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Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is shed in saliva, sputum, and feces of the novel coronavirus disease 2019 (COVID-19) patients, and SARS-CoV-2 RNA has been detected in sewage. Thus, many regions worldwide have implemented the measurement of SARS-CoV-2 RNA in sewage as a monitoring tool for COVID-19 prevalence. Here, we report the monitoring of two wastewater treatment plants in Tokyo from May 2020 to June 2022 using a fully automated genetic testing method for the solid fraction of sewage. We found that SARS-CoV-2 sewage monitoring using the Panther System with the Aptima SARS-CoV-2 Assay Kit is an effective method of qualitative monitoring. Furthermore, spike gene mutations (N501Y, L452R, E484A) by real-time PCR using test residues were detected in some samples, which reflected the epidemic status. Nevertheless, our findings demonstrate that the use of a fully automated testing platform is effective for SARS-CoV-2 RNA detection in the solid fraction of sewage.

Internal erosion has been frequently reported and has caused failures and instabilities of geotechnical structures. A plane strain erosion apparatus is developed in this study to allow the subsequent conduction of drained compression test after seepage test and the microscopic observation of particle movement through a transparent window. A drained compression test preceded by a seepage test is performed on specimens containing the same initial fines contents to investigate the mechanical consequence impacts of seepage-induced internal erosion. Experimental results reveal that, compared with uneroded soils, internally eroded soils show a larger secant stiffness at a small strain level (∼1 %). At medium strain level (∼15 %), the soils with erosion show smaller deviator stress comparing with soils without erosion. The analysis of images recorded by the microscope proves that the fines contacted with coarse particles possibly transferring the load are distinct between the soils with and without internal erosion at both small and medium strain levels during the drained compression test, which indicates that the soil fabric could affect the mechanical behaviors of soils subjected to internal erosion. Our designed equipment and microscopic observation could throw some light on the research of internal erosion from the view of particle scale.

An experimental investigation of multiple seepage-induced suffusion and its impact on the mechanical responses of internally unstable gap-graded soil, with a fines content of 25%, is presented in this paper. Using a modified triaxial erosion apparatus, with a redesigned seepage control system, erosion tests under multiple seepage conditions, as well as undrained monotonic and cyclic compression tests, are performed. It is found that multiple seepages cause an eroded mass without a marked change in volume and with a change in hydraulic conductivity as the number of seepage cycles increases. The monotonic compression tests show that eroded soil presents a smaller peak strength, residual strength, and a greater contractive response than non-eroded soil. The peak strength and stiffness of eroded soil are seen to decrease considerably as the number of seepage cycles increases. Multiple seepage-induced suffusion may create a collapsible soil structure in eroded soil, as shown by sudden decreases in deviator stress and stiffness, coupled by sharp increases in pore water pressure at small strain levels. As eroded soil might already be unstable, cyclic loading causes it to collapse, revealing a sudden increase in the generation of cyclic pore water pressure and a decrease in liquefaction resistance. The results highlight the importance of conducting laboratory tests to determine the impact of internal erosion on the strength and liquefaction resistance.

This study presents an experimental investigation of the contribution of non-plastic fines to the development of seepage-induced internal instability and its impact on the undrained mechanical response of gap-graded sands. The purpose of the laboratory tests is to observe the internal instability of two key microstructures: (1) an underfilled microstructure in which the coarser particles control the stress transfer and (2) an overfilled microstructure in which the finer particles play a primary role in the stress transfer. Tests on medium dense sands with seven different fines contents are conducted using a pressure-controlled triaxial erosion device. The device enables internal erosion tests with high back pressure under a pressure-controlled condition. The results indicate that the initial fines content significantly affects the initiation and progress of internal instability. The phenomena of self-filtering and suffusion, evident for underfilled soil, can occur at relatively small hydraulic gradients. Depending on the initial fines content, overfilled soil is vulnerable to suffosion, seepage-induced failure, or an internally stable state, which can occur at large hydraulic gradients. Undrained compression tests on eroded soils reveal that suffusion makes the soil looser and more contractive, while suffosion makes the soil more dilative at large strain levels. As suffusion may create an unstable structure in the soils, sudden drops in deviator stress and sharp increases in pore water pressure and radial strain with axial straining are detected in all the post-suffusion soils at small strain levels. Finally, the identificaton of internal instability is illustrated in terms of the void ratio and the fines content, for assessing the initiation and progress of instability phenomena, as well as the possible soil microstructures.

A hybrid foundation is developed in this study to mitigate the liquefaction-induced effects on shallow foundations. The proposed hybrid foundation is a combination of a gravel drainage system and friction steel piles with spiral blades, framed under the footing. The motivation behind having a gravel drainage system, as an integral part of the hybrid foundation, is its ability to improve the liquefaction resistance of the ground in the most economical way. However, case histories and the development of recent research have highlighted that gravel drainage systems have exhibited poor performances and could not prevent ground liquefaction during strong ground motion. To counteract these shortcomings, friction steel piles are provided which are supposed to yield frictional resistance during earthquakes and are presumed to minimize the rocking/tilting behavior of the foundation-structure system even if the ground undergoes liquefaction. The evolution of excess pore water pressure, specifically in the vicinity of the foundation-structure system, dominatingly influences the settlement mechanism of shallow foundations. Centrifuge test results show that the presence of gravel drainage can minimize the post-liquefaction settlement of shallow foundations through the rapid dissipation of excess pore water pressure. Moreover, friction piles are able to minimize the tilting/differential settlement of shallow foundations. It is found that the proposed hybrid foundation provides the desired function of reducing the overall liquefaction-induced effects on shallow foundations resting on liquefiable grounds.

The Guelph Permeameter (GP) test, one of the constant-head borehole permeameter tests, is a potential tool for studying the heterogeneous alluvial deposits in the foundation of river levees. However, the applicability in the targeted environment and adequacy of the information obtained by the tests are still unclear. Experiments are conducted in a model ground and in the field to verify the applicability of the GP test concerning underseepage through river levees. Discussions focus on the effects of the groundwater table, seepage behavior during the test, and the representative volume of soil tested. It is noted that for sandy and silty soils, reasonable estimations of the hydraulic conductivity can be made by applying the Reynolds’ solution, but the estimation of the hydraulic conductivity in clayey soil is affected by the macropores in the soil. The GP tests performed in this study have representative volumes on the order of a few to tens of centimeters so that heterogeneity can be investigated at the meter scale. In summary, the GP test is a useful tool for evaluating the underseepage through river levees.

The rise in the river water level in a levee raises the phreatic surface. This facilitates the development of positive pore water pressure in the region below the phreatic surface, and consequently, reduces the shear strength of the soil. Steel drainage pipes that can provide both drainage and reinforcement functions could be a better option for levee protection against flooding compared to the traditional method of protection which can provide only one or the other of these functions. This paper presents the results of a series of centrifugal tests for six cases conducted to investigate the effectiveness of newly designed steel drainage pipes for minimizing the flood-induced deformation of levees. The test results reveal that the installation of these steel drainage pipes (1) allows the levee to withstand a higher flood water head and extended flood duration and (2) is effective for limiting the continuation of the slip line in the slope. The quick drainage of the seepage water can restrict the development of positive pore water pressure in the slope, and the mobilization of the axial force in the pipes minimizes the flood-induced deformation of the levee.

It is well known that soils are prone to spatial non-uniformity, which affects evaluations of slope stability and failure mechanisms. This paper presents a probabilistic slope stability evaluation, considering the 3D spatial variation in the soil properties, by the random limit equilibrium method (RLEM). Specifically, 3D random fields of cohesion c, friction angle ϕ, and soil unit weight γare generated using a fast Fourier transform. The RLEMis applied to evaluate the effects of the 3D spatial variability of the soil properties on slope stability and failure mechanisms. A Monte Carlo simulation is used to interpret the slope reliability and variation in slope failure dimension. Based on the critical slip surface passing different portions of a slope (slope base, inclined face, and crest), four main failure mechanisms (two base failures and two face failures), and one additional failure mechanism (toe failure), are identified for spatially variable slopes, and the corresponding distributions of the stability number (Ns) and sliding volume (V) are investigated in detail. The results show that the large variation in the soil properties induces changes in the failure mechanisms, and a threshold of c-ϕvalues is found for a shift from base failure to toe failure. Lastly, associated sensitivity studies are performed to explore the effects of the uncertainties of the input parameters on the uncertainty of the output. The results estimated by partial Spearman correlation coefficients show that cohesion has the greatest influence on the stability number, and that a positive influence of the unit weight, contributing to slope stability, is found for a base failure mechanism.

Most natural slope failures are induced by seepage and/or rainfall. Soil bioengineering is an environmentally friendly method which employs vegetation to reinforce the soil in sloping terrain. The vegetation can contribute to slope stability in two ways, mechanical and hydrological. This paper demonstrates the effect of a vegetation root matrix on a soil slope and focuses on mechanical reinforcement using an example of vetiver grass. Vetiver grass (Vetiveria nemoralis A. Camus) specimens, grown for under a year, were used in this study. The investigation programme includes root observations, direct shear tests and centrifuge model tests. The growing rate of the vetiver roots and the root area ratios were observed during the tests. The cohesion and angle of internal friction of root-reinforced soils were determined from a standard direct shear apparatus and a large direct shear apparatus. A series of centrifuge tests was carried out to demonstrate the effect of vegetation on seepage- and rainfall-induced slope failures. The results indicate that the vetiver roots showed rapid growth within a year and that the shear strength of the root-reinforced soil was significantly increased by the bundle of roots. The results also reveal that the bundle of root fibres in the centrifuge model tests helped to reduce the deformation of the soil slope due to instability by increasing the shear strength of the slope.

Suffusion describes the phenomenon whereby finer particles are eroded through the voids of coarse particles by the seepage flow. This may cause the deterioration of the hydraulic structure and, in the worst case, result in the failure of the hydraulic structure. The suffusion process is presented in this paper in an embankment under transient and steady seepage conditions. A series of physical model tests on seepage-induced suffusion on a small-scale model embankment is performed under constant boundary head conditions. A binary mixture, consisting of two Silica sands (Silica sands Nos. 3 and 8), which is categorized as “internally unstable material” by several previous criteria for the seepage-induced internal stability, is used for the model embankment. The cumulative eroded soil mass and the discharged rate of water are recorded during the seepage tests. The spatial extent of the variation in erosion-induced fines contents is discussed through sieve analyzes on subdivided areas of the model embankment after seepage testing. The test results reveal that a decrease in fines propagates along the phreatic surface from downstream in the embankment. Below the phreatic surface, the eroded fines not only move laterally by the seepage flow, but also vertically due to the gravitational force, and are deposited in the foundation. This deposition of the fines results in the expansion of the fine-rich region in the foundation and causes a decrease in the permeability of the whole embankment.

To evaluate the lateral resistance of rigid monopiles for wind turbines in dense sand under lateral cyclic loading, centrifuge model tests are performed, focusing on the base resistance and degradation of the soil resistance under two-way lateral cyclic loading in the short-term. The slenderness ratio (embedded pile length to diameter) is varied from 3.75 to 8 and the loading frequency is in the range of 0.002 to 0.4 Hz in the prototype scale. Under cyclic loading with a maximum horizontal displacement of 5% of the pile diameter, the build-up of excess pore water pressure is observed, but the maximum value of the average excess pore water pressure ratio is around 50% in the steady-state for dense sand whose relative density is 80%. A simple analytical model for the rigid piles, considering the base resistance, is derived and then used to quantify the significance of the resistance at the pile base and the degradation of the soil resistance under cyclic loading. When the slenderness ratio is less than 5, a significant contribution of the moment resistance at the base is confirmed. The estimation of the degradation of the horizontal subgrade reaction coefficient using the simple analytical model suggests that, through cyclic shear tests for the determination of the deformation properties of the soil in a laboratory, it is possible to estimate the degradation of the soil stiffness and the parameters for the reduced sway-rocking type of foundation model.

The characteristics of suffusion and its mechanical consequences on saturated cohesionless soil with different initial fines contents at various stress states are presented in this paper. A series of seepage tests is performed by constant-flow-rate control mode with the measurement of the induced pore water pressure difference between the top and bottom of the tested specimen under the isotropic confining pressure. Back pressure is maintained constant in the tested soil specimen to ensure fully saturated soil condition. Cumulative eroded soil mass is continuously recorded by a consecutive monitoring system. Suffusion induced axial strain and radial strain of the 70mm-in-diameter and 150mm-in-height specimen is recorded during the seepage tests. The gap-graded cohesionless soil, which are assessed as internally unstable by existing evaluation methods, are tested. The mechanism of suffusion is demonstrated by the variation of hydraulic gradient, hydraulic conductivity, percentage of cumulative fines loss and volumetric strain during suffusion. The parametric study on the influence of two variables, effective stress level and initial fines content, on the mechanism of suffusion is elaborated. The mechanical consequences of suffusion are evaluated by conducting monotonic drained compression tests on the eroded specimens. Companion specimens without suffusion are tested for comparison purpose. The test results reveal that with the progress of suffusion, hydraulic gradient would drop and hydraulic conductivity would increase. Large amounts of fines are eroded away and correspondingly, contractive volumetric strain occurs. The larger effective confining pressure would lead to the less extent of suffusion. With larger initial fines content, more fines would be eroded away. The monotonic compression tests indicate that suffusion would cause the reduction of the soil strength at the major stage of drained shearing.

This paper presents a newly developed triaxial apparatus to directly investigate the mechanical behavior of eroded soils. Efforts are devoted to maintaining the back pressure in the tested specimens to ensure a relatively high degree of saturation during the erosion test. Instead of determining the cumulative eroded soil mass by the method of collecting and drying effluent at discontinuous periods, a consecutive monitoring system is installed to permit continuous recording of the eroded soil mass. Gap-graded non-cohesive soils, which are vulnerable to internal erosion, are tested. Erosion tests are performed by the constant-flow-rate control method with the measurement of the induced pressure difference between the top and bottom of the tested specimens under the preferred stress state. Volumetric strain of the 70-mm-diameter, 150-mm-high specimen is monitored during the erosion tests. The mechanical consequences of internal erosion, in terms of the stress–strain relationship, are evaluated by conducting monotonic compression and cyclic tests on the eroded soils. The test results reveal that internal erosion would cause the increase of hydraulic conductivity and volumetric deformation of the tested specimens. Internal erosion would mainly induce the reduction of the drained compressive strength. The undrained peak deviator stress of the soil that suffered from internal erosion is higher than that of the soil without erosion. Undrained cyclic tests indicate that, compared to the soil without erosion, the eroded soil would fail after more cyclic loops.

Starburst triblock copolymers consisting of 8-arm poly(ethylene glycol) (8-arm PEG), poly(L-lactide) (PLLA) or its enantiomer poly(D-lactide) (PDLA) and terminal PEG, 8-arm PEG-b-PLLA-b-PEG (Stri-L) and 8-arm PEG-b- PDLA-b-PEG (Stri-D), were synthesized. An aqueous solution of a 1:1 mixture (Stri-Mix) of Stri-L and Stri-D assumed a sol state at room temperature, but instantaneously formed a physically cross-linked hydrogel in response to increasing temperature. The resulting hydrogel exhibited a high storage modulus at 37 °C. The rapid temperature-triggered hydrogel formation, high mechanical strength, and degradation behavior render this polymer system suitable for use in injectable drug delivery system or a biodegradable scaffold for tissue engineering.

Suffusion, one of the modes of internal erosion, has been widely detected in both natural deposits and filled structures. It is the phenomenon that the fine particles in soil gradually migrate through the voids between the coarse particles, leaving behind the soil skeleton. In this paper, the main focus is on the changes in soil strength due to internal erosion. A series of one-dimensional upward seepage tests at a constant water head is performed to cause internal erosion in a soil sample by controlling the three variable parameters, namely (a) the fine content, (b) the relative density of the soil, and (c) the maximum imposed hydraulic gradient on the specimen. The mechanical consequences of the internal erosion are examined by cone penetration tests. The internal erosion indicated by the loss of fine particles causes changes in the void ratio and a significant increase in hydraulic conductivity, resulting in a decrease in the soil strength from its initial value.

Some slope failures along oblique faults experience arch to the extent that the stable scarp can be observed after collapse. The load resisting the scarp is transferred to the side supports by the circumferential forces across the exposed face, separating it from the force acting normal to the slope and the frictional resistance which runs along it. Therefore, the failure mechanism involves a passive condition where the major principal stresses dominate the force supporting the arches. This study presents the groundwork carried out to confirm the assumption of a passive condition appearing in the scarp of the inclined slope by measuring the pressure changes and the surface movement of a physical model. Moist sand was uniformly layered inside a rigid acrylic frame fixed on a slope and base made of rigid acrylic plates. The movement distributions of the slopes were recorded and analyzed using particle image velocimetry (PIV) and image processing software. As the toe of the slope was sliced and cut in sequence, starting from the middle part, the removal of the propped portion resulted in a slip along the surface. Since the moist sand fails inward rather than outward, it is reasonable to assume that the lateral compression is greater than the inclined compression, to the extent where it is sufficient to initiate arch action in a passive condition.

The report gives a brief overview of the history and development of Soils and Foundations from its founding in 1960 to the golden jubilee year 2010. The statistics concerning the journal's distribution and the academic contents of the published papers are presented, updated from those first published by Takemura et al. (1999). Major events are chronicled and their impacts the assessed on the readers, contributors and the course of the journal's later development. Such events include online publishing and adopting the impact factor, among others. The long-term trends in the research topics, employed approaches (experimental, analytical, etc.), authors' identity, etc. are discussed based on the statistics considering all the papers published in the past. The report also offers a complementary perspective to the journal's contributions to the geotechnical society by reviewing the award-winning papers.

The paper describes observed behaviour of a model tunnel embedded in dry sand subjected to cyclic ground shear deformation in a centrifuge, as well as the behaviour of the model ground during shear deformation. Detailed data on earth pressures acting on the tunnel lining and the sectional forces of the lining are presented during ground shear deformation. The data suggest that the earth pressure at tunnel crown before ground shear deformation is smaller than the full overburden pressure probably due to the formation of arch action and the arch action may deteriorate with the cyclic ground shear deformation, resulting in an increase in the earth pressure at crown and changing the distribution of the sectional forces, which are largely influenced by conditions between tunnel lining and invert.

This study focuses on the entire shape of the  twin-precipitate in two phase stainless steel, Fe-25Cr-6Ni in terms of the interphase and elastic strain energies generated between the precipitate and matrix. An investigation of this precipitation is important not only in terms of microstructure control but also for improving the mechanical properties of materials. Firstly, the three-dimensional near-coincidence site lattice (3D-NCS) model, which is based on the atomic matching model, is applied for estimating the preferred habit planes by evaluating the result of geometrical atomic matching. Subsequently, the precipitate shape is determined from candidates of the preferred habit plane produced by the 3D-NCS model, and the elastic strain surrounding and within the precipitate is investigated by FEM analysis, which can calculate the anisotropic elastic strain depending on the shape of the precipitate. The results are compared with observed precipitate by TEM.

In lateral resistance of piles with a pile cap, marked contribution of the pile cap resistance can be expected. For seismic performance assessment of pile foundations, mobilisation of the earth pressure acting on pile caps, induced by interactions between the pile cap and surrounding soils, has to be properly considered. In this study, a series of centrifuge model tests were conducted (1) to examine the effect of strain history on the mobilization of lateral earth pressure acting on pile caps and (2) to show the importance of considering strain history when modelling the interaction between a surface soil layer and a pile cap. Observations into the physical model tests reveal that mobilisation of the earth pressure acting on pile caps under cyclic loading can drastically change depending on soil type and/or conditions. Especially, relocation of soil adjacent to the pile cap in unload-reload phase plays an important role for the earth pressure mobilisation, as it completely alters the shape of the earth pressure-displacement curves. Based on the physical model test results, a simple empirical model that can be used for the beam on non-linear Winkler foundation type analysis is proposed and compared to the test results.

The iron(III) azido complex of 5,10,15,20-tetraisopropylporphyrin was characterized with NMR, EPR, Mössbauer, and magnetic susceptibility. These physical methods indicate mixing of the high (S=5/2) and intermediate (S=3/2) spin-states of the iron atom. The results were interpreted in terms of the core contraction after nonplanar deformation of porphyrin ring by the bulky isopropyl substituents. In the IR spectrum of this complex, there are two signals at 2062 and 2048 cm-1due to the antisymmetric vibration of the coordinated azido ligand. The split IR bands demonstrate that the two spin isomers are present, and that the S=5/2 and 3/2 transition occurs sufficiently slow on the IR timescale. This is in remarkable contrast with the homogeneous spin-mixing model proposed for the S=5/2 and 3/2 system. The present observations further suggests that the three S=5/2, 3/2, and 1/2 states in iron(III) porphyrin commonly mix through thermal spin equilibrium.

The five-coordinate ferric azide complex of 2,7,12,17-tetrapropylporphyrcene [Fe(TPrPc)N3] was characterized with proton NMR, electron paramagnetic resonance (EPR), Mössbauer, and IR techniques. The paramagnetic NMR showed the pyrrole-H signal that exhibits anomalous anti-Curie type of 1/T-dependence over a 310–190 K range. The EPR of the solid sample resolved a signal with g = 5.42, 5.40, and 2.00 at 5 K. The quadrupole splitting parameter of the Mössbauer spectrum was 2.20 mm s–1 at 290 K, and the magnetic moment was 4.70 μB at 290 K for the microcrystalline sample. These results suggest that [Fe(TPrPc)N3] is not pure high-spin (S = 5/2) but a spin mixture of the S = 5/2, 3/2 states. The azide in [Fe(TPrPc)N3] exhibited split IR bands ascribed to the two spin isomers at 2066 and 2049 cm–1. The 2049-cm–1 band, assigned to the S = 3/2 species, was reversibly intensified with decreasing temperature. The IR results demonstrate that the S = 3/2, 5/2 states are not quantum-mechanically admixed but in thermal equilibrium. The thermodynamic parameters associated with the spin equilibrium, ΔH = –3 990 cal mol–1 and ΔS = –16.5 cal mol–1 K–1, were obtained from the NMR shift analysis, and the population of the S = 3/2 isomer was calculated to be 0.19 at 293 K. A minimum lifetime of the two spin isomers was estimated to be 0.3 ps with IR. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

Starburst triblock copolymers consisting of 8-arm poly(ethylene glycol) (8-arm PEG), poly(L-lactide) (PLLA) or its enantiomer poly(D-lactide) (PDLA) and terminal PEG, 8-arm PEG-b-PLLA-b-PEG (Stri-L) and 8-arm PEG-b- PDLA-b-PEG (Stri-D), were synthesized. An aqueous solution of a 1:1 mixture (Stri-Mix) of Stri-L and Stri-D assumed a sol state at room temperature, but instantaneously formed a physically cross-linked hydrogel in response to increasing temperature. The resulting hydrogel exhibited a high storage modulus at 37 °C. The rapid temperature-triggered hydrogel formation, high mechanical strength, and degradation behavior render this polymer system suitable for use in injectable drug delivery system or a biodegradable scaffold for tissue engineering.

The pathogenesis of reflux esophagitis is not well understood and remains controversial. Distal gastrectomy serves as a model to assess the role of duodenal reflux with low gastric acidity in the development of reflux esophagitis. We investigated the relationship between the severity of esophagitis and gastroduodenal juice reflux, with particular focus on trypsin and bile acids after distal gastrectomy reconstructed with Billroth I anastomosis. Twenty-eight patients with gastroesophageal reflux disease after distal gastrectomy were enrolled. Esophageal and duodenal contents were aspirated under endoscopical examination, and their trypsin activity and bile acid concentrations were measured. The grade of reflux esophagitis was assessed by endoscopy and the symptoms were scored. Moreover, the grade of infiltration of inflammatory cells and the expression of COX-2 mRNA in the esophageal epithelium were evaluated. Patients with severe esophagitis had a higher amount of trypsin activity and bile acid concentrations in the esophagus, but not in the duodenum, compared to patients with mild esophagitis (P< 0.05). There was a strong positive correlation between the trypsin activity and the bile acid concentrations in the esophagus (r= 0.743, P= 0.0001). Moreover, the COX-2 mRNA expression and the grade of infiltrating inflammatory cells in the esophageal mucosa significantly correlated with the trypsin activity and bile acid concentrations in the esophagus. Thus, duodenogastroesophageal reflux with low gastric acidity is one of the pathogeneses in the development of reflux esophagitis from the present clinical study with patients after distal gastrectomy reconstructed with Billroth I anastomosis.The pathogenesis of reflux esophagitis is not well understood and remains controversial. Distal gastrectomy serves as a model to assess the role of duodenal reflux with low gastric acidity in the development of reflux esophagitis. We investigated the relationship between the severity of esophagitis and gastroduodenal juice reflux, with particular focus on trypsin and bile acids after distal gastrectomy reconstructed with Billroth I anastomosis. Twenty-eight patients with gastroesophageal reflux disease after distal gastrectomy were enrolled. Esophageal and duodenal contents were aspirated under endoscopical examination, and their trypsin activity and bile acid concentrations were measured. The grade of reflux esophagitis was assessed by endoscopy and the symptoms were scored. Moreover, the grade of infiltration of inflammatory cells and the expression of COX-2 mRNA in the esophageal epithelium were evaluated. Patients with severe esophagitis had a higher amount of trypsin activity and bile acid concentrations in the esophagus, but not in the duodenum, compared to patients with mild esophagitis (P< 0.05). There was a strong positive correlation between the trypsin activity and the bile acid concentrations in the esophagus (r= 0.743, P= 0.0001). Moreover, the COX-2 mRNA expression and the grade of infiltrating inflammatory cells in the esophageal mucosa significantly correlated with the trypsin activity and bile acid concentrations in the esophagus. Thus, duodenogastroesophageal reflux with low gastric acidity is one of the pathogeneses in the development of reflux esophagitis from the present clinical study with patients after distal gastrectomy reconstructed with Billroth I anastomosis.

Statins are the most used cholesterol-lowering agents worldwide. Earlier studies suggested that they may have preventive effects in Alzheimer's disease. However, prospective studies have questioned this hypothesis.

Purpose We previously reported a higher frequency of c-Met protein expression and high proliferative status in gastric cancers producing a-fetoprotein (AFP) than in those not producing AFP. Methods To investigate this further, we established an AFP-producing gastric cancer cell line, designated as AME-1, from the primary tumor of a patient with AFP-producing gastric cancer. Results a-Fetoprotein production in the AME-1 cell line was confirmed at the protein level by immunocytochemistry and at the mRNA level by reverse transcription–polymerase chain reaction (RT-PCR). A high amount of AFP was also detected in the supernatant of cultured AME-1. The AME-1 cell line expressed c-Met both at the mRNA and protein levels. A semiquantitative RT-PCR method indicated that AME-1 had a higher amount of c-Met mRNA than well-known gastric cancer cell lines (MKN-28, MKN-45) with strong c-Met expression. Hepatocyte growth factor (HGF), a ligand for the c-Met receptor, was not detected in the mRNA or protein of AME-1. The AME-1 cell line showed a proliferative response to exogenous HGF treatment in a dose-dependent manner, but the activity of migration was not stimulated by exogenous HGF. Conclusions The AME-1 cell line may be a useful model for elucidating aggressive behavior, especially related to regulation of the c-Met/HGF system, in AFP-producing gastric cancers.

Akt is a serine-threonine kinase that mediates a variety of cellular responses to external stimuli. During postnatal development, Akt signaling in the heart was up-regulated when the heart was rapidly growing and was down-regulated by caloric restriction, suggesting a role of Akt in nutrient-dependent regulation of cardiac growth. Consistent with this notion, reductions in Akt, 70-kDa S6 kinase 1, and eukaryotic initiation factor 4E-binding protein 1 phosphorylation were observed in mice with cardiac-specific deletion of insulin receptor gene, which exhibit a small heart phenotype. In contrast to wild type animals, caloric restriction in these mice had little effect on Akt phosphorylation in the heart. Furthermore, forced expression of Akt1 in these hearts restored 70-kDa S6 kinase 1 and eukaryotic initiation factor 4E-binding protein 1 phosphorylation to normal levels and rescued the small heart phenotype. Collectively, these results indicate that Akt signaling mediates insulin-dependent physiological heart growth during postnatal development and suggest a mechanism by which heart size is coordinated with overall body size as the nutritional status of the organism is varied.

The durability of isocyanate resins consisting of emulsion-type polymeric diphenylmethane diisocyanate (EMDI) was investigated under constant steam heating. Two kinds of resin, water only-added resin and polyol/water-added resin, were used in this study. The degradation of the resins under steam heating was observed using Fourier transform infrared spectroscopy (FT-IR), weight changes, and thermogravimetric analysis (TGA). FT-IR analysis showed that the degradation reaction of the resins scarcely proceeded for a few hours and then increased significantly. The weights of the resins decreased linearly during steam heating. The thermal stability of steam-treated resins was made clear by TGA. The bond strength reductions of the specimens bonded with the resins were also observed. The best fitting regression function for the behavior of bond strength reduction was determined statistically. The apparent activation energy of each resin was calculated from the regression function, for the half-life period. Considering the calculated values, the adhesion durability of using polyol-added resin was superior to that of using water only-added resin. It was clarified that the durability of the isocyanate resins under steam heating was markedly inferior to that under dry heating.

ABSTRACTBlood vessel recruitment is an important feature of normal tissue growth. Here, we examined the role of Akt signaling in coordinating angiogenesis with skeletal muscle hypertrophy. Hypertrophy of C2C12 myotubes in response to insulin-like growth factor 1 or insulin and dexamethasone resulted in a marked increase in the secretion of vascular endothelial growth factor (VEGF). Myofiber hypertrophy and hypertrophy-associated VEGF synthesis were specifically inhibited by the transduction of a dominant-negative mutant of the Akt1 serine-threonine protein kinase. Conversely, transduction of constitutively active Akt1 increased myofiber size and led to a robust induction of VEGF protein production. Akt-mediated control of VEGF expression occurred at the level of transcription, and the hypoxia-inducible factor 1 regulatory element was dispensable for this regulation. The activation of Akt1 signaling in normal mouse gastrocnemius muscle was sufficient to promote myofiber hypertrophy, which was accompanied by an increase in circulating and tissue-resident VEGF levels and high capillary vessel densities at focal regions of high Akt transgene expression. In a rabbit hind limb model of vascular insufficiency, intramuscular activation of Akt1 signaling promoted collateral and capillary vessel formation and an accompanying increase in limb perfusion. These data suggest that myogenic Akt signaling controls both fiber hypertrophy and angiogenic growth factor synthesis, illustrating a mechanism through which blood vessel recruitment can be coupled to normal tissue growth.

Blood vessel recruitment is an important feature of normal tissue growth. Here, we examined the role of Akt signaling in coordinating angiogenesis with skeletal muscle hypertrophy. Hypertrophy of C2C12 myotubes in response to insulin-like growth factor 1 or insulin and dexamethasone resulted in a marked increase in the secretion of vascular endothelial growth factor (VEGF). Myofiber hypertrophy and hypertrophy-associated VEGF synthesis were specifically inhibited by the transduction of a dominant-negative mutant of the Akt1 serine-threonine protein kinase. Conversely, transduction of constitutively active Akt1 increased myofiber size and led to a robust induction of VEGF protein production. Akt-mediated control of VEGF expression occurred at the level of transcription, and the hypoxia-inducible factor 1 regulatory element was dispensable for this regulation. The activation of Akt1 signaling in normal mouse gastrocnemius muscle was sufficient to promote myofiber hypertrophy, which was accompanied by an increase in circulating and tissue-resident VEGF levels and high capillary vessel densities at focal regions of high Akt transgene expression. In a rabbit hind limb model of vascular insufficiency, intramuscular activation of Akt1 signaling promoted collateral and capillary vessel formation and an accompanying increase in limb perfusion. These data suggest that myogenic Akt signaling controls both fiber hypertrophy and angiogenic growth factor synthesis, illustrating a mechanism through which blood vessel recruitment can be coupled to normal tissue growth.

Tepraloxydim [(EZ)‐(RS)‐2‐{1‐[(2E)‐3‐chloroallyloxyimino]propyl}‐3‐hydroxy‐5‐perhydropyran‐4‐ylcyclohex‐2‐en‐1‐one] showed high activity against annual bluegrass (Poa annuaL.), which is relatively tolerant to sethoxydim [(±)‐2‐(1‐ethoxyiminobutyl)‐5‐[2‐(ethylthio)propyl]‐3‐hydroxycyclohex‐2‐en‐1‐one]. Absorption and translocation rates of tepraloxydim and sethoxydim were higher in P. annuathan in Setaria faberi, but the absorption and translocation patterns of tepraloxydim in the two plants were similar to those of sethoxydim. Metabolic rates of tepraloxydim and sethoxydim in P. annuaand S. faberiwere found to be similar. The concentration for 50% inhibition (I50) of acetyl‐coenzyme A carboxylase (ACCase) with tepraloxydim was approximately 3 × 10−6mol L−1for P. annuaand 7 × 10−7mol L−1for S. faberi. For sethoxydim, the I50was found to be 2 × 10−6mol L−1with the enzyme of S. faberi, while sethoxydim showed a slight effect on ACCase from P. annuaactivity, even at 10−4mol L−1. The strong inhibition of ACCase with tepraloxydim is considered to be the major factor contributing to the high herbicidal activity against P. annua. Measuring the whole plant growth response, the ratio of the tepraloxydim I50dose of P. annuato that of S. faberi(P/S) was found to be 2.4, while the P/S ratio of sethoxydim and a tepraloxydim analog with a propyl chain at R2were 56.3 and 73.3, respectively. The herbicidal activity against P. annuawas remarkably influenced by the length of the R2alkyl chain, while the effect on S. faberiwas not affected. Acetyl‐coenzyme A carboxylase from P. annuaalso exhibited a higher resistance to the tepraloxydim analog with a propyl chain than to tepraloxydim. These results suggest that a binding site structure of cyclohexane‐1,3‐diones in the ACCase differs between P. annuaand S. faberi.

We have identified that HER-2/neu-derived peptides are naturally processed as tumor rejection antigens recognized by tumor-specific, HLA-A2-restricted cytotoxic T lymphocytes in gastric cancer. To evaluate candidates for immunotherapy using HER-2/neu-derived, HLA-A2-restricted peptides, we examined the frequency of HLA-A2 relating to HER-2/neu overexpression or the infiltrating grade of tumor-infiltrating lymphocytes (TILs) in Japanese patients with gastric cancer. HER-2/neu-overexpressing tumors detected by immunohistochemistry amounted to 19% of primary gastric cancers and HLA-A2-positive patients with gastric cancer were 31% of primary gastric-cancer cases. Finally, gastric-cancer patients with both HLA-A2-positive and HER-2/neu-overexpressing tumors amounted to 6.6% of these cases. There was no significant difference in the infiltrating grade of TILs between gastric cancers overexpressing HER-2/neu and those that did not. The candidate for HER-2/neu-based immunotherapy with HLA-A2-restricted peptides represent a very limited population of Japanese patients. © 2001 Wiley-Liss, Inc.

AbstractBackground:Patients with gastric cancers producing alpha-fetoprotein (AFP) were reported to have a poor prognosis with high rates of liver metastasis. The purpose of the present study was to clarify the clinicopathological features of AFP-producing gastric cancers, in particular characteristics of liver metastasis, and to evaluate treatment of these cancers. Methods:In 27 of the 29 cases with elevated preoperative serum AFP levels among a total of 974 primary gastric cancers, AFP production was confirmed in gastric cancer cells by immunohistochemistry. These cases were included in the AFP-positive gastric cancer group (AFP(+), 2.7%). The remaining 945 cases with normal serum AFP levels were designated the AFP-negative gastric cancer group (AFP(–)). Results:There was a higher incidence of lymph node metastasis, a deeper invasion of the gastric wall, a higher frequency of advanced stage, a more marked lymphatic invasion and a higher rate of liver metastasis in the AFP(+) group than in the AFP(–) group. The patients received curative resection in AFP(+) group had a significantly worse survival rates in comparison to that in AFP(–) group. With respect to liver metastasis (n = 17) in AFP(+) group, of 3 cases who received curative hepatic resection, 1 patient survived more than 3 years, while the remaining 2 died in less than 3 years due to multiple liver recurrence. The patients (n = 5) who received palliative resection for liver metastasis followed by transarterial continuous infusion chemotherapy all died in less than 1 year. Conclusion:AFP-producing gastric cancers had aggressive behavior and their clinical or biological features were quite different from the common AFP-negative gastric cancers. Surgical resection of liver metastasis from AFP-producing gastric cancers was unsatisfactory. The development of a novel multimodal therapy against AFP-producing gastric cancers is needed.Copyright © 2002 S. Karger AG, Basel

The effects of a novel pyrimidine herbicide, NS‐245852 [2‐chloro‐6‐fluorophenyl‐4‐(trifluoromethyl)thieno[2,3‐d]pyrimidine‐2‐yl‐ketone], on mitosis in oat (Avena sativaL. cv. Zenshin) root tips were investigated by using light and immunofluorescence microscopy. The root growth was strongly inhibited at 10−7mol L−1of NS‐245852, and swollen root tips were induced at 5 × 10−8mol L−1. As observed by the use of light microscopy, the herbicide produced disrupted mitosis and large polynucleate cells in the meristematic root tissue. These symptoms were similar to those of mitotic disrupter herbicides. The immunofluorescence microscopy studies of the root tip cells treated for 30 min revealed that spindle fibers and the preprophase band were reduced, although kinetochore fibers and the phragmoplast were not affected. Kinetochore fibers remained as small fluorescence spots, and the phragmoplast disappeared after a 3 h treatment. No microtubule arrays were observed by a longer treatment (longer than 3 h). Among the microtubule arrays, spindle fibers and the preprophase band were found to be the most sensitive to the herbicide, whereas kinetochore fibers were the most resistant. The phragmoplast was intermediate. Thus, the primary action of NS‐245852 is the inhibition of polymerization of tubulin into microtubules.

We describe herein the case of a 48-year-old man who underwent emergency massive resection of the small intestine due to a strangulated ileus, which led to short bowel syndrome (SBS), as he was left with only 7 cm of jejunum and 8 cm of ileum with ileocecal valve. He then received interposition of a colon segment between the jejunum and ileum remnants isoperistaltically. For 24 months after the operation, he has been able to tolerate oral intake, but still requires partial home parenteral nutritional support during the night on a bimonthly basis. Biochemical and nutritional parameters, including the analysis of minerals and trace elements, indicated that the patient was in relatively good health. Histological examination revealed that the mucosa of the interposed colon showed hypertrophy and hyperplasia of the crypt glands, and cells resembling Paneth cells which are usually seen in the small intestine, suggesting that the colon segment exhibits adaptive changes to the small intestine. Colon interposition may be a useful technique in patients with SBS when the small bowel is too short for the other surgical considerations.

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Serum HER-2/neu (c-erbB-2) levels in patients with gastric cancer were evaluated by an enzyme-linked immunosorbent assay and tissue levels of HER-2/neu in the same cohort were determined by immunohistochemistry. Nine (16%) of 57 gastric carcinomas had an overexpression of HER-2/neu detected immunohistochemically. Of these 9 patients, 6 had elevated serum HER-2/neu levels, while 45 of 48 tissue samples with negative staining exhibited normal serum HER-2/neu levels. These results indicated that overall accuracy, positive predictive value, and negative predictive values of their serum measurements were 89, 67 and 94%, respectively. Serum levels of HER-2/neu were correlated with tissue overexpression of HER-2/neu in patients with gastric cancer.

The thermal properties of isocyanate (IC) resins prepared with a small amount of polyether polyols and water were investigated using dynamic mechanical analysis (DMA). The bond strengths of 3-ply plywoods glued with these polyol-containing IC resins were also measured. The thermal stability was dramatically improved by addition of dipropylene glycol-type polyols with molecular weights of 400 and 1000. In addition, the bond strengths in a dry condition and after aging at 250°C for 10 min exhibited high values compared with that of an IC resin cured with water alone. However, addition of the same polyol type with a molecular weight of 3000 resulted in low heat stability and low bond strength. In the case of glycerin-type polyol with a molecular weight of 400, good thermal stability and slightly higher bond strength were obtained. When bisphenol A and pentaerythritol-type polyols were used, not much improvement in thermal stability was achieved. The bond strengths were similar or inferior to that of an IC resin cured with water only. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 1807–1814, 1999

The measurement of the velocities of ultrasonic waves has been used to detect the delamination cracking during tensile tests in an A2091 A1–Li alloy at both liquid helium and room temperatures. The measured tensile far–field stresses at the onset of the delamination cracking are 335 and 357 MPa, at cryogenic and room temperatures, respectively. The density of delamination cracks in the alloy is estimated from the reduction in the ultrasonic wave velocity and resultant decrease in modulus of elasticity. It is estimated that the interfacial bonding strengths normal to a grain boundary are 116 and 113 MPa, at cryogenic and room temperatures, respectively. Fracture mechanics analysis has been used to estimate the onset of delamination cracking in fracture toughness tests on the basis of the results of the tensile tests. The predicted levels of far field applied stresses are much lower than those for macroscopic crack initiation at both temperatures.

The authors report four cases of familial occurrence of moyamoya disease. Although the pathogenesis of moyamoya disease is not clear, there is extensive evidence that this disease has a tendency to show multifactorial inheritance. Therefore, a screening test for those at high risk, i.e., who have a moyamoya patient among their blood relatives, is clinically important. Magnetic resonance angiography (MRA) successfully revealed abnormal findings specific to moyamoya disease in members of the four probands families. MRA is a powerful and noninvasive way of detecting individuals at high risk of developing moymoya disease.

The thermal properties of isocyanate (IC) resin cured with water were studied using dynamic mechanical analysis (DMA) and Fourier transform infrared spectroscopy. The thermal properties of cured phenol formaldehyde (PF) resin were also studied for comparison purposes. The DMA specimens were prepared using a unique technique. The relation between the mechanical and chemical changes of the resin during DMA was clarified. The cured PF resin had better thermal stability than the IC resin cured with water. The improvement of thermal stability in cured IC resin by heat treatment was considered to be less effective. The effect of the heating rate on the mechanical properties was also investigated. The apparent activation energy in the thermal degradation of cured IC resin was calculated based on the results obtained.

BACKGROUND When we encounter an inaccessible internal carotid artery lesion, we sacrifice the inaccessible internal carotid artery and, at the same time, establish a high-flow extracranial-to-intracranial arterial bypass (EC-IC bypass). Questions and concerns remain, however, about the dynamics of the patient's cerebral blood flow postoperatively. METHOD Ten hemispheres from 9 patients had received radial artery grafting as an EC-IC bypass with the simultaneous obstruction of the internal carotid artery. Their mean hemispheric cerebral blood flow (mCBF) was measured longitudinally during 1 year after surgery by single photon emission computed tomography (SPECT) and a 133 Xenon-inhalation method. RESULTS The serial mCBF values of the five hemispheres with giant aneurysm or paracavernous meningioma were attenuated during the postoperative 3-month period and then returned to the normal range. In only one case did the postoperative reduction of mCBF fail to return to normal; in addition there was a memory disturbance that had developed and progressed. Five hemispheres with the ICA stenosis did not present reduction in mCBF. In three out of five hemispheres, transient elevation of mCBF at 1 month after surgery was observed. CONCLUSIONS We conclude from our study that the internal carotid artery can be safely substituted by the radial artery graft from the view point of cerebral blood flow.

Abstract: The present study was undertaken to ascertain the role of smooth muscles and pericytes in the microcirculation during hyperperfusion and hypoperfusion following ischemia in rats. Paired external carotids, the pterygopalatine branch of the internal carotids and the basilar artery were exposed and divided. Reversible inflatable occluders were placed around the common carotids. After 24 h, the unanesthetized rat underwent 10-min ischemia by inflating the occluders. Continuous cortical cerebral blood flow (c-CBF) was monitored by laser Doppler flowmetry. The measured c-CBF was below 20% of control (P < 0.001) during ischemia. A c-CBF of 227.5 ± 54.1% (P < 0.001) was obtained during reperfusion hyperemia. A c-CBF of 59.7 ± 8.8% (P < 0.001) occurred at the nadir of postischemic hypoperfusion, and this was followed by a second hyperemia. The cytoarchitecture of the vascular smooth muscles and pericytes was assessed by scanning electron microscopy. Samples were prepared using a KOH-collagenase digestion method. In control rats, arteriolar muscle cells showed smooth surfaces. Capillary pericytes were closely apposed to the endothelium. Immediately after reperfusion, transverse membrane creases were observed on the smooth muscle surfaces. During maximal hyperemia the creases disappeared. When c-CBF started to decrease the creases became visible again. Throughout the postischemic hypoperfusion the creases remained. Capillary endothelial walls became tortuous in the late phase of hypoperfusion. During the second hyperemia most arteriolar muscle cells showed smooth surfaces. Some pericytes appeared to have migrated from the vascular wall. The morphological changes of smooth muscle membranes suggest that they are related to specific perfusional disturbances during ischemia and reperfusion.