The effect of diclofenac sodium on neural tube development in the early stage of chick embryos

Background: Neural tube defects are congenital malformations of the central nervous system. Genetic predisposition and some environmental factors play an important role in the development of neural tube defects. This study aimed to investigate the effects of diclofenac sodium on the neural tube development in a chick embryo model that corresponds to the first month of vertebral deve- lopment in mammals.  Materials and methods: Seventy-five fertile, specific pathogen-free eggs were incubated for 28 h and were divided into five groups of 15 eggs each. Diclofenac sodium was administered via the sub-blastodermic route at this stage. Incubation was continued till the end of the 48th h. All eggs were then opened and embryos were dissected from embryonic membranes and evaluated morphologically and histopathologically.  Results: It was determined that the use of increasing doses of diclofenac sodium led to defects of midline closure in early chicken embryos. There were statistically significant differences in neural tube positions (open or close) among the groups. In addition; crown–rump length, somite number were significantly decreased in high dose experimental groups compared with control group.  Conclusions: This study showed that development of neurons is affected in chi- cken embryos after administration of diclofenac sodium. The exact teratogenic mechanism of diclofenac sodium is not clear; therefore it should be investigated.

Polymorphisms in Tumour Necrosis Factor Alpha (TNFα) Gene in Patients with Acute Pancreatitis

Proinflammatory cytokines, such as tumour necrosis factor α (TNFα), play fundamental roles in the pathogenesis of acute pancreatitis (AP). The aim of this study was to determine if polymorphisms in the TNFα gene are associated with AP. Two polymorphisms located in the promoter region (positions −308 and −238) in TNFα gene were determined using polymerase chain reaction- (PCR-) restriction fragment length polymorphism (RFLP) methods in 103 patients with AP and 92 healthy controls. Odds ratios (ORs) and 95% confidence intervals (CI) were estimated using logistic regression analysis adjusted for age, sex, BMI and smoking. The frequencies of TNFα polymorphisms were both similar in patients with mild or severe pancreatitis, so were in pancreatitis patients and in controls. We suggest that both SNPs of TNFα are not genetic risk factor for AP susceptibility (OR = 1.63; 95% CI: 1.13−4.01 for TNFα−308 and OR = 0.86; 95% CI: 0.75−1.77 for TNFα−238)

Insulator-to-Metal Transition in Selenium-Hyperdoped Silicon: Observation and Origin

Hyperdoping has emerged as a promising method for designing semiconductors with unique optical and electronic properties, although such properties currently lack a clear microscopic explanation. Combining computational and experimental evidence, we probe the origin of sub-band gap optical absorption and metallicity in Se-hyperdoped Si. We show that sub-band gap absorption arises from direct defect-to-conduction band transitions rather than free carrier absorption. Density functional theory predicts the Se-induced insulator-to-metal transition arises from merging of defect and conduction bands, at a concentration in excellent agreement with experiment. Quantum Monte Carlo calculations confirm the critical concentration, demonstrate that correlation is important to describing the transition accurately, and suggest that it is a classic impurity-driven Mott transition.Comment: 5 pages, 3 figures (PRL formatted

Age-related changes of nasal cavity and conchae volumes and volume fractions in children: a stereological study

Background: The anatomy of the human nasal cavity (NC) is complex and its structures are closely related to the functions of the NC. Studies which assessing the mean volumes of NC and conchae are very infrequent. The purpose of current study is to investigate development of NC and conchae according to age and sex by using stereological method. Materials and methods: This retrospective volumetric study was carried out on 342 individuals (166 females and 176 males) between 0 and 18 years old with no pathological conditions or medical procedures that affected the skeletal morphology of the NC. Volumetric estimations were determined on computed tomography (CT) images using point-counting approach of stereological methods. Results: NC, inferior nasal conchae (INC) and middle nasal conchae (MNC) volume measurements that obtained using point-counting method were increased with age in both sexes until 15 years old. Regardless of gender; no significant difference was determined between the left and right values for NC, conchae volumes and choanae measurements. Generally, significant differences were determined in NC and INC volumes according to gender after they reached maximum growth period. According to age the volume ratios of INC to NC and MNC to NC were ranged from 18% to 32% and 9% to15%, respectively. Conclusions: The current study demonstrated that the point-counting method is effective in determining volume estimation of NC and is well suited for CT studies. Our results could provide volumetric indexes for the NC and conchae, which could help the physician for both patient selections for surgery, and for the assessment of any surgical technique used to treatment of nasal obstruction. (

Volumetric evaluation of hemicerebellar changes in migraine patients without aura

Brain balance changes have been recognised in migraine, but cerebellar function between or during attacks has been assessed only in a few studies. Previous studies have indicated that migraine affects cerebellar function. In the present study we aimed to evaluate the hemicerebellar volume changes of patients with migraine without aura (MWoA). Volumetric changes of cerebellar hemispheres were evaluated in terms of asymmetry using stereological methods on magnetic resonance images (MRI) retrospectively. Nineteen patients with MWoA and 18 age- and gender-matched control subjects were included in the study. MRIs were analysed by using the point-counting approach of stereological methods by Cavalier’s principle. There was no statistically significant cerebellar atrophy or hemicerebellar asymmetry between the MWoA and control subjects. There was no cerebellar atrophy or asymmetry between the MWoA and age-matched control group. The stereological evaluation of cerebellar asymmetry and atrophy in humans is important for both clinicians and anatomists. The technique is simple, inexpensive, and reliable. (Folia Morphol 2011; 70, 4: 235–239

Estimation of spleen volume and surface area of the newborns’ cadaveric spleen using stereological methods

Background: The purpose of this study was to compare different techniques for the estimation of spleen volume and surface area using magnetic resonance imaging (MRI) images, ultrasonography (USG) images and cadaveric specimen, and to evaluate errors associated with volume estimation techniques based onfluid displacement.Materials and methods: Five new born cadavers, aged 39.7 ± 1.5 weeks, weighted 2.220 ± 1.056 g, were included in the present study. Three different methods were used to assess the spleen volume. The vertical section technique was applied using cycloid test probes for estimation of spleen surface area in MRI.Results: The mean ± standard deviation of spleen volumes by fluid displacement was 4.82 ± 3.85 cm3. Volumes determined by the Cavalieri’s principle using physical section and point-counting techniques were 4.45 ± 3.47 cm3 and 4.65 ± 3.75 cm3, respectively; volumes measured by USG and cadaver using ellipsoid formula were 4.70 ± 3.02 cm3 and 5.98 ± 4.58 cm3, respectively. No significant differences were found among all methods (p > 0.05). The spleen surface area was calculated as a 32.3 ± 20.6 cm2 by physical sections using cadaver and also it was determined on axial, sagittal and coronal MR planes as 24.9 ± 15.2 cm2, 18.5 ± 5.92 cm2 and 24.3 ± 12.7 cm2, respectively.Conclusions: As a result, MR images allow an easy, reliable and reproducible volume and surface area estimation of normal and abnormal spleen using Cavalieri’sprinciple. We consider that our study may serve as a reference for similar studies to be conducted in future

Registry-dependent potential energy and lattice corrugation of twisted bilayer graphene from quantum Monte Carlo

An uncertainty in studying twisted bilayer graphene (TBG) is the minimum energy geometry, which strongly affects the electronic structure. The minimum energy geometry is determined by the potential energy surface, which is dominated by van der Waals (vdW) interactions. In this work, large-scale diffusion quantum Monte Carlo (QMC) simulations are performed to evaluate the energy of bilayer graphene at various interlayer distances for four stacking registries. An accurate registry-dependent potential is fit to the QMC data and is used to describe interlayer interactions in the geometry of near-magic-angle TBG. The band structure for the optimized geometry is evaluated using the accurate local-environment tight-binding model. We find that compared to QMC, DFT-based vdW interactions can result in errors in the corrugation magnitude by a factor of 2 or more near the magic angle. The error in corrugation then propagates to the flat bands in twisted bilayer graphene, where the error in corrugation can affect the bandwidth by about 30% and can change the nature and degeneracy of the flat bands

Examination of inclinations of the spine at childhood and adolescence

Background: Spine is a column that consists of consecutively lined up vertebras. It includes medulla spinalis. It contributes the motions of head, neck and body. Spine is not a straight column. There is a convexity towards the front of the spine (lordosis) at cervical and lumbar areas in adults and a convexity towards the back of the spine (kyphosis) at thoracic and sacral spine areas.  Materials and methods: In this study, lateral magnetic resonance images of 731 children between 1 and 16 years of age were examined and their cervical lordosis, thoracic kyphosis and lumbar lordosis angles were measured with Cobb method using ImageJ programme for every age group.  Results: The mean calculated cervical lordosis angles in 1–16-year-old children were found to be 20.51o ± 6.11o (minimum 17.96o ± 6.29o, maximum 23.50o ± ± 4.14o). It has been observed that cervical angle values decrease with age. The mean thoracic kyphosis angle measured was 28.71o ± 6.99o (minimum 24.55o ± ± 5.65o, maximum 30.44o ± 4.68o). Lumbar lordosis angle was 28.08o ± 7.39o (minimum 20.36o ± 6.59o, maximum 32.68o ± 6.03o). Thoracic kyphosis and lumbar lordosis angle values increased with age. In our study, a statistical differ- ence was found in increasing thoracic kyphosis angle between 1-year-old group and 14-year-old group. Statistical difference was also found in decreasing cervical lordosis angle value between 1-year-old group and 16-year-old group. When we compare our study results with literature values, cervical lordosis values were similar, but lumbar lordosis values were lower.  Conclusions: In summary, we think that knowing sagittal plane inclinations of the spine developing in childhood and adolescence will contribute to earlier de- termination of pathologies. We also hope that it will contribute to clinical stages and other studies in this field.

Solitary and cnoidal wave scattering by a submerged horizontal plate in shallow water

Solitary and cnoidal wave transformation over a submerged, fixed, horizontal rigid plate is studied by use of the nonlinear, shallow-water Level I Green-Naghdi (GN) equations. Reflection and transmission coefficients are defined for cnoidal and solitary waves to quantify the nonlinear wave scattering. Results of the GN equations are compared with the laboratory experiments and other theoretical solutions for linear and nonlinear waves in intermediate and deep waters. The GN equations are then used to study the nonlinear wave scattering by a plate in shallow water. It is shown that in deep and intermediate depths, the wave-scattering varies nonlinearly by both the wavelength over the plate length ratio, and the submergence depth. In shallow water, however, and for long-waves, only the submergence depth appear to play a significant role on wave scattering. It is possible to define the plate submergence depth and length such that certain wave conditions are optimized above, below, or downwave of the plate for different applications. A submerged plate in shallow water can be used as a means to attenuate energy, such as in wave breakers, or used for energy focusing, and in wave energy devices