bluuebunny/crossref_metadata_2025 huggingface dataset:
The trivialization of diagnosis
Authors: Kushner Irving , Greco Peter J. , Saha P.K. , Gaitonde Shilpa
Published: September 2009

Although it is widely recognized that diagnosis plays a central role in clinical medicine, in recent years the primacy of diagnosis has come under attack from several sources. 1. “Billable terms” are replacing traditional medical diagnoses. The former are based on International Classification of Diseases lists, which include many non‐diagnoses such as symptoms and signs. 2. Diagnosis often gets short shrift because of the perceived urgency of discharge. 3. The problem oriented record, in practice, has frequently led to a shift in emphasis from synthesis of findings to fragmentation of problems. 4. Presumptive diagnoses frequently metamorphose into established diagnoses in medical records, even if incorrect. 5. A number of authors have apparently disparaged the importance of diagnosis. Nonetheless, it is clear that diagnosis must continue to play a central role in clinical medicine. We propose several ways by which we can resist these forces and assure that diagnosis retains its appropriate position of primacy. Journal of Hospital Medicine 2010;5:116–119. © 2010 Society of Hospital Medicine.
Hospitalist handoffs: A systematic review and task force recommendations
Authors: Arora Vineet M. , Manjarrez Efren , Dressler Daniel D. , Basaviah Preetha , Halasyamani Lakshmi , Kripalani Sunil
Published: September 2009

BACKGROUND:

Handoffs are ubiquitous to Hospital Medicine and are considered a vulnerable time for patient safety.

PURPOSE:

To develop recommendations for hospitalist handoffs during shift change and service change.

DATA SOURCES:

PubMed (through January 2007), Agency for Healthcare Research and Quality (AHRQ) Patient Safety Network, white papers, and hand search of article bibliographies.

STUDY SELECTION:

Controlled studies evaluating interventions to improve in‐hospital handoffs (n = 10).

DATA EXTRACTION:

Studies were abstracted for design, setting, target, outcomes (including patient‐level, staff‐level, or system‐level outcomes), and relevance to hospitalists.

DATA SYNTHESIS:

Although there were no studies of hospitalist handoffs, the existing literature from related disciplines and expert opinion support the use of a verbal handoff supplemented with written documentation in a structured format or technology solution. Technology solutions were associated with a reduction in preventable adverse events, improved satisfaction with handoff quality, and improved provider identification. Nursing studies demonstrate that supplementing verbal exchange with a written medium leads to improved retention of information. White papers characterized effective verbal exchange, as focusing on ill patients and actions required, with time for questions and minimal interruptions. In addition, content should be updated daily to ensure communication of the latest clinical information. Using this literature, recommendations for hospitalist handoffs are presented with corresponding levels of evidence. Recommendations were reviewed by hospitalists at the Society of Hospital Medicine (SHM) Annual Meeting and by an interdisciplinary team of expert consultants and were endorsed by the SHM governing board.

CONCLUSIONS:

The systematic review and resulting recommendations provide hospitalists a starting point from which to improve in‐hospital handoffs. Journal of Hospital Medicine 2009;4:433–440. © 2009 Society of Hospital Medicine.
Identification of N‐glycosylation in prolyl endoprotease from Aspergillus niger and evaluation of the enzyme for its possible application in proteomics
Authors: Šebela Marek , Řehulka Pavel , Kábrt Jaromír , Řehulková Helena , Oždian Tomáš , Raus Martin , Franc Vojtěch , Chmelík Josef
Published: September 2009

An acidic prolyl endoprotease from Aspergillus niger was isolated from the commercial product Brewers Clarex™ to evaluate its possible application in proteomics. The chromatographic purification yielded a single protein band in sodium dodecyl sulfate polyacrylamide gel electrophoresis providing an apparent molecular mass of 63 kDa and a broad peak (m/z 58 061) in linear matrix‐assisted laser desorption/ionization (MALDI) time‐of‐flight (TOF) mass spectrometry (MS) indicating the glycoprotein nature of the enzyme. Indeed, a colorimetric assessment with phenol and sulfuric acid showed the presence of neutral sugars (9% of weight). The subsequent treatment with N‐glycosidase F released a variety of high‐mannose type N‐glycans, which were successfully detected using MALDI‐TOF MS. MALDI‐TOF/TOF tandem MS analysis of glycopeptides from a tryptic digest of prolyl endoprotease unraveled the identity of the N‐glycosylation site in the primary structure. The data obtained also show that the enzyme is present in its processed form, i.e. without putative signal and propeptide parts. Spectrophotometric measurements demonstrated optimal activity at pH 4.0–4.5 and also high thermostability for the cleavage at the C‐terminal part of proline residues. In‐solution digestion of standard proteins (12–200 kDa) allowed to evaluate the cleavage specificity. The enzyme acts upon proline and alanine residues, but there is an additional minor cleavage at some other residues like Gly, Leu, Arg, Ser and Tyr. The digestion of a honeybee peptide comprising six proline residues (apidaecin 1A) led to the detection of specific peptides terminated by proline as it was confirmed by MALDI postsource decay analysis. Copyright © 2009 John Wiley & Sons, Ltd.
Group‐level organizational citizenship behavior: Effects of demographic faultlines and conflict in small work groups
Authors: Choi Jin Nam , Sy Thomas
Published: September 2009

Organizational scholars have recently shifted their attention to examining organizational citizenship behavior (OCB) as a group‐level phenomenon. Adopting the input‐mediator‐outcome model of group performance, we examined antecedents and intermediate processes that predict group‐level OCB (GOCB) in small work groups. The results, based on data from 62 work groups representing a variety of industries, revealed that demographic faultlines based on relation‐oriented attributes (gender, age, and race) and a task‐related attribute (tenure) had differentiated relationships with task and relationship conflict, which mediated the relationships between faultlines and group outcomes (GOCB and group performance). Both task and relationship conflict were negative predictors of group performance. However, task conflict increased GOCB, whereas relationship conflict decreased it. The present study offers evidence of the relationship between demographic faultlines and various group processes and outcome variables in natural work groups. Copyright © 2009 John Wiley & Sons, Ltd.
Raman and surface‐enhanced Raman spectroscopic studies of the 15‐mer DNA thrombin‐binding aptamer
Authors: Pagba Cynthia V. , Lane Stephen M. , Wachsmann‐Hogiu Sebastian
Published: September 2009

Aptamers are single‐stranded oligonucleotides that selectively bind to their target molecules owing to their ability to form secondary structures and shapes. The 15‐mer (5′‐GGTTGGTGTGGTTGG‐3′) DNA thrombin‐binding aptamer (TBA) binds to thrombin following the formation of a quadruplex structure via the Hoogsten‐type G–G interactions. In the present study, Raman and SERS spectra of TBA and thiolated TBA (used to facilitate covalent bonding to metal nanoparticle) in different conditions are investigated. The spectra of the two analogs exhibit vibrations, such as the C8N7H2 deformation band at ∼1480 cm−1 of the guanine tetrad, that are characteristic of the quadruplex structure in the presence of K+ ions or at low temperature. Interestingly, SERS spectra of the two analogs differ markedly from their respective normal Raman spectra, possibly due to changes in the conformation of the aptamer upon binding, as well as to the specific interaction of individual vibrational modes with the metal surface. In addition, the SERS spectra of the thiolated aptamer show significant changes with different concentrations, which may be due to different orientation of the molecule with respect to the metal surface. This study provides useful information for the development of label‐free aptamer‐based SERS sensors and assays. Copyright © 2009 John Wiley & Sons, Ltd.
Towards a specific characterisation of components on a cell surface—combined TERS‐investigations of lipids and human cells
Authors: Böhme R. , Richter M. , Cialla D. , Rösch P. , Deckert V. , Popp J.
Published: September 2009

Supported lipid structures and human cells (human dermal derived keratinocyte, HaCaT) were investigated using tip‐enhanced Raman spectroscopy (TERS) to use the high spatial resolution capabilities of TERS, which is assumed to be less than 10 nm, to determine specific components on the cell surface. As lipids are a main component of cellular membranes, the correlation of spectral properties of pure lipids with respect to the complex biological sample was investigated. Induced by dynamic structural changes as well as nanoscale effects, a particular spectral feature of the lipid TERS spectra is found to vary, and a similar spectral deviation appears among the TERS spectra measured on the cell. Modifications of the cell surface alone cannot cause such behaviour. In contrast to soft lipid agglomerates, the cells were fixed and therefore hampered for intrinsic structural changes. Hence, the main contribution for the cell TERS spectra variation results from nanoscale effects, determined by different spectral characteristics compared to conventional Raman spectroscopy. The present results demonstrate the capability of TERS to provide a detailed and fast insight into the composition of the cell surface, even allowing the detection of single components. Copyright © 2009 John Wiley & Sons, Ltd.
Subtracted shifted Raman spectroscopy of organic dyes and lakes
Authors: Rosi Francesca , Paolantoni Marco , Clementi Catia , Doherty Brenda , Miliani Costanza , Brunetti Brunetto G. , Sgamellotti Antonio
Published: September 2009

Resonance Raman spectroscopy has been utilized to identify vegetal and animal dyes and lakes. These compounds have been used by artists since antiquity, and their identification has important implications in art history and conservation. The resonance condition is useful when working with real ancient objects so as to enhance the Raman scattering of chromophores with respect to the strong signal of the matrix, such as the textile or parchment over which the colorant is supported. The strong fluorescence that generally characterizes the resonance Raman spectra was eliminated by using subtracted shifted Raman spectroscopy (SSRS). A systematic study on reference organic dyes was primarily carried out to evaluate the suitability of the method and to estimate the strengths and limitations of the spectrum reconstruction process. The method was then applied to the noninvasive identification of madder on ancient dyed silk textiles such as analtar table clothand amanutergiumattributed to the Egyptian artistic textile production of the 10th–11th Century A.D. Copyright © 2009 John Wiley & Sons, Ltd.
Characterization of Al(III) complexes with hematein in artistic alum logwood inks
Authors: Centeno Silvia A. , Ropret Polonca , Federico Eleonora Del , Shamir Jacob , Itin Boris , Jerschow Alexej
Published: September 2009

The complexes between Al(III) and hematein, the main coloring matter in alum logwood inks, were characterized by Raman and 27Al NMR (nuclear magnetic resonance) spectroscopies. Raman spectra of the crystallized complexes and of the compounds applied on a paper substrate are presented and assigned based on published data for the parent compounds. These Raman spectra show that the coordination of the hematein to the Al(III) ions takes place in both cases through the carbonyl and hydroxyl groups in the molecule, and that the aromatic rings are also involved in the interaction. The Raman spectra of the pure hematein–Al(III) complexes were found to be consistent with those recorded for a logwood ink prepared following a late 19th century recipe, using logwood chips instead of pure hematein, and applied on a paper substrate. These spectra can be used as references for the noninvasive identification of the compounds in works of art. 27Al solid‐state NMR showed that the coordination of the Al(III) atoms in the crystallized powder is predominantly octahedral, while when applied on a paper substrate the colorant is present mainly as a tetrahedral complex, with an octahedral coordination also present in a smaller proportion. The fact that the predominant coordinations for the complexes in the crystallized material and for the ones present on the paper substrate are different is relevant for the study of the lightfastness and thermal stability of works of art bearing these media. Copyright © 2009 John Wiley & Sons, Ltd.
Raman spectroscopy study of Na2MoO4·2H2O and Na2MoO4 under hydrostatic pressure
Authors: Luz‐Lima C. , Saraiva G. D. , Filho A. G. Souza , Paraguassu W. , Freire P. T. C. , Mendes Filho J.
Published: September 2009

Raman spectroscopy measurements of polycrystalline Na2MoO4·2H2O (NMHO) and Na2MoO4 (NM) under hydrostatic pressure (from 0 to 10 GPa) were performed. This study allowed us to monitor the stretching and bending vibrations of MoO4 ions as well as the translational modes as a function of pressure. The pressure dependence of the wavenumbers of the modes indicates that the Na2MoO4·2H2O undergoes two phase transitions at about ∼3 and ∼4 GPa. When releasing pressure, we have observed that the original spectrum is recovered, thereby pointing to a reversible process. The Na2MoO4 (NM) starting phase was found to be stable up to 10 GPa. The pressure‐dependent Raman data for NM did not reveal any structural modification. The influence of the pressure‐transmitting medium on the phase transitions is also discussed. Copyright © 2009 John Wiley & Sons, Ltd.
Maternal dietary conjugated linoleic acid is not directly toxic for the developing chick embryo, but causes embryo mortality by altering fatty acid composition of the egg yolk in the chicken
Authors: Aydin Rahim , Cook Mark E
Published: September 2009

BACKGROUND: Conjugated linoleic acid (CLA) was shown to cause embryo mortality when added into chicken diets. The objective of this study was to determine if CLA accumulation in yolk was directly responsible for embryo mortality.

MATERIAL AND METHODS: Forty‐two 30‐week‐old hens were assigned to seven groups and fed a diet containing 5 g kg−1 canola oil (Group A), 5 g kg−1 CLA (Group B), 5 g kg−1 CLA plus 20 g kg−1 canola oil (Group C), 5 g kg−1CLA plus 30 g kg−1 canola oil (Group D), 5 g kg−1 CLA plus 40 g kg−1 canola oil (Group E), 10 g kg−1 CLA plus 40 g kg−1 canola oil (Group F) or 20 g kg−1 CLA plus 40 g kg−1 canola oil (Group G) for 22 days. Collected eggs were held at 15 °C for 24 h, and then incubated. For fatty acid analysis, three eggs were collected on the 22nd day of the study.

RESULTS: After the sixth day, embryonic mortality was 100% in eggs from Group B versus 2, 30, 21, 4, 0, and 9% in groups A, C, D, E, F and G, respectively. The ratio of SFA/UFA of yolks from groups A, B, C, D, E, F and G was 0.64, 1.53, 1.07, 1.06, 1.08, 1.05 and 1.13, respectively. Relative levels (%) of CLA in the eggs from the groups A, B, C, D, E, F and G were 0.12, 2.29, 1.68, 1.80, 1.76, 3.04, and 5.25%, respectively.

CONCLUSION: This study showed that CLA was not directly toxic for developing embryo, but caused mortality in the fertile eggs by increasing the ratio of SFA to UFA in egg yolk. Copyright © 2009 Society of Chemical Industry
Predictive factors of early relapse in UICC stage I–III colorectal cancer patients after curative resection
Authors: Tsai Hsiang‐Lin , Chu Koung‐Shing , Huang Yu‐Ho , Su Yu‐Chung , Wu Jeng‐Yih , Kuo Chao‐Hung , Chen Chao‐Wen , Wang Jaw‐Yuan
Published: September 2009

Background and Objectives

To predict the clinicopathologic factors for early relapse of UICC stage I–III colorectal cancer (CRC) patients undergoing curative resection and thus to identify a subgroup of patients who are at high risk for postoperative early relapse.

Methods

Between January 2001 and June 2007, a total of 778 UICC stage I–III CRC patients who underwent a radical resection and regular follow‐up were retrospectively analyzed. Of these 778 CRC patients, 521 colon cancer and 257 rectal cancer cases were analyzed, respectively, to determine the predictors of early relapse postoperatively. These 778 patients were followed‐up intensively, and their outcomes were investigated retrospectively.

Results

Out of 521 colon cancer patients, postoperative relapse after primary resection was found in 142 (27.3%) patients, and 77 (54.2%) of 142 recurrent colon cancer patients were classified as postoperative early relapse. Meanwhile, among 257 rectal cancer patients, postoperative relapse was found in 68 (26.5%) patients and 44 (64.7%) of 68 recurrent rectal cancer patients were identified as postoperative early relapse. Forty‐nine (63.6%) of 77 early relapsed colon cancer patients were stage III, and likewise, 26 (59.1%) of 44 early relapsed rectal cancer patients were stage III. Univariately, postoperative early relapse of colon cancer patients was significantly correlated with the presence of vascular invasion (P < 0.001), perineural invasion (P < 0.001), high postoperative carcinoembryonic antigen (CEA) level (P = 0.001), and type of surgery (P = 0.016). Using a Cox proportional hazards analysis, the presence of vascular invasion (P = 0.033), perineural invasion (P = 0.005), and high postoperative CEA levels (P = 0.001) were demonstrated to be independent predictors of postoperative early relapse of colon cancer patients, while in rectal cancer patients, both vascular invasion (P = 0.039) and perineural invasion (P = 0.008) were statistically significant predictors of early relapse by univariate analysis. Using a Cox proportional hazards analysis, only perineural invasion (P = 0.043) was an independent factor. Early relapse cases had significant lower overall survival rates than non‐early relapse cases either in colon cancer (P < 0.001) or in rectal cancer (P = 0.0091) patients.

Conclusions

This study suggests that vascular invasion, perineural invasion, and postoperative CEA level may be significant factors for postoperative early relapse of colon cancer; while only perineural invasion is considered to be a significant predictor in rectal cancer patients. Identification of these high‐risk UICC stage I–III CRC patients of early relapse is important, and thus could help to define patients with this tumor entity for an enhanced follow‐up and therapeutic program. J. Surg. Oncol. 2009;100:736–743. © 2009 Wiley‐Liss, Inc.
Ab initio chemical kinetics for the NH2 + HNOx reactions, part II: Kinetics and mechanism for NH2 + HONO
Authors: Xu Shucheng , Lin M. C.
Published: September 2009

The kinetics and mechanism for the reaction of NH2 with HONO have been investigated by ab initio calculations with rate constant prediction. The potential energy surface of this reaction has been computed by single‐point calculations at the CCSD(T)/6‐311+G(3df, 2p) level based on geometries optimized at the CCSD/6‐311++G(d, p) level. The reaction producing the primary products, NH3 + NO2, takes place via precomplexes, H2N⋅⋅⋅c‐HONO or H2N⋅⋅⋅t‐HONO with binding energies, 5.0 or 5.9 kcal/mol, respectively. The rate constants for the major reaction channels in the temperature range of 300–3000 K are predicted by variational transition state theory or Rice–Ramsperger–Kassel–Marcus theory depending on the mechanism involved. The total rate constant can be represented by ktotal = 1.69 × 10−20 × T2.34 exp(1612/T) cm3 molecule−1 s−1 at T = 300–650 K and 8.04 × 10−22 × T3.36 exp(2303/T) cm3 molecule−1 s−1 at T = 650–3000 K. The branching ratios of the major channels are predicted: k1 + k3 producing NH3 + NO2 accounts for 1.00–0.98 in the temperature range 300–3000 K and k2 producing OH + H2NNO accounts for 0.02 at T > 2500 K. The predicted rate constant for the reverse reaction, NH3 + NO2 → NH2 + HONO represented by 8.00 × 10−26 × T4.25 exp(−11,560/T) cm3 molecule−1 s−1, is in good agreement with the experimental data. © 2009 Wiley Periodicals, Inc. Int J Chem Kinet 41: 678–688, 2009
Competitive binding exchange between alkali metal ions (K+, Rb+, and Cs+) and Na+ ions bound to the dimeric quadruplex [d(G4T4G4)]2: a 23Na and 1H NMR study
Authors: Cesare Marincola Flaminia , Virno Ada , Randazzo Antonio , Mocci Francesca , Saba Giuseppe , Lai Adolfo
Published: September 2009

A comparative study of the competitive cation exchange between the alkali metal ions K+, Rb+, and Cs+ and the Na+ ions bound to the dimeric quadruplex [d(G4T4G4)]2 was performed in aqueous solution by a combined use of the 23Na and 1H NMR spectroscopy. The titration data confirm the different binding affinities of these ions for the G‐quadruplex and, in particular, major differences in the behavior of Cs+ as compared to the other ions were found. Accordingly, Cs+ competes with Na+ only for the binding sites at the quadruplex surface (primarily phosphate groups), while K+ and Rb+ are also able to replace sodium ions located inside the quadruplex. Furthermore, the 1H NMR results relative to the CsCl titration evidence a close approach of Cs+ ions to the phosphate groups in the narrow groove of [d(G4T4G4)]2. Based on a three‐site exchange model, the 23Na NMR relaxation data lead to an estimate of the relative binding affinity of Cs+ versus Na+ for the quadruplex surface of 0.5 at 298 K. Comparing this value to those reported in the literature for the surface of the G‐quadruplex formed by 5′‐guanosinemonophosphate and for the surface of double‐helical DNA suggests that topology factors may have an important influence on the cation affinity for the phosphate groups on DNA. Copyright © 2009 John Wiley & Sons, Ltd.
Constant time gradient HSQC–iDOSY: practical aspects
Authors: McLachlan A. S. , Richards J. J. , Bilia A. R. , Morris G. A.
Published: September 2009

An improved constant time gradient HSQC–iDOSY pulse sequence is presented, and the corresponding form of the Stejskal–Tanner equation is derived. The pulse sequence is particularly well suited to the problem of analysing mixtures of chemically cognate species, where the high spectral resolution afforded by 1H13C correlation methods is needed for DOSY experiments to give good diffusion resolution. Its use is illustrated for a mixture of rutin and its aglycone quercetin. Copyright © 2009 John Wiley & Sons, Ltd.
Factors associated with a continuous regular analgesic use—a population‐based study of more than 45 000 Danish women and men 18–45 years of age
Authors: Hargreave Marie , Andersen Tina Veje , Nielsen Ann , Munk Christian , Liaw Kai‐Li , Kjaer Susanne K.
Published: September 2009

Purpose

Widespread use of and serious adverse effects associated with use of analgesics accentuates the need to consider factors related to analgesic use. The objective of this study was to describe continuous regular analgesics use and examine factors associated with a continuous regular analgesic use.

Methods

The study was based on data from two surveys and included a random sample of women and men aged 18–45 years from the general Danish population. Information on analgesics use, self‐rated health, demographic and lifestyle factors was collected using a self‐administered questionnaire. A total of 28 000 women and 33 000 men were invited to participate and 22 199 women (response‐rate 81.4%) and 23 080 men (response‐rate 71.0%), respectively, were included in the study. Data were analyzed using multivariate logistic regression.

Results

We found that 27% of the women and 18% of the men reported a regular monthly use of at least seven analgesic tablets during the last year (continuous regular analgesics use). Besides poor self‐rated health we found in both sexes that increasing age, poor self‐rated fitness, and smoking were related to a continuous regular analgesics use. Nulliparity, low level of education, overweight/obesity, binge drinking, and abstinence were associated with a continuous regular analgesics use for women, while underweight and marital/cohabiting status were associated with a continuous regular analgesics use only for men.

Conclusions

Regular monthly analgesic use during the last year was generally prevalent. Besides self‐rated health, several socio‐demographic and lifestyle factors were associated with a continuous regular analgesic use, although with some gender differences. Copyright © 2009 John Wiley & Sons, Ltd.
Polymeric nanofibers via flat spinneret electrospinning
Authors: Zhou Feng‐Lei , Gong Rong‐Hua , Porat Isaac
Published: September 2009

Electrospun nanofibers are most often produced by needle electrospinning process, which has inherent disadvantages like clogging and low efficiency. In this study, an alternative needleless electrospinning process is reported for the fabrication of nanofibers based on a novel spinneret. Firstly, a spinneret with a 0.5‐mm diameter hole in the middle of a flat plastic cap was custom‐made that may be readily scaled up for mass production. Then, polyethylene oxide (PEO) aqueous solution with 6.0 wt% concentration was used to demonstrate the needleless electrospinning process. The processing window for the jet formation in the flat spinneret electrospinning process was determined. The relationships between various processing parameters (applied voltage, working distance, and flow rate) and the resultant PEO nanofibers were also investigated. It was found that stable fluid jet launched from the tip of the coned droplet anchored at the rim of the hole and formed fibers. The morphology and diameter of electrospun fibers were examined using scanning electron microscopy. The results show that PEO nanofibers produced by this needleless electrospinning have similar structure and morphology to those from the single needle source. Finally, the hole number of spinneret was increased to four holes, which was still able to produce smooth nanofibers with a higher production rate. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers
Study on a novel ion‐conductive compound plasticizer for soft and antistatic PVC materials
Authors: Wang Jiliang , Yang Wanqing , Lei Jingxin
Published: September 2009

Ion‐conductive plasticizers (ICP) composed of dibutyl phthalate (DBP) and butyl 2‐poly(ethylene glycol) phthalate (BPEGP)/lithium bisoxalato borate (LiBOB) were successfully synthesized. The composites blended of poly(vinyl chloride) (PVC) and ICP were fabricated in a Haake torque rheometer. FTIR, surface resistivity measurement, and mechanical test were used to investigate the comprehensive properties of the PVC/ICP composites. The results show that all the synthesized ICP can reduce the surface resistivity of the PVC/ICP composites to 105 Ω sq−1 orders of magnitude as the content of ICP reaches 50 phr. The increasing temperature enhances both the mobility of PEG molecular chains and the diffusion of lithium cations, and thus effectively improves the antistatic ability of the PVC/ICP compounds. With two exceptions of PVC/ICP compounds which include those made of PEG800 and PEG1000, the temperature dependence of the surface resistivity of PVC/ICP does not obey the Arrhenius relationship. The introduction of ICP into PVC matrix would improve the antistatic ability of the composites remarkably. Meanwhile, the mechanical properties of the composites are reduced to some reasonable extent. POLYM. ENG. SCI., 2010. © 2009 Society of Plastics Engineers
Cure kinetics modeling and cure shrinkage behavior of a thermosetting composite
Authors: Ersoy Nuri , Tugutlu Mehmet
Published: September 2009

In this work, the cure kinetics and through‐the‐thickness cure shrinkage upon curing of a carbon fiber‐epoxy composite (AS4/8552) were studied. The study is composed of two major parts. Firstly, dynamic and isothermal Differential Scanning Calorimeter (DSC) scans were performed to develop a new cure kinetics model. The most appropriate kinetic model that produces a nearly perfect fit of all data sets corresponds to a process with two single‐step parallel autocatalytic reactions with diffusion control. Multivariate kinetic analysis was used to evaluate the parameters. In the second part of the study, the coefficients of thermal expansion (CTEs), the glass transition temperatures (Tg), and the through‐the‐thickness cure shrinkage strain values of the partially cured unidirectional and cross‐ply composite samples were measured by using a dynamic mechanical analyzer (DMA). Cure strains were measured throughout the Manufacturer's Recommended Cure Cycle (MRCC) with the same method. Results indicate that glass transition temperatures of partially cured samples can be measured very closely by the two methods (DSC and DMA). The methods proposed were proved to be very reliable to predict the degree of cure and to measure the through‐the‐thickness strains during the cure cycle. POLYM. ENG. SCI., 2010. © 2009 Society of Plastics Engineers
Influence of carbon nanofiber structure on properties of linear low density polyethylene composites
Authors: Lee Sungho , Kim Myung‐Soo , Ogale Amod A.
Published: September 2009

Three types of carbon nanofibers (MJ, Pyrograf®III PR‐19 and PR‐24) were incorporated into linear low density polyethylene (LLDPE) using intensive mixing. The electrical volume resistivity of composites decreased with the addition of CNFs from over 1012 Ω cm for pure LLDPE to less than 104 Ω cm for carbon nanofibers (CNF) contents of 15 wt% or more. Tensile modulus increased from 110 MPa for pure LLDPE to 200 MPa and 300 MPa for 15 wt% MJ and 15 wt% PR composites, respectively. However, the tensile strength remained fairly unchanged at about 20 MPa. Strain‐to‐failure decreased from 690% for pure LLDPE to 460% and 120% for 15 wt% MJ and 15 wt% PR composites, respectively. It was inferred that the interfacial interactions of LLDPE matrix with MJ fibers is better than that with PR fibers, resulting from the rougher surface of MJ fibers. POLYM. ENG. SCI., 2010. © 2009 Society of Plastics Engineers
Synthesis of N‐alkoxybenzimidoyl azides and their reactions in electrophilic media
Authors: Dolliver Debra D. , Sommerfeld Thomas , Lanier Megan L. , Dinser Jordan A. , Rucker Richard P. , Weber Rebecca J. , McKim Artie S.
Published: September 2009

A new general route to N‐alkoxybenzimidoyl azides [ArC(N3)=NOR] from a reaction of N‐alkoxybenzimidoyl bromide [ArC(Br)=NOR] with sodium azide in DMSO is described. These reactions result in the Z‐geometric configuration. These compounds show a moderate degree of thermal stability as assessed by differential scanning calorimetry, and lack reactivity in traditional 1,3‐dipolar cycloaddition ‘click’ reactions. Upon exposure to electrophilic compounds (trifluoroacetic acid or acetyl chloride), these azide compounds can react by two pathways: a Schmidt‐type rearrangement to form an N‐alkoxyurea or an isomerization–cyclization reaction pathway to form an N‐alkoxytetrazole. The route of the reaction has no dependence on solvent polarity and appears to depend upon the electrophile (H+ vs. CH3CO+): reaction of the azide with trifluoroacetic acid results predominantly in the urea; reaction with acetyl chloride results solely in the tetrazole. Calculations indicate that the urea product is thermodynamically favored over the tetrazole product. They also indicate that both reaction conditions result in an equilibration between the starting azide and the tetrazole with the tetrazole being the major component in this equilibrium mixture. The fact that the azide also undergoes a Schmidt‐type rearrangement to form an N‐alkoxyurea when treated with trifluoroacetic acid appears to indicate that the barrier for aromatic ring migration is lower in the protonated azide produced on reaction with trifluoroacetic acid than in the acetylated azide produced on reaction with acetyl chloride. Copyright © 2009 John Wiley & Sons, Ltd.
Magnetic‐Field Induced Strains in Ferromagnetic Shape Memory Alloy Ni55Mn23Ga22Deposited by RF‐Magnetron Sputtering
Authors: Bernard Florent , Rousselot Christophe , Delobelle Patrick , Hirsinger Laurent , Burdet Pierre
Published: September 2009

1.5 µm–Ni55Mn23Ga22ferromagnetic thin films were deposited onto silicon substrates and silicon single beam cantilever using radio‐frequency magnetron sputtering. As‐deposited sample and heat‐treated thin films were studied on their silicon substrates and peeled off to determine the influence of the stress. Post‐heat treatment process allows at the films to achieve the shape memory effect (SME). Vibrating sample magnetometer (VSM) and deflection measurement of the sample annealed at 873 K during 36 ks exhibit ferromagnetic martensitic structure with a typical SME response to the magnetic field induced strains which match the values of the bulk material.
Differential efficacy of three commonly used pyrethroids against laboratory and field‐collected larvae and adults of Helicoverpa zea (Lepidoptera: Noctuidae) and significance for pyrethroid resistance management
Authors: Hopkins Bradley W , Pietrantonio Patricia V
Published: September 2009

BACKGROUND: Helicoverpa zea (Boddie) pyrethroid resistance monitoring programs typically utilize cypermethrin in the adult vial test. Here we investigated if differences in insect growth stage and pyrethroid structure affect resistance ratios and discuss implications for pyrethroid resistance management.

RESULTS: Vial bioassays with cypermethrin, esfenvalerate and bifenthrin were conducted on H. zea third instars and male moths from a susceptible laboratory colony and the F1 generation of a pyrethroid‐resistant field population. In the susceptible population, both growth stages were most sensitive to bifenthrin and adults were more sensitive to esfenvalerate than cypermethrin. LC50 resistance ratios for the larvae and adults of the resistant population were approximately two times higher for bifenthrin than cypermethrin or esfenvalerate.

CONCLUSION: For the resistant population, vial assays using either growth stage gave similar resistance ratios for each of the three pyrethroids, respectively, proving the adult vial test accurately reflects larval resistance. However, as resistance ratios varied considerably depending on the pyrethroid used, resistance ratio values obtained with one pyrethroid may not be predictive of resistance ratios for other pyrethroids. Our results suggest that carefully chosen pyrethroid structures diagnostic for specific mechanisms of resistance could improve regional monitoring programs. Copyright © 2009 Society of Chemical Industry
A lightweight secure data transmission protocol for resource constrained devices
Authors: Yu Qian , Zhang Chang N.
Published: September 2009

In this paper we present a lightweight but robust security protocol based on the forward and backward property of RC4 stream cipher. The proposed protocol offers data confidentiality, data authentication, data integrity, and data freshness with less operation and low overhead. Also, it allows data packets to be received in any arbitrary order and achieves semantic security. Furthermore, it eliminates the requirement of frequent key renewal to overcome a special limitation of the stream ciphers. Due to the competitive efficiency and lightweight, the proposed protocol is considerable to provide secure data transmission among resource constrained devices, where the communication nodes have limited power resources and computational capabilities. This protocol not only applies to one‐to‐one communications, but also works for the broadcasting and multicasting. Copyright © 2009 John Wiley & Sons, Ltd.
Interoperable semantic access control for highly dynamic coalitions
Authors: Koshutanski Hristo , Maña Antonio
Published: September 2009

A coalition consists of independent organizations that share resources and skills to achieve significant mission objectives. Dynamic Coalition (DC) formations occur in response to some market demands, business requests, or disaster responses, to name a few. Partners forming a coalition are automatically selected given some business criteria and become active participants from the time the coalition is formed. Highly dynamic coalitions (HDCs) form a sub class of dynamic coalitions where the coalition formation and operation are strictly bound by time in order to provide a prompt reaction to some events. This type of dynamism poses the necessity of underlying security models and technologies allowing for automated coalition formation and operation. This paper presents a platform‐driven approach to HDCs. It first defines a life cycle inherent to HDC formations, and then presents a platform‐driven access control model that takes advantage of semantics of partners' requirements to provide interoperable access control to resources shared in a coalition. Coalition partners can achieve a high level of service interoperation by enhancing their access control requirements with semantics of usage, and interlinking their semantics using class relations based on standard ontology. Copyright © 2009 John Wiley & Sons, Ltd.
PAPA‐UIC: a design approach and a framework for secure mobilead hocnetworks
Authors: Zhao Shushan , Aggarwal Akshai
Published: September 2009

Security of MobileAd hocNetworks (MANETs) is still a hard problem after years of research. We propose a new design approach and a framework for securing a practical type of MANETs. The framework is namedPAPA‐UIC, short forPre‐planned Ad‐hoc Proactive Approach Using Identity‐based Cryptography. In proactive approach, the system starts from a secure status and fortifies this status by protecting packets using cryptography and updating cryptographic keys periodically or when necessary. The proposed scheme addresses the interdependency cycle of secure routing and security services by combining secure routing and key management in one framework. The framework proposes a secure routing protocol (SRP) using identity‐based cryptography and solutions to general problems of identity‐based cryptography. The routing protocol has several improvements over existing ones. The novel ideas to solve key escrow, identity disclosure and identity revocation issues can be integrated into the framework, and can be transplanted to other environments as well. Copyright © 2009 John Wiley & Sons, Ltd.
Balance diagnostics for comparing the distribution of baseline covariates between treatment groups in propensity‐score matched samples
Authors: Austin Peter C.
Published: September 2009

The propensity score is a subject's probability of treatment, conditional on observed baseline covariates. Conditional on the true propensity score, treated and untreated subjects have similar distributions of observed baseline covariates. Propensity‐score matching is a popular method of using the propensity score in the medical literature. Using this approach, matched sets of treated and untreated subjects with similar values of the propensity score are formed. Inferences about treatment effect made using propensity‐score matching are valid only if, in the matched sample, treated and untreated subjects have similar distributions of measured baseline covariates. In this paper we discuss the following methods for assessing whether the propensity score model has been correctly specified: comparing means and prevalences of baseline characteristics using standardized differences; ratios comparing the variance of continuous covariates between treated and untreated subjects; comparison of higher order moments and interactions; five‐number summaries; and graphical methods such as quantile–quantile plots, side‐by‐side boxplots, and non‐parametric density plots for comparing the distribution of baseline covariates between treatment groups. We describe methods to determine the sampling distribution of the standardized difference when the true standardized difference is equal to zero, thereby allowing one to determine the range of standardized differences that are plausible with the propensity score model having been correctly specified. We highlight the limitations of some previously used methods for assessing the adequacy of the specification of the propensity‐score model. In particular, methods based on comparing the distribution of the estimated propensity score between treated and untreated subjects are uninformative. Copyright © 2009 John Wiley & Sons, Ltd.
Missing values in longitudinal dietary data: A multiple imputation approach based on a fully conditional specification
Authors: Nevalainen Jaakko , Kenward Michael G. , Virtanen Suvi M.
Published: September 2009

Multiple imputation (MI) has increasingly received attention as a flexible tool to resolve missing data problems both in observational and controlled studies. Our goal has been to develop a valid and efficient MI procedure for the Diabetes Prediction and Prevention Nutrition Study, in which the diet of a cohort of newborn children with HLA‐DQB1‐conferred susceptibility to type 1 diabetes is repeatedly measured by 3‐day food records over early childhood. The estimation of risk is based on a nested case‐control design setup within the cohort. We have used an iterative procedure known as the fully conditional specification (FCS) to generate appropriate values for the missing dietary data, here playing the role of time‐dependent covariates. Our method extends the standard FCS to repeated measurements settings with the possibility of non‐monotone missingness patterns by being doubly iterative over the follow‐up time of the individuals. In addition, our proposed procedure is nonparametric in the sense that the variables can have distributions deviating strongly from normality: it makes use of quantile normal scores to transform to normality, performs imputations, and transforms back to the original scale. By the use of a moving time window and stepwise regression procedures, the two‐fold FCS method operates well with a great number of variables each measured repeatedly over time. Extensive simulation studies demonstrate that the procedure together with the proposed transformations and variable selection methods provides tools for valid and efficient statistical inference in the nested case‐control setting, and its applications extend beyond that. Copyright © 2009 John Wiley & Sons, Ltd.
Intermittent Pringle Maneuver and Hepatic Function: Perioperative Monitoring by Noninvasive ICG‐Clearance
Authors: Tralhão José Guilherme , Hoti Emir , Oliveiros Bárbara , Abrantes Ana M. , Botelho M. Filomena , Castro‐Sousa F.
Published: September 2009

Background

Intermittent Pringle maneuver or selective portal clamping often are used to control inflow during parenchymal liver transection. This study was designed to determinate whether these maneuvers are associated with adverse hepatic function.

Methods

Resection was performed without portal clamping in 17 patients (group 1). Selective continuous portal clamping was performed in 11 patients (group 2) and the remaining 33 patients (group 3) had intermittent nonselective portal clamping (occlusion of the main portal trunk). The centers’ protocol for total portal occlusion is 15‐min occlusion alternated with 5‐min reperfusion in patients with normal liver parenchyma or 10 min alternated with 5 min in patients with abnormal parenchyma. ICG elimination tests were conducted concurrently using a noninvasive monitor that tracks the plasma disappearance rate (PDR‐ICG‐%/min) and 15‐min retention rate after administration (ICG‐R15‐%).

Results

There was no statistically difference between the three studied groups in terms of sequential changes of ICG‐PDR (p < 0.625) or ICG‐R15 (p < 0.398).

Conclusions

Our study indicates that 15 min of intermittent Pringle maneuver or selective hemihepatic continuous portal clamping are safe methods of vascular control during liver resection, with no adverse effects on hepatocellular function.
A Critical Evaluation of Risk Factors for Complications After Cytoreductive Surgery and Perioperative Intraperitoneal Chemotherapy for Colorectal Peritoneal Carcinomatosis
Authors: Saxena Akshat , Yan Tristan D. , Morris David L.
Published: September 2009

Background

Cytoreductive surgery (CRS) combined with perioperative intraperitoneal chemotherapy (PIC) has demonstrated improved survival in selected patients with colorectal peritoneal carcinomatosis (CRPC). This treatment modality is associated with relatively high rates of perioperative morbidity and mortality. This study evaluated the clinical and treatment‐related risk factors for perioperative morbidity and mortality in patients with CRPC who underwent CRS and PIC.

Methods

Sixty‐three consecutive patients who underwent CRS and PIC for CRPC were evaluated. Adverse events were rated from grades I to V with increasing severity. Clinical and treatment‐related risk factors for grades III and IV/V morbidity were determined.

Results

There were no perioperative deaths (0%). The grades III and IV morbidity rates were 14 and 17%, respectively. A peritoneal cancer index >12 (p = 0.019), transfusion >4 units (p = 0.028), number of peritonectomy procedures >3 (p = 0.013), left upper quadrant peritonectomy procedure (p < 0.001), and number of primary colonic anastomosis >1 (p = 0.004) were associated with grade IV morbidity on univariate analysis. Only left upper quadrant procedure was associated with grade IV morbidity on multivariate analysis (p = 0.002). Only number of primary colonic anastomosis >1 (p = 0.037) was associated with grade III morbidity on univariate analysis. This also was associated with grade III morbidity on multivariate analysis (p = 0.028).

Conclusions

CRS and PIC has an acceptable risk of perioperative morbidity in carefully selected patients with CRPC. Patients who require extensive surgery have the highest risk for a severe adverse event. Preoperative evaluation of patients is essential to improve perioperative outcome.
The Lymph Node Ratio Is a Powerful Prognostic Factor of Node‐Positive Colon Cancers Undergoing Potentially Curative Surgery
Authors: Galizia Gennaro , Orditura Michele , Ferraraccio Francesca , Castellano Paolo , Pinto Margherita , Zamboli Anna , Cecere Sabrina , De Vita Ferdinando , Pignatelli Carlo , Lieto Eva
Published: September 2009

Background

The number of harvested (LNs) and metastatic nodes (LNs+) represents the most significant factor to define postoperative treatment and prognosis in colon cancer. However, its assessment may be inadequate causing an incorrect cancer staging. The lymph node ratio (LNR: the ratio between metastatic and resected nodes) has shown prognostic significance in many tumors; however, its role in colon cancer is not clearly elucidated. This study investigated LNR as a prognostic factor in node‐positive colon cancers.

Methods

A total of 145 consecutive patients with node‐positive colon cancer who underwent curative surgery and adjuvant chemotherapy in a single oncologic unit entered this study.

Results

LNR ranged from 0.0416 to 0.9; it was clearly lower in pN1 than pN2 patients, and increased as tumor stage worsened. ROC analysis selected 0.1818 as the best LNR cutoff value. Low LNR patients did significantly better than high LNR patients; this difference was not dependent on the number of LNs and stronger than differences observed by grouping patients according to LNs or LNs+. When stratified by low and high LNR value, pN1 and pN2 patients, as well as stage III subgroups were shown to display substantially different outcomes. LNR was an independent prognostic factor for disease‐specific survival, and the only covariate related to disease‐free survival.

Conclusions

LNR was a robust prognostic indicator for node‐positive colon cancers undergoing curative surgery. Because this ratio‐based staging was demonstrated to reduce stage migration and to aid in identifying high‐risk patients, it should be proposed as a standard tool for colon cancer staging.