bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Disinfection on the Dimensional Stability of Polyether Impression Materials
Authors: Yilmaz Handan , Aydin Cemal , Gul Basak , Yilmaz Caner , Semiz Mustafa 
Published: September 2007

Purpose:
Difficulties in sterilizing impressions have led to chemical disinfection solutions as an alternative; however, some impression materials are more sensitive to humidity. For example, polyether impression materials are more hydrophilic. This study investigated the effect of three disinfecting methods on the dimensional stability of three polyether impression materials.
Materials and Methods:
Three polyether impression materials (P2, Impregum Penta Soft, and Impregum Penta) were submitted to the following treatments: spray disinfectant (Mikrozid Liquid), immersion in 2% glutaraldehyde solution (Super‐On), immersion in 0.525% sodium hypochlorite solution for 10 minutes, and a control group (not disinfected). Each group included five samples. After treatment, dimensional change was evaluated according to ISO 4823. The data were analyzed by 2‐way analysis of variance at α= 0.05.
Results:
The mean percentages of linear dimensional change of materials P2, Penta Soft, and Penta were –0.040%, 0.098%, and 0.100%, respectively. The dimensional change associated with different disinfectant agents mikrozid liquid, 2% glutaraldehyde, room air (control), and 0.525% sodium hypochlorite was 0.013%, 0.024%, 0.077%, and 0.096%, respectively. The interaction between the impression materials and the disinfectant treatment was not significant. The disinfectant agents can be classified in two groups as low‐ and high‐effected. The control group did not significantly differ from either group.
Conclusion:
From the standpoint of dimensional change, the disinfectants tested for 10 minutes caused no significant linear dimensional change in the polyether impression materials, compared with the control group.
Development of a positive preference–performance relationship in an oligophagous beetle: adaptive learning?
Authors: Xue Huai‐Jun , Egas Martijn , Yang Xing‐Ke 
Published: September 2007

AbstractThe relationship between oviposition preference and larval performance is a central topic in insect–plant biology. In this study, we investigate whether the oligophagous flea beetle, Altica fragariae Nakane (Coleoptera: Chrysomelidae), exhibits a positive preference–performance relationship, and whether oviposition preference develops over time. We tested the beetles using four sympatric plant species: Duchesnea indica (Andrews) Focke (the normal host plant), Agrimonia pilosa Ledeb. (a secondary host plant), and Potentilla chinensis Ser. and Sanguisorba officinalis L. (host plants of two related Altica species) (all Rosaceae). In no‐choice experiments, both oviposition rate and offspring fitness parameters (eclosion rate, development time, and body mass) were highest on D. indica. Oviposition rate was much lower on P. chinensis than on A. pilosa, whereas offspring fitness parameters did not differ significantly between these two host plants. Offspring fitness were lowest for S. officinalis, and adult females refused to oviposit on this acceptable non‐host in a no‐choice situation. Repeated two‐choice experiments showed that the proportion of oviposition on one of the novel host plants decreased significantly over time when the alternative host plant was D. indica. In repeated two‐choice experiments using A. pilosa and P. chinensis, females mainly fed on A. pilosa but distributed their eggs equally over the two host plants, in accordance with the lack of difference in offspring fitness on those hosts. Together, these results showed that A. fragariae females develop a positive preference–performance relationship over time. We suggest that A. fragariae achieves this through adaptive learning of oviposition preference: not only does the female learn to discriminate among the host plants when there is a fitness difference for her offspring, but the female also fails to discriminate when there is no fitness difference.
Temporal variation in foraging activity and efficiency and the role of hitchhiking behaviour in the leaf‐cutting ant, Atta cephalotes
Authors: Yackulic Charles B. , Lewis Owen T. 
Published: September 2007

AbstractTwo phenomena are integral to the foraging behaviour of leaf‐cutting ants in the genus Atta: hitchhiking (where small ants ride on leaf fragments carried by larger workers) and rhythmic foraging (where foraging activity shows marked fluctuations over time). While parasitism by phorid flies has been implicated in eliciting both behaviours, recent research suggests fungal contaminants and the need to procure sap also play a key role in eliciting hitchhiking. For wild colonies of Atta cephalotes L. (Hymenoptera: Formicidae), we investigated the extent to which hitchhiking frequency varied in space and time and the foraging performance of day‐time and night‐time workers. Day‐time foragers were considerably smaller than nocturnal foragers, a trend previously described as a response to diurnal phorids. Despite their smaller size, day‐time foragers had higher foraging performance, perhaps as a consequence of decreased trail congestion. Larger leaf‐carriers were more likely to carry hitchhikers and hitchhiking frequency was higher at night, an observation that conflicts with the parasitoid defence hypothesis, but not with the leaf sap and fungal defence hypotheses. Hitchhikers constitute a major proportion (typically 12%) of the loads carried by workers, and have three times the effect of leaf fragment mass on forager velocity. However, they reduced energetic efficiency by only 2.6% and provisioning rate by 5.9%. Our results provide partial support for the parasitoid defence hypothesis, but suggest that both the risks of parasitism and the opportunity‐cost to foraging associated with carrying hitchhikers may be low.
Posttraumatic stress disorder as a risk factor for obesity among male military veterans
Authors: Vieweg W. V. R. , Julius D. A. , Bates J. , Quinn J. F. , Fernandez A. , Hasnain M. , Pandurangi A. K. 
Published: September 2007

Objective:  Obesity is a significant public health problem in the United States, particularly among military veterans with multiple risk factors. Heretofore, posttraumatic stress disorder (PTSD) has not clearly been identified as a risk factor for this condition.Method:  We accessed both a national and local database of PTSD veterans.Results:  Body mass index (BMI) was greater (P < 0.0001) among male military veterans (n = 1819) with PTSD (29.28 ± 6.09 kg/m2) than those veterans (n = 44 959) without PTSD (27.61 ± 5.99 kg/m2) in a sample of randomly selected veterans from the national database. In the local database of male military veterans with PTSD, mean BMI was in the obese range (30.00 ± 5.65) and did not vary by decade of life (P = 0.242).Conclusion:  Posttraumatic stress disorder may be a risk factor for overweight and obesity among male military veterans.
Mutual induction of noncollagenous bone proteins at the interface between epithelial cells and fibroblasts from human periodontal ligament
Authors: Shimonishi M. , Hatakeyama J. , Sasano Y. , Takahashi N. , Komatsu M. , Kikuchi M. 
Published: September 2007

Background and Objective:  Epithelial–mesenchymal interactions are responsible for cell differentiation during periodontal regeneration. The present study was undertaken to examine the expression of alkaline phosphatase and noncollagenous bone proteins, such as osteopontin, osteocalcin and bone sialoprotein, with respect to interaction between the cells of the epithelial rests of Malassez and fibroblasts from human periodontal ligament.Material and Methods:  Explants of human periodontal ligament tissues produced outgrowths containing both putative epithelial rests of Malassez cells and human periodontal ligament fibroblasts in a modified serum‐free medium. Putative epithelial rests of Malassez cells cultured alone, and human periodontal ligament fibroblasts cultured alone, were used as controls. The expression levels of amelogenin were analyzed by in situ hybridization. The expression and distribution of alkaline phosphatase and noncollagenous bone proteins in both cell populations at the interface between putative epithelial rests of Malassez cells and human periodontal ligament fibroblasts were analyzed by immunohistochemistry, in situ hybridization and reverse transcription‐polymerase chain reaction.Results:  Amelogenin mRNA was detected at high levels only in putative epithelial rests of Malassez cells at the interface. Alkaline phosphatase and bone sialoprotein mRNAs were detected significantly at the interface between putative epithelial rests of Malassez cells and human periodontal ligament fibroblast cells. In particular, bone sialoprotein and its mRNA were expressed significantly in human periodontal ligament fibroblasts at the interface between putative epithelial rests of Malassez cells and human periodontal ligament fibroblast cells. The expressions of osteopontin and its mRNA were not different between putative epithelial rests of malassez cells and human periodontal ligament fibroblasts at the interface. Osteocalcin and its mRNA were expressed strongly in putative epithelial rests of Malassez cells at the interface between putative epithelial rests of Malassez cells and human periodontal ligament fibroblasts.Conclusion:  These findings indicate that the epithelial–mesenchymal interaction modulates the expression of alkaline phosphatase, osteocalcin and bone sialoprotein in putative epithelial rests of Malassez cells and human periodontal ligament fibroblasts, suggesting that epithelial–mesenchymal interactions play a role in the maintenance of periodontal ligament.
Protective Effects of Sasanquasaponin on Injury of Endothelial Cells Induced by Anoxia and Reoxygenation in vitro
Authors: Huang Qiren , He Ming , Chen Heping , Shao Lijian , Liu Dan , Luo Yongming , Dai Yucheng 
Published: September 2007

Abstract:  The protective effects of sasanquasaponin, an effective compound from Chinese traditional herbs, on ischaemia and reperfusion injury in mouse hearts have been suggested through modulation of intracellular Cl− homeostasis. The effects of sasanquasaponin on injury of endothelial cells, however, induced by anoxia and reoxygenation remain unknown. Therefore, the present study attempted to observe the effects of sasanquasaponin on anoxia and reoxygenation injury in endothelial cells and investigate its putative mechanisms. Human umbilical vein endothelial cells (HUVECs) were exposed to normoxia or anoxia and reoxygenation in the absence or presence of sasanquasaponin (10.0, 1.0 and 0.1 µmol/l). Lactate dehydrogenase activity was determined in cultured HUVECs supernatant, and malondialdehyde content, superoxide dismutase and glutathione peroxidase activities were measured in HUVECs by a colorimetric method. Neutrophil adhesion to HUVECs was assayed colorimetrically. The levels of intercellular adhesion molecule‐1 and tumour necrosis factor‐α were detected. The activity of nuclear factor kappa B was determined by flow cytometry. The results show that sasanquasaponin decreased the lactate dehydrogenase activity and malondialdehyde contents, and inhibited the neutrophil adhesion to HUVECs; sasanquasaponin, moreover, inhibited nuclear factor kappa B transnuclear activity, lowered tumour necrosis factor‐α and intercellular adhesion molecule‐1 expression levels. On the other hand, sasanquasaponin increased the mitochondrial superoxide dismutase and glutathione peroxidase activities. It is suggested that sasanquasaponin could protect HUVECs against anoxia and reoxygenation injury, and the protective mechanisms appear to be related to anti‐lipoperoxidation and anti‐adhesion.
Combination Therapy of Rosiglitazone, a Peroxisome Proliferator‐Activated Receptor‐γ Ligand, and NMDA Receptor Antagonist (MK‐801) on Experimental Embolic Stroke in Rats
Authors: Allahtavakoli Mohammad , Shabanzadeh Alireza , Roohbakhsh Ali , Pourshanazari Aliasghar 
Published: September 2007

Abstract:  Peroxisome proliferator‐activated receptor‐γ (PPAR‐γ) agonists have been found to have potent anti‐inflammatory actions and suggested as potential therapies for brain ischaemia. Glutamate is the most common excitatory neurotransmitter in the central nervous system and is released excessively during ischaemia. Stroke therapy will require combinations of drug classes, because no single drug class has yet been proven efficacious in human beings. The present study was conducted to assess whether N‐methyl‐d‐aspartate (NMDA) receptor antagonist (MK‐801) treatment can improve recovery from ischaemic brain injury and whether rosiglitazone, a PPAR‐γ ligand, can increase its neuroprotective effect in an embolic model of stroke. Stroke was induced in rats by embolizing a preformed clot into the middle cerebral artery. Rosiglitazone (0.1 mg/kg, intraperitoneally) and MK‐801 (0.1 mg/kg, intravenously) were injected immediately after embolization. Forty‐eight hours later, the brains were removed, sectioned and stained with triphenyltetrazolum chloride and analysed by a commercial image processing software programme. Rosiglitazone and MK‐801 alone or in combination decreased infarct volume by 49.16%, 50.26% and 81.32%, respectively (P < 0.001). Moreover, the combination therapy significantly decreased the infarct volume when compared to any drug used alone (P < 0.05). MK‐801 reduced the brain oedema by 68% compared to the control group (P < 0.05), but rosiglitazone or combination did not show any significant effect. The drugs alone or in combination also demonstrated improved neurological function, but combination therapy was more effective on neurological deficits improving. Our data show that the combination of MK‐801 and rosiglitazone is more neuroprotective in thromboembolic stroke than given alone; this effect perhaps represents a possible additive effect in the brain infarction.
Ellagic Acid Prevents Cisplatin‐Induced Oxidative Stress in Liver and Heart Tissue of Rats
Authors: Yüce Abdurrauf , Ateşşahin Ahmet , Çeribaşı Ali Osman , Aksakal Mesut 
Published: September 2007

Abstract:  Cisplatin is one of the most active cytotoxic agents in the treatment of cancer. High doses of cisplatin have also been known to produce hepatotoxicity, and several studies suggest that supplemental antioxidants can reduce cisplatin‐induced hepatotoxicity. The present study was designed to determine the effects on the liver and heart oxidant/antioxidant system and the possible protective effects of ellagic acid on liver and heart toxicity induced by cisplatin. The control group received 0.9% saline; animals in the ellagic acid group received only ellagic acid (10 mg/kg); animals in the cisplatin group received only cisplatin (7 mg/kg); animals in cisplatin + ellagic acid group received ellagic acid for 10 days after cisplatin. The rats were killed at the end of the treatment period. Malondialdehyde (MDA) and glutathione (GSH) levels, glutathione‐peroxidase (GSH‐Px) and catalase (CAT) activities were determined in liver and heart tissue. While administration of cisplatin increased the MDA levels in liver and heart tissues, it decreased the GSH, GSH‐Px and CAT in these samples when compared to the control group. The administration of ellagic acid to cisplatin‐treated rats decreased the MDA levels, and increased GSH, GSH‐Px and CAT in these samples. Cisplatin caused marked damages in the histopathological status of liver and heart tissues. These damages were ameliorated by ellagic acid administration. In conclusion, ellagic acid may be used in combination with cisplatin in chemotherapy to improve cisplatin‐induced oxidative stress parameters.
EVALUATION OF FACTORS AFFECTING BARRIER, MECHANICAL AND OPTICAL PROPERTIES OF PECTIN‐BASED FILMS USING RESPONSE SURFACE METHODOLOGY
Authors: MAFTOONAZAD NEDA , RAMASWAMY HOSAHALLI S. , MARCOTTE MICHELE 
Published: September 2007

ABSTRACT Emulsion coatings were formulated and films were developed using pectin as the basic structural component. Preliminary experiments were carried out to determine the proper type and concentration of pectin, lipid and plasticizers in the film. The effects of pectin, beeswax and sorbitol concentration on water vapor permeability (WVP), mechanical properties and opacity of the films were evaluated using the response surface methodology. WVP increased by pectin and sorbitol concentration and was decreased by beeswax concentration. Mechanical properties were mainly affected by pectin and sorbitol concentration. Increasing the amount of pectin and decreasing the sorbitol concentration increased tensile strength (TS) and modulus of elasticity (EM), while elongation at break (EB) increased by increasing both pectin and sorbitol concentration. Beeswax was the most influential factor that affected opacity, which increased with increasing beeswax concentration. Models developed for WVP, EB, EM and opacity had high coefficient of multiple determination (R2) values (>0.87) and significant F values. The model for TS had a slightly lower R2 of 0.81.PRACTICAL APPLICATIONSThis research examined the preparation of pectin‐based edible films, providing an understanding of the main functionalities of these coatings. This film can help retain moisture and restrict its movement. Moisture levels in foods are critical for maintaining freshness, controlling microbial growth and providing texture. This film can control water activity, preventing either moisture loss or uptake. It can protect food from physical injuries. Since so many formulations were designed, based on the use of the film one can select each type of formulation that works best for the specific application. It can potentially limit fat migration, provide a barrier to gas, help to trap flavor and aroma, and carry and present antioxidants or antimicrobials. This article will be of value to anyone working with products where edible films have potential applications and particularly to technical personnel and product developers who wish to understand the potential of edible film and coating technology.
APPLICATION OF COEFFICIENT OF FRICTION TO THE SEPARATION OF COCOA HUSK–BEANS MIXTURE
Authors: OWOLARAFE O.K. , OGUNSINA B.S. , GBADAMOSI A.S. , FABUNMI O.O. 
Published: September 2007

ABSTRACT Investigation was carried out on the application of coefficient of friction in the separation of cocoa beans–husk mixture. An inclined plane at angles 20, 25 and 35°rotating at different speeds (215, 250 and 260 rpm) and receiving the mixture at heights 30, 60 and 90 mm, was used for the study. The result indicates that within the range of factors considered, the separation efficiency of the beans from the mixture increases with increase in speed of rotation and height of fall, while it decreases with increase in angle of inclination. Statistical analysis shows that the effects of each of the factors and that of their interaction are significant at 99%. The best separation efficiency (99%) was observed at a speed of 250 rpm, an angle of inclination of 25° and a height fall of 90 mm.PRACTICAL APPLICATIONSSeparation of cocoa beans from the husks has been a serious problem in cocoa processing. Handpicking is still being used to separate the mixture of cocoa beans–husk even with the mechanical pod breaker available. This therefore constitutes a tedious operation. An inclined plane mechanism tested for the separation of the mixture in this study can be incorporated into the design of the cocoa pod processor to reduce the drudgery involved in cocoa processing and improve the quality of the product.
CONCENTRATION BOUNDARY CONDITIONS IN THE THEORETICAL ANALYSIS OF CONVECTIVE DRYING PROCESS
Authors: KAYA AHMET , AYDIN ORHAN , DEMIRTAŞ CEVDET 
Published: September 2007

ABSTRACT In the theoretical analysis of convective drying process, two boundary conditions are common for concentration: constant concentration and convection. In this study, these two boundary conditions were comparatively examined by comparing theoretical results obtained with regard to experimental ones. Pumpkin (Cucurbita pepo) was considered as the product to be dried while air was the drying medium. The drying characteristics of pumpkin were determined for various values of drying air parameters, including temperature, velocity and relative humidity. Sorption isotherms of the dried pumpkin were also determined for different temperatures and water activities. The values of the effective moisture diffusivity, Deff, and the convective mass transfer coefficient, hm, were predicted, and these values were found to agree fairly well with those available in the existing literature. PRACTICAL APPLICATIONSConvective drying as well as other drying techniques are used in order to preserve and store agricultural products for longer periods by removing some of their moisture content. Drying is a complicated process involving simultaneous heat and mass transfer under transient conditions. Understanding the heat and mass transfer in the product will help to improve drying process parameters and hence the quality.
ELECTRICAL CONDUCTIVITY AND KINETIC PARAMETERS OF RICE STARCH
Authors: SANCHEZ E. MORALES , MARTINEZ M. GAYTAN , VEGA M.L. REYES , CARDENAS J.D.C. FIGUEROA 
Published: September 2007

ABSTRACT In the present work, rice starch was studied by differential scanning calorimetry (DSC) and electrical conductivity as a function of temperature. The gelatinization temperature was calculated using both methods. Three stages of electrical conductivity were found. When the logarithm of conductivity was plotted versus temperature, the data have been well adjusted to the linear equation, indicating that a model for conductivity may be created using an Arrhenius‐type expression to obtain kinetic parameters such as onset, peakset, endset temperatures and gelatinization energy (Eg). The conductivity Eg was calculated and compared to the enthalpy H calculated from the DSC data. It was found that Eg and enthalpy are similar processes. We conclude that electrical conductivity is an alternative method for the study of starch–water mixtures.PRACTICAL APPLICATIONSThis research provides a new methodology to obtain kinetic parameters such as temperature of the beginning, medium and ending of gelatinizaiton, which are important for determining the cooking range needed to obtain desired characteristics in a processed starch‐containing food.