Acetylcholinesterase genes and insecticide resistance in aphids.
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Acetylcholinesterase↗
Biomedical subjects
S L Dong
Publications and source records attributed to S L Dong.
Emergency management and infection control in a radiology department during an outbreak of severe acute respiratory syndrome.
The World Health Organization classified Taiwan as a serious epidemic-stricken area when the extent of severe acute respiratory syndrome (SARS) in Taiwan became clear. As of 11 July 2003, 671 probable SARS cases had been identified in Taiwan and 7 healthcare workers had died from the disease. Radiographers were easily infected by SARS because they had close contact with suspected or probable cases while conducting chest X-ray examinations. Three radiographers had been infected by the end of May 2003. Because of the impact of SARS on the Radiology Department, the department established a SARS emergency infection control team and re-designed the department's infection-control and emergency-management procedures based on the concept of risk-grade protection. This effort included installing a radiographic room at the fever-screening station, re-allocating human resources in the Radiology Department, training the department staff in infection control, and drafting new operational procedures for radiographers conducting X-ray examinations on SARS patients. The goal of this program was to reduce the infection rate and distribute materials efficiently in the department. This article introduces the emergency-management procedure of the Radiology Department during the SARS outbreak and the infection-protection experience of the department staff.
Disease Outbreaks↗
Characterization and demulsification of poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide) copolymers.
Four poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide) copolymers with different molecular weights and PPO/PEO composition ratios were synthesized. The characterization of the PEO-PPO-PEO triblock copolymers was studied by surface tension measurement, UV-vis spectra, and surface pressure method. These results clearly showed that the CMC of PEO-PPO-PEO was not a certain value but a concentration range, in contrast to classical surfactant, and two breaks around CMC were reflected in both surface tension isotherm curves and UV-vis absorption spectra. The range of CMC became wider with increasing PPO/PEO composition ratio. Surface pressure Pi-A curves revealed that the amphiphilic triblock copolymer PEO-PPO-PEO molecule was flexible at the air/water interface. We found that the minimum area per molecule at the air/water interface increased with the proportion of PEO chains. The copolymers with the same mass fractions of PEO had similar slopes in the isotherm of the Pi-A curve. From the demulsification experiments a conclusion had been drawn that the dehydration speed increased with decreased content of PEO, but the final dehydration rate of four demulsifiers was approximate. We determined that the coalescence of water drops resulted in the breaking of crude oil emulsions from the micrograph.
Emulsions↗
Estimation of mean-glandular dose from monitoring breast entrance skin air kerma using a high sensitivity metal oxide semiconductor field effect transistor (MOSFET) dosimeter system in mammography.
Estimation of mean-glandular dose (MGD) has been investigated in recent years due to the potential risks of radiation-induced carcinogenesis associated with the mammographic examination for diagnostic radiology. In this study, a new technique for immediate readout of breast entrance skin air kerma (BESAK) using high sensitivity MOSFET dosimeter after mammographic projection was introduced and a formula for the prediction of tube output with exposure records was developed. A series of appropriate conversion factors was applied to the MGD determination from the BESAK. The study results showed that signal response of the high sensitivity MOSFET exhibited excellent linearity within mammographic dose ranges, and that the energy dependence was less than 3% for each anode/filter combination at the tube potentials 25-30 kV. Good agreement was observed between the BESAK and the tube exposure output measurement for breasts thicker than 30 mm. In addition, the air kerma estimated from our prediction formula provided sufficient accuracy for thinner breasts. The average MGD from 120 Asian females was 1.5 mGy, comparable to other studies. Our results suggest that the high sensitivity MOSFET dosimeter system is a good candidate for immediately readout of BESAK after mammographic procedures.
Female↗
Characterization of high-sensitivity metal oxide semiconductor field effect transistor dosimeters system and LiF:Mg,Cu,P thermoluminescence dosimeters for use in diagnostic radiology.
Monitoring radiation exposure during diagnostic radiographic procedures has recently become an area of interest. In recent years, the LiF:Mg,Cu,P thermoluminescence dosimeter (TLD-100H) and the highly sensitive metal oxide semiconductor field effect transistor (MOSFET) dosimeter were introduced as good candidates for entrance skin dose measurements in diagnostic radiology. In the present study, the TLD-100H and the MOSFET dosimeters were evaluated for sensitivity, linearity, energy, angular dependence, and post-exposure response. Our results indicate that the TLD-100H dosimeter has excellent linearity within diagnostic energy ranges and its sensitivity variations were under 3% at tube potentials from 40Vp to 125kVp. Good linearity was also observed with the MOSFET dosimeter, but in low-dose regions the values are less reliable and were found to be a function of the tube potentials. Both dosimeters also presented predictable angular dependence in this study. Our findings suggest that the TLD-100H dosimeter is more appropriate for low-dose diagnostic procedures such as chest and skull projections. The MOSFET dosimeter system is valuable for entrance skin dose measurement with lumbar spine projections and certain fluoroscopic procedures.
Calibration↗
Dynamic evaluation of absorbed dose to the bladder wall with a balloon-bladder phantom during a study using [(18)F]fluorodeoxyglucose positron emission imaging.
An accurate evaluation of the absorbed dose to the bladder wall from 2-[(18)F]fluoro-2-deoxy-d-glucose (FDG) is clinically important because the bladder is considered as a critical organ in most positron emission tomography (PET) studies that cumulate about 20% of the total activity injection during image procedures. In the MIRD calculation, no allowance is made for the inclusion of all the dynamic parameters that affect the actual dose to the bladder wall to be taken in the dose assessment. The goal of the study is to propose a dose evaluation model by using a dynamic bladder phantom and time-activity curves from the bladder PET imaging. The proposed model takes all dynamic parameters into account and provides a much more accurate dose estimation to the bladder. In this study, the lowest dose to the bladder wall was obtained at the conditions of having a larger initial volume for the bladder contents and a higher production rate for urine. It is then advised patients to drink a bulk amount of water before the FDG injection or after urine voiding to facilitate urine production and to enlarge the bladder surface area, which are the most crucial steps in reducing the dose to the bladder wall. In our study, the voiding schedule in dose calculation plays certain roles although it is much more critical in the conventional MIRD calculation. The model estimated that the lowest dose to the bladder would occur at an initial void about 40 min after the FDG injection and the urine voiding was as complete as possible.
Adult↗
Brain abscess in patients with hereditary hemorrhagic telangiectasia: case report and literature review.
Hereditary hemorrhagic telangiectasia (HHT), or Osler-Weber-Rendu disease, affects multiple organ systems. Brain abscess is a potential complication, and this disease carries a high mortality. In the setting of HHT the abscess most likely results from paradoxical septic emboli or bacterial seeding of an ischemic portion of the brain after paradoxical sterile emboli. Brain abscess is the diagnosis that must be ruled out in patients with HHT presenting with new onset neurologic symptoms. The clinician can be misled by seemingly benign and nonspecific symptoms, signs, and laboratory test results. Appropriate diagnostic imaging with computed tomography or magnetic resonance imaging of the head is mandatory. We present a case of brain abscess in a patient with HHT presenting to the Emergency Department. The review of the literature deals with the pathophysiology and manifestations of HHT with particular focus on the pathologic and clinical features, and management of cerebral abscess in this setting. Differences between patients with brain abscess with or without HHT are highlighted.
Brain Abscess↗
ED management of cellulitis: a review of five urban centers.
Cellulitis is a common problem presenting to the emergency department (ED). This study examines the epidemiology of cellulitis in 5 Canadian urban EDs and determines the practice variation in this management among sites. From computerized provincial ED diagnosis information, 10% of cellulitis charts from April 1, 1997 to March 31, 1998 were randomly selected for review. All 5 EDs in one urban region were sampled; physicians were unaware of the study when seeing patients. A standardized audit form was used to collect information pertaining to visits for the incident infection case. Cases were excluded if simple cellulitis was not the primary diagnosis or if procedures such as incision and drainage were initially required. A total of 416 adult charts were retrospectively identified. The mean age was 46 years and 61% were men; 38% had seen another physician before the ED presentation. Cellulitis was most commonly located in the upper (41%) and lower (48%) extremities. Most cases were treated with intravenous cefazolin (58%; range among sites: 49%-66%); however, over 25 different antibiotics and doses were initially prescribed. Each case required a median of 4 (interquartile range [IQR]: 1, 9) ED visits. Some patients (14%) received an increase in dose (3%) or a change in antibiotic regimen (11%) during their treatment. Few patients (3%) required a second change in regimen. Specialist consultations were obtained in only 6% of patients and hospitalization was rare (7%). The most common discharge prescription was oral cephalexin (62%); however; many different regimens were prescribed. Cellulitis is a common ED problem which consumes considerable resources to treat. Considerable practice variation exists with respect to in-ED and post-ED management. These results suggest the need for the development of practice guidelines for the treatment of this common ED problem.
Alberta↗
Comparative studies on utilizing nitrogen capacity between two macroalgae Gracilaria tenuistipitata var. liui (rhodophyta) and Ulva pertusa (chlorophyta). I. Nitrogen storage under nitrogen enrichment and starvation.
This paper deals with the N storage of Gracilaria tenuistipitata var. liui and Ulva pertusa under ammonium enrichment and starvation. After 10 days of ammonium enrichment, ammonium NH4+, free amino acid (FAA), protein (pro), chlorophyll (Chl), phycoerythrin (PE) and total dissolved nitrogen (TDN) of the two macroalgae increased significantly. Total nitrogen (TN) increased significantly from 3.65% to 5.78% dry weight of G. tenuistipitata var. liui and 2.82% to 5.07% dw of U. pertusa, respectively. Protein and FAA were the most important N storage pools in the macroalgae. During N-starvation period, individual N pools of the two species were depleted at exponential rates. Each N pool in U. pertusa decreased more rapidly than in G. tenuistipitata, var. liui and the latter was able to sustain fast growth for more time (> 20 days) than U. pertusa. N demands for supporting growth were different between the two species, U. pertusa grew more rapidly and had higher N demands than G. tenuistipitata var. liui did.
Amino Acids↗
Comparative studies on utilizing nitrogen capacity between two macroalgae Gracilaria tenuistipitata var. liui (rhodophyta) and Ulva pertusa (chlorophyta). II. Feedback controls of intracellular nitrogen pools on nitrogen uptake.
The potential feedback by intracellular nitrogen pools on maximum N uptake (NH4+) rate were determined for Gracilaria tenuistipitata var. liui and Ulva pertusa. The results of correlation matrix analyzing showed that the surge uptake of ammonium seemed related to rapid changes in small intracellular pools of inorganic nitrogen or small peptide and amino acids rather than to changes in TN content of the macroalgae. The assimilation rates of nitrogen of U. pertusa and G. tenuistipitata increased slowly during N starvation and were mainly regulated by amino acids and some incorporation of amino acids into macromolecules. From ecological point of view, the fast-growing and uptaking nutrient U. pertusa is more suitable to improve water quality in integrated shrimp culture ponds in which external nutrient supplies are usually high and constant during the culture period, while G. tenuistipitata var. liui is more suitable to be polycultured in a waters with intermittence supply of nutrients.
Amino Acids↗
Estimation of organ dose equivalents from residents of radiation-contaminated buildings with Rando phantom measurements.
Since August 1996, a dose reconstruction model has been conducted with thermoluminescent dosimeter (TLD)-embedded chains, belts and badges for external dose measurements on the residents in radiation-contaminated buildings. The TLD dosimeters, worn on the front of the torso, would not be adequate for dose measurement in cases when the radiation is anisotropic or the incident angles of radiation sources are not directed in the front-to-back direction. The shielding and attenuation by the body would result in the dose equivalent estimation being somewhat skewed. An organ dose estimation method with a Rando phantom under various exposure geometries is proposed. The conversion factors, obtained from the phantom study, may be applicable to organ dose estimations for residents in the contaminated buildings if the incident angles correspond to the phantom simulation results. There is a great demand for developing a mathematical model or Monte Carlo calculation to deal with complicated indoor layout geometry problems involving ionizing radiation. Further research should be directed toward conducting laboratory simulation by investigating the relationship between doses delivered from multiple radiation sources. It is also necessary to collaborate with experimental biological dosimetry, such as chromosome aberration analysis, fluorescence in situ hybridization (FISH) and retrospective ESR-dosimetry with teeth, applied to the residents, so that the organ dose equivalent estimations may be more reliable for radio-epidemiological studies.
Construction Materials↗
Evaluation of external dose equivalent with thermoluminescent dosimeters from residents living in radiation-contaminated buildings.
As of October 1996 there are more than 90 radiation-contaminated steel supported rebar buildings (containing more than 1000 apartments) dispersed in the northern part of Taiwan. These apartments were contaminated with cobalt-60 at a total activity ranging from 1-140 microSv/yr. In this paper, a method is developed for evaluating external dose equivalent and dose equivalent rates encountered by the residents wearing specially designed thermoluminescent dosimeter (TLD)-embedded chains, belts and badges. Comparisons are also made between the TLD readings and the exposure readings from indoor layout personal dosimetry surveys and room occupancy adjustments to the buildings. The accuracy and sensitivity of the TLDs compared with the ionization chamber readings are judged to be considerable improvements over those of previous studies. From the present study, it is concluded that the reliability of the daily activity records provided by the residents during the entire TLD-wearing period is the most critical but challenging feature of the external dose equivalent measurement.
Activities of Daily Living↗
Conversion rates for prehospital paroxysmal supraventricular tachycardia (PSVT) with the addition of adenosine: a before-and-after trial.
OBJECTIVE: To determine whether the prehospital administration of adenosine to adults with stable and unstable paroxysmal supraventricular tachycardia (PSVT) influences conversion rate (CR) to sinus rhythm, scene time, use of synchronized electrical cardioversion (SEC), and accuracy of rhythm strip interpretation by paramedics. METHODS: This before-and-after study compared a retrospective control group (CG) prior to the introduction of adenosine with a prospective treatment group (TG) following the addition of adenosine to the PSVT treatment protocol in a large urban advanced life support emergency medical services system. The population represented patients > or = 18 years of age with PSVT diagnosed by the paramedic (defined as spontaneous onset of a regular narrow-complex tachycardia between 140 and 250 beats/minute). RESULTS: The CG comprised 74 calls and the TG 137 calls. The overall CR was higher in the TG (59% vs 32%, p < 0.001). The SEC and spontaneous conversion rates remained unchanged. The proportion of untreated patients with PSVT decreased from 26% CG to 12% TG (p < 0.01). Scene times were longer in the TG (26 vs 19 minutes, p < 0.001). Agreement between paramedic and physician rhythm strip interpretations was fair to moderate (CG kappa 0.43 [95% CI: 0.14, 0.72]; TG kappa 0.37 [95% CI: 0.13, 0.61]). CONCLUSIONS: The introduction of adenosine was associated with a significant increase in the prehospital CR of stable and unstable PSVT, while the SEC and spontaneous conversion rates were similar in each group; however, scene times were longer in the TG and paramedic accuracy in rhythm strip interpretation remained fair to moderate.
Adenosine↗