bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of star hydrophobically-modified acrylamide copolymers and its some properties in brine
Authors: Duan Ming , Fang Shenwen , Zhang Liehui
Published: August 2014

Star copolymers of acrylamide (AM) and N,N-dimethyl-Nvinylnonadecan- 1- aminium chloride (C18DMAAC) were synthesized by photopolymerization in water. Some properties of these star hydrophobically modified acrylamide copolymers (SHMPAM) with different C18DMAAC contents and the linear hydrophobically modified acrylamide copolymers (LHMPAM) in brine were characterized. The increase in C18DMAAC content resulted in decreased intrinsic viscosity and increased Huggins constant for SHMPAM. Similar results were observed for LHMPAM. With similar intrinsic viscosity and C18DMAAC content, the Huggins constant of SHMPAM was much higher than that of LHMPAM, which might be due to the fact that SHMPAM had much stronger intramolecular interaction in dilute polymer solutions. In semi-dilute solutions, the apparent viscosity of SHMPAM was increased with increasing C18DMAAC content, which was similar to that of LHMPAM. However SHMPAM exhibited higher apparent viscosity than LHMPAM because it had more arms and thus had more chances to form three-dimensional networks in semi-dilute solutions. In the flowinduced scission experiment, SHMPAM exhibited superior shear stability in comparison with LHMPAM. When the extensional shear rate was ≈ 40000 s-1, the reduction ratios of the apparent viscosities of the four SHMPAMs after the scission were about 80%. In contrast, when the extensional shear rate was ≈20000 s-1, the reduction ratio of the apparent viscosity of LHMPAM-0.40 had already reached around 80%.
Swelling studies and adsorption of safranin T by acrylamide/maleic acid/methylene-bis-acrylamide based hydrogels
Authors: Velásquez Cristóbal Lárez , Ramírez Marvelis , Millán Enrique , Medina Arelis
Published: August 2014

Swelling studies of an acrylamide/maleic acid/methylene-bis-acrylamidebased hydrogel prepared by free radical polymerization (weight ratio of 90/10/3) are presented. Water penetration mechanism was studied by using two classical definitions, i.e., Crank (FC = Wt/Weq) and Karadag (FK = (Wt-Wo)/Wo), of the water fraction into the hydrogel (F). An anomalous water penetration mechanism (0.5<n<1.0) was obtained by employing both definitions and Buckley equation (F = ktn); however, using the combined Peppas and Sahlin equation (F = k1t1/2 + k2t) pointing out that swelling occurs in two stages: at first controlled by diffusion and relaxation contributions and then defined mainly by the diffusion contribution. Hydrogel was also studied as a system for the adsorption of cationic dye Safranin. Results show that this system perfectly fit to a Langmuir isotherm and the dye adsorption process stops when coverage of all active sites on the hydrogel has been achieved. Interestingly, adsorption process does not seem to be affected even though the hydrogel concurrently suffers the well known collapse phenomenon.
Enhanced copper-catalyzed “click” reaction between homopolymers with terminal azide and alkyne groups in the presence of water
Authors: Liu Zhilei , He Guping , Hu Jiwen , Sun Jianping , Liu Guojun , Li Yinhui , Xiao Dingshu , Tu Yuanyuan
Published: August 2014

We report here that the efficiency of the click chemistry between the terminal azide and alkyne groups of different polymer chains could be drastically increased with the addition of an optimum amount of water into a reaction system. That is, the efficiency was only slightly promoted by the addition of a small amount of water into the reaction mixture. However, the reaction efficiency was increased dramatically near the water volume fraction to lead the reaction mixture into nanosized phase separation. Further increasing in water content caused the polymer(s) to undergo macroscopic phase separation and the click reaction efficiency was decreased once again. The enhanced efficiency of click coupling reaction including conversion and rate was also demonstrated via in-situ 1H-NMR. The reaction kinetics as well as reaction rate constant for these reaction system with typical water content were also evaluated. This finding on enhanced click reaction is of practical value, because click reactions in polymer synthesis are generally more difficult to be carried out and proceed relative slowly at low yield in most case because of the strong steric hindrance effect from “large and long” polymer chains, as compared to “click” reactions which are employed for preparation of the low molecular weight organic compounds.
The effect of P-chiral center on helical conformation of optically active N-propargylphosphonamidates
Authors: Lu Lihua , Mo Jiaoli , Yang Qiang , Zhang Liqun , Wang Weimin , Yue Dongmei
Published: August 2014

Novel chiral and achiral N-propargylphosphonamidate monomers [HC=CCH2NH(P=O)R1R2,where 1: R1=CH3,R2=NHC(CH3)32: R1=CH3,R2 =NHC5H93:R1=OPh,R2=NHC(CH3)3, 4:R1=R2=OPh] were synthesized by successive condensation in order to study the helical conformation properties of N-phosphonamidates. One diastereomer was successfully separated from the other in the cases of monomer 1-3(named 1a-3a) according to the single peak in the 31P NMR spectra. Polymerizations of the monomers 1-4 were carried out with (nbd)Rh+[η6-C6H5B-(C6H5)3] as catalyst in CHCl3 yielding the polymers with number-average molecular weights of 1300-22400. Poly(1a)-poly(3a) and poly(4) were characterized by UV and CD spectroscopy. Poly(1a)- poly(3a) showed an intense positive CD signal at 325 nm based on the conjugated polyacetylene backbone while poly(4) showed no peak there, indicating that the polymers had a helical structure with predominantly one-handed screw sense because of P-chiral centre sole contribution.
Synthesis and characterization of poly(St-co-DVB)/montmorillonite nanocomposites by suspension polymerization
Authors: Ji Jiaming , Cao KeSheng , Tang Hua , Li ChangSheng
Published: August 2014

Poly(styrene-co-divinylbenzene)/organic montmorillonite (OMMT) nanocomposites were prepared by suspension polymerization. OMMT was prepared by ion exchange method between sodium montmorillonite (SMMT) and cetyltrimethyl ammonium bromide (CTAB) in an aqueous solution. The character and structure of OMMT was revealed by XRD and FT-IR. The microstructure of polymer/OMMT nanocomposites was characterized by XRD, TEM and SEM. The thermal stability of polymer/OMMT nanocomposites was studied by TG and DTG. Also the effect of the amount of OMMT and divinylbenzene (DVB) on the thermal stability of polymer/OMMT nanocomposites has been discussed in this paper. It was observed that the crosslinked polymer/clay nanocomposites exhibited better thermal stability than pure polystyrene and polystyrene/clay nanocomposites under the experimental conditions.
Preparation of poly(methyl methacrylate) nano-latexes via UV irradiation in the presence of iron aqueous solution
Authors: Zhang Hong , Zang Limin , Luo Jiahe , Guo Jinshan
Published: August 2014

The UV-initiated emulsion polymerization of methyl methacrylate (MMA) in the presence of FeCl3 was studied. The photopolymerization presented high efficiency even though using a small percentage of photoinitiator. The entire polymerization could be performed within 10 min and displayed a conversion higher than 90% at ambient temperature. The particle sizes could be tuned in the range of 20-90 nm. The effects of content of initiator and emulsifying agent upon the reaction conversion, distribution of molecular weight, diameter of particles and glass-transition temperature were examined. 1H-NMR technique was used to investigate the structural properties of PMMA.
Synthesis, characterization of pyridine-based polyimides and their use as glucose oxidase immobilization media
Authors: Paşahan Aziz , Köytepe Süleyman , Ekinci Ergun
Published: August 2014

A novel diamine monomer, containing 2,6-diaminopyridine, bis-pdimethylaminophenyl- 2,6-pyridine (S26DAP), was prepared from 4- (dimethylamino)benzaldehyde and 2,6-diaminopyridine. The monomer was characterized by FT-IR, NMR and elemental analyzer. The monomer was then utilized to prepare polyimides with dianhydrides such as pyromellitic dianhydride (PMDA), 3,3’,4,4’-benzophenonetetracarboxylic dianhyride (BPDA), 4,4’- oxydiphthalic anhydride (ODPA) and 3,3’,4,4’-biphenyltetracarboxylic dianhydride (BTDA) by the one-step method; synthesis of polyimides, followed by thermal imidization. The polyimides were characterized by FT-IR, GPC with intrinsic viscosity and adhesive properties also being evaluated. The polyimides exhibited high Tg (°C) (186-209 °C), good thermal stability and good adhesive properties. Medium to high molecular weight polymers were attained, with inherent viscosities near or higher than 1.05-1.32 dL/g, the solubility in dipolar aprotic solvents of the polyimides were much better than that of the aromatic polyimides. Furthermore, chemically synthesized polyimides were used for immobilization of glucose oxidase (GOx). The amperometric responses of the prepared GOx-polyimide-coated electrodes to glucose were examined at a potential of 0.7 V in PBS solution by means of TB technique. The results show that polyimide (S26DAP-PI-4) can be used for immobilization of glucose oxidase.
A comparative study of the reactivity of three plant oil methyl esters with divinylbenzene by FTIR spectroscopy
Authors: Jin Fuqiang , Wang Bo , Hu Suqin , Wang Jianmei , Cai Feipeng , Yang Gai
Published: August 2014

Poly(divinylbenzene) microspheres were prepared by seed swelling polymerization of divinylbenzene in the presence of tung oil methyl esters, linseed oil methyl esters and soybean oil methyl esters, respectively. FTIR spectroscopy was used to characterize the polymers for investigating the reactivity of the three plant oil methyl esters. Results showed that tung oil methyl esters had strongest reactivity with divinylbenzene, and soybean oil methyl esters had weakest reactivity of the three oil methyl esters in the polymerization. These results were related with the fatty acid compositions of the oils.
UV-Curable organic-inorganic hybrid films based on tetraethylorthosilicate oligomer and special acrylated polyester
Authors: He Jianyun , Xiong Jinping , Xia Bingqian
Published: August 2014

Organic-inorganic hybrid films were prepared using tetraethylorthosilicate (TEOS) oligomer and special acrylated polyester (SAP) via a UV-curing process. TEOS oligomers were prepared in the presence of water and ethanol using hydrochloric acid as the catalyst and characterized using 1H NMR, 29Si NMR and MALDI-TOF mass spectra. Special acrylated polyester was synthesized by 1,4-cyclohexane dimethanol, neopentyl glycol, 1,4-butanediol, maleic anhydride, adipic acid, and acrylic acid. Hybrid films were cured by UV light and the thermal properties, dynamic mechanical properties, and tensile properties of the hybrid films were evaluated as the function of TEOS oligomer content. The morphology of the hybrid films was examined using atomic force microscopy (AFM). The microscopy and dynamic mechanical data indicated that the hybrid films were heterogeneous materials with various inorganic particle sizes dispersed within the organic matrix. The results indicated that after incorporating the TEOS oligomer, the strength and thermal stability of the hybrid films were enhanced.
Observation of oxygen inhibited layer of organic dental resin by confocal Raman-microscopy
Authors: Robin Jean Baptiste , Durand Jean Cédric , Derely Loic , Jacquot Bruno , Cuisinier Frédéric , Robin Jean-Jacques
Published: August 2014

This study investigated degrees of conversion of oxygen inhibited layer (OIL) of organic dental resins for restoration using Confocal-Raman spectroscopy. The aim was to determine which laser is adapted to determine the degrees of conversion of OIL and to measure variations of thickness and degrees of conversion in OIL with respect to monomers proportions. Bis-GMA (bis-phenol A glycidyl dimethacrylate) and TEGDMA (triethylene glycol dimethacrylate) based resins with various ratio of an equimolecular mixture of camphorquinone/EDMAB (ethyl (4-dimethyl amino) benzoate) were studied with different lasers by confocal- Raman spectroscopy. Results show that this technique is adapted for the non destructive measurement of OIL. The Thickness of OIL is not correlated with the proportions of Bis-GMA and TEGDMA in the resin and was close to 3-4μm. Thickness of OIL is very thin without inorganic fillers (3 or 4 μm). Inorganic fillers might be responsible of greater OIL in composite resins.
Monte Carlo simulation of chromatin fibre confined in a nanochannel
Authors: Cao Qianqian , Zuo Chuncheng , Ma Yanhong , Li Lujuan
Published: August 2014

We study 30-nm chromatin fibre restricted in a nanofluidic channel with square cross-section using Monte Carlo (MC) simulations. The chromatin fibre is modelled as cylinders-on-a-string with six alterable angles. The effects of the channel width and Emax on the configuration of the chromatin fibre are investigated in detail. Our results show that the channel width has a considerable influence on conformational characteristics of the chain. It is found that at large Emax, the chromatin fibre undergoes a conformational transition from stretched state to coiled state with increasing the channel width. Additionally, the influence of the channel width is lowered with enhancing Emax. At small values of the channel width, the chains for different Emax exhibit a similar structure, namely, a stretched conformation
Effects of nanoparticles in cells infected by Toxoplasma gondii
Authors: Leyke Silja , Köhler-Sokolowska Wanda , Paulke Bernd-Reiner , Presber Wolfgang
Published: August 2014

Core-shell model drug carriers on 2 nanoscale size levels have been applied in cell culture studies, focused on Toxoplasmosis therapy. In synthesis, a seed of Rhodamin B-labelled polystyrene latex particles was coated by polybutyl cyanoacrylate under physical inclusion of 2 different, new drugs against Toxoplasmosis. Drug-loaded as well as drug-free core-shell model drug carriers were added to a cell culture of human macrophages, infected by Toxoplasma gondii, following an infection plan. Drug release from the carriers had been studied before by enzymatic degradation by means of pork liver esterase. Particle size decrease by degradation was investigated in a UV/VIS spectrometer via transmission measurements. Drug release profiles were obtained by HPLC studies. The dynamics in the population of infected human macrophages, Toxoplasma gondii as well as model drug carrier numbers were registered by a FACS (fluorescence-activated cell sorter). As main result, the drug-free references in the 2 series of core-shell model drug carriers achieved ca.85% of the observed maximum in Toxoplasmosis therapy efficiency. These data were correlated with an immune stimulant effect on the side of the human macrophages, caused by the cell uptake of colloidal substrate, foreign to the body.
Investigation of the surface properties of POSS-modified polyacrylate by inverse gas chromatography
Authors: Zou Qi-chao , Yu Huan , Chen Hao
Published: August 2014

The surface properties of poly(methyl methacryl-ate-co-n-butyl methacrylate-co-cyclopentyl methacryloxy propyl-polyhedral oligomeric silsesquioxane) (poly(MMA-co -BMA-co-POSSMA)) were studied by means of inverse gas chromatography (IGC) using 10 non-polar and polar solvents as the probes. Thermodynamic parameters of adsorption, such as the dispersive component of the surface energy, the specific interaction contribution to the free energy of adsorption and the acid/base constants of polymer surface were determined. It was found that incorporation of POSSMA into polymer resulted in increasing interactions between polymers and solvents, dispersive component of surface free energy of polymer and acidity of the surfaces of the polymers. The more the POSSMA were embedded, the larger the dispersive component of the surface free energy was, and the acidic character of the polymer surface was more obvious.
Preparation of new FI-type catalyst for polymerization of ethylene
Authors: Sandaroos Reza , Damavandi Saman , Goldani Mohammad Taghi
Published: August 2014

A new FI-type Zr-based catalyst of bis[N-(3,5-dicumylsalicylidene)- anthracylaminato]zirconium(IV) dichloride was found to display a moderate ethylene polymerization activity of 42×104 g PE/mmol Zr. h with a viscosity average molecular weight (Mv) of 56×104 at the monomer pressure of 4 bars and temperature of 30 °C. HOMO (the highest occupied molecular orbital) and LUMO (the lowest unoccupied molecular orbital) energy level of the anionic phenoxyimine ligands, were calculated using HF/6-31G method. Plurality of the fused aromatic rings on the catalyst structure decreased the energy gap between the HOMO and LUMO, but could not increase the activity. The highest activity of the catalyst was obtained at about 30 °C following a sharp decrease at higher temperature. The catalyst showed the high activity at about [Al]:[Zr]=80000:1 molar ratio and further addition did not affect the activity of the catalyst. Experimental results revealed that low HOMO energy level is not a necessity to reach high activity of the catalyst. Despite low HOMO energy level, the prepared catalyst displayed moderate polymerization activity. Either the activity of the catalyst or the viscosity average molecular weight of the obtained polymer was affected by the hydrogen concentration slightly. However, activity of the catalyst showed higher sensitivity to amount of hydrogen and increased with increasing the hydrogen concentration. Higher monomer pressure increased productivity, crystallinity and the Mv values of the resulting polymer. Some specification of the obtained polymer was studied.
Biomedical applications of electrically conductive polymeric systems
Authors: Jagur-Grodzinski Joseph
Published: August 2014

Properties of the electrically conductive polymers (ECPs) enable introduction of several novel applications in various fields, among others, as biomedical materials. Their use as scaffolds for tissue engineering and recovery of damaged neural tissues is especially advantageous. They may also be used for the electrically induced drug release and delivery, and as very sensitive biosensors for clinical applications. Another use is the detection and precision of the biologically important chemical materials. They have been shown to modulate and accelerate activities of the nerve, skeletal, muscle, and bone cells. Cell growth, migration and adhesion, may be stimulated by applying electric potential. Synthesis of DNA, secretion of proteins, and transformations of stem cells may be enhanced. Clinical analysis using ECP-based biosensors make possible the precise determination of the exact composition of individual DNA molecules, and thus enable early detection and treatment of genetically related diseases. Electrochemical (EC) approach of ECP-sensors enables precise determination of concentrations of several biologically important chemicals.
Organoclay/thermotropic liquid crystalline polymer nanocomposites. Part I: Effects of concentration on morphology, liquid crystallinity and thermal properties
Authors: Tang Youhong , Gao Ping , Ye Lin , Zhao Chengbi , Lin Wei
Published: August 2014

Thermotropic liquid crystalline polymer (TLCP) nanocomposites with different organoclay contents were prepared by a method combining ultrasonication, centrifugation and solution casting methods. The effects of organoclay concentration on morphology, liquid crystallinity and thermal properties of nanocomposites were characterized. Molecular level interactions existed in nanocomposites. With a small amount of organoclay (nominal 3.0 wt %), it was enough to change TLCP properties with enhanced thermal stability though with a small negative effect on liquid crystallinity. When high concentration organoclay was added, thermal stability decreased and liquid crystallinity lost with shearinduced phase separation occurrence.
Condensation between guanidine hydrochloride and diamine/multi-amine and its influence on the structures and antibacterial activity of oligoguanidines
Authors: Wei Dafu , Guan Yong , Ma Qiangxiang , Zhang Xi , Teng Zheng , Jiang Hua , Zheng Anna
Published: August 2014

The polycondensation of guanidine hydrochloride and diamine leads to various types of oligoguanidines, including linear and branched/cyclic types, which constitutes the mixture of oligoguanidines exhibiting efficient biocidal activities. In the present work, a series of polyhexamethylene guanidine hydrochloride (PHMG) were prepared by varying the mole ratio of hexamethylenediamine to guanidine hydrochloride and the reaction conditions, and their antibacterial activities were investigated. The contents of linear and branched/cyclic types in the mixture varied with different reaction conditions, and more branched/cyclic types led to more efficient antibacterial activity. Other oligoguanidines PDMG and PMXMG were synthesized using guanidine hydrochloride and decamethylenediamine and 1,3- benzenedimethanamine, respectively. Their chemical structures were similar to PHMG’s while the antibacterial activities were slightly different from PHMG’s. Further when the polycondensation were conducted between guanidine hydrochloride and multi-amine, such as diethylenetriamine or trithylenetetramine, the chemical structures of products were completely different from the above oligoguanidines. A new five-membered ring structure was observed, and the fivemembered ring structure further decreased the antibacterial activities.
Interfacial synthesis and characterization of L-lysinederived optically active poly(hydrazide-imide)s
Authors: Zahmatkesh Saeed , Banaei Alireza , Yazdanpanah Ashkbous
Published: August 2014

Six novel poly(hydrazide-imide)s (PHIa-f) were prepared from the reaction of a novel L-lysine-derived chiral diacid, ethyl L-lysine-N,N'-ditrimellitoyl diacide (1), with six synthetic dihydrazides by interfacial polycondensation. These polymers have inherent viscosities in the range of 0.23 to 0.42 dl g-1, display optical activity, and are readily soluble in polar aprotic solvents. They start to decompose (T10%) above 248 ºC and display glass-transition temperatures at 164.37-210.20 0C All of the above polymers were fully characterized by UV, FT-IR and 1H NMR spectroscopy, elemental analysis, TGA, DSC, inherent viscosity measurement and specific rotation.
Dynamic lattice liquid (DLL) model in computer simulation of the structure and dynamics of polymer condensed systems
Authors: Blim Anna , Kowalczyk Tomasz
Published: August 2014

This review presents the use of Dynamic Lattice Liquid (DLL) model proposed by Pakula and coworkers. In the model polymer liquids are represented as dense systems of macromolecules. The model fulfils requirements of the local continuity and excluded volume conditions. The use of the model for numerical simulations of simple liquids, colloidal particles systems, solutions of linear polymers, branched like bottle-brush or star shaped polymers is described. The use of simulations for the prediction of the properties of the systems and their experimental validation is described. The model is presented as an universal tool for investigation of different systems that provides good agreement between numerical and experimental results for a broad range of the systems and conditions.
Preparation of a novel superhydrophobic PMMA surface with nanostructure and its blood compatibility
Authors: Wang Xiaobo , Yang Ningbo , Xu Qi , Mao Chun , Hou Xiaomei , Shen Jian
Published: August 2014

Superhydrophobic poly(methylmethacrylate) (PMMA) surface with nanostructure was prepared effectively via phase separation and selective solvent method. It is proposed that the cooperation of the nanostructure of PMMA surface and the surface group reorientation leads to the superhydrophobicity of PMMA surface. The superhydrophobic PMMA surface with nanostructure was characterized by scanning electron microscope (SEM) and water contact angle (WCA) measurements. The blood compatibility of the superhydrophobic PMMA surface with nanostructure was evaluated by platelet-rich plasma (PRP) and fresh human whole blood contacting experiments using pure flat PMMA film as the control. These two experiments demonstrated that blood compatibility of the superhydrophobic PMMA surface with nanostructure is better than that of the pure flat PMMA film. The significance of this research lies in that it will greatly broaden the application range of materials that can be used as biomaterials by fabrication of superhydrophobic surfaces.
Herleitung einer Instruktionsgrammatik
Authors: Kasper Simon
Published: August 2014

In this article a research programme is sketched, together with an outline of the theory of Instruction Grammar embedded within it. In the research programme, verbal action is viewed as a means for organizing and coordinating lifeworld interaction. Verbal interaction is a means to bring about action on the part of the interlocutor in order to realize purposes. Both the well-formedness and the situational appropriateness of utterances have to be determined with respect to the success and efficacy of that purpose. The competence of well-formed and appropriate verbal interaction (the “linking competence”) is the subject matter of the theory of Instruction Grammar. This competence draws on a number of sub-competences, ranging from action, perception, conceptualization and attribution to symbolization. In the research programme, all these sub-competences are constitutive of the linking competence whose exploration requires a multidisciplinary approach based on converging evidence. The basic claims of the theory of Instruction Grammar are then deduced using an example scenario. Utterances are characterized as instructions for an interlocutor to simulate perceptions, reenact attributions, and engage in action by himself.
IBM’s Health Analytics and Clinical Decision Support
Authors: Sun J. , Knoop S. , Shabo A. , Carmeli B. , Sow D. , Syed-Mahmood T. , Rapp W. , Kohn M. S.
Published: August 2014

Objectives: This survey explores the role of big data and health analytics developed by IBM in supporting the transformation of healthcare by augmenting evidence-based decision-making.

Methods: Some problems in healthcare and strategies for change are described. It is argued that change requires better decisions, which, in turn, require better use of the many kinds of healthcare information. Analytic resources that address each of the information challenges are described. Examples of the role of each of the resources are given.

Results: There are powerful analytic tools that utilize the various kinds of big data in healthcare to help clinicians make more personalized, evidenced-based decisions. Such resources can extract relevant information and provide insights that clinicians can use to make evidence-supported decisions. There are early suggestions that these resources have clinical value. As with all analytic tools, they are limited by the amount and quality of data.

Conclusion: Big data is an inevitable part of the future of healthcare. There is a compelling need to manage and use big data to make better decisions to support the transformation of healthcare to the personalized, evidence-supported model of the future. Cognitive computing resources are necessary to manage the challenges in employing big data in healthcare. Such tools have been and are being developed. The analytic resources, themselves, do not drive, but support healthcare transformation.
Challenges and Potential Solutions for Big Data Implementations in Developing Countries
Authors: Mayan J. C. , García M. J. , Almerares A. A. , Househ M. , Luna D. R.
Published: August 2014

Background: The volume of data, the velocity with which they are generated, and their variety and lack of structure hinder their use. This creates the need to change the way information is captured, stored, processed, and analyzed, leading to the paradigm shift called Big Data.

Objectives: To describe the challenges and possible solutions for developing countries when implementing Big Data projects in the health sector.

Methods: A non-systematic review of the literature was performed in PubMed and Google Scholar. The following keywords were used: “big data”, “developing countries”, “data mining”, “health information systems”, and “computing methodologies”. A thematic review of selected articles was performed.

Results: There are challenges when implementing any Big Data program including exponential growth of data, special infrastructure needs, need for a trained workforce, need to agree on interoperability standards, privacy and security issues, and the need to include people, processes, and policies to ensure their adoption. Developing countries have particular characteristics that hinder further development of these projects.

Conclusions: The advent of Big Data promises great opportunities for the healthcare field. In this article, we attempt to describe the challenges developing countries would face and enumerate the options to be used to achieve successful implementations of Big Data programs.
Transforming Health Care Delivery Through Consumer Engagement, Health Data Transparency, and Patient-Generated Health Information
Authors: Wald J. S. , Sands D. Z.
Published: August 2014

Objective: Address current topics in consumer health informatics.

Methods: Literature review.

Results: Current health care delivery systems need to be more effective in the management of chronic conditions as the population turns older and experiences escalating chronic illness that threatens to consume more health care resources than countries can afford. Most health care systems are positioned poorly to accommodate this. Meanwhile, the availability of ever more powerful and cheaper information and communication technology, both for professionals and consumers, has raised the capacity to gather and process information, communicate more effectively, and monitor the quality of care processes.

Conclusion: Adapting health care systems to serve current and future needs requires new streams of data to enable better self-management, improve shared decision making, and provide more virtual care. Changes in reimbursement for health care services, increased adoption of relevant technologies, patient engagement, and calls for data transparency raise the importance of patient-generated health information, remote monitoring, non-visit based care, and other innovative care approaches that foster more frequent contact with patients and better management of chronic conditions.
Are Electronic Cardiac Devices Still Evolving?
Authors: Mabo P. , Carrault G.
Published: August 2014

Objectives: The goal of this paper is to review some important issues occurring during the past year in Implantable devices.

Methods: First cardiac implantable device was proposed to maintain an adequate heart rate, either because the heart’s natural pacemaker is not fast enough, or there is a block in the heart’s electrical conduction system. During the last forty years, pacemakers have evolved considerably and become programmable and allow to configure specific patient optimum pacing modes. Various technological aspects (electrodes, connectors, algorithms diagnosis, therapies, ...) have been progressed and cardiac implants address several clinical applications: management of arrhythmias, cardioversion / defibrillation and cardiac resynchronization therapy.

Results: Observed progress was the miniaturization of device, increased longevity, coupled with efficient pacing functions, multisite pacing modes, leadless pacing and also a better recognition of supraventricular or ventricular tachycardia’s in order to deliver appropriate therapy. Subcutaneous implant, new modes of stimulation (leadless implant or ultrasound lead), quadripolar lead and new sensor or new algorithm for the hemodynamic management are introduced and briefly described. Each times, the main result occurring during the two past years are underlined and repositioned from the history, remaining limitations are also addressed.

Conclusion: Some important technological improvements were described. Nevertheless, news trends for the future are also considered in a specific session such as the remote follow-up of the patient or the treatment of heart failure by neuromodulation.
Laparoscopos májresectiók
Authors: Kupcsulik Péter
Published: August 2014

Absztrakt

A májdaganatok kezelésében a sebészi eltávolítás jelenti a gyógyítás legfontosabb módszerét. A diagnosztika és a sebészi módszerek fejlődése javította az eredményeket és a túlélést. Az utóbbi évtizedben a minimálisan invasiv laparoscopos (LAP) módszereket egyre több májsebészeti centrum alkalmazza. A LAP-technika a korábbi kisebb resectióktól a kiterjesztett műtétek irányába fejlődik. Ez a változás viszonylag lassú, amelynek oka a beavatkozás bonyolultsága és a vérzéstől való félelem. Ennek ellenére a nagy resectiók aránya egyre növekszik. Eddig hozzávetőlegesen 6000 LAP-májresectiót végeztek világszerte, a major műtétek száma 700–800 lehet. A LAP-májresectio esetén a kisebb vérvesztés, fájdalomcsillapító-igény, rövidebb kórházi ápolási idő előnyös a beteg számára, a szövődmények és a halálozás a nyitott műtétekével azonos. Mai álláspont szerint alkalmazható benignus és malignus elváltozások kezelésére. Colorectalis májáttétek késői túlélése tekintetében nincs különbség a LAP- és a nyitott módszer között. A hepatocellularis carcinomás esetek túlélése jobb LAP-resectio után, mint nyitott műtéteket követően.
A terhességgel összefüggő emlődaganatok kezelése
Authors: Tajti Jr. János , Pieler József , Simonka Zsolt , Paszt Attila , Lázár György
Published: August 2014

Absztrakt

Esetismertetés:A 25 éves primipara, terhességének 32. hetében, önvizsgálat során a bal emlő külső-felső negyedében csomót észlelt. A komplex emlővizsgálat 4 cm átmérőjű területen meszesedést írt le. A finomtű-biopsia malignus ductalis karakterű sejteket, „C5” kategóriát, a core-biopsia III-as gradusú, invasiv ductalis carcinomát véleményezett („B5b”), távoli disseminatio nem igazolódott. A terhesség terminálását követően az elváltozás széles excisióját végeztük sentinelnyirokcsomó-biopsiával, amelynek pozitivitása miatt axillaris blockdissectio történt. A sebészi kezelést adjuváns onkológiai kezelés követte. A későbbiekben a jobb inguinalis régióban lévő angiomyxoma jelent meg, amelyet in toto excindaltunk.Megbeszélés:A terhességgel összefüggő malignus betegségek incidenciája emelkedik, amelyek közül az emlődaganatok kitüntetett helyen állnak. Terhességasszociált emlődaganatról akkor beszélünk, amennyiben annak diagnózisa a graviditas alatt vagy az azt követő első évben történik. A terhességgel járó élettani változások miatt a betegség felismerése nehezebbé válik, s ennek következtében sokszor ezek a betegek elkésve kerülnek látókörünkbe. A betegség terápiája összetett, mivel az anya kezelése mellett a magzat biztonságára is nagy hangsúlyt kell fektetni – mindez a társszakmák fokozott együttműködését igényli. A kezelési stratégia az egyes trimeszterekben eltérő. Sebészi kezelés a terhesség bármely szakában végezhető. A sugárkezelésről, magzatkárosító hatása miatt, megoszlanak a vélemények. A kemoterápia a terhesség második és harmadik harmadában megengedett. Betegünk közel három évvel a műtétet követően panaszmentes, fiúgyermeke egészséges.
Seismic stability of braced excavations next to tall buildings
Authors: O'Riordan Nick , Almufti Ibrahim
Published: August 2014

It can take many years to complete the construction of deep, wide and long excavations in urban environments. In seismically active areas, there is a finite probability that a significant earthquake could take place during the construction period. The designer and builder are confronted with the need not only to maintain control of ground and retaining wall movements during the normal construction conditions but also to protect surrounding buildings during a seismic event. It follows that the seismic loads from adjacent structures and their foundations must be considered together with the available load pathways through the propping system. The paper considers the available methods of design and proposes a performance-based design philosophy in which the temporary shoring system and permanent installation are designed for static loading conditions and for the seismic condition only in as much as the performance objectives of adjacent buildings are achieved for various levels of earthquake shaking. An example of the use of performance-based design is presented for the effects of a 130 m tall building of 30 m square plan upon the temporary shoring system for a long and wide excavation. The results obtained are compared with code-based calculations and general conclusions are drawn.
Briefing: Young Coastal Scientists and Engineers Conference 2013
Authors: O'Hara Murray Rory B. , Thorne Peter D. , van den Bremer Ton S. , Bricheno Lucy M. , Sparrow Kathryn H. , Wright Jennifer C.
Published: August 2014

On 25–26 March 2013, 52 early career scientists and engineers, studying various aspects of coastal science, met at the University of Aberdeen for the ninth Young Coastal Scientists and Engineers Conference. The conference was jointly organised by the School of Engineering, University of Aberdeen, and Marine Scotland Science. Early-career scientists, researchers and practitioners presented 23 oral and 17 poster presentations over the 2-day meeting. The papers all had a coastal theme with a large diversity in the subjects covered, including waves, currents, tidal energy, coastal erosion, sediment transport, fluid mechanics and particle tracking. This briefing paper reports on the conference, and presents the keynote lecture and four papers voted to be of especially high quality by the panel of judges.
Flexural behaviour of amorphous metal-fibre-reinforced concrete
Authors: Choi Kyoung-Kyu , Ku Dong-Oh
Published: August 2014

In this study, the flexural behaviour of amorphous metal-fibre-reinforced concrete is experimentally investigated. These fibres are thinner than conventional steel fibres, and they have a coarser surface and increased flexibility. Flexural tests according to ASTM C 1609 are performed. Primary parameters are fibre length (5, 15 and 30 mm), fibre type (amorphous metal fibres (types I and II) as opposed to conventional steel fibres), fibre volume fraction (0·25, 0·5, 0·75, 1·0 and 1·5%) and concrete compressive strength (27 and 50 MPa). The equivalent flexural strength and flexural toughness of amorphous metal fibres and conventional steel fibres are investigated and compared. From the test results, it is found that the amorphous metal fibres increase both the flexural strength and the flexural toughness according to fibre volume fraction, whereas conventional steel fibres increase the flexural toughness only.
Experimental Study of Rill Evolution Processes and Relationships between Runoff and Erosion on Clay Loam and Loess
Authors: He Jijun , Li Xiaojuan , Jia Lijuan , Gong Huili , Cai Qiangguo
Published: August 2014

Rill erosion accounts for approximately 70% of the total erosion of upland areas in China's Loess Plateau. A laboratory rainfall experiment with deionized water was conducted to examine the process of rill evolution and the relationship between runoff, rill evolution, and erosion rates for clay loam and loess soils given a fixed slope gradient (10°) and two rainfall intensities (1.5 and 2.0 mm min−1). The results show that rills evolved from a series of parallel drop‐pit chains along the down‐slope direction. Clay loam soil produced rills under a rainfall intensity of 1.5 mm min−1, and loess soil produced rills only under higher rainfall intensity. The temporal change in sediment concentration and erosion rate shows good consistency with the emergence of drop pits and rills. An increase in rainfall intensity had little effect on the sediment concentration and erosion rate for clay loam soil, whereas for loess soil, both increased rapidly and exceeded those of clay loam soil, with the emergence of a rill when the rainfall intensity was higher. Rills have a much greater effect on sediment concentration and erosion rate for loess soil than for clay loam soil. This study indicates that soil texture has a major impact on rill formation; clay loam soil is more subject to rill formation, but the rills formed are generally small and do not substantially increase soil loss. In contrast, the well‐developed rills in silt loam soil can result in intensive soil loss, though rills occur infrequently. Basic understanding of these results, causes, and quantification are essential for the prediction and evaluation of soil loss.
Effect of Brackish Ice on Salt and Nutrient Contents of Saline Soil in Flue‐Gas Desulfurization Gypsum Amended, Raised Bed Agroecosystem
Authors: Tao Jun , Wu Linhong , Liu Xiaojing , Zhang Hua , Xu Yingjun , Gu Wei , Li Ying
Published: August 2014

The effect of brackish ice application on the salt content and nutrient levels of a saline soil was determined in a flue‐gas desulfurization (FGD) gypsum amended, raised bed agroecosystem. Experimental plots in the raised bed were exposed to six treatments: 0, 4000, and 8000 m3 ha−1 brackish ice mulch, with or without the use of FGD gypsum. The applied brackish ice significantly decreased (P < 0.05) the electrical conductivity of a saturated soil paste extract (ECe) to 4.22 (4000 m3 ha−1) and 3.85 dS m−1 (8000 m3 ha−1) from 7.20 dS m−1 (non‐brackish ice mulch) in the 0‐ to 20‐cm soil layers in the absence of FGD gypsum. Electrical conductivity was also significantly decreased in the 0‐ to 40‐cm soil layers following incorporation of FGD gypsum. The application of brackish ice significantly reduced (P < 0.05) soil Na adsorption ratio (SAR) to <11 and exchangeable Na percentage (ESP) in the 0‐ to 20‐cm soil layer, compared with the control treatment to which brackish ice had not been applied, regardless of FGD gypsum incorporation. The incorporation of FGD gypsum increased soil ECe to 12.89, 7.72, and 7.03 dS m−1 (P < 0.01) but gave a lower soil SAR (P < 0.05) in the 0‐ to 20‐cm soil layer following zero, low, and high volumes of brackish ice application compared with the same treatments without FGD gypsum. The incorporation of FGD gypsum significantly decreased soil pH in the 0‐ to 20‐cm soil layer compared with the treatment without FGD gypsum, regardless of brackish ice volume. The application of brackish ice significantly decreased the available P of the 0‐ to 20‐cm soil layer (P < 0.05) and NO3–N content of the 0‐ to 40‐cm soil layer (P < 0.05) compared with the control treatment without brackish ice when FGD gypsum was not incorporated. These results indicated that mulching of raised beds of saline soil by brackish ice seems to be a promising technology for growing spring crops on soils that would normally be unproductive.
Evapotranspiration estimate from water balance closure using satellite data for the Upper Yangtze River basin
Authors: Corbari C. , Mancini M. , Su Z. , Li J.
Published: August 2014

Application of hydrological models for water resources management at large continental river basins is often limited by the scarcity of in situ meteorological forcing data. Remote sensing information provides an alternative to in situ data, with observations that are, in some cases, at higher spatial and temporal resolutions than those available from traditional ground sources. In this work, the water balance equation is solved using precipitation retrieved from Tropical Rainfall Measuring Mission, water storage from Gravity Recovery and Climate Experiment satellite data and ground discharge. Evapotranspiration (ET) is then computed as a residual term of the water balance. Satellite data are compared with ground data to understand to what extent remote sensing observations can be used to improve estimates of the terrestrial water balance at regional scale. ET estimates are also compared with the ET computed from a detailed distributed energy water balance model and with the ET product from the Moderate Resolution Imaging Spectroradiometer Global Evapotranspiration Project. These analyses are performed for the Upper Yangtze River basin (China) in the framework of NRSCC-ESA DRAGON-2 Programme.
An investigation on the effect of geometric shape of streams on stream/ground water interactions and ground water flow
Authors: Boyraz Uğur , Kazezyılmaz-Alhan Cevza Melek
Published: August 2014

Ground water should be used efficiently and improved for sustainable water management plans. For this purpose, comprehensive ground water flow models are developed incorporating surface/ground water interactions. Typically, these models require a significant amount of hydrological parameters and the sensitivities of these parameters on interaction mechanisms need to be clarified. Therefore, in this study, the role of the geometric shape of the stream on stream/ground water interactions is investigated. First, an analytical solution for two-dimensional ground water flow is developed with sloping stream boundary in an isotropic and homogeneous aquifer. Then, ground water head distribution and hyporheic exchange flow between stream and aquifer are obtained by conducting sensitivity analyses with prototype models developed using Visual MODular Finite-Difference FLOW in order to observe individual effects of each stream property. Finally, by incorporating the highest possible stream/ground water interaction conditions into a conceptual stream-aquifer model, the combined effects of different stream shapes are interpreted. Results show that slope, abrupt slope change, and flow path of stream affect the interactions significantly. Moreover, interaction flow rates increase further under the combined effects of these stream properties. The outputs of this work will ultimately be used in site investigations and in forecasting ground water hydrology.
Groundwater recharge and discharge analysis for land use conditions suitable for the hydrology and ecology of semiarid regions
Authors: Moiwo Juana Paul , Tao Fulu
Published: August 2014

Land use is critical for the hydrology of arid/semiarid regions with fragile/valuable ecosystems. Using Western Jilin as proxy for arid/semiarid, four land use conditions were investigated for the sustainability of fragile/valuable ecosystems – land use conditions for 1930 (pre-development), 2010 (post-development), forestland and grassland. For forestland/grassland, barren/bare-lands and land surfaces with ≥10% slope in 2010 were replaced with grass and forest. Error analysis showed good agreements among the model-simulated and field-measured values, with average error <10%. Shifting from 1930 to 2010 land use condition decreased annual recharge and discharge by 17.09% (21.46 mm/yr or 1.01 × 109m3) and 34.14% (10.03 mm/yr or 4.70 × 108m3), respectively, in the 4.69 × 1010m2 study area. Rehabilitating 2010 land use with forest increased recharge and discharge, respectively, by 6.25% (6.51 mm/yr or 3.05 × 108m3) and 12.82% (2.88 mm/yr or 1.16 × 108m3). Replacing the forest with grass increased recharge and discharge, respectively, by 15.22% (15.85 mm/yr or 7.43 × 108m3) and 35.85% (6.93 mm/yr or 3.25 × 108m3). Although pre-development land use condition was most conducive, grass performed better than forest in the study area. Rehabilitation with grass little affects food production in the region, and is thus applicable to other arid/semiarid regions.