bluuebunny/crossref_metadata_2025 huggingface dataset:
Anatomy of Neurovascular Structures Around the Carpal Tunnel During Dynamic Wrist Motion for Endoscopic Carpal Tunnel Release
Authors: Hong Jae Taek , Lee Sang Won , Han Seung Ho , Son Byung Chul , Sung Jae Hoon , Park Choon Keun , Park Chun Kun , Kang Joon Ki , Kim Moon Chan
Published: February 2006

OBJECTIVE:

The purpose of this study is to investigate the anatomic relationship between neurovascular structures and the transverse carpal ligament (TCL) so as to avoid complications during an endoscopic carpal tunnel release procedure.

METHODS:

Fresh cadaver hands from seven men and 12 women (age range, 48–74 yr) were used. The neurovascular structures just over and under the TCL were meticulously dissected under loupe magnification. Several anatomic landmarks were calculated (average length of the TCL; average distance between the TCL distal margin and the neurovascular structures; and average lengths of the superficial palmar arch, ramus communicantes, recurrent motor branch, and palmar cutaneous branch of the median nerve). The ulnar neurovascular structure was studied with the wrist positioned in neutral, ulnar flexion, and radial flexion.

RESULTS:

The anatomic relationships between the TCL and vascular and neural structures were measured. The ulnar neurovascular structures usually passed just over ulnar to the superior portion of the hook of the hamate. However, in 11 hands, a looped ulnar artery coursed 1 to 4 mm radial to the hook of the hamate and continued to the superficial palmar arch. The looped ulnar artery migrates on the ulnar side of Guyon's canal (-2–2 mm radial to the hook of the hamate) with the wrist in radial flexion (of the wrist). During ulnar flexion of the wrist, the ulnar artery shifts more radially beyond the hook of the hamate (2–7 mm).

CONCLUSION:

It is appropriate to transect the ligament over 4 mm apart from the lateral margin of the hook of the hamate without placing the edge of the scalpel toward the ulnar side. We would also recommend not transecting the TCL in the ulnar flexed wrist position to protect the ulnar neurovascular structure. The proximal portal could be made just ulnar to the palmaris longus tendon to spare the neurovascular structures in the proximal portion of the TCL.
Subtemporal Approach To The Tentorial Incisura: Normative Morphometric Data Based On Magnetic Resonance Imaging Scans
Authors: Ardeshiri Ardeshir , Ardeshiri Ardavan , Wenger Emanuel , Holtmannspötter Markus , Winkler Peter A.
Published: February 2006

OBJECTIVE:

The tentorial notch can be contained within a transversal line made in front of the cerebral peduncles and another line through the posterior border of the quadrigeminal plate into the anterior, middle and posterior parts. Different approaches to the tentorial incisura have been established. The subtemporal approach represents one of those options. Since morphometrical analyses of this approach in this region have not yet been performed, the aim of the present study was to measure the surgical corridor along these borders.

METHODS:

Fifty-three magnetization prepared rapid acquisition gradient echo-sequences of individual brains without pathological lesions were analyzed. For this study, an axial section along the pontomesencephalic sulcus and two coronal sections along the above-described borders were measured using a program specially written by one of the coauthors to obtain various parameters. A triangle circumscribing the surgical corridor was delimited by exactly defined anatomic landmarks for the coronal section, and the depths of the temporal lobe at the incisural borders were measured for the axial section.

RESULTS:

Various data are given concerning the surgical corridor of a subtemporal approach to the tentorial incisura. The different shapes of this corridor to the incisural region were recorded. According to our measurements, four different types of the temporal lobe could be differentiated.

CONCLUSION:

Knowledge of these distances and various contours of the path is crucial to avoid brain damage during retraction or manipulation. The curvature of the floor of the middle cranial fossa is highly variable and thus determines the surgical path chosen.
Antero-Lateral Approach To The V3 Segment Of The Vertebral Artery
Authors: Bruneau Michaël , Cornelius Jan Frederick , George Bernard
Published: February 2006

OBJECTIVE:

We describe our surgical technique of exposure, control, and transposition of the third segment of the vertebral artery (VA V3 segment).

METHODS:

The VA V3 segment extends from the C2 transverse foramen to the dura mater of the foramen magnum. It initially courses vertically between the C2 and C1 transverse foramens, then runs horizontally over the atlas groove, and finally obliquely upwards before piercing the dura mater. Exposure of the VA V3 segment through an antero-lateral approach is performed by passing medially to the ster-nomastoid muscle. After exposure and protection of the spinal accessory nerve, the C1 transverse process is identified below and in front of the mastoid tip. The small muscles that insert on it are cut to expose the C1-C2 portion. The inferior aspect of the horizontal portion is safely separated from the atlas groove by elevating the subperiosteal plane and the superior aspect is freed by a cut a few millimeters above the VA on the occipital condyle. Complete unroofing of the C1 transverse foramen is achieved by resecting the bone while leaving intact the subperiosteal plane. The VA then can be transposed. Venous bleedings during the dissection from periosteal sheath tearing can be controlled by direct bipolar coagulation.

RESULTS:

The control of the VA V3 segment is essentially used for lesions in the VA vicinity and to improve the surgical exposure at the craniocervical junction level. Indications therefore are tumoral removal, VA decompression, and rarely, nowadays, VA revascularization.

CONCLUSION:

Perfect knowledge of the anatomy and the surgical technique permits a safe exposure, control, and transposition of the VA V3 segment. This is the first step of many surgical procedures.
The Orbitozygomatic Approach
Authors: Furth Wouter Ralph van , Agur Anne Maria R. , Woolridge Nicholas , Cusimano Michael D.
Published: February 2006

OBJECTIVE:

The orbitozygomatic approach is a modification and extension of the pterional craniotomy to gain a wider exposure of structures at a cranial base. To simplify the understanding and performance of the approach, we developed a teaching video that follows a systematic approach to the surgical anatomy and technique.

METHODS:

The authors have incorporated three-dimensional (3D) renderings into the descriptions of the surgical technique and contemporary computer animation is used to demonstrate surgical details and nuances of the procedure.

RESULTS:

A teaching video was compiled, and it was well received by neurosurgical residents in Europe and Canada.

CONCLUSION:

With mastery in the surgical laboratory and with guided supervision, the approach can be routinely applied without adding morbidity to a variety of pathologies such as aneurysms and tumors.
Biomarkers of Oxidative Damage in Human Disease
Authors: Dalle-Donne Isabella , Rossi Ranieri , Colombo Roberto , Giustarini Daniela , Milzani Aldo
Published: February 2006

Oxidative/nitrosative stress, a pervasive condition of increased amounts of reactive oxygen/nitrogen species, is now recognized to be a prominent feature of many acute and chronic diseases and even of the normal aging process. However, definitive evidence for this association has often been lacking because of recognized shortcomings with biomarkers and/or methods available to assess oxidative stress status in humans. Emphasis is now being placed on biomarkers of oxidative stress, which are objectively measured and evaluated as indicators of normal biological processes, pathogenic processes, or pharmacologic responses to therapeutic intervention. To be a predictor of disease, a biomarker must be validated. Validation criteria include intrinsic qualities such as specificity, sensitivity, degree of inter- and intraindividual variability, and knowledge of the confounding and modifying factors. In addition, characteristics of the sampling and analytical procedures are of relevance, including constraints and noninvasiveness of sampling, stability of potential biomarkers, and the simplicity, sensitivity, specificity, and speed of the analytical method. Here we discuss some of the more commonly used biomarkers of oxidative/nitrosative damage and include selected examples of human studies.
Crystal structure of new lanthanide diphosphates KLnP2O7 · 2 H2O (Ln = Gd, Tb, Yb)
Authors: Tahiri Aziz A. , El Bali Brahim , Lachkar Mohammed , Piniella Juan F. , Capitelli Francesco
Published: February 2006

Crystals of lanthanide diphosphates KLnP2O7 · 2 H2O [Ln = Gd, Tb, Yb] have been synthesized and investigated by single-crystal X-ray diffractometry. The three structures resulted to be isostructural within monoclinic space group P21/c, with unit cell parameters of a = 7.7522(2) Å, b = 10.6732(8) Å, c = 10.1375(7) Å, β = 93.308(5)°, V = 837.39(9) Å3 (KGdP2O7 · 2 H2O = (1)), a = 7.7380(6) Å, b = 10.6360(8) Å, c = 10.1060(7) Å, β = 93.283(6), V = 830.37(11) Å3 (KTbP2O7 · 2 H2O = (2)), a = 7.6791(3) Å, b = 10.4992(7) Å, c = 9.9554(9) Å, β = 93.214(6)°, V = 801.39(10) Å3 (KYbP2O7 · 2 H2O = (3)). The three-dimensional frameworks are made by zig-zag chains of KO9 irregular polyhedra down c, sharing vertices with LnO7 polyhedra and P2O7 units; intricate hydrogen bonding networks complete the arrays.
Effect of hydrostatic pressure on the crystal structure of sodium oxalate: X-ray diffraction study and ab initio simulations
Authors: Boldyreva Elena V. , Ahsbahs Hans , Chernyshev Vladimir V. , Ivashevskaya Svetlana N. , Oganov Artem R.
Published: February 2006

Effect of hydrostatic pressures up to 8 GPa on the crystals of Na2C2O4 (sp. gr. P21/c) was studied in situ in the diamond anvil cells a) in neon, b) in methanol-ethanol mixture by high-resolution X-ray powder diffraction (synchrotron radiation, λ = 0.7 Å, MAR345-detector). Below 3.3–3.8 GPa, anisotropic structural distortion was observed, which was similar to, but not identical with that on cooling. At 3.8 GPa, a reversible isosymmetric first-order phase transition without hysteresis occurred. The orientation of the oxalate anions changed at the transition point by a jump, and so did the coordination of the sodium cations by oxygen atoms. Ab initio simulations based on the generalized gradient approximation of density functional theory have reproduced the main features of the structural changes in the crystals of sodium oxalate with increasing pressure. The theoretical pressure for the isosymmetric phase transition is 3.65 GPa, close to the experimental value; in agreement with experiment the transition was predicted to be reversible. Ab initio calculations gave a pronounced hysteresis for this transition, and have also predicted a further isosymmetric phase transition at 10.9 GPa, also with a hysteresis. The role of temperature in the pressure-induced phase transitions in sodium oxalate is discussed.
Ion Channels in Mesenchymal Stem Cells from Rat Bone Marrow
Authors: Li Gui-Rong , Deng Xiu-Ling , Sun Haiying , Chung Stephen S.M. , Tse Hung-Fat , Lau Chu-Pak
Published: February 2006

Mesenchymal stem cells (MSCs) from bone marrow are believed to be an ideal cell source for cardiomyoplasty; however, cellular electrophysiology is not understood. The present study was designed to investigate ion channels in undifferentiated rat MSCs. It was found that three types of outward currents were present in rat MSCs, including a small portion of Ca2+-activated K+ channel (IKCa) sensitive to inhibition by iberiotoxin and/or clotromazole, a delayed rectifier K+ current (IKDR), and a transient outward K+ current (Ito). In addition, tetrodotoxin (TTX)-sensitive sodium current (INa.TTX) and nifedipine-sensitive L-type Ca2+ current (ICa.L) were found in a small population of rat MSCs. Moreover, reverse transcription-polymerase chain reaction revealed the molecular evidence of mRNA for the functional ionic currents, including Slo and KCNN4 for IKCa; Kv1.4 for Ito; Kv1.2 and Kv2.1 for IKDR; SCN2a1 for INa.TTX; and CCHL2a for ICa.L. These results demonstrate for the first time that multiple functional ion channel currents (i.e., IKCa, Ito, IKDR, INa.TTX, and ICa.L) are present in rat MSCs from bone marrow; however, physiological roles of these ion channels remain to be studied.
Prospective Isolation of Murine Hematopoietic Stem Cells by Expression of an Abcg2/GFP Allele
Authors: Tadjali Mehrdad , Zhou Sheng , Rehg Jerold , Sorrentino Brian P.
Published: February 2006

Stem cells from a variety of tissues can be identified by a side population (SP) phenotype based on Hoechst 33342 dye efflux. The Abcg2 transporter is expressed in hematopoietic stem cells (HSCs) and confers this dye efflux activity. To further explore the relationship among Abcg2 expression, the SP phenotype, and HSC activity, we have generated mice in which a green fluorescent protein (GFP) reporter gene was inserted into the Abcg2 locus. In these mice, the majority of bone marrow (BM) cells that expressed the Abcg2/ GFP allele were Ter119+ erythroid cells. The Abcg2/GFP allele was also expressed in approximately 10% of lineage-negative (Lin−) and in 91% of SP cells using stringent conditions for the SP assay. Flow cytometric sorting was used to isolate various Abcg2/GFP+ BM cell populations that were then tested for HSC activity in transplant assays. There was significant enrichment for HSCs in sorted Lin−/ GFP+ cells, with a calculated HSC frequency of approximately one in 75. There was no HSC activity detected in Lin−/GFP+ cells. Altogether, these results show that Abcg2 is expressed on essentially all murine BM HSCs and can be used as a prospective marker for HSC enrichment.
Phosphorus Compounds
Authors: Fee Darrell C. , Gard David R. , Yang Chen‐Hsyong
Published: February 2006

Phosphorus compounds exhibit an enormous variety of chemical and physical properties as a result of the wide range in the oxidative states and coordination numbers for the phosphorus atom. The intermediate electronegativity of phosphorus also plays a role. Phosphorus oxides, halides, sulfides, hydrides (phosphines), nitrogen compounds, and metal phosphides, as well as organophosphorus compounds, are reviewed. Emphasis is placed on the commercially important phosphorus trichloride, phosphorus pentachloride, phosphorus pentasulfide, phosphorus (V) oxide, and phosphine. Structure and nomenclature of phosphorus compounds and their organic derivatives are presented. Properties of the PO, PS, PH, PC, and PX (X = halogen) bonds are given. The manufacture of the commercial phosphorus compounds is outlined. Phosphorus compounds are found in or used as intermediates for the manufacture of oil additives, heat‐transfer and hydraulic fluids, water‐treatment chemicals, catalysts, herbicides, flame retardants, pesticides, pharmaceuticals, semiconductors, and surfactants. Intermediates in the preparation of organophosphorus derivatives are reviewed.
Smart Materials
Authors: Wilson Alan Richard
Published: February 2006

The field of smart materials is extremely large and probably includes representatives from all types of materials. The term, “smart material”, has some confusion attached to it as to what it actually means. A critical defining element for a material to qualify as “smart” is for it to have the ability to respond to a stimulus in a useful way, in an engineering sense, this response being both timely and in a controlled manner. Otherwise, all materials could be considered to be smart since all materials respond to external stimuli in same way. The discriminating factor is whether this response can be harnessed for some useful purpose. Stimuli may include mechanical deformation, stress and pressure, temperature, chemicals, incident radiation, electric and magnetic fields, electric current and charges, and other stimuli. Material responses to these types of stimuli include the rearrangement of atomic and molecular structures, the creation and motion of crystallographic defects or other local conformations, absorption of and emission of photons, chemical reactions, generation of charge and voltage, and other effects. Smart materials are most often reversible in nature with the stimulus and response being interchangeable actions.

This article includes examples of materials with piezoelectric, ferroelectric, shape memory, electrostrictive, magnetostrictive, electrorheological, magnetorheological, photo responsive, and sensitive and chemically and biochemically responsive properties. Some particular classes of materials are also considered including, conducting polymers, electroactive polymers, semiconductor films, metal oxides, nanotechnology (including carbon nanotubes), and smart catalysts.
Zinc and Zinc Alloys
Authors: Goodwin Frank E.
Published: February 2006

Zinc is a relatively active metal and its compounds are stable. Since it is not found free in Nature, it was discovered later than less‐reactive metals. The main application of zinc is to protect iron and other metals from corrosion. Occurrence and properties of zinc are discussed. Processing of the ore requires concentration of the ore followed by roasting, or reduction by electrolytic methods. Economic data, specifications and grades, health and safety factors are given. The uses of zinc coatings on iron and steel are described as die‐casting alloys and foundry alloys. Rolled zinc and zinc dust and powder also find industrial use. Ores exploited for zinc invariably contain one or more other valuable metals, such as cadmium and mercury.
Zinc Compounds
Authors: Goodwin Frank E.
Published: February 2006

Zinc usually occurs as the sulfide, but significant quantities of the oxide, carbonate, silicate, and basic compounds of the latter two are mined. Properties of many of the compounds of zinc are given, with special attention given to zinc oxide, zinc chloride, and zinc sulfate. The oxide is important because it completely absorbs ultraviolet light < 366 nm and it is unique among white pigments. In glass, zinc oxide reduces the thermal coefficient of expansion and improves stability against deformation under stress. Details on the American (Direct) process and French (Indirect) Process for the production and processing of zinc are given as well as a discussion of secondary zinc oxide obtained from scrap. Zinc is needed for the proper functioning of plants and animals and this is discussed along with health and safety aspects, uses, and economics.
Predictors of glass transition in the biodegradable poly‐lactide and poly‐lactide‐co‐glycolide polymers
Authors: In Pyo Park Peter , Jonnalagadda Sriramakamal
Published: February 2006

The biodegradable polylactide (PLA) and polylactide‐co‐glycolides (PLGAs) are being widely investigated for use as scaffolds in bone and ligament reconstruction. The glass transition temperatures (Tg) for these polymers are generally greater than 37°C, causing PLA and PLGA devices to possess brittle characteristics in physiological conditions. To evaluate the possibility of obtaining PLGA polymers with Tg values below 37°C, we evaluated the determinants of Tg in PLA and PLGA copolymers. The Tg, changes in specific heat capacity (ΔCp), and enthalpic relaxation (ΔHg) in two consecutive heating cycles were correlated with lactide/glycolide content and intrinsic viscosity [η] for PLA, PLGAs 90:10, 75:25, 65:35, and 50:50. A linear correlation was observed between Tg and intrinsic viscosity, with 0.1 dL/g increase in viscosity resulting in an increase in Tg by about 3.55°C. The selection of PLA and PLGA copolymers with [η] values <0.19 dL/g, corresponding to a viscosity average molecular weight of <70 kDa, will obtain PLA/PLGA polymers with Tg values below 37°C. The lowest attainable Tg values were found to be 28–30°C. Intrinsic viscosity also correlated with ΔCp differences between aged and rapidly cooled polymers, and is therefore important in predicting free volume changes within these polymers upon aging. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 1983–1987, 2006
Thermally initiated cationic polymerization and properties of epoxy siloxane
Authors: Morita Yasumasa , Tajima Seitarou , Suzuki Hiroshi , Sugino Hiroaki
Published: February 2006

Difunctional epoxy siloxane monomers containing disiloxane, trisiloxane, and tetrasiloxane were prepared by hydrosilylation of an α,ω‐difunctional SiH‐terminated siloxane with a vinyl‐functional epoxide. Cationic polymerization of these monomers using 3‐methyl‐2‐butenyltetramethylenesulfonium hexafluoroantimonate and their reactivities were examined. The reactivity order was disiloxane > trisiloxane > tetrasiloxane. Thermal discoloration of these polymers increased with catalyst concentration and also with the length of dimethyl siloxane. UV discoloration was also accelerated by catalyst. From the thermo gravimetric analysis, it was found that the thermal stabilities of polymers increased with increasing the length of dimethyl siloxane chain. Mechanical properties of polymers were also tested by thermal mechanical analysis and dynamic mechanical analysis, and it was found that the flexibility of polymers was increased with increasing siloxane chain length. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2010–2019, 2006
Postspinning draw of polymeric fibers: Multiscale micromechanical model for a solid polymer under finite deformation and strain‐induced crystallization
Authors: Makradi A. , Cox C. L. , Ahzi S. , Belouettar S.
Published: February 2006

A polymeric fiber postspinning draw model is developed. The fiber is stretched between the take‐up roll and the draw roll and then relaxed between the draw roll and the relax roll. The behavior of the polymeric material is described by a cooperative elastic–viscoplastic model for a wide range of temperatures and strain rates. The profiles of the fiber velocity, stress, strain rate, and temperature between the different rolls are simulated via the coupling of the cooperative model with the mass, momentum, and energy equations and the boundary conditions. Simulations are conducted with the finite‐element method. The computed results show an increase in the fiber stress between the take‐up roll and the draw roll due to the molecular orientation and the increase in the crystallization percentage. The sliding distance of the fiber on the draw roll is related to the draw ratio and fiber stiffness. A dramatic drop in the fiber strain rate on the draw roll leads to relaxation of the intermolecular resistance followed by a freeze of the fiber structure when the strain rate vanishes to zero on the draw roll and between the draw roll and the relax roll. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2259–2266, 2006
Thermoplastic elastomeric nanocomposites from poly[styrene–(ethylene‐co‐butylene)–styrene] triblock copolymer and clay: Preparation and characterization
Authors: Ganguly Anirban , De Sarkar Mousumi , Bhowmick Anil K.
Published: February 2006

Thermoplastic elastomer (TPE)–clay nanocomposites based on poly[styrene–(ethylene‐co‐butylene)–styrene] triblock copolymer (SEBS) were prepared. Natural sodium montmorillonite (MMT) clay was organically modified by octadecyl amine to produce an amine‐modified hydrophobic nanoclay (OC). Commercially available Cloisite 20A (CL20) and Cloisite 10A, tallow ammine modified nanoclays, were also used. The intergallery spacing of MMT increased on amine modification as suggested by the shifting of the X‐ray diffraction (XRD) peak from 7.6 to 4.5 and 3.8° in the cases of OC and CL20, respectively. The latter demonstrated no XRD peak when it was used at 2 and 4 parts phr in the SEBS system. Transmission electron microscopy studies showed the intercalation–exfoliation morphology in SEBS containing 4 parts of CL204–SEBS, agglomeration in SEBS having 4 parts of MMT, and mixed morphology in SEBS with 4 parts of OC systems. Locations of the clay particles were indicated by the atomic force micrographs. Mechanical and dynamic mechanical thermal analysis studies confirmed the best properties with the CL204–SEBS nanocomposites. Significant improvements in mechanical properties such as tensile strength, modulus, work to break, and elongation at break were achieved with the CL204–SEBS in polymer‐layered silicate nanocomposites. Dynamic mechanical studies further showed the affinity of the organoclays toward both segments of the TPE and a compatibilization effect with CL20 at a 4‐phr loading. Atomic force microscopy showed distinctly different morphologies in nanocomposites prepared through solution and melt processing. Comparisons of the mechanical, dynamic mechanical, and morphological properties of the nanocomposites prepared by melt and solution intercalation processes were done. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2040–2052, 2006
Preparation and properties of polyimide/silica hybrid composites based on polymer‐modified colloidal silica
Authors: Im Ji‐Sun , Lee Ju‐Hyung , An Seung‐Kook , Song Ki‐Won , Jo Nam‐Ju , Lee Jang‐Oo , Yoshinaga Kohji
Published: February 2006

A new type of polyimide/silica (PI/SiO2) hybrid composite films was prepared by blending polymer‐modified colloidal silica with the semiflexible polyimide. Polyimide was solution‐imidized at higher temperature than the glass transition temperature (Tg) using 3,3′,4,4′‐biphenyltetracarboxylic dianhydride (BPDA) and 4,4′‐diaminodiphenyl ether (ODA). The morphological observation on the prepared hybrid films by scanning electron microscopy (SEM) pointed to the existence of miscible organic–inorganic phase, which resulted in improved mechanical properties compared with pure PI. The incorporation of the silica structures in the PI matrix also increased both Tg and thermal stability of the resulting films. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2053–2061, 2006
Study of morphology influence on rheological properties of compatibilized TPU/SAN blends
Authors: Ulcnik‐Krump M.
Published: February 2006

The compatibilizing efficiency of three different compatibilizers on the thermoplastic polyurethane/styrene‐co‐acrylonitrile (TPU/SAN) blends properties was investigated after compatibilizer's incorporation via melt‐mixing. The compatibilizers studied were as follows: poly‐ε‐caprolactone (PCL) of different molecular weight (Mw), a mixture of polystyrene‐block‐polycaprolactone (PS‐b‐PCL) and polystyrene‐block‐poly (methyl methacrylate) (PS‐b‐PMMA), and a mixture of polyisoprene‐block‐polycaprolactone (PI‐b‐PCL) and polybutadiene‐block‐poly (methyl methacrylate) (PB‐b‐PMMA). In our study, the effect of 5 wt % added compatibilizers on TPU/SAN blends morphology was examined. The transmission electron microscopy (TEM) was used to study the morphology at different length scales and to determine the compatibilizer's location. Investigations showed the different improvement of properties, because of the different incorporation of compatibilizers in the polymer blend. The morphology influence on the rheological behavior of compatibilized blends was investigated with a stress‐controlled rheometer (Rheometric Dynamic Stress Rheometer, SR‐500). Different compatibilization activity was found for different system. It was also found that compatibilization activity of added compatibilizer strongly depends on the comaptibilizer'sMw. Blends compatibilized with PCL showed superior properties as compared with the other examined blends. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2303–2316, 2006
Ultraviolet curable dry polymer films from emulsion polymers
Authors: Chee Swee Yong , Gan Seng Neon
Published: February 2006

Low levels of functional acrylic monomers were incorporated into a core‐shell acrylic copolymer by seeded emulsion polymerization. The increase in glass transition temperature, Tg, from DSC measurement has showed that although certain amount of crosslinking reactions have occurred during the polymerization and isolation of the copolymer, the dried copolymer films could undergo further curing by UV irradiation. The structure and amount of the functional monomer, concentration of photoinitiator, and the extent of UV exposure have exerted significant influence on the Tg of the dry copolymer films. Because of the relatively low level of incorporated unsaturation, there was no significant change in FTIR during the curing of the film. Further, crosslinking of the copolymer film induced by UV irradiation has significantly increased the resistance to swelling in alkaline solution, although the gel content remained the same. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2317–2322, 2006
Synthesis and characterization of photo‐crosslinkable polyfluorene with acrylate side‐chains
Authors: Wu Guanglong , Yang Chunhe , Fan Benhu , Zhang Bin , Chen Xiaomin , Li Yongfang
Published: February 2006

A photo‐crosslinkable polymer, poly[2,7‐(9,9‐dioctylfluorene)‐co‐2,7‐(9‐hexyl‐9‐(2‐acrylate ethyl)‐9H‐fluorene)] (P3), was synthesized and the photo‐crosslinkable acrylate groups were introduced into the side‐chains of the polyfluorene derivative after its polymerization. This method avoids the possible crosslinkage of the crosslinkable groups on the monomers during polymerization in the traditional synthesis route by the polymerization of the monomers with the crosslinkable side‐chains. The soluble and processable polymer P3 could be crosslinked via the acrylate groups in its side‐chains upon exposure to UV light in nitrogen atmosphere. The crosslinking was confirmed by IR spectroscopy: the IR peak of CC bond at 1635 cm−1 decreased and that of the vinyl CH bond at 742 cm−1 disappeared after the UV exposure. The absorption spectra of P3 remain unchanged after crosslinking, but a longer wavelength emission at 517 nm appeared in the photoluminescent and electroluminescent spectra of the crosslinked P3, which could be attributed to the formation of keto defects during the photo crosslinking. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2336–2342, 2006
Mass transfer of dilute 1,2‐dimethoxyethane aqueous solutions during pervaporation process
Authors: Liang Liang , Dickson James M. , Jiang Jianxiong , Brook Michael A.
Published: February 2006

Pervaporation of 1,2‐dimethoxyethane (1,2‐DME) is evaluated by crosslinked oligosilylstyrene–poly(dimethylsiloxane) composite membranes. A low flow velocity of the feed solution (1.0 L/min), corresponding to a Reynolds number of 220, is used. The pervaporation models are developed by combining the resistance in series and solution–diffusion models. The effects of the boundary layer on the performance of pervaporation are estimated by comparing experimental and theoretical data. The permeation fluxes of 1,2‐DME and water fit very well with the calculated data from the models, but a deviation of the separation factor between the experimental and theoretical data is observed. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100:2075–2084, 2006
Distribution of calcium carbonate and silicone elastomer in a flame retardant system based on ethylene–acrylate copolymer, chalk and silicone elastomer and its effect on flame retardant properties
Authors: Hermansson Anna , Hjertberg Thomas , Sultan Bernt‐Åke
Published: February 2006

A combination of microscopy studies (SEM, ESEM/EDX, and TEM/EDX) is proven to be useful in locating chalk particles and silicone elastomer in a flame retardant system based on ethylene–acrylate copolymer, chalk, and silicone elastomer. The dispersion of the two additives was also obtained. The chalk particles were visually observed (at a certain degree of magnification), and the silicone elastomer was detected using characteristic X‐ray mapping and line scans. The analysis provided a good contrast between chalk particles and silicone elastomer in the surrounding polymer matrix. It is shown that dispersion of the additives depends on the mixing conditions, where tougher mixing conditions improve dispersion. A discussion is given on how dispersion correlates with the flame retardant properties of this system. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2085–2095, 2006
Preparation and characterization of polyvinyl alcohol based biomaterials: Water sorption and in vitro blood compatibility study
Authors: Mishra Shefali , Bajpai R. , Katare R. , Bajpai A. K.
Published: February 2006

Semi‐interpenetrating polymer networks (semi‐IPNs) based on polyvinyl alcohol (PVA) and crosslinked polyacrylamide (PAM) were prepared by redox polymerization and further characterized by FTIR, ESEM, and XRD techniques. The semi‐IPNs of varying compositions were investigated for their water sorption behavior, and the network parameters like average molecular weight between crosslinks (MC) and crosslink density were evaluated from water imbibition measurements. The semi‐IPNs were also judged for their in vitro blood compatibility by blood clot formation and percent hemolysis test. It was noticed that the chemical architecture exert a profound effect on the over all performance of the biomaterials. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2402–2408, 2006
Solution and solid‐state blend compatibility of poly(vinyl alcohol) and poly(methyl methacrylate)
Authors: Adoor S. G. , Manjeshwar L. S. , Rao K. S. V. Krishna , Naidu B. V. K. , Aminabhavi T. M.
Published: February 2006

The blend miscibility of poly(vinyl alcohol) and poly(methyl methacrylate) in N,N′‐dimethylformamide solution was investigated by viscosity, density, ultrasonic velocity, refractive index, and UV and fluorescence spectra studies. Differential scanning calorimetry and scanning electron microscopy were used to confirm the blend miscibility in the solid state. Blends were compatible when the concentration of poly(vinyl alcohol) was greater than 60 wt %. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2415–2421, 2006
Viscosity behavior of hydroxylated and acetoacetylated polyesters
Authors: Narayan Ramanuj , Chattopadhyay D. K. , Raju K. V. S. N. , Mallikarjuna N. N. , Jawalkar Sheetal S. , Aminabhavi Tejraj M.
Published: February 2006

Viscosity studies on polyester polymers are important for governing their processing characteristics before their industrial application. In this study, the viscosity properties of hydroxylated polyesters with different diols and partially acetoacetylated polyesters with different amounts of ethyl acetoacetate were examined. The melt viscosities of these polymers were measured with different shear rates and at varying temperatures. The results were analyzed with the Williams–Landel–Ferry equation. In high‐solid‐coatings applications, an understanding about the surface properties and thermodynamic quantities, such as cohesive energy density, the solubility parameter, and the Flory–Huggins interaction parameter, are important. To evaluate these quantities, an atomistic simulation methodology based on Accelrys software was used, which provided insights into the structures of these compounds for further applications. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2422–2435, 2006
Effects of annealing on morphology of polymer/polymer (PS/PMMA) blend; a fluorescence study
Authors: Uğur şaziye , Pekcan önder
Published: February 2006

Steady state fluorescence (SSF) technique conjunction with optical microscopy were used to study the morphology of polystyrene (PS)/poly(methyl methacrylate) (PMMA) blend upon annealing above glass transition in elevated time intervals. The PS/PMMA blends were prepared from dissolution of pyrene (P) and naphthalene (N) labeled PS and PMMA particles, respectively. Monte Carlo simulations were performed to model the N and P fluorescence intensities (IN and IP), using photon diffusion theory. Number of N and P photons (NN and NP) emerging from the front surface of the blend are calculated when only N is excited, where NP photons are combined of photons from radiative (NPR) and nonradiative (NPNR) energy transfer processes. Optical microscopy images were taken at each annealing step to support our findings from fluorescence measurements. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2104–2110, 2006
Synthesis and characterization of graft copolymer (guar gum–g–N‐vinyl‐2‐pyrrolidone) and investigation of metal ion sorption and swelling behavior
Authors: Srivastava Arti , Behari Kunj
Published: February 2006

Graft copolymer of N‐vinyl‐2‐pyrrolidone with guar gum was synthesized and its reaction conditions were optimized for better yield using potassium peroxymonosulfate (PMS) and glycolic acid (GA) as a redox initiator. The effect of PMS, GA, hydrogen ions, guar gum, and N‐vinyl‐2‐pyrrolidone (NVP) along with reaction time and temperature were studied by determining the grafting parameters: grafting ratio, efficiency, conversion, add‐on, homopolymer, and rate of grafting. It was observed that the maximum yield occurred at with a time of 120 min at a temperature of 45°C and a guar gum concentration of 0.4 g/L concentration. The graft copolymer was characterized by infrared spectroscopy and thermal analysis. The activation energy for the grafted and ungrafted gum was calculated. It was observed that the graft copolymer was thermally more stable than the pure gum. The swelling and metal ion sorption behavior of guar gum and guar gum‐g‐N‐vinyl‐2‐pyrrolidone also were studied. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2480–2489, 2006
Preparation of poly(4‐methyl‐1‐pentene) asymmetric or microporous hollow‐fiber membranes by melt‐spun and cold‐stretch method
Authors: Wang Jianli , Xu Zhikang , Xu Youyi
Published: February 2006

Poly(4‐methyl‐1‐pentene) (PMP) hollow fibers were prepared and fabricated into gas separation or microporous membranes by the melt‐spun and cold‐stretched method. PMP resin was melt‐extruded into hollow fibers with cold air as the cooling medium. The effects of take‐up speed and thermotreatment on the mechanical behavior and morphology of the fibers were investigated. Scanning electronic microscope (SEM) photos were used to reveal the geometric structure of the section and surface of the hollow fibers. It was found that the original fiber had an asymmetric structure. A “sandwich” mode was used to describe the formation of this special fine structure. And a series of PMP hollow‐fiber membranes were prepared by subsequent drawing, and it was found that there was a “skin–core” structure on the cross section of these hollow‐fiber membranes. Asymmetric or microporous PMP hollow‐fiber membranes could be obtained by controlling posttreatment conditions. The morphology of these membranes were characterized by SEM, and the gas (oxygen, nitrogen, and carbon dioxide) permeation properties of the membranes was measured. The results indicate that the annealing time of the original fiber and the stretching ratio were the key factors influencing the structure of the resulting membrane. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2131–2141, 2006
Preparation of nanometer‐sized poly(methacrylic acid) particles in water‐in‐oil microemulsions
Authors: Zhang Qiuyu , Bao Xujin , Lin Mian , Hourston Douglas J.
Published: February 2006

A water‐in‐oil microemulsion, water‐in‐cyclohexane stabilized by poly(ethylene glycol) tert‐octylphenyl, was developed to prepare poly(methacrylic acid) (PMAA) particles. Up to 100% conversion of the amphiphilic monomer, methacrylic acid (MAA), which could not be converted to the polymer efficiently in a dioctylsulfosuccinate sodium salt/toluene microemulsion, was achieved. The viscosity‐average molecular weight of the PMAA prepared was 1.45 × 105 g/mol. The effects of some polymerization parameters, including the reaction temperature and the concentrations of the initiator and the monomer, on the polymerization of MAA were investigated. The results showed that the polymerization rate of MAA was slower than that of acrylamide in the microemulsions reported in the literature. The degree of conversion increased with the initiator concentration, reaction temperature, and monomer concentration. However, the stable microemulsions became turbid during the polymerization when the reaction temperature was at 70°C or at a high monomer concentration (40 wt %) The synthesized PMAA particles were spherical and had diameters in the range of ∼50 nm. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2497–2503, 2006
Thermal conductivity of ramie fiber drawn in water in low temperature
Authors: Yamanaka Atsuhiko , Abe Shunzo , Tsutsumi Masayuki , Kitagawa Tooru , Fujishiro Hiroyuki , Ema Kimiko , Izumi Yoshinobu , Nishijima Shigehiro
Published: February 2006

To understand the effect of extension of molecular chain in amorphous region in polymer fibers to thermal conductivity, the thermal conductivity, tensile modulus and crystal orientation angle of ramie fibers and those drawn by the stress of 17.4 kg/mm2 (water treatment) in the water were investigated. The tensile modulus of ramie fiber in fiber direction increased from 61 to 130 GPa by drawing in the water. The crystal orientation angles of ramie fiber with and without water treatment were measured by X‐ray diffraction. The orientation degrees of ramie fibers without and with water treatment were estimated as 92.9 and 93.6%, respectively. Therefore, the tensile modulus increases two times as that of blank ramie by water treatment although crystal orientation angle does not change distinctly. The increasing of tensile modulus of ramie fiber by water treatment was explained by extension of the molecular chains in the amorphous region. Thermal conductivities of ramie fibers with and without water treatment were measured in the fiber direction in the temperature range from 10 to 150 K. Thermal conductivity of ramie fiber in the fiber direction increased by water treatment. The increasing ratio of thermal conductivity by water treatment agreed to that of sound velocity induced by increasing tensile modulus. Those results suggest that thermal conductivity of polymer fiber increase by the extension of molecular chains in the amorphous region. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2196–2202, 2006
Environmental durability of banana‐fiber‐reinforced phenol formaldehyde composites
Authors: Joseph Seena , Oommen Z. , Thomas Sabu
Published: February 2006

We explored the environmental aging behavior of banana‐fiber‐reinforced phenol formaldehyde (PF) composites. The composites were subjected to water aging, thermal aging, soil burial, and outdoor weathering. The effects of chemical modification and hybridization with glass fibers on the degradability of the composites in different environments were analyzed. The extent of degradation was measured by changes in the weight and tensile properties after aging. Absorbed water increased the weight of water‐aged composites, and chemical treatments and hybridization decreased water absorption. The tensile strength and modulus of the banana/PF composites were increased by water aging, whereas the strength and modulus of the glass/PF composites were decreased by water aging. As the glass‐fiber loading was increased in the hybrid composites, the increase in strength by water aging was reduced, and at higher glass‐fiber loadings, a decrease in strength was observed. The tensile properties of the composites were increased by oven aging. The percentage weight loss was higher for soil‐aged samples than for samples weathered outdoors. The weight loss and tensile strength of the glass/PF composites and banana/glass/hybrid/PF composites were much lower than those of the banana/PF composites. Silane treatment, NaOH treatment, and acetylation improved the resistance of the banana/PF composites on outdoor exposure and soil burial. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2521–2531, 2006
Optimizing multiple qualities in as‐spun polypropylene yarn by neural networks and genetic algorithms
Authors: Huang Chang‐Chiun , Tang Tsann‐Tay
Published: February 2006

This investigation considers a quantitative procedure for determining the values of critical process parameters in melt spinning to optimize the qualities of denier, tenacity, breaking elongation, and denier variance in as‐spun polypropylene yarn. An orthogonal array in the Taguchi method defines the minimum set of parameter‐level combinations that are experimentally tested. The significant process parameters, namely the third extruder barrel temperature, spinning temperature, metering pump speed, and take‐up velocity, are identified on the basis of the analysis of variance and F test. After a confirmation experiment is conducted to ensure the reproducibility of the experimental results, the back‐propagation neural network establishes a continuous system linking 10 process parameters and four qualities. The technique for order preference by similarity to an ideal solution can be used to obtain a performance measure for assessing multiple qualities. The genetic algorithm attempts to find parameter values for optimizing the quality performance, including the denier, tenacity, breaking elongation, and denier variance. Finally, the experimental results demonstrate that the smallest denier, largest tenacity, smallest breaking elongation, and second smallest denier variance of as‐spun polypropylene yarn can be achieved with the proposed approach in melt spinning. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2532–2541, 2006
Microstructural imaging and characterization of the mechanical, chemical, thermal, and swelling properties of starch–chitosan blend films
Authors: Mathew Sindhu , Brahmakumar M. , Abraham T. Emilia
Published: February 2006

Chitosan has wide range of applications as a biomaterial, but barriers still exist to its broader use due to its physical and chemical limitations. The present study evaluated the properties of the polymeric blend films obtained from chitosan and potato starch by the casting/solvent evaporation method. The swelling properties of the different films studied as a function of pH showed that the sorption ability of the blend films increased with the increasing content of starch. Fourier transform infrared (FTIR) analyses confirmed that interactions were present between the hydroxyl groups of starch and the amino groups of chitosan in the blend films while the x‐ray diffraction (XRD) studies revealed the films to exhibit an amorphous character. Thermogravimetric analyses showed that in the blend films, the thermal stability increased with the increasing starch content and the stability of starch and chitosan powders reduced when they were converted to film. The differential scanning calorimetry (DSC) studies revealed an endotherm corresponding to water evaporation around 100°C in all the films and an exotherm, corresponding to the decomposition in the chitosan and blend films. Scanning electron microscopy (SEM) observations indicated that the blend films were less homogenous and atomic force microscopy (AFM) studies revealed the chitosan films to be smooth and homogenous, while the starch films revealed characteristic granular pattern. The blend films exhibited an intermediate character with a slight microphase separation. The starch–chitosan blend films exhibited a higher flexibility and incorporation of potato starch into chitosan films improved the percentage elongation. © 2006 Wiley Periodicals, Inc. Biopolymers 82: 176–187, 2006

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Search for optimal coupling reagent in multiple peptide synthesizer
Authors: Hachmann John , Lebl Michal
Published: February 2006

Ten different coupling reagents and their combinations were tested in parallel in the synthesis of four model peptide sequences. Significant differences were found between uronium and phosphonium salt‐based reagents and carbodiimide. Diisopropylcarbodiimide was identified as an optimal reagent based on the purity of the product, stability of the reagent, and convenience of handling on plate‐based multiple parallel centrifugation synthesizer. © 2006 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 84: 340–347, 2006

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com