bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of various structural factors of claw pole transverse flux permanent magnet machines on internal voltage using finite element analysis
Authors: Alaeddini Ali , Darabi Ahmad , Tahanian Hamed
Published: July 2015

This paper presents the influence of several structural factors and
parameters involved in the design of Claw Pole Transvers Flux Permanent
Magnet Machines (TFPMs) on their internal voltage. Knowing the influence of
each factor is very important for an effective process of design and
optimization for these machines. In this paper by using the complete design
algorithm of Claw Pole TFPM, only one parameter is changed at a time and its
influence on the internal voltage is analyzed. Output torque is also studied,
because the internal voltage has effect on both the average and the ripple of
output torque. The most important factors and parameters which are considered
are: 1) number of poles; 2) length of air gap; 3) ratio of magnet arc to flux
concentrator arc in each pole of rotor; 4) shape of pole shoe of stator and
5) area of rotor pole covered by stator pole. Due to geometrical complexities
of TFPMs, analytical methods fail to describe the behavior of these machines.
For this reason, in this paper finite element analysis is used both in the
design and analysis of TFPMs.
Mixed methods research in pedagogy: Characteristics, advantages and difficulties in application
Authors: Matovic Natasa
Published: July 2015

The mixed methods research, as a new type of research, is discussed in the
context of re-examining the relation between the two approaches, i.e. the
possibility of not opposing, but connecting, combining and integrating them
within research. The possibility to use such grounding in research as well
could be quite important for pedagogy since the nature of the examined
phenomena in this field is such that the majority has both quantitative and
qualitative aspects. In order to explain the essence of a mixed methods
research, the paper analyses its characteristics, first of all, what elements
are combined, what is the nature of the relation between the combined
elements and why they are combined, as well as its advantages and
difficulties in application. The essential thing in a mixed methods research
is the fact that combining refers to the research process as a whole,
including the ontological and epistemological assumptions it is based on,
which implies that the elements that are combined are understood rather
broadly. The advantages and difficulties in application are considered in the
context of the discussion of the possibility to combine all research
elements, neutralise the limitations of quantitative and qualitative research
methodology, implement the complex combining procedures etc.
The link between teachers’ perception of autonomy in school and their behaviour towards students: An overview of contemporary research studies
Authors: Tadic Aleksandar
Published: July 2015

The pedagogical literature suggests that teachers often motivate students to
get involved in class activities and to adhere to work instructions by using
power-based procedures and hence jeopardise the sense of autonomy in
students. The paper points to the necessity of re-examining the contextual
and interpersonal factors that determine teachers? behaviour in the
classroom. We provide an overview of the results of relevant research studies
in the field in order to gain an insight into and establish the correlates of
teachers? controlling style towards students from the perspective of the
self-determination theory. Previous studies have shown that teachers who are
exposed to pressure at work tend to transfer this pressure to their students
by applying controlling procedures. The link between the feeling of pressure
and teachers? controlling style arises indirectly via teachers? work
motivation and the sense of fulfilment of their basic needs in school.
Teachers will most likely be intrinsically motivated for school work if they
think that a wider social context and other persons in their work environment
support the fulfilment of their need for autonomy. The concluding part
emphasises the necessity of planning education policies and future studies in
this area, along with presenting the possibilities and strategies for
creating the conditions to support work motivation of autonomous teachers.
Characteristics of written syntax in ten-year-old fourth-graders
Authors: Ivanovic Maja
Published: July 2015

The main purpose of this study is to present an inventory of different types
of syntactic constructions found in written discourse of ten-year-old fourth
graders, that is, to examine the existing variations in text syntactic
structures which were produced by fourth graders. Written text corpus was
collected from 88 fourth graders from Belgrade. In three different sessions,
students composed three texts in three different genres: narrative,
expository, and argumentative. Thematic and genre versatility enriched the
corpus and created favourable conditions for elicitation of different types
of syntactic constructions. Different quantitative and qualitative
characteristics of texts from the database were taken into account and
analysed: the mean length of text measured by the number of words, the number
of utterances, and the mean length of utterance measured by the number of
words and clauses, as well as the presence of various types of syntactic
constructions (kernel, simple, compound, complex and complex-compound
sentences). The frequency of appearance of each of these was then
established. The results provide an insight into the average length of texts
and sentences produced by the fourth-grade primary school pupils, as well as
into the means used to produce them (the kind of sentences they form). The
results are much more valuable because they are concerned with examining the
syntax in children who are native speakers of Serbian. They also show that in
ten-year-olds? texts all the analysed types of sentence structure may appear,
but the use frequency varies. Besides providing an inventory of syntactic
attainments in written production of ten-year-old children, the research
presented a new insight into their syntactic competence.
Early and Late G1/S Cyclins and Cdks Act Complementarily to Enhance Authentic Human β-Cell Proliferation and Expansion
Authors: Tiwari Shiwani , Roel Chris , Wills Rachel , Casinelli Gabriella , Tanwir Mansoor , Takane Karen K. , Fiaschi-Taesch Nathalie M.
Published: July 2015

β-Cell regeneration is a key goal of diabetes research. Progression through the cell cycle is associated with retinoblastoma protein (pRb) inactivation via sequential phosphorylation by the “early” cyclins and cyclin-dependent kinases (cdks) (d-cyclins cdk4/6) and the “late” cyclins and cdks (cyclin A/E and cdk1/2). In β-cells, activation of either early or late G1/S cyclins and/or cdks is an efficient approach to induce cycle entry, but it is unknown whether the combined expression of early and late cyclins and cdks might have synergistic or additive effects. Thus, we explored whether a combination of both early and late cyclins and cdks might more effectively drive human β-cell cell cycle entry than either group alone. We also sought to determine whether authentic replication with the expansion of adult human β-cells could be demonstrated. Late cyclins and cdks do not traffic in response to the induction of replication by early cyclins and cdks in human β-cells but are capable of nuclear translocation when overexpressed. Early plus late cyclins and cdks, acting via pRb phosphorylation on distinct residues, complementarily induce greater proliferation in human β-cells than either group alone. Importantly, the combination of early and late cyclins and cdks clearly increased human β-cell numbers in vitro. These findings provide additional insight into human β-cell expansion. They also provide a novel tool for assessing β-cell expansion in vitro.
Augmented Stat5 Signaling Bypasses Multiple Impediments to Lactogen-Mediated Proliferation in Human β-Cells
Authors: Chen Hainan , Kleinberger Jeffrey W. , Takane Karen K. , Salim Fatimah , Fiaschi-Taesch Nathalie , Pappas Kyrie , Parsons Ramon , Jiang Jing , Zhang Yue , Liu Hongtao , Wang Peng , Bender Aaron S. , Frank Stuart J. , Stewart Andrew F.
Published: July 2015

Pregnancy in rodents is associated with a two- to threefold increase in β-cell mass, which is attributable to large increases in β-cell proliferation, complimented by increases in β-cell size, survival, and function and mediated mainly by the lactogenic hormones prolactin (PRL) and placental lactogens. In humans, however, β-cell mass does not increase as dramatically during pregnancy, and PRL fails to activate proliferation in human islets in vitro. To determine why, we explored the human PRL–prolactin receptor (hPRLR)–Janus kinase 2 (JAK2)–signal transducer and activator of transcription 5 (STAT5)–cyclin–cdk signaling cascade in human β-cells. Surprisingly, adult human β-cells express little or no PRLR. As expected, restoration of the hPRLR in human β-cells rescued JAK2-STAT5 signaling in response to PRL. However, rescuing hPRLR-STAT5 signaling nevertheless failed to confer proliferative ability on adult human β-cells in response to PRL. Surprisingly, mouse (but not human) Stat5a overexpression led to upregulation of cyclins D1–3 and cdk4, as well as their nuclear translocation, all of which are associated with β-cell cycle entry. Collectively, the findings show that human β-cells fail to proliferate in response to PRL for multiple reasons, one of which is a paucity of functional PRL receptors, and that murine Stat5 overexpression is able to bypass these impediments.
Hormonal profile and body condition scoring in dairy cows during pre partum and post partum periods
Authors: Vargová Mária , Petrovič Vladimír , Konvičná Jana , Kadaši Marián , Zaleha Peter , Kováč Gabriel
Published: July 2015

The aim of this study was to evaluate the dynamics of selected indicators of energy, hormonal profile, body condition score (BCS) and their relationships in dairy cows of the Slovak Pied Cattle from 3 weeks before parturition to 9 weeks after. Significant differences were found in the mean values of non-esterified fatty acids (NEFA) (P < 0.001) and β-hydroxybutyrate (BHB) (P < 0.05). According to BCS results, the dry cows were overweight (4.42 ± 0.75 points). After calving the cows lost weight significantly, as the BCS was 3.25 ± 0.30 points at 9 weeks post partum (P < 0.001). The highest concentration of leptin was recorded before calving (26.80 ± 11.47 ng/ml). The concentrations of insulin and ghrelin did not change significantly (an increase in insulin concentrations from 580.8 ± 66.30 IU/ml to 625.50 ± 174.90 IU/ml and a decrease in ghrelin concentrations from 29.25 ± 4.82 pg/ml to 26.57 ± 5.35 pg/ml were found comparing 3 weeks to 1 week before parturition, respectively). Relationships between the hormones showed positive correlation between insulin and leptin (r = 0.220, P < 0.05), BCS and leptin (r = 0.360, P < 0.001), BCS and insulin (r = 0.232, P < 0.05) and negative correlation between leptin and ghrelin (r = -0.235, P < 0.05), BCS and ghrelin (r = -0.257, P < 0.05). These data provide evidence that the variations in the concentrations of leptin, ghrelin, and insulin are related to variations in the BCS. Negative correlation between leptin and ghrelin contributes to the argument that leptin negatively regulates ghrelin.
Structure of the digestive system of ducks depending on sex and genetic background
Authors: Wasilewski Rafał , Kokoszyński Dariusz , Mieczkowska Anna , Bernacki Zenon , Górska Alina
Published: July 2015

The aim of the study was to determine the effect of genotype and sex on body weight, body dimensions, intestinal length and diameter, percentage of intestinal segments, and weight and percentage of the main internal organs of ducks. The study was performed with 80 Pekin ducks, which were kept throughout rearing (1–49 days of age) in a confinement building and fed commercial waterfowl feed ad libitum. After 7 weeks of rearing, 40 ducks (10 drakes and 10 ducks of hybrid line SM3 Heavy and 10 drakes and 10 ducks of hybrid line AF51) were selected for slaughter. Birds were measured for body length and trunk length. During evisceration, the digestive tract and other internal organs were separated. At 7 weeks of age, SM3 Heavy broilers were heavier and had longer body length and trunk length compared to AF51 ducks. Significant differences were found for body weight in females and for body length in males. The AF 51 females were characterized by significantly greater intestinal length to body length and intestinal length to trunk length ratios, whereas AF51 males showed a greater (P ≤ 0.05) body length to trunk length ratio compared to SM3 Heavy birds. Genetic background of the ducks had no significant effect on the length of intestine and its segments, the diameter of different intestinal segments, and the weight and proportion of the gizzard, liver, heart and spleen. The same pattern was observed for the sex of birds except for gizzard weight, which was significantly greater in SM3 Heavy males than females.
Interval between injection of contrast material and positive contrast cheliography affects accurate diagnosis of diaphragmatic hernia
Authors: Sen Ismail A. , Akgul M. Baris , Gul Satar Nihal Y. , Topal Ayse
Published: July 2015

The aim of this study was to evaluate the clinical, surgical and diagnostic imaging findings in 11 cats and 3 dogs with suspected acute and chronic traumatic diaphragmatic hernia, and to compare the results of positive contrast cheliography (peritoneography) taken immediately and 5 min after the injection of contrast material. Thoracic and abdominal radiography, ultrasonography, and positive contrast cheliography of all animals were performed. Eight cases were considered as acute and six cases were considered chronic. The contrast images taken immediately after the injection of contrast material revealed the contrast material in the thoracic cavity in 8/8 acute trauma patients, but in none of the chronic cases. In 5/6 of these cases contrast material was seen in the thoracal cavity only in additional images taken after 5 min. One patient was diagnosed with FIP and excluded from the study. Twelve cases had complete resolution and one animal died during the early postoperative period. Our results suggest that positive contrast cheliography performed immediately after the injection of contrast material may not reveal chronic cases of diaphragmatic hernia and a second imaging (or imaging after 5 min) is indicated in order not to overlook chronic cases.
Comparison of serum protein electrophoretic pattern in cows and small ruminants
Authors: Nagy Oskar , Tóthová Csilla , Nagyová Veronika , Kováč Gabriel
Published: July 2015

Determination of the physiological electrophoretic patterns in animals is very useful for clinicians in diagnosing healthy and sick animals. The objective of this study was to investigate the serum protein electrophoretic pattern in cows, sheep, and goats in order to evaluate the differences in the size and number of protein fractions between the evaluated ruminant species. Ten adult multiparous high-yielding dairy cows, 10 adult female sheep and 10 adult female goats were included in this study. All the evaluated animals were clinically healthy. Serum was analyzed for total serum protein concentrations, and for the relative and absolute values of protein fractions with calculation of albumin/globulin ratios. Serum protein fractions were separated by zone electrophoresis on buffered agarose gel. Serum protein electrophoresis identified 6 distinct bands, comprising albumin, alpha1- (α1), alpha2- (α2), beta1- (β1), beta2- (β2), and gamma- (γ) globulins in cows. In sheep, serum proteins exhibited 6 fractions: albumin, α1-, α2-, β-, γ1- and γ2-globulins. In goats, serum proteins were separated into 5 fractions: albumin, α1-, α2-, β- and γ-globulins. Significant differences in the relative as well as absolute means were found for the albumin/globulin ratio and most of the protein fractions, except γ-globulins. No significant differences were found in the concentration of total proteins. These results describe the marked species differences in most of serum protein fractions between the evaluated groups of animals, and contribute to the current knowledge about the physiological electrophoretic pattern of serum proteins in ruminants, which can be used for diagnostic purposes.
Bacteriological Quality of Drinking Water in Mardan, Khyber Pakhtunkhwa, Pakistan
Authors: Ali Javid , Hassan Said , Ziaurahman Dr , Rahman Inayat Ur , Abbas Sadhair , Ullah Sana
Published: July 2015

The present study was aimed to isolate and identify micro-organisms load of drinking water of Mardan city, Khyber Pakhtunkhwa Pakistan. A total of 27 samples of drinking water were collected from different locations of the study area. Total Plate Count was determined by pour plate method, while total coliforms, total fecal coliforms and E. coli were determined by multiple tube fermentation method. Of the total collected samples, 17 (62.96%) samples were contaminated with either one or more than one type of microorganisms. The results of most probable number test showed that 13 (48.15%) samples were unsatisfactory. It was concluded that the water should be treated before consumption for drinking purpose. Regular assessment of the water quality is recommended as regular monitoring of the water quality for improvement not only prevents disease and hazards but also checks the water resources from becoming further polluted. ECOPRINT 21: 1-6, 2014DOI: http://dx.doi.org/10.3126/eco.v21i0.11897
Trends in Soil Carbon Stockpile of Three Major Forests Along an Altitudinal Gradient in Indian Central Himalaya
Authors: Bohra CS , Tewari SK , Bhatt MD
Published: July 2015

Current investigation reveals the stock of soil organic carbon (SOC) along with altitudinal gradients in Oak (Quercus leuchotrichophora), Pine (Pinus roxburghii) and Sal (Shorea robusta) dominant forests in Shiwalik region of Kumaun Himalayas in India. The estimated soil organic carbon was found 16.0 ± 4.3 to 19.4 ± 6.4 g kg-1 for Oak, 17.8 ± 2.0 to 25.6 ± 1.6 g kg-1 for Pine and 15.8 ± 2.2 to 21.4 ± 1.9 g kg-1 for Sal forests, respectively in 0-10, 10-20 and 20-30 cm soil depths. SOC stock was found to be in decreasing pattern with increasing altitude from 193.6 to 166.4, 146.4 to 137.6 and 159.2 to 141.6 t C ha-1 in Oak, Pine and Sal forests, respectively. It is an indicator of higher biological activity or anthropogenic disturbance associated with top layers of these forest areas. Higher SOC was recorded in Sal forest compared to Oak. In Sal forest, high tree density leads to higher accumulation of SOC compared to conifers while it was low in wide spread Pine forest, resulting in less storage of carbon stock in turn. ECOPRINT 21: 7-13, 2014DOI: http://dx.doi.org/10.3126/eco.v21i0.11898
Some Biological Characteristics of the Daysciaena albida (Cuvier 1830), on Largest Brackish Water Lagoon of India
Authors: Karna SK , Panda S
Published: July 2015

An attempt to study length-weight relationship (LWR), condition factor and reproductive aspects of Daysciaena albida was done in Chilika lagoon over one year. The fish specimens for the biological study were collected from landing centers of central and northern sector during pre-monsoon, monsoon and post-monsoon seasons. The LWR from total length and body weight were computed both by sex and seasons. The equations found from the relationships were y=0.010x2.992 for male, y=0.010x2.998 for female and y=0.010x2.996 as unsexed specimens. The highest condition factor (K) value was recorded during monsoon (1.42±0.08) followed by post-monsoon (1.4±0.09) and the lowest (0.92±0.11) during pre-monsoon seasons. The mean condition factor was registered as 1.06±0.09 in all the seasons of unsexed specimens. Among sex, males registered slightly higher K value than females. For reproductive study, maturation stages, gonad somatic index (GSI) and gastro somatic index (GaSI) were analyzed seasonally. Considering maturation stages highest maturation stages (stages 4 to 7) obtained during pre-monsoon season (in both sexes) which are considered as matured conditions for fish. The highest GSI was registered during pre-monsoon followed by postmonsoon and the lowest was during monsoon season among both the sexes. The GaSI value was lowest during pre-monsoon among males and gradually increased during monsoon and postmonsoon. But in case of female, lowest value was during monsoon and again increased afterwards and was highest in pre-monsoon. ECOPRINT 21: 15-21, 2014DOI: http://dx.doi.org/10.3126/eco.v21i0.11900
Allelopathic Effect of Artemisia Dubia Extracts on Seed Germination and Seedling Growth of Some Weeds and Winter Crops
Authors: Mallik Baby Babita Das , Acharya BD , Saquib M , Chettri MK
Published: July 2015

Allelopathic effects of aqueous extract of different plant parts (root, stem and leaf) of Artemisia dubia on seed germination and seedling growth of two winter crops (Triticum aestivum and Brassica campestries, and some associated weeds (Bidens pilosa, Ageratum conyzoides, Galinsoga parviflora and Cyperus rotundus) have been investigated in the present study. Extracts of root, stem and leaves of Artemisia dubia showed significant reduction in germination and seedling growth of test crops and weeds. Germination of crop and weed seeds and growth of shoot and root were reduced significantly in test treatments in comparison to the control. The seed germination, shoot length and root length were low at higher concentration. Complete inhibition of seed germination of Ageratum conyzoides, Galinsoga parviflora and Cyperus rotundus at 5 and 10% leaf extract of A.dubia was observed. Allelopathic effects were more pronounced with leaf extract than root or stem extract in most cases.The result indicated difference in allelopathic effect on crop seed and weed seed at higher concentrations. ECOPRINT 21: 23-30, 2014DOI: http://dx.doi.org/10.3126/eco.v21i0.11901
Interrelating Ecology and Health: Some Bio-Social Concerns
Authors: Kaur Reetinder
Published: July 2015

Ecology and health issues are often characterized by complex interactions between ecosystems and social systems, and demand integration of themes that span the environmental and socioeconomic determinants of health. The present paper emphasizes the health implications of interactions between human groups and their social, physical and biological environments which help in understanding how changes and fluctuations in ecology affects rate and pattern of diseases. ECOPRINT 21: 31-40, 2014DOI: http://dx.doi.org/10.3126/eco.v21i0.11902
Genotype X Environment Interaction of Food Barley
Authors: Welu Gebremedhin
Published: July 2015

The objective of this experiment was to estimate the magnitude of genotype X environment interaction on grain yield and yield related traits. Twelve varieties of food barley were included in the study planted in randomized complete block design with three replications. The ANOVA of combined and individual location revealed significant differences among the food barley genotypes for grain yield and other traits. The results of ANOVA for grain yield showed highly significant (p≤0.01) differences among genotypes evaluated for grain yield at Maychew and significant (p≤0.05) differences in Korem, Alage and Mugulat. The ANOVA over locations showed a highly significant (p≤0.01) variation for the genotype effect, environment effects, genotype X environment interaction (GEI) effect and significant (p≤0.05) variation for GEI effect of yield and for most of the yield related traits of food barley genotypes. Haftysene, Yidogit, Estayish and Basso were the genotypes with relatively high mean grain yield across all locations and they are highly performing genotypes to the area. Among locations, the highest mean grain yield was recorded at Korem and it was a suited environment to all the genotypes whereas Mugulat is unfavoured one. ECOPRINT 21: 41-48, 2014DOI: http://dx.doi.org/10.3126/eco.v21i0.11903
Land Use Changes and Livelihood Scenarios of Rajahar VDC, Nawalparasi District, Nepal
Authors: Ghimire Dhurba Prasad , Khatry Sunil Babu , Rimal Bhagawat
Published: July 2015

A digital land use map of the study area Rajahar VDC at Nawalparasi district was prepared with the aid of RS/GIS for 1989 to 2013 followed by land use map analysis. The obtained image was classified as forest, agricultural, settlement, water body and religious areas for the study year 1989 to 1999 where industrial area was included as new land use category (0.07%) for 2013. The study showed that there was considerable change in forest area (-3.47%) and religious area (-0.01%). But agriculture land, settlement area and water body were increased by 2.02%, 3.66% and 1.28%, respectively. The land use change for 1989 to 2013 followed polynomial (R2: 0.6577) pattern. The identified land use change key drivers were dependent on past events and reactions of the respondents. ECOPRINT 21: 55-62, 2014   DOI: http://dx.doi.org/10.3126/eco.v21i0.11905
Effects of Nitrogenous Fertilizers on Seed Germination of Orobanche solmsii C.D. Clarke
Authors: Bista Anjana
Published: July 2015

Seven nutrient chemicals were tested in vitro during pre- and post- conditioning period in order to know their effects on O. solmsii seed germination. All the concentrations (4, 8 and 16 mM) of nutrient applied during pre-conditioning period inhibited germination, whereas the effects of chemicals applied during post-conditioning period was either inhibitory or ineffective depending upon the nutrients. Ammonium nitrate and ammonium chloride was effective in reducing seed germination by 43% and 41%, respectively, and were more than any other ammonium salts. This study showed that all forms of nitrogen are not equally effective in reducing of germination. ECOPRINT 21: 73-78, 2014DOI: http://dx.doi.org/10.3126/eco.v21i0.11907
Temperature effects on tensile properties of laser sintered polyamide 12
Authors: Neugebauer Fabian , Müller Niels , Ploshikhin Vasily , Thiel Stefan , Ambrosy Janick , Witt Gerd
Published: July 2015

This paper focuses on a study of temperature effects on tensile properties of a polyamide 12 based polymer. Specimens for testing were generated using the additive manufacturing process of laser sintering. Tensile tests were conducted according to DIN EN ISO 527 at temperatures between 20 °C and 140 °C. A Zwick 250N5A was used for the tests. Fine strain up to 0.25 % was measured using a MTS biaxial extensometer. Crosshead displacement was recorded as well and used for generation of stress-strain curves. Within the paper, Young's modulus, Poisson ratio, tensile strength, tensile strain at tensile strength, stress and elongation at break and yielding are reported. The study showed that all analyzed mechanical properties depend significantly on temperature. Above 100 °C strain raised up to 100 %, however, it was limited by the traveling limit of the machine. The collected data were embedded in a table-driven elastic plastic material model for finite element simulation of tensile tests. Good agreements of simulations and experiments were obtained at all temperatures.
Effect of Ti-Al-O inclusions on the formation of intragranular acicular ferrite
Authors: Cai Zhengyu , Zhou Yahui , Tong Lianhai , Yue Qiang , Kong Hui
Published: July 2015

The role of Ti-Al-O inclusions on nucleation of intragranular acicular ferrite (IAF) was investigated by scanning electron microscope (SEM) and energy dispersive spectrometer (EDS). From SEM-EDS mapping images, two kinds of titanium containing oxides are observed. Type I is a Ti-Al-O phase, in which the elements of Al and Ti coexist. Type II is the titanium containing oxide, which precipitates on Al2O3. By statistical analysis, it can be seen that Type I is dominating in number, and its molar ratio of Ti/Al varied in a wide range, which reflects its composition complexity. After etching, microstructure of IAF is observed. It can be seen that sulfur accumulates on the periphery of nucleation Ti-Al-O inclusion, which is attributed to the precipitation of MnS. Moreover, this accumulation accompanies increasing in content ratio of Al/Ti, which could be explained by titanium vacancies. These vacancies can absorb Mn ions from the steel matrix around inclusions, which leads to a Mn depletion zone (MDZ). Its existence is confirmed by EDS line scanning, and considered to facilitate the formation of IAF since Mn is an austenite stabilizer.
Dynamic precipitation of nickel-based superalloys undergoing severe deformation below the solvus temperature
Authors: Nowotnik Andrzej , Rokicki Paweł , Mrówka-Nowotnik Grażyna , Sieniawski Jan
Published: July 2015

The authors performed uniaxial compression tests of nickel-based superalloys: single crystal CMSX–4, also precipitation hardened; Inconel 718 and X750, at temperatures below the γ′ solvus, in order to study the effect of temperature and strain rate on their flow stress and microstructural development. On the basis of the obtained flow stress values, the activation energy of a high-temperature deformation process was estimated. Microstructural observations of the deformed samples at high temperatures, previously solution heat treated and aged CMSX–4 and Inconel alloys revealed non-uniform deformation effects. Distribution of either molybdenum- or niobium-rich carbides was found to be affected by localized flow within the investigated strain range at relatively low deformation temperatures, 720–850 °C. Microstructural examination of the alloys also showed that shear banding and cavity growth were responsible for the decrease in flow stress and a specimen fracture at larger strains.
Material characterisation to identify the rheological behaviour for powder injection moulding
Authors: Claudel Dimitri , Sahli Mohamed , Barrière Thierry , Gelin Jean-Claude
Published: July 2015

For the purpose of powder injection moulding, a specific method is presented to identify the parameters for a combined rheological constitutive model. This model is a combination of three models used in powder injection moulding and accounts for the effects of the temperature, shear rate and particle size of the powder. The data obtained from experimental measurements were used for identification of the model parameters. The model with identified parameters could be used to realize accurate simulations.
Experimental investigation on the tensile behavior of a transparent polyurethane interlayer
Authors: Zhang LongHui , Zhang XiaoQing , Yao XiaoHu , Zang ShuGuang
Published: July 2015

The dynamic tensile response of a polyurethane interlayer was investigated using a series of tests, including differential scanning calorimetry and dynamic mechanical analysis, quasi-static tension tests and Kolsky tension bar tests. The suitable geometry of the polyurethane interlayer was analyzed and high-speed photography was employed to study the uniform deformation of the specimen at high strain rates. The tensile stress–strain responses of the polyurethane interlayer were sensitive to temperature and strain rate. The polyurethane interlayer exhibited brittle behavior and the failure occurred both in quasi-static and dynamic loading conditions at −40 °C. The experimental results can provide guidelines to a typical aeronautical windshield design.
Quick fabrication of appropriate morphology and composition CoFe films with desirable microwave properties
Authors: Zong BaoYu , Wu YuPing , Phuoc Nguyen Nguyen , Ho Pin , Qiu JinJun , Yang Yi , Chua Miao Jun , Ng Wei Beng , Chen YunJie , Han GuChang
Published: July 2015

A methodology to quickly prepare CoFe nanofilms with large magnetic permeability and resonance frequency from simple salt solutions is demonstrated. As the microwave properties of thin films are largely determined by their surface morphology and composition, CoFe film with unique morphology and composition is proposed based on theoretical analysis and subsequently electrodeposited with suitable parameters. This approach reveals that FexCo1-x(0.3 <x< 0.5 in atomic ratio) films consisting of sub-30 nm spherical nanoparticles, even in the form of bigger aggregated-nanoparticles, usually show a low coercivity (≤4240 A · m−1), moderate magnetic anisotropy (2900–8580 A · m−1), and high magnetic moment (≥1.4 T), permeability (>200) as well as resonance frequency (>1 GHz). Further experimental analyses show root causes of the phenomena. This methodology also provides useful references to rapidly identify microwave properties of thin films from their surface morphologies and main electrodeposition parameters.
Simulation of dendritic growth of Al-4 wt.% Cu alloy from an undercooled melt
Authors: Zhang Xianfei , Li Xikun
Published: July 2015

Three-dimensional dendritic growth of an Al-4 wt.% Cu alloy during solidification in the presence of forced flow was simulated by using a three-dimensional cellular automaton model. The three-dimensional Lattice–Boltzmann method was used in computing the flow dynamics. The effects of forced flow on the growth Péclet number, dendrite tip selection parameter, and secondary arm spacing were investigated. The simulated relationships of growth Péclet number and dendrite tip selection parameter with the forced flow are in good agreement with the Oseen–Ivantsov solution. The results indicate that with the increase in forced flow velocity, the secondary arm spacing first increases and then decreases.
Molsidomine for the prevention of vasospasm-related delayed ischemic neurological deficits and delayed brain infarction and the improvement of clinical outcome after subarachnoid hemorrhage: a single-center clinical observational study
Authors: Ehlert Angelika , Schmidt Christoph , Wölfer Johannes , Manthei Gerd , Jacobs Andreas H. , Brüning Roland , Heindel Walter , Ringelstein E. Bernd , Stummer Walter , Pluta Ryszard M. , Hesselmann Volker
Published: July 2015

OBJECT

Delayed ischemic neurological deficits (DINDs) and cerebral vasospasm (CVS) are responsible fora poor outcome in patients with aneurysmal subarachnoid hemorrhage (SAH), most likely because of a decreased availability of nitric oxide (NO) in the cerebral microcirculation. In this study, the authors examined the effects of treatment with the NO donor molsidomine with regard to decreasing the incidence of spasm-related delayed brain infarctions and improving clinical outcome in patients with SAH.

METHODS

Seventy-four patients with spontaneous aneurysmal SAH were included in this post hoc analysis. Twenty-nine patients with SAH and proven CVS received molsidomine in addition to oral or intravenous nimodipine. Control groups consisted of 25 SAH patients with proven vasospasm and 20 SAH patients without. These patients received nimodipine therapy alone. Cranial computed tomography (CCT) before and after treatment was analyzed for CVS-related infarcts. A modified National Institutes of Health Stroke Scale (mNIHSS) and the modified Rankin Scale (mRS) were used to assess outcomes at a 3-month clinical follow-up.

RESULTS

Four of the 29 (13.8%) patients receiving molsidomine plus nimodipine and 22 of the 45 (48%) patients receiving nimodipine therapy alone developed vasospasm-associated brain infarcts (p < 0.01). Follow-up revealed a median mNIHSS score of 3.0 and a median mRS score of 2.5 in the molsidomine group compared with scores of 11.5 and 5.0, respectively, in the nimodipine group with CVS (p < 0.001). One patient in the molsidomine treatment group died, and 12 patients in the standard care group died (p < 0.01).

CONCLUSIONS

In this post hoc analysis, patients with CVS who were treated with intravenous molsidomine had a significant improvement in clinical outcome and less cerebral infarction. Molsidomine offers a promising therapeutic option in patients with severe SAH and CVS and should be assessed in a prospective study.
Gamma Knife radiosurgery for recurrent or residual seizures after anterior temporal lobectomy in mesial temporal lobe epilepsy patients with hippocampal sclerosis: long-term follow-up results of more than 4 years
Authors: Lee Eun Mi , Kang Joong Koo , Kim Sang Joon , Hong Seok Ho , Ko Tae Sung , Lee Sang Ahm , Lee Do Heui , Lee Jung Kyo
Published: July 2015

OBJECT

Gamma Knife radiosurgery (GKRS) has proven efficacy in the treatment of drug-resistant mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS) and is comparable to conventional resective surgery. It may be effective as an alternative treatment to reoperation after failed temporal lobe surgery in patients with MTLE-HS. The purpose of this study was to investigate the efficacy of GKRS in patients with unilateral MTLE-HS who did not achieve seizure control or had recurrent seizures after anterior temporal lobectomy (ATL).

METHODS

Twelve patients (8 males; mean age 35.50 ± 9.90 years) with MTLE-HS who underwent GKRS after failed ATL (Engel Classes III–IV) were included. GKRS targets included the remnant tissue or adjacent regions of the previously performed ATL with a marginal dose of 24–25 Gy at the 50% isodose line in all patients. Final seizure outcome was assessed using Engel’s modified criteria during the final 2 years preceding data analysis. A comparison between signal changes on follow-up MRI and clinical outcome was performed.

RESULTS

All patients were followed up for at least 4 years with a mean duration of 6.18 ± 1.77 years (range 4–8.8 years) after GKRS. At the final assessment, 6 of 12 patients were classified as seizure free (Engel Class Ia, n = 3; Ic, n = 2; and Id, n = 1) and 6 patients were classified as not seizure free (Engel Class II, n = 1; III, n = 2; and IV, n = 3). Neither initial nor late MRI signal changes after GKRS statistically correlated with surgical outcome. Clinical seizure outcome did not differ significantly with initial or late MRI changes after GKRS.

CONCLUSIONS

GKRS can be considered an alternative option when the patients with MTLE-HS who had recurrent or residual seizures after ATL refuse a second operation.
Timing of deep vein thrombosis formation after aneurysmal subarachnoid hemorrhage
Authors: Liang Conrad W. , Su Kimmy , Liu Jesse J. , Dogan Aclan , Hinson Holly E.
Published: July 2015

OBJECT

Deep vein thrombosis (DVT) is a common complication of aneurysmal subarachnoid hemorrhage (aSAH). The time period of greatest risk for developing DVT after aSAH is not currently known. aSAH induces a prothrombotic state, which may contribute to DVT formation. Using repeated ultrasound screening, the hypothesis that patients would be at greatest risk for developing DVT in the subacute post-rupture period was tested.

METHODS

One hundred ninety-eight patients with aSAH admitted to the Oregon Health & Science University Neurosciences Intensive Care Unit between April 2008 and March 2012 were included in a retrospective analysis. Ultrasound screening was performed every 5.2 ± 3.3 days between admission and discharge. The chi-square test was used to compare DVT incidence during different time periods of interest. Patient baseline characteristics as well as stroke severity and hospital complications were evaluated in univariate and multivariate analyses.

RESULTS

Forty-two (21%) of 198 patients were diagnosed with DVT, and 3 (2%) of 198 patients were symptomatic. Twenty-nine (69%) of the 42 cases of DVT were first detected between Days 3 and 14, compared with 3 cases (7%) detected between Days 0 and 3 and 10 cases (24%) detected after Day 14 (p < 0.05). The postrupture 5-day window of highest risk for DVT development was between Days 5 and 9 (40%, p < 0.05). In the multivariate analysis, length of hospital stay and use of mechanical prophylaxis alone were significantly associated with DVT formation.

CONCLUSIONS

DVT formation most commonly occurs in the first 2 weeks following aSAH, with detection in this cohort peaking between Days 5 and 9. Chemoprophylaxis is associated with a significantly lower incidence of DVT.
Use of optical coherence tomography to predict visual outcome in parachiasmal meningioma
Authors: Park Hun Ho , Oh Min Chul , Kim Eui Hyun , Kim Chan Yun , Kim Sun Ho , Lee Kyu-Sung , Chang Jong Hee
Published: July 2015

OBJECT

The authors investigated the value of retinal nerve fiber layer (RNFL) thickness in predicting visual outcome after surgery for parachiasmal meningioma.

METHODS

Forty-nine eyes of 25 patients who underwent craniotomy and resection of a parachiasmal meningioma were analyzed retrospectively. Visual parameters including visual field (VF) (recorded as the mean deviation [MD]), visual acuity (VA), and RNFL thickness (via optical coherence tomography) were measured before and 1 week, 6 months, and 1 year after surgery. Postoperative visual outcome was compared among the patients with a thin or normal RNFL. A separate analysis of data pertaining to 22 eyes of 13 patients with severe VF defects (MD ≤ −10 dB) was performed to compare visual outcome for those with a thin or normal RNFL.

RESULTS

Of the 23 eyes that showed VF improvement, 22 (95.7%) had normal RNFL thickness. The positive predictive value of normal RNFL thickness for VF improvement was 78.6%. The VF of patients with normal RNFL thickness improved in 6 months and continued improving 1 year after surgery (MD −5.9 dB before surgery, −5.5 dB 1 week after surgery, −2.8 dB 6 months after surgery [p < 0.01], and −1.1 dB 1 year after surgery [p < 0.01]). In contrast, those with a thin preoperative RNFL showed deterioration at first and then slower, worse visual recovery after surgery (MD −18.1 dB before surgery, −22.4 dB 1 week after surgery, −21.2 dB 6 months after surgery, and −19.1 dB 1 year after surgery). VA also showed significant progress 6 months after surgery in patients with normal RNFL thickness (0.6 before surgery, 0.7 one week after surgery, 0.9 six months after surgery [p = 0.025], and 0.9 one year after surgery [p = 0.050]) compared to those with a thin RNFL (0.3 before surgery, 0.2 one week after surgery, 0.3 six months after surgery, and 0.4 one year after surgery). Preoperative differences in VF MD and VA were noted between the 2 groups (p < 0.01). Even patients with severe VF defects and normal RNFL thickness improved by 11.1 dB by 1 year after surgery compared with patients with a thin RNFL (−0.01 dB) (p < 0.01). Patients with normal RNFL thickness also did better in VA improvement (from 0.7 to 1.1) than those with a thin RNFL (from 0.2 to 0.3), but these results were not statistically significant.

CONCLUSIONS

RNFL thickness measured by optical coherence tomography has significant value as a prognostic factor of postoperative visual recovery for parachiasmal meningioma. Patients with normal RNFL thickness before surgery are more likely to have visual improvement after surgery than patients with a thin RNFL.
Neuroophthalmological outcomes associated with use of the Pipeline Embolization Device: analysis of the PUFS trial results
Authors: Sahlein Daniel H. , Fouladvand Mohammad , Becske Tibor , Saatci Isil , McDougall Cameron G. , Szikora István , Lanzino Giuseppe , Moran Christopher J. , Woo Henry H. , Lopes Demetrius K. , Berez Aaron L. , Cher Daniel J. , Siddiqui Adnan H. , Levy Elad I. , Albuquerque Felipe C. , Fiorella David J. , Berentei Zsolt , Marosfoi Miklos , Cekirge Saruhan H. , Kallmes David F. , Nelson Peter K.
Published: July 2015

OBJECT

Neuroophthalmological morbidity is commonly associated with large and giant cavernous and supraclinoid internal carotid artery (ICA) aneurysms. The authors sought to evaluate the neuroophthalmological outcomes after treatment of these aneurysms with the Pipeline Embolization Device (PED).

METHODS

The Pipeline for Uncoilable or Failed Aneurysms (PUFS) trial was an international, multicenter prospective trial evaluating the safety and efficacy of the PED. All patients underwent complete neuroophthalmological examinations both before the PED procedure and at a 6-month follow-up. All examinations were performed for the purpose of this study and according to study criteria.

RESULTS

In total, 108 patients were treated in the PUFS trial, 98 of whom had complete neuroophthalmological follow-up. Of the patients with complete follow-up, 39 (40%) presented with a neuroophthalmological baseline deficit that was presumed to be attributable to the aneurysm, and patients with these baseline deficits had significantly larger aneurysms. In 25 of these patients (64%), the baseline deficit showed at least some improvement 6 months after PED treatment, whereas in 1 patient (2.6%), the deficits only worsened. In 5 patients (5%), new deficits had developed at the 6-month follow-up, while in another 6 patients (6%), deficits that were not originally assumed to be related to the aneurysm had improved by that time. A history of diabetes was associated with failure of the baseline deficits to improve after the treatment. The aneurysm maximum diameter was significantly larger in patients with a new deficit or a worse baseline deficit at 6 months postprocedure.

CONCLUSIONS

Patients treated with the PED for large and giant ICA aneurysms had excellent neuroophthalmological outcomes 6 months after the procedure, with deficits improving in most of the patients, very few deficits worsening, and few new deficits developing.
Outcomes of chronic subdural hematoma drainage in nonagenarians and centenarians: a multicenter study
Authors: Lee Lester , Ker Justin , Ng Hui Yu , Munusamy Thangaraj , King Nicolas Kon Kam , Kumar Dinesh , Ng Wai Hoe
Published: July 2015

OBJECT

Chronic subdural hemorrhage (SDH) or hematoma is a condition that affects elderly individuals. With advances in medical care, the number of nonagenarians and centenarians will increase. However, surgical treatments in this age group are associated with high rates of morbidity and mortality. Because no data are available on the rates of survival among elderly patients with chronic SDHs who undergo surgical drainage or receive only conservative care, the goal of this study was to determine survival rates in patients 90 years of age or older with symptomatic chronic SDHs.

METHODS

The authors conducted a retrospective analysis of patient data that were collected at 3 hospitals over a 13-year period (from January 2001 to June 2013). The data from patients 90 years or older with symptomatic chronic SDHs and who were offered surgical treatment were included in the analysis. Patients who underwent surgical treatment were included in the surgical group and patients who declined an operation were included in the conservative care group. The patients’ Charlson Comorbidity Index score, Karnofsky Performance Scale score, dates of death, presenting symptoms, Glasgow Coma Scale score, length of stay in the hospital, discharge location, side of the SDH, and neurological improvements at 30-day and 6-month follow-ups were recorded. Data were statistically analyzed with Fisher exact test, Kaplan-Meier curves, and logistic regression.

RESULTS

In total, 101 patients met the inclusion criteria of this study; 70 of these patients underwent surgical drainage, and 31 received conservative care. Patients in the surgical group had statistically significantly (p < 0.001) higher survival at both the 30-day and 6-month follow-ups, with 92.9% and 81.4% of the patients in this group surviving for at least 30 days and 6 months, respectively, versus 58.1% and 41.9%, respectively, in the conservative care group. Moreover, the mean overall length of survival of 34.4 ± 28.7 months was longer in the surgical group than it was in the conservative care group (11.3 ± 16.6 months). Overall, 95.7% of patients in the surgical group exhibited an improvement in neurological status after the SDH drainage, whereas none of the patients in the conservative care group showed any neurological improvement during their hospital stay. The surgical complication rate was 11.4%, and the overall rate of chronic SDH recurrence after surgery was 12.9%.

CONCLUSIONS

Surgical drainage of chronic SDHs in nonagenarians and centenarians is associated with lower incidence of inpatient death and higher 30-day and 6-month survival rates.