bluuebunny/crossref_metadata_2025_split huggingface dataset:
Enantioselective Synthesis of Both Enantio­mers of Chiral Allenes Using Chiral N‐Methylcamphanyl Piperazine Templates
Authors: Periasamy Mariappan , Reddy Polimera Obula , Sanjeevakumar Nalluri 
Published: May 2013

AbstractThe reaction of unsubstitued camphanyl‐piperazine 4 with ZnCl2, phenylacetylene, and benzaldehyde in toluene gave the corresponding dipropargylamine (i.e., 15) with opposite configurations at the newly formed stereogenic centres, which, upon reaction with ZnI2 resulted in the formation of a racemic mixture of 1,3‐diphenyl allene in 45 % yield. N‐Methylcamphanyl‐piperazine regioisomer 5, prepared by selective N‐methylation of the NH moiety attached to the stereogenic centre with (S)‐configuration, upon reaction with ZnCl2, phenylacetylene, and benzaldehyde in toluene, gave the corresponding propargylamine in 90 % yield, with an (S)‐configuration at the newly formed stereogenic centre, and upon subsequent reaction with ZnI2, this intermediate gave (R)‐1,3‐diphenyl allene in 52 % yield and with 96 % ee. Reaction of N‐methylcamphanyl‐piperazine isomer 5 with several 1‐alkynes and aldehydes in the presence of ZnBr2 gave the corresponding (R)‐allenes in 40–75 % yield and 79–99 % ee. In contrast, regioisomeric N‐methylcamphanyl‐piperazine 6 reacted with ZnBr2 to give the corresponding (S)‐allenes in 38–71 % yield and with 79–99 % ee. The opposite chiral discriminating abilities of the two NH moieties in camphanyl‐piperazines was confirmed by single‐crystal X‐ray analysis of the propargylamines formed. The results are discussed considering mechanisms involving the in situ formation of alkynylzinc halides, followed by diastereoselective addition to chiral iminium ion derivatives to give the corresponding propargylamines, and subsequent conversion to chiral allenes by an intramolecular 1,5‐hydrogen shift.
Perylene‐Based Bis‐, Tetrakis‐, and Hexakis(terpyridine) Ligands and Their Ruthenium(II)–Bis(terpyridine) Complexes: Synthesis and Photophysical Properties
Authors: El‐Batal Hany , Guo Kai , Li Xiaopeng , Wesdemiotis Chrys , Moorefield Charles N. , Newkome George R. 
Published: May 2013

AbstractA series of metallodendrimers 9–11, as well as their corresponding ligands, were designed and synthesized. These materials integrate perylene as a functional core with <tpyRuIItpy> termini; both chromophores are known for their photovoltaic properties. The products were fully characterized by a combination of 1H NMR and 13C NMR spectroscopy, COSY, and MS. Their photophysical properties revealed a broad absorption spectrum with enhanced molar absorption coefficients corresponding to the increase in the number of <tpyRuIItpy> units, which is indicative of their potential as candidates for light harvesting.
Leaving Group and Regioselectivity Switches in the Aminoalkylation Reaction of Indoles and Related Heterocycles with α‐Amido Sulfones
Authors: Blay Gonzalo , Girón Rosa M. , Montesinos‐Magraner Marc , Pedro José R. 
Published: May 2013

AbstractThe regioselective aminoalkylation of indoles and related heterocycles with α‐amido sulfones under basic conditions has been studied. The reaction that employed the MeMgBr/MgBr2system provided high yields of 3‐(1‐carbamoylalkyl)indoles. On the other hand, the reaction that used Cs2CO3afforded 1‐(1‐carbamoylalkyl)indoles exclusively in high yields. The first reaction constitutes a switch of the leaving group of the α‐amido sulfone in comparison to previously reported reactions between indoles and α‐amido sulfones, which provided 3‐(1‐arylsulfonylalkyl)indoles. The second reaction constitutes a switch in the regioselectivity. The extensions of theseC‐ andN‐aminoalkylations starting from pyrroles and 7‐azaindole have also been studied. Structurally diverse aminoalkylated indoles, pyrroles, and 7‐azaindoles were obtained with excellent yield in most of the cases.
Pathway‐Based Approaches for Sequencing‐Based Genome‐Wide Association Studies
Authors: Wu Guodong , Zhi Degui 
Published: May 2013

ABSTRACTFor analyzing complex trait association with sequencing data, most current studies test aggregated effects of variants in a gene or genomic region. Although gene‐based tests have insufficient power even for moderately sized samples, pathway‐based analyses combine information across multiple genes in biological pathways and may offer additional insight. However, most existing pathway association methods are originally designed for genome‐wide association studies, and are not comprehensively evaluated for sequencing data. Moreover, region‐based rare variant association methods, although potentially applicable to pathway‐based analysis by extending their region definition to gene sets, have never been rigorously tested. In the context of exome‐based studies, we use simulated and real datasets to evaluate pathway‐based association tests. Our simulation strategy adopts a genome‐wide genetic model that distributes total genetic effects hierarchically into pathways, genes, and individual variants, allowing the evaluation of pathway‐based methods with realistic quantifiable assumptions on the underlying genetic architectures. The results show that, although no single pathway‐based association method offers superior performance in all simulated scenarios, a modification of Gene Set Enrichment Analysis approach using statistics from single‐marker tests without gene‐level collapsing (weighted Kolmogrov‐Smirnov [WKS]‐Variant method) is consistently powerful. Interestingly, directly applying rare variant association tests (e.g., sequence kernel association test) to pathway analysis offers a similar power, but its results are sensitive to assumptions of genetic architecture. We applied pathway association analysis to an exome‐sequencing data of the chronic obstructive pulmonary disease, and found that the WKS‐Variant method confirms associated genes previously published.
Hybrid photoacoustic and ultrasound section imaging with optical ultrasound detection
Authors: Nuster Robert , Schmitner Nicole , Wurzinger Gerhild , Gratt Sibylle , Salvenmoser Willi , Meyer Dirk , Paltauf Guenther 
Published: May 2013

AbstractA setup is proposed that provides perfectly co‐registered photoacoustic (PA) and ultrasound (US) section images. Photoacoustic and ultrasound backscatter signals are generated by laser pulses coming from the same laser system, the latter by absorption of some of the laser energy on an optically absorbing target near the imaged object. By measuring both signals with the same optical detector, which is focused into the selected section by use of a cylindrical acoustic mirror, the information for both images is acquired simultaneously. Co‐registered PA and US images are obtained after applying the inverse Radon transform to the data, which are gathered while rotating the object relative to the detector. Phantom experiments demonstrate a resolution of 1.1 mm between the sections of both imaging modalities and a in‐plane resolution of about 60 µm and 120 µm for the US and PA modes, respectively. The complementary contrast mechanisms of the two modalities are shown by images of a zebrafish. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fundamental investigations in orientation control process for anisotropic laser ceramics
Authors: Sato Yoichi , Akiyama Jun , Taira Takunori 
Published: May 2013

AbstractWe present theoretical studies on the orientation control of micro‐domains in anisotropic laser ceramics. The direction of the crystal axis that is parallel to easy magnetization in each micro‐domain can be aligned along the direction of the applied magnetic field via two steps of fabrication processes. In the first step the alignment is performed during the slip‐casting under the magnetic field, where directions of primary particles are forced to align along the direction of easy magnetization. However, even though rare‐earth trivalent ions doped into primary particles as luminous ions enhance their magnetic moment, the perfect alignment control is not always possible due to Brownian fluctuations by slurry solvent at this stage. The further orientation control can be processed by the preferential grain growth, where an adequate orientation distribution of primary articles in the casted green body is required for the nearly perfect alignment in sintered ceramics. Therefore, it is important for further improvements of anisotropic laser ceramics to find the orientation distribution of primary particles in the slurry, which is determined by the ratio between the anisotropic magnetic potential and the thermal fluctuations. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fluorination of Al2O3 blocking layer for improving the performance of metal‐oxide‐nitride‐oxide‐silicon flash memory
Authors: Tao Qingbo , Lai P. T. 
Published: May 2013

AbstractThe characteristics of Al2O3 film grown by atomic‐layer deposition as blocking layer with and without fluorine plasma treatment were investigated based on a capacitor structure of Al/Al2O3/TaON/SiO2/Si. The physical structure was studied by transmission electron microscopy, and the chemical composition of the blocking layer was analyzed by X‐ray photoelectron spectroscopy and secondary ion mass spectroscopy. Moreover, the surface roughness of the blocking layer was investigated by atomic force microscopy. Compared with a capacitor with Al2O3 blocking layer, the one with fluorinated Al2O3 displayed higher programming/erasing speeds, better endurance property and better charge retention characteristic because the fluorination could reduce excess oxygen and traps in the blocking layer, thus forming a larger barrier height at the interface between the charge‐trapping layer and the blocking layer. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Graphene/Polyaniline/Poly(4‐styrenesulfonate) Hybrid Film with Uniform Surface Resistance and Its Flexible Dipole Tag Antenna Application
Authors: Shin Keun‐Young , Cho Sunghun , Jang Jyongsik 
Published: May 2013

AbstractA graphene/polyaniline/poly(4‐styrenesulfonate) (G/PANI/PSS)‐based conducting paste is successfully fabricated by introducing a PANI/PSS nanofiller into a multilayer graphene matrix by mechanical blending. As a compatibilizer, the PSS binder increases the dispersibility, interfacial interactions, and mechanical interlocking between the multilayer graphene matrix and PANI, thereby allowing surface resistance with narrow distribution. High concentrations of this PSS binder, obtained using ex situ polymerization, further improve the adhesion of the hybrid film to a flexible substrate. The minimum surface resistance of the screen‐printed G/PANI/PSS hybrid film is approximately 10 Ω sq−1 for a 70 μm uniform thickness. When bent to angles of −30°, the flexible hybrid film exhibits an approximately 6% decrease in surface resistance. The surface resistance after 500 bending cycles increases by only 10 Ω sq−1, which is 14 times that of smaller, graphene‐based thin films. The micropatterned, screen‐printed G/PANI/PSS hybrid film is evaluated as a practical dipole tag antenna. High‐resolution patterns are formed in the hybrid film by the inherently high surface tension and the properties of grains within the domain‐based structure. The G/PANI/PSS‐based dipole tag antenna has a bandwidth of 28.7 MHz, a high transmitted power efficiency of 98.5%, and a recognition distance of 0.42 m at a mean frequency of 910 MHz. These characteristics indicate that the G/PANI/PSS‐based dipole tag antenna could be used as a signal‐receiving apparatus, much like a radio‐frequency identification tag, for detecting nearby objects.
Acid Active Receptor‐Specific Peptide Ligand for In Vivo Tumor‐Targeted Delivery
Authors: Han Liang , Guo Yubo , Ma Haojun , He Xi , Kuang Yuyang , Zhang Ning , Lim Ed , Zhou Wenjiang , Jiang Chen 
Published: May 2013

AbstractTargeting therapy of tumors in their early stages is crucial to increase the survival rate of cancer patients. Currently most drug‐delivery systems target the neoplasia through the tumor‐associated receptors overexpressed on the cancer cell membrane. However, the expression of these receptors on normal cells and tissues is inevitable, which leads to unwanted accumulation and side effects. Characteristics of the tumor microenvironment, such as acidosis, are pervasive in almost all solid tumors and can be easily accessed. It is shown that the different extracellular pH value can be used to activate/inactivate the receptor‐mediated endocytosis on tumor/normal cells. This idea is implemented by conjugating a shielding molecule at the terminus of a receptor‐specific ligand via a pH‐sensitive hydrazone bond. The acid‐activated detachment of the shielding molecule and enhanced tumor/background accumulation ratio are demonstrated. These results suggest that acid active receptor‐specific peptide ligand‐modified tumor‐targeting delivery systems have potential use in the treatment of tumors.
High Density Unaggregated Au Nanoparticles on ZnO Nanorod Arrays Function as Efficient and Recyclable Photocatalysts for Environmental Purification
Authors: Yang Tung‐Han , Huang Li‐De , Harn Yeu‐Wei , Lin Chun‐Cheng , Chang Jan‐Kai , Wu Chih‐I. , Wu Jenn‐Ming 
Published: May 2013

AbstractPhotodegradation of organic pollutants in aqueous solution is a promising method for environmental purification. Photocatalysts capable of promoting this reaction are often composed of noble metal nanoparticles deposited on a semiconductor. Unfortunately, the separation of these semiconductor‐metal nanopowders from the treated water is very difficult and energy consumptive, so their usefulness in practical applications is limited. Here, a precisely controlled synthesis of a large‐scale and highly efficient photocatalyst composed of monolayered Au nanoparticles (AuNPs) chemically bound to vertically aligned ZnO nanorod arrays (ZNA) through a bifunctional surface molecular linker is demonstrated. Thioctic acid with sufficient steric stabilization is used as a molecular linker. High density unaggregated AuNPs bonding on entire surfaces of ZNA are successfully prepared on a conductive film/substrate, allowing easy recovery and reuse of the photocatalysts. Surprisingly, the ZNA‐AuNPs heterostructures exhibit a photodegradation rate 8.1 times higher than that recorded for the bare ZNA under UV irradiation. High density AuNPs, dispersed perfectly on the ZNA surfaces, significantly improve the separation of the photogenerated electron‐hole pairs, enlarge the reaction space, and consequently enhance the photocatalytic property for degradation of chemical pollutants. Photoelectron, photoluminescence and photoconductive measurements confirm the discussion on the charge carrier separation and photocatalytic experimental data. The demonstrated higher photodegradation rates demonstrated indicate that the ZNA‐AuNPs heterostructures are candidates for the next‐generation photocatalysts, replacing the conventional slurry photocatalysts.
Impact of blood pressure changes and course on hematoma growth in acute intracerebral hemorrhage
Authors: Rodriguez‐Luna D. , Piñeiro S. , Rubiera M. , Ribo M. , Coscojuela P. , Pagola J. , Flores A. , Muchada M. , Ibarra B. , Meler P. , Sanjuan E. , Hernandez‐Guillamon M. , Alvarez‐Sabin J. , Montaner J. , Molina C. A. 
Published: May 2013

Background and purposeAn association between high blood pressure (BP) in acute intracerebral hemorrhage (ICH) and hematoma growth (HG) has not been clearly demonstrated. Therefore, the impact of BP changes and course on HG and clinical outcome in patients with acute ICH was determined.MethodsIn total, 117 consecutive patients with acute (<6 h) supratentorial ICH underwent baseline and 24‐h CT scans, CT angiography for the detection of the spot sign and non‐invasive BP monitoring at 15‐min intervals over the first 24 h. Maximum and minimum BP, maximum BP increase and drop from baseline, and BP variability values from systolic BP (SBP), diastolic BP and mean arterial pressure (MAP) were calculated. SBP and MAP loads were defined as the proportion of readings >180 and >130 mmHg, respectively. HG (>33% or >6 ml), early neurological deterioration (END) and 3‐month mortality were recorded.ResultsBaseline BP variables were unrelated to either HG or clinical outcome. Conversely, SBP 180‐load independently predicted HG (odds ratio 1.05, 95% CI 1.010–1.097, P = 0.016), whilst both SBP 180‐load (odds ratio 1.04, 95% CI 1.001–1.076, P = 0.042) and SBP variability (odds ratio 1.2, 95% CI 1.047–1.380, P = 0.009) independently predicted END. Although none of the BP monitoring variables was associated with HG in the spot‐sign‐positive group, higher maximum BP increases from baseline and higher SBP and MAP loads were significantly related to HG in the spot‐sign‐negative group.ConclusionsIn patients with acute supratentorial ICH, SBP 180‐load independently predicts HG, whilst both SBP 180‐load and SBP variability predict END.
A survey of attitudes of glaucoma subspecialists in England and Wales to visual field test intervals in relation to NICE guidelines
Authors: Malik Rizwan , Baker Helen , Russell Richard A , Crabb David P 
Published: May 2013

ObjectivesTo establish the attitudes of glaucoma specialists to the frequency of visual field (VF) testing in the UK, using the NICE recommendations as a standard for ideal practice.DesignInterview and postal survey.SettingUK and Eire Glaucoma Society national meeting 2011 in Manchester, UK, with a second round of surveys administered by post.ParticipantsAll consultant glaucoma specialists in England and Wales were invited to complete the survey.Primary and secondary outcome measures(1) Compliance of assigned follow-up VF intervals with NICE guidelines for three hypothetical patient scenarios, with satisfactory treated intraocular pressure and (a) no evidence of VF progression; (b) evidence of VF progression and (c) uncertainty about VF progression, and respondents were asked to provide typical follow-up intervals representative of their practice; (2) attitudes to research recommendations for six VF in the first 2 years for newly diagnosed patients with glaucoma.Results70 glaucoma specialists completed the survey. For each of the clinical scenarios a, b and c, 14 (20%), 33 (47%) and 28 (40%) responses, respectively, fell outside the follow-up interval recommended by NICE. Nearly half of the specialists (46%) agreed that 6 VF tests in the first 2 years was ideal practice, while 16 (28%) said this was practice ‘not possible’, with many giving resources within the NHS setting as a limiting factor.ConclusionsThe results from this survey suggest that there is a large variation in attitudes to follow-up intervals for patients with glaucoma in the UK, with assigned intervals for VF testing which are, in many cases, inconsistent with the guidelines from NICE.
Access to medicines in Latin America and the Caribbean (LAC): a scoping study
Authors: Emmerick Isabel Cristina Martins , Oliveira Maria Auxiliadora , Luiza Vera Lucia , Azeredo Thiago Botelho , Bigdeli Maryam 
Published: May 2013

ObjectiveTo assess scientific publication and map research gaps on access to medicines (ATM) in Latin American and the Caribbean low-income and middle-income countries (LMIC).DesignScoping review. Two independent reviewers assessed studies for inclusion and extracted data from each study.Information sourcesSearch strategies were developed and the following databases were searched: MEDLINE, ISI, SCOPUS and Lilacs, from 2000 to 2010.Eligibility criteriaResearch articles and reviews published in English, Spanish and Portuguese were included. Studies including only high-income countries were excluded, as well as those carried out in very limited settings and discussion papers.ResultsThe 77 articles retained were categorised through consensus among the research team according to the level of the health system addressed, ATM domain and research issues covered. Publications on ATM have increased over time during the study period (r 0.93, p=0.00; R20.85). The top five countries covered were Brazil (68.8%), Mexico (15.6%), Colombia (11.7%), Argentina (10.4%) and Peru (10.4%). ‘Health services delivery’ and ‘patients, household and communities’ were the health system levels most frequently covered. The ATM domains ‘leadership and governance’, ‘sustainable financing, affordability and price of medicines’, ‘medicines selection and use’ and ‘availability of medicines’ were the top four explored. There are research gaps in important areas such as ‘human resources for health’, ‘global policies and human rights’, ‘production of medicines’ and ‘traditional medicine’.ConclusionsThe upward trend on scientific publication reflects a growing research capacity in the region, which is concentrated on research teams in selected countries. The gaps on research capacity could be overcome through research collaboration among countries. It is important to strengthen these collaborations, assuring that interests and needs from the LMIC are addressed and local capacity building is promoted.
Differences in drug utilisation between men and women: a cross-sectional analysis of all dispensed drugs in Sweden
Authors: Loikas Desirée , Wettermark Björn , von Euler Mia , Bergman Ulf , Schenck-Gustafsson Karin 
Published: May 2013

ObjectivesAscertain the extent of differences between men and women in dispensed drugs since there is a lack of comprehensive overviews on sex differences in the use of prescription drugs.DesignCross-sectional population database analysis.MethodsData on all dispensed drugs in 2010 to the entire Swedish population (9.3 million inhabitants) were obtained from the Swedish Prescribed Drug Register. All pharmacological groups with ambulatory care prescribing accounting for >75% of the total volume in Defined Daily Doses and a prevalence of >1% were included in the analysis. Crude and age-adjusted differences in prevalence and incidence were calculated as risk ratios (RRs) of women/men.ResultsIn all, 2.8 million men (59%) and 3.6 million women (76%) were dispensed at least one prescribed drug during 2010. Women were dispensed more drugs in all age groups except among children under the age of 10. The largest sex difference in prevalence in absolute numbers was found for antibiotics that were more common in women, 265.5 patients (PAT)/1000 women and 191.3 PAT/1000 men, respectively. This was followed by thyroid therapy (65.7 PAT/1000 women and 13.1 PAT/1000 men) and antidepressants (106.6 PAT/1000 women and 55.4 PAT/1000 men). Age-adjusted relative sex differences in prevalence were found in 48 of the 50 identified pharmacological groups. The pharmacological groups with the largest relative differences of dispensed drugs were systemic antimycotics (RR 6.6 CI 6.4 to 6.7), drugs for osteoporosis (RR 4.9 CI 4.9 to 5.0) and thyroid therapy (RR 4.5 CI 4.4 to 4.5), which were dispensed to women to a higher degree. Antigout agents (RR 0.4 CI 0.4 to 0.4), psychostimulants (RR 0.6 CI 0.6 to 0.6) and ACE inhibitors (RR 0.7 CI 0.7 to 0.7) were dispensed to men to a larger proportion.ConclusionsSubstantial differences in the prevalence and incidence of dispensed drugs were found between men and women. Some differences may be rational and desirable and related to differences between the sexes in the incidence or prevalence of disease or by biological differences. Other differences are more difficult to explain on medical grounds and may indicate unequal treatment.