(

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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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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Circuit techniques to enhance the linearity of input-voltage-to-current (V/I) conversion and to increase the output impedance of a current source by compensating for the low intrinsic gain of a transistor were introduced to realize a high-frequency operational transconductance amplifier (OTA) for a low supply voltage using sub-100-nm CMOS processes. Applying these techniques, a MOS th-order Gm- linear-phase low-pass filter (LPF) was realized using a 65nm CMOS process. A simplified biquad LPF that can serve as a component of a th-order LPF was newly developed by replacing OTAs with resistors. As a result, the -dB frequency bandwidth, group delay ripple, rd-order distortion, and rd-order input intercept point (IIP) were 200MHz, 2.2%, ≤ -55dB with a 100MHz input, and +10.dBm, respectively, all with a ±0.1Vp-p input signal at each input terminal in the pseudodifferential configuration. The LPF including an output buffer dissipated 60mW in the case of a 1.2V supply. Wide spurious-free dynamic range (SFDR) characteristics were confirmed up to high frequencies.

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1. The chromosome numbers of 64 species have been studied on which 56 are investigated for the first time.
2. Morphological, anatomical and cytological findings on the Musaceae in the broad sense are considered from a phylogenetical standpoint and three distinct groups:
a) Musa-Ensete, b) Ravenala-Strelitzia-Phenakospermum and ) Holiconia are recognised as suggested by some authors. For these groups sub-familial status is proposed.
. Lowiaceae have been studied for the first time cytologically and their chromosome morphology, distinct from that of any other group of Zingiberales, confirms their claim to familial status.
4. Consideration of the conflicting theories proposed to account for the higher chromosome number in genera like Globba, Alpinia, and Phaemeria, etc. leads to rejection of Chakravorti's hypothesis of wholesale fragmentation of chromosomes and the acceptance of the opposed view of Raghavan and Venkatasubban and others.
5. Holttum's transference of the genus Zingiber to the tribe Hedychieae has been given cytological support on the following points:
a) the basic number in the genus Zingiber correlates with that of Kaempferia.
b) the new tribe Alpinieae (which is infact Zingibereae without Zingiber) have consistently 48 chromosomes in their somatic complements.
6. It is suggested that the African representatives of Kaempferia should be given the status of genus; Cienkowskya on the following points:
a) the difference in floral morphology
b) geographical separateness and
) the difference in the number and morphology of the chromosomes. By comparing the present and past findings, various lines of evolution of the chromosome complements within each group are discussed.
. The basic number 11 is considered to be probably the original one for the Zingiberales as a whole, being present in Ravenala which is the most primitive member in the order. From this secondary basic numbers have arisen through evolution.

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Repetitive liquefactions in angular and subangular gravels from an alluvial fan, in the case of two earthquakes with accelerations lower than that of a former which had caused liquefaction some months before, are described. The liquefaction took place from the surface, down to a depth of approximately 10 m. Water laden with sediments spouted out for some tens of minutes after the strong motion ceased. Knowledge of the grain size distribution of the sediments inside the body of the alluvial fan roughly defines the areas of the fan prone to future liquefaction. Non-repetitive liquefaction in overconsolidated fine fluvio-lacustrine sand of glacial origin at the unusual depth of 14 m to 16 m is also described. From the observation of sand lifted up for 10 m inside a large diameter well, and of that which spouted out from several microvents, it was estimated that extra-pore pressure was close to lithostatic conditions. Nevertheless, modeling of intrinsic pore pressure buildup on the DESRA2 programme gives lower values than the experimental one. Geotechnical characteristics of the 12 m-thick sandy stratum indicate that the upper part is unusually soft, either due to water circulation or past repetitive liquefactions which prevented reconsolidation. It is suggested that excess pore pressure generated by the earthquake was also due to redistribution of pressure from adjacent sediments.

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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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The effects of external and internal proton concentration on different cardiac K⁺ currents are reviewed. Emphasis is given to the diversity of the changes: agonist, antagonist or both, effects from outside or inside. Possible underlying mechanisms, such as changes in gating or conductance and voltagedependency are discussed.

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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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Improvements in horizontal drilling combined with recent advancement in hydraulic fracturing techniques have resulted in the production of natural gas from shale formation, being one of the fastest growing segments in the United States (U.S.) oil and gas industry today. The shale gas production boom is transforming the energy market place, where the U.S. was expecting increased volume of imported Liquefied Natural Gas (LNG) to meet its domestic natural gas demand five to six years ago, is now looking forward to exporting LNG produced from the domestic gas in less than five to six years. In addition, it is also expecting growth in a wide range of chemical manufacturing industries relying on the use of low cost natural gas and its co-products. This paper provides a general description for the shale gas with recent advancement in production techniques. The paper identifies U.S. shale gas resources and the expected increase in gas production which has revolutionized and transformed the U.S. energy picture. The paper also provides recently identified worldwide shale gas resources that can be exploited.

The growth in shale gas production will also spur the growth in the associated infrastructure including gas purification or treatment facilities installation requirement for the removal of contaminants from the gas making it suitable for the end use. The paper provides a description of the available technologies that are generally utilized in gas treatment or purification of shale gas. The paper further describes the extraction of Natural Gas Liquids (NGL), or co-products of natural gas, consisting of ethane, propane, butane and natural gasoline (or light naphtha) that provides a low cost feedstock to downstream chemical production reducing the dependency on the import of foreign oil. The increased production of ethane from the NGL will have a significant positive economic impact and added value as a chemical precursor in transforming ethane to ethylene production at a lower cost. Over the last five years, the advancement in the shale gas production techniques has not only transformed the energy industry in the U.S. but also has a potential to change the global energy picture in the future.

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ラットに

3H

-CU-

83

(S)を25μg/kgで静脈内あるいは経口投与し，血液中濃度および尿糞中排泄を検討した．
静脈内投与後の血液中濃度推移は投与後5分より上昇し，投与後45分に25.74ng eq./mlのC_maxを示し，それ以後t_1/2

3

.05時間とt_1/2 33.09時間の二相で減少した．投与後72時間までのAUCは135.42ng eq.·hr/mlであった．
経口投与では，投与後

3

時間でC_max 4.10ng eq./mlに達し，以後t_1/2α 4.46時間とt_1/2β 26.

83

時間の二相で減少した．投与後72時間までのAUCは48.62ng eq.·hr/mlであった．
静脈内投与と経口投与のいずれの場合も，尿および糞中への放射能の排泄は，投与後48時間でほぼ終了した．静脈内投与では，投与後72時間までに投与量の30.52%が尿中に，60.42%が糞中に排泄された．経口投与では，同じく72時間までに40.34%が尿中に，69.24%が糞中に排泄された．

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