bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of DNL‐6 with a High Concentration of Si (4 Al) Environments and its Application in CO2 Separation
Authors: Su Xiong , Tian Peng , Fan Dong , Xia Qinghua , Yang Yue , Xu Shutao , Zhang Lin , Zhang Ying , Wang Dehua , Liu Zhongmin
Published: April 2013

The synthesis of DNL‐6 with a high concentration of Si (4 Al) environments [Si/(Si+Al+P)=0.182 mol, denoted as M‐DNL‐6] is demonstrated. This represents the highest reported concentration of such environments in silicoaluminophosphate (SAPO) molecular sieves. Adsorption studies show that the high Si (4 Al) content in M‐DNL‐6, with an increased number of Brønsted acid sites in the framework, greatly promotes the adsorption of CO2. M‐DNL‐6 exhibits a large CO2 uptake capacity of up to 6.18 mmol g−1 at 273 K and 101 kPa, and demonstrates high ratios of CO2/CH4 and CO2/N2 separation. From breakthrough and cycling experiments, M‐DNL‐6 demonstrates the ability to completely separate CO2 from CH4 or N2 with a dynamic capacity of approximately 8.0 wt % before breakthrough. Importantly, the adsorbed CO2 is easily released from the adsorbent through a simple gas purging operation at room temperature to regain 95 % of the original adsorption capacity. These results suggest that M‐DNL‐6 can be used as a potential adsorbent for CO2 capture in pressure swing adsorption processes.
The Role of Technology in Policy Dynamics: The Case of Desalination in Israel
Authors: Teschner Naama , Garb Yaakov , Paavola Jouni
Published: April 2013

This article examines the relationship between technology and policy change, focusing on shifts in Israel's water regime as a case example. Technologies, especially systems of large‐scale infrastructures, have offered an explanation for the stability and stagnation of policy regimes in what has been termed “lock‐in” and path dependency. Our paper focuses on the reverse phenomenon: on how technology or change in it can induce policy change. Israeli decision‐makers have recently embraced desalination technology as a substitute for natural resources, because earlier policies, characterized by a strategy of environmental brinkmanship, have resulted in degradation of natural sources and risk future supply. This analysis is based on extensive document analysis and in‐depth interviews. We suggest that technological breakthroughs that rendered desalination economically feasible also undermined long‐lasting hydro‐ideological support for agriculture, introduced new ideas about water abundance and engendered policy change. Desalination contributed to these shifts because it allowed the displacement of environmental externalities, economic costs and hard political choices to other policy sectors and levels of governance as well as reallocating them between political actors, bureaucrats and professionals. It is important to make displacements like these more visible in order to emphasize more comprehensive and longer‐term problem solving rather than problem avoidance or postponement. Copyright © 2013 John Wiley & Sons, Ltd and ERP Environment.
Preparation of chitosan‐graft‐(β‐cyclodextrin) based sol‐gel stationary phase for open‐tubular capillary electrochromatography
Authors: Lü Haixia , Li Qingyin , Yu Xiaowei , Yi Jiaojiao , Xie Zenghong
Published: April 2013

A novel open‐tubular CEC column coated with chitosan‐graft‐(β‐CD) (CDCS) was prepared using sol‐gel technique. In the sol‐gel approach, owing to the 3D network of sol‐gel and the strong chemical bond between the stationary phase and the surface of capillary columns, good chromatographic characteristics and unique selectivity in separating isomers were shown. The column efficiencies of 55 000∼163 000 plates/m for the isomeric xanthopterin and phenoxy acid herbicides using the sol‐gel‐derived CDCS columns were achieved. Good stabilities were demonstrated that the RSD values for the retention time of thiourea and isoxanthopterin were 1.3 and 1.4% (run to run, n = 5), 1.6 and 2.0% (day to day, n = 3), 2.9 and 3.1% (column to column, n = 3), respectively. The sol‐gel‐coated CDCS columns have shown improved separations of isomeric xanthopterin in comparison with CDCS‐bonded capillary column.
SU‐8/Pyrex microchip electrophoresis with integrated electrochemical detection for class‐selective electrochemical index determination of phenolic compounds in complex samples
Authors: Castañeda Raquel , Vilela Diana , González María Cristina , Mendoza Sandra , Escarpa Alberto
Published: April 2013

A SU‐8/Pyrex single‐channel microchip integrating three 100 μm Pt electrodes (MCE‐ED) for class‐selective electrochemical index determination (CSEID) of phenolic acids and flavonoids in complex extracts of Tagetes lucida (Tl), Mentha piperita (Mp), Cymbopogon citratus (Cc), Calendula officinalis (Co), and Cynara scolymus (Cs) is proposed. Under strategic conditions controlled by a MES buffer (pH 5.0; 25 mM) and accordingly to the antioxidant acid‐base properties, the simultaneous measurement of total acids and flavonoids indexes was achieved in less than 100 s with excellent analytical performance. The reliability of MCE‐ED approach was demonstrated toward the high agreement between the total phenolic content obtained using microchip approach with those obtained by the well‐established HPLC‐DAD; revealing both identical order regarding the total phenolic content in the target samples. In addition, further comparison of MCE‐ED with the traditional Folin‐Ciocalteu antioxidant capacity assay, showed that MCE‐ED approach could become a class‐selective antioxidant capacity assay revealing that the sample antioxidant capacity was decreasing as Tl > Mp > Cs > Cc > Co according to their endogenous polyphenol content. These results suggested that the microchip approach is not only a reliable method for fast assessment of class‐selective antioxidants constituting a very good alternative to the long analysis times and the using of toxic solvents required in HPLC but a novel truly antioxidant capacity assay. This excellent analytical performance is connected with the key‐features of the “ready‐to‐use” system employed in this work such as portability, full integration of electrochemical detection, easy‐operation, and potential MCE‐ED disposability.
Seasonal emaciation causes tissue redistribution and an increased potential for toxicity of lipophilic pollutants in farmed arctic fox (Vulpes lagopus)
Authors: Helgason Lisa B. , Wolkers Hans , Fuglei Eva , Ahlstrøm Øystein , Muir Derek , Jørgensen Even H.
Published: April 2013

Many Arctic animals carry high body burdens of organochlorine contaminants (OCs) as a result of long-range transport of persistent pollutants. It has been shown that seasonal mobilization of body fat in these species results in increased blood concentration of OCs. The authors investigated OC assimilation, tissue distribution, and biotransformation in farmed Arctic fox (Vulpes lagopus) continuously fed a diet containing contaminated minke whale blubber or lard (control) from 8 wk of age in August 2003, until sampling when they were at their fattest (in November 2004) and leanest (in June 2005). Markedly higher tissue (liver, adrenals, brain, and blood) OC levels were found in June than in November despite low exposure to OCs during emaciation, suggesting that OCs had been redistributed from adipose tissues to vital organs. There were no differences in the activities of hepatic biotransforming enzymes between exposed fat and control fat foxes, except for 16α-hydroxylation, which was higher in exposed fat foxes. In emaciated foxes, ethoxyresorufin activity was higher in exposed than in control foxes, indicating an enhanced potential for toxicity of OCs with emaciation. Lower activities of 6β- and 2β-hydroxylation were found in lean than in fat foxes, irrespective of OC treatment. The results show that emaciation increase the toxic potential of accumulated OCs and emphasize that body adiposity must be considered when time-trend analyses, risk assessments, and effect studies are designed. Environ Toxicol Chem 2013;32:1784–1792. © 2013 SETAC
Options on Troubled Stock
Authors: Câmara António , Popova Ivilina , Simkins Betty
Published: April 2013

This study uses equilibrium arguments to derive closed‐form solutions for the price of European call and put options written on an individual stock when shareholders might lose all their claims on the firm. The stock price accounts for both a random probability of bankruptcy and a random probability of remaining a going concern. With a random probability of bankruptcy, shareholders lose all their claims in the firm. With a random probability of remaining a going concern, the stock price is lognormal as in the Black–Scholes model. The bankruptcy probability is correlated with aggregated wealth if the bankruptcy risk is systematic. The model is consistent with a bankruptcy probability negatively correlated with the firm's stock price. If the bankruptcy probability of a given firm increases then its stock price decreases which leads to the value of the call options written on that stock to decrease. This result is not obtainable under Merton's (1976) ruin model where the stock price and the bankruptcy probability are independent. © 2013 Wiley Periodicals, Inc. Jrl Fut Mark 34:637–657, 2014
Ontario Initiative Points to Renewal of Electricity Distribution Worldwide
Authors: McFadden David
Published: April 2013

The central importance of electricity distribution is often overlooked as attention is focused on the promise of shale gas generation; the renaissance of nuclear power; or the growth of wind, solar, and other forms of renewable generation. However, the efficient, reliable, and cost‐effective distribution of electricity is vital to any society's economic prosperity and standard of living.
Renewable Energy—Finance: Financing US Renewable Energy Projects in a Post‐Subsidy World
Authors: Sinaiko Daniel
Published: April 2013

The federal renewable energy production tax credit (PTC) was created in 1992 when Congress enacted the Energy Policy Act of 1992. The creation of the PTC for renewable energy generating projects signaled the birth of the modern renewable energy industry in the United States. In the years since its birth, the industry has grown in fits and starts, seeing the creation of the investment tax credit (ITC) in 2005 and no less than six extensions of the PTC.
End‐Users—Finance: Efficiency Financing That Provides Greatest Benefits
Authors: Benda George
Published: April 2013

Strong interest in reducing the energy component in building operation costs combined with challenges in availability of capital for improvements continues to drive demand for a variety of third‐party and off‐balance‐sheet financing methodologies for project implementation. There is no single right answer when it comes to financing. The key, always, is to pick the right arrangements for your building ownership.
Technology: Net‐Zero Buildings and Distributed Generation Forcing New Business Models
Authors: Skinner R. Kenneth
Published: April 2013

The Rocky Mountain Institute (RMI) recently published a report with an intriguing title—“Net Energy Metering, Zero Net Energy, and the Distributed Energy Resource Future: Adapting Electric Utility Business Models For The 21st Century.” Apart from the subject matter, the intriguing connection is the linking of net energy metering, zero net energy, and distributed energy with twenty‐first century business models. The report is intended to evaluate the potential implications for the utility and its customers of a future business environment characterized by high levels of customer energy efficiency, zero‐net‐energy buildings, and distributed generation (DG) by utility customers.
Validity of bioelectrical impedance analysis to assess fat‐free mass in patients with head and neck cancer: An exploratory study
Authors: Jager–Wittenaar Harriët , Dijkstra Pieter U. , Earthman Carrie P. , Krijnen Wim P. , Langendijk Johannes A. , van der Laan Bernard F.A.M. , Pruim Jan , Roodenburg Jan L.N.
Published: April 2013

ABSTRACT: Background

The purpose of this study was to validate bioelectrical impedance analysis (BIA) using the Geneva equation for fat‐free mass (FFM) in patients with head and neck cancer.

Methods

In 24 patients with head and neck cancer, agreement between BIA (FFMBIA) and dual energy x‐ray absorptiometry (FFMDXA) 1 week before (T0), 1 month (T1), and 4 months (T2) after cancer treatment was analyzed.

Results

FFMBIA did not differ from FFMDXA (mean difference 0.71 ± 1.9, 0.30 ± 1.9, and 0.02 ± 2.1 kg) at any time point. Only at T0, mean FFM correlated to the difference between FFMDXA and FFMBIA (r = 0.48; p = .017). Limits of agreement were 3.8, 3.7, and 4.1 kg, respectively. Concordance Correlation Coefficients were 0.98 at all time points.

Conclusion

BIA may be used to assess FFM with reasonable validity based on mean‐level comparisons, but differences between BIA and DXA may vary by about 4 kg in an individual patient. These results require confirmation in a larger sample of patients with head and neck cancer. © 2013 Wiley Periodicals, Inc. Head Neck 36: 585–591, 2014
Pharyngocutaneous fistula after salvage laryngectomy: Impact of interval between radiotherapy and surgery, and performance of bilateral neck dissection
Authors: Basheeth Naveed , O'Leary Gerard , Sheahan Patrick
Published: April 2013

Background

Pharyngocutaneous fistula is a serious complication of total laryngectomy. The purpose of this study was to examine predisposing factors at our institution.

Methods

We conducted a retrospective review of 94 consecutive patients undergoing total laryngectomy. Cases with hypopharyngeal primary tumors or undergoing extended hypopharyngeal resection with flap augmentation of the pharynx were excluded.

Results

Seventy‐four cases met inclusion criteria. A total of 25.7% patients developed a pharyngocutaneous fistula. The fistula rate was higher after salvage laryngectomy than after primary surgery (34.0% vs 11.1%; p = .05). Among salvage laryngectomies, performance of laryngectomy within 1 year of completion of radiotherapy (p = .006) and performance of concomitant bilateral neck dissection (p = .02) were significant risk factors for development of a fistula. Radiation dose, addition of chemotherapy, use of pectoralis major myofascial flap, preoperative tracheostomy, primary puncture, primary tumor subsite, and initial T classification were not significant.

Conclusion

Interval between completion of radiotherapy and surgery is significantly associated with pharyngocutaneous fistula after salvage total laryngectomy. © 2013 Wiley Periodicals, Inc. Head Neck 36: 580–584, 2014
The groundwater recharge regime of some slightly metamorphosed neoproterozoic sedimentary rocks: an application of natural environmental tracers
Authors: Yidana Sandow Mark , Koffie Eric
Published: April 2013

Isotope data of precipitation and groundwater in parts of the Voltaian Basin in Northern Ghana were used to explain the groundwater recharge regime in the area. Groundwater recharge is an important parameter in the development of a decision support system for the management and efficient utilization of groundwater resources in the area. It is therefore important to establish the processes and sources of groundwater recharge. δ18O and δ2H data for local precipitation suggest enrichment relative to the Global Meteoric Water Line (GMWL) and indicate that precipitation takes place at a relative humidity less than 100%. The groundwater data plot on an evaporation line with a slope of 5, suggesting a high degree of evaporative enrichment of the precipitation in the process of vertical infiltration and percolation through the unsaturated zone into the saturated zone. This finding is consistent with the observation of high evapotranspiration rates in the area and ties in with the fact that significant clay fraction in the unsaturated zone limits vertical percolation and thus exposes the percolating rainwater to the effects of high temperatures and low humidities resulting in high evapotranspiration rates. Groundwater recharge estimates from the chloride mass balance, CMB, method suggest recharge in the range of 1.8–32% of the annual average precipitation in the form of rainfall. The highest rates are associated with areas where open wells encourage significant amount of groundwater recharge from precipitation in the area. In the northern parts of the study area, groundwater recharge is lower than 12%. The recharge so computed through the application of the CMB methodology takes on a spatial distribution akin to the converse of the spatial pattern of both δ18O and δ2H in the area. As such, the locations of the highest recharge are associated with the most depleted values of the two isotopes. This observation is consistent with the assertion that low vertical hydraulic conductivities slow down vertical percolation of precipitation down to the groundwater water. The percolating precipitation water thus gets enriched in the heavier isotopes through high evapotranspiration rates. At the same time, the amount of water that finally reaches the water table is considerably reduced. Copyright © 2013 John Wiley & Sons, Ltd.
Occupational exposure to arsenic and risk of nonmelanoma skin cancer in a multinational European study
Authors: Surdu Simona , Fitzgerald Edward F. , Bloom Michael S. , Boscoe Francis P. , Carpenter David O. , Haase Richard F. , Gurzau Eugen , Rudnai Peter , Koppova Kvetoslava , Févotte Joëlle , Vahter Marie , Leonardi Giovanni , Goessler Walter , Kumar Rajiv , Fletcher Tony
Published: April 2013

Occupational studies show a high risk of lung cancer related to arsenic exposure by inhalation; however, only a few studies, and with conflicting results, previously examined a potential link between arsenic exposure at work and skin cancer. The aim of this study is to assess airborne arsenic exposures at the workplace and to quantify associations with nonmelanoma skin cancer (NMSC). The study sample consists of 618 incident cases of NMSC and 527 hospital‐based controls aged 30–79 years from Hungary, Romania and Slovakia. Exposures were evaluated by local experts using occupational histories. Information on host factors and other exposures was collected and used to adjust the associations of interest using multivariable logistic regression. The lifetime prevalence of exposure to work‐related arsenic is 23.9% for cases and 15.5% for controls. No significant association between arsenic exposure in the workplace and NMSC was detected, although an increased adjusted odd ratio was observed for participants with higher cumulative lifetime workplace exposure to arsenic in dust and fumes compared to referents [odds ratios (OR) = 1.94, 95% confidence interval (CI) = 0.76–4.95]. There is evidence for modification of the workplace arsenic–NMSC association by work‐related sunlight exposure in women, with a markedly increased adjusted OR in the presence of workplace sunlight exposure (OR = 10.22, 95% CI = 2.48–42.07). Workplace coexposure to arsenic and sunlight may thus pose an increased risk of NMSC.
Human Vγ2Vδ2 T cells limit breast cancer growth by modulating cell survival‐, apoptosis‐related molecules and microenvironment in tumors
Authors: Aggarwal Reeva , Lu Jingwei , Kanji Suman , Das Manjusri , Joseph Matthew , Lustberg Maryam B. , Ray Alo , Pompili Vincent J. , Shapiro Charles L. , Das Hiranmoy
Published: April 2013

Innate immune system has been known to play an important role in inhibiting the malignant transformation, tumor progression and invasion. However, the mechanistic basis remains ambiguous. Despite polyclonality of human γδ T cells, Vγ2Vδ2 T cell subset was shown to recognize and limit the growth of various tumors at various degrees. The differential recognition of the tumor cells by Vγ2Vδ2 T cells are yet to be defined. Our study reveals that γδ T cells limit in vitro growth of most breast tumor cells, such as SkBr7 (HER2+), MCF7 (ER+) and MDA‐MB‐231 (ER−) by inhibiting their survival and inducing apoptosis, except BrCa‐MZ01 (PR+) cells. To investigate detail mechanisms of antineoplastic effects, we found that cell death was associated with the surface expression levels of MICA/B and ICAM1. Molecular signaling analysis demonstrated that inhibition of cell growth by γδ T cells was associated with the lower expression levels of cell survival‐related molecules such as AKT, ERK and concomitant upregulation of apoptosis‐related molecules, such as PARP, cleaved caspase 3 and tumor suppressor genes PTEN and P53. However, opposite molecular signaling was observed in the resistant cell line after coculture with γδ T cells. In vivo, antineoplastic effects of γδ T cells were also documented, where tumor growth was inhibited due to the downregulation of survival signals, strong induction of apoptotic molecules, disruption of microvasculature and increased infiltration of tumor associated macrophages. These findings reveal that a complex molecular signaling is involved in γδ T cell‐mediated antineoplastic effects.
Optical coherence tomography for advanced screening in the primary care office
Authors: Shelton Ryan L. , Jung Woonggyu , Sayegh Samir I. , McCormick Daniel T. , Kim Jeehyun , Boppart Stephen A.
Published: April 2013

Optical coherence tomography (OCT) has long been used as a diagnostic tool in the field of ophthalmology. The ability to observe microstructural changes in the tissues of the eye has proved very effective in diagnosing ocular disease. However, this technology has yet to be introduced into the primary care office, where indications of disease are first encountered. We have developed a portable, handheld imaging probe for use in the primary care setting and evaluated its tissue site accessibility, ability to observe diseased tissue, and screening capabilities in in vivo human patients, particularly for pathologies related to the eye, ear and skin. Various stages of diabetic retinopathy were investigated using the handheld probe and early‐stage diabetic retinopathy was flagged as abnormal from the OCT images. At such early stages of disease, it is difficult to observe abnormalities with the limited tools that are currently available to primary care physicians. These results indicate that OCT shows promise to transform from being a diagnostic technology in the medical and surgical specialities to a screening technology in the primary care office and at the front‐line of healthcare. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Greenhouse gas fluxes and NO release from a Chinese subtropical rice‐winter wheat rotation system under nitrogen fertilizer management
Authors: Yao Zhisheng , Zheng Xunhua , Wang Rui , Dong Haibo , Xie Baohua , Mei Baoling , Zhou Zaixing , Zhu Jianguo
Published: April 2013

Although synthetic nitrogen fertilizers play an important role in increasing cereal grain yields, there have been increased concerns about their intensive utilization and environmental consequences. The overall goal of this study is to gain an insight into the integrated evaluation of greenhouse gas emission and nitric oxide (NO) release and grain yield as affected by nitrogen fertilization in a subtropical rice‐wheat rotation system. The assessment was based on four consecutive yearly measurements of the fluxes of methane (CH4), nitrous oxide (N2O) and ecosystem respiration (CO2), and the simultaneous observation of NO emissions in nonrice seasons under three fertilization practices (i.e., the conventional farmers’ practice with common nitrogen application rate, an alternative practice with reduced nitrogen input, and no nitrogen application as a control). Clearly, these trace gas fluxes showed largely intra‐annual and interannual variations, highlighting the importance of entire year measurement for multiple years to achieve representative annual estimates. The annual mean CH4 fluxes varied from 95 kg C ha–1 (7.8 kg C t–1 grain) for the farmers’ practice to 205 kg C ha–1 (25.7 kg C t–1 grain) for the control, indicating that nitrogen fertilization inhibited CH4 emissions. Across all the years, the annual N2O emissions increased exponentially with an increasing nitrogen rate and harvested aboveground biomass. The annual N2O emission averaged 1.3–5.3 kg N ha–1(159–444 g N t–1 grain) for all treatments. The annual direct emission factors of N2O‐N tended to increase with increasing nitrogen rate and averaged 0.61% and 0.85% for the alternative and farmers’ practices, respectively. Over all nonrice seasons, the seasonal mean NO emissions ranged from 0.15 to 1.4 kg N ha–1(58–253 g N t–1 grain), and were equivalent to 0.43% to 0.54% of the applied nitrogen. Averaging across the 4 years, the annual aggregate emissions of CH4 and N2O were 7.4 t CO2‐eq ha–1(928 kg CO2‐eq t–1grain) for the control and 5.6–5.7 t CO2‐eq ha–1(468–494 kg CO2‐eq t–1grain) for the fertilized treatments. Despite the comparable greenhouse effect between the alternative and farmers’ practices, reducing the common N rate by 37% resulted in decreased NO emission and increased nitrogen use efficiency, and negligible effects on economic return from grain yields.
Suzuki–Miyaura Cross‐Coupling of Potassium Organoborates with 6‐Sulfonate Benzimidazoles Using Microwave Irradiation
Authors: Jain Prashi , Yi Shuyan , Flaherty Patrick Thomas
Published: April 2013

This article focuses on the utility of organotrifluoroborate salts as coupling partners for Suzuki–Miyaura cross‐coupling with 4‐nitro‐6‐triflyl benzimidazoles using microwave irradiation. The C–C bond formation at the 6‐position of the electron‐rich 1‐,4‐,6‐trisubstituted benzimidazole core is challenging and was not achievable via Kumada, Negishi, Stille, or Heck coupling strategies. Yields of 37–70% could be obtained via palladium coupling strategies utilizing potassium benzyl trifluoroborates as the organometallic coupling partner.
Application of supercritical fluid extraction coupled with counter–current chromatography for extraction and online isolation of unstable chemical components from Rosa damascena
Authors: Li Sainan , Guo Liping , Liu Chunming , Zhang Yuchi
Published: April 2013

Supercritical fluid extraction (SFE) coupled with high‐speed counter‐current chromatography (HSCCC) was successfully used for the extraction and online isolation of the unstable compounds from Rosa damascene in a single extraction and separation operation in two stages. The solvent systems of SFE/HSCCC were optimized with the help of multiexponential function model. At the first stage, the upper phase of the solvent system of n‐butanol–tert‐butyl methyl ether–acetonitrile–0.1% aqueous TFA (1.7:1.0:0.8:4.0, v/v/v/v) was used as both the SFE entrainer and the HSCCC stationary phase, and the target compounds were eluted with the corresponding lower phase to separate the hydrophobic compounds. At the second stage, the upper phase of the solvent system of n‐hexane–ethyl acetate–methanol–water (3.2:1.0:2.8:2.6, v/v/v/v) was used as both the SFE entrainer and the HSCCC stationary phase, followed by elution with the corresponding lower phase to separate the moderate hydrophobic compounds. Six compounds including formononetin, delphinidin, cyaniding, 5,6,4′‐trihydroxy‐7,8‐dimethoxy flavone, 5,3′‐dihydroxy‐7,8‐dimethoxy flavone, and 5‐hydroxy‐6,7,8,3′,4′‐pentamethoxy flavone were successfully separated in one extraction–separation operation within 300 min. The targeted compounds were identified by MS and NMR spectroscopy. This research has opened up great prospects for industrial application of SFE/HSCCC to the extraction and separation of unstable compounds.
Tribological properties of nano‐calcium borate as lithium grease additive
Authors: Zhao Gaiqing , Zhao Qin , Li Weimin , Wang Xiaobo , Liu Weimin
Published: April 2013

Nano‐calcium borate (NCB) with an average particle size of about 70 nm was synthesised via ethanol supercritical fluid drying technique, and the morphology and microstructures of as‐prepared particles were characterised by means of scanning electron microscope (SEM, JEOL LTD., Tokyo, Japan) and X‐ray powder diffraction. The friction and wear behaviour of the NCB as additive in lithium grease were evaluated with an Optimol‐SRV IV (Optimol Instruments Prüftechnik GmbH, Munich, Germany) oscillating friction and wear tester (SRV tester). The morphology and surface composition of the worn surfaces of lower discs after SRV test were analysed by SEM and X‐ray photoelectron spectroscopy (XPS, Physical Electronics, Inc., USA). The result demonstrated that the anti‐wear and load‐carrying capacities of the lithium grease were significantly improved, and the friction coefficient of the lithium grease decreased with the addition of NCB additive. The analytical results of XPS indicate that the good tribological performance of NCB is attributable to the formation of a boundary lubrication film composed of deposited NCB and the tribochemical reaction products such as B2O3, CaO and iron oxides on the rubbing surface. Copyright © 2013 John Wiley & Sons, Ltd.
Generalized Appell bases
Authors: Maldonado M. , Prada J. , Senosiain M. J.
Published: April 2013

In the context of Köthe spaces we study the bases related with the backward unilateral weighted shift operator, the so‐called generalized derivation operator, extending known results for spaces of analytic functions. These bases are a subclass of Sheffer sequences called generalized Appell sequences and they are closely connected with the isomorphisms invariant by the weighted shift. We use methods of the non classical umbral calculi to give conditions for a generalized Appell sequence to be a basis.
Preparation and properties of PTFE/PAI nanocomposites
Authors: Antonioli Diego , Sparnacci Katia , Laus Michele , Boarino Luca , Righetti Maria Cristina
Published: April 2013

Polytetrafluoroethylene/poly(amide‐imide) PTFE/PAI nanocomposites were prepared by precipitation of TORLON® 4000TF (PAI) into a PTFE latex containing nanoparticles with average diameters of 41 nm and spherical shape. Several samples were obtained by varying the relative ratio between PAI and PTFE. SEM and PCS analysis indicates that the precipitation of PAI in the presence of PTFE leads mainly, if not exclusively, to bimodal mixtures of the two homoparticles. The PTFE crystallization process was quite complex and, depending on the sample composition, single or multiple crystallization exotherms were observed. This behavior, discussed within the fractionated crystallization frame, was revealing of the PTFE dispersion degree within the PAI matrix. When the PTFE amount is lower than 20%, a perfect PTFE nanoparticle dispersion is obtained. Partial aggregation is observed for PTFE amounts ranging from 20 to 40% whereas extensive aggregation is found for PTFE amount higher that 40%. The dynamic‐mechanical behavior indicates that the interactions at nanoparticle/polymer interface are rather weak. A greater increase in the relative modulus (Ec/Em) in the rubbery state region with respect to the glassy region is observed and was explained in terms of the particle aggregation state. POLYM. COMPOS., 34:1451–1459, 2013. © 2013 Society of Plastics Engineers
Resilience in the proteomics data ecosystem: How the field cares for its data
Authors: Martens Lennart
Published: April 2013

The public dissemination of data is an integral part of the life sciences. In the field of proteomics too, data sharing has taken off over the last few years, with the first downstream uses of these data quickly gaining prominence. At the same time, the recent unfortunate demise of two repositories, NCBI Peptidome and ProteomeCommons Tranche, has shown the frailty of such data gathering efforts. Heroic efforts by the PRIDE and Peptidome teams to rescue the Peptidome data have now ensured their continued availability to the field, and alternatives have already been put in place for Tranche. But with public data increasingly at the hub of the life sciences, it is a good time to look at the proteomics data ecosystem in some more detail.
Histone H4 lysine 16 acetylated isoform synthesis opens new route to biophysical studies
Authors: Pandita Tej K.
Published: April 2013

Histone H4 lysine acetylation regulated by MOF (males absent on the first) was initially discovered as a dosage compensation epigenetic mark. Recent studies have revealed, however, that the epigenetic mark has a critical role in cellular function both during oogenesis as well as oncogenesis. Detailed molecular analysis of H4K16 isoforms and other posttranslational modified histones has been limited by the lack of means to prepare sufficient material for in vitro study. This paper describes an improved method to prepare acetylated H4K16 as well as other covalently modified histone H4 isoform for biophysical studies.
Properties and use of statins in cardiovascular disease
Authors: Chaplin Steve , Collinson Paul
Published: April 2013

Steve Chaplin and Professor Paul Collinson provide an overview of the properties of statins and how they compare in lowering cholesterol levels and the prevention of cardiovascular disease.
Medicines optimisation — it's everybody's business
Authors: Mason Jonathan
Published: April 2013

Jonathan Mason explains the difference between medicines management and medicines optimisation, a new approach that places the focus on how or whether patients use their medicines.
Identification and characterization of peptides that bind the PPIase domain of Parvulin17
Authors: Elfaki Imadeldin , Knitsch Andre , Matena Anja , Bayer Peter
Published: April 2013

Peptidyl‐prolyl cis‐trans isomerases (PPIases) are the enzymes that increase the rate of isomerization of the peptide bond N‐terminal to the proline substrate. Par14 and its isoform Par17 belong to the Parvulin family of PPIases. Par14 can bind AT‐rich double‐stranded DNA and was shown to be part of the pre‐ribosomal ribonucleoprotein (pre‐rRNP) complexes, where it functions as an RNA processing factor that is involved in ribosome biogenesis. Its longer isoform Par17 is expressed only in cells of hominids, where it is targeted to the mitochondria. To find binding partners (peptides or proteins) for Par17, we applied the phage display technology. We panned 7‐mer and 12‐mer peptide libraries against Par17. The consensus sequence XHSXVHØ, where X can be any amino acid and Ø is a hydrophobic amino acid, was enriched from both libraries. We demonstrate the binding of this motif to the PPIase domain of Par17 using phage ELISA and NMR spectroscopy. We propose that residues Met90, Val91, Phe94, Gln95, Glu96, and Ala98 of Par17 are involved in substrate recognition, and that the phage display‐selected motif XHSXVHØ can be recognized by Par17 PPIase domain in vivo. Copyright © 2013 European Peptide Society and John Wiley & Sons, Ltd.
A graph‐based approach to find teleconnections in climate data
Authors: Kawale Jaya , Liess Stefan , Kumar Arjun , Steinbach Michael , Snyder Peter , Kumar Vipin , Ganguly Auroop R. , Samatova Nagiza F. , Semazzi Fredrick
Published: April 2013

Pressure dipoles are important long distance climate phenomena (teleconnection) characterized by pressure anomalies of the opposite polarity appearing at two different locations at the same time. Such dipoles have been proven important for understanding and explaining the variability in climate in many regions of the world, e.g. the El Niño Southern Oscillation (ENSO) climate phenomenon, which is described by opposite pressure anomalies between the west and east Pacific and is known to be responsible for precipitation and temperature anomalies worldwide. This paper presents a graph‐based approach called shared reciprocal nearest neighbor approach that considers only reciprocal positive and negative edges in the shared nearest neighbor graph to find the dipoles. One crucial aspect of our approach to the analysis of such networks is a careful treatment of negative correlations, whose proper consideration is critical for finding the dipoles. Further, our work shows the importance of modeling the time‐dependent patterns of the dipoles in a changing climate in order to better capture the impact of important climate phenomena on the globe. To show the utility of finding dipoles using our approach, we show that the data driven dynamic climate indices generated from our algorithm generally perform better than static indices formed from the fixed locations used by climate scientists in terms of capturing impact on global temperature and precipitation. Our approach can generate a single snapshot picture of all the dipole interconnections on the globe in a given dataset and thus makes it possible to study the changes in dipole interactions and movements. As teleconnections are crucial in the understanding of the global climate system, there is a pressing need to better understand the behavior and interactions of these atmospheric processes as well as to capture them precisely. Our systematic graph‐based approach to find the teleconnections in climate data is an attempt in that direction. © 2012 Wiley Periodicals, Inc. Statistical Analysis and Data Mining 6: 158–179, 2013
The relationship between end‐group concentrations and stability of spin‐coated thin polymer films investigated by ToF‐SIMS depth profiling
Authors: Ren Xianwen , Weng Lu‐Tao , Chan Chi‐Ming , Ng Kai‐Mo
Published: April 2013

Stable and unstable spin‐coated polymer films were prepared using various solvents and substrates. The relationship between polymer end‐group concentrations and stability of spin‐coated polymer films was revealed by time‐of‐flight secondary ion mass spectrometry depth profiling. A high concentration of bromine end groups at the interface between the polymer and the substrate helped to prevent the dewetting of films. In contrast, the bromine end groups were found to be more evenly distributed in unstable thin films. The extent to which the bromine end groups segregate to the interface depended on the competitive interactions between the polymer, the solvent and the substrate. Stronger polymer–solvent and solvent–substrate interactions prevented the segregation of the bromine end groups to the interface, resulting in unstable polymer films. Copyright © 2013 John Wiley & Sons, Ltd.
Cell Surface Engineering with Edible Protein Nanoshells
Authors: Drachuk Irina , Shchepelina Olga , Harbaugh Svetlana , Kelley‐Loughnane Nancy , Stone Morley , Tsukruk Vladimir V.
Published: April 2013

Natural protein (silk fibroin) nanoshells are assembled on the surface of Saccharomyces cerevisiae yeast cells without compromising their viability. The nanoshells facilitate initial protection of the cells and allow them to function in encapsulated state for some time period, afterwards being completely biodegraded and consumed by the cells. In contrast to a traditional methanol treatment, the gentle ionic treatment suggested here stabilizes the shell silk fibroin structure but does not compromise the viability of the cells, as indicated by the fast response of the encapsulated cells, with an immediate activation by the inducer molecules. Extremely high viability rates (up to 97%) and preserved activity of encapsulated cells are facilitated by cytocompatibility of the natural proteins and the formation of highly porous shells in contrast to traditional polyelectrolyte‐based materials. Moreover, in a high contrast to traditional synthetic shells, the silk proteins are biodegradable and can be consumed by cells at a later stage of growth, thus releasing the cells from their temporary protective capsules. These on‐demand encapsulated cells can be considered a valuable platform for biocompatible and biodegradable cell encapsulation, controlled cell protection in a synthetic environment, transfer to a device environment, and cell implantation followed by biodegradation and consumption of protective protein shells.
Resistless Nanoimprinting in Metal for Plasmonic Nanostructures
Authors: Varghese Leo T. , Fan Li , Xuan Yi , Tansarawiput Chookiat , Kim Sangsik , Qi Minghao
Published: April 2013

Metal nanostructures are the main building blocks of metamaterials and plasmonics which show many extraordinary properties not existing in nature. A simple and widely applicable method that can directly pattern metals with silicon molds without the need of resists, using pressures of <4 MPa and temperatures of 25–150 °C is reported. Three‐dimensional structures with smooth and vertical sidewalls, down to sub‐10 nm resolution, are generated in silver and gold films in a single patterning step. Using this nanopatterning scheme, large‐scale vivid images through extraordinary optical transmission and strong surface‐enhanced Raman scattering substrates are realized. Resistless nanoimprinting in metal (RNIM) is a new class of metal patterning that allows plasmonic nanostructures to be fabricated quickly, repeatedly, and at a low‐cost.
Generating Novel Options during Systems Architecting: Psychological Principles, Systems Thinking, and Computer‐Based Aiding
Authors: Madni Azad M.
Published: April 2013

Systems Architecting is a decision‐intensive process that stands to benefit from access to historical architectural options and the ability to rapidly generate novel ones. Despite this recognition, option generation, and, more precisely, the process of creative option generation has been underemphasized in both the decision making and system architecting literature. This paper reviews the literature on option generation from the perspective of systems architecting. It presents a framework for option generation that exploits systems thinking and psychological principles for stimulating creative option generation. It presents the system concept of an option generation aiding system that can assist systems architects in expanding and systematically exploring the option space in the early stages of architecting and design when cost avoidance is more easily achieved and change is possible.
Absorbable gelatin plug does not prevent iatrogenic preterm premature rupture of membranes after fetoscopic laser surgery for twin–twin transfusion syndrome
Authors: Papanna R. , Mann L. K. , Moise K. Y. , Johnson A. , Moise K. J.
Published: April 2013

Objective

Despite fetoscopic laser ablation (FLA) having emerged as an effective treatment for twin–twin transfusion syndrome (TTTS), major postintervention challenges, such as iatrogenic preterm premature rupture of membranes (iPPROM), remain. A chorioamniotic plug (CAP) made of absorbable gelatin sponge has been used to seal the trocar entry site in the chorioamniotic layers to promote healing and prevent iPPROM, yet the results have been equivocal. Our objective was to test the hypothesis that, following FLA for TTTS, iPPROM may be prevented by placement of an absorbable gelatin CAP.

Methods

A retrospective cohort study was performed on prospectively collected data from 134 consecutive patients who underwent FLA for TTTS. The decision for CAP placement was at the discretion of the physician. Preoperative, operative and postoperative variables were collected and analyzed. The primary outcome was the incidence of iPPROM, and the secondary outcomes were procedure‐to‐delivery interval and gestational age at delivery. Comparative statistical analysis was performed as appropriate.

Results

A CAP was placed in 72 (54%) of 134 patients. Factors significantly associated with CAP placement were higher gravidity (P = 0.03), anterior placentation (P = 0.04), general endotracheal intubation (P = 0.02) and a cannula diameter of 12‐Fr (P = 0.003). There were no differences between CAP and no‐CAP groups in the rate of iPPROM (39% vs 34%, respectively; P = 0.42) or in the procedure‐to‐delivery interval (65.3 ± 34.7 days vs 58.2 ± 30.8 days, respectively; P = 0.21). The gestational age at delivery was later in the CAP group compared with the no‐CAP group (30.7 ± 4.5 weeks vs 28.9 ± 3.9 weeks, respectively; P = 0.02).

Conclusions

CAP did not reduce the overall risk for iPPROM and did not increase the procedure‐to‐delivery interval. Further research is needed to identify other methods to prevent iPPROM and prolong pregnancy after laser therapy. Copyright © 2013 ISUOG. Published by John Wiley & Sons Ltd.
Nuchal translucency and major congenital heart defects in fetuses with normal karyotype: a meta‐analysis
Authors: Sotiriadis A. , Papatheodorou S. , Eleftheriades M. , Makrydimas G.
Published: April 2013

Objective

To pool published data regarding the sensitivity and specificity of nuchal translucency (NT) in the diagnosis of major congenital heart defects (CHDs) in fetuses with normal karyotype.

Methods

MEDLINE and Scopus searches using combinations of the terms ‘nuchal’ and ‘cardiac*’ were complemented by perusal of references of the retrieved articles and an additional automated search using the ‘search for related articles’ function on PubMed. Only fetuses with normal karyotype and major CHDs were analyzed. Weighted estimates were made and summary receiver–operating characteristics curves were constructed.

Results

The analysis included 20 studies (205 232 fetuses; 537 cases with major CHDs). The pooled sensitivity and specificity of NT > 95th centile for diagnosis of major CHDs was 44.4% (95% CI, 39.5–49.5) and 94.5% (95% CI, 94.4–94.6), respectively. The pooled sensitivity and specificity of NT > 99th centile was 19.5% (95% CI, 15.9–23.5) and 99.1% (95% CI, 99.1–99.2), respectively. For the subgroup of studies in which NT was measured by Fetal Medicine Foundation‐certified operators, the pooled sensitivity and specificity of NT > 95th centile was 45.6% (95% CI, 39.6–51.7) and 94.7% (95% CI, 94.6–94.9), respectively. The corresponding estimates for NT > 99th centile were 21.0% (95%CI, 16.5–26.1) and 99.2% (95% CI, 99.2–99.3). The pooled positive likelihood ratio for NT > 99th centile was 30.5 (95% CI, 24.3–38.6). There was high across‐studies heterogeneity for most estimates.

Conclusion

Approximately 44% of chromosomally normal fetuses with CHDs have NT > 95th centile and 20% have NT > 99th centile. However, there is high heterogeneity across studies, which largely remains even in subgroup analyses of studies of apparently similar design, potentially indicating the presence of some residual unidentified bias. Copyright © 2013 ISUOG. Published by John Wiley & Sons Ltd.
Human ferritin for tumor detection and therapy
Authors: Fan Kelong , Gao Lizeng , Yan Xiyun
Published: April 2013

Ferritin, a major iron storage protein found in most living organisms, is composed of a 24‐subunit protein cage with a hollow interior cavity. Serum ferritin serves as a critical marker to detect total body iron status. However, recent research reveals a number of novel functions of ferritin besides iron storage; for example, a ferritin receptor, transferrin receptor 1 (TfR1), has been identified and serum ferritin levels are found to be elevated in tumors. A particular new finding is that magnetoferritin nanoparticles, biomimetically synthesized using H‐chain ferritin to form a 24‐subunit cage with an iron oxide core, possess intrinsic dual functionality, the protein shell specifically targeting tumors and the iron oxide core catalyzing peroxidase substrates to produce a color reaction allowing visualization of tumor tissues. Here we attempt to summarize current research on ferritin, particularly newly identified functions related to tumors, in order to address current challenges and highlight future directions. WIREs Nanomed Nanobiotechnol 2013, 5:287–298. doi: 10.1002/wnan.1221

This article is categorized under:

Diagnostic Tools > In Vitro Nanoparticle-Based Sensing

Diagnostic Tools > In Vivo Nanodiagnostics and Imaging

Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease
Ammonothermal Synthesis and Crystal Structure of BaAl2(NH2)8·2NH3
Authors: Pust Philipp , Schmiechen Sebastian , Hintze Frauke , Schnick Wolfgang
Published: April 2013

BaAl2(NH2)8·2NH3 was synthesized starting from an intermetallic phase with nominal composition Al2Ba under ammonothermal conditions in a stainless‐steel autoclave at 823 K and 245 MPa. Single crystals were grown on aluminum substrates and prepared under low‐temperature conditions. The crystal structure (R$\bar{3}$c (no. 167), a = 15.7370(17), c = 28.804(6) Å, Z = 1, 1829 reflections, 65 parameters, wR2 = 0.07) was solved on the basis of single‐crystal X‐ray diffraction data. BaAl2(NH2)8·2NH3 contains isolated Al(NH2)4‐tetrahedra forming two different types of channels along [001].