. This pattern was observed regardless of the stage of the disease according to St?hl and regardless of the finding by technetium TC 99m-methylene diphosphonate scintigraphy. The significance of this finding is still unknown but questions the current concept that Kienb?ck's disease is caused by arterial insufficiency, because these results imply an interruption of the blood flow as a result of venous congestion.  相似文献   
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This paper presents a mathematical review of methods and algorithms used to compute milling cutter placement for multi-axis finished-surface machining. In general, these methods and algorithms compute tool path points based on tangent-plane contact between the milling cutter and the surface while maintaining a fixed tool orientation. This tangent-plane method of tool positioning and orientation is examined by discussing its strengths and weaknesses. Errors resulting from the tangent-plane approach are typically determined using a posteriori cutter path checking and graphic visualization techniques. Although these checking techniques have proved useful in identifying the tool path errors before actual machining, the problem of generating an error-free tool path remains. In this paper, we discuss the analysis of tool path position and orientation data as they are generated. This a priori analysis method is used to show error locations along the lateral face of the tool. The conclusion is reached that additional research is needed in the area of simultaneous multi-axis tool path planning, if errors are to be eliminated and the efficiency of the milling machine is to be improved. The reader is referred to research efforts that extend beyond the traditional or computer-aided design (CAD, vendor supplied) tool path planning methods. Some of these efforts show great promise in eliminating gouging and improves machine tool efficiency.  相似文献   
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The objective of this investigation was to demonstrate that the firmness of a commercial vegetable product, diced and frozen red pepper (Capsicum annum var. Sendt), could be improved by the use of exogenous pectinesterase in an industrially relevant process. The diced pepper pieces 10 × 10 × 7 mm3 were infused under vacuum with a commercially available pectinesterase. The range of optimal process conditions was: 15-20°C, 45 min infusion time, a 10-25 mM CaCl2 infusion brine, a w/w ratio of pepper fruit to infusion brine of 1.5:1, and an enzyme dosage of 30-60 pectinesterase units (PEU) per kg pepper fruit. The firmness as measured by back extrusion was improved by a factor of two to three. The effect of firming was robust and conserved after freezing and heating in a simulated household cooking process. The firming process seems easily adaptable to industrial conditions and may be applicable to other vegetable and fruit products.  相似文献   
36.
Only two tumor suppressor gene loci, one on 3p25 and the MEN1 gene on 11q13, have thus far been implicated in the pathogenesis of sporadic human pancreatic endocrine tumors (PETs). A genome-wide allelotyping study of 28 human PETs was undertaken to identify other potential tumor suppressor gene loci. In addition to those on chromosomes 3p and 11q, frequent allelic deletions were identified on 3q (32%), 11p (36%), 16p (36%), and 22q (29%). Finer deletion mapping studies localized the smallest regions of common deletion to 3q27, 11p13, and 16p12.3-13.11. Potential candidate genes at these loci include WT1 (11p13), TSC2 (16p13), and NF2 (22q12), but no known tumor suppressor gene localizes to 3q27. The mean fractional allelic loss among these human PETs is 0.126, and no correlation was observed between allelic loss and clinical parameters, including age, sex, hormonal subtype, and disease stage. These findings highlight novel locations of tumor suppressor gene loci that contribute to the pathogenesis of human PETs, and several of these on 3p, 3q, and 22q are syntenic with loci on mouse chromosomes 9 and 16 that are implicated in a murine transgenic model of PETs.  相似文献   
37.
An algorithm is presented to compute the distribution of the strain energy release rate along the crack front of a penny-shaped delamination in a layered orthotropic body. The method applies a finite element recently proposed for three-dimensional analysis of layered orthotropic circular plates. The algorithm is economical even though it treats a full three-dimensional state of stress. The method requires only a single virtual crack extension to accurately compute the strain energy release rate at a point along the crack front. The method is applied to the study of delamination crack growth in a nine layer cross-ply laminate. The variation of strain energy release rate, G, along the crack front, is determined. The significance of the plate aspect ratio, as well as length scale, on the fracture process is studied. The establishment of a loading case where a distributed transverse compressive loading causes delamination growth is given.  相似文献   
38.
Different techniques for measuring autogenous deformation in cement paste are discussed, and a newly developed dilatometer designed specially for measuring this deformation is described. A particular characteristic of the dilatometer is the encapsulation of the cement paste in corrugated moulds. This restricts moisture loss and ensures that the hardening cement paste suffers insignificant restraint. In addition, the encapsulation permits measurements to commence shortly after casting.  相似文献   
39.
Bovine acyl-coenzyme A binding protein is a four-helix bundle protein belonging to a group of homologous eukaryote proteins that binds medium and long-chain acyl-coenzyme A esters with a very high affinity. The three-dimensional structure of both the free and the ligated protein together with the folding kinetics have been described in detail for the bovine protein and with four new sequences reported here, a total of 16 closely related sequences ranging from yeasts and plants to human are known. The kinetics of folding and unfolding in different concentrations of guanidine hydrochloride together with equilibrium unfolding have been measured for bovine, rat and yeast acyl-coenzyme A binding protein. The bovine and rat sequences are closely related whereas the yeast is more distantly related to these. In addition to the three natural variants, kinetics of a bovine mutant protein, Tyr31 --> Asn, have been studied. Both the folding and unfolding rates in water of the yeast protein are 15 times faster than those of bovine. The folding rates in water of the two mammalian forms, rat and bovine, are similar, though still significantly different. A faster unfolding rate both for rat and the bovine mutant protein results from a lower stability of the native states of these. These hydrophobic regions, mini cores, have been identified in the three-dimensional structure of the bovine protein and found to be formed primarily by residues that have been conserved throughout the entire eukaryote evolution from yeasts to both plants and mammals as seen in the sample of 16 sequences. The conserved residues are found to stabilize helix-helix interactions and serve specific functional purposes for ligand binding. The fast one-step folding mechanism of ACBP has been shown to be a feature that seems to be maintained throughout evolution despite numerous differences in sequence and even dramatic differences in folding kinetics and protein stability. The protein study raises the question to what extent does the conserved hydrophobic residues provide a scaffold for an efficient one-step folding mechanism.  相似文献   
40.
Chen  Jiaoyan  Hu  Pan  Jimenez-Ruiz  Ernesto  Holter  Ole Magnus  Antonyrajah  Denvar  Horrocks  Ian 《Machine Learning》2021,110(7):1813-1845
Machine Learning - Semantic embedding of knowledge graphs has been widely studied and used for prediction and statistical analysis tasks across various domains such as Natural Language Processing...  相似文献   
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