93 research outputs found
LiFE Assessment Tool
As part of an ongoing study to construct a molecular Turing machine in which a polymer chain is encoded via allosteric information transfer between macrocyclic complexes, we describe the thermodynamic and kinetic characterization of a multicomponent self-assembled system based on a zinc porphyrin macrocyclic compound, a bidentate ligand (1,4-diazabicyclo[2.2.2]octane, DABCO), and a viologen-substituted polymer guest. Initial addition of DABCO to the porphyrin macrocycle in chloroform solution leads to the formation of a stable 2:1 (porphyrin:DABCO) dimeric complex, even under dilute conditions, by means of strong cooperative interactions involving hydrogen and metal-ligand bonds. Further titration of the porphyrin-DABCO mixtures with the polymer gives rise to a complex array of species in the solution. The system is analyzed in detail by a combination of spectroscopic measurements and computational modeling. Each association constant in the binding scheme and the fraction of each individual complex that is formed in solution are determined precisely using a mass-balance model. Kinetic studies revealed that the rates of the polymer threading and dethreading in and out of the dimeric system are remarkably slow, indicating that the polymer is locked inside the cavity of the stable 2:1 dimeric complex as a result of strong allosteric interactions
Consequences of conformational flexibility in hydrogen-bond-driven self-assembly processes
We report the synthesis and self-assembly of chiral, conformationally flexible C3-symmetrical trisamides. A strong Cotton effect is observed for the supramolecular polymers in linear alkanes but not in cyclic alkanes. MD simulations suggest 2:1 conformations of the amides within the aggregates in both types of solvents, but a chiral bias in only linear alkanes.JAB, MGI, RPAG, EWM and ARAP would like to thank the Gravity program 024.001.035, NWO TOP-PUNT 718.014.003 for financial support and Anneloes Oude Vrielink for TEM imaging. FDM and ML acknowledge the Swedish e-Research Center (SeRC) for financial support, the Swedish Research Council (Grant No. 621-2014-4646), SNIC (Swedish National Infrastructure for Computing) and Dr Julien Idé for providing the code for exciton coupling calculations
Evaluation of the Accessory Mental Foramen in a Pediatric Population Using Cone-Beam Computed Tomography
The aim of the present study was to clarib, the occurrence, diameter, and location of the accessory mental foramen (AMP) using cone-beam computed tomography (CBCT) images from a sample of Turkish children. Study design: This retrospective was carried out using a total of 275 CBCT images from child and adolescent patients were randomly selectedfrom existing records in the Department of Oral and Maxillofacial Radiology at the University of Erciyes, Kayseri, Turkey. The mental foramen (MF) and AMF were assessed on axial, sagittal, and coronal CBCT slices. Results: The mean age was 10.51 3.32 years, consisting of 139 males (mean age 10.64 3.42) and 126 females (mean age 10.38 3.18). Twenty-one Allff's were observed in 18 of 275 patients (6.5%, 10 boys and eight girls). There was no significant difference in gender in relation to the prevalence 0f AMP (p = 0.65). The mean area of the 21 AMFs and the ME on the side with the Alvh7 were 0.7 mm2 (SD 0.5) and 3.8 mm2 (SD 2.2), respectively. Conclusion: It is important to stress that detecting the AMN using CBCT with 3D reconstructions may reduce the risk of paralysis, hemorrhage, and postoperative pain in this region. Our study presents the first report assessing the occurrence, diameter, and location of the AMP in the pediatric population using CBCT images. In this respect, not surprisingly, the mean size of the AMP of our population is smaller than other reports in the literature that involve adult populations
Maxillary Dental Anomalies in Patients with Cleft Lip and Palate: A Cone Beam Computed Tomography Study
Objective: To compare the frequency of maxillary dental anomalies in patients affected by unilateral (UCLP) and bilateral (BCLP) cleft lip with palate and to determine whether statistical differences were present or not between cleft and normal sides in UCLP group by using cone beam computed tomography (CBCT). In addition, the frequency of those dental anomalies was compared with previous studies presenting the same population without cleft Study Design: Fifty non-syndromic patients affected by UCLP (28 patients) and BCLP (22 patients) were selected for analysis of dental anomalies by means of CBCT. The frequency of maxillary dental anomalies including tooth agenesis, microdontia of lateral incisor, ectopic eruption and impaction of canine and supernumerary tooth were examined. Pearson chi-square and Fisher's exact tests were performed for statistical comparisons. Results: All patients affected by UCLP and BCLP were found to have at least one maxillary dental anomaly. The most frequently observed dental anomaly was tooth agenesis (92.5% and 86.4%, respectively) in UCLP and BCLP groups. Tooth agenesis and canine impaction were observed more commonly in the cleft side (75.0% and 35.7%, respectively) than in the normal side (57.1% and 14.3%, respectively) in UCLP group (p>0.05). All dental anomalies were found to be higher in both cleft groups than in general populations not affected by cleft. Conclusion: Since patients affected by UCLP and BCLP had at least one dental anomaly and higher dental anomaly frequency as compared to patients without cleft, those patients should be examined carefully prior to orthodontic treatment
Clinical and radiographic evaluation of double teeth in primary dentition and associated anomalies in the permanent successors
Objective: Understanding potential problems associated with primary double teeth (PDT) are important to provide prophylactic measures, thereby preventing or minimizing possible complications. The purposes of this study were to investigate the prevalence of PDT in a group of Turkish children and to compare the distribution of the different types of double primary teeth and their relationship to permanent successors. Materials and Methods: A total of 17,268 children underwent a clinical examination to determine the presence of PDT. One hundred fifty-two PDT of 128 children were included in this study. All the 128 children with PDT underwent a clinical examination and had photographs taken at the time of the examination. The children underwent a further periapical or panoramic radiographic examination to determine the status of the underlying permanent successors. The PDT was classified according to Aguilo's classification. Results: The prevalence of PDT was 0.74%, with no significant statistical difference between the sexes. PDT was most frequently observed between the mandibular lateral incisors and canines. Of the 152 PDT, 10.7% were Type I, 15.3% were Type II, 26.1% were Type III, and 47.9% were Type IV. Dental anomalies on the succedaneous permanent teeth were diagnosed in 69.4% of the children with affected primary dentition. Aplasia of the permanent lateral incisor was observed most frequently in association with Type I (52.7%) PDT. Caries involvement was observed most frequently in Type III (56.2%) PDT. Conclusion: The findings of this study have clinical relevance for the diagnosis of children with PDT. Early clinical and radiographic identification of PDT can help the clinician to evaluate the number and condition of permanent successors and draw up a proper treatment plan
Hydrated sodium calcium aluminosilicate for reduction of aflatoxin in quails (Coturnix coturnix japonica)
Essiz, Dinc/0000-0002-4759-7858WOS: 000248379700002PubMed: 17724933The purpose of the present study was to evaluate the toxic effects of aflatoxin (AF) on growth performance and various processing parameters of quails and to determine the preventive efficacy of hydrated sodium calcium aluminosilicate (HSCAS). One hundred and eighty 1-d-old quails of both sexes were randomly divided into 4 experimental groups with 5 replicates and 45 birds following weighing.The experimental design consisted of four dietary treatments: 1) control with 0 mg AF/kg of diet and 0 % HSCAS; 2) 0.5 % HSCAS; 3) 2.5 mg AF/kg of diet; 4) 2.5 mg AF/kg of diet plus 0.5 % HSCAS.The chicks were housed in electrically heated battery cages and exposed to light for 24 h from hatching to 3 weeks of age. Quails consumed the diets and water od libitum. Body weight (BW) was significantly (p < 0.001) increased by addition of HSCAS to AF diet. The lowest BW gains in groups received AF alone was observed at all periods. The reduction in BW gain caused by 2.5 mg AF/kg of diet was significantly (p < 0.001) diminished by the addition of 0.5 % HSCAS to the diet. The addition of HSCAS to the AF diet significantly (p < 0.001) protected against decrease of feed intake at all periods with exception of the first period. None of the treatments altered significantly the feed conversion ratio (FCR).The relative weights of the liver, kidney and spleen were increased in the chickens consuming the AF alone diet. However, light microscopic examination demonstrated the addition of HSCAS to quail feed to partially decrease fat deposition caused by the toxin, and besides, electron microscopic examination of indicated a reorganization in the encloplasmic reticulum and increase in the number of ribosomes and polisomes. Furthermore, the decrease in the antibody titre induced by Newcastle vaccine, due to aflatoxins, was relatively prevented. No significant differences were observed for serum total protein, total cholesterol and glucose levels. The results of indicate that HSCAS is effective in preventing the deleterious effects of A
Confidence intervals and controlled clinical trials incompatible tools for medical research
- …