bluuebunny/crossref_metadata_2025 huggingface dataset:
Structure and properties of fully aromatic thermotropic liquid‐crystalline copolyesters containing m‐hydroxybenzoic acid units
Authors: Yerlikaya Zekeriya , Aksoy Serpil , Bayramli Erdal
Published: October 2003

A series of fully aromatic copolyesters based on p‐acetoxybenzoic acid (p‐ABA), hydroquinone diacetate (HQDA), terephthalic acid (TPA), and m‐acetoxybenzoic acid (m‐ABA) were prepared by a modified melt‐polycondensation reaction. The copolyesters were prepared in two series in which series I is based on a two monomer system (p‐ABA/m‐ABA) and series II is based on a three monomer system (HQDA/TPA/m‐ABA). The effect of different linear structures and kink moiety on the properties of the copolyesters were investigated systematically. The copolyesters were characterized by differential scanning calorimetry, thermogravimetric analysis, 1H‐NMR, polarized optical microscopy, X‐ray diffraction, and intrinsic viscosity measurements. It was found that the copolyesters exhibited nematic liquid‐crystalline phases when the content of linear (p‐ABA or HQDA/TPA) units was over 67 mol %. The melting or flow‐transition temperatures were decreased with an increase of the content of kink m‐ABA units. The copolyesters that contained p‐ABA as linear units had a significantly higher degree of crystallinity compared to the copolyesters that contain HQDA/TPA as the linear units, implying a higher blockiness in the polymer chains as a result of the higher reactivity of the p‐ABA units in the p‐ABA/m‐ABA system. All the copolyesters had poor solubility except the copolyesters containing at least 40 mol % of m‐ABA, which were soluble in a dichloromethane/trifloroacetic acid (70:30 v/v) mixture. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3260–3269, 2003
Energy absorption in glass‐reinforced continuous strand mat composites
Authors: Jacob George C. , Starbuck J. Michael , Simunovic Srdan , Fellers John F.
Published: October 2003

A unique test fixture was developed for determining the energy‐absorbing mechanisms in automotive composite material systems. The objective of the test method was to quantify the energy absorption and identify the failure mechanisms associated with the observed frond formation in progressive crush testing of composite tubes by testing less costly composite plates under progressive crush load conditions. Quasi‐static progressive crush tests were performed on glass/polyurethane continuous strand mat (CSM) composite plate specimens. The effect of various test parameters on energy absorption was evaluated by varying the following parameters during testing: the loading rate, profile radius, and profile constraint condition. The experimental data in conjunction with the test observations were used to develop analytical models for predicting the crashworthiness of automotive composite structures. The crushing process and the load‐deflection curves were similar to the progressive crushing of tubes. Modification of the basic specimen geometry was required when testing material systems that have low axial stiffness to prevent a global buckling mode. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3222–3232, 2003
Mechanical properties of an epoxy resin toughened by polyester
Authors: Cao Youming , Shao Yuefeng , Sun Jun , Lin Shang'An
Published: October 2003

The epoxy resins were toughened by 4–24 phr polyester with average molecular weight 1.9×104 g/mol in this investigation. The mechanical properties were examined and dynamic mechanics analyses were performed for the epoxy resins before and after the modification. The toughening mechanism of polyester to epoxy resin is discussed in light of the scanning electronic microscopy observation of the fracture surfaces. The results showed that the impact strength and tensile strength of the modified epoxy resin were remarkably greater than those of the unmodified cured epoxy resin. The most suitable composition for the modified epoxy resin was the addition of 16 phr polyester, which led to 138 and 46% increments in the impact strength and the tensile strength, respectively. And the mechanical properties depended greatly on the congregating state of polyester added. The polyester dispersing in the epoxy matrix was amorphous when its addition was less than or equal to 12 phr, and was sphere crystals when the addition was over 16 phr. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3384–3389, 2003
Influence of previous annealing on first stage of degradation of blends of low‐density polyethylene and Mater‐Bi AF05H aged in soil: Comparative thermal analysis study
Authors: Vallés‐Lluch A. , Contat‐Rodrigo L. , Ribes‐Greus A.
Published: October 2003

Samples of low‐density polyethylene (LDPE) filled with a commercial biodegradable material (Mater‐Bi AF05H) were subjected to an accelerated soil burial test in a culture oven. In addition, another series of these blends was subjected to thermal treatment and afterward buried in soil under the same conditions. Comparative studies of the changes in the thermal stability and the structural and morphological properties of the samples were carried out by means of differential scanning calorimetry, dynamic mechanical thermal analysis, and thermogravimetric analysis. The morphological properties under study were the melting temperature, the crystalline content, and the lamellar thickness distribution. The αI relaxation zone of the mechanical spectra was characterized in terms of tan δ, whereas the αII and relaxation zones were characterized in terms of E″ according to the Fuoss–Kirkwood equation and with the help of a deconvolution method. Finally, the kinetics of each thermodegradation process was studied using the Broido integral method. The Mater‐Bi hindered the uniform growth of crystallites in PE and facilitate molecular motions, but the thermal treatment seemed to rearrange the crystallites in the crystalline phase of PE and promote segregation of the crystallite sizes. These molecular reorganizations affected the degradation process so that the degradation of the polymeric matrix seemed to be obstructed by the annealing during the first 120 days of aging in soil and only the Mater‐Bi degradation could be observed. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3359–3373, 2003
Studies on novel binary accelerator system in sulfur vulcanization of natural rubber
Authors: Marykutty C. V. , Mathew G. , Mathew E. J. , Thomas Sabu
Published: October 2003

The synergistic activity of binary accelerator systems in rubber vulcanization is well known. Binary accelerator systems are being widely used in industry and are becoming increasingly popular because of the fact that such mixed systems can effectively prevent prevulcanization, permit the vulcanization to be carried out at a lower temperature in a shorter time, and produce a vulcanizate with superior mechanical properties compared to those of a stock cured with a single accelerator. Thiourea and its derivatives are important secondary accelerators in this context. It is suggested that thiourea containing binary accelerator systems cause rubber vulcanization to proceed by a nucleophilic reaction mechanism. In the present study 1‐phenyl‐5‐ortho, ‐meta, and ‐para‐tolyl derivatives of 2,4‐dithiobiurets, which are more nucleophilic than thiourea and vary in their nucleophilic reactivity, are used as secondary accelerators along with 2‐morpholinothiobenzothiazole in the vulcanization of natural rubber. The results show an appreciable reduction in the cure time for the mixes containing the dithiobiurets compared to the reference mix. These results are indicative of a nucleophilic reaction mechanism in the vulcanization reaction under consideration. These vulcanizates also demonstrate comparatively better tensile properties and good retention of these properties after aging. An attempt is also made to correlate the variation in physical properties to chemical crosslink formation in the various vulcanizates. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3173–3182, 2003
Morphology and stress relaxation in oriented polyolefin shrink films
Authors: Bobovitch Arthur , Gutman Emmanuel , Henning Sven , Michler Goerg H.
Published: October 2003

Morphology and stress relaxation of oriented polyolefin films has been studied. The influence of orientation on morphology of the films has been investigated using X‐ray, DSC, and TEM. The relaxation time spectrum of oriented films has been investigated. It was shown that relaxation time spectrum of composite film can be predicted if one knows the relaxation time spectrum of each component in the film. An influence of irradiation on relaxation behavior of polyethylene film was shown as well. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3424–3429, 2003
Preparation and properties of cellulose/chitin blend fiber
Authors: Pang Feng‐Jian , He Chun‐Ju , Wang Qing‐Rui
Published: October 2003

The blend solution of cellulose xanthate with chitin xanthate has excellent filtering property as an ordinary cellulose viscose. The SEM photos show that the fiber surface becomes coarse with increasing chitin content. The X‐ray diffraction shows that the addition of chitin interferes with the crystallization of cellulose. The dry and wet strength and density of blend fibers decrease with increasing chitin content. The hygroscopicity of the blend staples decreases with increasing chitin content, and there exists a minimum at 3.85% chitin mass percent, while the accessibility shows the same tendency. The fiber prepared has effective bacteriostatic effects on Staphylococcus aureus, Escherchia coli, etc., and the bacteriostastic rate increases with increasing chitin content. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3430–3436, 2003
Kinetics and thermodynamics of hydrolytic depolymerization of poly(ethylene terephthalate) at high pressure and temperature
Authors: Mishra S. , Zope V. S. , Goje A. S.
Published: October 2003

Hydrolytic depolymerization of PET (polyethylene terephthalate) waste in excess of water was studied using a 0.5‐L stirred high‐pressure autoclave at temperatures of 100, 150, 200, and 250°C and at 200, 300, 400, 500, 700, and 800 psi (pounds per square inch) pressure. Velocity constants of hydrolysis were calculated from the experimental data obtained. Maximum depolymerization (91.38%) of PET into monomer was obtained at 250°C and 800 psi. pressure. However, the maximum rate of reaction was recorded at 200°C and 500 psi temperature and pressure, respectively. The energy of activation and frequency factor were calculated, as 64.13 KJ/g mol and 7.336 × 104 min−1, respectively, for higher pressure and temperature conditions. It was also reported that the hydrolytic depolymerization is first order with the velocity constant 1.773 × 10−2 min−1 at 250°C. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3305–3309, 2003
Glycolytic aminolysis of poly(ethylene terephthalate) waste for recovery of value‐added comonomer at atmospheric pressure
Authors: Goje A. S. , Thakur S. A. , Patil Tushar M. , Mishra S.
Published: October 2003

Reaction of poly(ethylene terephthalate) waste (PETW) powder with ethylene glycol (EG) using 0.003 mol lead acetate as a catalyst was carried out in a batch reactor at 470 K under atmospheric pressure. Reactions were undertaken with various particle sizes ranging from 50 to 512.5 μm and reaction times ranging from 10 to 60 min at 10‐min intervals. A low molecular weight product of PETW was obtained using this reaction. Then hydrazine monohydrate, chlorobenzene, and cyclohexylamine (CHA) were introduced to convert the low molecular weight product of PETW into terephthalohydrazide (TPHD). To increase the PETW conversion rate, an external catalyst (lead acetate) was introduced during the reaction. The reaction product was deposited onto the surface of unreacted PETW that was removed from the surface by introducing dimethyl sulfoxide. To accelerate the reaction rate CHA was introduced during the second stage of reaction, which has industrial significance. Depolymerization of PETW was proportional to the reaction time and inversely proportional to the particle size of PETW. Analyses of value‐added products (TPHD and EG) as well as PETW were undertaken. A kinetic model was developed and experimental data were simulated consistent with the model. A thermodynamic study was undertaken because this is required during the transfer of laboratory data through the pilot plant for commercialization. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3437–3444, 2003
Miscibility in crystalline polymer blends: Isotactic polypropylene and linear low‐density polyethylene
Authors: Gorrasi Giuliana , Pucciariello Rachele , Villani Vincenzo , Vittoria Vittoria , Belviso Sandra
Published: October 2003

The phase behavior and the crystallization kinetics of blends composed of isotactic polypropylene (iPP) and linear low‐density polyethylene (LLDPE) were investigated by differential scanning calorimetry. The phase behavior indicates the formation of separate crystals of iPP and LLDPE at each investigated blend composition. The crystallization trace reveals that iPP crystallizes in its normal range of temperatures (i.e., at temperatures higher than that of LLDPE), when its content in the blend is higher than 25% by weight. In the blend whose iPP content is as high as 25%, at least a portion of iPP crystallizes at temperatures lower than that of LLDPE. This behavior has been proposed by Bassett to be attributed to a change in the kind of nucleation from heterogeneous to homogeneous. From the Avrami analysis of the isothermal crystallization of iPP in the presence of molten LLDPE, n values close to 2 are always obtained. According to our previously proposed interpretation of the Avrami coefficient, it can be related to the crystallite fractal dimension, through d = n + 1, which gives values close to 3, according to the spherulitic observed morphology. The kinetics parameter, i.e., the half‐time of crystallization, and the kinetic constant k show that a decrease in the overall rate of crystallization of iPP occurs on blending. Optical microscopy photographs, taken during the cooling of the samples from the melt, confirm the above results and show increasingly less resolved spherulite texture on increasing LLDPE content in the blend. The diffusion parameters evaluated for the neat polymers and for the blends in dichloromethane, which give information on the miscibility in the amorphous state, show that the diffusional behavior of the blends is governed by iPP, suggesting a two‐phase amorphous state. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3338–3346, 2003
Synthesis and characterization of proton‐conducting copolymers on the basis of vinylpyrrolidone and acrylamido sulfonic acid
Authors: Bozkurt A. , Ekinci Ö. , Meyer W. H.
Published: October 2003

Free‐radical copolymerizations of 1‐vinyl‐2‐pyrrolidone with 2‐acrylamido‐2‐methyl propane sulfonic acid at different feed ratios were investigated. The copolymers were characterized by 1H‐NMR, 13C‐NMR, and FTIR. The copolymer composition was determined from the elemental analysis. The molecular weights (Mw, Mn) and dispersities of the copolymers were determined by gel permeation chromatography. Thermogravimetric analysis indicated that copolymers are stable at least up to 200°C. Temperature dependency of the alternating current (ac) conductivities was investigated by means of impedance spectroscopy. The direct current (dc) conductivities of the samples were obtained from the ac conductivity data. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3347–3353, 2003
Contribution of connexin26 to electrical feedback inhibition in the turtle retina
Authors: Pottek Mark , Hoppenstedt Werner , Janssen‐Bienhold Ulrike , Schultz Konrad , Perlman Ido , Weiler Reto
Published: October 2003

The first synaptic integration in the neuronal cascade of vision in vertebrates includes a feedback from horizontal cells to cones by a mechanism yet not fully understood. Recent observations in teleosts suggested an electrical feedback mechanism mediated by connexin26 (Cx26) hemichannels at the terminal dendrites of horizontal cells. By using reverse transcription‐polymerase chain reaction and immunoblotting from retinal homogenate, we detected Cx26 mRNA transcripts in the turtle retina and demonstrated that they were translated into protein. Cx26 immunoreactivity was especially prominent in the outer plexiform layer. Subcellularly, immunoreactivity was located mainly between horizontal cell axon terminals and in horizontal cell dendrites forming the lateral elements at the ribbon synaptic complex of the cone pedicle. The label was confined to the horizontal cell membrane flanking the ribbon and was not found on the opposing photoreceptor membrane. No gap junctions at this location are known, so immunosignaling suggested the presence of hemichannels. Their relevance to the feedback mechanism was investigated by intracellular recordings from horizontal cells during application of the hemichannel blocker carbenoxolone. Carbenoxolone hyperpolarized the dark membrane potential by about 25 mV, decreased the amplitudes of responses to full‐field light flashes, and suppressed the feedback‐induced depolarizing inflexion in the response profile. These physiological findings are compatible with the involvement of hemichannels in the feedback between horizontal cells and cones and support the anatomical findings. Together, these data suggest the presence of an electrical feedback mechanism in the turtle retina, which therefore might be a common mechanism at the first visual synapse in vertebrates. J. Comp. Neurol. 466:468–477, 2003. © 2003 Wiley‐Liss, Inc.
Fine structural localization of connexin‐36 immunoreactivity in mouse cerebral cortex and thalamus
Authors: Liu Xiao‐Bo , Jones Edward G.
Published: October 2003

The mounting physiological evidence for low‐resistance electrical coupling between thalamic and cortical neurons contrasts with a lack of morphological data on gap junctions in thalamus and cortex. Connexin‐36 is a neuronally specific protein associated with low‐resistance gap junctions in the central nervous system. Connexin‐36 localization was studied in the mouse somatosensory cortex and thalamus by using immunocytochemistry and immunoelectron microscopy. Expression of connexin‐36 immunoreactivity is widespread in the forebrain and significantly enhanced in the barrel cortex and thalamic reticular nucleus during the second postnatal week, but it extends to other thalamic nuclei as well. At the electron microscopic level, pre‐ and postembedding immunogold labeling revealed that 70–76% of connexin‐36‐immunolabeled particles were localized at focal sites on apposed plasma membranes of cortical and thalamic dendrites; approximately 5% of the particles were associated with parasynaptic membranes; but on no occasion could overt, morphologically identifiable gap junctions be demonstrated in association with connexin‐36 immunoreactivity. The widespread distribution of focal concentrations of connexin‐36 subunits could provide a basis for the electrical coupling that exists between cortical and reticular thalamic neurons, but morphologically definable gap junctions may be too small to be adequately visualized by conventional immunoelectron microscopy. J. Comp. Neurol. 466:457–467, 2003. © 2003 Wiley‐Liss, Inc.
Extraordinary diversity in vasopressin (V1a) receptor distributions among wild prairie voles (Microtus ochrogaster): Patterns of variation and covariation
Authors: Phelps Steven M. , Young Larry J.
Published: October 2003

The vasopressin V1a receptor is a gene known to be central to species differences in social behavior, including differences between the monogamous prairie vole and its promiscuous congeners. To examine how individual differences compare with species differences, we characterize variability in the expression of the vasopressin V1a receptor (V1aR) in a large sample of wild prairie voles. We find a surprising degree of intraspecific variation in V1aR binding that does not seem attributable to experimental sources. Most brain regions exhibit differences between upper and lower quartiles that are comparable to differences between species in this genus. Regions that are less variable have been implicated previously in regulating monogamous behaviors, suggesting that the lack of variation at these sites could reflect natural selection on mating system. Many brain regions covary strongly. The overall pattern of covariation reflects the developmental origins of brain regions. This finding suggests that shared mechanisms of transcriptional regulation may limit the patterns of gene expression. Such biases may shape both the efficacy of selection and the pattern of individual and species differences. Overall, our data indicate that the prairie vole would be a useful model for exploring how individual differences in gene expression influence complex social behaviors. J. Comp. Neurol. 466:564–576, 2003. © 2003 Wiley‐Liss, Inc.
Stereotyped neuropil branching of an identified stomatogastric motor neuron
Authors: Wilensky Ann E. , Baldwin David H. , Christie Andrew E. , Graubard Katherine
Published: October 2003

Anatomical studies of the crab stomatogastric ganglion (STG) have suggested only minimal organization within the neuropil of this structure. Here, we present evidence that, for at least one intrinsic neuron type, the ventricular dilator (VD) neuron, a highly organized and stereotyped branching structure exists within the stomatogastric neuropil. Specifically, we show the morphology of the VD neuron consists of a single primary neurite that projects from the soma into the neuropil and bifurcates into a pair of subprimary neurites, which in turn exit the neuropilar region, one entering the left and the other the right medial ventricular nerve. Nearly all secondary neurite branching of the VD neuron is from the subprimary neurites. There are approximately 22 secondary branches/neuron (range 14–28), with no significant difference between the number of secondary branches off the right vs. the left subprimary neurite, although the ratio of secondary branches between subprimaries varies (range 0.4–1.6). The fine neurites that branch from the secondary processes segregate hemispherically within the neuropil, based on the subprimary neurite of origin. Within this hemispherical organization, another level of fine neurite segregation is present, namely, the fine neurites derived from each secondary branch are restricted to discrete regions of the hemisphere with only minimal overlap with those derived from other secondary branches. Monte Carlo simulations show that this segregation differs significantly from a random distribution. The organization of branching seen in the VD neuron may play a critical role in the electrotonic and local computational organization of this neuron and sets the stage for physiological experimentation addressing these issues. J. Comp. Neurol. 466:554–563, 2003. © 2003 Wiley‐Liss, Inc.
Genetic heterogeneity and ploidy level analysis among different gynogenetic clones of the polyploid gibel carp
Authors: Wei Wen‐Hui , Zhang Jing , Zhang Yi‐Bing , Zhou Li , Gui Jian‐Fang
Published: October 2003

Background

Some triploid and tetraploid clones have been identified in the gynogenetic gibel carp,Carassius auratus gibelioBloch, by karyotypic and cytologic analyses over many years. Further, 5–20% males and karyotypic diversity have been found among their natural and artificial populations. However, the DNA contents and the relation to their ploidy level and chromosome numbers have not been ascertained, and whether normal meiosis occurs in spermatogenesis needs to be determined in the different clones.

Methods

The sampled blood cells or sperms were mixed with blood cells from chicken or individual gibel carp and fixed in 70% pre‐cooled ethanol overnight at 4°C. The mixed cell pellets were washed 2–3 times in 1× phosphate buffered saline and then resuspended in the solution containing 0.5% pepsin and 0.1 M HCl. DNA was stained with propidium iodide solution (40 μg/mL) containing 4 kU/ml RNase. The measurements of DNA contents were performed with Phoenix Flow Systems.

Results

Triploid clones A, E, F, and P had almost equal DNA content, but triploid clone D had greater DNA content than did the other four triploid clones. DNA content of clone M (7.01 ± 0.15 pg/nucleus) was almost equal to the DNA content of clone D (5.38 ± 0.06 pg/nucleus) plus the DNA content of common carp sperm (1.64 ± 0.02 pg/nucleus). The DNA contents of sperms from clones A, P, and D were half of their blood cells, suggesting that normal meiosis occurs in spermatogenesis.

Conclusions

Flow cytometry is a powerful method to analyze genetic heterogeneity and ploidy level among different gynogenetic clones of polyploid gibel carp. Through this study, four questions have been answered. (a) The DNA content correlation among the five triploid clones and one multiple tetraploid clone was revealed in the gibel carp, and the contents increased with not only the ploidy level but also the chromosome number. (b) Mean DNA content was 0.052 pg in six extra chromosomes of clone D, which was higher than that of each chromosome in clones A, E, F, and P (about 0.032 pg/chromosome). This means that the six extra chromosomes are larger chromosomes. (c) Normal meiosis occurred during spermatogenesis of the gibel carp, because DNA contents of the sperms from clones A, P, and D were almost half of that in their blood cells. (d) Multiple tetraploid clone M (7.01 ± 0.15 pg/nucleus) contained the complete genome of clone D (5.38 ± 0.06 pg/nucleus) and the genome of common carp sperm (1.64 ± 0.02 pg/nucleus). Cytometry Part A 56A:46–52, 2003. © 2003 Wiley‐Liss, Inc.
Monitoring cell cycle distributions in living cells by videomicrofluorometry and discriminant factorial analysis
Authors: Savatier Julien , Vigo J. , Salmon J.‐M.
Published: October 2003

Background

The study of the cell cycle of living cells is often based on quantification of nuclear DNA. These studies may be improved by multifactorial analysis evaluating several parameters for each cell.

Methods

Single lymphoblastoid living cells were labeled with three fluorescent markers: Hoechst 33342 for nuclear DNA, Rhodamine 123 for mitochondria, and Nile Red for plasma membrane. Numerical image analysis allowed us to obtain, for each cell, morphological parameters (e.g., cell size, nuclear size, and shape) and functional information (e.g., nuclear DNA content, level of mitochondria energetic state, and the amount and properties of the plasma membrane) by fluorescence intensity. These parameters were used in a typological analysis that separated control cells into four groups.

Results

A discriminant factorial analysis (DFA) confirmed the four groups: G0–G1, S, G2+M, and polyploid cells called Gn. These groups were significantly different, with a classification probability of 0.9999; these control cells defined a learning population. Different populations of untreated and adriamycin‐treated cells were analyzed as additional individuals within a DFA and were classified into the G0–G1, S, G2+M, and Gn groups by their probability of belonging to each of the groups.

Conclusions

This approach is particularly efficient when it is used to determine variations in cellular properties and to objectively study cellular populations. Cytometry Part A 55A:8–14, 2003. © 2003 Wiley‐Liss, Inc.
Cell‐mediated cytotoxicity evaluation using monoclonal antibody staining for target or effector cells with annexinV/propidium iodide colabeling by fluorosphere‐adjusted counts on three‐color flow cytometry
Authors: Özdemir Öner , Ravindranath Yaddanapudi , Savaşan Süreyya
Published: October 2003

Background

In addition to 51chromium release assay, flow cytometric methods have been described to assess in vitro cell‐mediated cytotoxicity. In this report, we describe a new flow cytometric approach for determination of in vitro cell‐mediated cytotoxicity utilizing three‐color flow cytometric assay.

Methods

This method is based on monoclonal antibody staining of either effector or target cells to evaluate cytotoxicity with increased accuracy by utilizing fluorospheres for calibration. The basic strategy involves labeling effector or target cells with a specific fluorescent‐conjugated monoclonal antibody, in addition to staining with annexinV‐FITC and propidium iodide to identify apoptotic/dead cells. The effector and target cell populations as well as conjugates were clearly and easily identified by this approach.

Results

We obtained significant correlation between cytotoxicity calculated by this technique and 51chromium release assay results. The integration of fluorospheres allowed us to determine the absolute number of events reflective of the cumulative cell death rather than a cross‐sectional, percentage‐based cytotoxicity assessment in the target cell population at the time of analysis.

Conclusions

This method provides additional advantages to other methods and enables the study of target cell fate in more detail, as well as providing a potential contribution to understanding the mechanisms of cell elimination. Cytometry Part A 56A:53–60, 2003. © 2003 Wiley‐Liss, Inc.
Circulating levels of neuroactive steroids in patients with binge eating disorder: A comparison with nonobese healthy controls and non‐binge eating obese subjects
Authors: Monteleone Palmiero , Luisi Michele , De Filippis Gennaro , Colurcio Barbara , Monteleone Patrizia , Genazzani Andrea R. , Maj Mario
Published: October 2003

Objectives

Increased plasma levels of allopregnenolone (3α,5α‐tetrahydroprogesterone [3α,5α‐THP]), dehydroepiandrosterone (DHEA), and DHEA sulphate (DHEA‐S) have been reported in patients with anorexia nervosa or bulimia nervosa. To assess whether those changes are related to malnutrition, we investigated plasma levels of neuroactive steroids in women with binge eating disorder (BED) who compulsively binge as bulimic patients, but do not incur malnutrition.

Methods

Sixty‐eight women participated in the study (31 nonobese healthy controls, 9 nonobese patients with BED, 16 obese patients with BED, and 12 obese non‐binge eating women). Blood samples were collected in the morning for determination of plasma levels of 3α,5α‐THP, DHEA, DHEA‐S, and cortisol.

Results

Nonobese BED women had significantly higher plasma levels of DHEA, DHEA‐S, and 3α,5α‐THP than nonobese healthy women. Similarly, obese individuals with BED exhibited significantly higher neurosteroid plasma levels than non‐binge eating obese subjects. No significant differences in plasma cortisol levels were observed among the groups.

Discussion

This study shows increased plasma levels of neuroactive steroids in BED patients. These findings could have been influenced by methodologic limitations (e.g., the absence of diurnal sampling). However, they suggest that if malnutrition is involved in the determination of increased plasma levels of neuroactive steroids in people with anorexia or bulimia nervosa, then different factors may induce similar effects in people with BED. Alternatively, common unknown factors could be responsible for neurosteroid changes in anorexia nervosa, bulimia nervosa, and BED. © 2003 by Wiley Periodicals, Inc. Int J Eat Disord 34: 432–440, 2003.
Family interactions predict intraindividual symptom variation for adolescents with bulimia
Authors: Okon Deborah M. , Greene Anita L. , Smith Jane Ellen
Published: October 2003

Objective

Following family systems and stress theories, this study considered predictors of symptom variation experienced by adolescents with bulimia.

Methods

Using experience sampling methodology, 20 girls clinically diagnosed with bulimia nervosa completed questionnaires about hassles and bulimic symptoms for 1 week, eight times daily, whenever they were contacted by pager. Perceived family environment was defined by the Family Environment Scale and the Conflict Behavior Questionnaire.

Results

Regression analyses found that potent family hassles were positive predictors of bulimic symptoms later that day for girls who perceived their family as having high levels of conflict or low levels of emotional expressiveness. This was not found when girls perceived their family environment as more normal.

Discussion

Within the context of a perceived dysfunctional family environment, potent family hassles can predict interindividual and intraindividual bulimic symptom variation for adolescent girls. © 2003 by Wiley Periodicals, Inc. Int J Eat Disord 34: 450–457, 2003.
Binge eating and binge eating disorder in a small‐scale, indigenous society: The view from Fiji
Authors: Becker Anne E. , Burwell Rebecca A. , Navara Kesaia , Gilman Stephen E.
Published: October 2003

Objective

Although the cross‐cultural prevalence of anorexia and bulimia nervosa has been investigated in multiple studies, little is known about the prevalence and correlates of binge eating and binge eating disorder (BED) cross‐culturally. No published studies to date have explored BED in small‐scale, indigenous, or developing societies. The current study investigated the prevalence and correlates of binge eating in a community sample of Fijian women living in rural Fiji.

Methods

Fifty ethnic Fijian women completed a self‐report measure developed for this study on dieting and attitudes toward body shape and change, a Nadroga‐language questionnaire on body image, and the Questionnaire on Eating and Weight Patterns‐Revised (QEWP‐R). Their height and weight were also measured. Patterns of dieting, high body mass index (BMI), and attitudes toward eating and body image were compared between women with and without a history of binge eating.

Results

Ten percent of respondents reported at least weekly episodes of binge eating during the past 6 months and 4% endorsed symptoms consistent with BED. Binge eating in this sample was associated significantly with a BMI value above 35, a history of dieting, and a high concern with body shape. Binge eating was not associated with several markers of acculturation in this sample, although it was associated with a key, nontraditionally Fijian (i.e., acculturated) attitude toward the body.

Discussion

Binge eating occurred in a social context with traditions concerning weight and diet widely disparate from Western populations. However, correlates of binge eating in this sample suggest that nontraditional Fijian attitudes toward weight and body shape play a contributory role. © 2003 by Wiley Periodicals, Inc. Int J Eat Disord 34: 423–431, 2003.
Analysis of photocurrents in low‐temperature polysilicon thin‐film transistors and the use of simulation to design LDD devices
Authors: Nanno Yutaka , Senda Kohji , Mashimo Shunji , Kuramasu Keizaburou , Tsutsu Hiroshi
Published: October 2003

Design rules are presented for the suppression of photocurrents generated in the depletion layers of the channel/drain junction regions of low‐temperature poly‐Si thin‐film transistors (TFTs). Device simulation based on modeling the behavior of the density of states in a low‐temperature poly‐Si TFT was used to find the width of the junction depletion layer. These simulations show that in order to suppress photocurrents to below 6 pA, the LDD region must have a sheet resistance in the range of 30 and 70kΩ/□, which forces its length to exceed 1 µm. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 86(11): 29–36, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.10021
Stacked gate insulator of photooxide and PECVD film from SiH4 and N2O for low‐temperature poly‐Si thin‐film transistor
Authors: Nakata Yukihiko , Okamoto Tetsuya , Itoga Takashi , Hamada Toshimasa , Ishii Yutaka
Published: October 2003

A stacked gate insulator consisting of photooxide and PECVD film prepared from SiH4 and N2O for use in low‐temperature poly‐Si thin‐film transistors has been developed. The rate of photooxidation using a Xe excimer lamp is the same for (100) and (111) single‐crystal Si wafers, and SiO2 with good coverage of the poly‐Si can be formed by photooxidation. By applying low‐RF power conditions, under which the ion impact damage is smaller, the interface trap density can be improved in a thin oxide film with a thickness of several nanometers. When a PECVD film is formed from SiH4 and N2O, N is accumulated in the SiO2/Si surface, but the surface N can be reduced if the film is formed at the surface by oxidation. In the stacked gate insulator film consisting of photooxide and PECVD films constructed under these conditions, a good SiO2/Si interface with an interface trap density of 2 to 3 × 1010cm−2eV−1 can be formed by photooxidation with a substrate temperature of 200 to 300 °C. This interface trap density is equivalent to that of a thermal oxidation film formed at 950 °C, and is an improvement of approximately 1/10 compared to the PECVD film. The constructed stacked gate insulator film exhibited a flat‐band voltage shift in reliability tests. This is attributed to hole traps produced by N taken up by the SiO2 film during the formation of the PECVD film. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 86(11): 21–28, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.10100
Development of location and status management system for various systems
Authors: Oishi Haruo , Kurauchi Masaki , Kuwaki Nobuo , Osada Masanori , Ohkubo Masanori
Published: October 2003

Currently, many vehicle operation management systems that combine GPS and wireless communications devices are being used. Since these were developed as dedicated systems that were specialized to a vehicle operation management application, a major system overhaul is required to implement a connection with another system that requires the vehicle information. We proposed and developed a workforce location and status management system that operates in conjunction with multiple business systems and has the following three features: (1) it is an open system based on location and status management, (2) it has a multilayer data stream, and (3) it controls multiple business applications. We confirmed the effectiveness of the proposed system by applying it to NTT's failure repair application. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 86(11): 50–60, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.10200
The time course of stereopsis: The delayed VEP component correlate of figure–ground processes
Authors: Miyawaki Yoichi , Hayashi Ryusuke , Maeda Taro , Tachi Susumu
Published: October 2003

The authors sought to analyze the time course of human stereopsis process, and focused on the measurement of VEP. The evoked response in stereopsis has been considered as a single component appearing with a latency of approximately 200 ms, but it has recently been revealed that the response is composed of two components with different properties. This paper discusses the relation between the second latency range in the two‐peaked response and the figure‐ground process. The characteristics of the figure‐ground stimulus are defined and examined by the size ratio of the single rectangular region (figure) of the random‐dot stereogram with binocular disparity to the background (ground). As a result, two successively generated negative components are observed. Of those, the initial component of the latency of approximately 150 ms increases the response with the absolute amount of stimulus, and is independent of the size ratio to the background. The second component with a latency of approximately 250 ms exhibits a stronger response when the figure region is narrowed. The response decreased with increase of the stimulus size, and disappeared when the whole stimulus was uniform. The above tendency of the response is verified, independently of the kind of local cue that defines the figure region. These results indicate that the second component has a strong correlation to the figure‐ground process, and also the latency range related to the binocular fusion is located before the occurrence of the second component. A discussion of the neural mechanism underlying the two‐peaked response is also presented, from the viewpoints of the relative delay of the second component and the local cue‐independent continuous response modulation. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 86(11): 72–86, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.10202
An adaptive microphone array using multiple fictitious sources
Authors: Kobayashi Kazunori , Furuya Ken'ichi , Kataoka Akitoshi
Published: October 2003

This paper proposes a method of carrying out stable sound acquisition even if the targeted sound source moves, by constraining the sensitivity of an adaptive microphone array using multiple fictitious sources. Although the adaptive microphone array can achieve significant noise suppression, the conventional one has a problem in that the desired sound degrades and the noise increases when the desired sound source moves. In our method, multiple fictitious sources are used to constrain the sensitivity to the sound acquisition range. This effect is confirmed by a simulation comparing the proposed method and conventional ones. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 87(2): 20–32, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.10131
Metastasis of benign tumor cells in tuberous sclerosis complex
Authors: Henske Elizabeth Petri
Published: October 2003

Lymphangiomyomatosis (LAM) is a life‐threatening lung disease affecting almost exclusively young women. Histologically, LAM is characterized by the diffuse, bilateral proliferation of abnormal smooth muscle cells and cystic degeneration of the lung parenchyma. LAM can occur as an isolated disorder (sporadic LAM), or in women with tuberous sclerosis complex (TSC‐LAM). Patients with both sporadic LAM and TSC‐LAM often have benign renal angiomyolipomas. The smooth muscle cells within the angiomyolipomas are very similar to the smooth muscle cells in pulmonary LAM. Genetic data suggest that pulmonary LAM is the result of a highly unusual disease mechanism: the metastasis of benign cells. If LAM is the result of metastasis, it is remarkable that the metastasis occurs in women, but not in men. In this review, I discuss the genetic data supporting this metastatic model for LAM. The implications of the model for the functions of the TSC1 and TSC2 gene products, hamartin and tuberin, respectively, will also be considered. Hamartin and tuberin may play functional roles in the suppression of cell migration and/or metastasis, possibly through their regulation of the small GTPase Rho. © 2003 Wiley‐Liss, Inc.
Uterine leiomyoma in the Eker rat: A unique model for important diseases of women
Authors: Walker Cheryl Lyn , Hunter Deborah , Everitt Jeffery I.
Published: October 2003

Eker rats carry a defect in the Tsc‐2 tumor suppressor gene and female Eker rats develop uterine leiomyoma with a high frequency. The presentation, response to hormones and molecular alterations in these mesenchymal smooth muscle tumors, closely resembles their cognate human disease. Female rats and tumor‐derived cell lines from Eker rat leiomyomas (ELT lines) have been developed as an in vivo/in vitro model system for preclinical studies to identify novel therapeutic agents for this disease and for studying disease pathogenesis. In addition to serving as a model for uterine leiomyoma, Eker rats have proven valuable for studying lymphangioleiomyomatosis, a related proliferative smooth muscle disease of women. © 2003 Wiley‐Liss, Inc.
Long‐term synaptic depression in the adult entorhinal cortex in vivo
Authors: Bouras Raby , Chapman C. Andrew
Published: October 2003

The piriform cortex provides a major input to the entorhinal cortex. Mechanisms of long‐term depression (LTD) of synaptic transmission in this pathway may affect olfactory and mnemonic processing. We have investigated stimulation parameters for the induction of homosynaptic LTD and depotentiation in this pathway using evoked synaptic field potential recordings in the awake rat. In this study, 15 min of 1‐Hz stimulation induced a transient (<5 min) depression of evoked responses but did not induce LTD or depotentiation. To determine whether inhibitory and/or facilitatory mechanisms contribute to LTD induction, repetitive delivery of pairs of stimulation pulses was also assessed. Repetitive paired‐pulse stimulation with a 10‐ms interval between pulses, which activates inhibitory mechanisms during the second response, did not reliably induce LTD. However, repetitive paired‐pulse stimulation using a 30‐ms interval, which evokes marked paired‐pulse facilitation, resulted in synaptic depression that lasted ≥1 day, and which was reversible by tetanization. The selective induction of LTD by stimulation that evokes paired‐pulse facilitation suggests that strong synaptic activation is required for LTD induction. The N‐methyl‐D‐aspartate (NMDA) receptor antagonist MK‐801 (0.1 mg/kg) blocked the induction of LTD, indicating that NMDA receptor activation is required for LTD induction in this pathway. These results indicate that LTD in piriform cortex inputs to the entorhinal cortex in the awake rat is effectively induced by strong repetitive synaptic stimulation, and that this form of LTD is dependent on activation of NMDA receptors. © 2003 Wiley‐Liss, Inc.
Age‐dependent alterations of long‐term synaptic plasticity in thyroid‐deficient rats
Authors: Vara H. , Muñoz‐Cuevas J. , Colino A.
Published: October 2003

Thyroid hormone deficiency during a critical period of development profoundly affects cognitive functions such as attention, learning, and memory, but the synaptic alterations underlying these deficits remain unexplored. The present study examines the effect of congenital hypothyroidism on long‐term synaptic plasticity. This plasticity is believed to be essential for learning and memory and for activity‐dependent regulation of synapse formation in the developing brain. We found that the neonatal expression of long‐term potentiation (LTP), long‐term depression (LTD), depotentiation, and de‐depression in hippocampal slices from hypothyroid animals was similar to that of controls. To examine the postnatal development of these plasticities, we used slices from neonatal (2–3 weeks) and adult (7–8 weeks) rats. This work demonstrates that the ability to express all these forms of synaptic plasticity is reduced in an age‐dependent manner in control rats. LTP and depotentiation are also downregulated in adult hypothyroid rats, but we have found that de‐depression is not affected during maturation. In addition, these animals express LTD at ages at which controls fail to induce it. In contrast, input/output experiments have shown greater levels of basal synaptic efficacy in hypothyroid adults, and this effect is probably related to the higher probability of release observed by paired‐pulse experiments. Nevertheless, these effects appear to be unrelated to the differences observed in long‐term synaptic plasticity, as no correlation was found between basal synaptic efficacy and the degree of LTD and de‐depression. Furthermore, the NMDA‐receptor antagonist amino‐phosphonopentanoic acid (APV) completely blocked LTD, which suggests a postsynaptic locus of this alteration. Because LTD has been associated with novelty acquisition, we suggest that the greater LTD observed in adult hypothyroid rats might be related to the hyperactivity of these animals. However, other possibilities such as a retarded maturation of synaptic plasticity must be taken into account. © 2003 Wiley‐Liss, Inc.