bluuebunny/crossref_metadata_2025 huggingface dataset:
Role of γ‐aminobutyric acid in early neuronal development: Studies with an embryonic neuroectodermal stem cell clone
Authors: Jelitai M. , Anděrová M. , Markó K. , Kékesi K. , Koncz P. , Syková E. , Madarász E.
Published: April 2004

γ‐Aminobutyric acid (GABA) has been known to function as an autocrine/paracrine signal molecule in addition to its well‐known inhibitory neurotransmitter function. Studies on the developing brain and on primary brain cell cultures provided evidence for a variety of GABA functions in periods preceding the formation of synapses. The exact role of GABA in the early neural development, however, is still not well understood. In this study, one‐cell‐derived NE‐4C neuroectodermal stem cells were induced to form neurons and astrocytes in vitro, and the role of GABA was investigated in defined phases of neurogenesis. Noninduced NE‐4C cells contained GABA, expressed GABA(A)R α subunits, and carried functional GABA(A) ion channels. A moderate cytoplasmic GABA content was detected during the entire period of differentiation. By the time of the formation of differentiated neurons, neuron‐like cells with both high and low GABA content were clearly distinguishable. HPLC analysis indicated that NE‐4C cells released GABA into their fluid environment during all stages of neuronal development. By using the patch‐clamp technique, GABA‐evoked currents were recorded during the entire proliferation/differentiation period, whereas a GABA‐evoked increase in intracellular Ca2+ was detected only during the maturation of postmitotic neuronal precursors. Bicuculline blocked both the ion currents and the [Ca2+]i increase in response to GABA. Neuron formation was facilitated by GABA through GABA(A) ion channels during postmitotic differentiation, but not earlier during the phases of cell fate commitment. Although the data clearly demonstrate an early responsiveness to GABA, understanding the significance of GABA influence in early neural cell fate decisions will require further investigation. © 2004 Wiley‐Liss, Inc.
Early adoption modifies the effects of prenatal stress on dopamine and glutamate receptors in adult rat brain
Authors: Barros Virginia G. , Berger María A. , Martijena Irene D. , Sarchi María I. , Pérez Adriana A. , Molina Victor A. , Tarazi Frank I. , Antonelli Marta C.
Published: April 2004

Stressful stimuli during pregnancy induce complex effects that influence the development of offspring. These effects can be prevented by environmental manipulations during the early postnatal period. Repeated restraint during the last week of pregnancy was used as a model of prenatal stress, and adoption at birth was used to change the postnatal environment. No differences were found in various physical landmarks, except for testis descent, for which all prenatally stressed pups showed a 1‐day delay in comparison with control rats, regardless of the postnatal adoption procedure. Levels of dopamine (DA) D2 and glutamate (Glu) N‐methyl‐D‐aspartate (NMDA) receptors were differentially regulated in different forebrain regions of cross‐fostered adult offspring. Increased concentrations of cortical D2 receptors detected in stressed pups, raised by a gestationally stressed biological mother, were not detected when the pups were raised by a control mother. Control pups raised by a foster mother whether gestationally stressed or not had higher levels of NMDA receptors in cortical areas. These findings suggest that the normal expression of DA and Glu receptors is influenced by in utero experience and by lactation. The complex pattern of receptor changes reflects the high vulnerability of DA and Glu systems to variations both in prenatal and in postnatal environment, particularly for cortical D2 receptors and NMDA receptors in cerebral cortex and nucleus accumbens. In contrast, testis descent appears to be more susceptible to prenatal than to postnatal environmental events. © 2004 Wiley‐Liss, Inc.
Superensemble prediction of regional precipitation over Korea
Authors: Kim Maeng‐Ki , Kang In‐Sik , Park Chung‐Kyu , Kim Kyu‐Myong
Published: April 2004

Seasonal precipitation at the decadal time scale is predicted using the downscaling super ensemble (DSE) method, which is developed by combining the superensemble procedure with a statistical downscaling method in this study. The multi‐model data utilized are the long‐term integration of six atmosphere–ocean general circulation models (AOGCMs) and the downscaling method is based on the singular value decomposition with the empirical orthogonal function (EOF) truncation to correct the systematic bias in the dynamic models.

Interestingly, even though prediction skill in the training period is increased with increasing number of AOGCMs used, the skill is often decreased in the independent period. It is found that prediction skill in the independent period continues to rise when we use an optimal combination of predictors. The optimum combination used in constructing the superensemble model is the super‐3 ensemble, which is a combination of three AOGCMs (CCCma, CSIRO, and NCAR) among the six AOGCMs used in this study. In general, the first four EOFs of sea‐level pressure (SLP) in the super‐3 ensemble are very similar to those of the observed SLP. The dynamic link between Korean winter precipitation and East Asian monsoon circulation in the super‐3 ensemble is similar to that of the observed indicating that the super‐3 ensemble realistically simulates the circulations in the East Asian monsoon region. The cross‐validation for the prediction of the super‐3 ensemble shows that the correlation skill score is about 0.49, which is significant at the 5% level. The results provide hope for regional climate prediction in decadal time‐scales using superensemble methods together with statistical downscaling. Copyright © 2004 Royal Meteorological Society
Sustained Release of BSA from a Novel Drug Delivery Matrix – Bullfrog Skin Collagen Film
Authors: Li He , Wang Diqiang , Li Songjun , Liu Bailing , Gao Lizhen
Published: April 2004

Summary: A novel drug delivery system, bullfrog skin collagen film, was employed to release bovine serum albumin (BSA). The biophysical properties of bullfrog skin collagen film used were evaluated by thermal denaturation temperature and percentage water loss. The film obtained exhibited good stability and can be taken as a good candidate for drug delivery matrix. Compared with conventional collagen from molecular weight and amino acid composition, bullfrog skin collagen showed significant differences. For safety considerations, bullfrog skin collagen has great advantages. The release kinetics of BSA from bullfrog skin collagen film was measured in vitro. The results indicated bullfrog skin collagen film could be used for sustained release of BSA. Thus, bullfrog skin collagen film can be taken as a novel drug delivery system.

Morphology of frog collagen film with drug loaded after release.

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Morphology of frog collagen film with drug loaded after release.
Cover Picture: Macromol. Chem. Phys. 5/2004
Authors: Hu Xianbo , Lesser Alan J.
Published: April 2004

Cover: Modified nanoclays have higher nucleation activity and are more effective nucleating agents for poly(trimethylene terephthalate) (PTT) than the unmodified counterpart. The most effective nucleating concentration of nanoclay is between 1.0–3.0 wt.%

Further details can be found in the Full Paper by Xianbo Hu and Alan J. Lesser* on page 574.
Analysis of Polymorphism and Dual Crystalline Morphologies in Poly(hexamethylene terephthalate)
Authors: Woo Eamor , Wu Pi‐Ling , Chiang Chih‐Pei , Liu Hung‐Ling
Published: April 2004

Summary: The polymorphisms in poly(hexamethylene terephthalate) (PHT), along with their associated melting and spherulite morphologies, were examined by differential scanning calorimetry (DSC), wide‐angle X‐ray diffraction (WAXD), and polarized‐light microscopy (PLM). The morphology and crystal cells were dependent on the temperature of crystallization. When melt‐crystallized at low temperatures (90–135 °C), PHT showed at least five melting peaks and two re‐crystallization peaks upon DSC scanning, and the samples displayed various fractions of both α and β crystals. However, only a single melting peak was obtained in PHT melt‐crystallized at 140 °C or above, which displayed a single type of β crystal. In addition, two different forms of spherulites were identified in melt‐crystallized PHT, with one being a typical Maltese‐cross spherulite containing the α crystal, and the other being a dendrite‐type packed mainly with the β crystal. This study provides timely evidence for a critical interpretation of the relationship between multiple melting and polymorphisms (unit cells and spherulites) in polymers, including semi‐crystalline polyesters.

WAXD diffractograms for PHT melt‐crystallized at 140 °C, revealing a single type of β‐crystal cell.

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WAXD diffractograms for PHT melt‐crystallized at 140 °C, revealing a single type of β‐crystal cell.
Cover Picture: Macromol. Rapid Commun. 8/2004
Authors: Pan Qinmin , Rempel Garry L.
Published: April 2004

Cover: The cover picture features new progress on the catalytic hydrogenation of styrene‐butadiene copolymer (SBS), in which the hydrogenation can be realized efficiently and the residual catalyst metal in the polymer can be less than 7 ppm before any post treatment. This new progress will simplify the post treatment, potentially extending the applications of the hydrogenated SBS to biomedical fields.

Further details can be found in the Communication by Q. Pan* and G. L. Rempel* on page 843.
Risus sardonicus after thalamic haemorrhage
Authors: Sibon Igor , Burbaud Pierre
Published: April 2004

We describe an uncommon movement disorder after stroke. A 70‐year‐old man was admitted for a right thalamic haemorrhage and 1 week later developed bilateral contractions of the face. Electromyographic study revealed a bilateral facial dystonia. The association of this bilateral facial dystonia and vertical gaze palsy produced the aspect of a “risus sardonicus.” © 2003 Movement Disorder Society
Long‐term outcome of clozapine use for psychosis in parkinsonian patients
Authors: Fernandez Hubert H. , Donnelly Edward M. , Friedman Joseph H.
Published: April 2004

A retrospective analysis was carried out on 39 parkinsonian patients on clozapine treatment ≥24 months for psychosis. The cohort had a mean age of 76 years and an average clozapine dose of 47 mg/day over 60 months of clozapine use. Of 39 patients, 13 (33%) patients were eventually admitted to nursing homes, 6 (46%) of whom died over a period of 5 years. The overall 5‐year mortality rate in this cohort was 44% (17/39). Of 39 patients, 33 (85%) had continued partial/good response and 5 (13%) had complete resolution of psychosis. None discontinued clozapine due to motor worsening. Among patients who responded early on, the long‐term efficacy of clozapine for psychosis was sustained. The risk of nursing home placement and mortality among parkinsonian patients treated with clozapine for psychosis in this geriatric cohort was better than that reported previously. Our data are more consistent with recently published long‐term outcome data suggesting an improvement in the prognosis of parkinsonian patients with psychosis with the use of atypical antipsychotic agents such as clozapine. © 2004 Movement Disorder Society
Clinical signs and symptoms in a large hereditary spastic paraparesis pedigree with a novel spastin mutation
Authors: Nicholas Anthony P. , O'Hearn Elizabeth , Holmes Susan E. , Chen Dung‐Tsa , Margolis Russell L.
Published: April 2004

The most common form of autosomal dominant hereditary spastic paraparesis (HSP), SPG4, is caused by mutations in the spastin gene on chromosome 2p. This disease is characterized by intra‐ and interfamilial phenotypic variation. To determine the predictive values of clinical signs and symptoms in SPG4, we examined 43 members of a large pedigree with autosomal dominant HSP. We then identified the genetic etiology of the disorder in this family, a novel nonsense mutation in exon 1 of spastin, carried by 24 of the examined family members. The best clinical predictors of positive gene status were the presence of hyperreflexia in the lower extremities, >2 beats of ankle clonus, pes cavus, bladder symptoms and increased tone in the legs. The mean age of onset was 32.2 ± 7.4 years, but the age of onset was earlier in children from 10 of 12 child–parent gene‐positive pairs, with a mean difference of 10.8 ± 3.3 years. The finding of leg weakness was especially common in older‐onset affected family member with leg hyperreflexia. These results suggest that specific clinical signs and symptoms may be of value in differentiating individuals affected with SPG4 from family members with nonspecific neurological findings. © 2004 Movement Disorder Society
Safety and efficacy of botulinum toxin type B (Myobloc) in adductor spasmodic dysphonia
Authors: Adler Charles H. , Bansberg Stephen F. , Krein‐Jones Kari , Hentz Joseph G.
Published: April 2004

This single‐site, open‐label, dose‐finding study evaluated the safety and efficacy of botulinum toxin type B (BoNT‐B; Myobloc) for the treatment of adductor spasmodic dysphonia (AdSD) in 13 patients. Three patients received a total of 50 U (25 U per vocal fold); the same three subsequently received 100 U, and then 10 more received 200 U. The primary measure of efficacy was the patient's rating of the change in the severity of spasms on a scale from −3 to +3. There were seven secondary measures of efficacy, including blinded ratings of the sound of voice recorded on audiotape. At Week 8 after injection, spasms improved in 0 of 3 patients who received 50 U, 1 of 3 patients who received 100 U, and 8 of 10 patients who received 200 U. The mean (± standard deviation [SD]) score for the change in spasm severity at Week 8 in the 200 U group was 1.4 (±1.2) points (P = 0.004). All seven secondary measures also showed improvement. Breathiness was the most common side effect but was mild in intensity and of short duration. We conclude that BoNT‐B is safe and effective for the treatment of adductor spasmodic dysphonia. © 2004 Movement Disorder Society
Basigin expression and regulation in mouse ovary during the sexual maturation and development of corpus luteum
Authors: Chang Hong , Ni Hua , Ma Xing‐Hong , Xu Li‐Bin , Kadomatsu Kenji , Muramatsu Takashi , Yang Zeng‐Ming
Published: April 2004

Basigin is a highly glycosylated transmembrane protein belonging to the immunoglobulin superfamily. Basigin‐deficient male mice are azoospermic. The majority of basigin null embryos die around the time of implantation. However, basigin expression and regulation in mouse ovary is still unknown. The aim of this study was to investigate basigin expression in mouse ovary during sexual maturation, gonadotropin treatment, and luteal development by in situ hybridization and immunohistochemistry. Both basigin mRNA and immunostaining were not detected in the granulosa cells of preantral follicles until day 20 after birth. On day 30 after birth, basigin immunostaining dropped to a basal level, while basigin mRNA was still at a high level. Basigin expression was strongly induced by equine chorionic gonadotropin (eCG) treatment at 4 and 8 hr post‐eCG injection. Both basigin immunostaining and mRNA signals were strongly observed in the corpus luteum on days 2 and 3 post‐hCG injection. However, no basigin expression was detected from days 6 to 15 post‐hCG injection. In conclusion, our data suggest that basigin may play a role during the mouse follicle development and corpus luteum formation. Mol. Reprod. Dev. 68: 135–141, 2004. © 2004 Wiley‐Liss, Inc.
Transcriptome of mouse uterus by serial analysis of gene expression (SAGE): Comparison with skeletal muscle
Authors: Larose M. , St‐Amand J. , Yoshioka M. , Belleau P. , Morissette J. , Labrie C. , Raymond V. , Labrie F.
Published: April 2004

The aim of this study was to identify the transcriptome of the normal mouse uterus by Serial Analysis of Gene Expression method. mRNA was extracted from the uterus and also from the gastrocnemius muscle of mice. Short sequences (tags), each one usually corresponding to a distinct transcript, were isolated and concatemerized into long DNA molecules which were cloned and sequenced. We detected 44,484 tags for the uterus and 42,518 tags for the muscle, representing 14,543 and 14,958 potential transcript species, respectively. Seventy‐five and sixty‐nine genes were expressed at more than 0.1%, thus corresponding to 37 and 34% of the mRNA population detected in the respective tissues. In both cases, the most highly expressed genes are especially involved in muscle contraction, energy metabolism, and protein synthesis. Compared to skeletal muscle, some differentially expressed genes in the uterus are likely to correspond to its specific reproductive functions. The majority of these genes remain to be characterized. More than 70% of the different tags detected in the uterus did not match any sequence in the public databases and can represent novel or poorly identified genes. This study is the first quantitative description of the transcriptome of the uterus. Mol. Reprod. Dev. 68: 142–148, 2004. © 2004 Wiley‐Liss, Inc.
Lowering intracellular and extracellular calcium contents prevents cytotoxic effects of ethylene glycol‐based vitrification solution in unfertilized mouse oocytes
Authors: Takahashi Toshifumi , Igarashi Hideki , Doshida Masakazu , Takahashi Kazuhiro , Nakahara Kenji , Tezuka Naohiro , Kurachi Hirohisa
Published: April 2004

We investigated the characteristics of the changes in intracellular calcium (Ca2+) concentration ([Ca2+]i) and the viability of the unfertilized mouse oocytes exposed to various concentrations of ethylene glycol (EG)‐containing solutions or vitrification solutions. Oocytes exposed to EG (1, 5, 10, 20, and 40% (v/v)) exhibited a rapid and dose‐dependent increase in [Ca2+]i. The survival rate was 100% when oocytes were exposed to the EG concentration up to 5% through 5 min, while all oocytes were dead within 3 min when exposed to 10, 20, or 40% EG. When extracellular Ca2+ was removed, increase in [Ca2+]i at 10 and 20% EG was less than that at the same concentrations of EG with extracellular Ca2+. The survival rates of the oocytes exposed to 10, 20, and 40% EG at 3 min were 100, 97, and 0%, respectively. In the presence of 20 μM 1,2‐bis(o‐aminopheoxy)ethane‐N,N,N′,N′‐tetraacetic acid tetra acetoxymethyl ester (BAPTA‐AM), a Ca2+ chelator, a small increase in [Ca2+]i exposed to 10, 20, and 40% EG was observed until 4 min. Subsequently prolonged elevation of the [Ca2+]i was observed in the oocytes exposed to 40% EG but not with 10 and 20% EG. The survival rate of the oocytes, in the presence of 20 μM BAPTA‐AM, exposed to 10 and 20% EG was 100% throughout 5 min, while the oocytes exposed to 40% EG were alive only for 3 min. Treatment by the vitrification solution with various concentrations of EG (10, 20, and 40%) caused a smaller increase in [Ca2+]i, while the survival rates were higher compared to those without vitrification solution at the same concentrations of EG. These data suggested that the sustained [Ca2+]i rises by EG in unfertilized mouse oocytes resulted in cell death. Therefore, the lowering of [Ca2+]i in the oocytes exposed to the cryoprotectant may improve the viability of cryopreserved unfertilized oocytes. Mol. Reprod. Dev. 68: 250–258, 2004. © 2004 Wiley‐Liss, Inc.
Managing routing tables for URL routers in content distribution networks
Authors: Prodanoff Zornitza Genova , Christensen Kenneth J.
Published: April 2004

Large‐scale content distribution networks (CDNs) can be built using URL routers to redirect client HTTP requests to the nearest content source. URL routers employ very large routing tables. To improve the manageability of CDNs, we propose to use URL signatures to reduce the size of routing tables and aggressive hashing to speed‐up routing look‐ups. Copyright © 2004 John Wiley & Sons, Ltd.
Escaping from Flatland: clinical and biological aspects of human mammary duct anatomy in three dimensions
Authors: Going James J , Moffat David F
Published: April 2004

Accurate knowledge of breast duct anatomy in three dimensions is needed to understand normal breast development, how intraepithelial neoplasia may spread through a breast, and the potential for diagnostic and therapeutic access to breast parenchyma via the nipple. This paper reports three related exploratory studies. In study 1, the median number of milk‐collecting ducts in the nipple was determined in 72 breasts excised for cancer; in study 2, the volumes of all 20 complete duct systems (‘lobes’) in an autopsy breast were measured from 2 mm serial ‘subgross’ sections; and in study 3, a 3D digital model of all collecting ducts in a mastectomy nipple was made from 68 100 µm serial sections. The mastectomy nipples contained 11–48 central ducts (median 27, inter‐quartile range 21–30). In the autopsy breast, the largest ‘lobe’ drained 23% of breast volume; half of the breast was drained by three ducts and 75% by the largest six. Conversely, eight small duct systems together accounted for only 1.6% of breast volume. The 3D model of the nipple revealed three distinct nipple duct populations. Seven ducts maintained a wide lumen up to the skin surface (population A); 20 ducts tapered to a minute lumen at their origin in the vicinity of skin appendages (population B) on the apex of the nipple; and a minor duct population (C) arose around the base of the papilla. Major variations in duct morphology and extent define highly variable territories in which intraepithelial neoplasia could grow. While population A ducts appear accessible to duct endoscopy or lavage, population B and population C ducts may be less accessible. Copyright © 2004 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Drug use among fathers around time of conception: two register based surveys from Denmark and The Netherlands
Authors: Schirm Eric , Pedersen Lars , Tobi Hilde , Nielsen Gunnar L. , Sørensen Henrik T. , de Jong‐van den Berg Lolkje T. W.
Published: April 2004

Study objective

Despite the increasing attention for the role of paternal exposures around the period of conception, there is no factual information about drug utilisation of fathers. Therefore, the aim of this study was to describe the drugs dispensed to fathers around conception, using pharmacy dispensing data of community pharmacies in Denmark and The Netherlands.

Design and setting

Using pharmacy dispensing data from the Pharmaco‐epidemiological Prescription Database of North Jutland in Denmark and the InterAction database in the Netherlands, we examined the prescriptions reimbursed in the half year before conception of 56 735 Danish fathers from 1991 to 2000, and 5859 Dutch fathers from 1995 to 2000.

Main results

One third of all fathers had taken up prescriptions for at least one drug in the half year before conception, both in Denmark and in The Netherlands. In the majority of fathers only one type of drug was dispensed, but in both countries at least 5% of all fathers had redeemed three or more types of drugs. The main drugs purchased by fathers in Denmark and The Netherlands were antibiotics (14.3 and 6.3% of all fathers, respectively), analgesics (6.1 and 7.6%), antihistamines (2.0 and 2.0%) and anti‐ulcer drugs (1.6 and 2.5%).

Conclusion

A large proportion of fathers used drugs around the time of conception. This finding emphasises the importance of safety information on therapeutic drugs with respect to potential paternal teratogenicity. Copyright © 2004 John Wiley & Sons, Ltd.
Aluminum‐borate‐whiskers‐reinforced bismaleimide composites. 1: preparation and properties
Authors: Liang Guozheng , Hu Xiaolan
Published: April 2004

Aluminum‐borate‐whiskers‐reinforced bismaleimide (BMI/Al18B4O33) composites were prepared, and the mechanical and thermal properties were investigated. Results show that the coupling agent used for surface treatment of whiskers has a great effect on the properties of these materials. Composites containing surface‐untreated whiskers, or silane‐compound‐KH 921‐treated whiskers, exhibited initially only a slight increase in the flexural strength when the whiskers weight content increased up to 5 wt%; thereafter, they showed a sharp decrease when the whiskers content was higher than 5 wt%. On the other hand, impact strength tests showed that the addition of the two kinds of whiskers decreased the impact strength of the composites. However, studies of the composite containing borate (BE4)‐treated whiskers showed that its flexural strength greatly increased with increasing whisker content. Moreover, the composite showed initially an increase in impact strength with a whisker content up to 10 wt%, then showing a slight decrease when the whisker content reached 15 wt%. Scanning electron microscopy observations revealed that the two coupling agents (KH 921 and BE4) employed in this work tend to change the fracture features of the composites from brittleness to that of ductile behaviour. Copyright © 2004 Society of Chemical Industry
Thin‐film solar cells: device measurements and analysis
Authors: Hegedus Steven S. , Shafarman William N.
Published: April 2004

Characterization of amorphous Si, CdTe, and Cu(InGa)Se2‐based thin‐film solar cells is described with focus on the deviations in device behavior from standard device models. Quantum efficiency (QE), current–voltage (J–V), and admittance measurements are reviewed with regard to aspects of interpretation unique to the thin‐film solar cells. In each case, methods are presented for characterizing parasitic effects common in these solar cells in order to identify loss mechanisms and reveal fundamental device properties. Differences between these thin‐film solar cells and idealized devices are largely due to a high density of defect states in the absorbing layers and to parasitic losses due to the device structure and contacts. There is also commonly a voltage‐dependent photocurrent collection which affectsJ–Vand QE measurements. The voltage and light bias dependence of these measurements can be used to diagnose specific losses. Examples of how these losses impact the QE,J–V, and admittance characterization are shown for each type of solar cell. Copyright © 2004 John Wiley & Sons, Ltd.
In situ diagnostic methods for thin‐film fabrication: utilization of heat radiation and light scattering
Authors: Sakurai K. , Hunger R. , Scheer R. , Kaufmann C. A. , Yamada A. , Baba T. , Kimura Y. , Matsubara K. , Fons P. , Nakanishi H. , Niki S.
Published: April 2004

Deposition processes of Cu(In,Ga)Se2 (CIGS) thin films were observed by informative and low‐cost in situ monitoring means; the pyrometer technique, and the spectroscopic light‐scattering (SLS) technique. Intensities of thermal radiation and scattered white light were profiled from outside the vacuum chamber during growth, using a monochromatic pyrometer and a small CCD spectrometer. The deposition process was studied by systematic variations of major process parameters of CIGS, such as the substrate temperature, Ga concentration and Se supply. Various film properties, including the deposition speed, thickness, compositional ratios, surface roughness and precipitation of Cu‐rich phases have been monitored in situ. Copyright © 2004 John Wiley & Sons, Ltd.
Modeling thin‐film PV devices
Authors: Burgelman Marc , Verschraegen Johan , Degrave Stefaan , Nollet Peter
Published: April 2004

Numerical modeling is increasingly used to obtain insight in to the details of the physical operation of thin‐film solar cells. Over the years several modeling tools specific to thin‐film PV devices have been developed. A number of these tools have reached a mature status and are available to the PV community. Some of the most commonly used programs are presented and the possibilities as well as the shortcomings are discussed. Also, for the different thin‐film PV devices (CdTe, CIGS, and, to a lesser extent, amorphous silicon and nano‐structured solar cells) an overview is given of modeling efforts and achievements. Copyright © 2004 John Wiley & Sons, Ltd.
Accelerated testing and failure of thin‐film PV modules
Authors: McMahon T. J.
Published: April 2004

Packaging‐related PV module failure is distinguished from cell failure, and those failures specific to thin‐film modules are reviewed. These are categorized according to the type of stress that produced them, e.g., temperature, voltage, moisture, current, and thermal cycling. An example is given that shows how to relate time under accelerated stress to time in use. Diagnostic tools for locating the affected area within a large‐area module are pointed out along with the importance of interpretation of the visual appearance of the different damage mechanisms. Copyright © 2004 John Wiley & Sons, Ltd.
Development of thin‐film Cu(In,Ga)Se2and CdTe solar cells
Authors: Romeo A. , Terheggen M. , Abou‐Ras D. , Bätzner D. L. , Haug F.‐J. , Kälin M. , Rudmann D. , Tiwari A. N.
Published: April 2004

Cu(In,Ga)Se2and CdTe heterojunction solar cells grown on rigid (glass) or flexible foil substrates requirep‐type absorber layers of optimum optoelectronic properties andn‐type wide‐bandgap partner layers to form thep–n junction. Transparent conducting oxide and specific metal layers are used for front and back electrical contacts. Efficiencies of solar cells depend on various deposition methods as they control the optoelectronic properties of the layers and interfaces. Certain treatments, such as addition of Na in Cu(In,Ga)Se2and CdCl2treatment of CdTe have a direct influence on the electronic properties of the absorber layers and efficiency of solar cells. Processes for the development of superstrate and substrate solar cells are reviewed. Copyright © 2004 John Wiley & Sons, Ltd.
Thin‐film silicon solar cell technology
Authors: Shah A. V. , Schade H. , Vanecek M. , Meier J. , Vallat‐Sauvain E. , Wyrsch N. , Kroll U. , Droz C. , Bailat J.
Published: April 2004

This paper describes the use, withinp–i–n‐ andn–i–p‐type solar cells, of hydrogenated amorphous silicon (a‐Si:H) and hydrogenated microcrystalline silicon (μc‐Si:H) thin films (layers), both deposited at low temperatures (200°C) by plasma‐assisted chemical vapour deposition (PECVD), from a mixture of silane and hydrogen. Optical and electrical properties of thei‐layers are described. These properties are linked to the microstructure and hence to thei‐layer deposition rate, that in turn, affects throughput in production. The importance of contact and reflection layers in achieving low electrical and optical losses is explained, particularly for the superstrate case. Especially the required properties for the transparent conductive oxide (TCO) need to be well balanced in order to provide, at the same time, for high electrical conductivity (preferably by high electron mobility), low optical absorption and surface texture (for low optical losses and pronounced light trapping). Single‐junction amorphous and microcrystallinep–i–n‐type solar cells, as fabricated so far, are compared in their key parameters (Jsc, FF,Voc) with the [theoretical] limiting values. Tandem and multijunction cells are introduced; the μc‐Si: H/a‐Si: H or [micromorph] tandem solar cell concept is explained in detail, and recent results obtained here are listed and commented. Factors governing the mass‐production of thin‐film silicon modules are determined both by inherent technical reasons, described in detail, and by economic considerations. The cumulative effect of these factors results in distinct efficiency reductions from values of record laboratory cells to statistical averages of production modules. Finally, applications of thin‐film silicon PV modules, especially in building‐integrated PV (BIPV) are shown. In this context, the energy yields of thin‐film silicon modules emerge as a valuable gauge for module performance, and compare very favourably with those of other PV technologies. Copyright © 2004 John Wiley & Sons, Ltd.
Thin‐film solar cells: an overview
Authors: Chopra K. L. , Paulson P. D. , Dutta V.
Published: April 2004

Thin film solar cells (TFSC) are a promising approach for terrestrial and space photovoltaics and offer a wide variety of choices in terms of the device design and fabrication. A variety of substrates (flexible or rigid, metal or insulator) can be used for deposition of different layers (contact, buffer, absorber, reflector, etc.) using different techniques (PVD, CVD, ECD, plasma‐based, hybrid, etc.). Such versatility allows tailoring and engineering of the layers in order to improve device performance. For large‐area devices required for realistic applications, thin‐film device fabrication becomes complex and requires proper control over the entire process sequence. Proper understanding of thin‐film deposition processes can help in achieving high‐efficiency devices over large areas, as has been demonstrated commercially for different cells. Research and development in new, exotic and simple materials and devices, and innovative, but simple manufacturing processes need to be pursued in a focussed manner. Which cell(s) and which technologies will ultimately succeed commercially continue to be anybody's guess, but it would surely be determined by the simplicity of manufacturability and the cost per reliable watt. Cheap and moderately efficient TFSC are expected to receive a due commercial place under the sun. Copyright © 2004 John Wiley & Sons, Ltd.
Physical characterization of thin‐film solar cells
Authors: Durose Ken , Asher Sally E. , Jaegermann Wolfram , Levi Dean , McCandless Brian E. , Metzger Wyatt , Moutinho Helio , Paulson P.D. , Perkins Craig L. , Sites James R. , Teeter Glenn , Terheggen Mathias
Published: April 2004

The principal techniques used in the physical characterization of thin‐film solar cells and materials are reviewed, these being scanning probe microscopy (SPM), X‐ray diffraction (XRD), spectroscopic ellipsometry, transmission electron microscopy (TEM), Auger electron spectroscopy (AES), secondary‐ion mass spectrometry (SIMS), X‐ray photoelectron spectroscopy (XPS), photoluminescence and time‐resolved photoluminescence (TRPL), electron‐beam‐induced current (EBIC) and light‐beam‐induced current (LBIC). For each method the particular applicability to thin‐film solar cells is highlighted. Examples of the use of each are given, these being drawn from the chalcopyrite, CdTe, Si and III–V materials systems. Copyright © 2004 John Wiley & Sons, Ltd.
Polymeric stationary phase, based on (R,R)‐tartramide and bisphenol S, with potential chiral properties
Authors: Jabłońska‐Pikus T. , Charmas W. , Podkościelna B. , Gawdzik B.
Published: April 2004

A new polymeric stationary phase with potential chiral properties, obtained by the chemical modification of the parent copolymer of dimethacrylate esters of bisphenol S and divinylbenzene, is presented. Hydroxyl functional groups present in the copolymer chemical structure are blocked by optically active selectors of (R,R)‐tartramide derivatives. The influence of the chemical modification of the parent copolymer on its porous structure has been studied. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 2566–2574, 2004
Permeation, diffusion, and sorption of dimethyl ether in fluoroelastomers
Authors: Grazia De Angelis Maria , Cesare Sarti Giulio , Sanguineti Aldo , Maccone Patrizia
Published: April 2004

The permeation, diffusion, and sorption of dimethyl ether into a series of commercial fluoroelastomers were characterized at various pressures and temperatures. The polymers under study were based on tetrafluoroethylene and contained various amounts of other perfluorinated monomers: perfluoromethylvinylether, hexafluoropropylene, and a partially fluorinated monomer, vinylidene fluoride (VDF). These polymers were also filled with inorganic particles and cured with different techniques. The permeation rate of dimethyl ether in the elastomers examined, as well as the solubility value, increased as the content of the nonperfluorinated monomer (VDF) increased, and this was consistent with the solubility parameter theory. The diffusion coefficients, at a fixed concentration, had rather similar values for most of the elastomers examined. Both the permeability and diffusivity increased with temperature, and the corresponding activation energies were obtained for two selected polymers. The solubility of dimethyl ether, at a fixed temperature and activity, showed a linear dependence versus the weight fraction of the partially fluorinated monomer (VDF) in the polymeric matrix. The effect of the filler on the sorption and transport properties was also considered: the addition of the filler lowered the permeability and diffusivity, whereas the solubility was generally increased with respect to the crosslinked rubber. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 1987–2006, 2004
Morphology of polypropylene films treated in CO2plasma
Authors: Aouinti Mohammed , Gibaud Alain , Chateigner Daniel , Poncin‐Epaillard Fabienne
Published: April 2004

One of the most important claims for the plasma technique as a surface treatment is that it modifies only a few atomic layers of materials. However, with polymers, this assumption must be carefully verified to keep the bulk mechanical properties constant. Besides the oxidation of the film, with specific plasma conditions such as high power and duration, the polypropylene film structure is also modified in the bulk through vacuum ultraviolet absorption and thermal relaxation. This change is associated with smectic‐ and amorphous‐phase transformation into an α‐monoclinic phase, with a rapid rate for the smectic transformation and a slower rate for the amorphous transformation. At the same time, the crystallite size increases, and the polypropylene film texture is planar and moderated (1.7 mrd at the maximum of the distribution, with a discharge power of 100 W and a treatment duration of 10 min). © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 2007–2013, 2004
Solid polymer electrolytes X: Preparation and characterizations of polyether–siloxane, organic–inorganic, hybrid nanocomposites complexed with lithium perchlorate
Authors: Liang Wuu‐Jyh , Wu Chien‐Pang , Kuo Ping‐Lin
Published: April 2004

Organic–inorganic hybrid nanocomposites of poly(ethylene glycol)/siloxane were obtained via the sol–gel approach. In these composites, nanometric siloxane heterogeneity was embedded into a polymer matrix with a covalent bond at the interfaces. The 29Si magic‐angle spinning (MAS) spectrum exhibited a high degree of condensation through the relative abundance of T0 [RSi(OR)3], T1 [RSi(OR)2(OSi)], T2 [RSi(OR)(OSi)2], and T3 [RSi(OSi)3] silicone nuclei. The effect of lithium salt concentration on ionic interaction, conductivity, and thermal properties of these composite electrolytes were investigated by Fourier transform infrared spectroscopy, DSC, thermogravimetric analysis, alternating current impedance, and solid‐state 7Li MAS NMR measurements. These observations indicated that the different types of complexes by the interactions of Li+ and ClO ions are formed within a hybrid host, and the formation of transient crosslinks between Li+ ions and the ether oxygens results in an increased glass‐transition temperature of the polyether segment and decomposed rate of composite electrolyte. 7Li MAS NMR measurements revealed the changes in line shape of lithium resonances with different LiClO4 contents, suggesting that a significant degree of ionic association is present in the polymer‐salt complexes. The behavior of ion transport in these composite electrolytes was correlated with the interactions between ions and polymer host. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 1928–1937, 2004
Thermal‐contraction‐crack networks as evidence for late‐Pleistocene permafrost in Inner Mongolia, China
Authors: Vandenberghe J. , Zhijiu Cui , Liang Zhao , Wei Zhang
Published: April 2004

Numerous wedges on the Ordos Plateau show typical characteristics of periglacial sand wedges that enable them to be distinguished from desiccation cracks in clayey illuviation soil horizons. The sand wedges are organized in two generations of polygonal networks. The older generation is a large‐scale network with a diameter of 8 to 9 m and wedge depths up to more than 2 m. The younger generation has a mean diameter of 3 to 4 m and is formed within the large networks. It consists of shallow (0.6 to 1 m deep) but relatively wide wedges. In contrast to the typical sand wedges that form within continuous permafrost, the shallow wedges formed probably as ‘ground wedges’ by seasonal freezing. Ice wedges and cryoturbations developed only rarely, and exclusively in the most humid areas. Thermal‐contraction cracking occurred mainly between 26 and 20 ka BP, indicating mean annual temperatures at least 13°C lower than present. Before and after that period mean annual temperatures were at least 7 to 8.5° lower than today. The presence of these periglacial phenomena show that the southern limit of continuous permafrost in Inner Mongolia occurred south of 38°N during the Last Glacial Maximum. Copyright © 2004 John Wiley & Sons, Ltd.
The effect of different spray liquids on the foliar retention of agricultural sprays by wheat plants in a canopy
Authors: Butler Ellis M Clare , Webb Duncan A , Western Nigel M
Published: April 2004

The aim of this work was to examine the effect of liquid properties on spray retention in a range of situations representative of practical pesticide application. Liquids with different physical properties were sprayed with conventional flat‐fan and air‐induction nozzles onto outdoor‐grown wheat plants (Triticum aestivum L cv Axona) at growth stages between GS 22 and GS 35. Since total retention is affected by leaf surface as well as plant growth stage and canopy density, the experiments included spraying both single leaves and groups of plants with different canopy densities. Retention on whole plants was strongly influenced by plant growth and canopy properties. Individual leaf surfaces were not as water‐repellent as was found previously for younger indoor‐grown plants, reducing the effect of dynamic surface tension on retention. This, combined with the increased probability of droplets hitting foliage in a denser canopy, gave reduced differences in retention between liquids when compared with similar measurements made previously on younger plants. With a leaf area index greater than 7, retention on whole plants was almost independent of liquid. Air‐induction nozzles gave lower levels of retention than flat‐fan nozzles, with this difference greatest when spraying high dynamic surface tension liquids and at low crop densities. Copyright © 2004 Society of Chemical Industry
Arme Alte? Das Risiko von Altersarmut in Deutschland
Authors: Fasshauer Stephan
Published: April 2004

Die Reform der Alterssicherung steht aktuell wieder im Blickpunkt des öffentlichen und politischen Interesses. Die demografische Entwicklung, die Veränderungen in der Arbeitswelt mit einer Zunahme von unsteten Erwerbsbiographien sowie der gesellschaftliche Wandel und das neue Rollenverständnis von Mann und Frau sind nur einige Stichworte, die diese Reformentwicklung und die Herausforderungen der Alterssicherung kennzeichnen. Um diesen Entwicklungen gerecht zu werden, wird es durch die Verabschiedung des so genannten „Nachhaltigkeitsgesetzes”︁ zu weiteren Leistungseinschnitten bei der gesetzlichen Rentenversicherung zu Gunsten eines stabilen Beitragssatzes kommen. Mit der erneuten Reduzierung des Leistungsniveaus der staatlichen Alterssicherung stellt sich zunehmend die Frage, in welchem Umfang die gesetzliche Rentenversicherung noch zur Sicherung des Lebensstandards beitragen kann. Je geringer das Leistungsniveau wird, desto drängender stellt sich die Frage nach dem Risiko von Altersarmut. Im Folgenden wird zunächst der aktuelle Status dieses Risikos anhand von Kennzahlen abgeschätzt. Im Anschluss werden die wesentlichen Einflussfaktoren der zukünftigen Risiko‐Entwicklung betrachtet.
Improvement of performance to discriminate malignant tumors from normal tissue on mammograms by feature selection and evaluation of feature selection criteria
Authors: Furuya Sachiko , Wei Jun , Hagihara Yoshihiro , Shimizu Akinobu , Kobatake Hidefumi , Nawano Shigeru
Published: April 2004

This paper reports the results of improving the performance of a previous system for discriminating malignant tumors by selecting a small number of features effective for discriminating malignant tumors from normal tissue on mammograms from 39 features. Specifically, the efficacy of the new system is evaluated by comparing the results with the case of using the previous 9 features. The paper also reports on the results of comparing the areas Az under ROC curves using Mahalanobis distance ratios, the areas Az under ROC curves based on the maximum likelihood method, and the average recognition rates based on the nearest‐neighbor decision rule. © 2004 Wiley Periodicals, Inc. Syst Comp Jpn, 35(7): 72–84, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10587
Quantitative study of aluminum‐induced changes in synaptic ultrastructure in rats
Authors: Jing Yuhong , Wang Ziren , Song Yanfeng
Published: April 2004

Some evidence suggests that aluminum is one of the risk factors in Alzheimer's disease (AD); however, there is no study on the relationship between the synaptic configuration changes and aluminum uptake. In the present study, 40 rats were fed with water solution aluminum for 3 months and the effects of aluminum on the Gray's type I synapses in hippocampus and frontal cortex of rats were quantitatively investigated by electron microscopy. The effects of aluminum on the ability to learn and memorize were tested by a Morris water maze. Length of synaptic active zone, width of synaptic cleft, curvature of synapse, and thickness of postsynaptic density (PSD) were measured in the interface of synapses by the IBM‐PC microimage processing system. The flat synapse, positive and negative curvature synapses, as well as the perforated synapse were classified and counted according to the type of the interfacial structure of a synapse. The amounts of aluminum deposited in brain were measured with an atomic absorption spectrophotometer. Our results show that the time and the distance taken by the rats to find the water maze increased after the rats were fed aluminum for 3 months. As compared with control, the synapses in aluminum‐induced rats exhibited the following significant changes: decreased thickness of PSD (P < 0.01), increased width of synaptic cleft (P < 0.05), increased numbers of flat synapse, decreased numbers of positive curvature synapse and perforated synapse, and significantly increased aluminum deposits in hippocampus and frontal cortex (P < 0.01). Our study indicates that aluminum can decrease the ability of rats to learn and memorize and induce their synaptic configuration changes. These changes may be related to synaptic efficacy and may be one of the mechanisms for AL to induce AD. Synapse 52:292–298, 2004. © 2004 Wiley‐Liss, Inc.
Visceral pain: gender differences in response to experimental and clinical pain
Authors: Arendt‐Nielsen Lars , Bajaj Priti , Drewes Asbjørn Mohr
Published: April 2004

Gender differences in response to visceral pain have important implications for experimental studies and when evaluating clinical pain. Few studies have in details explored specific gender differences in response to experimental stimulation of selected visceral organs or specific visceral diseases. Lower pain threshold to e.g. oesophageal distension has however been shown in females. The effect of female sex hormones on visceral function and pain is studied in greater details in both experimental and clinical studies. Pronounced differences in pain sensitivity are found across the menstrual phases. This may also interact with pharmacological interventions. For clinicians assessing the pain level of female patients in the reproductive age group should take into consideration the physiological and clinical effects of the menstrual cycle and the somatic segmental sites related to the uterus and cervix when clinically evaluating the pain and assessing for disease activity.