bluuebunny/crossref_metadata_2025 huggingface dataset:
Health care disparities among octogenarians and nonagenarians with stage II and III rectal cancer
Authors: Cassidy Richard J. , Switchenko Jeffrey M. , Cheng En , Jiang Renjian , Jhaveri Jaymin , Patel Kirtesh R. , Tanenbaum Daniel G. , Russell Maria C. , Steuer Conor E. , Gillespie Theresa W. , McDonald Mark W. , Landry Jerome C.
Published: July 2017

BACKGROUND

Octogenarians and nonagenarians with stage II/III rectal adenocarcinomas are underrepresented in the randomized trials that have established the standard‐of‐care therapy of preoperative chemoradiation followed by definitive resection (ie, chemoradiation and then surgery [CRT+S]). The purpose of this study was to evaluate the impact of therapies on overall survival (OS) for patients with stage II/III rectal cancers and determine predictors of therapy within the National Cancer Data Base (NCDB).

METHODS

In the NCDB, patients who were 80 years old or older and had clinical stage II/III rectal adenocarcinoma from 2004 to 2013 were queried. Kaplan‐Meier analysis, log‐rank testing, logistic regression, Cox proportional hazards regression, interaction effect testing, and propensity score–matched analysis were conducted.

RESULTS

The criteria were met by 2723 patients: 14.9% received no treatment, 29.7% had surgery alone, 5.0% underwent short‐course radiation and then surgery (RT+S), 45.3% underwent CRT+S, and 5.1% underwent surgery and then chemoradiation (S+CRT). African American race and residence in a less educated county were associated with not receiving treatment. Male sex, older age, worsening comorbidities, and receiving no treatment or undergoing surgery alone were associated with worse OS. There was no statistical difference in OS between RT+S, S+CRT, and CRT+S. Interaction testing found that CRT+S improved OS independently of age, comorbidity status, sex, race, and tumor stage. In the propensity score–matched analysis, CRT+S was associated with improved OS in comparison with surgery alone.

CONCLUSIONS

A significant portion of octogenarians and nonagenarians with stage II/III rectal adenocarcinomas do not receive treatment. African American race and living in a less educated community are associated with not receiving therapy. This series suggests that CRT+S is a reasonable strategy for elderly patients who can tolerate therapy. Cancer 2017;123:4325‐36. © 2017 American Cancer Society.
Feasibility and preliminary effects of resistance training and nutritional supplements during versus after radiotherapy in patients with head and neck cancer: A pilot randomized trial
Authors: Sandmæl Jon Arne , Bye Asta , Solheim Tora Skeidsvoll , Stene Guro Birgitte , Thorsen Lene , Kaasa Stein , Lund Jo‐Åsmund , Oldervoll Line Merethe
Published: July 2017

BACKGROUND

Patients with head and neck cancer (HNC) experience involuntary weight loss that has a negative impact on physical function, morbidity, and survival. The objective of the current study was to evaluate the feasibility of an exercise and nutrition intervention during radiotherapy (RT) compared with after RT, and to examine preliminary effects on skeletal muscle mass.

METHODS

Patients with HNC were randomized to an exercise and nutrition intervention during RT (EN‐DUR) or after RT (EN‐AF). The EN‐DUR intervention was conducted at a hospital and the EN‐AF intervention took place at a rehabilitation center. The interventions consisted of progressive resistance training (PRT) and oral nutritional supplements (ONS). Feasibility outcomes were tracked weekly and muscle mass was measured by computed tomography scans before and after RT and at 2 months follow‐up.

RESULTS

Of the 50 eligible patients, 41 (82%) agreed to participate. 90% of patients completed the EN‐DUR intervention and the adherence to PRT and ONS was 81% and 57%, respectively. 52% of patients attended the EN‐AF intervention and adherence to PRT and ONS was 94% and 76%, respectively. The EN‐DUR demonstrated a trend toward mitigating loss of muscle mass during RT and the EN‐AF demonstrated a similar trend after RT. No difference in muscle mass was detected between the groups from baseline to week 14.

CONCLUSIONS

An exercise and nutrition intervention is feasible for patients with HNC during RT, and the intervention is potentially effective in mitigating loss of muscle mass both during and after RT. Future trials should assess the feasibility and effects of extended interventions during and after treatment. Cancer 2017;123:4440‐8. © 2017 American Cancer Society.
Nonlinear Stability of the Current‐Vortex Sheet to the Incompressible MHD Equations
Authors: Sun Yongzhong , Wang Wei , Zhang Zhifei
Published: July 2017

In this paper, we solve a long‐standing open problem: nonlinear stability of the current‐vortex sheet in the ideal incompressible magnetohydrodynamics under the Syrovatskij stability condition. This result gives the first rigorous confirmation of the stabilizing effect of the magnetic field on Kelvin‐Helmholtz instability.© 2017 Wiley Periodicals, Inc.
Nanocrystal–Dye Interactions: Studying the Feasibility of Co‐Sensitization of Dyes with Semiconductor Nanocrystals
Authors: Mittal Mona , Sapra Sameer
Published: July 2017

One of the recent developments in enhancing the performance of quantum dot sensitized solar cells (QDSSCs) is to combine QDs with dyes in order to overcome the drawbacks of QDSSCs. However, implementation of this requires a detailed investigation of the interaction between QDs and dye. Here, we have studied the effect of size and surface ligands in the interaction of CdSe nanocrystals (NCs) with Ru N‐719 dye. The interaction mechanism is investigated by steady‐state and time‐resolved photoluminescence spectroscopy, indicating the involvement of apparent static as well as dynamic quenching. Further analysis of dynamic quenching reveals the contribution of Förster resonance energy transfer and electron transfer from NCs to the dye. The Marcus model of electron transfer rationalizes the random trends of experimental electron transfer rates, which depend on the energetic offsets between the two species and the reorganizational energy. For understanding the kinetics of energy/charge transfer from CdSe NCs to Ru N‐719 dye, a Poisson binding model has been proposed that assumes a Poisson distribution of dye molecules around CdSe NCs. The variation of quenching rate constants and PL quenching rate both follow the same trend, supporting the main contribution of kinetics in the interaction of CdSe NCs with the dye.
Site‐Specific Protein Labeling via Sortase‐Mediated Transpeptidation
Authors: Antos John M. , Ingram Jessica , Fang Tao , Pishesha Novalia , Truttmann Matthias C. , Ploegh Hidde L.
Published: August 2017

Strategies for site‐specific protein modification are highly desirable for the construction of conjugates containing non‐genetically‐encoded functional groups. Ideally, these strategies should proceed under mild conditions, and be compatible with a wide range of protein targets and non‐natural moieties. The transpeptidation reaction catalyzed by bacterial sortases is a prominent strategy for protein derivatization that possesses these features. Naturally occurring or engineered variants of sortase A from Staphylococcus aureus catalyze a ligation reaction between a five‐amino‐acid substrate motif (LPXTG) and oligoglycine nucleophiles. By pairing proteins and synthetic peptides that possess these ligation handles, it is possible to install modifications onto the protein N‐ or C‐terminus in site‐specific fashion. As described in this unit, the successful implementation of sortase‐mediated labeling involves straightforward solid‐phase synthesis and molecular biology techniques, and this method is compatible with proteins in solution or on the surface of live cells. © 2017 by John Wiley & Sons, Inc.
Sulfasalazine‐Induced Agranulocytosis Is Associated With the Human Leukocyte Antigen Locus
Authors: Wadelius Mia , Eriksson Niclas , Kreutz Reinhold , Bondon‐Guitton Emmanuelle , Ibañez Luisa , Carvajal Alfonso , Lucena M. Isabel , Sancho Ponce Esther , Molokhia Mariam , Martin Javier , Axelsson Tomas , Kohnke Hugo , Yue Qun‐Ying , Magnusson Patrik K.E. , Bengtsson Mats , Hallberg Pär ,   on behalf of EuDAC
Published: August 2017

Agranulocytosis is a serious, although rare, adverse reaction to sulfasalazine, which is used to treat inflammatory joint and bowel disease. We performed a genome‐wide association study comprising 9,380,034 polymorphisms and 180 HLA alleles in 36 cases of sulfasalazine‐induced agranulocytosis and 5,170 population controls. Sulfasalazine‐induced agranulocytosis was significantly associated with the HLA region on chromosome 6. The top hit (rs9266634) was located close toHLA‐B, odds ratio (OR) 5.36 (95% confidence interval (CI) (2.97, 9.69)P = 2.55 × 10−8). We HLA‐sequenced a second cohort consisting of 40 cases and 142 treated controls, and confirmed significant associations withHLA‐B*08:01, OR = 2.25 (95% CI (1.02, 4.97)P = 0.0439), in particular theHLA‐B*08:01haplotypeHLA‐DQB1*02:01‐DRB1*03:01‐B*08:01‐C*07:01, OR = 3.79 (95% CI (1.63, 8.80)P = 0.0019), and withHLA‐A*31:01, OR = 4.81 (95% CI (1.52, 15.26)P = 0.0077). The number needed to test forHLA‐B*08:01andHLA‐A*31:01to avoid one case was estimated to be 1,500. We suggest that intensified monitoring or alternative treatment should be considered for known carriers ofHLA‐B*08:01orHLA‐A*31:01.
Altered theta oscillations in resting EEG of fibromyalgia syndrome patients
Authors: Fallon N. , Chiu Y. , Nurmikko T. , Stancak A.
Published: July 2017

Background

Fibromyalgia syndrome (FM) is a chronic pain disorder characterized by widespread pain, sleep disturbance, fatigue and cognitive/affective symptoms. Functional imaging studies have revealed that FM and other chronic pain syndromes can affect resting brain activity. This study utilized electroencephalographic (EEG) recordings to investigate the relative power of ongoing oscillatory activity in the resting brain.

Methods

A 64‐channel EEG was recorded at rest in 19 female FM patients and 18 healthy, age‐matched, control subjects. The Manual Tender Point Scale (MTPS) examination was performed to quantify tonic pain and tenderness on the day of testing along with measures of mood, arousal and fatigue. Oscillations in delta, theta, alpha, beta and gamma frequency bands were analysed using Standardised Low‐Resolution Brain Electromagnetic Tomography to evaluate sources of spectral activity throughout the whole brain.

Results

FM patients exhibited greater pain, tiredness and tension on the day of testing relative to healthy control participants and augmented theta activity in prefrontal and anterior cingulate cortices. No significant differences were seen in other frequency bands. Augmented frontal theta activity in FM patients significantly correlated with measures of tenderness and mean tiredness scores.

Conclusions

The findings indicate that alterations to resting‐state oscillatory activity may relate to ongoing tonic pain and fatigue in FM, and manifest in brain regions relevant for cognitive‐attentional aspects of pain processing and endogenous pain inhibition. Enhanced low‐frequency oscillations were previously seen in FM and other chronic pain syndromes, and may relate to pathophysiological mechanisms for ongoing pain such as thalamocortical dysrhythmia.

Significance

Increased prefrontal theta activity may contribute to persistent pain in fibromyalgia or represent the outcome of prolonged symptoms. The findings point to the potential for therapeutic interventions aimed at normalizing neural oscillations, while further research utilizing quantitative analysis of resting EEG could benefit our understanding of fibromyalgia pathophysiology.
Cable tray fire tests in a confined and mechanically ventilated facility
Authors: Zavaleta Pascal , Audouin Laurent
Published: July 2017

Cable fires are one of the main fire hazards in nuclear power plants. As part of the cable fire spreading (CFS) campaign of the OECD PRISME‐2 programme, 3 real‐scale cable tray fire tests were performed in open atmosphere (1 CFS support test, named CFSS‐2) and in a confined and mechanically ventilated facility (2 CFS tests, named CFS‐3 and CFS‐4). This study aims at investigating the effects of confined and ventilated conditions on cable tray fires that used a halogen‐free flame retardant cable‐type. The CFS‐3 and CFS‐4 tests involved 2 ventilation renewal rates of 4 and 15 h−1, respectively. The confined conditions lead to decrease the fire growth rate and the peaks of mass loss rate and heat release rate, compared with open atmosphere. The reductions are larger for the lower ventilation renewal rate. Furthermore, it is shown that the CFS‐4 test may be classified as a well‐ventilated fire and the CFS‐3 test as an under‐ventilated fire. For this last one, its fire characteristics and its consequences in the fire room highlight an oscillatory behaviour, with the same low frequency, for about 30 minutes. These oscillations arise from successive combustions of unburnt gases.
Innovative geophysical technologies for the exploration of faults, karst structures and cavities in tunnelling
Authors: Schmidt Markus , Richter Thomas , Lehmann Paul
Published: August 2017

In rock formations prone to karstification, there are no or only limited geological/hydrological principles that enable safe prognosis of the existence and location of karst and fault structures. The application of geophysical methods offers a high efficiency of detection and localisation of faults, cavities and karst structures, and when combined with targeted verification drillings, provides an extensive three‐dimensional structural investigation of rock formations. Four examples of geophysical karst and fault investigations in German tunnelling are presented here to demonstrate the innovative technologies and their respective survey results that in all cases contributed to a safe excavation process and later operation of the tunnels.
Engineering brown fat into skeletal muscle using ultrasound‐targeted microbubble destruction gene delivery in obese Zucker rats: Proof of concept design
Authors: Bastarrachea Raul A. , Chen Jiaxi , Kent Jack W. , Nava‐Gonzalez Edna J. , Rodriguez‐Ayala Ernesto , Daadi Marcel M. , Jorge Barbara , Laviada‐Molina Hugo , Comuzzie Anthony G. , Chen Shuyuan , Grayburn Paul A.
Published: August 2017

Ultrasound‐targeted microbubble destruction (UTMD) is a novel means of tissue‐specific gene delivery. This approach systemically infuses transgenes precoupled to gas‐filled lipid microbubbles that are burst within the microvasculature of target tissues via an ultrasound signal resulting in release of DNA and transfection of neighboring cells within the tissue. Previous work has shown that adenovirus containing cDNA of UCP‐1, injected into the epididymal fat pads in mice, induced localized fat depletion, improving glucose tolerance, and decreasing food intake in obese diabetic mice. Our group recently demonstrated that gene therapy by UTMD achieved beta cell regeneration in streptozotocin (STZ)‐treated mice and baboons. We hypothesized that gene therapy with BMP7/PRDM16/PPARGC1A in skeletal muscle (SKM) of obese Zucker diabetic fatty (fa/fa) rats using UTMD technology would produce a brown adipose tissue (BAT) phenotype with UCP‐1 overexpression. This study was designed as a proof of concept (POC) project. Obese Zucker rats were administered plasmid cDNA contructs encoding a gene cocktail with BMP7/PRDM16/PPARGC1A incorporated within microbubbles and intravenously delivered into their left thigh. Controls received UTMD with plasmids driving a DsRed reporter gene. An ultrasound transducer was directed to the thigh to disrupt the microbubbles within the microcirculation. Blood samples were drawn at baseline, and after treatment to measure glucose, insulin, and free fatty acids levels. SKM was harvested for immunohistochemistry (IHC). Our IHC results showed a reliable pattern of effective UTMD‐based gene delivery in enhancing SKM overexpression of the UCP‐1 gene. This clearly indicates that our plasmid DNA construct encoding the gene combination of PRDM16, PPARGC1A, and BMP7 reprogrammed adult SKM tissue into brown adipose cells in vivo. Our pilot established POC showing that the administration of the gene cocktail to SKM in this rat model of genetic obesity using UTMD gene therapy, engineered a BAT phenotype with UCP‐1 over‐expression. © 2017 IUBMB Life, 69(9):745–755, 2017
Rotator cuff repair with a novel mesh suture: An ex vivo assessment of mechanical properties
Authors: Zhang Tao , Hatta Taku , Thoreson Andrew R. , Lu ChengChang , Steinmann Scott P. , Moran Steven L. , Zhao Chunfeng
Published: August 2017

Surgical repair is a common treatment for rotator cuff tear; however, the retear rate is high. A high degree of suture repair strength is important to ensure rotator cuff integrity for healing. The purpose of this study was to compare the mechanical performance of rotator cuffs repaired with a mesh suture versus traditional polydioxanone suture II and FiberWire sutures in a canine in vitro model. Seventy‐two canine shoulders were harvested. An infraspinatus tendon tear was created in each shoulder. Two suture techniques—simple interrupted sutures and two‐row suture bridge—were used to reconnect the infraspinatus tendon to the greater tuberosity, using three different suture types: Mesh suture, polydioxanone suture II, or FiberWire. Shoulders were loaded to failure under displacement control at a rate of 20 mm/min. Failure load was compared between suture types and techniques. Ultimate failure load was significantly higher in the specimens repaired with mesh suture than with polydioxanone suture II or FiberWire, regardless of suture technique. There was no significant difference in stiffness among the six groups, with the exception that FiberWire repairs were stiffer than polydioxanone suture II repairs with the simple interrupted technique. All specimens failed by suture pull‐out from the tendon. Based on our biomechanical findings, rotator cuff repair with the mesh suture might provide superior initial strength against failure compared with the traditional polydioxanone suture II or FiberWire sutures. Use of the mesh suture may provide increased initial fixation strength and decrease gap formation, which could result in improved healing and lower re‐tear rates following rotator cuff repair. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:987–992, 2018.
Application of new insoluble dietary fibres from triticale as supplement in yoghurt – effects on physico‐chemical, rheological and quality properties
Authors: Miocinovic Jelena , Tomic Nikola , Dojnov Biljana , Tomasevic Igor , Stojanovic Sanja , Djekic Ilija , Vujcic Zoran
Published: July 2017

BACKGROUND

The need to increase the daily intake of dietary fibres opens a new chapter in the research of functional foods enriched with fibres. The potential application of an innovative product – insoluble dietary fibres from triticale in yoghurts – was deployed by characterising their food application and evaluating physico‐chemical, rheological and sensory properties and was the aim of this research.

RESULTS

Detailed characterisations of these fibres are presented for the first time and showed very good hydration properties, optimal pH (slightly acidic), optimal chemical composition, high antioxidant capacity which was proven by phenolics contents. Besides, these fibres showed negligible calorific value, with no phytates and high antioxidant capacity, mainly from ferulic acid. Therefore they could be successfully added to yoghurt. Enrichment of yoghurt having different milk fat content (1.5 and 2.8% w/w) with triticale insoluble fibre (1.5% and 3.0% w/w) significantly influenced the syneresis level, its apparent viscosity, yield stress and thixotropic behaviour. The overall sensory quality scores indicated that yoghurt enriched with 1.5% triticale insoluble fibres was recognised as ‘excellent’ and had enhanced antioxidant activity.

CONCLUSIONS

Insoluble triticale fibre could therefore be used as a supplement to produce functional yoghurt. © 2017 Society of Chemical Industry
Changes in rheological properties of wheat due to storage
Authors: Kamboj Uma , Guha Paramita , Mishra Sunita
Published: July 2017

BACKGROUND

The present study aimed to investigate changes in the fundamental rheological properties of dough prepared from wheat grains stored for 6 months at 20 °C, at ambient temperature (temperature varied with time) and at 4 °C. Stress/shear rate ramp, oscillation and creep‐recovery tests were performed to assess the changes in rheological properties as a result of storage.

RESULTS

Samples were observed to be non‐Newtonian; thus, the Bingham model estimated the yield stress, which was maximum for the wheat stored under ambient conditions and minimum for wheat stored at 20 °C. The stress required to break the bonds was maximum for wheat‐dough stored under ambient conditions and minimum for wheat stored at 20 °C. Wheat stored at 20 °C also had the highest maximum creep and recovery strain. The viscoelastic properties of the three wheat‐dough samples were compared.

CONCLUSION

The results obtained in the present study show that the wheat‐dough prepared under ambient conditions behaves as a rigid and stiff material. The dough prepared from wheat stored at 20 °C had the maximum elasticity. © 2017 Society of Chemical Industry
Direct online extraction and determination by supercritical fluid extraction with chromatography and mass spectrometry of targeted carotenoids from red Habanero peppers (Capsicum chinense Jacq.)
Authors: Zoccali Mariosimone , Giuffrida Daniele , Dugo Paola , Mondello Luigi
Published: July 2017

Recently, supercritical fluid chromatography coupled to mass spectrometry has gained attention as a fast and useful technology applied to the carotenoids analysis. However, no reports are available in the literature on the direct online extraction and determination by supercritical fluid extraction with chromatography and mass spectrometry. The aim of this research was the development of an online method coupling supercritical fluid extraction and supercritical fluid chromatography for a detailed targeted native carotenoids characterization in red habanero peppers. The online nature of the system, compared to offline approaches, improves run‐to‐run precision, enables the setting of batch‐type applications, and reduces the risks of sample contamination. The extraction has been optimized using different temperatures, starting from 40°C up to 80°C. Multiple extractions, until depletion, were performed on the same sample to evaluate the extraction yield. The range of the first extraction yield, carried out at 80°C, which was the best extraction temperature, was 37.4–65.4%, with a %CV range of 2–12. Twenty‐one targeted analytes were extracted and identified by the developed methodology in less than 17 min, including free, monoesters, and diesters carotenoids, in a very fast and efficient way. Quantification of the β‐carotene was carried out by using the optimized conditions.
Consumption of dissolved organic carbon by Caribbean reef sponges
Authors: Hoer Daniel R. , Gibson Patrick J. , Tommerdahl Jake P. , Lindquist Niels L. , Martens Christopher S.
Published: August 2017

Sponges are conspicuous and abundant within the benthic fauna on Caribbean reefs. The ability of these organisms to efficiently capture carbon from particulate sources is well known and the importance of dissolved organic carbon (DOC) uptake has been recognized for several species. We surveyed DOC ingestion by seven sponge species common to Florida Keys reefs using nondisruptive sampling methods on undisturbed individuals. Three of the seven species exhibited significant DOC removal ranging from 13% to 24% of ambient concentrations. The tested species that removed DOC host large microbial consortia within their tissues, while the converse was observed for those that did not. This divergent behavior may suggest an important role for sponge associated microbes in the utilization of DOC by these species. The feeding behaviors of individuals of Xestospongia muta were then monitored over time to investigate its respiratory consumption of particulate and DOC. The uptake rates of dissolved oxygen (DO) and organic carbon by two undisturbed individuals revealed that DOC represented 96% of removed C, and that the tested individuals removed approximately equal quantities of C and DO. This demonstrates that X. muta largely satisfies its respiration demands through DOC consumption, and that DOC likely represents the dominant C source for biomass production and cell overturn in this species. These results further illustrate the metabolic importance of DOC to sponges, and suggest that these organisms are an important pathway for remineralizing organic matter on Caribbean reefs.
Successful UV‐Induced RICFP of Epoxy‐Composites
Authors: Klikovits Nicolas , Liska Robert , D'Anna Alessandra , Sangermano Marco
Published: August 2017

The UV‐curing of epoxy monomers by cationic photopolymerization is a powerful method for the production of polymer materials. The limit of film thickness in cationic photopolymerization of epoxy monomers has been recently overcome by introducing a novel radical induced cationic frontal polymerization (RICFP) system within this research group. The possibility to cure epoxides in bulk by UV‐light promoted here presents the novel approach to photocured composites. In the present work, the recently established RICFP system is applied on SiO2‐filled epoxy formulations based on bisphenol‐A diglycidyl ether. The influence of filler content on frontal propagation is examined in RICFP experiments. The composite materials are also investigated by dynamic mechanical thermal analysis to determine mechanical properties of the frontally polymerized products.
Hydroquinone Based Sulfonated Copolytriazoles with Enhanced Proton Conductivity
Authors: Singh Asheesh , Bisoi Soumendu , Banerjee Susanta , Komber Hartmut , Voit Brigitte
Published: August 2017

A series of new fluorinated sulfonated copolytriazoles (PTHQSH‐XX) with ion exchange capacity (IECw) values ranging from 1.66 to 2.82 meq g−1 are prepared via cuprous ion catalyzed azide‐alkyne click polymerization reaction between 1,4‐bis(prop‐2‐ynyloxy)benzene, 4,4′‐diazido‐2,2′‐stilbene disulfonic acid disodium salt (SA), and 4,4‐bis[3′‐trifluoromethyl‐4′(4‐azidobenzoxy) benzyl] biphenyl (QAZ). The degree of sulfonation of the copolytriazoles is adjusted between 60% and 90% by varying the molar ratio of sulfonated monomer (SA) to the nonsulfonated monomer (QAZ). The structure of the copolytriazoles is characterized by Fourier transform infrared and NMR spectroscopy. The solution‐cast membranes of these copolymers exhibit high thermal, mechanical, oxidative and hydrolytic stability, and high proton conductivity (19–142 mS cm−1 at 80 °C and 22–157 mS cm−1 at 90 °C). Transmission electron microscopy confirms the formation of good phase separated morphology with ionic clusters in the range of 15–145 nm.
Minimal energy problems for strongly singular Riesz kernels
Authors: Harbrecht Helmut , Wendland Wolfgang L. , Zorii Natalia
Published: July 2017

We study minimal energy problems for strongly singular Riesz kernels , where and , considered for compact ‐dimensional ‐manifolds Γ immersed into . Based on the spatial energy of harmonic double layer potentials, we are motivated to formulate the natural regularization of such minimization problems by switching to Hadamard's partie finie integral operator which defines a strongly elliptic pseudodifferential operator of order on Γ. The measures with finite energy are shown to be elements from the Sobolev space , , and the corresponding minimal energy problem admits a unique solution. We relate our continuous approach also to the discrete one, which has been worked out earlier by D. P. Hardin and E. B. Saff.
A note on Torelli‐type theorems for Gorenstein curves
Authors: Rizzi Luca , Zucconi Francesco
Published: July 2017

Using the notion of generalized divisors introduced by Hartshorne (see ), we adapt the theory of adjoint forms to the case of Gorenstein curves. We show an infinitesimal Torelli‐type theorem for line bundles on Gorenstein curves. We also construct explicit counterexamples to the infinitesimal Torelli claim in the case of a reduced reducible Gorenstein curve.
Facile Synthesis of In‐Chain, Multicomponent, Functionalized Polymers via Living Anionic Copolymerization through the Ugi Four‐Component Reaction (Ugi‐4CR)
Authors: Shen Heyu , Ma Hongwei , Liu Pibo , Huang Wei , Han Li , Li Chao , Li Yang
Published: July 2017

By combining living anionic polymerization and the highly efficient Ugi four‐component reaction (Ugi‐4CR), in‐chain, multicomponent, functionalized polymers are facilely synthesized with efficient conversation and abundant functionality. l‐[4‐[N,N‐Bis(trimethylsilyl)‐amino]phenyl]‐l‐phenylethylene, which is redefined as Ugi‐DPE, is anionically copolymerized to synthesize the well‐defined in‐chain, multi‐amino functionalized polystyrene (P(St/DPE‐NH2)), the backbone for the Ugi‐4CR, via hydrolysis of the copolymerization (P(St/Ugi‐DPE)). Subsequently, several functionalized components are facilely clicked onto P(St/DPE‐NH2) to investigate the model reactions of the in‐chain, multicomponent functionalization via the Ugi‐4CR. In contrast to conventional postpolymerization modifications, this approach proceeds under mild reaction conditions without the use of a catalyst and meanwhile an efficient conversation is obtained. Finally, the modified experimental results investigated in this research show the promising potential of the combination of well‐defined amino functionalized polymers and Ugi‐4CR in the field of multicomponent, functionalized postpolymerization modification.
Effects of imaging gradients in sequences with varying longitudinal storage time—Case of diffusion exchange imaging
Authors: Lasič Samo , Lundell Henrik , Topgaard Daniel , Dyrby Tim B.
Published: July 2017

Purpose

To illustrate the potential bias caused by imaging gradients in correlation MRI sequences using longitudinal magnetization storage (LS) and examine the case of filter exchange imaging (FEXI) yielding maps of the apparent exchange rate (AXR).

Methods

The effects of imaging gradients in FEXI were observed on yeast cells. To analyze the AXR bias, signal evolution was calculated by applying matrix exponential operators.

Results

A sharp threshold for the slice thickness was identified, below which the AXR is increasingly underestimated. The bias can be understood in terms of an extended low‐pass diffusion filtering during the LS interval, which is more pronounced at lower exchange rates. For a total exchange rate constant larger than 1 s−1, the AXR bias is expected to be negligible when slices thicker than 2.5 mm are used.

Conclusion

In correlation experiments like FEXI, relying on LS with variable duration, imaging gradients may cause disrupting effects that cannot be easily mitigated and should be carefully considered for unbiased results. In typical clinical applications of FEXI, the imaging gradients are expected to cause a negligible AXR bias. However, the AXR bias may be significant in preclinical settings or whenever thin imaging slices are used. Magn Reson Med 79:2228–2235, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
Green coatings from renewable modified bentonite and vegetable oil based polyurethane for slow release fertilizers
Authors: Zhao Meihe , Wang Yaqi , Liu Lingxiao , Liu Lixian , Chen Min , Zhang Chaoqun , Lu Qiming
Published: July 2017

A series of modified bentonite (MBT)/polyurethane (PU) composites were synthesized from MBT, isocyanate, and soybean oil‐based polyols byin‐situpolymerization to coat urea granules for slowing nitrogen (N) release. Bentonite (BT) was modified by intercalation of polyethylene glycol inside the interlayer space, expanded the BT layer spacing and improved the performance of composites. The MBT and MBT/PU composites were characterized in terms of their structure, thermal stability, mechanical strength, surface wettability, and the urea slow‐release performance. With the addition of 5.0 wt% MBT, its tensile strength is 13.53 MPa and breaking elongation is 20.66%, increased by 27.52% and 67.97%, compared with pure PU, respectively. The release duration of the PU‐5%‐MBT composites coated urea was 74 days. The results indicated that the modified films are suitable for the slow release fertilizers. POLYM. COMPOS., 39:4355–4363, 2018. © 2017 Society of Plastics Engineers
Criterion‐related validity of two curriculum‐based measures of mathematical skill in relation to reading comprehension in secondary students
Authors: Anselmo Giancarlo A. , Yarbrough Jamie L. , Kovaleski Joseph F. , Tran Vi N.
Published: July 2017

This study analyzed the relationship between benchmark scores from two curriculum‐based measurement probes in mathematics (M‐CBM) and student performance on a state‐mandated high‐stakes test. Participants were 298 students enrolled in grades 7 and 8 in a rural southeastern school. Specifically, we calculated the criterion‐related and predictive validity of benchmark scores from CBM probes measuring math computation and math reasoning skills. Results of this study suggest that math reasoning probes have strong concurrent and predictive validity. The study also provides evidence that calculation skills, while important, do not have strong predictive strength at the secondary level when a state math assessment is the criterion. When reading comprehension skill is taken into account, math reasoning scores explained the greatest amount of variance in the criterion measure. Computation scores explained less than 5% of the variance in the high‐stakes test, suggesting that it may have limitations as a universal screening measure for secondary students.
Analyses of surface relief gratings inscription in epoxy‐azo linear and crosslinked polymers
Authors: Orofino Antonela B. , Galante María J. , Oyanguren Patricia A.
Published: July 2017

This work evaluates the inscription of surface relief gratings (SRG) in a series of epoxy‐azo prepolymers and networks, both based on the same azo chromophore. Variables such as matrix structure (thermoplastic/thermoset), film thickness, exposure time, power of the incident laser beam, and content of azobenzene were analyzed on the final modulation depth of the gratings. The main goal of the article is to achieve the efficient formation of SRGs on crosslinked azopolymer films in a single step, in a reasonable time, and to a significant extent. The progressive erasure of the obtained structures with increasing temperature showed that part of the photoinduced information remained encoded in the material: as the relief partially relaxed above the glass transition temperature of the bulk material (116 °C) and up to 200 °C, its modulation remained in about one third of the initial height, and did not completely disappear. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017, 55, 1542–1552
Crowd sourcing difficult problems in protein science*
Authors: Alexander Nathan S. , Palczewski Krzysztof
Published: August 2017

Dedicated computing resources are expensive to develop, maintain, and administrate. Frequently, research groups require bursts of computing power, during which progress is still limited by available computing resources. One way to alleviate this bottleneck would be to use additional computing resources. Today, many computing devices remain idle most of the time. Passive volunteer computing exploits this unemployed reserve of computing power by allowing device‐owners to donate computing time on their own devices. Another complementary way to alleviate bottlenecks in computing resources is to use more efficient algorithms. Engaging volunteer computing employs human intuition to help solve challenging problems for which efficient algorithms are difficult to develop or unavailable. Designing engaging volunteer computing projects is challenging but can result in high‐quality solutions. Here, we highlight four examples.
Cover Image, Volume 73, Issue 9
Authors: Oppedal Frode , Samsing Francisca , Dempster Tim , Wright Daniel W , Bui Samantha , Stien Lars H
Published: August 2017

The cover image, by Frode Oppedal et al., is based on the Research Article Sea lice infestation levels decrease with deeper ‘snorkel’ barriers in Atlantic salmon sea‐cages, DOI: 10.1002/ps.4560.

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IgY‐binding peptide screened from a random peptide library as a ligand for IgY purification
Authors: Khan Kamrul Hasan , Himeno Arisa , Kosugi Shouhei , Nakashima Yosuke , Rafique Abdur , Imamura Ayana , Hatanaka Takaaki , Kato Dai‐Ichiro , Ito Yuji
Published: July 2017

Chicken egg yolk immunoglobulin (IgY) is a functional substitute for mammalian IgG for antigen detection. Traditional IgY purification methods involve multi‐step procedures resulting in low purity and recovery of IgY. In this study, we developed a simple IgY purification system using IgY‐specific peptides identified by T7 phage display technology. From disulfide‐constrained random peptide libraries constructed on a T7 phage, we identified three specific binding clones (Y4‐4, Y5‐14, and Y5‐55) through repeated biopanning. The synthetic peptides showed high binding specificity to IgY‐Fc and moderate affinity for IgY‐Fc (Kd: Y4‐4 = 7.3 ± 0.2 μM and Y5‐55 = 4.4 ± 0.1 μM) by surface plasmon resonance analysis. To evaluate the ability to purify IgY, we performed immunoprecipitation and affinity high‐performance liquid chromatography using IgY‐binding peptides; the result indicated that these peptides can be used as affinity ligands for IgY purification. We then used a peptide‐conjugated column to purify IgY from egg yolks pre‐treated using an optimized delipidation technique. Here, we report the construction of a cost‐effective, one‐step IgY purification system, with high purity and recovery. © 2017 The Authors. Journal of Peptide Science published by European Peptide Society and John Wiley & Sons Ltd.
Field Effect Transistor Based on Solely Semiconducting Single‐Walled Carbon Nanotubes for the Detection of 2‐Chlorophenol
Authors: Chernov Alexander I. , Eremina Valentina A. , Shook James , Collins Aaron , Walker Peter , Fedotov Pavel V. , Zakhidov Alexander A. , Obraztsova Elena D.
Published: July 2017

We report a promoted sensitivity to 2‐chlorophenol (2‐CP) molecules of a fabricated back gated, interdigitated electrode field effect transistor based on separated semiconducting single‐walled carbon nanotubes (CNTFET). The origin of the interaction between the nanotubes that serve as channels across the source and drain contacts and organic volatile compound is suggested due to peculiarities gained after the nanotube separation technique. The semiconducting nanotubes that were used for building‐up the CNTFETs had an average diameter of 1.4 nm and have been separated by the efficient aqueous two‐phase extraction technique. The advantage of the technique is in the one‐step extraction of semiconducting type of conductivity nanotubes with high yield. Chlorophenols are widely studied due to the toxicity and hazardous health effects depending on the exposure. Previously chlorophenols were reported to be not interacting with pristine nanotubes. As prepared CNTFET device demonstrates a detection limit below 100 parts per million for the 2‐CP molecules with a reaction time of 150 s. CNTFET devices have good repeatability, low bias stress, and electron charge carrier mobility of 17.5 ± 0.1 cm2 (Vs)−1. We discuss possible physical mechanisms of the 2‐CP adsorption induced current drop and potential ways to improve sensitivity.
Structure of Fukui matrices
Authors: Bochicchio Roberto C.
Published: July 2017

Fukui matrices considered as the generalization of the concept of Fukui densities are decomposed into their pairing and unpairing contributions within the theory of the reduced density matrices. Their algebraic structure become clear from this decomposition providing their relationships with the spin density matrices and the irreducible part of the second‐order reduced density matrix cumulant, that is, the explicit contributions of the many‐body or correlation effects. The uncorrelated state function approximation is a simple way to emphasize the physical meaning of these matrices and represents the appropriate starting point for the treatment of a quasi‐analytical model to denote the occurrence of correlation effects.
Geometrical distortions and charge transfer in munchnöne regio‐selectivity: A conceptual density functional study
Authors: Martínez González Marco , Hernández‐Castillo David , Montero‐Cabrera Luis A. , Miranda‐Quintana Ramón Alain
Published: July 2017

Dipolar cycloaddition reactions involving munchnönes and simple dipolarophiles provide a versatile synthetic route toward pyrrole derivatives. However, despite their widespread use, there are still debates regarding the factors governing the regio‐selectivity of these reactions. In this contribution, we study the regio‐selectivity of 1,3‐dipolar cycloadditions of munchnönes and alkenes, and the ability of conceptual density functional theory (c‐DFT) descriptors to correctly study these processes. We base our analysis on the variation of different reactivity descriptors along the reaction path, calculated for the whole reacting complex, and for the isolated species, with the strained geometries they present within this supra‐molecular aggregate. The study of several global descriptors indicates that the path leading to the preferred product proceeds via an asynchronous mechanism, with the maximum extent of charge transfer occurring after the transition state. This helps to understand why several reactivity principles fail to correctly account for the position of the transition state in this case. This also explains why local c‐DFT descriptors fail to predict the observed majoritarian regio‐isomer. These results highlight the fundamental role of the distortion effects for determining the extent of charge transfer between the reactants, and thus their impact on the reactivity and regio‐selectivity in these reactions.
Impacts of the Mississippi River spillway opening on faecal coliform concentration in Lake Pontchartrain
Authors: Adebayo S. , Amer R.
Published: July 2017

This study focuses on explaining the role of the periodic opening of the Bonnet Carré Spillway on the faecal coliform levels in Lake Pontchartrain. Water quality data were collected by the Lake Pontchartrain Basin Foundation to analyse the faecal coliform bacteria levels, turbidity, salinity, temperature, and dissolved oxygen in the lake water. The results show that the faecal coliform concentrations were lower during the spillway opening than the preceding and subsequent months. Statistical analysis shows the dilution effect, characterized by an effective reduction in faecal coliform concentrations due to increase in water turbidity, coupled with decrease in water salinity and dissolved oxygen because of spillway opening. It is also indicated that the combine effect of more than one factor produces a significantly greater reduction in the faecal coliform than each factor acting independently. Periodic spikes in faecal coliform concentrations were observed at sampling points located near the outlets of streams and drainage canals with high settlement densities. A positive correlation (r = 0.78467) was found between the average faecal coliform counts and average monthly precipitations, highlighting the role of precipitation run‐offs. The results of this study indicate that the spillway opening contributed to a reduction in the faecal coliform concentration in the lake's surface water during the studied periods.
A method to address between‐subject heterogeneity for identification of principal surrogate markers in repeated low‐dose challenge HIV vaccine studies
Authors: Spieker Andrew J. , Huang Ying
Published: July 2017

Repeated low‐dose challenge designs in nonhuman primate studies have recently received attention in the literature as a means of evaluating vaccines for HIV prevention and identifying immune surrogates for their protective effects. Existing methods for surrogate identification in this type of study design rely on the assumption of homogeneity across subjects (namely, independent infection risks after each challenge within each subject and conditional on covariates). In practice, random variation across subjects is likely to occur because of unmeasured biologic factors. Failure to account for this heterogeneity or within‐subject correlation can result in biased inference regarding the surrogate value of immune biomarkers and underpowered study designs for detecting surrogate endpoints. In this paper, we adopt a discrete‐time survival model with random effects to account for between‐subject heterogeneity, and we develop estimators and testing procedures for evaluating principal surrogacy of immune biomarkers. Simulation studies reveal that the heterogeneous model achieves substantial bias reduction compared to the homogeneous model, with little cost of efficiency. We recommend the use of this heterogeneous model as a complementary tool to existing methods when designing and analyzing repeated low‐dose challenge studies for evaluating surrogate endpoints.
Enhancing Charge Separation and Photocatalytic Activity of Cubic SrTiO3 with Perovskite‐Type Materials MTaO3 (M=Na, K) for Environmental Remediation: A First‐Principles Study
Authors: Opoku Francis , Govender Krishna Kuben , van Sittert Cornelia Gertina Catharina Elizabeth , Govender Penny Poomani
Published: August 2017

Due to increasingly global environmental and energy crises, visible light semiconductor photocatalyst with a tunable bandgap and optical properties have received attention. This study aid in the design of bifunctional MTaO3/SrTiO3(010) (M=Na, K) heterostructure photocatalyst material for environmental remediation. In this study, the stability, electronic and optical properties of coupled MTaO3 and SrTiO3 are systematically studied using the hybrid HSE06 method. The MTaO3/SrTiO3(010) heterostructure show high photocatalytic activity under visible light irradiation with good stability and reduced bandgap compared to the bulk SrTiO3. The heterostructures formed a type‐II band alignment to accelerates the interfacial charge transfer process and the photocatalytic activity. By comparing the relative ratio of effective mass, we could conclude that MTaO3/SrTiO3(010) heterostructure has not only superior mobility of charge carriers but also higher separation of photoinduced electrons and holes. The band alignment results showed that the MTaO3/SrTiO3(010) heterostructure are highly efficient for pollutants degradation and energy conversion. Significantly, the origin of the enhanced photocatalytic activity is observed from the O 2p state of SrTiO3 to the Ta 5d state of MTaO3. In summary, this study shows a key role of SrTiO3 as an electron donor to enhance the optical properties and stability of MTaO3/SrTiO3(010) heterostructure.