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BHP Minerals discovered the Archean lode gold ULU deposit on the western margin of the High Lake Volcanic Belt in 1989. The greenschist to amphibolite facies mafic volcanic and sedimentary rocks on the property are folded into a 5 km-long anticline. There is a close spatial association of Au-As zones to the trace of this F2 ULU anticline. The largest of these auriferous zones, the Flood zone, is localized at the core of the fold. The southeast-trending Flood zone consists of several anastomosing lenses that have been traced for 435 m on surface. Overall, it dips steeply (70° to 80°) to the southwest and has been intersected to depths below 600 m. The hosting high-iron tholeitic basalt displays a lower amphibolite mineral assemblage of ferrohornblende + plagioclase + ilmenite with accessory quartz and epidote. Alteration minerals include biotite, chlorite, hornblende, actinolite-tremolite, and potassium feldspar (microcline) with minor calcite, epidote, tourmaline, and titanite. The highest gold values occur where brecciated basaltic wall-rock clasts are replaced by acicular arsenopyrite + quartz + K-feldspar. BHP Minerals completed 54,783 m of both exploration and resource development drilling before selling the ULU property to Echo Bay Mines in 1995. Development of ULU as a satellite deposit to Echo Bay’s Lupin mine began in 1996. A -15% ramp was extended to the 155-meter level, and 16,011 m of underground drilling were completed before the decline in gold prices forced a suspension of activities at ULU in August 1997. The current owners, Wolfden Resources Inc., drilled 18,569 m in 2004 to increase confidence in the resource blocks. Following this drill program, a revised resource calculated by an independent consultant determined that the ULU deposit contains an inferred/indicated mineral resource of 1,130,000 t grading 11.34 g/t gold (373,748 oz) to the 360-m level. The portal was re-opened in 2005 and a prefeasibility study is underway.

Spongy textures are observed in anhydrous Group 1 mantle xenoliths (harzburgite, lherzolite and wehrlite) hosted in Tertiary alkali basaltic lavas from the Hessian Depression, Germany. These textures are developed only on clinopyroxene and spinel, and occur as rims or cross-cutting veinlets and patches showing optical continuity with the host grain. They are often associated with pools of amorphous glassy material. There is no preferential development of spongy domains against the xenolith-lava contact suggesting that the host magma did not play any significant role in their formation. Spongy clinopyroxene and spinel occur in all rock types, but, are more pervasive in wehrlite. Chemically, spongy domains of clinopyroxene and spinel are more refractory than unaffected areas, which is consistent with their formation through a partial melting event. The associated glassy material shows chemical characteristics which suggest that the melt pools are genetically related to the development of the spongy textures. The partial melting event was probably triggered by the infiltration of a low-density fluid. The fluid may have evolved from a silicate melt responsible for the metasomatic Fe-enrichment recorded in wehrlite. In this context, the more pervasive development of spongy clinopyroxene in wehrlite may be explained by a higher concentration of the evolved fluid phase at proximity to its silicate melt source.

The relationship between lead concentration in the dry film of lead based paints applied to steel bulkheads aboard ship, the lead concentration found in the air when the paint is removed by mechanical means, and blood lead concentrations of workers involved in lead based paint removal has not been well characterized. Intuitively a direct relationship must exist but confounding factors confuse the issue. Simultaneous sampling procedures from the same paint removal operation may differ by several orders of magnitude. The process from dried film to aerosol (airborne dust) exposure, and on to dose can be separated into two major phases; (1) generation of the dust and its transport through the air to the worker and (2) uptake and dose related factors within the body. Both phases involve complex interactions and there are a number of factors within each phase that significantly affect the potential lead dose for the worker. This study attempts to clarify the mechanisms involved in the generation and transportation of the dust to the worker by evaluating the relationship of a number of key factors on particle size and lead distribution within the aerosol dust generated when lead based paint is removed by sanding. The study examined the relationship between particle size in the dust and grit size of the abrasive. It also examined the distribution of lead within selected particle sizes. The Mass Median Aerodynamic Diameter (MMAD) was used as an indicator of change in the particle size distribution. Particle size distributions were evaluated using a TSI Aerodynamic Particle Sizer, a five stage cyclone and scanning electron microscopy. Lead distribution was determined using the five stage cyclone, and personal or area samples analyzed using inductively coupled plasma (ICP). Mass concentrations were evaluated using a MIE Mass Concentration Analyzer and gravimetric analysis of filter samples collected in the breathing zone. Student's t-tests were used to evaluate changes in MMADs, mass concentrations and other indices for inter and intra-grit size samples. Correlation coefficients (Pearson's r) were used to determine the relationship between factors. Findings of the research indicated that the particle size distribution in the dust is directly related to the grit size of the abrasive (i.e. inversely related to the abrasive grit number). Particulate mass concentrations of dust varied directly with abrasive grit number. The distribution of lead did not appear to be affected by grit size of the abrasive in that the lead distribution within the particle size ranges remained homogeneous and consistent with the lead concentration in the dried film. Mass concentrations of lead in air samples varied directly with lead concentration in the bulk coating. Results of this project, coordinated with deposition modeling and bioavailability studies will be useful in the development of a model to characterize lead dose to workers based on known parameters within the work specifications.

The polarized and depolarized components of backscattered laser light are examined photographically. Effects of surface roughness and angle of incidence are determined by measuring contrasts and dynamic range of the laser imagery. Three effective scattering surfaces are deduced from Fung’s scatter theory to explain the results.

The aim of the study is to evaluate the test-retest reliability of measures of isokinetic and isometric leg strength and joint function among individuals exhibiting symptoms of mild osteoarthritis. Reliable procedures are needed to assess the effectiveness of an intervention on osteoarthritic symptoms.Test-retest reliability of two leg strength protocols was assessed using the intraclass correlation coefficient (R). Testing was completed on two occasions separated by 7 days. Eighteen subjects (9 male and 9 female; 54.1+/-11 years) completed an isokinetic testing trial, which consisted of a set of 5 maximal repetitions of the quadriceps and hamstrings at 60 deg/s followed by a set of 15 maximal contractions at 180 deg/s with a 2-min rest between sets and an isometric testing trial, which consist of 3 maximal contractions of the quadriceps for 6 s with a 30-s rest between contractions at 30, 45, and 80 degrees of knee flexion for a total of 9 isometric contractions. A 90-s rest occurred between angles.Most of the isokinetic variables showed moderate to high intraclass reliability (ICC). Two of the calculated isokinetic variables (work fatigue at 180 degrees /s for extension and for flexion) showed low intraclass reliability (ICC=0.78, resp. ICC=0.6). All calculated ICC values of the isometric variables were moderate to high.Test-retest reliability of isokinetic and isometric leg strength was high, allowing the intervention protocol to monitor changes in leg strength and joint function among those exhibiting symptoms of mild osteoarthritis.

Male Sprague-Dawley rats were exposed by whole body inhalation to 1000 mg/m3 +/- 10% JP-8 jet fuel vapor or room air control conditions for 6 h/day, 5 days/week for six consecutive weeks. Following a rest period of 82 days rats were sacrificed, and liver and kidney tissues examined by proteomic methods for both total protein abundance and protein charge modification. Kidney and lung samples were solubilized and separated via large scale, high resolution two-dimensional electrophoresis (2-DE) and gel patterns scanned, digitized and processed for statistical analysis. Through the use of peptide mass fingerprinting, confirmed by sequence tag analysis, three altered proteins were identified and quantified. Numerical, but not significantly different increases were found in total abundance of lamin A (NCBI Accession No. 1346413) in the liver, and of 10-formyltetrahydrofolate dehydrogenase (10-FTHF DH, #1346044) and glutathione-S-transferase (GST; #2393724) in the kidneys of vapor-exposed subjects. Protein charge modification index (CMI) analysis indicated significant alterations (P0.001) in expressed lamin A and 10-FTHF DH. These persisting changes in liver and kidney proteins are discussed in terms of possible alterations in the functional capacity of exposed subjects.

The relationship between lead concentration in the dry film of lead based paints applied to steel bulkheads aboard ship, the lead concentration found in the air when the paint is removed by mechanical means, and blood lead concentrations of workers involved in lead based paint removal has not been well characterized. Intuitively a direct relationship must exist but confounding factors confuse the issue. Simultaneous sampling procedures from the same paint removal operation may differ by several orders of magnitude. The process from dried film to aerosol (airborne dust) exposure, and on to dose can be separated into two major phases; (1) generation of the dust and its transport through the air to the worker and (2) uptake and dose related factors within the body. Both phases involve complex interactions and there are a number of factors within each phase that significantly affect the potential lead dose for the worker. This study attempts to clarify the mechanisms involved in the generation and transportation of the dust to the worker by evaluating the relationship of a number of key factors on particle size and lead distribution within the aerosol dust generated when lead based paint is removed by sanding. The study examined the relationship between particle size in the dust and grit size of the abrasive. It also examined the distribution of lead within selected particle sizes. The Mass Median Aerodynamic Diameter (MMAD) was used as an indicator of change in the particle size distribution. Particle size distributions were evaluated using a TSI Aerodynamic Particle Sizer, a five stage cyclone and scanning electron microscopy. Lead distribution was determined using the five stage cyclone, and personal or area samples analyzed using inductively coupled plasma (ICP). Mass concentrations were evaluated using a MIE Mass Concentration Analyzer and gravimetric analysis of filter samples collected in the breathing zone. Student's t-tests were used to evaluate changes in MMADs, mass concentrations and other indices for inter and intra-grit size samples. Correlation coefficients (Pearson's r) were used to determine the relationship between factors. Findings of the research indicated that the particle size distribution in the dust is directly related to the grit size of the abrasive (i.e. inversely related to the abrasive grit number). Particulate mass concentrations of dust varied directly with abrasive grit number. The distribution of lead did not appear to be affected by grit size of the abrasive in that the lead distribution within the particle size ranges remained homogeneous and consistent with the lead concentration in the dried film. Mass concentrations of lead in air samples varied directly with lead concentration in the bulk coating. Results of this project, coordinated with deposition modeling and bioavailability studies will be useful in the development of a model to characterize lead dose to workers based on known parameters within the work specifications.

Comparisons were made between the physicochemical properties of Spectronics Fire Extinguishant (SFE) atmospheres generated either in a fire extinguishment or inhalation toxicity assessment regimen. Aerosol and gas phase components in the atmospheres were dynamic as opposed to steady-state, having varying rates concentration change. Fire extinguishment test conditions closely approximate those proposed for deployment of SFE as a fire extinguishing agent. Significant differences in aerosol mass concentration, size distribution and shifts in size distribution were found between the two types of atmospheres, each generated at two comparable target (nominal) concentrations. Likewise, differences in CO2 and CO concentration and dissipation rates of these gases also were found between the two types of atmospheres. A series of theoretical calculations of CO2 induced hypercapnea were developed as a basis to examine possible interaction of the components of the atmospheres. A hypothetical case for aerosol deposition rate and carboxyhemoglobin formation and changes in the rates of these phenomena was formulated for each atmosphere.

In 1992, the Navy Environmental Health Center, Norfolk, VA was made aware of the concern about the discoloration (yellowing) of interiors (e.g. bulkheads and bedding) and the possible exposure of navy personnel aboard submarines, to an - unknown substance. The agent was identified as 2,6-di-tert-butyl-4-nitrophenol (DBNP). The yellowing process appeared to arise from the reaction of 2,6-di-tert-butylphenol (DBP), an antioxidant additive used in engine lubricant, with NO2 in the submarine atmosphere. A research program was initiated for health hazard assessment of DBNP. - This technical report summarizes the results of our research program and the information available in the literature.

Successful pain management requires knowing the type of surgical procedure that has been performed as well as patient characteristics that may influence the choice of analgesic. The risk of morbidity is increased in patients with certain underlying conditions such as unstable angina if they do not receive adequate postoperative analgesia. Frequent assessment of pain severity using techniques such as visual analog scales can help optimize pain control. Nonsteroidal anti-inflammatory agents provide good analgesia after most minor surgical procedures and can decrease the amount of opioid analgesics needed after more extensive procedures. Intravenous and epidurally administered opioids are useful; however, better analgesia may be achieved when local anesthetics are administered by infiltration, peripheral nerve block or continuous epidural infusion. The use of two or more analgesic techniques together produces better pain relief than a single medication or administration route. A team approach can lessen the amount of postoperative pain. Family physicians should aggressively treat postoperative pain and actively support hospital postoperative pain treatment programs.

A continuous spinal anesthetic was planned and conducted for a medically compromised and demented 80-year-old man presenting for repair of an intratrochanteric hip fracture.A peripheral nerve stimulator was successfully employed to monitor the height and to help time the redosing of the continuous spinal anesthetic.The use of a peripheral nerve stimulator allowed careful titration of our continuous spinal anesthetic to provide dense analgesia at the surgical site for 1 hour 5 minutes, using a total spinal dose of 27 mg lidocaine and 7.5 micrograms spinal fentanyl.A standard peripheral nerve stimulator is an effective monitor to help optimize management of continuous spinal anesthesia.

Epinephrine is frequently combined with local anesthesia to prolong analgesia. Determination of the minimal concentration and the dose of epinephrine that produces prolongation of analgesia is important in the face of epinephrine's potential for systemic and local toxicity. The authors undertook this study to determine a dose-response curve of epinephrine on duration of analgesia of both 1% lidocaine and 0.25% bupivacaine after local infiltration. In order to determine whether epinephrine-induced vasoconstriction affected duration of analgesia, the authors correlated duration of analgesia with magnitude of local vasoconstriction as measured with laser Doppler flowmetry.Six volunteers were studied in a randomized double-blind manner. Ten skin wheals of 0.2 mL solution were subcutaneously injected into both forearms of each volunteer. The solutions consisted of 1% lidocaine with epinephrine concentrations of 0, 1:50,000, 1:200,000, 1:800,000, and 1:3,200,000, and 0.25% bupivacaine with the same epinephrine concentrations. Duration of loss of sensation to pinprick at each wheal was recorded. Skin wheals with 0.2 mL of these same solutions were also subcutaneously injected into the abdomen of the same 6 volunteers, and laser Doppler flowmetry readings of skin blood flow were measured for 6 hours after injection.Epinephrine prolonged duration of analgesia for both lidocaine and bupivacaine in a dose-related manner (P.001). All concentrations of epinephrine attenuated the vasodilation observed in the first 15 minutes after injection with plain local anesthesia (P = .03), and blood flow returned to baseline by 30 minutes after injection of either plain or epinephrine-containing solutions. Duration of analgesia correlated with magnitude of vasoconstriction only at the 15-minute measurement (r = .53 and .57, P = .003 and 0.001 for lidocaine and bupivacaine, respectively).Epinephrine prolongs duration of analgesia after local infiltration in a dose-related manner. Addition of epinephrine in concentrations of 1:50,000 or 1:200,000 increases duration of analgesia after local infiltration by approximately 200%. Addition of doses as dilute as 1:3,200,000 still increases duration of analgesia by approximately 100%. Duration of analgesia appears to correlate with magnitude of epinephrine-induced vasoconstriction using laser Doppler flowmetry. Based on study data, the use of epinephrine in concentrations from 1:200,000 to 1:3,200,000 is recommended for prolongation of analgesia after local infiltration.

Results obtained in studying the origin and suppression of large-amplitude pressure oscillations in a 24 in. diameter hybrid motor using a liquid oxygen/hydroxylterminated polybutadiene/polycyclopentadiene propellant system are discussed. Tests conducted with liquid oxygen flow rates varying from 10 to 40 lbm/sec were designed to gauge the effectiveness of various vaporization chamber flow fields, injector designs, and levels of heat addition in suppressing high-frequency longitudinal mode oscillations. Longitudinal acoustic modes did not arise in any tests. However, initial testing revealed the presence of high-amplitude, sinusoidal, nonacoustic oscillations persisting throughout the burn durations. Analysis showed this to be analogous to chug mode instability in liquid rocket engines brought about by a coupling of motor combustion processes and the liquid oxygen feed system. Analytical models were developed and verified by test data to predict the amplitude and frequency of feed-system-coupled combustion pressure oscillations. Subsequent testing showed that increasing the feed system impedance eliminated the bulk mode instability. This paper documents the work completed to date in performance of the Hybrid Propulsion Technology for Launch Vehicle Boosters Program (NAS8-39942) sponsored by NASA's George C. Marshall Space Flight Center.

Combinations of bupivacaine and fentanyl are popular for postoperative epidural analgesia. However, there are little data from which to select a rational dose of bupivacaine. The study examined the effects of increasing amounts of epidural bupivacaine on postoperative analgesia, epidural fentanyl consumption, and side effects after thoracotomy.Twenty-four patients were randomized in a double-blind manner to receive intra- and postoperative epidural infusions of either saline, 0.01% bupivacaine, 0.05% bupivacaine, or 0.1% bupivacaine at 10 mL/h. All patients received a standardized combined epidural (120 mg lidocaine and 1.5 micrograms/kg of fentanyl) and general anesthesia. Further postoperative analgesia was provided with fentanyl patient-controlled epidural analgesia (PCEA) only.There were no differences between groups in visual analog scale (VAS) pain scores at rest or cough, but 10 and 5 mg/h of bupivacaine provided better analgesia during physiotherapy (P.05). The use of 10 and 5 mg/h of bupivacaine led to significant opioid sparing (50% decrease) when compared to saline and 1 mg/h bupivacaine (P.03). There was a trend toward a greater incidence of orthostasis with the use of bupivacaine at 10 mg/h (P = .09). Incidences of opioid side effects were not different between groups.The results demonstrate improved analgesia with physiotherapy and significant opioid sparing when 10 and 5 mg/h doses of bupivacaine are used. However, the incidence of orthostasis may be increased with the use of 10 mg/h. Thus, 5 mg/h of epidural bupivacaine (.05% at 10 mL/h) improved analgesia, decreased opioid requirements, and did not have detectable hemodynamic effects.

The authors recently determined that intravascular injection of an epinephrine test dose reliably produced an increase in heart rateor = 20 beats/min in young individuals. However, aging is associated with a significant reduction in beta-adrenergic responsiveness. This study was designed to determine whether aging decreases the magnitude of heart rate (HR) increase after intravascular injection of epinephrine.Heart rate and systolic blood pressure were recorded during randomized and double-blind injections of 3 mL lidocaine plain or lidocaine with 10 or 15 micrograms epinephrine in 30 elective surgical patients between 21 and 81 years old.Increasing age was associated with smaller increases in HR after intravascular injection of epinephrine. The reduction in HR increase was statistically significant after 10 micrograms (P = .006, r2 = .24), but not after 15 micrograms (P = .25, r2 = .05) of epinephrine. Heart rate increases were of greater magnitude for patients younger than 40 years old (P = .01 for 10 micrograms epinephrine, and P = .03 for 15 micrograms epinephrine). One patient (of 11) over 60 did not respond to the 15 micrograms test dose with tachycardia. Aging did not alter systolic blood pressure increases after 10 or 15 micrograms epinephrine (P = .27, r2 = .04 and P = .4, r2 = .03, respectively).Aging is associated with a reduction in the magnitude of HR increase after intravenous injection of epinephrine. The results suggest that to detect an intravascular injection in healthy people, a test dose containing 10 micrograms epinephrine will suffice before the age of 40. However, even 15 micrograms epinephrine will not be totally reliable in older patients, owing to decreased beta-adrenergic responsiveness.

It remains unclear whether epidural administration of hydromorphone results in spinal analgesia or clinical benefit when compared with intravenous administration. Therefore, we undertook this study to determine whether epidural administration of hydromorphone resulted in decreased opioid requirement, improved analgesia, reduced side effects, more rapid return of gastrointestinal function, or shorter duration of hospital stay than intravenous administration.Sixteen patients undergoing radical retropubic prostatectomy were randomized in a double-blind manner to receive either intravenous or epidural hydromorphone via patient-controlled analgesia (PCA) for postoperative analgesia. All patients underwent a standardized combined epidural and general anesthetic and all received ketorolac for 72 h postoperatively. To decrease variability, patients were cared for according to a standardized protocol and were deemed ready for discharge according to prospectively defined criteria.Patients in the intravenous PCA group required approximately twice as much opioid than the epidural PCA group (P0.008), but there were no differences between groups in pain scores or patient satisfaction. Epidural administration resulted in a greater incidence of pruritus (P = 0.02). Gastrointestinal function recovered quickly in all patients with little variation, and there were no differences between groups. All patients were deemed ready for discharge by the third postoperative day, and removal of surgical drains was the last discharge criterion reached in all patients.Our results indicate that epidural administration of hydromorphone results in spinally mediated analgesia. However, epidural administration did not provide significant benefits in terms of postoperative analgesia, recovery of gastrointestinal function, or duration of hospitalization. Furthermore, we suggest that radical retropubic prostatectomy no longer be used as a model to assess the effects of analgesic technique on postoperative recovery, because control of discharge criteria revealed that hospital discharge was primarily dependent on removal of surgical drains.

Bradycardia occurs during 9%-13% of spinal anesthetics and may lead to cardiac arrest. Several risk factors for the development of bradycardia have been identified, but the risk conferred by presence of abnormalities detected on preoperative electrocardiogram (ECG) has not been examined. The authors undertook the study to correlate abnormal ECG findings with the incidence of bradycardia.The data-base was previously collected from 952 patients undergoing spinal anesthesia. Patient records were reviewed and 537 had ECGs performed within 6 months of surgery. Intraoperative bradycardia was defined as a heart rate50 bpm (plus10% decrease from baseline). Abnormalities recorded from the ECG were prolonged PR interval (PR0.2 sec), atrial-ventricular conduction abnormalities, evidence of chamber hypertrophy, ischemia, and infarction. The findings were compared with incidence of bradycardia using contingency tables. Significant correlations were then evaluated with logistic regression. Significance was defined as P.05.The incidence of bradycardia in this population was 12%. Patients with a prolonged PR interval had an increased incidence of bradycardia (25%, P = .01). Other ECG abnormalities did not correlate with increased incidence of bradycardia. Duration of PR interval did correlate significantly (P = .001) but poorly (r2 = 0.014) with baseline heart rate. However, logistic regression demonstrated that prolonged PR interval was a significant and independent predictor for bradycardia (odds ratio = 3.2, P = .01).Risk factors previously identified for the development of bradycardia during spinal anesthesia include: baseline heart rate60 bpm, ASA physical status 1 versus 3 or 4, use of beta-blocking drugs, sensory block heightor = T5, and age50. The results demonstrate that prolonged PR interval on the preoperative ECG is another significant and independent predictor for bradycardia.

The parameters in a physiologically based pharmacokinetic (PBPK) model of methylene chloride were varied systematically, and the resulting variation in a number of model outputs was determined as a function of time for mice and humans at several exposure concentrations. The importance of the various parameters in the model was highly dependent on the conditions (concentration, species) for which the simulation was performed and the model output (dose surrogate) being considered. Model structure also had a significant impact on the results. For sensitivity analysis, particular attention must be paid to conservation equations to ensure that the variational calculations do not alter mass balance, introducing extraneous effects into the model. All of the normalized sensitivity coefficients calculated in this study ranged between -1.12 and 1, and most were much less than 1 in absolute value, indicating that individual input errors are not greatly amplified in the outputs. In addition to ranking parameters in terms of their impact on model predictions, time-dependent sensitivity analysis can also be used as an aid in the design of experiments to estimate parameters by predicting the experimental conditions and sampling points which will maximize parameter identifiability.

Establishment of a test facility and associated 11-in.-diameter motor for hybrid propulsion technology development at NASA's George C. Marshall Space Flight Center is discussed in this paper. Results of twenty 11-in.-diameter motor tests with a UTF-29901 (60 percent polycyclopentadiene, 40 percent hydroxyl-terminated polybutadiene)/gaseous oxygen propellant system are presented. Tests at this scale have developed fuel regression correlations for comparison with results of yet-to-be-completed, 24-in.-diameter motor tests; demonstrated combustion efficiency levels in the 95 percent range for both single- and multiple-port grain configurations; have shown smooth and stable throttling characteristics over flight-type throttle ranges; and have begun to establish criteria for stable combustion in hybrid motors. The testing of 24-in. motors has not as yet been initiated and is not addressed.

The objective of this study was to evaluate and compare the effect of lidocaine, mepivacaine, and bupivacaine on capillary blood flow in humans over therapeutic and subtherapeutic concentrations.The effect of each treatment in eight unmedicated male volunteers was measured in a randomized, controlled, double-blind comparison. Each participant received subcutaneous injections (total, 14), at separate sites on the abdomen, consisting of 0.2 ml lidocaine (0.05%, 0.5%, 1%, and 2%), mepivacaine (0.05%, 0.5%, 1%, and 2%), bupivacaine (0.025%, 0.25%, 0.5%, and 0.75%), saline, or saline with epinephrine (5 micrograms/ml), and at an additional site a needle stick was performed and no injection made. Cutaneous blood flow was measured with a laser Doppler capillary perfusion monitor before and for 60 minutes after these interventions.The maximum increase in cutaneous blood flow was 277 +/- 141% to 511 +/- 136% (mean +/- SE) after lidocaine, 124 +/- 110% to 316 +/- 155% after mepivacaine, and 242 +/- 193% to 725 +/- 198% after bupivacaine. The increase in blood flow depended on local anesthetic concentration: low concentrations induced minimal changes, whereas higher concentrations caused great increases in cutaneous blood flow. Injection of saline or needle stick alone increased cutaneous blood flow 285 +/- 237% and 260 +/- 121%, respectively.Our findings indicate that the trauma of needle stick or saline injection produces a significant increase in cutaneous capillary blood flow. Injection of clinically useful concentrations of bupivacaine and lidocaine produced even greater increases in capillary blood flow, indicating a vasodilatory effect. Injection of the lowest concentrations of lidocaine and bupivacaine caused flow to increase to a magnitude similar to that after injection of saline. In contrast, clinically useful concentrations of mepivacaine do not increase capillary blood flow to a greater extent than saline, and lower concentrations tend to blunt the increase in blood flow, indicating a mild vasoconstrictor effect.

The rate of failed spinal anaesthesia, defined as the need for unplanned general anaesthesia, was evaluated in a prospective study involving 137 patients undergoing transurethral resection of the prostate (TURP). The incidence of sensations at the operative site which did not require general anaesthesia was also evaluated. Attention to details was emphasized in the technique. Patients randomly received either hyperbaric Niphanoid tetracaine (n = 74; 6 or 10 mg) or hyperbaric bupivacaine (n = 61; 6 mg), with or without adrenaline. General anaesthesia was necessary in one patient (0.72%). Twelve additional patients reported sensations at the operative site which were rapidly relieved by light intravenous supplementation with low doses of fentanyl and/or thiopentone. The patients reporting sensations did not differ in demographic characteristics, spinal technique, local anaesthetic, or degree of sensory or motor blockade. Addition of adrenaline to the 6-mg doses of both tetracaine and bupivacaine decreased the incidence of sensations at the operative site.

In this randomized, blinded study, we sought to determine whether the vasoconstriction produced by ropivacaine after subcutaneous injection is sufficient to decrease surgical bleeding. Anesthesia was induced in seven piglets (weight, 12.2-20.4 kg) with intraperitoneal thiopental and maintained with intravenous methohexital. Five sites were injected with 10 ml of one of the following solutions: 0.25% ropivacaine, 0.25% bupivacaine, either solution plus 5 micrograms/ml epinephrine, or saline. Another site was left uninjected for control. Capillary blood flow was measured at each site with a laser Doppler before and ten minutes after the injections. An incision 5 cm in length was then made through the dermis, and blood loss was measured over ten minutes. We found no significant differences in capillary blood flow and blood loss between bupivacaine and ropivacaine. Addition of epinephrine decreased capillary blood flow (p less than 0.05) and tended to decrease blood loss. Capillary blood flow correlated with blood loss (r2 = 0.106; p less than 0.05). We conclude that, in contrast to previous studies, ropivacaine did not decrease capillary blood flow in our model. Similarly, ropivacaine did not reduce bleeding from surgical incisions. The reason for these surprising results is not clear but is unlikely to be the larger volume of solutions injected because no such effect was observed with saline alone.

The authors studied the optimal epinephrine content of an epidural test dose, and determined criteria to identify intravascular injections in subjects with or without beta-adrenergic blockade. Nine healthy nonpregnant subjects 25-36 years of age were given intravenous infusions of saline or esmolol in random order. During each infusion, they received a series of five injections (3 ml each) of either saline, 1% lidocaine or 1% lidocaine containing 5, 10, or 15 micrograms of epinephrine. Thirty minutes after completing these two infusions, propranolol was administered as a bolus injection, and the series of five injections repeated. All injections were double blind and randomized. During saline infusion, all injections containing epinephrine significantly increased heart rate (HR) by an average of 31-38 beats/min when compared with that following plain lidocaine (P less than 0.05), and increased systolic blood pressure by an average of 17-26 mmHg (P less than 0.05 for the 15-micrograms dose only). During esmolol infusion, epinephrine injections increased HR by an average of 23-31 beats/min (P less than 0.05), and increased systolic blood pressure by an average of 18-30 mmHg (P less than 0.05 for 10 and 15 micrograms). After propranolol injection, epinephrine injections caused a decrease in HR by an average of 21-28 beats/min (P less than 0.05), whereas systolic blood pressure increased by an average of 22-35 mmHg (P less than 0.05 for 10 and 15 micrograms only). Without beta-adrenergic blockade, an increase in HR greater than or equal to 20 beats/min was 100% sensitive and specific for intravascular injection of 10 or 15 micrograms of epinephrine.(ABSTRACT TRUNCATED AT 250 WORDS)

Changes in epidural compliance were investigated before and after extracorporeal shock wave lithotripsy (ESWL) in 11 outpatients. Epidural pressures were unchanged acutely by ESWL (p greater than 0.15). In contrast to previous reports of failures of epidural anesthesia in patients having repeat ESWL treatments, a review of our population of patients having repeat ESWL indicates that epidural anesthesia is reliable and not associated with any greater failure rate than for initial ESWL treatments. The difference between our results and previous reports of high failure rates is likely due to differences in anesthetic and surgical techniques such as: (1) use of air for loss-of-resistance when locating the epidural space, (2) differences in the time interval between ESWL treatments, and (3) frequency of use of epidural catheters.

A particulate sample was collected from the process stream of a low Btu gasifier in a cascade impactor operated at 400°C and 10–12 atmospheres pressure. Stainless steel shim stock was used as collection substrate. The sample, which weighed less than 1 mg, was successfully mounted and examined by ESCA, EDXA, and SEM. The ESCA spectra of the samples and of the blank impactor plates were taken before and after ion etching. The SEM and EDXA data were obtained for samples still on the impactor plate and for a sample transferred from the plate to a carbon, oxygen, and sulphur, but no significant peaks for alkali metals or calcium normally found on the surface of coal combustion fly ash. The EDXA data demonstrated that the core of the particles contained Al, Si, Mg, Ca, and S. Methods of sample manipulation are described.

Mutagenic and nonmutagenic extracts of fly ash from fluidized bed combustion were analyzed to determine the compounds responsible for the direct mutagenic activity (mutagenic activity that does not require added metabolic enzymes in the Salmonella mutagenicity assay). Some nitro derivatives of polycyclic aromatic hydrocarbons which are direct acting mutagens were detected by tandem triple quadrupole mass spectrometry. Treatment of a mutagenic and a nonmutagenic extract with excess N2O4 resulted in 28- and 3200-fold increases, respectively, in direct mutagenicity in Salmonella typhimurium strain TA98 and an increase in the relative abundance of nitroaromatic compounds. Polycyclic aromatic compounds were also detected and tentatively identified by gas chromatography-mass spectrometry. Since, previous studies have shown that polycyclic aromatic hydrocarbons may react with NO2 to form direct-acting mutagens, it appears that the direct-acting mutagens in these fly ash extracts may be products of reactions of polycyclic aromatic hydrocarbons with NOX in the combustion gases.

The responses of guinea pigs and rats to inhaled sulfuric acid aerosols were compared to define species differences and to determine the small‐animal model most relevant to human exposures. Rats were exposed for 6 h to 1, 10, and 100 mg H 2 SO 4 /m 3 . Guinea pigs were exposed for 6 h to 7, 10, and 27 mg H 2 SO 4 /m 3 . Tracheal mucous clearance of guinea pigs was slowed 7 d after exposures to 1 mg H 2 SO 4 /m 3 . A tendency toward faster clearance was observed at high concentrations of H 2 SO 4 for both guinea pigs and rats (statistically significant only for the rats). The speeding of mucous clearance was correlated with increases in airway sialic acid and also with the appearance of excess tracheal secretions, detected using scanning electron microscopy in both rats and guinea pigs. The responses of guinea pigs to sulfuric acid exposures were more similar to those reported for humans than were those of rats.

Samples were obtained from selected positions in the process stream of an experimental low Btu gasifier using a five-stage multicyclone train and a four-stage condenser train. These materials which represent potential fugitive emissions were screened for mutagenic activity (AmesSalmonella mammalian microsome mutagenicity assay) and forin vitro cytotoxicity (alveolar macrophages). Size-fractionated materials collected in the multicyclone train were mutagenic inSalmonella tester strains TA-98 and TA-100 and were also cytotoxic. There appeared to be no relationship between aerosol droplet size and mutagenic activity. Studies with condenser train samples indicate that neutral and basic polynuclear aromatic compounds contribute to the mutagenicity of process stream materials. Specific mutagenic and cytotoxic activity of material was reduced as gas underwent cleanup. A reduction in the mass loading of potentially toxic compounds is achieved by the control devices in the process stream of the experimental gasifier being developed and tested by METC, and assuming equal probability of emissions throughout the process stream, risk from exposure to potential fugitive emissions is reduced as the gas is cleaned.

The relationships between bed operation in a fluid bed aerosol generator and aerosol output were studied. A two-inch diameter fluid bed aerosol generator (FBG) was constructed using stainless steel powder as a fluidizing medium. Fly ash from coal combustion was aerosolized and the influence of FBG operating parameters on aerosol mass median aerodynamic diameter (MMAD), geometric standard deviation (sigma g) and concentration was examined. In an effort to extend observations on large fluid beds to small beds using fine bed particles, minimum fluidizing velocities and elutriation constant were computed. Although FBG minimum fluidizing velocity agreed well with calculations, FBG elutriation constant did not. The results of this study show that the properties of aerosols produced by a FBG depend on fluid bed height and air flow through the bed after the minimum fluidizing velocity is exceeded.

Organic components of effluents from a fluidized bed coal combustor were sampled by collecting vapor phase compounds on a Tenax polymer adsorbent trap and particulate samples with a concentric electrostatic precipitator (CESP). Samples of ash collected by the effluent cleanup devices were also analyzed. Samples were extracted to isolate the organic components. Extracts were characterized by gas chromatography to quantitate extractable hydrocarbons and by gas chromatography‐mass spectrometry to obtain molecular weights and tentative identification of components. The effluent contained higher concentrations of extractable hydrocarbons in the vapor phase than associated with particles.

A method has been developed to quantitate talc lung burdens in rats and mice after inhalation exposure to talc aerosols. The method is based on acid-insoluble magnesium (Mg) determination by flame atomic absorption. Precipitating protein from homogenates of lungs of unexposed rodents with 5% perchloric acid and washing with 5% trichloroacetic acid removed the soluble and naturally occurring Mg. This resulted in residual Mg content averaging 0.43 μg Mg per g lung in rats and less than 0.1 μg Mg per g lung in mice for young rodents less than 12 weeks old. Rodents 12–18 months old had residual mean (±SD) Mg contents of 3.4 ± 2.0 μg Mg per g rat lung (n =17) and 6.5 ± 2.9 μg Mg per g mouse lung (n =12). Thus, the background residual acid-insoluble Mg content in rodent lungs appears to increase with age. Negligible quantities of Mg were extracted directly from the talc treated by these procedures. Adding 50–2000 μg talc to lungs from unexposed rodents, followed by the sample treatment, gave mean (±SD) Mg recoveries of 89 ± 12% (n =19) for rat lungs and 96 ± 26% (n =15) for mouse lungs. The lung burden of talc in rodents exposed to talc aerosols for 6 h per day, 5 days per week for 4 weeks was determined. Mean lung burdens in rats were 77, 187, and 806 μg talc per g lung (n =10) for exposures at 2.3, 4.3, and 17 mg talc m3, respectively. Mean lung burdens in mice were 114, 325 and 1150 μg talc per g lung (n =10) for exposures at 2.2, 6.3 and 20.6 mg talc m3, respectively. The coefficient of variation for the lung burdens of the different exposure groups ranged from 8 to 21%.

Sized fractions of Mount St. Helens volcanic ash were examined by SEM, EDXA, and ESCA. Particle size distributions, density, and specific surface area were determined. The size distribution was bimodal. Both EDXA and AAS demonstrated the presence of Si, Al, Fe, Na, K, Ca, and Mg. The EDXA demonstrated that Si and Al were present in all particles, except one, which was over 99% Si. Particle-to-particle variation in composition was large. X-ray diffraction demonstrated the presence of labradorite (plagioclase), albite, orthoclase, and anorthite, with a high background from amorphous material. ESCA demonstrated the presence of Na as a surface contaminant. No surface sulfur was detected, nor hydrocarbons at levels exceeding those normally found on air-exposed surfaces. The variation of specific surface area with particle size showed that the surface of the ash has a fractal dimension of 2.23 ± 0.03. Specific surface areas ranged from 1 m2 g−1 to 10 m2 g−1. From our study we estimated that the total surface ar...

The size distribution of fly ash emitted from an atmospheric fluidized-bed coal combustor (AFBC) with a 20- m2 cross-section bed equipped with cyclones and a baghouse system to control the particulate emission is described. The Georgetown AFBC was designed to produce a maximum of 100,000 pounds/h of saturated steam at 275 or 625 psig to support space heating and to supply hot water to the university. A 2-cyclone dust collector was used to remove large fly ash particles from the effluent stream, and a baghouse system was used for fine control of the particulate emissions before discharging to the atmosphere. The fly ash concentration and size distribution before and after the baghouse dust control system were measured, and the collection efficiency of the baghouse system was determined. A bimodal size distribution of fly ash was observed. The mass fraction of submicron particles was 4.3% before the baghouse and increased to 18% at the stack because the collection efficiency of the baghouse was size depende...

Potential waste effluents produced by an experimental low Btu coal gasifier were assessed for mutagenic activity inSalmonella strain TA98. Cyclone dust, tar and water effluents were mutagenic, but only following metabolic activation. Neutral and polar polycyclic aromatics contributed significantly to mutagenic activity of Venturi scrubber water and tar. The results indicate that cyclone dust, tar, and water effluents of the experimental low Btu gasifier, as operated in 1979, contain mutagenic material. Potential health hazards associated with these materials should be considered in the design of future coal gasification facilities.

Let A be a commutative semisimple F-algebra with identity, and let D 0 , D 1 , ⋯ {D_0},{D_1}, \cdots be a system of derivations from A into the algebra of all continuous functions on the spectrum of A. It is shown that the transformations D 0 , D 1 , ⋯ {D_0},{D_1}, \cdots are necessarily continuous. This result is used to obtain a characterization of derivations on Hol ( Ω ) {\text {Hol}}(\Omega ) where Ω \Omega is an open polynomially convex subset of C n {C^n} .