Stability of the powdered dosage form prepared by unsealing the capsules: water vapor sorption and discoloration of the powdery contents of clorazepate dipotassium capsules

The hygroscopicity of the contents of clorazepate dipotassium (Mendon®) capsules (CM) was investigated by storage at various relative humidities (RHs). The CM adsorbed water vapor significantly at more than 75% RH. At the same time, a marked discoloration of CM from white to yellow was also observed during storage. On the basis of differential scanning calorimetry (DSC) and Fourier transform (FT) Raman spectroscopy, the discoloration seemed to be due to the change in clorazepate dipotassium to nordiazepam and other substances. It was found that, when opening of the Mendon capsule is necessary to prepare the powdered dosage form, the CM should be stored below 60% RH to avoid the adsorption of water vapor and discoloration.     

Inductive Synthesis of Recursive Processes from Logical Properties

This paper proposes an inductive synthesis algorithm for a recursive process. To synthesize a process, facts, which must be satisfied by the target process, are given to the algorithm one by one since such facts are infinitely many in general. When n facts are input to the algorithm, it outputs a process which satisfies the given n facts. And this generating process is repeated infinitely many times. To represent facts of a process, we adopt a subcalculus of μ-calculus. First, we introduce a new preorder _d on recursive processes based on the subcalculus to discuss its properties. p_d q means that pf implies qf, for all formulae f in the subcalculus. Then, its discriminative power and relationship with other preorders are also discussed. Finally, we present the synthesis algorithm. The correctness of the algorithm can be stated that the output sequence of processes by the algorithm converges to a process, which cannot be distinguished from the intended one (if we could know it) by a given enumeration of facts, in the limit. A prototype system based on the algorithm is stated as well.     

Vaporization of solid lithium nitride

The vaporization of solid lithium nitride has been studied by a mass spectrometric Knudsen effusion method. The solid was found to vaporize congruently to Li(g), Li₂(g) and N₂(g), and partial pressures of them may be represented by the equations: logp_Li (Pa) = (11.487 ± 0.102) ? (9.670 ± 0.081) 10³/T, logp_Li2 (Pa) = (14.306 ± 0.209) ? (14.090 ± 0.166) 10³/T and logp_N2 (Pa) = (10.959 ± 0.157) ? (9.638 ± 0.124) 10³/T in the temperature range 739–859 K. No identification of LiN(g) was made. From the combination of the determined enthalpy of the reaction Li₃N(c) = 3Li(g) + 0.5N₂(g) with appropriate literature data, the enthalpy ΔH°_f298, the free energy ΔG°_f298 and the entropy ΔS°_f298 of formation for solid lithium nitride have been obtained to be (?171.3 ± 7.7) kJ/mol, (?135.4 ± 7.7) kJ/mol and (?120.4 ± 36.5) J/mol · K, respectively.     

S/N and error rate evaluation for an optical FSK-heterodyne detection system using semiconductor lasers

Receiving performance is evaluated for an optical FSK-heterodyne detection system in which semiconductor lasers are used as both an FSK transmitter and an independent local oscillator. Noise and error rate are measured under feedback stabilization of IF signal frequency and electrical equalization of semiconductor laser FM modulation frequency characteristics. The minimum received signal power of -44 dBm, which is about 2 dB better than that in IM direct detection, is achieved at a 10^-9error rate for a 200 Mbit/s signal. Excess errors for FSK signals result from frequency broadening of the laser spectrum. Both AM and FM quantum noises in the lasers are primary factors which determine system performance. Error rate characteristics in an optical FSK direct detection system, in which a Michelson interferometer is employed as an optical frequency discriminator, are compared with the above results.     

Characteristics of wire-space-type submarine optical cable

A new type of submarine optical cable, called wire space cable, is proposed for utilisation in shallow sea areas. In the cable, optical fibres are inserted into spaces formed between stranded wires, which are used as tension members. It has been found from a cable pulling test that nonarmoured cable elongation at 8000 m in water depth is 0.3% and armoured cable elongation at 6000 m is 0.5%. Furthermore, a hydraulic pressure test has shown that single-mode-fibre loss at 1.3 ?m wavelength does not increase up to a water depth of 2700 m.     

Two large subunits of the fission yeast RNA polymerase II provide platforms for the assembly of small subunits

BACKGROUND: We analyse whether the tuberculin skin test is a good survival marker in a cohort of pulmonary tuberculosis patients with HIV infection (PTB/HIV). In all, 494 PTB/HIV patients were enrolled in Barcelona (Spain) between January 1992 and December 1994 in the Tuberculosis Program of Barcelona. The main data problem was the large proportion of missing values in the covariates percentage of T CD4+ lymphocytes and the tuberculin test results: only 157 patients (31.8%) had both covariates recorded. METHODS: Patients were dichotomized into two groups according to their level of immunosuppression (< or = 14 and >14% T CD4+ cells). First, we carried out the semiparametric and parametric complete case analysis. After this, we analysed the data assuming a missing at random non-response pattern. We developed a bootstrap approach where missing data in the markers are imputed via a two-way linear model. Using Weibull regression estimation, we used a multiple imputation scheme to estimate the parameters of interest. RESULTS: We found significative differences for the most immunosuppressed group when comparing positive tuberculin patients with those who were tuberculin negative. From a complete case approach and through a multivariate Cox analysis, we obtained a significant relative hazard of 0.3657 (95% CI: 0.13-1.02; P = 0.054). When a Weibull model was fitted, we estimated a constant relative percentile value of pR = 4.1329 (95% CI: 0.97-17.59). From a missing data approach, we obtain a higher constant relative percentile 5.48 (P = 0.079). CONCLUSIONS: The imputation method allows us to assess the protective character of positivity for the tuberculin test for the lowest CD4+ level. These findings strongly suggest the value of the tuberculin skin test as a qualitative measure of the immunological response and its interest for developing countries where specific laboratory tests are not affordable.     

The gel permeation chromatography of phenolic compounds

Gel permeation chromatography, using polystyrene gel and tetrahydrofuran as solvent, has been applied to hydroxybenzophenones, esters of salicylic acid, alkylphenols, alkylated methylenediphenols, and phenol–formaldehyde condensation products. The difference between the calculated molecular volume of these phenolic compounds and that obtained by actual determination with GPC has been ascribed to tetrahydrofuran solvation of the phenolic hydroxyl group. Furthermore, it has become clear that THF solvation is affected by the steric hindrance of ortho-substituted phenol and by inactivation of the phenolic hydroxyl group resulting from internal hydrogen bonding.     

100 km single mode VAD fibres

100 km single mode fibres with low loss values of 0.3 dB/km at 1.55 ?m and 0.5 dB/km at 1.3 ?m have been made by the VAD method. Swept frequency 6 dB down bandwidths at the two wavelengths were 40 MHz for 100 km length and 800 MHz for 50 km length, respectively.     

VLSI perspective of real-time hidden-surface elimination

VLSI (very large-scale integration) technology provides and demands new ways of solving large-scale computational problems. A pipelined version of a real-time hidden surface elimination algorithm is proposed. The approach is tuned to the requirements of the VLSI technology: it is simple and regular, employs only local communication, and attains a high degree of parallelism. The feasibility of the technique is demonstrated for a computer graphics system where objects are defined in terms of planar triangular surface elements. A case is made in terms of early 1980s technology.The use of VLSI will make high-power graphics available to the small user as well as the traditional flight simulator customer. This is achieved by enabling system expansion to take place through the addition of more identical chips. Consequently system cost is linear with respect to the number of chips used, a number determined by the maximum number of rendering elements needed by the specific user application.     

Perfect and subperfect regulation in linear multivariable control systems

This paper is concerned with the synthesis of a high-gain feedback control, called perfect regulation (p.r.), for linear multivariable systems with external signals. The existence condition for p.r. is derived, in which the minimum phase property plays an essential role. The use of an observer is discussed for achieving p.r. under restricted state observation. Some asymptotically ideal feedback properties are demonstrated, such as the complete desensitization, the complete servo performance with decoupling and the complete disturbance rejection, which formulate the loop-tightness for multivariable systems. A design method for applying p.r. to non-minimum phase systems, called subperfect regulation (s.p.r.), is proposed based on the factorization of the plant transfer function matrix into the minimum phase part and the totally non-minimum phase part. It is a multivariable extension of a well-known design technique for scalar systems to overcome the difficulty of phase non-minimality. Computational procedures for p.r. and s.p.r. are discussed. An illustrative example is shown.