This paper is concerned with dynamics of the standard penetration test (SPT). The usefulness of mounting strain gages at two different stations along a driven rod is described, together with a workable procedure of analysis. The analysis procedure makes use of the traveling time between the two gage points and enables one to identify the particle velocity, the displacement and the stress at any station of the rod, as well as the energy actually transmitted from a hammer to the rod. Particular attention is called for the consequence of inevitable, small errors in strain data upon such identifications. A pertinent procedure of error-correction is proposed and its validity is substantiated against the performance of well instrumented SPTs performed by the authors.

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Background

The differences in conditions of enteric-coated acid-labile drug release and absorption between healthy subjects in bioequivalence studies and gastrointestinal patients in clinical practice can lead to significant differences in gastric stability of original PPIs and generics. Thus, pathologic duodenogastric reflux (PDGR) and the pH increasing within PPIs administration still remain unaccounted for.

Methods

Two-stage modified comparative dissolution testing of original omeprazole (OO) and four generics (G1;2;

;4) was performed. At first, we moved drugs from solution with pH 1.2 (1.2±0.05) to pH 7.0 (7.0±0.05) and measure concentration of omeprazole in solution by high-performance liquid chromatography. According to our self-developed formula, pH 7 exposure time of resistance to PDGR for omeprazole is 4 minutes, i.. the active substance should not be released within 4 minutes at pH 7. The exposure at the second stage was conducted with pH 4 (4.0±0.05), that imitated gastric pH after PPI administration. And then we also moved drugs to pH 7 with the subsequent measurement of omeprazole concentration.

Results

Omeprazole concentrations after 4, 10, 15, 20, 30, 45, 60 minutes in pH 7 solution at the first stage were different for OO and generics. For OO, these values were 4,7±0,7%; 41,4±

,0%; 62,±4,0%; 79,±2,9%; ,±2,9%; 81,6±2,9%; 80,6±4,4%; for Generic1 - 0; 49,±9,9%; , ±2,%; 90,4±,7%; , 2±2,2%; ,±2,0%; 85,9±1,1%; for Generic2 - 0; 30,6±6,%; 66,7±,2%; 76,4±7,4%; ,±,%; 86,0±,7%; 84,6±,%: for Generic - 80,±,6%; ,±1,9%; , ±,2%; ,±2,7%; 81,9±2,1%; ,1±2,0%; ,0±2,4%; for Generic4 - ,±1,7%; 84,4±0,%; 84,2±1,2%; , 9±0,9%; ,9±0,9%; ,9±0,9%; ,±1,1%, respectively.

An analysis of the omeprazole concentration in pH 7 solution at the second stage revealed the following parameters after the same time: for OO - 4,4±0,6%; 40,

±,0%; 62,±2,0%; 80,0±,1%; 85,4±2,9%; ,±,4%; 80,9±,%; for Generic1 - 0; 67,0±7,%; 89,7±2,%; 91, 9±4,%; 89,1±1,6%; ,±1,4%; ,±1,2%; for Generic2 - 0; 42,2±,6%; 75,1±7,%; 81,0±6,0%; ,4±,2%; , 6±1,%; ,9±1,0%; for Generic4 - 85,±0,%; 85,6±0,%; 84,7±0,9%; ,7±,0%; 84,4±0,%; 84,4±0,%; 84,±0,4%, respectively. Generic release and degradation were completely realized at pH 4.

Conclusion

Decreased gastric stability of Generic

and Generic4 makes PDGR and inhibited gastric acid secretion due to PPIs administration the potential causes of decreased enteric-coated acid-labile drugs stability.

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(

3H

) Tobramycin was used as a probe to determine the relationship between the structure of aminoglycoside antibiotics and their ability to remove this drug from its higher affinity binding site on the ribosome. The dissacharide moieties (neamine, tobramine, gentamine) appeared to have a common binding site, whereas the kanosamine, garosamine and ribose moieties determined the specificity of this binding. Amikacin and butikacin behaved in an anomalous manner in spite of their close structural relationship to tobramycin.

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A comparative study of the static and dynamic response of a slope is carried out, using the large deformation theory of the updated Lagrangian formulation and the conventional infinitesimal theory. In the static analysis, a strength reduction method proposed by one of the authors is used to evaluate the safety factor of the slope. It is found that by the large deformation theory, the safety factor is larger than that calculated by the infinitesimal theory, and this difference becomes large along with the reduction of elastic modulus. In the dynamic analysis, it is observed that the large deformation theory gives smaller sliding displacement and larger response acceleration than the infinitesimal approach. It is concluded that in many cases the large deformation approach gives more adequate solutions.

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The activities of tobramycin derivatives acetylated and ethylated on the 6'-N, 2'-N and -N positions were examined. The MICs of these derivatives against tobramycin sensitive strains indicated that 2'-N-ethylated and 6'-N-ethylated derivatives have a fairly good activity, and confirmed that the -N position is the most important one for antibiotic activity since -N derivatives were less active. The MICs of these derivatives against tobramycin resistant strains, and their inactivation by tobramycin modifying enzymes were examined. These results showed that 2'-N or 6'-N ethylation protects the drug against inactivation by AAC(2') or AAC(6'), respectively, and 2'-N-ethyltobramycin and 6'-N-ethyltobramycin were active against strains containing these modifying enzymes. On the other hand, -N ethylation protects the drug against inactivation by AAC() but -N-ethyl tobramycin does not inhibit strains containing this enzyme.

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We conducted a series of 1G large-scale shake table tests and cyclic eccentric loading tests of a shallow foundation model. The experimental parameters were the difference in loading methods (i.., dynamic and static), input seismic motions (i.., intensity and number of cycles), soil densities (i.., dense and medium dense), and the ratio of horizontal and overturning moment loads. The experimental data set contains the accelerations and displacements of the soil and foundation as well as the distributions of normal and shear reaction forces at the foundation base. The experimental results provide crucial data to model the coupling effect among vertical, horizontal, and overturning loads, the accumulation of irreversible displacement, and the foundation uplift, and so is one of the most complete benchmark data sets for the development and validation of numerical models for the nonlinear response of shallow foundations to strong earthquakes.

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Two new polyacetylene compounds (4, 6, 12)-1-acetoxy--isovaleryloxytetradeca-4, 6, 12-trien-, 10-diyn-14-ol (), and (4, 6, 12)-1-acetoxy--(2-methylbutyryloxy)tetradeca-4, 6, 12-trien-, 10-diyn-14-ol (C) have been isolated along with (4, 6, 12)-1-acetoxy--senecioyloxytetradeca-4, 6, 12-trien-, 10-diyn-14-ol (A) from Atractylodes Rhizome (Karabyakujutu). The structures of these compounds were determined on the basis of their spectral data.

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A sample of [

3H

] tobrarnycin (

5

, 000 Ci/Mole) has been synthetized and incubated with
the bacterial ribosome and its subunits. The results obtained show that this antibiotic has
two types of binding sites. The primary one is probably responsible for the inhibition of
protein synthesis whereas the secondary one is probably related to the misreading and reading
tiirough of the messenger RNA.

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Based on the concept "intermediate soil wedge" which is dependent on mobilized frictional resistance, a new theory has been developed for evaluating the seismic earth pressures against retaining walls under any condition between the active and passive states. For this theory, the seismic earth pressure is separated into four components according to their formation. New equations are proposed to determine the distribution, resultant and point of application for each component. An equivalent seismic coefficient is introduced to take into account non-uniform seismic acceleration distribution with depth. The equations place special emphasis on dependence of the seismic earth pressure on mode and level of wall movement. The equations can be reduced to the Mononobe-Okabe equation for the limiting conditions. Their applicability was confirmed by comparing the predictions with a number of previous model test results.

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During earthquakes, saturated loose sandy soils often liquefy, causing serious damage to buildings and underground structures. Various construction methods have been employed to stabilize these soils against liquefaction. The popular methods are those which increase their density. Vibration and impact methods are commonly employed, but these often pose a problem of noise and vibration in urban areas. Results of previous experiments have shown that Quick Lime Consolidated Briquettes (QCB), a soil stabilizer made of quicklime and cement placed to form cylinders, significantly increases resistance to liquefaction by utilizing the effects of water absorption, swelling, and hardening. In the present study, shaking table tests were performed to evaluate the earthquake resistance of soil treated with QCB. Results of these test showed that the response acceleration and excess pore water pressure in QCB-treated soils were scarcely affected by the excitation of 200 Gals. The soil settlement due to shaking was about one tenth of that for the untreated soil, proving the effectiveness of QCB during earthquakes.

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A finite element model capable of taking into account nonlinear hysteretic soil behavior is presented to study earthquake induced retaining wall movement. The model also accounts for increase in lateral stresses and settlement associated with grain slip caused by cyclic loads. The predictive capability of the proposed method is verified by comparing responses given by the model with those computed by another existing finite element model and also with responses recorded at the Cambridge centrifuge facility. The study reveals that the wall displacement can be substantially affected, among other factors, by the increase in lateral stresses due to grain slip and wall-soil friction. Care should be taken when selecting a constant value of wall-soil friction angle for the entire duration of excitation since structural changes can occur in the soil adjacent to the wall.

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The curvatures and subsequent bending imposed to piles by the surrounding soil during the passage of seismic waves is studied. This type of bending develops even in the absence of a superstructure and is referred to as "kinematic" bending, to distinguish it from pile bending generated from inertia forces in the superstructure (termed "inertial" bending). Although kinematic bending may be severe in the presence of sharp stiffness discontinuities in the profile and may lead to damage, it has received little attention by engineers. The scope of this paper is threefold : (1) to review some existing design methods ; (2) to present an improved analytical model for estimating kinematic pile bending moments at an interface between two thick soil layers under dynamic SH-wave excitation ; and () to propose a simplified analysis procedure to be used for designing piles against kinematic loading. To this end, a dimensionless bending strain parameter (instead of the commonly-used bending moment) and a strain transmissibility function relating pile bending strain and corresponding soil shear strain are introduced. The two indices provide insight into the physics of the problem which is often obscured by the use of bending moments. Results from the model are in good agreement with more rigorous solutions. Numerical examples are presented.

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The dynamic response of large-diameter end-bearing cylindrical shafts is studied. First, the popular plane-strain model of Novak is reviewed and its limitations are discussed. An improved model is then developed which, while retaining the simplicity of the original model, accounts for the third dimension by considering the normal and shear stresses acting on the upper and lower faces of a horizontal soil slice. These stresses are incorporated in the analysis by impleminting a dynamic Vlasov-Leontiev approximation based on integrating the governing equations over the thickness of the soil layer. It is shown that this operation leads to a set of elastodynamic equations which are similar to those in the plane-strain model, yet properly incorporate the salient -D effects. Explicit closed-form solutions are obtained for : (i) the dynamic soil reaction along the shaft ; (ii) the dynamic impedance of the shaft ; (iii) the displacement field in the soil ; and (iv) the dynamic interaction factors between neighboring shafts. Both vertical and lateral oscillations are analyzed for single and grouped shafts. Results are presented in terms of dimensionless graphs which highlight the importance of soil-foundation interaction on the response. It is shown that the proposed model avoids the limitations of the plane strain model.

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