bluuebunny/crossref_metadata_2025 huggingface dataset:
Peginterferon alpha-based therapy for chronic hepatitis B focusing on HBsAg clearance or seroconversion: a meta-analysis of controlled clinical trials
Authors: Li Wen-cong , Wang Mao-rong , Kong Ling-bo , Ren Wei-guang , Zhang Yu-guo , Nan Yue-min
Published: June 2011

Background

Interferon alpha (IFNα) therapy has been widely used in the treatment of chronic hepatitis B (CHB) for decades. Nucleos(t)ide analogues are also increasingly used to treat CHB recently. More and more studies are being carried out concerning the clearance or seroconversion of HBsAg, which is recognized as an ideal goal of CHB therapy. This study conducted a meta-analysis to estimate the effect of pegylated interferon alpha (peginterferon α, PEG-IFNα)-based therapy on HBsAg clearance or seroconversion in CHB.

Methods

All available controlled clinical trials, published from 2004 to 2010, with the following antiviral therapies for CHB patients: PEG-IFNα combined with lamivudine (LAM), PEG-IFNα only, conventional IFNα and LAM, with a course ≥24 weeks, were meta-analysed for HBsAg clearance and seroconversion.

Results

Fourteen trials (involving a total of 2,682 patients) were identified, including seven high-quality and seven low-quality studies. The analysis results of the different antiviral therapies on HBsAg clearance or seroconversion were as follows: 1. No significant difference in HBsAg clearance or seroconversion was observed between the combination therapy group and PEG-IFNα monotherapy group [odds ratio (OR) = 1.16, 95% confidence intervals (CI) (0.73-1.85), P = 0.54 and OR = 1.07, 95% CI (0.58-1.97), P = 0.82, respectively]; 2. HBsAg clearance and seroconversion rates in patients with combination therapy were markedly higher than in those with LAM monotherapy [OR = 9.41, 95% CI (1.18-74.94), P = 0.03, and OR = 12.37, 95% CI (1.60-95.44), P = 0.02, respectively]; 3. There was significant difference in HBsAg clearance between the PEG-IFNα group and IFNα monotherapy group [OR = 4.95, 95% CI (1.23-20.00), P = 0.02], but not in seroconversion [OR = 2.44, 95% CI (0.35-17.08), P = 0.37]; 4. PEG-IFNα was superior to LAM in HBsAg seroconversion [OR = 14.59, 95% CI (1.91-111.49), P = 0.01].

Conclusions

PEG-IFNα facilitated HBsAg clearance or seroconversion in CHB patients. PEG-IFNα-based therapy was more effective than LAM monotherapy in achieving HBsAg clearance or seroconversion for both HBeAg-positive and HBeAg-negative CHB patients. There was no significant difference in HBsAg clearance or seroconversion between PEG-IFNα/LAM combination therapy and PEG-IFNα monotherapy. PEG-IFNα was obviously superior to conventional IFNα in HBsAg clearance, but not in HBsAg seroconversion. Although PEG-IFNα produced significantly higher rates of HBsAg clearance and seroconversion, the absolute change in the proportion of HBsAg clearance and seroconversion was low (about 3-6%). Therefore, additional interventions are needed to improve the rate of positive outcomes.
Sector analysis and predictive modelling reveal iterative shoot-like development in fern fronds
Authors: Sanders Heather L. , Darrah Peter R. , Langdale Jane A.
Published: June 2011

Plants colonized the terrestrial environment over 450 million years ago. Since then, shoot architecture has evolved in response to changing environmental conditions. Our current understanding of the innovations that altered shoot morphology is underpinned by developmental studies in a number of plant groups. However, the least is known about mechanisms that operate in ferns – a key group for understanding the evolution of plant development. Using a novel combination of sector analysis, conditional probability modelling methods and histology, we show that shoots, fronds (‘leaves’) and pinnae (‘leaflets’) of the fern Nephrolepis exaltata all develop from single apical initial cells. Shoot initials cleave on three faces to produce a pool of cells from which individual frond apical initials are sequentially specified. Frond initials then cleave in two planes to produce a series of lateral merophyte initials that each contributes a unit of three pinnae to half of the mediolateral frond axis. Notably, this iterative pattern in both shoots and fronds is similar to the developmental process that operates in shoots of other plant groups. Pinnae initials first cleave in two planes to generate lateral marginal initials. The apical and marginal initials then divide in three planes to coordinately generate the determinate pinna. These findings impact both on our understanding of fundamental plant developmental processes and on our perspective of how shoot systems evolved.
How has healthcare research performance been assessed? A systematic review
Authors: Patel Vanash M , Ashrafian Hutan , Ahmed Kamran , Arora Sonal , Jiwan Sejal , Nicholson Jeremy K , Darzi Ara , Athanasiou Thanos
Published: June 2011

Objectives

Healthcare research performance is increasingly assessed through research indicators. We performed a systematic review to identify the indicators that have been used to measure healthcare research performance. We evaluated their feasibility, validity, reliability and acceptability; and finally assessed the utility of these indicators in terms of measuring performance in individuals, specialties, institutions and countries.

Design

A systematic review was performed by searching EMBASE, PsycINFO, Ovid MEDLINE and Cochrane Library databases between 1950 and September 2010.

Setting

Studies of healthcare research were appraised. Healthcare was defined as the prevention, treatment and management of illness and the preservation of mental and physical wellbeing through the services offered by the medical and allied health professions.

Participants

All original studies that evaluated research performance indicators in healthcare were included.

Main outcome measures

Healthcare research indicators, data sources, study characteristics, results and limitations for each study were studied.

Results

The most common research performance indicators identified in 50 studies were: number of publications ( n = 38), number of citations ( n = 27), Impact Factor ( n = 15), research funding ( n = 10), degree of co-authorship ( n = 9), and h index ( n = 5). There was limited investigation of feasibility, validity, reliability and acceptability, although the utility of these indicators was adequately described.

Conclusion

Currently, there is only limited evidence to assess the value of healthcare research performance indicators. Further studies are required to define the application of these indicators through a balanced approach for quality and innovation. The ultimate aim of utilizing healthcare research indicators is to create a culture of measuring research performance to support the translation of research into greater societal and economic impact.
Inventory Management of Platelets in Hospitals: Optimal Inventory Policy for Perishable Products with Regular and Optional Expedited Replenishments
Authors: Zhou Deming , Leung Lawrence C. , Pierskalla William P.
Published: June 2011

Platelets are short-life blood components used in hospital blood transfusion centers. Excluding time for transportation, testing, and arrangement, clinically transfusable platelets have a mere three-day life span. This paper analyzes a periodic review inventory system for such a perishable product under two replenishment modes. Regular orders are placed at the beginning of a cycle. Within the cycle, the manager has an option of placing an additional order, referred to as an expedited order, characterized by an order-up-to level policy. For this platelet inventory problem, we prove the existence and uniqueness of an optimal policy that minimizes the expected cost. We then derive the necessary and sufficient conditions for the policy, based on which an algorithm is developed. Using real-life data, we provide a numerical illustration and a sensitivity analysis followed by extensive simulation experiments to examine the dynamics of platelet inventory management. It is shown that the optimal cost is significantly affected by demand uncertainty, lead times, seasonality, and vintage of expedited orders. Given a hospital's demand profile and the cost parameters, we are able to determine whether the hospital should order daily or every other day (i.e., adopting a combined use of regular and optional expedited orders). We also show that the analytical solution is a good approximation of the optimal policy obtained from simulation experiments, where more realistic features are incorporated. This inventory research problem can be classified as a fixed-lifetime perishable problem with dual modes of replenishments.
Crystal structure, chemical bonding and magnetic properties of the new antimonides Ce2Ir3Sb4, La2Ir3Sb4, and Ce2Rh3Sb4
Authors: Cardoso-Gil Raul , Caroca-Canales Nubia , Budnyk Serhij , Schnelle Walter
Published: June 2011

The antimonides Ce2Ir3Sb4, La2Ir3Sb4, and Ce2Rh3Sb4 were synthesized by solid state reaction from the elements. The crystal structures of these compounds were determined from single crystal X-ray diffraction data. Ce2Ir3Sb4 crystallises in a new structure type in the space group Pnma (no. 62) with a = 16.1510(8) Å, b = 4.5600(3) Å, c = 10.9463(5) Å. La2Ir3Sb4 and Ce2Rh3Sb4 crystallise in the Ce2Ir3Sb4 structure type as well with a = 16.2659(10) Å, b = 4.5896(3) Å, c = 10.9996(7) Å) and a = 16.2293(8) Å, b = 4.5604(2) Å, c = 10.9804(5) Å, respectively. The four- and five-bonded transition metal atoms and three- and four-bounded Sb atoms form a 3D-network with the rare-earth metal embedded in its cavities, resembling the topology of Ca in the CaBe2Ge2 or Th in ThCr2Si2 type. Magnetic susceptibility and X-ray absorption near edge spectroscopy data indicate a stable trivalent state for Ce in the Ce2Ir3Sb4 compound.
BRAFV600E mutation and expression of proangiogenic molecular markers in papillary thyroid carcinomas
Authors: Durante Cosimo , Tallini Giovanni , Puxeddu Efisio , Sponziello Marialuisa , Moretti Sonia , Ligorio Claudia , Cavaliere Antonio , Rhoden Kerry J , Verrienti Antonella , Maranghi Marianna , Giacomelli Laura , Russo Diego , Filetti Sebastiano
Published: June 2011

Objective

Tyrosine kinase inhibitors (TKIs) are evaluated for treatment of radioiodine refractory thyroid cancer. Their effects in this setting are based on blockade of proangiogenic signaling mediated by receptors for vascular endothelial growth factors (VEGFs) and platelet-derived growth factors (PDGF). Most TKIs also block other cancer-relevant kinases, such as B-type Raf kinase (BRAF), which are constitutively activated in approximately half of papillary thyroid carcinomas (PTCs), but the impact of these effects is not clear.

Design

The aim of our study was to investigate the impact of BRAFV600E on proangiogenic gene expression and microvascular features of PTCs.

Methods

mRNA levels for VEGFA, VEGF receptors, and coreceptors (VEGFRs 1, 2, and 3, neuropilin-1), and PDGF receptor β (PDGFRβ or PDGFRB) were measured with real-time PCR in BRAFV600E (n=55) and wild-type BRAF (BRAF-wt; n=35) PTCs. VEGF and VEGFR protein expression and microvessel densities (MVD) and lymphatic vessel densities (LVDs) were assessed by immunohistochemistry in 22 of the 90 PTCs (including 11 BRAFV600E cases). Angiogenic gene expression was also studied in vitro after induction/silencing of the BRAFV600E mutation in thyrocyte lines.

Results

Transcript levels of proangiogenic factors were significantly lower in BRAFV600E PTCs versus BRAF-wt PTCs (P<0.0001), but MVD and LVDs were not significantly different. VEGFA mRNA levels in thyroid cell lines decreased when BRAFV600E mutation was induced (P=0.01) and increased when it was silenced (P=0.01).

Conclusions

Compared with BRAF-wt PTCs, those harboring BRAFV600E exhibit downregulated VEGFA, VEGFR, and PDGFRβ expression, suggesting that the presence of BRAF mutation does not imply a stronger prediction of response to drugs targeting VEGF and PDGFB signaling pathways.
eNOS activation and NO function: Differential control of steroidogenesis by nitric oxide and its adaptation with hypoxia
Authors: Ducsay Charles A , Myers Dean A
Published: June 2011

Nitric oxide (NO) plays a role in a wide range of physiological processes. Aside from its widely studied function in the regulation of vascular function, NO has been shown to impact steroidogenesis in a number of different tissues. The goal of this review is to explore the effects of NO on steroid production and further, to discern its source(s) and mechanism of action. Attention will be given to the regulation of NO synthases in specific endocrine tissues including ovaries, testes, and adrenal glands. The effects of hypoxia on generation of NO and subsequent effects on steroid biosynthesis will also be examined. Finally, a potential model for the interaction of hypoxia on NO synthesis and steroid production is proposed.
The influence of the runner ordering of the plants on their quality, rooting and yield of strawberries
Authors: Najdenovska Olga , Selimovska Ana
Published: June 2011

In this work, we presented the influence of the runner ordering of the plants
on their quality, percentage of root hair formation, and yield of two
varieties of strawberries: Senga Sengana and Pocahontas depending on the time
of planting. The runner ordering of plants and time of their planting have
influence on the quality of plants, the percentage of root hair formation
after the planting, and the yield. There has been established strong
correlation among the diameter of the crown and the rooting when planted and
the yield. Primary plants have higher quality, with bigger diameter of the
crown, they take root better, and they have higher yield than secondary
plants. Rosettes planted in August have higher yield than the ones planted
later.
Study of aquatic macrophytes in the wetlands on the territory of Vrachanski Balkan nature park
Authors: Valcev Vladimir , Stojeva Danijela
Published: June 2011

An overall study of the species composition and abundance of macrophytes in
all open water bodies of a large protected territory was made for the first
time in Bulgaria. Four high-mountain eutrophic lakes and the upper stretches
of three rivers within the boundaries of Vrachanski Balkan Nature Park were
investigated. Thirty-nine macrophyte species (higher plants and mosses) were
identified scattered around, or forming more or less distinct vegetation
groups. Three of the lakes are new for the country locations of the species
Elatine alsinastrum and Peplis portula. The processes of eutrophication are
more advanced in the lakes. The habitats formed around the investigated water
bodies have been determined. They are three habitats of European Community
interest for Bulgaria. The major threats for the investigated wetlands on the
territory of the Park are pointed out.
Some laboratory blood indicators in tractor drivers exposed to pesticides
Authors: Prokes Bela
Published: June 2011

Pesticides represent group of extremely different compounds or mixed
compounds. They are produced in the form of powder for direct application,
powder for suspension, concentrated suspension, concentration of emulsion,
and in other forms as well. Influence of pesticides to exposed workers mainly
depends on technology of pesticide application use. All poisons, just like
pesticides that come in organism in some way and reach the location of their
metabolism, accumulation in the body or extraction must get there through
blood. Pesticides influence stem cells in bone marrow, then maturation
process of blood elements and can damage mature blood cells in blood
circulation. The sample encompassed 142 tractor drivers employed in state
agricultural unions who were exposed to pesticides during their work.
Concerning annual and daily exposure to pesticides in examined persons is
determined that daily extent ranged from 3 to 12 hours and annual from 5 to
125 days, 60.93 in average. In the paper are analyzed following blood count
parameters: erythrocytes, hemoglobin, leucocytes and thrombocytes The aim of
the paper is to investigate whether pesticides influence changed blood count
of tractor drivers exposed to pesticides during their work. Analysis of
obtained results indicates that exposure to pesticides, like in examined
group of workers, has not influenced damage in any of investigated blood
count parameter.
The arithmetic of distributions in free probability theory
Authors: Chistyakov Gennadii , Götze Friedrich
Published: June 2011

We give an analytical approach to the definition of additive and multiplicative free convolutions which is based on the theory of Nevanlinna and Schur functions. We consider the set of probability distributions as a semigroup M equipped with the operation of free convolution and prove a Khintchine type theorem for the factorization of elements of this semigroup. An element of M contains either indecomposable (“prime”) factors or it belongs to a class, say I
0, of distributions without indecomposable factors. In contrast to the classical convolution semigroup, in the free additive and multiplicative convolution semigroups the class I
0 consists of units (i.e. Dirac measures) only. Furthermore we show that the set of indecomposable elements is dense in M.
Adaptive nonlinear control of a continuous stirred tank reactor
Authors: Dostál Petr , Bakošová Monika , Vojtěšek Jiří , Bobál Vladimír
Published: June 2011

The paper deals with continuous-time nonlinear adaptive control of a continuous stirred tank reactor (CSTR). Control strategy is based on the application of a controller consisting of a linear and a nonlinear part. The static nonlinear part is derived as an inversion and exponential approximation of measured or simulated input-output data. Design of the dynamic linear part is based on an approximation of nonlinear elements in the control loop by a continuous-time external linear model with directly estimated parameters. In the control design procedure, polynomial approach with the pole assignment method was used. The nonlinear adaptive control was tested by simulations on a nonlinear model of a CSTR with a consecutive exothermic reaction.
Design of Robust PI Controllers and their Application to a Nonlinear Electronic System
Authors: Matušů Radek , Vaneková Katarína , Prokop Roman , Bakošová Monika
Published: June 2011

Design of Robust PI Controllers and their Application to a Nonlinear Electronic System

The principal aim of the paper is to present a possible approach to the design of simple Proportional-Integral (PI) robust controllers and subsequently to demonstrate their applicability during control of a laboratory model with uncertain parameters through the Programmable Logic Controller (PLC) SIMATIC S7-300 by Siemens Company. The proposed and utilized synthesis consists of two steps. The former one is determination of controller parameters area, which ensures the robustly stable control loop and is based on computing/plotting the stability boundary locus while the latter one lies in the final choice of the controller itself relying on algebraic techniques. The basic theoretical parts are followed by laboratory experiments in which the 3rd order nonlinear electronic model has been successfully controlled in various working points.
Hybrid Feature Selection for Myoelectric Signal Classification Using MICA
Authors: Naik Ganesh , Kumar Dinesh
Published: June 2011

Hybrid Feature Selection for Myoelectric Signal Classification Using MICA

This paper presents a novel method to enhance the performance of Independent Component Analysis (ICA) of myoelectric signal by decomposing the signal into components originating from different muscles. First, we use Multi run ICA (MICA) algorithm to separate the muscle activities. Pattern classification of the separated signal is performed in the second step with a back propagation neural network. The focus of this work is to establish a simple, yet robust system that can be used to identify subtle complex hand actions and gestures for control of prosthesis and other computer assisted devices. Testing was conducted using several single shot experiments conducted with five subjects. The results indicate that the system is able to classify four different wrist actions with near 100% accuracy.
Combined Operation of AC and DC Distribution System with Distributed Generation Units
Authors: Noroozian Reza , Abedi Mehrdad , Gharehpetian Gevorg
Published: June 2011

Combined Operation of AC and DC Distribution System with Distributed Generation Units

This paper presents a DC distribution system which has been supplied by external AC systems as well as local DG units in order to demonstrate an overall solution to power quality issue. In this paper, the proposed operation method is demonstrated by simulation of power transfer between external AC systems, DG units, AC and DC loads. The power flow control in DC distribution system has been achieved by network converters and DG converters. Also, the mathematical model of the network, DG and load converters are obtained by using the average technique, which allows converter systems accurately simulated and control strategies for this converters is achieved. A suitable control strategy for network converters has been proposed that involves DC voltage droop regulator and novel instantaneous power regulation scheme. Also, a novel control technique has been proposed for DG converters. In this paper, a novel control system based on stationary and synchronously rotating reference frame has been proposed for load converters for supplying AC loads connected to the DC bus by balanced voltages. The several case studies have been studied based on proposed methods. The simulation results show that DC distribution systems including DG units can improve the power quality at the point of common coupling (PCC) in the power distribution system or industrial power system.
Small-Signal Analysis of Autonomous Hybrid Distributed Generation Systems in Presence of Ultracapacitor and Tie-Line Operation
Authors: Ray Prakash , Mohanty Soumya , Kishor Nand
Published: June 2011

Small-Signal Analysis of Autonomous Hybrid Distributed Generation Systems in Presence of Ultracapacitor and Tie-Line Operation

This paper presents small-signal analysis of isolated as well as interconnected autonomous hybrid distributed generation system for sudden variation in load demand, wind speed and solar radiation. The hybrid systems comprise of different renewable energy resources such as wind, photovoltaic (PV) fuel cell (FC) and diesel engine generator (DEG) along with the energy storage devices such as flywheel energy storage system (FESS) and battery energy storage system (BESS). Further ultracapacitors (UC) as an alternative energy storage element and interconnection of hybrid systems through tie-line is incorporated into the system for improved performance. A comparative assessment of deviation of frequency profile for different hybrid systems in the presence of different storage system combinations is carried out graphically as well as in terms of the performance index (PI),ieintegral square error (ISE). Both qualitative and quantitative analysis reflects the improvements of the deviation in frequency profiles in the presence of the ultracapacitors (UC) as compared to other energy storage elements.
Influence of Nano Aluminium Powder Produced by Wire Explosion Process at Different Ambience on Hydrogen Generation
Authors: Sarathi Ramanujam , Sankar Binu , Chakravarthy Satyanarayanan
Published: June 2011

Influence of Nano Aluminium Powder Produced by Wire Explosion Process at Different Ambience on Hydrogen Generation

Nano-aluminium particles are produced through the wire explosion process in different gas medium. The particles produced by wire explosion process, in helium medium are of smaller size compared to argon/nitrogen medium. The nano aluminium powder on reaction with water forms oxides having bayerite and boehmite structure. It is observed that nano aluminium on reaction with KOH solution at room temperature it forms bayerite. The results of the study were confirmed through Wide Angle X-ray diffraction (WAXD) and by Transmission Electron Microscope (TEM) studies. The reaction of nano aluminium powder with KOH solution/water indicates that the rate of hydrogen generation is high when nano aluminium powder reacts with KOH solution than with water. The rate of hydrogen generation gets reduced drastically when the nano aluminium powder which is exposed to air medium for some period is used for reaction with KOH/water. It is also observed that the rate of hydrogen generation is high with nano size aluminium particles compared with ultrafine particles.
New Digital Architecture of CNN for Pattern Recognition
Authors: Raschman Emil , Záluský Roman , Ďuračková Daniela
Published: June 2011

New Digital Architecture of CNN for Pattern Recognition

The paper deals with the design of a new digital CNN (Cellular Neural Network) architecture for pattern recognition. The main parameters of the new design were the area consumption of the chip and the speed of calculation in one iteration. The CNN was designed as a digital synchronous circuit. The largest area of the chip belongs to the multiplication unit. In the new architecture we replaced the parallel multiplication unit by a simple AND gate performing serial multiplication. The natural property of this method of multiplication is rounding. We verified some basic properties of the proposed CNN such as edge detection, filling of the edges and noise removing. At the end we compared the designed network with other two CNNs. The new architecture allows to save till 86% gates in comparison with CNN with parallel multipliers.
Influence of ECAP on Densification Behaviour in the PM Aluminium Al-Mg-Si-Cu-Fe Alloy
Authors: Bidulská Jana , Kvačkaj Tibor , Kočiško Róbert , Bidulský Róbert , Grande Marco
Published: June 2011

Influence of ECAP on Densification Behaviour in the PM Aluminium Al-Mg-Si-Cu-Fe Alloy

The main aim of this paper is to show how ECAP influences the densification behaviour of PM aluminium alloys. An aluminium based powder (Al-Mg-Si-Cu-Fe) was used as material to be investigated. After applying different compacting pressures, specimens were dewaxed in a ventilated furnace at 400 °C for 60 min. Sintering was carried out in a vacuum furnace at 610 °C for 30 min. The specimens were ECAPed for 1 pass. Optical characterization was carried out on the minimum of 10 different image fields. The results were measured for each pore individually in order to describe the dimensional and morphological porosity characteristics. ECAP influences the porosity distribution in terms of the severe shear deformation involved.
Safety Evaluation of Fail-Safe Fieldbus in Safety Related Control System
Authors: Franeková Mária , Rástočný Karol
Published: June 2011

Safety Evaluation of Fail-Safe Fieldbus in Safety Related Control System

The paper deals with the problem of modelling safety features of the safety Fieldbus transmission system used within safety related control systems. The basic principles of the modelling failures effect upon the safety of closed transmission system and standards used in the process of safety evaluation are summarized in the paper. The practical part is oriented to a description of a realized Markov model for determination of the random failures effect on the safety of a closed transmission system. The model reflects the safety analysis of failures effect caused by electromagnetic interference in the communication channel and random HW failures of the transmission system. In the paper the results of simulation of parameters of the transmission system are discussed, such as the probability of an undetected corrupted message.
Ohmic contacts to p-GaN Using Au/Ni-Mg-O Metallization
Authors: Liday Jozef , Vogrinčič Peter , Hotový Ivan , Bonanni Alberta , Sitter Helmut , Lalinský Tibor , Vanko Gabriel , Řeháček Vlastimil , Breza Juraj , Ecke Gernot
Published: June 2011

Ohmic contacts to p-GaN Using Au/Ni-Mg-O Metallization

Electrical characteristics and elemental depth profiles of ohmic contacts to p-GaN using Au/Ni-Mg-Ox metallization have been investigated. The objective was to examine the possibilities of increasing the charge carrier concentration in the surface region of GaN by adding Mg, thus of a p-type dopant into the Au/NiOx metallization structure. For this purpose, a Ni-Mg-Ox layer with a low concentration of Mg was deposited on p-GaN by dc reactive magnetron sputtering. The top Au layer was deposited in a similar way. The fabricated contact structures were annealed in N2. When the Ni-Mg layer in the Au/Ni-Mg-Ox/p-GaN structure was deposited in an atmosphere with a low concentration of oxygen (0.2 at%), the structure exhibited a low resistance ohmic nature. The contact resistance was lower than in the case of a Au/Ni-Ox/p-GaN structure without the Mg dopant in the metallic layer. An increase in the concentration of oxygen in the working atmosphere resulted in higher values of the contact resistance of the Au/Ni-Mg-Ox/p-GaN structure. In our opinion the ohmic nature of the contact structure is related to the existence of a metal/p-NiO/p-GaN scheme. The measured values of the contact resistance in the Au/Ni-Mg-Ox/p-GaN structure in comparison with the Au/Ni-Ox/p-GaN structure are caused by an increased charge carrier concentration in the surface region of p-GaN, which is a consequence of Mg diffusion from the Ni-Mg-Ox layer.
Structural Evolution of Sputtered Indium Oxide Thin Films
Authors: Hotový Ivan , Kups Thomas , Hotový Juraj , Liday Jozef , Búc Dalibor , Čaplovičová Mária , Řeháček Vlastimil , Sitter Helmut , Simbrunner Clemens , Bonnani Alberta , Spiess Lothar
Published: June 2011

Structural Evolution of Sputtered Indium Oxide Thin Films

The indium oxide thin films were deposited at room temperature by reactive magnetron sputtering in the mixture of oxygen and argon on silicon and oxidized silicon substrates. The influence of the oxygen flow in the reactive mixture and post-deposition annealing on the structural properties were investigated. The as deposited In2O3 films showed a dominating randomly oriented nanocrystalline structure of cubic In2O3. The grain size decreased with increasing oxygen concentration in the plasma. Annealing in reducing atmospheres (vacuum, nitrogen and argon), besides improving the crystallinity, led to a partial cubic to rhombohedral phase transition in the indium oxide films.
Low Complex Forward Adaptive Loss Compression Algorithm and Its Application in Speech Coding
Authors: Nikolić Jelena , Perić Zoran , Antić Dragan , Jovanović Aleksandra , Denić Dragan
Published: June 2011

Low Complex Forward Adaptive Loss Compression Algorithm and Its Application in Speech Coding

This paper proposes a low complex forward adaptive loss compression algorithm that works on the frame by frame basis. Particularly, the algorithm we propose performs frame by frame analysis of the input speech signal, estimates and quantizes the gain within the frames in order to enable the quantization by the forward adaptive piecewise linear optimal compandor. In comparison to the solution designed according to the G.711 standard, our algorithm provides not only higher level of the average signal to quantization noise ratio, but also performs a reduction of the PCM bit rate for about 1 bits/sample. Moreover, the algorithm we propose completely satisfies the G.712 standard, since it provides overreaching the curve defined by the G.712 standard in the whole of variance range. Accordingly, we can reasonably believe that our algorithm will find its practical implementation in the high quality coding of signals, represented with less than 8 bits/sample, which as well as speech signals follow Laplacian distribution and have the time varying variances.
Understanding Electrical Treeing Phenomena in XLPE Cable Insulation Adopting UHF Technique
Authors: Sarathi Ramanujam , Nandini Arya , Danikas Michael
Published: June 2011

Understanding Electrical Treeing Phenomena in XLPE Cable Insulation Adopting UHF Technique

A major cause for failure of underground cables is due to formation of electrical trees in the cable insulation. A variety of tree structure can form from a defect site in cable insulationvizbush-type trees, tree-like trees, fibrillar type trees, intrinsic type, depending on the applied voltage. Weibull studies indicate that a higher applied voltage enhances the rate of tree propagation thereby reducing the life of cable insulation. Measurements of injected current during tree propagation indicates that the rise time and fall time of the signal is of few nano seconds. In the present study, an attempt has been made to identify the partial discharges caused due to inception and propagation of electrical trees adopting UHF technique. It is realized that UHF signal generated during tree growth have signal bandwidth in the range of 0.5-2.0 GHz. The formation of streamer type discharge and Townsend type discharges during tree inception and propagation alters the shape of the tree formed. The UHF signal generated due to partial discharges formed during tree growth were analyzed adopting Ternary plot, which can allow one to classify the shape of tree structure formed.
Lessons learned and experience gained from the application of the FEM to solve transient flow filtration tasks
Authors: Grambličková D. , Bednárová E. , Minárik M.
Published: June 2011

Lessons learned and experience gained from the application of the FEM to solve transient flow filtration tasks

The frequent occurrence of floods in recent times has motivated discussions of experts who concentrate on reviewing the safety of flood dikes. Due to their line character and the often unknown composition of their bodies and subsoil, this task is very complicated. The proposed paper deals with some risks involving the safety of flood dikes and possibilities for their treatment in Slovakia. Attention is also paid to the lessons learned and experience gained from the application of the finite element method by solving the above-mentioned problems.
On the use of the Muskingum method for the simulation of flood wave movements
Authors: Baláž M. , Danáčová M. , Szolgay J.
Published: June 2011

On the use of the Muskingum method for the simulation of flood wave movements

The Muskingum method is a hydrological flow routing model with lumped parameters, which describes the transformation of discharge waves in a river bed using two equations. The first one is the continuity equation (conservation of mass) and the second equation is the relationship between the storage, inflow, and outflow of the reach (the discharge storage equation). These equations are applied within a river reach between two cross sections of a river. The parameters of the model can be estimated by several methods. Here the classical graphic method is compared with two new methods where a genetic algorithm and harmony search was used for optimization. The discrete state space formulation of the Muskingum method was applied on the lower Morava reach between Moravský Svätý Ján and Záhorská Ves. The results showed a good degree of accuracy of all three methods, which were assessed by the Nash-Sutcliffe efficiency coefficient.
Association between Lipid Profile and Preeclampsia
Authors: Begum Zinat , Ara Iffat , Shah Abu Bakkar Siddique
Published: June 2011

Ibrahim Card Med J 2011; 1(1):41-44
Plitidepsin Has a Safe Cardiac Profile: A Comprehensive Analysis
Authors: Soto-Matos Arturo , Szyldergemajn Sergio , Extremera Sonia , Miguel-Lillo Bernardo , Alfaro Vicente , Coronado Cinthya , Lardelli Pilar , Roy Elena , Corrado Claudia Silvia , Kahatt Carmen
Published: June 2011

Plitidepsin is a cyclic depsipeptide of marine origin in clinical development in cancer patients. Previously, some depsipeptides have been linked to increased cardiac toxicity. Clinical databases were searched for cardiac adverse events (CAEs) that occurred in clinical trials with the single-agent plitidepsin. Demographic, clinical and pharmacological variables were explored by univariate and multivariate logistic regression analysis. Forty-six of 578 treated patients (8.0%) had at least one CAE (11 patients (1.9%) with plitidepsin-related CAEs), none with fatal outcome as a direct consequence. The more frequent CAEs were rhythm abnormalities (n = 31; 5.4%), mostly atrial fibrillation/flutter (n = 15; 2.6%). Of note, life-threatening ventricular arrhythmias did not occur. Myocardial injury events (n = 17; 3.0%) included possible ischemic-related and non-ischemic events. Other events (miscellaneous, n = 6; 1.0%) were not related to plitidepsin. Significant associations were found with prostate or pancreas cancer primary diagnosis (p = 0.0017), known baseline cardiac risk factors (p = 0.0072), myalgia present at baseline (p = 0.0140), hemoglobin levels lower than 10 g/dL (p = 0.0208) and grade ≥2 hypokalemia (p = 0.0095). Treatment-related variables (plitidepsin dose, number of cycles, schedule and/or total cumulative dose) were not associated. Electrocardiograms performed before and after plitidepsin administration (n = 136) detected no relevant effect on QTc interval. None of the pharmacokinetic parameters analyzed had a significant impact on the probability of developing a CAE. In conclusion, the most frequent CAE type was atrial fibrillation/atrial flutter, although its frequency was not different to that reported in the age-matched healthy population, while other CAEs types were rare. No dose-cumulative pattern was observed, and no treatment-related variables were associated with CAEs. Relevant risk factors identified were related to the patient’s condition and/or to disease-related characteristics rather than to drug exposure. Therefore, the current analysis supports a safe cardiac risk profile for single-agent plitidepsin in cancer patients.
Lichtheimia blakesleeana as a New Potencial Producer of Phytase and Xylanase
Authors: Neves Maria Luiza Carvalho , Silva Milena Fernandes da , Souza-Motta Cristina Maria , Spier Michele Rigon , Soccol Carlos Ricardo , Porto Tatiana Souza , Moreira Keila Aparecida , Porto Ana Lúcia Figueiredo
Published: June 2011

Brazil is known for its great potential for production of renewable resources such as agro-industrial residues. These residues can be used as alternative sources of new products. Meanwhile, solid-state fermentation, with its advantages of energy conservation and pollution reduction, has been identified as a process of great potential for the production of bioactive compounds, especially enzymes. In the present work, a 23 factorial design was used to evaluate the effects of pH, temperature and moisture on the production of phytase and xylanase by Lichtheimia blakesleeana URM 5604 through the fermentation of citrus pulp. Statistical analyses of the results showed that the only the pH influenced the production of these enzymes, with the best phytase production (264.68 U/g) ocurring at pH 6.0, 34 °C, initial moisture 50%, after 48 hours of culture. The best conditions for xylanase production (397.82 U/g) were fermentation for 120 hours at pH 4.0, 26 °C and initial moisture of 70%. The best parameters for the simultaneous production of phytase (226.92 U/g) and xylanase (215.59 U/g) were determined to be initial moisture of 50%, pH 6.0, 26 °C, and 48 hours of fermentation.
Effects of Fractionation and Combinatorial Evaluation of Tamarindus indica Fractions for Antibacterial Activity
Authors: Nwodo Uchechukwu U. , Iroegbu Christian U. , Ngene Augustine A. , Chigor Vincent N. , Okoh Anthony I.
Published: June 2011

Six fractions, named TiA – TiF, were obtained by fractionating the crude ethanol extract of the stem bark of Tamarindus indica using column chromatographic techniques. On TLC, fraction TiB showed five bands, TiC three bands, while TiD and TiE showed two bands each. TiC, TiD and TiE were re-eluted with different solvent systems to yield two fractions each, while TiB yielded four. These subfractions were designated B1-B4; C1-C2; D1-D2 and E1-E2, respectively. Tannins, flavonoids and alkaloids, among other components, were detected, albeit in different proportions with respect to fractions and subfractions and were compartmentalized with respect to the solvent systems used. The in vitro antibacterial activity of fractions and subfractions was tested separately and in combinations using the agar well diffusion technique. The susceptibly of test strains (expressed as %) were: 83.3% (TiA and TiB), 75.0% (crude extract and TiC), 66.7% (TiD), 50.0% (TiE) and 16.7% (TiF) when used singly, whereas in combination, the corresponding susceptibilities were 100% (CE), 83.3% (DE), 66.7% (AB, AF, BC, BD, DE and EF), 50% (AC and CD), 33.3% (BE and BF) and 16.7% (AD) against Gram negative bacteria strains and 100% (EF), 80% (DE), 60% (AB, BC and CE), 40% (AC, BD, BF, CF and DF) and 20% (AE, AF, BE and CD) against Gram positive strains. Percentage susceptibility with combinatorial use of re-fractions ranged from 85.7–57.1% and 60–40% against Gram negative and positive strains (TiB subfractions), respectively, 100–85.7% and 40–0% against Gram negative and positive strains (TiC, TiD and TiE sub-fractions).
Solvent- and ligand-induced switch of selectivity in gold(I)-catalyzed tandem reactions of 3-propargylindoles
Authors: Álvarez Estela , Miguel Delia , García-García Patricia , Fernández-Rodríguez Manuel A , Rodríguez Félix , Sanz Roberto
Published: June 2011

The selectivity of our previously described gold-catalyzed tandem reaction, 1,2-indole migration followed by aura-iso-Nazarov cyclization, of 3-propargylindoles bearing (hetero)aromatic substituents at both the propargylic and terminal positions, was reversed by the proper choice of the catalyst and the reaction conditions. Thus, 3-(inden-2-yl)indoles, derived from an aura-Nazarov cyclization (instead of an aura-iso-Nazarov cyclization), were obtained in moderate to good yields from a variety of 3-propargylindoles.
CONCEPTUALIZATION OF CRISIS SITUATION IN A COMPANY / ĮMONĖS KRIZINĖS SITUACIJOS KONCEPTUALIZACIJA
Authors: Valackienė Asta , Virbickaitė Rūta
Published: June 2011

The paper highlights theoretical construct of crisis situation in a company emphasizing the methodological positions of a social phenomenon. Applying systemic analysis of crisis situation in a company the paper discusses hardly spread social phenomenon, i.e. occurrence and expression of crisis situation in a company. On the basis of retrospective analysis of crisis situation, both crisis environment and bankruptcy features are presented and principal keywords defined with reference to crisis in a company as a social phenomenon and related to its environment: human, company-based, national and global. It shows the complexity of the scientific research object, that brings meaningful input into the analysis of crisis features in company life cycle. The paper aims at discussing and presenting critical reviews of crisis situation interpretations with emphasis on methodological positions of social phenomenon in different disciplines. The differences and links between crisis and crisis situation are also explained. Through explanation of logical construct of the paper, the authors specify crisis concept in a company: distinguishing negative changes in a company, that make the company staff apply crisis communication process and instrumentalities. In the above mentioned context the problem of crisis situation in a company remains significant from psychological, social and economic and managerial perspectives.

Santrauka

Straipsnis skirtas krizinės situacijos įmonėje teorinio konstrukto analizei, išryškinant šio socialinio reiškinio metodologines pozicijas. Taikant sisteminę krizinės situacijos įmonėje analizę, straipsnyje aptariamas nepakankamai plačiai ištirtas socialinis reiškinys – krizinės situacijos raiškaįmonėje. Retrospektyviai analizuojant krizinę situaciją, atskleidžiami krizės aplinkos ir bankroto bruožai (iliustruojama tiriant kelias įmones) bei patvirtinami pagrindiniai moksliniai teiginiai. Jais remiantis, krizė įmonėje apibrėžiama kaip socialinis reiškinys, kurio raišką galima tyrinėti įvairiose aplinkose ir jos lygiuose: psichologinėje aplinkoje kaip individo, įmonės aplinkoje, valstybės ir globalios aplinkos atžvilgiu.
Trajectoires de l'anthropologie du développement à la suédoise
Authors: Hagberg Sten
Published: June 2011

Résumé Même si, contrairement à la France et à d’autres pays européens, la Suède n’a pas été une puissance colonisatrice, elle a été impliquée dans nombre de projets de développement. L’article retrace l’histoire des rapports entre anthropologie théorique et anthropologie appliquée, d’autant plus complexe que de nombreux chercheurs ont travaillé dans le cadre d’agences de développement et même dans des unités créées au sein de départements universitaires. Partant de l’analyse d’une enquête au Mali, l’article montre que peuvent se créer des passerelles entre une anthropologie réflexive et une anthropologie appliquée.
Regards critiques sur le dispositif de lutte contre le blanchiment de capitaux : les obligations de vigilance et de déclaration des professionnels de l'expertise comptable et du commissariat aux comptes
Authors: André Caroline
Published: June 2011

Le dispositif français de lutte contre le blanchiment de capitaux et le financement du terrorisme (BCFT) ne cesse d’être réformé afin d’atteindre un objectif : celui de l’efficacité. Pour ce faire, la liste des professionnels assujettis aux obligations de vigilance et de déclaration ne cesse de s’allonger et elle le sera dans les prochaines années. En outre, l’ordonnance n? 2009-104 du 30 janvier 2009 relative à la prévention de l’utilisation du système financier aux fins de BCFT a procédé à une refonte du dispositif préventif de cette lutte. L’ordonnance a ainsi affermi le dispositif en renforçant les obligations de vigilance à la charge des professionnels et en élargissant le champ d’application de l’obligation de déclaration. Toutefois, le nombre de déclarations émanant des commissaires aux comptes et des experts-comptables reste marginal. Leur activité déclarative représente 0,13% et 0,03% du nombre total des déclarations de soupçon reçu par TRACFIN (rapport 2008). Or, au regard de l’importance du rôle de ces professionnels dans la régulation de l’économie, de fortes marges de progression apparaissent possibles et souhaitables. Cet article présente, de manière critique, le dispositif français de lutte contre le BCFT, instauré à l’attention de ces professionnels.
Modelling light scattering by mineral dust using spheroids: assessment of applicability
Authors: Merikallio S. , Lindqvist H. , Nousiainen T. , Kahnert M.
Published: June 2011

Abstract. We study the applicability of spheroidal model particles for simulating the single-scattering optical properties of mineral dust aerosols. To assess the range of validity of this model, calculations are compared to laboratory observations for five different dust samples at two wavelengths. We further investigate whether the best-fit shape distributions of spheroids for different mineral dust samples have any similarities that would allow us to suggest a generic first-guess shape distribution for suspended mineral dust. We find that best-fit shape distributions vary considerably between samples and even between wavelengths, making definitive suggestions for a shape distribution difficult. The best-fit shape distribution also depends strongly on the refractive index assumed and the cost function adopted. However, a power-law shape distribution which favours those spheroids that depart most from the spherical shape is found to work well in most cases. To reproduce observed asymmetry parameters, best results are obtained with a power-law shape distribution with an exponent around three.