bluuebunny/crossref_metadata_2025 huggingface dataset:
A Photographic Study of Flow Boiling Stability on a Plain Surface With Tapered Manifold
Authors: Kalani Ankit , Kandlikar Satish G.
Published: November 2015

Flow boiling in microchannels offers many advantages such as high heat transfer coefficient, higher surface area to volume ratio, low coolant inventory, uniform temperature control and compact design. The application of these flow boiling systems has been severely limited due to early critical heat flux (CHF) and flow instability. Recently, a number of studies have focused on variable flow cross-sectional area to augment the thermal performance of microchannels. In a previous work, the open microchannel with manifold (OMM) configuration was experimentally investigated to provide high heat transfer coefficient coupled with high CHF and low pressure drop. In the current work, high speed images of plain surface using tapered manifold are obtained to gain an insight into the nucleating bubble behavior. The mechanism of bubble nucleation, growth and departure are described through high speed images. Formation of dry spots for both tapered and uniform manifold geometry is also discussed.
Impedimetric Feedback in Particle Laden Digital Microfluidic Devices
Authors: Scott-Murrell Emrys , Lanza David , Schertzer Michael J.
Published: November 2015

Impedimetric measurement methods are a novel approach to the characterization of fluid in biological applications. Lab on a chip (LOAC) technologies could be combined with impedimetrics to benefit these applications. LOAC devices are currently being developed to pursue the miniaturization of larger scale processes. Current research shows great flexibility in using LOAC devices to reproduce biological processes such as those used in medical diagnostic applications. With a smaller form factor, testing that generally requires off-site lab usage can be deployed at the point-of-care. LOAC devices also have the potential to lower operating costs by reducing reagent volumes, labor costs, and cycle times.

Digital microfluidic devices (DMF) are one promising LOAC platform. These devices manipulate discrete droplets of fluid using electric fields. As such, DMF devices can create, move, merge, and mix droplets while eliminating mechanical components like channels, pumps, and valves. Manipulation of discrete volumes over a planar array of electrodes allows for the possibility of highly flexible, reconfigurable devices.

Addressable positions on a DMF device have conductive planes above and below the droplets which form a parallel plate capacitor. Using this principle, the electrical properties of the system can be measured in the same circuit that is used for droplet manipulation, removing the need for additional sensing components. This research tests the hypothesis that the impedance of a particle laden droplet in a DMF device can be modelled using an equivalent circuit model for particles that span more than half the gap height. The fundamental understanding gained increases sensitivity in impedimetric measurements, and can also be used for DMF applications in medical diagnostics, cell manipulation and observation, and condition based maintenance. This research presents an analytical model based on an equivalent circuit of a particle laden droplet. The proposed model predicts that droplet impedance is a function of device geometry, particle size, particle concentration, and the electrical properties of the particles and the surrounding medium.
Numerical Analysis of Fluid Flow Through a Flexible Microstructure Induced by Acoustic Streaming
Authors: Rich Bryan C. , Garafolo Nicholas G.
Published: November 2015

A fundamental understanding of fluid flow through oscillating, compliant structures is lacking; especially in the case of micro structures. An improved model of such dynamic micro flow is sought. A multi-physics, numerical based study is presented herein. Results obtained provide preliminary quantification of these phenomena to compare with future experiments. In particular the perturbations in boundary pressure, integral to future slip-conditions models within a transient oscillatory boundary model, is quantified. The geometric model consisted of flow through a compliant tubular -structure with an oscillating wall. This simple model tested the solvers ability to solve an irregular flow regime with its built-in capabilities and provided insight into the nature of fluid-structure interaction at the investigated scales. Results suggested that traditional constant slip conditions at compliant fluid-structure interfaces are not adequate to capture the physics of the problem, as pressure varies greatly within the test specimen. Success with this venture provided a measure of validation and assurance for a more in-depth study with comparison to a reference. Results of this entire study highlight the need for improved physics-based methods for the determining the slip condition with oscillatory boundaries.
Development and Analysis of Micro-Channel Heat Exchangers for Natural Gas Cooling
Authors: Menon S. , Ganti H. , Wang H. , Hagen C.
Published: November 2015

Abundant availability and potential for lower CO2 emissions are drivers for increased utilization of natural gas in automotive engines for transportation applications. However scarce refueling resources for on-road vehicles impose an infrastructure limited barrier on natural gas use in transportation. A novel ‘bimodal’ engine which can operate in a compressor mode has been developed that allows on-board refueling of natural gas where available without the need for any supplemental device. Engine compression of natural gas however results in considerable heating of the gas which is undesirable from a system stand-point. Micro-channel heat exchangers have been developed to absorb heat from the natural gas using engine coolant and compressed air. This work presents the design and development of the micro-channel heat exchangers as well as a preliminary analysis of system performance. Design methodology for the heat exchanger was based on trade-off studies that correlated system performance with component design. Energy flows through the system are analyzed as a function of engine compression ratio, operating speed, charge flow rate, and ambient air and natural gas conditions. These results are further used to estimate heat transfer co-efficient and effectiveness of the micro-channel heat exchanger. Future work involves developing CFD models of the heat exchanger to obtain a detailed understanding of the conjugate heat transfer and fluid flow processes within the micro-channels.
Synthetic Asymmetric Vesicles Built Using Microfluidic Technology at High-Throughput
Authors: Lu Li , Schertzer Jeffrey W. , Chiarot Paul R.
Published: November 2015

We report on a novel microfluidic strategy for building monodisperse asymmetric vesicles with customized composition, size, and interfacial properties at high-throughput. The microfluidic device encompasses a triangular post region and two flow-focusing regions. The major steps involved in the vesicle building process include: (1) forming highly uniform water emulsion templates in the inner-leaflet lipid solution, (2) replacing the inner-leaflet lipid solution with the outer-leaflet lipid solution, (3) creating water-in-oil-in-water double emulsions, and (4) extracting the excess outer-leaflet lipid solution from the double emulsions. Bilayer membrane asymmetry and unilamellarity are confirmed using a fluorescence quenching assay and quantitative measurements of fluorescent intensities. This method addresses many of the deficiencies found in existing technologies, and yields asymmetries as high as 95%. The asymmetric vesicles built using this strategy hold the potential to serve as model systems to investigate fundamental problems in membrane biology.
Computational and Experimental Study of Gas Bubbles Removal in a Microfluidic System
Authors: Derami Hamed Gholami , Darabi Jeff
Published: November 2015

Formation of unwanted bubbles is one the main issues in biomicrofluidics-based applications such as lab-on-a-chip devices, and adversely affects the performance of these systems. In this work we report a simple and efficient method for removing gas bubbles from liquid filled microchannels. This bubble removal system consists of a cavity on which a hydrophobic membrane is bonded parallel to the main fluidic channel to vent gas bubbles normal to the flow direction. A T-junction configuration is used to generate gas bubbles prior to entering the bubble removal cavity. A finite volume-based computational model is developed using ANSYS FLUENT to simulate gas removal characteristics of the system. The effects of various geometric parameters and operating conditions are studied both through numerical simulations and experimentally.
Impingement Cooling in a Simulated Data Center Servers With an Array of Elliptic Air Jets
Authors: Chang Sheng-Kai , Yuan-Hsiang Lo , Liu Yao-Hsien
Published: November 2015

Reducing the electricity consumption from the cooling systems in a data center can cut the energy cost. The development of the high efficiency cooling schemes can effectively save more energy from the computer room air conditioning (CRAC) system. Impingement cooling with air jets can achieve high heat transfer rates and could be used to cool local hot spots in the cabinets. A 5 × 5 jet array was designed utilizing circular and elliptic holes. The cross sectional area of the test region was 250 mm × 25 mm. The jet Reynolds numbers is 3300. Heat transfer coefficients on the target surface were investigated. Results indicated that the impingement cooling provided lower surface temperature than the traditional fan cooling.
Numerical Study of Bubble Instability During Microchannel Flow Boiling
Authors: Blomquist Matthew , Khalighi Arman , Mukherjee Abhijit
Published: November 2015

In recent years, the forced convection cooling for the heat dissipation of electronic components has become a significant area of research. Many high-end computing applications, from consumer gaming to scientific research, encounter performance limitations due to heat generation in micro-electronic components. Micro heat exchangers can offer an ideal cooling solution for these applications due to their compact size and heat dissipation characteristics. Single-phase heat exchangers are widely used in both industry and consumer applications, but are limited by operational temperature ranges as well as the working fluid’s thermo physical properties. Two-phase, convection cooling systems, however, can further increase the capabilities of micro-heat exchangers. In the present study, a model has been created to investigate bubble growth and the values of wall superheat, contact angle, and Reynolds number that cause instability at the liquid-vapor interface during microchannel flow boiling. The results show how bubble instability is caused by the transfer of heat being restricted by the liquid-vapor interface.
The Influence of Confinement on the Hydrodynamic Characteristics of a Cylindrical Pillar Within a Microchannel
Authors: O’Connor John , Punch Jeff , Jeffers Nicholas , Stafford Jason
Published: November 2015

Microfluidic cooling technologies for future electronic and photonic microsystems require more efficient flow configurations to improve heat transfer without a hydrodynamic penalty. Although conventional microchannel heat sinks are effective at dissipating large heat fluxes, their large pressure drops are a limiting design factor. There is some evidence in the literature that obstacles such as pillars placed in a microchannel can enhance downstream convective heat transfer with some increase in pressure drop. In this paper, measured head-loss coefficients are presented for a set of single microchannels of nominal hydraulic diameter 391μm and length 30mm, each containing a single, centrally-located cylindrical pillar covering a range of confinement ratios, β = 0.1–0.7, over a Reynolds number range of 40–1900. The increase in head-loss due to the addition of the pillar ranged from 143% to 479%, compared to an open channel. To isolate the influence of the pillar, the head-loss contribution of the open channel was extracted from the data for each pillar configuration. The data was curve-fitted to a decaying power-law relationship. High coefficients of determination were recorded with low root mean squared errors, indicating good fits to the data. The data set was surface-fitted with a power law relationship using the Reynolds number based on the cylinder diameter. This was found to collapse the data well below a Reynolds number of 425 to an accuracy of ± 20%. Beyond this Reynolds number an inflection point was observed, indicating a change in flow regime similar to that of a cylinder in free flow. This paper gives an insight into the hydrodynamic behavior of a microchannel containing cylindrical pillars in a laminar flow regime, and provides a practical tool for determining the head-loss of a configuration that has been demonstrated to improve downstream heat transfer in microchannels.
Effects of Temperature and Pore Size on Water Diffusion Inside Carbon Nanotubes
Authors: Zhao Kuiwen , Liu Zhenyu , Wu Huiying
Published: November 2015

Nanotube membranes show exceptional transport properties for water and other substances, which can be utilized in many attractive applications, such as molecular sieving, drug delivery, and water purification. To design effective nanotube membranes for these applications, it is necessary to understand the transport properties of water confined in nanotubes. The diffusion of water inside nanotubes plays an important role in this process. By performing extensive molecular dynamics simulations, we investigate the effects of temperature and pore size on water diffusion inside carbon nanotubes. The results demonstrate that the temperature dependence of self-diffusion coefficient of water inside carbon nanotubes is obviously different for various pore sizes. It can be found that for nanotube with diameter of 0.681 nm and 0.820–0.905 nm, the self-diffusion coefficient decreases remarkably with the decreasing temperature due to the change of water structure, which is not obvious for water in nanotubes with other pore sizes. This fundamental study attempts to provide deep insights in understanding the transport process across nanotube membranes.
Silica Synthesis and Coating of Quantum Dots in Droplet Based Microreactors
Authors: Özkan Alican , Keleştemur Yusuf , Demir Hilmi Volkan , Erdem E. Yegan
Published: November 2015

We present a microfluidic reactor that utilizes meandering microchannel shape to mix reagents inside droplets in a carrier fluid to synthesize silica and silica coated nanoparticles. Meandering channels decrease mixing time due to reduced diffusion lengths. Moreover, droplet-based flow provides uniform reaction times due to the circulating flow profile inside droplets as opposed to parabolic flow profile in straight channels. Before fabricating our device, we have simulated the mixing performance of droplets at different channel cross-sections and meandering geometries using Comsol Multiphysics©. As a result, we have concluded that channel cross-section and meandering dimensions should be as small as possible for faster mixing. Accordingly, we have fabricated our device in PDMS by using soft lithography technique and introduced chemicals to the microsystem by using syringe pumps. We will use this system to understand the effect of solvent concentration and residence time on silica formation to obtain better coating thickness distribution than in batch-wise methods. As a preliminary study, we tested the silica formation inside droplets and we obtained 102 nm ± 4 nm of silica nanoparticles. In the synthesis we followed a modified method of synthesis in the literature where droplets of solution composed of 20 mL Cyclohexane, 2.6 mL IGEPAL and 300 μL TEOS were formed inside the carrier fluid NH4OH at a flow rate ratio of 2:1. It is observed that nanoparticles were synthesized as a result of diffusion and mixing of NH4OH inside droplets. Currently, we are working on introducing QDs in droplets and coating them with silica shells inside the microreactor. We will also study the effects of NH4OH concentration, residence time on silica shell thickness and compare with batch-wise silica synthesis and coating of quantum dots and present these results at the conference.
Visualization of Two-Phase Flow Through Microchannel Heat Exchangers
Authors: Hoysall Dhruv C. , Keniar Khoudor , Garimella Srinivas
Published: November 2015

Multiphase flow phenomena in single micro- and minichannels have been widely studied. Characteristics of two-phase flow through a large array of microchannels are investigated here. An air-water mixture is used to represent the two phases flowing through a microchannel array representative of those employed in practical applications. Flow distribution of the air and water flow across 52 parallel microchannels of 0.3 mm hydraulic diameter is visually investigated using high speed photography. Two microchannel configurations are studied and compared, with mixing features incorporated into the second configuration. Slug and annular flow regimes are observed in the channels. Void fractions and interfacial areas are calculated for each channel from these observations. The flow distribution is tracked at various lengths along the microchannel array sheets. Statistical distributions of void fraction and interfacial area along the microchannel array are measured. The design with mixing features yields improved flow distribution. Void fraction and interfacial area change along the length of the second configuration, indicating a change in fluid distribution among the channels. The void fraction and interfacial area results are used to predict the performance of different microchannel array configurations for heat and mass transfer applications. Results from this study can help inform the design of compact thermal-fluid energy systems.
Microchannel Design Study for 3D Microelectronics Cooling Using a Hybrid Analytical and Finite Element Method
Authors: Collin L.-M. , Fiori V. , Coudrain P. , Lhostis S. L. , Chéramy S. , Colonna J.-P. , Mathieu B. , Souifi A. , Fréchette L. G.
Published: November 2015

For microelectronics cooling, microchannels are a potential solution to ensure reliability without sacrificing compactness, as they require relatively small space to remove high heat fluxes compared to air cooling. However, designing microchannels is a complex task where simulation models become a forefront tool to investigate and propose new solutions to increase the chip thermal performances with minimal impact on other aspects.

This work evaluates numerically the impact of microchannel cooling in a standalone chip and a 3D assembly of two stacked chips with localized heat sources. To do so, a modeling approach was developed to combine finite element modeling of conduction in the chip using commercial software with analytical relations to capture the heat transfer and fluid flow in the microchannels. This approach leverages the multiphysics and post-processing capabilities of commercial software, but avoids the extensive discretization that would normally be required in microchannels with full finite element modeling. The study shows that increasing the flow rate is not as beneficial as increasing the number of channels (with constant total cross-section area). The effect of heat spreading was also found to be critical, favoring thicker dies. When switching to 3D chip configuration, the interdie underfill layer significantly increases the total thermal resistance and must be considered for thermal design. This effect can be significantly alleviated by increasing the interdie thermal conductivity through adding copper micropillars.
Experimental Investigation of Geometrical Parameters for Gas-Liquid Droplet Generation in Flow-Focusing Configurations
Authors: Tirandazi Pooyan , Hidrovo Carlos H.
Published: November 2015

Over the last few years considerable research attention has been directed towards droplet-based microfluidic devices because of their numerous applications in chemical and biological fields, to name a few. Specifically, gas-liquid droplet systems are of great importance for applications in which a gaseous phase is required instead of a second liquid phase. In this paper we experimentally investigate the manipulation of water droplets in flow-focusing configurations using a high inertial air stream. Compared to a T-junction geometry, the flow-focusing geometry provides the injection of highly inertial air on both sides of the droplet generation region, producing a more consistent droplet generation process in this type of gas-liquid microfluidic system. For this study, we changed the width of the liquid channel, the air flow rate, and the liquid flow rate in order to experimentally investigate their effects on the flow regime and generation frequency. The interactions of different geometrical and physical parameters produce three distinct flow regimes in the gas-liquid flow rate space (co-flow, jetting, and dripping). The controlled size and generation rate of droplets in this scheme provide the capability for precise and oil-free delivery of discrete microliter volumes of fluid.
Neural-scaled entropy predicts the effects of nonlinear frequency compression on speech perception
Authors: Rallapalli Varsha H. , Alexander Joshua M.
Published: November 2015

The Neural-Scaled Entropy (NSE) model quantifies information in the speech signal that has been altered beyond simple gain adjustments by sensorineural hearing loss (SNHL) and various signal processing. An extension of Cochlear-Scaled Entropy (CSE) [Stilp, Kiefte, Alexander, and Kluender (2010). J. Acoust. Soc. Am. 128(4), 2112–2126], NSE quantifies information as the change in 1-ms neural firing patterns across frequency. To evaluate the model, data from a study that examined nonlinear frequency compression (NFC) in listeners with SNHL were used because NFC can recode the same input information in multiple ways in the output, resulting in different outcomes for different speech classes. Overall, predictions were more accurate for NSE than CSE. The NSE model accurately described the observed degradation in recognition, and lack thereof, for consonants in a vowel-consonant-vowel context that had been processed in different ways by NFC. While NSE accurately predicted recognition of vowel stimuli processed with NFC, it underestimated them relative to a low-pass control condition without NFC. In addition, without modifications, it could not predict the observed improvement in recognition for word final /s/ and /z/. Findings suggest that model modifications that include information from slower modulations might improve predictions across a wider variety of conditions.
A hybrid approach for simulating fluid loading effects on structures using experimental modal analysis and the boundary element method
Authors: Shepherd Micah R. , Fahnline John B. , Dare Tyler P. , Hambric Stephen A. , Campbell Robert L.
Published: November 2015

Many structural acoustics problems involve a vibrating structure in a heavy fluid. However, obtaining fluid-loaded natural frequencies and damping experimentally can be difficult and expensive. This paper presents a hybrid experimental-numerical approach to determine the heavy-fluid-loaded resonance frequencies and damping of a structure from in-air measurements. The approach combines in-air experimentally obtained mode shapes with simulated in-water acoustic resistance and reactance matrices computed using boundary element (BE) analysis. The procedure relies on accurate estimates of the mass-normalized, in vacuo mode shapes using singular value decomposition and rational fraction polynomial fitting, which are then used as basis modes for the in-water BE analysis. The method is validated on a 4.445 cm (1.75 in.) thick nickel-aluminum-bronze rectangular plate by comparing natural frequencies and damping obtained using the hybrid approach to equivalent data obtained from actual in-water measurements. Good agreement is shown for the fluid-loaded natural frequencies and one-third octave loss factors. Finally, the limitations of the hybrid approach are examined.
Optimization of the directivity in binaural sound reproduction beamforming
Authors: Shabtai Noam R.
Published: November 2015

Microphone arrays usually combine multiple input signals into one output signal, such that spatial information on the sound sources is not included in the output signal. Since spatial information on the sound sources may increase the intelligibility of a speech signal that is perceived by a human listener, recent works aim to include this spatial information in the output of the microphone array by utilizing binaural cues preservation. More current works apply binaural sound reproduction (BSR) using spherical microphone arrays by incorporating the head related transfer functions (HRTFs) in the weight function of a conventional maximum-directivity beamformer. However, the HRTFs may affect the optimality of beamformers that were already designed to provide a maximal directivity without the HRTFs. This work presents a more general mathematical framework than previously presented for the incorporation of HRTFs in the weight function, which allows the optimization of the weight function using an averaged maximum-directivity criterion under the condition that the HRTFs are already incorporated. It is shown that the proposed optimized BSR beamformer achieves higher directivity index.
Protease inhibitor passes oral exam
Authors: Traverso Giovanni
Published: November 2015

A bacterial protease inhibitor enables oral vaccination by protecting antigens from gastrointestinal proteases.
DNA-Containing Immunocomplexes Promote Inflammasome Assembly and Release of Pyrogenic Cytokines by CD14+CD16+CD64highCD32lowInflammatory Monocytes from Malaria Patients
Authors: Hirako Isabella C. , Gallego-Marin Carolina , Ataide Marco A. , Andrade Warrison A. , Gravina Humberto , Rocha Bruno C. , de Oliveira Rosane B. , Pereira Dhelio B. , Vinetz Joseph , Diamond Betty , Ram Sanjay , Golenbock Douglas T. , Gazzinelli Ricardo T.
Published: November 2015

High levels of circulating immunocomplexes (ICs) are found in patients with either infectious or sterile inflammation. We report that patients with eitherPlasmodium falciparumorPlasmodium vivaxmalaria have increased levels of circulating anti-DNA antibodies and ICs containing parasite DNA. Upon stimulation with malaria-induced ICs, monocytes express an NF-κB transcriptional signature. The main source of IC-induced proinflammatory cytokines (i.e., tumor necrosis factor alpha [TNF-α] and interleukin-1β [IL-1β])in peripheral blood mononuclear cells from acute malaria patients was found to be a CD14+CD16 (FcγRIIIA)+CD64 (FcγRI)highCD32 (FcγRIIB)lowmonocyte subset. Monocytes from convalescent patients were predominantly of the classical phenotype (CD14+CD16−) that produces high levels of IL-10 and lower levels of TNF-α and IL-1β in response to ICs. Finally, we report a novel role for the proinflammatory activity of ICs by demonstrating their ability to induce inflammasome assembly and caspase-1 activation in human monocytes. These findings illuminate our understanding of the pathogenic role of ICs and monocyte subsets and may be relevant for future development of immunity-based interventions with broad applications to systemic inflammatory diseases.

IMPORTANCEEvery year, there are approximately 200 million cases ofPlasmodium falciparumandP. vivaxmalaria, resulting in nearly 1 million deaths, most of which are children. Decades of research on malaria pathogenesis have established that the clinical manifestations are often a consequence of the systemic inflammation elicited by the parasite. Recent studies indicate that parasite DNA is a main proinflammatory component during infection with differentPlasmodiumspecies. This finding resembles the mechanism of disease in systemic lupus erythematosus, where host DNA plays a central role in stimulating an inflammatory process and self-damaging reactions. In this study, we disclose the mechanism by which ICs containingPlasmodiumDNA activate innate immune cells and consequently stimulate systemic inflammation during acute episodes of malaria. Our results further suggest that Toll-like receptors and inflammasomes have a central role in malaria pathogenesis and provide new insights toward developing novel therapeutic interventions for this devastating disease.
A Single Human Cerebral Malaria Histopathologic Study Can Be Worth a Thousand Experiments
Authors: Sullivan David J.
Published: November 2015

Severe malaria is a density-dependent disease that comprises infected-erythrocyte sequestration, with or without monocytic infiltration, as seen in renal, placental, and lung tissues from severe malaria patients. HIV induces a chronic proinflammatory state with higher numbers of inflammasome-activated monocytes and platelets circulating. The epidemiological and pathological study of S. E. Hochman et al. that was published in a recent issue of
mBio
(Hochman SE, Madaline TF, Wassmer SC, Mbale E, Choi N, et al., mBio 6:e01390-15, 2015, doi:10.1128/mBio.01390-15) analyzes a large cohort of Malawian children and shows that cerebral malaria in younger HIV-negative children presents as an acute disease predominated by sequestered infected erythrocytes. In contrast, they show that case presentation in older HIV-positive children is as a more lethal acute on chronic disease marked by double the monocytic infiltrates and 5 times as many platelets. This study suggests that cerebral involvement in severe malaria is a pathology similar to that of other organ involvement of severe malaria, with a bias in HIV-positive individuals toward more monocytic infiltrates. The study also addresses the important association of severe malaria and HIV prevalence.
Coeliac disease in the ERA of the new ESPGHAN and BSPGHAN guidelines: a prospective cohort study
Authors: Benelli Elisa , Carrato Valentina , Martelossi Stefano , Ronfani Luca , Not Tarcisio , Ventura Alessandro
Published: November 2015

Objective

To evaluate the consequences of the last European Society of Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) and British Society of Paediatric Gastroenterology, Hepatology and Nutrition (BSPGHAN) guidelines for the diagnosis of coeliac disease (CD) by means of a prospective study.

Design

Prospective cohort study.

Setting

Institute for Maternal and Child Health IRCCS Burlo Garofolo (Trieste, Italy).

Patients

Children diagnosed with CD without a duodenal biopsy (group 1), following the last ESPGHAN and BSPGHAN guidelines, and children diagnosed with a duodenal biopsy, matched for sex, age and year of diagnosis (group 2), were prospectively enrolled over a 3-year period. All patients were put on a gluten-free diet (GFD) and were followed up for clinical conditions and laboratory testing at 6 months every year since diagnosis (median follow up: 1.9 years).

Outcome measures

Resolution of symptoms, body mass index, laboratory testing (haemoglobin, anti-transglutaminase IgA), adherence to a GFD, quality of life, and supplementary post-diagnosis medical consultations.

Results

51 out of 468 (11%) patients were diagnosed without a duodenal biopsy (group 1; median age 2.1 years) and matched to 92 patients diagnosed with a biopsy (group 2; median age 2.4 years). At the end of follow-up the two groups were statistically comparable in terms of clinical and nutritional status, anti-transglutaminase IgA antibody titres, quality of life, adherence to a GFD, and number of supplementary medical consultations.

Conclusions

On the basis of this prospective study, diagnosis of CD can be reliably performed without a duodenal biopsy in approximately 11% of cases. At least during a medium-term follow-up, this approach has no negative consequences relating to clinical remission, adherence to diet, and quality of life of children with CD.
Conservative treatment in a patient with diabetic osteomyelitis: antibiotic treatment is sufficient for complete bone regeneration in selected cases
Authors: Jeppesen Sune Møller , Frøkjær Johnny , Yderstræde Knud
Published: November 2015

Diabetic foot ulcers are commonly complicated by bone involvement and osteomyelitis. Diagnosing diabetic osteomyelitis can be problematic. However, positive findings at clinical examination and X-ray may set the diagnosis. Recent guidelines suggest that selected cases of diabetic osteomyelitis can be treated conservatively with antibiotics. We report on the successful treatment of a 52-year-old man with diabetes with osteomyelitis in the distal phalanx of a toe. On X-ray, the affected phalanx appeared completely eroded. However, regeneration of the bone tissue was observed following outpatient treatment with antibiotics. We therefore encourage doctors to provide conservative treatment for selected cases of diabetic osteomyelitis.
Open three-stage transthoracic oesophagectomy versus minimally invasive thoraco-laparoscopic oesophagectomy for oesophageal cancer: protocol for a multicentre prospective, open and parallel, randomised controlled trial
Authors: Mu Juwei , Gao Shugeng , Mao Yousheng , Xue Qi , Yuan Zuyang , Li Ning , Su Kai , Yang Kun , Lv Fang , Qiu Bin , Liu Deruo , Chen Keneng , Li Hui , Yan Tiansheng , Han Yongtao , Du Ming , Xu Rongyu , Wen Zhaoke , Wang Wenxiang , Shi Mingxin , Xu Quan , Xu Shun , He Jie
Published: November 2015

Introduction

Oesophageal cancer is the eighth most common cause of cancer worldwide. In 2009 in China, the incidence and death rate of oesophageal cancer was 22.14 per 100 000 person-years and 16.77 per 100 000 person-years, respectively, the highest in the world. Minimally invasive oesophagectomy (MIO) was introduced into clinical practice with the aim of reducing the morbidity rate. The mechanisms of MIO may lie in minimising the reaction to surgical injury and inflammation. There are some randomised trials regarding minimally invasive versus open oesophagectomy, with 100–850 subjects enrolled. To date, no large randomised controlled trial comparing minimally invasive versus open oesophagectomy has been reported in China, where squamous cell carcinoma predominated over adenocarcinoma of the oesophagus.

Methods and analysis

This is a 3 year multicentre, prospective, randomised, open and parallel controlled trial, which aims to compare the effectiveness of minimally invasive thoraco-laparoscopic oesophagectomy to open three-stage transthoracic oesophagectomy for resectable oesophageal cancer. Group A patients receive MIO which involves thoracoscopic oesophagectomy and laparoscopic gastric mobilisation with cervical anastomosis. Group B patients receive the open three-stage transthoracic oesophagectomy which involves a right thoracotomy and laparotomy with cervical anastomosis. Primary endpoints include respiratory complications within 30 days after operation. The secondary endpoints include other postoperative complications, influences on pulmonary function, intraoperative data including blood loss, operative time, the number and location of lymph nodes dissected, and mortality in hospital, the length of hospital stay, total expenses in hospital, mortality within 30 days, survival rate after 2 years, postoperative pain, and health-related quality of life (HRQoL). Three hundred and twenty-four patients in each group will be needed and a total of 648 patients will finally be enrolled into the study.

Ethics and dissemination

The study protocol has been approved by the Institutional Ethics Committees of all participating institutions. The findings of this trial will be disseminated to patients and through peer-reviewed publications and international presentations.

Trial registration number

NCT02355249.
Nonlinear behaviour of reinforced concrete conical tanks under hydrostatic pressure
Authors: Elansary Ahmed A. , El Damatty Ashraf A. , El Ansary Ayman M.
Published: November 2015

Among the different shapes available, conical vessels are commonly used as water reservoirs because of their large storage capacities. Motivated by the lack of guidelines available for their analysis and design in the existing codes of practice, this study focuses on analyzing reinforced concrete conical tanks under the effect of hydrostatic pressure. A finite element model (FEM), which accounts for material nonlinearity experienced in reinforced concrete, is developed. This nonlinearity is considered by implementing a concrete plasticity constitutive model in the developed FEM. Analysis of a set of 12 tanks with different practical dimensions is performed under hydrostatic water pressure. The variations of meridional and hoop stresses through the thickness of the tanks are determined by plotting the stresses at the outer faces of the tank’s wall. The effect of including material nonlinearity in the FEM on the deformed shape is assessed. The developed FEM is used to find the location of maximum deflection and stresses. The variations in the maximum deflection and stresses with the dimensional parameters of the conical vessel are reported.
ECONOMIC REPERCUSSIONS OF EXTREME EVENTS FOR AN ISLAND NATION: CASE OF SINGAPORE
Authors: TAN SECK , YU-HUNG ALLEN LAI
Published: November 2015

Having achieved an export-led exponential economic growth, Singapore remains vulnerable to both natural disasters and economic crises. However, the economic repercussions and policy responses to extreme events for an island nation like Singapore are not as widely known or studied. This paper illustrates that impacts of a health disaster [Severe Acute Respiratory Syndrome (SARS)] and an economic crisis [Global Financial Crisis (GFC)] on the Singapore economy based on selected indicators of the financial market, macroeconomy and property sector. Crises of different nature entail different policy responses of different scales and this is highlighted in the policy responses to both SARS and GFC toward economic recovery. In the case of SARS, there were preventive measures toward diseases but no reactive measures as the SARS virus was a new strain. For GFC, the policy measures were simply reactive as preventive measures failed to regulate the financial markets effectively. Our paper makes the case that the impacts of such extreme events are systemic as they affect all aspects of Singaporean society and that, moreover, the island nation is more vulnerable to these shocks than is currently acknowledged.
A phase-space noncommutative picture of nuclear matter
Authors: Bertolami Orfeu , Mariji Hodjat
Published: November 2015

Noncommutative features are introduced into a relativistic quantum field theory model of nuclear matter, the quantum hadrodynamics-I nuclear model (QHD-I). It is shown that the nuclear matter equation of state (NMEoS) depends on the fundamental momentum scale, [Formula: see text], introduced by the phase-space noncommutativity (NC). Although it is found that NC geometry does not affect the nucleon fields up to [Formula: see text], it affects the energy density, the pressure and other derivable quantities of the NMEoS, such as the nucleon effective mass. Under the conditions of saturation of the symmetric NM under consideration, the estimated value for the noncommutative parameter is [Formula: see text].
Simple Deterministic Algorithms for Fully Dynamic Maximal Matching
Authors: Neiman Ofer , Solomon Shay
Published: November 2015

A maximal matching can be maintained in fully dynamic (supporting both addition and deletion of edges)
n
-vertex graphs using a trivial deterministic algorithm with a worst-case update time of
O
(
n
). No deterministic algorithm that outperforms the naïve
O
(
n
) one was reported up to this date. The only progress in this direction is due to Ivković and Lloyd, who in 1993 devised a deterministic algorithm with an
amortized
update time of
O
((
n
+
m
)
√2/2
), where
m
is the number of edges.

In this article, we show the first deterministic fully dynamic algorithm that outperforms the trivial one. Specifically, we provide a deterministic worst-case update time of
O
(√
m
). Moreover, our algorithm maintains a matching, which in fact is a 3/2-approximate maximum cardinality matching (MCM). We remark that no fully dynamic algorithm for maintaining (2 − ϵ)-approximate MCM improving upon the naïve
O
(
n
) was known prior to this work, even allowing amortized time bounds and randomization.

For low arboricity graphs (e.g., planar graphs and graphs excluding fixed minors), we devise another simple deterministic algorithm with sublogarithmic update time. Specifically, it maintains a fully dynamic maximal matching with amortized update time of
O
(log 
n
/log log 
n
). This result addresses an open question of Onak and Rubinfeld [2010].

We also show a deterministic algorithm with optimal space usage, which for arbitrary graphs maintains a maximal matching in amortized
O
(√
m
) time and uses only
O
(
n
+
m
) space.
Developing 3D Imaging Programmes--Workflow and Quality Control
Authors: Hess Mona , Robson Stuart , Serpico Margaret , Amati Giancarlo , Pridden Ivor , Nelson Tonya
Published: November 2015

This article reports on a successful project for 3D imaging research, digital applications, and use of new technologies in the museum. The article will focus on the development and implementation of a viable workflow for the production of high-quality 3D models of museum objects, based on the 3D laser scanning and photogrammetry of selected ancient Egyptian artefacts. The development of a robust protocol for the complete process chain for imaging cultural heritage artefacts, from the acquisition of 2D and/or 3D images to the development of interactive applications for the public audience, was a specific objective of the project. The workflow devised by the university museum team combines reference photography and 3D imaging with a curatorial review of the actual object to its digital counterpart. It also integrates methodologies for managing the accompanying metadatasets to record these activities. As final stage deliverables from the process, the museum is making high-quality 3D images of artefacts from its collection available through creation and dissemination of digital 3D multiplatform interactive applications in order to allow remote access and to enhance the museum's public engagement. This short article concludes with practical considerations for a 3D imaging workflow such as time and skills needed, 3D model quality, and expectation management.
A Simplified 1.5-Approximation Algorithm for Augmenting Edge-Connectivity of a Graph from 1 to 2
Authors: Kortsarz Guy , Nutov Zeev
Published: November 2015

The Tree Augmentation Problem (TAP) is as follows: given a connected graph
G
=(
V
,
ε
) and an edge set
E
on
V
, find a minimum size subset of edges
F
⊆
E
such that (
V
,
ε
∪
F
) is 2-edge-connected. In the conference version [Even et al. 2001] was sketched a 1.5-approximation algorithm for the problem. Since a full proof was very complex and long, the journal version was cut into two parts. The first part [Even et al. 2009] only proved ratio 1.8. An attempt to simplify the second part produced an error in Even et al. [2011]. Here we give a correct, different, and self-contained proof of the ratio 1.5 that is also substantially simpler and shorter than the previous proofs.
Four Metrics to Evaluate Heterogeneous Multicores
Authors: Tomusk Erik , Dubach Christophe , O’boyle Michael
Published: November 2015

Semiconductor device scaling has made single-ISA heterogeneous processors a reality. Heterogeneous processors contain a number of different CPU cores that all implement the same Instruction Set Architecture (ISA). This enables greater flexibility and specialization, as runtime constraints and workload characteristics can influence which core a given workload is run on. A major roadblock to the further development of heterogeneous processors is the lack of appropriate evaluation metrics. Existing metrics can be used to evaluate individual cores, but to evaluate a heterogeneous processor, the cores must be considered as a collective. Without appropriate metrics, it is impossible to establish design goals for processors, and it is difficult to accurately compare two different heterogeneous processors.

We present four new metrics to evaluate user-oriented aspects of sets of heterogeneous cores:
localized nonuniformity
,
gap overhead
,
set overhead
, and
generality
. The metrics consider sets rather than individual cores. We use examples to demonstrate each metric, and show that the metrics can be used to quantify intuitions about heterogeneous cores.
Generic Neighbor Discovery Accelerations in Mobile Applications
Authors: Zhang Desheng , He Tian , Liu Yunhuai , Gu Yu , Ye Fan , Ganti Raghu K. , Lei Hui
Published: November 2015

As a supporting primitive of many mobile applications, neighbor discovery identifies nearby devices so that they can exchange information and collaborate in a peer-to-peer manner. To date, discovery schemes trade a long latency for energy efficiency and require a collaborative duty cycle pattern, and thus they are not suitable for interactive mobile applications where a user is unable to configure others’ devices. In this article, we propose
Acc
, which serves as an on-demand generic discovery accelerating middleware for many deterministic neighbor discovery schemes.
Acc
leverages the discovery capabilities of neighbor devices, supporting both direct and indirect neighbor discoveries. Further, we present a proactive online rendezvous maintenance mechanism, which is used to reduce delays for the detection of leaving of neighbors. Our evaluations show that
Acc
-assisted discovery schemes reduce latency by up to 51.8% compared to schemes consuming the same amount of energy. More importantly, to prove the real-world value of
Acc
, we further present and evaluate a
Crowd-Alert
application where
Acc
is employed by taxi drivers to accelerate selection of a direction with fewer competing taxis and more potential passengers, based on a 280GB dataset of more than 14,000 taxis in Shenzhen, the most crowded city in China.
A Revised Neural Framework for Face Processing
Authors: Duchaine Brad , Yovel Galit
Published: November 2015

Face perception relies on computations carried out in face-selective cortical areas. These areas have been intensively investigated for two decades, and this work has been guided by an influential neural model suggested by Haxby and colleagues in 2000. Here, we review new findings about face-selective areas that suggest the need for modifications and additions to the Haxby model. We suggest a revised framework based on (a) evidence for multiple routes from early visual areas into the face-processing system, (b) information about the temporal characteristics of these areas, (c) indications that the fusiform face area contributes to the perception of changeable aspects of faces, (d) the greatly elevated responses to dynamic compared with static faces in dorsal face-selective brain areas, and (e) the identification of three new anterior face-selective areas. Together, these findings lead us to suggest that face perception depends on two separate pathways: a ventral stream that represents form information and a dorsal stream driven by motion and form information.
The Determination of Rod and Cone Photoreceptor Fate
Authors: Cepko Constance L.
Published: November 2015

Photoreceptors have been the most intensively studied retinal cell type. Early lineage studies showed that photoreceptors are produced by retinal progenitor cells (RPCs) that produce only photoreceptor cells and by RPCs that produce both photoreceptor cells and other retinal cell types. More recent lineage studies have shown that there are intrinsic, molecular differences among these RPCs and that these molecular differences operate in gene regulatory networks (GRNs) that lead to the choice of the rod versus the cone fate. In addition, there are GRNs that lead to the choice of a photoreceptor fate and that of another retinal cell type. An example of such a GRN is one that drives the binary fate choice between a rod photoreceptor and bipolar cell. This GRN has many elements, including both feedforward and feedback regulatory loops, highlighting the complexity of such networks. This and other examples of retinal cell fate determination are reviewed here, focusing on the events that direct the choice of rod and cone photoreceptor fate.