bluuebunny/crossref_metadata_2025 huggingface dataset:
Utility of Intraoperative Imprint Cytology in Diagnosis and Grading of Glioma: A Cross-sectional Study
Authors: Chakraborty Shivam , Das Chhanda , Sayantan DE , Sinha Mamata Guha Mallick
Published: April 2022

Introduction: Gliomas are most common primary Central Nervous System (CNS) neoplasm in adult population. Gliomas predominantly arise from brain parenchyma. Invasion of adjacent normal parenchyma is a prominent feature. Aim: To study the epidemiological incidence of glial tumours and the viability and accuracy of intraoperative cytology in diagnosis and grading glial tumours. Materials and Methods: A cross-sectional study was done on 30 patients who underwent excision surgery at Department of Neurosurgery at Institute of Postgraduate Medical Education and Research IPGMER and SSKM, Kolkata, West Bengal, India. Clinically, radiologically confirmed cases of Space Occupying Lesion (SOL) of brain with a history of neurosurgical intervention were included. Patients medically unfit for surgery or without radiological evidence of SOL in the brain were excluded from the study. Intraoperative imprint touch cytology of the specimens was done. Part of the tissue was kept for Formalin Fixation and Paraffin Embedding (FFPE) and subsequent histopathological examination were done. Results of intraoperative imprint cytology were compared with final histopathology report and grading. Matthews correlation coefficient t-test, Kohen's Kappa (κ), Chi square test (χ2 ) were used for the statistical analysis. A p-value of p<0.5 was considered statistically significant. Results: About 10 (33.3%) of the patients presented with frontal lobe lesion. Out of 30 cases 29 (96.6%) were histologically confirmed to be of glial origin, 1 (3.3%) was metastasis from other tumour. These 29 cases were diagnosed as different glial neoplasm on intraoperative imprint cytology and were confirmed by histology. According to histological subtype 12 (41.37%) were glioblastoma, 10 (34.48%) were diffuse astrocytoma, 3 (10.34%) were pilocytic astrocytoma, 3 (10.34%) was ependymoma. Intraoperative impression cytology diagnosis was compared with confirmatory histological diagnosis. Sensitivity and specificity was found to be 93% and 50%, respectively, Positive Predictive Values (PPV) 96%, Negative Predictive Values (NPV) 33%, diagnostic accuracy 89.65% and p<0.5 was statistically significant. Conclusion: In the present study, confirmatory histopathology report showed a significant association with imprint cytology report. Hence, it can be concluded that intraoperative imprint cytology is a fairly accurate, rapid and inexpensive method of diagnosis and grading of gliomas.
Carba M Test for Rapid Detection and Simultaneous Differentiation of Carbapenemases among Clinical Isolates of Gram Negative Bacteria
Authors: Rudresh Shoorashetty Manohar , Basavaraj . , Kusuma MV Naik , Ravi Giriyapura Siddappa
Published: April 2022

Introduction: Carbapenemase production is the most common mechanism of carbapenem resistance. The carbapenemases belongs to class A, class B and class D of Ambler's molecular classification. Various tests have been designed for screening and confirmation of these enzymes. The acidimetric based Carba NP (Nordmann Poirel) test is simple and detects carbapenemases within two hours. The test could not differentiate between the serine carbapenemases from Metallo β-Lactamase (MBL). Differentiation of these two classes of enzymes will help in choosing the newer carbapenemase inhibitors like avibactam which selectively act on serine carbapenemases. Aim: To design a test that can simultaneously confirm and differentiate Amblers class A and D from class B carbapenemase enzymes among clinical strains of the Gram-Negative Bacteria (GNB). Materials and Methods: An experimental study was conducted between January-December 2018 on 195 strains of carbapenem resistant and 40 strains of carbapenem sensitive GNB. The carbapenemase genes were detected among all the bacteria by multiplex Polymerase Chain Reaction (PCR). The Carba M test was designed and evaluated for the detection and differentiation of class A and D from class B carbapenemases among the study isolates. Results: The Carba M test had 100% sensitivity and specificity for identification of New Delhi Metallo-β-lactamase (NDM) and Verona Integron-encoded Metallo-β-lactamase (VIM) enzymes. The strains which co-produced two MBL enzymes were detected with 100% sensitivity. The test had 42.85% sensitivity for the detection of Oxacillinase (OXA)-48-like enzymes. Conclusion: The Carba M test is useful in detection and simultaneous differentiation of carbapenemase content of the GNB and will help to choose appropriate carbapenemase inhibitors judiciously
Comparison of NS1 Antigen Detection by RDT and ELISA and its Concordance with RT-PCR for the Early Diagnosis of Dengue in Ananthapuramu District, Andhra Pradesh, India
Authors: Naidu Adireddi Paradesi , Saikumar Chitralekha , Swarnalatha G , Sulthana Sardar , Meeniga Sailaja
Published: April 2022

Introduction: Early detection of dengue fever is important for effective clinical care and vector control. For the detection of dengue viral antigen and antibodies, several serological techniques based on the concept of immunochromatography and Enzyme-Linked Immunosorbent Assays (ELISA) are routinely utilised. The performance of these tests depends on the sensitivity and specificity. Aim: To compare Non Structural protein-1 (NS1) antigen detection by Rapid Diagnostic Tests (RDTs) and ELISA and its association with Real-Time Polymerase Chain Reaction (RT-PCR). Materials and Methods: This diagnostic cross-sectional study was done on 100 clinically suspected cases of Dengue between July-November 2021 at a tertiary care hospital in Ananthapuramu, Andhra Pradesh, India. All the sera samples were collected and subjected to NS1 antigen detection test by rapid test, NS1 ELISA, and RT-PCR, and also serotypes DENV-1, 2, 3, 4 were detected from serum sample by RT-PCR test. The results of rapid and ELISA tests were compared with RT-PCR. Data was analysed by Statistical Package for the Social Sciences (SPSS) version 16.0. Results: Out of total 100 samples, 29 samples were tested positive by NS1 rapid test, 30 samples were tested positive by NS1 ELISA, and 32 samples were tested positive by RT-PCR. The sensitivity, specificity of dengue NS1 antigen rapid test were 87.50% and 98.52%, respectively when compared to RT-PCR whereas that of NS1 ELISA were 93.75% and 100% when compared to RT-PCR. Out of 32 samples tested positive by RT-PCR, two samples were positive for DENV-1, 26 samples were positive for DENV-2, and four samples were positive were DENV-3. Conclusion: The NS1 ELISA test requires extra procedures and time. RDTs need a one-step operation that takes roughly 15-30 minutes. Despite the fact that RT-PCR and ELISA have better performance than RDTs, RDTs are more effective for early diagnosis and therapy of dengue fever in countries with limited infrastructure and in remote places.
The Impact of Advertising on the Performance of Nigeria's Small Business Enterprises
Authors: Galadanchi Hamza Aliyu , Bello Taofik A. , Garba Muddaha
Published: April 2022

The goal was to look at the link between advertising and the success of small beverage enterprises in Katsina. The study examines how conventional advertising, Internet advertising, advertising cost, advertising quality, and advertising Volume affect the successful performance of small beverage businesses. The research takes a quantitative approach and employs a survey design. The study used statistical software for social sciences to examine data from 71 respondents (SPSS). According to the study findings, Conventional advertising, internet advertising, advertising cost, and advertising quality have a substantial link with the successful performance of small beverage firms. On the other hand, findings indicated that advertising Volume had no impact on the success of small beverage enterprises. Therefore, companies who wish to improve their performance should focus on conventional advertising as well as internet advertising, according to the report, by spending more on the advertising process to increase the efficiency of the advertising programs.
Exploring Online Learning in Higher Education, Perception and Challenges during the Era of Coronavirus Pandemic
Authors: Tetteh Daniel Ako
Published: April 2022

The present study explores the perception and challenges students in tertiary institutions face in online teaching and learning during the pandemic. The paper employs a qualitative approach to study the perceptions and challenges of students on online teaching and learning. Online Collaborative Learning was found to be the most suitable model to be used. A total of three-hundred students were selected for the study. Data was collected for a period of two months, from October-November, 2020. A multi-stage sampling technique was adopted in the selection of students from different universities. Findings of the study revealed that more than half (54%) of the students used the Learning Management Systems teaching and learning platform tool. The majority (52.7%) of the students agreed that they had internet distortion during the course of lectures. More than half (53.7%) of the students agreed that they could not access the internet due to a lack of data. There is a need for future studies to focus on all government and private tertiary institutions in Ghana. University authorities and the ministry of education should formulate post-COVID 19 strategies to promote online learning in the country.
Needle-free Diabetes Management
Authors: Kumar R. Santosh , Thakur Prayash Raj
Published: April 2022

According to this article microneedles are used in automated diabetes therapy systems. By bridging diagnostics and therapeutics, advanced bioengineered systems could constitute a "smart" system for diabetes treatment. Oral, hypodermic, through the nose, and other modes of delivery all have limitations, such as pain and other side effects. Physical entities are transferred through the skin by most glucose monitoring devices and conservative insulin treatments. It is well known that automated diabetes treatment systems involve very multifaceted interdependencies between various entities, and as such require multidisciplinary research programs. To develop an iterative noninvasive bioengineered interface such as microneedles, we need a better understanding of the human skin's molecular architecture and its functioning as a functional unit of the body. Specifically for auto-diabetes therapy, The microneedle interfaces system in this article is examined from the perspective of application-specific requirements.
An Application of Interacting Boson Model-2 (IBM-2) Configuration Mixing in Tin Nuclei
Authors: Sharqi Hanadi H. , Abood Saad N.
Published: April 2022

Using IBM-2 configuration mixing calculations, the normal and intruder 2p-2h bands in even-even tin isotopes are examined. The states of the normal and intruder bands were computed separately and then mixed using a basic band-mixing Hamiltonian. The experimental data for energy levels and electronic transition probability from current and past investigations are compared.
Evaluation of the Effectiveness of the Use of “Hepa-Merz” in Burn Disease
Authors: Shakirov B. M. , Muradova R. R. , Haydarov M. M.
Published: April 2022

Introduction: A burn affects the structure and function of almost every organ including the liver.

Material and Methods: This study received approval from Samarkand Centre of Emergency Medical Care (RCSUMA), Uzbekistan. The research program included complex treatment and examination of 82 patients with IIIAB-IV (deep burns) degree burns from 30% to 60% of the body surface and included: a general clinical and instrumental examination, biochemical and clinical blood tests.

Results: The results of the study showed the effectiveness of the use of Hepa-Merz in the complex treatment of severely burned patients. Conclusions: The use of Hepa-Merz allows to enhance the targeted therapeutic effect on the functional and morphological state of the liver and is indicated for the prevention and treatment of post-burn intoxication hepatitis.
The Impact of Maturity on Role of Head and Eye on Ocular Motions to Intersection Scanning Conduct
Authors: Rehman Ateeq , Jamali Maqbool Ahmed , Jandan Nisar Ahmed , Abbasi Muhammad Ashfaque , Ghoto Abbas Ali , Ahmer Arslan
Published: April 2022

Objectives: The Objectives of researchers of this study are to find out if there was a relationship between age and the input of head and hand actions on scanning conduct at crossings. Impending junctions necessitates scanning a broad region, which necessitates big lateral head turns and eye movements.

Methodology: We selected 53 participants in two age sets: 27 older (14 females and 19 males; 62-82 years) and 25 youngers (11 females and 14 males; 23-42 years) with visual acuity that fulfilled MA driver's license standards (minimum 21/41 modified or unmodified). Randomized control data, as well as vehicle position, speed, and heading, and info regarding other programmed automobiles, remained gathered at a rate of 32 cycles per second (rpm). With the help of a six-camera remote digital authentication scheme operating at 60 Hz, data on head and eye movements were acquired. This research was conducted at People Medical College Hospital, Nawabshah from April 2020 to March 2021.

Results: When driving in a simulator, 29 drivers over the age of 28 were monitored to see how their eyes and heads moved as they drove. It was determined that there were two types of scans for each of the city's 19 four-way intersections: eye-only scans (which contained only eye actions) and head-plus-eye scans (head and eye movements). Experienced drivers' head-eye scans (47.7% vs. 55%), as well as eye-only scans, were lower than expected (9.3 percent vs. 11.2 percent). In head-eye scans, skilled drivers showed the lower head and visual attention percentage compared to younger drivers. Among senior drivers, more eye-only scans (7 vs. 6) were performed, even though there were lesser head-eye scans (just 2). If you look at all-gaze scans, you won't see any ageing effects. According to our results, eye and head motions have a significant influence in development of cognitive deficits. Our findings show that eye and head motions both contribute to age-related impairments in intersection scanning, emphasizing the necessity of evaluating both eye and head movements.

Conclusion: To evaluate head motions, and to highlight the necessity for training programmed for senior drivers this can emphasize before approaching the junction.
Saccadic as Well as Manual Reaction Times to Targets Given to the Amblyopic Eye are Faster than Those of the Opposite Eye or Normal Eyes
Authors: Jamali Maqbool Ahmed , Jandan Nisar Ahmed , Rehman Ateeq , Abbasi Muhammad Ashfaque , Ghoto Abbas Ali , Ahmer Arslan
Published: April 2022

Aim: Amblyopia is caused by a combination of neural and visual impairments caused by abnormal early visual growth. One of the many drawbacks of amblyopia is that the amblyopic eye's saccadic and physical reaction times to targets presented to it are much slower than the other eye or normal eyes.

Methodology: Assumed that amblyopic eye's recognized impairments in contrast sensitivity, the question immediately arises if the longer reaction times are merely a result of the stimuli's diminished visibility. Our current research was conducted at People Medical College Hospital Nawabshah from May 2019 to April 2020.

Results: RTs to perifoveal stimuli are measured in study 1 as a function of efficient stimulus contrast, i.e., contrasting as measured by the amblyopic eye's comparison threshold. In our anisometropic amblyopes, researchers find that the asymptotic RTs including both eyes are the same when the sensory differences among eyes are minimized or eliminated. Several cross-eyed amblyopes, though, might have had an insurmountable delayed at asymptote. However, after accounting for stimulus sensory changes, these individuals' saccadic response times exhibited considerable interocular discrepancies. According to our results, eliminating the fixation image does slow down the amblyopic eye's reaction time, and that the gap impact is the same in both eyes. Therefore, the amblyopic eye's intrinsic delayed is not eliminated by the gap impact.

Conclusion: Last but not least in Experiment 3, we looked at the interocular variations in saccadic and manual reaction times for the same participants. As a result, we were able to determine the relationship between latencies in the two modes.
Optimization and Simulation Analysis of Loader Driving Stability System based on Differential Connection
Authors: Hao Li , Aiguo Si , Pengfei Shi
Published: April 2022

Taking wheel loader as the research object, for the vibration problem under the driving condition of wheel loader, study an optimized differential connection loader driving stability system, model the whole vibration system of wheel loader with three degrees of freedom dynamics, and establish the mathematical model by using Lagrange's equation, combine with the stochastic engineering road excitation model under E-class road surface, and carry out the simulation analysis of the vibration system by MATLAB/Simulink module. Simulation analysis of the vibration system is carried out, and the results show that the body droop acceleration, body angular acceleration and work device angular acceleration under the driving condition of the wheel loader are significantly reduced after adding the driving stability system, and the three kinds of acceleration are further reduced after optimizing to the differential connection driving stability system, which indicates that the differential connection loader driving stability system further improves the driving smoothness of the loader.
INSURGÊNCIAS QUILOMBOLAS NO SERTÃO:
Authors: Santos Paula Odilon
Published: April 2022

Resumo: Este artigo reúne notas de experiências etnográficas desenvolvidas em comunidades quilombolas, localizadas na porção norte do sertão da Bahia. O objetivo principal é demonstrar como essas insurgências vêm acontecendo, subsidiadas pelo movimento “Barulho do Quilombo”, pensado como um agente político e educador, capaz de articular interações e promover vivências, estimulando a redescoberta da etnicidade, assim como a construção identitária. O estudo foi realizado nas comunidades de Tijuaçu e Cariacá, historicamente entrelaçadas por laços de parentesco, compadrio e vizinhança, e envolveu interlocução com sujeitos mais velhos e lideranças locais, tais como os participantes da mesa-diretora das associações, os brincantes das atividades culturais e os praticantes de expressões religiosas. O ressurgimento contínuo dessas comunidades quilombolas tem possibilitado repensar os sertões e interiores da Bahia, como espaços guardadores, multiplicadores de legados africanos e repositório de memórias ancestrais.Palavras-Chave: Comunidades Quilombolas, Sertão, Tijuaçu, Cariacá, Identidades.
Retinoblastoma protein dephosphorylation is an early event of cellular response to prooxidant conditions
Authors: Esposito Franca , Russo Lucia , Russo Tommaso , Cimino Filiberto
Published: July 2002

The modification of intracellular redox conditions with diethylmaleate (DEM), a glutathione‐depleting agent, induces a p53‐independent growth arrest mediated by the accumulation of p21waf1 mRNA and protein. The same treatment also induces the retinoblastoma protein (pRb) dephosphorylation. This dephosphorylation (i) is very fast, being observed already 5 min after the exposure of the cells to DEM, (ii) is dependent on the prooxidant effects of DEM, being prevented by the treatment with N‐acetylcysteine and (iii) is completely reversible, since the rephosphorylation of pRb is promptly obtained upon the removal of the glutathione‐depleting agent from the culture medium. The dephosphorylation of pRb is independent of the accumulation of p21waf1 induced by DEM; in fact, p21waf1 levels start to increase much later after DEM treatment and accordingly cyclin‐dependent kinase activities are not yet induced when pRb is already dephosphorylated following DEM treatment. Finally, pRb dephosphorylation is catalyzed by phosphatases activated by DEM treatment.
Expression Level Tuning for Optimal Heterologous Protein Secretion in Saccharomyces cerevisiae
Authors: Parekh Rajesh N. , Wittrup K. Dane
Published: July 2002

The relationship between expression level and secretion of bovine pancreatic trypsin inhibitor (BPTI) was determined in Saccharomyces cerevisiae using a tunable amplifiable δ integration vector. Optimal secretory productivity of 15 mg of BPTI/g cell dry weight yields 180 mg/L secreted active BPTI in test‐tube cultures, an order of magnitude increase over 2μ plasmid‐directed secretion. Maximum productivity is determined by the protein folding capacity of the endoplasmic reticulum (ER) . Unfolded protein accumulates in the ER as synthesis increases, until a physiological instability is reached and secretion decreases precipitously despite high BPTI mRNA levels. Optimal specific productivity of a standard laboratory strain of S. cerevisiae is double that reported for secretion of BPTI by Pichia pastoris, indicating that efficient utilization of S. cerevisiae's available secretory capacity can eliminate apparent differences among yeast species in their capacity for heterologous protein secretion. Although not generally recognized, the existence of an optimum synthesis level for secretion is apparently a general feature of eucaryotic expression systems and could be of substantial significance for maximization of protein secretion in mammalian and insect cell culture.
Altering Flavor Profiles in Onion (Allium cepa L.) Root Cultures Through Directed Biosynthesis
Authors: Prince C. L. , Shuler M. L. , Yamada Y.
Published: July 2002

Root cultures of Allium cepa L. (onion) were fed potential precursors in the sulfate reduction pathway to the (+) ‐S‐alk(en) yl‐l‐cysteine sulfoxides (RCSOs) which are flavor precursors in Alliumsp. Sulfate, valine, and methacrylic acid did not increase RCSO production, indicating that these steps were not rate limiting. Cysteine, glutathione, and methionine could increase both the methyl‐ and propenylcysteine sulfoxides. The ratio of the propenyl to methyl form could be dramatically altered (over a range of 8.5) depending on the amount and type of precursor used. Additionally, novel flavor components, not normally found in A. cepa L., were made in substantial amounts by feeding the corresponding thiol (propyl, 2‐propenyl (allyl), and ethyl) . These results demonstrate that customized flavor profiles can be produced from Allium root cultures and provide an example of the use of plant cell cultures to produce novel metabolites.
Decreasing Extracellular pH Increases CD13 Receptor Surface Content and Alters the Metabolism of HL60 Cells Cultured in Stirred Tank Bioreactors
Authors: McDowell Christi L. , Papoutsakis Eleftherios T.
Published: July 2002

Flow cytometry and Northern blotting were used to examine the effects of extracellular pH on CD13 receptor surface content and mRNA levels of HL60 (human promyelocytic leukemia) cells. Decreasing culture pH (7.4, 7.2, and 7.0) increased the CD13 receptor surface content of HL60 cells cultured at low agitation intensity (80 rpm) in 2‐L bioreactors. Unlike our earlier findings on the effects of increasing agitation rates and serum concentrations, changes in CD13 receptor content in response to decreasing culture pH did not correlate with changes in CD13 mRNA levels. Decreasing culture pH also decreased the average HL60 cell size. HL60 cells cultured at pH 7.0 and 7.2 exhibited glucose consumption and lactate production rates that were approximately 30−40% and 20−30% lower, respectively, than values of cells cultured at pH 7.4.
The influence of anaesthesia and surgery on the circadian rhythm of melatonin
Authors: Kärkelä J. , Vakkuri O. , Kaukinen S. , Huang W‐Q. , Pasanen M.
Published: July 2002

Background: Operations are typically associated with sleep and other circadian rhythm disturbances. The present study was set up to evaluate the influence of spinal and general anaesthesia associated with knee surgery on the circadian rhythm of melatonin, which has sleep inducing properties. Previously this context has been studied only in some invasive operations and it might be that general anaesthesia induces more disturbances on circadian rhythm of melatonin than operations done with patients awake.

Methods: The circadian secretion pattern of melatonin was monitored during the pre‐ and postoperative evenings, nights and mornings to clarify possible anaesthesia/surgery‐induced changes in the nocturnal secretion of melatonin and in the phase of the melatonin rhythm. The study included 20 patients scheduled for minor orthopaedic operations. The patients were randomised to receive either spinal or general anaesthesia. Melatonin was measured from evening and morning saliva samples radioimmunologically. The nocturnal urine before and after surgery was radioimmunologically examined for 6‐hydroxymelatonin sulphate.

Results: Melatonin secretion evaluated from the saliva samples was significantly diminished during the first postoperative evening as compared with that during the preoperative evening (P<0.001). There was also a significant decline of 26% (P<0.05) in postoperative 6‐hydroxymelatonin sulphate excretion. There was no significant difference in melatonin secretion between the spinal and general anaesthesia groups.

Conclusion: Our findings suggest that anaesthesia in conjunction with surgery acutely disturbed the normal circadian rhythm of melatonin by delaying the onset of nocturnal melatonin secretion.
Assembly and secretion of recombinant chains of human inter‐α‐trypsin inhibitor in COS‐7 cells
Authors: Martin‐Vandelet Nathalie , Paris Sébastien , Bourguignon Jeannette , Sesboüé Richard , Martin Jean‐Pierre , Diarra‐Mehrpour Maryam
Published: July 2002

The inter‐α‐trypsin inhibitor (ITI) family is a group of structurally related plasma serine protease inhibitors. The ITI family members consist of combinations of mature heavy chains named HC1, HC2, HC3 linked to bikunin (a Kunitz‐type protease inhibitor) by a covalent interchain protein–glycosaminoglycan–protein cross‐link. The biosynthesis of the ITI family members takes place in the liver. In this report we examine the biosynthesis of these proteins using transient transfected COS‐7 cells expressing one or more combinations of human ITI chains. The processing and secretion of α1‐microglobulin and bikunin does not require the ITI heavy chains. A small proportion of the H3 chain seems to be processed into the HC3 form in the absence of the other ITI chains. In contrast, the processing of H2 into HC2 needs the presence of the L chain. The COS‐7 cells are able to link the HC2 and HC3 heavy chains with bikunin by means of a chondroitin sulfate bridge, and thus to generate 260‐kDa ITI‐like proteins as well as pre‐α‐trypsin inhibitor (PαI). However, the maturation of the Hl chain into HC1 and the assembly of HC1 inside multichain proteins may take place according to a mechanism which differs from that of the H2 and H3 chains. These results indicate that the assembly of the constituent chains of the ITI‐like proteins and PαI is not dependent on the liver machinery.
Orbitofrontal involvement in the processing of unpleasant auditory information
Authors: Frey S. , Kostopoulos P. , Petrides M.
Published: July 2002

Although little is known about the contribution of the orbitofrontal cortex to the processing of new information in man, lesion studies in monkeys have suggested that it plays a critical role. The present study investigated changes in cerebral blood flow with positron emission tomography in normal human subjects during exposure to unpleasant auditory stimuli. The results indicated that the caudal orbitofrontal cortex, area 13, which is powerfully linked to the medial temporal limbic region and is involved in the regulation of autonomic responses, is a key part of the frontal cortex responding in the face of unpleasant incoming information.
Prenatal ultrasound diagnosis of Roberts syndrome in a family with negative history
Authors: Paladini D. , Palmieri S. , Lecora M. , Perone L. , Di Meglio A. , D'Armiento M. , Cascioli C. , Martinelli P.
Published: July 2002

A case is presented in which the ultrasonographic detection of multiple congenital anomalies led to the diagnosis of Roberts syndrome in the fetus of a woman with a negative family history. The fetus had bilateral cleft lip and palate, bilateral amesomelia with ectrodactyly, a complex congenital heart disease and intrauterine growth retardation. These malformations are frequent in Roberts syndrome and, therefore, an amniocentesis was performed to detect the cytogenetic marker of this syndrome, premature centromere separation. This phenomenon could not be detected in metaphases from amniocytes, but it was present in peripheral lymphocytes cultured at birth. The clinical implications of these findings are discussed. Furthermore, to our knowledge, this represents the first case in which the suspicion of Roberts syndrome was raised by ultrasound in a family with a negative family history. Copyright © 1996 International Society of Ultrasound in Obstetrics and Gynecology
A prospective study of the effect of education on non–compliant behaviour in contact lens wear
Authors: Claydon Bridget E. , Efront Nathan , Woods Craig
Published: July 2002

The contact lens practitioner and patient present a specific case for the study of non‐compliance in areas such as hygiene, solution use, appointment attendance and wearing times. Education is one of the factors thought to influence compliance among patients in general health care situations and contact lens practitioners are encouraged to educate patients in the care and maintenance of contact lenses. A prospective, randomized, controlled and double masked study was performed to assess the effect of a‘compliance enhancement strategy’ on levels of compliance among contact lens wearers over twelve months. Eighty experienced contact lens patients were randomly allocated to two experimental groups. A standard level of contact lens instruction was applied to the first group and in addition the compliance enhancement strategy was applied to patients assigned to the second group. The strategy consisted of extra education for patients using a video, booklets, posters, a checklist and a health care contract. Patients were given free supplies of RelMu multipurpose solution and Medalist 38 soft contact lenses IBausch and Lomb, Rochester. New York). Compliance levels were assessed at a twelve month aftercare appointment by demonstration and questionnaire. The results indicate that the compliance enhancement strategy had little significant effect on the compliance levels of the patients to whom it was applied. The population of contact lens wearers were generally very compliant and the contact lenses and care regimen were clinically successful. The possibility that the assessment of non–compliance was not adequately sensitive to highlight small differences in non‐compliant, behaviour is discussed. The standard level of eduction applied to this sample of contact lens patients was adequate to ensure generally high levels of compliance with the simple care and maintenance regimen recommended.
Genetic Evidence for the Allodiploid Origin of the Moss Species Polytrichum longisetum
Authors: van der Velde M. , Bijlsma R.
Published: July 2002

Abstract: Fixed heterozygous banding patterns observed for 4 allozyme and 12 microsatellite loci, in combination with a chromosome number of 14, show that Polytrichum longisetum is an allodiploid species. Comparison of these banding patterns with those of related Polytrichaceae species suggest that Polytrichum formosum, or an ancestor taxon of this species, is one of the haploid progenitors of P. longisetum. The second progenitor species of P. longisetum could not be designated in this study as it was not among the examined possible progenitor species. DNA sequence data for two microsatellite loci, however, suggest that the second progenitor species should possibly be more closely related to P. formosum than any of the other haploid possible progenitor species examined in this study. As the current systematic literature does not mention the existence of such a species, this could indicate that the second progenitor species is already extinct.
Developmental Changes in Effect of Cytokinin and Gibberellin on Shoot K+ and Na+ Accumulation in Salt‐Treated Sorghum Plants
Authors: Amzallag G. N.
Published: July 2002

Abstract: The effect of cytokinin (CK) and/or gibberellin (GA) treatments on shoot accumulation of Na+ and K+ was investigated in Sorghum bicolor exposed to 150 mM NaCl. These hormonal treatments modified the shoot content of Na+ and K+, but the effect varied throughout development. Comparison of ion concentration versus ion content in shoots indicates that regulation of shoot concentration of K+ is modified during a transition period of development. This change is concomitant with reorganization of the regulation network for meristem activity, an event also involving changes in sensitivity to CK and GA. This evidence suggests a strong interdependency between dynamic changes in a between‐organ network of relations and control of accumulation of monovalent ions in the shoot. Moreover, a new pattern of regulation of shoot Na+ concentration emerges during the transition period. During this process GA appears progressively involved in regulation of Na retranslocation, while CK is rather controlling the root uptake of Na+. Accordingly, the spontaneous emergence of Na‐includer and Na‐excluder individuals observed from an initially homogeneous population is interpreted as related to variations in sensitivity to GA and CK during differentiation of this newly emerging pathway of regulation.
Parameters for i
n s
i
t
u growth of high T
c superconducting thin films using an oxygen plasma source
Authors: Spah R. J. , Hess H. F. , Stormer H. L. , White A. E. , Short K. T.
Published: July 2002

Superconducting thin films of Dy-Ba-Cu-O have been grown on 3 in. sapphire wafers with a molecular beam deposition process. Dissociated oxygen from a glow discharge source was used to improve the oxygen incorporation. This allows growth on a relatively low-temperature substrate kept below 600 °C followed by an in situ anneal below 400 °C. Thin films of Dy-Ba-Cu-O which were fully superconducting at 40 K have been fabricated by this in situ growth process.
High-efficiency 2.09 μm flashlamp-pumped laser
Authors: Quarles Gregory J. , Rosenbaum Annette , Marquardt Charles L. , Esterowitz Leon
Published: July 2002

Utilizing the results of Cr3+→Tm3+ transfer efficiency studies, we have demonstrated that YAG is the preferred host for the Cr:Tm:Ho laser, and that highest efficiencies are obtained at relatively low Cr3+ concentrations. We have achieved a slope efficiency of 5.1% from a flashlamp-pumped room-temperature 2 μm laser.
Si as a diffusion barrier for Ge/GaAs heterojunctions
Authors: Strite S. , Ünlü M. S. , Adomi K. , Morkoç H.
Published: July 2002

We compare the electrical characteristics, before and after annealing, of p-Ge/N-GaAs heterojunction diodes to similar diodes which incorporate a nominally 10 Å layer of pseudomorphic Si at the Ge/GaAs interface. Both types of diodes exhibit excellent current-voltage characteristics before annealing. Diodes having no Si interlayer show significant degradation after a 20 min anneal at 640 °C. Diodes incorporating the Si interlayer retain excellent diode characteristics after a 20 min anneal at temperatures as high as 720 °C.
Neutral electron trap generation in SiO2 by hot holes
Authors: Ogawa Shigeo , Shiono Noboru , Shimaya Masakazu
Published: July 2002

Experimental evidence for neutral electron trap generation in SiO2 caused by injected holes is presented. The neutral electron traps are detected by Fowler–Nordheim (FN) tunneling electron injection after avalanche hole injection. The density of generated neutral traps increases with the number of injected holes, but does not saturate with that of the trapped holes. The centroid of generated neutral traps is found to be in the middle of the oxide. These results suggest that neutral traps are generated by the holes and not only by the recombination of electrons with trapped holes. The origin of neutral traps is considered to be associated with dipolar defects formed by SiO bond breaking under hole transport in the oxide.
Intrinsic and extrinsic recombination radiation from undoped and boron-doped diamonds formed by plasma chemical vapor deposition
Authors: Kawarada H. , Yokota Y. , Hiraki A.
Published: July 2002

In small particles of chemical vapor deposited (CVD) diamond and polycrystalline thin films composed of the particles, the recombination radiation of free excitons and bound excitons associated with multiple phonons has been observed using cathodoluminescence. The bound excitons are due to neutral acceptors of boron in the diamonds. The cathodoluminescence imaging reveals that the recombinations of free excitons are located at {100} sectors. The crystal perfection and purity is high in {100} sectors compared with {111} sectors formed in the CVD process.
Electrically tunable optical filter for infrared wavelength using liquid crystals in a Fabry–Perot étalon
Authors: Patel J. S. , Saifi M. A. , Berreman D. W. , Lin Chinlon , Andreadakis N. , Lee S. D.
Published: July 2002

Using the refractive index modulation in liquid crystals by an externally applied electric field, we show that common nematic liquid crystals can be used in a Fabry–Perot étalon to produce an electrically tunable optical filter for use in the infrared region. Using commercial liquid crystals we demonstrate that the wavelength can be tuned over 175 nm using less than 10 V. In our first device the free-spectral range of the étalon is about 75 nm with a passband of about 1–2 nm which is determined by the quality of the mirrors that we have used.
Epitaxial Ba1−xKxBiO3 films on MgO: Nucleation, cracking, and critical currents
Authors: Hellman E. S. , Hartford E. H. , Gyorgy E. M.
Published: July 2002

A two-step growth technique is used to obtain (100) oriented Ba1−xKxBiO3 films with good superconducting properties by molecular beam epitaxy. The films are nucleated without potassium at higher temperatures to get the perovskite (100) orientation on (100)MgO. Ba1−xKxBiO3 is then grown at a lower temperature using potassium flux from the decomposition of K2O. The oxygen content of the films is adjusted in a post-growth anneal in oxygen to reduce cracking which can result from oxidation-induced shrinkage. The annealed films have superconducting transitions as narrow as 0.5 K at temperatures between 20 and 25 K. Critical currents in the range of 105 A/cm2 at 4.2 K have been measured by the magnetization hysteresis loop method.
Sm2Fe17Nx: Site and valence of the interstitial nitrogen
Authors: Capehart T. W. , Mishra R. K. , Pinkerton F. E.
Published: July 2002

X-ray absorption fine structure from the samarium L3 edge reveals that there are 2.8±1.0 nitrogen atoms in Sm2Fe17Nx covalently bonded 2.54 Å from the Sm site. This coordination number and radial distance are consistent with N atoms occupying the 9(e) sites of the expanded Sm2Fe17 lattice.
Linear electro-optic effect in cubic silicon carbide
Authors: Tang Xiao , Irvine Kenneth G. , Zhang Dongping , Spencer Michael G.
Published: July 2002

We report the first observation of the electro-optic effect of cubic silicon carbide (β-SiC) grown by a low-pressure chemical vapor deposition reactor using the hydrogen, silane, and propane gas system. At a wavelength of 633 nm, the value of the electro-optic coefficient r41 in β-SiC is determined to be 2.7±0.5×10−12 m/V, which is 1.7 times larger than that in gallium arsenide measured at 10.6 μm. Also a half-wave voltage of 6.4 kV for β-SiC is obtained. Because of this favorable value of electro-optic coefficient we believe that silicon carbide may be a promising candidate in electro-optic applications for high optical intensity in the visible region.
Accurate measurement of atomic beam flux by pseudo-double-beam atomic absorption spectroscopy for growth of thin-film oxide superconductors
Authors: Klausmeier-Brown M. E. , Eckstein J. N. , Bozovic I. , Virshup G. F.
Published: July 2002

We report the use of pseudo-double-beam atomic absorption spectroscopy to make very accurate (0.1%–1%) measurements of the beam flux from Knudsen effusion cells in a molecular beam epitaxy system. This system has been used to grow Bi–Sr–Ca–Cu–O–based superconducting thin films and heterostructures in an atomic-layer-by-layer fashion. The resulting material displays excellent crystallographic and transport properties. Atomic absorption measurement of beam fluxes may also be of benefit for other materials systems, such as InGaAs/InP.
Residual strain analysis of InxGa1−xAs/GaAs heteroepitaxial layers
Authors: Krishnamoorthy V. , Lin Y. W. , Calhoun L. , Liu H. L. , Park R. M.
Published: July 2002

InxGa1−xAs/GaAs heteroepitaxial layers, having various compositions and thicknesses, have been analyzed using the high resolution x-ray diffraction technique which has revealed that the residual strain in the epilayers is strongly dependent on both the epilayer composition as well as thickness. However, published theoretical models concerning residual strain in InxGa1−xAs/GaAs epilayers suggest that the extent of relaxation is independent of epilayer composition. In this letter, we present an empirical model based on our findings which can be used to accurately predict the extent of lattice relaxation in InxGa1−xAs/GaAs epilayers which includes the influence of epilayer composition.
Self-pulsing, spectral bistability, and chaos in a semiconductor laser diode with optoelectronic feedback
Authors: Lee Chang-Hee , Shin Sang-Yung
Published: July 2002

We observed experimentally self-pulsing, subharmonic generation, spectral bistability, and chaos in a stable semiconductor laser diode with delayed optoelectronic feedback. The laser diode emits 200 ps optical pulses with 1.1 GHz repetition rate in the self-pulsing region, and the bistable region is critically dependent on the closed loop gain of the system. Theoretical explanations of observed experimental results are also given.
Optical characterization of pure ZnSe films grown on GaAs
Authors: Kim Young-Dong , Cooper S. L. , Klein M. V. , Jonker B. T.
Published: July 2002

We report the first spectroscopic ellipsometry study of the E0, E0+Δ0, E1, and E1+Δ1 critical points in high-quality ZnSe films. These data seem to be the best identification of E1 and E1+Δ1 peaks to date using ellipsometry. We also describe a chemical etching procedure which was successfully used to remove the natural surface oxide overlayer on the ZnSe films. X-ray photoelectron spectroscopy data after NH4OH treatment shows the disappearance of oxygen and oxidized Se peaks demonstrating the successful removal of surface oxide overlayer on ZnSe.
Elastic properties of spin-on glass thin films
Authors: Carlotti G. , Socino G. , Doucet L.
Published: July 2002

The elastic properties of siloxane spin-on glass films have been analyzed in order to achieve a characterization of this dielectric material, widely used in the technology of integrated circuits. Measurements of the biaxial stress as a function of time after deposition have shown that water inclusion strongly affects the intrinsic stress of the film, which is tensile in the as-deposited state and becomes compressive after a few days. Brillouin light scattering has then been used to determine the phase velocity of the Rayleigh and Sezawa acoustic modes in films with different thicknesses deposited on (100)-Si, leading to the evaluation of the elastic stiffness constants, of the Poisson’s ratio and of the Young’s modulus.
Photomultiplier characteristics and practice relevant to photon counting
Authors: Candy B. H.
Published: July 2002

Certain nonideal photomultiplier characteristics are particularly relevant to the practice of photon counting. The literature on some of these characteristics can be rather confusing in the description of the mechanisms involved, such as those associated with single electron response distortion, ringing in anode pulse shapes, etc. This review paper critically studies these areas and in so doing attempts to resolve them. Other relevant but well established areas are reviewed briefly and key papers referenced. The effects of photomultiplier characteristics on photon counting performance are discussed together with associated recommendations for optimum conditions, with due regard to electronic instrumentation.
Fullerene formation during production of chemical vapor deposited diamond
Authors: Chow Lee , Wang Hao , Kleckley Stephen , Daly Terry K. , Buseck Peter R.
Published: July 2002

We report a novel method for fullerene formation during diamond synthesis via a hot filament, chemical vapor deposition (CVD) procedure. The fullerenes occur in the soot that forms as a by-product on the edges and rear surface of the substrate holder, where the temperature does not favor diamond deposition. Mass spectrometry of the soot shows a peak having a mass to charge ratio corresponding to C60. From typical concentrations of gaseous species in the diamond-growing CVD chamber, we conclude that hydrocarbon species such as CH3 or C2H2 may be the precursors for the fullerene in the CVD chamber. The atomic hydrogen in the gaseous species is believed to play an important role in removing the hydrogen from hydrocarbon to form the all-carbon fullerene. Our observations also suggest that fullerenes produced in the CVD diamond growth chamber play a role in diamond nucleation on foreign substrates.
Angular-resolved ion-beam sputtering apparatus for large-area deposition
Authors: Motohiro T. , Yamadera H. , Taga Y.
Published: July 2002

A new apparatus to utilize the directional nature of ion-beam sputter deposition is presented. Employment of an angular setting slit together with translational substrate scanning enables large-area deposition, keeping the angular settings unchanged. The merits of this apparatus were demonstrated step by step on a typical example: CdTe obliquely deposited films known for the anomolous photovoltaic effect.
Water surface measurement in a shallow channel using the transmitted image of a grating
Authors: Kurata J. , Grattan K. T. V. , Uchiyama H. , Tanaka T.
Published: July 2002

In this work, the measurement of the depth or shape of a shallow water channel using the transmitted image of a grating is discussed. A noncontact approach, using a simple optical system is described and the angle and depth of the refracting surface may thus be determined. Other applications include simulation of air flow in engineering systems.
Temperature rise and thermal rise-time measurements of a semiconductor laser diode
Authors: Abdelkader H. I. , Hausien H. H. , Martin J. D.
Published: July 2002

A novel method is presented for measurement of the rise in temperature and thermal rise time of a semiconductor laser diode (LD) under pulsed operation. The technique employs the shift in LD threshold current which occurs with a rise in junction temperature. Practical results are given, showing a rise time of about 10 ns.
Application of an imaging plate to high-pressure x-ray study with a diamond anvil cell (invited)
Authors: Shimomura O. , Takemura K. , Fujihisa H. , Fujii Y. , Ohishi Y. , Kikegawa T. , Amemiya Y. , Matsushita T.
Published: July 2002

In order to obtain reliable data on d values and integrated intensities, an imaging plate (IP) has been applied to high-pressure diffraction experiments with a diamond anvil cell using synchrotron radiation. The IP was found to be more effective than a conventional x-ray film by a factor of 30, and more effective than an energy dispersive method by several times. In order to integrate the intensity data on the IP, a histogram method was successfully developed. This combination proved to give a lattice constant with relative accuracy of 2×10−4, and observed integrated intensities which excellently agree with calculated ones.