bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reactions of polymerization and degradation by gamma‐rays
Authors: Rossi C. , Bianchi U. 
Published: November 2014

AbstractThe polymerization of monomers and the degradation of polymers have been the object of numerous researches. In the scientific literature there are many experimental values and many relationships which try to explain the kinetics of the two reactions of polymerization and degradation. In general, it is observed that if a monomer such as styrene has been irradiated with a known dose, there is formation of a polymer, whereas if polystyrene high of molecular weight, is irradiated there is observable degradation. This led us to the supposition that there must be an equilibrium molecular weight which is characteristic of the dose of radiation employed. Our hypothesis surmised that for each polymerization and degradation one must have an equilibrium between the energy which the polymer receives from gamma radiation and the maximum energy that can be removed by the molecule, which is also related to its structure. Starting with this hypothesis we calculated the relations between the equilibrium molecular weight and the dose of radiation employed, as well as the distribution of molecular weight as a function of the time and dose of radiation received. We have verified our hypothesis experimentally in making tests of polymerization and degradation with styrene monomer and polystyrene in chloroform solution. A Co60 source was used and the experiments were carried out at three intensities: 20, 37, and 61 r/min. The experimental results have lead us to believe that there is really an equilibrium molecular weight which can be reached either by polymerizing the monomer in chloroform solution, or by degradating (also in solution) a polymer with a molecular weight higher than the equilibrium value. The results we obtained are in agreement with the predictions of the theory which was made.
Polymerization on oxide catalysts
Authors: Topchiev A. V. 
Published: November 2014

AbstractA short review of define polymerization on oxide catalysts is given. Crystalline polypropylene, polyvinyl cyclohexane, and other polymers were synthesized by means of chromium oxide catalysts. The effect of various factors on the activity of oxide catalysts in polymerization is discussed. Under certain conditions of thermal treatment of chromium oxide, CrO3 may be converted into chromium or aluminum chromates, thus increasing considerably the catalyst stability.
Polymerization in the presence of organic compounds of alkali metals
Authors: Spirin Yu. L. , Polyakov D. K. , Gantmakher A. R. , Medvedev S. S. 
Published: November 2014

AbstractA study was made of the effect of the nature of the alkaline metal and of the medium on the rate of polymerization and on the structure of the polymer chain. The rate of polymerization of styrene and isoprene with an ethyllithium catalyst in hydrocarbon medium has been shown to increase on addition of polar compound triethylamine, ether, and tetrahydrofuran, to the solvent. The limiting concentration of triethylamine, above which increase in the polymerization rate in the presence of ethyllithium is no longer observed, is considerably higher in the case of isoprene than styrene. This is in agreement with the data on the kinetics of ethyllithium‐catalyzed polymerization of styrene and isoprene in hydrocarbon medium, according to which the limiting concentration of ethyllithium, above which dependence of the polymerization rate on the catalyst concentration is no longer observed, is considerably lower for isoprene than for styrene. The difference in polymerization kinetics of isoprene and styrene is explained by the fact that more amine is required to dissociate polymerization‐inactive polyisoprene‐lithium associates. By the copolymerization method it has been shown, in harmony with published data, that the mechanism of chain growth in the presence of ethyllithium changes on passing over from a hydrocarbon to a polar solvent and also on changing alkyllithium for organosodium compounds. The specific features of alkyllithium catalysts in hydrocarbon medium are interpreted as due to the participation of the lithium component of the catalyst besides the carbanion in the chain growth.
Grafting of methyl methacrylate on polyvinyl alcohol films under the action of X‐radiation
Authors: Szántó I. , GÁL K. 
Published: November 2014

AbstractThe possibility of Converting water‐soluble polyvinyl alcohol films to water‐insoluble ones by graft copolymerization is of practical interest. With the use of x‐radiation we bave carried out the graft polymerization of methyl methacrylate onto polyvinyl alcohol films 0.025–0.03 mm. thick. To enhance the grafting effect the influence of various methanol‐methyl methacrylate mixtures on the process was studied. The kinetics was investigated dilatometrically with periodic irradiation. It was established that polymerization slows down on interruption of the irradiation. During irradiation the polymerization rate depends linearly upon the time, i.e., upon the radiation dose. The greatest grafting effect (1700%) was observed at a methanol concentration of 50–60 mole‐% with continuous radiation. The dependence of the grafting process on the methanol concentration is described by a convex curve with a maximum at the above value. We have also been able to throw some light on the part played by methanol in the graft copolymerization process. The products obtained at a radiation dose of 4 × 106 r are insoluble in water, benzene, and acetone.
Data on the reaction kinetics of ziegler catalysts
Authors: Simon A. , Ghymes G. 
Published: November 2014

AbstractThe purpose of this work was to study the formation and composition of the catalysts and the process of Ziegler polymerization of ethylene. In the investigation of the reaction rates we observed a great difference between the two types of catalyst complexes obtained with Al(C2H5)2Cl and Al(C2H5)3 with TiCl4, especially with respect to the effect of the molar ratio of the catalyst components. An increase in the Al/Ti molar ratio decreased the polymerization rate with the Al(C2H5)3−TiCl4 catalyst and increased the rate with the Al(C2H5)2Cl−TiCl4 catalyst. The rate of catalyst formation is much slower for the Al(C2H5)2Cl catalyst; moreover, with this catalyst, the overall polymerization rate shows a dependence on the catalyst age, i.e., the length of time between mixing of the catalyst components and the beginning of polymerization. For the triethylaluminum−TiCl4 catalyst this aging time does not play so important a role. The composition of the catalyst prepared with Al(C2H5)3 varies with the molar ratio of the components and becomes stable only at a molar ratio of 3; the composition of the solid residue obtained with Al(C2H5)2Cl−TiCl4 is constant for molar ratios of Al/Ti in the range 0.3–1.1, and its empirical formula is Al2Ti5Cl19(C2H5)2.
Proliferation and Osteogenic Differentiation of Mesenchymal Stem Cells Induced by a Short Isoform of NELL-1
Authors: Pang Shen , Shen Jia , Liu Yi , Chen Feng , Zheng Zhong , James Aaron W. , Hsu Ching-Yun , Zhang Hong , Lee Kevin S. , Wang Chunling , Li Chenshuang , Chen Xuepeng , Jia Haichao , Zhang Xinli , Soo Chia , Ting Kang 
Published: November 2014

Abstract
Neural epidermal growth factor-like (NEL)-like protein 1 (NELL-1) has been identified as an osteoinductive differentiation factor that promotes mesenchymal stem cell (MSC) osteogenic differentiation. In addition to full-length NELL-1, there are several NELL-1-related transcripts reported. We used rapid amplification of cDNA ends to recover potential cDNA of NELL-1 isoforms. A NELL-1 isoform with the N-terminal 240 amino acid (aa) residues truncated was identified. While full-length NELL-1 that contains 810 aa residues (NELL-1810) plays an important role in embryologic skeletal development, the N-terminal-truncated NELL-1 isoform (NELL-1570) was expressed postnatally. Similar to NELL-1810, NELL-1570 induced MSC osteogenic differentiation. In addition, NELL-1570 significantly stimulated MSC proliferation in multiple MSC-like populations such as murine C3H10T1/2 MSC cell line, mouse primary MSCs, and perivascular stem cells, which is a type of stem cells proposed as the perivascular origin of MSCs. In contrast, NELL-1810 demonstrated only limited stimulation of MSC proliferation. Similar to NELL-1810, NELL-1570 was found to be secreted from host cells. Both NELL-1570 expression lentiviral vector and column-purified recombinant protein NELL-1570 demonstrated almost identical effects in MSC proliferation and osteogenic differentiation, suggesting that NELL-1570 may function as a pro-osteogenic growth factor. In vivo, NELL-1570 induced significant calvarial defect regeneration accompanied by increased cell proliferation. Thus, NELL-1570 has the potential to be used for cell-based or hormone-based therapy of bone regeneration. Stem Cells 2015;33:904–915
Budgeting carbon for urbanization in China
Authors: Pan Jiahua , Liu Jie , Zhu Chun 
Published: November 2014

China's urbanization in the post‐reform period since 1978 is especially notable for three features: large scale, fast speed, and long process. And it is now facing challenges in land, energy, water resources, and environment. All these challenges are linked to the emissions of carbon dioxide. As China is expected to have a cap on emissions, there must be a limit to emissions over the process of urbanization in China. In this article, a comprehensive analysis is implemented aimed at budgeting carbon for China's urbanization from 2020 to 2040. By incorporating the concept and principle of ecological civilization into China's urbanization, the constraint on carbon budget not only increases the market demand for raw materials, labor, and commodities that act as the main driving forces for economic growth, but also guarantees the state energy safety and contributes to the global ecological security. WIREs Energy Environ 2015, 4:406–409. doi: 10.1002/wene.153This article is categorized under:

Energy and Climate > Climate and Environment
Energy Policy and Planning > Climate and Environment
Ionic α‐helical polypeptides toward nonviral gene delivery
Authors: Zhang Rujing , Song Ziyuan , Yin Lichen , Zheng Nan , Tang Haoyu , Lu Hua , Gabrielson Nathan P. , Lin Yao , Kim Kyung , Cheng Jianjun 
Published: November 2014

The advent of polymeric materials has significantly promoted the development and rapid growth of various technologies in biomedical applications, such as tissue engineering and controlled drug and gene delivery. Water‐soluble polypeptides bearing functional side chains and adopting stable secondary structures are a new class of functional polymeric materials of potentially broad applications in medicine and biotechnology. In this article, we summarize our recent effort on the design and synthesis of the water‐soluble α‐helical ionic polypeptides originally developed in our laboratory and highlight their applications in cell membrane penetration and nonviral gene/small interfering RNA (siRNA) delivery. WIREs Nanomed Nanobiotechnol 2015, 7:98–110. doi: 10.1002/wnan.1307This article is categorized under:

Nanotechnology Approaches to Biology > Nanoscale Systems in Biology
Biology-Inspired Nanomaterials > Peptide-Based Structures
Plasmonic biosensors
Authors: Hill Ryan T. 
Published: November 2014

The unique optical properties of plasmon resonant nanostructures enable exploration of nanoscale environments using relatively simple optical characterization techniques. For this reason, the field of plasmonics continues to garner the attention of the biosensing community. Biosensors based on propagating surface plasmon resonances (SPRs) in films are the most well‐recognized plasmonic biosensors, but there is great potential for the new, developing technologies to surpass the robustness and popularity of film‐based SPR sensing. This review surveys the current plasmonic biosensor landscape with emphasis on the basic operating principles of each plasmonic sensing technique and the practical considerations when developing a sensing platform with the various techniques. The ‘gold standard’ film SPR technique is reviewed briefly, but special emphasis is devoted to the up‐and‐coming localized surface plasmon resonance and plasmonically coupled sensor technology. WIREs Nanomed Nanobiotechnol 2015, 7:152–168. doi: 10.1002/wnan.1314This article is categorized under:

Diagnostic Tools > Biosensing
Diagnostic Tools > Diagnostic Nanodevices
Severe maternal morbidity and near miss due to postpartum hemorrhage in a national multicenter surveillance study
Authors: Rocha Filho Edilberto A. , Costa Maria L. , Cecatti Jose G. , Parpinelli Mary A. , Haddad Samira M. , Pacagnella Rodolfo C. , Sousa Maria H. , Melo Elias F. , Surita Fernanda G. , Souza Joao P. ,   Brazilian Network for Surveillance of Severe Maternal Morbidity Study Group
Published: November 2014

AbstractObjectiveTo assess the occurrence of severe maternal complications owing to postpartum hemorrhage (PPH) and its associated factors.MethodsA secondary analysis of data from a multicenter cross‐sectional prospective surveillance study included 9555 cases of severe maternal morbidity at 27 centers in Brazil between July 2009 and June 2010. Complications of PPH, conditions of severity management, and sociodemographic and obstetric characteristics were assessed. Factors independently associated with severe maternal outcome (SMO) were identified using multiple regression analysis.ResultsOverall, 1192 (12.5%) of the 9555 women experienced complications owing to PPH (981 had potentially life‐threatening conditions, 181 maternal near miss, and 30 had died). The SMO ratio was 2.6 per 1000 live births among women with PPH and 8.5 per 1000 live births among women with other complications. Women with PPH had a higher risk of blood transfusion and return to the operating theater than did those with complications from other causes. Maternal age, length of pregnancy, previous uterine scar, and cesarean delivery were the main factors associated with an increased risk of SMO secondary to PPH.ConclusionPPH frequently leads to severe maternal morbidity. A surveillance system can identify the main causes of morbidity and could help to improve care, especially among women identified as being at high risk of PPH.
Geochemistry of carbon dioxide mineral waters of the Choigan natural complex (northeastern Tuva)
Authors: Kopylova Yu.G. , Guseva N.V. , Arakchaa K.D. , Khvashchevskaya A.A. 
Published: November 2014

Abstract
The abundance of various chemical elements (including trace, rare-earth, and radioactive) in the carbon dioxide mineral waters of the Choigan complex has been investigated. Three groups of waters are recognized according to the geochemical conditions and chemical composition: groundwaters of regional-jointing zone with oxidizing conditions; CO2-enriched groundwaters of regional-jointing zone with oxidizing conditions; and groundwaters of fault zones with reducing conditions. It is shown that water–rock interaction intensified by high temperature and carbon dioxide action is the main process determining the chemical composition of groundwaters.
Scandium in the coals of Northern Asia (Siberia, the Russian Far East, Mongolia, and Kazakhstan)
Authors: Arbuzov S.I. , Volostnov A.V. , Mashen’kin V.S. , Mezhibor A.M. 
Published: November 2014

Abstract
We present new original data on the geochemistry of scandium in the coals of Asian Russia, Mongolia, and Kazakhstan. In general, the studied coals are enriched in Sc as compared with the average coals worldwide. Coal deposits with abnormally high, up to commercial, Sc contents were detected in different parts of the study area. The factors for the accumulation of Sc in coals have been identified. The Sc contents of the coals depend on the petrologic composition of coal basins (composition of rocks in their framing) and the facies conditions of coal accumulation. We have established the redistribution and partial removal of Sc from a coal seam during coal metamorphism. The distribution of Sc in deposits and coal seams indicates the predominantly hydrogenic mechanism of its anomalous concentration in coals and peats. The accumulation of Sc in the coals and peats is attributed to its leaching out of the coal-bearing rocks and redeposition in a coal (peat) layer with groundwater and underground water enriched in organic acids. The enrichment of coals with Sc requires conditions for the formation of Sc-enriched coal-bearing rocks and conditions for its leaching and transport to the coal seam. Such conditions can be found in the present-day peatland systems of West Siberia and, probably, in ancient basins of peat (coal) accumulation.
The Blagodatnoe gold-sulfide deposit (Yenisei Ridge, Russia): the nature of geophysical anomalies and the succession and causes of formation of petrophysical zoning
Authors: Kolmakov Yu.V. 
Published: November 2014

Abstract
Data on geophysical fields and petrophysical heterogeneity, parageneses and the thermodynamic conditions and age of their formation, and fluid inclusions were used for the genetic reconstruction of petrophysical zoning at the Blagodatnoe gold-sulfide deposit. Petrophysical associations of the preore and ore stages of the deposit formation are clearly reflected in anomalies of the magnetic and natural electric fields and the aureoles of radioactive elements. At the early preore stage (752 Ma), reduced solutions with high activity of K, enriched in U, Th, and, probably, Au, were supplied to intensely foliated tectonic zones. Their interaction with initial metasedimentary rocks gave rise to contiguous zones of quartz–muscovite and chlorite metasomatic rocks. Accompanying graphitization led to a high electrochemical activity of the metasomatic rocks, which generated anomalies of up to –300 mV in the natural electric field; the most intensely carbonized zones became enriched with U (up to 6.5 × 10–4%) and, probably, Au. The quartz–muscovite metasomatic rocks accumulated Th and K (up to 29 × 10–4% and 4%, respectively), whereas the chlorite metasomatic rocks accumulated rock-forming elements (particularly Fe), which led to the compaction of these rocks and the acceleration due to gravity in local positive anomalies. The nonmagnetic character of the fresh pre-ore metasomatic rocks suggests the predominantly pyritic composition of early sulfides. At the ore stage (698 Ma), the minerals were deposited from H2O–CO2–As–S solutions at 560 to 315 °C. The activity of these solutions caused a redistribution of radioactive elements and a high petrophysical differentiation of the ore-bearing structure. The amplitudes of the anomalies above this structure vary from 500 to 80 nT in the magnetic field and from –130 to + 10 mV in the natural electric field. It has been found that the hydrothermal fluid hardly affected the polarization properties of graphitized rocks at the maximum temperatures but caused an intense removal of U and the development of magnetic pyrrhotite after pyrite. The temperature decrease in the mineral-forming system was favorable for the formation of siderite. Carbonaceous schists which experienced carbonatization lost their electrochemical activity. The binding of carbon dioxide in the solid phase influenced the migration capability of trace elements and their zonal distribution. With this evolution of the solution, Th accumulated at the lower levels of the mineralized zone, whereas the upper levels of the deposit became enriched with U. Productive gold–arsenopyrite–pyrite–pyrrhotite paragenesis with anomalous magnetic susceptibility evolved at the ore stage. The late galena–sphalerite–chalcopyrite paragenesis (365 Ma) was of strictly local occurrence and reduced the magnetic susceptibility of ores.
Effects of borehole casing on TEM response
Authors: Kozhevnikov N.O. , Antonov E.Yu. , Kamnev Ya.K. , Olenchenko V.V. , Plotnikov A.E. , Stefanenko S.M. , Shein A.N. 
Published: November 2014

Abstract
The effect the metal casing of a vertical borehole may exert on transient electromagnetic (TEM) responses has been studied in a field experiment. Eddy currents in the casing affect transients only slightly at early times, but the casing effect predominates at late times. Therefore, early-time TEM response measured near a borehole can provide information on shallow subsurface. The late-time TEM signals induced by the eddy currents in the casing show exponential behavior b⋅ exp(–t/τ). The time constant τ refers to the rate of eddy current decay in the casing; the amplitude b is M12⋅ M23⋅ L–1⋅ τ–1, where L is the casing self-inductance, and M12 and M23 are the mutual inductances between the transmitter loop and the borehole and between the borehole and the receiver, respectively. Both M12 and M23 are controllable, while M23 is especially important for survey applications: by reducing it, one can reduce the casing effect on the TEM data.
© 2014, V.S. Sobolev IGM, Siberian Branch of the RAS. Published by Elsevier B.V. All rights reserved.
Community Stroke Rehabilitation Teams: Providing Home-Based Stroke Rehabilitation in Ontario, Canada
Authors: Allen L. , Richardson M. , McIntyre A. , Janzen S. , Meyer M. , Ure D. , Willems D. , Teasell R. 
Published: November 2014

ABSTRACTBackground: Community stroke rehabilitation teams (CSRTs) provide a community-based, interdisciplinary approach to stroke rehabilitation. Our objective was to assess the effectiveness of these teams with respect to client outcomes. Methods: Functional, psychosocial, and caregiver outcome data. were available at intake, discharge from the program, and six-month follow-up. Repeated measures analysis of covariance was performed to assess patient changes between time points for each outcome measure. Results: A total of 794 clients met the inclusion criteria for analysis (54.4% male, mean age 68.5±13.0 years). Significant changes were found between intake and discharge on the Hospital Anxiety and Depression Scale total score (p=0.017), Hospital Anxiety and Depression Scale Anxiety subscale (p<0.001), Functional Independence Measure (p<0.001), Reintegration to Normal Living Index (p=0.01), Bakas Caregiver Outcomes Scale (p<0.001), and Caregiver Assistance and Confidence Scale assistance subscale (p=0.005). Significant gains were observed on the strength, communication, activities of daily living, social participation, memory, and physical domains of the Stroke Impact Scale (all p<0.001). These improvements were maintained at the 6-month follow-up. No significant improvements were observed upon discharge on the memory and thinking domain of the Stroke Impact Scale; however, there was a significant improvement between admission and follow-up (p=0.002). All significant improvements were maintained at the 6-month follow-up. Conclusions: Results indicate that the community stroke rehabilitation teams were effective at improving the functional and psychosocial recovery of patients after stroke. Importantly, these gains were maintained at 6 months postdischarge from the program. A home-based, stroke-specific multidisciplinary rehabilitation program should be considered when accessibility to outpatient services is limited.