bluuebunny/crossref_metadata_2025 huggingface dataset:
Beneficial Cardiometabolic Actions of Telmisartan Plus Amlodipine Therapy in Elderly Patients With Poorly Controlled Hypertension
Authors: Bekki Hisatoshi , Yamamoto Kiichiro , Sone Masayoshi , Homma Tomoki , Nakata Masashi , Nohara Masatoshi , Fukami Kei , Okuda Seiya , Yamagishi Sho‐ichi
Published: February 2011

Background

There is a growing body of evidence that blood pressure (BP) level is one of the major determinants of cardiovascular morbidity and mortality in individuals, including elderly people. However, to achieve a target BP level in the elderly is more difficult compared with patients aged <65 years. Current guidelines recommend combination drug therapy with different modes of action for the treatment of elderly patients with moderate hypertension (HT). However, the optimal combination regimen is not well established in elderly HT.

Hypothesis

We hypothesized that combination therapy of telmisartan plus amlodipine would exert favorable cardiometabolic actions in elderly HT.

Methods

Seventeen elderly patients with essential HT who failed to achieve a target home BP level with treatment of 5 mg amlodipine plus 80 mg valsartan or 8 mg candesartan for at least 2 months were enrolled. Then the patients were assigned to replace their valsartan or candesartan with 40 mg telmisartan. The subjects were instructed to measure their own BP at home every day during the study periods.

Results

Replacement of valsartan or candesartan by telmisartan in amlodipine‐treated elderly hypertensive patients showed a significant reduction in morning home systolic BP and evening home systolic and diastolic BP at 12 weeks. Switching to telmisartan significantly increased serum adiponectin level.

Conclusions

Our present study suggests that combination therapy with telmisartan plus amlodipine may exert more beneficial cardiometabolic effects in elderly patients with HT compared with valsartan or candesartan plus amlodipine treatment. © 2011 Wiley Periodicals, Inc.

This work was supported in part by Grants of Collaboration with Venture Companies Project from the Ministry of Education, Culture, Sports, Science and Technology, Japan (to S.Y.). The authors have no other funding, financial relationships, or conflicts of interest to disclose.
A novel serum carbohydrate marker on mucin 5AC
Authors: Silsirivanit Atit , Araki Norie , Wongkham Chaisiri , Pairojkul Chawalit , Narimatsu Yoshiki , Kuwahara Kazuhiko , Narimatsu Hisashi , Wongkham Sopit , Sakaguchi Nobuo
Published: February 2011

BACKGROUND:

The incidence of cholangiocarcinoma (CCA) is increasing globally. Currently, there is no powerful marker for the diagnosis of CCA, which has led to late diagnosis and poor patient outcome. This study was designed to establish a new monoclonal antibody (MoAb) for detecting a serum marker associated with CCA.

METHODS:

Pooled CCA tissue extracts were immunized to germinal center associated nuclear protein (GANP)‐transgenic mice. The antibody‐producing hybridomas were prepared and initially screened by using an indirect enzyme‐linked immunosorbent assay (ELISA). A positive clone that reacted strongly with CCA serum or tumor tissue extract and failed to react with normal human serum and liver extract was selected.

RESULTS:

An S121 immunoglobulin M MoAb that recognized a novel glycan epitope was obtained. Immunohistochemistry of CCA tissues revealed that the MoAb reacted strongly with hyperplastic/dysplastic and neoplastic bile ducts but not with normal bile ducts. In addition, experiments demonstrated that mucin 5AC (MUC5AC) is a core glycoprotein for the S121 epitope. A sandwich ELISA using soybean agglutinin and an S121 MoAb was developed for detecting S121 reactive antigen in patient sera. The level of serum S121 from patients with CCA was reduced significantly after tumor removal, indicating the tumor origin of this antigen. The test was able to distinguish patients with CCA from healthy individuals, active Opisthorchis viverrini‐infected individuals and patients with various gastrointestinal cancers, hepatoma, and benign hepatobiliary diseases with 87.63% sensitivity, 89.58% specificity, an 80.95% positive predictive value, and a 93.47% negative predictive value. Moreover, high serum S121 levels were related to a poor patient outcome.

CONCLUSIONS:

The sugar antigen recognized by S121 MoAb is a new serum marker for the diagnosis and prognosis of CCA. Cancer 2011. © 2011 American Cancer Society.
On the regularization mechanism for the periodic Korteweg–de Vries equation
Authors: Babin Anatoli V. , Ilyin Alexei A. , Titi Edriss S.
Published: February 2011

In this paper we develop and use successive averaging methods for explaining the regularization mechanism in the the periodic Korteweg–de Vries (KdV) equation in the homogeneous Sobolev spaces Ḣs for s ≥ 0. Specifically, we prove the global existence, uniqueness, and Lipschitz‐continuous dependence on the initial data of the solutions of the periodic KdV. For the case where the initial data is in L2 we also show the Lipschitz‐continuous dependence of these solutions with respect to the initial data as maps from Ḣs to Ḣs for s ∈(−1,0]. © 2010 Wiley Periodicals, Inc.
Behavioral modeling of pipeline ADC building blocks
Authors: Ruiz‐Amaya Jesús , Delgado‐Restituto Manuel , Rodríguez‐Vázquez Ángel
Published: February 2011

This paper presents accurate behavioral models for the basic building blocks of pipeline data converters with emphasis on the MDAC circuit. These models take into account major circuit‐level non‐idealities, including small‐ and large‐signal effects, as well as the impact of switch‐on resistance effects and thermal noise contributions. The behavioral models have been validated against transistor‐level simulations under different scenarios, showing in all cases a worst‐case deviation of 0.3 bit effective resolution. Copyright © 2011 John Wiley & Sons, Ltd.
Routing and mobility approaches in IPv6 over LoWPAN mesh networks
Authors: Oliveira Luís M. L. , de Sousa Amaro F. , Rodrigues Joel J. P. C.
Published: February 2011

It is foreseeable that any object in the near future will have an Internet connection—this is the Internet of Things vision. All these objects will be able to exchange and process information, most of them characterized by small size, power constrained, small computing and storage resources. In fact, connecting embedded low‐power devices to the Internet is considered the biggest challenge and opportunity for the Internet. There is a strong trend of convergence towards an Internet‐based solution and the 6LoWPAN may be the convergence solution to achieve the Internet of Things vision. Wireless mesh networks have attracted the interest of the scientific community in recent years. One of the key characteristics of wireless mesh networks is the ability to self‐organize and self‐configure. Mesh networking and mobility support are considered crucial to the Internet of Things success. This paper surveys the available solutions proposed to support routing and mobility over 6LoWPAN mesh networks. Copyright © 2011 John Wiley & Sons, Ltd.
A low‐complexity MSK‐based M‐ary cyclic‐shift keying transceiver for direct sequence spread spectrum system over multipath fading channels
Authors: Deng Juinn‐Horng , Chiu Yu‐Lun , Hwang Jeng‐Kuang
Published: February 2011

In this paper, a low‐complexity spread spectrum system with M‐ary cyclic‐shift keying (MCSK) symbol spreading is proposed. In addition, by using the minimum‐shift‐keying (MSK) as the chip‐level modulation, we obtain a high‐rate QPSK‐MCSK transceiver scheme which not only provides a constant‐envelop and continuous‐phase transmitted signal, but can also achieve a better performance than the conventional direct sequence spread spectrum (DSSS) system. At the transmitter, the data stream is first mapped into QPSK‐MCSK symbols in terms of orthogonal Gold code sequences, then followed by the cyclic prefix (CP) insertion for combating the interblock interference, and finally applying the MSK scheme to maintain the constant‐envelope property. The receiver first performs MSK demodulation, then CP removal, and finally the channel‐included MCSK despreading and symbol demapping. Furthermore, the single input single output (SISO) QPSK‐MCSK transceiver can be easily extended to the multiple input single output (MISO) case by incorporating the space–time block coding for high‐link quality. Simulation results show that the proposed SISO and MISO QPSK‐MCSK systems significantly outperform the conventional DSSS counterparts under the AWGN channel, and attain a more robust performance under the multipath fading channel. Copyright © 2011 John Wiley & Sons, Ltd.
Long‐term diabetic complications may be ameliorated by targeting Rho kinase
Authors: Zhou Hong , Li Yongjun
Published: February 2011

This review addresses the roles of Rho/Rho‐kinase (ROCK) pathway in the pathogenesis of diabetes complications. Diabetes can cause many serious complications and can result in physical disability or even increased mortality. However, there are not many effective ways to treat these complications. The small guanosine‐5′‐triphosphate‐binding protein Rho and its downstream target Rho‐kinase mediate important cellular functions, such as cell morphology, motility, secretion, proliferation, and gene expression. Recently, the Rho/Rho‐kinase pathway has attracted a great deal of attention in diabetes‐related research. These studies have provided evidence that the activity and gene expression of Rho‐kinase are upregulated in some tissues in animal models of type 1 or type 2 diabetes and in cell lines cultured with high concentrations of glucose. Inhibitors of Rho‐kinase could prevent or ameliorate the pathological changes in diabetic complications. The inhibitory effects of statins on the Rho/Rho‐kinase signalling pathway may also play a role in the prevention of diabetic complications. However, the precise molecular mechanism by which the Rho/Roh‐kinase pathway participates in the development or progression of diabetic complications has not been extensively investigated. This article evaluates the relationship between Rho/Roh‐kinase tivation and diabetic complications, as well as the roles of Roh‐kinase inhibitors and statins in the complications of diabetes, with the objective of providing a novel target for the treatment of long‐term diabetic complications. Copyright © 2011 John Wiley & Sons, Ltd.
Predictors of response to dipeptidyl peptidase‐4 inhibitors: evidence from randomized clinical trials
Authors: Monami Matteo , Cremasco Francesco , Lamanna Caterina , Marchionni Niccolò , Mannucci Edoardo
Published: February 2011

Aim

Dipeptidyl peptidase‐4 (DPP‐4) inhibitors are used in the treatment of type 2 diabetes. Available sub‐group analysis of clinical trials does not allow a clear identification of predictors of therapeutic response to these drugs. The aim of this study is the assessment of predictors of response to DPP‐4 inhibitors.

Materials and methods

A meta‐analysis was performed, exploring correlation between 24‐week effects on HbA1c of maximal doses of DPP‐4 inhibitors, compared either with placebo or with other active drugs, matches to baseline characteristics of patients enrolled in 63 randomized clinical trials, either published or unpublished but disclosed on different websites were studied.

Results

DPP‐4 inhibitors significantly reduce HbA1c at 24 weeks [by 0.6 (0.5–0.7)%] when compared with placebo; no difference in HbA1c was observed in comparisons with thiazolidinediones and α‐glucosidase inhibitors, whereas sulfonylureas and metformin produced a greater reduction of HbA1c, at least in the short term. DPP‐4 inhibitors produced a smaller weight gain than thiazolidinediones, and showed a lower hypoglycaemia risk than sulfonylureas. The placebo‐subtracted effect of DPP‐4 inhibitors on HbA1c was greater in older patients and in those with lower fasting plasma glucose at baseline. Similar results were obtained in comparisons with thiazolidinediones and metformin.

Conclusions

Although drugs for type 2 diabetes are studied in heterogeneous samples of patients, their efficacy can be predicted by some clinical parameters. DPP‐4 inhibitors appear to be more effective in older patients with mild/moderate fasting hyperglycaemia. These data could be useful for a better definition of the profile of patients who are likely to benefit most from these drugs. Copyright © 2011 John Wiley & Sons, Ltd.
Precision improvement for omeprazole determination through stability evaluation
Authors: Peralta Cecilia Mariana , Fernández Liliana Patricia , Masi Adriana Noemí
Published: February 2011

A new spectrofluorimetric method for the determination of omeprazole (OMP) based on its degradation reaction catalyzed by ultraviolet (UV) light is proposed. OMP in aqueous solution is very unstable, which renders a serious difficulty for controlling its quality. It does not show native fluorescence, but when exposed to UV radiation, it generates a highly fluorescent degradation product with adequate stability for indirect OMP quantification. Under the studied optimal experimental conditions (pH, temperature, exposure time to UV radiation), a specific rate constant of 2.851 min−1‐described by zero‐order kinetic—was obtained for the degradation reaction. Using λexc 293 nm and λem 317 nm, a linear relationship was obtained (r2 0.9998) in the concentration range of 0.1 to 1.3 µg mL−1, with a detection limit of 1.07 10−3 µg mL−1 (S/N = 3). The methodology developed was successfully applied to OMP quality control in pure drugs and tablet dosage forms without previous treatment, with good tolerance to common excipient, and a high level of concordance between the nominal and experimental values. This work constitutes an important contribution to knowledge of the degradation mechanism of OMP. It has been shown to be appropriate for OMP quality control, to have an adequate sampling rate, low cost instrument, and to be a less polluting procedure. Copyright © 2011 John Wiley & Sons, Ltd.
Calix[4]arene with Lower‐Rim β‐Amino α,β‐Unsaturated Ketones Containing Bis‐Chelating Sites as a Highly Selective Fluorescence Turn‐On Chemosensor for Two Copper(II) Ions
Authors: Ho I‐Ting , Chu Jean‐Ho , Chung Wen‐Sheng
Published: February 2011

We report herein the synthesis of a fluorescence turn‐on chemosensor, 25,27‐bis{N‐[1‐(4‐{[4‐amino‐4‐(1‐naphthyl)‐2‐oxo‐3‐butenyl]oxy}phenyl)aminocarbonyl]methoxy}‐26,28‐dihydroxycalix[4]arene (3b), which is highly selective toward Cu2+. The fluorescence intensity of 3b was enhanced upon adding [Cu(ClO4)2], which reached a maximum with approximately 4 equiv. of Cu2+ but then started to decrease in intensity at higher Cu2+ concentrations. Job plot experiments revealed a 1:2 binding stoichiometry of 3b with Cu2+. Based on 1H NMR titration results, we infer that there are two possible binding sites for Cu2+ in 3b: one at the lower‐rim phenolic‐OH and amide groups, and the second at the β‐amino α,β‐unsaturated ketone groups. It is important to note that during the complexation of 3b with [Cu(ClO4)2], the Cu2+ ions were reduced to Cu+ by both the phenolic OH and the amines of the β‐amino α,β‐unsaturated ketones. Furthermore, control compounds 6 and 9b were synthesized to clarify the possible binding sites of Cu2+ in 3b. By comparing the binding constants of 3b, 6, and 9b with Cu2+, we found that 3b exhibited a positive allosteric behavior toward the coordination of two Cu2+ ions.
Potassium Fluoride Supported on Natural Nanoporous Zeolite: A New Solid Base for the Synthesis of Diaryl Ethers
Authors: Khalilzadeh Mohammad A. , Hosseini Abolfazl , Pilevar Afsaneh
Published: February 2011

An efficient and inexpensive synthesis of diaryl ethers has been developed. The process involves the nucleophilic aromatic substitution of electron‐deficient aryl halides and phenols and is mediated by potassium fluoride/Clinoptilolite (KF/CP) in dimethyl sulfoxide (DMSO). The approach affords good to excellent yields of the arylated products without the need for additional cation capture. The solid base is also efficient in the Ullmann ether synthesis.
Evolution and Synthetic Applications of the Heck–Matsuda Reaction: The Return of Arenediazonium Salts to Prominence
Authors: Taylor Jason G. , Moro Angélica Venturini , Correia Carlos Roque D.
Published: February 2011

This review highlights the potential and the versatility of arenediazonium salts as viable alternatives to conventional aryl halides and oxygen‐based electrophiles for Pd‐catalyzed Heck reactions. It also presents an overview of the field over the last decade, including some historical perspective of the Heck–Matsuda (HM) reaction with general considerations regarding reaction conditions, type of catalysts used, and the application of arenediazonium salts as reagents for the HM arylation of several types of alkenes. Throughout this review, the principal aspects related to reactivity and selectivity are discussed, and when applicable a comparison is made between the HM and the conventional Heck reactions. One‐pot procedures that involve generation of the arenediazonium salt in situ from the corresponding aniline have been presented as well as some useful heterogeneous catalytic protocols. Allylic alcohols, conjugated alkenes, unsaturated heterocycles, and unactivated alkenes are capable of being arylated with arenediazonium salts by using simple catalysts such as Pd(OAc)2 or Pd2(dba)3 at room temperature in air and in benign and conventional solvents. In addition to the intramolecular variant of the HM reaction, intermolecular tandem coupling–cyclization processes have also been developed for the construction of a range of oxygen and nitrogen heterocycles. Finally, several applications towards the total synthesis of biologically active natural and nonnatural compounds are highlighted as well as the use of the HM reaction in the synthesis of new chiral, nonracemic ligands.
Effect of humic substances on toxicity of inorganic oxidizer bioluminescent monitoring
Authors: Tarasova Anna S , Stom Devard I , Kudryasheva Nadezhda S
Published: February 2011

The current study deals with the effect of humic substances (HS) on toxicity of solutions of a model inorganic oxidizer, potassium ferricyanide. Chemical reactions responsible for toxicity changes are under consideration. The bioluminescent system of coupled enzymatic reactions catalyzed by bacterial luciferase and oxidoreductase was used as a bioassay. General and oxidative toxicity of ferricyanide solutions were evaluated. Ability of HS to decrease or increase general and oxidative toxicity of the solutions was revealed. Two types of chemical processes are supposed to be responsible for detoxification by HS: ferricyanide–HS complex formation and acceleration of endogenous redox reactions in the bioluminescent assay system. Decrease of oxidative toxicity of ferricyanide solution was observed under incubation with HS at all concentrations of HS used. Conditions for general toxicity decrease were prior incubation of ferricyanide with HS and low HS concentrations (<10−4 g/L). Acceleration of NADH auto-oxidation under higher HS concentrations was supposed to result in a toxicity increase. Environ. Toxicol. Chem. 2011; 30:1013–1017. © 2011 SETAC
Paper‐Fibres Used as a Pore‐Former for Anode Substrate of Solid Oxide Fuel Cell
Authors: Pan W.‐P. , Lü Z. , Chen K.‐F. , Zhu X.‐B. , Huang X.‐Q. , Zhang Y.‐H. , Wei B. , Su W.‐H.
Published: February 2011

Paper‐fibres are studied for use as a pore‐former to produce gas channels in the anode substrates of solid oxide fuel cells (SOFCs). These fibres produce cylindrical pores within the anode substrate, which are different from the pores formed by the conventional pore‐formers such as wheat flour and graphite. The cylindrical pores make it easier to connect each other to form continuous pathways for rapid gas diffusion. Paper‐fibres can create more open porosity than the same amount of flour. The application of the paper‐fibres significantly improves the cell performance by enhancing the gas diffusion process. The anode‐supported YSZ film cells with 5 wt.‐% and 10 wt.‐% paper‐fibres exhibit maximum power densities of 0.72 and 1.06 W cm–2, respectively, using hydrogen as fuel and ambient air as oxidant at 800 °C.
Effect of pH Value and Temperatures on Performances of Pd/C Catalysts Prepared by Modified Polyol Process for Formic Acid Electrooxidation
Authors: Wang Z.‐B. , Yuan G.‐H. , Zhou K. , Chu Y.‐Y. , Chen M.
Published: February 2011

The highly active Pd/C catalysts for formic acid electrooxidation have been prepared by a modified polyol process at different pH values of reaction solutions and different reducing temperatures, respectively. Their physical properties have been characterised by energy dispersive analysis of X‐ray, X‐ray diffraction and transmission electron microscopy. Their electrochemical performances for formic acid electrooxidation have been tested by cyclic voltammetry and amperometric i–t curves. The results of physical characterisations show that all the Pd/C catalysts present an excellent face centered cubic crystalline structure. Their particle sizes are decreasing firstly and then increasing with the increasing of the pH values of reaction solutions. The reducing temperatures also markedly affect the Pd particle sizes. And their nanoparticles have narrow size distributions and are highly dispersed on the surface of carbon support, and Pd metal loading in Pd/C catalyst is similar to the theoretical value of 20 wt.%. The results of electrochemical measurements present that the Pd/C catalyst prepared by waterless polyol process at the pH value of 10 and the reducing temperature of 120 °C has the smallest particle size of about 5.6 nm, and exhibits the highest catalytic activity (1172.0 A · gPd–1) and stability for formic acid electrooxidation.
Speculation and hedging in the currency futures markets: Are they informative to the spot exchange rates
Authors: Tornell Aaron , Yuan Chunming
Published: February 2011

This study presents an empirical analysis investigating the relationship between the futures trading activities of speculators and hedgers and the potential movements of major spot exchange rates. A set of trader position measures are employed as regression predictors, including the level and change of net positions, an investor sentiment index, extremely bullish/bearish sentiments, and the peak/trough indicators. We find that the peaks and troughs of net positions are generally useful predictors to the evolution of spot exchange rates, but other trader position measures are less correlated with future market movements. In addition, speculative position measures usually forecast price‐continuations in spot rates while hedging position measures forecast price‐reversals in these markets. © 2011 Wiley Periodicals, Inc. Jrl Fut Mark
Sediment targets for informing river catchment management: international experience and prospects
Authors: Collins A. L. , Naden P. S. , Sear D. A. , Jones J. I. , Foster I. D. L. , Morrow K.
Published: February 2011

Sediment plays a pivotal role in determining the physical, chemical and biological integrity of aquatic ecosystems. A range of factors influences the impacts of sediment pressures on aquatic biota, including concentration, duration of exposure, composition and particle size. In recognition of the need to assess environmental status for sediment and mitigate excessive sediment pressures on aquatic habitats, both water column and river substrate metrics have been proposed as river sediment targets. Water column metrics include light penetration, turbidity, sediment concentration summary statistics and sediment regimes. Substrate metrics include embeddedness, the fredle index and riffle stability. Identification of meaningful numeric targets along these lines has, however, been undermined by various issues including the uncertainty associated with toxicological dose‐response profiles and the impracticalities of deploying statistically robust sampling strategies capable of supporting catchment‐scale targets. Many of the thresholds reported are based on correlative relationships that fail to capture the specific mechanisms controlling sediment impacts on aquatic habitats and are stationary in nature. Temporal windows represented by the key life stages of specific species must be given greater emphasis. Given such issues and the need to support the revision of sediment targets for river catchment management, it is proposed that greater emphasis should be placed on developing generic modelling toolkits with the functionality for coupling current or future projected sediment regimes with biological response for a range of biota. Such tools should permit the identification of river catchment‐specific targets within a national context, based on biological effect and incorporate sufficient flexibility for utilizing updated physical, chemical, biological and catchment attribute data. Confidence will continue to be required in compliance screening to ensure cost‐effective management programmes for avoiding disproportionate investment in impacted river catchments. Copyright © 2011 John Wiley & Sons, Ltd.
Temporal trend in surface water resources in Tianjin in the Haihe River Basin, China
Authors: Wu Guanghong , Chen Shuirong , Su Ruixian , Jia Meiqing , Li Wanqing
Published: February 2011

Considering the highly stochastic nature of the hydrological process, wavelet transform was used to analyse the characteristics, trends and causes of variations in annual run‐off (1917–2006) into Tianjin in the Haihe River Basin. Run‐off was steadily declining due to climate change and human activity and a significant decrease in run‐off along the time series was discovered around the 1960s; however, the change in precipitation was insignificant. The time series of run‐off was heavily influenced by a nonlinear feature and mainly influenced by the natural climate before the 1960s, but after the 1970s the change remained steady, with an annual run‐off that fluctuated between 0·2 and 48·4 mm and was maintained at a low level (9·3 mm). The main cause of the run‐off decline in the 1960s was that more than 1900 reservoirs with a total holding capacity of up to 83 mm were constructed in the upper and middle reaches, which controlled 85% of the total run‐off. These projects have played an active role in the reservoir action and water conservation since they were implemented. At the beginning of the 1980s, the demand for water resources increased with the rapid growth of the population and the large‐scale development of industry and agriculture in the Haihe River Basin, which caused a reduction in run‐off into Tianjin. Overall, the hydrological effects of water storage projects regulating river run‐off were beneficial to flood control, but might cause a serious reduction in river run‐off into Tianjin and the lower reaches of the basin. In addition, a decrease in annual precipitation and changes in temperature in Northern China have also had an adverse effect on natural run‐off, which caused a greater decline in water resources, but this did not have a powerful influence on the overall decline in the run‐off. Copyright © 2011 John Wiley & Sons, Ltd.
Submarine groundwater discharge and seawater circulation in a subterranean estuary beneath a tidal flat
Authors: Nakada Satoshi , Yasumoto Jun , Taniguchi Makoto , Ishitobi Tomonori
Published: February 2011

A numerical simulation and stationary geophysical survey at Omaehama, Japan, described the hydrogeology in a tidal flat and adjacent sea water column. The simulation of a tidally influenced aquifer with inland fresh groundwater discharges showed three circulations in the subterranean tidal flat estuary: a small, tide‐induced recirculation (TIR) near the sloping beach, a deeper circulation (DC) across the interface between saltwater and freshwater, and a large, tidal flat‐induced circulation (TFIC) in the offshore subterranean tidal flat and slope. The horizontal distribution of the simulated submarine groundwater discharge (SGD) showed two peaks, depending on the distance from the coast along the transect line of tidal flat; the offshore peak was quantitatively consistent with the previously observed peak based on automated seepage measurements. Time‐series of the observed resistivity profiles using a marine cable (140 m) showed the structure of the fresh water/salt water interface, and indicated a salt wedge intruding from the bottom aquifer and infiltration at the surface in the beach and nearshore tidal flat. The qualitative structure of the resistivity hardly changed at each tidal stage. These results qualitatively validated the circulation patterns shown by the numerical simulation. The source of this discharging groundwater in the tidal flat is a complex mixture of fresh groundwater derived from the landward aquifer, as well as locally recycled seawater, which can contribute to the purification of the nearshore seawater. Copyright © 2011 John Wiley & Sons, Ltd.
Geometric and structural river channel complexity and the prediction of urban inundation
Authors: Fewtrell Timothy J. , Neal Jeffrey C. , Bates Paul D. , Harrison Peter J.
Published: February 2011

Recent research modelling floodplain inundation processes has concentrated on issues surrounding the level of physical, topographical, and numerical solver complexity needed to represent floodplain flows adequately. However, during flooding episodes the channel typically still conveys the bulk of the flow. Despite this, the effect of channel physical processes and topographic complexity on model results has been largely unexplored. To address this, the impact of channel cross‐section geometry, channel long‐profile variability and the representation of hydraulic structures on floodplain inundation are explored using a coupled dynamic 1D‐2D hydraulic model (ESTRY‐TUFLOW) of the Carlisle floods of January 2005. These simulations are compared with those from a simplified 1D‐2D model, LISFLOOD‐FP. In this case, the simpler model is sufficient to simulate the far‐field peak flood elevations. However, comparison of channel dynamics suggests that the full shallow water approximation used by ESTRY‐TUFLOW gives a more robust performance when models calibrated on maximum floodplain water elevations are used to predict channel water levels. Examination of the response of ESTRY‐TUFLOW to variations in channel geometric complexity shows that downstream variations in the channel long profile are more important than cross‐section variability for obtaining a dataset‐independent calibration. The results show, in general, that as model physical complexity is increased, calibrated parameters become less ‘effective’, and as a consequence, the values of performance measures reduce less rapidly away from the optimum value. This means that often more physically complex models are less likely to yield different optimum parameter values when calibrated on different datasets resulting in a more robust numerical model. Lastly, the inclusion of bridge structures can simulate substantial local backwatering effects, but the variability in observed water and wrack marks is such that it is not possible to discern the effect of the bridges at this site in the post‐event observational dataset. Copyright © 2011 John Wiley & Sons, Ltd.
Comparative study between tissue‐engineered periosteum and structural allograft in rabbit critical‐sized radial defect model
Authors: Zhao Lin , Zhao Junli , Wang Shuanke , Wang Junsheng , Liu Jia
Published: February 2011

The purpose of this study was to compare the efficacy of tissue‐engineered periosteum (TEP) to allgeneic bone in repairing segmental bone defect. TEP was fabricated with osteoinduced rabbit bone marrow mesenchymal stem cells (MSCs) and porcine small intestinal submucosa (SIS). Allogrfats were cryopreserved radial segments of New Zealand Rabbits. Forty‐eight radial critical‐sized defects (CSD) were bilaterally produced in 24 rabbits. The defects were divided into three groups, group A, TEP implantation, group B, SIS implantation, and group C allograft. Bone defect reconstruction was kinetically analyzed at 4, 8, and 12 weeks by radiographic and histological scoring system. In group A, bone defects were radiographically and histologically healed with mature cortex and marrow cavity by 12 weeks, while none of the defects healed in group B. Group C showed a slow process of creeping substitution with lymphocyte infiltration. Statistical comparison confirmed that group A had a more efficient and rapid bone defect reparation as well as remodelling than Group B and C. In conclusion, TEP is superior to structural allograft in reconstruction of allogenic segmental bone defect. Pure SIS cannot guide bone regeneration in this rabbit model. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.
Microstructure and drug‐release studies of sirolimus‐containing poly(lactide‐co‐glycolide) films
Authors: Ro Andrew J. , Falotico Robert , Davé Vipul
Published: February 2011

Sirolimus‐containing poly(lactide‐co‐glycolide) (PLGA) films were prepared by solution casting and removing the residual solvent, 1,4‐dioxane, by liquid and supercritical carbon dioxide (CO2) extraction. The effect of lactide:glycolide ratio, stereochemistry of PLGA, and extraction condition (i.e., temperature and pressure) on the polymer and drug morphologies was studied using wide‐angle X‐ray scattering and differential scanning calorimetry. The polymer and drug crystallinity increased after liquid and supercritical CO2extraction, and the level of drug crystallinity within the film depended on the extraction conditions. Generally, higher levels of drug crystallinity were observed in the films with amorphous polymer matrices, and the drug crystallinity increased with temperature and pressure of the extraction conditions.In vitrodrug elution from these films was studied using a USP 4 apparatus. Polymer crystallinity was found to be the determining factor for drug release, whereby films with higher polymer crystallinity eluted less drug compared to films with amorphous polymer matrices. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.
Dysregulation of monocytic cytokine secretion by endodontic sealers
Authors: Brackett Martha Goël , Lewis Jill B. , Messer Regina L. W. , Lei Li , Lockwood Petra E. , Wataha John C.
Published: February 2011

Recent studies have reported that sealers may alter the secretion of specific cytokines from THP1 monocytic cells in vitro. In this study, a cytokine array was used to determine if endodontic sealers changed secretion of 42 cytokines. White mineral trioxide aggregate (WMTA), MTA preparation (CS), AH‐Plus (AHP), and Pulp Canal Sealer (PCS) were mixed, allowed to set for 72 h, then “aged” in buffered‐saline for 12 weeks. Aged specimens were placed in direct contact with THP1 for 72 h and their cytotoxicity (MTT assay) was assessed. Materials that were not severely toxic were then exposed to THP1 with or without lipolysaccharide (LPS), and the culture medium was assayed for cytokine secretion. Secretion of cytokines was quantified using infrared scanning (Odyssey®); replicate pairs were averaged. PCS severely suppressed MTT activity and was not assessed for its influence on cytokine secretion. WMTA, CS, and AHP induced a broad‐based increase in cytokine secretion (>20% vs. Teflon controls), but AHP induced the greatest increase (>100% in 17 of 42 cytokines). The effects of the sealers on LPS‐activated THP1 were biphasic, with some increases and decreases cytokine secretion of >20%, but few larger effects. This work shows endodontic sealers may alter the secretion of a broad cross section of cytokines from monocytic cells. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.
In situ formation of silver nanoparticles in photocrosslinking polymers
Authors: Cheng Ya‐Jun , Zeiger Diana N. , Howarter John A. , Zhang Xinran , Lin Nancy J. , Antonucci Joseph M. , Lin‐Gibson Sheng
Published: February 2011

Nanocomposites of cross‐linked methacrylate polymers with silver nanoparticles have been synthesized by coupling photoinitiated free radical polymerization of dimethacrylates with in situ silver ion reduction. A polymerizable methacrylate bearing a secondary amino functional group was used to increase the solubility of the silver salt in the hydrophobic resin system. Fourier transform infrared spectroscopy (FTIR) revealed that the silver ion reduction had no significant effect on the degree of vinyl conversion of the methacrylate. X‐ray photoelectron spectroscopy (XPS) measurements showed an increased silver concentration at the composite surface compared to the expected concentration based on the total amount of silver salt added. Furthermore, the surface silver concentration leveled off when the silver salt mass fractions were 0.08% or greater. Composites with low concentrations of silver salt (< 0.08% by mass) exhibited comparable mechanical properties to those containing no silver. Transmission electron microscopy (TEM) confirmed that the silver nanoparticles formed within the polymer matrix were nanocrystalline in nature and primarily ≈ 3 nm in diameter, with some large particle aggregates. Composites containing silver nanoparticles were shown to reduce bacterial colonization with as little as 0.03% (by mass) silver salt, while additional amounts of silver salt did not further decrease their surface colonization. With a substantial effect on bacterial growth and minimal effects on mechanical properties, the in situ formation of silver nanoparticles within methacrylate materials is a promising technique for synthesizing antibacterial nanocomposites for biomedical applications. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.
In vitro assessment of strength, fatigue durability, and disassembly of Ti6Al4V and CoCrMo necks in modular total hip replacements
Authors: Nganbe Michel , Khan Usman , Louati Hakim , Speirs Andrew , Beaulé Paul E.
Published: February 2011

Modularity in total hip replacement offers advantages with regard to biomechanical adjustments and leg lengths. Recently, modular femoral necks were introduced as an added advantage to head modularity permitting further adjustments in femoral version as well as offset and ease of revision. Currently, most necks are made of Ti6Al4V for which cases of in vivo fractures and inseparable neck‐stem junctions have been reported. Therefore, we investigated CoCrMo head–Ti6Al4V stem hip replacements with necks made of CoCrMo as an alternative to Ti6Al4V. We compared the two materials with respect to (1) compressive load bearing capacity; (2) fatigue durability; and (3) component distraction. We performed in vitro fatigue‐pull‐off, microscopy, fatigue durability and compression investigations. The CoCrMo neck showed a load bearing capacity of 18 kN, 38% higher than 13 kN for the Ti6Al4V neck. A fatigue load of 11.2 kN for 1 million cycle failure was achieved with CoCrMo translating into nearly 1000 times longer fatigue life compared to Ti6Al4V necks. The neck‐stem distraction force showed large statistical variation and was similar for both neck materials. Overall, the results suggest a superiority of CoCrMo over Ti6Al4V as neck material with regard to mechanical behavior. However, the corrosion behavior was not appropriately assessed and necessitates additional investigations. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.
A pH‐sensitive chitosan‐tripolyphosphate hydrogel beads for controlled glipizide delivery
Authors: Sun Ping , Li Ping , Li Yu‐Min , Wei Qin , Tian Lin‐Hong
Published: February 2011

A chitosan(CS)‐tripolyphosphate (TPP) hydrogel bead was prepared by the ionic gelation method for the controlled delivery of glipizide. The structure and surface morphology of the beads were characterized by FT‐IR and SEM, separately. Factors influencing the swelling behavior of the hydrogel beads were also investigated, such as CS concentration (X1), TPP concentration (X2), the weight ratio of drug to polymer (X3), crosslinking time (X4), and the volume ratio of CS to TPP (X5). In addition, the swelling property and the delivery behavior of the hydrogel bead was studied as well. With decreasing of pH value, the swelling ratio of the bead was increasing. The swelling ratio of hydrogel bead at pH 1.5 was relatively high, while this value was low at pH 6.8. The amount of glipizide released from the hydrogel bead at pH 1.5 was about 90%, while this value approached 36% at pH 6.8. The results clearly suggested that the CS‐TPP hydrogel beads were used as a pH‐sensitive controlled release system for the delivery of glipizide. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.
DLK1 is a novel regulator of bone mass that mediates estrogen deficiency–induced bone loss in mice
Authors: Abdallah Basem M , Ditzel Nicholas , Mahmood Amer , Isa Adiba , Traustadottir Gunnhildur A , Schilling Arndt F , Ruiz-Hidalgo María-José , Laborda Jorge , Amling Michael , Kassem Moustapha
Published: February 2011

Delta-like 1/fetal antigen 1 (DLK1/FA-1) is a transmembrane protein belonging to the Notch/Delta family that acts as a membrane-associated or a soluble protein to regulate regeneration of a number of adult tissues. Here we examined the role of DLK1/FA-1 in bone biology using osteoblast-specific Dlk1-overexpressing mice (Col1-Dlk1). Col1-Dlk1 mice displayed growth retardation and significantly reduced total body weight and bone mineral density (BMD). Micro–computed tomographis (µCT) scanning revealed a reduced trabecular and cortical bone volume fraction. Tissue-level histomorphometric analysis demonstrated decreased bone-formation rate and enhanced bone resorption in Col1-Dlk1 mice compared with wild-type mice. At a cellular level, Dlk1 markedly reduced the total number of bone marrow (BM)–derived colony-forming units fibroblasts (CFU-Fs), as well as their osteogenic capacity. In a number of in vitro culture systems, Dlk1 stimulated osteoclastogenesis indirectly through osteoblast-dependent increased production of proinflammatory bone-resorbing cytokines (eg, Il7, Tnfa, and Ccl3). We found that ovariectomy (ovx)–induced bone loss was associated with increased production of Dlk1 in the bone marrow by activated T cells. Interestingly, Dlk1−/− mice were significantly protected from ovx-induced bone loss compared with wild-type mice. Thus we identified Dlk1 as a novel regulator of bone mass that functions to inhibit bone formation and to stimulate bone resorption. Increasing DLK1 production by T cells under estrogen deficiency suggests its possible use as a therapeutic target for preventing postmenopausal bone loss. © 2011 American Society for Bone and Mineral Research.
Composition‐induced structural transitions in mixed Lennard‐Jones clusters: Global reparametrization and optimization
Authors: Dieterich Johannes M. , Hartke Bernd
Published: February 2011

As extended benchmarks to global cluster structure optimization methods, we provide a first systematic point of entry into the world of strongly mixed rare gas clusters. A new set of generalized Lennard‐Jones pair potentials is generated for this purpose, by fitting them to high‐end ab initio reference data. Employing these potentials in our genetic algorithm‐based global structure optimization framework, we examined various systems from binary to quinary mixtures of atom types. A central result from this study is that the famous fcc structure for 38 atoms can survive for certain binary mixtures but appears to be prone to collapsing into the dominating icosahedral structure, which we observed upon introduction of one single atom of a ternary type. © 2011 Wiley Periodicals, Inc. J Comput Chem, 2011
Theoretical investigation of novel carbazole‐fluorene based D‐π‐A conjugated organic dyes as dye‐sensitizer in dye‐sensitized solar cells (DSCs)
Authors: Yakhanthip Thanisorn , Jungsuttiwong Siriporn , Namuangruk Supawadee , Kungwan Nawee , Promarak Vinich , Sudyoadsuk Taweesak , Kochpradist Palita
Published: February 2011

The ground state structure and frontier molecular orbital of newly synthesized carbazole‐fluorene based D‐π‐A organic dyes, CFP1A, CFP2A, CFP1CA, and CFP2CA, were theoretically investigated using density functional theory (DFT) at B3LYP/6‐31G(d,p) level. These dye molecules have been constructed based on carbazole‐fluorene as the electron‐donating moiety while introducing benzene units as π‐spacer connected to different anchor groups, such as acrylic acid and cyanoacrylic acid, as acceptors. The electronic vertical excitation energies and absorption wavelength were carried out using time‐dependent DFT (TD‐DFT). Furthermore, the adsorptions of phenylacrylic acid and phenylcyanoacrylic acid on the TiO2 anatase (101) surface were carried out by means of quantum‐chemical periodic calculations employing periodic PBE functional with DNP basis set. The results promise that anchor dyes with strong withdrawing CN group have easier injected electron to the conduction band of semiconductor implying that CFP1CA and CFP2CA show better performance among four dyes. Additionally, the intramolecular charge transfers (ICT) from electron donor group to anchoring group of CFP1CA and CFP2CA have shown better performance. The calculated results provide the efficiency trend of our new dyes as CFP1CA ≈ CFP2CA > CFP1A ≈ CFP2A which are excellently agree with experimental observation. © 2011 Wiley Periodicals, Inc. J Comput Chem, 2011
Extensive theoretical study on electronically excited states and predissociation mechanisms of sulfur monoxide including spin–orbit coupling
Authors: Yu Le , Bian Wensheng
Published: February 2011

The potential energy curves of the 69 Ω states generated from the 24 Λ–S states of sulfur monoxide are calculated for the first time using the internally contracted multireference configuration interaction method with the Davidson correction and the entirely uncontracted aug‐cc‐pV5Z basis set. Spin–orbit coupling is taken into account by the state interaction approach with the full Breit–Pauli Hamiltonian. Very good agreement is achieved between our computed spectroscopic properties and the available experimental data. The transition properties of the B3Σ−–X3Σ− and (4)1–X0+ transitions are predicted, and our computed Franck–Condon factors and radiative lifetimes match the experimental results very well. The predissociation mechanisms are investigated, and various new predissociation channels are located. We present a new interpretation on the breaking‐off of the rotational levels of the B3Σ− lower vibrational states observed in experiment, and propose that the predissociation is induced by the Coriolis coupling between the B3Σ− rovibrational levels and the A3Π state. Our calculations indicate that, at ν′ = 9, the B3Σ− state predissociates via the C3Π state; around ν′ = 14, three spin‐orbit‐induced predissociation pathways via (1)5Σ+, (2)5Π, and e1Π would be open; around ν′ = 17, the pathways via (2)1Σ+, (2)3Σ+ and (2)5Σ+ would contribute. These satisfactorily explain the experimental results about the diffuseness of the B3Σ− bands. Furthermore, various predissociation pathways of the C′3Π state are predicted, through which the C′3Π state could predissociate rapidly. © 2011 Wiley Periodicals, Inc. J Comput Chem, 2011
The through‐space transmission of 77Se — 77Se coupling constants
Authors: Contreras R. H. , Gavarini H. O. , Natiello M. A.
Published: February 2011

The IPPP‐INDO method is applied to study different interactions as well as transmission mechanisms of 77Se — 77Se coupling constants in cis‐ and trans‐1,2‐bis(methylseleno)ethene. Preferential conformations were determined using a modified version of the PCILO‐CNDO method. The preferential conformation of the cis compound is such that nonbonding electron pairs of both Se atoms overlap to some extent. In this conformation a large and positive through‐space transmission of the Fermi contact term of the 77Se — 77Se coupling takes place, which strongly depends on the Se — Se distances. The similarity between this coupling and others involving different nuclei is discussed. The total calculated coupling is in fair agreement with experimental values for similar compounds. The 77Se — 77Se coupling in the trans‐compound is largely dominated by the orbital interaction, which is mainly transmitted through the vinyl π‐electron system.