bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimum Joint Detail for a General Cold-Formed Steel Portal Frame
Authors: Wrzesien A. , Lim James B.P. , Nethercot D.A.
Published: October 2012

In cold-formed steel portal framing systems that use bolted moment connections, formed through brackets, for the eaves and apex joints, it is well-known that the joints are semi-rigid, have finite connection-lengths and limited moment capacity. For such frames, it is therefore necessary for these joint effects to be taken into account when conducting frame design and analysis. However, as the semi-rigidity and the finite connection-lengths of each joint influence the bending moment distribution as well as the deflected profile of the frame, the joint detail for the eaves and the apex should not be designed independently of the frame. In this paper, a method of determining the optimum joint detail is described. It is demonstrated that careful selection of the joint detail can result in as much as a 25% increase in efficiency of the frame. Including joint effects explicitly into the design process provides better opportunities to devise the most appropriate balance between joints and member properties and thus reduce material use and construction costs.
Verification and Validation of Numerical Models of the Transport of Insulation Debris
Authors: Glover G. M. Cartland , Kratzsch A. , Krepper E. , Renger S. , Seeliger A. , Zacharias F. , Alt S. , Kästner W. , Kryk H. , Weiss F.-P.
Published: October 2012

A combination of the two-fluid and drift flux models have been used to model the transport of fibrous debris. This debris is generated during loss of coolant accidents in the primary circuit of pressurized or boiling water nuclear reactors, as high pressure steam or water jets can damage adjacent insulation materials including mineral wool blankets. Fibre agglomerates released from the mineral wools may reach the containment sump strainers, where they can accumulate and compromise the long-term operation of the emergency core cooling system. Single-effect experiments of sedimentation in a quiescent rectangular column and sedimentation in a horizontal flow are used to verify and validate this particular application of the multiphase numerical models. The utilization of both modeling approaches allows a number of pseudo-continuous dispersed phases of spherical wetted agglomerates to be modeled simultaneously. Key effects on the transport of the fibre agglomerates are particle size, density and turbulent dispersion, as well as the relative viscosity of the fluid-fibre mixture.
Modeling the Interaction of a Molten Seal and Solid Particles Using DEM and SPH Simulations: Application for a Passive New Scram System for LMR
Authors: Vanmaercke S. , Van den Eynde G. , Tijskens E. , Bartosiewicz Y.
Published: October 2012

A new shutdown system that does not rely on absorber rods, is being developed at SCK.CEN and UCL for application in Liquid Metal Reactors (LMR). The system consists of tubes filled with absorber particles. During normal operation, these particles are kept above the active core by means of a metallic melt seal. In case of an accident, the system is activated by the temperature increase in the coolant. This leads to melting of the metal seal, releasing the absorber particles into the core. The resulting flow of the particles has been studied both experimentally, and with Discrete Element Method (DEM) simulations. This paper focuses on the second important aspect of the safety system, being the melting and flowing of the metallic seal in interaction with the solid absorber particles moving through the molten seal.
3D Archaeology at Çatalhöyük
Authors: Forte M. , Dell'Unto N. , Issavi J. , Onsurez L. , Lercari N.
Published: October 2012

The project “3D-Digging at Çatalhöyük” began in 2010 thanks to collaboration between Stanford University (Archaeological Center) and the University of California Merced with the scope to record, document (with different digital technologies) and visualize in virtual reality all the phases of archaeological excavation. Phase I (2010 excavation season) of the project was mainly oriented to test different technologies during the excavation (time of flight and optical laser scanners). In phase II (2011 excavation season) the UC Merced team initiated the excavation of a Neolithic house (building 89), recording all the layers by time phase-shift scanners and computer vision techniques. The recording of the excavation process through the use of digital technologies gave the team the ability to generate 3D models of layers and micro-stratigraphies in stereovision during the excavation (using stereo projectors), so as to stimulate a new digital hermeneutics in archaeology. At the end of the fieldwork all the 3D models are accessible through a Teleimmersive system created by UC Merced and UC Berkeley.
Complex Architecture in 3D: From Survey to Web
Authors: Fassi F. , Parri S.
Published: October 2012

The paper describes the final step of a four-year survey of Milan Cathedral. In the past years, several measurement surveys were conducted using innovative techniques such as laser scanning and close range photogrammetry. In particular, the last technique was the most studied, experimented with, and tested because it offers more suitable measurement of a huge complex marble structure. The final aim of the survey was to create a detailed 3D model of the big spire. The last phase of the job, here presented, was to transform the great static model into a 3D WEB BIM for managing and organizing the restoration work.
Potential of Automatic 3D Object Reconstruction from Multiple Images for Applications in Architecture, Cultural Heritage and Archaeology
Authors: Kersten T.P. , Lindstaedt M.
Published: October 2012

Constant improvements in the performance of internet and computer technologies combined with rapid advancements in computer vision algorithms now make it possible to efficiently and flexibly reconstruct the 3D geometry of objects. Objects of different sizes can be modelled using image sequences from commercial digital cameras that are processed by web services and freely available software packages, forming low cost systems for numerous applications (restoration, historical care of monuments, visualization, analysis of the state of construction and the damage, etc.). In this contribution various cultural objects (historical buildings, statues/figures, archaeological finds, etc.) have been reconstructed in order to investigate the potential of this technology which enables the automatic generation of 3D point clouds or surface models (as 3D polygons) with photo-realistic texture from image data. These so-called low cost systems represent an efficient alternative to expensive terrestrial laser scanning systems for the as-built documentation of 3D objects in architecture, cultural heritage and archaeology. The accuracy of the automatically generated 3D models is assessed by comparison with results from terrestrial laser scanning.
3D Recording and Total Archaeology: From Landscapes to Historical Buildings
Authors: Campana S. , Sordini M. , Bianchi G. , Fichera G. A. , Lai L.
Published: October 2012

The paper presents the experience and in particular two case studies of 3D recording undertaken by two laboratories of the University of Siena, Italy (LAP&T and LAAUM). The case studies focus respectively on landscape and on historical building recording. The paper describes the first step in a new approach to the documentation and interpretation of the archaeological record, discussing and emphasising the need to collect and analyse 3D documentation at different scales of detail: from artefact to landscape. As first result, this approach should improve the documentation of cultural contexts and therefore increase the opportunity to achieve archaeological understanding. The first part of the paper describes the contribution of LiDAR data in landscape analysis, underlining the importance of very accurate DTMs in geomorphological analysis and their influence on landscape archaeology. The geographical background is southern Tuscany and the Po Valley in northern Italy. At a completely different scale of detail the final part of the paper presents the results of the laser scanning and stratigraphical analysis of an historical building in southern Tuscany.
Simultaneous Measurements of Multiple Parameters at Elevated Temperature Using a Frequency-Division Multiplexing Scheme with Tunable Diode Lasers
Authors: Cai Tingdong , Gao Guangzhen , Liu Ying
Published: October 2012

A multiplexed diode-laser sensor system based on second harmonic detection of wavelength modulation spectroscopy (WMS) is developed for application at elevated temperatures with two near-infrared diode lasers multiplexed using a frequency-division multiplexing scheme. One laser is tuned over a H2O line pair near 7079.176 and 7079.855 cm−1, and another laser is tuned over a pair of CO2 and CO lines near 6361.250 and 6361.344 cm−1. Temperature and concentrations of H2O, CO2, and CO could be measured simultaneously by this system. In order to remove the need for calibration and correct for transmission variation due to beam steering, mechanical misalignments, soot, and windows fouling, the WMS-1 f normalized 2f method is used. Demonstration experiments are conducted in a heated static cell. The precision of temperature and the concentrations for H2O, CO2, and CO are found to be 1.57%, 3.87%, 3.01%, and 3.58%, respectively. These results illustrate the potential of this sensor for applications at high temperatures.
Home-Made N-Channel Fiber-Optic Spectrometer from a Web Camera
Authors: Sumriddetchkajorn Sarun , Intaravanne Yuttana
Published: October 2012

This paper demonstrates the high potential of a web camera to be utilized as a low-cost multichannel fiber-optic spectrometer suitable for either educational or quality-control purposes in small and medium enterprises. The key idea is to arrange N input optical fibers in a line and position an external dispersive element to separate incoming optical beams into their associated spectral components in a two-dimensional (2D) space. With a commercial web camera, each set of the spectral components is imaged through a plastic lens onto the 2D image sensor of the web camera. For the demonstration, a five-channel webcam-based fiber-optic spectrometer is implemented where each channel is calibrated by selected reference light sources. The constructed spectrometer can perform wavelength analysis of the spectral irradiance in the range of 400 to 655 nm. Experimental results also show that peak operating wavelengths of five light-emitting diodes and a laser pointer can be determined with a wavelength measurement error of less than 10.5 nm. The total cost of the webcam-based five-channel fiber-optic spectrometer is only approximately US$92.50 and effectively performs to the desired results.
Chlorophyll a and NADPH Fluorescence Lifetimes in the Microalgae Haematococcus pluvialis (Chlorophyceae) under Normal and Astaxanthin-Accumulating Conditions
Authors: Kristoffersen Arne S. , Svensen Øyvind , Ssebiyonga Nicolausi , Erga Svein R. , Stamnes Jakob J. , Frette Øyvind
Published: October 2012

In vivo fluorescence lifetimes of chlorophyll- a (chl- a) and nicotinamide adenine dinucleotide phosphate (NADPH) were obtained from the green microalgae Haematococcus pluvialis under normal and nutrient-stressed conditions (green stage and red stage, respectively), using two-photon excitation provided by a laser generating pulses in the femtosecond range, and a Leica microscope setup. Analysis of the fluorescence lifetime decay curve revealed two separate lifetime components in all our measurements. A short-lifetime component for chl- a of ~250 ps was completely dominant, contributing more than 90% of overall intensity in both green-stage and red-stage cells. Green-stage cells inhibited by 3-(3,4-dichlorophenyl)-1,1-dimethyl-urea (DCMU) displayed a significant chl- a lifetime increase for the short component. However, this was not the case for red-stage cells, in which DCMU inhibition did not significantly affect the lifetime. For green-stage cells, we found a short NADPH (free) lifetime component at ~150 ps to be completely dominating, but for red-stage cells, a longer component (protein bound) at ~3 ns contributed as much as 35% of the total intensity. We hypothesize that the long lifetime component of NADPH is connected to photoprotection in the cells and coupled to production of astaxanthin. DCMU does not seem to affect the fluorescence lifetimes of NADPH.
Photoluminescence Properties of Zinc Oxide in Paints: A Study of the Effect of Self-Absorption and Passivation
Authors: Clementi Catia , Rosi Francesca , Romani Aldo , Vivani Riccardo , Brunetti Brunetto G. , Miliani Costanza
Published: October 2012

Zinc oxide has been widely used as a white artist pigment since the end of the eighteenth century. The luminescence properties of this compound have received great interest during the last decades for promising applications in different fields of material science, but their diagnostic implications in the cultural-heritage context have been poorly exploited. This paper is intended to provide a clear picture of the luminescence behavior of zinc white in oil paintings. With this aim, three white pigments and three highly pure (analytical grade) zinc oxides were studied as powder substrates and as painting models by ultraviolet–visible (UV–VIS) fluorescence and Fourier transform infrared (FT-IR) spectroscopy. The quenching of the luminescence intensity of the UV excitonic emission due to self-absorption and multiple scattering phenomena has been investigated, pointing out the possible difficulty of detecting this signal with negative consequences in the diagnostics of works of art. By contrast, the UV emission is notably enhanced by interaction with the binder, whereas the visible emission decreases. This phenomenon is probably due to the formation of covalent bonds between zinc atoms and carboxylates from the lipidic medium that are chemisorbed on zinc oxide surfaces.
Water Uptake of Poly(2-N-Alkyl-2-Oxazoline)s: Temperature-Dependent Fourier Transform Infrared (FT-IR) Spectroscopy and Two-Dimensional Correlation Analysis (2DCOS)
Authors: Rettler Erik F.-J. , Unger Miriam V. , Hoogenboom Richard , Siesler Heinz W. , Schubert Ulrich S.
Published: October 2012

A library of poly(2-oxazoline)s with varying length of the alkyl side-chain has been investigated by variable-temperature Fourier transform infrared (FT-IR) spectroscopy. These polymers are suitable for studies of structure-property relationships as their cationic ring-opening polymerization and the relatively facile monomer synthesis enable a control of the molecular structure. In this contribution, the number of carbon atoms in the linear side-chain is systematically varied from a short methyl to a long nonyl group. Previous studies showed that the sample library can be split in two groups: poly(2-oxazoline)s with a short side-chain (methyl-, ethyl-, and isopropyl-) exhibit hygroscopic behavior, while those with longer side-groups (butyl- and longer) were found to be semi-crystalline. To gain further insight into the mechanisms of hydrogen bonding and crystallization, temperature-dependent infrared (IR) spectroscopy has been applied in the current study. The processes involved have been monitored by generalized two-dimensional correlation spectroscopy (2DCOS) and perturbation-correlation moving-window two-dimensional correlation spectroscopy (PCMW2D) in the C=O stretching region around 1645 cm−1. These advanced analysis techniques provided valuable additional information on the material behavior during heating. As water is removed from the samples in the course of the heating process, it was possible to clearly distinguish between “loosely associated” and hydrogen-bonded water. Furthermore, the melting process of the semi-crystalline samples could be depicted. For the poly(2-isopropyl-2-oxazoline) even a crystallization process could be monitored in the temperature range between glass transition and melting.
Metal Stearate Distributions in Modern Artists' Oil Paints: Surface and Cross-Sectional Investigation of Reference Paint Films Using Conventional and Synchrotron Infrared Microspectroscopy
Authors: Osmond Gillian , Boon Jaap J. , Puskar Ljiljana , Drennan John
Published: October 2012

Zinc oxide is a prevalent industrial-age pigment that readily reacts with fatty acids in oil-based paints to form zinc carboxylates. Zinc stearate aggregates are associated with deterioration in late nineteenth and twentieth century paintings. The current study uses both conventional and synchrotron Fourier transform infrared spectroscopy (FT-IR) to investigate metal carboxylate composition in a range of naturally aged artists' oil paints and reference paint film draw-downs. The paints contain zinc oxide alone or in combination with lead white, titanium white, and aluminum stearate and are prepared with linseed and safflower oils. Attenuated total reflectance (ATR)-FT-IR using the conventional source identifies marked differences in carboxylate profiles between exposed and protected surfaces in a large number of samples. Synchrotron FT-IR microspectroscopy of thin paint cross-sections maps metal carboxylate distributions at high spatial resolution and resolves broad concentration gradients and micrometer-scale phase separation of carboxylate species. Aluminum stearate, a common paint additive, is found to influence the distribution of zinc carboxylates more strongly than pigment composition or oil type. The presence of aluminum stearate results in higher concentrations and more pronounced separation of saturated C16 and C18 chain zinc carboxylates in the margin of paint nearest the polyester substrate. The presence of aluminum stearate in association with zinc oxide has a clear influence on zinc carboxylate formation and distribution, with potential implications for long term stability of vulnerable paintings.
Secant degree of toric surfaces and delightful planar toric degenerations
Authors: Postinghel Elisa
Published: October 2012

The k-secant degree is studied with a combinatorial approach. A planar toric degeneration of any projective toric surface X corresponds to a regular unimodular triangulation D of the polytope defining X. If the secant ideal of the initial ideal of X with respect to D coincides with the initial ideal of the secant ideal of X, then D is said to be delightful and the k-secant degree of X is easily computed. We establish a lower bound for the 2- and 3-secant degree, by means of the combinatorial geometry of non-delightful triangulations.
Prevalence and Correlates of Exergaming in Youth
Authors: O’Loughlin Erin K. , Dugas Erika N. , Sabiston Catherine M. , O’Loughlin Jennifer L.
Published: October 2012

OBJECTIVES:

Less than 15% of children and adolescents participate regularly in physical activity (PA) and, with ever-increasing obesity, strategies to improve PA levels in youth are urgently needed. Exergaming offers a PA alternative that may be especially attractive in our increasingly technophilic society. However, there are no observational studies of exergaming in population-based samples of adolescents. The purpose of this study was to investigate potential sociodemographic, lifestyle, psychosocial, weight-related, and mental health correlates of exergaming as well as describe the type, timing, and intensity of exergaming in a population-based sample of adolescents.

METHODS:

Data on exergame use and potential sociodemographic, lifestyle, psychosocial, weight-related, and mental health correlates of exergaming were collected in mailed self-report questionnaires completed by 1241 grade 10 and 11 students from the Montreal area with a mean age of 16.8 years (SD = 0.05 years; 43% male) participating in the AdoQuest study. The independent correlates of exergaming were identified in multivariable logistic regression models.

RESULTS:

Nearly one-quarter (24%) of participants reported exergaming. Exergamers played 2 days per week on average, for ∼50 minutes each bout; 73% of exergamers played at a moderate or vigorous intensity. Exergamers were more likely than nonexergamers to be girls, to play nonactive video games, to watch ≥2 hours of television per day, to be stressed about weight, and to be nonsmokers.

CONCLUSIONS:

Many adolescents exergame at intensity levels that could help them achieve current moderate-to-vigorous PA recommendations. Interventions that encourage exergaming may increase PA and decrease sedentary behavior in select youth subgroups, notably in girls.
Neurodevelopment in Children Born to HIV-Infected Mothers by Infection and Treatment Status
Authors: Le Doaré Kirsty , Bland Ruth , Newell Marie-Louise
Published: October 2012

BACKGROUND:

We reviewed the impact of HIV, HIV exposure, and antiretroviral therapy/prophylaxis on neurodevelopmental outcomes of HIV-infected and HIV-exposed-uninfected infants and children.

METHODS:

A literature search of Medline, Embase, PsychINFO, Web of Science, PubMed, and conference Web sites (1990–March 2011) using the search terms, infant, child, HIV, neurodevelopment, cognition, language, and antiretroviral therapy, identified 31 studies of HIV/antiretroviral exposure using standardized tools to evaluate infant/child development as the main outcome. Articles were included if results were reported in children <16 years of age who were exposed to HIV and antiretrovirals in fetal/early life, and excluded if children did not acquire HIV from their mothers or were not exposed to antiretrovirals in fetal/early life.

RESULTS:

Infants who acquired HIV during fetal and early life tended to display poorer mean developmental scores than HIV-unexposed children. Mean motor and cognitive scores were consistently 1 to 2 SDs below the population mean. Mean scores improved if the infant received treatment before 12 weeks and/or a more complex antiretroviral regimen. Older HIV-infected children treated with highly active antiretroviral therapy demonstrated near normal global mean neurocognitive scores; subtle differences in language, memory, and behavior remained. HIV-exposed-uninfected children treated with antiretrovirals demonstrated subtle speech and language delay, although not universally.

CONCLUSIONS:

In comparison with resource-rich settings, HIV-infected and HIV-exposed-uninfected infants/children in resource-poor settings demonstrated greater neurodevelopmental delay compared with HIV-unexposed infants. The effects on neurodevelopment in older HIV-infected children commenced on antiretroviral therapy from an early age and HIV-exposed-uninfected children particularly in resource-poor settings remain unclear.
Moth herbivory enhances resource turnover in subarctic mountain birch forests?
Authors: Kaukonen Maarit , Ruotsalainen Anna Liisa , Wäli Piippa R. , Männistö Minna K. , Setälä Heikki , Saravesi Karita , Huusko Karoliina , Markkola Annamari
Published: October 2012

Massive moth outbreaks cause large‐scale damage in subarctic mountain birch forests with a concomitant decrease in carbon flux to mycorrhizal fungi and an increased deposition of dissolved carbon and nutrients as moth frass into soil. We investigated impacts of moth herbivory along three replicated gradients with three levels of moth herbivory (undamaged, once damaged, repeatedly damaged) on soil nutrient levels and biological parameters. We found an increase in soil nutrients and in the biomass of enchytraeid worms, which are key faunal decomposers. Fungi : bacteria ratio and C:N ratio decreased in humus with increasing severity of herbivory. Our findings suggest enhanced resource turnover in mountain birch forests due to massive moth herbivory. This may provide a shortcut for carbon and nutrient input to subarctic soils, which largely bypasses the main routes of carbon from plants to soil via mycorrhizal and litter‐decomposing fungi. Moreover, a temporal shift occurs in carbon allocation to soil, providing decomposers an opportunity to use an early‐season peak in resource availability. Our results suggest a hitherto unappreciated role of massive insect herbivore attacks on resource dynamics in subarctic ecosystems.
Health Inequities, HIV, and Public Health Practice: Examining the Role of Qualitative Research
Authors: O’Byrne Patrick
Published: October 2012

Although communicable disease public health practice has traditionally been based on numbers (e.g., incidence, prevalence), in the domain of HIV prevention and control qualitative research has recently become a more commonly employed data collection strategy. Of particular benefit, this approach can supplement the numbers which typically underpin public health strategies by generating in-depth understandings about how specific populations define, describe, and perceive their health and the factors that affect it. However, the use of qualitative research in public health must be explored; it cannot simply be accepted without reflection or analysis. To guide such an investigation, the work of Michel Foucault and Michael Hardt and Antonio Negri is used to examine two previous research projects that were undertaken by the author. The outcome of this analysis is the somewhat paradoxical conclusion that although qualitative research can enhance public health work, it may also be a strategy that generates the information that can be used for capturing and normalizing marginalized populations. Qualitative research, in other words, may be a technique that can be used to achieve biopolitical goals.
Intermittent Hypoxia-Induced Renal Antioxidants and Oxidative Damage in Male Mice: Hormetic dose Response
Authors: Sun Weixia , Yin Xia , Wang Yuehui , Tan Yi , Cai Lu , Wang Bo , Cai Jun , Fu Yaowen
Published: October 2012

Obstructive sleep apnea causes cardiovascular disease via chronic intermittent hypoxia (IH), which may be related to oxidative stress. Nuclear factor-erythroid 2-related factor 2 (Nrf2) is an important cellular defense mechanism against oxidative stress by regulating its down-stream multiple antioxidants. The present study was to define whether IH can induce renal pathogenic damage and if so, whether Nrf2 and its down-stream antioxidants are involved in IH-induced pathogenic changes. Mice were culled for exposure to intermittent air as control or IH that consisted of 20.9% O2/8% O2 FIO2 alternation cycles (30 episodes per h) with 20 seconds at the nadir FIO2 for 12 h a day during daylight. Short-term IH exposure (3 −7 days) induced significant increases in renal inflammatory response and antioxidant levels along with a reduction of the spontaneous content of malondialdehyde while long-term IH exposure (8 weeks) induced a significant decrease of antioxidant levels and significant increases of renal inflammation, oxidative damage, cell death, and fibrosis. This study suggests that IH induces a hormetic response, i.e.: short-term IH exposure is able to induce a protective response to protect the kidney from oxidative damage while long-term IH exposure is able to induce a damage effect on the kidney.
Impact of an Exercise Intervention on DNA Methylation in Skeletal Muscle From First-Degree Relatives of Patients With Type 2 Diabetes
Authors: Nitert Marloes Dekker , Dayeh Tasnim , Volkov Peter , Elgzyri Targ , Hall Elin , Nilsson Emma , Yang Beatrice T. , Lang Stefan , Parikh Hemang , Wessman Ylva , Weishaupt Holger , Attema Joanne , Abels Mia , Wierup Nils , Almgren Peter , Jansson Per-Anders , Rönn Tina , Hansson Ola , Eriksson Karl-Fredrik , Groop Leif , Ling Charlotte
Published: October 2012

To identify epigenetic patterns, which may predispose to type 2 diabetes (T2D) due to a family history (FH) of the disease, we analyzed DNA methylation genome-wide in skeletal muscle from individuals with (FH+) or without (FH−) an FH of T2D. We found differential DNA methylation of genes in biological pathways including mitogen-activated protein kinase (MAPK), insulin, and calcium signaling (P ≤ 0.007) and of individual genes with known function in muscle, including MAPK1, MYO18B, HOXC6, and the AMP-activated protein kinase subunit PRKAB1 in skeletal muscle of FH+ compared with FH− men. We further validated our findings from FH+ men in monozygotic twin pairs discordant for T2D, and 40% of 65 analyzed genes exhibited differential DNA methylation in muscle of both FH+ men and diabetic twins. We further examined if a 6-month exercise intervention modifies the genome-wide DNA methylation pattern in skeletal muscle of the FH+ and FH− individuals. DNA methylation of genes in retinol metabolism and calcium signaling pathways (P < 3 × 10−6) and with known functions in muscle and T2D including MEF2A, RUNX1, NDUFC2, and THADA decreased after exercise. Methylation of these human promoter regions suppressed reporter gene expression in vitro. In addition, both expression and methylation of several genes, i.e., ADIPOR1, BDKRB2, and TRIB1, changed after exercise. These findings provide new insights into how genetic background and environment can alter the human epigenome.
High-Dose Vitamin D Supplementation in People With Prediabetes and Hypovitaminosis D
Authors: Davidson Mayer B. , Duran Petra , Lee Martin L. , Friedman Theodore C.
Published: October 2012

OBJECTIVE

Low vitamin D levels predict the development of diabetes. This double-blind, randomized, control study in subjects with prediabetes and hypovitaminosis D evaluated whether high doses of vitamin D for 1 year affected insulin secretion, insulin sensitivity, and the development of diabetes.

RESEARCH DESIGN AND METHODS

A total of 1,551 subjects ≥40 years of age not known to have diabetes were screened with A1C levels. Subjects with A1C levels of 5.8–6.9% underwent an oral glucose tolerance test (OGTT). Subjects with prediabetes and 25-OH vitamin D (25-OHD) levels <30 ng/mL were randomized to receive weekly placebo (n = 53) or vitamin D (n = 56) with doses based on body weight and baseline 25-OHD levels. OGTTs were performed 3, 6, 9, and 12 months later. Insulin secretion and sensitivity were measured, and the proportion of subjects developing diabetes was assessed.

RESULTS

25-OHD levels rapidly rose from 22 to nearly 70 ng/mL after vitamin D supplementation with a mean weekly dose of 88,865 IU. There were no differences between the placebo and vitamin D groups regarding fasting plasma glucose, 2-h glucose, or insulin secretion and sensitivity or in the percent developing diabetes or returning to normal glucose tolerance. No subjects experienced increased serum or urinary calcium levels. At 12 months, A1C levels were significantly slightly less (0.2%) in the vitamin D group.

CONCLUSIONS

In individuals with prediabetes and hypovitaminosis D, doses of vitamin D supplementation designed to raise serum 25-OHD levels into the upper-normal range for 1 year had no effect on insulin secretion, insulin sensitivity, or the development of diabetes compared with placebo administration.
Catalytic Conversion of Methane to Methanol Using Cu-Zeolites
Authors: Alayon Evalyn Mae C. , Nachtegaal Maarten , Ranocchiari Marco , Van Bokhoven Jeroen A.
Published: October 2012

The conversion of methane to value-added liquid chemicals is a promising answer to the imminent demand for fuels and chemical synthesis materials in the advent of a dwindling petroleum supply. Current technology requires high energy input for the synthesis gas production, and is characterized
by low overall selectivity, which calls for alternative reaction routes. The limitation to achieve high selectivity is the high C–H bond strength of methane. High-temperature reaction systems favor gas-phase radical reactions and total oxidation. This suggests that the catalysts for
methane activation should be active at low temperatures. The enzymatic-inspired metal-exchanged zeolite systems apparently fulfill this need, however, methanol yield is low and a catalytic process cannot yet be established. Homogeneous and heterogeneous catalytic systems have been described
which stabilize the intermediate formed after the first C–H activation. The understanding of the reaction mechanism and the determination of the active metal sites are important for formulating strategies for the upgrade of methane conversion catalytic technologies.
Prediction of the solidification path of Al-4.37Cu-27.02Mg ternary eutectic alloy with a unified microsegregation model coupled with Thermo-Calc
Authors: Yan Erhu , Li Xinzhong , Su Yanqing , Liu Dongmei , Xu Daming , Guo Jingjie , Fu Hengzhi
Published: October 2012

An extended unified microsegregation model with solid back diffusion effects and five different dendrite morphologies was used to investigate the solidification path of Al-4.37Cu-27.02Mg (wt.%) ternary eutectic alloy at different cooling rates and solid back diffusion coefficients, coupled with Thermo-Calc. It was indicated that the cooling rates (Rf
) had no obvious effect on the solidification path which was (L + α) → (L + α + T) → (L + α + β + T); but the solid back diffusion coefficient (Φ) had a great effect on the solidification path, which evolved gradually from (L + α) → (L + α + T) → (L + α + β + T) into (L + α) → (L + α + T) when Φ increased from 0 to 1. The volume fractions of primary α phase (V
α), binary eutectic (V
2E) and ternary eutectic (V
3E) at each solidification path were calculated. It was shown that V
2E decreased with the increase of Rf
whereas V
3E increased and V
α was almost invariant. The dependence of V
2E, V
3E and Rf
were determined by linear regression analysis given as: V
2E = −2.5lgRf
+ 47.5; V
3E = 6.4lgRf + 47. Increase in Φ lead to increases in V
α and V
2E and decrease in V
3E. The predicted soldification paths and volume fractions of Al-4.37Cu-27.02Mg ternary eutectic alloy at different cooling rates were in good agreement with experimental results.
A DFT Study on the Cycloaddition of Dimethyl Acetylenedicarboxylate and 3,4-dihydroisoquinoline-N-oxide
Authors: Zardoost Mohammad Reza , Siadati Seyyed Amir
Published: October 2012

A theoretical study of the kinetics and mechanism of the second-order intermolecular cycloaddition of dimethyl acetylenedicarboxylate and [3,4-dihydroiso-quinoline-N-oxide] was performed using DFT methods at B3LYP levels of theory with a 6-311G (d,p) basis set at 298.15 K. Equilibrium molecular geometries and harmonic vibrational frequencies of the reactants, transition state and product were calculated. The effect of solvent on the kinetic and thermodynamic parameters of the reaction were investigated. The calculated rate constants and activation parameters showed good agreement with experimental results. These calculations indicated that the reaction proceeds through a synchronous concerted mechanism.
Synthesis of Ethylenediamine in a Tubular Reactor: Experimental and Theoretical Kinetics
Authors: Chen Xinzhi , Zhou Shaodong , Zhang Haijiang , Qian Chao
Published: October 2012

The mechanism and kinetics of the ammonolysis of 1,2-dichloroethane in the liquid phase have been investigated using a combination of experimental and theoretical methods. The experiments was carried out in tubular reactors. The reaction as carried out at 6 MPa and 160°C, with 5 min of residence time, 60%wt of ammonia concentration and a reactant molar ratio n(ammonia): n(1,2-dichloroethane) = 30: 1 gave the optimum result. The parameters of the reaction kinetics were obtained using linear regression, and the reaction rate constant at a low conversion of 1,2-dichloroethane is 1.12s −1 (160°C, 6 MPa) according to the calculated kinetics equation. Theoretical calculation was performed using density functional theory and the reaction profile so calculated gave the dominant pathway. The results of calculation also indicated a reaction order of approximately 1 at low conversions of 1,2-dichloroethane with a related rate constant of 0.51s −1 (160°C, 6 MPa), which agreed with the experimental results.
Transfistula Anorectoplasty (TFARP): Better Surgical Technique for the Management of Vestibular Fistula
Authors: Khan JG , Ali MA , Yusuf MA , Islam MK , Rahaman MA , Hasina K , Akter J , Sharif AR , Talukder AR , Ahsan AI
Published: October 2012

Background: Many approach have been tried for management of vestibular fistula, most of them have post operative complication like wound infection, wound dehiscence, more hospital stay which compromise the functional out come and aesthetic appearance of the perineum. Objective: The aim of present study was to see the effectiveness of Transfistula Anorectplasty (TFARP) Which was required minimal dissection without interruption of perineal body and perineal skin. Methodology: The cross sectional study on 43 patients with vestibular fistula were held in Dhaka Shishu Hospital from September 2008 to April 2010. Patients were operated after obtaining informed consent and standard bowel preparation. Data on demographics, operation time and postoperative complications were collected as a questionnaire and plotted on Microsoft Excel and analyzed systematically by SPSS version 17. Patients were followed up for a period of 2½ months postoperatively. Results: There is no statistical deference in patient population regarding age, geographical distribution, and clinical presentation. Mean operation time was 76.5 min for TFARP and 84.34 min for ASARP. Two (02) cases had wound infection after TFARP operation and 11 patients after ASARP operation. One patient develops partial wound dehiscence after TFARP and was healed after conservative treatment within 7 days. On the other hand 05 patients developed partial wound dehiscence and 04 patients developed complete wound disruption after ASARP which were also treated conservatively need more than 2 weeks on an average. Mean hospital stay were 6.45 days after TFARP operation and mean hospital stay were 7.87 days after ASARP operation. 20 neonates and infant who were treated by TFARP operation have good bowel movement without laxative and symmetrical anal contraction after stimulation. Conclusion: TFARP is an operation produce less morbidity and is more effective procedures and superior procedures than that of ASARP operation and give aesthetic appearance of the perineum. DOI: http://dx.doi.org/10.3329/jssmc.v4i1.11996 J Shaheed Suhrawardy Med Coll, 2012;4(1):10-14
Role of FNAC in the Evaluation of Solitary Cold Thyroid Nodule
Authors: Quddus MA , Alimuzzaman M , Sardar MKH
Published: October 2012

Background: Fine needle aspiration cytology (FNAC) provides diagnostic information as to the nature of a solitary cold thyroid nodule. Objective: This study was carried out to evaluate the effectiveness of FNAC as a diagnostic method of malignancy in solitary cold thyroid nodule. Methodology: This cross sectional study was carried out among 40 cases of solitary cold thyroid nodule who were admitted in the Department Surgery and ENT of DMCH during period of January 2006 to December 2007. This study was conducted using convient type of non-probability sampling technique Data were collected by face to face interview, clinical examination and finding of both cytological and histological examination. Result: The study revealed that the mean age of the patients was 35.8± 2.36 year with female to male ratio 2.6:1. For all the patients, FNAC were done preoperatively and after definitive surgery histopathology were done for confirmed diagnosis and results of FNAC were compared with histopathology reports. 30 cases were diagnosed as benign and 10 case diagnosed as malignant cold thyroid solitary nodules among 40 cases. In this study, the sensitivity of FNAC was 80% for the presence of malignancy and specificity 96.7% for the absence of malignancy in solitary cold thyroid nodules. The positive predictive value was 88.9% and negative predictive value was 92.5% and diagnostic accuracy was 92.5%. Conclusion: FNAC can be used as a diagnostic method for the evaluation of malignancy as well as in the management of solitary cold thyroid nodule which has reasonable sensitivity and specificity. Finally, it is a quick, cost effective procedure and has excellent patient compliance. DOI: http://dx.doi.org/10.3329/jssmc.v4i1.11997 J Shaheed Suhrawardy Med Coll, 2012;4(1):15-17
Outcome of Dapsone in the Treatment of Ashy Dermatosis
Authors: Hossain MS , Bhuian I , Wahab A , Khan SA
Published: October 2012

Background: Ashy dermatosis or Erythema Dyschromicum Perstans is a rare disorder of unknown etiology characterized by asymptomatic,slowly progressive, ashen-gray macular pigmentation of the skin. Various therapies have been tried without any benefit. The anti-inflammatory activity of dapsone on Erythema Dyschromicum Perstans may be the first oral treatment option. Objective: The aim of the present study was to evaluate the efficacy of dapsone in the treatment of ashy dermatosis. Methodology: This study was carried out on total thirty (30) cases having ashy dermatosis & age group 20-60 years were selected for the study of which 16 females & 14 males during the period of January 2010 to December 2011 in the Department of Dermatology & Venereology of Shaheed Suhrawardy Medical College Hospital and Bangabandhu Sheikh Mujib Medical University at Dhaka city of Bangladesh. All the cases were diagnosed clinically & confirmed by histopathological examination. The patients were given Dapsone 100 mg daily for three months & follow up was done for the next 3 months. Results: 16(53.33%) females & 14(46.66%) males were included in the study. Out of thirty patients, two patients (6.66%) shown excellent response, seven patients (23.33%) shown good response, eight (26.66%) patients shown fair response, 8 patients (26.66%) shown poor response & remaining five patients (16.66%) did not show any response clinically. So improvement was shown in 25(83.33%) cases and 5(16.66%) cases show no improvement at all. Conclusion: This study suggests that dapsone has significant efficacy profile for treatment option of ashy dermatosis. DOI: http://dx.doi.org/10.3329/jssmc.v4i1.11998 J Shaheed Suhrawardy Med Coll, 2012;4(1):18-21
2-(4-Diethoxymethylphenyl)-6-(4-nitrophenyl)-4-phenyl-1,3-diazabicyclo[3.1.0]hex-3-ene
Authors: Kiyani Hamzeh
Published: October 2012

The photochromic compound was obtained from 4-diethoxymethyl-benzaldehyde and trans-2-benzoyl-3-(4-nitrophenyl)aziridine via a three component reaction. The structure of this compound was characterized by elemental analysis, 1H-NMR, 13C-NMR and UV-Visible spectral data.
Degradation Kinetics of Anthocyanins from European Cranberrybush (Viburnum opulus L.) Fruit Extracts. Effects of Temperature, pH and Storage Solvent
Authors: Moldovan Bianca , David Luminiţa , Chişbora Cristian , Cimpoiu Claudia
Published: October 2012

European cranberrybush (Viburnum opulus L.) fruits are well known for their biological properties, of which some are due to the presence of anthocyanins in the berries. Current literature provides little information concerning these fruits. The stability of anthocyanins from Viburnum opulus fruits, in aqueous and ethanolic extracts, stored under darkness for 7 days at different temperatures (2 °C, 37 °C and 75 °C) and pH values (pH = 3 and 7), was studied here. The lowest stability was showed by the anthocyanins from the water extract stored at 75 °C and pH = 7, with half-life and constant rate values of 1.98 h and 0.3488 h−1, respectively. The results showed a good correlation between the total anthocyanin content (determined using the pH differential method) and the time of storage, with determination coefficients varying from R2 = 0.9298 to R2 = 0.9971. Results indicate that the storage degradation of anthocyanins followed first-order reaction kinetics under all investigated conditions.
The Use of California Sagebrush (Artemisia californica) Liniment to Control Pain
Authors: Adams James D.
Published: October 2012

The incidence of arthritis is increasing every year, as does the need for pain medication. The current work reviews an American Indian liniment that is traditionally used for pain therapy. The chemistry, therapeutic use and safety of the liniment are reviewed. The liniment contains monoterpenoids, sesquiterpenes, flavonoids, alkaloids and other compounds.
Capability of C-Band SAR for Operational Wetland Monitoring at High Latitudes
Authors: Reschke Julia , Bartsch Annett , Schlaffer Stefan , Schepaschenko Dmitry
Published: October 2012

Wetlands store large amounts of carbon, and depending on their status and type, they release specific amounts of methane gas to the atmosphere. The connection between wetland type and methane emission has been investigated in various studies and utilized in climate change monitoring and modelling. For improved estimation of methane emissions, land surface models require information such as the wetland fraction and its dynamics over large areas. Existing datasets of wetland dynamics present the total amount of wetland (fraction) for each model grid cell, but do not discriminate the different wetland types like permanent lakes, periodically inundated areas or peatlands. Wetland types differently influence methane fluxes and thus their contribution to the total wetland fraction should be quantified. Especially wetlands of permafrost regions are expected to have a strong impact on future climate due to soil thawing. In this study ENIVSAT ASAR Wide Swath data was tested for operational monitoring of the distribution of areas with a long-term SW near 1 (hSW) in northern Russia (SW = degree of saturation with water, 1 = saturated), which is a specific characteristic of peatlands. For the whole northern Russia, areas with hSW were delineated and discriminated from dynamic and open water bodies for the years 2007 and 2008. The area identified with this method amounts to approximately 300,000 km2 in northern Siberia in 2007. It overlaps with zones of high carbon storage. Comparison with a range of related datasets (static and dynamic) showed that hSW represents not only peatlands but also temporary wetlands associated with post-forest fire conditions in permafrost regions. Annual long-term monitoring of change in boreal and tundra environments is possible with the presented approach. Sentinel-1, the successor of ENVISAT ASAR, will provide data that may allow continuous monitoring of these wetland dynamics in the future complementing global observations of wetland fraction.
Evaluation of Intrinsic Image Algorithms to Detect the Shadows Cast by Static Objects Outdoors
Authors: Isaza Cesar , Salas Joaquín , Raducanu Bogdan
Published: October 2012

In some automatic scene analysis applications, the presence of shadows becomes a nuisance that is necessary to deal with. As a consequence, a preliminary stage in many computer vision algorithms is to attenuate their effect. In this paper, we focus our attention on the detection of shadows cast by static objects outdoors, as the scene is viewed for extended periods of time (days, weeks) from a fixed camera and considering daylight intervals where the main source of light is the sun. In this context, we report two contributions. First, we introduce the use of synthetic images for which ground truth can be generated automatically, avoiding the tedious effort of manual annotation. Secondly, we report a novel application of the intrinsic image concept to the automatic detection of shadows cast by static objects in outdoors. We make both a quantitative and a qualitative evaluation of several algorithms based on this image representation. For the quantitative evaluation, we used the synthetic data set, while for the qualitative evaluation we used both data sets. Our experimental results show that the evaluated methods can partially solve the problem of shadow detection.