Universal antenatal human immunodeficiency virus testing in Hong Kong: consensus statement

Following the recommendations of the Advisory Council on AIDS, Hong Kong, the Hospital Authority announced plans to introduce universal antenatal screening for human immunodeficiency virus infection and hence, a consensus conference was held to discuss strategies for implementing such screening in Hong Kong. This paper reports the discussions of the consensus conference. The consensus meeting group consisted of 15 clinicians and scientists from Hong Kong, Macau, and Thailand. Seven commonly asked questions concerning mother-to-child transmission of human immunodeficiency virus were selected for discussion by the participating panellists. Information on the laboratory diagnosis of human immunodeficiency virus infection and the efficacy of preventive measures in reducing mother-to-child transmission of human immunodeficiency virus were reviewed. Data from local studies was also presented and discussed. The timing, potential problems, and cost issues involved in testing all pregnant women in Hong Kong for human immunodeficiency virus were then considered.

Two cases of pyomyositis caused by Klebsiella pneumoniae and review of the literature

Two patients with diabetes mellitus developed Klebsiella pneumoniae pyomyositis involving multiple muscles and other metastatic foci associated with bacteraemia. The cases are presented here, and the 22 cases of gram-negative pyomyositis reported previously in the literature are reviewed. As gram-positive cocci cause 99% of pyomyositis, it is postulated that the pathogenesis of pyomyositis may be associated with the ability of the bacteria to adhere to muscles by various cell surface adhesins that are not present in gram-negative bacilli. It is also postulated that a high serum glucose concentration may facilitate the growth and formation of the Klebsiella pneumoniae capsule, hence increasing its virulence and causing serious disseminated Klebsiella infections in diabetic patients.

Molecular subtyping of Shigella flexneri 3a isolates by plasmid profile analysis and pulsed-field gel electrophoresis

Twenty-two clinical isolates of Shigella flexneri 3a that were obtained from stool specimens from seven outbreaks of infection in northern Taiwan were subtyped and compared using plasmid profile analysis and pulsed-field gel electrophoresis (PFGE). Among 32 isolates, three distinct patterns were found by plasmid profile analysis and six by PFGE, with three different restriction enzymes, XbaI, SfiI, or NotI. Seven PFGE patterns were observed in a comparative analysis using a combination of these three enzymes. Isolates collected from the same outbreaks had the same PFGE combination patterns and were distinguishable from those obtained during other outbreaks. These findings suggest that PFGE may be the most powerful method of genotyping S. flexneri 3a in epidemiological studies.

Characterization and modeling of the metal diffusion from deep ultraviolet photoresist and silicon-based substrate

The radioactive tracer technique was applied to investigate the out-diffusion of the transition metals (Cu, Fe and Co) from deep ultraviolet (DUV) photoresist into underlying substrate. Two important process parameters, viz., baking temperatures and substrate types (i.e., bare silicon, polysilicon, silicon oxide and silicon nitride), were evaluated. Results indicate that the out-diffusion of Co is insignificant, irrespective of the substrate type and baking temperature. The out-diffusion of Cu is significant for substrates of bare silicon and polysilicon but not for silicon oxide and nitride; for Fe, the story is reversed. The substrate type appears to strongly affect the diffusion, while the baking temperature does not. Also, the effect of solvent evaporation was found to play an important role in impurity diffusion. Using the method of numerical analysis, a diffusion profile was depicted in this work to describe the out-diffusion of metallic impurities from photoresist layer under various baking conditions. In addition, the effectiveness of various wet-cleaning recipes in removing metallic impurities such as Cu, Fe and Co was also studied using the radioactive tracer technique. Among the six cleaning solutions studied, SC2 and SPM are the most effective in impurity removal. An out-diffusion cleaning model was first proposed to describe the cleaning process. A new cleaning coefficient, h(T), was suggested to explain the cleaning effect. The cleaning model could explain the tracer results.

Vibrio parahaemolyticus serovar O3:K6 as cause of unusually high incidence of food-borne disease outbreaks in Taiwan from 1996 to 1999

The occurrence of food-borne disease outbreaks in Taiwan increased dramatically in 1996, and the incidence has since remained elevated. This increase in outbreaks is correlated with a high rate of isolation of Vibrio parahaemolyticus, which caused between 61 and 71% of the total outbreaks for the period 1996 to 1999. By serotyping, 40 serovars were identified from 3743 V. parahaemolyticus isolates, of which O3:K6 was the most frequently detected. The O3:K6 serovar could have emerged in Taiwan as early as October 1995 and at that time accounted for only 0.6% of the V. parahaemolyticus infections. This level increased suddenly to 50.1% in 1996 and reached a peak (83.8%) in 1997. Comparison of the outbreak profiles for the etiology groups indicates that the high incidence of food-borne disease outbreaks during 1996 to 1999 can be attributed to the extraordinarily high O3:K6 infections. In 1999, the O3:K6 serovar was still prevalent, and accounted for 61.3% of all V. parahaemolyticus infections. Due to its extraordinarily high infection frequency and its capability to spread globally, this organism needs to be intensively monitored internationally.

Characteristics of Vibrio parahaemolyticus O3:K6 from Asia

A variety of serovars of the food-borne pathogen Vibrio parahaemolyticus normally cause infection. Since 1996, the O3:K6 strains of this pathogen have caused pandemics in many Asian countries, including Taiwan. For a better understanding of these pandemic strains, the recently isolated clinical O3:K6 strains from India, Japan, Korea, and Taiwan were examined in terms of pulsed-field gel electrophoresis (PFGE) typing and other biological characteristics. After PFGE and cluster analysis, all the O3:K6 strains were grouped into two unrelated groups. The recently isolated O3:K6 strains were all in one group, consisting of eight closely related patterns, with I1(81%) and I5(13%) being the most frequent patterns. Pattern I1 was the major one for strains from Japan, Korea, and Taiwan. All recently isolated O3:K6 strains carried the thermostable direct hemolysin (tdh) gene. No significant difference was observed between recently isolated O3:K6 strains and either non-O3:K6 reference strains or old O3:K6 strains isolated before 1996 with respect to antibiotic susceptibility, the level of thermostable direct hemolysin, and the susceptibility to environmental stresses. Results in this study confirmed that the recently isolated O3:K6 strains of V. parahaemolyticus are genetically close to each other, while the other biological traits examined were usually strain dependent, and no unique trait was found in the recently isolated O3:K6 strains.

Characterization of Vibrio parahaemolyticus isolates obtained from foodborne illness outbreaks during 1992 through 1995 in Taiwan

Vibrio parahaemolyticus is an important foodborne pathogen in Taiwan and many other Asian countries. A total of 371 isolates of V. parahaemolyticus collected from patients involved in foodborne illness outbreaks in Taiwan from 1992 to 1995 were characterized. These isolates had typical biochemical characteristics and only 4% were urease positive. The most frequently isolated serovars were O5:K15 (18.5%), O4:K8 (16.2%), O3:K29 (12.5%), O1:K56 (8.3%), O2:K3 (6.5%), and O4:K12 (6.0%). Most of the isolates were susceptible to nalidixic acid, tetracycline, tobramycin, cephalothin, and gentamicin. About 10% of the isolates were resistant to seven or more antibiotics. Approximately 92.4% of these V. parahaemolyticus showed beta-hemolysis on Wagatsuma blood agar plate and approximately 62.1% of these isolates exhibited detectable amounts of thermostable direct hemolysin. Most of the isolates examined exhibited two copies of tdh genes on the 1.3- and 2.5-kb HindIII-digested chromosome fragments with several variations on other fragments. A pulsed-field gel electrophoresis (PFGE) subspecies typing scheme was used to analyze these domestic isolates and the O3:K6 strains from Japan, Korea, and Taiwan. Fifty seven patterns were differentiated with A, B, C, E, and H being the major domestic types (cumulatively 76% of isolates), while O3:K6 strains (PFGE type I), abruptly occurring since 1996, were genetically distant from the major domestic types.

An iterative approach for TRIGA fuel burn-up determination using nondestructive gamma-ray spectrometry

The purpose of this work is to establish a method for evaluating the burn-up values of the rod-type TRIGA spent fuel by using gamma-ray spectrometry of the short-lived fission products 97Zr/97Nb, 132I, and 140La. Fuel irradiation history is not needed in this method. Short-lived fission-product activities were established by reirradiating the spent fuels in a nuclear reactor. Based on the measured activities, 235U burn-up values can be deduced by iterative calculations. The complication caused by 239Pu production and fission is also discussed in detail. The burn-up values obtained by this method are in good agreement with those deduced from the conventional method based on long-lived fission products 137Cs, 134Cs/137Cs ratio and 106Ru/137Cs ratio.

[Relatedness of Shigella sonnei isolates from six outbreaks in Tao-Yuan area, Taiwan]

Between November 1995 and January 1996, one larger-scale outbreak of Shigella sonnei infection occurred in the area of Tao-Yuan, Taiwan. Subsequently, five outbreaks of S. sonnei infection occurred in the same area during the period from October 1998 to February 1999. Fifty-five isolates obtained from these six outbreaks were differentiated by antimicrobial susceptibility testing, plasmid profile analysis (PPA) and pulsed-field gel electrophoresis (PFGE). They were classified into two and three types by antimicrobial susceptibility testing and PPA, respectively. However, only one pattern was observed by PFGE. The molecular epidemiology by PFGE in this study indicated that they were closely-related. These data suggest that the clinical isolates obtained during the period of January 1998 to January 1999 were probably derived from the outbreak strain of 1995.

Ribotyping of Vibrio parahaemolyticus isolates obtained from food poisoning outbreaks in Taiwan

Vibrio parahaemolyticus is a prevalent food-borne pathogen in Taiwan, Japan and other Asian countries. This work presents a novel ribotyping method for the molecular epidemiological examination of this pathogen. Genomic DNA was fragmented by HindIII digestion and hybridized with cDNA probe for Escherichia coli 16S and 23S RNA genes. A total of 121 isolates obtained from outbreaks during 1992 and 1994 in Taiwan were characterized by this ribotyping method. Four to seventeen restricted fragments were visualized in these isolates. After hierarchical cluster analysis, these isolates were grouped into thirty different ribotypes. In addition, A3, A7, E3 and F1 were the major ribotypes, consisting of 22.3, 13.2, 9.1, and 8.3% of the isolates, respectively. A, E, F, G and B were the major groups, consisting of 46.2, 14.0, 9.1, 6.7, and 6.7% of the isolates, respectively. The discriminatory ability of this ribotyping method, as determined by Simpson's index of diversity, was 0.93, which closely resembled that of a previously reported pulsed-field gel electrophoresis method.

Molecular typing of Vibrio parahaemolyticus isolates, obtained from patients involved in food poisoning outbreaks in Taiwan, by random amplified polymorphic DNA analysis

Vibrio parahaemolyticus is one of the most important food-borne pathogens in Taiwan, Japan, and other countries with long coastlines. This paper reports on the development of a new random amplified polymorphic DNA (RAPD) method for the molecular typing of this pathogen. The 10-mer primer 284 (5'-CAG GCG CAC A-3') was selected to generate polymorphic amplification profiles of the genomic DNA at an annealing temperature of 38 degrees C. A total of 308 clinical isolates of V. parahaemolyticus collected during food poisoning outbreaks in Taiwan, mostly occurring between 1993 and 1995, plus 11 environmental and clinical reference strains were analyzed by this RAPD method. A total of 41 polymorphic RAPD patterns were recognized, and these patterns were arbitrarily grouped into 16 types (A to P). Types A, B, C, D, and E were the major types, and subtypes C3, C5, E1, B1, D2, and A2 were the major patterns. The major types were phylogenetically more closely related to each other than to any of the minor types.

Use of pulsed field gel electrophoresis as an epidemiological tool for analysis of sporadic associated strains of Salmonella typhi isolated in Taiwan

In order to characterize the subtypes of Salmonella typhi which cause sporadic disease in Taiwan, 55 isolates of Salm. typhi obtained from unrelated patients of sporadic cases during 1992-96 were subjected to chromosomal DNA digestion and pulsed field gel electrophoresis (PFGE). When DNAs of these 55 Salm. typhi strains were digested with XbaI, 41 PFGE patterns were observed. Strains sharing the same XbaI digestion pattern could not be further discriminated by PFGE analysis using SpeI and NotI as digestion enzymes. Thus, considerable genetic diversity exists among the Salm. typhi isolates. Although strains of the same patterns were mainly isolated during the same time, recirculation of certain infectious strains could be possible. When 12 antibiotics, i.e. ampicillin, trimethoprim/sulfamethoxazole, erythromycin, norfloxacin, tetracycline, sulphonamide, streptomycin, neomycin, chloramphenicol, kanamycin, cefoperazone and gentamycin were used to test the antibiotic susceptibility for these Salmonella isolates, only three antibiogram patterns were obtained and 49 of the 55 Salm. typhi isolates were found to belong to one pattern. Phage typing and plasmid profiles were also poor in discriminating these strains. Thus, PFGE alone may be used as a powerful tool for analysis of sporadic associated Salm. typhi strains.

Anorectal leiomyosarcomas

In adults, rectal leiomyosarcoma is uncommon, and anal leiomyosarcoma is even more rare. We report one patient with anal leiomyosarcoma and one patient with a biphasic clinical history, with three occurrences of perineal leiomyosarcomas after surgically resected rectal leiomyoma. We discuss the characteristics of these rare entities based upon a review of the literature.

Colorectal perforation with barium enema in the elderly: case analysis with the POSSUM scoring system

Colorectal perforation is a serious complication of barium-enema examination, as the resultant contamination of the intraperitoneal or extraperitoneal space may result in a severe septic course. Between 1 October 1993 and 30 September 1996, four patients had colorectal injuries after barium-enema examinations at the Far Eastern Memorial Hospital, Taipei, Taiwan. Their mean age was 80 years and three of them died, despite the implementation of early and aggressive treatment. To examine the differences between this high crude mortality rate and reports of zero mortality, we retrospectively analyzed the data with the well established predictive surgical scoring system, the Physiological and Operative Severity Score for the enUmeration of Morbidity and mortality (POSSUM), to estimate the potential risk of death in these four patients.

Computed tomography in the diagnosis of adult midgut rotational anomalies: a report of two cases

Adult midgut rotational anomalies are difficult to diagnose. Any symptoms present in adults may be the result of intermittent volvulus of the midgut. Successful outcome of this clinical condition depends on prompt diagnosis and timely surgical intervention. Computed tomography (CT) is useful in early identification of these lesions in the abdomen. However, the specific CT signs, the "superior mesenteric vein rotation" sign and the "whirl" sign, are easy to overlook if not kept in mind, as occurred in one of our two patients. In the other patient, CT played the major role in preoperative diagnosis.

Food-borne disease outbreaks due to bacteria in Taiwan, 1986 to 1995

Between 1986 and 1995, 852 outbreaks of food-borne disease involving 26,173 cases and 20 deaths were reported in Taiwan. About 80% of the outbreaks occurred in the warmer months, i.e., between April and October. Of the 852 reported outbreaks, 555 (65%) were caused by bacterial pathogens. The three most common bacteria involved were Vibrio parahaemolyticus (35%, 197 of 555 outbreaks), Staphylococcus aureus (30%, 169 of 555 outbreaks), and Bacillus cereus (18%, 104 of 555 outbreaks).

Endotracheal tube size selection guidelines for Chinese children: prospective study of 533 cases

Appropriate selection of the size of an endotracheal tube (ETT) for use in children is important both in general anesthesia and critical care practice. Past published data on guidelines for selecting ETT size in children are based on Caucasian measurements. As body build is generally different in Chinese children compared with Caucasians of the same age group, guidelines for Chinese children are needed. The aim of this study was to determine guidelines for ETT size selection by recording and comparing age, body weight, length, head girth and circumference of the right fifth finger of the child. Correlations between internal diameter (ID) of the chosen ETT and the child's data were calculated and compared. In this study, 533 Chinese children. American Society of Anesthesiolgists class I or II, aged from 3 months to 6 years, undergoing oral intubation for general anesthesia for minor pediatric surgery were enrolled. Our results showed that body length (height) had the best correlation to the size of an uncuffed oral ETT. Through stepwise regression, a formula. ETT ID = 2 + (body length (cm)/30), was obtained.

[Diagnosis of Yersinia pestis]

There is no plaque case report in Taiwan since 1952. However, it is necessary to set up a laboratory system to investigate the distribution of Yersinia pestis in the natural environment to implement the public policy for preventing plague. Besides the traditional methods; e.g. culture, microscopic observation, biochemical characteristics, anti-F1 antigen detection by slide agglutination, immunofluorescence, and phage lytic assay, PCR was used as rapid screening test in our study. These laboratory methods were used to examine whether the flea samples harvested in King-Men island carry Y. pestis. The results showed that the flea index per mouse was high but no Y. pestis was detected in the fleas.

Determination of amphetamine in human urine by dansyl derivatization and high-performance liquid chromatography with fluorescence detection

A simple procedure for the determination of amphetamine in urine with minimal sample preparation is described. This method involves direct addition of human urine to an acetone-dansyl chloride solution for simultaneous deproteinization and fluorescence derivatization. The derivatized amphetamine is then measured by HPLC with fluorescence detection. It eliminates the extraction procedures often required by other HPLC or GC methods. The effects of pH, temperature and reaction time on the derivatization reaction were investigated. The stability of amphetamine-dansyl chloride in different storage conditions was examined. The detection limit and linearity associated with this assay are discussed.

[K-serotype analyses of Vibrio parahaemolyticus isolated in northern Taiwan, 1983 through 1993]

From 1983 through 1993, 786 strains of Vibrio parahaemolyticus were collected from food-borne disease outbreaks and sporadic cases of diarrheal illness in northern Taiwan, involving 42 K-serotypes. Five top leading serotypes were K8 (36.8%), K15 (10.8%), K12 (8.7%), K56 (7.9%) and K63 (4.7%). However, a variation of K-serotypes was found during this study period. From 112 food-borne outbreaks associated with this microorganism, only 54 (48.2%) outbreaks were caused by a single serotype, while 58 (51.8%) were caused by multiple K-serotypes. Numbers of outbreaks caused by two, three and more than three K-serotypes were 29 (26%), 16 (14.2%), and 13 (11.6%), respectively. In a special outbreak, eight K-serotypes was found. Outbreaks caused by party caterers were most frequently associated with multiple K-serotypes.

Food-borne disease outbreaks in Taiwan, 1994

In 1994, 102 outbreaks of food-borne disease involving 4,726 cases were reported to the Taiwan Department of Health. This is the highest number of outbreaks and cases in recent years in Taiwan. Of these outbreaks, 72.5% (74/102) were caused by bacterial pathogens, with Vibrio parahaemolyticus responsible for 56.7% (42/74), Staphylococcus aureus 20.3% (15/74), Bacillus cereus 14.9% (11/74) and Salmonella spp other than S. typhi and S. paratyphi 8.1% (6/74). V. parahaemolyticus has been a leading cause of problems in Taiwan for many years. Contamination of seafood with this organism has been reported frequently, particularly in the warmer months. In 1994, small outbreaks (fewer than 5 cases) and large outbreaks (more than 50 cases) represented 31.4% (32/102) and 12.7% (13/102), respectively, of the total. The median outbreak size was 10 cases. A high proportion (54%, 7/13) of the large outbreaks was associated with commercial lunch-boxes supplied to elementary and junior high schools. Health education to improve food sanitation and supervision of food sanitation practices need to be strengthened.

Polarized spectral emittance from periodic micromachined surfaces: V. Undoped silicon: angular measurement in shallow lamellar gratings

Experimental results of thermal emittance from lamellar gratings in intrinsic silicon are presented along with a theoretical discussion. For azimuthal angular directions in shallow gratings, enhanced thermal emission plateaus and maxima are observed. In the case of p-polarized emission in the Phi = 90 degrees azimuth (parallel to the grating vector), the plateau arises when two diffractive orders can be supported; it lies between the Rayleigh polar angles corresponding to the forbidden zone. The experimentally observed angular dependence of the s-polarized emission for the Phi = 90 degrees azimuth has been compared with a coupled-wave calculation, and a respectable agreement has been obtained. For the experimentally observed s-polarized emission in the Phi = 0 degrees azimuth (perpendicular to the grating vector), there is an onset of enhanced emission at the polar angles that follows a simple empirical relation unrelated to any known diffraction law. By contrast, the p-polarized emission in the Phi = 0 degrees azimuth shows relatively little structure. These data illustrate the value of thermal emission for surveying multivariate absorption processes involving microstructures.

Detection and identification of toxigenic Vibrio cholerae O1 strains by a simplified polymerase chain reaction method

The polymerase chain reaction (PCR) with three oligonucleotide primers was used to amplify both 184 bp and 425 bp DNA fragments of cholera toxin A subunit gene (ctxA) for detection and identification of toxigenic V. cholerae O1 strains in one step. For enhancing the sensitivity, we have used the chemiluminescent detection system for Southern hybridization. A total of 92 Vibrio strains were tested by both PCR and enzyme-linked immunosorbent assay (ELISA). Three E. coli (ETEC) strains, one toxigenic V. mimicus, and one toxigenic V. cholerae non-O1 were also tested for cross reactivities. Our results indicated that the correlation between the immunological ELISA method and the molecular biological PCR method were very well. The lowest detectable amount of the purified serotype Inaba chromosomal DNA by PCR is 2 pg and 0.4 pg by chemiluminescent detection system. In this work we report a PCR assay with a combination of three primers to detect and identify the ctxA of V. cholerae O1 in one step. The simplified and accurate method is useful for toxigenic V. cholerae O1 detection and identification.

Adaptative control of above knee electro-hydraulic prosthesis

Conventional designs of an above-knee prosthesis are based on mechanisms with mechanical properties (such as friction, spring and damping coefficients) that remain constant during changing cadence. These designs are unable to replace natural legs due to the lack of active knee joint control. Since the nonlinear and time-varying dynamic coupling between the thigh and the prosthetic limb is high during swing phase, an adaptive control is employed to control the knee joint motion. Two dimensional simulation indicates that the adaptive controller can improve the appearance of gait pattern. It is adaptable to walking speed and can compensate for the variations of hip moment, hip trajectory and toe-off conditions.

Adult descending colocolic intussusception caused by a large lipoma

Adult intussusception is uncommon and varies considerably from the more common occurrence of this disorder in infants and children. Although lipoma represents the most common benign tumor of the colon, it is a relatively rare cause of gastrointestinal symptoms. A rare case of adult intussusception of the descending colon caused by a giant lipoma is presented and discussed.

Polarized spectral emittance from periodic micromachined surfaces: IV. Undoped silicon: Normal direction in deep lamellar gratings

Experimental results of thermal emittance from deep gratings are presented along with a theoretical discussion. We have found that for a certain grating geometry thermal emission peaks coincide with the cutoff frequencies of slab waveguides. The coincidence was found with s- but not p-polarized emission. This suggests that coupling between grating fins for s-polarized emission is small. It was also found that emission peaks do not correlate directly with the well-known grating equation for these deep gratings.

[Experience of surgical treatment for colorectal endometriosis: report of 6 cases]

Endometriosis is a common disease with 8-15% occurrence in women during their reproductive period. Involvement of the bowel wall occurs rather frequently and probably presents in 12-34% of patient with pelvic endometriosis. However, it is classically asymptomatic and difficult to find out. From 1977 to 1987, we had six patients of colorectal endometriosis with mainly bowel symptoms. Five of them were located at rectum and sigmoid colon, one at the hepatic flexure of colon. All of the cases developed constipation or diarrhea, and four of them had severe abdominal pain. Four cases developed rectal bleeding. Previous operation for pelvic endometriosis was noted in two cases. The detailed examination included digital examination, endoscopy, barium enema and CT scan. Suspected malignancy was the indication for surgery in 4 cases and one in rectal stenosis. Low diagnostic rate was due to the fact that endometrial tissue rarely infiltrates the mucosa. Therefore, pathology of biopsied specimen often reveals non-conclusive finding to prevent differential diagnosis. However bowel resection offers conclusive diagnosis and chances of cure. In our study, only one suspected endometriosis case received bilateral oophorectomy. The stenotic segment of rectum restored to normal caliber after operation.

Junctional ectopic tachycardia in infancy: report of two cases

Junctional ectopic tachycardia (JET) in infancy is one of the serious arrhythmias which can be fatal. Typical features of JET include rapid and irregular heart beats with atrioventricular dissociation. Two cases of JET are reported: Case 1 was a 35-week-gestational age newborn who was found to have hydropsy and fetal tachycardia at the 21st week of gestational age. Antiarrhythmic agents including digoxin, propranolol and verapamil were administered to his mother to treat the fetal arrhythmia without success. JET was recognized at birth which was spontaneously converted into a sinus rhythm at 1 month of age. The maternal history revealed that two previous pregnancies ended in hydrops fetalis, and one of these was documented to have fetal tachycardia. Case 2 was a 6-month-old male infant with JET and congestive heart failure. After failure of various antiarrhythmic agents, amiodarone finally slowed down his heart rate and controlled his congestive heart failure.

Formulation and evaluation of a hydrophobic composite plastic

A hydrophobic co-polymer, heptafluorobutylmethacrylate co-para vinyl phenol, was compounded with ethylene glycol dimethacrylate and silanated quartz to produce a hydrophobic composite. The experimental composite had satisfactory working properties and had mechanical properties comparable to commercial composite but a higher modulus of resilience. The wear resistance was equal to or greater than the commercial composite depending on whether a two-body abrasion test or a track width versus normal load test was used for the evaluation. The thermal coefficient of expansion and water sorption values were somewhat higher than those of commercial composites.

Optical parallelism measurement of ruby laser rods

A simple method to examine the optical parallelism between planar end faces of a ruby rod is suggested. When the ruby rod is illuminated by an expanded He-Ne laser beam with linear polarization, the interference pattern due to the recombination of the E and O rays at a Polaroid analyzer shows its optical parallelism. This optical parallelism, which depends not entirely on the mechanical wedge angle but also on the equivalent wedge angle produced by lineage, can be employed as a criterion to show whether or not the ruby rod is suitable in an E-ray oscillation laser system.