bluuebunny/crossref_metadata_2025 huggingface dataset:
Control of ion content and nitrogen species using a mixed chemistry plasma for GaN grown at extremely high growth rates >9 μm/h by plasma-assisted molecular beam epitaxy
Authors: Gunning Brendan P. , Clinton Evan A. , Merola Joseph J. , Doolittle W. Alan , Bresnahan Rich C.
Published: October 2015

Utilizing a modified nitrogen plasma source, plasma assisted molecular beam epitaxy (PAMBE) has been used to achieve higher growth rates in GaN. A higher conductance aperture plate, combined with higher nitrogen flow and added pumping capacity, resulted in dramatically increased growth rates up to 8.4 μm/h using 34 sccm of N2 while still maintaining acceptably low operating pressure. It was further discovered that argon could be added to the plasma gas to enhance growth rates up to 9.8 μm/h, which was achieved using 20 sccm of N2 and 7.7 sccm Ar flows at 600 W radio frequency power, for which the standard deviation of thickness was just 2% over a full 2 in. diameter wafer. A remote Langmuir style probe employing the flux gauge was used to indirectly measure the relative ion content in the plasma. The use of argon dilution at low plasma pressures resulted in a dramatic reduction of the plasma ion current by more than half, while high plasma pressures suppressed ion content regardless of plasma gas chemistry. Moreover, different trends are apparent for the molecular and atomic nitrogen species generated by varying pressure and nitrogen composition in the plasma. Argon dilution resulted in nearly an order of magnitude achievable growth rate range from 1 μm/h to nearly 10 μm/h. Even for films grown at more than 6 μm/h, the surface morphology remained smooth showing clear atomic steps with root mean square roughness less than 1 nm. Due to the low vapor pressure of Si, Ge was explored as an alternative n-type dopant for high growth rate applications. Electron concentrations from 2.2 × 1016 to 3.8 × 1019 cm−3 were achieved in GaN using Ge doping, and unintentionally doped GaN films exhibited low background electron concentrations of just 1–2 × 1015 cm−3. The highest growth rates resulted in macroscopic surface features due to Ga cell spitting, which is an engineering challenge still to be addressed. Nonetheless, the dramatically enhanced growth rates demonstrate great promise for the future of III-nitride devices grown by PAMBE.
All-optical logic gate based on transient grating from disperse red 1 doped organic-inorganic hybrid films with an improved figure of merit
Authors: Gao Tianxi , Que Wenxiu , Shao Jinyou , Wang Yushu
Published: October 2015

Azobenzene dyes have large refractive index near their main resonance, but the poor figure of merit (FOM) limits their potential for all-optical applications. To improve this situation, disperse red 1 (DR1) molecules were dispersed in a sol-gel germanium/Ormosil organic-inorganic hybrid matrix. Z-scan measurement results showed a good compatibility between the dopant and the matrix, and also, an improved FOM was obtained as compared to the DR1/polymer films reported previously. To demonstrate the all-optical signal processing effect, a cw Nd:YAG laser emitting at 532 nm and a He-Ne laser emitting at 632.8 nm were used as pump and probe beams, respectively. DR1 acts as an initiator of the photo-induced transient holographic grating, which is attributed to the trans-cis-trans photoisomerization. Thus, a three inputs AND all-optical logic gate was achieved by using choppers with different frequencies. The detailed mechanism of operation is discussed. These results indicate that the DR1 doped germanium/Ormosil organic-inorganic hybrid film with an improved FOM has a great potential in all-optical devices around its main resonance.
Temperature dependent dielectric and conductivity studies of polyvinyl alcohol-ZnO nanocomposite films by impedance spectroscopy
Authors: Hemalatha K. S. , Sriprakash G. , Ambika Prasad M. V. N. , Damle R. , Rukmani K.
Published: October 2015

Dielectric and conductivity behaviors of nano ZnO doped polyvinyl alcohol (PVA) composites for various concentrations of dopant were investigated using impedance spectroscopy for a wide range of temperatures (303 K–423 K) and frequencies (5 Hz–30 MHZ). The dielectric properties of host polymer matrix have been improved by the addition of nano ZnO and are found to be highly temperature dependent. Anomalous dielectric behavior was observed in the frequency range of 2.5 MHz–5 MHz. Increase in dielectric permittivity and dielectric loss was observed with respect to temperature. The Cole-Cole plot could be modeled by low resistance regions in a high resistance matrix and the lowest resistance was observed for the 10 mol. % films. The imaginary part of the electric modulus showed asymmetric peaks with the relaxation following Debye nature below and non-Debye nature above the peaks. The ac conductivity is found to obey Jonscher's power law, whereas the variation of dc conductivity with temperature was found to follow Arrhenius behavior. Two different activation energy values were obtained from Arrhenius plot indicating that two conduction mechanisms are involved in the composite films. Fitting the ac conductivity data to Jonscher's law indicates that large polaron assisted tunneling is the most likely conduction mechanism in the composites. Maximum conductivity is observed at 423 K for all the samples and it is optimum for 10 mol. % ZnO doped PVA composite film. Significant increase in dc and ac conductivities in these composite films makes them a potential candidate for application in electronic devices.
Determination of active doping in highly resistive boron doped silicon nanocrystals embedded in SiO2 by capacitance voltage measurement on inverted metal oxide semiconductor structure
Authors: Zhang Tian , Puthen-Veettil Binesh , Wu Lingfeng , Jia Xuguang , Lin Ziyun , Yang Terry Chien-Jen , Conibeer Gavin , Perez-Wurfl Ivan
Published: October 2015

We investigate the Capacitance-Voltage (CV) measurement to study the electrically active boron doping in Si nanocrystals (ncSi) embedded in SiO2. The ncSi thin films with high resistivity (200–400 Ω cm) can be measured by using an inverted metal oxide semiconductor (MOS) structure (Al/ncSi (B)/SiO2/Si). This device structure eliminates the complications from the effects of lateral current flow and the high sheet resistance in standard lateral MOS structures. The characteristic MOS CV curves observed are consistent with the effective p-type doping. The CV modeling method is presented and used to evaluate the electrically active doping concentration. We find that the highly boron doped ncSi films have electrically active doping of 1018–1019 cm−3 despite their high resistivity. The saturation of doping at about 1.4 × 1019 cm−3 and the low doping efficiency less than 5% are observed and discussed. The calculated effective mobility is in the order of 10−3 cm2/V s, indicating strong impurity/defect scattering effect that hinders carriers transport.
The pressure dependence of the discharge properties in a capacitively coupled oxygen discharge
Authors: Gudmundsson J. T. , Ventéjou Bruno
Published: October 2015

We use the one-dimensional object-oriented particle-in-cell Monte Carlo collision code oopd1 to explore the evolution of the charged particle density profiles, electron heating mechanism, and the electron energy probability function (EEPF) in a capacitively coupled oxygen discharge with pressure in the pressure range of 10–500 mTorr. We find that at higher pressure (50–500 mTorr) the electron heating occurs mainly in the sheath region, and detachment by the metastable singlet molecule O2(a1Δg) has a significant influence on the electron heating process. At a low pressure (10 mTorr), Ohmic heating in the bulk plasma (the electronegative core) dominates, and detachment by O2(a1Δg) has only a small influence on the heating process. Thus at low pressure, the EEPF is convex and as the pressure is increased the number of low energy electrons increases and the number of higher energy electrons (>10 eV) decreases, and the EEPF develops a concave shape or becomes bi-Maxwellian.
Dispersal-induced synchrony, temporal stability, and clustering in a mean-field coupled Rosenzweig–MacArthur model
Authors: Arumugam Ramesh , Dutta Partha Sharathi , Banerjee Tanmoy
Published: October 2015

In spatial ecology, dispersal among a set of spatially separated habitats, named as metapopulation, preserves the diversity and persistence by interconnecting the local populations. Understanding the effects of several variants of dispersion in metapopulation dynamics and to identify the factors which promote population synchrony and population stability are important in ecology. In this paper, we consider the mean-field dispersion among the habitats in a network and study the collective dynamics of the spatially extended system. Using the Rosenzweig–MacArthur model for individual patches, we show that the population synchrony and temporal stability, which are believed to be of conflicting outcomes of dispersion, can be simultaneously achieved by oscillation quenching mechanisms. Particularly, we explore the more natural coupling configuration where the rates of dispersal of different habitats are disparate. We show that asymmetry in dispersal rate plays a crucial role in determining inhomogeneity in an otherwise homogeneous metapopulation. We further identify an unusual emergent state in the network, namely, a multi-branch clustered inhomogeneous steady state, which arises due to the intrinsic parameter mismatch among the patches. We believe that the present study will shed light on the cooperative behavior of spatially structured ecosystems.
Structural changes of small amplitude kinetic Alfvén solitary waves due to second-order corrections
Authors: Choi Cheong R.
Published: October 2015

The structural changes of kinetic Alfvén solitary waves (KASWs) due to higher-order terms are investigated. While the first-order differential equation for KASWs provides the dispersion relation for kinetic Alfvén waves, the second-order differential equation describes the structural changes of the solitary waves due to higher-order nonlinearity. The reductive perturbation method is used to obtain the second-order and third-order partial differential equations; then, Kodama and Taniuti's technique [J. Phys. Soc. Jpn. 45, 298 (1978)] is applied in order to remove the secularities in the third-order differential equations and derive a linear second-order inhomogeneous differential equation. The solution to this new second-order equation indicates that, as the amplitude increases, the hump-type Korteweg-de Vries solution is concentrated more around the center position of the soliton and that dip-type structures form near the two edges of the soliton. This result has a close relationship with the interpretation of the complex KASW structures observed in space with satellites.
Modeling of high harmonic fast wave current drive on EAST tokamak
Authors: Li J. C. , Gong X. Y. , Dong J. Q. , Gao Q. D. , Zhang N. , Li F. Y.
Published: October 2015

High harmonic fast waves (HHFW) are among the candidates for non-inductive current drive (CD), which is essential for long-pulse or steady-state operation of tokamaks. Current driven with HHFW in EAST tokamak plasmas is numerically studied. The HHFW CD efficiency is found to increase non-monotonically with the wave frequency, and this phenomenon is attributed to the multi-pass absorption of HHFW. The sensitivity of CD efficiency to the value of the parallel refraction index of the launched wave is confirmed. The quasilinear effects, assessed as significant in HHFW current drive with the GENRAY/CQL3D package, cause a significant increase in CD efficiency as RF power is increased, which is very different from helicon current drive. Simulations for a range of toroidal dc electric fields, in combination with a range of fast wave powers, are also presented and indicate that the presence of the DC field can also enhance the CD efficiency.
Ion acoustic shock wave in collisional equal mass plasma
Authors: Adak Ashish , Ghosh Samiran , Chakrabarti Nikhil
Published: October 2015

The effect of ion-ion collision on the dynamics of nonlinear ion acoustic wave in an unmagnetized pair-ion plasma has been investigated. The two-fluid model has been used to describe the dynamics of both positive and negative ions with equal masses. It is well known that in the dynamics of the weakly nonlinear wave, the viscosity mediates wave dissipation in presence of weak nonlinearity and dispersion. This dissipation is responsible for the shock structures in pair-ion plasma. Here, it has been shown that the ion-ion collision in presence of collective phenomena mediated by the plasma current is the source of dissipation that causes the Burgers' term which is responsible for the shock structures in equal mass pair-ion plasma. The dynamics of the weakly nonlinear wave is governed by the Korteweg-de Vries Burgers equation. The analytical and numerical investigations revealed that the ion acoustic wave exhibits both oscillatory and monotonic shock structures depending on the frequency of ion-ion collision parameter. The results have been discussed in the context of the fullerene pair-ion plasma experiments.
Carrier injection engineering in nanowire transistors via dopant and shape monitoring of the access regions
Authors: Berrada Salim , Bescond Marc , Cavassilas Nicolas , Raymond Laurent , Lannoo Michel
Published: October 2015

This work theoretically studies the influence of both the geometry and the discrete nature of dopants of the access regions in ultra-scaled nanowire transistors. By means of self-consistent quantum transport simulations, we show that discrete dopants induce quasi-localized states which govern carrier injection into the channel. Carrier injection can be enhanced by taking advantage of the dielectric confinement occurring in these access regions. We demonstrate that the optimization of access resistance can be obtained by a careful control of shape and dopant position. These results pave the way for contact resistance engineering in forthcoming device generations.
On the interaction between the external magnetic field and nanofluid inside a vertical square duct
Authors: Ali Kashif , Ahmad Shabbir , Ahmad Shahzad , Ashraf Muhammad , Asif Muhammad
Published: October 2015

In this paper, we numerically study how the external magnetic field influences the flow and thermal characteristics of nanofluid inside a vertical square duct. The flow is considered to be laminar and hydrodynamically as well as thermally developed, whereas the thermal boundary condition of constant heat flux per unit axial length with constant peripheral temperature at any cross section, is assumed. The governing equations are solved using the spectral method and the finite difference method. Excellent comparison is noted in the numerical results given by the two methods but the spectral method is found to be superior in terms of both efficiency and accuracy. We have noted that the flow reversal due to high Raleigh number may be controlled by applying an external magnetic field of suitable strength. Moreover, the Nusselt number is found to be almost a linear function of the nanoparticle volume fraction parameter, for different values of the Raleigh number and the magnetic parameter.
Myocardial NF-κB activation is essential for zebrafish heart regeneration
Authors: Karra Ravi , Knecht Anne K. , Kikuchi Kazu , Poss Kenneth D.
Published: October 2015

Significance

Heart failure occurs when the heart cannot pump enough blood to meet the body’s demands. The heart most often weakens through the loss of muscle cells, called cardiomyocytes. Heart failure is a devastating disease, and one possible cure is to replace the lost cardiomyocytes through regeneration. Unlike humans, zebrafish can efficiently regenerate their hearts after injury. Interestingly, zebrafish heart cells are similar to human heart cells at the molecular level. Understanding how zebrafish can regenerate cardiac tissue can help identify regenerative therapies for humans. Here, we find that NF-κB signaling is a link between the injury response and the regenerative program in zebrafish.
Hyphenated Turkishness: The plurality of lived nationhood in Turkey
Authors: Al Serhun , Karell Daniel
Published: October 2015

Is Turkish nationality one singular identity that does not permit ethnic modifiers? Or can it be understood as pluralistic, with identities nested — “hyphenated” — with Turkishness? Then, are Turkish and Kurdish identities necessarily mutually exclusive? Such questions over the boundaries of Turkishness have long been framed in the civic versus ethnic dichotomy — an approach that does not ask whether Turkish nationhood is monolithic or pluralistic. In response, this article aims to advance the public and scholarly debates over nationhood in Turkey by turning to the question of ways in which Turkishness can be hyphenated with other identity categories in Turkey, most particularly Kurdishness. First, we reframe the debate over identity by using the combinatorial approach to ethnicity to outline how Turkishness and Kurdishness can be overlapping and nested, or a hyphenated identity. Second, we draw on public opinion data to show that such a hyphenated identity is both theoretically possible and potentially salient in Turkey today. Together, these steps deconstruct the primordialist understandings of Turkishness and Kurdishness, on the one hand, and the taken-for-granted civic claims of Turkishness, on the other.
Identity and the developmental origins of fusion: an exploratory approach / La identidad y los orígenes de la fusión en el desarrollo: un enfoque exploratorio
Authors: Gaviria Elena , Ferreira Carolina , Martínez Mercedes , Whitehouse Harvey
Published: October 2015

Identity fusion involves a visceral feeling of oneness with a group, despite personal and social selves remaining differentiated. Previous research on identity fusion has focused on samples of adults and adolescents. The present studies aim at exploring how and when identity fusion develops in childhood. Our first goal was to find out to what extent personal and social identities must be developed for fusion to become possible. We conducted two exploratory studies where school-age children (six to 12 years old) participated in either focus group sessions or individual interviews. Our results show that although children are able to feel strongly connected with a group and express willingness to make significant personal sacrifices for the group, they fail to show fusion as it is found in adults, since their personal identity is not fully developed yet. Instead, these findings suggest the existence of a prior feeling that we called ‘protofusion’, the core of which is the strength of the relational ties with the members of the group.
The power of ‘feeling one’ with a group: identity fusion and extreme pro-group behaviours / El poder de ‘sentirse uno’ con un grupo: fusión de la identidad y conductas progrupales extremas
Authors: Gómez Ángel , Vázquez Alexandra
Published: October 2015

Why do some people make extreme sacrifices for their group? We propose that the identity fusion theory helps to understand extreme pro-group behaviour. Identity fusion entails a visceral feeling of oneness with the group. Since the borders between the personal and social self are highly permeable for fused persons, they care about the outcomes of the group as much as their own outcomes. In this article we start by introducing what identity fusion is and the four principles that conceptually capture its essence. After presenting the three alternative methods for measuring identity fusion, we review empirical evidence demonstrating what identity fusion predicts, and the underlying mechanisms that moderate and mediate its consequences. The next sections focus on the possible causes of identity fusion, and we introduce suggestions for diminishing undesirable extreme behaviours by decreasing fusion (i.e., ‘de-fusion’). In a final section, we briefly discuss alternative theories of the causes of extreme behaviours and their relation to identity fusion theory.
Personal identity and social identity: two different processes or a single one? / Identidad personal e identidad social. ¿Dos procesos diferentes o uno solo?
Authors: Gómez Ángel , Vázquez Alexandra
Published: October 2015

Personal identity, or the definition of oneself in terms of personal idiosyncratic attributes, and social identity, or the definition of oneself in terms of affiliations with different categories or groups, have often been examined as two separate phenomena in the psychosocial literature. However, there are at least two theories which have deliberately researched the relationship between the two. One of these theories has done so for almost five decades (Social Identity Theory), while the alternative approach (Identity Fusion, or the visceral sense of oneness with the group) began to be developed less than one decade ago. The purpose of this special issue is to survey how approaches grounded upon both theories have attempted to explain some individuals’ extreme behaviours for their group. It also includes studies that examine the origins of identity fusion, the processes that relate it with extreme behaviour (such as the extension of familial ties to groups or the acceptance of violence), as well as a subtle demonstration of how group identity can affect interpersonal relationships.
A novel bi-level meta-analysis approach: applied to biological pathway analysis
Authors: Nguyen Tin , Tagett Rebecca , Donato Michele , Mitrea Cristina , Draghici Sorin
Published: October 2015

Motivation: The accumulation of high-throughput data in public repositories creates a pressing need for integrative analysis of multiple datasets from independent experiments. However, study heterogeneity, study bias, outliers and the lack of power of available methods present real challenge in integrating genomic data. One practical drawback of many P-value-based meta-analysis methods, including Fisher’s, Stouffer’s, minP and maxP, is that they are sensitive to outliers. Another drawback is that, because they perform just one statistical test for each individual experiment, they may not fully exploit the potentially large number of samples within each study.

Results: We propose a novel bi-level meta-analysis approach that employs the additive method and the Central Limit Theorem within each individual experiment and also across multiple experiments. We prove that the bi-level framework is robust against bias, less sensitive to outliers than other methods, and more sensitive to small changes in signal. For comparative analysis, we demonstrate that the intra-experiment analysis has more power than the equivalent statistical test performed on a single large experiment. For pathway analysis, we compare the proposed framework versus classical meta-analysis approaches (Fisher’s, Stouffer’s and the additive method) as well as against a dedicated pathway meta-analysis package (MetaPath), using 1252 samples from 21 datasets related to three human diseases, acute myeloid leukemia (9 datasets), type II diabetes (5 datasets) and Alzheimer’s disease (7 datasets). Our framework outperforms its competitors to correctly identify pathways relevant to the phenotypes. The framework is sufficiently general to be applied to any type of statistical meta-analysis.

Availability and implementation: The R scripts are available on demand from the authors.

Contact:  sorin@wayne.edu

Supplementary Information:  Supplementary data are available at Bioinformatics online.
3DRobot: automated generation of diverse and well-packed protein structure decoys
Authors: Deng Haiyou , Jia Ya , Zhang Yang
Published: October 2015

Motivation: Computationally generated non-native protein structure conformations (or decoys) are often used for designing protein folding simulation methods and force fields. However, almost all the decoy sets currently used in literature suffer from uneven root mean square deviation (RMSD) distribution with bias to non-protein like hydrogen-bonding and compactness patterns. Meanwhile, most protein decoy sets are pre-calculated and there is a lack of methods for automated generation of high-quality decoys for any target proteins.

Results: We developed a new algorithm, 3DRobot, to create protein structure decoys by free fragment assembly with enhanced hydrogen-bonding and compactness interactions. The method was benchmarked with three widely used decoy sets from ab initio folding and comparative modeling simulations. The decoys generated by 3DRobot are shown to have significantly enhanced diversity and evenness with a continuous distribution in the RMSD space. The new energy terms introduced in 3DRobot improve the hydrogen-bonding network and compactness of decoys, which eliminates the possibility of native structure recognition by trivial potentials. Algorithms that can automatically create such diverse and well-packed non-native conformations from any protein structure should have a broad impact on the development of advanced protein force field and folding simulation methods.

Availiablity and implementation:  http://zhanglab.ccmb.med.umich.edu/3DRobot/

Contact:  jiay@phy.ccnu.edu.cn; zhng@umich.edu

Supplementary information:  Supplementary data are available at Bioinformatics online.
Effects of Soil Nitrogen and Atmospheric Carbon Dioxide on Wheat streak mosaic virus and Its Vector (Aceria tosichella Kiefer)
Authors: Miller Zachariah J. , Lehnhoff Erik A. , Menalled Fabian D. , Burrows Mary
Published: October 2015

Management of vector-borne plant viruses requires understanding how abiotic (e.g., resource availability) and biotic (e.g., virus–vector interactions) factors affect disease via effects on epidemiological parameters that drive disease spread. We conducted two complementary experiments using Wheat streak mosaic virus (WSMV): (i) a field study to determine the effects of nitrogen (N) fertilization on winter wheat (Triticum aestivum L.) susceptibility to WSMV infection and (ii) a growth chamber study to evaluate the effects of N and carbon dioxide (CO2) enrichment on population growth rates of the wheat curl mite (WCM), the vector of WSMV, and whether the effects of nutrient addition on WCM reproduction were modified by WSMV infection. The relationship between N fertilization and plant susceptibility to WSMV infection was nonlinear, with infection rates increasing rapidly as soil nitrate increased from 0 to 20 ppm and more gradually at higher nitrate concentrations. In the growth chamber study, N fertilization increased WCM population growth rates when the vectors transmitted WSMV but had the opposite effect on nonviruliferous mites. CO2 enrichment had no observable effects on WCM populations. These results suggest that, whereas the spread of WSMV is facilitated by N addition, increases in atmospheric CO2 may not directly alter WCM populations and WSMV spread.
Callose Synthase Family Genes Involved in the Grapevine Defense Response to Downy Mildew Disease
Authors: Yu Ying , Jiao Li , Fu Shufang , Yin Ling , Zhang Yali , Lu Jiang
Published: October 2015

The deposition of callose is a common plant defense response to intruding pathogens and part of the plant’s innate immunity. In this study, eight grapevine callose synthase (CalS) genes were identified and characterized. To investigate biological function of CalS in grapevine against the infection of Plasmopara viticola, expression patterns of grapevine CalS family genes were analyzed among resistant/susceptible cultivars. After P. viticola infection, expression of CalS1, 3, 7, 8, 9, 10, and 11 were significantly modified among the grapevine cultivars. For example, the expression of CalS1 and CalS10 were greatly increased in downy mildew (DM)-immune Muscadinia rotundifolia ‘Carlos’ and ‘Noble’. Transient expression assay with promoters of the CalS1 and CalS10 genes confirmed that they were regulated by the oomycete pathogen P. viticola. CalS1 promoter activity was also significantly up-regulated by ABA in DM-immune M. rotundifolia ‘Noble’, but down-regulated in DM-susceptible Vitis vinifera ‘Chardonnay’. The CalS1 promoter, however, was also down-regulated by GA in ‘Chardonnay’, but not affected in ‘Noble’. The promoter activity of CalS10 was significantly up-regulated by GA in ‘Chardonnay’, but not regulated by ABA at all. It is proposed that CalS1 and CalS10 were involved in grapevine defense against DM disease.
The Occurrence of Iron-Deficiency Anemia in Children with Type 1 Diabetes
Authors: Wójciak Rafał W. , Mojs Ewa , Stanisławska-Kubiak Maia
Published: October 2015

Objective

A higher risk for iron deficiency, which can lead to anemia, has been noticed in children with early stages of type 1 diabetes. Anemia in diabetes is not uncommon and thus may contribute to disease complications. The aim of the study was to determine the influence of type 1 diabetes incidence on the manifestation of iron-deficiency anemia.

Materials and Methods

The study included 100 children with type 1 diabetes, aged 6 to 17 years. The diagnosis of type 1 diabetes in all patients was made on the basis of clinical symptoms and, at a later stage, on the basis of the occurrence of islet cell autoantibodies. The patients were divided into groups according to the duration of the disease: those with newly diagnosed type 1 diabetes (ND), those who have the disease for 1 to 3 years (FMD), those who have it for 4 to 6 years (SMD), and those who have it for more than 6 years (LD). Morphological parameters of blood have been measured by means of the flame atomic absorption spectrometry method: red blood cells (RBC), hemoglobin (HGB), acetylated HGB, hematocrit (HCT), RBC volume (mean corpuscular volume [MCV]), HGB mass in RBC (mean corpuscular HGB [MCH]), mean HGB content in RBC (MCH concentration), and serum iron concentration.

Results

In the ND children, significantly lower concentrations of HCT and HGB as well as the amount of RBC and MCV have been shown, in comparison with the children who have type 1 diabetes longer: for HGB, compared with the FMD children; for HCT, compared with the SMD and LD children; for RBC, compared with the LD children; and for MCV, compared with the SMD children. Some significant inverse correlation has been observed in the MCH concentration in comparison with the children who have type 1 diabetes for more than 1 year. It has been shown that, when compared with the FMD, SMD, and LD children, more ND children are characterized by the coexistence of at least 3 reduced values of the morphological blood parameters associated with iron-deficiency anemia (26%, 17%, 7%, and 3%, respectively). At the same time, it has been found that the mean iron concentration in the blood serum of the ND group is significantly lower than that of the SMD and LD groups.

Conclusions

The incidence of anemia in the early stages of the disease justifies conducting the screening in all children with type 1 diabetes and taking appropriate preventive measures toward the patients at risk for iron-deficiency anemia.
The Role of Serum Soluble Urokinase-Type Plasminogen Activator Receptor in Stable Chronic Obstructive Pulmonary Disease
Authors: Can Ümmügülsüm , Güzelant Asuman , Yerlikaya Fatma Hümeyra , Yosunkaya Şebnem
Published: October 2015

Background

Chronic obstructive pulmonary disease (COPD) results from an abnormal inflammatory response of the lungs to noxious particles or gases. Serum soluble urokinase-type plasminogen activator receptor (suPAR) is a glycoprotein secreted during infections and inflammation. The main goal of this study was to evaluate the serum suPAR level in stable COPD patients compared with a control group.

Methods

Forty-six stable COPD patients and 41 control subjects were included in the study. Blood samples were collected from 46 stable COPD patients (40 men, 6 women; mean [SD] age, 55.92 [7.91] years; the forced expiratory volume in 1 second, 45.32% [19.1%] of predicted). Forty-one healthy subjects were selected as control subjects and were matched to COPD patients with respect to age and body mass index. Serum suPAR and plasma fibrinogen levels were measured in stable COPD patients and control subjects.

Results

Serum suPAR levels of the COPD patients were significantly higher than those of the control subjects (4.94 [2.79] and 2.40 [2.01] ng/mL, respectively; P < 0.001). Plasma fibrinogen levels of the COPD patients were significantly higher than those of the control subjects (406.77 [172.6] and 336.53 [96.1] g/L, respectively; P < 0.05).

Conclusions

Our study indicated that serum suPAR may play an important role in the inflammatory process of COPD, and this increase may be particularly large for patients in Global Initiative for Chronic Obstructive Lung Disease stages III and IV. Serum suPAR and plasma fibrinogen level measurements may be useful for the evaluation of stable COPD.
Age and Ethnicity in Cirrhosis
Authors: Sajja Krishna C. , Mohan Desh P. , Rockey Don C.
Published: October 2015

Background

Cirrhosis is diagnosed in patients of all ages and is the end result of many different diseases. The aim of this study was to characterize clinical and ethnic features of adult patients who were admitted to the hospital at different (young/old) ages and examine associations between age and ethnicity within these groups.

Methods

In this retrospective analysis of a diverse cohort of 2017 patients with a clinical diagnosis of cirrhosis between January 2001 and December 2011, we focused on age, ethnicity, and outcome of patients with cirrhosis.

Results

We identified 219 patients younger than the age of 40 years, including 87 (11%) of 802 white, 31 (6%) of 550 African American, and 89 (16%) of 550 Hispanic patients ( P < 0.001). Ethnicity and causes of cirrhosis were found to have a significant correlation with age. Overall, Hispanic and white patients together were more than twice as likely to be diagnosed with cirrhosis at an age younger than 40 years compared with African American patients ( P < 0.001). Autoimmune hepatitis caused cirrhosis at a younger age regardless of ethnicity ( P < 0.001), whereas cryptogenic/nonalcoholic fatty liver disease/nonalcoholic steatohepatitis was more likely identified at an older age ( P = 0.008). African American patients with cirrhosis due to either alcohol or hepatitis C virus were older than Hispanic ( P < 0.001 and P = 0.003, respectively) and white patients ( P < 0.001 and P < 0.001, respectively) at presentation. Finally, younger patients admitted with cirrhosis had a higher in-hospital mortality rate ( P < 0.001).

Conclusions

The data suggest an association between ethnicity and age of cirrhosis diagnosis, both overall and in patients with certain cirrhosis etiologies. This work raises the possibility of an ethnic and/or genetic basis for cirrhosis.
Association of Methylenetetrahydrofolate Reductase Gene C677T Polymorphism with Multiple Sclerosis in Turkish Patients
Authors: Cevik Betul , Yigit Serbulent , Karakus Nevin , Aksoy Durdane , Kurt Semiha , Ates Omer
Published: October 2015

Background and Aim

Multiple sclerosis (MS) is a chronic neurodegenerative autoimmune disease of the central nervous system. Genetic risk factors are known to contribute to the etiology of MS. Methylenetetrahydrofolate reductase (MTHFR) gene C677T polymorphism has been associated with susceptibility to various autoimmune diseases. The aim of this study was to investigate a possible association between the MTHFR gene C677T polymorphism and MS in Turkish patients.

Methods

The study included 130 MS patients and 150 group-matched controls. Genomic DNA was isolated and genotyped using polymerase chain reaction–based restriction fragment length polymorphism assay for the MTHFR gene exon C677T polymorphism.

Results

The genotype and allele frequencies of C677T polymorphism showed statistically significant differences between MS patients and controls ( P = 0.002 and P = 0.002; odds ratio, 1.79; 95% confidence interval, 1.23-2.63, respectively). A significant association was observed when the patients were compared with the controls according to CC genotype versus CT + TT genotypes ( P = 0.0005; odds ratio, 2.35; 95% confidence interval, 1.45-3.82). There were no statistically significant association between MTHFR gene C677T polymorphism and baseline clinical and demographical characteristics of MS patients.

Conclusions

These results showed that T allele of C677T polymorphism was associated with MS susceptibility in Turkish population.
The Syndrome of a Large Drop in Hematocrit in Hospitalized Patients: Clinical Features and Gastrointestinal Bleeding Outcomes
Authors: Ong Bryan , Rockey Don C.
Published: October 2015

Background

Hemoglobin/hematocrit decreases in hospitalized patients without evidence of obvious gastrointestinal (GI) bleeding are common and often attributed to GI lesions. We hypothesized that inpatients with hematocrit declines without clinically overt GI bleeding have distinct clinical features and hence aimed to evaluate this clinical syndrome.

Methods

We evaluated consecutive GI consults for patients with a decrease (drop) in hematocrit. Patients with documented prior GI bleeding, melena, hematochezia, hematemesis, and melenemesis were excluded. Hematocrit drops were calculated from preconsult zenith and nadir values and identified as acute (within 7 days), intermediate (7–30 days), or remote (beyond 30 days) on the basis of the shortest time to a hematocrit drop of at least 6%.

Results

We identified 101 patients having hematocrit drops without clinical evidence of GI bleeding. Seventy-six patients (75%) had an acute drop in hematocrit with a mean decline of 9.5%, whereas the 25 patients with an intermediate or remote drop in hematocrit had a mean decline of 12.5%. Endoscopic evaluation was performed in 55 patients. Five patients (5%) had a lesion consistent with GI bleeding; identified lesions included ischemic colitis, duodenal ulcer, esophageal varices, and postsphincterotomy ulcer. In the remaining 96 patients, a clinical explanation for the hematocrit drop was identified in 56 patients (58%), most commonly attributed to sepsis/shock, volume shifts, and postprocedure bleeding.

Conclusions

Hematocrit drops without visible GI bleeding were uncommonly caused by bleeding intestinal lesions, contrary to current dogma. Non-GI explanations for hematocrit drops were often identified, although the cause of hematocrit drop remained unexplained in many patients.
Low Vitamin D Level and Impact on Severity and Recurrence of Clostridium difficile Infections
Authors: Abdelfatah Mohamed , Nayfe Rabih , Moftakhar Bahar , Nijim Ala , El Zoghbi Maysaa , Donskey Curtis J. , Kandil Hossam , Watkins Richard R.
Published: October 2015

Background

Clostridium difficile infection (CDI) has recently markedly increased, incurring greater health care–associated costs and hospitalizations especially in vitamin D deficient patients. Accordingly, the aim of this study was to evaluate the relationship between low vitamin D levels and the severity and recurrence of CDI.

Methods

A retrospective case-control study evaluated patients hospitalized between 2007 and 2013 with CDI and a positive C. difficile toxin assay. Severe complicated CDI was defined based on (1) laboratory or radiological criteria correlated clinically and (2) sepsis requiring intensive care unit admission. Recurrent CDI (RCDI) was defined as a new episode of diarrhea occurring within 90 days of resolution of the initial episode for at least 10 days after discontinuing therapy and confirmed by positive stool C. difficile toxin assay or polymerase chain reaction. Patients were divided into 4 groups based on vitamin D level (ng/mL): severely deficient (<10), insufficient (10-19.9), predeficient (20-29.9), and control group (≥30).

Results

Two hundred seventy-one patients were diagnosed with CDI, of which 48 had RCDI distributed as 5 (12.5%), 15 (16.1%), 10 (15.6%), and 13 (17.5%) patients in each of the aforementioned groups, respectively ( P= 0.55). Severe complicated CDI was identified in 7 (17.5%), 17 (18.2%), 9 (14%), and 3 (4%) patients, respectively ( P = 0.04). Thirty-day mortality was 1 of 40, 1 of 93, 2 of 64, and 2 of 74 patients, respectively ( P = 0.43).

Conclusions

Normal vitamin D level has a protective effect against severe CDI, and low vitamin D is associated with greater severity of CDI but not with an increased risk of RCDI or 30-day mortality.
The Effect of Exercise on Lipid Profiles and Inflammatory Markers in Lean Male Adolescents: A Prospective Interventional Study
Authors: Huang Chun-Jui , Kwok Chin-Fai , Chou Chung-Hsing , Chou Yu-Ching , Ho Low-Tone , Shih Kuang-Chung
Published: October 2015

Background

Physical activity improves body composition and inflammatory markers in obese individuals, but little is known about the nonobese population.

Objective

The aim of this study was to investigate associations between exercise and inflammatory cytokines in lean male adolescents in Taiwan.

Methods

This interventional study enrolled a total of 79 normal body weight male adolescents [mean age, 16.8 (1.0) years] from the Army Academy of Taiwan. Body composition and inflammatory markers were measured at baseline and upon completion of a 12-week exercise intervention program.

Results

Subjects’ postintervention anthropometric measures, including waist circumference [74.6 (5.2) → 72.6 (5.2) cm], hip circumference [92.3 (4.1) → 89.9 (5.0) cm], body fat mass [10.2 (3.2) → 8.2 (3.2) kg], and body fat percentage [15.8% (4.2) → 12.6 (4.5)%] declined significantly compared to preintervention (all P < 0.001), as did systolic blood pressure ( P = 0.002) and mean blood pressure ( P = 0.020). Postintervention body height and free fat mass increased significantly (both P < 0.001). Subjects’ postintervention lipids including total cholesterol, low-density lipoprotein, high-density lipoprotein, and triglycerides increased significantly (all P < 0.001). Inflammatory markers including adiponectin [14.32 (6.68) → 31.31 (30.53) μg/mL, P < 0.001], interleukin 6 [2.15 (4.81) → 2.86 (6.37) pg/mL, P = 0.005], and C-reactive protein [1.00 (2.57) → 2.30 (4.17) μg/mL, P < 0.001] increased significantly postintervention, but not leptin.

Conclusions

Exercise training significantly improves body composition and anti-inflammatory adiponectin levels in lean male adolescents.
Assessment of Evidence for Positive Association and Seroprevalence of Hepatitis B and C in Diabetic Patients in a Developing Country
Authors: Korkmaz Huseyin , Kesli Recep , Onder Pamuk Barıs , Ipekci Suleyman Hilmi , Terzi Yuksel , Kebapcilar Levent
Published: October 2015

Background and Aim

The data related to the association between hepatitis virus infections and diabetes mellitus (DM) are conflicting. The aim of this study was to investigate the seroprevalence of hepatitis B virus (HBV) and hepatitis C virus (HCV) and to determine the risk factors affecting the prevalence in Turkish patients with type 1 DM and type 2 DM.

Methods

The study consisted of 736 diabetic and 505 nondiabetic patients. Serological investigation for the hepatitis B surface antigen (HBsAg) and the HCV antibody (anti-HCV) was performed with a third-generation commercial chemiluminescence assay. The presence of HBsAg was considered as indicator of HBV infection. The HCV infection in the patients with positive anti-HCV was confirmed by a real-time polymerase chain reaction assay. The patients were divided according to their HBV and HCV infection status, and their demographic features, diabetes properties, general risk factors, and aminotransferase levels were analyzed.

Results

There was no significant difference in the seropositivity rate for the HBsAg (3.8% vs 3.0%, P > 0.43; odds ratio, 1.292; 95% confidence interval, 0.683–2.444). However, anti-HCV seropositivity was significantly increased in the DM group (3.3% vs 1.8%, P < 0.03; odds ratio, 2.398; 95% confidence interval, 1.025–5.609). Increased aminotransferase levels and a history of blood transfusions were positively correlated with both HBV and HCV infection. Moreover, a history of surgical procedures and high glycated hemoglobin A1c levels were positively associated with HBsAg antigen seropositivity.

Conclusions

Although no significant difference in the seropositivity of the HBsAg was determined, a high prevalence of HCV infection was detected in the DM patients compared to healthy controls.
Impact of Staphylococcus Epidermidis Lysates on Middle Ear Epithelial Proinflammatory and Mucogenic Response
Authors: Val Stéphanie , Mubeen Humaira , Tomney Amarel , Chen Saisai , Preciado Diego
Published: October 2015

Background

Chronic otitis media with effusion (COME) develops after sustained inflammation and is characterized by secretory middle ear epithelial metaplasia and effusion, most frequently mucoid. Staphylococcus epidermidis, typically considered a commensal organism, is very frequently recovered in chronic middle ear fluid and in middle ear biofilms. Although it has been shown to drive inflammation in sinonasal epithelium, the impact of S. epidermidis on COME is markedly understudied. The goal of this study was to examine the in vitro effects of S. epidermidis lysates on murine and human middle ear epithelial cells.

Methods

Staphylococcus epidermidis lysates were generated and used to stimulate submerged and differentiated human and murine epithelial cells (MEECs) for 24 to 48 hours. Quantitative real time-polymerase chain reaction, Western blot, enzyme-linked immunosorbent assay, and immunocytochemistry techniques were performed to interrogate the mucin gene MUC5AC and MUC5B expression and protein production, chemokine response, as well as NF-κB activation. Luciferase reporter assays were performed to further evaluate nuclear factor κB (NF-κB) activation and query specific promoter responses after S. epidermidis exposure.

Results

Staphylococcus epidermidis induced a time- and dose-dependent MUC5AC and MUC5B overexpression along with a parallel overexpression of Cxcl2 in mouse MEEC and IL-8 in human MEEC. Further investigations in mMEEC showed a 1.3 to 1.5 induction of the MUC5AC and MUC5B promoters. As potential mechanisms for these responses, induction of an oxidative stress marker, along with early nuclear translocation and activation of NF-κB, was found. Finally, chronic exposure induced marked epithelial thickening of cells differentiated at the air liquid interface.

Conclusions

Staphylococcus epidermidis lysates activate a proinflammatory response in MEEC, including mucin gene expression and protein production. Although typically considered a nonpathogenic commensal organism in the ear, these results suggest that they may play a role in the perpetuation of an inflammatory and mucogenic response in COME.