bluuebunny/crossref_metadata_2025 huggingface dataset:
Tumor suppressor gene Co‐operativity in compound Patched1 and suppressor of fused heterozygous mutant mice
Authors: Svärd Jessica , Rozell Björn , Toftgård Rune , Teglund Stephan
Published: September 2008

Dysregulation of the Hedgehog signaling pathway is central to the development of certain tumor types, including medulloblastoma and basal cell carcinoma (BCC). Patched1 (Ptch1) and Suppressor of fused (Sufu) are two essential negative regulators of the pathway with tumor suppressor activity. Ptch1+/− mice are predisposed to developing medulloblastoma and rhabdomyosarcoma, while Sufu+/− mice develop a skin phenotype characterized by basaloid epidermal proliferations. Here, we have studied tumor development in Sufu+/−Ptch1+/− mice to determine the effect of compound heterozygosity on the onset, incidence, and spectrum of tumors. We found significantly more (2.3‐fold) basaloid proliferations in Sufu+/−Ptch1+/− compared to Sufu+/− female, but not male, mice. For medulloblastoma, the cumulative 1‐yr incidence was 1.5‐fold higher in Sufu+/−Ptch1+/− compared to Ptch1+/− female mice but this strong trend was not statistically significant. Together this suggests a weak genetic interaction of the two tumor suppressor genes. We noted a few rhabdomyosarcomas and pancreatic cysts in the Sufu+/−Ptch1+/− mice, but the numbers were not significantly different from the single heterozygous mice. Hydrocephalus developed in ∼20% of the Ptch1+/− and Sufu+/−Ptch1+/− but not in Sufu+/− mice. Interestingly, most of the medulloblastomas from the Sufu+/−Ptch1+/− mice had lost expression of the remaining Ptch1 wild‐type allele but not the Sufu wild‐type allele. On the contrary, Sufu as well as Gli1 and Gli2 expression was upregulated in the medulloblastomas compared to adult cerebellum in Ptch1+/− and Sufu+/−Ptch1+/− mice. This suggests that Sufu expression may be regulated by Hedgehog pathway activity and could constitute another negative feedback loop in the pathway. © 2008 Wiley‐Liss, Inc.
Constructive approximation of solution for fourth‐order nonlinear boundary value problems
Authors: Du Juan , Cui Minggen
Published: September 2008

In this paper, we obtain a sequence of approximate solution converging uniformly to the exact solution of a class of fourth‐order nonlinear boundary value problems. Its exact solution is represented in the form of series in the reproducing kernel space. The n‐term approximation un(x) is proved to converge to the exact solution u(x). Moreover, the derivatives of un(x) are also convergent to the derivatives of u(x). Copyright © 2008 John Wiley & Sons, Ltd.
Macromol. React. Eng. 5/2008
Authors: Tobita Hidetaka
Published: September 2008

Cover: The picture on the cover shows the concept of the overall active period introduced to account for the possible repetition of active radical periods on the same chain in RAFT polymerization (upper part), and the development of the calculated molecular weight distribution based on a proposed formula (lower part), which shows that the distribution becomes broader due to the repetition. Further details can be found in the article by H. Tobita* on page 371.
Gradient and dilatational stabilizations for stress‐point integration in the element‐free Galerkin method
Authors: Duan Qinglin , Belytschko Ted
Published: September 2008

Stabilized stress‐point integration schemes based on gradient stabilization and dilatational stabilization methods are presented for linear elastostaticity problems in the framework of element‐free Galerkin (EFG) method. The instability in stress fields associated with the stress‐point integration is treated by the addition to the Galerkin weak form of stabilization terms which contain product of the gradient of the residual or the trace of the gradient of the residual; the latter is called dilatational stabilization. Numerical results show that the oscillations in the stress fields are successfully removed by the presented stabilization methods, and that the convergence and stability properties of direct stress‐point integration are greatly improved. These stabilization methods are particularly suitable for the solution of non‐linear continua with explicit time integration methods. Copyright © 2008 John Wiley & Sons, Ltd.
A superconvergent point interpolation method (SC‐PIM) with piecewise linear strain field using triangular mesh
Authors: Liu G. R. , Xu X. , Zhang G. Y. , Nguyen‐Thoi T.
Published: September 2008

A superconvergent point interpolation method (SC‐PIM) is developed for mechanics problems by combining techniques of finite element method (FEM) and linearly conforming point interpolation method (LC‐PIM) using triangular mesh. In the SC‐PIM, point interpolation methods (PIM) are used for shape functions construction; and a strain field with a parameter α is assumed to be a linear combination of compatible stains and smoothed strains from LC‐PIM. We prove theoretically that SC‐PIM has a very nice bound property: the strain energy obtained from the SC‐PIM solution lies in between those from the compatible FEM solution and the LC‐PIM solution when the same mesh is used. We further provide a criterion for SC‐PIM to obtain upper and lower bound solutions. Intensive numerical studies are conducted to verify these theoretical results and show that (1) the upper and lower bound solutions can always be obtained using the present SC‐PIM; (2) there exists an αexact∈(0, 1) at which the SC‐PIM can produce the exact solution in the energy norm; (3) for any α∈(0, 1) the SC‐PIM solution is of superconvergence, and α=0 is an easy way to obtain a very accurate and superconvergent solution in both energy and displacement norms; (4) a procedure is devised to find a αprefer∈(0, 1) that produces a solution very close to the exact solution. Copyright © 2008 John Wiley & Sons, Ltd.
Fast single domain–subdomain BEM algorithm for 3D incompressible fluid flow and heat transfer
Authors: Ravnik Jure , Škerget Leopold , Žunič Zoran
Published: September 2008

In this paper acceleration and computer memory reduction of an algorithm for the simulation of laminar viscous flows and heat transfer is presented. The algorithm solves the velocity–vorticity formulation of the incompressible Navier–Stokes equations in 3D. It is based on a combination of a subdomain boundary element method (BEM) and single domain BEM. The CPU time and storage requirements of the single domain BEM are reduced by implementing a fast multipole expansion method. The Laplace fundamental solution, which is used as a special weighting function in BEM, is expanded in terms of spherical harmonics. The computational domain and its boundary are recursively cut up forming a tree of clusters of boundary elements and domain cells. Data sparse representation is used in parts of the matrix, which correspond to boundary‐domain clusters pairs that are admissible for expansion. Significant reduction of the complexity is achieved.

The paper presents results of testing of the multipole expansion algorithm by exploring its effect on the accuracy of the solution and its influence on the non‐linear convergence properties of the solver. Two 3D benchmark numerical examples are used: the lid‐driven cavity and the onset of natural convection in a differentially heated enclosure. Copyright © 2008 John Wiley & Sons, Ltd.
Optimal control approach for robust control design of neutral systems
Authors: Lin Yu‐Chen , Lin Chun‐Liang
Published: September 2008

This paper proposes an optimal control approach for a robust control design problem of the neutral type time‐delay systems, taking parameter uncertainties and state delay into account. The robust control design problem can be equivalently transformed into an optimal control problem, and the amount of plant uncertainties is indirectly reflected in the performance index. By introducing algebraic manipulations and appropriate uncertainty descriptions, the uncertain dynamical system can not only achieve stability, but can also reach the guaranteed level of performance. A suitable linear state feedback control law is characterized via Lyapunov stability theory to ensure quadratic stability and performance robustness of the closed‐loop system. Copyright © 2008 John Wiley & Sons, Ltd.
The design of excitation pulses for spin systems using optimal control theory: With application to NMR spectroscopy
Authors: Gershenzon Naum I. , Miller David F. , Skinner Thomas E.
Published: September 2008

This paper considers the use of optimal control theory in designing radio frequency excitation pulses for magnetic spin systems satisfying Bloch dynamics. Such pulses are required in applications of nuclear magnetic resonance to initially transfer sample magnetization vectors to the transverse plane. Once transferred, signals released by nuclei as they respond to a static magnetic field normal to the transverse plane are then analyzed and interpreted. Continuous time deterministic optimal control theory is employed to determine time‐dependent pulse amplitudes and frequencies that minimize the distance between final magnetization vectors and a chosen target vector. Pulses are designed to excite a range of resonant frequencies and to tolerate miscalibration errors in applied fields. The model presented permits a unified treatment of the control problem as considered by a variety of authors, and a thorough mathematical analysis of the existence, and characteristics of, optimal excitation pulses. Practical numerical algorithms for designing optimal pulses are given, and the effectiveness of the algorithms is illustrated by comparing the pulses that they generate with those commonly used in high‐resolution spectroscopy. Copyright © 2008 John Wiley & Sons, Ltd.
Long‐term use of antihypertensive drugs and risk of cancer
Authors: Assimes Themistocles L. , Elstein Eleanor , Langleben Adrian , Suissa Samy
Published: September 2008

Purpose

Determine the relative risk of cancer users of commonly prescribed antihypertensive drugs with a focus on documenting risk in long‐term users (>7.5 years).

Methods

We conducted a nested case–control study using the Saskatchewan Health databases. Cancer risks in users of β‐blockers, calcium channel blockers (CCBs), and rennin‐angiotensin system inhibitors (RASIs), respectively, were compared to risks in users of thiazide diuretics.

Results

A total of 11 697 first cases of cancer and the subset of 6918 subjects who died from cancer were each matched to 10 controls. The mean total duration of use of the four classes of antihypertensive drugs (estimated by dispensation of prescriptions) ranged from 3.6 to 5.7 years. A subgroup of cases was exposed long term (mean total duration of use: 9.7–11.4 years, range: 7.5–23.1 years). Modest differences in risk between users of the four classes were detected for colon, head & neck, lung, and hematological cancers but none of these associations demonstrated a clear dose response relationship for both first cancer and fatal cancer. Otherwise, for cancer at all sites combined and for the four most common cancers, we were able to rule out, with reasonable confidence, small to modest differences in the risk of cancer among users of any duration (upper 95% confidence intervals (CIs): 1.45) and modest to large differences in risk among long‐term users (upper 95%CI: 3.06).

Conclusions

The long‐term use of commonly prescribed classes of antihypertensive drugs does not appear to promote or initiate cancer. Copyright © 2008 John Wiley & Sons, Ltd.
Immiscibility–miscibility phase transitions in blends of poly(L‐lactide) with poly(methyl methacrylate)
Authors: Li Shu‐Hsien , Woo Eamor M
Published: September 2008

BACKGROUND: The nature of phase transitions and apparently irreversible phase homogenization upon heating in blends of biodegradable poly(L‐lactide) (PLLA) with poly(methyl methacrylate) (PMMA) were proven using differential scanning calorimetry, polarized optical microscopy, scanning electron microscopy and 1H NMR spectroscopy. The complex phase behaviour in this blend system is puzzling and is a matter of debate; this study attempts to clarify the true nature of the phase behaviour.

RESULTS: A PMMA/PLLA blend is immiscible at ambient temperature but can become miscible upon heating to higher temperatures with an upper critical solution temperature (UCST) at 230 °C. The blends, upon rapid quenching from the UCST, can be frozen into a quasi‐miscible state. In this state, the interaction strength was determined to be χ12 = − 0.15 to − 0.19, indicating relatively weak interactions between the PLLA ester and PMMA acrylic carbonyl groups.

CONCLUSION: The absence of chemical exchange reactions above the UCST and phase reversibility back to the original phase separation morphology, assisted by solvent re‐dissolution, in the heat‐homogenized PLLA/PMMA blend was shown. Verification of UCST behaviour, phase diagrams and solvent‐assisted phase reversibility were experimentally demonstrated in PMMA/PLLA blends. Copyright © 2008 Society of Chemical Industry
In situ proteomics with imaging mass spectrometry and principal component analysis in the Scrapper‐knockout mouse brain
Authors: Yao Ikuko , Sugiura Yuki , Matsumoto Mineo , Setou Mitsutoshi
Published: September 2008

Imaging MS is emerging as a useful tool for proteomic analysis. We utilized this technique to analyze gene knockout (KO) mice in addition to traditional 2‐DE analysis. The Scrapper‐knockout (SCR‐KO) mouse brain showed two types of neurodegenerative pathologies, the spongiform neurodegeneration and shrinkage of neuronal cells. 2‐DE analysis of the whole brain lysates of SCR‐KO mice indicated slight changes in annexin A6, Rap1 GTPase, and glyoxalase domain containing four spots while most of the main components did not show significant changes. By imaging MS analysis based on principal component analysis (PCA), we could find numerous alterations in the KO mouse brain. Furthermore, we could also know the information on the position of altered substances all together. PCA provides information about which molecules in tissue microdomains have altered and is helpful in analyzing large dataset of imaging MS, while exact identification of each molecule from peaks in MALDI imaging MS may require additional analyses such as MS/MS. Direct imaging with PCA is a powerful tool to perform in situ proteomics and will lead to novel findings. Our study shows that imaging MS yields information complementary to conventional 2‐DE analysis.
Mechanism of 3,4‐methylenedioxymethamphetamine (MDMA, ecstasy)‐mediated mitochondrial dysfunction in rat liver
Authors: Moon Kwan‐Hoon , Upreti Vijay V. , Yu Li‐Rong , Lee Insong J. , Ye Xiaoying , Eddington Natalie D. , Veenstra Timothy D. , Song Byoung‐Joon
Published: September 2008

Despite numerous reports citing the acute hepatotoxicity caused by 3,4‐methylenedioxymethamphetamine (MDMA) (ecstasy), the underlying mechanism of organ damage is poorly understood. We hypothesized that key mitochondrial proteins are oxidatively modified and inactivated in MDMA‐exposed tissues. The aim of this study was to identify and investigate the mechanism of inactivation of oxidatively modified mitochondrial proteins, prior to the extensive mitochondrial dysfunction and liver damage following MDMA exposure. MDMA‐treated rats showed abnormal liver histology with significant elevation in plasma transaminases, nitric oxide synthase, and the level of hydrogen peroxide. Oxidatively modified mitochondrial proteins in control and MDMA‐exposed rats were labeled with biotin‐N‐maleimide (biotin‐NM) as a sensitive probe for oxidized proteins, purified with streptavidin–agarose, and resolved using 2‐DE. Comparative 2‐DE analysis of biotin‐NM‐labeled proteins revealed markedly increased levels of oxidatively modified proteins following MDMA exposure. Mass spectrometric analysis identified oxidatively modified mitochondrial proteins involved in energy supply, fat metabolism, antioxidant defense, and chaperone activities. Among these, the activities of mitochondrial aldehyde dehydrogenase, 3‐ketoacyl‐CoA thiolases, and ATP synthase were significantly inhibited following MDMA exposure. Our data show for the first time that MDMA causes the oxidative inactivation of key mitochondrial enzymes which most likely contributes to mitochondrial dysfunction and subsequent liver damage in MDMA‐exposed animals.
Six Sigma and Information Systems Project Management: A Revised Theoretical Model
Authors: Zhang Weiyong , Xu Xiaobo
Published: September 2008

Previous information systems (IS) research has significantly improved the success rate of IS projects, but the result is still far from satisfying. The effort to advance IS project management theories continues. One notable effort is Ravichandran and Rai (2000). Based on quality management principles, they developed a model (the R&R model) describing a quality-oriented organizational system that leads to software development quality performance. This study analyzed Six Sigma to propose major revisions to the R&R model. Six Sigma is a recent approach to quality management with proven effectiveness. The analysis of Six Sigma suggested that several constructs in the R&R model need to be respecified, leading to the definition of a new quality-oriented organizational system. More importantly, the revised model posits that the new organizational system leads to IS project success that can be measured by organizational performance improvement. This study contributes to the literature and provides practical guidance to IS project managers.
Protecting Software Development Projects against Underestimation
Authors: Miranda Eduardo , Abran Alain
Published: September 2008

When a project in progress has been seriously underestimated, it is essential to figure out how much additional effort is required to complete it within its original scope and delivery date. This article posits that project contingencies should be based on the amount it will take to recover from the underestimation, and not on the amount that would have been required had the project been adequately planned from the beginning, and that these funds should be administered at the portfolio level. A model to calculate the required funds is developed.
Value Stream Mapping in Project Management: A Case Study
Authors: Bevilacqua Maurizio , Ciarapica Filippo E. , Giacchetta Giancarlo
Published: September 2008

This article describes the application of value stream mapping to analyze and redesign the way of managing the materials procurement stage of a project. A framework based on integrated definition (IDEF) methodology, the stream analysis approach, activity-based costing, and discrete event simulation is presented. The stream analysis approach is used to analyze, diagnose, and manage process changes represented using an IDEF model. A dynamic simulation is used to evaluate the impact of the changes considered, to support the analysis of the process, and to model the performance of the proposed process. The overall methodology is demonstrated by applying it to a company whose core business is the design and construction of offshore oil rigs. The company specializes in engineering, procurement, and construction projects and has an annual portfolio of about six projects. Many of these projects have common features in terms of design and components, and they are all also characterized by a short “time to delivery.” For this reason, this study was aimed at assessing the possible effects that the application of new materials management policies could have on reducing both project completion time and the resources required.
How Project Management Office Leaders Facilitate Cross-Project Learning and Continuous Improvement
Authors: Julian Jerry
Published: September 2008

The purpose of this study is to shed light on how project management office (PMO) leaders facilitate cross-project learning and continuous improvement. Twenty leaders of PMOs were interviewed; findings were validated by two focus groups. The research reveals that PMO leaders facilitate cross-project improvement by embedding accumulated knowledge from pas project experiences into project management routines that are utilized across multiple projects. The research also points to the phenome non of “red light learning,” where lesson learned sessions can be enculturated as punitive, undermining individual and organizational learning. Recommendations focus on enhancing the social capital of the PMO leader and improving the quality and quantity of reflective practice over the course of the project life cycle
A Project Portfolio Risk-Opportunity Identification Framework
Authors: Sanchez Hynuk , Robert Benoît , Pellerin Robert
Published: September 2008

This article introduces a framework to identify risks and opportunities during portfolio risk management that helps to decrease the uncertainty of achieving the strategic goals of the organization. The final output of the framework is a portfolio risk-opportunity register, which highlights the potential events that could impact the achievement of the goals. An illustrative example of how risk-opportunity identification can be conducted within this framework is also exposed. In spite of being theoretical in nature, the model contributes to the risk management domain applied specifically to project portfolio management, opening the possibility of further research for its verification.
Synthesis, self‐assembly, and thermosensitive properties of ethyl cellulose‐g‐P(PEGMA) amphiphilic copolymers
Authors: Li Yanxiang , Liu Ruigang , Liu Wenyong , Kang Hongliang , Wu Min , Huang Yong
Published: September 2008

Ethyl cellulose graft poly(poly(ethylene glycol) methyl ether methacrylate) (EC‐g‐P(PEGMA)) amphiphilic copolymers were synthesized via atom transfer radical polymerization (ATRP) and characterized by FTIR, 1H NMR, and gel permeation chromatography. Reaction kinetics analysis indicated that the graft copolymerization is living and controllable. The self‐assembly and thermosensitive property of the obtained EC‐g‐P(PEGMA) amphiphilic copolymers in water were investigated by dynamic light scattering, transmission electron microscopy, and transmittance. It was found that the EC‐g‐P(PEGMA) amphiphilic copolymers can self‐assemble into spherical micelles in water. The size of the micelles increases with the increase of the side chain length. The spherical micelles show thermosensitive properties with a lower critical solution temperature around 65 °C, which almost independent on the graft density and the length of the side chains. The obtained EC‐g‐P(PEGMA) graft copolymers have both the unique properties of poly(ethylene glycol) and cellulose, which may have the potential applications in biomedicine and biotechnology. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 46: 6907–6915, 2008
Health‐related fitness and trainability in children with cystic fibrosis
Authors: Gruber W. , Orenstein D.M. , Braumann K.M. , Hüls G.
Published: September 2008

The objective of this study was to examine the effects of a supervised exercise training program performed during an in patient rehabilitation course on various attributes of health‐related fitness, e.g., flexibility, balance and coordination. 286 patients with CF, age range 6–18 years (11.8 ± 3.4 years), mean forced expiratory volume in 1 sec (FEV1 82.7 ± 22.3% predicted) were included. Patients performed the modified Munich fitness test (mMFT) to assess flexibility, balance, strength and coordination. To assess aerobic capacity a 6‐min walk‐test (6MWT) was performed. In addition, some of the patients performed an incremental exercise test on a bicycle ergometer using the Godfrey protocol before and after the exercise training program. The supervised training program consisted of 4–6 weeks of different sports activities 5 times per week. After training, pulmonary function showed a significant (P < 0.05) increase. All test items of the mMFT improved significantly (P < 0.05). Compared to healthy children test scores achieved from children with CF in the mMFT were lower but within a normal range. Our children with CF had a lower walk distance in 6MWT (P < 0.05) compared to healthy. Our findings clearly demonstrated benefits of a systematic exercise training program on components of physical fitness in patients with CF, with improvements of test‐tasks to predicted normal in some cases. The results from our study suggested that an exercise training program in CF should be focused on several aspects of physical fitness including all components of physical fitness, e.g. aerobic endurance, flexibility, balance and motor skills. Pediatr Pulmonol. 2008; 43:953–964. © 2008 Wiley‐Liss, Inc.
Exhaled leukotriene B4 in children with community acquired pneumonia
Authors: Carraro Silvia , Andreola Barbara , Alinovi Rossella , Corradi Massimo , Freo Luisa , Da Dalt Liviana , Baraldi Eugenio
Published: September 2008

Background

The infiltrate in pneumonia is characterized by a large number of activated neutrophils, for which leukotriene B4 (LTB4) is a strong chemotactic agent. Exhaled breath condensate (EBC) is a non‐invasive technique for studying the lower airways. The present study was conducted to measure EBC LTB4 as a potential non‐invasive marker of inflammatory response in community acquired pneumonia (CAP).

Methods

Eighteen children with CAP and 17 healthy children were recruited (age 5–13). The CAP children underwent physical examination, chest X‐ray, leukocyte count and C‐reactive protein measurement. The CAP and the control children performed spirometry, exhaled nitric oxide measurement (FENO) and EBC collection for LTB4 assessment. In the CAP children spirometry, FENO and EBC collection were repeated twice over a 1‐month follow‐up.

Results

LTB4 EBC concentrations were higher in children with CAP than in healthy controls (10 pg/ml [7.0–15.3] vs. 3 pg/ml [3.0–6.9], P = 0.001) and decreased after 1 week (3 pg/ml [3.0–7.2], P < 0.01) with no further change a month later. In the acute phase spirometry demonstrated a restrictive pattern that gradually improved later. No difference in FENO levels was found between children with CAP and healthy controls.

Conclusion

Exhaled LTB4 levels increase in CAP and return to normal after 1 week. EBC collection is feasible in children with CAP and may represent a new way to non‐invasively monitor the lung's biological response to infections. Pediatr Pulmonol. 2008; 43:982–986. © 2008 Wiley‐Liss, Inc.
Structural and Preliminary Explosive Property Characterizations of New 3,4,5‐Triamino‐1,2,4‐triazolium (Guanazinium) Salts
Authors: Darwich Chaza , Klapötke Thomas M. , Sabaté Carles Miró
Published: September 2008

Two new highly stable energetic salts were synthesized in reasonable yield by using the high nitrogen‐content heterocycle 3,4,5‐triamino‐1,2,4‐triazole and resulting in its picrate and azotetrazolate salts. 3,4,5‐Triamino‐1,2,4‐triazolium picrate (1) and bis(3,4,5‐triamino‐1,2,4‐triazolium) 5,5′‐azotetrazolate (2) were characterized analytically and spectroscopically. X‐ray diffraction studies revealed that protonation takes place on the nitrogen N1 (crystallographically labelled as N2). The sensitivity of the compounds to shock and friction was also determined by standard BAM tests revealing a low sensitivity for both. B3LYP/6–31G(d, p) density functional (DFT) calculations were carried out to determine the enthalpy of combustion (ΔcH(1)=−3737.8 kJ mol−1, ΔcH(2)=−4577.8 kJ mol−1) and the standard enthalpy of formation (ΔfH°(1)=−498.3 kJ mol−1, (ΔfH°(2)=+524.2 kJ mol−1). The detonation pressures (P(1)=189×108 Pa, P(2)=199×108 Pa) and detonation velocities (D(1)=7015 m s−1, D(2)=7683 m s−1) were calculated using the program EXPLO5.
Thermal Analysis Studies on the Slow‐Propagation Tungsten Type Delay Composition System
Authors: Lu Kai‐Tai , Yang Ching‐Chyuan
Published: September 2008

Thermal analysis techniques were applied to investigate the reaction characteristics of a slow‐propagation tungsten type delay composition system by means of differential scanning calorimetry (DSC) and thermogravimetry (TG). The ingredients of the delay composition were tungsten, barium chromate, potassium perchlorate, diatomaceous earth, and Viton. A formula of delay composition with a weight percentage of W/BaCrO4/KClO4/D. E./Viton=27 : 54 : 11 : 6 : 2 has been used in a self‐destruction mechanism of fuse, which was set as the original formula. In the first place, the reaction heat and weight loss for different compositions without Viton were measured during the reaction. The influence of each ingredient of the formula on the reaction system was analyzed from these experimental results. Afterward Viton was added in the samples of experiment to measure and analyze the influence of Viton on the reaction system. Finally, 28 experimental formulas of delay composition were designed on the condition that the weight percentage of Viton was kept constant and the maximum variation of weight percentage of all the others was limited within 20%. The delay compositions of various formulas were granulated and then the variations of reaction characteristics were measured to analyze the influence of weight variation of each ingredient on reaction characteristics. The results of this study are very important and useful for improving the self‐destruction mechanism of fuse.
Very short peptides with stable folds: Building on the interrelationship of Trp/Trp, Trp/cation, and Trp/backbone–amide interaction geometries
Authors: Eidenschink Lisa , Kier Brandon L. , Huggins Kelly N. L. , Andersen Niels H.
Published: September 2008

By combining a favorable turn sequence with a turn flanking Trp/Trp interaction and a C‐terminal H‐bonding interaction between a backbone amide and an i‐2 Trp ring, a particularly stable (ΔGU > 7 kJ/mol) truncated hairpin, Ac‐WI‐(D‐Pro‐D‐Asn)‐KWTG‐NH2, results. In this construct and others with a W‐(4‐residue turn)‐W motif in severely truncated hairpins, the C‐terminal Trp is the edge residue in a well‐defined face‐to‐edge (FtE) aryl/aryl interaction. Longer hairpins and those with six‐residue turns retain the reversed “edge‐to‐face” (EtF) Trp/Trp geometry first observed for the trpzip peptides. Mutational studies suggest that the W‐(4‐residue turn)‐W interaction provides at least 3 kJ/mol of stabilization in excess of that due to the greater β‐propensity of Trp. The π–cation, and Trp/Gly‐HN interactions have been defined. The latter can give rise to >3 ppm upfield shifts for the Gly‐HN in ‐WXnG‐ units both in turns (n = 2) and at the C‐termini (n = 1) of hairpins. Terminal YTG units result in somewhat smaller shifts (extrapolated to 2 ppm for 100% folding). In peptides with both the EtF and FtE W/W interaction geometries, Trp to Tyr mutations indicate that Trp is the preferred “face” residue in aryl/aryl pairings, presumably because of its greater π basicity. Proteins 2009. © 2008 Wiley‐Liss, Inc.
Oxidative folding of synthetic polypeptides S‐protected as tert‐butylthio derivatives
Authors: Verdini Antonio , Terenzi Silvia , Brossard Vincent , Roggero Mario , Corradin Giampietro
Published: September 2008

A new method for oxidative folding of synthetic polypeptides assembled by stepwise solid phase synthesis is introduced. Folding is obtained in excellent yields by reacting S‐tert‐butylthiolated polypeptides with a 100‐fold molar excess of cysteine at 37 °C in a slightly alkaline buffer containing chaotropic salts, and in the presence of air‐oxygen. This novel protocol has been applied to the folding of S‐tert‐butylthiolated human thymus and activation‐regulated chemokine (hu‐TARC) derivatives as well as to larger segments of Plasmodium falciparum and Plasmodium berghei circumsporozoite proteins. Folded P. falciparum polypeptides have been used as substrates of endoproteinase Glu‐C (Glu‐C) and endoproteinase Asp‐N (Asp‐N) in an attempt to identify their disulfide connectivities. Particular practical advantages of the present method are (i) easy purification and storage of the S‐protected peptide derivatives, (ii) elimination of the risk of cysteine alkylation during the acidolytic cleavage deprotection and resin cleavage steps, (iii) possibility to precisely evaluate the extent of folding and disulfide bond formation by mass spectrometry, and (iv) facile recovery of the final folded product. Copyright © 2008 European Peptide Society and John Wiley & Sons, Ltd.
Liquid phase deposition of iron and cobalt doped TiO2 epitaxial thin films
Authors: Chan K. Y. S. , Goh G. K. L. , Han M. Y.
Published: September 2008

Liquid phase deposition (LPD) is a wet process in which metal oxide thin films can be deposited on substrates via a chemical equilibrium reaction between a metal fluoro‐complex and a metal oxide in aqueous solution. In this study, iron and cobalt doped TiO2 anatase thin films were deposited on (001) oriented SrTiO3 single crystal substrates using liquid phase deposition. The process involves the reaction of ammonium hexafluorotitanate and boric acid, in the presence of FeOOH–HF and Co(NO3)2–ethylenediamine (en) for the iron and cobalt doped TiO2 films respectively. Cobalt doping was also attempted by immersing a non‐doped TiO2 film in a solution of Co‐en ions. XRD shows that the films are c‐axis oriented and films epitaxy was confirmed using pole figure measurements. No metallic secondary phases were detected by XRD and XPS. The iron and cobalt doped films are observed to yield room temperature ferromagnetism. The insulating nature of the films suggests that bound magnetic polarons are responsible for the observed ferromagnetism. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Chemical spray deposition of zinc oxide nanostructured layers from zinc acetate solutions
Authors: Dedova T. , Klauson J. , Badre C. , Pauporté Th. , Nisumaa R. , Mere A. , Volobujeva O. , Krunks M.
Published: September 2008

Zinc oxide (ZnO) films were deposited by chemical spray from zinc acetate aqueous solutions using continuous and pulsed spray modes. ZnO films were characterized by scanning electron microscopy, atomic force microscopy, optical transmittance, and water contact angle (CA) measurements. ZnO films with highly structured surfaces comprising nanoneedles or nanorods with root mean square roughness (Sq) up to 60 nm were grown using the continuous spray mode. Doping with In or using pulsed spray mode leads to smoother ZnO surfaces with Sq of 20 nm. The optical transmittance of the film is controlled by its surface morphology and internal scattering. Water contact angle measurements reveal that as‐sprayed ZnO films with nanoneedle or nanorod‐like crystals on the surface are hydrophilic with CA ∼10°. Structured surfaces become hydrophobic with CA ∼134° after treatment with stearic acid. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electrochemical growth of ZnO nanowires inside nanoporous alumina templates. A comparison with metallic Zn nanowires growth
Authors: Ramirez Daniel , Pauporte Thierry , Gomez Humberto , Lincot Daniel
Published: September 2008

Molecular oxygen reduction in presence of Zn(II) allowed to get arrays of zinc oxide (ZnO) nanowires (NWs) inside thick anodic alumina membranes (AAM), previously made by anodization in oxalic acid. A Zinc (Zn) NWs array made by electrochemical deposition (ED) was employed as a metal reference in order to compare its growth behavior with respect to that of ZnO, a semiconducting material. Chronoamperometric measurements for Zn NWs showed a typical response for metallic growth inside porous templates while ZnO NWs did not show this behavior. We observed that Zn NWs grew faster than ZnO NWs as checked by the electrical charge. SEM images showed the presence of ZnO NWs only after long deposition time. X‐ray diffraction data confirmed the ZnO structure. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The characterizations of superconducting MoC/Mo2C nanocomposites embedded in a magnetic graphite matrix
Authors: Wang Z. H. , Li D. , Geng D. Y. , Ma S. , Liu W. , Zhang Z. D.
Published: September 2008

A three‐dimensional molybdenum‐carbides/graphite network formed by superconducting MoC/Mo2C nanograins embedded in a magnetic graphite matrix was fabricated. The temperature dependence of magnetization of the MoC/Mo2C nanocomposites indicates that the superconducting transition temperatures (TC) of Mo2C and MoC nanocrystals are 8 K and 11.5 K, respectively. These transition temperatures are lower than those of their corresponding bulk counterparts, due to the detrimental influence of magnetic graphite. The magnetization influenced by edge barrier and magnetic graphite are investigated for the MoC/Mo2C nancomposites embedded in the magnetic graphite matrix. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Characterization of solution‐processed pentacene thin film transistors
Authors: Natsume Yutaka
Published: September 2008

The electrical and chemical stability of solution‐processed pentacene thin film transistors (TFTs) was investigated using analytical models reported by Horowitz et al. in comparison with vacuum‐deposited TFTs. The estimated total trap density of the solution‐processed film was one to two order(s) of magnitude lower than that of the vacuum‐deposited film. The low trap density of the solution‐processed film is due to large crystalline domains, which include only a few structural defects, in contrast to the vacuum‐deposited film. The solution‐processed film is also superior to the vacuum‐deposited film in electrical stability during long‐term storage in air. That is, a considerable shift of the transistor characteristics in the subthreshold region including a threshold voltage was observed, especially in the case of the vacuum‐deposited TFT. The change in the electrical properties is attributed to the increase of oxidation‐induced chemical impurities, which were confirmed by surface mass spectroscopy. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Synthetic transverse thermoelements made from porous bismuth telluride and single crystal bismuth
Authors: Goldsmid H. J.
Published: September 2008

Synthetic transverse thermoelements may be produced from materials that have layered structures with two components. It is desirable that the electrical and thermal conductivities should be much greater for one component than for the other. It is also necessary that the longitudinal figure of merit for a conventional couple made from the two components should be high. Here we show that a transverse thermoelement made from single‐crystal bismuth and polycrystalline bismuth‐antimony telluride largely meets these requirements when the latter material is porous. If the porosity is such that the conductivities have about 20% of their values for the fully dense alloy, the dimensionless transverse figure of merit is over 0.6. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
High‐frequency permeability of sputtered Fe–Co–B‐based soft magnetic thin films
Authors: Liao Jiansheng , Feng Zekun , Qiu Jing , Tong Yanqun
Published: September 2008

High‐frequency characteristics of a series of soft magnetic Fe–Co–B‐based thin films are investigated in the range of 0.5–5 GHz. It is found that in‐plane anisotropy can be caused by oblique incidence or applying an external field during deposition. The permeability and the resonance frequency are basically consistent with Snoek's law. Ni can improve the magnetic properties greatly except for the decrease of resistivity. In order to reduce the dissipation and increase the resistivity, SiO2is added to the film. Excellent high‐frequency permeability of (Fe40Co40B20)0.619Ni12.642–(SiO2)25.416is obtained: the resonance frequency exceeds 2.2 GHz; the real and the imaginary parts of the permeability at 0.5 GHz are 476 and 92, respectively; the resistivity of the film reaches 682 μΩ cm. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Silicon nanowire optical Raman line shapes at cryogenic and elevated temperatures
Authors: Scheel H. , Khachadorian S. , Cantoro M. , Colli A. , Ferrari A. C. , Thomsen C.
Published: September 2008

We report the Raman spectra of silicon nanowires (SiNWs) in a wide temperature range, between 2 K and 850 K. At room temperature we find a strong influence on the spectrum from applied laser excitation powers. These effects can be attributed a laser heated sample, leading to an inhomogeneous temperature distribution within the laser‐spot. If the laser excitation power is small (below 100 μW) such effects are negligible, and we find a temperature dependence governed by threephonon decay processes. The results from temperature dependent measurements indicate a change of sample morphology due to heating. Raman measurements on SiNWs immersed in superfluid helium at ≈ 2 K show very strong red‐shifts, even though they still have the perfect thermal contact via the superfluid helium. Considering anharmonic effects we find massively increased Si core temperatures. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Molecular and electronic structure of PTCDA on bilayer graphene on SiC(0001) studied with scanning tunneling microscopy
Authors: Lauffer Peter , Emtsev Konstantin V. , Graupner Ralf , Seyller Thomas , Ley Lothar
Published: September 2008

Epitaxial growth of graphene on SiC surfaces by solid state graphitization is a promising route for future development of graphene based electronics. In the present work we study the morphology and molecular scale structure of monolayer films of 3,4,9,10‐perylene tetracarboxylic dianhydrid (PTCDA) on bilayer graphene on SiC(0001) by scanning tunneling microscopy (STM). First we discuss how the PTCDA molecules adsorb on bilayer graphene. We specially regard the density of PTCDA molecules at monolayer coverage. From the comparison with experiments on HOPG (Au(111) and Ag(110) from literature) we infer a non‐planar adsorption geometry of PTCDA molecules on bilayer graphene. The electronic structure of the surrounding bilayer graphene substrate is investigated via scanning tunneling spectroscopy (STS) and reveals n‐type doping of bilayer graphene during adsorption of PTCDA. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optical properties of metallic and semiconducting single‐wall carbon nanotubes
Authors: Miyata Yasumitsu , Yanagi Kazuhiro , Maniwa Yutaka , Kataura Hiromichi
Published: September 2008

Optical properties of high purity metallic and semiconducting single‐wall carbon nanotubes (SWCNTs) were investigated from far infrared to ultraviolet by optical absorption spectroscopy. It was found that the metallic SWCNT thin film has larger infrared absorption intensity than the semiconducting one. Furthermore, little changes in the optical absorption spectrum and the DC sheet resistance against molecular physisorptions were revealed in the metallic SWCNTs thin film. The stability of the metallic SWCNTs results from their constant electronic density of state near the Fermi level. On the other hand, the existence of semiconducting SWCNTs in the films makes their infrared absorption intensity and the sheet resistance more sensitive to the adsorption of molecules mainly due to carrier doping. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
G– and G+ in the Raman spectrum of isolated nanotube: a study on resonance conditions and lineshape
Authors: Telg H. , Fouquet M. , Maultzsch J. , Wu Y. , Chandra B. , Hone J. , Heinz T. F. , Thomsen C.
Published: September 2008

We analyze the high‐energy Raman modes, G+ and G–, in a pair of one metallic and one semiconducting nanotube grown across a 100 mm wide slit. By combining Raman resonance profiles of the radial breathing mode and the high‐energy modes, we assign the broad G– peak to a metallic and the G+ peak to a semiconducting nanotube. Considering theoretical predictions we show that both peaks, G– and G+, originate from the LO phonon. The G– peak is the longitudinal mode of the metallic tube; it is broadened and downshifted due to strong electron‐phonon coupling in the metallic nanotube. The G+ peak is due to the longitudinal mode in the semiconducting tube. An asymmetric lineshape of the G– peak agrees with observations of the asymmetry to be an intrinsic feature of metallic nanotubes. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Preparation and electronic properties of potassium doped graphite single crystals
Authors: Grüneis A. , Attaccalite C. , Rubio A. , Molodtsov S. L. , Vyalikh D. V. , Fink J. , Follath R. , Pichler T.
Published: September 2008

Here we revisited the electronic structure of potassium doped graphite using angle‐resolved photoemission spectroscopy (ARPES). We perform an analysis of the charge transfer from potassium to graphite employing a tight‐binding model for the band structure. Our ARPES measurements clearly show that the π* band of graphite becomes occupied upon deposition and intercalation of small amounts of potassium.

The observed shift in the Fermi level of ∼ 400 meV is well below the appearance of staged graphite compounds and is described by a rigid band shift model. The π* band in pristine graphite is unoccupied and can therefore not be measured by ARPES. Thus potassium doping in the dilute limit provides a key for measuring the π* bands close to the Fermi level by ARPES. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
High‐resolution profiling of oxylipin‐containing galactolipids in Arabidopsis extracts by ultra‐performance liquid chromatography/time‐of‐flight mass spectrometry
Authors: Glauser Gaetan , Grata Elia , Rudaz Serge , Wolfender Jean‐Luc
Published: September 2008

A high‐resolution ultra‐performance liquid chromatography/time‐of‐flight mass spectrometry (UPLC/TOFMS) method using in‐source collision‐induced dissociation (CID) was developed for globally profiling oxylipin‐containing galactolipids in Arabidopsis wounded leaves. MS and pseudo‐MS/MS spectra were obtained during a single analytical run by switching a lens of the TOFMS transfer optics from low to high voltage. Numerous known galactolipids were observed, and four novel mono‐ or di‐galactosyl monoacylglycerides (MGMGs or DGMGs) containing oxophytodienoic acid (OPDA) or dinor‐oxophytodienoic acid (dn‐OPDA), esterified respectively at the sn1 and the sn2 positions, were identified. Rapid microisolation of the galactolipids followed by alkaline and enzymatic hydrolyses enabled the release of the esterified oxylipins, which allowed for the unambiguous characterization of the oxylipin‐containing monoacylglycerides. Their strong induction in response to wounding indicates that these compounds are probably lysogalactolipids formed from galactosyldiglycerides in the injured tissues. Copyright © 2008 John Wiley & Sons, Ltd.
A comparison of relative quantification with isobaric tags on a subset of the murine hepatic proteome using electrospray ionization quadrupole time‐of‐flight and matrix‐assisted laser desorption/ionization tandem time‐of‐flight
Authors: Scheri Richard C. , Lee Junga , Curtis Lawrence R. , Barofsky Douglas F.
Published: September 2008

The use of isobaric tagging for relative and absolute quantification (iTRAQ) has increased dramatically over the past few years. Many factors can affect the accuracy of quantification. Some of these include the number of biological/technical replicates, sample complexity, instrumentation, method of peptide/protein identification and the statistical techniques used for data analysis. It has been observed that the low collision energies normally used in electrospray ionization quadrupole time‐of‐flight (ESI QTOF) can result in low iTRAQ reporter ion abundances. We used two‐way analysis of variance (ANOVA) to compare the iTRAQ ratios that were generated on an ESI QTOF and a matrix‐assisted laser desorption/ionization tandem time‐of‐flight (MALDI TOF/TOF). It appears that iTRAQ analyses performed on an ESI QTOF without any special modifications to instrumental parameters produce essentially the same protein ratios as those obtained on a MALDI TOF/TOF. Copyright © 2008 John Wiley & Sons, Ltd.