bluuebunny/crossref_metadata_2025 huggingface dataset:
Compliance boundaries for multiple‐frequency base station antennas in three directions
Authors: Thielens Arno , Vermeeren Günter , Kurup Divya , Joseph Wout , Martens Luc
Published: January 2013

In this article, compliance boundaries and allowed output powers are determined for the front, back, and side of multiple‐frequency base station antennas, based on the root‐mean‐squared electric field, the whole‐body averaged specific absorption rate (SAR), and the 10 g averaged SAR in both the limbs and the head and trunk. For this purpose, the basic restrictions and reference levels defined by the International Commission on Non‐Ionizing Radiation Protection (ICNIRP) for both the general public and occupational exposure are used. The antennas are designed for Global System for Mobile Communications around 900 MHz (GSM900), GSM1800, High Speed Packet Access (HSPA), and Long Term Evolution (LTE), and are operated with output powers at the individual frequencies up to 300 W. The compliance boundaries are estimated using finite‐difference time‐domain simulations with the Virtual Family Male and have been determined for three directions with respect to the antennas for 800, 900, 1800, and 2600 MHz. The reference levels are not always conservative when the radiating part of the antenna is small compared to the length of the body. Combined compliance distances, which ensure compliance with all reference levels and basic restrictions, have also been determined for each frequency. A method to determine a conservative estimation of compliance boundaries for multiple‐frequency (cumulative) exposure is introduced. Using the errors on the estimated allowed powers, an uncertainty analysis is carried out for the compliance distances. Uncertainties on the compliance distances are found to be smaller than 122%. Bioelectromagnetics. 34:465–478. © 2013 Wiley Periodicals, Inc.
Evaluation of the effects of weak and moderate static magnetic fields on the characteristics of human low density lipoprotein in vitro
Authors: Abdi Soheila , Dorranian Davoud , Razavi Amirnader Emami , Naderi Gholam Ali , Boshtam Maryam , Ghorannevis Mahmoud
Published: January 2013

It has been suggested that exposure to electromagnetic fields may be a risk factor for cardiovascular disease in humans. Low density lipoprotein (LDL) modifications such as peroxidation and aggregation have been implicated in the pathogenesis of atherosclerosis. The present study investigated the effects of weak (0.125–0.5 mT) and moderate (1–4 mT) static magnetic fields (SMFs) on LDL oxidation, aggregation and zeta potential in vitro. Our results demonstrated that magnetic flux densities of 0.25 and 0.5 mT decreased, and magnetic flux densities of 3 and 4 mT increased the zeta potential and LDL oxidation in comparison with the control samples. All doses of SMFs increased the LDL aggregation in a time‐ and dose‐dependent manner. It is concluded that SMFs can alter the susceptibility of LDL to oxidation and this alteration is dependent on the applied magnetic flux density. The SMF, in addition to its role in the production and stabilization of free radicals and promotion of lipid peroxidation, may influence the metabolism of lipoproteins and their interaction with other molecules such as apolipoproteins, enzymes and receptors through the alteration of the LDL zeta potential and its particles tendency to aggregation. Bioelectromagnetics 34:397–404, 2013. © 2012 Wiley Periodicals, Inc.
Synergistic effect of thrombus aspiration and abciximab in primary percutaneous coronary intervention
Authors: Pyxaras Stylianos A. , Mangiacapra Fabio , Verhamme Katia , Di Serafino Luigi , De Vroey Frederic , Toth Gabor , Perkan Andrea , Salvi Alessandro , Bartunek Jozef , De Bruyne Bernard , Wijns William , Sinagra Gianfranco , Barbato Emanuele
Published: January 2013

Background

Previous studies failed to assess the individual prognostic role of thrombus aspiration (TA) or abciximab in primary percutaneous coronary intervention (pPCI), due their prevalent combined use.

Methods and Results

A total of 644 consecutive ST‐segment elevation myocardial infarction patients treated with pPCI were included in this retrospective registry from January 2006 to December 2008. Patients were divided in: (a) Group 1, with conventional pPCI; (b) Group 2, with pPCI and abciximab; (c) Group 3, with pPCI and TA; (d) Group 4, with pPCI and abciximab plus TA. Primary end point was the composite of major adverse cardiovascular events (MACEs, defined as overall mortality, myocardial infarction, target vessel revascularization, and major bleedings) at 1 year. Baseline clinical and angiographic characteristics were not different among the groups, with the exception of a younger age in group 4. The two groups of patients treated with TA (group 3 and 4) received more frequently direct stenting (P < 0.001 vs. group 1 for both), presented higher rate of end‐procedural TIMI flow grade 3 (P < 0.001 vs. group 1 for both), and lower rate of no‐reflow (P = 0.016 and P < 0.001 vs. group 1, respectively). Patients of group 2 presented a borderline nonsignificant trend toward higher rate of end‐procedural TIMI flow grade 3 (P = 0.083 vs. group 1). MACEs at 1 year were 43 (29%) in group 1 versus 25 (22%) in group 2 versus 24 (19%) in group 3 versus 32 (13%) in group 4 (log‐rank P = 0.001). At the multivariate Cox regression analysis, combined TA plus abciximab in group 4 [hazard ratio (HR): 0.48, confidence interval (CI) 95% 0.28–0.84, P = 0.01] and a higher left ventricular ejection fraction (HR: 0.97, CI 95% 0.95–0.98, P < 0.001) were significantly associated with lower MACE rate.

Conclusions

The combination of pharmacologic and mechanic antithrombotic treatment during pPCI was associated with better 1‐year clinical outcome. © 2013 Wiley Periodicals, Inc.
Physiological impact of CTO recanalization assessed by coronary pressure measurement: A case report
Authors: Matsuo Hitoshi , Kawase Yoshiaki
Published: January 2013

In this case report, physiological changes of myocardial perfusion in the collateral recipient right coronary artery (RCA) and the collateral donor left anterior descending artery (LAD) with an intermediate lesion were assessed using intracoronary pressure measurement, before and after revascularization of chronic total occlusion (CTO). A 44‐year‐old male was referred for a catheter examination due to silent myocardial ischemia. An invasive coronary angiogram revealed diffuse narrowing of the RCA with focal occlusive segments in addition to intermediate stenosis in the LAD. A well developed collateral channel from the LAD to the RCA was also confirmed. Fractional flow reserve (FFRmyo) of the LAD before opening the RCA was 0.81. After successful revascularization of the RCA, FFRmyo of the LAD and the RCA were measured with and without an RCA balloon occlusion. Because collateral fractional flow reserve (FFRcoll) of the RCA could be regarded as FFRmyo before revascularization, FFRmyo of the RCA increased from 0.67 to 0.90, meaning a 23% increase of maximum flow by intervention. Interestingly, improvement of FFRmyo of the LAD from 0.81 to 0.93 was also observed, which means a 12% increase of maximum flow. Coronary steal in the LAD was reconfirmed by dramatic worsening of FFRmyo from 0.93 to 0.77 by an RCA balloon occlusion. This phenomenon may be explained by an immediate recruitment of collateral channels. This case clearly demonstrated that CTO opening improves perfusion in not only myocardium supplied by the CTO vessel, but also in that which is supplied by a contralateral collateral donor artery. © 2013 Wiley Periodicals, Inc.
Revealing Unexpected Mechanisms for Nucleophilic Attack on SS and SeSe Bridges
Authors: Heverly‐Coulson Gavin S. , Boyd Russell J. , Mó Otilia , Yáñez Manuel
Published: January 2013

The reactivity of disulfide and diselenide derivatives towards F−and CN−nucleophiles has been investigated by means of B3PW91/6‐311+G(2df,p) calculations. This theoretical survey shows that these processes, in contrast with the generally accepted view of disulfide and diselenide linkages, do not always lead to SS or SeSe bond cleavage. In fact, SS or SeSe bond fission is the most favorable process only when the substituents attached to the S or the Se atoms are not very electronegative. Highly electronegative substituents (X) strongly favor SX bond fission. This significant difference in the observed reactivity patterns is directly related to the change in the nature of the LUMO orbital of the disulfide or diselenide derivative as the electronegativity of the substituents increases. For weakly electronegative substituents, the LUMO is a σ‐type SS (or SeSe) antibonding orbital, but as the electronegativity of the substituents increases the π‐type SX antibonding orbital stabilizes and becomes the LUMO. The observed reactivity also changes with the nature of the nucleophile and with the S or Se atom that undergoes the nucleophilic attack in asymmetric disulfides and diselenides. The activation strain model provides interesting insights into these processes. There are significant similarities between the reactivity of disulfides and diselenides, although some dissimilarities are also observed, usually related to the different interaction energies between the fragments produced in the fragmentation process.
Airborne Microorganisms Emitted from Wastewater Treatment Plant Treating Domestic Wastewater and Meat Processing Industry Wastes
Authors: Gotkowska‐Płachta Anna , Filipkowska Zofia , Korzeniewska Ewa , Janczukowicz Wojciech , Dixon Beverly , Gołaś Iwona , Szwalgin Damian
Published: January 2013

Experiments were conducted to study the airborne microbial contamination generated by a wastewater treatment plant (WWTP). Aerosol samples were collected simultaneously, by sedimentation and impact methods, from the area and the surroundings of the WWTP. Total colony forming units (CFUs) of heterotrophic bacteria (HPC), as well as members of the Enterobacteriaceae, staphylococci, enterococci, actinomycetes, and microscopic fungi were determined. Bacterial (HPC) concentrations ranged between 101 and 104 CFU/m3, fungi 0 and 104 CFU/m3. Higher numbers of HPC bacteria in air samples were observed in summer, fungi in autumn. The main emission of microorganisms to atmospheric air was from the mechanical sewage treatment devices of the WWTP. The facilities of the biological sewage treatment of the plant did not generate large amounts of bioaerosols. In the air obtained from the premises of the WWTP, 25 species of the Enterobacteriaceae were isolated (Salmonella spp., Klebsiella pneumoniae, Escherichia coli). At the fence and in the surroundings only Pantoea spp. were identified. This suggests that the sewage bacteria were mainly discharged in the area of the WWTP. The presence of enteric bacteria, especially Enterobacteriaceae reflects the level of air pollution with bioaerosols from sewage and is an important factor during monitoring the quality of the air around WWTPs.
Catalyzed Reactions on Mineral Plaster Materials Used for Indoor Air Purification
Authors: Gunschera Jan , Markewitz Doreen , Koberski Ulrich , Salthammer Tunga
Published: January 2013

Zeolites have been used for a long time for purification and catalytical purposes. Recently, first products appeared on the market using zeolites also for improving the indoor air quality so far volatile organic compounds (VOC) are concerned. However, porous compounds like zeolites can be found also in plaster material. Therefore, it was manifest to evaluate the capability of plaster with regard to air cleaning. In this article, the contribution of plaster compounds toward adsorption and catalytical decomposition of VOCs is evaluated using α‐pinene, chlorobenzene, 2‐ethoxyethylacetate, and pentanal as target substances under standard conditions (23°C, 50% r.H.). These compounds were chosen because of their VOC typical physicochemical properties like molecular dimensions, density, boiling point, vapor pressure, and octanol–water distribution coefficient (logkow). Hydrated lime and metakaolin were found out to have good adsorption properties under these circumstances. Also natural zeolites showed good results especially on pentanal. By investigations in environmental chambers the reduction potential of test plasters on chlorobenzene and 2‐ethoxyethylacetate concentrations could be shown. Application of coatings had no or only temporary influence on the performance of the plaster. Additional tests in small chambers demonstrated the possibility to improve the properties of plasters with help of FAU‐ or MFI‐type zeolites but the experiments also showed that α‐pinene and pentanal undergo chemical reactions. Further effort should be made on investigations also toward other compounds, especially more volatile ones like formaldehyde. Also additional building materials like insulation material or boards should be taken into account.
Ammonium Transport Simulation in Horizontal Soil Columns from a Natural Inland Alkaline Wetland
Authors: Bai Junhong , Xiao Rong , Ye Xiaofei , Yan Denghua , Gao Haifeng , Wang Junjing
Published: January 2013

Ammonium transport was simulated in horizontal soil columns from an inland alkaline wetland (Fulaowenpao wetland) of Northeast China. The primary objectives of this work are to investigate the changes in ammonium transport rate with increasing distances along horizontal soil column and to determine the effects of water diffusion rate and volumetric water content on ammonium transport rate. Our results showed that water diffusion coefficient was the lowest at the soil layer of 10–20 cm, followed by the 0–10 cm soil layer, and the highest value occured at the soil layer of 20–60 cm. The highest ammonium transport rate also appeared at the soil layer of 20–60 cm, while the lowest value was observed at the soil layer of 10–20 cm. Ammonium transport rates decreased with increasing distances along horizontal soil columns. The ammonium transport rates showed higher values at the distance from 0 to 6 cm and then decreased rapidly from 6 to 18 cm. However, they nearly kept constant and approached to zero after exceeding the distance of 18 cm. Ammonium transport rates increased exponentially with increasing volumetric water contents and water diffusion rates. The alkaline wetland soils prevented ammonium from horizontal diffusion at all soil layers under drying conditions.
Plant Species Richness Increased Belowground Plant Biomass and Substrate Nitrogen Removal in a Constructed Wetland
Authors: Wang Hai , Chen Zheng‐Xin , Zhang Xiao‐Yu , Zhu Si‐Xi , Ge Ying , Chang Scott‐X. , Zhang Chong‐Bang , Huang Cheng‐Cai , Chang Jie
Published: January 2013

The effects of plant species richness on both above‐ and belowground plant biomass, plant nitrogen (N) pool size, and substrate N concentrations were studied in a full‐scale subsurface vertical‐flow constructed wetland (CW). Results showed that (i) plant species richness increased belowground plant biomass and its N pool size but had no effect on aboveground plant biomass and its N pool size; (ii) plant species richness increased substrate N removal, especially ammonium N removal; and (iii) plant species richness had no effect on plant N use efficiency, suggesting that the N pool size increased with increasing plant species richness. More N accumulation could be removed through harvesting plant biomass. We concluded that the N removal performance of the CW improved by plant species richness through increasing belowground biomass and relevant N pool size.
Identification of a Small‐Molecule Inhibitor of HIV‐1 Assembly that Targets the Phosphatidylinositol (4,5)‐bisphosphate Binding Site of the HIV‐1 Matrix Protein
Authors: Zentner Isaac , Sierra Luz‐Jeannette , Fraser Ayesha K. , Maciunas Lina , Mankowski Marie K. , Vinnik Andrei , Fedichev Peter , Ptak Roger G. , Martín‐García Julio , Cocklin Simon
Published: January 2013

The development of drug resistance remains a critical problem for current HIV‐1 antiviral therapies, creating a need for new inhibitors of HIV‐1 replication. We previously reported on a novel anti‐HIV‐1 compound, N2‐(phenoxyacetyl)‐N‐[4‐(1‐piperidinylcarbonyl)benzyl]glycinamide (14), that binds to the highly conserved phosphatidylinositol (4,5)‐bisphosphate (PI(4,5)P2) binding pocket of the HIV‐1 matrix (MA) protein. In this study, we re‐evaluate the hits from the virtual screen used to identify compound 14 and test them directly in an HIV‐1 replication assay using primary human peripheral blood mononuclear cells. This study resulted in the identification of three new compounds with antiviral activity; 2‐(4‐{[3‐(4‐fluorophenyl)‐1,2,4‐oxadiazol‐5‐yl]methyl})‐1‐piperazinyl)‐N‐(4‐methylphenyl)acetamide (7), 3‐(2‐ethoxyphenyl)‐5‐[[4‐(4‐nitrophenyl)piperazin‐1‐yl]methyl]‐1,2,4‐oxadiazole (17), and N‐[4‐ethoxy‐3‐(1‐piperidinylsulfonyl)phenyl]‐2‐(imidazo[2,1‐b][1,3]thiazol‐6‐yl)acetamide (18), with compound 7 being the most potent of these hits. Mechanistic studies on 7 demonstrated that it directly interacts with and functions through HIV‐1 MA. In accordance with our drug target, compound 7 competes with PI(4,5)P2 for MA binding and, as a result, diminishes the production of new virus. Mutation of residues within the PI(4,5)P2 binding site of MA decreased the antiviral effect of compound 7. Additionally, compound 7 displays a broadly neutralizing anti‐HIV activity, with IC50 values of 7.5–15.6 μM for the group M isolates tested. Taken together, these results point towards a novel chemical probe that can be used to more closely study the biological role of MA and could, through further optimization, lead to a new class of anti‐HIV‐1 therapeutics.
Phase 2 study of pre‐excision single‐dose intraoperative radiation therapy for early‐stage breast cancers
Authors: VanderWalde Noam A. , Jones Ellen L. , Kimple Randall J. , Moore Dominic T. , Klauber‐DeMore Nancy , Sartor Carolyn I. , Ollila David W.
Published: January 2013

BACKGROUND:

Intraoperative radiation therapy (IORT) allows delivery of high‐dose radiation at the time of lumpectomy, potentially sparing adjuvant daily radiation. A phase 2 study of pre‐excision IORT was performed for early‐stage breast cancer.

METHODS:

Patients ≥ 48 years of age with invasive ductal carcinoma, ≤ 3 cm, and clinically node‐negative were eligible for this study, which was approved by institutional review board. Ultrasound was used to select electron energy and cone size to cover the tumor plus 1.5‐ to 2.0‐cm lateral margins and 1‐cm‐deep margins (90% isodose). Fifteen Gy was delivered with a Mobetron irradiator, and immediate needle‐localized partial mastectomy followed. Local event results were updated using the Kaplan‐Meier method.

RESULTS:

A total of 53 patients received IORT alone. Median age was 63 years, and median tumor size was 1.2 cm. Of these, 81% were positive for estrogen receptor or progesterone receptor, 11% were positive for human epidermal growth factor receptor 2, and 15% were triple‐negative. Also, 42%, 49%, and 9% would have fallen into the Suitable, Cautionary, and Unsuitable groups, respectively, of the American Society of Therapeutic Radiation Oncology consensus statement for accelerated partial breast irradiation. Median follow‐up was 69 months. Ipsilateral events occurred in 8 of 53 patients. The 6‐year actuarial rate of ipsilateral events was 15% (95% confidence interval = 7%‐29%). The crude event rate for Suitable and Cautionary groups was 1 of 22 (5%) and 7 of 26 (27%), respectively. Overall survival was 94.4%, and breast cancer–specific survival was 100%.

CONCLUSIONS:

The rate of local events in this study is a matter of concern, especially in the Cautionary group. On the basis of these findings, pre‐excision IORT, as delivered in this study, may not provide adequate local control for less favorable early‐stage breast cancers. Cancer 2013. © 2013 American Cancer Society.
Exploiting compression and approximation paradigms for effective and efficient online analytical processing over sensor network readings in data grid environments
Authors: Cuzzocrea Alfredo , Saccà Domenico
Published: January 2013

Aggregate queries are useful tools in the context of sensor network‐based systems as they retrieve knowledge from huge amounts of summarized readings to be exploited for knowledge discovery purposes. Actually, data representation and query models are problematic issues for managing sensor network data, because streams produced by sensors are theoretically unbounded. In this paper, we present a Grid framework, called SensorGrid, on the basis of data compression and approximation paradigms, which allows us to provide approximate answers to aggregate queries on summarized sensor network data. These queries are the basis for achieving Online Analytical Processing (OLAP) over sensor network readings in Data Grid environments, with both effectiveness and efficiency. We also present our experience in the context of a real‐life system focused on the management of environmental sensor network data. Another contribution of our research is represented by the extensive experimental evaluation and analysis of SensorGrid, which, in more details, focuses on two main classes of aggregate range queries over sensor readings, namely, (i) the window queries, which apply an SQL aggregation operator over a fixed window over the reading stream produced by the sensor network, and (ii) the continuous queries, which instead consider a ‘moving’ window and produce as output a stream of answers. Both classes of queries are extremely useful to extract summarized knowledge to be exploited by OLAP‐like analysis tools over sensor network data. The experimental results, conducted on both synthetic and real‐life data sets, clearly confirm the benefits deriving from embedding data compression and approximation paradigms into Grid‐based sensor network data‐intensive management systems.Copyright © 2013 John Wiley & Sons, Ltd.
Improvement on the Catalytic Performance of Mg–Zr Mixed Oxides for Furfural–Acetone Aldol Condensation by Supporting on Mesoporous Carbons
Authors: Faba Laura , Díaz Eva , Ordóñez Salvador
Published: January 2013

A new procedure for improving the performance of the most common catalysts used in aqueous‐phase aldol condensation (Mg–Zr mixed oxides) reactions is presented. This reaction is of interest for upgrading carbohydrate feedstocks. The procedure involves supporting Mg–Zr oxides on non‐microporous carbonaceous materials, such as carbon nanofibers (CNFs) or high‐surface‐area graphites (HSAGs), using either incipient wetness or coprecipitation procedures. The use of HSAGs together with the coprecipitation method provides the best performance. Results obtained for the cross‐condensation of acetone and furfural at 323 K reveal that the catalyst performance is greatly improved compared to the bulk oxides (96.5 % conversion vs. 81.4 % with the bulk oxide; 87.8 % selectivity for C13 and C8 adducts vs. 76.2 % with the bulk oxide). This difference is even more prominent in terms of rates per catalytically active basic site (four and seven times greater for C8 and C13 adducts, respectively). The improved performance is explained in terms of a more appropriate basic site distribution and by greater interaction of the reactants with the carbon surface. In addition, deactivation behavior of the catalyst is improved by tuning the morphology of the carbonaceous support. An important enhancement of the catalytic stability can be obtained selecting a HSAG with an appropriate pore diameter. With HSAG100 the activity decreased by less than 20 % between successive reaction cycles and the selectivity for the condensation products remained almost unaltered. The decrease is greater than 80 % for the bulk oxides tested at these conditions, with important increases in the selectivity for by‐product formation.
Generation of knock‐in mice that express nuclear enhanced green fluorescent protein and tamoxifen‐inducible Cre recombinase in the notochord from Foxa2 and T loci
Authors: Imuta Yu , Kiyonari Hiroshi , Jang Chuan‐Wei , Behringer Richard R. , Sasaki Hiroshi
Published: January 2013

The node and the notochord are important embryonic signaling centers that control embryonic pattern formation. Notochord progenitor cells present in the node and later in the posterior end of the notochord move anteriorly to generate the notochord. To understand the dynamics of cell movement during notochord development and the molecular mechanisms controlling this event, analyses of cell movements using time‐lapse imaging and conditional manipulation of gene activities are required. To achieve this goal, we generated two knock‐in mouse lines that simultaneously express nuclear enhanced green fluorescent protein (EGFP) and tamoxifen‐inducible Cre, CreERT2, from two notochord gene loci, Foxa2 and T (Brachury). In Foxa2nEGFP‐CreERT2/+ and TnEGFP‐CreERT2/+ embryos, nuclei of the Foxa2 or T‐expressing cells, which include the node, notochord, and endoderm (Foxa2) or wide range of posterior mesoderm (T), were labeled with EGFP at intensities that can be used for live imaging. Cre activity was also induced in cells expressing Foxa2 and T 1 day after tamoxifen administration. These mice are expected to be useful tools for analyzing the mechanisms of notochord development. genesis 51:210–218, 2013. © 2013 Wiley Periodicals, Inc.
Conditional and domain‐specific inactivation of the Tsc2 gene in neural progenitor cells
Authors: Fu Cary , Ess Kevin C.
Published: January 2013

Tuberous sclerosis complex (TSC) is a genetic disease characterized by multiorgan benign tumors as well as neurological manifestations. Epilepsy and autism are two of the more prevalent neurological complications and are usually severe. TSC is caused by mutations in either the TSC1 (encodes hamartin) or the TSC2 (encodes tuberin) genes with TSC2 mutations being associated with worse outcomes. Tuberin contains a highly conserved GTPase‐activating protein (GAP) domain that indirectly inhibits mammalian target of rapamycin complex 1 (mTORC1). mTORC1 dysregulation is currently thought to cause much of the pathogenesis in TSC but mTORC1‐independent mechanisms may also contribute. We generated a novel conditional allele of Tsc2 by flanking exons 36 and 37 with loxP sites. Mice homozygous for this knock‐in Tsc2 allele are viable and fertile with normal appearing growth and development. Exposure to Cre recombinase then creates an in‐frame deletion involving critical residues of the GAP domain. Homozygous conditional mutant mice generated using Emx1Cre have increased cortical mTORC1 signaling, severe developmental brain anomalies, seizures, and die within 3 weeks. We found that the normal levels of the mutant Tsc2 mRNA, though GAP‐deficient tuberin protein, appear unstable and rapidly degraded. This novel animal model will allow further study of tuberin function including the requirement of the GAP domain for protein stability. genesis 51:284–292. © 2013 Wiley Periodicals, Inc.
Lewis Acid–Base Adducts of 1‐Mesityl‐ and 1‐Chloro‐2,3,4,5‐tetraphenylborole
Authors: Braunschweig Holger , Chiu Ching‐Wen , Gamon Daniela , Gruß Katrin , Hörl Christian , Kupfer Thomas , Radacki Krzysztof , Wahler Johannes
Published: January 2013

Electron‐deficient borole compounds exhibit a pronounced Lewis acidity that is enhanced due to their antiaromatic character so that even weak donors datively coordinate to form Lewis acid–base adducts. This contribution presents the synthesis and structural characterization of Lewis acid–base adducts formed by the reaction of 1‐mesityl‐2,3,4,5‐tetraphenylborole and 4‐picoline as well as 1‐chloro‐2,3,4,5‐tetraphenylborole with various donors. The new compounds are characterized by means of multinuclear NMR spectroscopy and single‐crystal X‐ray diffraction techniques and compared to related systems.
Palladium‐Catalyzed Allylic Arylation of Allylic Ethers with Arylboronic Acids Using Hydrazone Ligands
Authors: Mino Takashi , Kogure Taketo , Abe Taichi , Koizumi Tomoko , Fujita Tsutomu , Sakamoto Masami
Published: January 2013

Unsymmetrical 1,3‐diarylpropenes were synthesized in good to high yields by the palladium‐catalyzed allylic arylation of allylic ethers, such as a cinnamyl phenyl ether, with a variety of arylboronic acids using a hydrazone 1a–Pd(OAc)2 system in DMAc/H2O. Using this catalyst, eugenol was also synthesized from allyl phenyl ether with (4‐hydroxy‐3‐methoxyphenyl)boronic acid pinacol ester.
One‐Pot Preparation of Arylethynyl Sulfides and Bis(arylethynyl) Sulfides
Authors: Su Qiong , Zhao Zi‐Jian , Xu Feng , Lou Peng‐Cai , Zhang Kai , Xie De‐Xun , Shi Lei , Cai Qing‐Yun , Peng Zhi‐Hong , An De‐Lie
Published: January 2013

An efficient preparation for arylethynyl sulfides 1 and bis(arylethynyl) sulfides 2 has been accomplished through a one‐pot, three‐step strategy that starts from arylethanonyl sulfides and bis(arylethanonyl) sulfides, respectively, without the use of various terminal arylacetylenes as substrates. When lithium hexamethyldisilazane (LHMDS), ClP(O)(OEt)2, and LHMDS were sequentially added to a tetrahydrofuran solution of different substrates [arylethanonyl sulfides or bis(arylethanonyl) sulfides], 1 or 2 were obtained in moderate to good yields. The reaction procedure involves the formation of an enol phosphate and a subsequent base‐induced elimination.
Diversity ideologies and intergroup relations: An examination of colorblindness and multiculturalism
Authors: Rattan Aneeta , Ambady Nalini
Published: January 2013

In this review, we highlight the importance of understanding diversity ideologies, or people's beliefs and practices regarding diversity, for social psychological research on intergroup relations. This review focuses on two diversity ideologies, colorblindness and multiculturalism, and their impact on core issues related to intergroup conflict, such as stereotypes, prejudice, attitudes toward inequality, interracial interactions, and disparate outcomes between minority and majority group members. We close by highlighting some of the areas in which future research has the potential to be especially illuminating. Copyright © 2013 John Wiley & Sons, Ltd.
Graphite‐Composite Electrodes Bulk‐Modified with (BiO)2CO3 and Bi2O3 Plates‐Like Nanostructures for Trace Metal Determination by Anodic Stripping Voltammetry
Authors: Marinho Juliane Z. , Silva Rodrigo A. B. , Barbosa Tatielli G. G. , Richter Eduardo M. , Muñoz Rodrigo A. A. , Lima Renata C.
Published: January 2013

We describe the preparation of bismutite ((BiO)2CO3) and bismuth‐oxide (Bi2O3) plates‐like nanostructures and their incorporation within graphite‐composite electrodes for the determination of trace metals by anodic‐stripping‐voltammetry. The bismuth nanostructures were produced under microwave‐hydrothermal conditions followed by thermal conversion of as‐prepared precursor and characterized by X‐ray diffraction, Fourier‐transformed infrared and field‐emission scanning‐electron‐microscopy. Graphite‐composite electrodes bulk‐modified with Bi2O3 nanostructures provided higher sensitivity and lower detection limits for determinations of cadmium, lead and zinc (0.26; 0.52; and 2.23 µg L−1, respectively) employing short deposition time (60 s). The results indicate that the modification of graphite‐composite electrodes with Bi2O3 nanostructures improved analytical characteristics of electrochemical sensors for trace‐metal determinations.
Space shift keying with amplify‐and‐forward MIMO relaying
Authors: Mesleh Raed , Ikki Salama S.
Published: January 2013

Space shift keying (SSK) is a multiple‐input, multiple‐output system where the indices of the transmit antennas form the constellation symbols and no other data symbol is transmitted. In this paper, amplify‐and‐forward (AF) multiple‐input, multiple‐output relaying techniques with an SSK system are proposed and analysed. Single and multiple relays are located between the source and the destination and used to forward the transmitted messages from the source to the destination. Conventional AF relaying in which all relays amplify their received signal and forward it to the destination at specific time slot and opportunistic AF relaying where only the best relay is activated and all other relays are kept silent are considered. The receiver, with a single receive antenna, applies optimum detector to retrieve the transmitted information bits. Closed‐form bit error ratio expressions are provided for a source equipped with two transmit antennas. Additionally, a good approximate upper bound is derived for higher number of transmit antennas. The analytical results are validated through Monte Carlo simulation results. It is revealed that multiple relays can be considered to significantly enhance the performance of SSK system, and the diversity gain equals the number of existing relays. Copyright © 2013 John Wiley & Sons, Ltd.
Prehistoric Warfare in Central Arizona, USA: Assessing Its Scale with Ceramic Chemistry
Authors: Abbott David R. , Lack Andrew D.
Published: January 2013

The scale of warfare and alliance in the ancient American Southwest is hotly debated for the interval from A.D. 1100 to 1450. Some archaeologists posit conflict persistently waged in central Arizona, which thereby promoted the emergence of region‐sized polities, including the so‐called Verde Confederacy. Relying largely on settlement‐pattern data, these theorists have hypothesized warfare and alliance practiced at a regional scale, apparently larger than anywhere else in the prehistoric American Southwest. Other evidence, however, has challenged the Verde Confederacy model and the level at which hostilities raged in central Arizona. It calls into question the organizational capabilities of hostile tribal groups and their strategic goals. In this paper, we add a new line of complementary information based on the compositional analysis of phyllite‐tempered plain ware ceramics. By reconstructing the pottery's movement and exchange across the region, we outline patterns of interaction useful for evaluating the scale of alliance and warfare in central Arizona. We find, contrary to the expectations of regional scale alliances, that the ceramic exchange networks segregated some populations previously proposed to have been aligned, while integrating groups thought previously to have been enemies. The ceramic data indicate alliances and hostilities at a relatively local scale.
Hypofractionated palliative radiotherapy for advanced head and neck cancer: The IHF2SQ regimen
Authors: Monnier Laurie , Touboul Emmanuel , Durdux Catherine , Lang Philippe , St Guily Jean Lacau , Huguet Florence
Published: January 2013

Background

Standard treatment for unresectable advanced head and neck squamous cell carcinoma is chemoradiotherapy, which can be toxic, particularly among patients with coexisting medical conditions. We report our experience with the hypofractionated radiotherapy regimen Irradiation HypoFractionnée 2 Séances Quotidiennes (IHF2SQ).

Methods

We retrospectively reviewed 78 patients treated with the IHF2SQ regimen. Radiotherapy was administrated as 2 fractions of 3 Gy per day (days 1 and 3), during the first, third, fifth, and seventh week of treatment with concurrent platinum‐based chemotherapy.

Results

Tolerance was excellent. Forty‐one patients had complete or partial response. Median overall survival (OS) was 12.9 months and median progression‐free survival (PFS) was 10.3 months. One‐year OS, specific survival (SS), and PFS were 58%, 71%, 51.5%, respectively. Independent predictive factors increasing the PFS were response to chemoradiotherapy, male sex, and laryngeal tumor location.

Conclusions

This regimen is an alternative to conventional chemoradiotherapy with good response rates and acceptable toxicity for selected patients. © 2013 Wiley Periodicals, Inc. Head Neck 35: 1683–1688, 2013
Predictors of poor outcome in patients w ith autoimmune hepatitis: A population-based study
Authors: Ngu Jing Hieng , Gearry Richard Blair , Frampton Chris Miles , Stedman Catherine A.M.
Published: January 2013

Autoimmune hepatitis (AIH) can lead to cirrhosis, hepatic failure, and death. We aimed to identify predictors of advanced liver fibrosis at presentation, predictors of incomplete response to initial immunosuppression, and predictors of poor liver-related outcomes in the population-based AIH cohort from Canterbury, New Zealand. Cases diagnosed after 1980 that fulfilled standard diagnostic criteria were included. Cases were censored at death or liver transplantation and had a median follow-up of 9 years. Analyses were performed with Cox proportional hazards regression and logistic binary regression. The times to event outcomes were summarized using Kaplan-Meier curves. A total of 133 AIH patients were included. Predictors for advanced liver fibrosis at diagnosis were age at presentation of ≤20 years or >60 years (

P

= 0.02), serum albumin <36 g/L (

P

< 0.01), platelet <150 U/L (

P

< 0.01), and International Normalized Ratio (INR) >1.2 (

P

< 0.01). The only independent predictor for incomplete normalization of alanine aminotransferase (ALT) at 6 months was age at presentation ≤20 years. Independent predictors of poor liver-related outcomes were incomplete normalization of ALT at 6 months (

P

< 0.01), serum albumin <36 g/L (

P

< 0.01), and age at presentation of ≤20 years or >60 years (

P

= 0.01). Kaplan-Meier estimates showed that 10-year adverse liver event-free survival was 80% for age at presentation ≤20 years and >60 years, and 93% and 100% for age at presentation between 21-40 years and 41-60 years, respectively.

Conclusion

: Incomplete normalization of ALT at 6 months, low serum albumin concentration at diagnosis, and age at presentation of ≤20 years or >60 years were significant independent predictors of liver-related death or requirement for liver transplantation. Histological cirrhosis at diagnosis was not associated with poor prognosis and did not influence the response to initial immunosuppressive treatment.
In vitro cytocompatibility assessment of amorphous carbon structures using neuroblastoma and Schwann cells
Authors: Jain Shilpee , Sharma Ashutosh , Basu Bikramjit
Published: January 2013

The development of scaffolds for neural tissue engineering application requires an understanding of cell adhesion, proliferation, and migration of neuronal cells. Considering the potential application of carbon as scaffold materials and the lack of understanding of compatibility of amorphous carbon with neuronal cells, the carbon‐based materials in the forms of carbon films and continuous electrospun carbon nanofibers having average diameter of ∼200 nm are being investigated with or without ultraviolet (UV) and oxy‐plasma (OP) treatments for cytocompatibility property using mouse Neuroblastoma (N2a) and rat Schwann cells (RT4‐D6P2T). The use of Raman spectroscopy in combination with Fourier transform infrared (FTIR) and X‐ray diffraction establishes the amorphous nature and surface‐bonding characteristics of the studied carbon materials. Although both UV and OP treatments make carbon surfaces more hydrophilic, the cell viability of N2a cells is statistically more significant on OP treated fibers/films compared to UV fiber/film substrates after 4 days in culture. The electrospun carbon fibrous substrate provides the physical guidance to the cultured Schwann cells. Overall, the experimental results of this study demonstrate that the electrospun amorphous carbon nanofibrous scaffolds can be used as a suitable biomaterial substrate for supporting cell adhesion and proliferation of neuronal cells in the context of their applications as artificial nerve implants. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2013.
Fabrication of crosslinked carboxymethylchitosan microspheres and their incorporation into composite scaffolds for enhanced bone regeneration
Authors: Reves Benjamin T. , Bumgardner Joel D. , Haggard Warren O.
Published: January 2013

Carboxymethylchitosan (CMCS) microspheres were prepared by the carboxymethylation of chitosan (CS) beads using monochloroacetic acid. The CMCS microspheres were crosslinked using two different methods: the amine‐amine crosslinker genipin and carbodiimide chemistry, yielding Gen‐X CMCS and X‐CMCS beads, respectively. The Gen‐X CMCS beads were found to have poor degradation and drug release profiles. The X‐CMCS microspheres displayed good potential for use in tissue engineering applications in which degradation and local drug delivery are desired. The X‐CMCS beads displayed enzymatic degradation of 82.7 ± 1.2% in 100 μg/mL lysozyme after 1 month. An extended release of rhBMP‐2 for at least 45 days was also observed with the X‐CMCS microspheres. Scaffolds were formed by fusing beads together, and the X‐CMCS beads were successfully incorporated into composite X‐CMCS/CS scaffolds. The composite scaffolds had increased degradation of 14.5 ± 6.6% compared to 0.5 ± 0.4% for CS‐only scaffolds, and the X‐CMCS/CS scaffolds released more rhBMP‐2 at all timepoints. The composite scaffolds also supported the attachment and proliferation of SAOS‐2 cells. The addition of X‐CMCS beads resulted in fabrication of scaffolds with improved properties for use in bone tissue engineering. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2013.
Porous TiO2 surface formed on nickel‐titanium alloy by plasma electrolytic oxidation: A prospective polymer‐free reservoir for drug eluting stent applications
Authors: Huan Zhiguang , Fratila‐Apachitei Lidy E. , Apachitei Iulian , Duszczyk Jurek
Published: January 2013

In this study, a porous oxide layer was formed on the surface of nickel‐titanium alloy (NiTi) by plasma electrolytic oxidation (PEO) with the aim to produce a polymer‐free drug carrier for drug eluting stent (DES) applications. The oxidation was performed galvanostatically in concentrated phosphoric acid electrolyte at low temperature. It was found that the response of NiTi substrate during the PEO process was different from that of bulk Ti, since the presence of large amount of Ni delayed the initial formation of a compact oxide layer that is essential for the PEO to take place. Under optimized PEO conditions, the resultant surface showed porosity, pore density and oxide layer thickness of 14.11%, 2.40 × 105 pores/mm2 and 0.8 μm, respectively. It was additionally noted that surface roughness after PEO did not significantly increase as compared with that of original NiTi substrate and the EDS analyses revealed a decrease in Ni/Ti ratio on the surface after PEO. The cross‐section morphology showed no discontinuity between the PEO layer and the NiTi substrate. Furthermore, wettability and surface free energy of the NiTi substrate increased significantly after PEO treatment. The PEO process could be successfully translated to NiTi stent configuration proving for the first time its feasibility for such a medical device and offering potential for development of alternative, polymer‐free drug carriers for NiTi DES. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2013.
In vitro response of preosteoblastic MG63 cells on Ni‐free Ti shape memory substrates
Authors: Arciniegas M. , Peña J. , Gil F. J. , Manero J. M.
Published: January 2013

Ni‐free Ti alloys are a potential strategy to overcome the risk of Ni‐adverse reactions and rigidity mismatch for implant materials. Here, we report the biological behavior induced for two promising candidate alloys—Ti19.1Nb8.8Zr (MS temperature of 46°C and elastic modulus of 74 GPa) and Ti41.2Nb6.1Zr (elastic modulus of 67 GPa)—on cultured MG63 cells, as well as their physical and chemical properties. Contact angle results revealed the hydrophobic character of the former alloy (59.02° ± 2.35°) attributed to the presence of the martensitic phase, while the latter one presented a hydrophilic response (67.77° ± 2.78°). Results showed also that the cell adhesion response (after 4 and 8 h of incubation) in both substrates was not statistically different to that obtained in the cp Ti as control material. These surfaces induced well spread cell morphology with cytoplasmic extension like filopodia of up to 100 μm even at short culture times and presented an uninterrupted proliferation after longer incubation times (9 days). A decrement in the proliferation rate was appreciated from the Ti19.1Nb8.8Zr surface at that time, which was attributed to an earlier activation of the cell differentiation stage, as confirmed by the twofold increment of alkaline phosphatase activity. The results also evidenced that the presence of a 2 nm thick layer of amorphous Nb2O5, which was detected on both alloys, has a significant effect on cell behavior favoring the cell adhesion and morphology response of the new alloys studied. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2013.
Prediction of mechanical properties of multilayer gradient hydroxyapatite reinforced poly(vinyl alcohol) gel biomaterial
Authors: Yusong Pan , Qianqian Shen , Chengling Pan , Jing Wang
Published: January 2013

Functional graded materials provided us one new concept for artificial articular cartilage design with graded component and graded structure. In this article, a novel functional material design was proposed by functionalizing hydroxyapatite (HA) particles in poly(vinyl alcohol) (PVA) hydrogel. The goal of the present study was to fabricate a multilayer gradient HA/PVA gel biocomposites through layer‐by‐layer casting method combining with freeze/thaw cycle technology and establish a mechanical model to predict the compressive mechanical properties of multilayer gradient gel biocomposites. The results showed that the compressive strength of the multilayer gradient gel biocomposites increased with the rise of HA content, but it presented decreasing trend with the rise of interlayer gradient concentration of HA particles. Furthermore, the compressive strength of multilayer gradient biocomposites would be approximately predicted by the established mechanical model. The maximum error between theoretical compressive strength predicted by the model and the experimental strength is less than 7%. On the other hand, the compressive mechanical properties of multilayer gradient composites could be designed and controlled by the mechanical model as established in this study. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2013.
Self‐activated mesh device using shape memory alloy for periosteal expansion osteogenesis
Authors: Yamauchi Kensuke , Takahashi Tetsu , Tanaka Kenko , Nogami Shinnosuke , Kaneuji Takeshi , Kanetaka Hiroyasu , Miyazaki Toshiki , Lethaus Bernd , Kessler Peter
Published: January 2013

The present study evaluated the use of this self‐activated shape memory alloy (SMA) device, with a focus on its effects in the region under the periosteum. Twelve Japanese white rabbits were used in this study. The device was inserted under the periosteum at the forehead. In the experimental group, the device was pushed, bent, and attached to the bone surface and fixed with a titanium screw. In control group, the device was only inserted under the periosteum. After 14 days, the screw was removed and the mesh was activated in the experimental group. Rabbits were sacrificed 5 and 8 weeks after the operation and newly formed bone was histologically and radiographically evaluated. The quantitative data by the area and the occupation of newly formed bone indicated that the experimental group had a higher volume of new bone than the control group at each consolidation period. Histologically, some newly formed bone was observed and most of the subperiosteal space underneath the device was filled with fibrous tissue, and a thin layer of immature bone was observed in the control group. In the experimental group, multiple dome‐shaped bones, outlined by thin and scattered trabeculae, were clearly observed under the SMA mesh device. The use of self‐activated devices for the periosteal expansion technique may make it possible to avoid donor site morbidity, trans‐skin activation rods, any bone‐cutting procedure, and the following intermittent activation procedure. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2013.