Crystal and magnetic structures of R2Ni2In compounds (R = Tb and Ho)

Crystal and magnetic structures of R2Ni2In (R = Tb and Ho) have been studied using powder neutron diffraction at low temperatures. The compounds crystallize as orthorhombic crystal structures of the Mn2AlB2 type. At low temperatures, the magnetic moments localized solely on the rare earth atoms form antiferromagnetic structures. The Tb magnetic moments, equal to 8.8 (4) μB and parallel to the c axis, form a collinear magnetic structure described by the propagation vector k = [½ , ½ , ½]. This magnetic structure is stable up to the Néel temperature TN = 40 K. For Ho2Ni2In a complex, temperature-dependent magnetic structure is detected. In the temperature range 6.1-8.6 K, an incommensurate sinusoidal magnetic structure, described by the propagation vector k1 = [0.24, 1, 0.52] is observed, while in the temperature interval 2.2-2.5 K a square-modulated magnetic structure, related to k2 = [0.17,{{5} \over {6}},{{1} \over {2}}] (the component along the a axis slightly differs from the commensurate value) and its third harmonics 3k2 = [0.50,{{5} \over {2}},{{3} \over {2}}] is found. At 3.1-3.7 K as well as below 2 K, a coexistence of both detected magnetic structures is observed. The Ho magnetic moments remain parallel to the c axis in both the sine- and square-modulated magnetic structures. The low-temperature heat capacity data confirm a first-order transition near 3 K.

Investigation of Chiral Smectic Phases and Conformationally Disordered Crystal Phases of the Liquid Crystalline 3F5FPhH6 Compound Partially Fluorinated at the Terminal Chain and Rigid Core

Complementary methods are applied to investigate the phase transitions and crystallization kinetics of the liquid crystalline compound denoted as 3F5FPhH6. Two crystal phases are confirmed, and one of them is the conformationally disordered (CONDIS) phase. Complexity of the melt crystallization process is revealed by the analysis with Friedman’s isoconversional method. The melt crystallization of 3F5FPhH6 shows different mechanisms depending on temperature, which is explained by the relation between the thermodynamic driving force and the thermal energy of translational degrees of freedom. The studied compound crystallizes even during fast cooling (30 K/min), unlike similar compounds with different fluorosubstitutions of the benzene ring, which form the smectic glass for moderate cooling rates. The tendency to vitrification of the smectic phase decreases apparently with the decreasing stability width of the SmC_A* phase and the increasing relaxation time of the collective relaxation process in this phase, at least for homologues differing from 3F5FPhH6 only by the type of fluorosubstitution.

The High-Temperature Soft Ferromagnetic Molecular Materials Based on [W(CN)6(bpy)]2-/- System

The synthesis of molecular materials with magnetic properties, in particular ferromagnetic properties, has been the subject of interest in coordination chemistry for decades. In the last three decades, research has accelerated, as it has emerged that creating bridging systems based on cyanido ligands is a good and relatively simple way to create complex polymer structures exhibiting magnetic properties. Based on many years of personal experience in the field of the synthesis of polycyanido systems, supported by comprehensive structural analysis, a simple method of transforming cyanido complexes into soft ferromagnetic materials with a Curie temperature (T_C) higher than the thermal decomposition temperature, usually above 150 °C has been developed. Two soft ferromagnetic materials based on zinc and cadmium hexacyanido salts in the system with [W(CN)₆(bpy)]^2−/− anions are presented. The crystal structures (X-ray single crystal as well as XRD) of the precursors and the properties of the ferromagnetic materials are discussed. Most importantly, a patented method of synthesizing this type of material, based on which we obtain more than 80 soft, high-temperature ferromagnetic compounds, which proves the wide spectrum of this method, is also presented.

Symmetry analysis of complex magnetic structure in monoclinically distorted Er3Cu4Sn4

The magnetic structure in Er₃Cu₄Sn₄ has been determined using high-resolution powder neutron diffraction, supported by symmetry analysis. At low temperatures, Er₃Cu₄Sn₄ assumes a crystal structure of the Tm₃Cu₄Sn₄ type (in the monoclinic space group C2/m). The Er atoms occupy two distinct Wyckoff sites: 2c and 4i. It has been found that the Er magnetic moments on the 2c site form a commensurate antiferromagnetic structure (k₁ = [0, 0, ½]) below 6 K. The magnetic moments reach 8.91 (8) μ_B at 1.4 K and are parallel to the b axis. The Er magnetic moments on the 4i site order below 2 K and form an incommensurate antiferromagnetic sine-modulated structure (k₂ = [1, 0.4667 (1), ½]), with magnetic moments lying in the ac plane and perpendicular to the a axis. The amplitude of modulation equals 8.7 (1) μ_B at 1.4 K.

Bulky ligands shape the separation between the large spin carriers to condition field-induced slow magnetic relaxation

Crystal engineering of magnetic relaxation in supramolecular networks based on almost isotropic cyanido-bridged {Mn9[W(CN)8]6L8(solv)8} clusters decorated by bulky 4,4'-di-tert-butyl-2,2'-bipyridine (But2bpy) and 4,7-diphenyl-1,10-phenanthroline (Ph2phen) ligands is presented. The three new compounds {MnII9[WV(CN)8]6(But2bpy)8(MeOH)8}·Pri2O·13MeOH (1), {MnII9[WV(CN)8]6(But2bpy)8(MeOH)6(H2O)2}·4Pri2O·2H2O (1a), and {MnII9[WV(CN)8]6(Ph2phen)8(MeOH)8}·29MeOH·6H2O (2) were characterized structurally and magnetically. Compound 1 exhibits unequivocal domination of repulsive intercluster contacts operating between the side But groups leading to intercluster distances exceeding 10 Å in all three dimensions. Compound 1a reveals a 1-dimensional (1D) supramolecular chain structure with very close intercluster distances of 6.7 Å realized through the direct W-CNHO-Mn hydrogen bonds along the chain, further isolated by the above repulsive ButBut synthons. Compound 2 shows significant separation in all three directions with the intercluster distances close to 10, 12 and 13.5 Å. However, in contrast to 1, these separations are accompanied by indirect hydrogen bond arrays and local π-π interactions of potential to assist in the transfer of weak magnetic interactions. The dc magnetic data show the signature of S = 39/2 in the ground state, which is typical in this group of compounds. The high-spin clusters are accompanied by different intercluster interactions, illustrated by the effective zJ' values of +0.010 cm-1 (1), +0.008 cm-1 (1a) and +0.001 cm-1 (2). The low temperature ac susceptibility measurements revealed a temperature- and field-dependent magnetic relaxation time for all 1, 1a and 2 compounds (τ1, τ1a-fast, and τ2-fast in the range 10-3-10-4 s). In contrast and only in the case of 1a and 2, an additional temperature independent slow process was detected (τ1a-slow and τ2-slow located between 0.1 s and 1 s). The magnetic relaxations were correlated with the obtained supramolecular networks, indicating the significant role of dipolar fields, weak non-covalent interactions, hydrogen bonds and π-π interactions.

Identical anomalous Raman relaxation exponent in a family of single ion magnets: towards reliable Raman relaxation determination?

The results described herein suggest that the exponent n for the temperature dependence of the Raman relaxation process in the series of solid-state diluted isostructural Ln^III SIMs should be identical.

Comparing the interpretation of emergency department computed tomography between emergency physicians and attending radiologists: A multicenter study

Introduction

Computed tomography (CT) interpretation in the emergency department is one of the vital issues that should be carried out rapidly and accurately. The objective of this study was to examine the interpretation accuracy of emergency physicians (EPs) regarding CT scans at the emergency department for traumatic and nontraumatic purposes.

Materials and Methods

The study that was carried out as a prospective, observational study was completed at four centers during 1 year.

Results

Accuracy ratios of CT interpretations of EP regarding cranial injuries, thoracic injuries and vertebral spine injuries are above 95% in addition to the fact that the concordance's with the final result are perfect, the concordance with the final results of the CT interpretations of EP for abdominal injuries was moderate (<0.75). Accuracy ratios of the CT interpretations of EP for nontrauma patients were above 90% for brain hemorrhage and chest injuries and that the concordance with the final results was perfect (≥0.75). The CT interpretation accuracy rates of EP for spontaneous pneumothorax and aortic aneurysm/aortic dissection cases were 100%. CT interpretation rate of EP for pulmonary embolism was 89.4%, whereas the level of concordance with the final results was moderate (<0.75). Whereas the CT interpretation accuracy rates of EP for nontraumatic abdominal injuries varied between 83.3% and 93.1%, their levels of concordance with the final results were moderate (<0.75).

Conclusions

The CT interpretations for abdominal traumatic patients in addition to pulmonary embolism and acute nontraumatic abdominal injuries should be carried out more carefully.

Mixture EMOS model for calibrating ensemble forecasts of wind speed

Ensemble model output statistics (EMOS) is a statistical tool for post-processing forecast ensembles of weather variables obtained from multiple runs of numerical weather prediction models in order to produce calibrated predictive probability density functions. The EMOS predictive probability density function is given by a parametric distribution with parameters depending on the ensemble forecasts. We propose an EMOS model for calibrating wind speed forecasts based on weighted mixtures of truncated normal (TN) and log-normal (LN) distributions where model parameters and component weights are estimated by optimizing the values of proper scoring rules over a rolling training period. The new model is tested on wind speed forecasts of the 50 member European Centre for Medium-range Weather Forecasts ensemble, the 11 member Aire Limitée Adaptation dynamique Développement International-Hungary Ensemble Prediction System ensemble of the Hungarian Meteorological Service, and the eight-member University of Washington mesoscale ensemble, and its predictive performance is compared with that of various benchmark EMOS models based on single parametric families and combinations thereof. The results indicate improved calibration of probabilistic and accuracy of point forecasts in comparison with the raw ensemble and climatological forecasts. The mixture EMOS model significantly outperforms the TN and LN EMOS methods; moreover, it provides better calibrated forecasts than the TN-LN combination model and offers an increased flexibility while avoiding covariate selection problems.

Magnetic structures and physical properties of Tm3Cu4Ge4 and Tm3Cu4Sn4

Tm(3)Cu(4)Ge(4) crystallizes in the orthorhombic Gd(3)Cu(4)Ge(4)-type crystal structure (space group Immm) whereas Tm(3)Cu(4)Sn(4) crystallizes in a distorted variant of this structure (monoclinic space group C2/m). The compounds were studied by means of neutron diffraction, specific heat, electrical resistivity and magnetic measurements. Analysis of experimental data revealed the presence of an antiferromagnetic order below 2.8 K in both compounds. In Tm(3)Cu(4)Ge(4) the magnetic unit cell is doubled in respect to the crystal unit cell and the magnetic structure can be described by a propagation vector k = [0, 1/2, 0]. A larger magnetic unit cell was found in Tm(3)Cu(4)Sn(4), given by a propagation vector k = [1/2, 1/2, 0] (for simplicity the orthorhombic description is used for both the germanide and the stannide). Close to 2 K, in each compound an incommensurate antiferromagnetic order develops. This low-temperature magnetic phase is characterized by a propagation vector k = [1/4, 0, k(z)], where k(z) is close to 0.49 and 0.47 in Tm(3)Cu(4)Ge(4) and Tm(3)Cu(4)Sn(4), respectively. The antiferromagnetic phase transitions are clearly seen in the bulk magnetic and specific heat data of both compounds.

Lung function: occupational exposure to wood dust

Objectives

Occupational exposure to wood dust has been shown to cause several respiratory disorders, such as allergic rhinitis, chronic bronchitis, asthma, sino-nasal adenocarcinoma, and impairment of lung function. The aim of the study was to estimate lung function (in the woodworking industry) among workers employed by wood processing, who run the risk of being expose to wood dust.

Methods

The study concerns a group of 70 workers aged 24-55. All the workers underwent general and laryngological examination. A group of 20 workers, working at the positions where dustiness exceeded TLV (threshold limit value) took X-ray of the chest and spirometry. The following parameters were measured: VC, IC, ERV, TV, BF, FEV₁, FVC, PEF, MEF^25-75, FEV₁%FVC, FEV₁%VC. The data are presented as means ± SD and the authors applied references values according to ERS guidelines.

Results

The results show that there was no decline in FEV₁ (3.7 ± 0.7) and FVC (4.5 ± 0.8). Normal lung function was defined as FEV₁/VC ratio ≥0.7. None of the tested workers had obstructive pattern in spirometry. The mean FEV₁%VC was 77.1 ± 10.2. These results suggest that wood dust exposure might not lead to significant pulmonary damage.

Conclusions

These data do not corroborate that wood dust plays significant role in lung function impairment. Future studies of respiratory health among workers exposed to wood dust are needed.

Deformation of the nasal septum in children, adolescents, and adults in Western Pomerania province of Poland

OBJECTIVES

Nasal septum deformation (NSD) contributes to the occurrence of upper respiratory tract diseases in around 45-55% of Poland's population. The evaluation of frequency of occurrence and type of nasal septum deformation among randomly chosen representatives of the Szczecin and surrounding area population was the aim of this study.

METHODS

NSD was assessed in 235 patients (123 male, 112 female) aged 5-60. Mladina's classification system was used for the evaluation.

RESULTS

Deformations of nasal septum were found in 43% of the examined subjects. Type 3 of NSD dominated (12.4%), while types 2 and 1 were found in 10.3% and 4.2% of the subjects, respectively. 9.2% of the patients showed type 5 of deformation, while types 6, 4, and 7 were found in 1.3%, 3.2% and 2.7% of the patients, respectively.

CONCLUSIONS

Straight nasal septum was found in females more often than in males, mostly on the left side. Associations between NSD, on one side, and age, sex, and traumas, on the other were found. NSD influenced the quality of respiration and frequency of upper respiratory tract diseases in the examined subjects.

Use of over-the-counter medications in prevention and treatment of upper respiratory tract infections

Over-the-counter (OTC) medications are a fast developing branch of the pharmaceutical industry, in both Poland and rest of the world. The aim of the work was to evaluate the factors that influence the purchase and use of OTC medications in prevention and treatment of upper respiratory tract infections. The analysis involved 450 randomly chosen subjects, aged 19-80. The study was performed using a questionnaire which included a number of questions related to the characteristics of respondents such as: health, socio-demographic data, and factors influencing the purchase of OTC medications used in respiratory tract infections. The self-medication phenomenon in upper respiratory tract infections is significant in Poland and will continue to increase with support of many demographic and socio-economic factors. Despite certain health risks resulting from the inappropriate use of OTC medications, it should continue to be offered as a part of the pharmaceutical market.

Upper respiratory tract diseases in self-evaluation of health status of Polish students based on the SF-36 questionnaire

People's health beliefs have remained under the influence of various factors. Our health is determined by physical and social environment, health behaviors, and lifestyle. The evaluation of frequency of upper respiratory tract diseases among Polish students was the aim of the study. Survey was conducted among 476 students of medicine and dentistry in the Pomeranian Medical University of Szczecin and pedagogy students of the Zielona Góra University, Poland. SF 36 questionnaire with few additional questions concerning health and disease was used in the study. Students' participation in the research was voluntary and anonymous. More than 80% of medical students treat their upper respiratory infections by themselves. From all surveyed subjects only 48 (9.4%) of the students did not suffer from any illness during an academic year. Part of the students (39.7%) spends their leisure time in a passive way. Pedagogy students more often than medical ones spend their leisure time actively. Male medical students showed much lower values comparing to female medical students. Pedagogy students showed reversed situation. There was a high variability of general health components observed among female, but not male students. Frequent respiratory tract infections, lack of systematic physical activity, and low amount of sleep cause lower level of self evaluation in regard to health status among medical students.

Quality of life of patients with diseases of sinuses

Contemporary studies provide proof of coincidence between diseases of upper and lower airways ("united airways disease"; "one-airway disease"). 184 patients from Szczecin with acute (AS) and chronic sinusitis (CS), aged between 18-78 years (mean age 45.7+/-14.7) were examined. The questionnaire used (SF-36; short form, 36 questions) allowed for a comparison of the quality of life of patients with sinuses' disease with healthy subjects. Patients from the groups studied indicated more restrictions of their daily life than did the subjects from a control group (CG). Among the CS patients the mean quality of life index was 75.5, among the AS patients--60.8 and among healthy subjects--51.8. The differences between the groups were significant at P<0.001. Our study indicate that sinusitis strongly influenced functioning of patients in all eight domains of life.

Respiratory dysfunction in patients with Marfan syndrome

Marfan syndrome (MS) is inherited in an autosomal dominant way. MS is characterized by a high degree of penetration and expression of the pathological gene. Fibrillin, the gene product is a protein that acts in the composing of elastic fiber. Therefore, MS syndrome is a multisystem disorder that affects connective tissue. The aim of this paper is to evaluate the frequency of occurrence of factors influencing abnormalities in respiratory tract functioning. The study encompassed 45 patients with MS syndrome ranging in age from 2 to 54. Both clinical examination and morphological measurements were performed in each case. The following anthropometrical measurements were performed: cephalometric and measurements of the chest. All measurements were standardized as mean values for healthy population. Based on the measurements recorded, the following indexes were evaluated: width/length index of the head, morphological index of the face, and index of chest flattening. The occurrence of chest deformities was also evaluated. The study indicate that several factors can result in pulmonary disease in patients with Marfan's syndrome.

Wood dust: an occupational hazard which increases the risk of respiratory disease

The main source of emission of harmful dust in the work place comes from technological processes. European legislation aims to minimize the health risks from dangerous substances in the workplace. European Directives are transferred into national legislation. Such matters as risk assessment, technical measures, and exposure limits are regulated by the law. In Poland, manufacturing processes in which hardwood dust is discharged, are considered as carcinogenic. Numerous studies have shown that occupational exposure to wood dust is strongly associated with the development of cancer of the nasal cavity and paranasal sinuses (NSC), but data regarding the development of lung cancer are conflicting and inconclusive. In the study, the exposure to inhalable wood dust was assessed among wood-workers in mid-west Poland. The assessment of occupational exposure was made on the basis of measurements of the concentration of dust in the work place. This was defined by exposure rates to dust in reference to daily work time and by comparing that to the maximum acceptable concentration values of dust defined by the regulation by the Minister of Work and Social Policy. The health assessment of workers was made on the basis of periodical medical check-ups, whose range and frequency is defined by the regulation of the Minister of Health and Social Security. The study did not show effects of wood dust exposure on the of lung cancer.

Adolescent growth in main somatometric traits of Japanese boys: Ogi Longitudinal Growth Study

Considerable information is available on peak growth velocity characteristics of various body dimensions but the age at minimal velocity (AMV) and the duration of the spurt are not that well documented. Authors applied the mathematical growth model of Preece and Baines (PBGM1) to six longitudinally followed somatometric traits [height, sitting height, iliospinal height (B-ic), upper limb length (a-da), biacromial diameter (a-a), and biiliocristal diameter (ic-ic)] of Japanese boys of Ogi Growth Study. Biological variables derived from the estimated parameters were studied with emphasis on duration and velocity characteristics of the adolescent spurt. Ages for measurements at peak velocities tend to be younger than previously reported non-Japanese ones. Spurt duration in limb measurements was significantly the shortest. Earlier AMV and later age at peak velocity (APV), thus the longest spurt duration, are the characteristic for transverse measurements (a-a, ic-ic). B-ic and a-da had the largest, while a-a and ic-ic had the smallest relative velocity at AMV. Another result for the transverse measurements is that the magnitudes of differences between relative minimal and peak velocities (RMV, RPV) are the largest. It is suggested that a high level of RMV results from early maturation of bones, thus leading to the shortest spurt duration in limb dimensions, while a low level of RMV results from late maturation of the bones, consequently leading to the longest spurt duration in transverse measurements. This tendency of reverse relation was present in the rest of the measurements as well. Transformation of velocity variables (minimal velocity -- MV, peak velocity -- PV) to relative ones, proved to be useful in observing the relation of spurts in measurements.

Influence of soil fertilization by sewage sludge on the content of polycyclic aromatic hydrocarbons (PAHs) in crops

The aim of the present study was an evaluation of the influence of the addition of different sewage sludge doses on the uptake of polycyclic aromatic hydrocarbons from fertilized soil. Sewage sludge was introduced into the soil in the following doses: 30, 75, 150, 300, and 600 Mg/ha. The content of polycyclic aromatic hydrocarbons (PAH) was determined by means of HPLC-UV method. The addition of increasing doses of sludge into the soil resulted in a gradual increase in the amount of the polycyclic aromatic hydrocarbons contained therein. During the period of the study, continuous changes in the content of all the compounds studied were found in all the experimental variants. Finally, on the last day of the study, the highest degree of degradation (73%) of 16 PAHs' sum (US EPA) was noted for sludge doses of 30 and 300 Mg/ha. In the case of individual PAHs, the change in their content differed and clearly depended on the sewage sludge dose. The introduction of sewage sludge into the soil influenced the increase of the sum of 16 PAHs in the plants grown in this soil. The influence mentioned above depended on the sewage sludge dose and the plant species grown, as well as the PAH content in the soil. The evaluation of individual PAHs in plants showed an increase in their content with the increase of the amount of sewage sludge. A statistically significant increase in their content was most often observed for sewage sludge doses above 150 Mg/ha. Moreover, it was found that fertilization of the soil with sewage sludge resulted in pollution of the plants with PAHs of high molecular weight.

Application of solid-phase extraction to determination of polycyclic aromatic hydrocarbons in sewage sludge extracts

The study presents the efficiency of sewage sludge sample clean-up with the application of SPE columns with various types of adsorbents. Six columns were tested: C8-octyl, C18 PolarPlus, C18-octadecyl, silicagel (SG), phenyl, cyano. The highest efficiency of recovery was observed for C18-octadecyl. Then, using C18, the method was optimised by changing the following parameters: eluent type and volume, column drying and effect of washing of cartridge.

83ANALYSIS OF RAPID COOLING V. SLOW COOLING COMBINED WITH ICE CRYSTAL SEEDING FOR CRYOPRESERVATION OF PRIMATE EMBRYONIC STEM CELLS

Primate embryonic stem (ES) cells have the ability to self-renew indefinitely while maintaining the ability to differentiate. This unique property allows scientists to study the factors necessary for stem cell self-renewal and differentiation in vitro that reflect in vivo processes. Work with primate ES cells is handicapped by the poor survival (1–5%) of rhesus and human ES cells following standard tissue culture methods of rapid cryopreservation. The purpose of this study was to compare and contrast two cryopreservation techniques, slow cooling combined with ice crystal seeding commonly used for mammalian embryos v. rapid cooling commonly used for tissue culture, to find a method for efficient primate ES cell cryopreservation. A combination of trials was run to compare dimethyl sulfoxide (DMSO) v. ethylene glycol as a cryoprotectant, a cooling rate of 0.3°C per minute following ice crystal seeding at −7°C v. placement at −80°C with no seeding, and rapid thaw with step-wise cryoprotectant removal v. one-step sucrose cryoprotectant removal. Cell survival was assessed through a combination of cell surface markers, alkaline phosphatase staining and morphology to look for undifferentiated cells and quantitate survival. All cryopreservations were performed with the same cell density. The survival of the cells with slow embryo-style cooling in DMSO with a step-wise cryoprotectant removal was 64.0% v. 12.8% with rapid cooling.

Degradation of soil environment in the post-flooding area: content of polycyclic aromatic hydrocarbons (PAHs) and s-triazine herbicides

Impacts of flooding on the soil environment with regard to soil pollution with polycyclic aromatic hydrocarbons and s-triazine (cyanazine, simazine, atriazine, propazine, prometryn) herbicides have been evaluated. No clear differences in the sum of the PAHs content were observed in the present studies. Only changes in the levels of individual PAHs were noted. In soils covered with flooding both at a depth of 0-20 and 20-40 high molecular weight PAHs were predominant (especially mutagenic and carcinogenic 5-rings PAHs) whereas in non-flooded areas, 2- and 3-rings PAHs constituted over 80%. In the case of s-triazine herbicides, no influence of flooding on the changes in their content in agriculturally used soils was noted. On the other hand, clearly lower levels of cyanazine, simazine and atriazine were not in the flooded forest soil as compared to the non-flooded forest soil.

Changes in the content of polycyclic aromatic hydrocarbons (PAHs) in light soil fertilized with sewage sludge

In the present work the influence of soil fertilization with sewage sludge on the changes in the content of polycyclic aromatic hydrocarbons (PAH) in this soil was studied during a one-year field experiment. The experiment consisted of six plots to which sewage sludge was introduced at doses of 30 (1%), 75 (2.5%), 150 (5%), 300 (10%) and 600 ton/ha (20%) as calculated for dry mass. The PAH content at a depth of 0-20 and 20-40 cm was determined. With time, an increase in the PAH content in the lower soil layer (20-40 cm) and a gradual decrease of the PAH content in the 0-20 cm layer was observed. In most cases, a decrease by half in the PAH content in the soil fertilised with sewage sludge was observed.

The influence of the masticatory hypofunction on the craniofacial growth and development in rats

In the present study, one masticatory hypofunction group and one normal function group were comprised of growing Wistar albino rats. The influence of the masticatory hypofunction on the growth and development of the craniofacial skeleton in rats was examined. The normal function group received the diet in the form of hard pellets, but the hypofunction group was fed powdered food. To avoid growth reduction because of nutritional deficiency, the animals were fed ad libitum, diet and water. At the end of the experimental period, the 90-day-old adult animals were killed and the direct anthropometric cranial, maxillary, and mandibular measurements were made on the skulls. The significant results can be summarized as follows: Total skull length, total anterior face height, lower anterior face height, ramus mandibula height, corpus mandibula height, premaxillary length, and maxillary width have been reduced but foramen incisivum width has been increased. This study showed that there is no significant effect of the masticatory hypofunction on the cranial growth and development in the growing rats, but that masticatory hypofunction affected the growth and development of the maxillofacial skeleton.

An investigation of the effects of the local use of 1:25 dihydroxycholecalciferol (1:25 D) on tension sites during experimental tooth movement in rats

The aim of this work was to investigate the local effects of 1:25 dihydroxychole-calciferol, one of the most potent osteoclastic activity stimulants. Tests were conducted on 32 Wistar albino rats divided into 3 groups: an experimental (appliance + drug, n = 11), control (appliance only, n = 11) and a no therapy group (n = 10) which was used for purposes of interpreting histological findings in the others. A significantly higher area of unilateral apposition, relative to the control group, was observed in the experimental group local to the area of administration of the 1:25 D.

Loculated mediastinal chylothorax resulting from esophagogastrectomy: a case report

The thoracic duct is closely related to the esophagus and the pleura. During an esophagogastrectomy, the thoracic duct is at risk for injury, which usually results in chylous pleural effusions. We present an uncommon situation, however, where the pleura was not violated and a large mediastinal lymph collection resulted.