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In the manufacturing of optical products, precise adjustments are made to maintain the optical axis alignment of optical components, which are then securely positioned using adhesives. To achieve positional accuracy at the micron level, it is essential to comprehend the deformation of the adhesive joint over time during processing. This study focuses on investigating the displacement of optical components resulting from the deformation of a cationic photopolymerized epoxy adhesive, which cures under ultraviolet (UV) radiation. First, the conversion of the adhesive was formulated based on a curing reaction model. This conversion can be divided into three stages: the initial reaction during UV irradiation, the subsequent dark reaction, and the reaction induced by heating. Moreover, formulations were developed to describe changes in curing shrinkage, thermal expansion, and viscoelasticity in relation to the conversion. These equations, governing the adhesive properties, were then used to perform finite element method (FEM) simulations to analyze the position of the optical component. Experimental tests on adhesively bonded components were conducted under conditions identical to those employed in the simulation. Throughout the curing process of the adhesive, the optical component was continuously imaged using a coherence-scanning interferometer, enabling the quantification of its displacement from the acquired images. The results of the FEM simulation and experimental analysis exhibited a consistent trend, indicating the effectiveness of the modeling and simulation methods employed in this study. The majority of the displacement of the optical component occurred over several hours during the dark reaction stage, rather than during UV irradiation. Notably, the movement of the optical component was not limited solely to the thickness direction of the adhesive layer because of curing shrinkage but also extends to the in-plane direction because of the non-uniform distribution of the UV irradiation intensity. [ABSTRACT FROM AUTHOR]

In this study, the relationship between the energy release rate (G1C), crack propagation rate (da/dN), and the fracture morphology of specimens with deteriorated adhesives after moisture absorption were investigated through the double cantilever beam (DCB) method. The specimens were prepared using a thermosetting epoxy adhesive based on compound carboxyl-terminated butadiene–nitrile rubber and Al 6061-T6 adherends. To accelerate the deterioration of the adhesives, open-faced specimens were immersed in water at 63°C at varying durations. Prior to the assembly of the DCB specimens, the adherends were either treated using acidic solutions or sand blasted. Consequently, the effect of the moisture deterioration of adhesive and the surface treatment performed on the adherend on the fracture morphology was studied. Furthermore, the relationship between G1C and da/dN was systematically investigated. At a constant crack opening speed, the failure mode changed from cohesive to interfacial fracture, and then reverted back cohesive fracture as the deterioration of the specimens progressed due to increasing immersion time. Interfacial fracture was not observed for the specimens with sandblasted adherends. Lastly, a decrease in da/dN was not observed even with increasing G1C values of the immersed specimens because interfacial fracture was easy to occur when the cyclic strains were applied. [ABSTRACT FROM AUTHOR]

Double lap joints were prepared using epoxy adhesive and aluminum plates, and their high-temperature strength properties were studied. Tensile, thermal aging, creep, and cyclic fatigue tests were performed to systematically investigate the effects of the aging temperature, testing temperature, stress waveform, and stress ratio on the strength and fracture morphology of the double lap joints. When the specimen was exposed to 135°C, the strength decreased significantly. Also, the relationship between the test temperature and shear strength could be expressed using an equation obtained from thermal activation theory. Additionally, in the fatigue test at room temperature, the strength of the specimen subjected to constant stress was higher than that of the specimen subjected to cyclic strain. The effect of creep deformation increased in the creep test at high temperatures, and therefore, the strength decreased significantly. [ABSTRACT FROM AUTHOR]

Optical components are often adjusted to maintain their alignment along the optical axis. They are fixed at their optimal positions particularly using ultraviolet (UV) ray-curable adhesives. To achieve a micron-level positional accuracy, it is necessary to understand adhesive shrinkage while curing and the resulting deformation of the adhesive joint. However, it is challenging to perform a quantitative evaluation of the cure shrinkage and mechanical properties of adhesives given the process complexity and strong dependence on curing conditions. Therefore, this study clarified the effects of various curing conditions on the curing extent of an adhesive under UV curing for positioning and heat curing as a post-curing process. The cure shrinkage, coefficient of thermal expansion, and viscoelastic properties of the adhesive were also measured. Each material property could be defined as a function of the curing extent to predict the changes in the properties under different curing conditions. The adhesive curing process was divided into three stages: adhesive gelation under UV irradiation, fast reaction stage under heating, and slow reaction stage under heating. The adhesive state changed from viscous to viscoelastic to elastic as it cured, and this process proceeded in the aforementioned three stages. Three different formulae were fitted corresponding to each stage, with good agreement with the experimental measurements. [ABSTRACT FROM AUTHOR]

Context: Habitat loss and fragmentation can interact with other threats, including altered fire regimes, and responses to these effects can be mediated by functional traits. Objectives: To determine how richness and abundance of reptile trait groups respond to habitat fragmentation, patch isolation and fire. Methods: We surveyed reptiles in 30 sites over 3 years. Sites in remnant patches in farmland were adjacent to a conservation park with either recently burnt or long-unburnt habitat. The remnant patches were stratified by distance from the reserve. Sites were spatially paired, and we experimentally burnt one of each pair in farmland. Trait groups included size, reproduction, habitat position, diet, and activity period. Results: None of the trait groups benefited from experimental burns, while the burns reduced abundance of viviparous, small, and above-ground species. Species richness was lower in isolated sites than in sites close to the conservation park, while generalist trait groups appeared unaffected by patch isolation. Large-sized reptiles had higher abundance in remnants. There was not more rapid colonisation of burnt sites near recently burnt conservation park. Instead, low initial abundance may have been caused by fire in combination with drought, with high rainfall during the study allowing recovery and spill-over into adjacent remnants. Conclusions: Landscape structure appears to interact with natural fires, restoration burns and longer-term climatic trends to influence the abundance and distribution of reptiles. Traits mediate responses, enabling us to formulate a set of testable mechanistic hypotheses, which illustrates a pathway to generalisation and prediction. [ABSTRACT FROM AUTHOR]

The effect of cyclic moisture-absorption/desorption on adhesive strength was investigated using water at 23°C. Bulk plates and open face lap joints were prepared using epoxy adhesive, and their weight transition and shear strength were measured. The diffusion coefficient of the absorption process increased with the number of cycles and reached a constant value. In contrast, the diffusion coefficient of the desorption process was not affected by the number of cycles. As a part of the calcium carbonate disappeared from the surface, the weight of the bulk plates was reduced, and this weight reduction was irreversible. However, the strength of the lap joint was not significantly damaged by moisture absorption at 23°C. [ABSTRACT FROM AUTHOR]

This article discusses the effectiveness of endoscopic hand suturing (EHS) in preventing postoperative bleeding in patients undergoing gastric endoscopic submucosal dissection (ESD). Postoperative bleeding is a common complication of ESD, especially in patients taking antithrombotic agents (ATAs). The study found that EHS, which involves suturing the mucosal defect using a flexible needle holder and absorbable barbed suture, was successful in preventing bleeding in high-risk patients. Further studies are needed to confirm the efficacy of this technique. [Extracted from the article]

The effect of strain rate on the mechanical properties of two epoxy adhesives was investigated by conducting experiments on dumbbell-shaped specimens prepared from the adhesives. The tensile rate was changed stepwise from 5.2 × 10–5 to 1.2 × 106 mm/min, and the yield stress, Young's modulus, elongation, and tensile strength were evaluated. The yield stress and tensile strength showed a clear dependence on the strain rate. The results from this study allowed us to propose a procedure for predicting the creep strength and high-rate impact strength from the results of a simple tensile test. [ABSTRACT FROM AUTHOR]

The application of primer is one of the most widely used pre-treatments to improve adhesion. However, few studies on the adhesive mechanism have investigated the effect of the organic solvent used for the primer on the improving of adhesion strength. In this study, attenuated total reflection infrared spectroscopy was performed to evaluate the interphases of multiple primers with different organic solvents for dilution. The main conclusion of this work is that the interphase thickness depends on the relative permittivity and viscosity of the organic solvent used for the primer. [ABSTRACT FROM AUTHOR]

Adhesive properties are often affected by water. In this study, to clarify the water-resistant properties of a thermosetting epoxy adhesive containing dicyandiamide (DICY) and carboxyl-terminated butadiene acrylonitrile rubber (CTBN), immersion tests of open-faced specimens and bulk specimens in water were performed, and the changes in the properties were investigated in terms of chemistry and mechanical strength. After immersing the open-faced specimens in water, the mechanical strengths were evaluated by two different methods: interfacial cutting method and secondary bonding method. Using both methods, a decrease in strength with immersion time was obtained, and the tendencies of the strength change were found to be very similar for the different evaluation methods. Chemical changes were also evaluated by infrared spectroscopy. Through periodical measurements of the infrared spectra of a fully-cured bulk adhesive specimen during water immersion, the chemical degradation of the epoxy adhesive containing DICY and CTBN was investigated, revealing an association with the change in mechanical strength in which hydrolysis of the cyano groups in DICY and CTBN led to a decrease in strength. Strength recovery experiments were also conducted by drying the specimens after water immersion, determining that the mechanical recovery strength changed with water temperature and immersion time. [ABSTRACT FROM AUTHOR]

Conventional test methods to evaluate the water resistance of adhesive joints are time-consuming. To reduce experimental time, open-faced specimens have been proposed. Numerical analysis indicated that the water absorption of an open-faced specimen was 3000 times faster than that of a conventional closed specimen. The strength of the interface between the adhesive and the adherend of the open-faced specimen was measured using the interfacial cutting method in this research. The resultant strength decreased with respect to immersion time in water, and this trend accelerated with an increase in the water temperature. When water was absorbed at temperatures below the glass transition temperature (Tg) of the adhesives, the strength was constant at 80–90% of the initial value in the first stage, and it decreased proportionally with logarithmic immersion time in the following stage. At water absorption above Tg, the interfacial strength initially proportionally decreased with the logarithmic immersion time. After the initial absorption, the slopes changed, and the strength slowly decreased. After further immersion for 59 days at 87°C, a sharp decrease in strength occurred. The reducing behaviour of the interfacial strength fitted the Arrhenius plot, which provided the estimated time to reach a specific strength by water immersion. [ABSTRACT FROM AUTHOR]

The improvement in adhesion technology for joining different types of materials has led to expectations of weight reduction in cars and commercial vehicles. Various levels of stress and stress ratios are loaded onto the joints of such transport vehicles. Therefore, the fatigue shear strength of an adhesive lap joint is important. This study is related to the fatigue properties of structural adhesive joints. Lap-joint specimens using epoxy adhesive were prepared, and fatigue tests with four different stress ratios were conducted. Subsequently, the fatigue limit diagram was plotted, and the effect of stress ratio on the fatigue limit was investigated. Moreover, the strength of the specimens subjected to various cyclic stress levels was investigated systemically. With cyclic shear stress, the influence of the shear stress amplitude on the resistance to fatigue failure was more significant than that of the number of cycles. The specimens that endured the fatigue tests maintained approximately the same shear strength as that of the as-received specimens. The findings of this study can provide important guidance for the design of a car body. [ABSTRACT FROM AUTHOR]

Surface contamination of an adherend has an influence on its adhesive bonding properties. To investigate this phenomenon, various contaminants, including silicone oil, mineral oil, a fluorine release agent, and surfactants, were quantitatively applied to an aluminium plate (6061) using a spray apparatus. The contaminated adherends were bonded with acrylic and epoxy adhesives, and their adhesion strengths were examined using single lap-shear tests. Mineral oil did not affect the adhesion strength, but silicone oil and surfactant agents were found to significantly affect the adhesion strength. Atomic force microscopy observations and Fourier transform infrared spectroscopy of these surfaces revealed a specific interaction between silicone oil and aluminium. [ABSTRACT FROM AUTHOR]

Background: Hemotherapy in ruminants is limited to whole blood transfusions, sometimes with stored blood for up to 42 days, but little attention has been given to the effect of blood storage times and recipient responses after transfusions. Objectives: We aimed to evaluate the hematologic and serum biochemical effects after allogeneic blood transfusion with either fresh or stored blood in sheep. We also sought to examine hematologic and biochemical analyte changes in the store blood. Methods: Eighteen sheep underwent a single phlebotomy to remove 40% of their blood volume. The sheep were divided into three experimental groups, G0, G15, and G35, which included six animals, each receiving 20 mL/kg of either fresh blood or blood stored in citrate, phosphate, dextrose, and adenine (CPDA‐1) bags for 15 and 35 days, respectively. Biochemical, hematologic, coagulation, blood gas, lipid peroxidation, and oxidative stress test evaluations were performed using the blood samples gathered at T0 (before transfusion), 30 minutes (T30m), 6, 12, 24, 48, 72, and 96 hours (T6h‐T96h), 8 days (T8d), and 16 days (T16d) after transfusions. Results: Sheep exhibited increases in packed cell volumes, red blood cell counts, and total hemoglobin concentrations at T30m (P <.05). G35 animals had greater plasma hemoglobin concentrations at T12h and decreased blood pH values at T6h, characterized by slight metabolic acidemia. Regarding oxidative stress, G35 animals had decreased catalase activities from T0 at T30m, T6h, T12h, and T24h, indicating that hemolysis had occurred, which was supported by concomitant increases in bilirubin. Conclusions: Sheep transfused with 35‐day stored blood exhibited greater hematologic, blood gas, biochemical, and oxidative alterations; however, anemic animals without comorbidities effectively reversed those alterations. [ABSTRACT FROM AUTHOR]

The wide and diverse application of adhesives in the automotive industry has increased over the last decades, driven by the need to produce efficient yet strong vehicles, able to meet both fuel economy and safety standards. This method allows to bond a variety of dissimilar materials used for structural parts, as well as to achieve lighter structures, and higher failure loads over other traditional methods such as fastening or welding. It is therefore important to understand the behaviour of adhesives under a wide range of strain rates and temperatures. These data are fundamental to ensure vehicle safety, as adhesives must be able to sustain impact conditions, deforming but at the same time keeping the integrity of the structure and transmitting the loads without damaging the joint. The aim and novelty of this work is the complete mechanical characterization of a high-performance crash resistant adhesive under varied strain rate and temperature conditions, necessary for the validation of structures used in the automotive industry. The mechanical behaviour of these materials is still poorly understood and described in the literature. The results showed a change in the mechanical properties of the adhesive with the variation of strain rate (quasi-static and impact of 3 m/s) and temperature (−30, 24 and 80 ℃). With the mechanical properties determined it was possible to define cohesive laws for implementation in finite element simulation, as a function of strain rate and temperature. [ABSTRACT FROM AUTHOR]

This article discusses the mechanism of nematic liquid crystal alignment in stretched porous polymer films. The polymer films were formed by extreme stretching of an isotropic porous polyolefin, such that the draw ratio was 12:1. A 6-μm-thick porous film with a high porosity coefficient of 92% revealed fine string-shaped areas that exhibited optical anisotropy due to their possessing a high degree of molecular alignment. The porous film was filled with nematic liquid crystal and then the composite film was sandwiched between transparent electrodes coated onto glass substrates, without the use of conventional alignment layers. From polarizing microscopy observations it was found that the string-like polymer areas induce liquid crystal molecular alignment. The liquid crystal cells can exhibit an electrically controlled birefringence effect. This alignment technique enables us to realize three-dimensional control of liquid crystal alignment. © 2003 American Institute of Physics. [ABSTRACT FROM AUTHOR]

A method for fabricating adhesively bonded joints with graded properties along the bond-line was proposed. By utilizing two types of acrylic adhesives, one hard and the other soft, the properties of the mixture were changed by controlling the mixing ratio. An applicator for the adhesives was developed and used for the experiments, in which property-graded adhesive layers were actually produced. The properties, i.e., stress-strain curves at various points of the property-graded adhesive layer, were experimentally measured, and the validity of the proposed method was confirmed. The Young's moduli at multiple points of the adhesive layer changed from 34.7 MPa to 634 MPa by changing the mixing ratio of the adhesives. [ABSTRACT FROM AUTHOR]

The high-speed liquid (water) jet has distinctive characteristics in surgical applications, such as tissue dissection without thermal damage and small blood vessel preservation, that make it advantageous over more conventional instruments. The continuous pressurized jet has been used since the first medical application of water jets to liver surgery in the 1980s, but exhibited drawbacks partly related to the excess water supply required and unsuitability for application to microsurgical instruments intended for deep, narrow lesions (endoscopic instrumentation and catheters) due to limitations in miniaturization of the device. To solve these issues, we initiated work on the pulsed micro-liquid jet. The idea of the pulsed micro-liquid jet originated from the observation of tissue damage by shock/bubble interactions during extracorporeal shock wave lithotripsy and evolved into experimental application for recanalization of cerebral embolisms in the 1990s. The original method of generating the liquid jet was based on air bubble formation and microexplosives as the shock wave source, and as such could not be applied clinically. The air bubble was replaced by a holmium:yttrium-aluminum-garnet (Ho:YAG) laser-induced bubble. Finally, the system was simplified and the liquid jet was generated via irradiation from the Ho:YAG laser within a liquid-filled tubular structure. A series of investigations revealed that this pulsed laser-induced liquid jet (LILJ) system has equivalent dissection and blood vessel preservation characteristics, but the amount of liquid usage has been reduced to less than 2 $$\upmu $$ l per shot and can easily be incorporated into microsurgical, endoscopic, and catheter devices. As a first step in human clinical studies, we have applied the LILJ system for the treatment of skull base tumors through the transsphenoidal approach in 9 patients (7 pituitary adenomas and 2 chordomas), supratentorial glioma (all high grade glioma) in 8 patients, including one with fine perforating vessel involvement, and cerebrovascular disease (1 arteriovenous malformation and 2 intracerebral hemorrhages) in 3 patients. Precise dissection and mass reduction of the tumor were obtained in all tumor cases except for one chordoma with significant fibrosis. Small arteries down to 100 $$\upmu \hbox {m}$$ were preserved, allowing subsequent microsurgical devascularization. Veins were also preserved occasionally. The arachnoid membrane and the tumor capsule were resistant to the LILJ except for one case with prolonged exposure. No complications related to use of the LILJ system were observed. No disturbance of the surgical field by splashing, aerosol, or dissemination of pathological tissue occurred with placement of the optimal suction system. The Ho:YAG LILJ system enhances the advantages of commercialized pressure-driven continuous liquid jet instrumentation in terms of small vessel preservation and accessibility in confined spaces for minimally invasive neurosurgery, and solves some of the drawbacks involved with excessive liquid use and size. [ABSTRACT FROM AUTHOR]

A novel method to manufacture functionally graded adhesive joints that is easier to implement than previous methods is proposed and investigated in this study. For this method, a mixture of two adhesives, one that is rigid and brittle and one that is flexible, was applied to adherends with various mixing ratios. Second generation acrylic adhesives (SGAs) were used in this study because they can be cured at a wide range of mixing ratios. To evaluate the mechanical properties of the resulting adhesive mixtures, bulk specimens with different mixing ratios were prepared and tested. Each of the adhesives had two components (e.g., agents A and B), with similar chemical compositions, but agent A includes an oxidizer, and agent B includes a reducer. Thus, mixing of both agents A does not produce any chemical reaction and similarly for agents B; this property enabled us to perform honeymoon adhesion. A mixture of agents A was applied to the surface of an adherend, and a mixture of agents B was applied to that of the other adherend at various mixing ratios. Then, one of the adherends was placed onto the other to make a joint. After the joint cured, the hardness of the adhesive layer was evaluated at certain points on the surface using nano-indentation to verify the applicability of the proposed method. Based on bulk tensile tests, it was concluded that the mechanical properties of SGAs could be controlled by changing the mixing ratio of the SGAs. In addition, the results of the hardness test of the adhesive layer, which corresponds to the Young’s modulus of the material, depended strongly on the mixing ratio of adhesive. [ABSTRACT FROM PUBLISHER]

Thermal effects on welded joints between fiber-reinforced thermoplastics (FRTPs) and metals have been investigated theoretically and experimentally. Because FRTPs use thermoplastics as the matrix resin, they have advantages over fiber-reinforced thermoset plastics (FRPs or FRSPs), including the ability to be welded. When dissimilar materials are welded together, however, thermal stress occurs due to the different thermal expansions of the materials and affects the energy release rate of the joint. Therefore, a method for evaluating the true energy release rate, including the effect of thermal stress, is necessary for strength evaluation tests. Although several theories that compensate for the thermal stress and evaluate the true energy release rate have already been proposed, they require parameters that are difficult to measure. Therefore, it is difficult to apply them in experimental investigations. In this article, a theoretical method with easily measurable parameters is proposed to calculate the energy release rate of welded double cantilever beam (DCB) joints. The effect of the thermal stress on the critical energy release rate is discussed in terms of the experimental results of a welded DCB specimen composed of a FRTP and an aluminum alloy. [ABSTRACT FROM AUTHOR]

Herbivory and fire are two disturbances that often co-occur, but studies of their interactive effects are rare outside of grassland ecosystems. We experimentally tested the interactive effects of prescribed fire and macropod herbivory on forest understory vegetation and its vertebrate fauna. Fire and herbivory interacted synergistically to affect forest understory vegetation, with palatable plants showing poor post-fire recovery in unfenced sites compared with herbivore exclusion sites. Despite this strong interactive effect on vegetation, small vertebrates responded to the individual, and not the interactive effects of disturbance. The native insectivorous mammal A ntechinus stuartii was more frequently encountered on large herbivore exclusion sites, as was the introduced European rabbit. In contrast, the small skink L ampropholis delicata was more common on sites with high densities of large herbivores. Skinks, snakes and European rabbits were also more active on burnt than unburnt sites. Our results suggest that it may be necessary to manage the macropod herbivore population after fire to prevent the decline of palatable plants, and maintain the dense habitat required by some small mammals. However, as the invasive rabbit was most active in macropod-free sites after fire, any management must include control of both types of herbivores. A mix of understory densities may also need to be maintained to ensure the persistence of species preferring more open habitats. Our study demonstrates that interactive effects of disturbance on vegetation communities may not lead to predictable effects on animals, and highlights the importance of considering both multiple stressors, and multiple species, in the management of disturbance regimes. [ABSTRACT FROM AUTHOR]

Alpine-subalpine areas are sensitive environments that support large numbers of endemic species. They are also popular for human recreation. Increasing demands for tourism means that infrastructure in alpine resorts is expanding. Consequently, habitat is being modified and fragmented, potentially adversely affecting fauna. However, research investigating the effects of ski resorts on wildlife, particularly reptiles, is limited, and the effectiveness of management strategies in mitigating adverse impacts is unknown. To quantify the effects of ski-related disturbances on specialist and generalist reptile species, we surveyed sites in disturbed and undisturbed subalpine habitats. We also examined vegetation composition and habitat structure to determine whether structural or compositional habitat features were driving patterns of reptile occurrence. Our results indicate that the effects of ski-related disturbance varied between species, but that adverse effects - particularly on ski runs - were more pronounced for specialists. Given that each species studied was positively associated with compositional or structural features of the environment, we argue that alterations to these habitat attributes when creating ski runs will suppress lizard abundances in these areas. However, while ski runs have an adverse effect on reptiles, the persistence of these animals in ski resorts can be facilitated by retaining habitat structure and minimizing disturbance to native vegetation. [ABSTRACT FROM AUTHOR]

Hydrogen peroxide is an oxidative agent commonly used for dental bleaching procedures. The structural and biochemical responses of enamel, dentin, and pulp tissues to the in vivo bleaching of human (n = 20) premolars were investigated in this study. Atomic force microscopy (AFM) was used to observe enamel nanostructure. The chemical composition of enamel and dentin was analyzed by infrared spectroscopy (FTIR). The enzymatic activities of dental cathepsin B and matrix metalloproteinases (MMPs) were monitored with fluorogenic substrates. The amount of collagen in dentin was measured by emission of collagen autofluorescence with confocal fluorescence microscopy. The presence of Reactive Oxygen Species (ROS) in the pulp was evaluated with a fluorogenic 2′,7′-dichlorodihydrofluorescein diacetate (DCFDA) probe. Vital bleaching of teeth significantly altered all tested parameters: AFM images revealed a corrosion of surface enamel nanostructure; FTIR analysis showed a loss of carbonate and proteins from enamel and dentin, along with an increase in the proteolytic activity of cathepsin-B and MMPs; and there was a reduction in the autofluorescence of collagen and an increase in both cathepsin-B activity and ROS in pulp tissues. Together, these results indicate that 35% hydrogen peroxide used in clinical bleaching protocols dramatically alters the structural and biochemical properties of dental hard and soft pulp tissue. [ABSTRACT FROM PUBLISHER]

To determine the effect of denaturants [guanidine hydrochloride (GdnHCl) and urea] and polyols [with various molecular masses (62.1-600)] on calcium binding at the two hypothesized conformers (A and B forms) of the chemically equivalent sarcoplasmic reticulum Ca(2+)-ATPase, which bind two calcium ions in different manners, we examined the effect of these reagents on the calcium dependence of ATP-supported phosphorylation of the ATPase molecules and of their calcium-activated, acetyl phosphatate hydrolytic activity. (1) GdnHCl (~0.05 M) and urea (~0.5 M) increased the apparent calcium affinity (K (0.5)) of 2-6 μM of noncooperative binding [Hill coefficient (n (H)) ~ 1] of the A form to 10-40 μM. (2) The employed polyols transformed the binding of the A form into cooperative binding (n (H) ~ 2), accompanying the approach of its K (0.5) value to that (K (0.5) = 0.04-0.2 μM) of the cooperative binding (n (H) ~ 2) of the B form; the transition concentration (0.025-2 M) of the polyols, above which such transformation occurs, was in inverse relation to their molecular mass. (3) The binding of the B form was resistant to these denaturants and polyols. Based on these data, a structural model of the two forms, calcium-binding domains of which are loosely and compactly folded, is presented. [ABSTRACT FROM AUTHOR]

Inflammatory process is involved in the pathogenesis of diabetic nephropathy. In this article, we show that cholecystokinin (CCK) is expressed in the kidney and exerts renoprotective effects through its anti-inflammatory actions. DNA microarray showed that CCK was upregulated in the kidney of diabetic wild-type (WT) mice but not in diabetic intracellular adhesion molecule-1 knockout mice. We induced diabetes in CCK-1 receptor (CCK-1R) and CCK-2R double-knockout (CCK-1R(-/-),-2R(-/-)) mice, and furthermore, we performed a bone marrow transplantation study using CCK-1R(-/-) mice to determine the role of CCK-1R on macrophages in the diabetic kidney. Diabetic CCK-1R(-/-),-2R(-/-) mice revealed enhanced albuminuria and inflammation in the kidney compared with diabetic WT mice. In addition, diabetic WT mice with CCK-1R(-/-) bone marrow-derived cells developed more albuminuria than diabetic CCK-1R(-/-) mice with WT bone marrow-derived cells. Administration of sulfated cholecystokinin octapeptide (CCK-8S) ameliorated albuminuria, podocyte loss, expression of proinflammatory genes, and infiltration of macrophages in the kidneys of diabetic rats. Furthermore, CCK-8S inhibited both expression of tumor necrosis factor-α and chemotaxis in cultured THP-1 cells. These results suggest that CCK suppresses the activation of macrophage and expression of proinflammatory genes in diabetic kidney. Our findings may provide a novel strategy of therapy for the early stage of diabetic nephropathy. [ABSTRACT FROM AUTHOR]

We describe a 62-year-old woman with advanced chronic hepatitis C who showed no response to low-dose long-term interferon-beta monotherapy (3 MU, three times a week). The interferon monotherapy was continued for 2 years and 9 months. Despite this lack of response to interferon, the patient's clinical course was good and liver function assessed by (99m)Tc-galactosyl human serum albumin single photon emission computed tomography ((99m)Tc-GSA SPECT) analysis improved significantly. Improvement of the data obtained by (99m)Tc-GSA SPECT analysis justified continuation of the treatment. (99m)Tc-GSA SPECT analysis was clinically useful to evaluate the effect of interferon in a patient with interferon non-responsive chronic hepatitis C, despite a lack of reduction of the ALT level and HCV-RNA titer. [ABSTRACT FROM AUTHOR]

ims/hypothesis: Glucagon-like peptide-1 (GLP-1) has various extra-pancreatic actions, in addition to its enhancement of insulin secretion from pancreatic beta cells. The GLP-1 receptor is produced in kidney tissue. However, the direct effect of GLP-1 on diabetic nephropathy remains unclear. Here we demonstrate that a GLP-1 receptor agonist, exendin-4, exerts renoprotective effects through its anti-inflammatory action via the GLP-1 receptor without lowering blood glucose. Methods: We administered exendin-4 at 10 μg/kg body weight daily for 8 weeks to a streptozotocin-induced rat model of type 1 diabetes and evaluated their urinary albumin excretion, metabolic data, histology and morphometry. We also examined the direct effects of exendin-4 on glomerular endothelial cells and macrophages in vitro. Results: Exendin-4 ameliorated albuminuria, glomerular hyperfiltration, glomerular hypertrophy and mesangial matrix expansion in the diabetic rats without changing blood pressure or body weight. Exendin-4 also prevented macrophage infiltration, and decreased protein levels of intercellular adhesion molecule-1 (ICAM-1) and type IV collagen, as well as decreasing oxidative stress and nuclear factor-κB activation in kidney tissue. In addition, we found that the GLP-1 receptor was produced on monocytes/macrophages and glomerular endothelial cells. We demonstrated that in vitro exendin-4 acted directly on the GLP-1 receptor, and attenuated release of pro-inflammatory cytokines from macrophages and ICAM-1 production on glomerular endothelial cells. Conclusions/interpretation: These results indicate that GLP-1 receptor agonists may prevent disease progression in the early stage of diabetic nephropathy through direct effects on the GLP-1 receptor in kidney tissue. [ABSTRACT FROM AUTHOR]

Objective: Activation of the nuclear hormone receptor peroxisome proliferator-activated receptor (PPAR)-δ has been shown to improve insulin resistance, adiposity, and plasma HDL levels. Several studies have reported that activation of PPARδ is atheroprotective; however, the role of PPARδ in renal function remains unclear. Here, we report the renoprotective effects of PPARδ activation in a model of streptozotocin-induced diabetic nephropathy.Research Design and Methods: Eight-week-old male C57BL/6 mice were divided into three groups: 1) nondiabetic control mice, 2) diabetic mice, and 3) diabetic mice treated with the PPARδ agonist GW0742 (1 mg/kg/day). GW0742 was administered by gavage for 8 weeks after inducing diabetes.Results: GW0742 decreased urinary albumin excretion without altering blood glucose levels. Macrophage infiltration, mesangial matrix accumulation, and type IV collagen deposition were substantially attenuated by GW0742. The gene expression of inflammatory mediators in the kidney cortex, such as monocyte chemoattractant protein-1 (MCP-1) and osteopontin (OPN), was also suppressed. In vitro studies demonstrated that PPARδ activation increased the expression of anti-inflammatory corepressor B-cell lymphoma-6, which subsequently suppressed MCP-1 and OPN expression.Conclusions: These findings uncover a previously unrecognized mechanism for the renoprotective effects of PPARδ agonists and support the concept that PPARδ agonists may offer a novel therapeutic approach for the treatment of diabetic nephropathy. [ABSTRACT FROM AUTHOR]

Aim: We aimed to clarify the relationship between assertiveness and burnout among nurse managers at university hospitals. Methods: The directors at three university hospitals agreed to cooperate with our study. During a one-month period from May to June 2007, a self-administered questionnaire was distributed to 203 nurse managers (head and sub-head nurses). The Japanese version of the Rathus Assertiveness Schedule (J-RAS) and the Japanese version of the Maslach Burnout Inventory (MBI) were used as scales. Burnout was operationally defined as a total MBI score in the highest tertile. Results: Valid responses were obtained from 172 nurse managers. The mean J-RAS score of the burnout group (-14.3) was significantly lower than that of the non-burnout group (-3.3). Responses about work experience and age showed no significant group difference. Total MBI score was inversely correlated with J-RAS score (R = -0.30, P < 0.01). Multiple logistic regression analyses indicated a decrease in the risk of burnout by 26% (0.74 times) for every 10 point increase in the J-RAS score, and by 60% (0.40 times) for greater satisfaction with own care provision. Conclusions: The results suggest that increasing assertiveness and satisfaction with own care provision contributes to preventing burnout among Japanese nurse managers. [ABSTRACT FROM AUTHOR]

This paper presents the experimental results of high-speed tests using PVB sheets and PVB laminated glass. PVB showed a non-linear visco-elastic property in the low-speed tests. The non-linear visco-elastic property could be described using a simple spring-dashpot model including a non-linear spring. The visco-elastic parameters were determined by comparing the experimentally obtained stress-strain curves to the simulated model in which the various visco-elastic parameters are used. The strain-stress curves of PVB under high strain rates are elasto-plastic and those under the low strain rates are non-linear visco-elastic. The phenomenon can be explained from the phase transition from rubbery phase to glassy phase. Considering the results of PVB tensile tests, a simple fracture-mechanical model of PVB laminated glass was formulated to determine energy release rate G. Fracture toughness GC of the PVB laminated glass specimens were calculated from both the experimental results and the energy release rate. Potential energy UC was defined and also compared to the fracture toughness. Nevertheless, the critical loads increase with respect to the increase of tensile speed; potential energy and the fracture toughness remain the same order in all of the chosen tensile speeds. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the effects of various 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors (statins) on ectopic osteoinduction by recombinant human bone morphogenetic protein-2 (rhBMP-2) using different administration methods. Materials and methods: Disks containing 5 μg of rhBMP-2 and type I collagen were implanted into the calf muscles of 6-week-old male rats ( n = 64). Either the lactone form of simvastatin (SV), open hydroxy-acid form of simvastatin (SVA), cerivastatin (CVA), or vehicle (control) was then administered per orally (PO group) or subcutaneously (SC group) for 20 days. The disks were removed on day 21 after implantation, and ectopic induced bone formation was evaluated by radiographic, histologic, and biochemical analysis. Results: Both the projected and radiopaque area on X-ray film, and the calcium content of the SV group in the SC group (SV–SC group) were significantly greater than those in the other SC and PO groups. Alkaline phosphatase activity and tartrate-resistant acid phosphatase activity in the SV–SC group were significantly lower than those in the other SC and PO groups. Histologic examination revealed an increase of ectopic induced bone volume in the SV–SC group. Conclusion: Subcutaneous administration of SV stimulates ectopic osteoinduction by rhBMP-2 through reduction of bone turnover. [ABSTRACT FROM AUTHOR]

Long-term or high-dosel-DOPA therapy in patients with Parkinson's disease (PD) may accelerate degeneration of dopaminergic neurons, possibly by increasing oxidative stress. To investigate the effects of cabergoline on peroxynitrite-mediated oxidative damage caused byl-DOPA, the concentration of 3-nitrotyrosine in cerebrospinal fluid (CSF) of 18 PD patients was compared with that in 20 normal controls. The concentration of 3-nitrotyrosine in patients followingl-DOPA therapy was significantly higher than in untreated PD patients and controls. On the other hand, the concentration in PD patients after cabergoline therapy was significantly lower than in PD patients afterl-DOPA therapy alone. These data suggest that cabergoline scavenges peroxynitrite induced byl-DOPA in patients with PD. [ABSTRACT FROM AUTHOR]

This research aimed to examine whether early discharge can be performed by nurses of a ward participating in the process of critical path method supporting with offer and evaluation of standard and efficient medical treatments and nursing cares. In order to enrich the system that performs hospitable medical treatment and nursing cares standardized at the psychiatry acute term and to prevent chronic, critical path method was introduced into the acute term ward, then the investigation for nursing job satisfaction that was important to establish critical path method was conducted. By introducing critical path method, it became possible to assess the patients in standard, and the subject of business or a system became clear towards early discharge. It became possible to tie up this subject to a future improvement. Consequently, as for comparison of the patient who applied the schedule table of critical path method at the first and second term, the latter decreased the average length of hospitalization period significantly. The satisfaction of the task requirement, which was important to maintain systems, was decreased by the introduction of critical path method but the score of autonomy in satisfaction increased significantly by the improvement of usage of critical path method. From these, it was suggested that the introduction of critical path method in the acute-care unit psychiatry had possibility to aim at standardization of treatment and nursing and patients' early discharge from hospitals. [ABSTRACT FROM AUTHOR]

In hepatitis C virus (HCV) genotype 2b infection, viral eradication (sustained viral response; sVR) is obtained in about 40% by interferon monotherapy, whereas a considerable proportion of non-sVR patients exhibit sustained biochemical response (sBR) showing normal biochemical values despite persistent viraemia. However, the mechanism of sBR has not yet been established. In this study, we analysed serial changes in full-length sequences of HCV genotype 2b before and after interferon (IFN) therapy in five patients with sBR and five with no response (NR; persistent viraemia and abnormal biochemical values after IFN therapy). The overall substitution rate of amino acids in the full-length HCV genome was higher in the sBR group than in the NR group [2.22 ± 0.48 (10−3 changes/site/year)vs1.04 ± 0.30:P = 0.002]. When the genetic changes were analysed for individual HCV proteins, the sBR group had significantly higher substitution rates of amino acid in NS4A [8.82 ± 2.80 (10−3 changes/site/year)vs0:P = 0.001]. These amino acid changes in sBR were mainly located in the binding motifs of HLA class I molecules including those frequently found in the Japanese population. These results demonstrated that the greater amino acid changes of HCV arising during interferon therapy are associated with the establishment of sBR. Although functional significance of these changes awaits further investigation, the finding that amino acid changes in NS4A in sBR patients are mainly located in the HLA class I binding motifs illustrated the potential roles of the escape mutations of HCV genome from CTLs in the decreasing activities of hepatitis in sBR. [ABSTRACT FROM AUTHOR]

The one-domain voltage-gated sodium channel ofBacillus halodurans(NaChBac) is composed of six transmembrane segments (S1-S6) comprising a pore-forming region flanked by segments S5 and S6 and a voltage-sensing element composed of segment S4. To investigate the role of the S4 segment in NaChBac channel activation, we used the cysteine mutagenesis approach where the positive charges of single and multiple arginine (R) residues of the S4 segment were replaced by the neutrally charged amino acid cysteine (C). To determine whether it was the arginine residue itself or its positive charge that was involved in channel activation, arginine to lysine (R to K) mutations were constructed. Wild-type (WT) and mutant NaChBac channels were expressed in tsA201 cells and Na+ currents were recorded using the whole-cell configuration of the patch-clamp technique. The current/voltage (I-V) and conductance/voltage (G-V) relationships steady-state inactivation (h8) and recovery from inactivation were evaluated to determine the effects of the S4 mutations on the biophysical properties of the NaChBac channel. R to C on the S4 segment resulted in a slowing of both activation and inactivation kinetics. Charge neutralization of arginine residues mostly resulted in a shift toward more positive potentials ofG-Vandh8 curves. TheG-Vcurve shifts were associated with a decrease in slope, which may reflect a decrease in the gating charge involved in channel activation. Single neutralization of R114, R117, or R120 by C resulted in a very slow recovery from inactivation. Double neutralization of R111 and R129 confirmed the role of R111 in activation and suggested that R129 is most probably not part of the voltage sensor. Most of the R to K mutants retained WT-like current kinetics but exhibited an intermediateG-Vcurve, a steady-state inactivation shifted to more hyperpolarized potentials, and intermediate time constants of recovery from inactivation. This indicates that R, at several positions, plays an important role in channel activation. The data are consistent with the notion that the S4 is most probably the voltage sensor of the NaChBac channel and that both positive charges and the nature of the arginine residues are essential for channel activation. [ABSTRACT FROM AUTHOR]

To determine the distribution of endocrine disruptors (EDs) in lake water and sediments, field investigation was conducted in Lake Teganuma, which is a shallow eutrophic lake, highly affected by human activities. Concentration profiles with sediment depths were obtained for estrogens, nonylphenol (NP), nonylphenol ethoxylates (NPnEO), and nonylphenoxy acetic acids (NPnEC). 17β-Estradiol (E2) was rarely detected, and 17α-ethynylestradiol (EE2) and estriol (E3) were undetected at all depths (0-98 cm) in any of the sediment core samples. The sediment concentrations of estrone (E1) ranging from <0.05 to 3.5 µg/kgdry wt. and NP from 11.8 µg/kg-dry wt. to 21 mg/kg-dry wt. were obtained. The maximum concentrations of NPnEO and NPnEC in the core sediments were 2.5 mg/kg-dry wt. and 1.4 mg/kg-dry wt., respectively. The EDs concentrations are higher at the inlet than at the outlet (except for NP) in the sediments near the surface. The longitudinal distributions of E1, NPnEO and NPnEC in the benthic sediments show that the concentrations are highest at the inlet, and are fairly constant at lower levels towards the downstream. The obtained results also indicate that NP tends to be adsorbed to the organic particulates produced by algae, followed by sedimentation near the outlet of the lake. [ABSTRACT FROM AUTHOR]

This paper describes an analytical procedure for free estrogens and their conjugates in domestic wastewater. The procedure demonstrated in this study is innovative in terms of levels of detection and quantification of the following substances: estrone (E1); 17β-estradiol (E2); 17α-ethynylestradiol (EE2); estriol (E3); estrone-3-sulfate (E1-S); β-estradiol 3-sulfate (E2-S); estriol 3-sulfate (E3-S); estrone β-D-glucuronide (E1-G); β-estradiol 17-(β-D)-glucuronide (E2-G); estriol 3-(β-D)-glucuronide (E3-G); β-estradiol 3-sulfate 17-glucuronide (E2-S&G); and estradiol 3,17-disulfate (E2-diS). The detection limits of this method ranged from 0.1 to 1.4 ng/l. The recovery efficiencies of the estrogens in the analysis from influent and effluent of the secondary settling tank in a wastewater treatment plant (WWTP) were higher than 94% for the free estrogens, but were less than 50% for the conjugated estrogens. The field study using this method was conducted at twenty WWTPs in Japan. The median concentrations of the estrogens ranged from ND to as high as >100 ng/l. In the influent and secondary effluent samples, the concentrations of E1, E2 and E3 were the same levels as those previously reported. We found that the conjugated estrogens exist at higher concentrations in the influent and the secondary effluent than in the other studies, and that the concentrations of the conjugated estrogens were higher than those of the free estrogens. [ABSTRACT FROM AUTHOR]

Hepatitis C virus (HCV) subgenomic replicon has been reported to replicate efficiently and continuously in human hepatoma Huh-7 cells. To extend the previous results to other isolated HCV clones, we constructed another HCV replicon from HC-J4, one of chimpanzee-infectious HCV clones. An HCV replicon derived from HC-J4 (RpJ4) consists of HCV-5′ untranslated region, neomycin phosphotransferase gene, the encephalomyocarditis virus internal ribosomal entry site, HCV nonstructural region, NS3 to NS5B, and HCV-3′ untranslated region. The adaptive mutations known to be required for HCV-Con1 replicon were introduced in RpJ4 replicon, aa.(amino acids number according to HC-J4) 2197 serine to proline, deletion of serine at aa.2201, and aa.2204 serine to isoleucine (RpJ4-S2197P, RpJ4-S22001del, and RpJ4-S2204I). RpJ4/ISDR mutant and RpJ4-S2201del/ISDR mutant were also constructed by introducing six amino acid mutations into the interferon sensitivity determining region (ISDR). After transfection into Huh-7 cells and G418 selection, RpJ4 and RpJ4/ISDR mutants did not produce any colony. In contrast, G418-resistant cells were transduced efficiently by RpJ4-S2197P, RpJ4-S2204I, RpJ4-S2201del and RpJ4-S2201del/ISDR mutant, with the RpJ4-S2201del/ISDR mutant being most efficient. Hence the HCV replicon derived from HC-J4 can replicate efficiently following the introduction of adaptive mutations into the upstream region of ISDR. Moreover, additional introduction of mutations into ISDR further enhanced its replication. These findings demonstrate that the genetic structure of the NS5A domain is critical in HCV replications. [ABSTRACT FROM AUTHOR]

Gastric adenomas may eventually progress to adenocarcinomas at varying rates. The purpose of the present study was to identify gene-expression profiles linked to the heterogeneous nature of gastric adenoma as compared to adenocarcinoma. Suppression subtractive hybridisation analysis was performed to extract relevant genes from two cases of low- and high-grade gastric adenomas. The identified genes were quantified by RT-PCR in 14 low-grade adenoma, nine high-grade adenoma and nine adenocarcinoma samples, followed by hierarchical clustering analysis to separate tumours into groups according to their gene-expression profiles. Nine genes previously implicated in carcinogenesis in a variety of organs, including three genes related to gastric adenocarcinoma, were identified. The overexpression of these genes in gastric adenoma has not been reported previously. The clustering analysis of these nine genes across 32 cases identified three groups, one of which consisted primarily of adenocarcinomas, whereas the other two groups consisted of adenomas. One group of adenomas, characterised by larger tumour size, exhibited gene-expression profiles of an intestinal cell lineage implicated in the pathogenesis of an intestinal-type gastric adenocarcinoma. Another adenoma group consisting of low-grade adenomas with smaller tumour size exhibited a unique expression profile. In conclusion, clustering analysis of expression profiles using a limited number of genes may serve as molecular markers for gastric adenoma with different biological properties. Although the prognostic values of these gene-expression profiles need to be evaluated in further follow-up study of adenoma cases, these findings add new insights to (a) our understanding of the pathogenesis of gastric tumours, (b) the development of specific tumour markers for clinical practice, and (c) the design of novel therapeutic targets.British Journal of Cancer (2004) 90, 216-223. doi:10.1038/sj.bjc.6601399 www.bjcancer.com [ABSTRACT FROM AUTHOR]

At 0 to 20 degrees C, the Ca(2+)-ATPase activity of the scallop sarcoplasmic reticulum (SR) was observed to be 7-60% of the peak activity at 30 degrees C, while the ATPase activity of the rabbit SR was 0-7% of its peak at 55 degrees C. The relative rabbit ATPase activity (0.7-7.0%) at 7-20 degrees C became higher (6-15 times) and lower (1/4-1/2), respectively, by the solubilization of the rabbit ATPase with a detergent, dodecyloctaethylenglycol monoether, and by the reconstitution of the ATPase with asolectin (soybean lecithin). No activity at 0 degrees C remained irrespective of these treatments. The relative scallop ATPase activity at 0-20 degrees C was, however, scarcely affected by such solubilization and reconstitution. In contrast to the rabbit ATPase, the scallop ATPase seems to be capable of operating independently without the help of the membrane lipid at low temperature. [ABSTRACT FROM AUTHOR]