bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nanostructures from Self‐Assembling Triazine Tertiary Amine N‐Oxide Amphiphiles
Authors: Beecham Matthew P. , Clarkson Guy J. , Hall Gareth , Marsh Andrew 
Published: November 2013

AbstractA new set of amphiphilic tertiary amine N‐oxides has been prepared and their self‐assembly properties observed in aqueous solution by tensiometry, dynamic and static light scattering. X‐ray crystallographic analysis of parent amines and sulfoxide congeners indicates the formation of hydrogen‐bonded dimers as the primary assembly unit for formation of vesicles in preference to the compact micelles typical of lauryl dimethylamine N‐oxide (LDAO). 6‐Benzyloxy‐N,N′‐bis(5‐diethylaminopentylamine oxide)[1,3,5]triazine‐2,4‐diamine forms a 1 μm vesicle observed to entrap fluorescein. The [1,3,5]triazine core thus allows variation of the new self‐assembled structures from nano‐ to micrometre length scales.
ZnII–Dipyridylamide‐Based Coordination Frameworks: Structural Transformation and Anion Effect
Authors: Tzeng Biing‐Chiau , Yeh Chien‐Ting , Chang Tsung‐Yi 
Published: November 2013

AbstractWe have synthesized a series of 1 D double‐zigzag ({[Zn(paps)2(H2O)2](PF6)2}n (1), {[Zn(papo)2(H2O)2](PF6)2}n (3), and {[Zn(papc)2(H2O)2](PF6)2}n (5)) and 2 D polyrotaxane ([Zn(papc)2(PF6)2]n (6)) frameworks through the reaction of Zn(PF6)2 with dipyridylamide ligands (N,N′‐bis(pyridylcarbonyl)‐4,4′‐diaminodiphenyl thioether (paps), N,N′‐bis(pyridylcarbonyl)‐4,4′‐diaminodiphenyl ether (papo), and N,N′‐(methylenedi‐p‐phenylene)bispyridine‐4‐carboxamide (papc), respectively), and their molecular structures have been determined through X‐ray diffraction studies. From the powder X‐ray diffraction (PXRD) experiments, it is found that on heating, the double‐zigzag frameworks 1 and 3 undergo structural transformation to give the respective polyrotaxane frameworks 2 ([Zn(paps)2(PF6)2]n) and 4 ([Zn(papo)2(PF6)2]n), which matched well with those of their Zn(ClO4)2 analogues. Furthermore, grinding the solid samples of 2 and 4 in the presence of moisture resulted in total conversion back to the double‐zigzag frameworks 1 and 3, respectively. Although the 1 D double‐zigzag and 2 D polyrotaxane frameworks of ZnII‐paps and ‐papo with ClO4− anions can be also interconverted through heating and grinding in the presence of moisture, the related ZnII‐papc framework with ClO4− can only undergo a structural transformation process through heating. Surprisingly, reversible structural transformation between 5 and 6 has been proven successfully. In this work, we show that by replacing ClO4− with PF6−, a series of ZnII‐papx‐based frameworks can be obtained. Significantly, this indicates that a remarkable anion effect on such a novel structural transformation process has been demonstrated.
Direct Reduction of Carbon Dioxide to Formate in High‐Gas‐Capacity Ionic Liquids at Post‐Transition‐Metal Electrodes
Authors: Watkins John D. , Bocarsly Andrew B. 
Published: November 2013

AbstractAs an approach to combat the increasing emissions of carbon dioxide in the last 50 years, the sequestration of carbon dioxide gas in ionic liquids has become an attractive research area. Ionic liquids can be made that possess incredibly high molar absorption and specificity characteristics for carbon dioxide. Their high carbon dioxide solubility and specificity combined with their high inherent electrical conductivity also creates an ideal medium for the electrochemical reduction of carbon dioxide. Herein, a lesser studied ionic liquid, 1‐ethyl‐3‐methylimidazolium trifluoroacetate, was used as both an effective carbon dioxide capture material and subsequently as an electrochemical matrix with water for the direct reduction of carbon dioxide into formate at indium, tin, and lead electrodes in good yield (ca. 3 mg h−1 cm−2).
Hydropnictination Reactions of Carbodiimides and Isocyanates with Protonated Heptaphosphide and Heptaarsenide Zintl Ions
Authors: Turbervill Robert S. P. , Goicoechea Jose M. 
Published: November 2013

AbstractBy following a similar procedure to that employed for the synthesis of [HP7]2–(1), the synthesis and characterization of the hydrogenheptaarsenide dianion [HAs7]2–(2) was achieved. Building on previous research that has shown that [HP7]2–can react with carbodiimides to yield amidine‐functionalized cluster anions [P7C(NHR)(NR)]2–, we have found that the analogous hydroarsination reactions are also possible by reaction of2with RC=N=CR to yield [As7C(NHR)(NR)]2–[R = Dipp (3),iPr (4) and Cy (5); Dipp = 2,6‐diisopropylphenyl]. Furthermore, we also demonstrate that such hydropnictination reactions can be extended to other heteroallenes such as isocyanates (O=C=NAd; Ad = adamantyl) to afford the amide‐derivatized cluster anions [E7C(CO)(NHAd)]2–[E = P (6) and As (7)]. All new compounds were characterized by multinuclear NMR spectroscopy, elemental analyses and electrospray mass spectrometry. Clusters2,4,6and7were also characterized by single‐crystal X‐ray diffraction of [K(18‐crown‐6)]2[2], [K(18‐crown‐6)]2[4], [K(18‐crown‐6)]2[6]·py (py = pyridine) and [K(18‐crown‐6)]2[7]·py. Crystal structures confirming composition and connectivity were also obtained for anions3and5.
Outcome in squamous cell carcinoma of the nasal vestibule: A single center experience
Authors: Vital Domenic , Morand Grégoire , Huber Gerhard F. , Studer Gabriela , Holzmann David 
Published: November 2013

AbstractBackgroundThe purpose of this study was to analyze the outcome of squamous cell carcinomas (SCCs) of the nasal vestibule and to identify factors predicting recurrence.MethodsAll patients treated between 1995 and 2012 were included in this study. Outcome was analyzed with respect to modality of therapy, age, sex, tobacco consumption, staging, surgical margins, and histological differentiation pattern.ResultsThirty patients were included. Fourteen patients (47%) were found with T4, 1 patient (3%) with T3, 7 patients (23%) with T2, and 8 patients (27%) with T1 disease. Twenty‐one patients (70%) were treated surgically. Six patients (29%) needed postoperative radiation because of insufficient surgical margins. Radiation was the first‐line treatment in 9 patients (30%). Surgically treated patients with surgical margins <3 mm had significantly more locoregional recurrence compared to those with sufficient resections.ConclusionAdvanced T4 carcinomas show a high recurrence rate. Insufficient surgical margins are the main predictor for a locoregional recurrence and should be avoided. © 2014 Wiley Periodicals, Inc. Head Neck 37: 46–51, 2015
Sensorineural hearing loss in patients with head and neck cancer after chemoradiotherapy and radiotherapy: A systematic review of the literature
Authors: Theunissen Eleonoor A. R. , Bosma Sophie C. J. , Zuur Charlotte L. , Spijker René , van der Baan Sieberen , Dreschler Wouter A. , de Boer Jan Paul , Balm Alfons J. M. , Rasch Coen R. N. 
Published: November 2013

ABSTRACTBackgroundBoth radiotherapy (RT) and cisplatin‐based chemoradiotherapy (CRT) in patients with head and neck cancer may cause sensorineural hearing loss (SNHL). The purpose of this review was to provide more insight into SNHL because of CRT compared to RT.MethodsComprehensive search of Medline and Embase with the terms “radiotherapy” combined with “ototoxicity,” “head and neck squamous cell carcinoma,” and synonyms.ResultsOf the 2507 studies found, 21 were included in this study. Pooled analysis could not be committed because of heterogeneity. Incidence rates of SNHL after RT and CRT varied considerably, with percentages ranging from 0% to 43% and 17% to 88%, respectively. Factors that influenced the risk of SNHL were radiation dose to the cochlea, follow‐up time, age, baseline hearing level, and cisplatin dose.ConclusionThe wide range of SNHL incidence rates makes it impossible to draw any conclusions on the severity of RT‐ and CRT‐induced ototoxicity. To allow for future comparison of study outcomes, development of uniform criteria is of utmost importance. © 2014 Wiley Periodicals, Inc. Head Neck 37: 281‐292, 2015
Spending by primary care practices—does it show what we expect?
Authors: James Marilyn , Stokes Elizabeth 
Published: November 2013

SUMMARYBackgroundOver recent years, a number of policies and financial incentives in primary care have been proposed to tackle issues such as deprivation and health outcomes. This article investigates the association between healthcare spending, deprivation and outcomes. It argues that individual practice data are analysed before blanket application and acceptance that one size fits all in a local area.MethodsFinancial data were analysed alongside key outcome data, including quality and outcomes framework (QOF) indicators for a large urban primary care trust (PCT) in the UK. The PCT had a large population and number of practices, including single‐handed practices and an average list size in excess of 5000. The PCT will remain anonymous.ResultsThere was no relationship between primary care investment and the practices' deprivation score. There was a strong statistically significant negative correlation between QOF payments and deprivation, (correlation = −0.46, p < 0.001). There were only weak links between primary care investment and health outcomes. There was no relationship between high emergency spending and health outcome.ConclusionsThe data presented suggest that one size does not necessarily fit all—in terms of providing the appropriate incentives in primary care, nor do national incentives and policies always have the desired effect. © 2013 The Authors. International Journal of Health Planning and Management published by John Wiley & Sons, Ltd.
Implementation of Community Health Fund in Tanzania: why do some districts perform better than others?
Authors: Maluka Stephen Oswald , Bukagile Godfrey 
Published: November 2013

SUMMARYIn early 1990s, Tanzania, like other African countries, introduced user fees in public health systems. Although user fees were considered important in promoting health, they appear to reduce people's access to health services. To counteract the detrimental effects of the user fees, various types of health insurances were introduced, including the Community Health Fund (CHF). Drawing from the review of minutes, health facility visits and key informant interviews, this study explored why implementation of the CHF in Tanzania has been more successful in some districts than in others.The findings indicate that in Lindi district, the enrolment rate for the CHF was very low. This was attributed to high premium rates, frequent drug stock‐out, lack of trust by the community members to the health providers, low incentives and local politics. In contrast, in Iramba district, the performance was better. Availability of drugs in the health facilities, effective supervision, commitment of the top district‐level officials and incentives to the health facility committees were the main factors that facilitated good performance of the fund in Iramba district.The focus of the implementation needs to be placed on the active engagement of the local‐level leaders and politicians who are responsible for the implementation of the policy. Equally important is the availability of quality health services in the health facilities. Copyright © 2013 John Wiley & Sons, Ltd.
The changes of gap junctions between pituitary folliculo‐stellate cells during the postnatal development of zucker fatty and lean rats
Authors: Sakuma Eisuke , Wada Ikuo , Soji Tsuyoshi , Wakabayashi Kenjiro , Otsuka Takanobu , Herbert Damon C. 
Published: November 2013

ABSTRACTWe investigated the effect of leptin on the postnatal development of gap junctions between folliculo‐stellate cells by using Zucker fatty (fa/fa) rats that have defects of the functional leptin receptor. Male Zucker fatty rats (fa/fa) and male Zucker lean rats (+/+) were used at each of the following postnatal ages: 20, 30, 40, 50, 60, 70, 80, 90 days, and 1 year. On one of the aforementioned dates, the anterior pituitary glands were prepared for observation by transmission electron microscopy. We quantified the number of follicles and gap junctions, and calculated the rate of occurrence as the ratio of the number of gap junctions existing between folliculo‐stellate cells per intersected follicular profile. In Zucker lean male rats, the number of gap junctions remained relatively constant from days 50 to 90 (0.44 ± 0.02 to 0.49 ± 0.03), and was similar in 1 year old rats (0.47 ± 0.03). These data were statistically higher compared to Zucker fatty male rats. In Zucker fatty male rats, very few gap junctions were observed in 30‐day‐old rats (0.04 ± 0.01: mean ± SE). This disruption of gap junction formation persisted, and the number of gap junctions remained constant and showed a low level from days 40 to 90 (0.11 ± 0.02 to 0.17 ± 0.02); this finding was similar in 1‐year‐old rats (0.17 ± 0.02). These observations indicate that the effect of leptin over the gap junction formation within the anterior pituitary glands was directly mediated by interaction with the functional leptin receptor present on the folliculo‐stellate cells. Microsc. Res. Tech. 77:31–36, 2014. © 2013 Wiley Periodicals, Inc.
Evaluation of liver fibrosis and hepatic venous pressure gradient with MR elastography in a novel swine model of cirrhosis
Authors: Huang Steven Y. , Abdelsalam Mohamed E. , Harmoush Samer , Ensor Joe E. , Chetta Justin A. , Hwang Ken-Pin , Stafford R. Jason , Madoff David C. , Avritscher Rony 
Published: November 2013

PurposeTo assess the correlation among MR elastography (MRE) measured liver stiffness (LS), liver fibrosis, and hepatic venous pressure gradient (HVPG) in a swine model of cirrhosis.Materials and MethodsThree swine served as controls, and liver fibrosis was induced in eight swine by transarterial embolization. LS and HVPG were obtained at baseline and 4 weeks (prenecropsy) following induction of liver fibrosis.ResultsFour weeks following the induction of liver cirrhosis, experimental animals developed an increase in HVPG of 8.0 ± 6.4 mmHg compared with 0.3 ± 1.2 mmHg for controls (P = 0.08). Over the same timeframe, mean MRE‐measured LS increased 0.82 ± 0.39 kPa for experimental swine and 0.1 ± 0.05 kPa for controls (P = 0.01). A positive correlation was observed between increases in HVPG and LS (ρ = 0.682; P = 0.02). Liver fibrosis was measured on explanted livers at 4 weeks and yielded mean fibrosis scores of 2.8 for experimental animals and 0 for controls (P = 0.0016). A positive correlation was observed between higher LS and liver fibrosis (ρ = 0.884; P = 0.0003).ConclusionMRE is a reliable noninvasive technique to measure LS in a swine model of cirrhosis. Significant positive correlations were observed between LS and HVPG as well as LS and fibrosis. J. Magn. Reson. Imaging 2014;39:590–597. © 2013 Wiley Periodicals, Inc.
Rapidly cleaving bovine two‐cell embryos have better developmental potential and a distinctive mRNA pattern
Authors: Orozco‐Lucero Ernesto , Dufort Isabelle , Robert Claude , Sirard Marc‐André 
Published: November 2013

SUMMARYMammalian embryos that rapidly reach the two‐cell stage in culture have a higher probability of becoming viable blastocysts. Our goal was to separate two‐cell bovine embryos based on their zygotic cleavage timing, and to assess their global mRNA levels. Following in vitro fertilization, all embryos that cleaved by 29.5 hpi (early) were cultured separately from those that divided at 46 hpi (late). The blastocyst rates were 46.1 ± 3.7% and 6.1 ± 3.4% for early‐ and late‐cleavers, respectively (P < 0.01). Seven replicates of selected two‐cell embryos were collected at each time point for microarray characterization (n = 4) and quantitative reverse‐transcriptase PCR (n = 3); the rest were left in culture for blastocyst evaluation. A total of 774 and 594 probes were preferentially present in early‐ and late‐cleaving embryos, respectively (fold change ± 1.5, P < 0.05), with important contrasts related to cell cycle, gene expression, RNA processing, and protein degradation functions. A total of 12 transcripts were assessed by quantitative PCR, of which ATM, ATR, CTNNB1, MSH6, MRE11A, PCNA, APC, CENPE, and GRB2 were in agreement with the hybridization results. Since most of these molecules are directly or indirectly associated with cell‐cycle regulation, DNA damage response, and transcription control, our results strongly suggest key roles for those biological functions in mammalian preimplantation development. Mol. Reprod. Dev. 81: 31–41, 2014. © 2013 Wiley Periodicals, Inc.
Poly(ether ketone)s bearing pendent sulfonate groups via copolyacylation of a sulfonated monomer and isomeric AB‐type comonomers
Authors: Zhang Zhenghui , Xu Tongwen 
Published: November 2013

ABSTRACTPoly(ether ketone)s bearing pendent sulfonate groups (SPEK‐x/y/z) have been successfully synthesized via copolyacylation of a presulfonated monomer SBP and two isomeric AB‐type self‐condensable comonomers, that is, 4‐phenoxybenzoic acid (p‐POBA) and 3‐phenoxybenzoic acid (m‐POBA). Proton‐exchange membranes (PEMs) with precisely controlled ion‐exchange capacity (IEC) and high strength can be readily prepared from these ionomers. PEMs prepared from p‐POBA other than m‐POBA exhibit much higher dimensional stability and proton conductivity at elevated temperature above 60 °C, showing prominent isomeric (para vs. meta) effects of polymer structural units. Furthermore, properties of PEMs prepared from p‐POBA are optimized by tuning IEC. SPEK‐1.0/2.2/0 with an IEC of 1.84 mmol g−1 exhibits acceptable swelling, much higher proton conductivity, and lower methanol permeability than commercial Nafion 115, implying potential application in direct methanol fuel cells. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 200–207
Ordering poly(trimethylsilyl styrene‐block‐D,L‐lactide) block copolymers in thin films by solvent annealing using a mixture of domain‐selective solvents
Authors: Cushen Julia D. , Wan Lei , Pandav Gunja , Mitra Indranil , Stein Gila E. , Ganesan Venkat , Ruiz Ricardo , Grant Willson C. , Ellison Christopher J. 
Published: November 2013

ABSTRACTControlling the morphology, domain orientation, and domain size of block copolymer (BCP) thin films is desirable for many applications in nanotechnology. These properties can be tuned during solvent annealing by varying the solvent choice and degree of swelling which affect the effective miscibility and volume fraction of the BCP domains. In this work, we demonstrate with a bulk lamellae‐forming BCP, poly(4‐trimethylsilylstyrene‐block‐D,L‐lactide) (PTMSS‐b‐PLA), that varying the composition of a mixture of solvent vapors containing cyclohexane (PTMSS‐selective) and acetone (PLA‐selective), enables formation of perpendicularly oriented lamellae with sub‐20‐nm pitch lines. The BCP domain periodicity was also observed to increase by 30%, compared to bulk, following solvent annealing. Furthermore, solvent annealing alone is shown to induce a transition from a disordered to an ordered BCP. We rationalize our observations by hypothesizing that the use of a combination of domain selective solvent mixtures serves to increase the effective repulsion between the blocks of the copolymer. We furnish results from self‐consistent field theory calculations to support the proposed mechanism. © 2013 Wiley Periodicals, Inc. J. Polym. Sci. Part B: Polym. Phys. 2014, 52, 36–45
Factors Influencing Destruction of Triacetone Triperoxide (TATP)
Authors: Oxley Jimmie C. , Smith James L. , Brady Joseph E. , Steinkamp Lucus 
Published: November 2013

AbstractAcid catalyzes the formation of triacetone triperoxide (TATP) from acetone and hydrogen peroxide, but acid also destroys TATP, and, under certain conditions, converts TATP to diacetone diperoxide (DADP). Addition of strong acids to TATP can cause an explosive reaction, while reaction with dilute acid reduces the decomposition rate so drastically that gentle destruction of TATP is impractical. However, combined use of dilute acid with slightly solvated TATP made gentle destruction of TATP feasible. Variables including acid type, concentration, solvent and ratios thereof have been explored, along with kinetics, in an attempt to provide a field‐safe technique for gently destroying this homemade primary explosive. The preferred method is moistening TATP with an alcoholic solution (aqueous methanol, ethanol, or iso‐propanol) followed by addition of 36 wt‐% hydrochloric acid. Preliminary experiments have shown the technique to be safe and effective for destruction of hexamethylene triperoxide diamine (HMTD), as well.
Predicting Solubility of Military, Homemade, and Green Explosives in Pure and Saline Water using COSMO‐RS
Authors: Alnemrat Sufian , Hooper Joseph P. 
Published: November 2013

AbstractThe conductor‐like screening model for real solvents (COSMO‐RS) has previously been shown to give accurate aqueous solubilities for a range of organic compounds using only quantum chemical simulation data. Application of this method for solid organic explosives, however, faces two difficulties; it requires correction for the free energy of fusion (a generally unknown quantity for these compounds) and it shows considerable error for common explosive classes such as nitramines. Herein we introduce a correction factor for COSMO‐RS that is applicable to a wide range of explosives, and requires no data beyond a quantum chemistry calculation. This modification allows COSMO‐RS to be used as a predictive tool for new proposed explosives or for systems lacking experimental data. We use this method to predict the temperature‐dependent solubility of solid explosives in pure and saline water to an average accuracy of approximately 0.25 log units at ambient temperature. Setschenow (salting‐out) coefficients predicted by this method show considerable improvement over previous COSMO‐RS results, but are still slightly overestimated compared to the limited experimental data available. We apply this method to a range of military, homemade, and “green” explosives that lack experimental seawater solubility data, an important property for environmental fate and transport modeling.
Effect of Initial Oxide Layer on Ignition and Combustion of Boron Powder
Authors: Ao Wen , Wang Yang , Li Heping , Xi Jianfei , Liu Jianzhong , Zhou Junhu 
Published: November 2013

AbstractOnly few data exist for experimental studies on ignition and combustion of boron particles with initial oxide thickness. The oxidation, ignition and combustion characteristics including the onset temperatures, weight gain, apparent activation energy, emission spectra during combustion, and ignition delay time of crystalline boron powders with different initial oxide thickness (x0) were studied by a laser ignition and thermogravimetric (TG) analyses. Simulations of the kinetics of oxide layer during boron ignition were conducted using a common model. The results indicated that the onset temperature was approximately 775 °C, independent of x0. The total weight gain decreased with increasing x0, whereas the weight gain at 775 °C did not change. The apparent activation energy was found to be insensitive to x0 and had a constant value of about 210 kJ mol−1. The intensity of the emission spectra gradually decreased while the ignition delay time increased with increasing x0. Numerical simulation showed that the removal rate of oxide layer enhanced with increasing x0. The experimental results revealed that the oxidation of boron powder was no diffusion‐controlled process at low temperatures. But the diffusion of oxygen could become important to the oxidation reaction at high temperatures