On the use of band-target entropy minimization to simplify the interpretation of two-dimensional correlation spectroscopy

Two-dimensional (2D) correlation spectroscopy has been extensively applied to analyze various vibrational spectroscopic data, especially infrared and Raman. However, when it is applied to real-world experimental data, which often contains various imperfections (such as noise interference, baseline fluctuations, and band-shifting) and highly overlapping bands, many artifacts and misleading features in synchronous and asynchronous maps will emerge, and this will lead to difficulties with interpretation. Therefore, an approach that counters many artifacts and therefore leads to simplified interpretation of 2D correlation analysis is certainly useful. In the present contribution, band-target entropy minimization (BTEM) is employed as a spectral pretreatment to handle many of the artifact problems before the application of 2D correlation analysis. BTEM is employed to elucidate the pure component spectra of mixtures and their corresponding concentration profiles. Two alternate forms of analysis result. In the first, the normally vxv problem is converted to an equivalent nvxnv problem, where n represents the number of species present. In the second, the pure component spectra are transformed into simple distributions, and an equivalent and less computationally intensive nv'xnv' problem results (v'相似文献   

Enzymatic synthesis of fructose 1,6-diphosphate with ATP regeneration in a batch reactor and a semibatch reactor using purified enzymes of Bacillus stearothermophilus

The enzymatic synthesis of fructose 1,6-diphosphate (FDP), an important glycolytic intermediate whose applications in the field of medicine have generated a great deal of interest, was performed in a batch reactor and a semibatch reactor. Using the batch reactor, FDP was first synthesized from glucose by three enzymatic reactions and the ATP consumed was regenerated simultaneously using conjugated enzymes, all of which were purified from crude cell extract of thermophilic Bacillus stearothermophilus. The results of the experiments performed using several enzyme concentrations suggest the existence of an optimum concentration for each enzyme at which the maximum FDP yield can be attained. Since the thermal decomposition of acetyl phosphate reduced the yield of FDP in the batch reactor, the use of a semibatch reactor in which acetyl phosphate was fed continuously was examined. The yield of FDP was improved but the time required to complete the reaction was longer, resulting in a lower productivity of FDP. The yields observed in the two reactors using various enzyme and substrate concentrations were in good agreement with the theoretical predictions calculated based on differential equations derived for the system using the rate equations and the kinetic parameters determined previously. This means that these equations can be used for the analysis of the experimental results as well as for determining the optimum experimental conditions.     

Improved Adiabatic Pseudo Domino Logic 2 (IAPDL-2)

IAPDL-2 - a modification of Improved Adiabatic Pseudo Domino Logic (IAPDL) - is presented. The basic structure is similar to the IAPDL, with a reduction of one diode and implementation of a trapezoidal power clock. This results in a smaller device count, area savings, and reduced power dissipation at low supply voltage.     

Investigating the effect of moisture protection on solid-state stability and dissolution of fenofibrate and ketoconazole solid dispersions using PXRD, HSDSC and Raman microscopy

Enhanced dissolution of poorly soluble active pharmaceutical ingredients (APIs) in amorphous solid dispersions often diminishes during storage due to moisture-induced re-crystallization. This study aims to investigate the influence of moisture protection on solid-state stability and dissolution profiles of melt-extruded fenofibrate (FF) and ketoconazole (KC) solid dispersions. Samples were kept in open, closed and Activ-vials(?) to control the moisture uptake under accelerated conditions. During 13-week storage, changes in API crystallinity were quantified using powder X-ray diffraction (PXRD) (Rietveld analysis) and high sensitivity differential scanning calorimetry (HSDSC) and compared with any change in dissolution profiles. Trace crystallinity was observed by Raman microscopy, which otherwise was undetected by PXRD and HSDSC. Results showed that while moisture protection was ineffective in preventing the re-crystallization of amorphous FF, KC remained X-ray amorphous despite 5% moisture uptake. Regardless of the degree of crystallinity increase in FF, the enhanced dissolution properties were similarly diminished. Moisture uptake above 10% in KC samples also led to re-crystallization and significant decrease in dissolution rates. In conclusion, eliminating moisture sorption may not be sufficient in ensuring the stability of solid dispersions. Analytical quantification of API crystallinity is crucial in detecting subtle increase in crystallinity that can diminish the enhanced dissolution properties of solid dispersions.     

Extravisceral masses in the peritoneal cavity: sonographically guided biopsies in 52 patients

To establish a possible correlation between the rate of cellular proliferation and already documented functional and morphological characteristics of the rat pineal gland during postnatal development, the bromodeoxyuridine labelling method was used to evaluate the fraction of cells at the S phase of the cell cycle in paraffin sections from 1-, 7-, 14- and 28-day-old rats. Numerical density, taken as an indirect measure of cell hypertrophy, was also evaluated. During the first week after birth the percentage of S phase-cells in the rat pineal gland sharply decreased from around 9% to 1.3%. A smaller but also significant decrease was found from the 7th to the 14th postnatal day where S phase cells were less than 0.5% of all pineal cells. A very low percentage was also seen in samples from 28-day-old rats. Numerical density, namely, the total number of cells per surface unit of pineal section, decreased from birth to the end of the first month. This decrease was also steeper from birth to the 7th postnatal day than at any other period of the study. These results support the idea that a strong expansion of the cellular population of the rat pineal gland precedes morphological and functional maturation and opens the way to further exploration of the relationship between functional and proliferative responses of the pineal gland.     

Influence ofR-curve behaviour on strength degradation due to Hertzian indentation

The influence ofR-curve behaviour on the post-indentation strength of two types of alumina was studied using Hertzian indentation. Soda-lime glass was included in the study to represent a material which does not exhibitR-curve behaviour. Specimens were indented with a spherical indentor with increasing loads. Post-indentation strength was measured in a mineral-oil environment using a ring-on-ring biaxial fixture. Indentation of the two aluminas produced the typical Hertzian crack pattern with a somewhat greater statistical variability than that found in soda-lime glass. The strength of the two aluminas fell into four different regimes that were separated by the onset of ring, cone, and radial crack formation, respectively.R-curve behaviour did not appreciably influence the results, undoubtedly due to the relatively narrow range of indentation loads where failure was controlled by ring and cone cracks. These strength results contrast to those obtained for soda-lime glass. In soda-lime glass, ring and cone crack nucleation occurred simultaneously with a sudden drop in strength followed by a gradual decline in strength with increasing indentation load, in accordance with the prediction of Hertzian cone-crack theory.     

Humoral immune response to tetanus-diphtheria vaccine given during extended use of chloroquine or primaquine malaria chemoprophylaxis

Immune suppression resulting from prolonged chemoprophylaxis and potential drug-vaccine interaction were investigated within the context of a randomized placebo-controlled trial that compared daily primaquine or weekly chloroquine administration for malaria prevention. After 11 months of prophylaxis, adult male subjects received a tetanus-diphtheria (Td) vaccination. Prophylaxis continued 4 weeks longer. Anti-tetanus and anti-diphtheria antibody levels were measured by ELISA at baseline and at 1, 3, 7, and 14 months after Td vaccination. All groups were comparable at baseline. Immunization triggered significant increases in anti-tetanus and anti-diphtheria IgG levels over each group's pre-Td baseline levels and those of an unvaccinated control group. Geometric mean anti-tetanus titers (GMTs) in the primaquine group were significantly higher than those of the placebo group at 1, 3, and 14 months. Anti-tetanus GMTs in placebo and chloroquine groups declined over 14 months to levels comparable to those of unvaccinated controls, but levels in the primaquine group remained significantly higher than in controls.     

Optical triple-in digital logic using nonlinear optical four-wave mixing

A new programmable optical processor is proposed for implementing triple-in combinatorial digital logic that uses four-wave mixing. Binary-coded decimal-to-octal decoding is experimentally demonstrated by use of a photorefractive BaTiO(3) crystal. The result confirms the feasibility of the proposed system.     

Nutzenpotenziale und Herausforderungen des Einsatzes von Serviceorientierten Architekturen

This article summarizes the results of an empirical study among large German enterprises regarding the value potentials and challenges of service-oriented architectures (SOA).The 21 value potentials and 13 challenges examined were identified and structured based on an advancement of SOA value models already existing in literature as well as on a series of expert interviews.Key results regarding the implementation and evaluation of the SOA-concept are: The majority of the users only run one or a few SOA-based applications and the share of services in their IT-landscape is on average about 10%. Among the design principles proposed in literature, especially loose coupling and good documentation of interfaces are implemented. Clear capsulation of functionality and the definition of Service Level Agreements (SLAs), however, are hardly applied. The interviewed companies assess the relation of the value of a SOA introduction compared to its cost currently as slightly negative, but with a positive trend for the upcoming years. It is shown that the assessment of the overall value positively correlates with the duration of SOA usage. Among the 21 examined value potentials, optimization of business processes, increased agility and cost reduction due to parallel re-use of services receive the highest ratings. According to the interviewed experts, the main challenges are operation (performance/security) and the management (governance) of the architecture. These challenges hinder value realization and lead to a moderately positive assessment of the overall concept.