bluuebunny/crossref_metadata_2025 huggingface dataset:
Ensemble rainfall forecasting with numerical weather prediction and radar‐based nowcasting models
Authors: He Shan , Raghavan Srivatsan V. , Nguyen Ngoc Son , Liong Shie‐Yui
Published: February 2012

The overall objective of this study is to improve the forecasting accuracy of the precipitation in the Singapore region by means of both rainfall forecasting and nowcasting. Numerical Weather Predication (NWP) and radar‐based rainfall nowcasting are two important sources for quantitative precipitation forecast. In this paper, an attempt to combine rainfall prediction from a high‐resolution mesoscale weather model and a radar‐based rainfall model was performed. Two rainfall forecasting methods were selected and examined: (i) the weather research and forecasting model (WRF); and (ii) a translation model (TM). The WRF model, at a high spatial resolution, was run over the domain of interest using the Global Forecast System data as initializing fields. Some heavy rainfall events were selected from data record and used to test the forecast capability of WRF and TM. Results obtained from TM and WRF were then combined together to form an ensemble rainfall forecasting model, by assigning weights of 0.7 and 0.3 weights to TM and WRF, respectively. This paper presented results from WRF and TM, and the resulting ensemble rainfall forecasting; comparisons with station data were conducted as well. It was shown that results from WRF are very useful as advisory of anticipated heavy rainfall events, whereas those from TM, which used information of rain cells already appearing on the radar screen, were more accurate for rainfall nowcasting as expected. The ensemble rainfall forecasting compares reasonably well with the station observation data. Copyright © 2012 John Wiley & Sons, Ltd.
Identification of CXCL5/ENA‐78 as a factor involved in the interaction between cholangiocarcinoma cells and cancer‐associated fibroblasts
Authors: Okabe Hirohisa , Beppu Toru , Ueda Mitsuharu , Hayashi Hiromitsu , Ishiko Takatoshi , Masuda Toshiro , Otao Ryu , Horlad Hasita , Mima Kosuke , Miyake Keisuke , Iwatsuki Masaaki , Baba Yoshifumi , Takamori Hiroshi , Jono Hirofumi , Shinriki Satoru , Ando Yukio , Baba Hideo
Published: February 2012

Knowledge of tumor‐stromal interactions is essential for understanding tumor development. We focused on the interaction between cholangiocarcinoma and cancer‐associated fibroblasts (CAFs) in intrahepatic cholangiocarcinoma and reported their positive interaction in vitro and in vivo. The aim of this study is to identify the key protein involved in the interaction between cholangiocarcinoma cells and CAFs and its role on cholangiocarcinoma progression. Using the conditioning medium from cholangiocarcinoma cells, hepatic stellate cells and coculture of them, Protein‐Chip analysis with SELDI–TOF–MS showed that the peak of an 8,360‐Da protein remarkably increased in the coculture medium. This protein was identified as CXCL5/ENA78, epithelial cell‐derived neutrophil‐activating peptide‐78, by q‐TOF/MS/MS analysis. Two cholangiocarcinoma cell lines, HuCCT1 and RBE, produced CXCL5 that promoted their invasion and migration in an autocrine fashion. These effects of CXCL5 significantly decreased by inhibition of CXC‐receptor 2, which is the receptor for CXCL5. In addition, IL‐1β produced by hepatic stellate cells induced the expression of CXCL5 in cholangiocarcinoma cells. In human tissue samples, a significant correlation was observed between CAFs and CXCL5 produced by cholangiocarcinoma cells in intrahepatic cholangiocarcinoma (p = 0.0044). Furthermore, the high‐CXCL5‐expression group exhibited poor overall survival after curative hepatic resection (p = 0.027). The presence of tumor‐infiltrating neutrophils expressing CD66b was associated with CXCL5 expression in tumor cells (p < 0.0001). These data suggest that CXCL5 is important for the interaction between cholangiocarcinoma and CAFs, and inhibition of tumor‐stromal interactions may be a useful therapeutic approach for cholangiocarcinoma.
Subsurface near‐infrared laser stimulation of the periprostatic cavernous nerves
Authors: Tozburun Serhat , Lagoda Gwen A. , Burnett Arthur L. , Fried Nathaniel M.
Published: February 2012

Successful identification and preservation of the cavernous nerves (CN), which are responsible for sexual function and vulnerable to damage during prostate cancer surgery, will require subsurface detection of the CN's beneath a thin fascia layer. This study explores the feasibility of optical nerve stimulation (ONS) in the rat with a fascia layer placed over the CN. Two near‐infrared diode lasers with wavelengths of 1455 and 1550 nm were operated in continuous‐wave mode for stimulation of the CN in 8 rats, in vivo. Successful ONS was confirmed by an intracavernous pressure (ICP) response in the rat penis at 1455 nm through fascia with a thickness up to 110 μm and at 1550 nm through fascia with a thickness up to 450 μm. Higher incident laser power was required to produce an ICP response as fascia thickness was increased. Also, weaker and slower ICP responses were observed as fascia thickness was increased. Subsurface ONS of the rat CN at a depth of 450 μm using a 1550 nm laser is feasible as an intermediate step towards developing ONS as an intra‐operative diagnostic tool for identification and preservation of the cavernous nerves during prostate cancer surgery. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Curvature correction for microiterative optimizations with QM/MM electronic embedding
Authors: Rokob Tibor András , Rulíšek Lubomír
Published: February 2012

One of the most common methods to treat the electrostatic effect of the environment in QM/MM calculations is to include the MM atoms as point charges in the QM Hamiltonian. In this case, a microiterative geometry optimization ignoring the QM contributions to the forces in the relaxation of the environment cannot yield exact stationary points. One solution that has been suggested in the literature is based on using a constant additive correction to the MM gradient during the microiterations, determined in the preceding macroiteration. Here, we analyze the convergence properties of the gradient correction method and point out that a smooth relaxation is not ensured if the curvature of the approximate, MM‐based description of the potential energy surface of the environment is too small in comparison with the exact one. We suggest a computationally cheap second‐order correction that uses an estimated Hessian from the Davidon–Fletcher–Powell method to tackle the problems caused by the too small curvature. Test calculations on four metalloenzymatic systems (∼100 QM atoms, ∼2000 relaxed MM atoms, ∼20,000 atoms in total) show that our approach efficiently restores the convergence where gradient correction alone would lead to oscillations. © 2012 Wiley Periodicals, Inc.
Visible light photocatalytic activity of TiO2/heat‐treated PVC film
Authors: Li Xueyan , Shi Lei , Wang Desong , Luo Qingzhi , An Jing
Published: February 2012

BACKGROUND: Semiconductor TiO2 has been investigated extensively due to its chemical stability, nontoxicity and inexpensiveness. However, the wide band gap of anatase TiO2 (about 3.2 eV) only allows it to absorb UV light. TiO2 nanoparticles modified by conditional conjugated polymers show excellent photocatalytic activity under visible light. However, these conjugated polymers are not only expensive, but also difficult to process. Polyvinyl chloride (PVC) was heat‐treated at high temperature to remove HCl and a CC conjugated chain structure was obtained. When TiO2 nanoparticles were dispersed into the conjugated polymer film derived from PVC, this composites film exhibited high visible light photocatalytic activity.

RESULTS: The photocatalytic activity of TiO2/heat‐treated PVC (HTPVC) film was investigated by degrading Rhodamine B (RhB) under visible light irradiation. The photodegradation of RhB follows apparent first‐order kinetics. The rate constants of RhB photodegradation in the presence of the TiO2/HTPVC films with different mass content of TiO2 are 16–56 and 4–14 times that obtained in the presence of the pure HTPVC and TiO2/polymethyl methacrylate (PMMA) composite film, respectively. The TiO2/HTPVC film showed excellent photocatalytic activity and stability after 10 cycles under visible light irradiation.

CONCLUSION: TiO2/HTPVC film exhibits high visible light photocatalytic activity and stability. Copyright © 2012 Society of Chemical Industry
Central gland and peripheral zone prostate tumors have significantly different quantitative imaging signatures on 3 tesla endorectal, in vivo T2‐weighted MR imagery
Authors: Viswanath Satish E. , Bloch Nicholas B. , Chappelow Jonathan C. , Toth Robert , Rofsky Neil M. , Genega Elizabeth M. , Lenkinski Robert E. , Madabhushi Anant
Published: February 2012

Purpose:

To identify and evaluate textural quantitative imaging signatures (QISes) for tumors occurring within the central gland (CG) and peripheral zone (PZ) of the prostate, respectively, as seen on in vivo 3 Tesla (T) endorectal T2‐weighted (T2w) MRI.

Materials and Methods:

This study used 22 preoperative prostate MRI data sets (16 PZ, 6 CG) acquired from men with confirmed prostate cancer (CaP) and scheduled for radical prostatectomy (RP). The prostate region‐of‐interest (ROI) was automatically delineated on T2w MRI, following which it was corrected for intensity‐based acquisition artifacts. An expert pathologist manually delineated the dominant tumor regions on ex vivo sectioned and stained RP specimens as well as identified each of the studies as either a CG or PZ CaP. A nonlinear registration scheme was used to spatially align and then map CaP extent from the ex vivo RP sections onto the corresponding MRI slices. A total of 110 texture features were then extracted on a per‐voxel basis from all T2w MRI data sets. An information theoretic feature selection procedure was then applied to identify QISes comprising T2w MRI textural features specific to CG and PZ CaP, respectively. The QISes for CG and PZ CaP were evaluated by means of Quadratic Discriminant Analysis (QDA) on a per‐voxel basis against the ground truth for CaP on T2w MRI, mapped from corresponding histology.

Results:

The QDA classifier yielded an area under the Receiver Operating characteristic curve of 0.86 for the CG CaP studies, and 0.73 for the PZ CaP studies over 25 runs of randomized three‐fold cross‐validation. By comparison, the accuracy of the QDA classifier was significantly lower when (a) using all 110 texture features (with no feature selection applied), as well as (b) a randomly selected combination of texture features.

Conclusion:

CG and PZ prostate cancers have significantly differing textural quantitative imaging signatures on T2w endorectal in vivo MRI. J. Magn. Reson. Imaging 2012;36:213–224. © 2012 Wiley Periodicals, Inc.
Carboxy‐terminal sequence variation of LMP1 gene in Epstein–Barr‐virus‐associated mononucleosis and tumors from Serbian patients
Authors: Banko Ana , Lazarevic Ivana , Cupic Maja , Stevanovic Goran , Boricic Ivan , Jovanovic Tanja
Published: February 2012

Seven strains of Epstein–Barr virus (EBV) are defined based on C‐terminal sequence variations of the latent membrane protein 1 (LMP1). Some strains, especially those with a 30‐bp deletion, are thought to be related to tumorigenic activity and geographical localization. The aims of the study were to determine the prevalence of different LMP1 strains and to investigate sequence variation in the C‐terminal region of LMP1 in Serbian isolates. This study included 53 EBV‐DNA‐positive plasma and tissue block samples from patients with mononucleosis syndrome, renal transplantation, and tumors, mostly nasopharyngeal carcinoma. The sequence of the 506‐bp fragment of LMP1 C terminus was used for phylogenetic analyses and identification of LMP1 strains, deletions, and mutations. The majority of isolates were non‐deleted (66%), and the rest had 30‐bp, rare 69‐bp, or yet unknown 27‐bp deletions, which were not related to malignant or non‐malignant isolate origin. However, the majority of 69‐bp deletion isolates were derived from patients with nasopharyngeal carcinoma. Less than five 33‐bp repeats were found in the majority of non‐deleted isolates (68.6%), whereas most 69‐bp deletion isolates (75%) had five or six repeats. Serbian isolates were assigned to four LMP1 strains: B95‐8 (32.1%), China 1 (24.5%), North Carolina (NC; 18.9%), and Mediterranean (Med; 24.5%). In NC isolates, three new mutations unique for this strain were identified. EBV EBNA2 genotypes 1 and 2 were both found, with dominance of genotype 1 (90.7%). This study demonstrated noticeable geographical‐associated characteristics in the LMP1 C terminus of investigated isolates. J. Med. Virol. 84:632–642, 2012. © 2011 Wiley Periodicals, Inc.
Changes induced by chronic in vivo load alteration in the tibiofemoral joint of mature rabbits
Authors: Roemhildt Maria L. , Beynnon Bruce D. , Gardner‐Morse Mack , Badger Gary , Grant Calsey
Published: February 2012

We investigated the relationship between the magnitude and duration of chronic compressive load alteration and the development and progression of degenerative changes in the rabbit tibiofemoral joint. Varus loading devices were attached to the hind limb of mature NZW rabbits. Altered compressive loads of 0%, 50%, and 80% body weight (BW) were applied to the tibiofemoral joint for 12 h per day for 12 and 24 weeks (n = 4 animals/group). Compartment‐specific assessment of the tibial plateau included histological assessments (articular cartilage, calcified cartilage, and subchondral bone thicknesses, degeneration score, and articular cartilage cellularity) and biomechanical measures (aggregate modulus, permeability, Poisson's ratio). Analyses of variance techniques were used to examine the relationship between each outcome measure with load magnitude and duration as independent variables in the model. Degenerative changes developed in the medial compartment with increased magnitude of compressive loading and included fibrillation, increased degeneration score, and reduced cellularity of the articular cartilage. Increased calcified cartilage thickness was observed in both the medial and lateral compartments following exposure to altered loading of 80% BW for 24 weeks. This work demonstrates that in vivo chronic compressive load alteration to the tibiofemoral joint can initiate progressive macroscopic and histological‐based degenerative changes analogous to the early changes occurring in OA. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 30:1413–1422, 2012
Decision‐making for mergers and acquisitions: the role of agency issues and behavioral biases
Authors: Dhir Sanjay , Mital Amita
Published: February 2012

Rational and dynamic strategies can be formed by applying game theory along with real options tools for incorporating bias analysis in takeover decisions.
Collaborative Marketing in a Regional Destination: Evidence from Central Florida
Authors: Wang Youcheng , Hutchinson Joe , Okumus Fevzi , Naipaul Sandra
Published: February 2012

This paper aims to explore a collaborative approach to regional destination marketing. Research questions were constructed for empirical data collection via documentary analysis and semistructured interviews with senior executives of destination marketing organizations (DMOs) in the Central Florida region. The research findings suggest that collaboration among DMOs is beneficial in terms of cost reduction and market penetration. Several issues emerge as inhibiting factors to their collaborative destination marketing efforts. Discussions and implications are provided both from a theoretical and practical perspective on the basis of the findings of the study. Copyright © 2012 John Wiley & Sons, Ltd.
Seaside sparrow reproductive success in relation to prescribed fire
Authors: Kern Rebecca A. , Shriver W. Gregory , Bowman Jacob L. , Mitchell Laura R. , Bounds Dixie L.
Published: February 2012

In North American tidal marshes, prescribed burning has been used to manage waterfowl, furbearers, invasive plants, and fuels, but its effects on non‐target species, such as marsh birds, are relatively unknown, particularly in the mid‐Atlantic region. To address this informational need, we studied seaside sparrows (Ammodramus maritimus) in Dorchester County, Maryland, where prescribed marsh burning has been conducted since at least the 1930s. We compared the effects of 4 fire treatments (<1 yr since burn, 1–2 yr since burn, 3–4 yr since burn, and ≥5 yr since burn) on seaside sparrow density and reproductive output, and examined the impact of fire treatment, nest‐site characteristics, and weather on nest survival from 2007 to 2009. We found that nest and territory densities were greatest on marshes <1 year post‐burn, indicating that burning did not displace seaside sparrows. Nest and territory densities also declined as time since burn increased, and were about 50% less on marshes that were ≥5 years post‐burn compared to marshes <1 year post‐burn. Egg density (the number of eggs produced per ha) was 50% greater on marshes burned <1 year ago than on marshes burned 3–4 years ago, but we found no difference in fledgling density, indicating that predation may have disproportionately affected recently‐burned marshes. Study year and percent cover of smooth cordgrass (Spartina alterniflora) best explained nest survival, which was lowest in 2009, a year with high precipitation and tides. We recommend that prescribed burning continue to be used at 1–4 year intervals to maintain habitat quality for breeding seaside sparrows in the mid‐Atlantic, but suggest that the effects of fire management may be less influential than predicted impacts of global climate change. © 2012 The Wildlife Society.
Estimating breeding season abundance of golden‐cheeked warblers in Texas, USA
Authors: Mathewson Heather A. , Groce Julie E. , Mcfarland Tiffany M. , Morrison Michael L. , Newnam J. Cal , Snelgrove R. Todd , Collier Bret A. , Wilkins R. Neal
Published: February 2012

Population abundance estimates using predictive models are important for describing habitat use and responses to population‐level impacts, evaluating conservation status of a species, and for establishing monitoring programs. The golden‐cheeked warbler (Setophaga chrysoparia) is a neotropical migratory bird that was listed as federally endangered in 1990 because of threats related to loss and fragmentation of its woodland habitat. Since listing, abundance estimates for the species have mainly relied on localized population studies on public lands and qualitative‐based methods. Our goal was to estimate breeding population size of male warblers using a predictive model based on metrics for patches of woodland habitat throughout the species' breeding range. We first conducted occupancy surveys to determine range‐wide distribution. We then conducted standard point‐count surveys on a subset of the initial sampling locations to estimate density of males. Mean observed patch‐specific density was 0.23 males/ha (95% CI = 0.197–0.252, n = 301). We modeled the relationship between patch‐specific density of males and woodland patch characteristics (size and landscape composition) and predicted patch occupancy. The probability of patch occupancy, derived from a model that used patch size and landscape composition as predictor variables while addressing effects of spatial relatedness, best predicted patch‐specific density. We predicted patch‐specific densities as a function of occupancy probability and estimated abundance of male warblers across 63,616 woodland patches accounting for 1.678 million ha of potential warbler habitat. Using a Monte Carlo simulation, our approach yielded a range‐wide male warbler population estimate of 263,339 (95% CI: 223,927–302,620). Our results provide the first abundance estimate using habitat and count data from a sampling design focused on range‐wide inference. Managers can use the resulting model as a tool to support conservation planning and guide recovery efforts. © 2012 The Wildlife Society.
Calcium carbonate composite hydrogel films: Particle packing and optical properties
Authors: Guvendiren Murat , Soshinski Andre A. , Gambogi Robert J. , Yang Shu
Published: February 2012

Composite hydrogel films are prepared by photocrosslinking of partially polymerized poly(2‐hydroxyethyl methacrylate‐co‐methyl methacrylate) prepolymer solution dispersed with aragonite precipitated calcium carbonate (PCC) particles. The effects of PCC aspect ratio (AR, 4.2–6.6) and volume fraction (ϕPCC) are studied with respect to the prepolymer viscosity, the maximum packing fraction (ϕm), and optical properties. ϕmobtained from Kreigher–Dougherty fitting is found to decrease with increasing AR of PCC particles, from ϕm= 0.33 (AR = 4.2) to ϕm= 0.21 (AR = 6.6). Scanning electron microscopy images revealed that the particles are uniformly dispersed and randomly orientated in the polymer network when ϕPCC< ϕm. Optically transparent neat hydrogel films become opaque with increasing particle concentration and AR because of random light scattering from the PCC particles. A whiteness up to 80 is obtained from 100 μm thick composite hydrogel film in the wet state with PCC AR = 6.6 and ϕPCC= 0.19 (near ϕm). POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers
The rheological, thermostable, and mechanical properties of polypropylene/fullerene C60 nanocomposites with improved interfacial interaction
Authors: Wan Dong , Wang Yujie , Wen Xin , Qiu Jian , Jiang Zhiwei , Tan Haiying , Tang Tao
Published: February 2012

Polypropylene (PP)/C60 nanocomposites with improved interfacial interaction were prepared via in situ melt radical reaction. It was found that the relaxation time of PP/C60 nanocomposites containing peroxide increased due to the reaction between C60 and PP macroradicals and the formation of long chain branched or crosslinking structure. Thermogravimetric analysis (TGA) results showed that the thermal stability of PP/C60 nanocomposites was enhanced. The initial decomposition temperatures and activation energy of PP/C60 nancomposites were strongly influenced by the content of unreacted C60. Because of the improved interfacial interaction, PP/C60 nanocomposites containing peroxide showed obvious increase in tensile strength, Young' modulus, flexural strength, flexural modulus, and impact strength, compared to PP/C60 nanocomposites (without peroxide) containing the same content of C60. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers
A new microcellular injection molding process for polycarbonate using water as the physical blowing agent
Authors: Peng Jun , Turng Lih‐Sheng , Peng Xiang‐Fang
Published: February 2012

This article presents a new process for producing microcellular injection molded plastic parts using water as the physical blowing agent and micro‐scaled particles as the cell nucleating agents. Distilled water with dissolved salt were fed through the hopper of an injection molding machine at a preset rate and mixed with polycarbonate (PC) in the machine barrel. Microcellular PC tensile bars were then injection molded with different shot volumes, water/salt solution feed rates, and salt concentrations. Tiny salt crystals of 10–20 μm recrystallized during molding acted as nucleating agents in the PC foamed parts. The surface roughness, mechanical properties, and microstructure of the solid and foamed parts were measured and compared with microcellular injection molded parts using supercritical fluid (SCF) nitrogen as the physical blowing agent. At a similar weight reduction of about 10%, the water foamed PC parts have a smooth surface comparable to that of solid injection molded parts. They also possess similar, if not better, mechanical properties compared to SCF nitrogen foamed PC parts. Without the nucleating agent, PC/water foamed parts exhibit much larger and fewer bubbles within the molded parts. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers
Preparation and characteristics of a novel nano‐sized calcium carbonate (nano‐CaCo3)‐supported nucleating agent of poly(L‐lactide)
Authors: Han Lijing , Han Changyu , Bian Junjia , Bian Yijie , Lin Haijuan , Wang Xuemei , Zhang Huiliang , Dong Lisong
Published: February 2012

Nano‐sized calcium carbonate (nano‐CaCO3)‐supported nucleating agent for poly(L‐lactide) (PLLA) was prepared by supporting calcium phenylphosphonate (PPCa) on nano‐CaCO3 surface. The thermal properties of phenylphosphonic acid (PPOA) and nano‐CaCO3‐supported nucleating agent and its dispersion in PLLA matrix were investigated by differential scanning calorimetry and field emission scanning electron microscopy. The results indicated that the formation of nucleating agent supported on nano‐CaCO3 was attributed to the chemical reaction between nano‐CaCO3 and PPOA. The nano‐CaCO3‐supported nucleating agents were dispersed evenly in the PLLA matrix even with 5 wt% loading. The supported nucleating agent was added to PLLA to examine its nucleating ability for PLLA. The results of the investigation showed that the nano‐CaCO3‐supported nucleating agent exhibited higher nucleation ability compared to PPCa nucleating agent. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers
New Takes on Nitrate Ester Chemistry: Salts with Oxygen‐Rich Ammonium Cations
Authors: Drake Gregory W. , Bolden Sarah , Dailey Jami , McQuaid Michael J. , Parrish Damon
Published: February 2012

Nitrate (anion) salts with nitroxy‐functionalized ammonium cations were synthesized. Several revealed surprising thermal and hydrolytic stability. Various physical properties were measured, and Gibbs free energy (ΔGr(298)) differences between the salts and postulated products of their thermal decomposition were computed. The computed differences indicate that salts with cations that have more than one nitroxy group are endothermic at 298 K. Nevertheless, the stability observed for some salts with this property indicates that kinetic barriers are sufficient to prevent facile decomposition at this temperature. This is in contrast to the case observed for nitrate salts of nitroxy‐functionalized ammonium cations with acidic protons.
Vapor Pressure of Explosives: A Critical Review
Authors: Östmark Henric , Wallin Sara , Ang How Ghee
Published: February 2012

A critical review of vapor pressure data for military, civilian, and homemade explosives, explosive precursors, and explosive taggants is presented. It gives reference to a large number of papers and reports presenting original vapor pressure measurements and additionally an overview of measurements techniques for vapor pressure measurements and data analysis of vapor pressure measurements. Vapor pressure data, including Clausius–Clapeyron parameters (A and B in: log10(p)=A−B/T), calculated vapor pressure at room temperature, and heat of sublimation or heat of vaporization are included. The following classes of compounds are treated; military explosives (TNT, RDX, HMX, PETN, HNS, TATB, AP), civilian explosives (NG, EGDN, AN), explosive taggants (EGDN, DNMB, 2‐NT, 4‐NT), home‐made explosives (TATP, DADP, HMTD). and explosive precursors [HP(aq), NM, IPN, DNT].
Explosion of fixed roof atmospheric storage tanks, part 3: Gas explosion and structural response simulations
Authors: Taveau Jérôme , Moras Benoît
Published: February 2012

Many flammable products are stored in large tanks at atmospheric pressure. Ignition of a hydrocarbon–air mixture in such tanks can lead to an explosion and cause lethal casualties or damage the surrounding facilities and buildings. To apprehend this, safety distances for humans, structures, and equipments need to be defined. Several simple methodologies have been set up to estimate safety distances in case of an atmospheric storage tank explosion.

This third and last article concerning fixed roof atmospheric storage tank explosions focuses on numerical modeling, including gas explosion and structural response simulations.

Three‐dimensional gas explosion simulations using the CFD code FLACS have been performed to define a typical pressure load profile to apply on the inner side of the tank shell. Then, the structural response of the tank (deformation and displacement), under the loading conditions previously obtained, has been computed with LS–DYNA.

Consequently, the findings question some of the assumptions used in analytical methods described previously.

The specific input data needed to obtain a reasonably conservative estimation of the safety distances have been identified. © 2011 American Institute of Chemical Engineers Process Saf Prog, 2012
Growth of AlN bulk single crystals on 4H‐SiC substrates and analyses of their structural quality and growth mode evolution
Authors: Sumathi R. R. , Barz R. U. , Gigler A. M. , Straubinger T. , Gille P.
Published: February 2012

Aluminium nitride (AlN) bulk single crystals were grown on off‐oriented 4H‐SiC substrates by the sublimation method. High‐quality crystals with about 25 mm in diameter and up to 5 mm in thickness were obtained with an optimized growth process. The crystals show hexagonal symmetry with well developed {10$\overline {1} $1} side facets. Confocal‐Raman spectroscopy and double‐crystal X‐ray diffraction rocking curve (DCXRD‐RC) measurements confirm the high structural quality of the grown crystals. In Raman spectroscopy, the full‐width at half maximum (FWHM) of E2(high) phonon mode decreases from 40 cm−1 for thin layers (800 µm) to 22 cm−1 for a 5 mm thick crystal, showing the improvement in quality with thickness. The DCXRD rocking curve FWHM obtained for a 5 mm thick crystal is about 120 arcsec. A basal plane bending of 100 arcsec is observed by rocking curve measurements while scanning 17 mm of the sample's diameter. Two kinds of growth modes namely, step flow growth and spiral growth modes were observed under similar growth conditions. This may be attributed to a slight variation of super‐saturation in the gas phase. In both cases, a single active hexagonal growth centre is formed. As‐grown surfaces have been found to be always Al‐polar. Wet chemical etching revealed both, threading type and basal‐plane dislocations (BPD) on the surfaces of the samples with total etch pit densities (EPDs) in the range of 8 × 105–1 × 106 cm−2.
Multiangle combined magnetic‐field annealing of Co‐based amorphous microwires for sensor applications
Authors: Liu Jing‐Shun , Zhang Da‐Yue , Cao Fu‐Yang , Xing Da‐Wei , Chen Dong‐Ming , Xue Xiang , Sun Jian‐Fei
Published: February 2012

The effect of multiangle combined magnetic‐field annealing (MCMFA) on the GMI performance of melt‐extracted Co‐based amorphous microwires for sensor applications is studied using a precision impedance analyzer. Experimental results indicated that MCMFA treatment can effectively improve the GMI effect comparing with as‐cast and conventional vacuum‐annealed (CVA) wires. The maximum GMI ratio [ΔZ/Zmax]max and field response sensitivity ξmax of transverse combined magnetic‐field annealed (TCMFA, α = 90°) wires can be increased at 10 MHz to 310.7 and 30.91%/Oe, respectively, through with circumferential anisotropy field expanded and GMI changed from single peak (SP) to double peaks (DPs). DPs behavior of TCMFA wire is due to the typically “nail‐sticked” action of magnetic moment rotation at relatively high frequency (up to ≥1 MHz). It can therefore be concluded that MCMFA could be used to develop Co‐based microwires with enhanced GMI effect for high‐resolution sensor applications.
Formation of defects in cubic GaN grown on nano‐patterned 3C‐SiC (001)
Authors: Kemper R. M. , Häberlen M. , Schupp T. , Weinl M. , Bürger M. , Ruth M. , Meier C. , Niendorf T. , Maier H. J. , Lischka K. , As D. J. , Lindner J. K. N.
Published: February 2012

We report an anisotropic formation of defects in cubic GaN grown on nano‐patterned 3C‐SiC/Si (001) by molecular beam epitaxy. Nano‐patterning of 3C‐SiC/Si (001) is achieved by nanosphere lithography and a reactive ion etching process. Atomic force microscopy and scanning electron microscopy show that the selective‐area‐grown cubic GaN nucleates in two structurally different domains, which most probably originate from the substrate. In adjacent domains the formation of defects, especially hexagonal inclusions, is different and leads to two different surface morphologies. The dominant phase within these domains was measured by electron backscatter diffraction. Optical properties were investigated by micro‐photoluminescence and cathodoluminescence spectroscopy (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Preparation and characterization of high‐k aluminium nitride (AlN) thin film for sensor and integrated circuits applications
Authors: Souza J. F. , Moreira M. A. , Doi I. , Diniz J. A. , Tatsch P. J. , Gonçalves J. L.
Published: February 2012

In last years considerable interest has been shown in aluminium nitride (AlN) films because of their optical, electrical, dielectric and acoustic properties. Owing to these characteristics, AlN thin films are suitable for the use in micro‐electronic applications. In this work, AlN thin films were deposited on p‐Si(100) and SiO2/p‐Si(100) substrates by dc reactive magnetron sputtering technique under the same deposition conditions (500 W of discharge power, 30 sccm N2 flow, 80 sccm Ar flow and deposition pressure of 3x10‐3 Pa). These conditions were defined by prior analysis in order to achieve films with smooth surface morphology, hexagonal wurtzite phase, and refractive index compatible with polycrystalline AlN films (between 2.0 and 2.2). The films were physically characterized using a variety of techniques such as atomic force microscopy (AFM), X‐ray diffraction spectroscopy (XRD), Fourier infrared spectroscopy (FTIR) and ellipsometry. Electrical characteristics of films were compared by using metal‐insulator‐semiconductor (MIS) structures. Using a set of metal insulator semiconductor field effect transistors (MISFETs) and electrolyte‐insulator‐semiconductor field effect transistors (EISFETs) fabricated, electrical characteristics and sensing properties were investigated. The electrical quality of the AlN film and AlN/SiO2/p‐Si interface obtained suggests that AlN is an adequate insulator on silicon device and pH sensors application (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Stable structure of di‐amino‐terphenyl molecule on Si(001) surfaces
Authors: Oda Masato
Published: February 2012

The adsorption structures of 4,4''‐di‐amino‐terphenyl (DAT) on Si(001) surfaces are investigated using density functional theory. Comparison of the total energies of two adsorption models with that of a non‐adsorbed model reveals that the DAT molecule is stable when it is tilted at about 17° relative to the Si(001) dimer line. There are three important interactions between a DAT molecule and a Si surface: the center phenyl ring forms a butterfly‐like bond with a Si dimer and the two terminal amino groups covalently bond to a Si atom of a dimer. To form these three stable bonds, the DAT molecule needs to be tilted at about 17° relative to the Si(001) dimer line. These results agree with experimental results. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Blinded assessment of treatment effects for survival endpoint in an ongoing trial
Authors: Xie Jun , Quan Hui , Zhang Ji
Published: February 2012

Many assumptions, including assumptions regarding treatment effects, are made at the design stage of a clinical trial for power and sample size calculations. It is desirable to check these assumptions during the trial by using blinded data. Methods for sample size re‐estimation based on blinded data analyses have been proposed for normal and binary endpoints. However, there is a debate that no reliable estimate of the treatment effect can be obtained in a typical clinical trial situation. In this paper, we consider the case of a survival endpoint and investigate the feasibility of estimating the treatment effect in an ongoing trial without unblinding. We incorporate information of a surrogate endpoint and investigate three estimation procedures, including a classification method and two expectation–maximization (EM) algorithms. Simulations and a clinical trial example are used to assess the performance of the procedures. Our studies show that the expectation–maximization algorithms highly depend on the initial estimates of the model parameters. Despite utilization of a surrogate endpoint, all three methods have large variations in the treatment effect estimates and hence fail to provide a precise conclusion about the treatment effect. Copyright © 2012 John Wiley & Sons, Ltd.
Composite distance metric integration by leveraging multiple experts' inputs and its application in patient similarity assessment
Authors: Wang Fei , Sun Jimeng , Ebadollahi Shahram
Published: February 2012

In the real world, it is common that different experts have different opinions on the same problem due to their different experience. How to come up with aconsistentdecision becomes a critical issue. As an example,patient similarity assessmentis an important task in the context of patient cohort identification for comparative effectiveness studies and clinical decision‐support applications. The goal is to derive clinically meaningful distance metric to measure the similarity between patients represented by their key clinical indicators. It is desirable to learn the distance metric based on experts' knowledge of clinical similarity among subjects. However, often different physicians have different understandings of patient similarity based on the specifics of the cases. The distance metric learned for each individual physician often leads to a limited view of the true underlying distance metric. The key challenge will be how to integrate the individual distance metrics obtained for a group of physicians into a globally consistent unified metric.

To achieve this goal, we propose thecomposite distance integration(Comdi) approach in this paper. Comdi first constructs discriminative neighborhoods from each individual metrics, then it combines all discriminative information in those neighborhoods to learn a single optimal distance metric. We formulate Comdi as a quadratic optimization problem and propose an efficient alternating strategy to find the solution. Besides learning a globally consistent metric, Comdi provides an elegant way to share knowledge across multiple experts without sharing the underlying data, which lowers the risk of disclosing private data. Our experiments on several benchmark data sets show approximately 10% improvement in classification accuracy over baseline methods, which suggests that Comdi is an effective and general metric learning approach. We also demonstrate two case studies on applying Comdi to real‐world clinic data sets. © 2012 Wiley Periodicals, Inc. Statistical Analysis and Data Mining 5: 54–69, 2012
Lost audio packets steganography: the first practical evaluation
Authors: Mazurczyk Wojciech
Published: February 2012

This paper presents first experimental results for an Internet Protocol (IP) telephony‐based steganographic method called lost audio packets steganography (LACK). This method utilises the fact that in typical multimedia communication protocols such as Real‐time Transport Protocol, excessively delayed packets are not used for the reconstruction of transmitted data at the receiver; that is, these packets are considered useless and discarded. The results presented in this paper were obtained on the basis of a functional LACK prototype and show the method's impact on the quality of voice transmission. Achievable steganographic bandwidth for the different IP telephony codecs is also calculated. Copyright © 2012 John Wiley & Sons, Ltd.
Multifrequency Imaging in the Intermittent Contact Mode of Atomic Force Microscopy: Beyond Phase Imaging
Authors: Guo Senli , Solares Santiago D. , Mochalin Vadym , Neitzel Ioannis , Gogotsi Yury , Kalinin Sergei V. , Jesse Stephen
Published: February 2012

The cantilever dynamics in single‐frequency scanning probe microscopy (SPM) are undefined due to having only two output variables, which leads to poorly understood image contrast. To address this shortcoming, generalized phase imaging scanning probe microscopy (GP‐SPM), based on broad band detection and multi‐eigenmode operation, is developed and demonstrated on diamond nanoparticles with different functionalization layers. It is shown that rich information on tip–surface interactions can be acquired by separating the response amplitude, instant resonance frequency, and quality factor. The obtained data allow high‐resolution imaging even in the ambient environment. By tuning the strength of tip–surface interaction, different surface functionalizations can be discerned.
Identifying Multiple Configurations of Complex Molecules on Metal Surfaces
Authors: Liu Qi , Du Shixuan , Zhang Yuyang , Jiang Nan , Shi Dongxia , Gao Hong‐Jun
Published: February 2012

Experimental identification of molecular configurations in diffusion processes of large complex molecules has been a demanding topic in the field of molecular construction at solid surfaces. Such identification is needed in order to control the self‐assembly process and the properties and configurations of the resulting structures. This paper provides an overview of state‐of‐the‐art techniques for identification of molecular configurations in motion. First, a brief introduction to the conventional tools is presented, for example, low‐energy electron diffraction and IR/Raman spectroscopy. Second, currently used techniques, scanning probe microscopy, and its application in molecular configuration identification are reviewed. In the last part, a methodology combining time‐resolved tunneling spectroscopy and density functional theory calculation is reviewed in detail; this strategy has been successfully applied to two typical molecular systems, (t‐Bu)4‐ZnPc and FePc (where Pc is phthalocyanine), with molecular rotation and laterial diffusion on the Au(111) surface.
Hemocompatibility and Macrophage Response of Pristine and Functionalized Graphene
Authors: Sasidharan Abhilash , Panchakarla Leela S. , Sadanandan Aparna R. , Ashokan Anusha , Chandran Parwathy , Girish Chundayil Madathil , Menon Deepthy , Nair Shantikumar V. , Rao C. N. R. , Koyakutty Manzoor
Published: February 2012

Graphene and its derivatives are being proposed for several important biomedical applications including drug delivery, gene delivery, contrast imaging, and anticancer therapy. Most of these applications demand intravenous injection of graphene and hence evaluation of its hemocompatibility is an essential prerequisite. Herein, both pristine and functionalized graphene are extensively characterized for their interactions with murine macrophage RAW 264.7 cells and human primary blood components. Detailed analyses of the potential uptake by macrophages, effects on its metabolic activity, membrane integrity, induction of reactive oxygen stress, hemolysis, platelet activation, platelet aggregation, coagulation cascade, cytokine induction, immune cell activation, and immune cell suppression are performed using optimized protocols for nanotoxicity evaluation. Electron microscopy, confocal Raman spectral mapping, and confocal fluorescence imaging studies show active interaction of both the graphene systems with macrophage cells, and the reactive oxygen species mediated toxicity effects of hydrophobic pristine samples are significantly reduced by surface functionalization. In the case of hemocompatibility, both types of graphene show excellent compatibility with red blood cells, platelets, and plasma coagulation pathways, and minimal alteration in the cytokine expression by human peripheral blood mononuclear cells. Further, both samples do not cause any premature immune cell activation or suppression up to a relatively high concentration of 75 μg mL−1 after 72 h of incubation under in vitro conditions. This study clearly suggests that the observed toxicity effects of pristine graphene towards macrophage cells can be easily averted by surface functionalization and both the systems show excellent hemocompatibility.
Linking genome to epigenome
Authors: Yuan Guo‐Cheng
Published: February 2012

Recent epigenomic studies have identified significant differences between developmental stages and cell types. While the importance of epigenetic regulation has been increasingly recognized, it remains unclear how the global epigenetic patterns are established and maintained. Here I review a number of recent studies with the emphasis on the role of the genomic sequence in shaping the epigenetic landscape. These studies strongly suggest that the sequence information is important not just for controlling target specificity but for orchestrating the diversity of epigenetic patterns among different cell types. The epigenome is maintained by the complex network of a large number of interactions. Integrative approaches are needed to gain insights into these networks. WIREs Syst Biol Med 2012. doi: 10.1002/wsbm.1165

This article is categorized under:

Analytical and Computational Methods > Computational Methods

Laboratory Methods and Technologies > Genetic/Genomic Methods

Biological Mechanisms > Regulatory Biology
Prognostic Factors for Traumatic Bowel Injuries: Killing Time
Authors: Faria Gil R. , Almeida Ana Beatriz , Moreira Herculano , Barbosa Elisabete , Correia‐da‐Silva Pedro , Costa‐Maia José
Published: February 2012

Background

Intestinal rupture/perforation after abdominal trauma is a rare complication, but it is related to significant morbidity and mortality. Our objective is to identify determinants of prognosis in patients surgically treated for a bowel injury (small bowel and colon) after abdominal trauma.

Methods

The present study is a retrospective analysis of 102 patients seen at our hospital during a 10‐year period in whom laparotomy for traumatic bowel injury was performed. Predictors for morbidity and mortality were assessed in univariate and multivariate analysis models.

Results

Mean age at diagnosis was 40 years, and most patients were male. There was a slight preponderance of blunt abdominal trauma, and the most frequent mechanism of injury was motor vehicle accident. In 75% of patients there was a small bowel lesion, and the colon was affected in 47%. There was no statistical relation between stoma construction and mortality, but an increase in morbidity was ultimately dependent on the severity of the underlying trauma. The univariate determinants of mortality were the new injury severity score (NISS) and American Society of Anesthesiologists (ASA) scores, the presence of blunt trauma and multiple intestinal or extra‐abdominal lesions, and the elapsed time to surgery. The occurrence of postoperative complications was related to all these factors, as well as to tachycardia, hypotension, and bleeding. In multivariate analysis ASA score (p = 0.015), NISS (p = 0.002), time to surgery (p = 0.007), and presence of colonic lesions (p = 0.02) were identified as independent prognostic factors for postoperative morbidity.

Conclusions

The only modifiable determinant of morbidity seems to be the time to surgery. Only an expeditious evaluation and diagnosis and prompt surgical intervention can improve the prognosis of these patients.