Induction of labor by acupuncture electro-stimulation

Induction of labor by acupuncture electro-stimulation was carried out in 31 patients. This was successful in 21 cases. The pattern of uterine contractions induced in these patients was similar to that in normal labor. No serious fetal or maternal complications occurred. The delay between the commencement of stimulation and the onset of contractions suggests that a humoral mechanism may be involved.     

An investigation of the deposition and reactions of sulphur on gold electrodes

The oxidation of sulphide species in solution has been investigated on a gold electrode in borate solutions of pH 6.8 and 9.2 and in 1 mol dm^?3 NaOH. Sub-monolayer coverage by sulphur occurs at underpotentials. At more positive potentials, multilayers of sulphur can be deposited. The reaction producing sulphur, and the reverse process, involve the formation of poly sulphides as intermediates. The predominant polysulphide intermediate is S ₂ ^2? . Oxidation of sulphide to sulphate occurs to some extent in parallel with sulphur deposition. Both reactions are inhibited by the presence of a surface layer of sulphur. At high potentials, sulphur is oxidized to sulphate.     

The evaluation of a PCR-based method for identification of Salmonella enterica serotypes from environmental samples and various food matrices

The most commonly used method for serotyping Salmonella spp. is based on the Kaufmann–White scheme, and is composed of serological reactions using antibodies to LPS agglutinins. The multiplex PCR used in this investigation was established by Kim et al. to serotype the 30 most common clinical Salmonella serotypes, as determined by CDC. The PCR assay consists of two five-plex reactions and a single two-plex PCR reaction, based on six genetic loci from Salmonella enterica serotype Typhimurium and four loci from S. enterica serotype Typhi. In this investigation, we further evaluated the method for serotyping Salmonella spp. using a reference collection, environmental samples collected from a Mid-Atlantic region tomato farm study, four food matrices spiked with different Salmonella serotypes and a proficiency test. The PCR assay was first evaluated using DNA isolated from pure cultures of isolates obtained from various clinical and environmental samples, and then DNA isolated from broth cultures of food matrices of “Red round” and Roma tomatoes, Romaine lettuce, green onions and Serrano peppers spiked with serotypes Newport, Typhimurium, Javiana and Saintpaul, respectively. The results showed that the PCR assay correctly serotyped Salmonella spp. from the clinical, environmental, spiked food matrices, and proficiency test samples. These findings are significant because the PCR assay was successful in the identification of Salmonella in the spiked samples in a broth culture containing other non-salmonella organism. This method may be a useful resource for the food safety community.     

Investigation of the surface oxidation of bornite by linear potential sweep voltammetry and X-ray photoelectron spectroscopy

The products of surface oxidation of a natural sample of the copper iron sulphide mineral, bornite, have been determined from analysis of linear potential sweep voltammograms and from X-ray photoelectron spectroscopic examination of the oxidized layer. Anodic oxidation of bornite in alkaline media results initially in the formation of an iron(III) oxide/hydroxide and an iron-free copper sulphide of stoichiometry Cu₅S₄. The latter species is oxidized further at higher potentials to form a copper sulphide of lower copper content and cupric hydroxide. Air oxidation involves the first of these two steps. In acid solution, anodic oxidation yields iron(II) ions rather than an iron oxide in the first stage and copper(II) ions in the second. Sulphate and elemental sulphur are not formed under the experimental conditions investigated.     

Riboflavin-Sensitized Photodynamic UV Spectrophotometry for Ascorbic Acid Assay in Beverages

Riboflavin-sensitized photodynamic ultraviolet spectrophotometric assay of various commercial beverages was carried out. The maximum concentration of ascorbic acid for obtaining a background correction (15 min illumination and pH 7.5) was 21 μg/mL ascorbic acid in the testing solution. The upper limit of the measurement range for a straight line in the calibration graph of standard ascorbic acid was 10 μg/mL, (working range 0–10 μg/mL). The results in repeatability of the method for ascorbic acid contents in commercial fruit juices and soft-drinks showed a maximum of 4% relative standard deviation. Recovery tests with known amounts of added ascorbic acid in different fruit juices and sports drink showed the recovery of added ascorbic acid was 97.5–102.3%. Indophenol, iodine and/or HPLC methods were used in parallel to ascertain the reliability of the proposed method. This type assay could be successfully applied to many commercial beverages for determination of ascorbic acid with good accuracy, precision and reliability.     

Spray drying with a two-fluid nozzle to produce fine particles: Atomization,scale-up,and modeling

This article presents experimental and modeling work to complete previously reported work on spray drying. Back-calculated droplet sizes have been verified by measurements with a laser imaging rig. Flow patterns in a cylindrical spray chamber have been simulated by computational fluid dynamics and demonstrated that droplet residence times are much shorter than expected. A droplet tracking population balance model has been implemented in gSOLIDS and shows how drying times vary with droplet diameter. Particle collection by cyclone and bag filter have also been compared experimentally.     

Buffer Management Issues in the Implementation of Fast Interprocess Communication

This paper presents our experience with building a cross-domain object invocation mechanism that is conscious about memory usage. Cross-domain object invocation issues are very similar to cross-domain procedure call issues. Although the cross-domain procedure call performance issues have been discussed widely, there is very little reference to issues regarding space. It is a typical example of a case where the issues arising in practice are more complicated than the ones described in the reference literature. Our mechanism is discussed in terms of the Spring modular operating system, but the same principles are applicable to other operating systems. The Spring system is a distributed computing environment running on a networked collection of computers. Each individual Spring system is based around a microkernel known as the nucleus. The nucleus is structured to support fast and secure cross address-space object invocations. Most of the traditional operating system services are provided by servers running as user-mode domains. In a system such as Spring, fast, secure, and space-efficient cross-domain invocation is extremely important. Argument buffers are used to pass data from one process to another. For fast cross address-space procedure calls the maximum size of this buffer should accommodate a small number of page frames. In typical contemporary architectures this size varies between 5 and 10K. In a system such as Spring, where there is a large number of active calls, this size leads to excessive memory usage. Earlier measurements have shown that at run-time the marshalled form of the arguments of most of the calls is less than a hundred bytes. Copying page size objects is the only notable exception. Our implementation uses small 128 byte buffers by default. A very fast mechanism is used to extend the small buffer for calls with marshaled arguments that do not fit in the small buffer. Therefore, it is very space efficient and does not affect the overall system performance. Measurements from our implementation that support these claims are presented.     

Predicting the function and subcellular location of Caenorhabditis elegans proteins similar to Saccharomyces cerevisiae beta-oxidation enzymes

The role of peroxisomal processes in the maintenance of neurons has not been thoroughly investigated. We propose using Caenorhabditis elegans as a model organism for studying the molecular basis underlying neurodegeneration in certain human peroxisomal disorders, e.g. Zellweger syndrome, since the nematode neural network is well characterized and relatively simple in function. Here we have identified C. elegans PEX-5 (C34C6.6) representing the receptor for peroxisomal targeting signal type 1 (PTS1), defective in patients with such disorders. PEX-5 interacted strongly in a two-hybrid assay with Gal4p-SKL, and a screen using PEX-5 identified interaction partners that were predominantly terminated with PTS1 or its variants. A list of C. elegans proteins with similarities to well-characterized yeast beta-oxidation enzymes was compiled by homology probing. The possible subcellular localization of these orthologues was predicted using an algorithm based on trafficking signals. Examining the C termini of selected nematode proteins for PTS1 function substantiated predictions made regarding the proteins' peroxisomal location. It is concluded that the eukaryotic PEX5-dependent route for importing PTS1-containing proteins into peroxisomes is conserved in nematodes. C. elegans might emerge as an attractive model system for studying the importance of peroxisomes and affiliated processes in neurodegeneration, and also for studying a beta-oxidation process that is potentially compartmentalized in both mitochondria and peroxisomes.     

O6-alkylguanine-DNA alkyltransferase inactivation by ester prodrugs of O6-benzylguanine derivatives and their rate of hydrolysis by cellular esterases

To modulate the bioavailability and perhaps improve the tumor cell selectivity of O6-alkylguanine-DNA alkyltransferase (AGT) inactivators, pivaloyloxymethyl ester derivatives of O6-benzylguanine (BG) were synthesized and tested as AGT inactivators and as substrates for cellular esterases. The potential prodrugs examined were the 7- and 9-pivaloyloxymethyl derivatives of O6-benzylguanine (7- and 9-esterBG), and of 8-aza-O6-benzylguanine (8-aza-7-esterBG and 8-aza-9-esterBG) and the 9-pivaloyloxymethyl derivative of 8-bromo-O6-benzylguanine (8-bromo-9-esterBG). The benzylated purines were all potent inactivators of the pure AGT and of the AGT activity in HT29 cells and cell extracts. Each ester was at least 75 times less potent than the corresponding benzylated purine against the pure human AGT. In contrast, the activities of esters and their respective benzylated purine were similar in crude cell extracts and in intact cells. The increase in potency of esters in cellular extracts could be explained by a conversion of the respective prodrug to the more potent benzylated purine in the presence of cellular esterases. The apparent catalytic activity (Vmax/Km) of liver microsomal esterase for 8-azaBG ester prodrugs was 70-130 times greater than for BG prodrugs and 10-20 times greater than for 8-bromo-9-esterBG. Tumor cell hydrolysis of the esters varied considerably as a function of cell type and prodrug structure. These data suggest that these or related prodrugs may be advantageous for selective AGT inactivation in certain tumor types.     

Evaluation of nefazodone as a serotonin uptake inhibitor and a serotonin antagonist in vivo

Nefazodone (2-[3-[4-(3-chlorophenyl)-1-piperazinyl]propyl]-5-ethyl- 2,4-dihydro-4-(2-phenoxyethyl)-3H-1,2,4-triazol-3-one) has been reported to be effective in the treatment of depression. Antagonism of serotonin type 2A (5HT2A) receptors, as well as inhibition of the serotonin (5HT) uptake carrier, has been suggested to contribute to the antidepressant action of nefazodone in vivo (Eison et al., 1990). Nefazodone weakly antagonized the quipazine-induced rise in rat serum corticosterone levels and the quipazine-induced increase in rat hypothalamic 3-methoxy-4-hydroxy-phenylglycol sulfate, suggesting blockade of 5HT2A receptors in vivo. Nefazodone, however, failed to antagonize the p-chloroamphetamine-induced depletion of mouse or rat brain 5HT, displaying a lack of effect on the 5HT uptake carrier. These data extend previous in vitro and in vivo data (Eison, et al. 1990) reporting nefazodone to be an antagonist at 5HT2A receptors, but fail to show inhibition of the 5HT uptake carrier in the same dose range.