bluuebunny/crossref_metadata_2025 huggingface dataset:
Clinical Characteristics of Photodermatoses in Indian Patients and their Phototesting Findings: A Cross-sectional Study
Authors: Suresh Aishwaria , Thankappan TP
Published: December 2022

Introduction: Phototesting helps to confirm photosensitivity, identify the action spectra, reproduce lesions by photo provocation for biopsy, calculate starting dose of desensitisation therapy, assess the severity of the photodermatoses, and monitor response to treatment. The effect of sunlight on darker skin has only been sparingly studied and hence, this study was undertaken in our population. Aim: To identify the spectrum of photodermatoses, with their clinical characteristics and phototesting findings. Materials and Methods: A cross-sectional study was conducted in Outpatient Department (OPD) of the Department of Dermatology, Pushpagiri Medical College, Tiruvalla, Kerala, India from January to December 2015. A total of 30 patients clinically diagnosed as photodermatoses were subjected to phototesting using the whole body phototherapy unit with Ultraviolet A (UVA) and UVB exposure. After 24 hours the UV-exposed areas were examined for the Minimal Erythema Dose (MED), and for the reoccurrence of skin lesions to determine the action spectra for the disorder, and the values were expressed in mean, frequency, and percentage. Results: Polymorphic Light Eruption (PLE) remains the most common photodermatosis (n=25) with a definite female preponderance (n=19). The mean MED-UVB for type IV skin with photodermatoses was found to be 766 mj/cm2 and for type V skin was found to be 900 mj/cm2 . MED-UVA was not observed in the majority of patients (n=24). Among the 25 patients with PLE, 16 patients had normal MED values to both UVA and UVB, four had reduced MED-UVB alone, one patient to UVA alone, and three patients had reduced MED to both. MED-UVB was not observed in one patient. MED-UVA was not observed in 21 patients (normal). Of the three patients with photoallergic dermatitis, one patient had reduced MED-UVB and MED-UVA. The other two patients had normal MEDs. The chronic actinic dermatitis patient had reduced MED to UVB and UVA and the actinic lichen planus patient had normal MEDs. Conclusion: Phototesting remains a very useful tool in the evaluation and management of photodermatoses and PLE was the most common photodermatoses in studied population.
Social and Poverty Reduction Programme Provided in Chilia and Huancaspata, Peru: A Comparative Study
Authors: Sandoval Marco Antonio Ponce
Published: December 2022

The present research aimed to determine the relationship between the social program together and poverty reduction in the districts of Chilia and Huancaspata, Pataz-2022, the study is conducted with quantitative approach, non-experimental design, causal comparison, count with 90 users of both districts, through the application of the questionnaire for each of them, in order to obtain the program's acquisition rates and poverty level. The results, in the district of Chilia in terms of the social program focuses on a good level 72.2%; where 11.1% is located in regular and 61.1% high in poverty, and in the district of Huancaspata in 51.1% good; where 4.4% focus on regular and 46.7% high on poverty. In the same way, rho = 0.762 ** and rho = 0.838** and p < 0.05 are evidenced, therefore the Ha is admitted and the Ho is refuted, therefore, the social program together significantly reduces the reduction of poverty in the districts of Chilia and Huancaspata, Pataz - 2022. In conclusion, an efficient social program together favorably reduces poverty in the districts.
NMR studies of the methionine methyl groups in calmodulin
Authors: Siivari Kirsi , Zhang Mingjie , Palmer Arthur G. , Vogel Hans J.
Published: July 2002

Calmodulin (CaM) is a ubiquitous Ca2+‐binding protein that can regulate a wide variety of cellular events. The protein contains 9 Met out of a total of 148 amino acid residues. The binding of Ca2+ to CaM induces conformational changes and exposes two Met‐rich hydrophobic surfaces which provide the main protein‐protein contact areas when CaM interacts with its target enzymes. Two‐dimensional (1H,13C)‐heteronuclear multiple quantum coherence (HMQC) NMR spectroscopy was used to study selectively 13C‐isotope labelled Met methyl groups in apo‐CaM, Ca2+‐CaM and a complex of CaM with the CaM‐binding domain of skeletal muscle Myosin Light Chain Kinase (MLCK). The resonance assignment of the Met methyl groups in these three functionally different states were obtained by site‐directed mutagenesis (Met→Leu). Chemical shift changes indicate that the methyl groups of the Met residues are in different environments in apo‐, calcium‐, and MLCK‐bound‐CaM. The T
1 relaxation rates of the individual Met methyl carbons in the three forms of CaM indicate that those in Ca2+‐CaM have the highest mobility. Our results also suggest that the methyl groups of the unbranched Met sidechains in general are more flexible than those of aliphatic amino acid residues such as Leu and Ile.
Clinical evaluations of a new ovarian cancer marker, COX‐1
Authors: Lee G. , Ng H.‐T.
Published: July 2002

A monoclonal antibody was generated against an ovarian cancer cell line, OC‐3‐VGH and was shown to recognize a unique tumor‐associated antigen, COX‐1 found in ovarian or cervical tumors. COX‐1 can be detected in the cultured shed medium of several ovarian/cervical cancer cell lines, and in the sera of ovarian or cervical cancer patients when assayed by a sandwich immunoassay kit employing this monoclonal antibody. Multi‐medical centers clinical trials have been conducted since 1989 to evaluate the efficacy of using this immunoassay procedure for the cancer monitoring. In the case of ovarian cancer, COX‐1 immunoassay kit has the sensitivity of 68% as compared to 71% for the corresponding CA 125 kit. When both COX‐1 and CA 125 kits were combined for the simultaneous monitoring of cancer patients, the sensitivity could be increased to as high as 87%. Further analysis revealed that serum COX‐1 levels in cancer patients are correlated with stages of tumor progression. Following the surgical removal of tumors, greater than 50% of the cancer patients showed dramatic and significant decrease of serum levels of COX‐1 antigen. The results of these multi‐center clinical studies clearly suggested that COX‐1 is a suitable marker for the monitoring and diagnosis of ovarian cancer patients, when used alone or in combination with CA 125.
A segment corresponding to amino acids Gln199‐Lys208 of murine IL‐1α cross‐reacts with an antigenic determinant localized in the Z‐line of Drosophila melanogaster myofibrils
Authors: Riparbelli Maria Giovanna , Callaini Giuliano , Dallai Romano
Published: July 2002

Summry— Immunofluorescence microscopic observations indicated that a monoclonal antibody, Vmp 18, raised against the peptide 199–208 of murine interleukin 1α, cross‐reacted with an antigenic determinant of Drosophila thorax muscles. Immunoelectron microscopic analysis showed that the gold particles were mainly localized in the Z‐line which is the attachment site of thin filaments from adjacent sarcomeres. On the contrary, the antibody failed to mark the Z‐line in vertebrate skeletal muscle. A Western blot of total protein extract from Drosophila thorax muscles bound a protein of 43 kDa. Our observations suggest that the Vmp 18 antibody could contribute to clarify the composition of the Z‐line in insect's flight muscles.
Purification and characterisation of epithiospecifier protein from Brassica napus: enzymic intramolecular sulphur addition within alkenyl thiohydroximates derived from alkenyl glucosinolate hydrolysis
Authors: Foo Hooi L. , Grønning Line M. , Goodenough Lucy , Bones Atle M. , Danielsen Brit-Eli , Whiting Don A. , Rossiter John T.
Published: July 2002

Epithiospecifier protein (ESP), a ferrous ion dependent protein, has a potential role in regulating the release of elemental sulphur, nitriles, isothiocyanates and cyanoepithioalkanes from glucosinolates. Two classes of ESP polypeptides were purified with molecular masses of 39 and 35 kDa, and we show that the previously reported instability was conditionally dependent. The 39 kDa polypeptide was made up of two distinct isozymes (5.00, 5.14) whilst several were present for the 35 kDa form of ESP (5.40–5.66). An anti‐ESP antibody reacted with both the 39 and 35 kDa ESP forms in Brassica napus and strongly with a polypeptide corresponding to the 35 kDa ESP form in Crambe abyssinica, but did not detect any ESP in Sinapis alba or Raphanus sativus. A cytochrome P‐450 mediated iron dependent epoxidation type mechanism is suggested for ESP.
D‐Serine inhibits serine palmitoyltransferase, the enzyme catalyzing the initial step of sphingolipid biosynthesis
Authors: Hanada Kentaro , Hara Tomoko , Nishijima Masahiro
Published: July 2002

Serine palmitoyltransferase (SPT), responsible for the initial step of sphingolipid biosynthesis, catalyzes condensation of palmitoyl coenzyme A and L‐serine to produce 3‐ketodihydrosphingosine (KDS). For determination of the stereochemical specificity of the amino acid substrate, a competition analysis of the production of [3H]KDS from L‐[3H]serine was performed using purified SPT. D‐Serine inhibited [3H]KDS production as effectively as non‐radioactive L‐serine, whereas neither D‐alanine nor D‐threonine showed any significant effect. Incubation of purified SPT with [palmitoyl 1‐14C]palmitoyl coenzyme A and D‐serine did not produce [14C]KDS, while the control incubation with L‐serine did. These results suggest that D‐serine competes with L‐serine for the amino acid recognition site of SPT, but that D‐serine is not utilized by this enzyme to produce KDS.
Aminopeptidase N isoforms from the midgut of Bombyx mori and Plutella xylostella – their classification and the factors that determine their binding specificity to Bacillus thuringiensis Cry1A toxin
Authors: Nakanishi Kazuko , Yaoi Katsuro , Nagino Yasushi , Hara Hirotaka , Kitami Madoka , Atsumi Shogo , Miura Nami , Sato Ryoichi
Published: July 2002

Novel aminopeptidase N (APN) isoform cDNAs, BmAPN3 and PxAPN3, from the midguts of Bombyx mori and Plutella xylostella, respectively, were cloned, and a total of eight APN isoforms cloned from B. mori and P. xylostella were classified into four classes. Bacillus thuringiensis Cry1Aa and Cry1Ab toxins were found to bind to specific APN isoforms from the midguts of B. mori and P. xylostella, and binding occurred with fragments that corresponded to the BmAPN1 Cry1Aa toxin‐binding region of each APN isoform. The results suggest that APN isoforms have a common toxin‐binding region, and that the apparent specificity of Cry1Aa toxin binding to each intact APN isoform seen in SDS–PAGE is determined by factors such as expression level in conjunction with differences in binding affinity.
Production of a recombinant antimicrobial peptide in transgenic plants using a modified VMA intein expression system
Authors: Morassutti Carla , De Amicis Francesca , Skerlavaj Barbara , Zanetti Margherita , Marchetti Stefano
Published: July 2002

Tobacco plants were engineered to express SMAP‐29, a mammalian antimicrobial peptide of innate immunity, as fusion protein with modified vacuolar membrane ATPase intein. The peptide was purified taking advantage of the intein‐mediated self‐cleaving mechanism. SMAP‐29 was immunologically detected in the chromatographic eluate and appeared tightly bound to copurified plant proteins. Electrophoretic separation under disaggregating conditions indicated that the recombinant peptide was cleaved off by intein at the expected site and an overlay gel assay demonstrated that the peptide retained antimicrobial activity. These results indicate that a modified intein expression system can be used to produce pharmaceutical peptides in transgenic plants.
Lack of modulation of the galectin‐3 and asialoglycoprotein receptor transcription in hepatocarcinoma of transgenic mice
Authors: Hébert Eric , Monsigny Michel
Published: July 2002

Galectin‐3 and asialoglycoprotein receptor are lectins belonging to the classes of soluble lectins and of membrane C type lectins respectively. Conflicting results have been reported concerning their transcription level in the time course development of tumours. In the present study we investigated the abnormalities and the transcription levels of galectin‐3 and asialoglycoprotein receptor genes in liver‐targeted SV40 large T transgenic mice related to normal mice. In the strain expressing the highest level of large T, 100% of the male mice reproducibly developed an hepatocarcinoma. We provide evidence that the galectin‐3 and asialoglycoprotein receptor genes are stable in such mice. The galectin‐3 gene is weakly transcribed and its level is identical and constant in normal and transgenic mice, suggesting a lack of involvement in the development of large T‐induced hepatocarcinoma. The asialoglycoprotein receptor gene is actively transcribed and its level remains high all along the development of the tumour; therefore, in such an hepatocarcinoma the asialoglycoprotein receptor could be used to take up drugs, genes or oligonucleotides associated with glycosylated carriers bearing galactose residues in a terminal non‐reducing position.
Language and Identity in Kazakhstan: Formulations in Policy Documents 1987–1997
Authors: Fierman William
Published: July 2002

In the twentieth century the identity of Kazakhstan and the Kazakh people has been closely intertwined with the identity of Russia and the Russian people. Since Kazakhstan began to move toward sovereignty in the late 1980s, official republic documents relevant to language have reflected attempts to redefine republic and ethnic identity. This study traces the evolution of images of identity through examination of the title of language laws, legally declared status for Kazakh, Russian, and other languages, linguistic requirements for employment, and differential treatment of Kazakhs and non-Kazakhs. The continuing debate on language demonstrates that even though Kazakhstan is now an independent country, fundamental questions remain about its identity.
Human Chymotrypsinogen B Production with Pichiapastoris by Integrated Development of Fermentation and Downstream Processing. Part 1. Fermentation
Authors: Curvers Simon , Brixius Peter , Klauser Thomas , Thömmes Jörg , Weuster‐Botz Dirk , Takors Ralf , Wandrey Christian
Published: July 2002

Based on an integrated approach of genetic engineering, fermentation process development, and downstream processing, a fermentative chymotrypsinogen B production process using recombinant Pichia pastorisis presented. Making use of the P. pastorisAOX1‐promotor, the demand for methanol as the single carbon source as well as an inducer of protein secretion enforced the use of an optimized feeding strategy by help of on‐line analysis and an advanced controller algorithm. By using an experimental system of six parallel sparged column bioreactors, proteolytic product degradation could be minimized while also optimizing starting conditions for the following downstream processing. This optimization of process conditions resulted in the production of authentic chymotrypsinogen at a final concentration level of 480 mg·L−1 in the whole broth and a biomass concentration of 150 g·L−1 cell dry weight, thus comprising a space‐time yield of 5.2 mg·L−1·h−1. Alternatively to the high cell density fermentation approach, a continuous fermentation process was developed to study the effects of reduced cell density toward oxygen demand, cooling energy, and biomass separation. This development led to a process with a highly increased space‐time yield of 25 mg·L−1·h−1 while reducing the cell dry weight concentration from 150 g·L−1 in fed‐batch to 65 g·L−1 in continuous cultivation.
Non‐equilibrium spatio‐temporal patterns in models of non‐linear plankton dynamics
Authors: MALCHOW HORST
Published: July 2002

1. Mathematical models of biological population dynamics have not only to account for growth and interactions but also for spatial processes, like random or directed and joint or relative motion of species, as well as the variability of the environment.

2. Early attempts began with physico‐chemical diffusion, exponential growth and Lotka‐Volterra type interactions. These approaches have been continuously refined to more realistic descriptions of the development of natural populations.

3. The main aim of this paper is to give an extensive introduction to the subject and the bibliography. It then focusses on minimal models of the temporally and spatially continuous dynamics of freshwater and marine plankton as well as other microorganisms, which is best described by non‐linear reaction–diffusion and advection equations.

4. The fascinating variety of spatio‐temporal patterns in such systems and the governing mechanisms of their generation and further dynamics are introduced, making use of a model example of the nutrient–plankton–fish food chain. The formation of rotating spiral patterns is presented.
Non‐traumatic spinal extradural haematoma: Magnetic resonance findings
Authors: Smith Em Law, Pj , Fitt G , Hennessy OF
Published: July 2002

Non‐traumatic extradural spinal haematoma is an uncommon condition that is usually associated with a poor outcome. It may present acutely with signs and symptoms of major neurological dysfunction secondary to cord compression, or subacutely over a number of days or weeks with fluctuating symptoms. The exact aetiology of this condition is incompletely understood, but it is believed that the blood is venous in origin, as distinct from the arterial origin of intracranial extradural haematomas. Causes of non‐traumatic extradural spinal haematoma include anticoagulation, vasculitis such as systemic lupus erythematosus (SLE), and spinal arteriovenous malformations. Conditions that may mimic an acute spinal haematoma include extradural abscess and extradural metastatic infiltration. It is important to make a diagnosis of extradural compression because surgery may offer the best hope in restoring neurological function in these patients. Imaging modalities used for the investigation of extradural haematomas include myelography, CT myelography (CTM) and MRI with or without gadolinium enhancement. The MR appearances of acute extradural abscess and extradural tumour can mimic an extradural haematoma. In subacute haematoma, owing to the magnetic properties of blood degradation products, MR is more specific in diagnosing and ageing of the haematoma.
Group A streptococcal myositis
Authors: Daley AJ , Atkinson M , Nallusamy R
Published: July 2002

Abstract: Myositis is a relatively uncommon presentation of group A streptococcal infection. We present a case of a 3‐year‐old girl with group A streptococcal myositis primarily involving the soleus muscle. Magnetic resonance imaging was valuable in localizing the affected muscle and avoiding surgical exploration.
Risk and representation: older people and noncompliance
Authors: Chater Keri
Published: July 2002

In this paper it is argued that the way in which ageing is portrayed is culturally constructed and historically located. The terminology used to describe older people becomes part of nursing taxonomy but the issue that it is a cultural construct remains hidden. Nurses use histories and records as a means of communication about the condition of the client or patient. The notes mediate the way in which the patient comes to be known as an individual in need of services and help define the way in which nursing care is undertaken. Nursing notes help construct the ‘manageable’ patient. Noncompliance disrupts this notion of the manageable patient and it challenges medical and nursing dominance of the body. However, noncompliance then becomes reinterpreted as ‘risk’, which has the effect of extending the clinical gaze from the confines of the body to extra‐corporeal spaces. Older people, because of their corporeality, can subvert and resist this clinical gaze.
Development and validation of an audit instrument: the Prostate Outcomes Questionnaire
Authors: Lamping  , Rowe  , Black  , Lessof
Published: July 2002

Objective

 To develop a short, patient‐based questionnaire for auditing the outcomes of treatment for benign prostatic hyperplasia (BPH) and to evaluate the acceptability, reliability and validity of the measure.

Patients and methods

 Data from a long research questionnaire used in the Oxford/North West Thames Prostatectomy Study were analysed to identify the subset of items which contained the most scientifically sound indicators of outcome. Items were selected on the basis of standard psychometric analyses to develop a short questionnaire, the Prostate Outcomes Questionnaire (POQ), a 27‐item instrument covering urinary symptoms, complications after surgery, quality of life and patient satisfaction with outcome. The POQ was field tested for acceptability, reliability and validity in a postal survey of 125 men undergoing transurethral resection of the prostate for BPH from seven hospitals in south‐east England.

Results

 The POQ was highly acceptable to patients, as indicated by a 95% response rate, the absence of ‘floor’ and ‘ceiling’ effects and a low proportion of missing data. It showed excellent internal consistency reliability (Cronbach’s α of 0.82–0.93 for the five summary scales and a mean item‐total correlation of 0.56) and test‐retest reliability (test‐retest correlations for items were 0.40–1.00, with a mean test‐retest correlation of 0.85, and for summary scales of 0.91–0.95). Construct validity was confirmed by: high intercorrelations between the five summary scales and the total score (0.88–0.95), with a pattern of intercorrelations among specific subscales that showed item‐convergent and discriminant validity; higher scores for patients who reported an improvement after surgery than in those who were not improved (P<0.001); the expected gradient of scores for patients reporting different levels of symptom distress (P<0.001); high correlations with the longer parent questionnaire (0.75–0.88); and low to moderate correlations with the Nottingham Health Profile and Activities of Daily Living scores (0.15–0.67), with the pattern of correlations providing evidence of scale convergent and discriminant validity. Correlations with age and social class were low, suggesting that responses were not biased by sociodemographic factors.

Conclusion

 The POQ is a practical and scientifically sound patient‐based measure of outcome after treatment for BPH which can be used for routine audit. It takes <5 min to complete, is feasible for routine monitoring of large numbers of patients by postal survey, and is accompanied by a Users’ Manual which provides practical help in conducting a local patient survey, and a computer program for scoring data. Most importantly, the POQ has been shown scientifically to perform well, having met standard psychometric criteria for reliability and validity.
Parenteral polyoestradiol phosphate vs orchidectomy in the treatment of advanced prostatic cancer. Efficacy and cardiovascular complications: a 2‐year follow‐up report of a national, prospective prostatic cancer study
Authors: Mikkola  , Ruutu  , Aro  , Rannikko  , Salo on behalf of the Finnprostate Group
Published: July 2002

Objective

 To evaluate the clinical efficacy and cardiovascular complications of orchidectomy or polyoestradiol phosphate (PEP) in the treatment of advanced prostatic cancer.

Patients and methods

 In a prospective, randomized study 444 patients (mean age 73 years, range 45–91) with T3–4 M0 or T1–4 M1 prostatic cancer were treated either by orchidectomy (group 1, n=217) or parenteral PEP (group 2, n=227; 240 mg/month). The patients were examined at 3 and 6 months after start of the therapy and thereafter every 6 months; they were also assessed whenever they had symptoms indicating progression. Possible cardiovascular complications included myocardial infarction, cerebrovascular accident, pulmonary embolism and deep vein thrombosis.

Results

 After a follow‐up of 2 years there was no statistically significant difference between the groups in progression‐free time; 65 of 217 (30%) patients in group 1 showed evidence of progression, including seven (3%) who died from prostate cancer. In group 2, 64 of 227 (28%) patients showed progression and eight (3.5%) died from prostatic cancer. There were 10 (5%) cardiovascular complications in patients in group 1, including five (2%) cardiovascular deaths; in group 2 there were 24 (11%) and 14 (6%), respectively. During the first year of treatment there were three (1.4%) cardiovascular complications in group 1 and 14 (6%) in group 2 (P<0.05), and during the second year, seven (4%) and 10 (6%), respectively.

Conclusion

 Parenteral PEP (240 mg/month) seems to be as efficient as orchidectomy in inhibiting disease in patients with advanced prostatic cancer (T3–4 M0 and T1–4 M1). There were more cardiovascular complications in patients treated with PEP than after orchidectomy; the difference was statistically significant during the first year of treatment.
Correcting lens system for perimetry
Authors: Henson David B. , Earlam Richard A.
Published: July 2002

A lens system to correct for both refractive error and perimeter test distance is frequently needed for accurate perimetry. Patients often lack appropriate near vision corrections and full aperture trial case lenses, when they are available, barely cover the central 30° and hence frequently produce lens rim artefacts. A special system of correction lenses has been developed for perimetry which overcomes these problems. This system is head mounted, being based upon the Essilor presbyopia demonstration set, and is suitable for use with most perimeters.
Shared care within the HES‐experience from the Walton diabetic eye screening service
Authors: Dengler‐Harles Maria , Laws Fiona , Clark David , Hancock Richard
Published: July 2002

Hospital optometrists are involved in the care of diabetic patients in a variety of ways, e.g. performing screening as well as training, coordinating and acting in an advisory capacity in local schemes involving GOS optometrists. In response to local need and purchaser interest, an optometrically led diabetic eye screening service has been set up at Walton Hospital. All patients are referred from the Walton Hospital Diabetic Centre, screened by the hospital optometrists and either reviewed by the optometrists or referred to an ophthalmologist routinely for review or referred immediately if it is considered that laser treatment may be required.

This paper reports on the protocols, implementation and first year of operation of the service. Patients referred to the clinic were those who had not had an eye examination within the last 12 months (excluding newly diagnosed insulin‐dependent patients) and all newly diagnosed non‐insulin dependent diabetics. An audit was performed over the first 3 months (n = 85). At the same visit, each patient was examined by an HES optometrist using a Volk lens with dilation, the patient was assessed by a consultant ophthalmologist with a specialty interest in diabetics and retinal photography was performed. The same consultant also assessed the slides. The mean age of the patients was 64 years (SD 12 years) and only 6.0% were frank type 1 insulin‐dependent patients.

Laser treatment for retinopathy was required in 7.1% of patients and other treatable pathology was found in 9.4% of patients. When compared with the consultant's assessment, the optometrists' examination showed a sensitivity of 87.5% and specificity of 93.5% in the detection and appropriate referral of diabetic eye disease. Peripheral new vessels were missed in one patient due to the presence of lens opacities, and thus the patient was referred routinely instead of immediately. Using the photographic technique, a significant number of images were ungradeable due to poor quality, and the sensitivity was only 66.7%. The lower sensitivity resulted from the inability to detect macula oedema in the absence of hard exudates and peripheral proliferative retinopathy outside the field photographed. In addition, inadequate resolution confounded the detection of microaneurysms in non‐referrable cases. Over the following 9 months a further 182 patients were examined. Laser treatment for retinopathy was required in 6.6% of patients and other treatable pathology was found in 8.2% of patients.

Additional funding to expand the service in 1995 has been successfully sought from the purchasers. The results and experiences from this study will be considered in relation to the HES optometrist working within a trust, the St Vincent's declaration and some economic aspects of diabetic healthcare.
Distribution of γ‐Tubulin in Higher Plant Cells: Cytosolic γ‐Tubulin is Part of High Molecular Weight Complexes
Authors: Stoppin‐Mellet V. , Peter C. , Lambert A. M.
Published: July 2002

Abstract: γ‐Tubulin is a protein found in all eukaryotic cells, where it plays a key role in the nucleation of microtubules. In higher plant cells, γ‐tubulin is localized at the nuclear surface, a known microtubule‐organizing centre, and is codistributed with all microtubule arrays. Functions of plant γ‐tubulin remain to be determined. This study describes some properties of higher plant γ‐tubulin. The overall level of γ‐tubulin was constant during the cell cycle in synchronized tobacco BY‐2 cells. Biochemical analysis of the subcellular distribution of γ‐tubulin in maize cells revealed that, in contrast with animal γ‐tubulin, plant γ‐tubulin is mainly associated with endomembranes. We showed for the first time that the pool of soluble cytosolic γ‐tubulin contained two main γ‐tubulin complexes. γ‐tubulin, Hsp70 and TCP1‐related proteins might interact in a small complex of 750 kDa. A second γ‐tubulin complex, larger than 1500 kDa was purified. The protein profile of this large complex was very similar to animal γ‐tubulin complexes. The putative functions of these two complexes in plant microtubule nucleation are discussed.
Relationship Between Growth, Secondary Metabolism, and Resistance of Apple
Authors: Rühmann S. , Leser C. , Bannert M. , Treutter D.
Published: July 2002

Abstract: The paper shows that N‐induced vigorous shoot growth increases susceptibility of apple trees to Venturia inaequalis. This is due to a weakened defence in infected leaves of the high N cultures showing large lesions with excessive sporulation, whereas infected leaves from the low N cultures exhibited successful defence with only small chlorotic lesions and no sporulation. This might be explained by biosynthesis of phenylpropanoids in the young leaves of the resistant trees. A negative correlation between shoot growth of apple trees and the concentration of phenolic compounds in young leaves was found. Studies on in vitro shoot cultures revealed that the availability of sugars for the phenylpropanoid pathway is a strong regulatory factor. The ratio of sucrose and nitrogen in the medium influenced the total level of secondary products in the in vitro grown plantlets. Moreover, the relative deficiency of sugars was responsible for a metabolic block mainly at the level of glucosyl transferase and concomitant aglycone accumulation.
Comparison of SiIII-SiV and SiIII-VIII diffusion models in III-V heterostructures lattice matched to GaAs
Authors: Deppe D. G. , Plano W. E. , Baker J. E. , Holonyak N. , Ludowise M. J. , Kuo C. P. , Fletcher R. M. , Osentowski T. D. , Craford M. G.
Published: July 2002

The diffusion of SiIII-SiV neutral pairs versus the diffusion of SiIII-VIII complexes in III-V crystals is compared in the light of experimental data showing the effect of Si diffusion on self-diffusion of column III and column V lattice atoms. Secondary-ion mass spectroscopy is used to compare the enhanced diffusion of column III or column V atoms in several different Si-diffused heterostructures closely lattice matched to GaAs. Enhancement of the lattice-atom self-diffusion, via impurity diffusion, is found to occur predominantly on the column III lattice. Supporting the SiIII-VIII diffusion model, these data indicate that the main native defects accompanying the Si diffusion are column III vacancies, which diffuse directly on the column III sublattice.
Nature of the pulsed laser process for the deposition of high T
c superconducting thin films
Authors: Venkatesan T. , Wu X. D. , Inam A. , Jeon Y. , Croft M. , Chase E. W. , Chang C. C. , Wachtman J. B. , Odom R. W. , di Brozolo F. Radicati , Magee C. A.
Published: July 2002

The pulsed laser thin-film deposition process can enable preparation of thin films of complex composition with good control over the film stoichiometry. The film compositions are similar to that of the target pellet and as a consequence this technique appears to be an ideal method for preparing high Tc thin films on a variety of substrates.The factors which contribute to this beneficial phenomenon have been explored by a laser ionization mass spectrometry (LIMS) and a post ablation ionization (PAI) neutral velocity analysis technique in order to determine the mass and velocities of the laser ejected material. In addition, x-ray absorption measurements on films deposited onto substrates at room temperature were performed in order to identify the presence of short-range crystalline order in the films. Both of these studies rule out the ejection of stoichiometric clusters of material from the pellet during the laser ablation/deposition process. Instead, binary and ternary suboxides are emitted from the target pellet. These suboxides most likely have unit sticking coefficient to the substrate which could contribute to the preservation of the film stoichiometry. The velocity distribution of several neutral species (e.g., BaO) indicates that particles have energies of several eV. Thus the effective temperatures of the emitted species are ∼15×103 K, and these energetic particles may facilitate growth of the crystalline films at low substrate temperatures.
Highly oriented as-deposited superconducting laser ablated thin films of Y1Ba2Cu3O7−δ on SrTiO3, zirconia, and Si substrates
Authors: Koren G. , Polturak E. , Fisher B. , Cohen D. , Kimel G.
Published: July 2002

KrF excimer laser ablation of an Y1Ba2Cu3O7−δ pellet in 0.1–0.2 Torr of O2 ambient was used to deposit thin superconducting films onto SrTiO3, yttria-stabilized zirconia (YSZ), and silicon substrates at 600–700 °C. The as-deposited 1-μm-thick films at 650–700 °C substrate temperature were superconducting, without further high-temperature annealing. All films had a similar Tc onset of ∼92 K but different zero-resistance Tc of 90, 85, and 70 K for the films on SrTiO3, YSZ, and Si substrates, respectively. Angular x-ray diffraction analysis showed that all the films were highly oriented with the c axis perpendicular to their surface. Critical current densities at 77 K were about 40 000 and 10 000 A/cm2 for the films on SrTiO3 and YSZ, respectively. Smooth surface morphology was observed in all films, with occasional defects and cracks in the films on YSZ, which seems to explain the lower critical current in these films.
Investigation of harmonic generation in the alternating magnetic response of superconducting Y-Ba-Cu-O
Authors: Shaulov A. , Dorman D.
Published: July 2002

The magnetic behavior of a sintered Y-Ba-Cu-O superconductor has been investigated by monitoring the harmonic components of its magnetic response to an alternating field. As the steady bias field is incrementally raised, a transition from a linear, reversible behavior of the magnetization to a nonlinear, irreversible behavior is indicated by the appearance of magnetic losses and odd harmonic components in the response. These harmonics disappear as the bias field or the temperature is increased above a certain point, indicating a linear behavior. The disappearance of the odd harmonics, while the magnetic losses persist, is interpreted as signifying a transition to a state of dissipative flux motion without pinning. These measurements demonstrate a new technique for determination of the lower critical field and the ‘‘irreversibility’’ field below which irreversibility in the magnetization sets in as a result of flux pinning.
Generation of tunable 9 femtosecond optical pulses in the near infrared
Authors: Becker P. C. , Fragnito H. L. , Fork R. L. , Beisser F. A. , Shank C. V.
Published: July 2002

We report the generation of tunable femtosecond pulses in the 800–850 nm range. These pulses were obtained by generating a femtosecond continuum and selectively amplifying a portion of that continuum. The amplified femtosecond infrared pulses thus obtained were then compressed to a duration of 9 fs by a fiber followed by a grating and prism sequence.
Study of novel chemical surface passivation techniques on GaAs p
n junction solar cells
Authors: Mauk M. G. , Xu S. , Arent D. J. , Mertens R. P. , Borghs G.
Published: July 2002

Novel methods of GaAs surface passivation are investigated. Passivation is acheived by simple chemical treatments using aqueous solutions of Na2S, KOH, RuCl3, and K2Se. GaAs pn homojunction solar cells are used to evaluate the effectiveness of these passivation techniques. A significant reduction in minority-carrier surface recombination velocity is demonstrated. In the best case, the surface recombination velocity decreased from 5×106 cm/s (untreated surface) to 103 cm/s. In addition, we observe improvements in solar cell photogenerated current, short wavelength spectral response, open-circuit voltage, and junction ‘‘dark’’ current.
Mass spectroscopic investigation of the CH3 radicals in a methane rf discharge
Authors: Toyoda H. , Kojima H. , Sugai H.
Published: July 2002

Neutral CH3 radicals in a capacitively coupled rf discharge in methane have been detected with a quadrupole mass spectrometer utilizing a threshold ionization technique. The absolute density of CH3 radicals was measured at pressures from 0.5 to 20 mTorr, together with the ionic composition of the methane plasma. The principal ionic species were CH+5 and C2H+5 , except in the low-pressure region, suggesting the importance of ion-molecule reactions in the plasma. The lifetime of CH3 radicals in the afterglow of pulsed rf discharges was measured and explained in terms of the recombination reaction CH3 +CH3 →C2 H6.
Ultrafast imaging of ultraviolet laser ablation and etching of polymethylmethacrylate
Authors: Srinivasan R. , Braren Bodil , Casey Kelly G. , Yeh Mildred
Published: July 2002

Ablation and etching of the surface of polymethylmethacrylate (PMMA) by pulses of 248 nm laser radiation [∼20 ns full width at half maximum (FWHM)] have been probed by pulses of visible laser radiation (596 nm; <1 ns FWHM). The results were recorded photographically. Modification of the surface structure of the polymer is first visible at 12 ns and appears to be complete in about 60 ns. Emerging solid material, preceded by a shock wave which first becomes visible at 60 ns, reaches a maximum in intensity at 6 μs and continues until about 20 μs. The average velocity of the solid material, which is probably a low molecular weight polymer of PMMA, is 1.5×104 cm/s.
Calculation of phonon-assisted tunneling and valley current in a double-barrier diode
Authors: Chevoir F. , Vinter B.
Published: July 2002

We have calculated the longitudinal optical phonon scattering contribution to electron tunneling through a double-barrier diode. Our model takes into account the delocalization of the incident electron over the whole structure as well as the momentum transfer between electrons and phonons. Our results, obtained without fitting parameters, give considerably improved estimates of the experimentally observed valley current and its dependence on temperature.
Noncritically phase-matched frequency doubling using 994 nm dye and diode laser radiation in KTiOPO4
Authors: Risk W. P. , Payne R. N. , Lenth W. , Harder C. , Meier H.
Published: July 2002

The characteristic properties of noncritically phase-matched frequency doubling in KTiOPO4 have been investigated using ∼1 μm radiation from a Styryl-13 dye laser. Noncritically phase-matched type II second-harmonic generation was found to occur at 994.3 nm. The unusually wide angle, temperature, and wavelength tolerances observed for this nonlinear process are attractive for the design of practical blue-green laser sources. A special strained-layer InGaAs diode laser was fabricated to operate at 994 nm and generation of blue-green 497 nm radiation by noncritically phase-matched frequency doubling was demonstrated.
Effects of the local environment on the properties of D
X centers in Si-doped GaAs and dilute AlxGa1−xAs alloys
Authors: Calleja E. , Garcia F. , Gomez A. , Muñoz E. , Mooney P. M. , Morgan T. N. , Wright S. L.
Published: July 2002

Si-doped GaAs and dilute AlxGa1−xAs alloys under hydrostatic pressure have been studied using deep level transient spectroscopy (DLTS). In GaAs the DLTS spectrum of the DX center is a single peak. In AlGaAs however, multiple peaks, resulting from different thermal emission rates from donors having different numbers of Al atoms as near neighbors, are observed. The pressure dependence of the electron occupation of individual DX levels shows that the larger the number of Al atoms near the Si donor, the lower the energy position of the DX level.
Preparation of magnetic tips for a scanning force microscope
Authors: den Boef A. J.
Published: July 2002

A simple technique for peparing magnetic tips used in a scanning force microscope is described. In this technique a thin layer of ferromagnetic material is deposited on an etched tungsten tip via sputtering or galvanic deposition. Images of magnetic domains obtained with these tips are presented, demonstrating a lateral resolution of the order of 50–100 nm.
Charge trapping properties in thin oxynitride gate dielectrics prepared by rapid thermal processing
Authors: Lo G. Q. , Ting W. C. , Shih D. K. , Kwong D. L.
Published: July 2002

In this letter, effects of post-nitridation anneals on charge trapping properties and charge-to-breakdown (Qbd) of thin (∼8.6 nm) rapidly thermal nitrided (RTN) gate SiO2 have been studied. Post-nitridation anneals consist of either rapid thermal reoxidation (RTO) in pure O2 or rapid thermal anneal (RTA) in pure N2 ambient. Both the gate voltage shift (ΔVg) and flatband voltage shift (ΔVfb) have been used to characterize the charge trapping properties under Fowler–Nordheim electron injection. It is found that both RTO and RTA reduce ΔVfb and/or ΔVg resulting from the reduction of trapped electrons as well as high-field stress-induced positive charge generation. Positive charge generation resulting from either donor-type interface state generation or trapped holes is discussed. Qbd of RTN SiO2 has been improved after RTO, and can be even larger than that of the thermal SiO2. RTA of RTN SiO2 in N2 also improves Qbd; however, the charge trapping behavior is different from that of RTO/RTN SiO2. The physical mechanism is discussed to account for the observation.
High electrical resistivity diamond films deposited from an oxyacetylene flame
Authors: Tzeng Y. , Tin C. C. , Phillips R. , Srivinyunon T. , Chen Y.
Published: July 2002

Diamond films with electrical resistivity as high as 1014 Ω cm have been deposited on silicon, molybdenum, and other foreign substrates from an oxyacetylene flame. Exposure of the highly resistive diamond films to a hydrogen plasma leads to the decrease of the electrical resistivity by several orders of magnitude. Low level incorporation of atomic hydrogen in the oxyacetylene flame into the diamond film under the flame deposition conditions is believed to be the cause of the high electrical resistivity of the flame-grown diamond films. In contrast to the relatively low resistivity of diamond films deposited in a hydrogen/methane plasma, flame deposition provides a means of growing electrically insulating diamond thin films.
Effect of temperature on the operating characteristics of asymmetric Fabry–Perot reflection modulators
Authors: Yan R. H. , Coldren L. A.
Published: July 2002

The temperature-dependent performance of low-voltage asymmetric Fabry–Perot transverse modulators is studied. While the heavy hole exciton moves with a rate of 2.4 Å/°C, the Fabry–Perot mode shifts with a rate three times slower, 0.8 Å/°C. This can provide a large and nearly constant value of reflection modulation (∼13%/V) over a relatively wide (15 °C) temperature range, as compared to more simple transverse absorption modulators. However, the contrast ratio varies from 15 to 3.5.
Effect of small changes in composition on the electrical and structural properties of YBa2Cu3O7 thin films
Authors: Chew N. G. , Goodyear S. W. , Edwards J. A. , Satchell J. S. , Blenkinsop S. E. , Humphreys R. G.
Published: July 2002

Epitaxial thin films of YBa2Cu3O7 have been grown in situ by evaporation onto (001) MgO substrates. The composition was varied systematically to investigate the effects of changes in Cu content and Ba/Y ratio on the film properties. The results demonstrate that deviations from stoichiometry at the limit of resolution of most analytic techniques can have a large effect on structural and transport properties, as well as causing marked changes in surface morphology. The best properties (Jc≳3×106 A/cm2 at 77 K) are only found for a narrow range of compositions, which can be readily identified from the surface morphology.
Elimination of dark line defects in GaAs-on-Si by post-growth patterning and thermal annealing
Authors: Chand Naresh , Chu S. N. G.
Published: July 2002

Post-growth patterning to <15 μm×15 μm size patterns combined with thermal annealing at 850 °C for ≳15 min eliminates the dark line defects (DLDs) in GaAs-on-Si as shown by the spatially resolved photoluminescence technique. Patterning to small size islands of GaAs facilitates dislocation migration laterally out of the crystal, and thermal annealing provides the activation energy for the dislocations to migrate and interact. Patterning to small size features also significantly reduces the thermally induced biaxial tensile stress as reported earlier. On large size patterns, the density of DLDs is significantly reduced near the surface leaving larger volume of the material free from DLDs.
Amorphization of ion-implanted layers in silicon using photoacoustic detection
Authors: Neto A. Pinto , Vargas H. , Miranda L. C. M.
Published: July 2002

The influence of ion implantation in the thermal properties of silicon wafers at room temperature is investigated using the photoacoustic technique. It is suggested that the observed decrease of the values of both thermal diffusivity and conductivity, as the implantation dose increases, is due to the amorphization of the implanted layer.
Molecular beam epitaxy and characterization of CdTe(211) and CdTe(133) films on GaAs(211)B substrates
Authors: Lange M. D. , Sporken R. , Mahavadi K. K. , Faurie J. P. , Nakamura Y. , Otsuka N.
Published: July 2002

CdTe films were grown in both the (211) and (133) orientations on GaAs(211)B substrates by molecular beam epitaxy. The orientation of the epitaxy is dependent on the thermal cleaning process. Studies of these films included in situ reflected high-energy electron diffraction, x-ray double-crystal diffractometry, transmission electron microscopy, and photoluminescence, which revealed high quality for both CdTe growth orientations, and especially for the CdTe(133). The lattice of the CdTe(211) growth tilts 3° with respect to its GaAs(211) substrate about the CdTe[01̄1]//GaAs[01̄1] coincidence axis. The CdTe(133) has no tilt with respect to its substrate, and its coincidence axes are CdTe[01̄1]//GaAs[01̄1] and CdTe[61̄1̄]//GaAs[1̄11].
Electroluminescence in the visible range during anodic oxidation of porous silicon films
Authors: Halimaoui A. , Oules C. , Bomchil G. , Bsiesy A. , Gaspard F. , Herino R. , Ligeon M. , Muller F.
Published: July 2002

Porous silicon/silicon structures under anodic oxidation conditions give rise to an electroluminescence phenomenon in the visible range. Using an optical multichannel analyzer the spectral distribution of the emitted light was measured−in situ−during the anodic oxidation step. Recorded spectra show a maximum which shifts continuously from red-orange at the beginning of the process towards the yellow range. The visible emission well above the band gap of bulk silicon is attributed to a quantum size effect in the very small size (5–20 Å) silicon island which constitutes the porous silicon skeleton. The light emission is interrupted when the current flow stops due to the formation of a continuous oxide layer at the porous silicon/silicon interface.