bluuebunny/crossref_metadata_2025_split huggingface dataset:
QSPR Approach to Predict Nonadditive Properties of Mixtures. Application to Bubble Point Temperatures of Binary Mixtures of Liquids
Authors: Oprisiu I. , Varlamova E. , Muratov E. , Artemenko A. , Marcou G. , Polishchuk P. , Kuz'min V. , Varnek A. 
Published: July 2012

AbstractThis paper is devoted to the development of methodology for QSPR modeling of mixtures and its application to vapor/liquid equilibrium diagrams for bubble point temperatures of binary liquid mixtures. Two types of special mixture descriptors based on SiRMS and ISIDA approaches were developed. SiRMS‐based fragment descriptors involve atoms belonging to both components of the mixture, whereas the ISIDA fragments belong only to one of these components. The models were built on the data set containing the phase diagrams for 167 mixtures represented by different combinations of 67 pure liquids. Consensus models were developed using nonlinear Support Vector Machine (SVM), Associative Neural Networks (ASNN), and Random Forest (RF) approaches. For SVM and ASNN calculations, the ISIDA fragment descriptors were used, whereas Simplex descriptors were employed in RF models. The models have been validated using three different protocols: “Points out”, “Mixtures out” and “Compounds out”, based on the specific rules to form training/test sets in each fold of cross‐validation. A final validation of the models has been performed on an additional set of 94 mixtures represented by combinations of novel 34 compounds and modeling set chemicals with each other. The root mean squared error of predictions for new mixtures of already known liquids does not exceed 5.7 K, which outperforms COSMO‐RS models. Developed QSAR methodology can be applied to the modeling of any nonadditive property of binary mixtures (antiviral activities, drug formulation, etc.)
Photochemie im Kampf gegen Malaria
Authors: Kopetzki Daniel , Seeberger Peter H. 
Published: July 2012

AbstractArtemisinin, der zurzeit effektivste Wirkstoff gegen Malaria, ließ sich bisher nur aus Pflanzen extrahieren. Er könnte Millionen Menschen retten, gäbe es einen einfachen und kostengünstigen Zugang zu diesem komplexen Naturstoff. Dieses Ziel ist nun in greifbare Nähe gerückt.
Kältemittel entflammt Widerstand
Authors: Osterath Brigitte 
Published: July 2012

AbstractEine organische Fluorverbindung namens R1234yf soll in Zukunft das Kältemittel in allen europäischen Autoklimaanlagen sein. Doch Behörden und Umweltorganisationen warnen, die europäische Chemikalienagentur fordert weitere Tests, und die EU leitet zudem noch ein Kartellrechtsverfahren ein.
Rastersondenmethoden für Polymere und Biomoleküle
Authors: Berger Rüdiger , Gutmann Jochen , Schäfer Rolf 
Published: July 2012

AbstractUm weiche Materialien wie Biopolymere mit Rasterkraftmikroskopie zu untersuchen, sind die Methoden so anzupassen, dass die Sonde die Oberflächen nicht zerstört. Neben der Topografie erfasst die Rasterkraftmikroskopie weitere Informationen, beispielsweise lokale elektrische Eigenschaften und Bindungskräfte zwischen Molekülen.
Der Bachelor und die Industrie
Authors: Schmitz Karin 
Published: July 2012

AbstractWie kommen Unternehmen und Absolventen mit den Hochschulabschlüssen Bachelor und Master zurecht? In vielen größeren Unternehmen der Chemie‐ und Pharmabranche arbeiten Bachelors inzwischen erfolgreich. Allerdings sind sie meist FH‐Absolventen oder Absolventen eines dualen Studiengangs. Tätigkeitsfelder für Chemie‐Bachelors von den Universitäten gibt es in der Industrie es nicht.
Rapid Analysis of Volatile Components from Teucrium polium L. by Nanoporous Silica‐polyaniline Solid Phase Microextraction Fibre
Authors: Gholivand Mohammad Bagher , Piryaei Marzieh , Abolghasemi Mir Mahdi , Maassoumi Seyed Mohammad 
Published: July 2012

ABSTRACTIntroductionThe development of simple, rapid and solvent‐free methods for the analysis of essential oils is highly desirable. Microwave‐assisted headspace solid‐phase microextraction (MA‐HS‐SPME) is a new sampling and concentration technique for the extraction of volatile components in medicinal plants. The main advantages of this method are the reduction of extraction time and of organic solvent.ObjectiveA highly porous Santa Barbara amorphous (SBA‐15)/polyaniline material was prepared in order to produce a SPME fibre. The proposed fibre was evaluated for the extraction of the volatile component of Teucrium polium L.MethodologyA homemade MA‐HS‐SPME apparatus was used for the extraction of volatile components. Highly porous SBA‐15/polyaniline materials were prepared for SPME. The prepared nanomaterial was immobilized onto a stainless steel wire for fabrication of the SPME fibre.ResultsThe SBA‐15/polyaniline nanonporous fibre could adsorb volatile components of T. polium efficiently. In comparison with a HD method, the proposed technique could equally monitor almost all the components of the sample, but in an easier way that was rapid and required a much lower amount of sample.ConclusionThe experimental results showed that the nanoporous fibre was suitable for the semi‐quantitative study of the composition of essential oils in plant materials and monitoring the variations in the volatile components of the plants. Copyright © 2012 John Wiley & Sons, Ltd.
Preparation and characterization of polyvinylidene fluoride nanofibrous membranes by forcespinning™
Authors: Vazquez Beny , Vasquez Horacio , Lozano Karen 
Published: July 2012

AbstractNanofibers of polyvinylidene fluoride (PVDF) were prepared using solutions of PVDF with acetone and dimethylacetamide. The solutions were prepared at different concentrations (18, 21.5, and 25% wt) of PVDF. The nanofiber membranes were produced by using the Forcespinning™ method. Parameters such as the orifice size and spinneret angular velocity were varied. The produced membranes were characterized using scanning electron microscopy, differential scanning calorimetry, and X‐ray diffraction to determine the effect of varying parameters in the Forcespinning™ process on fiber diameter, bead formation, thermal stability, polymorphism, and morphology of the fibers and overall structure of the membrane. It was observed that polymer concentration played a key role in fiber and bead formation; at higher concentrations (such as 25 wt%), the fiber diameter increased but the bead formation decreased. The prepared composite membranes have potential applications on separators for Li‐ion batteries, ultra filtration membranes, and proton conductivity membranes for fuel cells applications. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers
Preparation and properties of heat curable blended methylfluorosilicone rubber
Authors: Liu Yuetao , Liu Hongzhi , Zhang Rong , Zhou Chuanjian , Feng Shengyu 
Published: July 2012

AbstractHeat curable blended methylfluorosilicone rubber (MFSR) was prepared by combination of methylsilicone rubber (MSR) and fluorosilicone rubber (FSR). 2,5‐Bis(tert‐butylperoxy)‐2,5‐dimethylhexane (DBPMH) was chosen as a curing agent. Poly(methylsiloxane‐co‐fluorosiloxane) with low molecular weight was used as an interfacial agent. Curing characteristics, mechanical properties, low temperature performance, and hot oil resistance of blended MFSR was studied in details. The results showed that MSR and FSR could reach co‐vulcanization by DBPMH in blended MFSR. Higher FSR content could improve the scorch safety, lower the rate of curing reaction, and lead to the poor processability of blended MFSR. An increase of FSR content also improved the hot oil resistance of blended MFSR. Interfacial agent could limit the phase separation of MSR and FSR, make the blended system more thermodynamically stable and elevate the mechanical properties of blended MFSR. Differential scanning calorimetry (DSC) measurements revealed that increasing MSR content lowered the glass transition temperature (Tg) and improved the low‐temperature flexibility of blended MFSR when MSR was no more than 15%. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers
Surface‐modified talc particles by acetoxy groups grafting: Effects on mechanical properties of polypropylene/talc composites
Authors: Castillo Luciana A. , Barbosa Silvia E. , Capiati Numa J. 
Published: July 2012

AbstractThis article deals with the effects of surface‐modified talc particles on mechanical properties of polypropylene (PP)/talc composites. These materials were prepared by injection molding of PP blended with different concentrations of nontreated and treated talc, under the same processing conditions. Differential thermal calorimetry and scanning electron microscopy were used to assess thermal properties and morphology of the final composites. The reinforcing effect of talc, either treated or nontreated surface, on PP is analyzed through the tensile properties as a function of the mineral content (0–10 wt%). Morphological structure of composites revealed that the talc treatment improved the particle dispersion and distribution within the PP matrix and enhanced the interfacial PP‐talc adhesion. The mechanical properties of these composites, especially the Young modulus, tensile strength and elongation at break, were found to be improved respect to PP‐untreated talc ones. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers
Plasma Processing: Technology for the Batch Fabrication of Carbon Nanotube Film Electrodes for Biointerfaces
Authors: Kim Joon Hyub , Lee Myung Jin , Park Eun Jin , Lee Jun‐Yong , Lee Cheol Jin , Min Nam Ki 
Published: July 2012

AbstractWe review our research activity on the use of plasma processes for the batch fabrication of miniaturized single‐walled carbon nanotube (SWCNT) electrodes and their application to electrochemical biosensors. The SWCNT film was spray‐deposited onto a Pt support and exhibited excellent adhesion to the electrode. O2‐plasma patterning and subsequent activation of the deposited films realized efficient biointerfaces between SWCNTs and biomolecules. The film was integrated into miniaturized electrode systems for biosensor applications. The benefits of this new batch‐fabrication technology were demonstrated by the design and fabrication of integrated SWCNT three‐electrode systems on glass substrates. These systems had an effective area about six times that of untreated SWCNT, consistent with a significant increase in the peak current. Finally, the effectiveness of plasma‐processed SWCNT electrodes as biointerfaces was examined by detecting long target DNA sequences. magnified image
Frontiers in pulmonary hypertension in infants and children with bronchopulmonary dysplasia
Authors: Collaco Joseph M. , Romer Lewis H. , Stuart Bridget D. , Coulson John D. , Everett Allen D. , Lawson Edward E. , Brenner Joel I. , Brown Anna T. , Nies Melanie K. , Sekar Priya , Nogee Lawrence M. , McGrath‐Morrow Sharon A. 
Published: July 2012

AbstractPulmonary hypertension (PH) is an increasingly recognized complication of premature birth and bronchopulmonary dysplasia (BPD), and is associated with increased morbidity and mortality. Extreme phenotypic variability exists among preterm infants of similar gestational ages, making it difficult to predict which infants are at increased risk for developing PH. Intrauterine growth retardation or drug exposures, postnatal therapy with prolonged positive pressure ventilation, cardiovascular shunts, poor postnatal lung and somatic growth, and genetic or epigenetic factors may all contribute to the development of PH in preterm infants with BPD. In addition to the variability of severity of PH, there is also qualitative variability seen in PH, such as the variable responses to vasoactive medications.To reduce the morbidity and mortality associated with PH, a multi‐pronged approach is needed. First, improved screening for and increased recognition of PH may allow for earlier treatment and better clinical outcomes. Second, identification of both prenatal and postnatal risk factors for the development of PH may allow targeting of therapy and resources for those at highest risk. Third, understanding the pathophysiology of the preterm pulmonary vascular bed may help improve outcomes through recognizing pathways that are dysregulated in PH, identifying novel biomarkers, and testing novel treatments. Finally, the recognition of conditions and exposures that may exacerbate or lead to recurrent PH is needed to help with developing treatment guidelines and preventative strategies that can be used to reduce the burden of disease. Pediatr Pulmonol. 2012. 47:1042–1053. © 2012 Wiley Periodicals, Inc.
Neonatal non‐invasive respiratory support: Physiological implications
Authors: Shaffer Thomas H. , Alapati Deepthi , Greenspan Jay S. , Wolfson Marla R. 
Published: July 2012

AbstractThe introduction of assisted ventilation for neonatal pulmonary insufficiency has resulted in the successful treatment of many previously fatal diseases. During the past three decades, refinement of invasive mechanical ventilation techniques has dramatically improved survival of many high‐risk neonates. However, as with many advances in medicine, while mortality has been reduced, morbidity has increased in the surviving high‐risk neonate. In this regard, introduction of assisted ventilation has been associated with chronic lung injury, also known as bronchopulmonary dysplasia. This disease, unknown prior to the appearance of mechanical ventilation, has produced a population of patients characterized by ventilator or oxygen dependence with serious accompanying pulmonary and neurodevelopmental morbidity. The purpose of this article is to review non‐invasive respiratory support methodologies to address the physiologic mechanisms by which these methods may prevent the pathophysiologic effects of invasive mechanical ventilation. Pediatr Pulmonol. 2012. 47:837–847. © 2012 Wiley Periodicals, Inc.
Optimization of designed armadillo repeat proteins by molecular dynamics simulations and NMR spectroscopy
Authors: Alfarano Pietro , Varadamsetty Gautham , Ewald Christina , Parmeggiani Fabio , Pellarin Riccardo , Zerbe Oliver , Plückthun Andreas , Caflisch Amedeo 
Published: July 2012

AbstractA multidisciplinary approach based on molecular dynamics (MD) simulations using homology models, NMR spectroscopy, and a variety of biophysical techniques was used to efficiently improve the thermodynamic stability of armadillo repeat proteins (ArmRPs). ArmRPs can form the basis of modular peptide recognition and the ArmRP version on which synthetic libraries are based must be as stable as possible. The 42‐residue internal Arm repeats had been designed previously using a sequence‐consensus method. Heteronuclear NMR revealed unfavorable interactions present at neutral but absent at high pH. Two lysines per repeat were involved in repulsive interactions, and stability was increased by mutating both to glutamine. Five point mutations in the capping repeats were suggested by the analysis of positional fluctuations and configurational entropy along multiple MD simulations. The most stabilizing single C‐cap mutation Q240L was inferred from explicit solvent MD simulations, in which water penetrated the ArmRP. All mutants were characterized by temperature‐ and denaturant‐unfolding studies and the improved mutants were established as monomeric species with cooperative folding and increased stability against heat and denaturant. Importantly, the mutations tested resulted in a cumulative decrease of flexibility of the folded state in silico and a cumulative increase of thermodynamic stability in vitro. The final construct has a melting temperature of about 85°C, 14.5° higher than the starting sequence. This work indicates that in silico studies in combination with heteronuclear NMR and other biophysical tools may provide a basis for successfully selecting mutations that rapidly improve biophysical properties of the target proteins.
Time‐resolved spectroscopy of carrier dynamics in graded ZnCdx O multilayer structures
Authors: Trunk Mareike , Venkatachalapathy Vishnukanthan , Zhang Tianchong , Azarov Alexander , Galeckas Augustinas , Kuznetsov Andrej Yu. 
Published: July 2012

AbstractWe report on time‐resolved photoluminescence studies of charge carrier dynamics in graded bandgap ZnCdxO (x=0‐60%) multilayers. Analysis of the spectral peak position and intensity under different excitation intensities and temperatures suggest excitonic origin of emission components forming a characteristic plateau in the region from 3.3 eV to 2.5 eV. The carrier recombination processes in ZnCdO alloys are found to be multi‐exponential with characteristic time constants spread from sub‐ nanosecond to microsecond time domains. Temperature dependencies of the radiative and non‐radiative recombination lifetime parameters have been extracted providing further evidence for the excitonic nature of the emission. Carrier dynamics in single and multilayer structures is compared and discussed in terms of surface and interface recombination also taking into account different photo‐generation profiles and their role in subsequent drift and diffusion processes. Generally lower lifetime and quantum efficiency parameters observed in multilayers suggest detrimental role of the interfaces in carrier relaxation process (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Temperature quenching of PL intensity and mechanisms of carrier recombination in CdTe/ZnTe self‐assembled quantum dots
Authors: Reznitsky Alexander , Klochikhin Albert , Permogorov Sergei 
Published: July 2012

AbstractWe have studied the temperature dependence of the photoluminescence (PL) intensity of nano‐size heterostructures ZnTe/CdTe/ZnTe containing self‐organized CdTe quantum dots (QDs) in temperature range 5‐250 K at different intensities of optical excitation. It has been found that the temperature quenching of PL intensity is governed by thermal activation of electrons and holes to the centers of non‐radiative recombination.These two processes should be considered as independent which leads to the two‐exponential character of the thermal decay curves. The character of temperature quenching of PL intensity strongly depends on the pumping power. The higher is the excitation power, the slower is the temperature decay of the PL intensity. We attribute the observed effect to the saturation of the centers of non‐radiative recombination for electrons or holes in the barrier regions of heterostructures. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The Internal Pressure Test in Experiment and Simulation—Influence of the Wall Thickness Variation and the Change of the Packaging Behavior after the Impact of Standard Liquids
Authors: Menrad Andreas , Goedecke Thomas , Gruender Klaus‐Peter , Wagner Manfred H. 
Published: July 2012

The effect of the wall thickness variation of blow‐moulded bodies made of high‐density polyethylene on an internal pressure test after prestoring the packaging with standard liquids was evaluated in experiments and simulations. The objects of the investigation were jerrycans used for the transportation and storage of dangerous goods.The wall thickness was determined using two alternative methods to the magnetostatic measurement. These alternative methods are used for research purpose to get a volumetric model of the jerrycan wall as a geometric model for the simulation. The comparison of the experiments and the simulations of the internal pressure test were performed using the digital image correlation method. The integral strain and deformation of the whole jerrycan was detected by measuring the total mass of the jerrycan being filled with water during the internal pressure test. This is a suitable alternative to the optical measurements of local deformation by the digital image correlation method. Prestorage at 40 °C without the influence of chemicals strengthens the jerrycan, whereas the swelling effect of butyl acetate and hydrocarbon mixture softens the jerrycan. The comparison with the experiment is necessary to verify the accuracy of the simulation. It shows that the deformation can be simulated more precisely by using the actual measured geometry. The weakening of the high‐density polyethylene caused by a hydrocarbon mixture can be simulated using the Arrhenius equation. The aim of the simulation was to discover whether it is possible to use specimens to predict the behaviour of a packaging both after the influence of standard liquids. Copyright © 2012 John Wiley & Sons, Ltd.
High Payload Dual Therapeutic‐Imaging Nanocarriers for Triggered Tumor Delivery
Authors: Kim Jin‐Ki , Yuan Hong , Nie Jingxin , Yang Yu‐Tsai , Leggas Markos , Potter Philip M. , Rinehart John , Jay Michael , Lu Xiuling 
Published: July 2012

AbstractThe in vitro and in vivo characterization of an optimized formulation of nanoparticles (NPs) loaded with a high content of dexamethasone palmitate (DEX‐P), a chemotherapeutic adjuvant that decreases interstitial fluid pressure in tumors, and 111In, a signaling agent, is described. These NPs are uniform in size and composition. Single photon emission computed tomography imaging demonstrates significant tumor uptake of 111In‐labeled DEX‐P NPs in tumor‐bearing mice. As with many nanoparticle‐based drug delivery systems, significant liver accumulation is observed. Assessment of liver histology and blood tests show no apparent hepatic or renal toxicity of the DEX‐P NPs. Conversion of DEX‐P to DEX occurs when DEX‐P NPs are incubated with mouse plasma, human tumor homogenate and ascites from tumor bearing mice, but not with human plasma. This conversion is slower in plasma from Es1e(‐/‐)/SCID mice, a potential alternative animal model that better mimics humans; however, plasma from these mice are not completely devoid of esterase activity. The difference between blood and tumor esterase activity in humans facilitates the delivery of DEX‐P NPs to tumors and the release of dexamethasone by an esterase trigger.
Superparamagnetic Iron Oxide Nanoparticles (SPION) for the Treatment of Antibiotic‐Resistant Biofilms
Authors: Taylor Erik N. , Kummer Kim M. , Durmus Naside Gozde , Leuba Kohana , Tarquinio Keiko M. , Webster Thomas J. 
Published: July 2012

AbstractBacterial infections caused by antibiotic‐resistant strains are of deep concern due to an increasing prevalence, and are a major cause of morbidity in the United States of America. In particular, medical device failures, and thus human lives, are greatly impacted by infections, where the treatments required are further complicated by the tendency of pathogenic bacteria, such as Staphylococcus aureus, to produce antibiotic resistant biofilms. In this study, a panel of relevant antibiotics used clinically including penicillin, oxacillin, gentamicin, streptomycin, and vancomycin are tested, and although antibiotics are effective against free‐floating planktonic S. aureus, either no change in biofilm function is observed, or, more frequently, biofilm function is enhanced. As an alternative, superparamagnetic iron oxide nanoparticles (SPION) are synthesized through a two‐step process with dimercaptosuccinic acid as a chelator, followed by the conjugation of metals including iron, zinc, and silver; thus, the antibacterial properties of the metals are coupled to the superparamagnetic properties of SPION. SPION might be the ideal antibacterial treatment, with a superior ability to decrease multiple bacterial functions, target infections in a magnetic field, and had activity better than antibiotics or metal salts alone, as is required for the treatment of medical device infections for which no treatment exists today.