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Ardisia silvestris is a traditional medicinal herb used in Vietnam and several other countries. However, the skin-protective properties of A. silvestris ethanol extract (As-EE) have not been evaluated. Human keratinocytes form the outermost barrier of the skin and are the main target of ultraviolet (UV) radiation. UV exposure causes skin photoaging via the production of reactive oxygen species. Protection from photoaging is thus a key component of dermatological and cosmetic products. In this research, we found that As-EE can prevent UV-induced skin aging and cell death as well as enhance the barrier effect of the skin. First, the radical-scavenging ability of As-EE was checked using DPPH, ABTS, TPC, CUPRAC, and FRAP assays, and a 3-(4-5-dimethylthiazol-2-yl)-2-5-diphenyltetrazolium bromide assay was used to examine cytotoxicity. Reporter gene assays were used to determine the doses that affect skin-barrier-related genes. A luciferase assay was used to identify possible transcription factors. The anti-photoaging mechanism of As-EE was investigated by determining correlated signaling pathways using immunoblotting analyses. As-EE had no harmful effects on HaCaT cells, according to our findings, and As-EE revealed moderate radical-scavenging ability. With high-performance liquid chromatography (HPLC) analysis, rutin was found to be one of the major components. In addition, As-EE enhanced the expression levels of hyaluronic acid synthase-1 and occludin in HaCaT cells. Moreover, As-EE dose-dependently up-regulated the production of occludin and transglutaminase-1 after suppression caused by UVB blocking the activator protein-1 signaling pathway, in particular, the extracellular response kinase and c-Jun N-terminal kinase. Our findings suggest that As-EE may have anti-photoaging effects by regulating mitogen-activated protein kinase, which is good news for the cosmetics and dermatology sectors. [ABSTRACT FROM AUTHOR]

Cementation influences the mechanical behavior of soils. The effects of cementation and bond degradation are investigated for lightly cemented rigid sand and soft rubber particle mixtures subjected to vertical loading under the [K.sub.0] condition. Cemented and uncemented specimens were prepared with various sand volume fractions. The propagation velocity of small strain body waves was measured by pie/o materials, incorporated within an oedomeler. Cemented specimens exhibited a bilinear behavior in the semi-log plot (vertical strain versus log of vertical stress). Vertical strains of a cemented specimen normalized by an uncemented specimen show that the stress-strain behavior is controlled by several different mechanisms and forces: capillary force, cementation bonds, and interparticle contact stresses after bond degradation. The elastic wave velocities dramatically increase due to cementation hardening under fixed vertical stress, and are constant after curing even though vertical stress increases. Additional loading of the vertical effective stress decreases the elastic wave velocities due to bond degradation. The shear wave velocity presents three behavior regions as a function of the sand fraction for both uncemented and cemented specimens: rubber-like, sand-like, and transition behaviors. The vertical stress-strain response and the elastic wave velocities can serve as indicators of cementation and bond degradation. Key words: bond degradation, cementation, elastic waves, rigid-soft particle mixtures, small strain stiffness, stress-strain response. La cimentation influence le comportement mecanique des sols. Dans cet article, les effets de la cimentation et de la degradation des liens sont evalues pour le cas de melanges legerement cimentes composes de sable rigide et de particules de caoutchouc souple. Ces melanges sont soumis a un chargement vertical en condition [K.sub.0]. Les echantillons cimentes et non cimentes sont prepares avec des fractions volumetriques de sable differentes. La vitesse de propagation des ondes causees par des faibles deformations est mesuree a l'aide de piezo-materiaux incorpores a l'interieur d'un odometre. Les echantillons cimentes ont un comportement bilineaire dans un graphique semi-logarithmique (deformation verticale versus log de la contrainte verticale). Les deformations verticales d'un echantillon cimente normalisees avec un echantillon non cimente montrent que le comportement en contrainte-deformation est controle par differents mecanismes et differentes torces : force capillaire, liens de cimentation et contraintes de contad inter-particules suite a la degradation des liens. Les vilesses des ondes elastiques augmentent de facon significative durant le durcissement sous une contrainte verticale fixe, et deviennent constantes apres le curage meme si la contrainte verticale augmente. Le chargement supplemental re de la contrainie effective verticale diminue la vitesse des ondes elastiques en raison de la degradation des liens. La vitesse des ondes de cisaillement presente trois regions de comportements differents selon la fraction de sable aulant dans les echantillons cimentes que non cimentes : un comportement de type caoutchouc, un comportement de type sable, et un comportement transitoire. Le comportement en contrainte-de formation verticale et les vitesses des ondes elastiques peuvent servir d'indicateurs de l'etat de la cimentation et de la degradation des liens cimentaires. Mots-cles : degradation des liens, cimentation, ondes elastiques, melange de particules rigides et souple, rigidite en faible deformation, comportement en contrainte-deformation. [Traduit par la Redaction], Introduction Disposed tires have been widely used as recycled materials in civil engineering projects. Rigid-soft particle mixtures using shredded tires are often used for lightweight backfill, highway embankments, retaining walls [...]

In this study, rubber-sand particle mixtures are investigated to understand their stress-deformation and elastic modulus characteristics. Specimens are prepared with various size ratios, sr (=[D.sub.rubber]/[D.sub.sand]), between sand and robber particles, and different volumetric sand fractions, sf (=[V.sub.sand]/[V.sub.total]). Small strain shear waves are measured under a [K.sub.0],- loading condition incorporated with the stress-deformation test by using an oedometer cell with bender elements. The stress-deformation and small strain shear- wave characteristics of rigid-soft particle mixtures show the transition from a rigid particle behavior regime to a soft particle behavior regime under a fixed size ratio. A sudden rise of the A factor and the maximum value of the [zeta] exponent in [G.sub.max]= [LAMBDA][([[sigma]'.sub.0],/kPa).sup.[zeta]] is observed at sf [approximately equal to] 0.4-0.6 regardless of the size ratio (sr). The transition mixture shows a high sensitivity to the confining stress. The volume fraction for the minimum porosity may depend on the applied stress level in the rigid-soft particle mixtures because the soft rubber particles easily distort under load. In this experimental study, the size ratio and volumetric sand fraction are the important factors which determine the behavior of rigid and soft particle mixtures. DOI: 10.1061/(ASCE)MT.1943-5533.0000027 CE Database subject headings: Mixtures; Shear waves; Velocity; Stiffness; Rubber; Sand, material; Size effect. Author keywords: Ko-loading; Mixtures; Shear-wave velocity; Size ratio; Stiffness; Volume fraction.

This paper explores the standard penetration test (SPT) hammer-anvil behavior and investigates the effect of secondary impact on SPT energy and sampler penetration. It is observed that the hammer-anvil behavior after the impact depends on the characteristics of the wave reflected from the sampler. The type-I secondary impact, which is dominant for N < 25, is induced due to the rapid downward movement of the anvil and the recontact of the following hammer on the rebounding anvil. The maximum energy calculated by integrating force and velocity (EFV) is achieved immediately after the occurrence of the type-I secondary impact and an additional sampler penetration is triggered by the type-I secondary impact. The type-II secondary impact, which is dominant for N > 50, is produced by the restrike of the pushed-up hammer on the resting anvil. The type-II secondary impact causes only recoverable anvil deformation and does not contribute to the maximum EFV energy. For N-values of 25-50, both or either types of secondary impacts happen. As N-value increases, the type-I secondary impact fade away progressively and the type-II secondary impact becomes more distinctive. DOI: 10.1061/(ASCE)GT.1943-5606.0000236 CE Database subject headings: Impact; Penetration tests; Energy. Author keywords: Secondary impact; Standard penetration test (SPT); Energy transfer ratio.

The assessment of the shear stiffness of dredged soft ground and soft clay is extremely difficult due to soil disturbances caused during sampling and field access. Several in situ methods such as spectral analysis of surface waves, multichannel analysis of surface wave, cross hole, and downhole methods have been developed to measure the shear-wave velocity, but a few disadvantages hinder the adoption of existing methods to soft ground. This study presents a new apparatus, the penetration type field velocity probe (FVP), which overcomes several of the limitations of commonly used shear-wave measurement methods in the field. Design concerns of the FVP include the tip shape, soil disturbance, transducers, self acoustic insulation, protectors, and the electromagnetic coupling from transducer-to-transducer and cable-to-cable. The crosstalk between cables is eliminated by grouping and extra grounding of the cables. The shear-wave velocity of the FVP is directly calculated, without any inversion process, by using the travel distance and the travel time. After calibration tests are carded out in the laboratory, application tests in the field are conducted up to 29 m in depth. Calibration results show the velocity profiles obtained by the FVP and by the rods fitted with transducers are similar to each other. The experimental results obtained in the field show that the FVP can produce reasonable and detailed shear-wave velocity profiles in soft clay. This study suggests that the FVP may be an effective technique for measuring the shear-wave velocity in soft ground. DOI: 10.1061/(ASCE)1090-0241(2010)136:1(199) CE Database subject headings: Calibration; In situ tests; Shear modulus; Shear waves; Soft soils; Velocity. Author keywords: Calibration chamber; In situ test; Shear modulus; Shear waves; Soft soils.

The installation of a prefabricated vertical drain (PVD) using a mandrel results in soil disturbance adjacent to the PVD, which is known as the smear zone. The smear zone is investigated by a series of radial penetration tests including a micro-cone penetrometer and an electrical resistance probe in the clay specimen prepared in a large-scale chamber. The 5 mm diameter micro-cone penetrometer and the 2.1 mm diameter electrical resistance probe produce continuous soil strength and electrical resistivity profiles around the PVD. Almost-constant values of the cone tip resistance and electrical resistivity are measured within the undisturbed zone. The outer boundary of the smear zone is clearly defined by the locations where the deviations of the measured cone tip resistance and electrical resistivity from the constant values are observed. Significant changes in both measurements are observed in the smear zone with remarkably consistent patterns. The smear zone induced by the PVD installation using a rectangular mandrel has an elliptical shape and extends to approximately 3.2 ~ 3.4 times the half-length of the mandrel and 5.3*5.4 times the half-width of the mandrel. Key words: cone tip resistance, electrical resistivity, large-scale consolidometer, prefabricated vertical drain, smear zone. Resume : L'installation d'un drain vertical prefabrique (DVP) al'aide d'un mandrin cause des derangements dans le sol adjacent au DVP, ce qui est communement appele zone de souillure. La zone de souillure a ete examinee par une serie d'essais en penetration radiale, incluant un penetrometre a micro-cone et une sonde a resistance electrique dans un echantillon d'argile prepare dans une boite a grande echelle. Le penetrometre a micro-cone d'un diametre de 5 mm et la sonde a resistance electrique d'un diametre de 2,1 mm ont genere des profils de resistance du sol et de resistivite electrique en continu autour du DVP. Dans la zone non derangee, les mesures de resistance a la pointe du cone et de resistivite electrique sont restees a peu pres constantes. La frontiere externe de la zone de souillure est bien definie par l'emplacement des endroits ou on observe une deviation des mesures de resistance a la pointe du cone et de resistivite electrique par rapport aux valeurs constantes. Des variations significatives sont observees de facon consistante pour les deux types de mesures dans la zone de souillure. La zone de souillure produite par l'installation d'un DVP a l'aide d'un mandrin rectangulaire a une forme elliptique et s'etend jusqu'a approximativement 3,2 ~ 3,4 fois la demi longueur du mandrin et 5,3 ~ 5,4 fois la demi largeur du mandrin. Mots-cles : resistance a la point du cone, resistivite electrique, consolidometre a grande echelle, drain vertical prefabrique, zone de souillure. [Traduit par la Redaction], Introduction As consolidation time is proportional to the square of the drainage length, the optimum method to reduce the consolidation time is to shorten the drainage path. The prefabricated vertical [...]