bluuebunny/crossref_metadata_2025 huggingface dataset:
Deciphering the late steps in the biosynthesis of the anti‐tumour indolocarbazole staurosporine: sugar donor substrate flexibility of the StaG glycosyltransferase
Authors: Salas Aaroa P. , Zhu Lili , Sánchez César , Braña Alfredo F. , Rohr Jürgen , Méndez Carmen , Salas José A.
Published: September 2005

The indolocarbazole staurosporine is a potent inhibitor of a variety of protein kinases. It contains a sugar moiety attached through C‐N linkages to both indole nitrogen atoms of the indolocarbazole core. Staurosporine biosynthesis was reconstituted in vivo in a heterologous host Streptomyces albus by using two different plasmids: the ‘aglycone vector’ expressing a set of genes involved in indolocarbazole biosynthesis together with staG (encoding a glycosyltransferase) and/or staN (coding for a P450 oxygenase), and the ‘sugar vector’ expressing a set of genes responsible for the biosynthesis of the sugar moiety. Attachment of the sugar to the two indole nitrogens of the indolocarbazole core was dependent on the combined action of StaG and StaN. When StaN was absent, the sugar was attached only to one of the nitrogen atoms, through an N‐glycosidic linkage, as in the indolocarbazole rebeccamycin. The StaG glycosyltransferase showed flexibility with respect to the sugar donor. When the ‘sugar vector’ was substituted by constructs directing the biosynthesis of l‐rhamnose, l‐digitoxose, l‐olivose and d‐olivose, respectively, StaG and StaN were able to transfer and attach all of these sugars to the indolocarbazole aglycone.
Giardia lamblia infection induces different secretory and systemic antibody responses in mice
Authors: VELAZQUEZ C. , BELTRAN M. , ONTIVEROS N. , RASCON L. , FIGUEROA D. C. , GRANADOS A. J. , HERNANDEZ‐MARTINEZ J. , HERNANDEZ J. , ASTIAZARAN‐GARCIA H.
Published: September 2005

The adult mouse model of Giardia lamblia infection serves as an excellent animal model to understand the immunological mechanisms involved in the control and clearance of Giardia infection. Little is known about the G. lamblia‐specific antigens that stimulate the humoral immune response in this model of giardiasis. We analysed the secretory and systemic antibody responses to G. lamblia during primary and secondary infection in C3H/HeJ adult mice. Faecal IgA and Serum IgG anti‐G. lamblia antibodies were observed at week 2 post‐infection. Serum IgG responses remained constant over the next several weeks, whereas faecal IgA titres continued to rise from weeks 2–6 post‐infection. Western blot analysis revealed that intestinal IgA and serum IgG antibody responses were directed toward several distinct proteins of G. lamblia. Certain proteins appeared to be recognized by both faecal IgA and serum IgG, whereas other antigens were specific for either the secretory or systemic antibody responses. G. lamblia primary and secondary infections were associated with differences in the antibody recognition pattern. The biochemical and immunological characterization of these antigens will help us to better understand the immunobiology of the G. lamblia–host interaction.
Microwave power and duration without extrauterine thermal damage in microwave endomyometrial ablation at 2.45 GHz
Authors: Kanaoka Yasushi , Hirai Kouzo , Ishiko Osamu
Published: September 2005

Aim: We investigated microwave power and duration of use, which does not affect extrauterine organs, in order to treat organic menorrhagia caused by myomas or adenomyosis.

Methods: Electric fields around a microwave applicator at a frequency of 2.45 GHz were calculated using the finite element method with commercially available software for analysis of electromagnetic fields. Transient temperature distributions around the applicator were obtained by numerically solving the bioheat transfer equation during microwave irradiation for 120 s in the human uterus and swine liver. We compared areas enclosed by the 60°C isotherm obtained using numerical simulations and necrosis areas after microwave irradiation. Postoperative avascular areas in a Gd‐enhanced MRI of a uterus enlarged by adenomyosis after clinical microwave endomyometrial ablation were compared with numerical simulations.

Results: There was good agreement between the calculated results and the experiments. At 40 W of output power for 50 s of duration and 64.5 W for 100 s, the depth of the necrotized uterine wall did not increase beyond 7 mm and 11 mm, respectively, either in the calculations or the experiments. Generally, the 50°C isotherm was located approximately 2 mm external to the 60°C isotherm in temperature distributions. The Gd‐enhanced MRI after the operation depicted avascular areas, which agreed with the results of numerical simulations.

Conclusions: The myometrial portion of a uterine wall ≥13 mm throughout the uterus irradiated for ≤64.5 W for 100 s is sufficient to avoid thermal damage of the extrauterine organs during microwave endomyometrial ablation.
Ultrasonic estimation of fetal weight at term: An evaluation of eight formulae
Authors: Mirghani Hisham M. , Weerasinghe Sarath , Ezimokhai Mutaira , Smith John R.
Published: September 2005

Aim: To compare the accuracy of eight sonographic formulae for predicting fetal birth weight at term in a multiethnic population.

Methods: Pregnant women at term who were booked for induction of labor or elective cesarean section were included in the study. Eight ultrasonic fetal biometric formulae were used to predict fetal birth weight.

Results: A total of 173 patients were included in the study; 53 (30.6%) patients were from the Indian subcontinent, 44 (25.4%) patients were from Africa, 33 (19.1%) patients were from the Arabian Peninsula and 43 (24.9%) were from other ethnic groups. The mean absolute error ranged from a minimum of 0.3% (±11.3) for Hadlock (biparietal diameter [BPD], head circumference [HC], abdominal circumference [AC], femur length [FL]) to a maximum of 37.5% (±10.0) for Warsof (FL). The correlation of estimated fetal weight with actual birth weight ranged from a minimum of 0.09 with Warsof (FL) to a maximum of 0.77 with Shepard and Warsof (BPD, AC) and Hadlock (BPD, HC, AC, FL). The combination of AC with BPD measurements rather than FL achieves a high level of accuracy.

Conclusions: Shepard (BPD, AC) provides a simple and accurate logarithm for the prediction of fetal weight at term in the studied multiethnic population.
Establishment of a prediction method for premature rupture of membranes in term pregnancy using active ceruloplasmin in cervicovaginal secretion as a clinical marker
Authors: Ogino Mitsuharu , Hiyamuta Shuichi , Takatsuji‐Okawa Masako , Tomooka Yasuhiro , Minoura Shigeki
Published: September 2005

Aim: Term pregnancy complicated by premature rupture of membranes (PROM) is thought to be associated in part with subclinical infection, and places mothers and neonates at an increased risk for several complications. Therefore, perinatal care would be greatly helped if a reliable clinical measure were available for predicting the incidence of PROM.

Methods: One hundred and ninety‐six pregnant women who consented to enter this study were screened using a method developed to assess active ceruloplasmin in cervicovaginal secretion as a clinical marker for predicting the incidence of PROM. Cervicovaginal secretions were obtained from the cervical canal at about 36 weeks of pregnancy. The active ceruloplasmin level in the cervicovaginal secretion was measured using an original enzyme‐linked immunoabsorbent assay.

Results: Of 196 women, 27 women (13.8%) developed PROM and 169 women (86.2%) did not develop PROM. Active ceruloplasmin in the cervicovaginal secretion was significantly higher in the PROM group than in the non‐PROM group (P < 0.001). Analysis using receiver‐operating characteristic curves showed that the active ceruloplasmin level (1420.0 ng/mL) proved to be the proper cut‐off value to best predict the incidence of PROM.

Conclusion: Active ceruloplasmin in the cervicovaginal secretion might be a reliable clinical marker for term PROM.
Prenatal diagnosis and management for a large fetal cardiac tumor complicated with hydrops fetalis
Authors: Nakata Masahiko , Fujiwara Motoki , Ishikawa Yuichi , Sumie Masahiro , Hasegawa Keiko , Miwa Ichiro , Kusaka Emiko , Sase Masakatsu , Sugino Norihiro
Published: September 2005

Fetal cardiac tumor is a rare disease, and its prognosis varies in relation to the complications such as arrhythmia and out‐flow obstruction. Hydrops fetalis is one of severe complications that result in an unfavorable outcome. A case is presented herein of a large fetal cardiac tumor diagnosed at 28 weeks gestation. At 30 weeks gestation, the fetus complicated with hydrops fetalis because of impaired cardiac function. Increased peak systolic velocity in the ascending aorta and marked reversed flow in the ductus venosus were observed. Oral digoxin therapy was administered to the mother as a cardiotonic agent and the hydropic condition was immediately diminished. After normal delivery, the cardiac tumor gradually decreased in size and the infant developed normally, but required an antiarrhythmic drug. The case indicates that the in utero digoxin therapy could be a choice for hydrops fetalis caused by cardiac tumor.
Effects of an overload event on crack closure in 3‐D small‐scale yielding: finite element studies
Authors: ROYCHOWDHURY S. , DODDS R. H.
Published: September 2005

This paper describes the effects of a single overload event, within otherwise constant amplitude cycles, on the plasticity‐induced closure process for mode I fatigue crack growth in the small‐scale yielding (SSY) regime. The 3‐D finite element (FE) analyses extend the initially straight, through‐thickness crack front by a fixed amount in each load cycle, using a node release procedure. Crack closure during reversed loading occurs when nodes behind the growing crack impinge on a frictionless, rigid plane. A bilinear, purely kinematic hardening model describes the constitutive response of the elastic–plastic material. Extensive crack growth in the analyses, both before and after the overload, allows the crack to grow out of the initial and the post‐overload transient phases, respectively. The work presented here shows that the large plastic deformation in the overload cycle reduces the crack driving force through enhanced closure. Further, the residual plastic deformations due to the overload cause a disconnected pattern of closure in the wake long after the crack front passes through the overload plastic zone. The computational studies demonstrate that the 3‐D scaling relationship for crack opening loads established in our earlier work for constant amplitude cycling (with and without a T‐stress) also holds before, during and after the overload event. For a specified ratio of overload‐to‐constant amplitude loading (ROL=KOLmax/Kmax), the normalized opening load (Kop/Kmax) at each location along the crack front remains unchanged when the constant amplitude peak load (Kmax), thickness (B) and material flow stress (σ0) all vary to maintain a fixed value of . The paper concludes with a comparison of the post‐overload response predicted by the 3‐D analyses and by the conventional Wheeler model.
Anesthetic implications of Jacobsen syndrome
Authors: BLAINE EASLEY R. , SANDERS DEVIN , McELRATH‐SCHWARTZ JAMIE , MARTIN JACKIE , MARK REDMOND J.
Published: September 2005

Jacobsen syndrome (JS), also known as 11q‐syndrome, is a congenital disorder associated with a deletion of the long arm of chromosome 11. Patients with JS characteristically exhibit multiple dysmorphic features, developmental delay, cardiac anomalies, and platelet abnormalities. Anesthetic issues related to the care of patients with JS concern airway management secondary to short neck, abnormal mouth shape and micrognathia/retrognathia, a high incidence of cardiac anomalies, and platelet dysfunction. Importantly, platelet abnormalities affect 95% of reported JS patients and involve platelet number, size and function. Two children with JS who required open heart surgery are presented and anesthetic management issues discussed. These patients represent the first reports regarding the perioperative issues in caring for patients with JS.
Relations Among Positive Parenting, Children's Effortful Control, and Externalizing Problems: A Three‐Wave Longitudinal Study
Authors: Eisenberg Nancy , Zhou Qing , Spinrad Tracy L. , Valiente Carlos , Fabes Richard A. , Liew Jeffrey
Published: September 2005

In a 3‐wave longitudinal study (with assessments 2 years apart) involving 186 early adolescents (Mages of approximately 9.3, 11.4, and 13.4), the hypothesis that parental warmth/positive expressivity predicts children's effortful control (EC) (a temperamental characteristic contributing to emotion regulation) 2 years later, which in turn predicts low levels of externalizing problems another 2 years later, was examined. The hypothesis that children's EC predicts parenting over time was also examined. Parents were observed interacting with their children; parents and teachers reported children's EC and externalizing problems; and children's persistence was assessed behaviorally. Children's EC mediated the relation between positive parenting and low levels of externalizing problems (whereas there was no evidence that children's EC predicted parenting).
Inheritance and recombination of mitochondrial genomes in plants, fungi and animals
Authors: Barr Camille M. , Neiman Maurine , Taylor Douglas R.
Published: September 2005

It is generally assumed that mitochondrial genomes are uniparentally transmitted, homoplasmic and nonrecombining. However, these assumptions draw largely from early studies on animal mitochondrial DNA (mtDNA). In this review, we show that plants, animals and fungi are all characterized by episodes of biparental inheritance, recombination among genetically distinct partners, and selfish elements within the mitochondrial genome, but that the extent of these phenomena may vary substantially across taxa. We argue that occasional biparental mitochondrial transmission may allow organisms to achieve the best of both worlds by facilitating mutational clearance but continuing to restrict the spread of selfish genetic elements. We also show that methodological biases and disproportionately allocated study effort are likely to have influenced current estimates of the extent of biparental inheritance, heteroplasmy and recombination in mitochondrial genomes from different taxa. Despite these complications, there do seem to be discernible similarities and differences in transmission dynamics and likelihood of recombination of mtDNA in plant, animal and fungal taxa that should provide an excellent opportunity for comparative investigation of the evolution of mitochondrial genome dynamics.
Plant–water relations and the fibre saturation point
Authors: Berry Sandra L. , Roderick Michael L.
Published: September 2005

This review is about the behaviour of water in cell walls. The aim is to introduce to biologists the concept of the fibre saturation point (FSP), and the related research of material scientists and engineers on the thermodynamics and chemistry of water in timber and wood. In the review, we first summarise what the FSP is, why it is important and how the FSP is routinely used by engineers and material scientists to estimate the volume fractions of solid, liquid and gas phases in bulk timber. We then show that the FSP can be intuitively understood using equilibrium thermodynamics. That analysis shows that the FSP is based on the concept that a certain (and repeatable) amount of water is chemically bound to cellulose and other substances in wood. That water, sometimes called bound water, exists in a water–cell wall mixture. The noted physical chemist and wood scientist, A. J. Stamm, called this mixture a ‘solid solution’. In timber, the ‘solid solution’ is considered a separate phase from adjacent water in either a pure liquid phase or a vapour phase. Following that, we examine the FSP and wood–water dynamics at the molecular and cellular level. Despite differences between timber and living trees, we conclude that the FSP‐based framework long used by material scientists and engineers is likely to be useful to biologists.

Contents

Summary
1

I.
Introduction
2

II.
The FSP: an overview
2

III.
Equilibrium thermodynamics and the FSP
5

IV.
Inside the FSP
7

V.
Living trees and the FSP
10

VI.
Conclusions
11

Acknowledgements
12

References
12
Gene order in plants: a slow but sure shuffle
Authors: Vision Todd J.
Published: September 2005

Comparative mapping studies have revealed a great deal about the patterns of gene order and gene content evolution in plants. These findings have practical importance for leveraging genomic information from model to nonmodel plant species. However, there is much to be learned about the processes by which gene order and content evolve. The role of gene duplication and loss in the evolution of plant gene order, in particular, appears to be more important than commonly appreciated. An exciting area of current research is the study of gene order and content polymorphism within species. Some recent findings suggest that there may be a functional, and adaptive, relationship between gene order and phenotype that is mediated by the effects of gene order on transcriptional regulation.
GEOGRAPHICAL PATTERNS IN BIOLOGICALLY AVAILABLE STRONTIUM, CARBON AND OXYGEN ISOTOPE SIGNATURES IN PREHISTORIC SW GERMANY*
Authors: BENTLEY R. A. , KNIPPER C.
Published: September 2005

In order to interpret strontium and oxygen isotope values in Neolithic human skeletons analysed previously, we begin to map the biologically available strontium, carbon and oxygen isotopic signatures of prehistoric southern Germany by analysing tooth enamel of pigs from archaeological sites distributed around the region. The mapping shows a marked upland–lowland difference in biologically available

87

Sr/

86

Sr values, ranging between 0.7086 and 0.7103 in the sedimentary lowlands, and from 0.710 to as high as 0.722 in the crystalline uplands of the Odenwald, the Black Forest and the Bavarian Forest. In addition, carbon isotopes in the carbonate fraction of pig enamel were generally about 1–2 more enriched in

13

C in the uplands. Despite the expected depletion of

18

O with altitude, oxygen isotopes in pig enamel showed little correlation with site altitude, although for pig samples not older than the Iron Age there was some geographical correlation withδ18O patterns in modern precipitation.
A Longitudinal Study of Idiopathic Exudative Lymphocytic Pleural Effusion in Older People
Authors: El Solh Ali A. , Abdo Toufic , Pineda Lilibeth , Ramadan Fadi , Berbary Eileen
Published: September 2005

Objectives: To assess the long‐term prognosis of older patients with idiopathic exudative lymphocytic pleural effusion.

Design: Prospective observational study.

Setting: A university‐affiliated tertiary care center.

Participants: Forty‐seven consecutive patients (aged 74.9±5.4) with idiopathic exudative lymphocytic pleural effusion were enrolled over a 42‐month period.

Measurements: Baseline sociodemographic information, clinical data, and Charlson Comorbidity Index score were obtained. After an exhaustive examination, clinical evaluation and periodic chest radiographs were taken until one of the endpoints was met: complete resolution of the pleural effusion, death from all causes, or the end of the study period.

Results: The mean follow‐up period was 16.3±17.0 months. During the course of the study, complete resolution of the pleural effusion occurred in 17% of the patients, whereas it remained stable in 45%, and progressed in 38%. In seven cases, the cause of the effusion was established after an average of 84 days, and in another two, the diagnosis was made postmortem. Malignancy was documented in eight of the nine cases. Although the burden of comorbidities and cardiac function at baseline were similar in the three categories, the 3‐year survival rate was 63%, 5%, and 0%, respectively. None of the patients developed active tuberculosis, although 15% had positive tuberculin test.

Conclusion: By categorizing the presence of idiopathic effusion into resolving, persistent, or progressive, this study may provide a more practical approach to the long‐term prognosis of older patients with idiopathic exudative lymphocytic effusion who refuse or are considered too frail to undergo an invasive procedure.
Effects of Ultra‐Low‐Dose Estrogen Therapy on Muscle and Physical Function in Older Women
Authors: Kenny Anne M. , Kleppinger Alison , Wang Yahzen , Prestwood Karen M.
Published: September 2005

Objectives: To determine the effects of ultra‐low‐dose hormone therapy on muscle mass and physical function in community‐dwelling women.

Design: Double‐blind, placebo‐controlled trial.

Setting: Clinical research center in Connecticut.

Participants: Healthy, community‐dwelling women aged 65 and older (n=167).

Intervention: Eligible women were randomly assigned to treatment with 0.25 mg 17‐beta estradiol or placebo for 36 months. All women (estradiol or placebo) with an intact uterus received micronized progesterone 100 mg/d for 2 weeks every 6 months. All participants received 1,300 mg elemental calcium with 1,000 IU vitamin D per day.

Measurements: Appendicular skeletal muscle mass (ASM), lean body mass (LBM), and percentage body fat were measured using dual x‐ray absorptiometry. Sarcopenia was defined as skeletal muscle mass (ASM/height2) 2 standard deviations or less than young, healthy reference population mean. Physical activity (Physical Activity Scale in the Elderly (PASE)) and performance were measured. Serum estrone, estradiol, and sex hormone–binding globulin were measured.

Results: The prevalence of sarcopenia at baseline was 13%. There were no baseline differences between groups except for PASE score and chair rise time, in which the estrogen group had better performance. No changes in ASM, LBM, percentage of body fat, or physical performance were found after 3 years of estrogen therapy.

Conclusion: Sarcopenia was present in 13% of this group of community‐dwelling, postmenopausal older women. Ultra‐low‐dose estrogen therapy neither improves nor harms ASM. Similarly, no changes in body fat or physical performance were detected.
High Pacing Impedances: Are You Overtorquing Your Leads?
Authors: LASKE TIMOTHY G. , VIEAU SARAH A. , SKADSBERG NICHOLAS D. , IAIZZO PAUL A.
Published: September 2005

Background: Variations in measured pacing impedances that occur at the time of lead implantation remain largely unexplained and may be due to the morphology of the tissue‐lead interface.

Methods: An endocardial pacing lead was implanted under direct endoscopic visualization and parameters were measured for defined stages of implantation into multiple sites within the right atrium of in vitro swine hearts (n = 6, 38 implants), in vivo swine hearts (n = 2, 10 implants), and an in vitro human heart (n = 1, 15 implants).

Results: Steady increases in impedance values up to 2 turns fully fixed (2TF) were associated with minimal tissue distortion in all implants. Overtorquing of the in vitro swine implants resulted in severe distortion at the tissue‐lead interface demonstrating either tissue wrapping (24 implants) or tissue coring (14 implants). Impedance and threshold values remained elevated (953 ± 282 Ω, 7.86 ± 3.0 V; both P < 0.05 vs 2TF) during tissue distortion/wrapping, while tissue‐cored implants were associated with significant decreases (552 ± 187 Ω, 6.2 ± 2.2 V; both P < 0.05 vs 2TF). P‐wave amplitudes demonstrated no significant changes or correlation to tissue distortion. Importantly, both swine in vivo and human in vitro data demonstrated similar trends compared with the swine in vitro data.

Conclusions: In this study, one is able to directly observe and correlate the degree of distortion at the tissue‐lead interface with measured electrical parameters. Instantaneous impedance values obtained during fixation serve as a superior indicator of an acceptable lead implantation, and should therefore be carefully monitored during implantation.
Placement of Transvenous Pacemaker and ICD Leads Across Total Chronic Occlusions
Authors: McCOTTER CRAIG J. , ANGLE J. FRITZ , PRUDENTE LIZA A. , MOUNSEY J. PAUL , FERGUSON JOHN D. , DiMARCO JOHN P. , HUMMEL JAMES P. , MANGRUM J. MICHAEL
Published: September 2005

Objective: To establish a method of implantation for device leads across total venous occlusions.

Background: Indications for pacemaker and implantable cardiac defibrillator implantation continue to expand. Chronic venous occlusions are increasingly encountered with lead placement. Some degree of obstruction can be as high as 13% before device implantation and 50% after transvenous device implantation. We report an approach of venoplasty/dilatation of chronic total occlusions to allow lead placement.

Methods: From January 1, 2002 through December 16, 2004, 1,356 systems (initial and upgrade) were implanted at the University of Virginia. At the time of device implant, seven patients were noted to have chronic venous occlusions and alternative access was precluded. Four of the seven patients had an existing system; the other three received initial implantations. Subsequently, these seven patients had a 5 Fr catheter placed in the basilic/axillary/subclavian vein and a venogram was obtained to demonstrate the area of chronic occlusion. A guide wire was advanced across the lesion for initial recanalization. Dilatation or venoplasty was performed at the occluded site. A guide wire was retained across the lesion and the patient underwent lead implantation.

Results: In all seven patients, recanalization was achieved and leads were successfully placed. There were no complications or damage to the vessels or existing leads.

Conclusions: Venoplasty or dilatation of chronic total venous occlusion is a safe and effective technique, which allows for placement of transvenous leads.
Determination of the Optimal Atrioventricular Interval in Sick Sinus Syndrome During DDD Pacing
Authors: KATO MASAYA , DOTE KEIGO , SASAKI SHOTA , GOTO KENJI , TAKEMOTO HIROAKI , HABARA SEIJI , HASEGAWA DAIJI , MATSUDA OSAMU
Published: September 2005

Background: Although the AAI pacing mode has been shown to be electromechanically superior to the DDD pacing mode in sick sinus syndrome (SSS), there is evidence suggesting that during AAI pacing the presence of natural ventricular activation pattern is not enough for hemodynamic benefit to occur. Myocardial performance index (MPI) is a simply measurable Doppler‐derived index of combined systolic and diastolic myocardial performance. The aim of this study was to investigate whether AAI pacing mode is electromechanically superior to the DDD mode in patients with SSS by using Doppler‐derived MPI.

Methods: Thirty‐nine SSS patients with dual‐chamber pacing devices were evaluated by using Doppler echocardiography in AAI mode and DDD mode. The optimal atrioventricular (AV) interval in DDD mode was determined and atrial stimulus‐R interval was measured in AAI mode. The ratio of the atrial stimulus‐R interval to the optimal AV interval was defined as relative AV interval (rAVI) and the ratio of MPI in AAI mode to that in DDD mode was defined as relative MPI (rMPI).

Results: The rMPI was significantly correlated with atrial stimulus‐R interval and rAVI (r = 0.57, P = 0.0002, and r = 0.67, P < 0.0001, respectively). A cutoff point of 1.73 for rAVI provided optimum sensitivity and specificity for rMPI >1 based on the receiver operator curves.

Conclusions: Even though the intrinsic AV conduction is moderately prolonged, some SSS patients with dual‐chamber pacing devices benefit from the ventricular pacing with optimal AV interval. MPI is useful to determine the optimal pacing mode in acute experiment.
Thermodynamic Stability of Potassium‐beta‐Alumina
Authors: Shqau Krenar , Näfe Helfried
Published: September 2005

The thermodynamic stability of K‐beta‐Al2O3 (KBA) has been determined by characterizing the equilibrium between K‐β‐ and K‐β″‐Al2O3 using a potentiometric technique with yttria‐stabilized zirconia (YSZ) as solid electrolyte. The cell

image

allows an in situ check of the establishment and maintenance of the phase equilibrium by changing the composition of the KBA material reversibly. The activity of the potassium oxide dissolved in KBA amounts to (375°–600°C)

image

from which the standard Gibbs free energy of formation of K‐β″‐Al2O3 can be obtained as

image
Comparison of the Luminescence Properties of Dy3+ in α‐Sialon and Oxynitride Glass
Authors: Chen Wei‐Wu , Su Xin‐Lu , Wang Pei‐Ling , Yan Dong‐Sheng , Cheng Yi‐Bing , Watari Koji
Published: September 2005

Dy‐α‐sialon and β‐Si3N4 materials containing Dy‐oxynitride glass were hot pressed at 1800°C for 1 h. The luminescence spectra of Dy3+ in these samples were compared when excited at 350 nm. The results showed that two strong emission bands in the region 470–500 nm and 570‐600 nm, associated with the 4F9/2→6H15/2 and 4F9/2→6H13/2 transitions of Dy3+ ions, were observed in Dy‐α‐sialon. However, no emission peak was detected from the β‐Si3N4 sample, despite it containing the same amount of Dy3+ cations. This proved that only the Dy3+ cations in the α‐sialon structure, not those in the oxynitride glass, produce the luminescence spectrum.
Relationship Between Microstructures and Material Properties of Novel Fibrous Al2O3–(m‐ZrO2)/t‐ZrO2 Composites
Authors: Lee Byong‐Taek , Jang Dong‐Hwi , Kang In‐Cheol , Lee Chi‐Woo
Published: September 2005

Novel fibrous Al2O3–(m‐ZrO2)/t‐ZrO2 (m, monoclinic; t, tetragonal) composites having a core/shell structure were fabricated by multi‐extrusion, and their microstructures and material properties were investigated depending on the number of extrusions. The composites acquired a homogeneously fine fibrous structure as the number of extrusions increased. The bending strength and fracture toughness increased remarkably as the number of extrusions increased. In the fracture surface of the second passed composite, an Al2O3–(m‐ZrO2) core region appeared, flat type, although some local regions existed with an intergranular fracture. However, the fracture mode of the t‐ZrO2 region was of intergranular type having a sharp and rough surface. In the composite made by the fifth passed extrusion, the fracture strength and toughness values were high at about 665 MPa and 9.6 MPa·m1/2, respectively. The main fracture mode was a typical intergranular mode having a rough fracture surface, and the main multi‐toughening was because of mechanisms such as crack bridging, microcracking, and phase transformation.
Leaching Behavior of Sodium from Fine Particles of Soda–Lime–Silicate Glass in Acid Solution
Authors: Akai Tomoko , Kuraoka Koji , Chen Danping , Yamamoto Yoshihiro , Shirakami Tatsuya , Urabe Kazuyori , Yazawa Tetsuo
Published: September 2005

The leaching behavior of Na from soda–lime–silicate glass was investigated by preparing glass powders with average particle diameters of 53 and 19 μm, and leaching in HNO3 at 90°−140°C. A new theoretical equation for Na leaching from a spherical particle is proposed based on the assumption that a rate‐determining process is the three‐dimensional self‐diffusion of Na in glass. The diffusion constant (D) of Na in glass was obtained by fitting the experimental data to a theoretical equation. The values of D and activation energy obtained are comparable to those obtained in other studies on larger particles.
Psychological profile in oral lichen planus
Authors: Ivanovski Kiro , Nakova Marija , Warburton Gary , Pesevska Snezana , Filipovska Angelina , Nares Salvador , Nunn Martha E. , Angelova Dragana , Angelov Nikola
Published: September 2005

Aim: Oral lichen planus (OLP) is an oral lesion with an enigmatic etiology. To explore the possibility of psycho‐somatization, we evaluated the psychological personality profiles of OLP patients.

Methods: Twenty patients with reticular; 20 with erosive form of OLP, and 25 controls were tested with the psychological Minnesota Multiphasic Personality Inventory (MMPI)‐202 test. Eight clinical scales (hypochondriasis, depression, hysteria, psychopathic deviate, paranoia, psychasthenia, schizophrenia, and hypomania) as well as cortisol level, CD3, CD4, CD8, and CD16 markers by group were compared. Psychosomatization was evaluated by the use of internalization ratio (IR) Index.

Results: A characteristic MMPI profile was noted in the OLP groups with high IR index value. Significant differences among the groups were detected for cortisol, CD4, CD8, and CD16 counts. Mean values for hypochondriasis, depression, and hysteria were all significantly different with significantly higher mean scores for both reticular and erosive OLP subjects compared with controls.

Conclusions: Prolonged emotive stress in many OLP patients may lead to psychosomatization and may contribute to the initiation and clinical expression of this oral disorder.

Clinical significance: If additional research involving a larger and more diverse sample of patients confirms these findings, clinical trials will be needed to determine whether adjunctive psychological intervention provides a benefit in treating patients with OLP.
The Empirical Case for Specific Performance: Evidence from the IBP‐Tyson Litigation
Authors: Listokin Yair
Published: September 2005

Contract scholars debate the relative merits of specific performance and damages, but few studies assess remedies from an empirical perspective. This article examines the stock market response to an unusual specific performance award granted to IBP, Inc. in material adverse change (MAC) clause litigation against Tyson Foods, Inc. The combined value of Tyson and IBP rose after specific performance was granted, implying that specific performance created value. This result contrasts with other papers indirectly showing large decreases in combined market value after damages remedies are awarded. These results suggest that, from a postbreach perspective, the common law's preference for damages may be misplaced. The article identifies a number of settings, such as certain types of MAC clause controversies, wherein the use of specific performance rather than damages should be encouraged.
Overlooked in the Tort Reform Debate: The Growth of Erroneous Removal
Authors: Eisenberg Theodore , Morrison Trevor W.
Published: September 2005

Disputes over forum often center on whether a case should proceed in state or federal court. Removal to federal court can trigger a costly forum struggle. When a state case is removed to federal court only to be sent back to state court, the time and resources incurred in the detour are a toll on the judicial system and waste parties’ resources. We find erroneous removal to be an increasing problem. From 1993 to 2002, a period when state tort filings noticeably decreased, the number of removed diversity tort cases increased by about 10 percent to about 8,900 per year. By 2003, removed cases comprised over 30 percent of the federal diversity docket. The percentage of removals ultimately remanded to state court increased significantly to about 20 percent in 2003, with the remand rate exceeding 50 percent in some districts. Thus, as more cases purporting to satisfy diversity jurisdiction were being removed to federal court, and just as removals were occupying an increasing part of the federal docket, removed cases were being remanded to state court at increasing rates. Erroneous removal is a growing phenomenon that should be addressed as part of serious consideration of tort reform.
Career Story: Actuarial Researcher
Authors: Whelan Shane
Published: September 2005

In school, Shane Whelan loved science and had ambitions to become a physicist. But, although he has fulfilled his ambition of doing research, it is in actuarial science rather than physics. He tells Helen Joyce how the switch happened.
Ion chemistries in hexamethyldisiloxane
Authors: Jiao C. Q. , DeJoseph C. A. , Garscadden A.
Published: September 2005

Dissociative ionization of hexamethyldisiloxane (HMDSO) by electron impact is investigated using Fourier transform mass spectrometry. Absolute total and partial ionization cross sections are measured and the results compared with previous studies. The collision-induced dissociation technique is used to probe the fragmentation pathways of ions, providing insight into the production of neutral products from the electron impact ionization. Ion-molecule reactions of Ar+ and HMDSO ions with the parent gas molecule are studied, and isotope studies are used to evaluate the possible reaction mechanisms.
Changes in surface roughness and work function of indium-tin-oxide due to KrF excimer laser irradiation
Authors: Lin Yow-Jon , Baikie Iain D. , Chou Wei-Yang , Lin Shih-Ting , Chang Hsing-Cheng , Chen Yao-Ming , Liu Wen-Fung
Published: September 2005

In this study, from the observed x-ray photoelectron spectroscopy and atomic force microscopy results, and Kelvin probe measurements, it is suggested that the induced indium-tin-oxide (ITO) surface chemical changes by KrF excimer laser irradiation had strong effects on the surface work function (SWF) and surface roughness of ITO. During the laser irradiation, the incorporation of O22− peroxo species or the dissolution of oxygen species near the ITO surface leads to the reduction of the surface roughness and an increase in the SWF. In addition, it is worth noting that the laser-irradiated ITO sample has an excellent stability in the SWF.
Optical recording characteristics of WO3 films grown by pulsed laser deposition method
Authors: Aoki Takanori , Matsushita Tatsuhiko , Suzuki Akio , Tanabe Kenji , Okuda Masahiro
Published: September 2005

W O 3 films were deposited on the glass substrate (Corning No. 7059 with an area of 26×38mm) by the pulsed laser deposition method using an ArF excimer laser. It was found that after annealing at 500°C for 10min, the film thickness became 1.8 times compared with that (approximately 40nm) in the as deposited state. At this time, the difference in the transmittance, ΔT, between the annealed state and the as deposited state was about 40% at the wavelength of 400nm. From x-ray diffraction spectra and x-ray photoelectron spectroscopy spectra, it was considered that the ratio of the peak values of W6+ 4f5∕2 (tungsten oxide) versus W 4f5∕2 (metal tungsten) increased steeply after the annealing process. From this, it was considered that oxygen was absorbed into the WO3 films through the annealing process. From the revolution test for the sample without the protection layer in which the WO3 films were deposited upon the digital versatile disk disk substrate, a write peak-power dependence of carrier to noise ratio (CNR) (at λ=406nm, NA=0.65) of 3T signal (58.5MHz) was measured at a linear velocity of 5m∕s and a read power of 0.6mW. It was confirmed that the values of CNR obtained at the write peak-power 5–6mW were near 50dB (the region A) and the ones obtained at the write power 7–10mW were more than 60dB (the region B). From scanning electron microscopy observation, it was recognized that bits with 0.16–0.25μm size, having the fine-shaped dots with clear-cut edge, were made in the region A. This corresponded to the maximal storage capacity of 25GB in the “Blu-ray disk” specification. However, it was also identified that holes were formed in the region B and the film materials were scattered by receiving a train of high write power impulses. Next, it was found that the write power corresponding to region A for the structures with the WO3 layer sandwiched between a Al2O3 or ZnS–SiO2 protection layer increased or decreased, respectively. Larger values of the CNR will be obtained if the film thickness of each layer including the active layer were optimized.
Numerical modeling of the Holweck pump
Authors: Sharipov Felix , Fahrenbach Peter , Zipp Andreas
Published: September 2005

A numerical model of the Holweck pump based on the kinetic equation is proposed. The modeling is realized in two stages. The first one consists of calculations of gas flows along and across a groove due to longitudinal and transversal pressure gradients, respectively. Analogous gas flows caused by longitudinal and transversal surface motions are calculated. These four solutions are determined by geometrical parameters of grooves. In the second stage, the pumping speed and the torque of the rotating cylinder are calculated as a linear superposition of the four solutions. The proposed methodology allows us easily to vary many parameters such as height and radius of the pump, angular velocity of the rotating cylinder, inclination of grooves, species, and temperature of the gas. A comparison of the numerical results with experimental data confirms that the groove curvature is not a predominant factor, while the gas rarefaction significantly affects the main characteristics of the pump.
Synchrotron radiation induced Si–H dissociation on H–Si(111)–1×1 surfaces studied by in situ monitoring in the undulator-scanning tunneling microscope system
Authors: Nonogaki Y. , Urisu T.
Published: September 2005

Irradiation effects of the synchrotron radiation (SR) have been investigated on the hydrogen terminated- (H-) Si (111) surfaces by using the undulator beam and the in situ scanning tunneling microscope (STM). The small protrusions (SPs) generated by the undulator beam irradiation were assigned to the rest atoms with missing H. From the observed relation among the SP density, photon energy of the undulator beam and the total photon flux, it has been concluded that the main mechanism of the Si–H bond dissociation by the undulator beam irradiation is valence electron excitations of the Si–H bond by incident photons.
In situ x-ray diffraction studies concerning the influence of Al concentration on the texture development during sputter deposition of Ti–Al–N thin films
Authors: Beckers M. , Schell N. , Martins R. M. S. , Mücklich A. , Möller W.
Published: September 2005

In situ x-ray diffraction was employed during the growth of thin Ti1−xAlxN films, using a deposition chamber installed at a synchrotron radiation beamline. The films were deposited by reactive cosputtering from Ti and Al targets. In a previous experiment, the substrate temperature, bias voltage, and nitrogen partial pressure, and thus growth rate, were varied at constant x≈0.07. High deposition rates of ∼1Å∕s lead to the typical crossover behavior between initial (001) and final (111) off-plane preferred orientation. Reducing the deposition rate to <0.5Å∕s leads to a reversed behavior with a clear (001) preferred orientation above a film thickness of 600 Å, which is essentially independent of the substrate temperature. For the results presented here, the studies were extended to a systemical variation of x from 0 to 0.73 while keeping all the other parameters constant. For a Al concentration up to x∼0.15 the (001) preferred orientation is persistent. On the other hand, at low deposition rates, a (111) preferred orientation can also be recovered for x>0.15. This can be addressed to the higher adatom mobility of Al compared to Ti in the presence of atomic nitrogen, which leads to enrichtment of Al in (111) oriented grains. As a consequence, an increase of Al towards the segregation threshold of hexagonal AlN leads to preferred precipitation in (111) oriented grains, reducing the (111) intensity and giving rise to a mixed (111)+(001) texture. Increasing the Al content even further up to x≈0.60 forces the formation of hard nanocomposite nc-TiAlN∕AlN structures, and finally an Al content of x>0.73 leads to dominant AlN with an a-axis off-plane texture.
Feature-scale model of Si etching in SF6∕O2 plasma and comparison with experiments
Authors: Belen Rodolfo Jun , Gomez Sergi , Cooperberg David , Kiehlbauch Mark , Aydil Eray S.
Published: September 2005

We have developed a semiempirical feature scale model of Si etching in SF6∕O2 plasma. The kinetic parameters in the model are determined by matching simulated profiles with experimentally observed feature profiles obtained at various pressures, rf-bias voltages, and O2 mole fraction in the feed gas. The model parameters are further constrained by using information about the relative radical concentrations, ion flux, and ion energy obtained from plasma diagnostics. Excellent agreement between experiments and simulations is obtained. The combined experimental and simulation study reveals that chemical etching in the lateral direction is significantly reduced through competitive adsorption of O on the feature sidewalls and subsequent formation of a fluorinated oxide layer that passivates the sidewalls. The flux of F and SFx radicals is focused toward the feature bottom due to increased neutral reflection off the passivated sidewalls. The net result is enhanced etching in the vertical direction and improved feature anisotropy with decreasing F-to-O ratio (increasing O2 fraction). However, too much O2 addition eventually leads to the slowing down of the vertical etch rate as O adsorption on active surface sites dominates even at the feature bottom.
Evaluation of surface and build‐up region dose for intensity‐modulated radiation therapy in head and neck cancer
Authors: Chung Heeteak , Jin Hosang , Dempsey James F. , Liu Chihray , Palta Jatinder , Suh Tae‐Suk , Kim Siyong
Published: September 2005

Despite much development, there remains dosimetric uncertainty in the surface and build‐up regions in intensity‐modulated radiation therapy treatment plans for head and neck cancers. Experiments were performed to determine the dosimetric discrepancies in the surface and build‐up region between the treatment planning system (TPS) prediction and experimental measurement using radiochromic film. A head and neck compression film phantom was constructed from two semicylindrical solid water slabs. Treatment plans were generated using two commercial TPSs (PINNACLE3 and CORVUS) for two cases, one with a shallow ( depth) target and another with a deep ( depth) target. The plans were evaluated for a 54 Gy prescribed dose. For each case, two pieces of radiochromic film were used for dose measurement. A small piece of film strip was placed on the surface and another was inserted within the phantom. Overall, both TPSs showed good agreement with the measurement. For the shallow target case, the dose differences were within (5.6% with respect to the prescribed dose) for PINNACLE3 and (4.4%) for CORVUS in 90% of the region of interest. For the deep target case, the dose differences were (6.5%) for PINNACLE3 and (4.8%) for CORVUS in 90% of the region of interest. However, it was found that there were significant discrepancies from the surface to about 0.2 cm in depth for both the shallow and deep target cases. It was concluded that both TPSs overestimated the surface dose for both shallow and deep target cases. The amount of overestimation ranges from 400 to 1000 cGy ( to 18.5% with respect to the prescribed dose, 5400 cGy).
Maxwell to Einstein — A Liberal-Arts Physics Course
Authors: Erlichson Herman
Published: September 2005

The December 1997 issue of The Physics Teacher contained an article describing a liberal-arts physics course entitled Galileo to Newton.1 This course has been successfully offered for a number of years at the College of Staten Island, and interest in it has been substantial as evidenced by requests for reprints of the TPT article and requests for copies of the course lab manual. A follow-on course was designed called Maxwell to Einstein and Beyond. We offered this course for the first time in the fall 2003 semester.
Predicting Turning Points for Toy Cars
Authors: Ramsdell M. W. , Wick D. P.
Published: September 2005

A simple experiment can be performed to estimate a toy car's effective coefficient of friction without the use of sophisticated equipment. The results can be used to predict the car's turning points when traveling on an arbitrarily shaped track containing multiple hills and valleys in a 2-D vertical plane. This activity is based on a team-oriented modeling-based project conducted at Clarkson University, which was published in the American Journal of Physics.1