bluuebunny/crossref_metadata_2025 huggingface dataset:
Exploiting Chemical Switching in a Diels–Alder Polymer for Nanoscale Probe Lithography and Data Storage
Authors: Gotsmann B. , Duerig U. , Frommer J. , Hawker C. J.
Published: June 2006

Reversibly crosslinked polymer films have properties that are beneficial to scanned‐probe data storage and lithographic applications that use thermomechanical nanoindentation as a write or expose mechanism. The novel polymer under study contains linkages based on thermally reversible Diels–Alder crosslinking. Thermomechanical properties on the nanometer scale are analyzed by indentation experiments on polymer thin films using heated tips. The underlying indentation mechanism is studied at varying tip temperatures and indentation times, revealing Arrhenius kinetics. This is in contrast to the Williams–Landau–Ferry kinetics usually observed for polymer systems. The discrepancy is explained by the reversible crosslinking incorporated into the structure of the polymer that allows switching between two different states: a rigid, highly crosslinked, low‐temperature state, and a deformable, fragmented, high‐temperature state. An individual indentation volume of less than 10–20 L (10 000 molecule pairs) is estimated. These kinetics experiments demonstrate that a chemical reaction of only a few thousand molecules can be transduced into a mechanically measurable action. The ability to cycle between two sets of properties in these materials opens up new perspectives in lithography and data storage. Examples of data storage with densities up to 1 Tb in.–2 and maskless lithography with resolution below 20 nm are demonstrated at writing times of 10 μs per bit/pixel.
AL amyloidosis associated with B‐cell lymphoproliferative disorders: Frequency and treatment outcomes
Authors: Sanchorawala V. , Blanchard E. , Seldin D.C. , O'Hara Carl , Skinner M. , Wright D.G.
Published: June 2006

AL amyloidosis, a systemic disorder characterized by widespread deposition of amyloid fibrils derived from monoclonal Ig light chains in organs and soft tissues, is typically caused by an underlying plasma cell dyscrasia. However, this disease can also be associated rarely with a B‐cell lymphoproliferative disorder. In this report, we describe the presentation and clinical course of 16 patients with this association. Although amyloid‐related organ involvement in these patients was typical of AL amyloidosis, the patients in this series were on average older and more likely to be female than patients with disease associated with a plasma cell dyscrasia. They were also more likely to have multisystem involvement. Treatment decisions were based primarily on the dominent hematopathologic features of the associated lymphoproliferative disorder. However, high‐dose melphalan and stem cell transplantation was the primary therapy in 5 patients, and each of these patients had prolonged survival, ranging from 36 to 102 months. Am. J. Hematol., 2006. © 2006 Wiley‐Liss, Inc.
Pulmonary hypertension in thalassemia: Association with platelet activation and hypercoagulable state
Authors: Singer Sylvia T. , Kuypers Frans A. , Styles Lori , Vichinsky Elliott P. , Foote Drucella , Rosenfeld Howard
Published: June 2006

The pathogenesis of pulmonary hypertension (PAH), a serious complication in thalassemia, is not well understood. Thromboembolism has been postulated as one of the causative factors; however, there are currently limited specific data on its role. To examine whether increased platelet activation and hypercoagulability are linked to PAH, 25 β‐thalassemia major and β‐thalassemia intermedia patients were evaluated with Doppler echocardiograms for estimation of pulmonary artery pressure and with laboratory assays for indications of a prothrombotic state. The association of clinical variables and abnormal coagulation assays with PAH was determined. PAH was identified in 17 (68%) patients; mean pulmonary artery systolic pressure was 39.8 ± 5.4 mm Hg. PAH was significantly associated with prior splenectomy, older age, and evidence for chronic hemolysis, diagnosed in both transfused (n = 10) and nontransfused (n = 7) patients. Increased platelet activation, measured by P‐selectin, was significantly associated with PAH (P = 0.001). Increased thrombin‐antithrombin III level was more prevalent in the presence of PAH, but increased fibrinolysis or low protein C levels were not. This study underscores the role of platelet activation in the development of PAH and stresses its occurrence even among patients who are regularly transfused, especially those who are older and have had splenectomies. Am. J. Hematol., 2006. © 2006 Wiley‐Liss, Inc.
Bloodstream infections in hospitalized adults with sickle cell disease: A retrospective analysis
Authors: Chulamokha Lalita , Scholand Stephen J. , Riggio Jeff M. , Ballas Samir K. , Horn David , DeSimone Joseph A.
Published: June 2006

Bloodstream infections (BSI) are a common cause of morbidity and mortality in people with sickle cell disease (SCD). In children with SCD, BSI are most often caused by encapsulated organisms. There is a surprising paucity of medical literature that is focused on evaluating SCD adults with BSI. We reviewed the charts of adults with SCD and BSI who were admitted to our hospital between April 1999 and August 2003. During this period a total of 1,692 hospital admissions for 193 adults with SCD were identified and 28% of these patients had at least 1 episode of positive blood cultures, with 69 episodes (17%) considered true BSI. Nosocomial BSI occurred in 34 episodes (49%). Among community BSI, in contrast to BSI in children with SCD, Streptococcus pneumoniae was rarely encountered. A high incidence of staphylococcal BSI in adults with SCD was noted. Twenty‐eight percent of all BSI were caused by Staphylococcus aureus, and 15 of 22 isolates (68%) of these were methicillin‐resistant. Gram‐negative organisms, anaerobes, and yeast were found in 21 (27%), 3 (4%), and 4 isolates (5%) of BSI, respectively. Since over 80% of BSI were considered catheter‐related, the higher incidence of gram‐positive bacterial infections was likely due to the presence of indwelling central venous catheters. Empiric therapy for adults with SCD suspected of having BSI, especially in the presence of indwelling central venous catheters, should include antimicrobial therapy targeted at gram‐positive bacteria (especially MRSA) and gram‐negative bacteria. Also, if patients are critically ill, consideration should be made to include antifungal agents. Additional research into the adult SCD population appears necessary to further define this problem. Am. J. Hematol., 2006. © 2006 Wiley‐Liss, Inc.
Gelatin/tannin complex nanospheres via molecular assembly
Authors: Yi Kejing , Cheng Guoxiang , Xing Fubao
Published: June 2006

Nanospheres were produced by molecular assembly between tannin and gelatin because of the synergistic interaction of the hydrophobic effect and hydrogen bonding. The factors that influenced the production of nanospheres, such as sample concentration, mass ratio between tannin and gelatin, reaction temperature, pH, and reaction time, were studied. Moreover, the nanospheres were analyzed and characterized by a particle size analyzer, UV–vis spectrophotometer, and TEM. It was concluded that the critical point was important for the assembled nanospheres. The tannin/protein mass ratio should be lower than the critical point. The concentration of tannin should be confined to a relatively low level. The proper range of the reaction temperatures was usually between 10°C and 50°C. It was steady for nanospheres assembled when the pH value of the gelatin solution was within ±1 IEP of the gelatin. After the reaction had gone on for more than 48 h, the assembled nanospheres became stable. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3125–3130, 2006
Preparation and swelling behavior of macroporous poly(acrylamide‐co‐sodium methacrylate) superabsorbent hydrogels
Authors: Murali Mohan Y. , Keshava Murthy P. S. , Mohana Raju K.
Published: June 2006

Macroporous superabsorbent hydrogels (SAHs) composed of acrylamide (AAm) and sodium methacrylate (NMA) were prepared by aqueous solution polymerization in the presence of a glucose solution. Their swelling capacity was investigated as a function of the concentrations of the glucose solution, sodium methacrylate, crosslinker, initiator, and activator. The porosity of the poly(acrylamide‐co‐sodium methacrylate) superabsorbent hydrogels was confirmed using scanning electron microscopy. The SAHs were characterized by IR spectroscopy. To estimate the effect on the swelling behavior, three types of crosslinkers were employed: N,N′‐methylenebisacrylamide, 1,4‐butanediol diacrylate, and diallyl phthalate. Network structural parameters such as initial swelling rate, swelling rate constant, and maximum equilibrium swelling were evaluated by water absorption measurement. The equilibrium water content (EWC%) of the AAm–NMA macroporous SAHs was found to be in the range of 93.31–99.68, indicating that these SAHs may have applications as biomaterials in the medicinal, pharmaceutical, and veterinary fields. Most of the SAHs prepared in this investigation followed non‐Fickian‐type diffusion, and few followed a case II– or super–case II‐type diffusion. The diffusion coefficients of these macroporous SAHs were investigated. Further, the swelling behavior of these SAHs also was investigated at different pHs and in different salt solutions and simulated biological fluids. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3202–3214, 2006
Curing characteristics and mechanical properties of alkali‐treated grass‐fiber‐filled natural rubber composites and effects of bonding agent
Authors: De Debasish , De Debapriya , Adhikari Basudam
Published: June 2006

To improve adhesion between fiber and matrix, natural rubber was reinforced with a special type of alkali‐treated grass fiber (Cyperus Tegetum Rox b). The cure characteristics and mechanical properties of grass‐fiber‐filled natural rubber composites with different mesh sizes were studied with various fiber loadings. Increasing the amount of fibers resulted in the composites having reduced tensile strength but increased modulus. The better mechanical properties of the 400‐mesh grass‐fiber‐filled natural rubber composite showed that the rubber/fiber interface was improved by the addition of resorcinol formaldehyde latex (RFL) as bonding agent for this particular formulation. The optimum cure time decreased with increases in fiber loading, but there was no appreciable change in scorch time. Although the optimum cure time of vulcanizates having RFL‐treated fibers was higher than that of the other vulcanizates, it decreased with fiber loading in the presence of RFL as the bonding agent. But this value was lower than that of the rubber composite without RFL. Investigation of equilibrium swelling in a hydrocarbon solvent was also carried out. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3151–3160, 2006
Correlations between processing parameters, morphology, and properties of blown films of linear low‐density polyethylene/low‐density polyethylene blends. I. Crystalline biaxial orientation by IR and mechanical properties
Authors: Branciforti M. C. , Pimentel R. , Bernardi A. , Bretas R. E. S.
Published: June 2006

The change of the processing parameters of a blown film operation alters the mechanical and optical properties of the films. This work studied the influence of some of these parameters on the properties of blown films made of blends of linear low‐density polyethylene (LLDPE) and LDPE. Correlations between the crystalline biaxial orientations of these films and the mechanical properties were found. The crystalline biaxial orientation was measured by IR following the Krishnaswamy approach. The a axis of the unit cell was oriented along the machine direction (MD) at all LDPE concentrations, and it was not affected by the blow‐up ratio (BUR). In contrast, the b axis changed its orientation from orthogonal to MD to along the transverse direction (TD), and it was affected by the BUR. Finally, the c axis changed its orientation from equiplanar between the MD and TD to along the thickness of the film, and it was influenced by the BUR. The decrease of the tensile mechanical properties along the MD with the increase in the amount of LDPE in the blends was attributed to the tilting of the c axis toward the film thickness. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3161–3167, 2006
Hydroxybisphosphonate‐containing polymeric drug‐delivery systems designed for targeting into bone tissue
Authors: Hrubý Martin , Etrych Tomáš , Kučka Jan , Forsterová Michaela , Ulbrich Karel
Published: June 2006

The preparation and characterization of a novel polymeric drug‐delivery system designed for bone targeting of antineoplastics is described. The system was based on biocompatible poly[N‐(2‐hydroxypropyl)methacrylamide] carrier containing hydroxybisphosphonate targeting moieties and the model radiotherapeutics 125I or 111In or the anticancer drug doxorubicin. The in vitro binding studies with hydroxyapatite as a bone model proved that the system was efficiently adsorbed on this mineral. The systems contained model drugs bound by stable (amide), hydrolytically cleavable (hydrazone) or enzymatically cleavable (Gly‐Phe‐Leu‐Gly tetrapeptide) spacers. It was proven in vitro that, in the case of cleavable spacers, the drug could be released from the polymer carrier at a rate depending on the pH or enzymatic stimulus. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci: 3192–3201, 2006
Tensile behavior of symmetrical laminates made of PCBA and PMMA layers
Authors: Papadopoulos G. A. , Sideridis E.
Published: June 2006

The stiffness and strength of a composite material in form of laminate is obtained from the properties of the constituent laminae. The stacking sequence of the laminate affects the mechanical behavior. The interface between different laminae is also an important factor, since it influences the stresses that are developed in the laminate, and hence the strengths. In this study, a theoretical investigation of the mechanical behavior of symmetrical laminates made of isotropic layers [Lexan (PCBA) and Plexiglas (PMMA)] was attempted. An analysis based on the lamination theory was performed to determine the stress distribution and strains as well as the elastic constants. Experimental measurements with specimens made of laminates with different stacking sequences were carried out. The obtained values were compared with the theoretical values given by the lamination theory and mechanics of materials approach. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3215–3226, 2006
State of water in chitosan–PVA hydrogel
Authors: Wang Tao , Gunasekaran Sundaram
Published: June 2006

The bound water fraction (XBW) of a newly‐ developed pH‐sensitive, biodegradable chitosan‐polyvinyl alcohol (PVA) hydrogel crosslinked with glutaraldehyde (GA) was investigated as a function of the chitosan/PVA molar ratio, GA concentration (CGA), and ionization state. Differential scanning calorimetry (DSC) was used to determine the XBW of the initial hydrogel, and of the hydrogel equilibrated in pH 3 and pH 7 buffers. Changes in XBW during swelling and shrinking of hydrogel were also investigated. In the initial state of hydrogel, XBW increased with increasing PVA concentration (CPVA), without being significantly affected by CGA. In the buffer‐equilibrated hydrogels, XBW decreased with increasing CPVA and decreasing CGA. The amount of bound water based on dry mass (CBW) was substantially higher when the hydrogel was in the ionized (swollen) state compared to its unionized counterpart. This may be due to the association of a large quantity of water molecules with NH3+ groups of chitosan when the gel swelled in the acidic environment. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3227–3232, 2006
Syntheses of triblock polybutadiene–polydimethylsiloxane copolymers by coupling reactions
Authors: Hetflejš Jiří , Šabata Stanislav , Podešva Jiří , Netopilík Miloš , Látalová Petra , Spěváček Jiří
Published: June 2006

The reaction of epoxy‐telechelic polydimethylsiloxanes with polybutadienyllithium was used to prepare a series of low‐molecular‐weight polybutadiene‐block‐polydimethylsiloxane‐block‐polybutadiene copolymers. The copolymers were purified by repeated fractional precipitation/centrifugation and characterized with NMR, vapor pressure osmometry, size exclusion chromatography, and elemental analysis. The applicability of this method is discussed. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3233–3240, 2006
Effect of chitosan addition to BTCA/CA processed cotton fabrics for adsorbing metallic ions from waste water
Authors: Hsieh Sung Huang , Lin En Shang , Wei Hsueh Chou
Published: June 2006

One of the most important properties of chitosan, a derivative of chitin, is that it is able to chelate with certain heavy metal ions, and this property can be applied to process waste water containing heavy metal ions. In this research, using BTCA/CA as a crosslinking reagent with chitosan added, cotton fabrics were cured and allowed to undergo an adsorption reaction in CuSO4 and ZnSO4 solutions. The effect of different curing temperatures and time, as well as different adsorptive temperatures and time, were studied. The cotton processed fabrics were analyzed by Fourier transform infrared analysis (FTIR), scanning electronic microscope (SEM), and thermal gravity analysis (TGA) to study the crosslinking reaction with the cotton‐processed fabrics. The results indicate: (1) the BTCA/CA‐processed cotton fabrics with an addition of chitosan have a better adsorptive capacity than the processed fabrics without chitosan; (2) the crosslinked fabrics are better in adsorbing copper ions as chitosan concentration, curing temperature and time, and adsorptive temperature and time increase; (3) the adsorption rate of copper and zinc ions are linearly proportional to the changes of time, so that the slope shows that the adsorption rate of crosslinked fabrics for copper ions is faster than for zinc ions. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3264–3269, 2006
Influence of the nigrosine dye on the thermal behavior of polyamide 66
Authors: Sukata Kazuaki , Takeuchi Hiroshi , Shimada Masayuki , Agari Yasuyuki
Published: June 2006

To reveal the effect of the nigrosine dye, that the addition of the dye lowers the crystallization point (Tc) of molten polyamide resins with substantially no shift in the melting point (Tm), thus suppressing the crystallization enhancement of the crystalline nucleation agents, the characteristics of polyamide 66 (PA‐66) containing nigrosine dye EX (N‐EX) were investigated. Differential scanning calorimetry (DSC) analysis showed that the addition of N‐EX reduced the crystallization rate and Tc of molten PA‐66 with substantially no shift in Tm, and the crystallization enthalpy per unit of weight of PA‐66 was substantially constant. Tc of molten PA‐66 was lowered with an increase in the amount of N‐EX and reached its maximum at 13 wt % N‐EX. Dynamic mechanical analysis showed that the glass‐transition temperature and the secondary glass‐transition temperature increased with an increasing amount of the dye. On the other hand, the DSC and X‐ray diffraction results indicated that no dye molecule was present in the crystal structure of PA‐66. This effect of the nigrosine dye on PA‐66 is in contrast to those of crystalline nucleation agents, plasticizers, and antiplasticizers. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3270–3274, 2006
Improvement of optical quality and vibration characteristics of injection molded disk with processing condition control
Authors: Nam Ji‐Geun , Sin Hyo‐Chol , Na Sang‐Sik
Published: June 2006

Increased application of optical disks has required a rotating disk with more dynamic stability and better optical quality. A new concept of controlling the processing condition of injection molded disks is developed to improve their optical quality and vibration characteristics. To assess the effect of process conditions on residual stresses, birefringence, and critical speed, an orthogonal array for design of experiments is used. Melt temperature, filling speed, and packing pressure were effective parameters, but mold temperature and interactions among process conditions were not. The birefringence and critical speed were affected by the residual stress distribution, which varied according to the distance from the gate and processing condition. Considering the effect of the processing conditions and distance from the gate, we calculated the weight factors on residual stresses along the radial direction. Choosing weighted stress to be the target value for optimization of residual stresses, processing conditions control was accomplished. Under the newly proposed conditions, optical quality and stability of injection molded disk were simultaneously improved. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3275–3285, 2006
Assembly of polyelectrolyte multilayers on nylon fibers
Authors: Dubas Stephan T. , Limsavarn Luxsana , Iamsamai Chularat , Potiyaraj Pranut
Published: June 2006

Non‐woven nylon fibers were investigated as a new type of substrate for the deposition of polyelectrolyte multilayers (PEM) thin films. PEM assembled from cationic poly(diallyldimethylammonium chloride) PDADMAC, and anionic Scarlet dye (λmax absorbance = 510 nm) were deposited directly on Nylon fibers and characterized using a reflectometer spectrophotometer. Evidences of the film assembly are presented as well as a study of the factors controlling the growth of the PDAMAC/dye PEM film on the fiber. The relation between the sorption coefficient (K) and the scattering (S) extracted from the reflectance data is commonly used to represent the dye fixation or the dye content of a given textile fiber. The increase in K/S value at 510 nm was correlated with the dye deposition and was found to increase linearly with the number of layers. The effect of increasing number of layers, ionic strength of the solutions, concentration of chemicals, and dipping time on the film growth was investigated. Our results show that while increase in dye and PDADMAC concentrations from 0 to 1 mM enhance the deposition process, further increase in PDADMAC concentration to 50 mM led to a decrease in K/S value. The optimum salt concentration for the PDAMAC/dye film growth was found to be 0.5M and dipping times as short as 15 s were found to be sufficient for the deposition of the PEM. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3286–3290, 2006
Mechanical properties of injection‐molded isotactic polypropylene/roselle fiber composites
Authors: Junkasem Jirawut , Menges James , Supaphol Pitt
Published: June 2006

Natural fiber‐thermoplastic composite materials, based on their cost‐effectiveness and environmental friendliness, have attracted much interest both scientifically and technologically in recent years. Other advantages of natural fibers are good specific strength, less abrasion, and less irritation upon inhalation (in comparison with some common inorganic fillers). In the present contribution, roselle (Hibiscus sabdariffa L.) fibers were chosen and used as reinforcing fillers for isotactic polypropylene (iPP) for the first time, due mainly to the cost‐effectiveness and natural abundance on Thai soil. Processibility and mechanical properties of the resulting composites were investigated against the type and the mean size of the fibers. The results showed that the highest mechanical properties were observed when roselle bast fibers were incorporated. When whole‐stalk (WS) fibers (i.e., the weight ratio of bast and core fibers was 40 : 60 w/w) were used, moderate mechanical properties of the resulting composites were realized. The optimal contents of the WS fibers and the maleic anhydride‐grafted iPP compatibilizer that resulted in an improvement in some of the mechanical properties of the resulting composites were 40 and 7 wt %, respectively. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3291–3300, 2006
Surface free energy analysis of poly(HEMA)‐poly(perfluoroacrylate) copolymer networks
Authors: Eroğlu Mehmet S.
Published: June 2006

Copolymer networks of 2‐hydroxyethylmethacrylate (HEMA) and 2‐(N‐ethyl perfluorooctane sulfonamido)ethyl acrylate (FOSEA) were prepared by free‐radical polymerization. Ethylene glycol dimethacrylate (EGDM) was used as crosslinker and 2,2′‐azobisisobutyronitrile (AIBN) was used as radical initiator. HEMA/FOSEA ratio of the copolymer networks changed from 50/1 to 10/1 (mol/mol). The contact angles of water, ethylene glycol, glycerin, diiodomethane, paraffin, and formamide were measured on copolymer surfaces and results were evaluated in term of surface free energy components using van Oss–Good methodology. It was determined that the Lifshits–van der Waals component (γ) and total surface tension (γ) of networks decreased drastically with the increase of the FOSEA content. However, the electron donor and acceptor components of the surface free energy did not differ that much. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3343–3347, 2006
Gas barrier changes and structural alterations induced by retorting in a high barrier aliphatic polyketone terpolymer
Authors: Lopez‐Rubio A. , Giménez E. , Gavara R. , Lagaron J.M.
Published: June 2006

Analysis of the consequences of a typical humid thermal plastic food packaging sterilization (retorting) process over the crystalline morphology and gas barrier properties of a high barrier aliphatic polyketone terpolymer was carried out by in situ simultaneous synchrotron WAXS and SAXS experiments an by DSC, ATR‐FTIR spectroscopy, and oxygen transmission rate measurements. From a structural view point, it was observed that the retorting process led to a less crystalline material; however, crystallinity was fully restored by a postdrying process. The humid thermal treatment also favored the sorption of moisture in the amorphous phase to a saturation level, i.e., 2% water uptake. As a result, the oxygen permeability at 21°C was observed to increase by about nine times immediately after the humid treatment, but the barrier character was observed to quickly recover over time. From the results, it is suggested that a simple postdrying process at moderate temperatures can restore morphology and barrier properties. In the overall, it is also suggested that aliphatic polyketones withstand far better the process of retorting in comparison with, for instance, other high barrier polymers such as ethylene‐vinyl alcohol copolymers reported earlier and can therefore offer even as a monolayer an alternative in retortable food‐packaging applications. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3348–3356, 2006
Rheological properties and foam processibility of precured EPDM
Authors: Wang Biqin , Peng Zonglin , Zhang Yong , Zhang Yinxi
Published: June 2006

EPDM foam was prepared by dynamically vulcanizing EPDM compound in a HAAKE rheometer firstly, then mixing the partially precured EPDM compound with a blowing agent and a sulfur vulcanizing system on a two roll mill. The compound was extruded through a cold feed extruder, and the extrudate was foamed in a circulating hot air oven. EPDM compound was vulcanized partly in the HAAKE rheometer, the final torque increases with increasing sulfur content. Rheological measurement shows the dynamic storage modulus, the loss modulus, and the complex viscosity of precured EPDM compound increase with increasing sulfur content. Then the partially precured EPDM compound was compounded with a blowing agent and a sulfur vulcanizing systems, Rheometric measurement shows that the rate of vulcanization of partially precured EPDM compound is not affected by the precure. The blowing results show that the foam processibility could be improved and the expansion ratio increases in the same processing condition for optimum partially precured EPDM compound, which indicates the optimum crosslink density for EPDM could enhance the efficiency of blowing agent AC. SEM shows that the foam articles have a closed‐cell structure with few open cells, and the large cells inlay among the small cells. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3387–3394, 2006
CaCO3/natural rubber latex nanometer composite and its properties
Authors: Deng Chun‐Mei , Chen Mei , Ao Ning‐Jian , Yan Dan , Zheng Zhong‐Qian
Published: June 2006

Calcium carbonate/natural rubber (NR) latex nanometer composites were prepared by adding nanometer CaCO3 whose surface had been treated to natural rubber latex (NRL) before sulfuration. The physical, thermooxidative aging, and thermal degradation properties and the ultra‐microstructure were analyzed with a multipurpose material testing meter, a thermal analysis meter and a Philips XL‐30 SEM, respectively. The results showed that the structures and properties of nanometer composites could be clearly improved by NRL mixed with surface‐treated nanometer CaCO3. The physical properties of the nanometer composites were best when the content of surface treatment agent was 2.5% (to nanometer CaCO3), the nanometer CaCO3/NRL content was 3:100, and the stirring time for treating the surface of the nanometer CaCO3 was 20 min. Simultaneously, the thermooxidative aging resistance of the nanometer composites also was significantly improved. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3442–3447, 2006
Biocidal hydantoinylsiloxane polymers. IV. N‐halamine siloxane‐functionalized silica gel
Authors: Liang J. , Owens J. R. , Huang T. S. , Worley S. D.
Published: June 2006

The monomer 5,5‐dimethyl‐3‐(3′‐triethoxysilylpropyl)hydantoin and its hydrolysis product polymer poly[3‐(5,5‐dimethylhydantoinylpropyl)hydroxysiloxane] were employed to functionalize the surfaces of silica gel particles in order to produce an adhered film that becomes biocidal upon chlorination with dilute sodium hypochlorite bleach. The biocidal efficacy of the functionalized silica gel was demonstrated in a cartridge filter experiment against the bacterial pathogens Staphylococcus aureus and Escherichia coli O157:H7. Complete 6 log inactivations of the two bacterial species were observed within 30 s of contact. Moreover, upon loss of biocidal activity due to depletion of bound chlorine, the coated silica gel particles could be recharged by further exposure to dilute bleach. Potential uses of the biocidal silica gel include disinfection and odor control in water treatment facilities and recirculating baths. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3448–3454, 2006
Ammonia‐gas and liquid ammonia treatments of silk fabric
Authors: Lee Myung Sun , Lee Muncheul , Tokuyama Takako , Wakida Tomiji , Inoue Goichi , Ishida Shinzo
Published: June 2006

Silk fabric, Habutae, was treated with 100% ammonia‐gas under atmospheric pressure and at pressures of 2, 4, and 6 kgf/cm2, and with liquid ammonia at −33°C. The effects of the treatment were investigated on the basis of the X‐ray diffraction, DSC thermogram, moisture regain, water absorption, dyeing property, and mechanical property of the fabric. Crystallinity and equilibrium dye uptake were increased apparently by the liquid ammonia treatment, whereas effect of the ammonia‐gas treatment was less than the liquid ammonia treatment. KES (Kawabata Evaluation System) shearing, bending, and tensile parameters were obtained. The modulus G, B, and hysteresis widths 2HG, 2HG5, and 2HB were decreased with the ammonia‐gas treatment. On the contrary, the liquid ammonia treatment increased the parameters considerably. Therefore, it seemed that the ammonia‐gas treatment is effective in enhancing the soft hand of the silk fabric. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3487–3492, 2006
Curing of epoxy resin using imide‐amines
Authors: Sharma Pooja , Choudhary Veena , Narula A. K.
Published: June 2006

The curing behavior of diglycidyl ether of bisphenol‐A (DGEBA) was investigated by differential scanning calorimetry, using varying molar ratios of imide‐amines and 4,4′‐diaminodiphenyl sulfone (DDS). The imide‐amines were prepared by reacting 1 mol of pyromellitic dianhydride (P) with excess (2.5 mol) of 4,4′‐diaminodiphenyl ether (E), 4,4′‐diaminodiphenyl methane (M), or 4,4′‐diaminodiphenyl sulfone (S) and designated as PE, PM, PS. Structural characterization was done using FTIR, 1H NMR, 13C NMR spectroscopic techniques and elemental analysis. The mixture of imide‐amines and DDS at ratio of 0 : 1, 0.25 : 0.75, 0.5 : 0.5, 0.75 : 0.25, and 1 : 0 were used to investigate the curing behavior of DGEBA. The multiple heating rate method (5, 10, 15, and 20°C/min) was used to study the curing kinetics of epoxy resins. The peak exotherm temperature was found to be dependent on the heating rate, structure of imide‐amine, and also on the ratio of imide‐amine : DDS used. Activation energy was highest in case of epoxy cured using a mixture of DDS : imide‐amine of a ratio of 0.75 : 0.25. Thermal stability of the isothermally cured resins was also evaluated in a nitrogen atmosphere using dynamic thermogravimetry. The char yield was highest in case of resins cured using mixture of DDS : PS (0.25 : 0.75; EPS‐3), DDS : PM (0.25 : 0.75; EPM‐3), and DDS : PE (0.75 : 0.25; EPE‐1). © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3502–3510, 2006
The swelling behavior of interpenetrating polymer networks composed of polyurethane and unsaturated polyester
Authors: Król Piotr , Wojturska Joanna
Published: June 2006

The kinetics of swelling and the sorption performance were observed for the polymer compositions with interpenetrating polymer networks made up of polyurethane and unsaturated polyester during their exposure to chlorobenzene at 25°C. It was found that the rates for solvent transport and solvent absorption processes were controlled by the chemical composition of the formulation studied. On the basis of the observed swelling process, parameters could be assessed which were specific for the mass transfer process, i.e., diffusion coefficient, sorption coefficient, and permeability coefficient. Moreover, an attempt was made to evaluate structural parameters that describe topology of the obtained networks. It was found that the increasing share of polyurethane in the composition reduced crosslinking density in the polyester network that resulted in faster diffusion of the solvent and higher sorption capacity for the solvent. The higher the styrene content in the composition, the higher the crosslinking density in the system, and hence the diffusion of solvent and its sorption inside the polymer network was much more difficult. In the scanning electron microscope analysis of samples, which had been subjected to swelling, no leaching was observed for any phase present in the system, despite phase separation for both the components. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3511–3519, 2006
Electrical/mechanical properties and activation energies of some poly(2‐vinylpyridine)‐metal complexes
Authors: Dimitry O. I. H. , Mazrouaa A. M. , Saad A. L. G.
Published: June 2006

Poly(2‐vinylpyridine) (P2VP) and its metal‐based complexes have been synthesized and characterized through analytical measurements, such as thermal analysis and IR‐ spectroscopy. The electrical conductivity of these complexes was studied as a function of temperature. The conductivity of P2VP is seen to increase by many orders of magnitude on complexation with some metal chlorides such as BaCl2, ZnCl2, NiCl2, or CoCl2. The activation energy for electrical conductivity of either of these complexes is found to be lower than that of the host polymer. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3537–3549, 2006
Suspension copolymerization of styrene and divinylbenzene: Formation of beads
Authors: Gupta D. C. , Beldar A. G. , Tank R.
Published: June 2006

Suspension copolymerization of styrene and divinylbenzene (DVB) was carried out using benzoyl peroxide as initiator and magnesium hydroxide as suspending agent in water at 80°C under nitrogen atmosphere to produce styrene–DVB copolymer beads. These beads were characterized by infrared spectroscopy, thermal gravimetric analysis, and scanning electron microscopy. Porosity generated in styrene–DVB copolymer beads by incorporation of solvents in the polymerization system was confirmed by SEM micrograph, apparent density, swelling measurements, and Brunauer, Emmett, Teller surface area. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3559–3563, 2006
A novel soft and cotton‐like chitosan‐sugar nanoscaffold
Authors: Phongying Sasiprapha , Aiba Sei‐ichi , Chirachanchai Suwabun
Published: June 2006

A novel type of chitosan nanoscaffold with a soft and cotton‐like appearance is proposed. The key to success is based on two points: (i) the change in morphology of chitin whisker to chitosan nanoscaffold and (ii) the surface modification of the nanoscaffold chitosan with a sugar unit. Simple deacetylation of chitin whisker gives a colloidal solution of chitosan, of which the chitosan is in a nanoscaled scaffold. Surface functionalization of the chitosan nanoscaffold with lactose or maltose via a heterogeneous system in water at room temperature results in a soft and cotton‐like chitosan containing mesopores. As all steps are organic solvent free, this chitosan–sugar nanoscaffold might be a promising material for biopolymer‐supported tissue engineering. © 2006 Wiley Periodicals, Inc. Biopolymers 83:280–288, 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
Morphometric study of the human metatarsals and phalanges
Authors: Dogan Ali , Uslu Mustafa , Aydinlioglu Atif , Harman Mustafa , Akpinar Fuat
Published: June 2006

Mathematical relation between metatarsals and between phalanges in terms of their lengths and widths in themselves is considered to be significant with respect to its functional and aesthetic roles. The objective of this study is to conduct measurements for determining lengths and widths of metatarsals and phalanges on the foot radiographs and to determine possible mathematical correlations between metatarsals themselves and between phalanges themselves in terms of their lengths and widths. Anteroposterior right and left foot radiographs were taken from 100 volunteers (50 men and 50 women). Lengths and widths of the metatarsals and phalanges were measured in millimeter on radiographs. The mean, minimum and maximum values, and standard deviations of each bone's length and width were studied and data were put into formulation. The results were evaluated by Regression statistical test, and the relation between metatarsals and between phalanges in terms of their lengths and widths was studied. As a result of the measurements, we found fixed proportions between metatarsals in themselves and between phalanges in themselves in terms of their lengths and widths. Knowing these morphometric relations may be useful for performing any surgical procedures designed to manage any defects or imperfections of the foot, chief among them is shortness. Clin. Anat. 20:209–214, 2007. © 2006 Wiley‐Liss, Inc.
The contributions of the Bartholin family to the study and practice of clinical anatomy
Authors: Hill Robert V.
Published: June 2006

Between 1585 and 1738, four members of the celebrated Bartholin family made significant contributions to anatomical science and medicine. Caspar Bartholin (the elder), two of his sons (Thomas and Rasmus), and his grandson (Caspar the younger) all served on the medical faculty of the University of Copenhagen, and helped to gain international acclaim for the institution. Over three generations, the Bartholins challenged traditional ideas about science and the human body, and discovered anatomical structures and phenomena that would prove crucial to the practice of modern medicine. Clin. Anat. 20:113–115, 2007. © 2006 Wiley‐Liss, Inc.
The impact of alternating dissection on student performance in a medical anatomy course: Are dissection videos an effective substitute for actual dissection?
Authors: Granger Noelle A. , Calleson Diane
Published: June 2006

The way in which anatomy is taught to first year medical students at the University of North Carolina at Chapel Hill was recently changed, so that first year students are now divided into two groups that dissect alternately. The effect of this change on both written and practical test performance was analyzed by comparing grades from 2004 with those from the previous year (2003), when students performed all the dissections. A statistically significant decrease (P ≤ 0.05) from 2003 was noted on three of the four written test scores in 2004, while practical examination scores in 2004 fluctuated from lower to higher than those in 2003, depending on the unit of material being covered. However, the number of students failing each of the examinations (written and practical combined) was statistically greater on only one of the four examinations in 2004. Scores of the two groups dissecting alternately in 2004 were essentially the same on the practical examinations. There was no difference in the number of questions answered incorrectly between these two groups in the two practical examinations where comparisons were made. Furthermore, students who dissected a particular structure did not score significantly better on practical questions concerning that structure than students who had not dissected it. The effect of the availability of step‐by‐step dissection videos on student practical examination scores is also discussed. We conclude that the change in the curriculum had a significant impact on the students' written examination performance, given the same material in the course. The reasons for this include student course load, increased need for self‐study, and a loss of a learning opportunity in the dissection laboratory, all of which affect student comprehension and retention of the material and their ability to use it in problem solving. Clin. Anat. 20:315–321, 2007. © 2006 Wiley‐Liss, Inc.
Superficial temporal artery as an external landmark for deeper‐lying brain structures
Authors: Tubbs R. Shane , O'Neil James T. , Key Christopher D. , Zarzour Jessica G. , Fulghum Sarah B. , Kim Eugenia J. , Lyerly Michael , Shoja Mohammadali M. , Salter E. George , Oakes W. Jerry
Published: June 2006

Additional localizing superficial landmarks for intracranial structures can be of use to the neurosurgeon. This study was performed to evaluate the usefulness of the superficial temporal artery (STA) as an external landmark for deeper brain structures. Thirteen adult cadavers (26 sides) underwent latex injection of their STA bilaterally. Dissections were next carried out to identify this vessel. Once the STA and its frontal and parietal branches were skeletonized, craniectomies were performed and the underlying dura mater excised. Measurements were made between the frontal and parietal branches of the STA and deeper brain structures. The STA was found to branch on average 3 cm superior to the tragus. The bifurcation of the STA was found to commonly bifurcate at the level of the floor of the middle cranial fossa or superior temporal gyrus. The Sylvian fissure was found at a mean of 2 cm superior to the STA bifurcation. The angle between the frontal branch of the STA and the zygomatic arch had a mean of 37°. The angle between the frontal and parietal branches of the STA had a mean of 87°. At the level of the glabella, the frontal branch of the STA was on average 3 cm posterior to the frontal pole. The temporal tip was located a mean of 3.2 cm anterior to the frontal branch of the STA. The plane of the foramen of Monro was found to lie at a mean distance of 2.3 cm posterior to the frontal branch of the STA. The parietal branch of the STA was noted to travel more or less parallel with the central sulcus in all specimens and to travel an average of 2 cm posterior to this sulcus. At the level of the lateral attachment of the tentorium cerebelli, the parietal branch of the STA was found to travel a mean of 4.8 cm anterior to the entrance of the vein of Labbé into the transverse sinus. The parietal branch of the STA was also found to travel a mean of 4.2 cm anterior to the angular gyrus and 3.9 cm anterior to the supramarginal gyrus. Palpation or Doppler identification of the STA and its branches with subsequent mapping on the lateral cranium may prove useful as an additional superficial landmark for the neurosurgeon. Clin. Anat. 20:498–501, 2007. © 2006 Wiley‐Liss, Inc.
Persistence of embryonic pattern of hepatocaval venous junction and patent ductus venosus in Budd‐Chiari syndrome
Authors: Macchi V. , Porzionato A. , Tiengo C. , Parenti A. , De Caro R.
Published: June 2006

We report an autopsy study on a case of Budd‐Chiari syndrome (BCS) in a 44‐year‐old woman. Dissection showed that the outlets of the right hepatic vein (HV) and of the common trunk of the middle and left HVs appeared as two small depressed areas with narrow ostia. Histological examination showed recent thrombosis of the tributaries of the HVs and centrilobular congestion with necrosis of the hepatic parenchyma. The juxtacaval portions of the major HVs showed a cuneiform shape, because of marked dilation, with thread‐like ostia, and multiple small outlets of minor hepatic veins were also present. The coexistence of patent ductus venosus may have prevented the development of the hepatocaval venous junction, with persistence of the embryonic pattern, composed of multiple small channels draining into the right hepatocardiac channel. The unusual hepatocaval venous junction may have predisposed to thrombosis of the HVs, causing BCS. Clin. Anat. 19:673–677, 2006. © 2006 Wiley‐Liss, Inc.
Anatomical variations of the cords of brachial plexus and the median nerve
Authors: Pandey S.K. , Shukla V.K.
Published: June 2006

The variations in formation, location, and courses of the cords of brachial plexus and the median nerve were studied in both axillae of 172 cadavers. The total prevalence of variation was 12.8% (CI, 7.6–17.4) and it was found in 13.2% (CI, 7.5–18) of male and in 10.7% (CI, −0.6–19.6) of female cadavers. These variations were divided into three groups. The first group was abnormal location of the cords, which was either posterolateral or anteromedial in relation to the axillary artery in 2.3% (CI, 0.1–4.5) cadavers. The lateral cord and the medial root of the median nerve had received communicating branches from the posterior cord in most of the cases of this group. The second group was absence of the posterior cord in 3.5% (CI, 0.7–6.1) of cadavers. The lateral and medial cords of this group were connected with the communicating branches, which had a course in front of the axillary artery. The third group was abnormal formation and course of the median nerve in 7% (CI, 3.1–10.6) of cadavers. In all cases of this group the medial root received communicating branch/branches either from the lateral or posterior cord. In eight (4.7%) cadavers, both roots of the median nerve were joined on medial side of the axillary artery to form a median nerve, which traveled medial to the artery. In four (2.3%) cadavers the roots of the median nerve did not join and both traveled separately anteromedial to the axillary and brachial arteries. This study indicates that all three cords and median nerve vary considerably in levels of origin, location and course in relation to the axillary artery and these variable cases were joined with the communicating branch/branches. The observed variations are of anatomical and clinical interest. These kinds of variations are more prone to injury in radical neck dissection and in other surgical operation of the axilla. Clin. Anat. 20:150–156, 2007. © 2006 Wiley‐Liss, Inc.
Ligands for Molecular Imaging: The Synthesis of Bis(thiosemicarbazone) Ligands
Authors: Christlieb Martin , Dilworth Jonathan R.
Published: June 2006

Bis(thiosemicarbazones) have been of interest to chemists for over fifty years; they display antitumour, antibiotic and antiviral properties. Recently it has become apparent that they may also provide a convenient way of labelling biologically active molecules by using metallic radionuclides and/or fluorescence. Although apparently simple, the synthesis of bis(thiosemicarbazone) ligands can be problematic. This article provides a summary of the published literature, based on the synthetic strategies used and indicates some of the difficulties that may arise.