Degrees Of Shrinkage Research Articles

Reconstruction of Deformed Bite Marks Using Affine Transformations

Bite marks inflicted on animate and inanimate objects will undergo a certain degree of deformation. This fact remains one of the biggest stumbling blocks when analyzing evidence for court presentation. It has been demonstrated that the reliability of pattern association analysis will not be affected by minimal degrees of warping, shrinkage, and distortion. In this study, affine transformations were applied to bite marks to establish if minimal distortions would affect the mathematically determined relationships of the defined features. In a real case study, it was then tested whether the distorted bite mark matched the dentition of the perpetrator by applying an affine transformation. This was confirmed to be the case. Affine transformations will thus not affect the relationships of the individual features found in bite marks. The numerical calculations validate the reliability of pattern association analysis in the presence of minimal amounts of warping, shrinkage, and distortion.

The application of affine transformations in matching distorted forensic samples with a common origin

The practice of forensic odontology regularly requires the forensic dental expert to establish a degree of concordance between two objects, one or both of which have undergone minimal degrees of warping, shrinkage and distortion collectively described as deformations. These comparisons can be between the suspect's or victim's dentition and bite marks on inanimate objects/skin, two radiological images, palatal rugae patterns, dental arches, lip prints and other unique scenarios which are presented in forensic odontological cases. This paper will define the mathematical concept of affine transformation as it pertains to forensic matters and explains how it can be applied to a case study involving pattern deformations. Although the deformation of the evidence may be minimal in extent, it creates a measure of uncertainty when expert evidence is given in court cases. Any metric discrepancy caused by deformation of the evidence will necessitate the application of pattern association and negate the use of metric analysis. It has been shown that a pattern association analysis of evidence will not be affected by minimal amounts of deformation. The mathematical limits of these deformations which will significantly affect the comparisons have not yet been determined. In the case study presented the deformations were considered minimal and thus explainable by a pattern association analysis. The mathematical concepts will empower the expert to explain to a court of law how two samples which were not a perfect match, could in fact be deformed equivalents of common origin.

Treatment of Diabetic Foot Ulcers Using a Blood Bank Platelet Concentrate

Many clinical trials have shown the effectiveness of platelet releasate on chronic wound healing, but large volumes of blood must be aspirated from patients and a platelet separator is required. Moreover, in the case of using homologous platelets, time and effort are needed to locate a suitable donor, and the donor's blood sample must be tested for a history of infectious disease. The current study was undertaken to evaluate the effect of a straightforward method using a blood bank platelet concentrate in treating diabetic foot ulcers. Fifty-two patients with diabetic foot ulcers were treated using a blood bank platelet concentrate. A control treatment (i.e., treatment with topical fibrinogen and thrombin) was performed on 48 patients. Twelve weeks after treatment, the percentage of complete healing, mean healing time, percentage of wound shrinkage, and patient satisfaction were compared. Complete wound healing was achieved in 79 percent of the blood bank platelet concentrate-treated group and 46 percent of the control group (p < 0.05). The times required for complete healing were 7.0 +/- 1.9 and 9.2 +/- 2.2 weeks in the blood bank platelet concentrate-treated and control groups, respectively (p < 0.05). The degrees of wound shrinkage were 96.3 +/- 7.8 and 81.6 +/- 19.7 percent for the treated and control groups, respectively (p < 0.05). Patient satisfaction with the blood bank platelet concentrate treatment yielded better results than the control method (mean score, 7.6 +/- 1.6 and 5.3 +/- 1.4, respectively; p < 0.05). No adverse events related to the study treatment occurred. Treatment of diabetic foot ulcers using a blood bank platelet concentrate showed results superior to control treatment. A blood bank platelet concentrate offers a simple and effective treatment for diabetic foot ulcers.

Low-shrinkage visible-light-curable urethane-modified epoxy acrylate/SiO 2 composites as dental restorative materials

In this study, low-shrinkage high-strength dental restorative materials were prepared and their properties were investigated. Epoxy acrylates modified with various stoichiometric amounts of urethane acrylates were used as the resin matrix and 3-(trimethoxysilyl)propyl methacrylate (MSMA)-modified monodisperse nano-sized SiO 2 particles were synthesized and used as the inorganic reinforcing filler. Polymer composites suitable for using as dental restorative materials were formed by curing the resin matrices containing MSMA-SiO 2 with visible-light. The viscosities of the obtained resin matrices, their polymerization shrinkages, hardness, flexural strengths, and flexural moduli of the obtained polymer composites were investigated. Compared with bisphenol-A/glycidyl dimethacrylate (Bis-GMA)-based dental restorative materials, the polymer composites obtained in this study exhibited greatly reduced degrees of shrinkage and better mechanical and physical properties.

Long-Term CO2 Sorption on Upper Freeport Coal Powder and Lumps

Powder and lumps of the Argonne Premium Upper Freeport coal were compared in a 9-month-long CO2 sorption−desorption study. On the basis of the slope analysis, CO2 induced the lumps swelling by 7%. The powder swelled by 8% and then rapidly shrank by 3% on desorption. This was verified by a “single point” injection of helium and the pressure-and-density technique, which was sufficiently sensitive. Low-pressure Langmuir-fit parameters suggest that the microporous textures of the powder and lumps are similar. The samples demonstrated greatly increased sticking coefficients and a slightly larger number of the “sorption ready” sites, after the CO2-induced swelling and structural rearrangement resulted in variable degrees of the matrix shrinkage. No permanent changes in the void volume and dry mass were detected after complete desorption. The observed hysteresis in sorption−desorption behavior of both samples upon the approach to the CO2 density fluctuation ridge is interpreted as a contribution of condensation and coalescence of CO2 clusters in mesopores. The differences between the two samples in the magnitude of the enhanced capillary condensation, with or without dissolution, demonstrate the importance of changes in mesoporous texture caused by grinding of coal lumps into powder.

Nature of smectic A*-C* phase transitions in a series of ferroelectric liquid crystals with little smectic layer shrinkage

The smectic layer spacing of two homologous series of ferroelectric liquid crystal compounds was characterized by small-angle x-ray diffraction and different degrees of smectic layer shrinkage on cooling from the SmA* into the SmC* phase were observed. The smectic A*-smectic C* phase transition was further studied by measuring the thermal and electric field effects on the optical tilt angle and the electric polarization. With decreasing length of the alkyl terminal chain the phase transition changes from tricritical exhibiting high layer shrinkage to a pure second-order transition with almost no layer shrinkage. This is explained by the increased one-dimensional translational order of the smectic layers, which seems to promote the "de Vries"-type [Mol. Cryst. Liq. Cryst. 41, 27 (1977)] smectic A*-C* phase transition with no or little layer shrinkage.

Sensing Ionic Strength

Bacteria, which may be exposed to widely varying osmotic conditions, respond to hyperosmotic stress by accumulating solutes. For instance, the ABC (ATP-binding cassette) transporter OpuA of Lactococcus lactis takes up glycine betaine to combat water loss and cell shrinkage. OpuA reconstituted in proteoliposomes is activated by increased luminal ion concentration, with the threshold depending on the ionic lipid content of the membrane; however, the mechanism has been unclear. Biemans-Oldehinkel et al. reconstituted OpuA into liposomes containing MgATP and various concentrations of potassium phosphate, exposed the liposomes to solutions of different osmolality (eliciting varying degrees of shrinkage), measured transport of radiolabeled glycine betaine, and determined that transport varied as a function of internal ionic strength. OpuA contains tandem CBS (cystathionine-β-synthase) domains with an anionic C-terminal tail at the C-terminal end of its ATPase subunits. Analysis of the effects of ionic strength on the transport properties of OpuA mutants reconstituted into liposomes containing different fractions of anionic lipids (in which the lumen contained an ATP-regenerating system) indicated that the CBS domain acted as a sensor for ionic strength. The anionic tail modulated the ion-sensing properties of the transporter, shifting the ionic strength dependence of the transporter to higher values. The authors proposed a model in which the OpuA domains gate membrane transport through an electrostatic switching mechanism in which interactions between the CBS domain and the negatively charged membrane are dependent on surface charge and ionic strength, allowing the transporter to switch into an active "on" position in response to changes in ionic strength. CBS domains are found in more than 4000 proteins, including transporters, voltage-gated chloride channels, and various enzymes; this research raises the intriguing possibility that other CBS-containing proteins may be similarly regulated. E. Biemans-Oldehinkel, N. A. B. N. Mahmood, B. Poolman, A sensor for intracellular ionic strength. Proc. Natl. Acad. Sci. U.S.A. 103 , 10624-10629 (2006). [Abstract] [Full Text]

Morphology and Structure of Constituent Fibres in Thermally Bonded Nonwovens

A new process has been developed to produce three-dimensional nonwovens directly from staple fibres. In order to establish suitable windows of the process parameters to achieve high-quality nonwoven products, the effects of thermal bonding temperature, dwell time and mould material on the morphology and structure of the fibre have been investigated using PP/PET bi-component fibres. It was evident from both scanning electron microscope images and Raman spectra that thermal-induced shrinkage of the PP sheath fibre occurred in the thermal bonding process, leading to deformation and cracking of the PP sheath and exposure of the PET core. X-ray diffraction results revealed crystal imperfection and/or less ordered polymer chains, more γ-form and thermal contraction of the crystal lattice for the PP sheath fibre, while birefringence measurements indicated that both the birefringence and the orientation factor for the PP fibre decreased after the thermal bonding process. The degrees of the thermal-induced shrinkage increased, and the crystallinity, birefringence and orientation factor of the PP sheath fibre decreased with increasing thermal bonding temperature, dwell time and thermal conductivity of the mould material. All these can be attributed to the different levels of modification of chemical composition caused by thermal oxidative degradation and thermal-induced relaxation of the orientation during the thermal bonding process.

Dielectric spectroscopy of de Vries-type smectic-A*–smectic-C*transitions

We report results of dielectric investigations on a number of ferroelectric liquid crystalline (FLC) compounds with different degrees of layer shrinkage in the smectic-A(*) -smectic-C(*) phase transitions. With a decreasing extent of layer shrinkage the investigated FLCs exhibit a significantly increasing soft-mode absorption, decreasing leading Landau coefficient alpha, and a considerably broader mean-field regime. We explain these tendencies by the fact that the low layer shrinkage materials come closer to the diffuse cone model of de Vries than to the common model of rigid rods which maintain their orientational order during tilting. In the case of the diffuse cone model the tilt-angle fluctuations are decoupled from variations of the smectic layer spacing, which explains the observed behavior.

PALEORADIOLOGIA: ESTUDIO IMAGENOLOGICO DEL NIÑO DEL CERRO EL PLOMO

Objectives: To describe the imagenologic findings of the «Nino del Cerro El Plomo» mummy. To check preservation status and look for clues of disease and make death related findings using a multisistemic evaluation and describe anthropometric features. Methods: A whole body multislice CT scan was done, followed by multiplanar reconstructions. We did an exhaustive analysis of internal organs. Results: The mummy is in a fetal position. The musculoskeletal system is well preserved. The age was estimated by the growth patterns of the teeth, it was 8 years old. The internal organs are distinguishible but with different degrees of shrinkage and volume loss. The best preserved organ is the central nervous system. The oropharinx, esophagus and stomach are partially filled with contents. The subcutaneous fat layer thickness, bone mineralization and development suggest normal nutritional status. There is no evidence of traumatic injuries related to death. Conclusions: Multislice CT help us to determinate the general conditions of the mummy and the state of the internal organs, avoiding damaging its integrity. We generated important anthropologic and paleopathologic data that wasn't available before.

Reduced shrinkage of sol–gel derived silicas using sugar-based silsesquioxane precursors

Monolithic siliceous materials were prepared, using sol–gel based methods, from mixtures of trifunctional silanes based on sugar lactones, including silyl-modified gluconamide GLS and maltonamide MLS, and a tetrafunctional silane derived from glycerol. The tri- and tetrafunctional compounds cured at different rates, which led to an enhanced presence of sugar moieties at the external surface of the pores in the monoliths. The resulting silicas exhibited dramatically reduced degrees of shrinkage (<10%) when compared to silica monoliths prepared in the absence of trifunctional silanes (up to 85%). The sugars also alter the morphology of the material, with significant reductions in both micropore volume and surface area for materials containing GLS. The reduced shrinkage, presence of sugars on the silica surface, and altered morphology are likely to be important factors in providing such materials with the ability to stabilize entrained proteins.

Curing Process Window and Thermal Stability of Porous MSQ-Based Low-Dielectric-Constant Materials

The curing process window and properties of both nitrogen and ammonia cured porous methyl silsesquioxane (MSQ) based low-dielectric-constant (low-k) spin-on dielectric (SOD) films are comprehensively explored and compared in this research. Higher curing temperatures, longer curing time, and an atmosphere provide more complete poragen removal and H-OR/H-OH hydration, and thus achieve higher degrees of cross-linking and volume shrinkage of these films. The desorption of water and ethylic organics confirms the release of hydrated and is dominated by the curing temperatures. Smaller refractive indexes, better electrical properties, and stronger mechanical properties are obtained with curing and increased curing temperatures and time because of more complete hydration. With consideration of total thermal budget, the appropriate curing process window locates at 350°C for only 10 min or 300°C for 20-30 min with flows of 10/0.1-10/2.0 slm. All the properties do not degrade with extended thermal-cycle treatments, exhibiting good thermal stability. © 2004 The Electrochemical Society. All rights reserved.

Developing seamless shaped woven medical products

Currently, the cutting and sewing process is utilized to produce medical products with tailored shape, which leads to a number of adverse consequences due to seams. These drawbacks have prompted us to undertake research to develop new methods by which seamless tubular woven products with inherent shape could be produced. The methods could potentially lead to the design and production of seamless shaped textiles that might be used in a wide variety of medical applications. Three variables were tested, specifically yarn shrinkage, weave designs, and thread density. A variety of samples were woven using different combinations of these variables to create structures with different shrinkage properties. Upon finishing in a solution containing a surfactant and soda ash, the structures experience different degrees of shrinkage resulting in desired shapes. Length and width dimensions of each sample were taken before and after finishing. The change in sample shape due to differential shrinkage in terms of yarn shrinkage, weave, and thread density is reported.

Corneal shrinkage induced by nonmechanical Q-switched erbium:YAG laser trephination for penetrating keratoplasty in porcine eyes.

To assess the degree of corneal diameter shrinkage induced by Q-switched mid-infrared laser corneal trephination for penetrating keratoplasty in an experimental model. Corneal trephination was performed in 80 enucleated porcine eyes fixed in a holder centered on an automated globe rotation device, by Q-switched (2.94 microm) Er:YAG laser along open masks. Four types of masks were used to protect the underlying corneal tissue: metal masks (donor and recipient) and ceramic masks (donor and recipient). Two spot diameters (0.65 mm and 0.96 mm) were combined with two energy settings (40 mJ/pulse and 50 mJ/pulse) for each of the masks used. Repetition rate was fixed at 5 Hz. Diameters of donor buttons/recipient beds (horizontal and vertical) were measured immediately after the trephination and compared to the given mask size. Minimum corneal shrinkage was found in the recipient metal mask group (mean +/- SD=0.3+/-0.4%) with 50 mJ pulse energy and 0.65 mm spot diameter (in the horizontal diameter), while the maximum shrinkage (5.3+/-2.8%) was found in the donor metal mask group with 50 mJ pulse energy and 0.96 mm spot diameter. Corneal shrinkage was less pronounced in recipient beds than in donor buttons (P<0.01). The differences in shrinkage between the use of ceramic and metal masks were insignificant (P>0.05). Mean induced corneal diameter discrepancies between the donor button and the recipient bed (with metal and ceramic masks) were 2.5% and 2.5% in vertical diameter and 3.4% and 2.4% in horizontal diameter. The Q-switched Er:YAG laser experimental corneal trephination for penetrating keratoplasty may induce minor degrees of corneal diameter shrinkage in donor buttons and recipient openings. Oversizing of donor masks by 0.25-0.35 mm (i.e. 3-4% of graft size) may be a valid option to avoid refractive consequences.

Closed-loop identification with MPC for an industrial scale CD-control problem

An approach to implementing closed-loop identification in a model predictive-control framework for the cross-direction control of basis weight is proposed. The closed-loop-identification technique uses the concepts of Markov parameters to determine a step-response model that can then be used within a model predictive controller. The technique is applied to an industrial-scale paper-machine-simulation benchmark problem for cases of varying degrees of shrinkage. The performance of wet- and dry-end full-array sensors are compared. Also, the performance of the closed-loop identification is compared for a nominal case and two cases in which shrinkage occurs in the drying process.

Menadione-Induced Oxidative Stress Inhibits Cholecystokinin-Stimulated Secretion of Pancreatic Acini by Cell Dehydration

The present study evaluated the effects of free radicals generated by menadione on morphology and function of pancreatic acinar cells focusing on enzyme secretion, stimulus-secretion coupling, and cell hydration. Various experiments evaluated morphology and function of isolated rat pancreatic acinar cells exposed to menadione. Menadione instantaneously generated free radicals (luminol and deoxyribose assays) followed by a time-dependent cell injury (uptake of trypan blue). Early ultrastructural changes included vacuolization and alterations of mitochondria, endoplasmic reticulum, and nucleus. Menadione caused a rapid glutathione oxidation followed by a depletion in reduced glutathione. An increase in lipid peroxides and a depletion of adenosine triphosphate were seen only after 30-60 minutes. Menadione markedly inhibited amylase release stimulated by cholecystokinin (CCK) and carbachol and simultaneously caused cell shrinkage after a few minutes. Similar degrees of cell shrinkage induced by hyperosmolar incubation and by menadione inhibited amylase secretion to a similar extent. CCK binding and its effect on calcium and inositol 1,4,5-trisphosphate (IP3) were not affected by menadione. Menadione (without CCK) induced an instantaneous increase of intracellular calcium followed by a slow constant increase. In single cells, menadione induced calcium oscillations with a frequency lower than that seen after CCK stimulation. Some morphologic and functional alterations owing to menadione-induced oxidative stress may be caused by adenosine triphosphate and glutathione depletion, lipid peroxidation, and changes in cytosolic calcium. The marked inhibition of secretagogue-stimulated enzyme secretion owing to menadione may be mediated to a large part by cell dehydration, whereas classical steps of stimulus-secretion coupling like receptor binding, calcium release, and IP3 generation remained unchanged.

MALES WITH EATING DISORDERS: CHALLENGES FOR TREATMENT AND RESEARCH

Males represent only 10 percent of eating disorder cases. This gender discrepancy is among the most extreme in psychiatry and medicine. Determining what differences in etiology and mechanism best explain the discrepancy presents an intellectual challenge. Beginning at about the third grade, boys and girls diverge in social development. Boys show significantly less desire to lose weight, express dissatisfaction with the upper rather than the lower body, and use dieting to achieve specific external goals rather than as a cultural norm. Males reach a significantly higher body mass index (BMI) than females do before they beginning dieting. (27.2 versus 24.3, p < .01). While overall treatment principles are similar, males in treatment require attainment of a different hormonal milieu (testosterone), attention to past and future sexual role, amelioration of perception of stigma, and preparation for return to male social roles. Males and females suffer comparable degrees of osteopenia and brain shrinkage during anorexia nervosa. The effectiveness of antidepressants in males with eating disorders (compared with that in females) has not been well studied. Male gender is not an adverse factor in short-term or long-term treatment outcome. Understanding the lower frequency of these illnesses in males may lead to more effective means of protecting girls from eating disorders and from the culturally induced distress about normal body size and shape that burdens adolescent development and adult life.

Radical Ring-Opening Polymerization of Novel Vinylcyclopropanes Designed as Low Shrinkage Monomers. Structure of the Polymer, Mechanism of the Polymerization, and Volume Change on the Polymerization

Synthesis and radical polymerization of new vinylcyclopropane derivatives, 1,1-bis-(ethoxycarbonyl)-2-isopropenylcyclopropane (4a) and 1,1-bis(ethoxycarbonyl)-2-isopropenyl-2-methylcyclopropane (4b), were carried out. 4a and 4b were prepared by treating 1,4-dibromo-2-butene derivatives and diethyl malonate with sodium ethoxide. The radical polymerization of 4 was carried out in the presence of an appropriate initiator (3 mol % vs monomer) at 60-120 °C. The polymers which were insoluble in methanol/water (volume ratio = 80 :20), were obtained as transparent solids. The conversion of 4a in the polymerizations in both bulk and chlorobenzene was 95-99%. On the other hand, the conversion of 4b was 40-48%. From the detailed analyses of 1 H and 13 C NMR spectra of the polymers obtained, poly(4a) was determined to consist of 1,5-ring-opened units in cis and trans configurations in the main chain and a cyclobutane-containing unit. The content ratio of poly(4a) in the trans configuration to that of the cis configuration increased as the polymerization temperature was raised. Poly(4b) was determined to consist of a 1,5-ring-opened unit in the trans configuration and a cyclobutane-containing unit. MM and MO calculations were carried out to examine the difference in the selectivity of radical ring-opening polymerizations of 4a and 4b. The results of examination of the conformation of 4 and activation energy in the addition reaction of the trimethylmethyl radical to 4 agreed well with the selectivity in the configuration of the main chain of the polymers. The degrees of volume shrinkage on the polymerization of 4a and 4b were 10.4 and 10.2%, and the T g 's of 4a and 4b were 24 and 3 °C, respectively.

Presurgical octreotide treatment in acromegaly

The aim of this study was to determine the role of octreotide administration in acromegalic patients as a preparation for selective adenomectomy using transsphenoidal route. Octreotide was administered for 3 to 6 weeks before surgery in 12 patients and for 4 to 39 months in 25 patients. The clinical response was judged as excellent or good in 10 of 12 patients from group I and in 23 of 25 patients from group II. Marked reduction (ie, >50% of initial values) in serum growth hormone (GH) levels was seen in all patients, with levels to less than 5 μg/L in 68% of patients and less than 2 μg/L in 27%. Insulin-like growth factor 1 (IGF-1) levels decreased to within normal limits in half the cases. During long-term treatment, an escape phenomenon could be seen. Varying degrees of tumor shrinkage were seen in more than 50% of cases. During surgery, with regard to the relative ease or difficulty in removing the tumor, the consistency of the tumor and the separation of normal from pathological tissue, no significant difference was observed between patients given octreotide and those from control series. Morphological changes in adenomatous tissue were rather small. The surgical outcome was similar in the pretreated series as in the control series, except in enclosed adenomas, which showed a tendency to a higher success rate. Since octreotide improves both the clinical condition and hormonal parameters and induces varying degrees of tumor shrinkage, it is potentially useful as an adjunct to surgery. Morphological data suggest that octreotide exercises a functional inhibitory effect on GH release.

Synthesis and evaluation of new oxaspiro monomers for double ring-opening polymerization.

Polymerization with expansion in volume can be achieved with spiro orthocarbonate monomers through a double ring-opening process wherein two bonds are cleaved for each new bond formed. The resulting expansion can be applied to counter the polymerization shrinkage associated with the conventional methacrylate monomers used in dental composites and thereby provide formulations with drastically reduced degrees of shrinkage. New monomers have been prepared that exhibit enhanced reactivities and ring-opening efficiencies compared with earlier free-radical-polymerizable oxaspiro compounds. In dental composite formulations, the monofunctional oxaspiro monomers provided DTS values equivalent to those of the controls under certain curing conditions; however, only modest reductions in polymerization shrinkage were observed. 2,3-Bis(methylene) spiro orthocarbonate monomers with a conjugated diene structure were also synthesized and evaluated. These novel monomers appear to offer significant potential for future development of free-radical ring-opening polymerization. While visible-light-cured formulations of the bis(methylene) compounds with methacrylate comonomers did not yield acceptable composite materials in this initial attempt, the high reactivity and the ability to form rigid, cross-linked polymers make this type of monomer worthy of continued investigation. These properties may allow the bis(methylene) oxaspiro monomers to be used alone or in concert with other ring-opening monomers for special applications.