bluuebunny/crossref_metadata_2025 huggingface dataset:
Raman and SERS study on cimetidine–metal complexes with biomedical interest
Authors: Bonora Sergio , Foggia Michele Di , Tugnoli Vitaliano , Righi Valeria , Benassi Enrico , Maris Assimo
Published: August 2010

Cimetidine (cim) is one of the most potent histamine H2‐receptor antagonists for inhibiting excessive acid secretion caused by histamine; it has been hypothesized that the therapeutic effects can be related to its interactions with metal ions. Raman spectra of the solid cim with Co(II), Cu(II), Ni(II) and Zn(II) metal complexes show that they can adopt two different structures: one is octahedral and the other, with Zn(II), is probably tetrahedral. The octahedral structure appears to be distorted both by the different metal ions as well as by the different anion present. The study was extended to very dilute solutions (ppm range) by using the surface‐enhanced Raman scattering (SERS) technique, mimicking the physiological concentrations of cim and its metal complexes. SERS spectra suggest that, upon the binding of cim to silver colloids, the formation of stable 1:2 cim–metal complexes is excluded, the formation of 1:1 adduct appearing more probable; in this product the metal reaches its total coordination shell by complexion with water molecules. To better explain the binding mechanism of cim to a metal (Ag) surface, we performed theoretical B3LYP calculations on cim alone as well as on cim bonded to an Ag2 metal cluster in presence of water, observing a sufficiently good agreement between experimental and theoretical wavenumbers. Copyright © 2010 John Wiley & Sons, Ltd.
Raman identification of strongly absorbing phases: the ceramic black pigments
Authors: Caggiani Maria Cristina , Colomban Philippe
Published: August 2010

To get black decorations requires high ceramic technology and there are different ways of achieving this. Their identification can be very useful to discriminate between different manufactures or periods of production but this information is often very hard to achieve because of their strong absorption of the illuminating laser beam, whatever the wavelength used, causing a very low scattering intensity and, in case of power increase, a transformation of phase which may lead to the misinterpretation of the spectra obtained. We test the use of five instruments with different characteristics (wavelength and power of excitation, spectral resolution, filters and microscope) applied to a group of heterogeneous samples which have in common the presence of a black glaze. The results obtained (manganese oxides, cobalt oxides or a mixture of the two even with the addition of haematite) are compared considering the different methodologies used and leading to a preference towards high‐sensitivity rather than high‐resolution spectrometers, notch‐filtered rather than edge‐filtered instruments and microscopic configuration used on freshly created cross‐sections. The importance of the objective choice is demonstrated. Small grains may be preferred. Copyright © 2010 John Wiley & Sons, Ltd.
Chromatographic behavior of a new hybrid type RP material containing silica bonded 1,3‐alternate 25,27‐bis‐[cyanopropyloxy]‐26,28‐bis‐[3‐propyloxy]‐calix[4]arene
Authors: Śliwka‐Kaszyńska Magdalena , Łępicka Kamila , Ślebioda Marek
Published: August 2010

A novel 1,3‐alternate 25,27‐bis‐[cyanopropyloxy]‐26,28‐bis‐[3‐propyloxy]‐calix[4]arene‐bonded silica gel stationary phase (CalixPrCN) was prepared and its structure was confirmed by ATR‐FTIR spectroscopy and elemental analysis. The CalixPrCN phase was characterized in terms of its surface coverage, hydrophobic selectivity, aromatic selectivity, shape selectivity, hydrogen bonding capacity, residue metal content, and silanol activity based on Tanaka, Lindner, and SMR 870 test protocols. The effect of the acetonitrile content on the retention and selectivity of the selected neutral, basic, and acidic solutes was studied. The neutral and acidic analytes exhibited classical RP behavior, in which retention time decreases with increasing acetonitrile content. In contrast, basic analytes showed an increase in retention at low and high percentages of acetonitrile, forming “U‐shaped” retention profiles. The new calixarene phase was compared with previously reported 1,3‐alternate 25,27‐bis‐[propyloxy]‐26,28‐bis‐[3‐propyloxy]‐calix[4]arene stationary phase and commercial cyanopropyl column. The results indicate that the CalixPrCN stationary phase behaves like RP packing; however, inclusion complex formation, dipole–dipole, and π–π interactions seem to be involved in the separation process. The selectivity of this phase was demonstrated in separation of polynuclear aromatic hydrocarbons, non‐steroidal anti‐inflammatory drugs, and sulfonamides as analytes.
On comparing competing models of PTSD: Response to Simms
Authors: Miller Mark W.
Published: August 2010

This is a response to Simms' commentary on Miller, Wolf, Harrington, Brown, Kaloupek, and Keane (2010) comparing the convergent and discriminant validity of two 4‐factor models of posttraumatic stress disorder (PTSD) using external measures of comorbidity. The author reviews the importance of the distinction between numbing and hyperarousal, clarifies the logic and rationale for the study's aims and hypotheses, and responds to specific concerns about the conclusions. He addresses the relationship between hyperarousal symptoms and internalizing comorbidity and notes the limitations of representing the latter construct using only two symptoms. The author concludes by underscoring the need for future research to place greater emphasis on examining the external correlates of alternative models of the factor structure of PTSD.
Melanocytic nevi with spitz differentiation: Diagnosis and management
Authors: Ahmadi Neda , Davison Steven P. , Kauffman Catharine L.
Published: August 2010

Objectives:

Melanocytic proliferations with Spitz differentiation present a difficult clinicopathologic dilemma, as their spectrum ranges from benign to malignant. Distinct entities include Spitz nevus, atypical Spitz nevus, and Spitzoid melanoma. Their histopathologic differentiation can be challenging, and cases of Spitzoid melanoma initially diagnosed as benign Spitz nevi are reported in the literature. The goal of this article is to discuss the diagnostic tools (including comparative genomic hybridization), which may be helpful in differentiating benign Spitz nevi from malignant melanoma with Spitzoid features, and to propose an appropriate management strategy for each entity.

Study Design:

Retrospective case reports.

Methods:

Medical records of patients referred for suspicious nevi were reviewed. Data regarding demographics, site, pathology reports, and treatment were reviewed.

Results:

Four patients with three distinct diagnoses involving Spitz differentiation were identified. The pathologic interpretation of these biopsies was difficult and multiple dermatopathologists were involved. All four patients underwent excision with or without sentinel node biopsy.

Conclusions:

Otolaryngologists, plastic surgeons and dermatopathologists will encounter patients who have melanocytic lesions with Spitz differentiation at some point in their career. The management of these patients is significantly impacted by the histopathologic diagnosis, and should not be undertaken until it is confirmed, possibly with comparative genomic hybridization. In our experience, it is not unusual to have multiple independent pathologic examinations. We believe that a team approach between the surgeon and the dermatopathologist is crucial when diagnosing and managing patients with Spitz lesions. Laryngoscope, 2010
A rare case of laryngeal dystonia associated with neurosyphilis: Response to botulinum toxin injection1
Authors: Ho Ki‐Hong Kevin , Wright Christopher C. , Underbrink Michael P.
Published: August 2010

We report a unique case of laryngeal dystonia in a 43‐year‐old male with neurosyphilis who underwent successful treatment with botulinum toxin injection. To date there have been no reports of laryngeal dystonia associated with neurosyphilis. The patient initially presented with strained and stuttering voice despite systemic penicillin therapy. After 2 months of speech therapy with limited relief, the patient received botulinum toxin injection to each thyroarytenoid muscle. Postinjection videostroboscopy showed marked improvement of voice quality. Laryngoscope, 2011
Posttransplant bacteremia in adult living donor liver transplant recipients
Authors: Iida Taku , Kaido Toshimi , Yagi Shintaro , Yoshizawa Atsushi , Hata Koichiro , Mizumoto Masaki , Mori Akira , Ogura Yasuhiro , Oike Fumitaka , Uemoto Shinji
Published: August 2010

Infectious complications such as bacteremia after living donor liver transplantation (LDLT) are associated with significant morbidity and mortality. We retrospectively analyzed the frequency and characteristics of posttransplant bacteremia in 181 adult LDLT recipients between April 2006 and November 2009, and we evaluated the risk factors for posttransplant bacteremia. One hundred seventeen episodes of bacteremia occurred in 62 of 181 recipients (34.3%) within 12 days (median) after transplantation (range = 1-71 days). The most frequently isolated pathogens were Pseudomonas aeruginosa (26 episodes), methicillin-resistant coagulase-negative staphylococci (22 episodes), and Enterococcus sp. (11 episodes). The overall survival rate at 1 year for patients with bacteremia (n = 62) was significantly lower than the rate for patients without bacteremia (n = 119; 69.6% versus 92.3%, respectively, P < 0.0001). Multivariate analysis showed that Child-Pugh class C (P = 0.0002), preoperative massive pleural effusion or ascites requiring drainage (P = 0.0384), postoperative cytomegalovirus infection (P = 0.0014), ABO incompatibility (P = 0.0188), and older donor age (P = 0.015) were independent risk factors for postoperative bacteremia. In conclusion, bacteremia occurred at a high rate after adult LDLT and induced a higher mortality rate in those who developed it. Infection control may play a pivotal role in improving early outcomes after LDLT. Liver Transpl 16:1379–1385, 2010. © 2010 AASLD.
Long-term survival after 67 hours of anhepatic state due to primary liver allograft nonfunction
Authors: Arora Harendra , Thekkekandam Janine , Tesche Leora , Sweeting Raeshell , Gerber David A. , Hayashi Paul H. , Andreoni Kenneth , Kozlowski Tomasz
Published: August 2010

Primary liver allograft nonfunction immediately after transplantation poses a life-threatening situation for the recipient. Emergency retransplantation may not be immediately possible due to organ unavailability. Total hepatectomy with temporary portacaval shunt has been described as a bridge to retransplantation when the presence of the graft appears to be harming the recipient. Case reports of retransplantation after total hepatectomy with anhepatic times greater than 48 hours routinely describe poor outcomes. We present a case with excellent patient outcome after 95 hours of clinical anhepatic state, including 67 hours of anatomical anhepatic time, because of primary liver allograft nonfunction. This case report documents the longest anhepatic time with subsequent successful transplant to date. Liver Transpl 16:1428–1433, 2010. © 2010 AASLD.
Quality of life for donors after living donor liver transplantation: A review of the literature
Authors: Parikh Neehar D. , Ladner Daniela , Abecassis Michael , Butt Zeeshan
Published: August 2010

Living donor liver transplantation (LDLT) decreases the shortage of liver grafts for patients in need of a liver transplant, but it involves 2 patients: a recipient and a living donor. Despite the magnitude of the procedure for LDLT donors, only a few studies have investigated the effect of LDLT on the quality of life (QOL) of donors. We performed a systematic search of the MEDLINE database to identify peer-reviewed articles assessing QOL in adults after LDLT donation. Nineteen studies describing 768 unique donors met our inclusion criteria for this review. The median number of donors enrolled in each study was 30 (range = 10-143), and the median follow-up period was 10.4 months (range = 3-51.3 months). Before donation, donor QOL was significantly better than that in control adult populations across all measured QOL domains. Within the first 3 months after donation, the physical domains of QOL were significantly worse than the predonation levels, but they returned to baseline levels within 6 months for the majority of patients (80%-93%). Mental domains of QOL remained unchanged throughout the donation process. Common donor concerns after LDLT included bloating, loss of muscle tone, poor body image, and fatigue. In conclusion, according to our review of the existing literature, most LDLT donors return to their baseline QOL within 6 months. However, there is a lack of long-term data on donor QOL after LDLT, and few standardized assessments include measures of common patient concerns. Additional studies are necessary to develop a comprehensive risk profile for LDLT that includes a rigorous assessment of donor QOL. Liver Transpl 16:1352–1358, 2010. © 2010 AASLD.
Extrusion Foaming of Poly(styrene‐co‐acrylonitrile)/Clay Nanocomposites Using Supercritical CO2
Authors: Urbanczyk Laetitia , Alexandre Michaël , Detrembleur Christophe , Jérôme Christine , Calberg Cédric
Published: August 2010

Supercritical CO2 has been used as a blowing agent to foam poly(styrene‐co‐acrylonitrile)‐based materials in a single screw extruder specially adapted to allow fluid injection. The cellular morphology depends on foaming temperature, more regular cells being obtained with decreasing extrusion temperature. In a second step, a natural and an organomodified nanoclay have been added for the purpose of imparting some flame resistance to the foamed material. The filler efficiency in reducing sample combustion rate appeared to be dependent on its delamination level inside the matrix and better results were obtained when the organomodified clay was first delaminated in the polymer in an efficient twin screw extruder using water assistance, prior to foaming in the single screw extruder.

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Applications of Oligomers for Nanostructured Conducting Polymers
Authors: Wang Yue , Tran Henry D. , Kaner Richard B.
Published: August 2010

This Feature Article provides an overview of the distinctive nanostructures that aniline oligomers form and the applications of these oligomers for shaping the nanoscale morphologies and chirality of conducting polymers. We focus on the synthetic methods for achieving such goals and highlight the underlying mechanisms. The clear advantages of each method and their possible drawbacks are discussed. Assembly and applications of these novel organic (semi)conducting nanomaterials are also outlined. We conclude this article with our perspective on the main challenges, new opportunities, and future directions for this nascent yet vibrant field of research.

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Importance of the Position of the Chromophore Group on the Dissociation Process of Light Sensitive Alkoxyamines
Authors: Guillaneuf Yohann , Versace Davy‐Louis , Bertin Denis , Lalevée Jacques , Gigmes Didier , Fouassier Jean‐Pierre
Published: August 2010

New photosensitive alkoxyamines have been designed using molecular orbital calculations to improve the selective CO versus NO cleavage. The targeted light‐sensitive alkoxyamine is synthesized in one step and its reactivity under UV has been investigated using both ESR and LFP. The ability of this alkoxyamine to control the photopolymerization of n‐butyl acrylate is evidenced through a process called nitroxide‐mediated photopolymerization NMP2. The selected alkoxyamine is finally used to prepare covalently bonded multilayered micropatterns. This original application highlights the high potential of this technique for some specific applications that require spatial control.

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Impact of imaging landmark on the risk of MRI‐related heating near implanted medical devices like cardiac pacemaker leads
Authors: Nordbeck Peter , Ritter Oliver , Weiss Ingo , Warmuth Marcus , Gensler Daniel , Burkard Natalie , Herold Volker , Jakob Peter M. , Ertl Georg , Ladd Mark E. , Quick Harald H. , Bauer Wolfgang R.
Published: August 2010

Implanted medical devices such as cardiac pacemakers pose a potential hazard in magnetic resonance imaging. Electromagnetic fields have been shown to cause severe radio frequency‐induced tissue heating in some cases. Imaging exclusion zones have been proposed as an instrument to reduce patient risk. The purpose of this study was to further assess the impact of the imaging landmark on the risk for unintended implant heating by measuring the radio frequency‐induced electric fields in a body phantom under several imaging conditions at 1.5T. The results show that global radio frequency‐induced coupling is highest with the torso centered along the superior–inferior direction of the transmit coil. The induced E‐fields inside the body shift when changing body positioning, reducing both global and local radio frequency coupling if body and/or conductive implant are moved out from the transmit coil center along the z‐direction. Adequate selection of magnetic resonance imaging landmark can significantly reduce potential hazards in patients with implanted medical devices. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
Analytic solution for the nucleolus of a three‐player cooperative game
Authors: Leng Mingming , Parlar Mahmut
Published: August 2010

The nucleolus solution for cooperative games in characteristic function form is usually computed numerically by solving a sequence of linear programing (LP) problems, or by solving a single, but very large‐scale, LP problem. This article proposes an algebraic method to compute the nucleolus solution analytically (i.e., in closed‐form) for a three‐player cooperative game in characteristic function form. We first consider cooperative games with empty core and derive a formula to compute the nucleolus solution. Next, we examine cooperative games with nonempty core and calculate the nucleolus solution analytically for five possible cases arising from the relationship among the value functions of different coalitions. © 2010 Wiley Periodicals, Inc. Naval Research Logistics, 2010
Region‐specific changes in ascorbate concentration during rat brain development quantified by in vivo1H NMR spectroscopy
Authors: Terpstra Melissa , Rao Raghavendra , Tkac Ivan
Published: August 2010

Ascorbate (vitamin C, Asc) was quantified in vivo using short‐TE 1H NMR spectra from a previously published study on regional and developmental changes in the neurochemical profile of the rat brain (Tkac I, Rao R, Georgieff MK, Gruetter R. Magn Reson Med. 2003; 50: 24–32). Asc concentration was quantified on postnatal days P7–P28 from three regions that are of interest in the study of neurocognitive development, i.e. the hippocampus, striatum and cerebral cortex. The previously measured 1H NMR spectra were re‐analyzed using LCModel with the Asc spectrum included in the basis set. The Asc concentration was consistently quantified from all 110 re‐analyzed spectra with an estimated fitting error of 7% (i.e. the average Cramer–Rao lower bound). The sensitivity of Asc quantification was sufficiently high to detect regional and developmental changes in Asc concentration. The concentration of Asc was highest on P7, and decreased with age in all three brain regions (p < 0.001) in agreement with previous in vitro studies. At P10 and older postnatal ages, an inhomogeneous distribution of Asc among brain regions was detected. In addition to facilitating the quantification of this important antioxidant concentration, the inclusion of the Asc spectrum in the LCModel basis set improved the quantification accuracy of other brain metabolite concentrations in the neurochemical profile. Copyright © 2010 John Wiley & Sons, Ltd.
Tumour‐infiltrating T‐cell subsets, molecular changes in colorectal cancer, and prognosis: cohort study and literature review
Authors: Nosho Katsuhiko , Baba Yoshifumi , Tanaka Noriko , Shima Kaori , Hayashi Marika , Meyerhardt Jeffrey A , Giovannucci Edward , Dranoff Glenn , Fuchs Charles S , Ogino Shuji
Published: August 2010

The abundance of tumour‐infiltrating T‐cells has been associated with microsatellite instability (MSI) and a favourable prognosis in colorectal cancer. However, numerous molecular alterations have been associated with clinical outcome, and potentially confounding the biological and prognostic significance of tumour‐infiltrating T‐cells. We utilized a database of clinically and molecularly‐annotated colon and rectal carcinoma cases (N = 768; stage I–IV) in two prospective cohort studies (the Nurses' Health Study and the Health Professionals Follow‐up Study) and quantified the densities of CD3+, CD8+, CD45RO+ (PTPRC), and FOXP3+ cells within neoplastic epithelial areas using an Ariol image analysis system and tissue microarray. We used Cox proportional hazard models to compute the mortality hazard ratio, adjusting for clinical and molecular features including KRAS, BRAF, and PIK3CA mutations, MSI, CIMP, and LINE‐1 hypomethylation. The densities of CD8+, CD45RO+, and FOXP3+ cells were significantly associated with patient survival in univariate analyses ($p_{\rm{trend}} < 0.007$). In the multivariate model, tumour‐infiltrating CD45RO+‐cell density, but not CD3+, CD8+ or FOXP3+‐cell density, was significantly associated with survival (p = 0.0032). In multivariate linear regression analysis, MSI‐high (p < 0.0001) and high‐level tumour LINE‐1 methylation (p = 0.0013) were independently associated with higher CD45RO+‐cell density. The survival benefit associated with CD45RO+ cells was independent of MSI and LINE‐1 status. In conclusion, tumour‐infiltrating CD45RO+‐cell density is a prognostic biomarker associated with longer survival of colorectal cancer patients, independent of clinical, pathological, and molecular features. In addition, MSI‐high and tumour LINE‐1 methylation level are independent predictors of CD45RO+‐cell density. Our data offer a possible mechanism by which MSI confers an improved clinical outcome and support efforts to augment the host immune response in the tumour microenvironment as a strategy of targeted immunotherapy. Copyright © 2010 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Hydrogenated nitrile butadiene rubber and hindered phenol composite. I. Miscibility and dynamic mechanical property
Authors: Cao Yuanyi , Shen Fei , Mou Haiyan , Cao Deming , Xu Haiyan , Wu Chifei
Published: August 2010

In this study, miscibility and dynamic mechanical properties of hydrogenated nitrile butadiene rubber (HNBR) and 3,9‐bis{1,1‐dimethyl‐2‐[β‐(3‐tert‐butyl‐4‐hydroxy‐5‐methylphenyl) propionyloxy]ethyl}‐2,4,8,10‐tetraoxaspiro[5,5]‐undecane (AO‐80) composites were investigated. The composites with low‐AO‐80 content showed the incomplete miscibility, and a part of AO‐80 dissolved into HNBR, while the rest was dispersed into HNBR in the form of deep‐submicron‐sized microspheres based on the micromorphological and thermal analyses. However, with the increasing AO‐80 content, the system became completely miscible. When blending with AO‐80, the resulting composite exhibited the remarkably improved dynamic mechanical property. The loss tangent (tan δ) peak of the composites gradually shifted to room temperature with the increasing AO‐80 content. In this work, two classical equations (Gorden‐Taylor and Fox) were used to predict the glass transition temperature of the HNBR/AO‐80 composites. The calculated value based on Fox equation was more close to the experimental data. POLYM. ENG. SCI., 2010. © 2010 Society of Plastics Engineers
Microstructure morphology of poly(trimethylene terephthalate)/amorphous poly(ethylene terephthalate) blends studied via small angle X‐ray scattering
Authors: Chiu Hsiu‐Jung
Published: August 2010

The microstructure morphology of the poly(trimethylene terephthalate) (PTT) and amorphous poly(ethylene terephthalate) (aPET) blends prepared by solution precipitation has been investigated by means of optical polarized microscopy (POM) and small angle X‐ray scattering (SAXS). From the observation of POM, it was suggested that aPET was predominantly segregated into the interlamellar and/or interfibrillar regions upon PTT crystallization with the evidence that the PTT spherulitic morphologies of blends were volume filling. From results of SAXS data analysis, the maximum scattering peak (qmax) of Lorentz‐corrected SAXS profiles, amorphous layer thickness (la) and lamellar volume stacking fraction (ϕs), the segregation morphology of PTT/aPET blends is characterized to be the interlamellar segregation morphology when the weight friction of aPET (waPET) ≤ 0.2 and the interlamellar and interfibrillar segregation coexisted when waPET > 0.2. The extent of aPET segregation was promoted by increasing aPET composition. POLYM. ENG. SCI., 2010. © 2010 Society of Plastics Engineers
Solid‐state microcellular polycarbonate foams. II. The effect of cell size on tensile properties
Authors: Weller John E. , Kumar Vipin
Published: August 2010

The effect of cell size on the tensile behavior of high‐relative‐density microcellular polycarbonate foams is investigated. Microcellular PC foams were produced in a way that allowed the average cell size to be varied, while the foam density was held constant. The polycarbonate‐CO2 system offers an order of magnitude variation in the average cell size at a given density, allowing the tensile properties of microcellular polycarbonate to be investigated as a function of cell size. It was found that the tensile modulus, tensile strength, elongation to break, and toughness are not significantly affected when the average cell size is varied from 2.8 to 37.1 μm, and the nominal relative density is held constant at 0.5. This result is significant for solid‐state processing of microcellular polycarbonate foams of the type produced here, for it shows that regardless of the processing conditions and regardless of the average cell size, if two foams have the same density then they will also have the same tensile properties. POLYM. ENG. SCI., 2010. © 2010 Society of Plastics Engineers
Influence of the process parameters of an intermeshing co‐rotating twin screw extruder on the morphology and notched Izod impact strength of PBT/ABS/MGE blends
Authors: Ambrósio José D. , Larocca Nelson M. , Pessan Luiz A. , Hage Elias
Published: August 2010

In this research, it was studied the effects of the processing parameters applied to a twin screw extruder on the morphology and impact strength of poly(butylene terephthalate)/acrylonitrile‐butadiene‐styrene blends with and without a reactive compatibilizer. It was found that the increase of the feed rate highly decreased the ductile brittle transition temperature (DBTT) and slightly increased the room temperature impact strength (RTIS) of the compatibilized blends. Besides the influence of the feed rate, it was also found that the compatibilized blends could reach high RTIS and low DBTT values by an appropriate combination of the compatibilizer feeding position in the extruder, the screw rotation speed and the width of the kneading discs of the screw. The DBTT was found to be at least partially controlled by the spatial distribution of the rubbery particles, which was quantified by finite body tessellation, a method applied for the first time in polymer blends. POLYM. ENG. SCI., 2010. © 2010 Society of Plastics Engineers
Mechanical and water vapor transport properties of polyurethane/superfine down powder composite membranes
Authors: Liu Xin , Xu Weilin , Li Wenbin , Chen Yubo , Rao Jue
Published: August 2010

To develop a novel microporous polyurethane (PU) membrane that has higher water vapor transmission rate (WVTR) for use in functional application, down powder with different average particle sizes was blended with PU by using the solution casting method. Scanning electron microscope was used to investigate the changes in the porous structures of PU/superfine down powder (SDP) composite membranes. Attenuated total reflectance Fourier transform infrared spectroscopy curves showed that the addition of SDP decreased the hydrogen bonds of PU matrix. On the basis of wide‐angle X‐ray diffraction curves, the small crystallinity of the PU matrix in PU/SDP composite membranes was lower than that of pure PU membrane. The densities of PU/SDP composite membranes decreased with the increase in SDP content. PU/SDP composite membranes showed a large increase in WVTR and a small decrease in mechanical properties compared to pure PU membrane. Moreover, the WVTR and mechanical properties of PU/down powder composite membranes were found absolutely dependent on the average particle size of down powder. POLYM. ENG. SCI., 2010. © 2010 Society of Plastics Engineers
Nanocellular foams—cell structure difference between immiscible and miscible PEEK/PEI polymer blends
Authors: Nemoto Tomoyuki , Takagi Jun , Ohshima Masahiro
Published: August 2010

Plastic foam with a nanoscale cell structure was prepared from poly(ether ether ketone) (PEEK)/para‐diamine poly(ether imide) (p‐PEI) as well as PEEK/meta‐diamine poly(ether imide) (m‐PEI) blends by a temperature quench foaming method with CO2. The difference in chemical configuration between m‐ and p‐PEI gave rise to a prominent change in the higher order blend morphology and cell structure of the respective foams. The bubble nucleation site and bubble size were controlled by templating the morphology of the PEEK/p‐PEI blend, which shows an immiscible and unique strip‐patterned crystalline morphology. The properties influenced by the immiscibility of the PEEK/p‐PEI blend were investigated using SEM, thermal analysis and rheology and compared with the properties of the miscible PEEK/m‐PEI blend. The bubble size and location were highly controlled in the PEI disperse domain that was aligned between the PEEK crystalline layers in the PEEK/p‐PEI blend. POLYM. ENG. SCI., 2010. © 2010 Society of Plastics Engineers
Splashing needleless electrospinning of nanofibers
Authors: Tang Shan , Zeng Yongchun , Wang Xinhou
Published: August 2010

This article proposes a new needleless electrospinning apparatus applying the method of splashing polymer solution onto the surface of a metal roller spinneret. When a high voltage is applied, many spinning jets form on the free surface of polymer solutions. Multiple electrified jets undergo strong stretching and bending instability, solvent evaporates, and solidified nanofibers deposit on the collector, as in an ordinary single‐needle electrospinning process. The production of nanofibers is enhanced by 24–45 times comparing with a single‐needle system. And the productivity is easy to scale up. The effects of processing parameters, including solution concentration, applied voltage, distance between spinneret to collector, and rotational speed of the roller spinneret on the morphology of nanofibers are investigated in this article. POLYM. ENG. SCI., 2010. © 2010 Society of Plastics Engineers
Analysis of polymer flow in embossing stage during thermal nanoimprint lithography
Authors: Kim S.M. , Kang J.H. , Lee W.I.
Published: August 2010

Viscous polymer flow in embossing stage during thermal nanoimprint lithography was investigated. Flow behavior of the thermoplastic polymer was analyzed numerically and experimentally. Fixed grid scheme along with the finite element method was used for numerical analysis. Effects of process parameters such as the temperature, the stamp speed, and the stamp geometry on the filling pattern for single cavity were studied. Also the patterns with several cavities were analyzed to understand the flow behavior between adjacent cavities. Experiments were performed using PMMA sheets to confirm the effects of parameters obtained from numerical analyses. Two different types of geometries were considered and the filled patterns were observed using a scanning electron microscopy. Numerical results exhibited a similar tendency as the experimental observation. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers
Plasma Deposited Organosilicon Multistacks for High‐Performance Low‐Carbon Steel Protection
Authors: Coclite Anna Maria , Milella Antonella , Palumbo Fabio , Le Pen Christophe , d'Agostino Riccardo
Published: August 2010

The alternated deposition of silicon oxide and organosilicon layers, yielding to ultra‐barrier films against the transmission of vapors and gases through plastic substrates, has been demonstrated to be also an effective tool for the deposition of highly corrosion protective coatings on low‐carbon steel substrate. PECVD is really efficient for the deposition of multilayered stacks since it allows the deposition of the organosilicon and silicon oxide layers in the same process chamber and using the same precursor, the tetraethoxysilane. The multilayer approach leads to 600‐nm‐thick coatings with high corrosion resistance (1.1 × 107 Ωcm2), while a layer of SiOx has the same protective effectiveness only for thickness greater than 1 µm. The use of modulated discharges for the multilayer deposition exhibits an improved resistance to corrosion by two orders of magnitude with respect to continuous mode.

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One Step Polymerization of Sulfonated Polystyrene Films in a Dielectric Barrier Discharge
Authors: Merche Delphine , Hubert Julie , Poleunis Claude , Yunus Sami , Bertrand Patrick , De Keyzer Philippe , Reniers François
Published: August 2010

Thin sulfonated polystyrene films were prepared by high pressure PECVD of styrene and trifluoromethane sulfonic acid using a DBD. Argon or helium was used as carrier gas. The chemical composition of the pp‐sulfonated polystyrene was investigated by XPS, SSIMS, and FTIR. XPS shows that the content in sulfonated groups of the films deposited in the discharge can be tuned by varying the temperature of the acid monomer or by improving the HF voltage. Therefore, the films obtained are rich in ionizable groups (more than Nafion). TOF‐SSIMS and FTIR spectra allow to confirm the presence of sulfonic groups (observed on S2p XPS spectra) grafted in the polystyrene matrix.

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Potential anti‐bacterial drug target: Structural characterization of 3,4‐dihydroxy‐2‐butanone‐4‐phosphate synthase from Salmonella typhimurium LT2
Authors: Kumar Pankaj , Singh Mirage , Gautam Ruchi , Karthikeyan Subramanian
Published: August 2010

3,4‐Dihydroxy‐2‐butanone‐4‐phosphate synthase (DHBPS) encoded by ribB gene is one of the first enzymes in riboflavin biosynthesis pathway and catalyzes the conversion of ribulose‐5‐phosphate (Ru5P) to 3,4‐dihydroxy‐2‐butanone‐4‐phosphate and formate. DHBPS is an attractive target for developing anti‐bacterial drugs as this enzyme is essential for pathogens, but absent in humans. The recombinant DHBPS enzyme of Salmonella requires magnesium ion for its activity and catalyzes the formation of 3,4‐dihydroxy‐2‐butanone‐4‐phosphate from Ru5P at a rate of 199 nmol min−1 mg−1 with Km value of 116 μM at 37°C. Further, we have determined the crystal structures of Salmonella DHBPS in complex with sulfate, Ru5P and sulfate‐zinc ion at a resolution of 2.80, 2.52, and 1.86 Å, respectively. Analysis of these crystal structures reveals that the acidic loop (residues 34–39) responsible for the acid‐base catalysis is disordered in the absence of substrate or metal ion at the active site. Upon binding either substrate or sulfate and metal ions, the acidic loop becomes stabilized, adopts a closed conformation and interacts with the substrate. Our structure for the first time reveals that binding of substrate Ru5P alone is sufficient for the stabilization of the acidic active site loop into a closed conformation. In addition, the Glu38 residue from the acidic active site loop undergoes a conformational change upon Ru5P binding, which helps in positioning the second metal ion that stabilizes the Ru5P and the reaction intermediates. This is the first structural report of DHBPS in complex with either substrate or metal ion from any eubacteria. Proteins 2010. © 2010 Wiley‐Liss, Inc.
Measurement of DNA denaturation on B‐NCD coated diamond micro‐cantilevers
Authors: Bongrain A. , Uetsuka H. , Rousseau L. , Valbin L. , Saada S. , Gesset C. , Scorsone E. , Lissorgues G. , Bergonzo P.
Published: August 2010

We report the detection of DNA denaturation using diamond micro‐cantilevers operating in dynamic mode in liquid environment. Intrinsic diamond cantilevers were fabricated using a bottom up approach which consists of a selective growth of diamond patterns in micro‐machined silicon moulds. They were then coated with a thin layer of boron doped diamond to allow electrochemical immobilization of DNA on their surface. DNA was attached onto the measuring cantilever using a four‐step electrochemical process involving diazonium salt grafting on diamond surface. The DNA immobilization was validated by cyclic voltammetry and fluorescence imaging. DNA denaturation was detected by comparing the resonance frequency shift of the measuring diamond cantilever against that of a reference cantilever when adding the denaturing agent in the solution. A frequency shift was measured and was attributed to surface stress modification upon denaturation.
On the development of the morphology of ultrananocrystalline diamond films
Authors: Kulisch Wilhelm , Popov Cyril , Sasaki Takao , Sirghi Lucel , Rauscher Hubert , Rossi Francois , Reithmaier Johann Peter
Published: August 2010

The development of the unique morphology of ultrananocrystalline diamond (UNCD) films has been investigated by varying three important parameters which are expected to have a pronounced influence on the morphology and structure of any thin film, namely the deposition time, the growth rate, and the nucleation density. The films have been characterized, among others, by scanning electron microscopy (SEM), atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR), nuclear reaction analysis and variable angle ellipsometry. It turned out, however, that the morphology and the rms roughness are almost independent of these parameters. Growth starts from individual nucleation sites created by the substrate pre‐treatment. From these sites individual isolated semispherical nodules develop which finally coalesce to form a continuous film. Once coalescence has taken place, the films loose their “memory” of their nucleation history. Rather, morphology and roughness are solely determined by the rate of secondary nucleation, which is very high and distinguishes UNCD from poly‐ and nanocrystalline diamond films.
Transport in carbon nanotubes: Contact models and size effects
Authors: Zienert Andreas , Schuster Jörg , Streiter Reinhard , Gessner Thomas
Published: August 2010

We present electronic transport calculations for single wall carbon nanotubes (CNTs) using two highly idealized models to describe the electrodes and their contact to the CNT. In the first model we use CNT‐electrodes and in the second one we apply the wide‐band approximation, neglecting any atomic structure within the electrodes. The single orbital tight‐binding approximation is used to describe the electronic structure of the CNTs. This enables us to apply highly efficient decimation techniques to reduce the size of the finite central Hamiltonian. Semi‐infinite CNT‐electrodes can be included iteratively using a similar method. Electronic transport calculations are carried out within the Landauer formalism.
Ab initio calculations of weakly bonded He2 and Be2 molecules by MRCI method with pseudo‐natural molecular orbitals
Authors: Mitin Alexander V.
Published: August 2010

The X1Σ curves of He2 and Be2 have been calculated by extrapolating the BSSE corrected MRCI total energies obtained with large Gaussian basis sets, large reference configuration spaces, and pseudo‐natural molecular orbitals to an infinite basis. The direct calculated He2 nonrelativistic dissociation energies (De) of 11.0031 K is in excellent agreement with the recent theoretical evaluations, whereas the Be2 nonrelativistic De = 822 cm−1 and relativistically corrected De = 818 cm−1 are in good agreement with most known values including the experimental De = 790 ± 30 cm−1. An analysis of the configuration structure of Be2 wave function and calculated vibration spectrum displays unusual type of chemical bond in this molecule and explains a unique form of the Be2 potential curve. Thus, near the equilibrium point the bond can be classified as a conventional covalent bond, whereas at larger distances, it can be classified as van der Waals interaction. The problems of high precision Be2 potential curve calculations are also discussed. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
Magnetic neutron scattering anti‐Bragg solution
Authors: Zagoulaev Serge N.
Published: August 2010

A new solution for the elastic spin magnetic scattering of slow neutrons by a N‐electron target is obtained. The angular dependence of the differential cross section (DCS) has very unusual (anti‐Bragg) shape for a target, which degenerate ground state has zero z ‐projection (M = 0) of the total spin. Contrary to usual assumption that neutron is scattered by each atomic spin independently, the scattering by the whole target spin system is considered. The many‐electron many‐determinant wave functions Ψa(x1,…,xN) (xj ≡rjσj) are used for analytical calculations of the scattering amplitude. The total spin square eigenfunctions ΘϰS0(σ1,…,σN) have been used for the spin part of Ψa . Explicit analytical expressions for the DCS are obtained and the initial and final neutron polarization effects are discussed. It is shown that the regular pattern of the anti‐Bragg diffraction has no relation to the periodic magnetization of the target. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
Transport properties of two‐dimensionally fused zinc porphyrins from linear‐response approach
Authors: Yamaguchi Yoichi
Published: August 2010

Transport properties, temperature‐dependent phonon‐limited electrical and thermal resistivities in the normal state of two‐dimensionally (2D) infinite‐fused zinc porphyrin with a directly meso‐meso‐, β‐β‐, and β‐β‐linked array structure ZnP∞ were theoretically calculated using linear‐response approach based on density functional theory (DFT). The calculated transport electron–phonon coupling (EPC) constant using the density functional perturbation theory (DFPT) shows almost equal to the superconducting EPC constant, which is the similar situation within a difference by ca. 10% between them for the transition metals. The calculated electrical and thermal resistivities at 300 K obtained by solving the Boltzmann equation within the lowest‐order variational approximation (LOVA) are only larger by one digit than those of the reference metal Al, expecting to become a fantastic 2D synthetic metal without an injection of conductive carriers from outside, e.g., by doping. The calculated results for the 2D infinite‐fused lithium porphyrin LiP∞ with the same ground state as the one‐electron oxidative state of ZnP∞ were also discussed for comparison. This simple approach using the first applied plane‐wave ultrasoft pseudopotentials (US‐PPs) is a usable technique for the prediction of the transport properties of simple metallic materials within the practical temperature range. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
Lagrange‐type iterative methods for calculation of extreme eigenvalues of generalized eigenvalue problem with large symmetric matrices
Authors: Mitin Alexander V.
Published: August 2010

The new block and the block diagonal Lagrange iterative methods together with the block generalizations of the Newton–Rayleigh type methods are proposed. It is also shown that the Jacobi–Davidson correction vector is a Newton–Raphson correction vector for the Lagrange functional of the generalized eigenvalue problem. For a simplification of a solution of the Newton–Raphson equation for calculations of correction vectors, a skeleton matrix approximation was introduced and used in the new methods as well in a few known ones. The numerical algorithms of the new methods are described in details and their performances are compared in several numerical test calculations. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
Electron‐pair extracule densities for low‐lying excited states of He and Li+
Authors: McCarthy Shane P. , Thakkar Ajit J.
Published: August 2010

The electron‐pair extracule density is the probability density function for the position vector of the center‐of‐mass of an electron pair. Accurate calculations of spherically averaged extracule densities d(R) and their moments are reported for the 23S, 23P, and 21P states of the helium atom and lithium cation. The computations are based on explicitly correlated wave functions with energy errors of only 2–3 nanohartrees. The role of electron correlation is probed by comparison with Hartree‐Fock calculations, and Fermi correlation is probed by the differences between the singlet and triplet P states. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
Nikolai F. Stepanov: Half‐a‐century passion for quantum chemistry
Authors: Pupyshev Vladimir I.
Published: August 2010

The article describes some aspects of the scientific biography of the teacher of a large number of russian quantum chemists, Professor Nikolai F. Stepanov (in honor of his 75th birthday). © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
David Bishop's approach to vibrational dynamic contributions to molecular properties: Application to Jones and magnetoelectric birefringences in diatomic molecules
Authors: Rizzo Antonio , Cappelli Chiara
Published: August 2010

The expressions derived by D. M. Bishop for the pure vibrational contributions to the dynamic electric dipole polarizabilities and hyperpolarizabilities of polyatomic molecules (see Bishop, D. M. Rev Mod Phys, 1990, 62, 343) are generalized to arbitrary linear, quadratic and cubic response functions, and then applied to determine the effect of nuclear motion on two diatomic molecules (N2 and CO) on Jones (and Magnetoelectric) linear birefringences. The influence of nuclear motion on the anisotropy of the refractive index appears to be quite contained: the observable differs from the equilibrium electronic estimate by ≈4% for N2, and by ≈8–9% in CO. As a case study, also the effect of vibrations on the temperature independent contribution to Buckingham birefringence of H2 and D2 is analyzed and discussed. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
Embedding and atomic orbitals hybridization
Authors: Abarenkov I. V. , Boyko M. A. , Sushko P. V.
Published: August 2010

In calculation, the electronic structure of crystals, especially those containing point defects, the embedding approach is proved to be useful and convenient. In this approach, a finite part of the crystal, referred to as cluster, is considered instead of infinite crystal and the influence of the rest of the crystal is simulated by the embedding potential. The key problems of this approach are the cluster selection and the embedding potential generation. To select a cluster, the Wigner‐Seitz unit cell is used in the present approach and every border atom, situated at the unit cell face, edge, or vertex is symmetrically “divided” among adjacent unit cells sharing this atom. The atomic hybrid orbitals are used for the border atoms partition between neighboring clusters. It is shown that contrary to the conventional hybridization scheme, the nonorthogonal and even linearly dependent atomic hybrid orbitals can be used to construct the border atom density matrix. This density matrix can be made to satisfy the proper point symmetry and to match the number of equivalent hybrid orbitals and the number of nearest neighbors. Two different types (one‐center and multicenters) of the embedding potential corresponding to the border atom are considered in the article. As a particular example of the border atom the oxygen ion in ZrO2, MgO, and TiO2 rutile crystals is considered. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011