bluuebunny/crossref_metadata_2025 huggingface dataset:
Remembered International Index of Erectile Function Domain Scores Are Not Accurate in Assessing Preoperative Potency in Candidates for Bilateral Nerve-Sparing Radical Retropubic Prostatectomy
Authors: Salonia Andrea , Gallina Andrea , Briganti Alberto , Zanni Giuseppe , Saccà Antonino , Dehò Federico , Karakiewicz Pierre , Guazzoni Giorgio , Rigatti Patrizio , Montorsi Francesco
Published: February 2008

Introduction

The reliability of reported postoperative data in patients undergoing nerve-sparing radical retropubic prostatectomy is often limited because the degree of sexual function (SF) has not been assessed objectively both before and after treatment. Most reports include only a retrospective chart review, and there is a question of whether such data are accurate.

Aim

To test the agreement between a remembered International Index of Erectile Function (IIEF) score, which targeted SF regarding a period preceding the surgery by 6 months and a real-time IIEF, 4 weeks prior to surgery, in candidates for bilateral nerve-sparing radical retropubic prostatectomy (BNSRRP).

Methods

From May 2005 to May 2006, 333 consecutive patients were candidates for BNSRRP at our institution. Upon admission on the day prior to surgery, each patient was asked to complete a set of validated questionnaires including both a remembered and a real-time IIEF. Two-tailed Student's t-test, χ2 test, Pearson correlation coefficient, multivariate regression analyses, and interrater agreement (kappa) were used to test the agreement between the two assessments.

Main Outcome Measures

Assessing the preoperative SF characteristics of candidates for a BNSRRP, and testing the reliability of a remembered IIEF with the interrater agreement (kappa) test.

Results

Mean scores for the remembered IIEF were overall better than the real-time IIEF scores, as supported by direct comparison of the mean IIEF domain scores. Univariate correlation analysis and multivariate regression analysis indicated a significant correlation in the quality of the SF during the two periods. However, the remembered IIEF scores did not show a good statistical agreement with those of the real-time assessment, as demonstrated by the interrater agreement analysis.

Conclusions

Because of the lack of significant agreement between remembered and real-time IIEF scores, the present findings indicate that remembered IIEF should not be used to assess SF in a real-life clinical setting in candidates for BNSRRP.
Erectile Dysfunction and Constructs of Masculinity and Quality of Life in the Multinational Men's Attitudes to Life Events and Sexuality (MALES) Study
Authors: Sand Michael S. , Fisher William , Rosen Raymond , Heiman Julia , Eardley Ian
Published: February 2008

Introduction

The Men's Attitudes to Life Events and Sexuality (MALES) study assessed the prevalence and correlates of erectile dysfunction, and examined men's attitudes and behavior in relation to this dysfunction.

Aim

To report on the attitudes of men, with and without self-reported erectile dysfunction, concerning masculine identity and quality of life.

Methods

The MALES Phase I study included 27,839 randomly selected men (aged 20–75 years) from eight countries (United States, United Kingdom, Germany, France, Italy, Spain, Mexico, and Brazil) who responded to a standardized computer-assisted telephone interview.

Main Outcome Measure

Perceptions of masculinity and quality of life in men with and without erectile dysfunction.

Results

Men's perceptions of masculinity differed substantially from stereotypes in the literature. Men reported that being seen as honorable, self-reliant, and respected by friends were important determinants of self-perceived masculinity. In contrast, factors stereotypically associated with masculinity, such as being physically attractive, sexually active, and successful with women, were deemed to be less important to men's sense of masculinity. These findings appeared consistently across all nationalities and all age groups studied. For quality of life, factors that men deemed of significant importance included good health, harmonious family life, and a good relationship with their wife/partner. Such factors had significantly greater importance to quality of life than concerns such as having a good job, having a nice home, living life to the full, or having a satisfying sex life. Of note, rankings of constructs of masculinity and quality of life did not meaningfully differ in men with or without erectile dysfunction, and men with erectile dysfunction who did or did not seek treatment for their sexual dysfunction.

Conclusions

The present findings highlight the significance of partnered relationships and interpersonal factors in the management of erectile dysfunction, and empirically challenge a number of widely held stereotypes concerning men, masculinity, sex, and quality of life.
The Effect of Comorbidities and Socioeconomic Status on Sexual and Urinary Function in Men Undergoing Prostate Cancer Screening
Authors: Bhojani Naeem , Perrotte Paul , Jeldres Claudio , Suardi Nazareno , Hutterer Georg , Shariat Shahrokh F. , Karakiewicz Pierre I.
Published: February 2008

Introduction

Comorbidities and socioeconomic status (SES) represent known confounders of baseline health-related quality of life.

Aim

To assess the effect of comorbidities and of SES variables on urinary function (UF) and sexual function (SF) and on associated bother items.

Methods

A cohort of 1,162 men without an established diagnosis of prostate cancer (PCa) completed questionnaires addressing SES characteristics, the lifetime prevalence of 12 comorbid conditions, SF and UF as well as their associated bother.

Main Outcome Measures

Crude and adjusted logistic regression models tested the association between the predictors, SES and comorbidity, and four separate outcomes, namely SF and UF and their associated bother.

Results

Of all men, aged 40–79 years, 172 (14.8%) reported poor or very poor ability to have an erection, and for 165 (14.2%), erectile function (EF) was a big or moderate problem. Daily or weekly urinary incontinence was reported by 98 (8.4%) men, and for 94 (8.1%) men, UF was a big or moderate problem. One or more comorbidities were present in 437 (37.6%) men. In age- and SES-adjusted analyses, major depression and diabetes had the most detrimental effect on EF (5.8 [P <0.001] and 4.8 [P <0.001], respectively) and on sexual bother (4.3 [P <0.001] and 7.2 [P <0.001], respectively). Stroke (4.7 [P =0.004]) and drug problems (4.8 [P =0.002]) had the most detrimental effect on urinary incontinence. Alcoholism and alcohol-related problems (3.1 [P =0.004]) had the most detrimental effect on the urinary bother scale. Finally, SES only affected urinary incontinence, which was poorer in men who lived with a spouse or partner (2.1 [P =0.03]).

Conclusion

Select comorbidities have very strong effects on UF and EF. Conversely, for most SES variables, the effect was weak and insignificant. In consequence, when patients are assessed for definitive PCa therapy, comorbidities require an adjustment, whereas SES assessment may potentially be omitted, especially if questionnaire brevity is a consideration.
Expression and Distribution of Cyclic GMP-Dependent Protein Kinase-1 Isoforms in Human Penile Erectile Tissue
Authors: Waldkirch Eginhard , Uckert Stefan , Sigl Katja , Imkamp Florian , Langnaese Kristina , Richter Karin , Jonas Udo , Sohn Michael , Stief Christian , Wolf Gerald , Hedlund Petter
Published: February 2008

Introduction

Besides the bioavailability of nitric oxide (NO), downstream guanine monophosphate (cGMP) effector proteins are also considered to play a significant role in penile vascular disease. In animal studies, a downregulation of the cGMP-dependent protein kinase-1 (cGKI) α isoform has been linked to erectile dysfunction and diabetes mellitus. So far, the expression of cGKI α and β isoforms has not been evaluated in human penile erectile tissue.

Aim

To evaluate the expression of cGKI α and β isoforms in relation to smooth muscle α-actin, cGMP, and endothelial NO synthase (eNOS) in human cavernous arteries (HCAs) and human corpus cavernosum (HCC).

Methods

Cryostat sections of HCA and HCC were incubated with primary antibodies directed against α-actin, cGMP, eNOS, cGKI, cGKI α, and cGKI β. Visualization of double-labeled immunofluorescent stainings was achieved by laser microscopy. Western blot analysis was performed in order to confirm the expression of cGKI isoforms.

Main Outcome Measures

Expression of cGKI α and β isoforms in relation to smooth muscle α-actin, cGMP, and eNOS in human penile erectile tissue.

Results

Immunoreactivities specific for cGKI, cGKI α, and cGKI β were observed within the smooth musculature and the endothelium of cavernous arteries and sinusoids. Double stainings revealed the colocalization of alpha-actin, cGMP, eNOS, and cGKI isoforms. The expression of cGKI isoforms was confirmed by Western blot analysis.

Conclusions

Our results demonstrate, for the first time, the expression of both cGKI α and β isoforms in the smooth musculature of HCA and HCC. Corresponding to recent findings from animal studies, the presence of cGKI α and β provides further evidence for a significant role of these enzymes in the control of smooth muscle function in human penile erectile tissue.
Assessment of Cerebrocortical Areas Associated with Sexual Arousal in Depressive Women Using Functional MR Imaging
Authors: Yang Jong-Chul , Park Kwangsung , Eun Sung-Jong , Lee Moo-Suk , Yoon Jin-Sang , Shin Il-Seon , Kim Yong-Ku , Chung Tae-Woong , Kang Heoung-Keun , Jeong Gwang-Woo
Published: February 2008

Introduction

Mental illness is closely related with sexual dysfunction. A number of investigators have reported that depressive women have difficulties in sexual arousal.

Aim

The purpose of this study was to compare the cerebrocortical regions associated with sexual arousal between the healthy and depressive women using functional magnetic resonance imaging (fMRI) based on the blood-oxygenation-level-dependent (BOLD) technique.

Methods

Together with nine healthy women (mean age: 40.3), seven depressive women (mean age: 41.7 years, mean Beck Depression Inventory: 35.6, mean Hamilton Rating Scale Depression-17: 34.9) underwent fMRI examinations using a 1.5T MR scanner (Signa Horizon; GE Medical Systems, Milwaukee, WI, USA). The fMRI data were obtained from seven oblique planes using gradient-echo EPI. Sexual stimulation paradigm began with a 1-minute rest and then 4-minute stimulation using an erotic video film. The brain activation maps and their resulting quantification were analyzed by the statistical parametric mapping (SPM99) program. The number of pixels activated by each task was used as brain activity, where the significance of the differences was evaluated by using independent t-test.

Main Outcome Measures

We measured brain activation areas using BOLD-based fMRI with visual sexual stimulation in healthy volunteers and depressive patients.

Results

Healthy women were significantly (P <0.05) activated in the regions of middle occipital gyrus, middle temporal gyrus, inferior frontal gyrus, insula, hypothalamus, septal area, anterior cingulate gyrus, parahippocampal gyrus, thalamus, and amygdala by erotic visual stimulation. In comparison with the healthy women, the depressive women gave lower activity, especially in the brain regions of hypothalamus (55.5:3.0), septal area (49.6:8.6), anterior cingulate gyrus (23.5:11.0), and parahippocampal gyrus (18.2:5.8).

Conclusions

This preliminary study performed by fMRI gives valuable information on differentiation of the activated cerebral regions associated with visually evoked sexual arousal between healthy and depressive women. In addition, these findings might be useful to understand neural mechanisms for female sexual dysfunction in depressive women.
Efficient Gene Expression System Using the RTP801 Promoter in the Corpus Cavernosum of High-Cholesterol Diet-Induced Erectile Dysfunction Rats for Gene Therapy
Authors: Lee Minhyung , Ryu Ji-Kan , Piao Shuguang , Choi Min Ji , Kim Hyun Ah , Zhang Lu-Wei , Shin Hwa-Yean , Jung Haeng In , Kim In-Hoo , Kim Sung Wan , Suh Jun-Kyu
Published: February 2008

Introduction

The application of gene therapy for a nonlife-threatening disease, such as erectile dysfunction (ED), requires a higher safety level and more efficacious systems for gene transfer.

Aim

To establish a novel technique for gene expression in a rat model of hypercholesterolemic ED that uses the RTP801 promoter, a hypoxia-inducible promoter.

Methods

Two-month-old male Sprague–Dawley rats were fed a diet containing 4% cholesterol and 1% cholic acid, and age-matched control animals were fed a normal diet, for 3 months.

Main Outcome Measures

Cavernous expression of hypoxia-inducible factor (HIF)-1α was evaluated by Western blot. After intracavernous injection of pSV-Luc or pRTP801-Luc, gene expression was evaluated by luciferase assay, and the gene expression area was evaluated by immunohistochemistry.

Results

HIF-1α was up-regulated in the corpus cavernosum of hypercholesterolemic rats. Although pSV-Luc did not induce gene expression in either the control or the cholesterol group, pRTP801-Luc significantly induced gene expression in the cholesterol group and resulted in higher luciferase activity than did pSV-Luc up to 14 days after injection. Immunohistochemistry showed that the gene expression area was also greater in the pRTP801-Luc group than in the pSV-Luc group, but the difference was not as great as that in luciferase activity. This suggests that pRTP801-Luc exerts its effect mainly by inducing promoter activity under hypoxia, not by increasing the number of transfected cells.

Conclusion

The RTP801 promoter-driven gene expression system increased gene expression in the corpus cavernosum tissue of rats with cholesterol-induced ED. This may be a useful system for the development of gene therapy in vasculogenic ED.
Investigating Women's Preference for Sildenafil or Tadalafil Use by Their Partners with Erectile Dysfunction: The Partners' Preference Study
Authors: Conaglen Helen M. , Conaglen John V.
Published: February 2008

Introduction

Several preference studies comparing a short-acting with a longer-acting phosphodiesterase type 5 inhibitor have been conducted in men. Most men in those studies preferred tadalafil rather than sildenafil, and recent post hoc analysis of one study described several factors associated with men's treatment preference. No prospective studies have investigated the woman partners' preferences.

Aim

To investigate the treatment preference of women who were partners of men using oral medications for erectile dysfunction (ED) in a single-center open-label crossover study.

Methods

One hundred heterosexual couples in stable relationships, with male partners having ED based on the erectile function subscale of the International Index of Erectile Function, were randomly assigned to receive sildenafil or tadalafil for a 12-week phase, followed by another 12-week period using the alternate drug. Male and female participants completed sexual event diaries during both study phases, and the female participants were interviewed at baseline, midpoint, and end of study.

Main Outcome Measures

Primary outcome data were the women's final interviews during which they were asked which drug they preferred and their reasons for that preference.

Results

A total of 79.2% of the women preferred their partners' use of tadalafil, while 15.6% preferred sildenafil. Preference was not affected by age or treatment order randomization. Women preferring tadalafil reported feeling more relaxed, experiencing less pressure, and enjoying a more natural or spontaneous sexual experience as reasons for their choice. Mean number of tablets used, events recorded, events per week, and days between events were not significantly different during each study phase.

Conclusion

Women's preferences were similar to men when using these two drugs. While the women's reasons for preferring tadalafil emphasized relaxed, satisfying, longer-lasting sexual experiences, those preferring sildenafil focused on satisfaction and drug effectiveness for their partner.
C-Type Natriuretic Peptide Hyperpolarizes and Relaxes Human Penile Resistance Arteries
Authors: Kun Attila , Kiraly Istvan , Pataricza Janos , Marton Zoltan , Krassoi Iren , Varro Andras , Simonsen Ulf , Papp Julius Gy. , Pajor Laszlo
Published: February 2008

Introduction

In addition to nitric oxide (NO), it is thought that an endothelium-derived hyperpolarizing factor (EDHF) plays an important role in the relaxation of penile arteries. Recently, it has been shown that C-type natriuretic peptide (CNP) shows the characteristics of EDHF in systemic small arteries.

Aim

To investigate the mechanism involved in CNP-evoked vasodilatation and to address whether CNP is an EDHF in human penile resistance arteries.

Methods

Erectile tissue was obtained in connection with transsexual operations. Intracavernous penile resistance arteries were isolated and mounted in microvascular myographs for recording of isometric tension. Membrane potential was recorded by the use of a small glass electrode inserted in the smooth muscle layer.

Main Outcome Measure

In vitro evidence for hyperpolarization and vasorelaxation induced by CNP.

Results

Acetylcholine (ACh) and CNP hyperpolarized smooth muscle membrane potential in resting penile resistance arteries. In penile small arteries incubated with inhibitors of NO synthase and cyclooxygenase and contracted with phenylephrine, ACh and CNP evoked concentration-dependent relaxations with maximum of 56±6% and 71±6%, respectively. Addition of a combination of blockers of small- and intermediate-conductance calcium-activated K+ channels, apamin plus charybdotoxin, respectively, and a combination thought to block the smooth muscle response of EDHF-type relaxation, barium plus ouabain, markedly reduced ACh- and CNP-evoked relaxation. Iberiotoxin, a blocker of big-conductance calcium-activated K+ channels inhibited the vasorelaxant responses evoked by ACh and CNP. A selective natriuretic peptide receptor type C (NPR-C) agonist, C-atrial natriuretic factor4−23 (cANF4−23), induced relaxations with less maximum response compared to CNP.

Conclusion

The present findings suggest that CNP possesses the characteristics of an EDHF in human penile resistance arteries. By activation of natriuretic peptide receptor type B and NPR-C receptors, CNP causes relaxation by activation, respectively, of large-conductance calcium-activated K+ channels and Na+/K+-adenosine triphosphatase (ATPase), and barium-sensitive inward rectifier K+ channels. Modulation of the CNP pathway opens for new treatment modalities of erectile dysfunction.
Tribological Behavior of Si3N4 and Si3N4/Carbon Fiber Composites Against Stainless Steel Under Water Lubrication for a Thrust‐Bearing Application
Authors: Hyuga Hideki , Yoshizawa Yu‐ichi , Hirao Kiyoshi , Amutha Rani D. , Jones Mark I.
Published: February 2008

The tribological behavior of Si3N4 ceramics and Si3N4/carbon fiber composites sliding against stainless steel under water lubrication was investigated using a thrust‐bearing‐type test method with normal applied loads varying from 0 to 1000 N in 100 N increments. In the case of the monolithic Si3N4, the friction coefficient was found to increase up to 0.4 the first time the applied load was increased from 100 to 200 N, and sudden failure of the ceramic ring specimen occurred. In the case of the Si3N4/carbon fiber composite, a low friction coefficient was maintained up to the maximum normal load of 1000 N. The addition of the carbon fibers to the silicon nitride ceramics effectively restricts material transfer from the stainless steel to the Si3N4 worn surface due to reduction of solid–solid contact through the solid lubricating effect of the carbon fibers.
Evaluation of Silicon‐Nitride Ceramic Valves
Authors: Sun Jiangang G. , Zhang Jianmei M. , Andrews Mark J. , Trethewey Jeremy S. , Phillips Nate S. L. , Jensen Jeff A.
Published: February 2008

Silicon‐nitride ceramic valves can improve the performance of both light‐ and heavy‐duty automotive engines because of the superior material properties of silicon nitrides over current metal alloys. However, ceramics are brittle materials that may introduce uncertainties in the reliability and durability of ceramic valves. As a result, the lifetime of ceramic valves are difficult to predict theoretically due to wide variations in the type and distribution of microstructural flaws in the material. Nondestructive evaluation (NDE) methods are therefore required to assess the quality and reliability of these valves. Because ceramic materials are optically translucent and the strength‐limiting flaws are normally located near the valve surface, a laser‐scatter method can be used for NDE evaluation of ceramic valves. This paper reviews the progress in the development of this NDE method and its application to inspect silicon‐nitride ceramic valves at various stages of manufacturing and bench and engine tests.
Sintered Reaction‐Bonded Silicon Nitride with High Thermal Conductivity and High Strength
Authors: Zhou You , Zhu Xinwen , Hirao Kiyoshi , Lences Zoltan
Published: February 2008

Sintered reaction‐bonded silicon nitride (SRBSN) materials were prepared from a high‐purity Si powder doped with Y2O3 and MgO as sintering additives by nitriding at 1400°C for 8 h and subsequently postsintering at 1900°C for various times ranging from 3 to 24 h. Microstructures and phase compositions of the nitrided and the sintered compacts were characterized. The SRBSN materials sintered for 3, 6, 12, and 24 h had thermal conductivities of 100, 105, 117, and 133 W/m/K, and four‐point bending strengths of 843, 736, 612, and 516 MPa, respectively. Simultaneously attaining thermal conductivity and bending strength at such a high level made the SRBSN materials superior over the high‐thermal conductivity silicon nitride ceramics that were prepared by sintering of Si3N4 powder in our previous works. This study indicates that the SRBSN route is a promising way of fabricating silicon nitride materials with both high thermal conductivity and high strength.
Microstructural Characterization and Mechanical Properties of Si3N4 Formed by Fused Deposition of Ceramics
Authors: Iyer S. , McIntosh J. , Bandyopadhyay A. , Langrana N. , Safari A. , Danforth S. C. , Clancy R. B. , Gasdaska C. , Whalen P. J.
Published: February 2008

We present processing (green and sintered), part shrinkage and warping, microstructural characterization, and mechanical properties of Si3N4 made by fused deposition of ceramics (FDC), using optical microscopy, scanning electron microscopy, and X‐ray diffraction. The mechanical properties (fracture strength, fracture toughness, and Weibull modulus) are also reported. Proper FDC build parameters resulted in dense, homogeneous, near‐net‐shape Si3N4, with microstructures and mechanical properties similar to conventionally processed material. Mechanical properties are shown to be isotropic, while there is some degree of microstructural texturing (preferred β‐Si3N4 grain orientation) in sintered components.
Nitrogen superfractionation in dense cloud cores
Authors: Rodgers S. D. , Charnley S. B.
Published: February 2008

We report new calculations of interstellar 15N-fractionation. Previously, we have shown that large enhancements of 15N/14N can occur in cold, dense gas where CO is frozen out, but that the existence of an NH + N channel in the dissociative recombination of N2H+ severely curtails the fractionation. In the light of recent experimental evidence that this channel is in fact negligible, we have reassessed the 15N chemistry in dense cloud cores. We consider the effects of temperatures below 10 K, and of the presence of large amounts of atomic nitrogen. We also show how the temporal evolution of gas-phase isotope ratios is preserved as spatial heterogeneity in ammonia ice mantles, as monolayers deposited at different times have different isotopic compositions. We demonstrate that the upper layers of this ice may have 15N/14N ratios an order of magnitude larger than the underlying elemental value. Converting our ratios to δ-values, we obtain δ15N > 3000 ‰ in the uppermost layer, with values as high as 10 000 ‰ in some models. We suggest that this material is the precursor to the 15N ‘hotspots’ recently discovered in meteorites and IDPs.
Unplugging the Universe: the neglected electromagnetic consequence of decoupling
Authors: Diver Declan A. , Teodoro Luís F. A.
Published: February 2008

This Letter concentrates on the non-equilibrium evolution of magnetic field structures at the onset of recombination, when the charged particle current densities decay as neutrals are formed.

We consider the effect that a decaying magnetic flux has on the acceleration of particles via the transient induced electric field. Since the residual charged-particle number density is small as a result of decoupling, we will consider the magnetic and electric fields essentially to be imposed, neglecting the feedback from any minority accelerated population.

We find that the electromagnetic treatment of this phase transition can produce energetic electrons scattered throughout the Universe. Such particles could have a significant effect on cosmic evolution in several ways: (i) their presence could influence the overall physics of the recombination era; and (ii) a population of energetic particles might lend a Coulomb contribution to localized gravitational collapse.
SDSS J124155.33+114003.7 – a missing link between compact elliptical and ultracompact dwarf galaxies
Authors: Chilingarian Igor V. , Mamon Gary A.
Published: February 2008

We report the discovery of a compact object (Re= 32 pc, MB=−12.34 mag) at a projected distance of 9 kpc from Messier 59, a giant elliptical in the Virgo cluster. Using HST imaging and SDSS spectroscopy, both available in the Virtual Observatory, we find that this object has a blue core containing one-quarter of the light, and a redder n= 1 Sérsic envelope, as well as luminosity-weighted age of 9.3 ± 1.4 Gyr, a metallicity of −0.03 ± 0.04 dex and a velocity dispersion of 48 ± 5 km s−1. While ultracompact dwarf galaxies (UCDs) in the face-on view of the Fundamental Plane are found to form a sequence connecting the highest-luminosity globular clusters with the lowest-luminosity dwarf ellipticals, the compact object near M59 lies in between this UCD sequence and the positions of compact ellipticals. Its stellar age, metallicity, and effective surface brightness are similar to low-luminosity ellipticals and lenticulars, suggesting that SDSS J124155.33+114003.7 is a result of the tidal stripping of such an object.
COMPUTING OPTIMAL DYNAMIC EXPERIMENTS FOR MODEL CALIBRATION IN PREDICTIVE MICROBIOLOGY
Authors: BALSA‐CANTO E. , ALONSO A.A. , BANGA J.R.
Published: February 2008

The potential of mathematical models describing the microbial behavior during food processing and storage largely depends on their predictive capabilities and, in this concern, model calibration plays a crucial role. Unfortunately, model calibration may only be performed successfully if the sources of information are sufficiently rich. Therefore, a careful experimental design is required.

This contribution formulated the optimal experimental design (OED) problem as a general dynamic optimization problem where the objective was to optimize a certain criterion depending on the Fisher information matrix. This formulation allows for more flexibility in the experimental design, including initial conditions, sampling times, experimental durations, time‐dependent manipulable variables and number of experiments as degrees of freedom. Moreover, the use of robust confidence regions for the parameter estimates was suggested as an alternative to evaluate the quality of the proposed experimental schemes.

The OED for the calibration of the thermal death time and Ratkowsky‐type secondary models was considered for illustrative purposes, showing how the usually disregarded E‐optimality criterion results in the experimental schemes offering the best compromise precision/decorrelation among the parameters.

PRACTICAL APPLICATIONS

This work addresses a general methodology for designing optimal dynamic experiments for the purpose of model calibration. This methodology is general in the sense that it may be applied to any type of food processing model, being particularly relevant for predictive microbiology and quality assessment as the experimentation is both time consuming and expensive.

The main advantages of the proposed technique are twofold: on one hand, it is able to significantly reduce the overall experimental burden, contributing not only to simplify the experimental planning, devising the most adequate experiments, but also minimizing the number of experiments, and on the other hand, the resultant experiments provide the maximum quantity and quality of information to improve the predictive capabilities of the models under consideration, of key importance for process design, optimization and control.
EFFECTIVE DIFFUSION COEFFICIENTS BEHAVIOR IN OSMOTIC DEHYDRATION OF APPLE SLICES CONSIDERING SHRINKING AND LOCAL CONCENTRATION DEPENDENCE
Authors: RODRIGUES ALAN EDUARDO , MAURO MARIA APARECIDA
Published: February 2008

The mass transfer during osmotic dehydration of apple slices immersed in 40, 50 and 60% (w/w) aqueous sucrose solutions was investigated to evaluate the influence of solution concentration on diffusivities. In the mathematical model, the diffusion coefficients were functions of the local water and sucrose concentration. The mass transfer equations were, simultaneously, solved for water and sucrose using an implicit numerical method. Material coordinates following the shrinkage of the solid were used. The predicted concentration profiles were integrated and compared to experimental data, showing a reasonable agreement with the measured data. On average, the effective diffusion coefficients for water and sucrose decreased as the osmotic solution concentration increased; that is the behavior of the binary coefficients in water–sucrose solutions. However, the diffusivities expressed as a function of the local concentration in the slices varied between the treatments. Water diffusion coefficients showed a remarkable variation throughout the slice and unusual behavior, which was associated to the cellular structure changes observed in tissue immersed in osmotic solutions. Cell structure changes occurred in different ways: moderate plasmolysis at 40%, accentuated plasmolysis at 50% and generalized damage of the cells at 60%. Intact vacuoles were observed after a long time of exposure (30 h) to 40 and 50% solutions. Effects of the concentration on tissue changes make it difficult to generalize the behavior of diffusion coefficients.

PRACTICAL APPLICATIONS

The main innovation introduced in this study is represented by the model formulation that allows simulation of the concentration profiles during osmotic dehydration with a reasonable degree of accuracy. The model is useful for the design and control of this process and of further operations such as convective drying, as nonhomogeneous initial conditions can be established. In addition, the diffusivities expressed as a function of the local concentration in the slices allows interpretation of some of the physical changes in plant tissues exposed to concentrated solutions.
SHELF LIFE OF WHEY PROTEIN‐COATED PISTACHIO KERNEL (PISTACIA VERA L.)
Authors: JAVANMARD MAJID
Published: February 2008

Dried pistachio kernels were coated with whey protein concentrate (WPC)/glycerol (Gly) solutions. Accelerated rancidity tests of uncoated and coated nuts were performed.

Lipid oxidation in pistachios results in “flavor‐fade” and off‐flavor development. WPC‐based coatings are excellent oxygen barriers and have the potential to be formed as coatings on pistachio kernels to extend their shelf life. Thus, I hypothesized that whey protein isolate films formed as coatings on pistachios would reduce the rate of peanut lipid oxidation. The objectives of this study were to determine coated and uncoated pistachio kernels' oxidation in pistachios stored at ambient conditions. Nine different formulations of WPC‐based coatings were used to coat the pistachios. Besides an uncoated pistachio kernel reference, controls were used to investigate the effects of other ingredients in the coating formulation. The pistachio samples were stored in duplicate at ambient conditions for up to 24 weeks and then analyzed peroxide value (PV) and sensory properties. The objective of this work was to evaluate how WPC/lipid‐based edible coatings affect the development of rancidity. Products resulting from lipid oxidation were measured by PV as an indicator of the formation of hydroperoxide, the primary initial product of lipid oxidation.

The results indicate that the coated samples were oxidized significantly slower than the reference (uncoated pistachios); hence, the predicted shelf life is longer for the coated samples. The control samples also showed a delay in oxidation.

The results also indicate that the WPC coatings, regardless of composition or thickness, provided a glossy appearance that made the coated nuts very distinctive from the uncoated nuts. In addition, coated nuts were slightly darker.

PRACTICAL APPLICATIONS

Edible films and coatings add value to their products, increase shelf life and/or reduce packaging. Applications of interest to the food industry include:

coating oxygen‐sensitive foods such as nuts to extend shelf life and reduce packaging;

coating nuts to prevent oil migration into surrounding food components (e.g., nuts in chocolate).
TREATMENT OF CULTIVATED HIGHBUSH BLUEBERRIES (VACCINIUM CORYMBOSUM L.) WITH ELECTRON BEAM IRRADIATION: DOSIMETRY AND PRODUCT QUALITY
Authors: MORENO M.A. , CASTELL‐PEREZ M.E. , GOMES C. , DA SILVA P.F. , KIM J. , MOREIRA R.G.
Published: February 2008

We determined the dose distribution within a tray of highbush blueberries (Vaccinium corymbosum L.) exposed to electron beam irradiation at medium levels (1.0–3.2 kGy) using Monte Carlo and computer tomography scanning technology. We also evaluated the quality of irradiated and nonirradiated (control) fruits stored at 5C and 70% relative humidity during 14 days by a series of chemical analyses. Blueberries packed in plastic clamshell containers (trays) were irradiated using a 10‐MeV linear accelerator with single‐beam fixture (top only). Irradiation of blueberries at 1.1 kGy had no significant (P > 0.05) effect on the fruit quality with the exception of ascorbic acid, which decreased by 17% by the end of storage. Irradiation had an enhancing effect on the total phenolic and tannin content of all the irradiated fruits (10–20% increases). The calculated dose distribution in a pack of blueberries confirmed that the dose is not uniformly distributed within the pack because of density inhomogeneities (flesh, skin air). Dose levels at the bottom of the trays were 18 (±8%) higher than at the top. These results suggest that careful dose distribution examination must be conducted prior to setting up of an irradiation run for the packed fruits. Excellent agreement was found between measured and calculated doses at different electron beam conveyor speeds.

PRACTICAL APPLICATIONS

Little information is available on how electron beam irradiation penetrates a complex medium such as packed blueberries. This study presents unique results from a dose distribution calculation method using Monte Carlo simulation and computed tomography scanning techniques, which can be an effective tool for the development of proper irradiation treatment planning of packed fruits and other fresh produce. The suitability of using electron beam technology to preserve the quality characteristics and shelf life of packed blueberries was verified.
Comparison of AM1 and B3LYP‐DFT for Inhibition of MAO‐A by Phenylisopropylamines: A QSAR Study
Authors: Deeb Omar , Clare Brian W.
Published: February 2008

The aim of this study is to provide an initial indication regarding the scope and limitations of some state‐of‐the‐art methods in computational chemistry, including semiempirical (AM1) and density functional theory (B3LYP), in the flip regression procedure applied to the inhibition of phenylisopropylamines. The results show that the models established based on the density functional theory‐B3LYP are better than that based on semiempirical method (AM1). It is demonstrated that electron‐rich ring systems and highest occupied molecular orbital levels tended to increase activity. In this contribution, it is shown that the orientation of nodes in their occupied π orbitals, and also the energies of these orbitals explain a further large portion of the variance in their inhibitory activity.
The effect of trilostane treatment on circulating thyroid hormone concentrations in dogs with pituitary‐dependent hyperadrenocorticism
Authors: Kenefick S. J. , Neiger R.
Published: February 2008

Objective:To assess thyroid hormone levels in hyperadrenocorticoid dogs before and after therapy with trilostane, a reversible inhibitor of steroidogenesis.

Methods:Serum total thyroxine, free thyroxine and endogenous canine thyroid‐stimulating hormone concentrations were measured in 20 dogs with spontaneously occurring hyperadrenocorticism before and six months after successful treatment with trilostane.

Results:Fourteen dogs demonstrated an increase in thyroxine following trilostane treatment; however, this was not significant (P=0·108). Fourteen dogs demonstrated an increase in canine thyroid‐stimulating hormone concentrations with trilostane therapy (P=0·006). Of the 14 dogs that demonstrated an increase in thyroxine concentrations following therapy, 10 also showed an increase in canine thyroid‐stimulating hormone concentrations. Before treatment, free thyroxine values were within, above and below the reference range in 10, six and two dogs, respectively. Sixteen of 18 dogs had free thyroxine values within the reference range after treatment, with 11 dogs showing a decrease in free thyroxine levels following therapy (P=0·029).

ClinicalSignificance:While treatment with trilostane did not induce a significant change of thyroxine concentrations, there was a significant increase in canine thyroid‐stimulating hormone concentrations following treatment, a finding that supports thyroid‐stimulating hormone suppression as one of the factors that contributes to the effects of glucocorticoids on the hypothalamic‐pituitary‐thyroid axis. The significant elevation in free thyroxine values following treatment with trilostane was unexpected and did not support the findings of previous studies in this area.
An Investigation of the Formability of Long Fiber Thermoplastic Composite Sheets
Authors: Lee J. H. , Vogel J. H.
Published: February 2008

An experimental and analytical investigation was undertaken to improve understanding of the form of long fiber reinforced thermoplastic sheets. The materials tested contained 30 percent by weight of glass fibers in a polypropylene matrix, with the fibers approximately randomly oriented in the plane of sheet. The forming tests covered a range of forming temperatures between the glass transition temperature and the melting point of the polypropylene matrix. The testing geometry was that of a Swift flat-bottomed cup test, which primarily tests bending and drawing behavior of the sheet. An analysis of the process was developed in terms of a continuum model of material behavior with normal anisotropy and rotational symmetry. Results of the forming tests are compared with analytical predictions. Limitations of both the form of the material and the modeling approach are discussed.
ASME 1993 Nadai Lecture—Elastoplastic Stress and Strain Concentrations
Authors: Sharpe William N.
Published: February 2008

Elastic stress concentration factors are familiar and easily incorporated into the design of components or structures through charts or finite element analysis. However when the material at the most concentrated location no longer behaves elastically, computation of the local stresses and strains is not so easy. Local elastoplastic behavior is an especially important consideration when the loading is cyclic. This paper summarizes the predictive capability of the Neuber and the Glinka models that relate gross loading to the local stresses and strains. The author and his students have used a unique laser-based technique capable of measuring biaxial strains over very short gage lengths to evaluate the two models. Their results, as well as those from earlier studies by other researchers using foil gages, lead to the general conclusion that the Neuber model works best when the local region is in a state of plane stress and the Glinka model is best for plane strain. There are intermediate levels of constraint that are neither plane stress nor plane strain. This paper presents a recommended practice for predicting the local elastoplastic stresses and strains for any constraint. First, one computes or estimates the initial elastic strains. Then, based on the amount of elastic constraint, one selects the appropriate model to compute the local elastoplastic stresses and strains.
Strain-Hardening and Thermal-Softening Effects on Shear Angle Prediction: New Model Development and Validation
Authors: Song Xueshu
Published: February 2008

The strain-hardening and thermal-softening effects on shear stress and shear angle in orthogonal machining are discussed in this paper. The temperature effect on strain hardening was quantitatively related to the shear angle using Merchant’s upper bound condition to reduce the number of experimentally-obtained coefficients and thus to both reduce cost and increase accuracy in share angle prediction. This quantitative relationship was then integrated with a force based process model and an equal energy type approach in developing a new model. A statistical analysis with experiment data indicated that the new model yielded improved result in accuracy, reliability, insensitivity to nonmodel parameters, and adaptability.
Life Prediction of Notched Components
Authors: Giglio M. , Vergani L.
Published: February 2008

In this study, keyhole and smooth specimens, made from a low alloy pressure vessel steel (ASTM A-533 grade B), were subjected to monoaxial fatigue tests. The results show the influence of the stress concentration factor, Kt, on the number of cycles to failure, Nf. Total strain energy per cycle, ΔWt = ΔWp + ΔWe, was proved to be a good parameter for predicting the life of notched components. Elasto-plastic FEM analysis, utilizing the cyclic and monotonic curve of the material, showed close agreement with the experimental values.
Fatigue Gage Utilizing Surface Roughening of Aluminum Foil
Authors: Nagase Y. , Sawaki Y. , Moritake F. , Yoshida H.
Published: February 2008

The surface roughening phenomenon of an aluminum foil is utilized as the measure of stress measurements under variable amplitude stressing and fundamental characteristics of the evolution of the roughness are investigated. The effect of load history on the surface roughening does not appear when the stress amplitude varies many times. Under such a loading condition, the average stress amplitude is measured from the surface roughness of the foil, and this is defined by (∑σiαNi/∑Ni)1/α, where σi, Ni and α are the stress amplitude, the number of stress cycles of σi, and the material factor, respectively.
Asymptotic Approach to the Hill Model of Spread in Rolling
Authors: Domanti S. , McElwain D. L. S. , Middleton R. H.
Published: February 2008

A simplified procedure for the solution of the spread model proposed by Hill (1963) is presented for situations where the strip width is greater than the roll-gap length. The method utilizes a perturbation expansion for the width function and results in a simple analytical solution, overcoming the difficulties involved in solving the original complex, nonlinear, fourth-order differential equation. The solution provides insight into the relationship between the spread predicted and the roll gap parameters, and allows the assumptions made to be evaluated as leading order estimates to the stresses are produced.
Shape of the Free Surfaces of the Jet in Mold Casting Numerical Modeling and Experiments
Authors: Gilotte P. , Huynh L. V. , Etay J. , Hamar R.
Published: February 2008

This paper deals with the filling steps in the mold casting process. Attention is focused on the shapes of the free surfaces of the filling jet. The shapes are determined through an experimental device and a numerical code. Although the assumptions for the calculations are strong, the obtained results agree well with the experimental results.
Viscoplastic Model Development With an Eye Toward Characterization
Authors: Freed Alan D. , Walker Kevin P.
Published: February 2008

A viscoplastic theory is developed that reduces analytically to creep theory under steady-state conditions. A viscoplastic model is constructed within this theoretical framework by defining material functions that have close ties to the physics of inelasticity. As a consequence, this model is easily characterized—only steady-state creep data, monotonic stress-strain curves, and saturated stress-strain hysteresis loops are required. The model is applied to the copper alloy NARloy Z.
On Testing Requirements for Viscoplastic Constitutive Parameter Estimation
Authors: Senseny P. E. , Fossum A. F.
Published: February 2008

Parameter estimation in viscoplastic models using nonlinear least squares fitting shows potential for reducing testing requirements. An efficient test matrix must include information to estimate each parameter, but must impose load histories in which the material behavior is dominated by only a few of the constitutive parameters at any time. Sensitivity coefficients are derived for each model parameter in MATMOD and evaluated for several load histories. Results show the adequacy of the test matrix performed to provide information for parameter evaluation.
A Modeling Investigation of Thermal and Strain Induced Recovery and Nonlinear Hardening in Potential Based Viscoplasticity
Authors: Arnold S. M. , Saleeb A. F. , Wilt T. E.
Published: February 2008

Specific forms for both the Gibb’s and the complementary dissipation potentials were chosen such that a complete potential based multiaxial, isothermal, viscoplastic model was obtained. This model, in general, possesses three internal state variables (two scalars associated with dislocation density and one tensor associated with dislocation motion) both thermal and dynamic recovery mechanisms, and nonlinear kinematic hardening. This general model, although possessing associated flow and evolutionary laws, is shown to emulate three distinct classes of theories found in the literature, by modification of the driving threshold function F. A parametric study was performed on a specialized nondimensional multiaxial form containing only a single tensorial internal state variable (i.e., internal stress). The study was conducted with the idea of examining the impact of including a strain-induced recovery mechanism and the compliance operator, derived from the Gibb’s potential, on the uniaxial and multiaxial response. One important finding was that inclusion of strain-induced recovery provided the needed flexibility in modeling stress-strain and creep response of metals at low homologous temperatures, without adversely affecting the high temperature response. Furthermore, for nonproportional loading paths, the inclusion of the compliance operator had a significant influence on the multiaxial response, but had no influence on either uniaxial or proportional load histories.
Plane-Strain Tension Tests on Aluminum Alloy Sheet
Authors: Taha Fadi , Graf Alejandro , Hosford William
Published: February 2008

A simple way of making plane-strain tension tests on sheet specimens has been developed. This method was used to test sheets of aluminum alloy 2008 T4 and the results were analyzed in terms of a high exponent yield criterion and isotropic hardening. Experimentally measured forces agreed with those calculated from strain measurements using uniaxial tension test curves.