bluuebunny/crossref_metadata_2025 huggingface dataset:
Reduction of Thiocarbonyl Compounds with Lithium Diisopropylamide
Authors: Gebert Andreas , Jasiński Marcin , Mlostoń Grzegorz , Heimgartner Heinz
Published: July 2014

Treatment of 4,4‐disubstituted 2‐phenyl‐1,3‐thiazole‐5(4H)‐thiones with lithium diisopropylamide (LDA; LiNiPr2) in THF at −78° yielded the corresponding 1,3‐thiazole‐5(4H)‐thioles in moderate yields. Sequential treatment with LDA and MeI under the same conditions led to the 5‐methylsulfanyl derivatives. Similarly, reaction of some cycloalkanethiones as well as diaryl thioketones with LDA and MeI gave cycloalkyl methyl sulfides and diarylmethyl methyl sulfides, respectively. A reaction mechanism via H transfer from LDA to the thiocarbonyl C‐atom via a six‐membered transition state is proposed for this unprecedented reduction of the CS bond.
Dynamic balance of multiple myeloma clonogenic side population cell percentages controlled by environmental conditions
Authors: Wen Jianguo , Tao Wenjing , Kuiatse Isere , Lin Pei , Feng Yongdong , Jones Richard J. , Orlowski Robert Z. , Zu Youli
Published: July 2014

Cancer stem cells are key drivers of tumor progression and disease recurrence in multiple myeloma (MM). However, little is known about the regulation of MM stem cells. Here, we show that a population of MM cells, known as the side population (SP), exhibits stem‐like properties. Cells that constitute the SP in primary MM isolates are negative or seldom expressed for CD138 and CD20 markers. In addition, the SP population contains stem cells that belong to the same lineage as the mature neoplastic plasma cells. Importantly, our data indicate that the SP and nonside population (NSP) percentages in heterogeneous MM cells are balanced, and that this balance can be achieved through a prolonged in vitro culture. Furthermore, we show that SP cells, with confirmed molecular characteristics of MM stem cells, can be regenerated from purified NSP cell populations. We also show that the percentage of SP cells can be enhanced by the hypoxic stress, which is frequently observed within MM tumors. Finally, hypoxic stress enhanced the expression of transforming growth factor β1 (TGF‐β1) and blocking the TGF‐β1 signaling pathway inhibited the NSP dedifferentiation. Taken together, these findings indicate that the balance between MM SP and NSP is regulated by environmental factors and TGF‐β1 pathway is involved in hypoxia‐induced increase of SP population. Understanding the mechanisms that facilitate SP maintenance will accelerate the design of novel therapeutics aimed at controlling these cells in MM.
MENTAL HEALTH SERVICE SEEKING AMONG KOREAN INTERNATIONAL STUDENTS IN THE UNITED STATES: A PATH ANALYSIS
Authors: Lee Eun‐Jeong , Ditchman Nicole , Fong Mandy W. M. , Piper Lauren , Feigon Maia
Published: July 2014

South Koreans represent the third largest group of international students in the United States, yet little is known about their help‐seeking behaviors, nor how these behaviors might be influenced by Asian cultural values. The purpose of this study is to (a) explore the effects of public stigma, self‐stigma, and attitudes associated with seeking counseling services on the relationship between cultural values and willingness to seek counseling services and (b) develop a more culturally sensitive help‐seeking model based on modified labeling theory. Participants included 177 Korean international students in the United States. Results indicated that the effect of cultural values on mental health service‐seeking behaviors is mediated by one's perception of public stigma toward counseling services, self‐stigma, and attitudes toward counseling services among Korean international students. Implications for developing outreach programs to promote help‐seeking behaviors among Asian international students are discussed.
A Multicomponent, Catalyst‐free, One‐Pot Synthesis of Functionalized 1,4‐Dihydroquinolines and Their Antimicrobial Studies
Authors: Chidurala Praveen , Jetti Venkateshwarlu , Pagadala Ramakanth , Meshram Jyotsna S. , Jonnalagadda Sreekantha B.
Published: July 2014

An atom‐efficient, catalyst‐free, and environmentally friendly approach towards the synthesis of substituted 1,4‐dihydroquinolines (5a, 5b, 5c, 5d, 5e, 5f, 5g, 5h, 5i, 5j) through a one‐pot multicomponent reaction involving resorcinol, aromatic aldehyde, acetoacetanilide, and ammonium acetate has been developed. The reactions were carried out under both conventional and microwave irradiation conditions. In general, improvement in rate and yield were observed when reactions were carried out under microwave irradiation compared with classical conditions. Most of the new compounds possessed moderate to significant antibacterial and antifungal activities.
Red blood cell transfusion: Impact of an education program and a clinical guideline on transfusion practice
Authors: Corwin Howard L. , Theus John W. , Cargile Christopher S. , Lang Nicholas P.
Published: July 2014

BACKGROUND

Red blood cell (RBC) transfusion guidelines have been developed by professional societies. These guidelines recommend a restrictive RBC transfusion practice for most clinical populations. Despite the consistency of guidelines and limited evidence for RBC transfusion efficacy, there is variability in RBC transfusion practice.

METHODS

A program was initiated in a tertiary medical center to align RBC transfusion practice with best‐practice RBC transfusion guidelines. The program included an educational program, followed after 6 months by RBC transfusion decision support that included the approval of a best‐practice RBC transfusion guideline by the hospital medical board and an RBC transfusion order form that included the guideline recommendations. RBC transfusion practice was followed over an 18‐month period and compared with transfusion practice over the prior 18 months. The primary outcome variables were adult inpatient RBC units transfused, RBC units per admission, and RBC units per 100 patient‐days.

RESULTS

The mean RBC units transfused decreased with initiation of each component of the program: from 923 ± 68 units to 852 ± 40 (P = 0.025) with education and further to 690 ± 52 (P < 0.0001) with the RBC transfusion decision support. Similarly, RBC transfusions per 100 patient‐days fell from 10.56 ± 0.80 to 9.69 ± 0.49 (P = 0.02) and to 7.68 ± 0.63 (P = 0.0001) during the 3 time periods.

CONCLUSION

An education program coupled with institutional adoption of a best‐practice RBC transfusion guideline and RBC transfusion order set resulted in a reduction in total RBC units transfused. Journal of Hospital Medicine 2014;9:745–749. © 2014 Society of Hospital Medicine
Comparison of brown and white adipose tissues in infants and children with chemical‐shift‐encoded water‐fat MRI
Authors: Hu Houchun H. , Yin Larry , Aggabao Patricia C. , Perkins Thomas G. , Chia Jonathan M. , Gilsanz Vicente
Published: July 2014

Purpose

To compare fat‐signal fractions (FFs) and T2* values between brown (BAT) and white (WAT) adipose tissue located within the supraclavicular fossa and subcutaneous depots, respectively.

Materials and Methods

Twelve infants and 39 children were studied. Children were divided into lean and overweight/obese subgroups. Chemical‐shift‐encoded water‐fat magnetic resonance imaging (MRI) was used to quantify FFs and T2* metrics in the supraclavicular and adjacent subcutaneous adipose tissue depots. Linear regression and t‐tests were performed.

Results

Infants had lower supraclavicular FFs than children (P < 0.01) but T2* values were similar (P = 0.5). Lean children exhibited lower supraclavicular FFs and T2* values than overweight children (P < 0.01). In each individual infant and child, supraclavicular FFs were consistently lower than adjacent subcutaneous FFs. Supraclavicular T2* values were consistently lower than subcutaneous T2* values in children, but not in infants. FFs in both depots were positively correlated with age and weight in infants (P < 0.01). In children, they were correlated with weight and body mass index (BMI) (P < 0.01), but not age. Correlations between T2* and anthropometric variables existed in children (P < 0.01), but were absent in infants.

Conclusion

Cross‐sectional comparisons suggest variations in FF and T2* values in the supraclavicular and subcutaneous depots of infants and children, which are potentially indicative of physiological differences in adipose tissue fat content, amount, and metabolic activity. J. Magn. Reson. Imaging 2013;38:885–896. © 2013 Wiley Periodicals, Inc.
Quantitative MRI of articular cartilage and its clinical applications
Authors: Li Xiaojuan , Majumdar Sharmila
Published: July 2014

Cartilage is one of the most essential tissues for healthy joint function and is compromised in degenerative and traumatic joint diseases. There have been tremendous advances during the past decade using quantitative MRI techniques as a noninvasive tool for evaluating cartilage, with a focus on assessing cartilage degeneration during osteoarthritis (OA). In this review, after a brief overview of cartilage composition and degeneration, we discuss techniques that grade and quantify morphologic changes as well as the techniques that quantify changes in the extracellular matrix. The basic principles, in vivo applications, advantages, and challenges for each technique are discussed. Recent studies using the OA Initiative (OAI) data are also summarized. Quantitative MRI provides noninvasive measures of cartilage degeneration at the earliest stages of joint degeneration, which is essential for efforts toward prevention and early intervention in OA. J. Magn. Reson. Imaging 2013;38:991–1008. © 2013 Wiley Periodicals, Inc.
An 18 000‐year pollen and sedimentary record from the cedar forests of the Middle Atlas, Morocco
Authors: EL BAIT M. NOUR , RHOUJJATI A. , EYNAUD F. , BENKADDOUR A. , DEZILEAU L. , WAINER K. , GOSLAR T. , KHATER C. , TABEL J. , CHEDDADI R.
Published: July 2014

A new record from the heart of the Moroccan Middle Atlas cedar forests spans the last 18 000 years and provides valuable insight into our understanding of the natural vegetation and environmental changes. The approach is based on the study of pollen content, geochemical elements and grain size analysis. The pollen data indicate that the vegetation was dominated by herbaceous plants until 9000 BP. Such open landscape allowed greater soil erosion and an input of chemical elements from the watershed. After 9000 BP, tree cover, mainly oak, increased slightly and was accompanied by a higher taxonomic diversity. However, several steppe elements remain well represented in the area until 5000 BP, which suggests that the climate was rather dry during the first part of the Holocene. After 6000 BP, the climate became more favourable to expansion of the forest ecosystems, including Cedrus atlantica, thereby reducing erosion. A strong reduction of the tree pollen percentages is recorded after 2000 BP, which may be related to increasing human activities during the Roman period. These forest changes are concomitant with an increase of lead and copper concentrations in the record, probably related to Roman metalworking activities.
West Greenland and global in situ14C production‐rate calibrations
Authors: YOUNG NICOLÁS E. , SCHAEFER JOERG M. , GOEHRING BRENT , LIFTON NATHANIEL , SCHIMMELPFENNIG IRENE , BRINER JASON P.
Published: July 2014

The in situ cosmogenic nuclide 14C is unique compared with other nuclides because of its short half‐life, and when combined with longer‐lived isotopes (e.g. 10Be), in situ 14C can be a powerful tool for deciphering recent and complex surface exposure histories. Like all in situ cosmogenic nuclides, quantifying earth surface processes with in situ 14C requires a well‐constrained in situ 14C production rate. We present a production‐rate calibration from an independently dated moraine in West Greenland, previously used as an in situ 10Be production‐rate calibration site. The local in situ 14C production rate is 22.8 ± 1.4 atoms g−1 a−1 (69.28°N, 50.76°W; 350 m asl) and when scaled to sea level/high latitude using time‐dependent Lal/Stone scaling (Lm), we calculate a spallation‐only in situ 14C production rate of 12.0 ± 0.9 atoms g−1 a−1 and a 14C/10Be production rate ratio of 3.1 ± 0.2. The West Greenland in situ 14C production rate is indistinguishable from the New Zealand, Promontory Point and Scottish Highlands in situ 14C production rates. When combined, we calculate a global production rate of 12.1 ± 0.5 atoms g−1 a−1 (Lm).
Testate amoebae as a proxy for reconstructing Holocene water table dynamics in southern Patagonian peat bogs
Authors: VAN BELLEN SIMON , MAUQUOY DMITRI , PAYNE RICHARD J. , ROLAND THOMAS P. , DALEY TIM J. , HUGHES PAUL D. M. , LOADER NEIL J. , STREET‐PERROTT F. ALAYNE , RICE EMMA M. , PANCOTTO VERÓNICA A.
Published: July 2014

Testate amoebae are abundant and diverse in Sphagnum peat bogs and have been used extensively as indicators of past water table depths. Although these unicellular protists are widely dispersed with globally similar hydrological preferences, regional variations in communities demand region‐specific transfer functions. Here we present the first transfer function for southern Patagonian bogs, based on 154 surface samples obtained from transects in five bogs sampled in 2012 and 2013. Significant variance was explained by pH, electrical conductivity and, in particular, water table depth. Transfer functions for water table were constructed using weighted averaging and evaluated by cross‐validation and independent test sets. The optimal transfer function has predictive ability, but relatively high prediction errors given the wide range in sampled water tables. The use of independent test sets, as well as cross‐validation, allows a more rigorous assessment of model performance than most previous studies. For a subset of locations we compare surface and subsurface samples to demonstrate significant differences in community composition, possibly due to vertical zonation. Our results provide the first quantification of hydrological optima and tolerances for several rare species, which may include Southern Hemisphere endemics and pave the way for palaeohydrological reconstructions in southern Patagonian bogs.
36Cl production rate from K‐spallation in the European Alps (Chironico landslide, Switzerland)
Authors: SCHIMMELPFENNIG IRENE , SCHAEFER JOERG M. , PUTNAM AARON E. , KOFFMAN TOBY , BENEDETTI LUCILLA , IVY‐OCHS SUSAN , TEAM ASTER , SCHLÜCHTER CHRISTIAN
Published: July 2014

The abundant production of in situ cosmogenic 36Cl from potassium renders 36Cl measurements in K‐rich rocks or minerals, such as K‐feldspars, potentially useful for precisely dating rock surfaces, either in single‐nuclide or in multi‐nuclide studies, for example combined with 10Be measurements in quartz. However, significant discrepancies in experimentally calibrated 36Cl production rates from spallation of potassium (36PK‐sp), referenced to sea‐level/high‐latitude (SLHL), limit the accuracy of 36Cl dating from K‐rich lithologies. We present a new 36Cl calibration using K‐feldspars, in which K‐spallation is the most dominant 36Cl production pathway (>92% of total 36Cl), thus minimizing uncertainties from the complex multi‐pathway 36Cl production systematics. The samples are derived from boulders of an ∼13.4 ka‐old landslide in the Swiss Alps (∼820 m, 46.43°N, 8.85°E). We obtain a local 36PK‐sp of 306 ± 16 atoms 36Cl (g K)−1 a−1 and an SLHL 36PK‐sp of 145.5 ± 7.7 atoms 36Cl (g K)−1 a−1, when scaled with a standard scaling protocol (‘Lm’). Applying this SLHL 36PK‐sp to determine 36Cl exposure ages of K‐feldspars from 10Be‐dated moraine boulders yields excellent agreement, confirming the validity of the new SLHL 36PK‐sp for surface exposure studies, involving 36Cl in K‐feldspars, in the Alps.
Processes of flood‐triggered detrital layer deposition in the varved Lake Mondsee sediment record revealed by a dual calibration approach
Authors: KÄMPF LUCAS , BRAUER ACHIM , SWIERCZYNSKI TINA , CZYMZIK MARKUS , MUELLER PHILIP , DULSKI PETER
Published: July 2014

A succession of 23 sub‐millimetre to maximum 12‐mm‐thick, mostly flood‐triggered detrital layers, deposited between 1976 and 2005, was analysed in 12 varved surface sediment cores from meso‐scale peri‐alpine Lake Mondsee applying microfacies and high‐resolution micro X‐ray fluorescence analyses. Detailed intrabasin comparison of these layers enabled identification of (i) different source areas of detrital sediments, (ii) flood‐triggered sediment flux and local erosion events, and (iii) seasonal differences of suspended flood sediment distribution within the lake basin. Additional calibration of the detrital layer record with river discharge and precipitation data reveals different empirical thresholds for flood layer deposition for different parts of the basin. At proximal locations detrital layer deposition requires floods exceeding a daily discharge of 40 m3 s−1, whereas at a location 2 km more distal an hourly discharge of 80 m3 s−1 and at least 2 days of discharge above 40 m3 s−1 are necessary. Furthermore, we observe a better correlation between layer thickness and flood amplitude in the depocentre than in distal and proximal areas of the basin. Although our results are partly site‐specific, the applied dual calibration approach is suitable to precisely decipher flood layer formation processes and, thereby, improve the interpretation of long flood time series from lake sediments.
IntCal13 calibrated ages of the Vedde and Saksunarvatn ashes and the Younger Dryas boundaries from Kråkenes, western Norway
Authors: LOHNE ØYSTEIN S. , MANGERUD JAN , BIRKS HILARY H.
Published: July 2014

From Kråkenes Lake in western Norway there exist 118 accelerator mass spectrometry 14C dates for the time interval 12 000–8000 14C a BP that we earlier calibrated using the IntCal09 data set. These yielded the most accurate and precise ages available for the Younger Dryas boundaries and the Vedde and Saksunarvatn ashes. Here we present a new calibration using the recently published IntCal13 data set. All differences between the two sets of calibrated ages are within the ± 1σ error of the original IntCal09 results. The most significant differences are that the error for the Allerød/Younger Dryas boundary decreased, that this boundary became slightly older and that the length of the Younger Dryas increased slightly.
On‐line surface enhanced Raman spectroscopic detection in a recyclable Au@SiO2 modified glass capillary
Authors: Wang Weiwei , Guo Qinghua , Xu Minmin , Yuan Yaxian , Gu Renao , Yao Jianlin
Published: July 2014

A facile method was developed to fabricate a high sensitive, reproducible and recyclable surface enhanced Raman spectroscopy (SERS) active glass capillary. The Au nanoparticles were synthesized through a seed‐mediated growth approach and then self‐assembled onto the inner wall of glass capillaries. The attached Au nanoparticles were homogeneously coated with thin silica shell by using the silane coupling agent to functionalize the Au surface. By using thiophenol (TP) as SERS probe molecules, the substrate exhibited robust SERS effects. The adsorbed SERS probe molecules could be rapidly and completely removed away by flowing sodium borohydride solution and thus to obtain a refresh Au@SiO2 film‐coated substrate for the cyclic detection on different species. The on‐line detection of TP and malachite green (MG) with different concentrations was performed in the flowing system. The intensities of SERS signals were dependent on concentrations of the detected molecules. The results indicated that the SERS‐active substrate has potential applications on the on‐line qualitative and quasi‐quantitative analysis. Copyright © 2014 John Wiley & Sons, Ltd.
Effect of the addition of soy flour on sensory quality of extrusion and conventionally cooked cassava complementary porridges
Authors: Muoki Penina N , Kinnear Marise , Emmambux Mohammad Naushad , de Kock Henriëtte L
Published: July 2014

BACKGROUND

The sensory properties of the usual conventionally cooked cassava porridge consumed in some regions of Africa and porridges consisting of composited cassava and either defatted or full fat soy flour, with or without extrusion cooking, were evaluated to better understand consumers' acceptance. The composited and extruded porridges have superior nutritional quality and added convenience value in the case of extrusion cooked products.

RESULTS

Extrusion cooking allowed preparation of porridges with 25% solids content (compared with 10% for conventional cooking) with a viscosity suitable for consumption by infants. Compositing and extrusion cooking reduced the apparent negative sensory attributes of high viscosity, stickiness, translucency, jelly‐like appearance and bland flavour that characterise conventionally cooked cassava porridge while increasing slimy appearance of the porridge. The caramel aroma and overall flavour of all extrusion cooked porridges was more intense, with more toasted nutty flavour and aftertaste compared to the corresponding conventionally cooked porridges. Slightly more consumers preferred the conventionally cooked cassava–soy flour porridges.

CONCLUSIONS

Compositing cassava flour with full‐fat or defatted soy flour and extrusion cooking change the appearance and flavour of porridges while improving the textural properties for better mastication and swallowing by infants. Hedonic adjustment to the changed sensory properties of the porridges in comparison to what mothers and caregivers are used to (conventionally cooked cassava only porridges) is required to ensure acceptance. © 2014 Society of Chemical Industry
Mastoidectomy performance assessment of virtual simulation training using final‐product analysis
Authors: Andersen Steven A. W. , Cayé‐Thomasen Per , Sørensen Mads S.
Published: July 2014

Objectives/Hypothesis

The future development of integrated automatic assessment in temporal bone virtual surgical simulators calls for validation against currently established assessment tools. This study aimed to explore the relationship between mastoidectomy final‐product performance assessment in virtual simulation and traditional dissection training.

Study Design

Prospective trial with blinding.

Methods

A total of 34 novice residents performed a mastoidectomy on the Visible Ear Simulator and on a cadaveric temporal bone. Two blinded senior otologists assessed the final‐product performance using a modified Welling scale. The simulator gathered basic metrics on time, steps, and volumes in relation to the on‐screen tutorial and collisions with vital structures.

Results

Substantial inter‐rater reliability (kappa = 0.77) for virtual simulation and moderate inter‐rater reliability (kappa = 0.59) for dissection final‐product assessment was found. The simulation and dissection performance scores had significant correlation (P = .014). None of the basic simulator metrics correlated significantly with the final‐product score except for number of steps completed in the simulator.

Conclusions

A modified version of a validated final‐product performance assessment tool can be used to assess mastoidectomy on virtual temporal bones. Performance assessment of virtual mastoidectomy could potentially save the use of cadaveric temporal bones for more advanced training when a basic level of competency in simulation has been achieved.

Level of Evidence

NA Laryngoscope, 125:431–435, 2015
The role of elective neck dissection in early stage buccal cancer
Authors: Huang Shiang‐Fu , Tung‐Chieh Chang Joseph , Liao Chun‐Ta , Kang Chung‐Jan , Lin Chien‐Yu , Fan Kang‐Hsing , Wang Hung‐Ming , Chen I‐How
Published: July 2014

Objectives/Hypothesis

The benefits of elective neck dissection (END) in early‐stage tongue cancer have been widely discussed but are still controversial regarding early‐stage buccal cancer. In this study, we evaluate the role of END and the treatment outcome in early‐stage buccal cancer in an areca‐quid endemic area.

Study Design

Retrospective case‐control study.

Methods

One hundred seventy‐three cT1‐2N0M0 buccal cancer patients all staged by computed tomography or magnetic resonance imaging were recruited. A total of 151 patients received radical surgery with END, whereas 22 received observation (OBS). Adjuvant radiotherapy with or without chemotherapy was given in selected high‐risk patients.

Results

The 5‐year overall survival (OS) rates for cT1 lesions and cT2 lesions were 86.14% and 75.45%, respectively (P = .105). In the END group, the occult metastasis rate was 1.8% for cT1 lesions and 10.6% for cT2 lesions (P = .053). The 5‐year neck control rate rates (P = .001) and disease‐free survival rates (P = .0101) were significantly better in the END group compared to the OBS group but were not significant in OS (P = .689). Eighteen (10.41%) patients developed a second primary tumor (SPT), and five (2.89%) patients developed a third primary tumor. Ninety‐four percent of SPTs were located within the oral cavity.

Conclusions

END was suggested in T1–T2N0 buccal cancer to improve the neck control rate. In patients for whom END is not performed at the time of tumor excision, regular follow‐up of neck status is necessary because the metastatic lesions are mostly salvageable and do not influence the OS.

Level of Evidence

4 Laryngoscope, 125:128–133, 2015
Vinylsulfide‐Containing Polyesters and Copolyesters from Fatty Acids: Thiol‐yne Monomer Synthesis and Thiol‐ene Functionalization
Authors: Beyazkilic Zeynep , Lligadas Gerard , Ronda Juan Carlos , Galià Marina , Cádiz Virginia
Published: July 2014

The synthesis of a vinylsulfide‐containing hydroxy acid (VSHA) from undecylenic fatty acid via thiol‐yne monoaddition is described. Metal‐ and enzymatic‐catalyzed polycondensation of VSHA is investigated to obtain functional polyesters with a view to further modification. Higher molecular weights are obtained when using enzymatic polymerization. Random copolymers are prepared by direct enzymatic copolymerization of VSHA and ε‐caprolactone (CL) and triblock CL‐VSHA‐CL copolymers are obtained by consecutive VSHA self‐condensation and ring‐opening polymerization. The copolymers display semicrystalline behavior and a good thermal stability with no significant weight loss below 300 °C. Thiol‐ene chemistry‐type crosslinking and surface functionalization are employed to open new application fields. Evidence of the successful reactions is obtained by NMR, IR, and fluorescence measurements.

image
UV Curing of Perfluoropolyether Oligomers Containing Graphene Nanosheets to Enhance Water‐Vapor Barrier Properties
Authors: Vitale Alessandra , Merlo Simone , Rizza Giancarlo , Melilli Giuseppe , Sangermano Marco
Published: July 2014

Recently, graphene and its derivative nanosheets have been considered as potential candidates for gas barrier membranes. Here, the effect on the water‐vapor barrier properties of incorporating graphene nanoplatelets into a UV‐curable perfluoropolyether methacrylic oligo­mer is investigated. By combining the hydrophobicity of the highly fluorinated polymer with the tortuous path induced by the graphene sheets, the barrier properties of the crosslinked films are further enhanced, acting both on the thermodynamic (low solubility) and kinetic (longer diffusion path) contribution of the water‐vapor diffusion through the polymeric films. Good performance in increasing water‐vapor barrier properties at a very low filler loading is obtained: the permeability is halved in the presence of only 0.3 wt% graphene.

image
Chemical Structure and Microstructure of Poly(alkylene terephthalate)s, their Copolyesters, and their Blends as Studied by NMR
Authors: de Ilarduya Antxon Martínez , Muñoz‐Guerra Sebastián
Published: July 2014

The use of NMR spectroscopy in solution to investigate the chemical structure of engineering poly(alkylene terephthalate)s such as poly(ethylene terephthalate) (PET), poly(trimethylene terephthalate) (PTT), and poly(butylene terephthalate) (PBT) is reviewed. Chemical defects present in the polyester chain, such as oxydialkylene units, as well as accompanying side products such as cyclic oligomers generated in the polycondensation, are well detected in 1H NMR spectra. The technique is also demonstrated to be effective for identifying, and even for quantifying in certain cases, the end groups of these polyterephthalates, including those that are generated in small amounts as a consequence of thermal degradation. The application of NMR to the study of the chemical microstructure of copolyesters derived from such polyterephthalates is also reviewed for its unique ability to determine comonomeric sequence lengths and degree of randomness (R). Copolyesters synthesized by either melt polycondensation or entropically driven ring opening polymerization, in addition to those prepared by solid‐state modification or melt blending, are the object of this review.

image
On characteristic matrices and eigenfunction expansions of two singular point symmetric systems
Authors: Mogilevskii Vadim
Published: July 2014

We study general (not necessarily Hamiltonian) first‐order symmetric systems on an interval with both singular endpoints a and b. For such a system we give a criterion of existence and description of self‐adjoint separated boundary conditions. We prove the Titchmarsh type formula for the characteristic matrix of the self‐adjoint linear relation in generated by separated boundary conditions as well as by a certain type of mixed boundary conditions. This formula enables one to express in terms of the m‐functions at the endpoints of . By using the Titchmarsh type formula we parametrize all spectral functions corresponding to boundary problems with the mentioned boundary conditions immediately in terms of self‐adjoint boundary parameters at the end points a and b.
A new approach for assimilation of 2D radar precipitation in a high‐resolution NWP model
Authors: Korsholm Ulrik Smith , Petersen Claus , Sass Bent Hansen , Nielsen Niels Woetmann , Jensen David Getreuer , Olsen Bjarke Tobias , Gill Rasphal , Vedel Henrik
Published: July 2014

A new approach for assimilation of 2D precipitation in numerical weather prediction models is presented and tested in a case with convective, heavy precipitation. In the scheme a nudging term is added to the horizontal velocity divergence tendency equation. In case of underproduction of precipitation, the strength of the nudging is proportional to the offset between observed and modelled precipitation, leading to increased moisture convergence. If the model over‐predicts precipitation, the low level moisture source is reduced, and in‐cloud moisture is nudged towards environmental values. The method was implemented in the Danish Meteorological Institute numerical weather prediction (DMI NWP) nowcasting system, running with hourly cycles, performing a surface analysis and 3D variational analysis for upper air assimilation at each cycle restart, followed by nudging assimilation of precipitation and then a free forecast. The precipitation fields are based on a 2D composite CAPPI (constant altitude plan position indicator) field made from observations with the DMI weather radars, and have a 10 min time resolution. The results obtained in this study indicate that the new method implies fast adjustment of the dynamical state of the model to facilitate precipitation release when the model precipitation intensity is too low. Removal of precipitation is shown to be of importance and the position of the model precipitation cells becomes skilful even at the smallest scales (∼3 km). Bias is reduced for low and extreme precipitation rates. In this meteorological case, the usage of the nudging procedure has been shown to improve the prediction of heavy precipitation substantially.
Nonstationary Stokes system in anisotropic Sobolev spaces
Authors: Zaja̧czkowski Wojciech M.
Published: July 2014

The nonstationary Stokes system with slip boundary conditions is considered in a bounded domain
. We prove the existence and uniqueness of solutions to the problem in anisotropic Sobolev spaces
. Thanks to the slip boundary conditions, the Stokes problem is transformed to the Poisson and the heat equation. In this way, difficult calculations that must be performed in considerations of boundary value problems for the Stokes system are avoided. This approach does not work for the Dirichlet and the Neumann boundary conditions. Because solvability of the Poisson and the heat equation is carried out by the regularizer technique, we have that
σ > 3,α > 0. Copyright © 2014 John Wiley & Sons, Ltd.
Impact of processing on the bioavailability and vascular effects of blueberry (poly)phenols
Authors: Rodriguez‐Mateos Ana , Pino‐García Raquel Del , George Trevor W. , Vidal‐Diez Alberto , Heiss Christian , Spencer Jeremy P. E.
Published: July 2014

Scope

Blueberries are a rich source of flavonoids and phenolic acids. Currently, little information is available regarding the impact of processing on the bioavailability and the bioactivity of blueberry (poly)phenols.

Methods and results

In a randomized, controlled crossover trial, ten healthy volunteers consumed (a) blueberry‐containing baked products, (b) an unprocessed blueberry drink containing the same amount of freeze‐dried blueberry powder as used in the baked products, and (c) matched control baked products. Endothelial function was measured as flow‐mediated dilation (FMD) and plasma samples taken at baseline and at 1, 2, 4, and 6 h postconsumption. Although processing did not significantly change the total (poly)phenolic amount, the processed products contained significantly less anthocyanins (−42%), more chlorogenic acid (23%), no flavanol nonamers or decamers, and significantly more flavanol dimers and trimers (36% and 28%, respectively). FMD increased after 1, 2, and 6 h consumption of the baked products to a similar degree as the unprocessed blueberries, despite significant differences in the levels of individual plasma metabolites. No changes were observed after the consumption of the control product.

Conclusion

Careful processing can preserve important biological activities of blueberries despite changing the blueberry (poly)phenol composition and plasma metabolite profile.
Optimized radiofrequency coil setup for MR examination of living isolated rat hearts in a horizontal 9.4T magnet
Authors: Lohezic Maelene , Bollensdorff Christian , Korn Matthias , Lanz Titus , Grau Vicente , Kohl Peter , Schneider Jürgen E.
Published: July 2014

Purpose

(i) To optimize an MR‐compatible organ perfusion setup for the nondestructive investigation of isolated rat hearts by placing the radiofrequency (RF) coil inside the perfusion chamber; (ii) to characterize the benefit of this system for diffusion tensor imaging and proton (1H‐) MR spectroscopy.

Methods

Coil quality assessment was conducted both on the bench, and in the magnet. The benefit of the new RF‐coil was quantified by measuring signal‐to‐noise ratio (SNR), accuracy, and precision of diffusion tensor imaging/error in metabolite amplitude estimation, and compared to an RF‐coil placed externally to the perfusion chamber.

Results

The new design provided a 59% gain in signal‐to‐noise ratio on a fixed rat heart compared to using an external resonator, which found reflection in an improvement of living heart data quality, compared to previous external resonator studies. This resulted in 14–29% improvement in accuracy and precision of diffusion tensor imaging. The Cramer–Rao lower bounds for metabolite amplitude estimations were up to 5‐fold smaller.

Conclusion

Optimization of MR‐compatible perfusion equipment advances the study of rat hearts with improved signal‐to‐noise ratio performance, and thus improved accuracy/precision. Magn Reson Med 73:2398–2405, 2015. © 2014 The Authors. Magnetic Resonance in Medicine Published by Wiley Periodicals, Inc. on behalf of International Society of Medicine in Resonance.
A novel design of an isochronous integration [iIntegration] framework for first/second order multidisciplinary transient systems
Authors: Shimada M. , Masuri S. , Tamma K. K.
Published: July 2014

Of fundamental interest are multidisciplinary interactions encompassing: (1) first order systems such as those encountered in parabolic heat conduction, first order hyperbolic systems such as fluid flow, and so on, and (2) second order systems such as those encountered in hyperbolic heat conduction, hyperbolic second order systems such as elastodynamics and wave propagation, and so on. After space discretization using methods such as finite differences, finite volumes, finite elements, and the like, the consequent proper integration of the time continuous ordinary differential equations is extremely important. In particular, the physical quantities of interest may need to be mostly preserved and/or the equations should be optimally integrated so that there is minimal numerical dissipation, dispersion, algorithm overshoot, capture shocks without too much dissipation, solve stiff problems and enable the completion of the analysis, and so on. To‐date, practical methods in most commercial and research software include the trapezoidal family (Euler forward/backward, Galerkin, and Crank Nicholson) for first order systems and the other counterpart trapezoidal family (Newmark family and variants with controllable numerical dissipation) for second order systems. For the respective first/second order systems, they are totally separate families of algorithms and are derived from altogether totally different numerical approximation techniques. Focusing on the class of the linear multistep (LMS) methods, algorithms by design was first utilized to develop GS4‐2 framework for time integration of second order systems. We have also recently developed the GS4‐1 framework for integrating first order systems. In contrast to all past efforts over the past 50 years or so, we present the formalism of a generalized unified framework, termed GS4 (generalized single step single solve), that unifies GS4‐1 (first‐order systems) and GS4‐2 (second‐order systems) frameworks for simultaneous use in both first and second order systems with optimal algorithms, numerical and order preserving attributes (in particular, second‐order time accuracy) as well. The principal contribution emanating from such an integrated framework is the practicality and convenience of using the same computational framework and implementation when solving first and/or second order systems without having to resort to the individual framework. All that is needed is a single novel GS4‐2 framework for either second‐ and/or first‐order systems, and we show how to switch from one to the other for illustrative applications to thermo‐mechanical problems influenced by first/second order systems, respectively. Copyright © 2014 John Wiley & Sons, Ltd.
Recycling ground tire rubber (GTR) scraps as high‐impact filler of in situ produced polyketone matrix
Authors: Sulcis Roberta , Vizza Francesco , Oberhauser Werner , Ciardelli Francesco , Spiniello Roberto , Dintcheva Nadka Tz. , Passaglia Elisa
Published: July 2014

A sustainable procedure for recycling powdered rubber coming from scrap tires (ground tire rubber [GTR]) is proposed as based on the dispersion in polyketone (PK) matrix, obtained in situ by CO/ethylene copolymerization. Three types of catalysts are used operative in solvents of different polarities. The catalyst productivity and the hybrids morphology are evaluated and optimized to final composites features. The obtained products are characterized by scanning electron microscopy, atomic force microscopy, and solvent extractions in order to investigate the occurrence and the extent of interactions between PK macromolecular chains and the GTR components; and their effects on the final properties were tested by differential scanning calorimetry, thermogravimetric analysis, and rheological measurements. For comparison purpose, a composite with GTR included into the matrix through blending is prepared. The results evidenced the key role exerted by the catalyst that, when operative in apolar solvent (able to swell the rubber phase), provides composites with good interfacial adhesion and breaking up of the particles with beneficial effects on final properties particularly thermal features and processability. Copyright © 2014 John Wiley & Sons, Ltd.
How (not) to inform patients about drug use: use and effects of negations in Dutch patient information leaflets
Authors: Burgers Christian , Beukeboom Camiel J. , Sparks Lisa , Diepeveen Vera
Published: July 2014

Purpose

Under EU regulations, patient information leaflets (PILs) are required to be clear and understandable. Negations (e.g., not, no) are a linguistic aspect that may impact PIL comprehension, yet go unmentioned in these regulations. We conducted two studies to determine (1) how negations are used in Dutch PILs (study 1) and (2) the effects of negations on readers (study 2).

Methods

Study 1 was a content analysis of 30 PILs of different brands of pollinosis drugs, half of which were freely available in drugstores and half only by physician prescription. We mapped negation use in PIL sections on ‘proper usage’ and ‘potential side effects’. Study 2 was an experiment in which participants (N = 80, Mage = 33.19 years, SDage = 13.66; 76.3% female) were presented with one of two PIL texts on proper drug usage. Texts were identical except for the use of negations. After reading, participants answered questions about comprehension, PIL appreciation and medical adherence intentions.

Results

Study 1 demonstrates that negations are often used in PILs as 21.0% of clauses contain at least one negation. This number is higher in sections related to potential side effects than proper usage. Study 2 demonstrates that negations decrease both actual and subjective comprehension. Negations also decrease PIL appreciation and medical adherence intentions. The reduction in medical adherence intentions is driven by the decrease of subjective and not actual comprehension.

Conclusions

In general, participants prefer PILs that contain clear and comprehensible language. To increase comprehensibility, PIL designers should refrain from using negations as much as possible. Copyright © 2014 John Wiley & Sons, Ltd.
Effect of uniaxial stretching on thermal, oxygen barrier, and mechanical properties of polyamide 6 and poly(m‐xylene adipamide) nanocomposite films
Authors: Fereydoon Maryam , Tabatabaei Seyed H. , Ajji Abdellah
Published: July 2014

In this study, the effect of uniaxial stretching on the thermal, oxygen barrier and mechanical properties of aliphatic polyamide 6 (PA6) and aromatic Poly(m‐xylene adipamide) (MXD6) nylon films as well as their in‐situ polymerized nanocomposites with 4 wt% clay were studied. Cast films were prepared by extrusion process and rapidly cooled using an air knife. The precursor films were uniaxially stretched at 110°C with draw ratios varying from 1.5 to 5. DSC results showed that the cold crystallization temperature (Tcc) of the uniaxially stretched MXD6 and MXD6/clay films drastically shifted to the lower temperatures when draw ratio increased. The aromatic nylon films had lower oxygen permeability than those of the aliphatic films, due to more rigidity and chain packing. However, the oxygen permeability of the stretched films increased with draw ratio (DR) up to a critical value for each sample, while further stretching resulted in a reduction in the oxygen permeation. This phenomenon was related to the changes in free volume upon uniaxial stretching. The ability of different geometrical models to describe the experimental relative permeability data was investigated. The Bharadwaj model that took into account clay orientation was the most successful one to predict the oxygen barrier characteristics of the stretched nanocomposites at high draw ratios. The Young's modulus and tensile strength of the aliphatic and aromatic nylons increased with uniaxial deformation, while the flexibility and elongation at break of the former decreased with increasing DR. A larger increase in the Young's modulus of the uniaxially stretched nanocomposite films compared with the neat samples was observed and could be related to the improvement in the clay orientation as well as a better alignment of the crystalline phase due to incorporating the clay platelets in the polymer matrix. In contrast, the flexibility of the stretched MXD6 improved remarkably (ca., 25 times) compared with the precursor film (DR = 1) when the draw ratio increased to 1.5. This could be related to the effect of hot stretching on the enhancement of polymer chains relaxation and mobility at low draw ratios. POLYM. ENG. SCI., 55:1113–1127, 2015. © 2014 Society of Plastics Engineers
Development of a high/low concentration photovoltaic module with dichroic spectrum splitting
Authors: Antonini Andrea , Butturi Mariangela A. , Zurru Paolo , Norton Matthew , Parretta Antonio
Published: July 2014

A concentrating photovoltaic module design incorporating a spatial spectral splitting approach with dichroic mirrors is presented. The advantages of this technology are reported, as well as a short description of the design evolution process. The experimental results are summarised, highlighting possible improvements through the use of different production processes and components. Materials, design and assembly procedures are taken into account, keeping in mind the fundamental constrains of cost and reliability of the final product. Finally, the possibilities for market exploitation of this technology in the current photovoltaic landscape are analysed. Copyright © 2014 John Wiley & Sons, Ltd.
Rapid, Reversible Release from Thermosensitive Liposomes Triggered by Near‐Infra‐Red Light
Authors: Forbes Natalie , Pallaoro Alessia , Reich Norbert O. , Zasadzinski Joseph A.
Published: July 2014

A novel drug carrier is presented consisting of plasmonic hollow gold nanoshells (HGN) chemically tethered to liposomes made temperature sensitive with lysolipids (TSL). Continuous‐wave irradiation by physiologically friendly near‐infra‐red light at 800 nm for 2.5 min at laser intensities an order of magnitude below that known to damage skin generates heating localized to the liposome membrane. The heating increases the liposome permeability in an irradiation dose dependent, but reversible manner, resulting in rapid release of small molecules such as the self‐quenching dye carboxyfluorescein or the chemotherapeutic doxorubicin, without raising the bulk temperature. The local rise in nanoshell temperature under laser irradiation is inferred by comparing dye release rates from the TSL via bulk heating to that induced by irradiation. Laser‐irradiation of TSL enables precise control of contents release with low temperature gradients confined to areas irradiated by the laser focus. The combined effects of rapid local release and localized hyperthermia provide a synergistic effect as shown by a near doubling of androgen resistant PPC‐1 prostate cancer cell toxicity compared to the same concentration of free doxorubicin.
Combustion Effects of Nitrofulleropyrrolidine on RDX‐CMDB Propellants
Authors: Jin Bo , Peng Rufang , Zhao Fengqi , Yi Jianhua , Xu Siyu , Wang Sengbo , Chu Shijin
Published: July 2014

The effect of N‐methyl‐2‐(3‐nitrophenyl)pyrrolidino[3′,4′:1,2]fullerene (mNPF) on the decomposition characteristics of hexogen (RDX) was investigated using differential scanning calorimetry (DSC). The results show that mNPF can accelerate the decomposition of RDX, the peak temperature (Tp) of the exothermal decomposition is reduced by 6.4 K, and the corresponding apparent activation energy (Ea) is decreased by 8.7 kJ mol−1. N‐methyl‐2‐(3‐nitrophenyl)pyrrolidino[3′,4′:1,2]fullerene (mNPF), carbon black (CB), and C60 were used as combustion catalysts to improve the combustion performance of a composite modified double‐base propellant containing RDX (RDX‐CMDB). The burning rate experimental results show that mNPF has a stronger catalytic effect than C60 and CB. The magnitude of the effect of the three carbon substances on the enhancement of the burning rate is as follows: mNPF>C60>CB. The catalytic effects of different contents of mNPF on the burning rates of RDX‐CMDB propellants were also studied, and the results show that the burning rates of RDX‐CMDB propellants are improved with increasing mNPF content. The plateau burning rate of a RDX‐CMDB propellant can be increased to 19.6 mm s−1 when 1.0 % mNPF is added, and the corresponding plateau combustion region occurs at 8–22 MPa.