bluuebunny/crossref_metadata_2025 huggingface dataset:
Using Latent Mixed Markov Models for the choice of the best pharmacological treatment
Authors: Reuter Martin , Hennig Juergen , Netter Petra , Buehner Markus , Hueppe Michael
Published: April 2004

The choice of the best pharmacological treatment for an individual patient is crucial to optimize convalescence. Due to their effects on pharmacokinetics variables like gender and age are important factors when the pharmacological regimen is planned. By means of an example from anaesthesiology the usefulness of Latent Mixed Markov Models for choosing the optimal anaesthetic considering patient characteristics is demonstrated. Latent Mixed Markov models allow to predict and compare the quality of recovery from anaesthesia for different patient groups (defined by age and gender and treated with different anaesthetic regimens) in a multivariate non‐parametric approach. On the basis of observed symptoms immediately after surgery and a few days later the probabilities for the respective dynamic latent status (like health or illness) and the probabilities for transition from one status to another are estimated depending on latent class membership (patient group). Copyright © 2004 John Wiley & Sons, Ltd.
Tracing magma sources in an arc‐arc collision zone: Helium and carbon isotope and relative abundance systematics of the Sangihe Arc, Indonesia
Authors: Jaffe Lillie A. , Hilton David R. , Fischer Tobias P. , Hartono Udi
Published: April 2004

The Sangihe Arc is presently colliding with the Halmahera Arc in northeastern Indonesia, forming the world's only extant example of an arc‐arc collision zone. We report the first helium and carbon isotopic and relative abundance data from the Sangihe Arc volcanoes as a means to trace magma origins in this complicated tectonic region. Results of this study define a north‐south trend in 3He/4He, CO2/3He, and δ13C, suggesting that there are variations in primary magma source characteristics along the strike of the arc. The northernmost volcanoes (Awu and Karangetang) have higher CO2/3He and δ13C (up to 179 × 109 and −0.4‰, respectively) and lower 3He/4He (∼5.4 RA) than the southernmost volcanoes (Ruang, Lokon, and Mahawu). Resolving the arc CO2 into component structures (mantle‐derived, plus slab‐derived organic and carbonate CO2), the northern volcanoes contain an unusually high (>90%) contribution of CO2 derived from isotopically heavy carbonate associated with the subducting slab (sediment and altered oceanic basement). Furthermore, the overall slab contribution (CO2 of carbonate and organic origin) relative to carbon of mantle wedge origin is significantly enhanced in the northern segment of the arc. These observations may be caused by greater volumes of sediment subduction in the northern arc, along‐strike variability in subducted sediment composition, or enhanced slab‐derived fluid/melt production resulting from the superheating of the slab as collision progresses southward.
Relationship between temperature sensitivity of capillary pressure and soil particle size
Authors: Grant Steven A. , Or Dani
Published: April 2004

In a review of data in the published literature, we found that the effect of temperature on capillary pressure in natural soils increased with decreasing geometric mean soil particle diameter. This observation had implications both for hydrologic modeling and for elucidating the mechanisms that controlled the temperature sensitivity of capillary pressure. Two mechanisms were suggested to explain this observation. The first mechanism proposed that changes in soil mineral particle size resulted in changes in the proportion of hydrophyllic and hydrophobic surfaces, yielding changes in their wettabilities, and temperature effects on capillary pressure. The second mechanism proposed that the observation was due to the effect of soil particle size on disjoining pressure. A model derived from the second mechanism could be fitted to the available data and yielded parameter estimates consistent with current models of disjoining pressure profiles above surfaces.
Quantifying the net slab pull force as a driving mechanism for plate tectonics
Authors: Schellart W. P.
Published: April 2004

It has remained unclear how much of the negative buoyancy force of the slab (FB) is used to pull the trailing plate at the surface into the mantle. Here I present three‐dimensional laboratory experiments to quantify the net slab pull force (FNSP) with respect to FB during subduction. Results show that FNSP increases with increasing slab length and dip up to ∼8–12% of FB, making FNSP up to twice as large as the ridge push force. The remainder of FB is primarily used to drive rollback‐induced mantle flow (∼70%), to bend the subducting plate at the trench (∼15–30%) and to overcome shear resistance between slab and mantle (0–8%).
Decomposition of hydrazoic acid in nitric acid
Authors: Maya Brian M. , Stedman Geoffrey
Published: April 2004

Hydrazoic acid in solution in nitric acid at 97 °C decomposes to form a mixture of N2, N2O, and NO. The reaction is strongly acid catalysed and the kinetics of decomposition are first order with respect to hydrazoic acid concentration. The mechanism proposed involves electrophilic attack by NO2+ on hydrazoic acid to form N3ONO, which can then fragment to N2+ 2NO˙ or dissociate to N3˙+ NO2˙. Dinitrogen monoxide is thought to arise from the reaction sequence: 2NO2˙→ N2O4; N2O4+ HN3→ N3NO + HNO3; N3NO → N2+ N2O.
Green tea‐induced asthma: relationship between immunological reactivity, specific and non‐specific bronchial responsiveness
Authors: Shirai T. , Reshad K. , Yoshitomi A. , Chida K. , Nakamura H. , Taniguchi M.
Published: April 2004

Background
The relationships between immunological reactivity and bronchial responsiveness to allergen and non‐specific bronchial responsiveness are unclear in occupational asthma caused by low molecular weight substances.

Objective
We assessed the above relationships in green tea‐induced asthma, an occupational asthma of green tea factory workers, in which epigallocatechin gallate (EGCg), a low molecular weight component of green tea leaves, is the causative agent.

Methods
Subjects consisted of 21 patients suspected of having green tea‐induced asthma, on whom skin test and inhalation challenge with EGCg were performed. The skin sensitivity or end‐point titration to EGCg as a measure of immunological reactivity, together with the provocative concentrations causing a 20% or greater fall in forced expiratory volume in 1 s (PC20) of EGCg and methacholine, were determined.

Results
We found that 11 patients had green tea‐induced asthma, with immediate asthmatic reactions in eight and dual asthmatic reactions in three. We also found that 11 of 13 patients (85%) with immunological reactivity and bronchial hyper‐responsiveness to methacholine experienced an asthmatic reaction and that no subject without immunological reactivity reacted. There were significant correlations among skin sensitivity, EGCg PC20 and methacholine PC20. Multiple linear regression analysis showed the relationship: log (EGCg PC20)=0.42 log (skin sensitivity)+1.17 log (methacholine PC20)+0.93 (r=0.796, P<0.05).

Conclusion
It is concluded that bronchial responsiveness to EGCg can be highly satisfactorily predicted by skin sensitivity to EGCg and bronchial responsiveness to methacholine.
Elevated basal serum tryptase and hymenoptera venom allergy: relation to severity of sting reactions and to safety and efficacy of venom immunotherapy
Authors: Haeberli G. , Brönnimann M. , Hunziker T. , Müller U.
Published: April 2004

Background
Mastocytosis and/or elevated basal serum tryptase may be associated with severe anaphylaxis.

Objective
To analyse Hymenoptera venom‐allergic patients with regard to basal tryptase in relation to the severity of sting reactions and the safety and efficacy of venom immunotherapy.

Methods
Basal serum tryptase was measured in 259 Hymenoptera venom‐allergic patients (158 honey bee, 101 Vespula). In 161 of these (104 honey bee, 57 Vespula), a sting challenge was performed during venom immunotherapy.

Results
Nineteen of the 259 patients had an elevated basal serum tryptase. Evidence of cutaneous mastocytosis as documented by skin biopsy was present in 3 of 16 patients (18.8%). There was a clear correlation of basal serum tryptase to the grade of the initial allergic reaction (P<0.0005). Forty‐one of the 161 sting challenged patients reacted to the challenge, 34 to a bee sting and 7 to a Vespula sting. Thereof, 10 had an elevated basal serum tryptase, i.e. 1 (2.9%) of the reacting and 2 (2.9%) of the non‐reacting bee venom (BV) allergic individuals, as compared to 3 (42.9%) of the reacting and 4 (8%) of the non‐reacting Vespula venom‐allergic patients. Thus, there was a significant association between a reaction to the sting challenge and an elevated basal serum tryptase in Vespula (χ2=6.926, P<0.01), but not in BV‐allergic patients. Systemic allergic side‐effects to venom immunotherapy were observed in 13.9% of patients with normal and in 10% of those with elevated basal serum tryptase.

Conclusions
An elevated basal serum tryptase as well as mastocytosis are risk factors for severe or even fatal shock reactions to Hymenoptera stings. Although the efficacy of venom immunotherapy in these patients is slightly reduced, most of them can be treated successfully. Based on currently available data, lifelong treatment has to be discussed in this situation.
Assessment of cytoplasmic polymorphisms by PCR‐RFLP of the mitochondrial orfB region in wild and cultivated radishes (Raphanus)
Authors: Yamagishi H.
Published: April 2004

In order to determine the genetic relationship between wild and cultivated radish species, and those among the cultivated species, structural and sequence variations in the mitochondrial orfB gene region were studied in one cultivated and two wild species of Raphanus. Using PCR amplification patterns and RFLP of a PCR product of the region, 232 wild and 420 cultivated radish plants were classified into one of three types of orfB variation. The wild radish (especially the Japanese one) showed large polymorphism in each population with eight of 13 Japanese populations studied containing all three types, whereas cultivars were generally monomorphic. Although type 1 having Ogura male sterile cytoplasm was present with the highest frequency in Japanese wild radish, most cultivars were divided into type 2 or 3 with normal cytoplasm. Type 2 was widely distributed in European, Chinese and major Japanese varieties, while some Chinese varieties and several Japanese local radishes had type 3 cytoplasm. The comparison provides valuable information about the origin and differentiation of cultivated radishes and the relationship between cultivated and wild radishes.
Allelic variation in linolenic acid content of high erucic acid Ethiopian mustard and incorporation of the low linolenic acid trait into zero erucic acid germplasm
Authors: Velasco L. , Nabloussi A. , de Haro A. , Fernandez‐Martinez J. M.
Published: April 2004

Zero erucic acid germplasm of Ethiopian mustard is characterized by high levels of linolenic acid (about 21%). Two genetic sources of low linolenic acid (N2‐4961 and HF‐186, about 5%), have been developed in a high erucic acid background. The objectives of this research were to study the genetic relationship between the two low linolenic acid lines and to transfer the trait to zero erucic acid germplasm. F1 seed generations from crosses between both lines had higher average linolenic acid concentration than both parents. F2 seeds segregated for linolenic acid content following a continuous variation from 1.8 to 7.4%, exceeding the limits of the parental distribution ranges. Transgressive recombinants with very low linolenic acid concentration (0.7‐2.7%) were confirmed in the F3 seed generation. The results suggested that N2‐4961 and HF‐186 possess alleles for low linolenic acid at different loci. Transgressive low linolenic acid F3 plants were crossed with plants of a zero erucic acid line and a selection for zero erucic, low linolenic acid was conducted. As a result, a zero erucic acid F3:4 line containing 1.5 ± 0.7% linolenic acid was developed.
Genetic variability for seed oil content and seed index in some wild species and perennial races of cotton
Authors: GOTMARE V. , SINGH P. , MAYEE C. D. , DESHPANDE V. , BHAGAT C.
Published: April 2004

A 3‐year study was made on genetic variability of seed oil content and seed index with 20 wild species, two cultivated species and six perennial races of Gossypium arboreum cotton maintained at the Central Institute for Cotton Research, Nagpur, India. The mean seed oil content varied from 10.26 to 22.89% in 22 species of Gossypium and six races of G. arboreum. In this material the weight of delinted seed varied from 43.33 to 54.54 mg/seed. The highest seed oil content was recorded in the species G. lobatum followed by G. harknessii. On average, for both traits, the means were higher for G. arboreum and its races. However, G. africanum and G. harknessii reached the level of G. arboreum and its races for seed weight, while five wild species surpassed the best races and G. arboreum in seed oil content, among them was G. harknessii. To breed simultaneously for seed oil content and seed weight, crosses between races of G. arboreum and wild species of Gossypium seem to be promising.
Evaluation of cultivated barley (Hordeum vulgare) germplasm for the presence of thermostable alleles of β‐amylase
Authors: Malysheva L. , Ganal M. W. , Röder M. S.
Published: April 2004

A cleaved amplified polymorphic sequence marker was used to detect the alleles Bmy‐Sd2H and Bmy‐Sd3 identifying highly thermostable isoforms of the enzyme b‐amylase, which improves fermentability during brewing. Among the 889 accessions of barley (Hordeum vulgare) investigated, and two accessions of H. spontaneum a total of 166 accessions were identified carrying the superior b‐amylase alleles. These thermostable alleles of b‐amylase were most frequently observed in six‐rowed varieties originating from Asia, especially Japan, with 61.9% of the accessions from Asia carrying the alleles of interest. Additional six‐rowed barleys carrying the relevant alleles were identified among accessions from America, Africa and the Near East. In the European varieties, the percentage of accessions with the alleles of interest was 5.1% with a strong predominance in two‐rowed spring barleys. A pedigree analysis identified the cross ‘Binder’ x ‘Gull’ as the main source of the thermostable b‐amylase alleles in European varieties. The data suggest that an improvement of malting quality in barley could be achieved by introduction of the Bmy1‐Sd2H and Bmy1‐Sd3 alleles into the European breeding programmes.
Genetic maps of RAPD, AFLP and ISSR markers in Ananas bracteatus and A. comosus using the pseudo‐testcross strategy
Authors: CARLIER J. D. , REIS A. , DUVAL M. F. , D'EECKENBRUGGE G. COPPENS , LEITÃO J. M.
Published: April 2004

Genetic maps of random amplified polymorphic DNA (RAPD), amplified fragment length polymorphisms (AFLP) and inter simple sequence repeats (ISSR) markers in pineapple (2n = 2x = 50) are reported for the first time. On the basis of a segregating population of 46 F1 individuals from a cross Ananas comosus x A. bracteatus, genetic maps of these two species were constructed using the two‐way pseudo‐testcross approach. The A. bracteatus map consists of 335 markers (60 RAPDs, 264 AFLPs and 11 ISSRs) assembled into 50 linkage groups, 26 of them with at least four markers. The A. comosus map consists of 157 markers (33 RAPDs, 115 AFLPs, eight ISSRs and the ‘piping’ trait locus) organized into 30 linkage groups, 18 of them with at least four markers. These maps cover, respectively, 57.2% of the A. bracteatus genome estimated as 3693 cM long, and 31.6% of the A. comosus genome calculated as 4146 cM. A rough estimate of 120 and 127 kbp/ cM on average was found for the relationship between physical and genetic distance for A. bracteatus and A. comosus, respectively.
Resynthesis of Brassica juncea through interspecific crosses between B. rapa and B. nigra
Authors: SRIVASTAVA A. , MUKHOPADHYAY A. , ARUMUGAM N. , GUPTA V. , VERMA J. K. , PENTAL D. , PRADHAN A. K.
Published: April 2004

The objective of this study was to broaden the genetic base in oleiferous Brassica juncea by resynthesis, using 10 diverse parental lines of oleiferous B. rapa and two lines of B. nigra of both Indian and exotic origin. Out of 14 crosses attempted using B. rapa as the female parent, eight were successful. Embryo rescue was necessary to obtain interspecific plants. A total of 29 fertile interspecific plants were obtained after colchicine treatment. In the S2 generation, the expression of component characters in the majority of the resynthesized plants showed a negative trend. The resynthesized B. juncea lines are being maintained through repeated selfing and selection at each generation for desirable plant types. This process will continue till the progeny lines of the desirable plants achieve uniformity.
The genetic diversity of old and modern Siberian varieties of common spring wheat as determined by microsatellite markers
Authors: Khlestkina E. K. , Röder M. S. , Efremova T. T. , Börner A. , Shumny V. K.
Published: April 2004

The objective of this study was to assess genetic diversity within old and modern common spring wheat (Triticum aestivumL.) varieties cultivated in Siberia and to find out whether old Siberian varieties could be a potential source for genetic diversity in modern wheat breeding in Siberia. A set of 54 varieties was analysed using 22 wheat microsatellite markers (WMS), determining 23 loci located on 19 different chromosomes. In total, 151 alleles were detected with an average of 6.6, ranging from three to 11 alleles per locus. The average genetic diversity value (polymorphic information content) was 0.70. WMS located in the B genome produced more alleles per locus (7.6) compared with WMS located in the A (6.0) and D (6.0) genomes. Genetic similarity values between varieties ranged from 0.19 to 0.96 and were used to produce a dendrogram. With a few exceptions the varieties studied were clustered in two nearly equal groups consisting of predominantly old (released before 1960) and modern (released in 1960‐90s) varieties, respectively. Genetic diversity values within these two groups were similar with 0.60 and 0.58, respectively. The numbers of group‐specific alleles were 34 and 29, respectively. A significant variation in frequencies of 79 shared alleles was observed. The results obtained by using genomic microsatellite sequences demonstrated that breeding has not resulted in a decrease in the genetic diversity in Siberian spring wheat. However, significant quantitative and qualitative changes in allelic frequencies of different loci were detected. It may be suggested, that old Siberian common spring wheat varieties are a potential basis for genetic diversity in modern wheat breeding in Siberia.
Genetic diversity estimates in Cicer using AFLP analysis
Authors: NGUYEN T. T. , TAYLOR P. W. J. , REDDEN R. J. , FORD R.
Published: April 2004

Amplified fragment length polymorphism (AFLP) analysis was used to evaluate the genetic variation among cultivated chickpea and wild Cicer relatives. In total, 214 marker loci were assessed, of which 211 were polymorphic (98.6%) across the 95 accessions that represented 17 species of Cicer. The genetic variation within a species was highest in C. pinnatifidum followed by C. reticulatum and lowest in C. macracanthum. Three main species groups were identified by UPGMA clustering using Nei's pair‐wise distance calculations. Group I included the cultivated species C. arietinum, C. reticulatum and C. echinospermum. Within this group, C. reticulatum accessions were clustered closest to the C. arietinum cultivars ‘Lasseter’, ‘Kaniva’ and ‘Bumper’, supporting the hypothesis that C. reticulatum is the most probable progenitor of the cultivated species. Cicer bijugum, C. judaicum and C. pinnatifidum were clustered together creating group II. Group III contained all nine perennial species assessed and two annual species C. yamashitae and C. cuneatum. The genetic distance detected between group I and group III (0.13) was equivalent to the genetic distance detected between group I and group II (the primary and annual tertiary species, respectively; 0.14). This indicated that the perennial tertiary species may be as valuable for increasing variation to incorporate novel germplasm in the cultigen as the annual tertiary species.
Chromosomal location of aluminium tolerance genes in rye
Authors: Aniol A.
Published: April 2004

Rye is known for its high tolerance of aluminium in the soils in comparison with wheat and other cereals. To localize the major gene/ genes controlling aluminium tolerance on the rye chromosomes, four series of wheat‐rye addition lines, two sets of triticale D(R) substitution lines and several wheat/rye translocation lines were tested in experiments on seedlings grown in nutrient solutions with various concentrations of aluminium. The results indicate that the major locus responsible for Al tolerance in rye is located on the short arm of chromosome 3R. The importance of these results for controlled introgressions into cereals is discussed.
Approximating the degrees of freedom for contrasts of genotypes laid out as subplots in an alpha‐design in a split‐plot experiment
Authors: SPILKE J. , PIEPHO H. P. , MEYER U.
Published: April 2004

Alpha‐designs have become popular in cultivar trials. Analysis is based on a mixed model. As a result of imbalance, inference tests require approximate methods. This paper investigates the Type I error control of different Satterthwaite approximations for the denominator degrees of freedom of Wald‐type F‐tests and t‐tests in a two‐factorial alpha‐design with cultivars as the subplot factor and management intensities (fertilization, plant protection) as the main plot factor. Simulation results demonstrate good error control for cultivar comparison at the same intensity, with the need for an approximation which diminishes as the number of cultivars increases. By contrast, a comparison of intensities entails a more substantial departure from the nominal significance level, and this is not entirely offset by any of the approximations. The methods are demonstrated using two real data sets.
Vine‐1 retrotransposon‐based sequence‐specific amplified polymorphism for Vitis vinifera L. genotyping
Authors: LABRA M. , IMAZIO S. , GRASSI F. , ROSSONI M. , SALA F.
Published: April 2004

The sequence‐specific amplification polymorphism (S‐SAP) method, derived from the amplified fragment length polymorphism (AFLP) technique, produces amplified fragments containing retrotransposon long terminal repeat (LTR) sequence at one end and a host restriction site at the other. The development and application of this procedure to the LTR of the Vine‐1 element from grapevine is reported. Two primers derived from one of the LTR sequences flanking the retrotransposon were used in combination with MseI degenerated primers on 15 grapevine accessions. S‐SAP results were compared with AFLP data. The heterozygosity and gene diversity values were higher for S‐SAP than for the AFLP procedure. Results show that S‐SAP amplification is effective in identifying polymorphisms and defining genetic distances among cultivars, and could be used for fingerprinting and for ‘Traminer’ clone identification. To the contrary Vine‐1 retrotransposon‐based S‐SAP was not able to distinguish ‘Pinot’ clones.
Greenhouse and field techniques for testing sugar beet for resistance to Rhizoctonia root and crown rot
Authors: BÜTTNER G. , PFÄHLER B. , MÄRLÄNDER B.
Published: April 2004

Rhizoctonia‐resistant sugar beet varieties are the key to an integrated control strategy for Rhizoctonia root rot. Because of the unpredictable occurrence of Rhizoctonia solani in the field testing of sugar beet for resistance to Rhizoctonia root rot is difficult. The aim of the study was to develop advanced greenhouse and field techniques which allow a reliable assessment of sugar beet for resistance to R. solani. A highly infectious liquid inoculum was used for the first time in this study. It can be produced in large quantities of a standardized quality, sterile, and exactly quantified according to its carbon content. In a greenhouse trial, sugar beet grown in the same way as field grown beet was inoculated by applying a suspension of Rhizoctonia mycelium (equivalent to 10 mg carbon per plant) to the beet crown. After 3 weeks, inoculation had led to uniform and severe root rot. Disease symptoms were similar to those found under natural conditions in the field. No ‘escapes’, i.e. susceptible plants apparently expressing resistance were observed in the test. A new nine‐class disease scale was established and a Rhizoctonia index (RI) was calculated. Reliability of disease assessment was demonstrated on progeny of plants, selected from segregating populations, showing Rhizoctonia resistance more closely related to the resistant parent lines than to the susceptible ones. Sugar beet varieties could be assessed in the greenhouse within only 11 weeks. All varieties were affected by the pathogen but partially resistant varieties could be clearly recognized by a significantly lower Rhizoctonia index. Significant differences in susceptibility were also found within the group of new resistant genotypes. Infection studies performed in the field showed the superiority of the new liquid inoculum compared with a solid form and revealed the influence of inoculation date and inoculum level on the development of Rhizoctonia root rot. In field tests performed at different sites under different environmental conditions, susceptible and partially resistant sugar beet varieties could be reproducibly rated according to their susceptibility to R. solani. On average, susceptible varieties showed a Rhizoctonia index of 8 while resistant genotypes ranged from 5 to 6. The newly developed techniques allow fast and reliable evaluation of sugar beet for resistance to R. solani.
Detection of human papillomaviruses of high oncogenic potential in oral squamous cell carcinoma in a Venezuelan population
Authors: Correnti M , Rivera H , Cavazza ME
Published: April 2004

Objective:  The aim of this work was to detect and typify human papillomaviruses (HPV) in oral squamous cell carcinoma (OSCC) in a Venezuelan population.

Material(s) and Methods:  Eighteen tissue samples were obtained from biopsies, formalin‐fixed, and paraffin‐embedded; 16 were diagnosed as SCC. We isolated DNA from paraffin‐embedded tissue; two to three sections of 5 μm were obtained and resuspended in digestion buffer and proteinase K. Five microliters of the aqueous phase was used for polymerase chain reaction (PCR). The PCR for HPV amplification was carried out with consensus primers for L1 region (MY09 and MY11) and β‐globin gene was used as internal control. The viral types were determined by molecular hybridization with a mix of probes for high/intermediate and low HPV oncogenic risk types.

Results:  The HPV‐DNA was detected in 50% (eight of 16) of the SCC cases. Of these HPV‐DNA‐positive samples, 68% were histopathologically diagnosed as moderately differentiated SCC. The most common anatomical location was the alveolar ridge mucosa. All positive biopsies contained high oncogenic HPV types.

Conclusions:  We observed a high prevalence of HPV infection of high oncogenic potential types in patients with SCC in our studied group. The moderately differentiated SCCs were more associated to HPV infection. These differences could be influenced by nutritional, environmental and genetical factors in our population but further studies should be carried out to determine these aspects.
Oral manifestations of HIV infection in relation to clinical and CD4 immunological status in northern and southern Thai patients
Authors: Kerdpon D , Pongsiriwet S , Pangsomboon K , Iamaroon A , Kampoo K , Sretrirutchai S , Geater A , Robison V
Published: April 2004

Objectives:  To assess prevalence and variations in the oral manifestations of HIV in HIV‐infected subjects in southern Thailand (a new HIV epidemic) and northern Thailand (a mature epidemic), and the association with age, sex, risk behaviours, CD4 count and medication used.

Subjects and Methods:  A total of 102 and 135 HIV‐infected individuals were enrolled in northern and southern hospitals, respectively. Oral and haematological examination was performed after sociodemographic interview of the patients. Clinical history was retrieved from patients’ medical records.

Results:  Oral candidiasis (OC, 55%), oral hairy leucoplakia (OHL, 21%) and HIV‐associated‐periodontal disease (14%) were among the most common oral lesions in southern Thailand. OHL (38%), OC (25%), HIV‐associated‐periodontal disease (15%) were the three most common lesions in the north. A significant association was found between any oral lesion, OC, particularly the pseudomembranous type (PC), and CD4 < 200 cells mm−3 at both sites. A negative relationship was found between systemic antifungal treatment and OC including PC and erythematous candidiasis (EC) in the southern data. OHL showed a positive relationship with male sex and a negative relationship with antiretroviral treatment in the northern site. Younger age and being a current smoker were positively associated with oral lesions in the southern group.

Conclusion:  OC, particularly PC, could be useful as a marker for immunosuppression, particularly where CD4 count cannot be determined routinely. Antifungal treatment is of benefit in the subjects who cannot afford highly active antiretroviral therapy (HAART).
Multiple parotid lymphoepithelial cysts in patients with HIV‐infection: report of two cases
Authors: Favia G , Capodiferro S , Scivetti M , Lacaita MG , Filosa A , Muzio L Lo
Published: April 2004

Objective:  Bilateral and multiple lymphoepithelial cysts (LECs) of major salivary glands, in particular of parotid glands, are quite rare and have been reported in human immunodeficiency virus (HIV) infected patients with an incidence of about 3–6%. These lesions represent an early manifestation of HIV infection and are rarely found in patients with advanced acquired immunodeficiency syndrome.

Materials:  Two cases of parotid LECs, the first occurring in a middle‐age white woman and the second in a young white boy, both in advanced phases of HIV infection, are reported.

Results:  Clinical, cytological, histological and immunohistochemical (cytokeratin AE1/AE3, CD20, CD45RA, CD8, κ and λ immunoglobulin light chains, S‐100, MLA and Ki67) features are described.

Conclusions:  Fine needle aspiration (FNA), a relatively non‐traumatic procedure, could represent both a diagnostic and a therapeutic tool in parotid LECs. No surgical therapy is usually required for these lesions and aspiration of cystic fluid with FNA is quite resolutive, although evidence of further relapses does exist. Surgical excision may become necessary when pain, because of persistent and progressive swelling of the parotid gland, occurs.
Dense uniform arrays of site-controlled quantum dots grown in inverted pyramids
Authors: Watanabe S. , Pelucchi E. , Dwir B. , Baier M. H. , Leifer K. , Kapon E.
Published: April 2004

We report on the growth and optical properties of homogeneous, dense arrays of site-controlled, single GaAs/AlGaAs quantum dot (QD) heterostructures with periodicities as small as 300 nm. The samples were grown by organometallic chemical vapor deposition on (111)B GaAs substrates containing dense inverted pyramid recess patterns prepared by electron beam lithography and wet chemical etching. Low-temperature microphotoluminescence spectra of the samples show distinct luminescence from the QDs with 1–3 meV linewidth. Low-temperature cathodoluminescence spectrally resolved images reveal uniform emission energy within an ensemble of 900 QDs.
Fe- and Ni-doped TiO2 thin films grown on LaAlO3 and SrTiO3 substrates by laser ablation
Authors: Hong Nguyen Hoa , Prellier W. , Sakai Joe , Hassini Awatef
Published: April 2004

Room temperature ferromagnetic Fe- and Ni-doped TiO2 thin films were grown by the laser ablation on both LaAlO3 and SrTiO3 substrates. Most of the films are pure anatase, and only the films of Ni content of 3.6% and 4.6% are rutile. Films on LaAlO3 substrates are more crystallized than films on SrTiO3 substrates resulting from the lattice mismatch. Our magnetic measurements also suggest that the ferromagnetism in Fe/Ni:TiO2 films is not due to Fe/Ni segregations but due to Fe/Ni:TiO2 matrices.
Magnetic imprinting of submicron ferromagnetic wires on a diluted magnetic semiconductor quantum well
Authors: Schömig H. , Forchel A. , Halm S. , Bacher G. , Puls J. , Henneberger F.
Published: April 2004

Hybrid structures consisting of submicron ferromagnetic dysprosium wires on a diluted magnetic semiconductor quantum well have been prepared and investigated by micro-magnetoluminescence spectroscopy. A magnetic field dependent redshift of the semiconductor band gap just beneath the dysprosium wires with respect to a reference area clearly demonstrates the impact of the magnetic fringe field on the optical properties of the underlying semiconductor.
Band gaps and localization of water waves over one-dimensional topographical bottoms
Authors: An Zhong , Ye Zhen
Published: April 2004

In this article, the phenomenon of band gaps and Anderson localization of water waves over one-dimensional periodic and random bottoms is investigated by the transfer matrix method. The results indicate that the range of localization in random bottoms can be coincident with the band gaps for the corresponding periodic bottoms. Inside the gap or localization regime, a collective behavior of water waves appears. The results are also compared with acoustic and optical situations.
Observation of room-temperature magnetoelectric coupling in pulsed-laser-deposited Bi0.6Tb0.3La0.1FeO3 thin films
Authors: Palkar V. R. , Kumara K. Ganesh , Malik S. K.
Published: April 2004

Magnetoelectrics, characterized by simultaneous ferroelectric and magnetic ordering, have potential applications in information storage, sensors, etc. However, there are very few materials exhibiting the coexistence of ferroelectric and ferromagnetic ordering at room temperature. Hence, in normal practice, desired magnetoelectric effect is achieved by growing heterostructures of ferroelectric and magnetic materials. Realization of heterostructures with desired properties is not only difficult but also involves complicated lengthy procedures. BiFeO3 is weakly ferroelectric and antiferromagnetic at and above room temperature. We have been successful in enhancing both the ferroelectric and the magnetic properties of BiFeO3 by partial substitution of Tb at Bi site. Thin films of Bi0.6Tb0.3La0.1FeO3, integrated on Si/SiO2/TiO2/Pt substrate by using pulsed laser deposition technique, show good ferroelectric and magnetic properties and also coupling between them. Single step growth of thin films with desired magnetoelectric properties is certainly a cost effective, reliable, and simple alternative to heterostructures.
Electric coupling to the magnetic resonance of split ring resonators
Authors: Katsarakis N. , Koschny T. , Kafesaki M. , Economou E. N. , Soukoulis C. M.
Published: April 2004

We study both theoretically and experimentally the transmission properties of a lattice of split ring resonators (SRRs) for different electromagnetic (EM) field polarizations and propagation directions. We find unexpectedly that the incident electric field E couples to the magnetic resonance of the SRR when the EM waves propagate perpendicular to the SRR plane and the incident E is parallel to the gap-bearing sides of the SRR. This is manifested by a dip in the transmission spectrum. A simple analytic model is introduced to explain this interesting behavior.
Warm-white-light emitting diode utilizing a single-phase full-color Ba3MgSi2O8:Eu2+, Mn2+ phosphor
Authors: Kim J. S. , Jeon P. E. , Choi J. C. , Park H. L. , Mho S. I. , Kim G. C.
Published: April 2004

The Ba3MgSi2O8:Eu2+, Mn2+ shows three emission colors: 442, 505, and 620 nm. The 442 and 505 nm emission originate from Eu2+ ions, while the 620 nm emission originates from Mn2+ ions. The excitation bands of three emission colors are positioned around 375 nm. Electron paramagnetic resonance measurement demonstrates that Eu2+ ions are occupied with three different Ba2+ sites. The red emission of Mn2+ ions has a long decay time of 750 ms due to persistent energy transfer from oxygen vacancies to Mn2+ ions, while the blue and green bands of Eu2+ ions have decay times of 0.32 and 0.64 μs, respectively. The fabricated white-light emitting diode using a 400-nm-emissive chip with a white-light emitting Ba3MgSi2O8:Eu2+, Mn2+ phosphor shows warm white light and higher color stability against input power in comparison with a commercial GaN-pumped (Y1−xGdx)3(Al1−yGay)5O12:Ce3+ phosphor.
Strain-rate and temperature dependent plastic yield in carbon nanotubes from ab initio calculations
Authors: Dumitrică Traian , Yakobson Boris I.
Published: April 2004

Lattice yield to tension within practical time and temperatures is determined by the probability of defect formation. Its rate in nanotubes depends in turn on the transition state and activation barrier for the Stone–Wales bond rotations. Systematic ab initio computations of the barriers for the tubes of various symmetries and radii led to accurate calculation of plastic yield strain as a function of temperature and test duration.
Magnetic phase diagram of two identical coupled nanomagnets
Authors: Worledge D. C.
Published: April 2004

The theoretical magnetic phase diagram of two identical nanomagnets is presented. The nanomagnets are assumed to be single domains in the shape of very flat ellipsoids, in order to approximate technologically relevant thin-film samples patterned into ellipses. The phase diagram is organized by type of easy axis hysteresis loop and takes into account, using exact closed analytic expressions, the effect of thickness, width, length, magnetization, and uniaxial intrinsic anisotropy of the two nanoparticles, and exchange coupling between the two particles. Two phase diagrams are presented for the two cases where the intrinsic anisotropy is parallel to either the long or short in-plane axis of the nanoparticles. Complete descriptions of all hysteresis loops and exact analytic formulas for all switching fields are given.
Efficient electron spin detection with positively charged quantum dots
Authors: Gündoğdu K. , Hall K. C. , Boggess Thomas F. , Deppe D. G. , Shchekin O. B.
Published: April 2004

We report the application of time- and polarization-resolved photoluminescence up-conversion spectroscopy to the study of spin capture and energy relaxation in positively and negatively charged, as well as neutral InAs self-assembled quantum dots. When compared to the neutral dots, we find that carrier capture and relaxation to the ground state is much faster in the highly charged dots, suggesting that electron–hole scattering dominates this process. The long spin lifetime, short capture time, and high radiative efficiency of the positively charged dots, indicates that these structures are superior to both quantum well and neutral quantum dot light-emitting diode spin detectors for spintronics applications.
Structural study of nitrogen-doping effects in bamboo-shaped multiwalled carbon nanotubes
Authors: Jang Jae Won , Lee Cheol Eui , Lyu Seung Chul , Lee Tae Jae , Lee Cheol Jin
Published: April 2004

We have investigated nitrogen doping effects on the structure and crystallinity of bamboo-shaped multiwalled carbon nanotubes (BS-MWNTs) by means of x-ray photoemission spectroscopy (XPS) and transmission electron microscopy. By controlling the NH3/C2H2 flow ratio during the chemical vapor deposition, the nitrogen concentrations of 0.4% to 2.4% were obtained. According to the XPS measurements, the increasing nitrogen concentration gave rise to an increase of the N-sp3 C bonds as well as the deterioration of the crystallinity of the BS-MWNTs. Besides, the N-sp3 C bonds were found to prevail over the N-sp2 C bonds above 5% nitrogen concentration. At higher nitrogen concentrations, the BS-MWNTs showed shorter compartment distances, presumably due to the suppressed surface diffusion of carbon on the catalyst particles.
Effects of spacer thickness on quantum efficiency of the solar cells with embedded Ge islands in the intrinsic layer
Authors: Alguno Arnold , Usami Noritaka , Ujihara Toru , Fujiwara Kozo , Sazaki Gen , Nakajima Kazuo , Sawano Kentaro , Shiraki Yasuhiro
Published: April 2004

We report on the effects of spacer thickness on the external quantum efficiency (EQE) of the solar cells with Ge islands embedded into the intrinsic region of the Si-based p-i-n diode. The EQE response of the solar cells in the near-infrared region is dependent on the spacer thickness that separates the layers of self-assembled Ge islands. It was found that the EQE response has an optimum value when the spacer thickness can sustain a good vertical ordering of islands. On the other hand, random nucleation of islands due to a thicker spacer layer exhibits an inferior EQE response. Furthermore, a drastic decrease of the EQE response of the solar cells for a thinner spacer layer was observed.
Massively parallel, large-area maskless lithography
Authors: Klosner Marc , Jain Kanti
Published: April 2004

We have developed a high-throughput scanning maskless lithography technology for patterning high-resolution features on large-area substrates. This technology, which features a spatial light modulator array and a seamless-stitching scanning technique, was used to perform imaging exposures at micron-level resolution, patterning seamlessly over exposure areas significantly larger than the field size of the projection lens. This technology is attractive for a variety of applications that currently rely on mask-based lithographic processes.
Magnetic patterning of exchange-coupled multilayers
Authors: Demidov Vladislav E. , Kholin Dmitry I. , Demokritov Sergej O. , Hillebrands Burkard , Wegelin Frederik , Marien Jan
Published: April 2004

The local modification of antiferromagnetic (AF) interlayer exchange coupling by focused ion-beam irradiation has been studied experimentally in the epitaxial Fe/Cr/Fe(001) trilayer systems. Square ferromagnetic (FM) areas of 200×200 μm2 were created in the initially AF trilayer by ion irradiation with a fluence of 1015 ions/cm2. It was found, that in the range of the external magnetic field of about ±200 Oe, the change of magnetic properties at the boundaries separating FM and AF areas occurs within distances of less than 200 nm. This fact allows the use of the technique for magnetic patterning of antiferromagnetically coupled trilayers on the submicrometer scale.
Visualization of electrochemical doping and light-emitting junction formation in conjugated polymer films
Authors: Gao Jun , Dane Justin
Published: April 2004

In situ electrochemical doping and light-emitting junction formation in conjugated polymer films have been visualized by direct imaging of a massive planar device structure under UV illumination. Both p- and n-doping of conjugated polymers have been observed. When the p- and n-doped regions meet, a light-emitting p–n junction forms and significant current flow begins. The reversal of applied bias creates many tiny and transient light-emitting p–n junctions in the previously n-doped region by the uneven growth of new p-doped areas. Eventually a stable emission zone is formed closer to the new cathode, from a polymer film that shows almost no photoluminescence due to doping.
Superconducting properties of the 18 K phase in yttrium sesquicarbide system
Authors: Nakane T. , Mochiku T. , Kito H. , Itoh J. , Nagao M. , Kumakura H. , Takano Y.
Published: April 2004

The metastable phase of an yttrium sesquicarbide compound, which was recently reported as having a superconductive phase with a Tc of 18 K (18 K phase), was prepared under high pressure from the nominal composition of Y2C3 and Y2C2.9B0.1 in order to investigate this phase. We have succeeded in reproduction, and in the transport measurement for this 18 K phase. It is considered that the reason for the higher Tc than the 11.5 K reported previously is not the small amount of B as the impurity element from the BN crucible. The Bc2 at 0 K estimated from the resistivity data for the 18 K phase seems to be over 30 T. It means that the Tc and the Bc2 of the 18 K phase are as high as those of the general A15-type intermetallic compounds.
Role of free carriers from two-photon absorption in Raman amplification in silicon-on-insulator waveguides
Authors: Liang T. K. , Tsang H. K.
Published: April 2004

We show experimentally that free carriers generated by two-photon-absorption in silicon-on-insulator (SOI) waveguides can introduce large losses which limit the usable pump power for Raman amplification at telecommunication wavelengths. The measured pump loss agreed with a theoretical model of the free-carrier absorption arising from two-photon-induced free carrier generation inside the waveguide.
Nanopropeller arrays of zinc oxide
Authors: Gao Pu Xian , Wang Zhong L.
Published: April 2004

Polar surface dominated ZnO nanopropeller arrays were synthesized by a two-step high temperature solid-vapor deposition process. The axis of the nanopropellers is a straight nanowire along the c axis and enclosed by {21̄1̄0} surfaces, which grew first; the sixfold symmetric nanoblades are later formed along the crystallographic equivalent a axes (〈21̄1̄0〉) perpendicular to the nanowire; and the array is formed by epitaxial growth of nanoblades on the nanowire. The top surface of the nanoblade is the Zn terminated +c plane, showing surface steps and possible secondary growth of nanowires due to higher self-catalytic activity, while the back surface is the oxygen-terminated −c plane, which is smooth and inert.
Influence of surface and grain-boundary scattering on the resistivity of copper in reduced dimensions
Authors: Wu W. , Brongersma S. H. , Van Hove M. , Maex K.
Published: April 2004

We examine the influence of surface and grain-boundary scattering on the total electrical resistivity of copper as dimensions are reduced close to the bulk electron mean free path (39 nm). Through resistivity and grain size characterization on copper wires with sizes down to 95×130 nm2 in a temperature range of 4.2 to 293 K, it was found that the influence of surface scattering is less than previously speculated, while grain-boundary scattering is dominant. A reduction of the background scattering length due to small grains accounts for the observed behavior. The reflection coefficient varies as expected from impurity enrichment in the grain boundaries.
Tunable terahertz emission from difference frequency in biased superlattices
Authors: Liu Ren-Bao , Zhu Bang-Fen
Published: April 2004

The terahertz emission from difference frequency in biased superlattices is calculated with the excitonic effect included. Owing to the doubly resonant condition and the excitonic enhancement, the typical susceptibility is larger than 10−5 m/V. The doubly resonant condition can always be realized by adjusting the bias voltage and the laser frequencies, thus the in situ tunable emission is efficient in the range of 0.5–6 THz. Continuous wave operation with 1% quantum efficiency and microwatt output power is feasible while the signal absorption in undoped superlattices is negligible.
Nanocrystalline diamond from carbon nanotubes
Authors: Sun L. T. , Gong J. L. , Zhu Z. Y. , Zhu D. Z. , He S. X. , Wang Z. X. , Chen Y. , Hu G.
Published: April 2004

Structural phase transformation from multiwalled carbon nanotubes to nanocrystalline diamond by hydrogen plasma post-treatment was carried out. Ultrahigh equivalent diamond nucleation density above 1011 nuclei/cm2 was easily obtained. The diamond formation and growth mechanism was proposed to be the consequence of the formation of sp3 bonded amorphous carbon clusters. The hydrogen chemisorption on curved graphite network and the energy deposited on the carbon nanotubes by continuous impingement of activated molecular or atomic hydrogen are responsible for the formation of amorphous carbon matrix. Diamond nucleates and grows in the way similar to that of diamond chemical vapor deposition processes on amorphous carbon films.