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SARS-CoV-2 emergent variants are characterized by increased transmissibility and each show multiple mutations predominantly localized to the spike (S) protein. Here, amide hydrogen/deuterium exchange mass spectrometry has been applied to track correlative changes in S dynamics from multiple SARS-CoV-2 variants. Our results highlight large differences across variants at two loci with impacts on S dynamics and stability. A significant enhancement in stabilization first occurred with the emergence of D614G S followed by smaller, progressive stabilization in Omicron BA.1 S traced through Alpha S and Delta S variants. Stabilization preceded progressive enhancement in dynamics in the N-terminal domain, wherein Omicron BA.1 S showed the largest magnitude increases relative to other preceding variants. Changes in stabilization and dynamics resulting from specific S mutations detail the evolutionary trajectory of S protein in emerging variants. These carry major implications for SARS-CoV-2 viral fitness and offer new insights into variant-specific therapeutic development.

The sound of a 3,000 year old mummified individual has been accurately reproduced as a vowel-like sound based on measurements of the precise dimensions of his extant vocal tract following Computed Tomography (CT) scanning, enabling the creation of a 3-D printed vocal tract. By using the Vocal Tract Organ, which provides a user-controllable artificial larynx sound source, a vowel sound is synthesised which compares favourably with vowels of modern individuals.

Radar interferometry (InSAR) deformation measurements are afflicted by artifacts associated with the atmosphere and errors in removing the topographic phase contribution. We present a new time series algorithm that eliminates high-spatial-frequency atmospheric effects (bubbles) not removed with existing advanced InSAR approaches applied to measurements of smoothly varying deformation through time. Our High-Resolution Atmospheric Phase Screen (APS) (HiRAPS) algorithm initially uses a connected set of short-period interferograms, each spanning no more than three satellite-orbit repeat cycles. We estimate height error differences between a pixel and its neighbors within a radius chosen to be significantly smaller than a bubble. The height errors are unwrapped and removed from those pixels with high values of a newly defined multi-interferogram phase correlation. We then create a deformation time series for the pixels using singular value decomposition. The high-resolution APS are estimated from a dense set of pixels using spatiotemporal filtering. We evaluate the HiRAPS algorithm on simulated data consisting of realistic time-linear and nonlinear deformation, height errors, and bubbles. The root mean square error between all simulated and estimated APS pixels is 0.26 rad with the HiRAPS algorithm and 0.39 rad with a persistent scatterer (PS) algorithm. We also apply the HiRAPS algorithm to 66 Radarsat-1 images of Phoenix, AZ. Our HiRAPS approach results in an 18-fold increase in APS pixel density over PS processing. After removing the HiRAPS and PS APS from PS interferograms, we find that HiRAPS provides an 18% increase in the number of final PS detected.

Endovascular aortic aneurysm repair (EVAR) has currently replaced open surgical repair as the primary method for treating aneurysm disease of the abdominal aorta and common iliac artery. Current EVAR devices, despite undergoing multiple improvement iterations, continue to have relatively high secondary intervention rates. Device migration, endoleak and limb occlusion continue to be challenges not completely met by any of the current devices. Investigational devices presently in clinical trials may provide significant resolution for many of the identified endograft deficiencies.

Chronic alcohol misuse by human subjects leads to neuronal loss in regions such as the superior frontal cortex. Reduced GABA transmission may mediate this. The expression of GABA(A) receptor beta(1), beta(2), and beta(3) isoform proteins was analyzed by western blotting in vulnerable (superior frontal cortex) and spared (primary motor cortex) cortical tissue obtained at autopsy from Caucasian subjects, and the effect of genotypes of candidate genes for alcoholism assessed. There was a significant regional difference in global isoform expression, but no significant overall group difference in beta(2) or beta(3)expression between controls and alcoholics undifferentiated by genotype in either cortical region. There were significant, regionally selective, interactions of DRD2B, SLC1A2 and APOE genotypes with beta protein expression when alcoholics were compared with controls. In each instance possession of the alcoholism-associated allele increased the beta(2):beta(3) ratio in the pathologically vulnerable region, by two distinct mechanisms. The SFC beta(2):beta(3) ratio in DRD2B-B2,B2 alcoholics was 22% higher than that in DRD2B-B1,B1 alcoholics, and 17% higher than that in DRD2B-B2,B2 controls. The SFC beta(2):beta(3) ratio in SLC1A2A603 homozygote alcoholics was 25% higher than that in alcoholics with at least one 603G allele, and 75% higher than that in SLC1A2A603 homozygote controls. The SFC beta(2):beta(3) ratio in alcoholics lacking an APOE epsilon3 allele was 73% higher than that in alcoholics with at least one epsilon3 allele, and 70% higher than that in controls without an epsilon3 allele. ADH1C genotype also differentiated cases and controls, but the effect was not localized. GABRB2 and GRIN2B genotypes were associated with significant regional differences in the pattern of beta subunit expression, but this was not influenced by alcoholism status. DRD2A and SLC6A4 genotypes were without significant effect. A restricted set of genotypes may influence subunit expression in this group of high-consumption alcoholics.

Chronic alcohol misuse leads to both widespread and localized damage in human cerebral cortex. The latter, as neuronal loss, is marked in superior frontal cortex (SFC) but milder in primary motor cortex (PMC) and elsewhere. Quantitative morphometry by Harper et al showed that neuronal loss is greater in alcoholics with comorbidity (Wernicke Korsakoff syndrome, liver cirrhosis). Previous work revealed a paradox: the marked differences in GABAA receptor density, pharmacology, and expression between alcoholics without cormorbidity and controls are muted or absent in cirrhotic alcoholics. This concurs with work by the Butterworth group on hepatic encephalopathy cases — most of whom had an alcoholic aetiology — who show only minor differences from controls. Glutamate receptor differences are muted in many autopsy studies, though we have evidence that NMDA site pharmacology may vary in cirrhotic alcoholics. Here we used Real-Time PCR normalized to GAPDH deltaCT to quantify NMDA NR1, NR2A and NR2B subunit expression in SFC and PMC samples obtained at autopsy from alcoholics with and without comorbid cirrhosis and matched controls. Overall subunit transcript expression was signifi cantly lower in alcoholic cirrhotics than in either of the other groups (F2,42 = 12.942, P < 0.001). The effect was most marked for the NR1 subunit; males differed from females, particularly in SFC. The data suggest that if excitotoxicity mediates neuronal loss in SFC, it may be implemented differently: passively in uncomplicated alcoholics, by altered GABAergic transmission; actively in cirrhotic alcoholics, by altered glutamatergic transmission. We also subdivided cases on a panel of genetic markers. Different genotypes interacted with NMDA and GABAA pharmacology and expression. Cirrhotic and uncomplicated alcoholics may differ pathogenically because of inherent characteristics in addition to possible neurotoxic sequelae to the liver damage.

Severe long-term alcohol misuse leads to localized brain damage that is prominent in superior frontal cortex but less so in other cortical areas e.g. primary motor. Alcohol dependence is also associated with several genetic markers. GABAA receptor expression differs selectively between alcoholics and controls in a manner that conforms to the pathology, whereas glutamate receptors are much less regionally variable in these subjects. We determined whether genotype differentiated the pharmacology of glutamate-NMDA receptors and the expression GABAA receptor subunits transcripts in a locally appropriate way so as to influence the severity of alcohol-induced brain damage.

A competitive RT-PCR assay was used to quantify the expression of the GABA(A) receptor beta(1), beta(2) and beta(3) isoform mRNA transcripts in the superior frontal cortex and motor cortex of 21 control and 22 alcoholic cases. A single set of primers was designed that permitted amplification of all three transcripts and the internal standard simultaneously; differentiation of the individual transcripts was achieved by restriction enzyme digestion. Construction of a standard curve, using the internal standard and a concentration range of beta(2) cRNA-enabled quantitation of mRNA expression levels. No significant difference in mRNA expression was found between the control and alcoholic case groups in either the superior frontal or motor cortex for the beta(2) or beta(3) isoforms. A significant interaction was found between isoform and area, although, the two case groups did not partition on this measure. The interaction was due to a significant difference between superior frontal and motor cortex for the beta(3) isoform; this regional comparison was not significant for beta(2) mRNA. Age at death and post-mortem delay (PMD) had no significant effect on beta mRNA expression in either case group in either region. A beta(1) signal could not be detected in the RT-PCR assay.

Dimethylsulphide (DMS) is a trace sulphur gas found in most atmospheric and surface water samples, which is derived from dimethylsulphonioproprionate (DMSP). Although it has been extensively studie...

This investigation focuses on the oxidation of chlorobenzene izn a laboratory-scale molten salt reactor. A Fourier transform infrared spectrometer with a long-path cell is used to monitor the organic waste oxidation process, including the formation of by-products as a function of temperature. The measured oxidation by-products are compared with results reported in the literature and are obtained in a combustion-driven flow reactor at similar oxidation temperatures; the results are modeled using detailed chemical kinetics. The results outlined in this work provide a direct comparison of the effectiveness of molten salt oxidation compared with conventional combustion oxidation and highlight the advantages and disadvantages associated with the molten salt oxidation process.

Long-term alcohol abuse is known to target specific areas of the brain such as the superior frontal cortex (SFC), resulting in neuronal cell loss. Abnormal transmission of the inhibitory neurotransmitter GABA may contribute to this damage. Previous work in our laboratory has found differential expression and distribution of certain a subunit genes of the GABAA receptor in the SFC of human alcoholic brain, suggesting that differences in GABAA receptor subunit expression could give rise to the locally altered GABAA pharmacology which is associated with alcohol abuse. A competitive RT-PCR assay has been developed to study the expression of the GABAA receptor beta-subunit genes beta1, beta2, and beta3. A single set of primers homologous to all three beta isoform sequences has been shown to amplify each of the beta isoforms from mRNA isolated from human brain tissue obtained at autopsy. An internal standard has been designed which is identical to the target except for a 61-bp deletion and a unique restriction enzyme (RE) site. This is co-amplified with the target sequences to allow amplification efficiency to be assessed and thus enable the quantitation of gene expression. A range of GABAA receptor ligands were used to look at differential distribution of receptor subtypes in the cortical laminae by autoradiography. Differences in distribution of the ligands were demonstrated, consistent with a hypothesis of alcohol-induced variations in the expression of receptor subunits.

Previous studies have demonstrated that a novel source of ozone gas (O3) maybe used to chemically degrade numerous mycotoxins, including aflatoxin (AF) B1. Subsequent in vitro analyses demonstrated detoxification of AFB1, suggesting a potential method of remediate AF-contaminated grain. The objective of this study was to evaluate the capability of electrochemically produced ozone to degrade AFB1 in naturally contaminated whole kernel corn and confirm detoxification in turkey poults. Corn was procured from the southern coastal areas of Texas and HPLC revealed 1,220 +/- 73.3 ppb AFB1. Control and contaminated corn were treated for 92 h with O3 at 200 mg/min in 30 kg batches; greater than 95% reduction of AFB1 in contaminated corn was achieved. One-day-old female turkey poults were fed 1) control corn, 2) control corn + O3, 3) AFB1 corn, or 4) AFB1 corn + O3 mixed in rations (46% by wt.) and consumed ad libitum for 3 wk. When compared with controls, turkeys fed AFB1 corn had reduced body weight gain and relative liver weight, whereas turkeys fed control corn + O3 or AFB1 corn + O3 did not differ from controls. Furthermore, alterations in the majority of relative organ weight, liver discoloration, serum enzyme activity, hematological parameters, and blood chemistry caused by AFB1 were eliminated (no difference from controls) by treatment with O3. These data demonstrate that treatment of contaminated corn with electrochemically produced O3 provided protection against AFB1 in young turkey poults. It is important to note that treatment of control corn with O3 did not alter the performance of the turkey poults.

Structural mapping and U-Pb dates from mafic sills in the Perma culmination of west-central Montana constrain the timing of a major rifting event in the early history of the Belt basin. Magmatic zircon from the Plains and Paradise mafic sills within the Prichard Formation yielded U-Pb ages of 1469 ± 2.5 and 1457 ± 2 Ma, respectively. The older sill invaded unconsolidated, wet sediments at a depth of less than 1.6 km, and its emplacement is coeval with widespread soft-sediment folding, mud diapirism, and bathymetric collapse of the basin between members E and F of the Prichard Formation. The youngest sill intruded near the base of the exposed section after significant accumulation of sediment had occurred in the basin. Correlation of these data with recent geochronologic results from the Moyie sills in British Columbia and Purcell lava in Montana suggests that the rifting and subsidence event was basin-wide, and that at least two thirds of the deposition of the Belt Supergroup occurred between ~1470 and 1440 Ma. These results support a continental rift model for the formation of the Belt basin.

Previous studies with cyclopiazonic acid (CPA) have indicated that this mycotoxin strongly adsorbs onto the surface of a naturally acidic phyllosilicate clay (AC). The objective of this study was to determine whether AC (and similar adsorbents) could protect against the toxicity of CPA in vivo. Acidic phyllosilicate clay, neutral phyllosilicate clay (NC, or hydrated sodium calcium aluminosilicate), and a common zeolite (CZ, or clinoptilolite) were evaluated. One-day-old broiler chicks consumed diets containing 0 or 45 mg/kg CPA alone or in combination with 1% AC, NC, or CZ ad libitum from Day 1 to 21. Body weight, feed consumption, feed:gain, hematology, serum biochemical values, and enzyme activities were evaluated. Compared to controls, CPA alone reduced body weight at Day 21 by a total of 26% and resulted in a significantly higher feed:gain ratio. Toxicity of CPA was also expressed through increased relative weights of kidney, proventriculus, and gizzard. Also, there were some alterations in hematology, serum biochemical values, and enzyme activities. Treatment with inorganic adsorbents did not effectively diminish the growth-inhibitory effects of CPA or the increased weights of organs, although there was some protection from hematological, serum biochemical, and enzymatic changes produced by CPA. The results of this study suggest that in vitro binding of CPA to clay does not accurately forecast its efficacy in vivo; the reasons for this discrepancy are not clear, but they may be related to differences in clay binding capacity and ligand selectivity for CPA in vitro vs in vivo. Predictions about the ability of inorganic adsorbents to protect chickens from the adverse effects of mycotoxins should be approached with caution and should be confirmed in vivo, paying particular attention to the potential for nutrient interactions.

Early spica cast treatment is one method used for children's femoral shaft fractures; it is increasingly advocated as treatment that allows early hospital discharge. The outcome of early spica cast treatment in 100 children, ages 2 to 10 years, with uncomplicated and isolated closed femoral shaft fractures treated at Johns Hopkins Hospital between October 1987 and March 1994 were analyzed. The objective was to identify those children who can be treated safely and dependably with early spica casting without excessive shortening of the fracture fragments. Eighty-one (81%) children had an acceptable outcome and 19 (19%) had an unacceptable outcome by the definition of more than 25 mm of fracture fragment overlap after clinical healing. A new clinical test, the telescope test, was statistically significant for correlation with spica cast outcome. Age, gender, fracture, location, mechanism of injury, fracture type, and resting radiograph of fracture fragment overlap were not statistically significant. The telescope test had a sensitivity of 80% and a specificity of 85% for predicting outcome. The relative risk for failure of spica cast treatment with a positive telescope test was 20.4 (95% confidence limits = 2.7-225.1). Children 2 to 10 years of age with uncomplicated femoral shaft fractures and a negative telescope test can be treated appropriately in most cases with early application of a spica cast.

Patients with supranuclear and internuclear ocular motility disorders may have nystagmus and oscillopsia, or need to adopt an abnormal head posture to either fixate or maintain binocularity. Many have a cosmetically unsatisfactory appearance. In addition, because of lesions involving ocular motor nuclei or nerve fascicles, double vision is also a common problem. The usual management of these patients is symptomatic with occlusion or prisms. We report on 11 patients who underwent extraocular muscle surgery with the aim of reducing symptoms and restoring or improving binocular single vision. Three patients had bilateral internuclear ophthalmoplegia with exotropia, 3 had dorsal midbrain syndrome, 2 had residual upgaze palsies after cerebral vascular accidents, 2 had oculopalatal myoclonus and one skew deviation. After surgery, symptoms, visual function and cosmesis improved in nearly all patients. We recommend that surgery should be considered more readily in the rehabilitation of these patients.

The purpose of this study was to measure the blood pressure and electrocardiographic responses of a small, matched group of women (n = 8) and men (n = 9) who experienced typical, effort angina during an exercise on the treadmill (up to the second stage of a Bruce protocol). These responses were measured before and after therapy with diltiazem (60 mg four times daily for 1 week). Reports of previous studies have described significant gender differences in blood pressure responses to diltiazem in healthy volunteers tested with the same protocol. In contrast to the data in healthy individuals, gender differences in blood pressure responses to exercise before and after diltiazem administration were not observed. Results of analysis of pulse pressure responses to exercise were also similar in male and female patients with angina. A significant postexercise drop in blood pressure was observed, which was augmented by diltiazem. These data suggest that gender differences in drug action may be difficult to demonstrate in patients with vascular disease.

A prospective, randomized study was undertaken to compare the effectiveness of nitrous oxide with intramuscular sedation (meperidine and promethazine) in providing analgesia and amnesia during the reduction and treatment of children's fractures in an outpatient clinic setting. Fifteen patients received a 50:50 mixture of nitrous oxide and oxygen, and 15 received intramuscular injection. The two groups were similar in regard to gender distribution, age, and fracture types. Pain response was recorded using the Children's Hospital of Eastern Ontario (Canada) Pain Scale (CHEOPS) at the time of fracture reduction and 30 min postreduction. At the first follow-up visit a questionnaire regarding the patient's memory and subjective experience of the fracture reduction was answered. Data between the two groups were compared using the Mann-Whitney test. The CHEOPS scores, and the memory and subjective experience of the fracture reduction were similar between the two groups. Time in the outpatient department averaged 83 min for the intramuscular group and 30 min for the nitrous oxide group (p < 0.01). All of the nitrous oxide patients stated they would use nitrous oxide again, whereas only eight of 15 intramuscular patients stated they would try intramuscular sedation again. Nitrous oxide is as effective as intramuscular sedation in providing analgesia and amnesia in the treatment of children's fractures while having a more rapid onset and a shorter recovery period with greater patient acceptance.

We analyzed the early spica casting outcomes of 50 children age 2 to 10 years with uncomplicated femoral shaft fractures treated at Johns Hopkins Hospital between October 1987 and October 1990. Our objective was to develop criteria for the prospective identification of patients who can be safely and dependably treated with early spica casting without excessive shortening of the fracture fragments. Forty-one (82%) children had an acceptable outcome and nine (18%) had an unacceptable outcome according to our definition of25 mm of fracture fragment overlap at 3 to 4 weeks follow-up. A new clinical test, the telescope test, was statistically significant (p0.001) for association with spica casting outcome. Age, sex, fracture location, mechanism of injury, fracture type, and resting roentgenogram fracture fragment overlap were not statistically significant (p0.10). The telescope test had a sensitivity of 78%, a specificity of 85%, and a negative predictive value of 95% for predicting spica casting outcome. The relative risk of failing spica casting after a positive telescope test was 20.4 (95% CI, 2.74-225.10). We conclude that children 2 to 10 years of age with uncomplicated femoral shaft fractures and a negative telescope test can be safely treated with early spica casting and have a 95% change of having a successful outcome with this treatment.

An exceptionally sensitive calorimetric technique has been devised for measuring microwave absorption by small samples of ultra-low-loss dielectrics at cryogenic temperatures. The loss factor of sapphire at 2.45 GHz diminished progressively with decreasing temperature from 3.5*10-5 at 300 K down to 2*10-10 at 4.2 K. The rate of decrease showed no tendency to attenuate at temperatures down to 4.2 K.

[1] Anomalous uplift is observed at the Lop Nor, China nuclear test site using ERS satellite SAR data. Using an InSAR time-series analysis method, we show that an increase in absolute uplift with time is observed between 1997 and 1999. The signal is collocated with past underground nuclear tests. Due to the collocation in space with past underground tests we postulate a nuclear test-related hydrothermal source for the uplift signal. A possible mechanism is presented that can account for the observed transient uplift and is consistent with documented thermal regimes associated with underground nuclear tests conducted at the Nevada National Security Site (NNSS) (formerly the Nevada Test Site).

Acetabular morphology in congenital and neuromuscular hip instability was evaluated with computed tomography (CT) and plain radiography. Thirty-three unstable hips in 27 children with congenital hip dysplasia, cerebral palsy, or spina bifida were studied. Fourteen normal hips in 14 children served as controls. Unstable hips in the children with congenital hip dysplasia demonstrated anterior and superior acetabular deficiency with increased acetabular anteversion. Global deficiency was present in acetabuli of cerebral palsy and spina bifida patients with anterior, posterior, and superior deficiencies. The acetabuli in cerebral palsy patients had significant posterior deficiency and were the shallowest of the groups evaluated.

For given acoustic frequencies of premixed gas-turbine combustors, a classical method not currently in use is explored for assessing whether acoustically driven oscillatory combustion will occur. The method involves cataloging linear amplification and attenuation mechanisms and estimating magnitudes of their rates. Linear approximations to nonlinear mechanisms are included in an effort to obtain a reasonably complete description. A stability index is defined such that oscillation is predicted to occur when the value of the index exceeds unity. The method is tested on the basis of new experiments and experimental data available in literature. Moderate success is achieved in rationalizing these experimental results. The objective of the method is to enable quick and inexpensive decisions to be made for a wide variety of potential design configurations and operating conditions, without the complexity of computational fluid dynamics. The approach therefore may complement other approaches already in use.

Forty-one children who had forty-two open fractures of the tibial metaphysis or diaphysis were studied retrospectively. Twelve fractures were Type I; eighteen, Type II; six, Type IIIA; four, Type IIIB; and two, Type IIIC, according to the classification of Gustilo et al. All fractures were irrigated and debrided, and antibiotics were given for a minimum of forty-eight hours after the injury. Twenty fractures were initially treated with external fixation and twenty-two, with immobilization in a plaster cast. Three patients had an early infection of the wound, one of which was associated with osteomyelitis; all were successfully treated. The average time to healing of the fracture was five months (range, two to twenty-one months). The time to union was related to the severity of the soft-tissue injury, the pattern of the fracture, the amount of segmental bone loss, the occurrence of infection, and the use of external fixation. There were six delayed unions. Four patients had an angular malunion of more than 10 degrees, which spontaneously corrected in three. One patient who had a proximal metaphyseal-diaphyseal segmental fracture had a progressive valgus deformity. Four patients who had a severe fracture that was treated with external fixation had more than one centimeter of tibial over-growth. There were no amputations. The incidences of compartment syndrome, vascular injury, infection, and delayed union were similar to those reported for open tibial fractures in adults.

For given acoustic frequencies of premixed gas-turbine combustors, a classical method not currently in use is explored for assessing whether acoustically driven oscillatory combustion will occur. The method involves cataloging linear amplification and attenuation mechanisms and estimating magnitudes of their rates. Linear approximations to nonlinear mechanisms are included in an effort to obtain a reasonably complete description. A stability index is defined such that oscillation is predicted to occur when the value of the index exceeds unity. The method is tested on the basis of new experiments and experimental data available in the literature. Moderate success is achieved in rationalizing these experimental results. The objective of the method is to enable quick and inexpensive decisions to be made for a wide variety of potential design configurations and operating conditions, without the complexity of computational fluid dynamics. The approach therefore may complement other approaches already in use.Copyright © 2007 by ASME

An overview is given of the development of advanced nanoporous carbons as storage ma-terials for natural gas (methane) and molecular hydrogen in on-board fuel tanks for next-generation clean automobiles. The carbons are produced in a multi-step process from corncob, have surface areas of up to 3500 m2/g, porosities of up to 0.8, and reversibly store, by physisorp-tion, record amounts of methane and hydrogen. Current best gravimetric and volumetric storage capacities are: 250 g CH4/kg carbon and 130 g CH4/liter carbon (199 V/V) at 35 bar and 293 K; and 80 g H2/kg carbon and 47 g H2/liter carbon at 47 bar and 77 K. This is the first time the DOE methane storage target of 180 V/V at 35 bar and ambient temperature has been reached and exceeded. The hydrogen values compare favorably with the 2010 DOE gravimetric and volu-metric targets for hydrogen. A prototype adsorbed natural gas (ANG) tank, loaded with carbon monoliths produced accordingly and currently undergoing a road test in Kansas City, is de-scribed. A preliminary analysis of the surface and pore structure is given that may shed light on the mechanisms leading to the extraordinary storage capacities of these materials. The analysis includes pore-size distributions from nitrogen adsorption isotherms; spatial organization of pores across the entire solid from small-angle x-ray scattering (SAXS); pore entrances from scanning electron microscopy (SEM) and transmission electron microscopy (TEM); H2 binding energies from temperature-programmed desorption (TPD); and analysis of surface defects from Raman spectra. For future materials, expected to have higher H2 binding energies via appropriate sur-face functionalization, preliminary projections of H2 storage capacities based on molecular dy-namics simulations of adsorption of H2 on graphite, are reported.

A new approach for modeling combustion instabilities using acoustic energy conservation is proposed. This approach allows the flexibility to calculate contributions from amplification and/or attenuation across all frequencies, rather than predicting eigenmodes. It is likely that such a direct acoustic energy approach could be of benefit in determining the susceptibility of all frequencies to growth or decay as operating conditions in a gas turbine change. This approach may also give designers a method for improving passive damping in the initial design phase, with the ability to scan various frequencies and investigate the susceptibility to oscillatory instability at different operating conditions. A linear model, including linear approximations to nonlinear processes, is introduced whereby the mechanisms contributing to amplification and damping of acoustic energy are assessed independently to find a net amplification coefficient, a reciprocal time (or a rate). Stability for each frequency is assessed by examining a ratio between amplification and damping. It is anticipated that this effort may provide a useful new perspective on and enhanced prediction capability for combustion oscillatory instabilities.Copyright © 2006 by ASME

Chronic alcoholism leads to localized brain damage, which is prominent in superior frontal cortex but mild in motor cortex. The likelihood of developing alcohol dependence is associated with genetic markers. GABAA receptor expression differs between alcoholics and controls, whereas glutamate receptor differences are muted. We determined whether genotype differentiated the localized expression of glutamate and gamma-aminobutyric acid (GABA) receptors to influence the severity of alcohol-induced brain damage. Cerebrocortical tissue was obtained at autopsy from alcoholics without alcohol-related disease, alcoholics with cirrhosis, and matched controls. DRD2A, DRD2B, GABB2, EAAT2, and 5HTT genotypes did not divide alcoholic cases and controls on N-methyl-d-aspartate (NMDA) receptor parameters. In contrast, alcohol dehydrogenase (ADH)3 genotype interacted significantly with NMDA receptor efficacy and affinity in a region-specific manner. EAAT2 genotype interacted significantly with local GABAA receptor beta subunit mRNA expression, and GABB2 and DRD2B genotypes with beta subunit isoform protein expression. Genotype may modulate amino acid transmission locally so as to mediate neuronal vulnerability. This has implications for the effectiveness of pharmacological interventions aimed at ameliorating brain damage and, possibly, dependence.

We have developed a competitive RT-PCR assay, adapted from Lewohl et al. [Brain Res. Brain Res. Protoc. 1 (1997) 347]. for the quantitation of GABA, receptor beta isoforms in human brain using an internal standard that shares high sequence homology to the targets. The internal standard is identical to the beta(1) sequence except for a 61 bp deletion and the incorporation of a Hind III restriction enzyme site. Unlike traditional competitive RT-PCR, which requires a range of internal standard concentrations to be titrated against a constant amount of unknown, this method relies on a standard curve for quantitation of each sample and thus permits increased sample throughput. This method is suitable for the quantitation of beta(1), beta(2) and beta(3) isoforms of the GABA(A) receptor in human alcoholic and control brain. (C) 2003 Elsevier Science B.V. All rights reserved.

Laser panretinal photocoagulation (PRP) reduces visual loss in proliferative diabetic retinopathy but decreases peripheral retinal function. The Driver and Vehicle Licensing Centre (DVLC) states that when a patient volunteers that he or she has had photocoagulation, a questionnaire will then be sent to the patient's diabetic physician who can refer the patient for formal field testing. Of 30 patients who had PRP, 15 failed DVLC visual field regulations using the Esterman binocular field test on the Humphrey field analyser. The failures were more likely to have had treatment with a xenon laser, but there was no difference between the groups as regards age, number of burns or whether an argon or diode laser was used. The patients who failed were more likely to be hypertensive (p = 0.04). Two patients with unilateral PRP could not meet the driving regulations because of other field defects. Diabetes itself causes field defects, and therefore even with small amounts of laser, formal field testing may be necessary.

We conducted an epidemiological survey of antibiotic resistance in Salmonella recovered from market-age swine at five different Texas farms. These farms, which were visited between October 1997 and June 1998, were completely integrated, farrow-to-finish operations. Samples were taken from the lymph nodes and cecal contents at the time of slaughter. The Salmonella samples that were recovered were sent to the National Veterinary Services Laboratory for serotyping. Antibiotic resistance was determined using the Dispens-O-Disc Susceptibility Test System using 13 different antimicrobial agents that have been utilized in either veterinary medicine, human medicine, or both. Preliminary analysis of the first 183 samples out of approximately 400 Salmonella samples recovered indicated that 183 (100%) of the Salmonella samples were resistant to penicillin G, and 122 (66.7%) were resistent to chlortetracycline. Six (3.3%) were resistant to four antibiotics (chlortetracycline, penicillin G, streptomycin, and sulfisoxazole), and 25 (13.7%) were resistant to three antibiotics (chlortetracycline, penicillin G, and either streptomycin, sulfisoxazole, or ampicillin). Variation was seen between serotypes, with four out of five S. agona samples (80.0%) and two out of eight S. derby samples (25.0%) resistant to four antibiotics. Variation in antibiotic resistance also was seen between farms. There is an increasing concern about the prevalent usage of antibiotics in medicine and agriculture and the relationship this may have on emerging microbial resistance patterns; therefore, continued surveillance on antibiotic resistance in animal production is warranted.

The objective of this investigation is to determine the suitability of cofiring as a recycle / reuse option to landfill disposal for solid rocket motor washout residue. Solid rocket motor washout residue (roughly 55% aluminum powder, 40% polybutadiene rubber binder, 5% residual ammonium perchlorate, and 0.2-1% asbestos) has been fired in Sandia's MultiFuel Combustor (MFC). The MFC is a down-fired combustor with electrically heated walls, capable of simulating a wide range of fuel residence times and stoichiometries. This study reports on the fate of AP-based chlorine and asbestos from the residue following combustion.

Editor,—We describe two cases of recurrent corneal epithelial breakdown following indirect diode laser panretinal photocoagulation (PRP) in diabetic patients. The particular nature of diode laser burns may have contributed to this event. ### CASE 1 A 21 year old insulin dependent diabetic woman underwent bilateral indirect diode laser PRP under general anaesthesia for proliferative diabetic retinopathy (PDR). She presented 4 weeks later with a 3 week history of a painful left eye. Visual acuity was 6/12 and a 3 mm × 2 mm infiltrative corneal ulcer was noted. There was total corneal anaesthesia bilaterally and both pupils were mid dilated and non-reactive to light and accommodation. Microbiology was negative and the ulcer gradually healed with intensive topical antibiotic treatment. Over the next 3 months corneal anaesthesia persisted in the left eye, but resolved in the right. She had two further episodes of corneal epithelial breakdown on the left which were successfully managed with topical lubricants. One year after laser treatment visual acuity was 6/6 in the right eye and 6/12 in the left, with residual stromal scarring on the left (Fig 1). Both pupils remained mid dilated and non-reactive. …

Antibiotics which are actively secreted into gastric fluid may be more efficacious in the eradication of Helicobacter pylori in peptic ulcer disease. Other agents used in the treatment of this disease such as omeprazole or other anti-secretory agents may alter the secretion and/or distribution characteristics of antibiotics. In order to test the applicability of these concepts to metronidazole, a sensitive and specific high performance liquid chromatography (HPLC) assay was developed to quantitate omeprazole in plasma, and metronidazole in plasma and gastric fluid. The HPLC system consisted of a multi-phase column combining anion exchange and reversed phase separation (OmniPac Pax-500, Dionex), and a variable wavelength UV detector set at 254 nm. The mobile phase was a mixture of 0.1 M sodium phosphate buffer:methanol:acetonitrile (60:20:20) with final pH adjusted to approximately 7.0. Metronidazole and omeprazole were extracted by adsorption onto a C2-bonded silica gel solid phase extraction column, and eluted with methanol. The extract was dried, reconstituted in a solution of acetyl salicylic acid (ASA), and then injected into the HPLC system. Under these conditions, metronidazole, omeprazole and ASA were well separated and recoveries in plasma were greater than 80%. Omeprazole could not be measured in gastric fluid because of rapid decomposition. Using 0.3 ml of sample, the assay sensitivity was less than 0.1 microgram ml-1 and linear up to 10 micrograms ml-1. Both intra- and inter-assay CV were greater than 15%. It was applied successfully in determining metronidazole concentrations in clinical samples of plasma and gastric fluid.

Ceftiofur, a recently introduced antibiotic of the beta-lactam group, is rapidly converted to both free and protein-bound metabolites when administered by the prescribed procedure, intramuscular injection. Free metabolites retain antimicrobial activity and may be detected by antibiotic-screening tests based on antimicrobial activity. It is thus desirable to distinguish ceftiofur metabolites from other antibiotics. A multiresidue procedure for beta-lactams in milk was adapted for determination of free ceftiofur metabolites by collecting appropriate liquid chromatographic fractions during cleanup. Analysis of tissues from treated animals showed that the principal free metabolite was the desfuroylceftiofurcysteine conjugate.