bluuebunny/crossref_metadata_2025 huggingface dataset:
Packing Structure of Particles in a Green Compact and Its Influence on Sintering Deformation
Authors: Tanaka Satoshi , Kuwano Yutaka , Uematsu Keizo
Published: September 2007

The anisotropy of the structure in a die‐pressed compact was studied directly through detailed analysis by confocal scanning laser fluorescent micrographs. The use of confocal optics and an immersion liquid produced micrographs that represented the structure of a cross section at a certain depth along two directions: parallel and normal to the pressing direction. The network formed by particles in contact was analyzed by measuring the components of particle contact parallel and normal to the pressing direction in the green compact. Different values were obtained in the total components of particle contact for the horizontal and normal directions for the cross section parallel to the direction of pressing: the ratio between these values was 1.15. This suggests that there should be 15% more shrinkage in the direction parallel to pressing, at least during the initial stages of sintering when the particle geometry is preserved.
Lattice Expansion and Saturation Magnetization of Nickel–Zinc Ferrite Nanoparticles Prepared by Aqueous Precipitation
Authors: Naughton Brian T. , Clarke David R.
Published: September 2007

Nanoparticles of nickel–zinc ferrite prepared across the solid solution compositional range by aqueous precipitation at 100°C are all found to have both a larger lattice parameter and a lower saturation magnetization than bulk forms of the same compositions. The lower saturation magnetization is attributed to a combination of the larger lattice parameter, decreasing the super‐exchange interactions between the Ni2+ and Fe3+ ions, and incomplete ordering of the cations between the octahedral and tetrahedral sites in the spinel structure. Annealing experiments suggest that the lattice expansion is probably due to the incorporation of OH−groups during synthesis. Characterization of the nanoparticles indicates that the saturation magnetization can be restored while preserving their super‐paramagnetic behavior by heating to temperatures below which they coarsen, typically 900°C.
Binder‐Free Formation of Alumina Ceramics by a Microwave‐Assisted Hydration Reaction
Authors: Shirai Takashi , Yasuoka Masaki , Watari Koji
Published: September 2007

A novel binder‐free formation of ceramics via microwave irradiation is developed. The irradiation of microwave to an alumina green body enhances strongly the hydration reaction between the water and the particle surfaces, creating surface aluminum trihydroxide structures of adjacent particles that bind together tightly. This process makes it possible to manufacture mechanically strong green bodies with excellent shape retention without organic binders.
A Pulse Combustion‐Spray Pyrolysis Process for the Preparation of Nano‐ and Submicrometer‐Sized Oxide Particles
Authors: Widiyastuti W. , Wang Wei‐Ning , Purwanto Agus , Lenggoro I. Wuled , Okuyama Kikuo
Published: September 2007

The preparation of nano‐ and submicrometer particles using an integrated pulse combustion–spray pyrolysis process was investigated for the first time. Zinc oxide nanoparticles with average sizes ranging from 20 to 40 nm were synthesized using a salt precursor with a lower decomposition temperature than the pulse combustion (PC) temperature. Particles of a doped‐type oxide, gadolinium oxide‐doped with europium, were also produced from a precursor, whose decomposition temperature was higher than the PC temperature, and were observed to be ellipsoidal–toroidal in shape and submicrometer in size. The high‐intensity fluctuating pressures generated by PC and the precursor decomposition temperature are proposed as the reasons for the formation of either nanoparticles or aspherical particles. In addition, hot gas fluctuating flow in PC enhanced energy transfer, resulting in more crystalline particles, as compared with particles produced by conventional spray pyrolysis.
Chemical Expansion, Crystal Structural Stability, and Oxygen Permeability of SrCo0.4Fe0.6−xAlxO3−δ Oxides
Authors: Dong Xueliang , Xu Zhi , Chang Xianfeng , Zhang Chun , Jin Wanqin
Published: September 2007

A series of SrCo0.4Fe0.6−xAlxO3−δ (x=0, 0.1, 0.2, 0.3) perovskite oxides were synthesized using a gel‐combustion method. The doping of Al ions and its effect on the crystal structural stability, chemical expansion, and oxygen permeability of SrCo0.4Fe0.6−xAlxO3−δ have been investigated. The introduction of Al ions suppressed the oxygen loss and reduced the chemical‐induced expansion at high temperature. The oxygen permeability of SrCo0.4Fe0.6−xAlxO3−δ membranes decreased with increasing Al content. When x=0.2, the order–disorder phase transition of SrCo0.4Fe0.6O3−δ in nitrogen atmosphere was suppressed, and oxygen permeation was not deleteriously affected.
Root coverage assessment: validity and reproducibility of an image analysis system
Authors: Kerner Stéphane , Etienne Daniel , Malet Jacques , Mora Francis , Monnet‐Corti Virginie , Bouchard Philippe
Published: September 2007

Aim: The aim of this methodological study was to validate a new method for root coverage evaluation following periodontal plastic surgery.

Material and Methods: Thirty recessions were treated in 21 consecutive patients, using a subepithelial connective tissue graft technique. Clinical measurements and photographs were taken at baseline and 12±6 months after treatment. The mean percentage of root coverage for linear and surface area measurements was calculated using conventional clinical evaluation, and compared with ImageJ, a public domain Java image processing program. Bland–Altman plots were used for assessing repeatability and agreement between clinical and ImageJ measurements. The strength of the relationship was calculated using the Pearson product moment correlation coefficient.

Results: The repeatability of ImageJ was excellent for both linear and surface area measurements. The agreement between clinical and ImageJ measurements was good for the linear evaluation, showing lower and upper limits of −13.14% and 17.42%, respectively. Significant correlations (p<0.001) were found between clinical and ImageJ measurements, ranging from 0.93 to 0.94 for linear evaluation, and from 0.89 to 0.90 for surface evaluation.

Conclusions: The outcomes of this study show that the ImageJ analysis is a reliable, reproducible method to evaluate the percentage of root coverage after periodontal plastic surgery, when a midfacial linear measurement is used.
Development of a questionnaire measuring treatment concerns in regular dental patients
Authors: Klages U. , Sadjadi Z. , Lojek L. D. , Rust G. , Wehrbein H.
Published: September 2007

Abstract –  Objectives:  The aim of this study was to develop an instrument measuring core concerns about dental treatment guided by Reiss’ expectancy theory of fear. This would include the content domains of injury, somatic reaction and interpersonal concerns, to study the underlying factorial structure, and to determine the test quality of the resulting subscales.

Methods:  A total of 555 regular dental patients answered the item pool. Subsamples filled in the Dental Anxiety Scale (DAS) (n = 346) and the Anxiety‐Present Scale of the state‐form of the State‐Trait Anxiety Inventory (STAI‐S) (n = 187). A second sample (n = 89) was used to determine test‐retest reliability and bias for social desirability [Self Disclosure Scale of the Freiburg Personality Inventory (FPI)].

Results:  Exploratory and confirmatory factor analyses identified a stable three‐dimensional structure underlying the items convergent to the content domains of interpersonal, injury and somatic reaction concerns. Internal consistencies of the resulting subscales were between α = 0.84 and α = 0.87, test‐retest reliabilities were from rtt = 0.72–0.78. No evidence for a social desirability response bias was found. All subscales discriminated between patients with low and high dental trait anxiety at a level of P < 0.00001. Dental treatment concerns predicted 36% of variations in actual anxiety during treatment.

Conclusions:  The results suggest that the proposed instrument, namely the Dental Treatment Concerns Inventory, shows good test qualities according to construct, discriminant and predictive validity, and may be a promising tool for research and clinical applications.
Relationship between caregiver’s and child’s caries prevalence among disadvantaged African Americans
Authors: Reisine S. , Tellez M. , Willem J. , Sohn W. , Ismail A.
Published: September 2007

Abstract –  Objective:  To assess the relationship between African‐American caregivers’ and children’s caries levels adjusting for sociodemographic factors.

Methods:  A representative sample of 1021 children (0–5 years) and their caregivers were recruited using a stratified two‐stage area probability sample of households in Detroit. The response rate was 73.7%. Caries was measured using the International Caries Detection and Assessment System. Caries was defined as D1S/d1s (noncavitated) or D2S/d2s (cavitated lesions) for both caregivers and children. Sociodemographic data included caregivers’ employment status, sex, age, income and education. Negative binomial regression techniques were used for the multivariable analyses because of the highly skewed distribution of caries among the children.

Results:  48% of the children were male, 39% had employed caregivers, 46% had caregivers with less than a high school education and 44% had family incomes less than $10 000. A total of 47% of the children had at least one noncavitated lesion and 31% had a cavitated lesion. Younger children (ages 0–3 years) had lower caries rates with 24% having one or more noncavitated lesion,18% having a cavitated lesion and 31% with any lesion compared with 78%, 51% and 81%, respectively, among the 4‐ to 5‐year olds. Because of these differences in prevalence in the age groups, subsequent analyses were conducted separately for the two age groups. Multivariable analyses found that the number of cavitated surfaces among the caregivers was significantly related to the number of cavitated and noncavitated lesions among their children for both age groups. The prevalence of children’s caries increased with increasing caregivers’ caries score when demographic characteristics of caregivers were controlled. Younger children with family incomes of less than $10 000 had a significantly increased risk of higher caries prevalence compared with children in families with incomes greater than or equal to $20 000.

Conclusions:  Caregivers’ caries levels were modestly correlated with children’s caries. However, higher caries prevalence among caregivers significantly increased the risk of caries prevalence among their children. Thus, efforts aimed at improving caregiver’s oral health could result in reducing caries risk among their children, regardless of whether the mechanism was biologically or behaviorally based. Efforts also should be aimed directly at reducing caries risk among children by increasing fluoride exposure among children and improving access to preventive dental care. Finally, even the poorest of the poor experienced additional health disadvantages associated with income suggesting even small increases in family income raising families could have a significant effect on reducing caries risk among young children.
Testing the applicability of a conceptual model of oral health in housebound edentulous older people
Authors: Baker Sarah R. , Pearson Nicola K. , Robinson Peter G.
Published: September 2007

Abstract –  Objectives:  The aim of the study was to test prospectively Wilson and Cleary’s (1) conceptual model of the direct and mediated pathways between symptom burden, functional status and health perceptions in relation to the oral health of housebound elderly edentulous people.

Methods:  The data were collected as part of a community based randomized control trial of a domiciliary denture service for older people. Measures of self‐reported symptoms, functional status and global oral and general health perceptions were collected from 133 participants prior to treatment and at 3‐month follow‐up.

Results:  The results indicated support for the dominant direct and indirect pathways within the model; worse patient reported symptoms predicted a lower functional status; worse daily functioning predicted lower global oral health perceptions. In addition, the impact of symptom status on oral health perceptions was mediated by patient reported functioning. The treatment (domiciliary denture service) significantly improved functional status and global oral health perceptions. All relationships were significant prospectively that is, from baseline, prior to the intervention, to 3‐month follow‐up, with the exception of between symptoms functioning.

Conclusion:  The results support Wilson and Cleary’s conceptual model of patient outcomes as applied to elderly edentulous people. They highlight the importance of assessing a range of patient‐orientated variables in order to help gain a greater understanding of how oral health impacts on individuals’ daily lives and well‐being. Further conceptual development of the model is discussed, particularly the role of individual difference factors.
Oral health‐related quality of life in a birth cohort of 32‐year olds
Authors: Lawrence Herenia P. , Thomson W. Murray , Broadbent Jonathan M. , Poulton Richie
Published: September 2007

Abstract –  Objectives:  To describe oral health‐related quality of life (OHRQoL) among New Zealand adults and assess the relationship between clinical measures of oral health status and a well‐established OHRQoL measure, controlling for sex, socioeconomic status (SES) and use of dental services.

Methods:  A birth cohort of 924 dentate adults (participants in the Dunedin Multidisciplinary Health and Development Study) was systematically examined for dental caries, tooth loss, and periodontal attachment loss (CAL) at age 32 years. OHRQoL was measured using the 14‐item Oral Health Impact Profile questionnaire (OHIP‐14). The questionnaire also collected data on each study member’s occupation, self‐rated oral health and reasons for seeing a dental care provider. SES was determined from each individual’s occupation at age 32 years.

Results:  The mean total OHIP‐14 score was 8.0 (SD 8.1); 23.4% of the cohort reported one or more OHIP problems ‘fairly often’ or ‘very often’. When the prevalence of impacts ‘fairly/very often’ was modeled using logistic regression, having untreated caries, two or more sites with CAL of 4+ mm and 1 or more teeth missing by age 32 years remained significantly associated with OHRQoL, after adjusting for sex and ‘episodic’ dental care. Multivariate analysis using Poisson regression determined that being in the low SES group was also associated with the mean number of impacts (extent) and the rated severity of impacts.

Conclusions:  OHIP‐14 scores were significantly associated with clinical oral health status indicators, independently of sex and socioeconomic inequalities in oral health. The prevalence of impacts (23.4%) in the cohort was significantly greater than age‐ and sex‐standardized estimates from Australia (18.2%) and the UK (15.9%).
Preliminary development and validation of the Jaw Functional Limitation Scale*
Authors: Ohrbach Richard , Granger Carl , List Thomas , Dworkin Samuel
Published: September 2007

Abstract –  Objective:  Functional limitation is a construct distinct from disability, but the distinction between these constructs is often blurred when measuring jaw status because of content overlap in measurement instruments that include items pertaining to mechanical jaw functions, jaw functions that have obvious social implications, and only social functions. We describe analyses in support of assessing functional limitation as distinct from disability by using both factor analysis and the Rasch measurement model in reanalyzing two existing instruments and then create a preliminary version of a new instrument that has excellent psychometric properties.

Study Design and Setting:  Subjects in three separate studies from two university settings completed two existing self‐report instruments (Research Diagnostic Criteria for Temporomandibular Disorders and Mandibular Functional Impairment Questionnaire). Rasch methodology, factor analysis, and the combination of both were used in these analyses. Unidimensionality, in support of an instrument assessing a single construct, was also assessed.

Results:  Problems identified in the existing instruments included scaling, internal reliability, length, unidimensionality, and content validity; the preliminary version of the Jaw Functional Limitation Scale (JFLS) resolves these problems critical to delineating functional limitation and it exhibits internal reliability coefficients of 0.82 for persons and 0.99 for items. Construct validity, via convergent and discriminant validity with other associated constructs, of the JFLS was established via low correlations with depression, anxiety, somatization, pain interference, pain‐free opening, and palpation sensitivity, and via moderate correlations with pain and jaw symptoms.

Conclusion:  While areas of further development are outlined, we conclude that this preliminary version of the JFLS is a valid instrument for the measurement of temporomandibular disorder (TMD)‐related functional limitation, and consequently delineates functional limitation from disability.
In vivo assessment of pigmentary and vascular compartments changes in UVA exposed skin by reflectance‐mode confocal microscopy
Authors: Yamashita Toyonobu , Akita Hirotaka , Astner Susanne , Miyakawa Michio , Lerner Ethan Arthur , González Salvador
Published: September 2007

Abstract:  Exposure of the skin to ultraviolet A (UVA) results in various biological responses, skin‐colour changes being among the major ones. Although intense research has been performed on UVA‐induced pigmentation and vascular changes, the process of skin‐colour changes after UVA irradiation remains unclear. For a better understanding of the UVA tanning mechanism, we here performed a human study in 27 healthy volunteers with skin phototype (SPT) II to VI. After a single UVA exposure to inner forearm, the skin sites were imaged using reflectance‐mode confocal microscopy (RCM), for analysis of melanin and vascular changes. Punch biopsies were also taken from the UVA‐exposed or non‐exposed sites for histological examination. Skin sections were stained with Fontana‐Masson and evaluated by a sensitive tyrosinase assay for comparison with RCM images. Furthermore, the effect of blood flow on skin‐colour changes was evaluated visually after administration of an intradermal anesthesia of lidocaine with or without epinephrine. Our RCM analysis showed dendritic melanocytes and a different melanin distribution in the epidermal layer, clearly visible 1 week after the UVA exposure in subjects of SPT V which were supported by histological examination. However, no melanin distribution pattern changes were apparent immediately after the exposure, while RCM images showed accelerated capillary flow patterns. The restriction of this UVA induced‐accelerated blood flow by epinephrine inhibited partially or completely the immediate pigment darkening and delayed tanning. These in vivo studies confirmed that vascular change is an important factor for the development of the immediate pigment darkening and delayed tanning.
Topical tacrolimus in combination with simulated solar radiation does not enhance photocarcinogenesis in hairless mice
Authors: Lerche Catharina M. , Philipsen Peter A. , Poulsen Thomas , Wulf Hans Christian
Published: September 2007

Abstract:  Numerous studies have demonstrated the utility of topical tacrolimus ointment in atopic dermatitis. However, there is a concern that local immunosuppression by calcineurin inhibitors may enhance dermal photocarcinogenesis and carcinogenesis. Therefore, we investigated the influence of topical tacrolimus ointment on squamous cell carcinoma formation in hairless female C3.Cg/TifBomTac immunocompetent mice exposed to solar simulated radiation (SSR). In a first experiment, mice (n = 200) had tacrolimus applied on their dorsal skin three times weekly followed by SSR (2, 4 or 6 standard erythema doses, SED) 3–4 h later. Tacrolimus did not reduce the time to tumor development and in the group receiving 4 SED it even had a protective effect (156 days vs 170 days, P = 0.008). In a second experiment, mice (n = 50) were irradiated with 6 SED three times weekly for 3 months and subsequently treated five times weekly with topical tacrolimus to mimic the use of tacrolimus on sun‐damaged skin. The median time to the first skin tumor was 234 days in SSR + tacrolimus group compared with 227 days in the only SSR‐irradiated group (P = 0.160). In a third experiment, mice (n = 25) had tacrolimus applied on their dorsal skin every day for 1 month, thereafter the group was irradiated with 4 SED three times weekly. The median time to the first skin tumor was 142 days in tacrolimus + SSR group compared with 156 days in the only SSR‐irradiated group from experiment 1 (P = 0.363). We conclude that tacrolimus ointment does not accelerate photocarcinogenesis or induce any dermal carcinogenicity in hairless mice.
The angiotensin‐converting enzyme insertion/deletion and the endothelin ‐134 3A/4A gene polymorphisms in patients with chronic plaque psoriasis
Authors: Weger Wolfgang , Hofer Angelika , Wolf Peter , El‐Shabrawi Yosuf , Renner Wilfried , Kerl Helmut , Salmhofer Wolfgang
Published: September 2007

Background:  Psoriasis is a common chronic inflammatory skin disease. Vasoactive peptides such as endothelin‐1 (ET‐1) and bradykinin have previously been implicated in the pathogenesis of chronic plaque psoriasis. The angiotensin‐converting enzyme (ACE) gene carries a 287‐base pair insertion/deletion (I/D) gene polymorphism, which is associated with plasma concentrations of bradykinin‐degrading ACE. A functional polymorphism (EDN1

‐134 3A/4A) in the gene encoding ET‐1 has been shown to affect ET‐1 expression. The purpose of the present study was thus to investigate a hypothesized association between these gene polymorphisms and the presence of chronic plaque psoriasis.

Methods:  The present case‐control study comprised 207 patients with chronic plaque psoriasis (136 with early onset and 71 with late onset disease) and 182 control subjects. Genotypes of EDN1 and ACE were determined by a 5′ exonuclease assay (Taqman).

Results:  The prevalence of the homozygous ACE II genotype was significantly higher in patients with early‐onset psoriasis than among control subjects (30.9% vs 19.2%, P = 0.016), yielding an odds ratio of 1.88 [95% confidence interval (CI): 1.12–3.15] for early‐onset disease. For late‐onset psoriasis, presence of the ACE II genotype was associated with a non‐significant odds ratio 1.54 (95% CI: 0.81–2.92). As for the EDN1 ‐134 3A/4A gene polymorphism, no significant differences in genotype distributions were found between patients with either early‐ or late‐onset psoriasis and control subjects (EDN1 ‐134 4A/4A: 9.6% in early‐onset and 5.6% late‐onset psoriasis vs 7.7% in controls; P > 0.05).

Conclusions:  Our data suggest that homozygosity for the ACE I allele may affect susceptibility to early‐onset psoriasis.
Structural alterations provoked by narrow‐band ultraviolet B in immortalized keratinocytes: assessment by atomic force microscopy
Authors: Reich Adam , Lehmann Bodo , Meurer Michael , Muller Daniel J.
Published: September 2007

Abstract:  We applied atomic force microscopy (AFM) to visualize ultrastructural changes of the keratinocyte morphology after narrow‐band ultraviolet B (NB‐UVB) irradiation. Immortalized human keratinocytes were cultured under standard conditions, irradiated with NB‐UVB light at doses ranging from 50 to 800 mJ/cm2 and imaged by AFM mounted on an inverted optical microscope. It was observed, that NB‐UVB irradiation provoked dose‐dependent alterations of the keratinocyte morphology. While the surface of non‐irradiated cells exhibited homogenously distributed crest‐like shaped protrusions (height 0.16 ± 0.05 μm), cells irradiated with a dose of 800 mJ/cm2 in addition showed round shaped protrusions (height 0.14 ± 0.06 μm) distributed predominantly around the nucleus and bleb‐like protrusions irregularly distributed on the cell surface (height 0.95 ± 0.29 μm). These irradiated cells easily detached from the supporting glass surface, showed impaired contact with adjacent keratinocytes and significantly rearranged their cytoskeleton network. We hypothesize that these structural and functional alterations reflect ongoing apoptosis in UVB treated cells.
Human epidermal Langerhans cells express the tight junction protein claudin‐1 and are present in human genetic claudin‐1 deficiency (NISCH syndrome)
Authors: Zimmerli Simone C. , Kerl Katrin , Hadj‐Rabia Smail , Hohl Daniel , Hauser Conrad
Published: September 2007

Abstract:  Claudin‐1 (CLDN1) is a structural tight junction (TJ) protein and is expressed in differentiating keratinocytes and Langerhans cells in the epidermis. Our objective was to identify immunoreactive CLDN1 in human epidermal Langerhans cells and to examine the pattern of epidermal Langerhans cells in genetic human CLDN1 deficiency [neonatal ichthyosis, sclerosing cholangitis (NISCH) syndrome]. Epidermal cells from healthy human skin labelled with CLDN1‐specific antibodies were analysed by confocal laser immunofluorescence microscopy and flow cytometry. Skin biopsy sections of two patients with NISCH syndrome were stained with an antibody to CD1a expressed on epidermal Langerhans cells. Epidermal Langerhans cells and a subpopulation of keratinocytes from healthy skin were positive for CLDN1. The gross number and distribution of epidermal Langerhans cells of two patients with molecularly confirmed NISCH syndrome, however, was not grossly altered. Therefore, CLDN1 is unlikely to play a critical role in migration of Langerhans cells (or their precursors) to the epidermis or their positioning within the epidermis. Our findings do not exclude a role of this TJ molecule once Langerhans cells have left the epidermis for draining lymph nodes.
Melatonin prevents nitric oxide‐induced apoptosis by increasing the interaction between 14‐3‐3β and p‐Bad in SK‐N‐MC cells
Authors: Choi Seung‐Il , Joo Seong‐Soo , Yoo Yeong‐Min
Published: September 2007

Abstract:  The anti‐apoptotic effect of melatonin has been described in vivo and in vitro. A previous report has revealed that melatonin suppresses nitric oxide (NO)‐induced apoptosis via the induction of Bcl‐2 expression in PGT‐β pineal cells. To investigate the protective mechanism of melatonin on NO donor S‐nitroso‐N‐acetyl‐penicillamine (SNAP)‐induced apoptosis, we examined the anti‐apoptotic upstream signaling pathway of Bcl‐2 in the human neuroblastoma cell line SK‐N‐MC. The flow cytometry results revealed that apoptosis occurred in NO‐treated cells, while cell death was inhibited by pretreatment with melatonin (100 μm). In addition, decreased Bax expression, increased Bcl‐2 expression and a decreased release of cytochrome c into the cytosol were observed in the melatonin‐pretreated SK‐N‐MC cells. We also found that melatonin treatment induced the activation of Akt/PKB and the phosphorylation of GSK3α/β and Bad. Furthermore, melatonin treatment not only increased the protein–protein interactions between 14‐3‐3β and p‐Bad, but also decreased the release of cytochrome c from mitochondria into the cytosol. In summary, the protective effect of melatonin against NO‐induced apoptosis was mediated by the inhibition of Bad translocation from the cytosol to the mitochondria by the induction of protein–protein interactions between 14‐3‐3β and p‐Bad.
Cytoprotective effects of melatonin against necrosis and apoptosis induced by ischemia/reperfusion injury in rat liver
Authors: Kim Sung‐Hwa , Lee Sun‐Mee
Published: September 2007

Abstract:  Melatonin protects against organ ischemia; this effect has mainly been attributed to the antioxidant properties of the indoleamine. This study examined the cytoprotective properties of melatonin against injury to the liver caused by ischemia/reperfusion (I/R). Rats were subjected to 60 min of ischemia followed by 5 hr of reperfusion. Melatonin (10 mg/kg) or the vehicle was administered intraperitoneally 15 min before ischemia and immediately before reperfusion. The serum aminotransferase activity and lipid peroxidation levels were increased markedly by hepatic I/R, which were suppressed significantly by melatonin. In contrast, the glutathione content, which is an index of the cellular redox state, and mitochondrial glutamate dehydrogenase activity, which is a maker of the mitochondrial membrane integrity, were lower in the I/R rats. These decreases were attenuated by melatonin. The rate of mitochondrial swelling, which reflects the extent of the mitochondrial permeability transition, was higher after 5 hr of reperfusion but was attenuated by melatonin. Melatonin limited the release of cytochrome c into the cytosol and the activation of caspase‐3 observed in the I/R rats. The melatonin‐treated rats showed markedly fewer apoptotic (TUNEL positive) cells and DNA fragmentation than did the I/R rats. These results suggest that melatonin ameliorates I/R‐induced hepatocytes damage by inhibiting the level of oxidative stress and the apoptotic pathway. Consequently, melatonin may provide a new pharmacological intervention strategy for hepatic I/R injuries.
Estimation of sCD14 levels in saliva obtained from patients with various periodontal conditions
Authors: Isaza‐Guzmán DM , Aristizábal‐Cardona D , Martínez‐Pabón MC , Velásquez‐Echeverri H , Tobón‐Arroyave SI
Published: September 2007

Aim: To assess the concentration of soluble CD14 receptor in saliva of people with periodontal disease and healthy patients and its relationship with periodontal status.

Subjects and Methods: Unstimulated whole saliva samples from patients with chronic periodontitis (n = 34), aggressive periodontitis (n = 19) and healthy controls (n = 17) were obtained for the study. The periodontal status of each subject was assessed by criteria based on probing depth, clinical attachment loss and the extent of periodontal breakdown. The levels of sCD14 were measured in saliva samples with an enzyme‐linked immunosorbent assay (ELISA).

Results: Although no significant difference (P > 0.05) was found for salivary sCD14 levels between periodontitis groups, they were significantly greater (P < 0.05) than those detected for healthy controls. Furthermore, Spearman’s correlation analysis showed statistically significant correlations (P < 0.01) between data from salivary sCD14 levels and clinical measurements.

Conclusion: The findings of the present study re‐emphasize the importance of whole saliva as sampling method in terms of immunological purposes in periodontal disease and suggest that the elevated sCD14 concentration may be one of the host‐response components associated with the clinical manifestations of periodontal disease.
Bone formation in rat calvaria ceases within a limited period regardless of completion of defect repair
Authors: Honma T , Itagaki T , Nakamura M , Kamakura S , Takahashi I , Echigo S , Sasano Y
Published: September 2007

A bone defect that is not repaired with bone completely is designated a non‐union defect or a critical‐size defect. The biological mechanism that regulates the process of bone repair of the critical‐size defect remains unknown. The present study was designed to investigate bone repair in a critical‐size defect compared with that in a smaller or non‐critical‐size defect. Our original standardized rat calvarial bone defect model was used for the experiment. The rate of bone formation was examined with X‐ray morphometry and the bone production of osteoblasts and osteocytes was assessed by molecular histology with in situ hybridization for type I collagen and osteocalcin. Formation of repaired bone ceased within 24 weeks in both critical‐ and non‐critical‐size defects i.e. regardless of completion of the defect repair. The results suggested that osteoblasts and osteocytes cease bone formation, and the differentiation of osteoblast progenitors declines in 24 weeks. Also, bone repair proceeds from the periosteum on both sides of the parietal bone but not from the surface of the bony edge around the original defect. The results could provide useful information for clinical research on bone repair.
Interaction between BDNF Val66Met and childhood trauma on adult’s violent suicide attempt
Authors: Perroud N. , Courtet P. , Vincze I. , Jaussent I. , Jollant F. , Bellivier F. , Leboyer M. , Baud P. , Buresi C. , Malafosse A.
Published: September 2007

Genetic factors, specially those related to serotoninergic activities, and childhood maltreatment have both been implicated in suicidal behaviour (SB). However, little attention has been paid to the possible interaction between genes and childhood maltreatment in the comprehension of SB. Brain‐derived neurotrophic factor (BDNF) plays an important role in the growth of serotoninergic neurons during childhood and therefore is a good candidate for studies on SB. Moreover, decreased levels of BDNF have been found in the prefrontal cortex of suicide victims. In our study we wanted to see if Val66Met (a BDNF functional single‐nucleotide polymorphism) could moderate the effect of childhood maltreatment on the onset, number and violence of SB in a sample of 813 Caucasian suicide attempters. Childhood maltreatment was evaluated using the Childhood Trauma Questionnaire. We used a regression framework to test the interaction between Val66Met and childhood maltreatment. Childhood sexual abuse was associated with violent suicide attempts (SA) in adulthood only among Val/Val individuals and not among Val/Met or Met/Met individuals (P = 0.05). The severity of childhood maltreatment was significantly associated with a higher number of SA and with a younger age at onset of suicide attempt. This result suggests that Val66Met modulates the effect of childhood sexual abuse on the violence of SB. It is proposed that childhood sexual abuse elicits brain structural modifications through BDNF dysfunction and enhances the risk of violent SB in adulthood.
Beta N‐acetylglucosaminyltransferase V (Mgat5) deficiency reduces the depression‐like phenotype in mice
Authors: Soleimani L. , Roder J. C. , Dennis J. W. , Lipina T.
Published: September 2007

The central nervous system (CNS) is rich in glycoconjugates, located on cell surface and in extracellular matrix. The products of Golgi UDP‐GlcNAc:N‐acetylglucosaminyltransferases (encoded by Mgat1, Mgat2, Mgat4 and Mgat5) act sequentially to generate the GlcNAc‐branched complex‐type N‐glycans on glycoprotein receptors. While elimination of all the branched N‐glycans in Mgat1−/− mouse embryos is lethal at neural tube fold stage, decreased branching is associated with late developmental defects similar to type 2 of congenital disorders of glycosylation, with developmental and psychomotor abnormalities. To study the role of complex‐type N‐glycans in brain function, we tested Mgat5−/− mice in a battery of neurological and behavioral tests. Despite the absence of tri‐ and tetra‐antennary products, Mgat5−/− mice were not different from their wild‐type littermates in physical and neurological assessments, anxiety level, startle reactivity and sensorimotor gating. However, they displayed a robust decrease in the immobility time in the forced swim test and the tail suspension test independent of locomotor activity, interpreted as a change in depression‐like behavior. This effect was accentuated after chronic mild stress. Comparable increase in plasma corticosterone of Mgat5+/+ and Mgat5−/− mice in response to acute stress shows an intact function of the hypothalamus–pituitary–adrenal axis. A change in social interactions was also observed. Our results indicate that Mgat5 modification of complex‐type N‐glycans on CNS glycoproteins is involved in the regulation of depression‐like behavior.
SIMULATION OF COATING PROCESS: RHEOLOGICAL APPROACH IN COMBINATION WITH ARTIFICIAL NEURAL NETWORK
Authors: BHATTACHARYA SUVENDU , PATEL BHAVESH K.
Published: September 2007

The coating of foods is a complex process involving many variables, and obtaining repeatable results is difficult as the surface of foods varies widely because of the presence of pores, cracks and vacuoles. A simulation study using metal flakes is thus employed. Coating of cereal flakes with maltodextrin and/or malt dispersions containing 0–25% solids was simulated by measuring the adhesion to metal strips. The amount of coating was related to the rheological properties of the dispersion. Dispersions containing malt were shear‐thinning liquids with yield stress, and obeyed the Herschel‐Bulkley model (r ≥ 0.98, P ≤ 0.01). Coating adhesion was quantified and explained as a dimensionless uptake. A system analytical model was proposed, which consisted of influencing variables (solids in the dispersion and rheological parameters) and influenced variables (adhesion characteristics) that were analyzed by two artificial neural networks having configurations 3‐28‐12‐4 and 4‐9‐9‐3‐3, respectively.

PRACTICAL APPLICATIONS

The application of the present research lies in the development of coated foods. It gives information about the presence of important variables of coating and their effect on the parameters of coating (e.g., the extent of batter uptake and coat thickness). An understanding of the relationship between batter and coating parameters is possible, and has been supported by the proposed system of analytical model. Potential also exists to extend this model in real situations involving the manufacture of coated/flavored breakfast cereals, snacks, chocolates, confectionery and multilayered products.
MEASUREMENT OF FIRMNESS OF FRESH‐CUT SLICED TOMATO USING PUNCTURE TESTS – STUDIES ON SAMPLE SIZE, PROBE SIZE AND DIRECTION OF PUNCTURE
Authors: LANA MILZA M. , TIJSKENS LEOPOLD M.M. , DE THEIJE ANEMARIE , DEKKER MATTHIJS , BARRETT DIANNE M.
Published: September 2007

In order to investigate the firmness of tomato slices, two experiments were performed. In the first one, Monte Carlo simulation was used to study the variation in firmness within and between slices. Adding more slices and more measurements per slice reduced the SD, but in general, the efficiency of adding more slices was higher. In the second experiment, the firmness of tomato slices was measured by puncture test during storage, using one of three flat‐tipped cylindrical probes (3.5‐, 2.5‐ and 1.5‐mm diameter) in two directions, along or perpendicular to the main axis of the fruit. Changes in firmness were studied by nonlinear regression analysis. The same model could be applied to all combinations of probe size and direction with the same correction for shear and compression. It suggests that shear and compression forces decay with storage time according to the same mechanism, irrespective of the measurement direction.

PRACTICAL APPLICATIONS

Methodologies for both firmness evaluation and data analysis were presented. Monte Carlo simulation was used to optimize the number of samples for firmness assays. After calculating the experimental SD from preliminary experimental results, simulations were performed with different numbers of replicates and measurements per replicate, to find an optimal experimental design where the SD is minimized. Using nonlinear regression, the effects on firmness of probe size, puncture direction in relation to the plant tissue and storage time can be analyzed simultaneously. The incorporation of a correction factor to account for differences in firmness due to probe size was proposed. The relative influence of shear (s) and compression force (c) on the observed force is estimated. Results of interest for the industry were presented, confirming previous findings that the firmness of ripened tomato slices measured by puncture analysis does not change significantly during short‐term storage at low temperature.
A RESEARCH NOTE ON INTRINSIC VISCOSITY OF HIGH METHOXYL PECTIN IN DILUTE SOLUTION: INFLUENCE OF SWEETENERS
Authors: SAMAVATI VAHID , RAZAVI SEYED HADI , MOUSAVI SEYED MOHAMMAD , AMINIFAR MEHRNAZ
Published: September 2007

A Brookfield rheometer (Middleboro, MA) was used to investigate the effects of some synthetic sweeteners (aspartame, acesulfame–k, cyclamate and neotame) on intrinsic viscosity of high‐methoxyled pectin (HMP) in dilute solutions. The concentration of these sweeteners were 0.1, 0.2% w/v for aspartame, acesulfame–k and cyclamate, and 0.001, 0.002% w/v for neotame. We used various equations such as Huggins, Kraemer, Tanglertpaibul and Rao equations to assess the best model for the determination of the intrinsic viscosity of HMP. The results showed that the values obtained for intrinsic viscosity were different based on the equation used for estimating the intrinsic viscosity. We found 1‐1/ηrel versus concentration plot as the best model. The results showed that the addition of any of these four synthetic sweeteners at these concentrations had no important effect on the intrinsic viscosity of HMP in solutions.

PRACTICAL APPLICATIONS

One of the key parameters to measure the rheological behavior of gums is to study intrinsic viscosity. Rheological property is very important for several aspects such as the effect on mouth feeling, texture, structure and other characteristics of food products. Because gums are widely used for modifying the rheological properties of food systems, investigation on the effect of sweeteners on rheological behavior of gums is very important. By this work, we can conclude that the effect of replacing sucrose with acesulfame–k on the rheological property of food products is minimal, and acesulfame–k is a suitable alternative sweetener for sucrose in dietary products.
Effect of Rapidly Changing River Stage on Uranium Flux through the Hyporheic Zone
Authors: Fritz Brad G. , Arntzen Evan V.
Published: September 2007

Measurement of ground water/surface water interaction within the hyporheic zone is increasingly recognized as an important aspect of subsurface contaminant fate and transport. Understanding the interaction between ground water and surface water is critical in developing a complete conceptual model of contaminant transport through the hyporheic zone. At the Hanford Site near Richland, Washington, ground water contaminated with uranium discharges to the Columbia River through the hyporheic zone. Ground water flux varies according to changes in hydraulic gradient caused by fluctuating river stage, which changes in response to operation of dams on the Columbia River. Piezometers and continuous water quality monitoring probes were installed in the hyporheic zone to provide long‐term, high‐frequency measurement of hydraulic gradient and estimated uranium concentrations. Subsequently, the flux of water and uranium was calculated for each half‐hour time period over a 15‐month study period. In addition, measurement of water levels in the near‐shore unconfined aquifer enhanced the understanding of the relationship between river stage, aquifer elevation, and uranium flux. Changing river stage resulted in fluctuating hydraulic gradient within the hyporheic zone. Further, influx of river water caused lower uranium concentrations as a result of dilution. The methods employed in this study provide a better understanding of the interaction between surface and ground water in a situation with a dynamically varying vertical hydraulic gradient and illustrate how the combination of relatively standard methods can be used to derive an accurate estimation of water and contaminant flux through the hyporheic zone.
Neural Networks to Simulate Regional Ground Water Levels Affected by Human Activities
Authors: Feng Shaoyuan , Kang Shaozhong , Huo Zailin , Chen Shaojun , Mao Xiaomin
Published: September 2007

In arid regions, human activities like agriculture and industry often require large ground water extractions. Under these circumstances, appropriate ground water management policies are essential for preventing aquifer overdraft, and thereby protecting critical ecologic and economic objectives. Identification of such policies requires accurate simulation capability of the ground water system in response to hydrological, meteorological, and human factors. In this research, artificial neural networks (ANNs) were developed and applied to investigate the effects of these factors on ground water levels in the Minqin oasis, located in the lower reach of Shiyang River Basin, in Northwest China. Using data spanning 1980 through 1997, two ANNs were developed to model and simulate dynamic ground water levels for the two subregions of Xinhe and Xiqu. The ANN models achieved high predictive accuracy, validating to 0.37 m or less mean absolute error. Sensitivity analyses were conducted with the models demonstrating that agricultural ground water extraction for irrigation is the predominant factor responsible for declining ground water levels exacerbated by a reduction in regional surface water inflows. ANN simulations indicate that it is necessary to reduce the size of the irrigation area to mitigate ground water level declines in the oasis. Unlike previous research, this study demonstrates that ANN modeling can capture important temporally and spatially distributed human factors like agricultural practices and water extraction patterns on a regional basin (or subbasin) scale, providing both high‐accuracy prediction capability and enhanced understanding of the critical factors influencing regional ground water conditions.
Strategies for Offsetting Seasonal Impacts of Pumping on a Nearby Stream
Authors: Bredehoeft John , Kendy Eloise
Published: September 2007

Ground water pumping from aquifer systems that are hydraulically connected to streams depletes streamflow. The amplitude and timing of stream depletion depend on the stream depletion factor (SDFi) of the pumping wells, which is a function of aquifer hydraulic characteristics and the distance from the wells to the stream. Wells located at different locations, but having the same SDF and the same rate and schedule of pumping, will deplete streamflow equally. Wells with small SDFi deplete streamflow approximately synchronously with pumping. Wells with large SDFi deplete streamflow at approximately a constant rate throughout the year, regardless of the pumping schedule. For large values of SDFi, artificial recharge that occurs on a different schedule from pumping can offset streamflow depletion effectively. The requirements are (1) that the pumping and recharge wells both have the same SDFi and (2) that the annual total quantities of recharge and pumping be equal. At larger SDFi values, it takes longer for pumping to impact streamflow in a wide aquifer than it does in a narrow aquifer. In basins that are closed to further withdrawals because streamflow is fully allocated, water‐use changes replace new allocations as the source of water for new developments. Ground water recharge can be managed to offset the impacts of new ground water developments, allowing for changes in the timing and source of withdrawals from a basin without injuring existing users or instream flows.
Trade Rules, Intellectual Property, and the Right to Health
Authors: Forman Lisa
Published: September 2007

In perpetuating and exacerbating restricted access to essential medicines, current trade-related intellectual property rules on medicines may violate core human rights to health and medicines. In this light, their impact on the global disease burden raises serious questions about their necessity, and their justification should be critically assessed from the perspective of human rights standards. These standards require that international trade rules on medicines be justified to the fullest extent possible, and permitted only to the extent to which they can be justified. In this article I explore the impact of trade rules on medicines access, and the growing force of the human right to health. I argue that the limited justification for strong patents in poor countries suggests the need for significant reform of trade-related intellectual property rights. I argue further that human rights standards may offer both normative and practical tools for achieving this reform and for challenging trade rules on medicines at various levels.