Wearable EDA sensor gloves using conducting fabric and embedded system

We developed wearable EDA sensor gloves using conducting fabric and embedded system. EDA(Electro-dermal Activity) signal is an electric response on the skin of the human body. There are SCL(Skin Conductance Level) and SCR(Skin Conductance Response) in EDA. Mostly, SCL consists of DC elements. On the other hand, SCR consists of AC elements. We use the relationship between the drowsiness condition and EDA signal We made EDA sensors using conducting fabric instead of Agcl electrode for a more suitable wearable device. And we used an embedded system for EDA signal acquisition and processing instead of a personal computer, which is connected to the EDA sensor gloves through conducting fabric lines. Also, the embedded system is linked to a Notebook PC that shows the results of EDA signal processing analysis and gives proper feedback to the user. This system, for example, can be used in detecting and preventing drowsiness driving accidents for automobile drivers.

Phase I study of troxacitabine administered by continuous infusion in subjects with advanced solid malignancies

BACKGROUND

Troxacitabine is a novel L-nucleoside analogue. Preclinical studies showed improved activity with infusions of at least 3 days compared with bolus regimens, especially at concentrations >20 ng/ml. This phase I study tested the feasibility of achieving a troxacitabine steady-state concentration of 20 ng/ml for at least 72 h in patients with solid tumors.

PATIENTS AND METHODS

Patients with solid tumors received troxacitabine as a progressively longer infusion on days 1-4 of a 28-day cycle. The initial length of infusion and infusion rate were 48 h and 3 mg/m(2)/day.

RESULTS

Twenty-one patients were treated at infusion lengths that increased from 48 to 72 h and then 96 h. The infusion rate was decreased from 3 to 1.88 mg/m(2)/day due to toxicity. Dose-limiting toxicities consisted of grade 4 neutropenia (three) and grade 3 constipation (one). The maximum tolerated dose of continuous infusion troxacitabine in patients with solid tumors is 7.5 mg/m(2) administered over 96 h. This dose level resulted in steady-state drug concentration of at least 20 ng/ml for 72 h.

CONCLUSIONS

Administration of troxacitabine by continuous infusion achieved the prospectively defined target plasma concentration. Pharmacokinetics (PK) modeling coupled with real-time PK assessment was an efficient approach to conduct hypothesis-driven phase I trials.

Molecular characteristics of the porcine DLK1 and MEG3 genes

Imprinted genes play important roles in embryo survival and postnatal growth regulation. The DLK1 and MEG3 (previously GTL2) genes are linked and reciprocally imprinted in several mammals, but their imprinting status is still unknown in pigs. In this study, we report polymorphisms, imprinting status and QTL analyses of the porcine DLK1 and MEG3 genes. Muscle and adipose DNA and RNA samples from 30-day-old animals generated with reciprocal crosses between the Korean native pig (KNP) and Yorkshire breeds were used to analyse DLK1 and MEG3 variation and expression. The samples exhibited paternal expression of DLK1 and maternal expression of MEG3 in pigs. These results indicated that the imprinting status of the DLK1 and MEG3 genes is conserved across mammalian species. By linkage analyses, we assigned the DLK1 and MEG3 genes to the telomeric region of SSC7. By QTL analyses, we confirmed a significant polar overdominance (POD) effect in DLK1, which was previously detected for several growth traits in pigs. However, no significant POD effect was found with the MEG3 locus.

Effect of a new infrared light device (1100-1800 nm) on facial lifting

Laser skin resurfacing procedures can be classed into two categories - invasive and non-invasive. The last several decades have witnessed a host of advancements in ablative laser therapy and other ablative modalities for the rejuvenation of skin, including the CO(2) laser, the erbium : yttrium aluminum garnet laser, chemical peels, and dermabrasion. Despite the excellent results that can result from the practice of these techniques by experienced surgeons, the invasive nature of these devices is associated with inherent risks and patient discomfort. Therefore, much of the focus has been on non-ablative lasers and intense-pulsed light devices. We evaluated the efficacy and safety of treatment with the new infrared light device (1100-1800 nm), Titan, and assessed the degree of improvement associated with two-time laser treatments, as compared to one-time laser treatment.

Enhancing intensity of emitted light from a ring by incorporating a circular groove

We fabricated a ring containing a single circular groove (RCG) on silver film and which was supported on a glass substrate. We found that by changing the mean radius of the circular groove, the light intensity emitted from the RCG can be modulated by using the scattering light from the circular groove. In addition, we also fabricated circular grooves with the same depth but of different widths so that we could examine the scattering light behavior of the grooves. Herein, we propose a theoretical model which takes into account the amplitude modulation of the cylindrical waves. Our results showed that our proposed model agreed well with the experimental results.

Removal of basic and reactive dyes using ethylenediamine modified rice hull

Wastewaters from textile industries may contain a variety of dyes that have to be removed before their discharge into waterways. Rice hull, an agricultural by-product, was modified using ethylenediamine to introduce active sites on its surface to enable it to function as a sorbent for both basic and reactive dyes. The sorption characteristics of Basic Blue 3 (BB3) and Reactive Orange 16 (RO16) by ethylenediamine modified rice hull (MRH) were studied under various experimental conditions. Sorption was pH and concentration dependent. Simultaneous removal of BB3 and RO16 occurred at pH greater than 4. The kinetics of dye sorption fitted a pseudo-second order rate expression. Increase in agitation rate had no effect on the sorption of BB3 but increased uptake of RO16 on MRH. Decreasing particle size increased the uptake of dyes in binary dye solutions. Equilibrium data could be fitted into both the Langmuir and Freundlich isotherms. Maximum sorption capacities calculated from the Langmuir model are 14.68 and 60.24 mg/g for BB3 and RO16, respectively in binary dye solutions. This corresponds to an enhancement of 4.5 and 2.4 fold, respectively, compared to single dye solutions. MRH therefore has the potential of being used as an efficient sorbent for the removal of both dyes in textile wastewaters.

Successful management of recurrent coccygeal hernia with the de-epithelialised rectus abdominis musculocutaneous flap

OBJECTIVE

Little data exist about the optimal management of the rare coccygeal hernia. A novel method of repair is reported.

METHODS

A 46-year-old woman presented with a symptomatic coccygeal hernia after resection of the coccyx for a tumour. She had previously been reconstructed with an on-lay polytetrafluorethylene (PTFE) mesh but subsequently developed a hernia. A de-epithelialised vertical rectus abdominis musculocutaneous flap was elevated and passed through the hernia defect. The de-epithelialised dermis was secured to the levator ani and to the periosteum of the sacrum via access through a posterior approach. The gluteal skin was closed primarily over the inset flap.

RESULTS

The de-epithelialised rectus abdominis musculocutaneous flap is a viable option for the treatment of coccygeal hernia.

RELEVANCE

The de-epithelialised rectus abdominis flap has several advantages over other techniques including mesh repair and anterior or posterior flap repairs of the coccygeal hernia. The transposed muscle blocks herniation through the pelvic floor and does not create the dead space that is associated with posterior flap repairs such as the bilateral gluteal advancements. It also has the advantages of the posterior approach mesh repair, as the de-epithelialised dermis provides significant strength when secured like mesh to healthy local tissue.

Enzymatic deinking of laser printed office waste papers: some governing parameters on deinking efficiency

The protocol for the enzymatic deinking of laser printed waste papers on a laboratory scale using cellulase (C) and hemicellulase (H) of Aspergillus niger (Amano) was developed as an effective method for paper recycling. A maximum deinking efficiency of almost 73% by the enzyme combination of C:H was obtained using the deinking conditions of pulping consistency of 1.0% (w/v) with the pulping time of 1.0min, temperature of 50 degrees C, pH=3.5, agitation rate of 60rpm, pulp concentration of 4% (w/v), concentration of each enzyme of 2.5U/g air dried pulp and the enzyme ratio of 1:1. The deinking efficiency was further enhanced to 95% using the optimized flotation system consisting of pH=6.0, Tween 80 of concentration 0.5% (w/w), working air flow rate of 10.0L/min and temperature of 45 degrees C. The deinked papers were found to exhibit properties comparable to the commercial papers suggesting the effectiveness of the enzymatic process developed.

Portable microscopic cell counter for the determination of residual leucocytes in blood components

BACKGROUND AND OBJECTIVES

The accurate determination of residual white blood cell (WBC) in blood components is of considerable clinical importance, and a variety of methods have been devised for the counting of low levels of residual WBC. In this study, we evaluated the performance of microscopic cell counter with microchannel plastic chip (C-reader) with regard to its ability to quantify WBC in WBC-reduced red cell concentrates.

MATERIALS AND METHODS

In order to quantify residual WBC with the microscopic cell counter, WBC-reduced red cell concentrate was stained using propidium iodide. Three studies were performed: linearity, precision and correlation compared to those of manual Nageotte chamber counting and automatic flow cytometric methods.

RESULTS

Dilution experiments, conducted over a range of 0.7-712 WBC/microl, showed a linearity of r(2) > 0.999, with coefficient of variation values of < or = 15.6% and accuracy of 93.8% over all tested ranges. In comparison with the Nageotte chamber counting and flow cytometric methods, the correlation coefficients were r(2) > 0.995. The detection limit of this method was 0.24 WBC/microl. Total analysis time per sample was approximately 5 min.

CONCLUSION

The microscopic cell counter for residual WBC counting was determined to be efficient at the level of currently defined standards, with acceptable precision and accuracy. This method may prove useful for the quality assurance and control of WBC-depleted blood products.

Predicting potential drop-out and future commitment for first-time donors based on first 1·5-year donation patterns: the case in Hong Kong Chinese donors

BACKGROUND AND OBJECTIVES

Adequate blood supply is crucial to the health-care system. To maintain a stable donor pool, donation-promotion strategies should not only be targeted in recruitment but also focus on retaining donors to give blood regularly. A study using statistical modelling is conducted to understand the first 4-year donation patterns for drop-out and committed first-time blood donors and to build model for the donor-type identification based on their first 1.5-year donation patterns.

SUBJECTS AND METHODS

First-time whole blood (n= 20 631) adult donors recruited in year 2000 and 2001 in Hong Kong were observed for more than 4 years. Cluster analysis was first applied to group donor type by their similarities in donation behaviour under the surveillance period. A decision tree model based on a shorter surveillance period (1.5 years) is then built to predict the donor type.

RESULTS

Three donation patterns - one-time, drop-out, and committed donor behaviour - were identified in cluster analysis. Three variables - donation frequencies in the first-year and in the half-year period after first year, and the number of donation centre visits in the following half year after first year, were able to predict drop-out donors with potential to become committed and committed donors with relatively lower donation frequency.

CONCLUSIONS

The present statistical modelling is able to identify those donors with potential to become committed donors and those committed donors who can donate more frequently. This information is useful for development of targeted donor retention strategies.

Tissue microarrays characterise the clinical significance of a VEGF-A protein expression signature in gastrointestinal stromal tumours

A tissue microarray analysis of 22 proteins in gastrointestinal stromal tumours (GIST), followed by an unsupervised, hierarchical monothetic cluster statistical analysis of the results, allowed us to detect a vascular endothelial growth factor (VEGF) protein overexpression signature discriminator of prognosis in GIST, and discover novel VEGF-A DNA variants that may have functional significance.

Evaluation of surface and superficial dose for head and neck treatments using conventional or intensity-modulated techniques

With increased use of intensity-modulated radiation therapy (IMRT) for head and neck treatment questions have arisen as to selection of an optimum treatment approach when either superficial sparing or treatment is desired. Other work has pointed out the increased superficial dose resulting from obliquity effects when multiple tangential beams are applied to head and neck treatment, as is the general case in IMRT planning. Helical tomotherapy might be expected to result in even further enhanced superficial dose compared with conventional bilateral field treatment. We have designed a typical right oropharynx target volume in an anthropomorphic head and neck phantom. Three different treatment techniques have been used to optimally treat this target, including bilateral static fields, eight-field IMRT and helical tomotherapy. The phantom was immobilized in a standard treatment position and treated on a Varian 2300cd linear accelerator and on a Hi-Art Helical Tomotherapy unit. 1 mm3 lithium-fluoride thermoluminescent dosimeters (TLDs) were placed on the surface of the phantom at a number of axial test positions. Film strips (Kodak EDR2) were either wrapped around the surface or sandwiched within the phantom. Measured doses at the surface and as a function of depth are compared with the planning system predictions for each treatment technique. The maximum surface doses on the proximal treatment side, averaged from TLDs and films, were measured to be 69-82% of the target dose with the bilateral fields yielding the lowest surface doses (69%), tomotherapy about 2% more than that (71%) and IMRT 13% more (82%). Anterior to the target volume, doses are always low for bilateral treatment. In this case the minimum anterior surface dose (chin area) was 6% of the prescription dose from that technique as compared with 26% and 35% from the IMRT and tomotherapy methods, respectively. The Eclipse and Tomotherapy planning systems both modelled deep and superficial doses well. Surface doses were better modelled by Eclipse at the test points, while the tomotherapy plans consistently overestimated the measured doses by 10% or more. Depth dose measurements, extracted from embedded films, indicated the depth of dose build-up to >99% to be the shallowest for IMRT (2-5 mm) followed by tomotherapy (5-8 mm) and bilateral fields (10-15 mm). The amount of surface dose is clearly technique dependent and should be taken into account in the planning stage.

Congenitally missing maxillary primary canines: report of three cases

BACKGROUND

Hypodontia is uncommon in the primary dentition and lateral incisors are the most commonly missing primary teeth in the patients affected. Studies have found that hypodontia in the primary dentition involving only maxillary canine is rare.

CASE REPORTS

Three cases of hypodontia in the primary dentition involving only maxillary canine are presented. Two of them were affected by hypodontia and hyperdontia in the permanent dentitions respectively, yet all the permanent canines developed normally in these three cases.

CONCLUSION

In children with congenitally missing maxillary canines, the permanent dentitions may show diverse anomalies in tooth numbers, ranging from hypodontia to hyperdontia.

[A field epidemiological study on the risk factors of injury caused by typhoon]

OBJECTIVE

To determine the risk factors involved in the typhoon episodes and to put forward and evaluate the intervention measures.

METHODS

We defined a confirmed injury case as: 'a person with fall,scalpel and stab, collision, drowning, injuries and trauma due to flying debris and building collapse, asphyxiation due to entrapment in collapsed buildings by typhoon from 0 am,August 12 to 6 pm, August 14 2004' and a death case as: 'a person with fall, scalpel and stab, collision, drowning, injuries and trauma due to flying debris and building collapse, asphyxiation due to entrapment in collapsed buildings by typhoon from 0 am, August 12 to 12 am, August 18 2004'. We investigated all hospitalized injured cases in ten hospitals and telephoned to those who were not hospitalized and the cases of death. We did case-control study with 1 pair versus 2 cases. 74 cases were selected in ten hospitals. The controls were neighbors of the controls matched by occupation, sex, village, and within 5 years of age without injury in this typhoon. We asked the cases and the controls on their alertness regarding typhoon and what actions taken when typhoon arrived.

RESULTS

There were 392 injury cases in all ten hospitals and 50 death cases. The attack rate of injury was 27.3 per 100 000. The fatal rate was 11.3% with the death rate 3.1 per 100 000. We investigated 209 injury cases and 31 death cases. The number of cases who were injured from 1 to 6 hours before typhoon landing accounted for 64.6% (155) of all cases. The peak of epidemic curve was 4 hours before the landing of typhoon. Data on the analysis of 74 cases and 148 controls revealed that 42% (31) of the cases were outside their homes before and during typhoon compared to 15% (22) of the controls (OR = 3.9, 95% CI: 1.9-7.7). Compared with 20% (30) control persons (OR = 17,95% CI: 4.2-68). 28% (21) cases did not receive the alert of typhoon before it arrived compared with 18% (27) control persons (OR = 3.3, 95% CI:1.3-8.6). 53% (39) of the cases did not pay attention to the alert of typhoon before typhoon arrived.

CONCLUSION

Staying outdoor, not receiving or did not take seriously about the alert of typhoon seemed to be the risk factors of injury by the typhoon episode, suggesting that the government should increase the emergency preparedness and to raise the awareness on risks associated with typhoon.

Similarities and differences for light-induced surface plasmons in one- and two-dimensional symmetrical metallic nanostructures

Two types of double-sided nanostructure, one possessing a slit aperture with parallel grooves and the other possessing a circular aperture with concentric grooves, were fabricated to examine the similarities and differences of their diffraction behavior in one-dimensional (1-D) and two-dimensional (2-D) nanostructures. Based on the projection-slice theory, we conjecture that the surface plasmons in these two different nano-scale grooves possess similar modes. A localized surface plasmon (LSP) was used to examine the transmission characteristics induced by the apertures. The transmission characteristics of the slitted nanostructure and the circular nanostructure aperture were then measured. We coupled the transmission spectra measured from these two apertures with a 1-D parallel groove transmission curve simulated by a 1-D rigorous coupled wave analysis. Measured spectra results show reasonable agreement with the simulated data. We propose that the apparent blueshift observed in the peak frequency of a 2-D nanostructure is due to the difference in the shape of the aperture and the spot transmission characteristics of 1-D and 2-D systems as induced by a LSP.

Association of melanocortin 4 receptor (MC4R) and high mobility group AT-hook 1 (HMGA1) polymorphisms with pig growth and fat deposition traits

The aim of this study was to analyse the combined effect of melanocortin 4 receptor (MC4R) and high mobility group AT-hook 1 (HMGA1) polymorphisms on growth and fatness traits in Duroc pigs. No significant interaction was observed between MC4R and HMGA1 for back-fat traits. An additive mode of inheritance of both gene effects was found for average daily gain and lean meat content. Maximum mean differences from combined genotypic effects were over 2 mm for back fat, 70 g/day for average daily gain and 2% for lean meat content. Therefore, utilization of polymorphisms in both MC4R and HMGA1 for marker-assisted selection could result in an economic benefit to the pig industry.

Oxidative Metabolism in Pediococcus pentosaceus III. Glucose Dehydrogenase System

Lee, Chin K. (North Carolina State of the University of North Carolina, Raleigh), and Walter J. Dobrogosz. Oxidative metabolism in Pediococcus pentosaceus. III. Glucose dehydrogenase system. J. Bacteriol. 90:653-660. 1965.-A method was developed for the purification of glucose dehydrogenase from Pediococcus pentosaceus Az-25-5. The procedures included treatments with protamine sulfate, ammonium sulfate, and heat in addition to acid precipitation, calcium phosphate adsorption and elution, and diethylaminoethyl-Sephadex column chromatography. The final preparation thus obtained was purified 255-fold and exhibited both similarities and dissimilarities to the same enzyme isolated from other sources. The enzyme is absolutely specific for nicotinamide adenine dinucleotide phosphate (NADP) as a cofactor, and oxidizes only glucose or its analogue 2-deoxyglucose via the following reversible reaction: beta-d-glucose + NADP right harpoon over left harpoon d-glucono-delta-lactone + NADPH(2) + H(+). K(m) values were 2.3 x 10(-2) for glucose and 2 x 10(-4) for NADP. Monovalent cations were required for stability of the enzyme and stimulated activity. The pH optimum was 7.0, and the equilibrium constant was determined to be 13.4 x 10(-7) at pH 6.4. Among the Lactobacillaceae, glucose dehydrogenase activity was found to be essentially limited to members of the genus Pediococcus. Studies on the enzymatic composition of P. pentosaceus viewed in conjunction with other available data led to the conclusion that this enzyme is not involved to any significant extent in the energy metabolism of this organism.

Beaming light from a subwavelength metal slit surrounded by dielectric surface gratings

In this article, we demonstrate that a subwavelength metal slit surrounded by dielectric surface gratings possesses a directional beaming effect. We propose a surface plasmon diffraction scheme to explain the three kinds of beaming conditions. The numerical simulations of the illustrative structures undertaken used a Finite Difference Time Domain (FDTD) Method and a Rigorous Coupled Wave Analysis (RCWA) Method. Our simulations were found to be consistent and in agreement with the experimental results. In comparison with other metal structures, we find that dielectric metal structures offer better performance as well as the advantage of being able to be efficiently mass produced for large volume industrial applications.

Accumulation of chromium (VI) from aqueous solutions using water lilies (Nymphaea spontanea)

This study describes an investigation using tropical water lilies (Nymphaea spontanea) to remove hexavalent chromium from aqueous solutions and electroplating waste. The results show that water lilies are capable of accumulating substantial amount of Cr(VI), up to 2.119 mg g(-1) from a 10 mg l(-1) solution. The roots of the plant accumulated the highest amount of Cr(VI) followed by leaves and petioles, indicating that roots play an important role in the bioremediation process. The maturity of the plant exerts a great effect on the removal and accumulation of Cr(VI). Plants of 9 weeks old accumulated the most Cr(VI) followed by those of 6 and 3 weeks old. The results also show that removal of Cr(VI) by water lilies is more efficient when the metal is present singly than in the presence of Cu(II) or in waste solution. This may be largely associated with more pronounced phytotoxicity effect on the biochemical changes in the plants and saturation of binding sites. Significant toxicity effect on the plant was evident as shown in the reduction of chlorophyll, protein and sugar contents in plants exposed to Cr(VI) in this investigation.

Implications of increased tumor blood flow and oxygenation caused by mild temperature hyperthermia in tumor treatment

In many past clinical studies in which hyperthermia enhanced the efficacy of radiotherapy, the tumor temperatures could be raised only to 40-42 degrees C range in most cases. The heat-induced cell death, cellular radiosensitization, and vascular damage induced by such mild temperature hyperthermia (MTH) are likely to be insignificant despite the increased response of tumors to radiotherapy. Heating rodent tumors at 40-42 degrees C was found to cause an enduring increase in blood flow and oxygenation in the tumors. Recent studies with canine soft tissue sarcoma and human tumor clinical studies also demonstrated that MTH improves tumor oxygenation, and enhances response of the tumors to radiotherapy or chemoradiotherapy. The increased blood flow and vascular permeability caused by MTH may also improve the delivery of various therapeutic agents such as chemotherapy drugs, immunotherapeutic agents and genetic constructs for gene therapy to tumor cells. MTH as a means to potentiate the efficacy of radiotherapy and others warrants further investigation.

Effects of growth factors and feeder cells on porcine primordial germ cells in vitro

As embryonic stem (ES) cells are not available in swine, embryonic germ (EG) cells derived from primordial germ cells (PGCs) are an alternate source of pluripotent embryonic cells for genetic modification through homologous recombination. Although morphological and biochemical characteristics are similar between ES and EG cells, culture conditions are quite different. To optimize the culture condition for the establishment of porcine EG cells, porcine PGCs were cultured in vitro with various combinations of growth factors (leukemia inhibitory factor [LIF], stem cell factor [SCF], and basic fibroblast growth factor [bFGF]) and on different kinds of feeder cells (STO, TM(4), Sl/Sl(4) m220, porcine embryonic fibroblasts, and COS-7 cells). Optimal results were obtained when all three growth factors (LIF, SCF, and bFGF) were present in the media. Also, feeder cells expressing membrane-bound SCF are required for survival and establishment of porcine EG cells. Therefore, a combination of growth factors and proper feeder cells are critical for the establishment of undifferentiated porcine EG cells.

Inhibition of histone deacetylase 2 increases apoptosis and p21Cip1/WAF1 expression, independent of histone deacetylase 1

Histone deacetylases (HDACs) 1 and 2 share a high degree of homology and coexist within the same protein complexes. Despite their close association, each possesses unique functions. We show that the upregulation of HDAC2 in colorectal cancer occurred early at the polyp stage, was more robust and occurred more frequently than HDAC1. Similarly, while the expression of HDACs1 and 2 were increased in cervical dysplasia and invasive carcinoma, HDAC2 expression showed a clear demarcation of high-intensity staining at the transition region of dysplasia compared to HDAC1. Upon HDAC2 knockdown, cells displayed an increased number of cellular extensions reminiscent of cell differentiation. There was also an increase in apoptosis, associated with increased p21Cip1/WAF1 expression that was independent of p53. These results suggest that HDACs, especially HDAC2, are important enzymes involved in the early events of carcinogenesis, making them candidate markers for tumor progression and targets for cancer therapy.

Prevention of transfusion-transmitted hepatitis E by donor-initiated self exclusion

Safety in blood transfusion has all along been focused on blood borne viruses like HIV, hepatitis B and C. However, infective agents that are not usually transmitted through blood may also pose risk to transfusion if the donor gives blood in the early-viraemic phase. A case report of potential transfusion-transmitted hepatitis E (HEV) is described. It shows the virus can be transmissible via blood because of the presence of HEV RNA in the blood donated. Pre-donation health screening was unable to exclude this asymptomatic donor. But donor-initiated call back system which acts as an additional safety net prevented the release of the potential infective blood products.

Use of convalescent plasma therapy in SARS patients in Hong Kong

In order to evaluate the efficacy of convalescent plasma therapy in the treatment of patients with severe acute respiratory syndrome (SARS), 80 SARS patients were given convalescent plasma at Prince of Wales Hospital, Hong Kong, between 20 March and 26 May 2003. Good outcome was defined as discharge by day 22 following the onset of SARS symptoms. Poor outcome was defined as death or hospitalization beyond 22 days. A higher day-22 discharge rate was observed among patients who were given convalescent plasma before day 14 of illness (58.3% vs 15.6%; P<0.001) and among those who were PCR positive and seronegative for coronavirus at the time of plasma infusion (66.7% vs 20%; P=0.001).

Polysaccharide vaccines for preventing serogroup A meningococcal meningitis

BACKGROUND

Randomised trials carried out over two decades ago showed that the polysaccharide vaccine prevented serogroup A meningococcal meningitis. Subsequent non-randomised studies, however, suggested significant variations in the age-specific duration of protection among young children.

OBJECTIVES

The aim of the review was to determine the effect of polysaccharide serogroup A vaccine for preventing serogroup A meningococcal meningitis. The specific objectives were to assess the age-specific effects of the vaccine, the effect of booster doses in children under five years of age, and the duration of protection in children and adults.

SEARCH STRATEGY

In 2004, the review was updated. The following databases were searched for records of new trials: the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 4, 2004); MEDLINE (January 1966 to November Week 1 2004); and EMBASE (January 1990 to September 2004).

SELECTION CRITERIA

The first stage of the review included randomised trials. The second stage included non- randomised studies that addressed specific outcomes not answered by the randomised trials.

DATA COLLECTION AND ANALYSIS

One reviewer assessed the methodological quality of the randomised trials and two reviewers independently identified and assessed the non-randomised studies. Of the twelve eligible Randomized trials, four were excluded because of the high risk of bias in assessing vaccine efficacy. Data from the trials were pooled using the Exact method to assess vaccine efficacy at one, two and three years post vaccination. Of the 15 non-randomised studies, only two addressed the specific objectives not answered by the randomised trials but were assessed to be at high risk of bias.

MAIN RESULTS

The protective effect within the first year of vaccination was consistent across the randomised trials, and the summary vaccine efficacy was 95% (95% confidence interval (CI) 87% to 99%). Protection extended into the second and third year after vaccination but the results did not attain statistical significance. The vaccine was protective in Finnish children aged 3 months to five years. The latter was also the only trial that assessed the effect of a booster dose in children under two years of age but lacked power to yield statistically significant results. The vaccine was protective in one- to five-year old children in developing countries (Nigeria and Sudan) but the age-specific efficacy in strata between one and five years of age could not be determined.

AUTHORS' CONCLUSIONS

For the first year after vaccination, the polysaccharide serogroup A vaccine was strongly protective against serogroup A meningococcal meningitis in participants over five years of age. It was also protective beyond the first year after vaccination in this age group but the level of vaccine efficacy could not be determined with precision. Children aged one to five years in developing countries were also protected but the level of efficacy in this age group could not be determined. While the vaccine was strongly protective among children aged three months to five years in developed countries the level of efficacy across age strata within this age group could not be determined. The number of children aged under two years was too small to draw conclusions on the protective effect of a booster dose of vaccine.

Congenitally missing maxillary permanent canines: report of 32 cases from an ethnic Chinese population

Cases of congenitally missing permanent teeth involving only maxillary canines are uncommon. Prevalence studies have revealed that it is a rare finding in Caucasian populations, but it may be relatively more common in Asian groups. This report describes radiographic findings in 32 Chinese children with congenitally missing maxillary permanent canines. The aetiology of such an anomaly is obscure, but the racial difference in prevalence suggests that genetic factors may be more influential than environmental ones.

Association of the oestrogen receptor alpha gene polymorphisms with disease onset in systemic lupus erythematosus

OBJECTIVE

To evaluate the genetic influence of PvuII and XbaI polymorphisms of oestrogen receptor alpha (ORalpha) in patients with systemic lupus erythematosus (SLE) in Korea.

METHODS

Genomic DNA from 268 female controls and 137 female SLE patients (41 childhood onset and 96 adult onset) were analysed using PvuII and XbaI restriction fragment length polymorphism. Comparison of the frequencies of alleles and genotypes was made in control and patient groups and in childhood onset and adult onset SLE subgroups.

RESULTS

Although the Pp genotype occurred more often in SLE patients than in controls (p(c) = 0.017), ORalpha genotype distributions of adult onset SLE did not differ significantly from controls. The PP, Pp, and xx genotypes occurred less often in childhood onset SLE (p(c) = 0.0045, 0.0498, and 0.0255, respectively) than in controls. Additionally, the PP genotype was less common in childhood onset than in adult onset SLE (p(c) = 0.016). SLE patients with the PP genotypes were older at disease onset than those with the other genotypes (p = 0.001). Patients with the Xx genotype had an earlier onset of SLE than those with the xx genotype (p = 0.025). The frequency of the combined ppXx genotype was greater in childhood onset SLE than in controls (p(c) = 0.0009) or adult onset SLE (p(c) = 0.027). The same trend was supported by subgroup analyses according to age at menarche and logistic multivariate analyses.

CONCLUSIONS

ORalpha polymorphisms are significantly associated with the age at disease onset in Koreans with SLE.

The system design of UV-assisted catalytic oxidation process--degradation of 2,4-D

Unlike the conventional first- or second-order model, a novel approach to design for the removal of 2,4-dichlorophenoxy (2,4-D) by the UV-catalytic oxidation process (UVCOP) was investigated. Two distinctive parameters, initial decay rate and maximum oxidative capacity, were characterized. By using these parameters, the performance of the degradation of 2,4-D by UVCOP regarding to the reagent dosages could be successfully predicted. Low concentrations of ferrous ion was found to be a rate-limiting factor for the process while the dosage of hydrogen peroxide was concluded as a dominant species in determining the maximum oxidation capacities. This information can be used to optimize the treatment process and achieve the expected performance target; an "optimal-dose model" was developed accordingly. The model is an intelligent and useful tool to evaluate the optimal doses of hydrogen peroxide with the minimum dose of ferrous ion, which leads to a better design of the treatment process.

Impact of severe respiratory syndrome on anxiety levels of front-line health care workers

OBJECTIVE

To identify anxiety levels among front-line health care workers during the 2003 severe acute respiratory syndrome outbreak.

DESIGN

Questionnaire survey.

SETTING

Regional hospital, Hong Kong.

PARTICIPANTS

All hospital staff were given a questionnaire; administrative staff who had not had any patient contact served as controls.

MAIN OUTCOME MEASURES

Levels of contact with patients who had severe acute respiratory syndrome were measured and correlated with anxiety levels as determined by the State-Trait Anxiety Inventory.

RESULTS

Of 4252 questionnaires distributed between May and June 2003, 2040 (48.0%) were returned and 1926 (45.3%) were valid for analysis. Overall, 534 (27.7%) respondents had had contact with patients with severe acute respiratory syndrome. Anxiety scores ranged from 20 to 80, and mean (standard deviation) scores were higher among staff who had had contact with patients with severe acute respiratory syndrome than among those who had not (52.6 [10.5] versus 49.8 [10.1], respectively; P<0.01). Mean anxiety levels were higher among workmen, health care assistants, and nurses than among administrative staff controls or doctors (P<0.01). Anxiety scores were correlated with burnout scores (Pearson's correlation coefficient, 0.52-0.59) and with discomfort from wearing protective gear (0.21-0.32).

CONCLUSION

Severe acute respiratory syndrome has likely stressed the public health care system. Prediction and early identification of adverse factors in a crisis situation would allow early implementation of interventions to reduce and counteract the impact of this stress.

Simulation and fabrication of subwavelength structures for a nanometer feature enabling lens-less laser writers

A set-up was proposed to propagate submicrometer light beams without resorting to the conventional approach of using a lens. The main target was to develop a method of either by passing or circumventing the diffraction limit to develop a new optical head for a laser writer system with submicrometer resolution. Starting from using surface plasma theory to explain the mechanism of extraordinary transmission phenomenon, we move to discuss the fabrication processes for free-standing metal films and the corresponding transmission light beam images in the far field. A finite difference time domain (FDTD) method was adopted to simulate the electromagnetic field distribution of transmission light beams from the near field to the far field. The experimental results confirm that surface structures on the incident side of incoming light beams can excite surface plasma and enhance the throughput energy of transmission light beams. In addition, we also established that surface structures on the exit side can suppress the diffraction effect and make transmission light beams directional. The experimental and simulation results were found to agree well with each other, which validates the effectiveness of the FDTD simulation approach. As a free-standing film was too fragile to be of practical use, a proposition to develop a substrate-based nanostructured film to ease the construction of an optical head for a laser writer was developed.

Challenge model for Helicobacter pylori infection in human volunteers

BACKGROUND

A reliable challenge model is needed to evaluate Helicobacter pylori vaccine candidates.

METHODS

A cag pathogenicity island negative, OipA positive, multiple antibiotic susceptible strain of H pylori obtained from an individual with mild gastritis (Baylor strain 100) was used to challenge volunteers. Volunteers received 40 mg of famotidine at bedtime and 10(4)-10(10) cfu of H pylori in beef broth the next morning. Infection was confirmed by (13)C urea breath test ((13)C-UBT), culture, and histology. Eradication therapy was given four or 12 weeks post challenge and eradication was confirmed by at least two separate UBTs, as well as culture and histology.

RESULTS

Twenty subjects (nine women and 11 men; aged 23-33 years) received a H pylori challenge. Eighteen (90%) became infected. Mild to moderate dyspeptic symptoms occurred, peaked between days 9 and 12, and resolved. Vomitus from one subject contained >10(3) viable/ml H pylori. By two weeks post challenge gastric histology showed typical chronic H pylori gastritis with intense acute and chronic inflammation. The density of H pylori (as assessed by cfu/biopsy) was similarly independent of the challenge dose. A minimal infectious dose was not found. Gastric mucosal interleukin 8 levels increased more than 20-fold by two weeks after the challenge.

CONCLUSION

Challenge reliably resulted in H pylori infection. Infection was associated with typical H pylori gastritis with intense polymorphonuclear cell infiltration and interleukin 8 induction in gastric mucosa, despite absence of the cag pathogenicity island. Experimental H pylori infection is one of the viable approaches to evaluate vaccine candidates.

Thick aluminium nitride films deposited by room-temperature sputtering for ultrasonic applications

Materials in film form for electromechanical transduction have a number of potential applications in ultrasound. They are presently under investigation in flexural transducers for air-coupled ultrasound and underwater sonar operating at frequencies up to a few megahertz. At higher frequencies, they have the potential to be integrated with electronics for applications of ultrasound requiring high spatial resolution. However, a number of fabrication difficulties have arisen in studies of such films. These include the high temperatures required in many thick and thin film deposition processes, making them incompatible with other stages in transducer fabrication, and difficulties maintaining film quality when thin film--typically sub-1 microm--processes are extended to higher thicknesses. In this paper, we first outline a process which has allowed us to deposit aluminium nitride (AlN) films capable of electromechanical transduction at thicknesses up to more than 5 microm without substrate heating. As an ultrasonic transduction material, AlN has functional disadvantages, particularly a high acoustic velocity and weak electromechanical transduction. However, it also has a number of advantages relating to practicality of fabrication and functionality. These include the ability to be deposited on a variety of amorphous substrates, a very high Curie temperature, low permittivity, and low electrical and mechanical losses. Here, we present experimental results highlighting the transduction capabilities of AlN deposited on aluminium electrodes on glass and lithium niobate. We compare the results with those from standard simulation processes, highlighting the reasons for discrepancies and discussing the implications for incorporation of AlN into standard ultrasonic transducer design processes.

Surviving male with incontinentia pigmenti: a case report

Incontinentia pigmenti, or Block-Sulzberger Syndrome, is an X-linked dominant disorder with characteristic skin, hair, eye and tooth abnormalities. It is classically considered a male-lethal disorder with recurrent miscarriages of male foetuses. A few cases of surviving males with incontinentia pigmenti have been reported in the medical literature. This article reports the medical and dental findings of a boy diagnosed with incontinentia pigmenti.

Sorption of Cr(VI) and Cu(II) in aqueous solution by ethylenediamine modified rice hull

The sorption characteristics of Cr(VI) and Cu(II) by ethylenediamine modified rice hull from single and binary metal ion solutions were evaluated under various experimental conditions. Optimal Cr(VI) and Cu(II) removal from single metal ion solutions occurred at pH 2.0 and 5.5, respectively. Simultaneous removal of Cr(VI) and Cu(II) occurred at pH greater than 3.0. The sorption kinetics of Cr(VI) and Cu(II) from single and binary metal ion solutions were studied with reference to metal concentration, agitation rate and particle size. Sorption of Cr(VI) was more rapid than Cu(II). The kinetics of metal ion sorption fitted a pseudo-second order expression. The variation in the initial uptake rates was very small at an agitation rate beyond 150 rpm and sorption was generally independent of particle size. Equilibrium sorption data could be fitted into the Langmuir isotherm equation. Maximum sorption capacities of ethylenediamine modified rice hull for Cr(VI) at pH 2 and Cu(II) at pH 4 in single metal solutions were 0.45 and 0.06 mmol g(-1), respectively. This corresponds to an enhancement factor of 2.6 and 3 fold for Cr(VI) and Cu(II), respectively, compared to natural rice hull. A synergistic effect was observed for sorption of these ions in binary metal solutions.

Monitoring PAH-contaminated soil using laser-induced fluorescence (LIF)

The heterogeneity and opacity of soil matrices pose considerable challenges for the quantification of soil contaminants. In order to investigate the feasibility of applying the Laser-Induced Fluorescence technique to measure contamination levels of soils, statistical analyses of contaminant levels and intensity of fluorescence were investigated in relation to soil properties. A significant correlation (R2 > 0.97) between contaminant levels and intensity of fluorescence was shown under different matrix conditions, such as moisture content and particle size distribution. Higher fluorescence intensities were obtained from soils with higher sand and moisture content. The statistical results in relation to the interaction between fluorescence intensity and matrix properties rejected the hypothesis that all properties of the matrices and contaminants had an equal influence on fluorescence. This implied that the concentrations of contaminants had the greatest contribution to the fluorescence intensity, but other variables also showed a considerable influence.

Prevalence and specificity of clinically significant red cell alloantibodies in Chinese women during pregnancy--a review of cases from 1997 to 2001

Guidelines for the prevention and management of red cell alloantibodies during pregnancy, related to anti-D in particular, are well established in Caucasian populations. However, because of the racial difference of the blood group distribution, applicability to Chinese is unknown as a result of insufficient data on the prevalence and their outcome. In a retrospective review of 28,303 (21,327 Chinese) antenatal attendances from 1997 to 2001, 213 (0.79%) women were found to have a total of 230 irregular antibodies. About 137 (0.64%) were ethnic Chinese, and a total of 160 irregular antibodies were identified in their blood samples. About 58 of these Chinese women (0.27%) were found to have 66 clinically significant antibodies. There was only one case of anti-D detected in an Rh(D)-negative subject. Our study shows the overall prevalence of clinically significant antibodies in Chinese women, which was not different from that of the Western population. However, the specificities of the antibodies differ with the commonest antibodies encountered; these being anti-Mi (57.6%), anti-E (19.7%), anti-S (10.6%) and anti-c (7.6%). Neonatal jaundice was observed in 37 babies and 10 of them required phototherapy. The findings support the previous recommendation that routine antenatal antibody screening for Chinese women may not be worthwhile except in Rh(D)-negative subjects or those with an antecedent history of haemolytic disease of the newborn (HDN). The relative high incidence of anti-Mi in the present study and the local population, in general, may warrant a large-scale prospective study of pregnancy outcome in these subjects, especially in the light of the previous case reports of HDN because of anti-Mi.

Estimation of bacterial risk in extending the shelf life of PLT concentrates from 5 to 7 days

BACKGROUND

The use of bacterial culture to prevent bacterial contamination of blood components has renewed interest for extending the shelf life of PLT concentrates to 7 days after collection.

STUDY DESIGN AND METHODS

This study was therefore conducted to determine the residual risk of bacterial contamination in PLT concentrates at the end of 5 and 7 days after collection in a center where all PLT concentrates are routinely screened by taking samples on Day 2 for culture. PLT units with no growth after 48 hours were sampled a second time on Day 5 or Day 7 after collection, followed by inoculation into aerobic culture bottles. The inoculated bottles were then monitored for up to 7 days at 35 degrees C in an automatic monitoring and detection system.

RESULTS

During a 16-month study period, a total of 6020 PLT concentrates were tested 5 days (Group A, n=3010) and 7 days (Group B, n=3010) after collection. Four units in each group (0.133%) were found to be contaminated. In 6 units, bacteria were seen on direct Gram stain. In addition, 5 of the associated RBC units grew the same organisms on culture. The organisms include three coagulase-negative staphylococci and five Propionibacterium acnes. The positive rate of routine short-term bacterial culture was 0.035 percent during the same study period.

CONCLUSION

Despite routine short-term bacterial culture, a significant risk of bacterial contamination remains at 5 and 7 days after collection. For now, the shelf life of PLT concentrates should remain 5 days.

Copper vapour laser ID labelling on metal dentures and restorations

Denture marking is accepted as a means of identifying dentures and persons in geriatric institutions, or post-mortem during war, crimes, civil unrest, natural and mass disasters. Labelling on the acrylic resin component of the denture can easily be damaged or destroyed by fire but on cobalt-chromium components it would be more resistant. A copper vapour laser (CVL) can be used to label the cobalt-chromium components of dentures and metal restorations easily, and legibly, and miniaturised for the incorporation of more personal particulars necessary for the identification of the deceased person. The CVL beam is focussed by its optics and delivered to the material surface by the two-axis scanner mounted with mirrors. A personal computer controls the movement of the scanner and the firing of the CVL. The high peak power of the pulsed CVL is focussed to very high energy density producing plasma ablation of the alloy surface. Very fine markings of a few microns width can be produced enabling the storage of detailed information of the deceased person on a metal surface for the purpose of rapid identification.

Acid-activated spent bleaching earth as a sorbent for chromium (VI) in aqueous solution

Spent bleaching earth, an industrial waste produced after the bleaching of crude palm oil, was investigated for its potential in removing Cr(VI) from aqueous solution. The earth was treated with different amounts of sulfuric acid and under different activation temperatures. Results show that the optimum treatment process involved 10% sulfuric acid at 350 degrees C. The effects of contact time, pH, initial concentration, sorbent dosage, temperature, sorption isotherms and the presence of other anions on its sorption capacity were studied. Isotherm data could be fitted into a modified Langmuir isotherm model implying monolayer coverage of Cr(VI) on acid activated spent bleaching earth. The maximum sorption capacity derived from the Langmuir isotherm was 21.2 mg g(-1). This value was compared with those of some other low cost sorbents. Studies of anion effect on the uptake of Cr(VI) on acid activated spent bleaching earth provided the following order of suppression: EDTA >PO4(3-)>SO4(2-)>NO3(-)>Cl(-).

Leakage of cement in percutaneous transpedicular vertebroplasty for painful osteoporotic compression fractures

e analysed the CT scans and radiographs of 76 vertebrae in 49 patients who underwent vertebroplasty for painful osteoporotic compression fractures. Leaks of cement were classified into three types: those via the basivertebral vein (type B), via the segmental vein (type S), and through a cortical defect (type C). More leaks were identified on CT scans than on radiographs by a factor of 1.5 (74/49). Most type-B (93%) and type-S (86%) leaks were missed or underestimated on a lateral radiograph which is usually the only view used during the injection of cement. Of the leaks into the spinal canal, only 7% (2/28) were correctly identified on radiographs. The areas on lateral radiographs where this type of leak may be observed were divided into four zones, and their diagnostic value in predicting a leak into the spinal canal was evaluated. The results showed that cement in the neural foramina had the highest positive predictive value (86%).

Removal of Cu and Pb by tartaric acid modified rice husk from aqueous solutions

A study on the modification of rice husk by various carboxylic acids showed that tartaric acid modified rice husk (TARH) had the highest binding capacities for Cu and Pb. The carboxyl groups on the surface of the modified rice husk were primarily responsible for the sorption of metal ions. A series of batch experiments using TARH as the sorbent for the removal of Cu and Pb showed that the sorption process was pH dependent, rapid and exothermic. The sorption process conformed to the Langmuir isotherm with maximum sorption capacities of 29 and 108 mg/g at 27 +/- 2 degrees C for Cu and Pb, respectively. The uptake increased with agitation rate. Decrease in sorbent particle size led to an increase in the sorption of metal ions and this could be explained by an increase in surface area and hence binding sites. Metal uptake was reduced in the presence of competitive cations and chelators. The affinity of TARH for Pb is greater than Cu.

Impact of donor arm skin disinfection on the bacterial contamination rate of platelet concentrates

BACKGROUND AND OBJECTIVES

Despite improved methods for detecting bacterial contamination of blood products, bacterial sepsis remains a significant risk in blood transfusion. This study was undertaken to investigate whether adopting a different skin disinfection protocol could reduce the rate of bacterial contamination of platelet concentrates.

MATERIALS AND METHODS

Two skin disinfection protocols were consecutively used in the routine blood collection setting during two 10-month periods: 0.5% cetrimide/0.05% chlorhexidine solution followed by 70% isopropyl alcohol (first 10-month time-period); and 10% povidone-iodine followed by 70% isopropyl alcohol (second 10-month time-period). The rates of bacterial contamination of platelet concentrates were monitored by using a surveillance programme described previously.

RESULTS

The overall bacterial contamination rate in the first time-period was 0.072%. After introduction of the povidone-iodine and isopropyl alcohol protocol, the bacterial contamination rate decreased to 0.042% (relative risk reduction: -0.42; 95% confidence interval, -0.12 to -0.61, P= 0.009). There were no differences in the types of micro-organisms identified (P = 0.7).

CONCLUSIONS

Skin disinfection by povidone-iodine and isopropyl alcohol is more effective than that by cetrimide/chorhexidine and isopropyl alcohol in reducing venepuncture-associated contamination of platelet concentrates by skin flora. Our data indicate that the disinfection protocol should be used on a routine basis and such implementation should translate into a significant improvement in blood safety to patients receiving platelet transfusion.

Efficacy of enzyme immunoassay for the detection of Helicobacter pylori antigens in frozen stool specimens: local validation

AIM

To investigate the efficacy of measurement of Helicobacter pylori stool antigen (HpSA) using stored frozen stool specimens, and to assess whether there were factors affecting efficacy in Hong Kong.

METHODS

Patients undergoing upper endoscopy at Tuen Mun Hospital were recruited. Stool samples were saved for HpSA testing and questionnaires were completed. Stool samples were frozen immediately upon receipt and stored at -70 degrees C until tested. HpSA results were compared with rapid urease test and histology.

RESULTS

One hundred and eighty-one patients were recruited. One hundred and seventy-eight patients were suitable for analysis. Eighty-three were H. pylori positive and 95 were H. pylori negative. The mean duration of storage of the stool samples was 120 days (range, 40-225 days). The sensitivity, specificity and positive and negative predictive values were 84.3%, 97.9%, 97.2% and 88.6%, respectively. In patients with a false negative HpSA test, there was a significant delay in collecting the stool specimen after endoscopy when compared with those with a true positive HpSA test (4.2 vs. 2.3 days; P < 0.05). However, the duration of storage of the specimens was not longer, and consumption of coffee or tea and smoking habits were similar.

CONCLUSIONS

HpSA testing showed good sensitivity and specificity, even with frozen stool samples stored for up to 225 days. The efficacy was not affected by coffee, tea or smoking.

Does the extent of surgery have an impact on the survival of patients who receive postoperative radiation therapy for supratentorial low-grade gliomas?

We evaluate the impact of extent of surgery (EOS) on survival of patients with supratentorial nonpilocytic low-grade gliomas (LGG) treated with postoperative radiation therapy (PORT). Sixty-five patients with pathologically confirmed supratentorial nonpilocytic LGG (36 astrocytomas and 29 oligodendrogliomas) were treated with PORT after different extents of surgery: 12 gross total resections (GTR), 27 minimal or subtotal resections (MR/SR), and 26 biopsies (B). EOS was confirmed with postoperative imaging. The median radiation dose delivered was 5,940 cGy (range, 4,950-6,620 cGy). One of 12 patients (8%) in the GTR group and 12 of 53 patients (23%) in the less than GTR group demonstrated contrast enhancement. The median follow-up was 61 months (range 5-194 month). The 10-year overall survival (OS) was 82.5% and 32% for the GTR and the less than GTR groups, respectively (P = 0.0008). The corresponding 10-year disease-specific survival (DSS) was 90% and 41.4%%, respectively (P = 0.001). Multivariate analysis showed that only contrast enhancement and EOS were predictors for OS and DSS. Our data suggest that EOS correlates with OS and DSS in patients who have PORT. GTR should be the goal if technically achievable without causing significant morbidity, and its combination with PORT is compatible with long-term survival.

Application of narrow band laser ultrasonics to the nondestructive evaluation of thin bonding layers

In this paper, a modified laser induced grating technique (LIG) has been utilized to generate narrow band surface waves in an epoxy-bonded copper-aluminum layered structure. A high performance optical interferometer system was utilized to detect the laser-generated surface waves. The dispersion of surface wave in an epoxy-bonded copper-aluminum specimen was measured and compared with the theoretical solution. An inverse algorithm based on the simplex method was then introduced to determine the bonding thickness as well as the elastic properties of the bonding layer. The inversion results demonstrated that the thickness in the microm range or the elastic properties of the bonding layer could be successfully determined.