bluuebunny/crossref_metadata_2025_split huggingface dataset:
CLC in AMG solvers for saddle‐point problems
Authors: Webster Ronald 
Published: January 2018

SummaryAn algebraic multigrid (AMG) solution method for saddle‐point problems is described. The indefinite nature of the saddle‐point matrix makes it unsuitable for the simple smoothing methods normally used in AMG. Moreover, even if presented in a stabilised form, as is done here, poorly conditioned matrices will be generated when constructing the coarse‐grid approximation. This is because, with each successive coarsening step, the off‐diagonal matrix blocks (of interfield coupling) reduce in size more slowly than the diagonal blocks (of intrafield coupling). Stabilised smoothing operators are therefore considered. The first is based on an incomplete decomposition of the complete system matrix into the product of lower‐triangular (L) and upper‐triangular (U) matrices, an ILU factorisation. The second is based on an exact block decomposition of an incomplete (simplified) system matrix into lower and upper block‐triangular matrices, a BILU factorisation. However, the degree of stabilisation thus established in the smoothing operators does not guarantee an efficient smoothing at all grid levels. There can still be inefficiency on the least‐stable coarser grids. The breakdown in efficiency begins at a grid level where the ratio of the inter‐ to intrafield coupling strengths exceeds a critical ratio. Provision is thus made for a further conditioning of coarse‐grid operators, a coarse‐level conditioning (CLC). This is another block‐LU factorisation that is only applied at and beyond the critical grid level. It is not applied directly to the operator for any chosen level but to its fine‐grid progenitor. Thus, while ILU and BILU use postcoarsening‐step factorisations, CLC uses precoarsening‐step factorisations. With CLC so deployed, ILU and BILU become efficient at all grid levels, resulting in an AMG convergence that is independent of the total number of grids.
Multiphase topology design with optimal material selection using an inversep‐norm function
Authors: James Kai A. 
Published: January 2018

SummaryWe present an original mathematical formulation for optimizing structural topology while simultaneously identifying an optimal set of design materials that are selected from a larger set of candidate materials. This design task is analogous to that, which is commonly encountered in additive manufacturing applications in which the 3D printer can print parts containing up to 3 distinct materials that can be selected from a larger suite of usable materials. The material distribution is parameterized via the shape functions with penalization formulation in which a set of activation functions, which are derived from a partition of the unit hypercube, is used to determine the effective local elasticity modulus within a single finite element. Additionally, we introduce an inversep‐norm function, which is used to ensure that the optimized material properties converge to a set of discrete values corresponding to the available candidate materials. The algorithm has been implemented on a set of 2D benchmark problems. Numerical results show that the formulation combining the inversep‐norm function with the activation functions successfully produces optimized multimaterial solutions containing no more than the prescribed number of distinct materials.
Cross‐metathesis functionalized exo‐olefin derivatives of lactide
Authors: Sinclair Fern , Shaver Michael P. 
Published: January 2018

ABSTRACTPoly(lactic acid) is at the forefront of research into alternative replacements to fossil fuel derived polymers, yet preparation of derivatives of this key biodegradable polymer remain challenging. This article explores the use of two derivatives of lactide, each of which features an exocyclic olefin, and their pre‐polymerization modification by olefin cross‐metathesis. Methylenation of lactide with Tebbe's reagent generates a novel 5‐methylenated lactide monomer, (3S,6S)‐3,6‐dimethyl‐5‐methylene‐1,4‐dioxan‐2‐one, complementing the previously reported 3‐methylenated (6S)‐3‐methylene‐6‐methyl‐1,4‐dioxan‐2,5‐dione. While ring‐opening of each monomer is not productive, olefin cross‐metathesis can be used to functionalize each of the exocyclic olefins to produce a family of monomers. The ring‐opening polymerization of these new monomers, and their hydrogenated congeners, is facilitated by organo‐ and Lewis‐acid catalysts. Together, they offer a new strategy for derivatizing and altering the properties of poly(lactic acid). © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 741–748
Microcapsule synthesis via RAFT photopolymerization in vegetable Oil as a green solvent
Authors: Ishizuka Fumi , Stenzel Martina H. , Zetterlund Per B. 
Published: January 2018

ABSTRACTPolymeric capsules with an aqueous core have great potential for a wide range of applications, for example food/biomedical applications. However, synthesis of such capsules often involves the use of toxic organic solvents. Herein, an organic solvent‐free approach is developed for the synthesis of polymeric microcapsules with an aqueous core. The method is based on RAFT polymerization of divinyl monomer around the periphery of inverse emulsion water droplets acting as templates, with an amphiphilic macroRAFT species fulfilling the dual roles of RAFT agent and colloidal stabilizer. Vegetable oils, which are non‐toxic and renewable, are used as the continuous phase of these inverse emulsions, which are prepared using membrane emulsification to control the emulsion droplet size and size distribution. Relatively monodisperse emulsions with tunable droplet size in the range of approximately 10–30 µm are prepared, followed by the RAFT polymerization step to generate polymeric microcapsules having similar size as the initial droplets. This approach will be beneficial for various applications where toxic solvents need be minimized or removed completely to avoid adverse effects. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 831–839
The influence of nano‐PS particle on structure evolution and electrical properties of PP/PS
Authors: Guo Qiyang , Yang Lichuan , Li Xiaotian , Li Wenfei , Yao Zhanhai 
Published: January 2018

ABSTRACTThe polypropylene‐g‐polystyrene (PP‐g‐PS) copolymers with different grafting ratios are used as compatibilizers to control the size of polystyrene (PS) particles at nanometer scale in polypropylene (PP) matrix. Then the PP/PS insulating nanocomposites (containing 10 wt % PS calculated from PS and PP‐g‐PS) are manufactured. With the increase in grafting ratio of PP‐g‐PS, the size of PS particle is reduced and the interfacial adhesion is enhanced. Meanwhile, the dielectric properties, DC breakdown strength and volume resistivity are increased with the decreasing of PS particle size. The spherulite size of PP is decreased and the boundary between crystals and amorphous regions is blurred or even disappears due to the presence of PS nanoparticles. This evolution of PP structure is attributed to the serious entanglements of PP and PS molecular chains. Finally, the correlation between morphological structure and electrical properties is ultimately established based on the in‐depth understanding of the molecular chain movement, crystal structure, and phase morphology. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018, 56, 706–717
Fragmentation of Ammonium Nitrate Particles under Thermal Cycling
Authors: Maggi Filippo , Garg Priya 
Published: January 2018

AbstractAmmonium nitrate finds application in explosives and chlorine‐free slow‐burning propellants. Different phases are known for this ammonium salt, each of them featured by peculiar bulk densities. As a consequence, the variation of storage temperature induces processes of expansion‐contraction in the crystals, unless specific stabilization is performed. In this paper, a batch of raw ammonium nitrate particles has been thermally cycled between −30 °C to +60 °C and analyzed. Microscopic observations, particle size measurement, and X‐ray microtomography showed that the particles undergo a progressive fragmentation process, with opening of internal cracks and voids. The tested material halved its mass‐mean diameter after five thermal cycles. As a term of comparison, a phase‐stabilized ammonium nitrate batch was tested under the same conditions, showing no effect.
Integration of paper spray ionization high‐field asymmetric waveform ion mobility spectrometry for forensic applications
Authors: Tsai Chia‐Wei , Tipple Christopher A. , Yost Richard A. 
Published: January 2018

RationalePaper spray ionization (PSI) is an attractive ambient ionization source for mass spectrometry (MS) since it allows the combination of surface sampling and ionization. The minimal sample preparation inherent in this approach greatly reduces the time needed for analysis. However, the ions generated from interfering compounds in the sample and the paper substrate may interfere with the analyte ions. Therefore, the integration of PSI with high‐field asymmetric ion mobility spectrometry (FAIMS) is of significant interest since it should reduce the background ions entering the mass analyzer without complicating the analysis or increasing analysis time. Here we demonstrate the integration of PSI with FAIMS/MS and its potential for analysis of samples of forensic interest.MethodsIn this work, the parameters that can influence the integration, including sampling and ionization by paper spray, the FAIMS separation of analytes from each other and background interferences, and the length of time that a usable signal can be observed for explosives on paper, were evaluated with the integrated system.ResultsIn the negative ion analysis of 2,4,6‐trinitrotoluene (TNT), pentaerythritol tetranitrate (PETN), octahydro‐1,3,5,7‐tetranitro‐1,3,5,7‐tetrazocine (HMX), and 1,3,5‐trinitroperhydro‐1,3,5‐triazine (RDX), amounts as low as 1 ng on paper were readily observed. The successful positive ion separation of a set of illicit drugs including heroin, methamphetamine, and cocaine was also achieved. In addition, the positive ion analysis of the chemical warfare agent simulants dimethyl methylphosphonate (DMMP) and diisopropyl methylphosphonate (DIMP) was evaluated.ConclusionsThe integration of PSI‐FAIMS/MS was demonstrated for the analyses of explosives in negative ion mode and for illicit drugs and CW simulants in positive mode. Paper background ions that could interfere with these analyses were separated by FAIMS. The compensation voltage of an ion obtained by FAIMS provided an additional identification parameter to be combined with the mass spectrum for each analyte.
Carbon and nitrogen stable isotopes in U.S. milk: Insight into production process
Authors: Bostic Joshua N. , Hagopian William M. , Jahren A. Hope 
Published: January 2018

RationaleStable isotope analysis (SIA), a potential method of verifying the geographic origin and production method of dairy products, has not been applied to United States (U.S.) dairy samples on a national scale. To determine the potential of carbon and nitrogen SIA in authenticity assessment of U.S. dairy products, we analyzed a geographically representative collection of conventional milk samples to determine isotopic variations with (1) Purchase Location and (2) Macronutrient Content.MethodsA total of 136 milk samples spanning five commercially available varieties (3.25% [i.e., 'whole'], 2%, 1%, 0% [i.e., 'skim'] and 1% chocolate) were collected from randomly selected counties across the U.S. as part of the United States Department of Agriculture's (USDA's) National Food and Nutrient Analysis program. δ13C and δ15N values of bulk samples determined via elemental analysis/isotope ratio mass spectrometry (EA/IRMS) were used to assess the contribution of fat content, added sugar content and census‐designated region of collection to isotopic variations within the dataset.ResultsThere was a negative linear relationship between fat content and δ13C values, with average milk δ13C values decreasing by 0.33‰ for each 8.75% increase in dry weight (1% wet weight) fat content. The average δ13C value of flavored 1% chocolate milk samples, which contain an additional 12 g of added sugar, was 2.05‰ higher than that of 1% unflavored milk (−16.47‰ for chocolate milk vs −18.52‰ for unflavored milk). When controlling for macronutrient content, milk samples collected in West region supermarkets possessed significantly lower δ13C values than samples collected from Midwest, South, and Northeast regions. δ15N values did not vary with macronutrient content or region of collection.ConclusionsCarbon stable isotope ratios in U.S. milk samples varied with macronutrient content and region of purchase, suggesting that SIA can provide insight into production processes within the U.S. dairy industry, with potential applications in national food adulteration and authentication efforts.
Human T‐lymphotropic virus type 1 infection and solid organ transplantation
Authors: Taylor Graham P. 
Published: January 2018

SummaryHTLV infection appears to be more common among renal transplant candidates than in the related general population. HTLV‐1‐associated diseases may occur in carriers who are transplanted but there is insufficient evidence to confirm whether these occur more frequently as a result of the associated immunosuppression. Consequently, pre‐existing HTLV‐1 infection should not be considered a contra‐indication to transplantation.The risk of transmission of HTLV‐1 through solid organ transplantation from a confirmed infected donor is unknown. There are anecdotes of multiple infections from a single donor. Biologically due to the significant volume of blood and the lack of storage, transmission would be expected to be higher than following blood transfusion. The rate of subsequent disease is unknown, but there are now 11 reports of HAM and 2 of ATL occurring within 4 years of transplantation associated infection. There are insufficient data to know whether the time from infection to onset of disease and the rate of progression differ from transmission through other routes, but early onset and rapid progression is a concern. Responses to enhanced immunosuppression for the treatment of HAM are variable.The risk of HTLV‐1 associated disease in exchange for a life‐saving major organ transplantation from an infected donor might be considered worth taking by some HTLV‐1 uninfected patients. Peri‐transplantation antiretroviral prophylaxis with zidovudine and raltegravir is biologically sound but therapeutically unproven. The risks related to HTLV‐1 infection appear to preclude the use of any other tissue. All transplant donors should be screened for HTLV‐1 infection regardless of perceived risk.
Hydrogels: Promising Energy Storage Materials
Authors: Singh Ram , Veer Babita 
Published: January 2018

AbstractEnergy is essential for the economic growth of any country. There is a strong demand for the development of materials that can show potential towards higher power density and energy density. In this article, a promising class of polymeric materials, hydrogels have been discussed as an energy storage material. The hydrogels are advantageous as they possess in them the unique combination of organic conductors and conventional polymers. The article covers the synthetic approach of hydrogels which includes both the conventional synthesis and the new routes adopted followed by the application of hydrogels as energy storage materials. Finally, the future opportunities and prospects in the development of hydrogels as advanced energy storage materials are highlighted.
Adrenal Ganglioneuroma: Features and Outcomes of 42 Cases in a Chinese Population
Authors: Xie Jing , Dai Jun , Zhou Wen‐long , Sun Fu‐kang 
Published: January 2018

AbstractBackgroundAdrenal ganglioneuromas (AGNs) are extremely rare benign neoplasms. This study is to share our experience regarding diagnostic and operative management of these tumors.MethodsClinical details as well as follow‐up data were retrospectively analyzed in 42 primary AGN patients who received operative resection at a tertiary referral hospital in China between May 2005 and July 2016.ResultsThe mean age of the patients at diagnosis was 35.3 years (range 13–59 years). Among the patients, 28 were asymptomatic. The mean preoperative size was 5.3 ± 2.2 cm (range 2.1–14.0 cm), and 17 cases were larger than 5 cm. All patients underwent operative resection as open adrenalectomy in 20 patients and laparoscopy in 22 patients. The mean tumor size on pathologic examination was 6.0 ± 2.6 cm (range 2.2–17.0 cm). Laparoscopic operation showed its advantages over open surgery on the postoperative duration (5.0 vs. 7.3 days, p < 0.001) and estimated blood loss (69.5 vs. 157.5 ml, p = 0.047). No patient had recurrence or metastasis during a median follow‐up of 70.5 months (range 3.7–164.3 months).ConclusionsWe describe the largest AGN series reported to date. The preoperative diagnosis of AGN remains difficult despite of the progression of imaging examination. After complete resection, the prognosis of AGN patients is excellent. Laparoscopic approach has its advantages in the resection of AGNs.
Prospective Randomized Trial of Use of In‐House Prepared Low‐Cost Radiopharmaceutical Versus Commercial Radiopharmaceutical for Sentinel Lymph Node Biopsy in Patients with Early Stage Invasive Breast Cancer
Authors: Agarwal Gaurav , Rajan Sendhil , Mayilvaganan Sabaretnam , Mishra Anjali , Krishnani Narendra , Gambhir Sanjay 
Published: January 2018

AbstractBackgroundThe current standard‐of‐care for surgical staging of the axilla in clinically node‐negative (N0) early breast cancers is sentinel lymph node biopsy (SLNB), which requires expensive radiopharmaceuticals for efficacious results. In‐house produced low‐cost radiopharmaceuticals may be the solution and have shown efficacy in earlier observational/pilot studies. We compared SLNB using in‐house prepared radiopharmaceutical (99mTc‐Antimony‐colloid) versus commercially marketed radiopharmaceutical (99mTc‐Sulphur‐colloid) in this prospective randomized study.Study Design78 clinically N0 early breast cancer patients (T1/2, N0 stages), undergoing primary surgery were prospectively randomized 1:1 into two groups; to receive SLNB using methylene blue, and either 99mTc‐Antimony colloid (Group‐1) or 99mTc‐Sulphur colloid (Group‐2). Completion axillary dissection was done in all (validation SLNB). SLNB indices were compared between the groups.ResultsThe groups were comparable with regard to age, stage, tumour size, hormone receptors and HER2neu status. Cost of the in‐house prepared 99mTc‐antimony colloid was 16‐times lesser compared to 99mTc‐sulphur colloid. SLN identification rates (IR) in Groups 1 and 2 were 100 and 97.4% respectively, (p > 0.05). False negative rates (FNR) in Group 1 and 2 were 6.3% (1/16 patients) and 7.7% (1/13 patients), respectively, (p > 0.05). There were no major allergic reactions in either group.ConclusionIn this prospective randomized trial on early breast cancer patients, accuracy of SLNB was comparable using in‐house prepared, 99mTc‐antimony colloid and commercially marketed 99mTc‐sulphur colloid as radiopharmaceutical, while 99mTc‐antimony colloid was much cheaper than 99mTc‐sulphur colloid.
Rational design of a synthetic Entner–Doudoroff pathway for enhancing glucose transformation to isobutanol in Escherichia coli
Authors: Liang Shaoxiong , Chen Hong , Liu Jiao , Wen Jianping 
Published: January 2018

Abstract
Isobutanol as a more desirable biofuel has attracted much attention. In our previous work, an isobutanol-producing strain Escherichia coli LA09 had been obtained by rational redox status improvement under guidance of the genome-scale metabolic model. However, the low transformation from sugar to isobutanol is a limiting factor for isobutanol production by E. coli LA09. In this study, the intracellular metabolic profiles of the isobutanol-producing E. coli LA09 with different initial glucose concentrations were investigated and the metabolic reaction of fructose 6-phosphate to 1, 6-diphosphate fructose in glycolytic pathway was identified as the rate-limiting step of glucose transformation. Thus, redesigned carbon catabolism was implemented by altering flux of sugar metabolism. Here, the heterologous Entner–Doudoroff (ED) pathway from Zymomonas mobilis was constructed, and the adaptation of upper and lower parts of ED pathway was further improved with artificial promoters to alleviate the accumulation of toxic intermediate metabolite 2-keto-3-deoxy-6-phospho-gluconate (KDPG). Finally, the best isobutanol-producing E. coli ED02 with higher glucose transformation and isobutanol production was obtained. In the fermentation of strain E. coli ED02 with 45 g/L initial glucose, the isobutanol titer, yield and average producing rate were, respectively, increased by 56.8, 47.4 and 88.1% to 13.67 g/L, 0.50 C-mol/C-mol and 0.456 g/(L × h) in a shorter time of 30 h, compared with that of the starting strain E. coli LA09.
Urban robotics and responsible urban innovation
Authors: Nagenborg Michael 
Published: January 2018

AbstractRobots are leaving factories and entering urban spaces. In this paper, I will explore how we can integrate robots of various types into the urban landscape. I will distinguish between two perspectives: (1) the responsible design and use of urban robots and (2) robots as part of responsible urban innovations. The first viewpoint considers issues arising from the use of a robot in an urban environment. To develop a substantive understanding of Responsible Urban Robotics, we need to focus on normative implications of city life as the context in which in robots are being used. I will refer to the desirable qualities of city life as “cityness” and will argue that we should design for cityness. The second approach asks how robots might be used to address challenges specific to cities. From the perspective of RRI, this may require participatory approaches in which the needs of the stakeholders are addressed. But we may also find inspiration in the work undertaken in architecture on expanding the concept and field to ensure that architects not only provide services to the lucky few but also create useful and beautiful spaces for the many. A dialogue with architects, urban designers, and urban planners may also be needed to successfully address the spatial issues raised by the presence of robots in the city.
Talking with Children About Adult‐Onset Hereditary Cancer Risk: A Developmental Approach for Parents
Authors: Werner‐Lin Allison , Merrill Shana L. , Brandt Amanda C. 
Published: January 2018

AbstractFamilies often express difficulty to their providers and request guidance regarding the task of communicating with children about potential adult‐onset inherited cancer risks. This disclosure is often complicated by the parent's ongoing adjustment to their mutation status, guilt at potential transmission of the mutation to the child, concern over inciting distress in children, and the varied capacities of children in the home to understand genetic information. Providers often do not have adequate resources to support or facilitate disclosure of genetic test results to children. Optimally, communication about inherited cancer risk is an open, ongoing process within the family. We recommend that parents tailor conversations to the child's developmental, cognitive, emotional, and behavioral abilities to support comprehension. Based on well‐established theories of child development, empirical research on family communication of hereditary cancer risk, and clinical counseling experience, we offer recommendations for parental disclosure of genetic risk to children, case examples with critical discussion of relevant topics, common child questions with sample scripted responses, and additional printed and online resources.