bluuebunny/crossref_metadata_2025 huggingface dataset:
Enhanced production of IL-17A during zymosan-induced peritonitis in obese mice
Authors: Pini Maria , Fantuzzi Giamila
Published: September 2009

Neutrophils from obese mice produce high levels of the pro-inflammatory cytokine IL-17A following zymosan administration; this cytokine contributes to exacerbation and delayed resolution of peritoneal inflammation in obesity.

IL-17A is a proinflammatory cytokine critical for host defense and involved in the pathogenesis of autoimmune disorders. Obesity is associated with chronic low-grade inflammation but also with a heightened acute inflammatory response. We investigated the effect of obesity on IL-17A production using the model of ZY-induced peritonitis. Compared with lean controls, administration of ZY induced a significantly exacerbated inflammatory response in obese leptin-deficient ob/ob mice and in mice with diet-induced obesity (DIO). Levels of IL-17A in the peritoneal fluid in response to ZY were elevated significantly in ob/ob and DIO mice compared with lean animals. Reconstitution of ob/ob mice with exogenous leptin did not alter production of IL-17A significantly in response to ZY. Peritoneal cells and adipose tissue obtained from ZY-injected obese mice expressed significantly higher levels of IL-17A mRNA compared with lean mice. Approximately 2% of peritoneal Ly6G+ neutrophils from ZY-injected obese mice expressed IL-17A protein, compared with 0.2% of cells obtained from lean mice. Neutralization of IL-17 in ob/ob mice inhibited neutrophil recruitment and production of neutrophil-attracting CXC chemokines and IL-6, without affecting macrophage infiltration or levels of IL-10 and the chemokine CCL2. In contrast, neutralization of IL-6 did not affect production of IL-17A or chemokines while reducing production of the acute-phase protein serum amyloid A significantly. These data demonstrate that neutrophil-derived IL-17A is increased in obese mice during acute inflammation and contributes to exacerbation of inflammatory responses.
The effects of testosterone on immune function in quail selected for divergent plasma corticosterone response
Authors: Roberts Mark L. , Buchanan Katherine L. , Evans Matthew R. , Marin Raul H. , Satterlee Daniel G.
Published: September 2009

The immunocompetence handicap hypothesis (ICHH) suggests that the male sex hormone testosterone has a dual effect; it controls the development and expression of male sexually selected signals, and it suppresses the immune system. Therefore only high quality males are able to fully express secondary sexual traits because only they can tolerate the immunosuppressive qualities of testosterone. A modified version of the ICHH suggests that testosterone causes immunosuppression indirectly by increasing the stress hormone corticosterone (CORT). Lines of Japanese quail (Coturnix japonica)selected for divergent responses in levels of plasma CORT were used to test these hypotheses. Within each CORT response line (as well as in a control stock) we manipulated levels of testosterone in castrated quail by treatment with zero (sham), low or high testosterone implants, before testing the birds'humoral immunity and phytohaemagglutinin (PHA)-induced immune response, as well as body condition. The PHA-induced response was not significantly affected by CORT selected line, testosterone treatment or their interaction. There was, however, a significant effect of CORT line on humoral immunity in that the control birds exhibited the greatest antibody production, but there was no significant effect of testosterone manipulation on humoral immunity. The males in the sham implant treatment group had significantly greater mass than the males in the high testosterone group, suggesting a negative effect of high testosterone on general body condition. We discuss these results in the context of current hypotheses in the field of sexual selection.
Acoustic behaviour of echolocating porpoises during prey capture
Authors: DeRuiter Stacy L. , Bahr Alexander , Blanchet Marie-Anne , Hansen Sabina Fobian , Kristensen Jakob Højer , Madsen Peter T. , Tyack Peter L. , Wahlberg Magnus
Published: September 2009

Porpoise echolocation has been studied previously, mainly in target detection experiments using stationed animals and steel sphere targets, but little is known about the acoustic behaviour of free-swimming porpoises echolocating for prey. Here, we used small onboard sound and orientation recording tags to study the echolocation behaviour of free-swimming trained porpoises as they caught dead, freely drifting fish. We analysed porpoise echolocation behaviour leading up to and following prey capture events,including variability in echolocation in response to vision restriction, prey species, and individual porpoise tested. The porpoises produced echolocation clicks as they searched for the fish, followed by fast-repetition-rate clicks(echolocation buzzes) when acquiring prey. During buzzes, which usually began when porpoises were about 1–2 body lengths from prey, tag-recorded click levels decreased by about 10 dB, click rates increased to over 300 clicks per second, and variability in body orientation (roll) increased. Buzzes generally continued beyond the first contact with the fish, and often extended until or after the end of prey handling. This unexplained continuation of buzzes after prey capture raises questions about the function of buzzes, suggesting that in addition to providing detailed information on target location during the capture, they may serve additional purposes such as the relocation of potentially escaping prey. We conclude that porpoises display the same overall acoustic prey capture behaviour seen in larger toothed whales in the wild,albeit at a faster pace, clicking slowly during search and approach phases and buzzing during prey capture.
Metabolic function inDrosophila melanogasterin response to hypoxia and pure oxygen
Authors: Van Voorhies Wayne A.
Published: September 2009

This study examined the metabolic response of Drosophila melanogaster exposed to O2 concentrations ranging from 0 to 21% and at 100%. The metabolic rate of flies exposed to graded hypoxia remained nearly constant as O2 tensions were reduced from normoxia to ∼3 kPa. There was a rapid, approximately linear reduction in fly metabolic rate at PO2s between 3 and 0.5 kPa. The reduction in metabolic rate was especially pronounced at PO2 levels <0.5 kPa, and at a PO2 of 0.1 kPa fly metabolic rate was reduced∼10-fold relative to normoxic levels. The metabolic rate of flies exposed to anoxia and then returned to normoxia recovered to pre-anoxic levels within 30 min with no apparent payment of a hypoxia-induced oxygen debt. Flies tolerated exposure to hypoxia and/or anoxia for 40 min with nearly 100%survival. Fly mortality increased rapidly after 2 h of anoxia and >16 h exposure was uniformly lethal. Flies exposed to pure O2 for 24 h showed no apparent alteration of metabolic rate, even though such O2 tensions should damage respiratory enzymes critical to mitochondria function. Within a few hours the metabolic rate of flies recovering from exposure to repeated short bouts of anoxia was the same as flies exposed to a single anoxia exposure.
Quantitative miRNA expression analysis: Comparing microarrays with next-generation sequencing
Authors: Willenbrock Hanni , Salomon Jesper , Søkilde Rolf , Barken Kim Bundvig , Hansen Thomas Nøhr , Nielsen Finn Cilius , Møller Søren , Litman Thomas
Published: September 2009

Recently, next-generation sequencing has been introduced as a promising, new platform for assessing the copy number of transcripts, while the existing microarray technology is considered less reliable for absolute, quantitative expression measurements. Nonetheless, so far, results from the two technologies have only been compared based on biological data, leading to the conclusion that, although they are somewhat correlated, expression values differ significantly. Here, we use synthetic RNA samples, resembling human microRNA samples, to find that microarray expression measures actually correlate better with sample RNA content than expression measures obtained from sequencing data. In addition, microarrays appear highly sensitive and perform equivalently to next-generation sequencing in terms of reproducibility and relative ratio quantification.
A High-Sensitivity, Medium-Density, and Target Amplification–Free Planar Waveguide Microarray System for Gene Expression Analysis of Formalin-Fixed and Paraffin-Embedded Tissue
Authors: Schwers Stephan , Reifenberger Elke , Gehrmann Mathias , Izmailov Alexandre , Bohmann Kerstin
Published: September 2009

Background: Many microarray platforms and their associated assay chemistries do not work properly with RNA extracted from formalin-fixed, paraffin-embedded (FFPE) tissue samples, a feature that severely hampers the use of microarrays in oncology applications, for which FFPE tissue is the routine specimen. Furthermore, the limited sensitivity of most microarray platforms requires time-consuming and costly amplification reactions of the target RNA, which negatively affects clinical laboratory work flow.

Methods: We developed an approach for sensitively and reliably measuring mRNA abundances in FFPE tissue samples. This approach involves automated RNA extractions, direct hybridization of extracted RNA to immobilized capture probes, antibody-mediated labeling, and readout with an instrument applying the principle of planar waveguides (PWG). A 14-gene multiplex assay conducted with RNA isolated from 20 FFPE blocks was correlated to an analysis of the same with reverse-transcription quantitative real-time PCR (RT-qPCR).

Results: The assay sensitivity for gene expression analysis obtained for the PWG microarray platform was <10 fmol/L, eliminating the need for target preamplification. We observed a correlation coefficient of 0.87 to state-of-the-art RT-qPCR technology with RNA isolated from FFPE tissue, despite a compressed dynamic range for the PWG system (a 2.9-log dynamic range for PWG in our test system vs 5.0 logs for RT-qPCR). The precision of the PWG platform was comparable to RT-qPCR (Pearson correlation coefficient of 0.9851 for PWG vs 0.9896 for RT-qPCR) for technical replicates.

Conclusions: The presented PWG platform demonstrated excellent sensitivity and precision and is especially well suited for any application for which fast, simple, and robust multiplex assays of RNA in FFPE tissue are required.
Verification of the ASTM G-124 Purge Equation
Authors: Robbins Katherine E. , Davis Samuel Eddie , Herald Stephen D.
Published: September 2009

ASTM G-124 seeks to evaluate combustion characteristics of metals in high-purity (>99 %) oxygen atmospheres. ASTM G-124 provides the following equation to determine the minimum number of purges required to reach this level of purity in a test chamber: n = −4/log10(Pa/Ph), where n is the total number of purge cycles required, Ph is the absolute pressure used for the purge on each cycle, and Pa is the atmospheric pressure or the vent pressure. The origin of this equation is not known and has been the source of frequent questions as to its accuracy and reliability. This paper provides the derivation of the G-124 purge equation, and experimentally explores the equation to determine if it accurately predicts the number of cycles required.
Retail Return Policy, Endowment Effect, and Consumption Propensity: An Experimental Study
Authors: Wang Xianghong
Published: September 2009

The impact of retail return policy on consumer behavior has not drawn enough attention from researchers. Lenient return policies insure consumers against having regret after purchasing, so they may increase consumers' likelihood of purchasing. The behavioral theory of endowment effect suggests that consumers may then have a harder time returning purchased goods because people value objects more highly once they own them. We conducted a test of our hypotheses on how return policy and endowment effect influence purchasing tendency and return rate. This experiment proved that endowment effect did affect the returning behavior of consumers. It showed that lenient return policies significantly increased initial purchasing tendency but did not increase return rate. This suggests a potential to increase consumption by adopting lenient return policies.
A Conceptual Model of Optimal International Service-Learning and Its Application to Global Health Initiatives in Rehabilitation
Authors: Pechak Celia M. , Thompson Mary
Published: September 2009

Background

There is growing involvement by US clinicians, faculty members, and students in global health initiatives, including international service-learning (ISL). Limited research has been done to examine the profession's increasing global engagement, or the ISL phenomenon in particular, and no research has been done to determine best practices. This study was intended as an early step in the examination of the physical therapy profession's role and activities in the global health arena within and beyond academics.

Objectives

The purposes of this study were: (1) to identify and analyze the common structures and processes among established ISL programs within physical therapist education programs and (2) to develop a conceptual model of optimal ISL within physical therapist education programs.

Design

A descriptive, exploratory study was completed using grounded theory.

Methods

Telephone interviews were completed with 14 faculty members who had been involved in international service, international learning, or ISL in physical therapist education programs. Interviews were transcribed, and transcriptions were analyzed using the grounded theory method.

Results

Four major themes emerged from the data: structure, reciprocity, relationship, and sustainability. A conceptual model of and a proposed definition for optimal ISL in physical therapist education were developed. Seven essential components of the conceptual model are: a partner that understands the role of physical therapy, community-identified needs, explicit service and learning objectives, reflection, preparation, risk management, and service and learning outcome measures. Essential consequences are positive effects on students and community.

Conclusions

The conceptual model and definition of optimal ISL can be used to direct development of new ISL programs and to improve existing programs. In addition, they can offer substantive guidance to any physical therapist involved in global health initiatives.
The Patient Goal Priority Questionnaire Is Moderately Reproducible in People With Persistent Musculoskeletal Pain
Authors: Åsenlöf Pernilla , Siljebäck Kim
Published: September 2009

Background

The Patient Goal Priority Questionnaire (PGPQ) is a patient-specific measure for identification of behavioral goals and evaluation of clinically significant changes. The use of such a measure in clinical settings and research requires that identified goals be consistent over time. Self-reports of behaviors related to the goals should be reliably estimated.

Objective

The purpose of this study was to estimate chance-corrected agreement and test-retest reliability of the PGPQ. Chance-corrected agreement between the PGPQ and a similar therapist-guided goal identification tool, the Patient Goal Priority List (PGPL), also was estimated.

Design

A correlative and prospective design with 3 measurement points (M1, M2, and M3) was used in the study.

Methods

Fifty-four people who consulted physical therapists in primary care for persistent musculoskeletal pain were included in the study. Analyses of chance-corrected agreement and test-retest reliability of the PGPQ were done at M1 and M2. Chance-corrected agreement between procedures (PGPQ and PGPL) also was analyzed at M1 and M3.

Results

The percentage of agreement on content of the priority lists of the PGPQ at M1 and M2 was 52%. Cohen kappa values for agreement of rankings ranged between .47 and .64. Test-retest reliability coefficients for the self-report scales of the PGPQ ranged from .35 to .81. Chance-corrected agreement decreased when physical therapists were involved in the goal identification process using the PGPL (kappa=.08–.46).

Limitations

Varying item content and a small, heterogeneous sample possibly increased variation and the standard error of measurements. The feasibility of using traditional approaches to psychometric evaluation of patient-specific measures is questionable.

Conclusions

Chance-corrected agreement and test-retest reliability of the PGPQ were moderate. Involving a physical therapist in the goal identification procedure possibly introduced further bias. The size of the measurement error must be taken into account when using the PGPQ for estimations of clinically important changes.
Raymond M. P. Donaghy: a pioneer in microneurosurgery
Authors: Link Timothy E. , Bisson Erica , Horgan Michael A. , Tranmer Bruce I.
Published: September 2009

Raymond M. P. Donaghy was one of the true pioneers of modern neurosurgery. His restless dedication, innovation, and desire to humbly disseminate his knowledge facilitated the advancement of the field of microneurosurgery. Many of his trainees—most notably M. Gazi Yaşargil—continued to advance the field, developing innovative microsurgical instruments and techniques. The history of microneurosurgery is incomplete without a glimpse at the life of this remarkable man.
Gamma Knife stereotactic radiosurgery for idiopathic trigeminal neuralgia
Authors: Kondziolka Douglas , Zorro Oscar , Lobato-Polo Javier , Kano Hideyuki , Flannery Thomas J. , Flickinger John C. , Lunsford L. Dade
Published: September 2009

Object

Trigeminal neuralgia pain causes severe disability. Stereotactic radiosurgery is the least invasive surgical option for patients with trigeminal neuralgia. Since different medical and surgical options have different rates of pain relief and morbidity, it is important to evaluate longer-term outcomes.

Methods

The authors retrospectively reviewed outcomes in 503 medically refractory patients with trigeminal neuralgia who underwent Gamma Knife surgery (GKS). The median patient age was 72 years (range 26–95 years). Prior surgery had failed in 205 patients (43%). The GKS typically was performed using MR imaging guidance, a single 4-mm isocenter, and a maximum dose of 80 Gy.

Results

Patients were evaluated for up to 16 years after GKS; 107 patients had > 5 years of follow-up. Eighty-nine percent of patients achieved initial pain relief that was adequate or better, with or without medications (Barrow Neurological Institute [BNI] Scores I–IIIb). Significant pain relief (BNI Scores I–IIIa) was achieved in 73% at 1 year, 65% at 2 years, and 41% at 5 years. Including Score IIIb (pain adequately controlled with medication), a BNI score of I–IIIb was found in 80% at 1 year, 71% at 3 years, 46% at 5 years, and 30% at 10 years. A faster initial pain response including adequate and some pain relief was seen in patients with trigeminal neuralgia without additional symptoms, patients without prior surgery, and patients with a pain duration of ≤ 3 years. One hundred ninety-three (43%) of 450 patients who achieved initial pain relief reported some recurrent pain 3–144 months after initial relief (median 50 months). Factors associated with earlier pain recurrence that failed to maintain adequate or some pain relief were trigeminal neuralgia with additional symptoms and ≥ 3 prior failed surgical procedures. Fifty-three patients (10.5%) developed new or increased subjective facial paresthesias or numbness and 1 developed deafferentation pain; these symptoms resolved in 17 patients. Those who developed sensory loss had better long-term pain control (78% at 5 years).

Conclusions

Gamma Knife surgery proved to be safe and effective in the treatment of medically refractory trigeminal neuralgia and is of value for initial or recurrent pain management. Despite the goal of minimizing sensory loss with this procedure, some sensory loss may improve long-term outcomes. Pain relapse is amenable to additional GKS or another procedure.
Biopsy versus resection in the management of malignant gliomas: a systematic review and meta-analysis
Authors: Tsitlakidis Abraham , Foroglou Nicolas , Venetis Christos A. , Patsalas Ioannis , Hatzisotiriou Athanasios , Selviaridis Panagiotis
Published: September 2009

Object

The aim of this study was to answer the question whether quality of life and progression-free and overall survival are increased in adults with supratentorial malignant glioma who are treated with cytoreductive resection as compared with those who only undergo biopsy.

Methods

A literature search of the electronic databases MEDLINE, EMBASE, and CENTRAL was performed to identify relevant studies published before May 2008. Hand-searching of reference lists of the identified studies and relevant review articles was also performed. A study was considered eligible, regardless of study design (prospective or retrospective), if: 1) quality of life and/or progression-free and/or overall survival was compared among adult patients undergoing biopsy or resection, and 2) patient age and Karnofsky Performance Scale scores were not significantly different among the 2 groups compared.

Results

One randomized controlled trial and 4 retrospective studies (involving a total of 1111 patients) were found eligible for this systematic review. A meta-analysis of the eligible studies demonstrated a significant increase in overall survival in the patients treated with resection instead of biopsy (hazard ratio 0.61, 95% CI 0.52–0.71, p < 0.0001, fixed-effect model). Although statistical pooling was not feasible, the available data suggest that quality of life was increased in patients treated with resection rather than biopsy, while there did not seem to be any significant difference in progression-free survival between the 2 groups.

Conclusions

Based on the best available evidence, it appears that cytoreductive resection in adults with supratentorial malignant glioma is associated with improved overall survival as compared with biopsy. However, well-designed prospective studies are needed for more solid conclusions to be drawn.
Comparison of diffusion tensor imaging tractography of language tracts and intraoperative subcortical stimulations
Authors: Leclercq Delphine , Duffau Hugues , Delmaire Christine , Capelle Laurent , Gatignol Peggy , Ducros Mathieu , Chiras Jacques , Lehéricy Stéphane
Published: September 2009

Object

Diffusion tensor (DT) imaging tractography is increasingly used to map fiber tracts in patients with surgical brain lesions to reduce the risk of postoperative functional deficit. There are few validation studies of DT imaging tractography in these patients. The aim of this study was to compare DT imaging tractography of language fiber tracts by using intraoperative subcortical electrical stimulations.

Methods

The authors included 10 patients with low-grade gliomas or dysplasia located in language areas. The MR imaging examination included 3D T1-weighted images for anatomical coregistration, FLAIR, and DT images. Diffusion tensors and fiber tracts were calculated using in-house software. Four tracts were reconstructed in each patient including the arcuate fasciculus, the inferior occipitofrontal fasciculus, and 2 premotor fasciculi (the subcallosal medialis fiber tract and cortical fibers originating from the medial and lateral premotor areas). The authors compared fiber tracts reconstructed using DT imaging with those evidenced using intraoperative subcortical language mapping.

Results

Seventeen (81%) of 21 positive stimulations were concordant with DT imaging fiber bundles (located within 6 mm of a fiber tract). Four positive stimulations were not located in the vicinity of a DT imaging fiber tract. Stimulations of the arcuate fasciculus mostly induced articulatory and phonemic/syntactic disorders and less frequently semantic paraphasias. Stimulations of the inferior occipitofrontal fasciculus induced semantic paraphasias. Stimulations of the premotor-related fasciculi induced dysarthria and articulatory planning deficit.

Conclusions

There was a good correspondence between positive stimulation sites and fiber tracts, suggesting that DT imaging fiber tracking is a reliable technique but not yet optimal to map language tracts in patients with brain lesions. Negative tractography does not rule out the persistence of a fiber tract, especially when invaded by the tumor. Stimulations of the different tracts induced variable language disorders that were specific to each fiber tract.
Relationship of aggressive monitoring and treatment to improved outcomes in severe traumatic brain injury
Authors: Stein Sherman C. , Georgoff Patrick , Meghan Sudha , Mirza Kasim L. , El Falaky Omar M.
Published: September 2009

Object

Despite being common practice for decades and being recommended by national guidelines, aggressive monitoring and treatment of patients with severe traumatic brain injury (TBI) have not been supported by convincing evidence.

Methods

The authors reviewed trials and case series reported after 1970 in which patients were treated for severe closed TBI, and mortality rates and favorable outcomes at 6 months after injury were analyzed. The patient groups were divided into those with and without intracranial pressure (ICP) monitoring and intensive therapy, and the authors performed a meta-analysis to assess the effects of treatment intensity on outcome.

Results

Although the mortality rate fell during the years reviewed, it was consistently ~ 12% lower among patients in the intense treatment group (p < 0.001). Favorable outcomes did not change significantly over time, and were 6% higher among the aggressively treated patients (p = 0.0105).

Conclusions

Aggressive ICP monitoring and treatment of patients with severe TBI is associated with a statistically significant improvement in outcome. This improvement occurs independently of temporal effects.
Global Amphibian Extinction Risk Assessment for the Panzootic Chytrid Fungus
Authors: Rödder Dennis , Kielgast Jos , Bielby Jon , Schmidtlein Sebastian , Bosch Jaime , Garner Trenton W. J. , Veith Michael , Walker Susan , Fisher Matthew C. , Lötters Stefan
Published: September 2009

Species are being lost at increasing rates due to anthropogenic effects, leading to the recognition that we are witnessing the onset of a sixth mass extinction. Emerging infectious disease has been shown to increase species loss and any attempts to reduce extinction rates need to squarely confront this challenge. Here, we develop a procedure for identifying amphibian species that are most at risk from the effects of chytridiomycosis by combining spatial analyses of key host life-history variables with the pathogen's predicted distribution. We apply our rule set to the known global diversity of amphibians in order to prioritize pecies that are most at risk of loss from disease emergence. This risk assessment shows where limited conservation funds are best deployed in order to prevent further loss of species by enabling ex situ amphibian salvage operations and focusing any potential disease mitigation projects.
Relationship between Dietary Beef, Fat, and Pork and Alcoholic Cirrhosis
Authors: Bridges Francis  Stephen
Published: September 2009

Nanji and French [1] investigated the relationship between per-caput consumption of total fat, beef, and pork and for alcohol consumption and rates of mortality for cirrhosis for 16 countries for 1965. The present study reports significant and positive associations for 1996 and 2003 between the following: alcohol consumption and cirrhosis mortality, pork consumption and cirrhosis mortality, the product of alcohol and pork consumption and the product of alcohol and fat consumption. These supportive associations may represent a relationship between the risk of alcoholic cirrhosis and some heretofore unknown dietary or environmental factor related to conditions of pork or fat consumption. Limitations of the study design are discussed.
Degradability of Polymers for Implantable Biomedical Devices
Authors: Lyu SuPing , Untereker Darrel
Published: September 2009

Many key components of implantable medical devices are made from polymeric materials. The functions of these materials include structural support, electrical insulation, protection of other materials from the environment of the body, and biocompatibility, as well as other things such as delivery of a therapeutic drug. In such roles, the stability and integrity of the polymer, over what can be a very long period of time, is very important. For most of these functions, stability over time is desired, but in other cases, the opposite–the degradation and disappearance of the polymer over time is required. In either case, it is important to understand both the chemistry that can lead to the degradation of polymers as well as the kinetics that controls these reactions. Hydrolysis and oxidation are the two classes of reactions that lead to the breaking down of polymers. Both are discussed in detail in the context of the environmental factors that impact the utility of various polymers for medical device applications. Understanding the chemistry and kinetics allows prediction of stability as well as explanations for observations such as porosity and the unexpected behavior of polymeric composite materials in some situations. In the last part, physical degradation such interfacial delamination in composites is discussed.
Synthesis of 3-Methyl-1-morpholin-4-ylmethyl-2,6-diphenylpiperidin-4-one
Authors: Kumar Samiappan , Kavitha Helen , Venkatraman Bathey
Published: September 2009

This paper describes the synthesis of 3-methyl-1-morpholin-4-ylmethyl-2,6-diphenylpiperidin-4-one from 3-methyl-2,6-diphenylpiperidin-4-one. The synthesized compound was characterized by FT-IR, 1H NMR, EI-MS and elemental analysis.
Modelling of Grain Growth Kinetics in Porous Ceramic Materials under Normal and Irradiation Conditions
Authors: Veshchunov Mikhail  S.
Published: September 2009

Effect of porosity on grain growth is both the most frequent and technologically important situation encountered in ceramic materials. Generally this effect occurs during sintering, however, for nuclear fuels it also becomes very important under reactor irradiation conditions. In these cases pores and gas bubbles attached to the grain boundaries migrate along with the boundaries, in some circumstances giving a boundary migration controlled by the movement, coalescence and/or sintering of these particles. New mechanisms of intergranular bubble and pore migration which control the mobility of the grain boundary under normal and irradiation conditions are reviewed in this paper.
Optimization of the Laser Properties of Polymer Films Doped with N,N´-Bis(3-methylphenyl)-N,N´-diphenylbenzidine
Authors: Calzado Eva M. , Boj Pedro G. , Díaz-García María A.
Published: September 2009

This review compiles the work performed in the field of organic solid-state lasers with the hole-transporting organic molecule N,N´-bis(3-methylphenyl)-N,N´-diphenylbenzidine system (TPD), in view of improving active laser material properties. The optimization of the amplified spontaneous emission characteristics, i.e., threshold, linewidth, emission wavelength and photostability, of polystyrene films doped with TPD in waveguide configuration has been achieved by investigating the influence of several materials parameters such as film thickness and TPD concentration. In addition, the influence in the emission properties of the inclusion of a second-order distributed feedback grating in the substrate is discussed.
Microwave-Assisted Solvent-Free Acetylation of Cellulose with Acetic Anhydride in the Presence of Iodine as a Catalyst
Authors: Li Jing , Zhang Li-Ping , Peng Feng , Bian Jing , Yuan Tong-Qi , Xu Feng , Sun Run-Cang
Published: September 2009

In this work an optimization of the solvent-free acetylation of cellulose with acetic anhydride under microwave heating with iodine as a catalyst was performed. The optimized parameters included the microwave irradiation power from 300 W to 800 W, the reaction time between 5 to 40 min, the reaction temperature from 80 to 130 °C, and the amount of iodine from 1 to 15 mol%. The extent of the acetylation was measured by yield and the degree of substitution (DS), which was determined by a back-titration method. Acetylated cellulose was characterized by FT-IR, CP/MAS 13C-NMR, WRXD, and thermogravimetric analysis. The results showed that within the range of catalyst amounts studied, the DS increased as the amount of iodine used increased, however, it was barely affected by microwave output. It was also found that the reaction time and temperature had an active influence on the extent of acetylation, however, this did not mean that at the higher temperature a better acetylation of cellulose would be obtained. The optimal reaction time and temperature found in this work were 30 min and 130 °C.
Antihypertensive Drug and Inner Ear Perfusion: An Otologist’s Point of View
Authors: Pirodda Antonio
Published: September 2009

A number of labyrinthine disorders with sensorineural hearing loss, vertigo, and tinnitus are known to occur to young people without vascular risk factors, thus being classified as “idiopathic” in the absence of satisfactory explanations; in the last decade, this phenomenon has found a reliable explanation by the adverse effect of a sharp decrease of blood pressure values followed by an abnormal vasomotor regulation. This model may not only be applied to healthy subjects, but even had some confirmation in conditions possibly affecting hemodynamic changes, such as heart failure or treated hypertension. In particular, the results of a recent study on the impact of different antihypertensive therapies, which was analyzed by monitoring the onset or enhancement of tinnitus as a symptom of inner ear sufferance, unequivocally demonstrated an increased prevalence of tinnitus in subjects submitted to more “aggressive” treatments. This seems in agreement with recent observations about the model of fluid homeostasis of the inner ear, and suggests, when possible, to resort to treatments with modulatory effects in order to maintain a steady perfusion to the labyrinth thus protecting its function.
Accounting for Uncertainties of the TRMM Satellite Estimates
Authors: AghaKouchak Amir , Nasrollahi Nasrin , Habib Emad
Published: September 2009

Recent advances in the field of remote sensing have led to an increase in available rainfall data on a regional and global scale. Several NASA sponsored satellite missions provide valuable precipitation data. However, the advantages of the data are limited by complications related to the indirect nature of satellite estimates. This study intends to develop a stochastic model for uncertainty analysis of satellite rainfall fields through simulating error fields and imposing them over satellite estimates. In order to examine reliability and performance of the presented model, ensembles of satellite estimates are simulated for a large area across the North and South Carolina. The generated ensembles are then compared with original satellite estimates with respect to statistical properties and spatial dependencies. The results show that the model can be used to describe the uncertainties associated to TRMM multi-satellite precipitation estimates. The presented model is validated using random sub-samples of the observations based on the bootstrap technique. The results indicate that the model performs reasonably well with different numbers of available rain gauges.
Bistatic Radar Configuration for Soil Moisture Retrieval: Analysis of the Spatial Coverage
Authors: Pierdicca Nazzareno , De Titta Ludovico , Pulvirenti Luca , Della Pietra Giuliano
Published: September 2009

Some outcomes of a feasibility analysis of a spaceborne bistatic radar mission for soil moisture retrieval are presented in this paper. The study starts from the orbital design of the configuration suitable for soil moisture estimation identified in a previous study. This configuration is refined according to the results of an analysis of the spatial resolution. The paper focuses on the assessment of the spatial coverage i.e., on the verification that an adequate overlap between the footprints of the antennas is ensured and on the duty cycle, that is the fraction of orbital period during which the bistatic data are acquired. A non-cooperating system is considered, in which the transmitter is the C-band Advanced Synthetic Aperture Radar aboard Envisat. The best performances in terms of duty cycle are achieved if the transmitter operates in Wide Swath Mode. The higher resolution Image Swath Modes that comply with the selected configuration have a duty cycle that is never less than 12% and can exceed 21%. When Envisat operates in Wide Swath Mode, the bistatic system covers a wide latitude range across the equator, while in some of the Image Swath Modes, the bistatic measurements, collected from the same orbit, cover mid-latitude areas. In the latter case, it might be possible to achieve full coverage in an Envisat orbit repeat cycle, while, for a very large latitude range such as that covered in Wide Swath Mode, bistatic acquisitions could be obtained over about 65% of the area.
Hazardous Odor Recognition by CMAC Based Neural Networks
Authors: Bucak İhsan  Ömür , Karlık Bekir
Published: September 2009

Electronic noses are being developed as systems for the automated detection and classification of odors, vapors, and gases. Artificial neural networks (ANNs) have been used to analyze complex data and to recognize patterns, and have shown promising results in recognition of volatile compounds and odors in electronic nose applications. When an ANN is combined with a sensor array, the number of detectable chemicals is generally greater than the number of unique sensor types. The odor sensing system should be extended to new areas since its standard style where the output pattern from multiple sensors with partially overlapped specificity is recognized by a neural network or multivariate analysis. This paper describes the design, implementation and performance evaluations of the application developed for hazardous odor recognition using Cerebellar Model Articulation Controller (CMAC) based neural networks.
Nanomaterial-Assisted Signal Enhancement of Hybridization for DNA Biosensors: A Review
Authors: Liu Jinhuai , Liu Jinyun , Yang Liangbao , Chen Xing , Zhang Meiyun , Meng Fanli , Luo Tao , Li Minqiang
Published: September 2009

Detection of DNA sequences has received broad attention due to its potential applications in a variety of fields. As sensitivity of DNA biosensors is determined by signal variation of hybridization events, the signal enhancement is of great significance for improving the sensitivity in DNA detection, which still remains a great challenge. Nanomaterials, which possess some unique chemical and physical properties caused by nanoscale effects, provide a new opportunity for developing novel nanomaterial-based signal-enhancers for DNA biosensors. In this review, recent progress concerning this field, including some newly-developed signal enhancement approaches using quantum-dots, carbon nanotubes and their composites reported by our group and other researchers are comprehensively summarized. Reports on signal enhancement of DNA biosensors by non-nanomaterials, such as enzymes and polymer reagents, are also reviewed for comparison. Furthermore, the prospects for developing DNA biosensors using nanomaterials as signal-enhancers in future are also indicated.
VIBRATION-BASED DAMAGE DETECTION IN A BEAM STRUCTURE WITH MULTIPLE DAMAGE LOCATIONS
Authors: Ručevskis Sandris , Wesolowski Miroslaw , Chate Andris
Published: September 2009

During the last two decades structural damage identification using dynamic parameters of the structure has become an important research area for civil, mechanical, and aerospace engineering communities. The basic idea of the vibration‐based damage detection methods is that a damage as a combination of different failure modes in the form of loss of local stiffness in the structure alters its dynamic characteristics, i.e., the modal frequencies, mode shapes, and modal damping values. A great variety of methods have been proposed for damage detection by using dynamic structure parameters; however, most of them require modal data of the healthy state of structure as a reference. In this paper a vibration‐based damage detection method, which uses the mode shape information determined from only the damaged state of the structure is proposed. To establish the method, two aluminium beams containing different sizes of mill‐cut damage at a single location as well as two aluminium beams containing different sizes of mill‐cut damage at multiple locations are examined. The experimental modal frequencies and the corresponding mode shapes for the first 15 flexural modes are obtained by using a scanning laser vibrometer with a PZT actuator. From the mode shapes, mode shape curvatures are obtained by using a central difference approximation. In order to exclude the influence of measurement noise on the modal data and misleading damage indices, it is proposed to use the sum of mode shape curvature squares for each mode. With the example of the beams with free‐free and clamped boundary conditions, it is shown that the mode shape curvature squares can be used to detect damage in the structures. The extent of mill‐cut damage is identified via the modal frequencies by using mixed numerical‐experimental technique. The method is based on the minimization of the discrepancy between the numerically calculated and the experimentally measured frequencies. The numerical frequencies are calculated by employing a finite‐element model for beam with introduced damage. Further, by using the response surface approach, a relationship (second‐order polynomial function) between the modal frequencies and the damage extent is constructed. The damage extent is obtained by solving the minimization problem.

Santrauka

Tyrimo metu buvo ieškomos sijines konstrukcijos pažeidimo frezuojant vietos, apimtis ir pažeidimo dydis pagal atlikto vibraciju eksperimento dinamines charakteristikas. Pažeidimo padetis ir apimtis buvo nustatomi pagal išlinkio formos virpesiu kvadrato dydi. Pažeidimo dydis buvo nustatomas skaitiniu‐eksperimentiniu metodu, taikant modalinius dažnius. Šio metodo efektyvumas ir patikimumas parodytas tiriant dvi aliuminio sijas, kurios buvo pažeistos frezos vienoje vietoje ir kurios buvo pažeistos skirtingose vietose.
DEFINITION OF CONTACT STRESS IN FRICTION UNITS ON THE BASIS OF THE ACOUSTIC EMISSION METHOD
Authors: Filonenko Sergay , Stadnychenko Viacheslav , Stakhova Anzhelika
Published: September 2009

The following results of acoustic emission signals researches were obtained during the change in contact stress. It is shown that the theoretical regularity of change in average level of the acoustic emission resulting signal at contact stress has a linear character. Analogical regularity is received during experimental researches. It is showed that the sensitivity of the acoustic emission method and the precision of determining contact stresses are considerably better, than the tensometry method. The recording of the moment when friction unit seize begins is also considerably more precise.

Santrauka

Nagrineti akustines emisijos galutinio signalo rezultatai kintant kontaktiniams itempimams. Nustatyta, kad akustines emisijos galutinio signalo vidutinio lygio kitimo teorine priklausomybe nuo kontaktiniu itempimu yra tiesine. Analogiška priklausomybe gauta ir eksperimento metu. Taip pat nustatyta, kad akustines emisijos metodo jautrumas ir kontaktiniu itempimu nustatymo tikslumas yra kur kas geresnis nei tenzometrijos metodo. Be to, kur kas anksčiau fiksuojamas laiko momentas, kai pradeda strigti trinties mazgas.
PAN AM FLIGHT 103 INVESTIGATION AND LESSONS LEARNED
Authors: Ushynskyi Sergey
Published: September 2009

On 21 December 1988, one of the most tragic incidents in the history of civil aviation took place. But the lessons of that tragic day and the impact of “Pan Am 103” or “Lockerbie” remain valuable and deserve attention.

Santrauka

1988 m. gruodžio 21 d. ivyko vienas tragiškiausiu incidentu civilines aviacijos istorijoje. Tačiau šios tragiškos dienos pamokos ir Pan Am 103 arba kitaip Lockerbie katastrofa turi išliekamaja verte.
Correlation between asymmetric profiles in slits and standard prewetting lines
Authors: Sartarelli Salvador A. , Szybisz Leszek
Published: September 2009

The adsorption of Ar on substrates of Li is investigated within the framework of a density functional theory which includes an effective pair potential recently proposed. This approach yields good results for the surface tension of the liquid-vapor interface. The behavior of the adsorbate in the cases of a single planar wall and a slit geometry is analyzed as a function of temperature. Asymmetric density profiles are found for fluid confined in a slit built up of two identical planar walls leading to the spontaneous symmetry breaking (SSB) effect. We found that the asymmetric solutions occur even above the wetting temperature $T_w$ in a range of average densities $\rho^*_{ssb1} \le \rho^*_{av} \le \rho^*_{ssb2}$, which diminishes with increasing temperatures until its disappearance at the critical prewetting point $T_{\rm cpw}$. In this way a correlation between the disappearance of the SSB effect and the end of prewetting lines observed in the adsorption on a one-wall planar substrate is established. In addition, it is shown that a value for $T_{\rm cpw}$ can be precisely determined by analyzing the asymmetry coefficients.Received: 17 June 2009, Accepted: 28 August 2009; Edited by: S. A. Cannas; DOI: 10.4279/PIP.010001
Molekulare und supramolekulare Netzwerke auf Oberflächen: vom zweidimensionalen Kristall‐Engineering bis zur Reaktivität
Authors: Elemans Johannes A. A. W. , Lei Shengbin , De Feyter Steven
Published: September 2009

Seit der Erfindung des Rastertunnelmikroskops können Moleküle auf atomar flachen, leitenden Substraten im Echtraum sichtbar gemacht werden. Eine Folge war die rasante Entwicklung der supramolekularen Chemie auf Oberflächen. In diesem Aufsatz beschreiben wir aktuelle Entwicklungen beim Entwurf und der Funktionalität supramolekularer Oberflächenmuster und setzen dabei die Schwerpunkte auf chirale und hochporöse Netzwerke sowie auf die Reaktivität, eine der wichtigsten neuen Entwicklungen der supramolekularen Oberflächenchemie.
The phytoecdysteroid profiles of 7 species of Silene (Caryophyllaceae)
Authors: Zibareva Larisa , Yeriomina Valentina I. , Munkhjargal Nyamjav , Girault Jean‐Pierre , Dinan Laurence , Lafont Rene
Published: September 2009

The phytoecdysteroid profiles of extracts of aerial parts of flowering plants of 7 ecdysteroid‐containing species in the genus Silene (Caryophyllaceae; S. fridvaldszkyana Hampe, S. gigantea L., S. graminifolia Otth, S. mellifera Boiss. & Reuter, S. repens Patr., S. schmuckeri Wettst., and S. sendtneri Boiss.) have been examined and identified by HPLC and, in the case of two new compounds, by mass spectrometry and NMR. S. frivaldszkyana was found to contain predominantly 20‐hydroxyecdysone (20E), with smaller amounts of 2‐deoxyecdysone (2dE), 2‐deoxy‐20‐hydroxyecdysone (2d20E), polypodine B (polB), integristerone A (IntA), 26‐hydroxypolypodine B (26polB), and 20,26‐dihydroxyecdysone (20,26E). Additionally, a new minor ecdysteroid, 26‐hydroxyintegristerone A, has been identified from this species. S. gigantea contains 3 major ecdysteroids (2dE, 2d20E, and 20E) and much smaller amounts of intA and 2‐deoxy‐20‐hydroxyecdysone 25‐β‐D‐glucoside, which is a new ecdysteroid. Ecdysteroids in the other 5 species have been identified by co‐chromatography with reference compounds on RP‐ and NP‐HPLC systems. There is considerable variability with regard to ecdysteroid profiles within the genus Silene. The chemotaxonomic value of ecdysteroid profiles within the genus Silene is discussed. © 2009 Wiley Periodicals, Inc.