A comprehensive review of the structure-morphology-property relations in segmented thermoplastic polyurethanes and polyureas (TPU) is provided. Special emphasis is given to the influence of the soft segment structure, polarity, and molecular weight, diisocyanate symmetry and the nature, extent, and strength of hydrogen bonding on the morphology and thermal and mechanical properties of TPUs. Experimental results obtained on composition-dependent TPU morphology and properties by various techniques were also compared by the morphology profiles generated by computational methods such as quantum mechanical calculations and molecular dynamics simulations.
View Article and Find Full Text PDFFood spoilage results in food waste and food-borne diseases. Yet, standard laboratory tests to determine spoilage (mainly volatile biogenic amines) are not performed regularly by supply chain personnel or end customers. Here we developed a poly(styrene-co-maleic anhydride)-based, miniature (2 × 2 cm) sensor for on-demand spoilage analysis via mobile phones.
View Article and Find Full Text PDFEffective skeletal muscle tissue engineering relies on control over the scaffold architecture for providing muscle cells with the required directionality, together with a mechanical property match with the surrounding tissue. Although recent advances in 3D printing fulfill the first requirement, the available synthetic polymers either are too rigid or show unfavorable surface and degradation profiles for the latter. In addition, natural polymers that are generally used as hydrogels lack the required mechanical stability to withstand the forces exerted during muscle contraction.
View Article and Find Full Text PDFSynthesis of hydroxyapatite (HA) through sol-gel process in different solvent systems is reported. Calcium nitrate tetrahydrate (CNTH) and diammonium hydrogen phosphate (DAHP) were used as calcium and phosphorus precursors, respectively. Three different synthesis reactions were carried out by changing the solvent media, while keeping all other process parameters constant.
View Article and Find Full Text PDFPreparation and characterization of chitosan/hydroxyapatite (CS/HA) nanocomposites displaying an intercalated structure is reported. Hydroxyapatite was synthesized through sol-gel process. Formic acid was introduced as a new solvent to obtain stable dispersions of nano-sized HA particles in polymer solution.
View Article and Find Full Text PDFActa Otorhinolaryngol Ital
April 2016
Alloplastic materials are frequently used in facial plastic surgeries such as rhinoplasty and nasal reconstruction. Unfortunately, the ideal alloplastic material has not been found. This experimental study evaluates the tissue response and durability of five novel polymers developed as an alloplastic material.
View Article and Find Full Text PDFObjectives: This study was performed to evaluate the biocompatibility and tensile strength of two new polymeric materials--a polyfluoro ether-modified thermoplastic polyurethane urea and a polydimethyl silicone elastomer--in an experimental rabbit model.
Methods: The two polymers were implanted inside separate subperichondrial pockets created over the auricular cartilages of 12 rabbits. A control pocket received no implant.
A simple method was developed for the preparation of polymeric materials with controlled surface wettability or tunable surface wetting. The method is applicable to a large number of polymers, thermoplastic or thermoset. With this method, it is possible to prepare polymer surfaces with static water contact angles ranging from 0° (superhydrophilic) to greater than 170° (superhydrophobic).
View Article and Find Full Text PDFWe report on a twenty-two months old male patient with hypotonia, mental and motor retardation and trigonocephaly. Standard GTG banding chromosomal analysis (from metaphyses of a periferal blood lymphocyte culture) showed 46,XY, der(9) monosomy 9pter-->p22, trisomy 10q26--> qter karyotype. This unbalanced translocation resulted from the father's t(9,10) (p22;p26) karyotype.
View Article and Find Full Text PDFBackground: The purpose of this study was to evaluate left and right ventricular functions by using the Doppler myocardial performance index (MPI), in children with sickle cell anemia (SCA).
Methods: We examined 32 patients with SCA and 30 age-matched healthy children. Echocardiography and Doppler examinations were completed for each of the subjects.
An 8-month-old girl was admitted to an outpatient clinic with significant hypotonia and weakness. Organic acid analysis in urine revealed a significant increase in ethylmalonic acid. A deoxyribonucleic analysis revealed the presence of a 625G>A (G-to-A substitution at nucleotide 625) variant short-chain acyl-coenzyme A dehydrogenase gene polymorphism.
View Article and Find Full Text PDFDorfman-Chanarin syndrome is a rare, autosomal recessive disorder characterized by congenital ichthyosis and presence of intracellular lipid droplets in most tissues. Here, we present a patient from Turkey, who is the fourth Turkish case in the literature with this syndrome, and we review the previous reported cases. He was also the second case reported with hyperlipidemia.
View Article and Find Full Text PDFBackground: Although it is the most common lower respiratory infection of infancy, the optimal treatment for acute bronchiolitis is still controversial. The aim of this study was to compare the early and late effects of nebulized L-epinephrine (EPI) and intramuscular dexamethasone (DEX) combination therapy with nebulized salbutamol (SAL) and dexamethasone combination and bronchodilators alone in outpatients with acute bronchiolitis.
Methods: A total of 69 infants aged 2-21 months who were admitted to the Pediatrics Department of the Faculty of Medicine, Mersin University, with acute bronchiolitis were included in a randomized, placebo-controlled, prospective trial study.
This study was undertaken to evaluate resting electroencephalographic (EEG) changes and their relations to cerebral maturation in children with primary nocturnal enuresis. Cerebral maturation is known to be important in the pathogenesis of this disorder. Twenty-five right-handed patients with primary nocturnal enuresis, aged 6 to 14 years, and 23 age- and sex-matched healthy children were included in this cross-sectional case-control study.
View Article and Find Full Text PDFBackground: The primary aim of this study was to find widely available, inexpensive, and non-invasive parameters for early identification or prediction of the infants with hypoxic-ischemic encephalopathy (HIE) who will have a severe adverse outcome (classified as death or a major neurological deficit).
Methods: Fifty-seven full-term or near-term newborn infants with a diagnosis of HIE were consecutively admitted to the neonatal intensive care unit and studied. Occurrence of seizures during the first 24 h, cranial ultrasonography (US) findings within the first 5 days of life, and Denver developmental screening test II (DDST II) at 6 months of age, were analyzed in relation to mortality and neurological status at 2 years of age.
A negative correlation between leptin and appetite or food intake has been shown in healthy individuals. However, the role of leptin in clinical conditions characterized by anorexia has not been established. One of the well-known clinical features of iron-deficiency anemia is poor appetite.
View Article and Find Full Text PDFBackground: Fibronectin (FN) is known to have important roles in host defense against infection. The risk for neonatal sepsis increases with the degree of immaturity of the host. Conflicting results have been reported on the relationship between plasma FN levels and gestational age (GA) in the preterm neonate.
View Article and Find Full Text PDFTo identify premarital couples who are carriers for hemoglobinopathies, a screening study was conducted in one of the southern cities of Turkey. For 2,113 couples, total blood count, Hb A2 and Hb F levels were determined and hemoglobin electrophoresis was performed. The frequency of Hb S was 4.
View Article and Find Full Text PDFMikrobiyol Bul
October 1979
A fatal case of Purpura fulminans associated with miliary tuberculosis is presented. To our best knowledge, this is the first case of this type reported.
View Article and Find Full Text PDF