Quantitative ultrasound techniques and biochemical markers to assess liver steatosis and fibrosis in newly diagnosed acromegaly.

PURPOSE: The liver is known to be protected from steatosis under the influence of high GH/IGF-1. Cytokeratin 18 (CK18) and insulin-like growth factor binding protein 7 (IGFBP7) increase in liver steatosis and fibrosis. The aim of this study was to use quantitative ultrasound techniques and biochemical markers to assess liver steatosis and liver fibrosis in newly diagnosed acromegaly. METHODS: This single-center, cross-sectional study included 23 patients with newly diagnosed acromegaly and 46 age, sex, body mass index (BMI) and waist circumference (WC)-matched controls. Liver steatosis was assessed using tissue attenuation imaging (TAI), and stiffness, indicative of fibrosis, was assessed by shear wave elastography (SWE). Serum IGFBP7 and CK18 were studied by ELISA. RESULTS: The acromegaly group had significantly lower liver steatosis (p = 0.006) and higher liver stiffness (p = 0.004), serum IGFBP7 (p = 0.048) and CK18 (p = 0.005) levels than the control group. The presence of fibrosis (p = 0.012) was significantly higher in the acromegaly group than in the control group. Moreover, CK18 was positively correlated with liver stiffness, WC, HOMA-IR, HbA1c, and triglyceride. In the acromegaly group, liver steatosis was negatively correlated with GH level. Stepwise multiple linear regression analysis revealed that BMI (p = 0.008) and CK18 (p = 0.015) were independent risk factors for increased liver stiffness. CONCLUSION: This study showed that there was an increased presence of liver fibrosis independent of liver steatosis in newly diagnosed acromegaly. Serum CK18 appears to be a potential marker of increased liver fibrosis in acromegaly.

Prevalence of neonatal calf diarrhea caused by Escherichia coli and investigation of virulence factors, serotypes, and antibiotic susceptibility.

Neonatal calf diarrhea (NCD) is one of the most important concerns in cattle production. Escherichia coli is the most important bacterial agent of NCD. Although vaccination and antibiotic treatment are common in NCD, the high antigenic diversity of E. coli and the increase in antibiotic resistance cause difficulties in the control. The study aimed to investigate the rate of E. coli in calf diarrhea, isolate an agent of the NCD E. coli strain, determine antimicrobial resistance, and find out about some surface antigens. Fecal samples (n=115) were analyzed to isolate pathogenic E. coli strains with nine mixed infections; sixty-one strains isolate from fifty diarrhoeic calves. Among the isolates from diseased animals, 22 K99+STa+F41, 3 K99+STa, 3 strains F41, 2 strains Stx1, one strain K99, one strain eae, and one strain Stx2+eae were detected. 27 strains of F17- associated fimbriae have been identified. 17 strains F17a, 6 strains F111, 3 strains F17c, one strain carrying the F17a and F17c gene regions, whereas subfamily typing of one strain could not be performed. Serotypes were determined by molecular and serological methods: 32/61 (52.5%) isolates were O101 and 2/61 (3.3%) isolates were O9 serotypes. But 27 strain serotypes could not be detected. The antibiotic resistance profiles of the isolates were determined by the disc diffusion method. The resistance rates to antibiotics were trimethoprim- sulphamethoxazole 91.7%, ampicillin 86.7%, enrofloxacin 86.7%, gentamicin 45%, tobramycin 41.7%, cefotaxime 3.3%, and ceftazidime 1.7%. Due to increasing antibiotic resistance, prophylaxis is gaining importance. In further research, E. coli surface antigenic structures should be examined in detail, and it should form the basis for vaccine and hyperimmunization studies to be developed.

Prevalence, comorbidities and mediators of childhood anxiety disorders in urban Turkey: a national representative epidemiological study.

PURPOSE: The aim of this study is to evaluate the prevalence of anxiety disorders, its correlation with sociodemographic characteristics, its comorbidities with other psychiatric disorders and its predictors in school-aged children. METHODS: This study is part of a representative, multi-centered national study that is planned by the Turkish Association of Child and Adolescent Mental Health to evaluate the prevalence of psychopathology among elementary school students in Turkey between the years 2014-2015. Children are screened via Kiddie Schedule for Affective Disorders and Schizophrenia for School Age Children Present and Lifetime Version. Impairment is assessed by a 3-point Likert type scale independently by the parent and the teacher. The final sample included 5842 children with the mean age of 8.7 years. RESULTS: The prevalence of any anxiety disorder without considering impairment is 16.7% and considering impairment is 5.2% in children according to our study. We found significant differences for comorbid Attention Deficit Hyperactivity Disorder, Disruptive Behavior Disorder, Mood Disorders, Tic Disorders, Obsessive Compulsive Disorder, Enuresis Nocturna, Encopresis, and Intellectual Disability. Having a history of paternal physical disorder, living in the regions of Marmara, Mediterranean and Black Sea were found to be the main predictors of having childhood anxiety disorders according to the logistic regression analysis. CONCLUSION: Better understanding of childhood anxiety disorders, comorbid conditions and predictors will result in earlier diagnosis and more appropriate treatment.

The temperature induced current transport characteristics in the orthoferrite YbFeO3-δ thin film/p-type Si structure.

The perovskite ytterbium ferrite is a new ferroelectric semiconductor material. We presented the temperature induced current-voltage (I-V) characteristics of the Al/YbFeO3-δ/p-Si/Al hetero-junction. The orthoferrite YbFeO3-δ thin films were deposited on a single crystal p-type Si substrate by a radio frequency magnetron sputtering system. The potential barrier height (BH) [Formula: see text] and ideality factor n of the heterojunction were obtained by thermionic emission current method based on the recommendations in the literature. The fact that the calculated slopes of I-V curves become temperature independent implying that the field emission current mechanism takes place across the device, which has been explained by the presence of the spatial inhomogeneity of BHs or potential fluctuations. Moreover, a tunneling transmission coefficient value of 26.67 was obtained for the ferroelectric YbFeO3-δ layer at the Al/p-Si interface.

Academic performance after neurosurgery residency training in Turkey: a national survey.

OBJECTIVE: Neurosurgery training programs aim to train specialists. In addition, they are expected to equip the residents with necessary knowledge and skills for academic development. This study aims to gain insights into academic productivity after neurosurgeons graduated from residency training in Turkey. METHODS: An electronic survey was sent to all Turkish Neurosurgical Society members (n = 1662 neurosurgeons) between September and November 2019. The number of participants was 289 (17.4%). Participants were divided into subgroups based on three main factors: training institution type (university hospital [UH] vs training and research hospital [TRH]), training institution annual case volume (low [< 1000 or inadequate cranial/spinal case numbers] vs high [> 1000 and adequate cranial/spinal case numbers]), and training program accreditation status (accredited vs nonaccredited). RESULTS: The majority of the participants (64.7%) graduated from the UHs. Those trained at UHs (vs TRHs) and high- (vs low-) volume centers had their dissertations more frequently published in Science Citation Index/Science Citation Index-Expanded journals, gave more oral presentations after residency, had higher h-indices, had higher rates of reviewership for academic journals, and had greater participation in projects with grant support. In addition, graduates of accredited programs reported more PhD degrees than those of nonaccredited programs. CONCLUSIONS: Neurosurgeons trained in higher-case-volume, accredited programs, mostly in the UHs, performed better in terms of scientific activities and productivity in Turkey. Strong research emphasis and supportive measures should be instituted to increase academic performance during and after residency training.

Analysis of Survival of Patients with Brain Metastases According to Prognostic Indexes and Treatment Strategies.

AIM: To retrospectively evaluate the overall survival (OS) of patients with brain metastases (BMs) who had been treated with whole brain radiotherapy (WBRT) and Gamma Knife (GK) according to prognostic factors and prognostic index scores. MATERIAL AND METHODS: The study included 91 patients with BMs who had been treated with WBRT and/or GK between 2014 and 2017. The patients with BMs were retrospectively evaluated regarding age, sex, Karnofsky Performance Status (KPS), recursive partitioning analysis (RPA) class, basic score for BM (BS-BM), Graded Prognostic Assessment (DS-GPA) index, primary tumour type, extracranial metastases, primary tumour control, number of BMs, and brain metastasectomy. A univariate analysis of the OS was performed using the Kaplan-Meier method, supplemented by the log-rank test. We also applied a multivariate survival analysis using the Cox regression model. RESULTS: The median OS for all patients with BMs was 6 months. Meanwhile, the median OSs for those with WBRT, GK, and WBRT-GK treatment were 6, 4, and 15 months, respectively (p=0.00). In the multivariate analysis, the female sex (p=0.030), brain metastasectomy (p=0.047), treatment with WBRT-GK (p=0.001), and the controlled primary tumour (p=0.007) significantly correlated with the OS. Furthermore, the BS-BM (p=0.022) was closely related with the OS compared to the RPA and DS-GPA in the multivariate analysis. CONCLUSION: The BS-BM was found to better predict the survival of patients with BMs according to the prognostic index scores in the multivariate analysis. Thus, our data suggest that the BS-BM is the most appropriate prognostic index.

Diagnostic value of four-dimensional computed tomography and four-dimensional magnetic resonance imaging in primary hyperparathyroidism when first-line imaging was inadequate.

INTRODUCTION: Accurate localisation of the abnormal hyperfunctioning gland with preoperative imaging has a critical role in parathyroid surgery to obtain a successful outcome. This study aimed to evaluate the diagnostic performance of second-line imaging and their contribution to the treatment success in primary hyperparathyroidism when the first-line methods were negative or discordant. METHODS: Among the patients who underwent parathyroidectomy due to primary hyperparathyroidism, 33 who underwent four-dimensional computed tomography and/or four-dimensional magnetic resonance imaging because of negative or discordant first-line imaging results were included. Persistent and recurrent cases were excluded. RESULTS: The majority of the patients were female (84.8%) and the mean age was 59.2 years. Seventeen patients had four-dimensional computed tomography and 25 had four-dimensional magnetic resonance imaging, respectively. Four-dimensional computed tomography and four-dimensional magnetic resonance imaging localised the culprit gland successfully in 52.9% and 84%, respectively. Twenty-five patients in whom single adenoma was detected underwent focused parathyroidectomy. The culprit gland was solitary in 32 cases and one patient had double adenoma. Normocalcaemia was achieved in all cases. Among the 29 patients who completed their postoperative sixth month success rate was 100%. CONCLUSION: Four-dimensional magnetic resonance imaging had high accuracy with fast dynamic imaging in detecting parathyroid adenomas. When the first-line imaging methods were negative or inconclusive, four-dimensional magnetic resonance imaging should be considered primarily since it is cost effective in Turkey and emits no radiation.

Frequency and temperature-dependent electric modulus spectroscopy of osmium-doped YbFeO3 structure.

Orthoferrites have occupied important place in the material science and condensed matter physics investigations due to their unique features such as electrical, magnetic and optical. The present investigation illuminates light on the electrical properties of osmium (Os) doped YbFeO3 (YbFO) rare-earth orthoferrite. The undoped YbFO and YbFe1-x Os x O3 (YbFOO) (x = 0.01 and 0.05) powders were synthesized via solid-state. X-ray diffractometer (XRD) has been utilized to examine the crystal structure of the YbFO and YbFOO powders. The cross sectional morphology of the obtained pellets was inspected via scanning electron microscope (SEM). Moreover, x-ray photoelectron spectroscopy was exploited to determine the oxidation states of the constituted elements. The electrical features for instance electrical modulus, dielectric constant and conductivity of the synthesized pellets were detailed at different frequencies and temperatures by dielectric/impedance spectroscopy studies. The x = 0.01 Os doped sample exhibits higher dielectric constant and conductivity compared to other samples. Moreover, in order to explain conductivity mechanism of the studied samples, multiple conduction models are needed to employ.

A high bandwidth microelectromechanical system-based nanopositioner for scanning tunneling microscopy.

Limited Z-axis bandwidth of piezotube scanners employed in conventional Scanning Tunneling Microscopes (STMs) has been a major limiting factor in achieving high scan speeds in STM applications. Slow Z-axis dynamics of typical piezotube scanners combined with the weight of the STM tip/tip holder assembly, that the scanner has to carry, substantially limit the achievable Z-axis bandwidth in both imaging and lithography modes. To tackle this issue, we propose a high bandwidth microelectromechanical-system-based nanopositioner to be integrated into an existing STM scanner. The device is designed to replace the STM tip and fine Z-positioning mechanisms in the conventional STM setup, while providing an order of magnitude higher bandwidth in Z axis. The device is microfabricated using double silicon-on-isolator technology, and standard cleanroom processes. Experiments show that tunneling current between the device tip and a highly ordered pyrolytic graphite sample can be successfully established and maintained in air using the proposed device in a feedback loop. Results indicate that the proposed device uniquely combines a very high resolution and a large stroke with a substantially larger Z-axis bandwidth compared to that of conventional STM piezotube scanners, enabling higher scanning speeds in STM operations.

Plateletcrit: A possible biomarker of inflammation in hepatitis A infection.

OBJECTIVES: Hepatitis A (HepA) virus is a common infection worldwide that causes inflammation of the liver. Platelet index, particularly plateletcrit (PCT) which shows percentage of blood occupied by platelets, is thought to be potential marker of inflammation. Therefore, we aimed to investigate the changes in PCT percentages during HepA infection. SUBJECTS AND METHODS: Seventy-three children with a diagnosis of acute HepA infection and 68 age- and sex-matched healthy controls were enrolled in this study. Their values of platelet indices [PCT and mean platelet volume (MPV)] obtained from complete blood counts, which were analyzed by XN-1000 analyzer, were statistically compared with each other. RESULTS: PCT and MPV of the patients were found to be higher than those of controls (8.89 ± 1.30 vs 8.03 ± 0.89 for MPV and 0.29 ± 0.11 vs 0.24 ± 0.05 for PCT; P = 0.000, P = 0.002, respectively). In addition, PCT and platelet counts showed a significant negative correlation with alanine aminotransferase (ALT) levels, which indirectly represents inflammation in the liver (PCT: r = -0.368, P = 0.002; platelet count: r = -0.304, P = 0.009). In contrast, MPV levels were not found to demonstrate any correlation with ALT (r = -0.205, P = 0.082). CONCLUSION: Both MPV and PCT are capable of reflecting the inflammation during acute HepA inflammation. Also, PCT shows a significant negative correlation with the degree of inflammation.

The electrical modulus and other dielectric properties by the impedance spectroscopy of LaCrO3 and LaCr0.90Ir0.10O3 perovskites.

We have prepared LaCrO3 (LCO) and 10% Ir doped LCO samples by the solid state reaction method and studied the electrical modulus and the other dielectric properties of the samples by means of the impedance spectroscopy in the -100 °C to 100 °C range, with steps of 20 °C. It has been clearly observed that the dielectric properties change due to Ir doping. The absolute dielectric constant value of Ir doped LCO has decreased and this reduction was attributed to decreasing Cr6+ ions which may play a vital role in space charge polarization and charge hopping. A plateau region appeared in the temperature-dependent real electrical modulus M' versus f curves of the pure LCO sample while almost no plateau region is visible in the Ir doped LCO sample. The temperature-dependent imaginary modulus M'' versus f curves has two peaks at each temperature; one of the peaks is at low frequency and the other at the high frequency region, which shifts through higher frequency region with increasing temperature. This originates from free charge accumulation at the interface with the increase of the temperature. Furthermore, it has been seen that the Ir doped LCO sample has higher impedance and resistance values than the undoped LCO sample at the same frequency and temperature. This phenomenon was attributed to doped Ir ions behaving like a donor in LCO because LCO is a p-type compound. Moreover, the activation energy values of 0.224 eV and 0.208 eV for LCO and of 0.161 eV and 0.265 eV for the Ir doped LCO have been obtained from the slopes of the ρ dc vs. (kT)-1 curves, respectively. Also the activation energies were calculated from the slopes of the f max vs. (kT)-1 curves and the obtained results from low frequency region were in good agreement with ρ dc vs. (kT)-1 ones.

Association between neutrophil/lymphocyte ratio with ductus arteriosus patency in preterm newborns.

OBJECTIVE: The aim of this study was to assess the influence of neutrophil to lymphocyte (N/L) ratio and platelet indices on patent ductus arteriosus (PDA) in preterm infants. BACKGROUND: PDA is a common problem with potentially serious associated morbidities in preterm neonates. METHODS: Premature infants with hemodynamically significant PDA (n = 47) and a control group without PDA (n = 50) who were hospitalized in the neonatal intensive care unit were retrospectively evaluated. The characteristics, perinatal factors, N/L ratio, platelet counts and other platelet indices of the infants in both groups during the first 3 days of life were recorded. RESULTS: Platelet counts were significantly lower in the patient group than in the control group (p = 0.0343). There was a marked positive correlation between body weight and N/L ratio in preterm infants with PDA (p = 0.0001). PDA was associated with low platelet count. CONCLUSION: Our results showed that N/L ratio is positively correllated with body weight in PDA group. These data suggest that platelet counts and N/L ratio might be useful predictors for the early diagnosis and evaluation of the clinical course of PDA in preterm infants (Tab. 2, Ref. 28).

Detecting Subtle Vibrations Using Graphene-Based Cellular Elastomers.

Ultralight graphene elastomer-based flexible sensors are developed to detect subtle vibrations within a broad frequency range. The same device can be employed as an accelerometer, tested within the experimental bandwidth of 20-300 Hz as well as a microphone, monitoring sound pressures from 300 to 20 000 Hz. The sensing element does not contain any metal parts, making them undetectable by external sources and can provide an acceleration sensitivity of 2.6 mV/g, which is higher than or comparable to those of rigid Si-based piezoresistive microelectromechanical systems (MEMS).

Ultrasensitive Strain Sensor Produced by Direct Patterning of Liquid Crystals of Graphene Oxide on a Flexible Substrate.

Ultrasensitive flexible strain sensors were developed through the combination of shear alignment of a high concentration graphene oxide (GO) dispersion with fast and precise patterning of multiple rectangular features on a flexible substrate. Resistive changes in the reduced GO films were investigated under various uniaxial strain cycles ranging from 0.025 to 2%, controlled with a motorized nanopositioning stage. The devices uniquely combine a very small detection limit (0.025%) and a high gauge factor with a rapid fabrication process conducive to batch production.

Ultrafast Dynamic Piezoresistive Response of Graphene-Based Cellular Elastomers.

Ultralight graphene-based cellular elastomers are found to exhibit nearly frequency-independent piezoresistive behaviors. Surpassing the mechanoreceptors in the human skin, these graphene elastomers can provide an instantaneous and high-fidelity electrical response to dynamic pressures ranging from quasi-static up to 2000 Hz, and are capable of detecting ultralow pressures as small as 0.082 Pa.

Changes in retinal vessels related to varicocele: a pilot investigation.

The aim of this study was to investigate whether retinal vasculature changes had occurred (retinal artery diameter, retinal vein diameter and artery/vein ratio) in patients with varicocele. This pilot study included 50 healthy subjects with any eye disease apart from slight refractive errors and 55 patients with varicocele. Retinal arteriolar and venular diameters were measured and summarised as central retinal arteriolar equivalent (CRAE) and central retinal venular equivalent (CRVE). Retinal microvascular diameters and the arteriolar-to-venular ratio (AVR) were assessed with a digital retinal camera. All measurements and calculations were performed using a computer-based program. The mean CRAE value was 151.8 ± 3.6 µm in the study group and 150.4 ± 4.5 µm in the control group. Mean CRVE value was 209.4 ± 5.9 µm in the study group and 200.1 ± 8.7 µm in the control group. AVR was found 0.72 ± 0.02 in the study group and 0.75 ± 0.03 in the control group. There were significant differences between groups in terms of CRVE and AVR. There were no significant differences between groups in terms of CRAE. The results of this study showed that the patients with varicocele showed significant changes on retinal vascular diameter.

Vibrating membrane with discontinuities for rapid and efficient microfluidic mixing.

This study presents a novel acoustic mixer comprising of a microfabricated silicon nitride membrane with a hole etched through it. We show that the introduction of the through hole leads to extremely fast and homogeneous mixing. When the membrane is immersed in fluid and subjected to acoustic excitation, a strong streaming field in the form of vortices is generated. The vortices are always observed to centre at the hole, pointing to the critical role it has on the streaming field. We hypothesise that the hole introduces a discontinuity to the boundary conditions of the membrane, leading to strong streaming vortices. With numerical simulations, we show that the hole's presence can increase the volume force responsible for driving the streaming field by 2 orders of magnitude, thus supporting our hypothesis. We investigate the mixing performance at different Peclet numbers by varying the flow rates for various devices containing circular, square and rectangular shaped holes of different dimensions. We demonstrate rapid mixing within 3 ms mixing time (90% mixing efficiency at 60 µl min(-1) total flow rate, Peclet number equals 8333 ± 3.5%) is possible with the current designs. Finally, we examine the membrane with two circular holes which are covered by air bubbles and compare it to when the membrane is fully immersed. We find that coupling between the holes' vortices occurs only when membrane is immersed; while with the bubble membrane, the upstream hole's vortices can act as a blockage to fluid flow passing it.

MDCT evaluation of early pulmonary infection types after liver transplantation.

INTRODUCTION: Opportunistic pulmonary infections frequently occur after liver transplantation, and affect mortality and morbidity significantly. The purpose of this study was to define the incidence, types, and imaging characteristics of pulmonary infections in liver transplant recipients with multidetector CT (MDCT) evaluation. METHODS: Thirty-five adult transplant recipients diagnosed with a pulmonary infection within the first 45 days posttransplantation were reviewed retrospectively from March 2002 to December 2013. MDCT features were evaluated retrospectively by 2 radiologists in consensus. All diagnoses were made by sputum analysis, cultures, biopsies, and postmortem histopathologic evaluation. RESULTS: Pneumococcus pneumonia was found in 7 patients. Five patients had nonspecific pneumonia, Candidiasis, Klebsiella, and Aspergillosis separately. S aureus pneumonia was detected in 2 patients and the other 2 patients had Escherichia coli pneumonia. Two patients had active tuberculosis and 1 patient had Acinetobacter pneumonia also. Four main MDCT patterns were identified: patchy infiltrations (10%), tree-in-bud pattern (9.5%), ground-glass opacity (8.5%), and nodules with halo sign (6%). One patient had a cavitary lesion owing to tuberculosis. CONCLUSION: Although the incidence of pulmonary complications in liver recipients was relatively low, mortality from serious infections was high. Care must be taken with pulmonary infectious complications in the posttransplant period. For any suspicious case, MDCT evaluation for specific patterns of early accurate diagnosis is very important.

Genomic damage in patients with type-2 diabetes mellitus.

DNA damage seems to play a role in the pathogenesis of type-2 diabetes mellitus (DM2) and its complications. Several in vitro assays have been used to measure the DNA damage. In the present study, we aimed to investigate the frequency of sister chromatid exchange (SCE) and micronuclei (MN) in DM2 patients compared with healthy controls. SCE and MN tests were carried out with the blood-cell cultures from 50 DM2 patients and 30 healthy, age- and sex-matched control subjects. The mean age of the DM2 patients was 58.12 +/- 13.39 years, with a mean duration of the diabetes of 5.40 +/- 4.32 years. The mean level of HbAlc of the DM2 patients was 8.93 +/- 2.56. Patients with DM2 showed a higher frequency of SCE compared with controls (7.11 +/- 1.14 and 4.96 +/- 0.92, p < 0.001). Furthermore, the SCE frequency was positively correlated with the plasma HbA1c level (p < 0.05), but there was no significant correlation between the duration of diabetes and SCE. On the other hand, our result showed a MN frequency significant increase in DM2 patients (3.45 +/- 1.01 per 1000 cells) relative to that of the control group (1.79 +/- 0.67 per 1000 cells) (p < 0.001), but there was no significant correlation between the duration of diabetes, HbA1c and MN. In conclusion, these results suggest that DM2 is a condition with genomic instability characterized by an increased level of SCE and MN. Hyperglycemia-induced oxidative stress may be the underlying factor of the increased SCE and MN frequency.

Anaerobes in nosocomial and community acquired pleural infections.

Anaerobes are important causes of pleural space infections. The aim of the study is to evaluate the role of the anaerobic bacteria in pleural infections. The study involved 278 consecutive clinical samples sent to the Clinical Microbiology Laboratory of Tertiary Chest Hospital. Anaerobes were isolated in 39 community acquired and five nosocomial cases out of 278 anaerobic cultivations (15.8%). Total of 56 anaerobe strains were identified and 21 aerobes were accompanied to anaerobic isolates. Aerobe isolates were associated with anaerobic microorganisms in 19 cases (43.2%). Bacteroides species (21.4%) and Pseudomonas aeruginosa (33.3%) were the most common anaerobic and aerobic isolates.