Interfacial Shear Strength of Thin Polymeric Coatings on Glass

The interfacial adhesive shear strengths of epoxy and acrylate coatings on glass substrates were measured by the indentation and lap shear tests. The lap shear strengths were about an order of magnitude less and exhibited considerably more variability than those measured by indentation. It is believed that the lap shear strength is controlled by large processing flaws (pores in this study); whereas, the indentation test measures the “intrinsic” strength of the coating.

Removal of acetone and methylacetate mixtures from waste gases by a trickle-bed air biofilter

The biofilter process is a relatively new technology that has been proven more cost-effective than traditional technologies for treating low-strength and some high-strength volatile organic compounds (VOCs) from waste gases. Acetone (AT) and methylacetate (MA) mixtures are commonly encountered from the manufacture of artificial rubber or polyurethane resin. This research attempts to employ a trickle-bed air biofilter (TBAB) for treating AT and MA mixtures under different influent carbon loadings. In the pseudo-steady-states, the elimination capacities of AT and MA increased but the removal efficiencies decreased with increased influent carbon loading. The removal efficiencies of MA were higher than those of AT showing that MA is a preferred substrate in the ATMA waste gas and the differences were enhanced at a high carbon loading. Greater than 95% AT removal and nearly complete MA removal were achieved with influent carbon loadings of AT and MA below 20 and 27 g m(-1) h(-1), respectively. The TBAB appears very efficient for treating ATMA emission with low to medium carbon loadings.

Coordination trends in alkali metal crown ether uranyl halide complexes: the series [A(crown)]2[UO(2)X(4)] where A=Li, Na, K and X=Cl, Br

UO(2)(C(2)H(3)O(2))(2).2H(2)O reacts with AX or A(C(2)H(3)O(2) or ClO(4)) (where A = Li, Na, K; X = Cl, Br) and crown ethers in HCl or HBr aqueous solutions to give the sandwich-type compounds [K(18-crown-6)](2)[UO(2)Cl(4)] (1), [K(18-crown-6)](2)[UO(2)Br(4)] (2), [Na(15-crown-5)](2)[UO(2)Cl(4)] (3), [Na(15-crown-5)](2)[UO(2)Br(4)] (4), [Li(12-crown-4)](2)[UO(2)Cl(4)] (5), and [Li(12-crown-4)](2)[UO(2)Br(4)] (6). The compounds have been characterized by single-crystal X-ray diffraction, powder diffraction, elemental analysis, IR, and Raman spectroscopy. The [UO(2)X(4)](2-) ions coordinate to two [A(crown)](+) cations through the four halides only (2), through two halides only (3), through the two uranyl oxygens and two halides (3, 4), or through the two uranyl oxygen atoms only (5, 6). Raman spectra reveal nu(U-O) values that correlate with expected trends. The structural trends are discussed within the context of classical principles of hard-soft acid-base theory.

Treatment of N,N-dimethylacetamide waste gas by a trickle-bed air biofilter

The system performance of a trickle-bed air biofilter (TBAB) for treating N,N-dimethylacetamide (DMAC) waste gas was investigated under different gas flow rates and influent concentrations. In the pseudo-steady-state conditions, the DMAC elimination capacity increased but the removal efficiency decreased as the influent loading increased. More than 90% and 80% DMAC removal efficiencies are achieved for influent loadings below 20.2 and 34.5 g DMAC/m3/h, respectively. The TBAB appears to be an effective treatment process for controlling DMAC emission with low-to-medium loadings and the effectiveness could be maintained over a long-period operation.

Removal of ethylacetate vapor from waste gases by a trickle-bed air biofilter

Biofilter system is a relatively new process that has been proven to be more cost-effective than traditional technologies such as carbon adsorption, liquid scrubbing, condensation, thermal incineration, and catalytic incineration for removing low-strength volatile organic compounds from waste gases. The trickle-bed air biofilter (TBAB) performance for ethylacetate (EA) removal was evaluated under different influent loadings. In the pseudo-steady states, the elimination capacity increased, but the removal efficiency decreased with increased influent loading. More than 95 and 90% removal efficiencies could be achieved for EA loadings below 490 and 810 g m(-3) h(-1), respectively. The TBAB appears to be very effective for controlling EA emission under low to high loading conditions, and the effectiveness could be maintained over 190 days of laboratory operation.

Removal of styrene vapor from waste gases by a trickle-bed air biofilter

The trickle-bed air biofilter (TBAB) performance for the removal of high-strength styrene was evaluated under different gas flow rates and influent concentrations. Under pseudo-steady-state conditions, the elimination capacity increased but the removal efficiency decreased with the increase of styrene loading. More than 90 and 80% removal efficiencies were achieved for influent styrene loadings below 32 and 55g/m(3)/h, respectively. The TBAB appears to be an effective treatment process for controlling high-strength styrene emission under low-to-medium loading conditions, and the effectiveness could be maintained over 140 days of laboratory operation.

Crash severity, injury patterns, and helmet use in adolescent motorcycle riders

BACKGROUND

This study examined crash severity and injury patterns between helmeted and unhelmeted adolescent motorcycle riders.

METHODS

Among an initial population of 4,721 junior college students, 1,284 students were involved in 1,889 motorcycle crashes during a 20-month follow-up period. Crash severity was measured by both the type of collision object and the repair cost of motorcycle damage.

RESULTS

The incidence rates of crash, injury, hospitalization, and deaths per 1,000 person-years in the cohort were 358, 104, 14, and 1.3, respectively. Compared with helmeted riders, unhelmeted riders had more noncollisions and fewer collisions with a moving car but there was no significant difference in repair cost of motorcycle damage between these groups. More injuries to the external skin, face, and head and more severe injuries occurred in unhelmeted than in helmeted riders. Among crashes resulting in hospitalization/death, more injuries to the face and head occurred in unhelmeted riders than in helmeted riders.

CONCLUSION

Crashes involving unhelmeted riders were not more severe but more frequently involved face and head injuries than crashes involving helmeted riders.

Treatment of methylacetate waste gas using a trickle-bed air biofilter

The trickle-bed air biofilter (TBAB) performance for methylacetate (MA) removal from waste gases was evaluated under different gas flow rates and influent concentrations. In the pseudo-steady-state conditions, the elimination capacity increased but the removal efficiency decreased with the increase of MA loading. More than 95 and 90% removal efficiencies were achieved for influent MA loadings below 390 and 727 g/m3/h, respectively. The TBAB appears to be a very effective treatment process for controlling MA emission under low to high loading conditions, and the effectiveness could be maintained over 190 days of laboratory operation.

Removal of BTEX vapor from waste gases by a trickle bed biofilter

The system performance of a trickle bed biofilter for treating single and mixed benzene, toluene, ethylbenzene, and o-xylene (BTEX) vapors from waste gases was investigated under different gas flow rates and influent BTEX concentrations. When a single substrate was fed, removal efficiencies of greater than 90% could be achieved for the loads below 64 g benzene/m3/hr, 110 g toluene/m3/hr, 53 g ethylbenzene/m3/hr, and 55 g o-xylene/m3/hr. When a mixed substrate was fed, removal efficiencies of each compound could be above 90% at BTEX loads below 96 g/m3/hr. The trickle bed biofilter appears to be an effective treatment process for removing both single and mixed BTEX vapors with low to high loads. Under similar substrate loads, BTEX vapors were preferentially biodegraded in the order of toluene, benzene, o-xylene, and ethylbenzene. The volumetric removal rates (elimination capacities) of BTEX vapors for a single-substrate feed were higher than those for a mixed-substrate feed under similar substrate loads; these differences were enhanced at higher substrate loads and less significant for a preferred substrate.

Malfunction of an active fixation J-shaped screw-in atrial electrode lead: a case report

Active fixation leads, using active grasping devices, ensure good postoperative lead fixation, long-term performance, and make possible later lead removal on demand. However, these delicate designs have not been without practical difficulties. We present two cases of fixation stylet fracture during helix extension and retraction maneuver respectively with resultant lead inoperability and abandonment. The fixed leads could be removed by torquing the entire lead counterclockwise.

Determinants of Economic Cost Related to Low Back Pain among Nurses at a University Hospital

The objectives of this study were to determine the economic cost related to low back pain (LBP) among nurses, and to identify factors associated with this cost. All 998 nurses at the National Taiwan University Hospital (NTUH) were asked to complete a questionnaire designed to examine whether the nurses had experienced LBP and whether their LBP had been related to the incurring of economic cost between May 1, 1990, and April 30, 1991. Of the 863 respondents, 417 had had LBP and 102 of these had incurred economic costs related to the LBP. Personal interviews of the 102 nurses, as well as of an additional four nurses who had resigned due to LBP within the 12 months, were performed to determine the related economic costs. The total monthly costs over the 12 months ranged from U.S. $105,405 to $149,083. Twenty percent of the 106 cases were responsible for 70% of the total overall cost. There was no difference in demographics between the two groups of non-LBP and LBP-without-cost. However, statistical analysis using logistic regression showed that the occurrence of economic cost was positively associated with subjective pain, lifting and carrying babies and small children at home, and age or work years or parity. In addition, multiple linear regression analysis showed that medical cost was positively associated with parity and sick leave; and productivity loss was associated with sick leave, lifting and carrying babies at home, unspecified housework, patient transport, and performing cardiopulmonary resuscitation.

Prevalence of antibody to hepatitis E virus among healthy individuals in southern Taiwan

The seroprevalence of hepatitis E virus (HEV) among 997 healthy individuals aged 6 to 84 years, collected between July 1993 and June 1994 at Kaohsiung-Pingtung area in Southern Taiwan was studied. Of the study populations of vegetable farmers, elementary school children, volunteer blood donors and college students, the prevalence of IgG anti-HEV ranged from 6.4% to 8.8%. In suburban elemantary school children of Mang-Chou Village at Pingtung-Hsien, the seroprevalence rate (9.6%) was significantly higher than the positive rate (1.5%) found in rural aboriginal elementary school of San-Min Village at Kaohsiung-Hsien. IgG anti-HEV antibodies were widely distributed among all age groups, with a significantly higher percentage (13.1%) in the age group of 46-55 years old.

Transvenous permanent left ventricular pacing. A case report

This case report presents a patient who inadvertently received transvenous permanent left ventricular pacing through an unexpected atrial septal defect. This lead malpositioning was proved by two-dimensional and transesophageal echocardiography. The abnormal pattern of electric activation was demonstrated by radionuclide phase image analysis. He has been followed up for a total of forty-three months with antiplatelet therapy and has been free from systemic embolic phenomena. A simple and readily available method that could lead to early recognition of lead malpositioning is reiterated and the various causes, methods of detection, and prognosis of left ventricular pacing are discussed.

Cost and determinants of morbidity from work related disabling injuries in Taiwan

OBJECTIVES

To estimate the cost and determinants of morbidity from work related disabilities.

METHODS

114 people who lived in metropolitan Taipei and who had received disability compensation from the Labor Insurance Bureau from March to June, 1991 were randomly selected. There were 77 workers interviewed through a questionnaire that inquired about possible loss of productivity including the duration of morbidity, the ability to return to work, and any change in monthly income upon returning to work.

RESULTS

The mean (SD) duration of a stay in hospital was 29 (39) days, median: 15 days. The average duration between discharge from the hospital and returning to work was 111 (146) days, median: 45 days. The main determinants of the duration of the stay in hospital were the number of stays in hospital and the severity of the injury. A multivariate linear analysis showed that old age and the severity of injury determine the durations of morbidity. An ordinal logistic regression analysis showed that the severity of injury, size of the factory, and age determined the magnitude of future productivity loss. Based on these models, it was estimated that the total duration of morbidity (in hospital and at home) due to occupational disability was 660,000 person-days each year. When the percentage of the decrease in income because of permanent disability was converted into a loss of work days, the annual morbidity costs were about 19,000-26,000 person-years between 1985-1990.

CONCLUSION

The morbidity cost was about five times as high as the lump sum payment that a worker usually received for disability compensation. We conclude that morbidity cost should be evaluated carefully in the future for the establishment of accurate and fair disability compensation payments.

Vaporizer for volatile anesthetics during high-frequency jet ventilation

At present, the potent inhalation anesthetics cannot be used during high-frequency jet ventilation (HFJV) because a suitable vaporizer is not available. A vaporizer for enflurane during HFJV was designed, built, and tested, based on the principle of airblast atomization in which liquid enflurane is delivered to the vaporizer by an infusion pump. Eight dogs were kept anesthetized with enflurane for 2 h using this device. Vital signs and arterial blood gases were within normal limits during anesthesia. The concentration of vaporized enflurane, measured by mass spectrometry, could be reliably and accurately controlled within the clinical range at any minute volume by adjusting the infusion rate. Measurements of blood enflurane indicated that enflurane uptake could be adequately achieved.

Hyperoxia produces neuronal necrosis in the rat

Widespread cerebral neuronal necrosis occurred in newborn Sprague-Dawley rats submitted to three hours of pure oxygen (100% O2) at normal atmospheric pressure. Neuronal necrosis (NN) was most severe in the immediate newborn period and less marked with advanced maturation. It was minimal and different in its morphological characteristics in rats 10, 15 and 20 days old, and in adults breathing pure oxygen at normal atmospheric pressure for three hours. In the newborn rat, hyperoxemic NN was different in topography and cytopathology from that induced by hypoxia in the same animals. Hyperoxemic NN was similar to the NN described in human premature infants submitted to episodic hyperoxemia. Neuronal damage with karyorrhexis was most prominent in the subiculum of the hippocampus, thalamus, reticular nuclei of the brain stem and the granular cells of the cerebellum. Ultrastructural studies demonstrated nuclear and cytoplasmic membrane damage in neurons and the cellular accumulation of electron-dense lipid droplets. The pathogenesis of NN produced by hyperoxia in the human premature newborn infant may be related to lipid peroxidation of cell membranes such as that induced by oxygen-free radicals in other experimental and in vitro studies, when the anti-oxidant cellular defenses (mainly enzymes such as superoxide dismutase) are overwhelmed.

Naloxone does not antagonize the analgesic effects of inhalation anesthetics

A previous demonstration that the ratio of analgesic to anesthetic endpoints is not constant across inhalation anesthetic agents implies that more than one mechanism of action may be operant in general anesthesia. We hypothesized that the endogenous opiate systems might account for this observed disparity in ratios. The tail flick ED50 (TFED50) in response to a heat stimulus, as an index of analgesia, and MAC as an index of anesthesia, were determined in rats treated with either saline or naloxone, 20 mg/kg, and exposed to halothane, enflurane, or isoflurane. Our findings confirmed those of Deady et al., showing a lack of uniformity of ratios of TFED50/MAC, with values of 0.90 +/- 0.03 for halothane, 0.80 +/- 0.04 for enflurane, and 0.70 +/- 0.04 for isoflurane. Naloxone had no effect on TFED50, MAC, or their ratio. If the endogenous opiate system were involved in the analgesic effect of general anesthetics, naloxone would have affected the ratios. We conclude that opiate systems are not involved in the analgesic action of general anesthetics.

Noradrenalin-inducible cyclic-AMP accumulation in rat cerebral cortex: changes during complete global ischemia

Neurologic dysfunction after cerebral ischemic insults may be due not only to neuronal death, but also to a possibly reversible failure in synaptic transmission. Because noradrenaline (NA)-inducible cyclic-AMP (cAMP) accumulation in brain may reflect the integrity of synaptic transmission mechanisms and brain viability, we studied its changes in cerebral cortex after various durations of decapitation ischemia. Unanesthetized rats were decapitated and the brains were kept at 37 degrees C for times ranging from 0 to 60 min. Cerebral cortical slices were incubated in vitro and NA (11.2 microM)-induced cAMP accumulation was evaluated over 10 min. At 0 min of ischemia, NA-induced cAMP accumulation was 56 pmol/mg protein/10 min. Between 0 and 20 min of ischemia, a linear eightfold increase, to 435 +/- 49 pmol/mg protein/10 min, occurred in NA-induced cAMP accumulation, with no further increase after longer durations of ischemia. The mechanisms modulating the increase in cortical NA-inducible cAMP accumulation with a maximum response after 20 min of ischemia remain to be defined.