bluuebunny/crossref_metadata_2025 huggingface dataset:
Magnetic fingerprint of southern Portuguese speleothems and implications for paleomagnetism and environmental magnetism
Authors: Font Eric , Veiga‐Pires Cristina , Pozo Manuel , Carvallo Claire , de Siqueira Neto António Carlos , Camps Pierre , Fabre Sébastien , Mirão José
Published: October 2014

Environmental magnetism of speleothems is still in its early stage of development. Here we report on our investigation of the environmental and paleomagnetic information that has been recorded in speleothems, and what are the factors that control its preservation and reliability. To address these issues, we used a multidisciplinary approach, including rock magnetism, petrography, scanning electron microscopy, stable carbon and oxygen isotope compositions, and major and trace element concentrations. We applied this to a set of samples from different stages of speleothem evolution: present‐day dripwater (glass plates), a weathered stalactite, a fresh stalagmite, cave sediments, and terra rossa soils. These samples come from the Penico and Excentricas caves, located in two distinct aquifers of the Algarve region, South Portugal. Our results show that the main magnetic carriers of the speleothems under study are primary (detrital) and consist of maghemite (and magnetite?). Similarities in coercivity and temperature dependence of the studied set of samples suggest that iron oxides are inherited from the terra rossa soils that cap the cave and were transported to the speleothems by dripwater. Hence, they represent a regional environmental signature. Interestingly, a stable and probably detrital remanent magnetization could be isolated in the fresh stalagmite, whereas the weathered stalactite yielded chaotic magnetic directions and very low remanent intensities. We propose that these low intensities can be the result from (i) different remanence acquisition mechanisms between stalagmite and stalactite and/or (ii) iron dissolution by fungal activity. We also suggest that magnetic properties and color and the content in detrital elements in the fresh speleothem inform about environmental processes acting on the interface of rock (soil)‐atmosphere, while oxygen isotope composition and alkaline‐earth element concentrations inform about calcite‐water interaction processes. These results provide a better understanding of how environmental information is recorded in speleothems and what the factors are that control the reliability of the paleomagnetic and paleo‐environmental signal.
Organic aerosol emission ratios from the laboratory combustion of biomass fuels
Authors: Jolleys Matthew D. , Coe Hugh , McFiggans Gordon , McMeeking Gavin R. , Lee Taehyoung , Kreidenweis Sonia M. , Collett Jeffrey L. , Sullivan Amy P.
Published: October 2014

Organic aerosol (OA) emission ratios (ER) have been characterized for 67 burns during the second Fire Laboratory at Missoula Experiment. These fires involved 19 different species representing 6 major fuels, each of which forms an important contribution to the U.S. biomass burning inventory. Average normalized ΔOA/ΔCO ratios show a high degree of variability, both between and within different fuel types and species, typically exceeding differen‐ces between separate plumes in ambient measurements. This variability is strongly influenced by highly contrasting ΔOA levels between burns and the increased partitioning of semivolatile organic compounds to the particle phase at high ΔOA concentrations. No correlation across all fires was observed between ΔOA/ΔCO and modified combustion efficiency (MCE), which acts as an indicator of the proportional contributions of flaming and smoldering combustion phases throughout each burn. However, a negative correlation exists with MCE for some coniferous species, most notably Douglas fir, for which there is also an influence from fuel moisture content. Changes in fire efficiency were also shown to dramatically alter emissions for fires with very similar initial conditions. Although the relationship with MCE is variable between species, there is greater consistency with the level of oxygenation in OA. The ratio of the m/z 44 fragment to total OA mass concentration (f44) as measured by aerosol mass spectrometer provides an indication of oxygenation as influenced by combustion processes at source, with ΔOA/ΔCO decreasing with increasing f44 for all fuel types. Inconsistencies in the magnitude of the effects associated with each potential influence on ΔOA/ΔCO emphasize the lack of a single dominant control on fire emissions, and a dependency on both fuel properties and combustion conditions.
Spatiotemporal change of diurnal temperature range and its relationship with sunshine duration and precipitation in China
Authors: Shen Xiangjin , Liu Binhui , Li Guangdi , Wu Zhengfang , Jin Yinghua , Yu Pujia , Zhou Daowei
Published: October 2014

We examined the spatiotemporal variation in diurnal temperature range (DTR) and discussed the reasons for the changes of DTR in China based on data from 479 weather stations from 1962 to 2011. Results showed that DTR decreased rapidly (0.291°C/decade) from 1962 to 1989 due to slightly decreased Tmax and significantly increased Tmin, but the decrease in DTR has stopped since 1990 as Tmax and Tmin kept pace with each other. During 1990–2011, DTR remained trendless, with slight increase in the 1990s and slight decrease after 2000. During the whole study period from 1962 to 2011, DTR decreased at a rate of 0.157°C/decade nationally. Spatially, decreases in DTR were greatest in Northeast China and lowest in Southwest China with a transect running from northeast to southwest showing the decreasing trends change from high to low. Seasonally, DTR decreases were greatest in winter and lowest in summer, and the magnitudes of decrease reduced from the north to south of China. The changes in DTR were closely correlated with changes in sunshine duration (SD) in China except the Tibetan Plateau, suggesting that SD decrease is an important contributor to the decrease of DTR through its influence on Tmax. In addition to the contribution of SD decrease, the increasing of precipitation played an important role in DTR decrease in Northwest China, the most arid region of China. It appeared that changes of cloud cover (CC) were not the reasons for DTR changes in the past 50 years as CC has decreased during the study period.
Hyperghrelinemia in Prader‐Willi syndrome begins in early infancy long before the onset of hyperphagia
Authors: Kweh Frederick A. , Miller Jennifer L. , Sulsona Carlos R. , Wasserfall Clive , Atkinson Mark , Shuster Jonathan J. , Goldstone Anthony P. , Driscoll Daniel J.
Published: October 2014

Circulating total ghrelin levels are elevated in older children and adults with Prader‐Willi syndrome (PWS). However, the presence or absence of hyperghrelinemia in young children with PWS remains controversial. We hypothesized that a more robust way to analyze appetite‐regulating hormones in PWS would be by nutritional phases rather than age alone. Our objectives were to compare total serum ghrelin levels in children with PWS by nutritional phase as well as to compare total ghrelin levels in PWS (5 weeks to 21 years of age) to normal weight controls and individuals with early‐onset morbid obesity (EMO) without PWS. Fasting serum total ghrelin levels were measured in 60 subjects with PWS, 39 subjects with EMO of unknown etiology, and in 95 normal non‐obese sibling controls of PWS or EMO subjects (SibC) in this 12 year longitudinal study. Within PWS, total ghrelin levels were significantly (P < 0.001) higher in earlier nutritional phases: phase 1a (7,906  ±  5,887); 1b (5,057 ± 2,624); 2a (2,905 ± 1,521); 2b (2,615 ± 1,370) and 3 (2,423 ± 1,350). Young infants with PWS also had significantly (P = 0.009) higher total ghrelin levels than did the sibling controls. Nutritional phase is an important independent prognostic factor of total ghrelin levels in individuals with PWS. Circulating ghrelin levels are elevated in young children with PWS long before the onset of hyperphagia, especially during the early phase of poor appetite and feeding. Therefore, it seems unlikely that high ghrelin levels are directly responsible for the switch to the hyperphagic nutritional phases in PWS. © 2014 Wiley Periodicals, Inc.
4q12–4q21.21 deletion genotype–phenotype correlation and the absence of piebaldism in presence of KIT haploinsufficiency
Authors: Hemati Parisa , du Souich Christèle , Boerkoel Cornelius F.
Published: October 2014

Chromosome 4q deletion syndrome is a rare intellectual disability disorder caused by a variety of non‐recurrent deletions of 4q. We describe the evolution of the phenotypic features of a female patient with a previously unreported deletion of 4q12–4q21.21 (hg 18; 54,711,575–79,601,919). By review reported individuals with interstitial deletions extending telomeric from 4q12 have syndromic intellectual disability with variable piebaldism. We expand the phenotype to include dolichocephaly, pectus excavatum, hip dysplasia, pes planus, myopia, lens opacities, and an absence of spoken language but not of communication through sign. The proposita also did not have piebaldism suggesting again that piebaldism arises from a mechanism more complex than simple haploinsufficiency of KIT. Comparing deletions among affected individuals localizes the critical interval within 4q12–4q13.1, although the absence of molecular boundaries for nearly all reported cases precludes precise delineation and genotype–phenotype correlation. © 2014 Wiley Periodicals, Inc.
Synthesis of and Specific Antibody Generation for Glycopeptides with Arginine N‐GlcNAcylation
Authors: Pan Man , Li Shan , Li Xiang , Shao Feng , Liu Lei , Hu Hong‐Gang
Published: October 2014

As a unique and unappreciated protein posttranslational modification, arginine N‐glycosylation was recently discovered to play an important role in the process that bacteria counteract host defenses. To provide chemical tools for further proteomic and biochemical studies on arginine N‐glycosylation, we report the first general strategy for a rapid and cost‐effective synthesis of glycopeptides carrying single or multiple arginine N‐GlcNAcyl groups. These glycopeptides were successfully utilized to generate the first antibodies that can specifically recognize arginine N‐GlcNAcylated peptides or proteins in a sequence‐independent manner.
Mass Spectrometry Quantifies Protein Interactions—From Molecular Chaperones to Membrane Porins
Authors: Hopper Jonathan T. S. , Robinson Carol V.
Published: October 2014

Proteins possess an intimate relationship between their structure and function, with folded protein structures generating recognition motifs for the binding of ligands and other proteins. Mass spectrometry (MS) can provide information on a number of levels of protein structure, from the primary amino acid sequence to its three‐dimensional fold and quaternary interactions. Given that MS is a gas‐phase technique, with its foundations in analytical chemistry, it is perhaps counter‐intuitive to use it to study the structure and non‐covalent interactions of proteins that form in solution. Herein we show, however, that MS can go beyond simply preserving protein interactions in the gas phase by providing new insight into dynamic interaction networks, dissociation mechanisms, and the cooperativity of ligand binding. We consider potential pitfalls in data interpretation and place particular emphasis on recent studies that revealed quantitative information about dynamic protein interactions, in both soluble and membrane‐embedded assemblies.
One‐Pot Synthesis of Tri‐ and Tetrasubstituted Pyridines by Sequential Ring‐Opening/Cyclization/Oxidation of N‐Arylmethyl 3‐Aziridinylpropiolate Esters
Authors: Yoshida Masahiro , Mizuguchi Tomotaka , Namba Kosuke
Published: October 2014

A novel strategy for the one‐pot synthesis of substituted pyridines from N‐arylmethyl 3‐aziridinylpropiolate esters is described. The method employs a three‐step procedure including the formation of allenyl imines, phosphine‐catalyzed cyclization, and subsequent oxidation of the dihydropyridines. Depending on the reaction conditions of the final oxidation step, tri‐ and tetrasubstituted pyridines can be selectively produced.
Stereospecific and Stereoselective Rhodium(I)‐Catalyzed Intramolecular [2+2+2] Cycloaddition of Allene‐Ene‐Ynes: Construction of Bicyclo[4.1.0]heptenes
Authors: Ohta Yuu , Yasuda Shigeo , Yokogawa Yuka , Kurokawa Kei , Mukai Chisato
Published: October 2014

Treatment of the allene‐ene‐yne substrates with [{RhCl(CO)2}2] effected the intramolecular [2+2+2]‐type ring‐closing reaction to produce various of tri‐ and tetracyclic derivatives containing a cyclopropane ring. The reaction is highly stereoselective as well as stereospecific with good to excellent yields.
Copper‐Catalyzed Radical Carbooxygenation: Alkylation and Alkoxylation of Styrenes
Authors: Liao Zhixiong , Yi Hong , Li Zheng , Fan Chao , Zhang Xu , Liu Jie , Deng Zixin , Lei Aiwen
Published: October 2014

A simple copper‐catalyzed direct radical carbooxygenation of styrenes is developed utilizing alkyl bromides as radical resources. This catalytic radical difunctionalization accomplishes both alkylation and alkoxylation of styrenes in one pot. A broad range of styrenes and alcohols are well tolerated in this transformation. The EPR experiment shows that alkyl halides could oxidize Cu(I) to Cu(II) in this transformation.
Synthesis and luminescence properties of pyrazolone derivatives and their terbium complexes
Authors: Xiao Haihua , Jiang Xi , Li Dong , Wu Limin , Zhang Wu , Guo Dongcai
Published: October 2014

Seven novel pyrazolone derivatives were synthesized and characterized by1H NMR and13C NMR spectra, mass spectra, infrared spectra and elemental analysis. Their terbium complexes were prepared and characterized by elemental analysis, EDTA titrimetric analysis, UV/vis spectra, infrared spectra and molar conductivity, as well as thermal analysis. The fluorescence properties and fluorescence quantum yields of the complexes were investigated at room temperature. The results indicated that pyrazolone derivatives had good energy‐transfer efficiency for the terbium ion. All the terbium complexes emitted green fluorescence characteristic of terbium ions, possessed strong fluorescence intensity, and showed relatively high fluorescence quantum yields. Cyclic voltammograms of the terbium complexes were studied and the highest occupied molecular orbital (HOMO) and lowest occupied molecular orbital (LUMO) energy levels of these complexes were estimated. Copyright © 2014 John Wiley & Sons, Ltd.
Meta-analysis of ultrasound-guided biopsy of suspicious axillary lymph nodes in the selection of patients with extensive axillary tumour burden in breast cancer
Authors: van Wely B J , de Wilt J H W , Francissen C , Teerenstra S , Strobbe L J A
Published: October 2014

Background

Recent studies show that not all patients with breast cancer and positive axillary lymph nodes need additional axillary surgery. A systematic review and meta-analysis of the literature was performed to test the hypothesis that ultrasound-guided biopsy of suspicious nodes can be a useful tool to identify patients with extensive axillary tumour burden.

Methods

PubMed and Embase were searched to identify articles reporting on ultrasound-guided techniques to stage the axilla of patients with breast cancer. The emphasis was to study the number of positive nodes found after axillary lymph node dissection (ALND) following a positive ultrasound-guided biopsy or a positive sentinel lymph node biopsy (SLNB). Information regarding the number of positive nodes thus had to be available. Results were tested for heterogeneity and a meta-analysis was performed.

Results

A total of 894 articles were identified, and 115 were selected based on title and abstract information by two independent reviewers. After extensive review, 18 articles were eligible for analysis. Eight studies reported sufficient data to perform a meta-analysis comparing 532 patients with a positive ultrasound-guided biopsy with 248 patients with a negative ultrasound-guided biopsy but a positive SLNB. The number of involved nodes was significantly higher in patients in whom axillary metastasis was detected by ultrasound-guided biopsy (P < 0·001). No heterogeneity in the observed effect was found (I2 = 22 per cent, P = 0·26).

Conclusion

Patients with breast cancer in whom axillary metastases are detected by ultrasound-guided biopsy have significantly more involved nodes than SLNB-positive patients. This finding enables further preoperative tailoring of axillary treatment in breast cancer.
An Evolutionary Model Encompassing Substrate Specificity and Reactivity of Type I Polyketide Synthase Thioesterases
Authors: Hari Taylor P. A. , Labana Puneet , Boileau Meaghan , Boddy Christopher N.
Published: October 2014

Bacterial polyketides are a rich source of chemical diversity and pharmaceutical agents. Understanding the biochemical basis for their biosynthesis and the evolutionary driving force leading to this diversity is essential to take advantage of the enzymes as biocatalysts and to access new chemical diversity for drug discovery. Biochemical characterization of the thioesterase (TE) responsible for 6‐deoxyerythronolide macrocyclization shows that a small, evolutionarily accessible change to the substrate can increase the chemical diversity of products, including macrodiolide formation. We propose an evolutionary model in which TEs are by nature non‐selective for the type of chemistry they catalyze, producing a range of metabolites. As one metabolite becomes essential for improving fitness in a particular environment, the TE evolves to enrich for that corresponding reactivity. This hypothesis is supported by our phylogenetic analysis, showing convergent evolution of macrodiolide‐forming TEs.
Combined Operando UV/Vis/IR Spectroscopy Reveals the Role of Methoxy and Aromatic Species during the Methanol‐to‐Olefins Reaction over H‐SAPO‐34
Authors: Qian Qingyun , Vogt Charlotte , Mokhtar Mohamed , Asiri Abdullah M. , Al‐Thabaiti Shaeel A. , Basahel Suliman N. , Ruiz‐Martínez Javier , Weckhuysen Bert M.
Published: October 2014

The methanol‐to‐olefins (MTO) process over H‐SAPO‐34 is investigated by using an operando approach combining UV/Vis and IR spectroscopies with on‐line mass spectrometry. Methanol, methoxy, and protonated dimethyl ether are the major species during the induction period, whereas polyalkylated benzenes and polyaromatic species are encountered in the active stage of the MTO process. The accessibility of SAPO‐34 is linked with the amount of methoxy species, whereas the formation of polyaromatic species that block the pores is the main cause of deactivation. Furthermore, the reaction pathways responsible for the formation of olefins and polyaromatics co‐exist and compete during the whole MTO process, and both routes are directly related to the amount of surface polyalkylated benzene carbocations and methoxy species. Hence, a first‐order kinetic model is proposed and comparable activation energies for both processes are obtained.
Control of blood pressure by the renin‐angiotensin‐aldosterone system
Authors: Hall John E.
Published: October 2014

Modification of the renin‐angiotensin system, part of a powerful feedback system for long‐term control of arterial pressure and volume homeostasis, through use of angiotensin‐converting enzyme (ACE) inhibitors, offers a powerful means of reducing blood pressure in many hypertensive patients. There is considerable evidence to suggest that the chronic renal and blood pressure actions of ACE inhibitors are mediated mainly by blockade of angiotensin II formation, rather than by other effects such as increased levels of kinins or prostaglandins. The long‐term actions of angiotensin II and aldosterone on blood pressure are closely intertwined with their effects on volume homeostasis and the renal pressure natriuresis mechanism. In most instances, changes in angiotensin II and aldosterone act to amplify the effectiveness of pressure natriuresis and minimize changes in blood pressure needed to maintain sodium balance. When angiotensin II or aldosterone levels are inappropriately elevated, the antinatriuretic effects of these hormones shift pressure natriuresis to higher levels, thereby necessitating increased blood pressure to maintain sodium balance. Control of renal excretory function and modulation of pressure natriuresis by angiotensin II is mediated by intrarenal and extrarenal effects, including stimulation of aldosterone secretion. Current evidence indicates that the intrarenal effects of angiotensin II are quantitatively more important than changes in aldosterone in regulating renal excretion and arterial pressure. The intrarenal actions of angiotensin II include a direct effect on tubular sodium transport as well as a potent constrictor action on efferent arterioles, which increases reabsorption by altering peritubular capillary forces. The constrictor effect of angiotensin II on efferent arterioles also helps to stabilize glomerular filtration rate and therefore excretion of metabolic waste products, an action that may be particularly important when renal perfusion is impaired (e.g., in renal artery stenosis or heart failure).
The pharmacokinetics of benazepril relative to other ace inhibitors
Authors: Gengo Fran M. , Brady Ellen
Published: October 2014

Benazepril is a prodrug that, following rapid conversion to benazeprilat, is a potent nonsulfhydryl inhibitor of angiotensin‐converting enzyme. The absorption, bioactivation, distribution, and elimination of benazepril and benazeprilat have been evaluated in healthy subjects, hypertensive patients, and patients with characteristics known to alter the pharmacokinetic disposition of ACE inhibitors, such as renal impairment, hepatic impairment, and advanced age. Following oral administration, benazepril is absorbed and transformed into benazeprilat in the liver. Coadministration of benazepril with food delays absorption slightly but does not affect the ultimate bioavailability of benazeprilat. Severe hepatic impairment slows conversion of benazepril to benazeprilat but does not affect the overall bioavailability of benazeprilat; thus dosage adjustment is not necessary in the hepatically impaired population. Mild‐to‐moderate renal impairment (creatinine clearance > 30 ml/min) slightly increases benazeprilat concentrations; severe renal impairment (creatinine clearance < 30 ml/min) reduces benazeprilat elimination and requires dosage reduction. In elderly patients, benazepril disposition is the same as in younger patients, although benazeprilat clearance is slightly reduced. No clinically significant drug‐drug interactions occur with benazepril and many other medications commonly prescribed to elderly hypertensive patients. The pharmacokinetic characteristics of benazepril are stable over a wide range of conditions, and dosage adjustments for pharmacokinetic reasons are required infrequently.
Hyaline matrix in hyalinizing trabecular tumor
Authors: Bakuła‐Zalewska Elwira , Cameron Robert , Gałczyński Jacek P. , Domanski Henryk A.
Published: October 2014

Hyalinizing trabecular tumor (HTT) is a rare neoplasm which usually follows an indolent clinical course. The cytologic diagnosis of HTT can be challenging as these neoplasms share cytomorphological features with other thyroid neoplasms and paraganglioma. In fine‐needle aspiration (FNA) smears a diagnosis of papillary thyroid carcinoma (PTC) or suspicion of PTC is often made. Herein we report cytologic findings in two patients with HTT examined by FNA. The key to a correct diagnosis is the recognition of a hyaline and colloid/amyloid‐like material in the background of the smears. Immunocytochemical examination showing aberrant membranous and peripheral cytoplasmic staining for MIB‐1 can help in rendering a correct diagnosis. Diagn. Cytopathol. 2015;43:710–713. © 2014 Wiley Periodicals, Inc.
Enantioselective Allylation of tert‐Butyldimethylsilyl‐Protected Vanillin and Synthesis of a Lignan Derivative Isolated from Machilus wangchiana
Authors: Cadart Timothée , Koukal Petr , Kotora Martin
Published: October 2014

Various enantioselective allylations and crotylations of tert‐butyldimethylsilyl‐protected vanillin were undertaken to assess the best methodology to provide the corresponding homoallylic alcohols in high yields with high enantiopurity. In general, most of the tested allylations proceeded with high enantioselectivities (>92 % ee) and in the case of crotylation also with excellent diastereoselectivity (96 % ee, >98 % de). The product obtained from the crotylation reaction was used in the enantioselective synthesis of the unnatural diastereoisomer of a recently isolated lignan derivative.
Comparison of Linear and Cross‐Conjugation from Rates of Vinylheptafulvene Ring‐Closure
Authors: Fjelbye Kasper , Christensen Trine Nørgaard , Jevric Martyn , Broman Søren Lindbæk , Petersen Anne Ugleholdt , Kadziola Anders , Nielsen Mogens Brøndsted
Published: October 2014

The concept of cross‐conjugation has in recent years attracted increasing interest in materials science as well as in the field of molecular electronics as a means to tune the optical properties and molecular conductance of nanoscale devices. In this paper we show how the rate of an electrocyclic reaction, the conversion of vinylheptafulvene (VHF) into dihydroazulene (DHA), is influenced by an electron‐withdrawing p‐nitrophenyl group separated from the VHF by either cross‐conjugated or linearly π‐conjugated bridging units. A selection of DHA/VHF molecules with ethyne, 1,1‐ and 1,2‐diethynylethene, and 1,3‐butadiyne bridges was prepared by metal‐catalyzed coupling reactions. The effect of the different conjugated spacers on the kinetics of the conversion of VHF into DHA was examined by UV/Vis absorption spectroscopy by monitoring the decay of the VHF absorption. The cross‐conjugated diethynylethene spacer was found to increase the half‐life of the VHF relative to the linearly conjugated spacers.
Cohort study evaluating the risk of hip fracture among patients with dementia in Taiwan
Authors: Huang Shih‐Wei , Lin Jia‐Wei , Liou Tsan‐Hon , Lin Hui‐Wen
Published: October 2014

Background

To investigate the incidence and risk of hip fracture among dementia patients

Methods

This is a retrospective population‐based 7‐year cohort study using case–control matched analysis database from Taiwan's Longitudinal Health Insurance Database 2005. Patients were diagnosed with codes or International Classification of Diseases‐9‐CM codes of dementia, between 1 January 2004 and 31 December 2006. The prevalence and the adjusted odds ratio of hip fracture among dementia patients and the controls were estimated.

Results

We enrolled 3101 patients with dementia in the dementia cohort and 12,404 (1:4) patients in the control group. Of these, 202 patients experienced hip fractures. The incidence of hip fracture was 1178 per 100,000 person‐years in the dementia cohort and 624 per 100,000 person‐years in the comparison cohort. The hip fracture hazard ratio during the follow‐up period was 1.89 (95% confidence interval [CI] 1.60–2.23,p < 0.001) for dementia patients. After adjusting for the covariates, the hazard ratio of hip fracture was 1.41 (95% CI, 1.19–1.69,p < 0.001) for dementia patients.

Conclusion

People with dementia experience an increased incidence of hip fracture and are at a higher risk of sustaining a hip fracture in the future. Proper and effective hip fracture‐prevention strategies are essential for dementia patients. Copyright © 2014 John Wiley & Sons, Ltd.
Interaction of quantitative 18F‐FDG‐PET‐CT imaging parameters and human papillomavirus status in oropharyngeal squamous cell carcinoma
Authors: Schouten Charlotte S. , Hakim Sara , Boellaard R. , Bloemena Elisabeth , Doornaert Patricia A. , Witte Birgit I. , Braakhuis Boudewijn J. M. , Brakenhoff Ruud H. , Leemans C. René , Hoekstra Otto S. , de Bree Remco
Published: October 2014

Background

Patients with human papillomavirus (HPV)‐positive oropharyngeal squamous cell carcinoma (SCC) have a better survival than with HPV‐negative oropharyngeal SCC. An 18F‐fluorodeoxyglucose positron emission tomography‐CT (18F‐FDG‐PET‐CT) may also provide prognostic information. We evaluated glycolytic characteristics in HPV‐negative and HPV‐positive oropharyngeal SCC.

Methods

Forty‐four patients underwent pretreatment 18F‐FDG‐PET‐CT. Standardized uptake values (SUVs) and metabolic active tumor volumes (MATVs) were determined for primary tumors. HPV status was determined with p16 immunostaining, followed by high‐risk HPV DNA detection on the positive cases.

Results

Twenty‐seven patients were HPV‐positive (61.4%). Median MATV was 2.8 mL (range = 1.6–5.1 mL) for HPV‐positive and 6.0 mL (range = 4.4–18.7 mL) for HPV‐negative tumors (p < .001). SUV values are volume dependent (partial volume effect), therefore, MATV was included as covariate in multivariate analysis. In this multivariate analysis, the maximum SUV in HPV‐positive tumors was 3.9 units lower than in HPV‐negative tumors (p = .01).

Conclusion

The 18F‐FDG‐PET‐CT parameters are lower in HPV‐positive than in HPV‐negative patients. Low pretreatment SUV values in HPV‐positive oropharyngeal SCC may be at least partly explained by HPV‐induced tumor changes. © 2015 Wiley Periodicals, Inc. Head Neck 38: 529–535, 2016
Evaluation of a class of polyurethane materials for intraocular lens manufacturing
Authors: Bozukova Dimitriya , Bertrand Virginie , Pagnoulle Christophe , De Pauw‐Gillet Marie‐Claire
Published: October 2014

Ophthalmic lenses are medical devices with considerable requirements in terms of optical, biomechanical and biological performance. There is limited number of materials used for their manufacturing, comprising mainly silicones and poly(meth)acrylates. This series of publications aims at investigating the applicability of thermoplastic polyurethane elastomers (TPU) for the manufacturing of ophthalmic lenses and examining the properties of the respective devices. This study is related to the synthesis of TPUs with chemical compositions that comprise chemically grafted filters for the hazardous‐light. GC‐MS, attenuated total reflectance Fourier transform infrared spectroscopy, and UV–vis spectroscopies confirmed the reaction completion and the beneficial effect of the filters on the light transmittance, respectively. Relatively high refractive index of the material was measured and allows for the manufacturing of thinner lenses. The contrast sensitivity determined for a model intraocular lens (IOL) was satisfactory. Few optical defects were, however, present on the model lens prepared by thermoplastic injection molding. The elasticity of the materials was evaluated in view to their potential applicability as foldable IOLs by determining their glass transition temperature and their Young modulus and measuring their shore A. The TPU materials demonstrated more bioadhesive character compared with a benchmark hydrophilic acrylic reference material, which is already used for IOL manufacturing. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 103B: 1274–1286, 2015.
Mesenchymal stem cell expression of stromal cell‐derived factor‐1β augments bone formation in a model of local regenerative therapy
Authors: Herberg Samuel , Kondrikova Galina , Hussein Khaled A. , Johnson Maribeth H. , Elsalanty Mohammed E. , Shi Xingming , Hamrick Mark W. , Isales Carlos M. , Hill William D.
Published: October 2014

Bone has the potential for spontaneous healing. However, this process often fails in patients with co‐morbidities requiring clinical intervention. Numerous studies have revealed that bone marrow‐derived mesenchymal stem/stromal cells (BMSCs) hold great potential for regenerative therapies. Common problems include poor cell engraftment, which can be addressed by irradiation prior to transplantation. Increasing evidence suggests that stromal cell‐derived factor‐1 (SDF‐1) is involved in bone formation. However, osteogenic contributions of the beta splice variant of SDF‐1 (SDF‐1β), which is highly expressed in bone, remain unclear. Using the tetracycline (Tet)‐regulatory system we have shown that SDF‐1β enhances BMSC osteogenic differentiation in vitro. Here we test the hypothesis that SDF‐1β augments bone formation in vivo in a model of local BMSC transplantation following irradiation. We found that SDF‐1β, expressed at high levels in Tet‐Off‐SDF‐1β BMSCs, augments the cell‐mediated therapeutic effects resulting in enhanced bone formation, as evidenced by ex vivo μCT and bone histomorphometry. The data demonstrate the specific contribution of SDF‐1β to BMSC‐mediated bone formation, and validate the feasibility of the Tet‐Off technology to regulate SDF‐1β expression in vivo. In conclusion, SDF‐1β provides potent synergistic effects supporting BMSC‐mediated bone formation and appears a suitable candidate for optimization of bone augmentation in translational protocols. Published 2014. This article has been contributed to by US Government employees and their work is in the public domain in the USA. J Orthop Res 33:174–184, 2015.
Generation of sub‐terahertz repetition rates from a monolithic self‐mode‐locked laser coupled with an external Fabry‐Perot cavity
Authors: Chen Y. F. , Chang M. T. , Zhuang W. Z. , Su K. W. , Huang K. F. , Liang H. C.
Published: October 2014

A novel scheme to multiply the repetition rate of a monolithic self‐mode‐locked laser for generating sub‐terahertz pulse sources is successfully demonstrated. A coated Yb:KGW crystal is designed to achieve a self‐mode‐locked operation at a repetition rate of 24 GHz with an average output power exceeding 1.0 W at a pump power of 4.8 W. A partially reflective mirror is utilized to combine with the output surface of the gain medium to constitute an external Fabry‐Perot cavity. It is theoretically and experimentally verified that adjusting the external cavity length to satisfy the commensurate condition can lead to the frequency spacing to be various order harmonics of the mode spacing of the monolithic cavity. The maximum pulse repetition rate of the laser output can be up to 216 GHz and the pulse duration is as short as 330 fs. More importantly, the overall characteristics of the first‐order temporal autocorrelation traces obtained by sequentially scanning the external cavity.length display an intriguing phenomenon of temporally fractional revivals, similar to the feature of spatial Talbot revivals.

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Diagnostic Performance of the “Huffing and Puffing” Sign in Functional (Psychogenic) Movement Disorders
Authors: Laub Holly N. , Dwivedi Alok K. , Revilla Fredy J. , Duker Andrew P. , Pecina‐Jacob Cara , Espay Alberto J.
Published: October 2014

We aimed at determining the diagnostic value of effort‐associated behaviors (“huffing and puffing” spectrum) in patients with psychogenic movement disorders. Three blinded clinicians rated presence, severity, and duration of effort‐associated features during standing and walking tasks on edited videos of 131 patients with psychogenic gait disorders and 37 with organic gait disorders. Huffing, grunting, grimacing, and breath holding were the most common effort‐associated behaviors in patients with psychogenic gait disorders, with a combined prevalence of 44% and disproportionate to the severity of gait impairment, compared to organic gait disorders. The presence of huffing and puffing–type behaviors yielded a relatively low sensitivity, but high specificity, for the diagnosis of psychogenic movement disorders, increasing the odds of diagnosis 13‐fold (95% confidence interval: 4.2–43.8), compared to organic gait disorders. Demonstration of effort‐associated behaviors during standing and walking strongly supports the psychogenic nature of disorders when gait is involved.
Design, fabrication and characterisation of a 24.4% efficient interdigitated back contact solar cell
Authors: Franklin Evan , Fong Kean , McIntosh Keith , Fell Andreas , Blakers Andrew , Kho Teng , Walter Daniel , Wang Da , Zin Ngwe , Stocks Matthew , Wang Er‐Chien , Grant Nicholas , Wan Yimao , Yang Yang , Zhang Xueling , Feng Zhiqiang , Verlinden Pierre J.
Published: October 2014

The interdigitated back contact (IBC) solar cells developed at the Australian National University have resulted in an independently confirmed (Fraunhofer Institut für Solare Energiesysteme (ISE) CalLab) designated‐area efficiency of 24.4 ± 0.7%, featuring short‐circuit current density of 41.95 mA/cm2, open‐circuit voltage of 703 mV and 82.7% fill factor. The cell, 2 × 2 cm2 in area, was fabricated on a 230 µm thick 1.5 Ω cm n‐type Czochralski wafer, utilising plasma‐enhanced chemical vapour deposition (CVD) SiNx front‐surface passivation without front‐surface diffusion, rear‐side thermal oxide/low‐pressure CVD Si3N4 passivation stack and evaporated aluminium contacts with a finger‐to‐finger pitch of 500 µm. This paper describes the design and fabrication of lab‐scale high‐efficiency IBC cells. Characterisation of optical and electronic properties of the best produced cell is made, with subsequent incorporation into 3D device modelling used to accurately quantify all losses. Loss analysis demonstrates that bulk and emitter recombination, bulk resistive and optical losses are dominant and suggests a clear route to efficiency values in excess of 25%. Additionally, laser processing is explored as a means to simplify the manufacture of IBC cells, with a confirmed efficiency value of 23.5% recorded for cells fabricated using damage‐free deep UV laser ablation for contact formation. Meanwhile all‐laser‐doped cells, where every doping and patterning step is performed by lasers, are demonstrated with a preliminary result of 19.1% conversion efficiency recorded. Copyright © 2014 John Wiley & Sons, Ltd.
Toward model‐driven engineering of supramolecular copolymers
Authors: Korevaar Peter A. , Grenier Christophe , Meijer E. W.
Published: October 2014

The coassembly of two oligo‐(p‐phenylene vinylene) (OPV) derivatives with different sizes and opposite chirality is studied. Short R‐chiral ROPV3 molecules experience a high energetic mismatch penalty when incorporated in helices formed by long S‐chiral SOPV4 molecules. In contrast, SOPV4 easily coassembles into helices dominated by ROPV3. As a result, the coassembly behavior (i.e., mixing or phase separation of ROPV3 and SOPV4 within the assemblies) highly depends on the ratio between both molecular building blocks. By a combination of experiments and models, the assembly pathways are analyzed. Furthermore, the model allows identifying key parameters in the coassembly behavior, such as the cooperativity and the mismatch penalties. The model‐driven approach is anticipated to be generally applicable in the engineering of functional supramolecular copolymers. This article is dedicated to the 70th birthday of Jean Fréchet and we thank him for being a continuous source of inspiration for our group. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 385–391
Detailed analysis of temperature dependences of spherulite morphology and crystallite orientation of poly(vinylidene fluoride) via a combinatorial method
Authors: Xu Duigong , Bin Yuezhen , Tashiro Kohji
Published: October 2014

Temperature dependences of spherulite morphology and crystal orientation of poly(vinylidene fluoride) (PVDF) were systematically investigated via a combinatorial method. The method created a temperature gradient ranging from 130 to 200 °C. Results show that the preferential orientation of the crystallites changes with the crystallization temperature. The crystallization at 169 °C gives the most highly developed crystalline state of PVDF crystalline form II (α form), in which the spherulite size is maximal, and the crystallite sizes are also the longest, about 200 nm along the b axes. Besides, the a‐axis is almost parallel to the film normal. It indicates that the crystallization rate is the highest in the b‐axis direction. The perferential orientation at higher temperatures may be attributed to the confined 2D growth of the PVDF spherulites in the thin film, whereas the spherulites grow in the 3D mode at lower temperatures. The crystallization behavior revealed in the method is consistent with the results of melt isothermal crystallization experiments. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015, 53, 253–261
Study on optical properties and γ‐ray irradiation resistance of heavy metal oxide tellurite glasses
Authors: Zhou Yongtao , Baccaro Stefania , Cemmi Alessia , Yang Yunxia , Chen Guorong
Published: October 2014

Optical properties and irradiation resistance of heavy metal oxide tellurite glasses in the TeO2‐PbO‐Bi2O3‐B2O3 system doped with different ions are investigated. The results indicate that the matrix glass has a moderate UV cut‐off edges at about 386 nm wavelength. The UV cut‐off positions are obviously shifted to red by the addition of Ce4+. The introduction of Cr3+, Ce4+ and Ni2+ into the matrix glass exerts positive influences on irradiation resistance of glasses and cerium plays the most pronounced role. Such phenomena are mainly attributed to the variable valences of these cations. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Dynamic Biointerfaces: From Recognition to Function
Authors: Chang Baisong , Zhang Mingxi , Qing Guangyan , Sun Taolei
Published: October 2014

The transformation of recognition signals into regulating macroscopic behaviors of biological entities (e.g., biomolecules and cells) is an extraordinarily challenging task in engineering interfacial properties of artificial materials. Recently, there has been extensive research for dynamic biointerfaces driven by biomimetic techniques. Weak interactions and chirality are two crucial routes that nature uses to achieve its functions, including protein folding, the DNA double helix, phospholipid membranes, photosystems, and shell and tooth growths. Learning from nature inspires us to design dynamic biointerfaces, which usually take advantage of highly selective weak interactions (e.g., synergetic chiral H‐bonding interactions) to tailor their molecular assemblies on external stimuli. Biomolecules can induce the conformational transitions of dynamic biointerfaces, then drive a switching of surface characteristics (topographic structure, wettability, etc.), and eventually achieve macroscopic functions. The emerging progresses of dynamic biointerfaces are reviewed and its role from molecular recognitions to biological functions highlighted. Finally, a discussion is presented of the integration of dynamic biointerfaces with the basic biochemical processes, possibly solving the big challenges in life science.
In vivo Gold Nanoparticle Delivery of Peptide Vaccine Induces Anti‐Tumor Immune Response in Prophylactic and Therapeutic Tumor Models
Authors: Almeida Joao Paulo Mattos , Lin Adam Yuh , Figueroa Elizabeth Raquel , Foster Aaron Edward , Drezek Rebekah Anna
Published: October 2014

Gold nanoparticles (AuNPs) are promising vehicles for cancer immunotherapy, with demonstrated efficacy in immune delivery and innate cell stimulation. Nevertheless, their potential has yet to be assessed in the in vivo application of peptide cancer vaccines. In this study, it is hypothesized that the immune distribution and adjuvant qualities of AuNPs could be leveraged to facilitate delivery of the ovalbumin (OVA) peptide antigen and the CpG adjuvant and enhance their therapeutic effect in a B16‐OVA tumor model. AuNP delivery of OVA (AuNP‐OVA) and of CpG (AuNP‐CpG) enhanced the efficacy of both agents and induced strong antigen‐specific responses. In addition, it is found that AuNP‐OVA delivery alone, without CpG, is sufficient to promote significant antigen‐specific responses, leading to subsequent anti‐tumor activity and prolonged survival in both prophylactic and therapeutic in vivo tumor models. This enhanced therapeutic efficacy is likely due to the adjuvant effect of peptide coated AuNPs, as they induce inflammatory cytokine release when cultured with bone marrow dendritic cells. Overall, AuNP‐mediated OVA peptide delivery can produce significant therapeutic benefits without the need of adjuvant, indicating that AuNPs are effective peptide vaccine carriers with the potential to permit the use of lower and safer adjuvant doses during vaccination.
Detection of Nitroaromatic Explosives with Fluorescent Molecular Assemblies and π‐Gels
Authors: Kartha Kalathil K. , Sandeep Anjamkudy , Praveen Vakayil K. , Ajayaghosh Ayyappanpillai
Published: October 2014

Molecular assemblies and gels made up of fluorescent π‐systems through noncovalent interactions are fascinating materials with a wide range of properties and applications. Fluorescence is an extremely sensitive property, which gets perturbed upon molecular self‐assembly and gelation. Further manipulation of fluorescence in such materials is possible with external stimuli, such as stress, temperature, or with different analytes. Explosives are a class of analytes that respond to certain fluorescent molecular systems; thus allowing their sensing in a required environment. In recent times, this research has become a topic of great demand, resulting in a large number of publications, due to their relevance in safety and security issues. In this account, we record some of the major developments in the field of explosive sensing with fluorescent molecular assemblies and gels.
Throughput and cost‐efficient interference cancelation strategies for the downlink of spectrum‐sharing Long Term Evolution heterogeneous networks
Authors: Nasri Raouia , Latrach Ahmed , Affes Sofiène
Published: October 2014

In a heterogeneous network (HetNet), small cells such as femtocells considered in this work are deployed jointly with macrocells. This new cells' layer, when added to the network, generates interference, which could hamper neighboring macro‐user equipment (MUE) and femto‐user equipment (FUE) transmissions. In fact, this interference results in degradation of the network performance. In this paper, we propose a downlink interference cancelation (DL‐IC) strategy for spectrum‐sharing Long Term Evolution (LTE) HetNet. This DL‐IC strategy aims to reduce the interference impact on users by optimizing their received signal to interference plus noise ratio (SINR) using new utility functions for both FUEs and MUEs. These utility functions allow relaxation of the cancelation ratios in order to reduce implementation complexity while maximizing SINR, QoS, and throughput. We support by different system‐level simulations that both global network performance and user experience in terms of total throughput and received SNR or link‐level throughput, respectively, are significantly enhanced. Throughput gains achievable by the new DL‐IC strategy can reach as much as 200% against a homogeneous LTE network without IC along with an extra 48% per additional femtocell base station against a basic spectrum‐sharing LTE HetNet without IC. These performance figures are shown to surpass those achieved by interference avoidance techniques using either power or frequency resource allocation. Copyright © 2014 John Wiley & Sons, Ltd.