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ImportanceFor some patients receiving warfarin, adding aspirin (acetylsalicylic acid) increases bleeding risk with unclear treatment benefit. Reducing excess aspirin use could be associated with improved clinical outcomes.ObjectiveTo assess changes in aspirin use, bleeding, and thrombosis event rates among patients treated with warfarin.Design, Setting, and ParticipantsThis pre-post observational quality improvement study was conducted from January 1, 2010, to December 31, 2019, at a 6-center quality improvement collaborative in Michigan among 6738 adults taking warfarin for atrial fibrillation and/or venous thromboembolism without an apparent indication for concomitant aspirin. Statistical analysis was conducted from November 26, 2020, to June 14, 2021.InterventionPrimary care professionals for patients taking aspirin were asked whether an ongoing combination aspirin and warfarin treatment was indicated. If not, then aspirin was discontinued with the approval of the managing clinician.Main Outcomes and MeasuresOutcomes were assessed before and after intervention for the primary analysis and before and after 24 months before the intervention (when rates of aspirin use first began to decrease) for the secondary analysis. Outcomes included the rate of aspirin use, bleeding, and thrombotic outcomes. An interrupted time series analysis assessed cumulative monthly event rates over time.ResultsA total of 6738 patients treated with warfarin (3160 men [46.9%]; mean [SD] age, 62.8 [16.2] years) were followed up for a median of 6.7 months (IQR, 3.2-19.3 months). Aspirin use decreased slightly from a baseline mean use of 29.4% (95% CI, 28.9%-29.9%) to 27.1% (95% CI, 26.1%-28.0%) during the 24 months before the intervention (P P = .001 for slope before and after intervention). In the primary analysis, the intervention was associated with a significant decrease in major bleeding events per month (preintervention, 0.31%; 95% CI, 0.27%-0.34%; postintervention, 0.21%; 95% CI, 0.14%-0.28%; P = .03 for difference in slope before and after intervention). No change was observed in mean percentage of patients having a thrombotic event from before to after the intervention (0.21% vs 0.24%; P = .34 for difference in slope). In the secondary analysis, reducing aspirin use (starting 24 months before the intervention) was associated with decreases in mean percentage of patients having any bleeding event (2.3% vs 1.5%; P = .02 for change in slope before and after 24 months before the intervention), mean percentage of patients having a major bleeding event (0.31% vs 0.25%; P = .001 for change in slope before and after 24 months before the intervention), and mean percentage of patients with an emergency department visit for bleeding (0.99% vs 0.67%; P = .04 for change in slope before and after 24 months before the intervention), with no change in mean percentage of patients with a thrombotic event (0.20% vs 0.23%; P = .36 for change in slope before and after 24 months before the intervention).Conclusions and RelevanceThis quality improvement intervention was associated with an acceleration of a preexisting decrease in aspirin use among patients taking warfarin for atrial fibrillation and/or venous thromboembolism without a clear indication for aspirin therapy. Reductions in aspirin use were associated with reduced bleeding. This study suggests that an anticoagulation clinic–based aspirin deimplementation intervention can improve guideline-concordant aspirin use.

Patients’ international normalized ratios (INRs) often fall slightly out of range. In these cases, the American College of Chest Physicians (ACCP) guidelines suggest maintaining the current warfarin dose and retesting the INR within the following 2 weeks (watchful waiting). We sought to determine whether watchful waiting or dose changes for slightly out-of-range INRs is more effective in obtaining in-range INRs at follow-up. INRs and management strategies of warfarin-treated patients within the Michigan Anticoagulation Quality Improvement Initiative registry were analyzed. Management strategies included watchful waiting or dose changes. INRs slightly out of range (target range 2.0-3.0) and their associated management were identified. Multilevel mixed-effects logistic regression was used to estimate the probability of the next INR being in range, adjusted for clustering due to multiple out-of-range INRs per patient. A total of 45 351 slightly out-of-range INRs (ranging 1.50-1.99 and 3.01-3.49) from 8288 patients were identified. The next INR was slightly less likely to be in range with watchful waiting than with a dose change (predicted probabilities 58.9% vs 60.0%, P = 0.024). Although a significant statistical difference was detected in the probabilities of the next INR being back in range when managed by a dose change compared with watchful waiting following a slightly out-of-range INR, the magnitude of the difference was small and unlikely to represent clinical importance. Our study supports the current guideline recommendations for watchful waiting in cases of slightly out-of-range INRs values.

Current guidelines recommend targeting an international normalized ratio (INR) of 2.5 to 3.5 for patients with mechanical aortic valve replacement (AVR) and additional risk factors for thromboembolic events. Available literature supporting the higher intensity (INR) goal is lacking. We aimed to evaluate the association of standard and higher intensity anticoagulation on outcomes in this patient population. The Michigan Anticoagulation Quality Improvement Initiative database was used to identify patients with mechanical AVR and at least one additional risk factor. Patients were classified into 2 groups based on INR goal: standard-intensity (INR goal 2.5) or higher-intensity (INR goal 3.0). Cox-proportional hazard model was used to calculate adjusted hazard ratios. One hundred and forty-six patients were identified of whom 110 (75.3%) received standard-intensity anticoagulation and 36 (24.7%) received higher intensity anticoagulation. Standard-intensity patients were older and more likely to be on aspirin. Atrial fibrillation was the most common additional risk factor for inclusion. The primary outcome of thromboembolic events, bleeding, or all-cause death was 13.9 and 19.5/100-person-years in the standard-intensity and higher intensity groups, respectively (adjusted HR 2.58, 95% confidence interval 1.28 to 5.18). Higher-intensity anticoagulation was significantly associated with any bleeding (adjusted HR 2.52, 95% confidence interval 1.27 to 5.00) and there were few thromboembolic events across both groups (5 events total). These results challenge current guideline recommendations for anticoagulation management of mechanical AVR in patients with additional risk factors.

Introduction The direct oral anticoagulants (DOACs) including apixaban, dabigatran, edoxaban, and rivaroxaban are increasingly utilized for the management of venous thromboembolic disease (VTE) and/or non-valvular atrial fibrillation (NVAF). Adding aspirin (ASA) to warfarin or DOAC therapy increases bleeding risk. Patients on combination therapy with ASA and an anticoagulant were not well represented in clinical trials comparing DOACs to warfarin. We sought to compare bleeding and thrombotic outcomes with DOACs and ASA compared to warfarin and ASA in a non-trial setting. Methods We conducted a retrospective registry-based cohort study of adults on DOAC or warfarin therapy for VTE and/or NVAF. Warfarin treated patients were followed by six anticoagulation clinics. Four out of the six clinics contributed data on their patients that were on DOACs in the Michigan Anticoagulation Quality Improvement Initiative (MAQI 2) from January 2009 to June 2021. Patients were excluded if they had a history of heart valve replacement, recent myocardial infarction, or less than 3 months of follow-up. Two propensity matched cohorts (warfarin+ASA vs DOAC+ASA) of patients were analyzed based on ASA use at the time of study enrollment. The primary outcome was any new bleeding event. Secondary outcomes included new episodes of arterial or venous thrombosis, bleeding event type (major, fatal, life threatening, central nervous system, and non-major bleeding), emergency room visits, hospitalizations, transfusions, and death. Random chart audits were done to confirm the accuracy of the abstracted data. Event rates were compared using Poisson regression. Results We identified a total of 1,139 patients on DOACs plus ASA and 4,422 patients on warfarin plus ASA. After propensity matching, we compared two groups of 1,114 matched patients. DOAC treated patients were predominately on apixaban (62.3%) and rivaroxaban (30.4%), most often at therapeutic doses (Table 1). Patients were largely (90.5%) on low dose ASA (≤ 100 mg). Patient demographics, co-morbidities, indication for anticoagulation, history of bleeding or clotting, medications, and duration of follow-up were well-balanced after matching. Patients were followed for a median of 11.7 months (interquartile range 4.4 and 34 months). Patients treated with DOAC+ASA had 2.4 thrombotic events per 100 patient years compared to 2.2 thrombotic events per 100 patient years with warfarin+ASA (P=0.78). There were no significant differences observed between groups by thrombotic subtype (stroke, transient ischemic attack, pulmonary embolism, deep vein thrombosis, table 1). Bleeding was also similar with 30.1 bleeding events per 100 patient years with DOAC+ASA compared to 27.8 bleeds per 100 patient years with warfarin+ASA (P=0.24). There were no significant differences by bleeding subtype (table 1). Hospitalizations for clotting occurred less frequently with DOAC+ASA (0.9 hospitalizations per 100 patient years) compared to warfarin+ASA (1.7 hospitalizations per 100 patient years, P=0.03). Mortality, transfusions, and healthcare utilization were otherwise similar between the two groups. Conclusions For patients on a DOAC versus warfarin with ASA for atrial fibrillation and/or venous thromboembolic disease without a recent myocardial infarction or heart valve replacement, bleeding and thrombotic outcomes were similar. Figure 1 Figure 1. Disclosures Kaatz: Gilead: Consultancy; CSL Behring: Consultancy; Novartis: Consultancy; Bristol Myer Squibb: Consultancy, Research Funding; Pfizer: Consultancy; Alexion: Consultancy; Janssen: Consultancy, Research Funding; Osmosis Research: Research Funding. Kline-Rogers: Janssen: Consultancy; American College of Physicians: Consultancy. Sood: Bayer: Consultancy. Froehlich: Merck: Consultancy; Janssen: Consultancy; Novartis: Consultancy; Boehringer-Ingelheim: Consultancy; Pfizer: Consultancy; Blue Cross Blue Shield of Michigan: Research Funding; Fibromuscular Disease Society of America: Research Funding. Barnes: National Certification Board of Anticoagulation Providers: Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy; Acelis: Consultancy; AMAG Pharmaceuticals: Consultancy; Connected Health: Consultancy; Blue Cross Blue Shield of Michigan: Research Funding; AC Forum: Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy; Bristol-Myers Squibb: Consultancy.

Atmospheric sodium at the Moon was observed for altitudes from the ground up to 1800 km from 18 April to 13 May 1998, a period including an entire lunar month. Because of bad weather, coverage was incomplete but we present the analysis of 36 spectra largely from near first and third quarter phases and passage through full moon. The apparatus used was the specially built clear aperture 16.5 cm, 203 cm focal length, Mt. Lemmon Lunar Coronagraph on Mt. Lemmon in the Catalina Mountains of Tucson, Arizona. Data are interpreted in terms of Chamberlain fits to the observed emission rate using both one equivalent temperature and two source components (with both cold and hot density distributions). The extent and equivalent temperatures of the exosphere during this period trended towards an extended coma with very little fraction in the thermally accommodated regime, even near the surface. Preliminary data–model comparisons suggest that these measurements are consistent with rates and spatial distributions expected from a photon-stimulated desorption source, although evidence for one, or possibly two, periods of notable meteoroid impact source might be present. A compilation of new and previously published observations illustrates an increased emission by sodium at third quarter over that of first quarter, a result that suggests that the dayside exospheric content increases, at least occasionally, following transit of the Moon through the Earth’s magnetosphere.

We present infrared spectra of Mercury and the Moon in the wavelength range 0.7--5.3 $\mu$m obtained with the SpeX spectrograph at the NASA Infrared Telescope Facility. The spectra were acquired from pole and terminator locations of Mercury'ssurface and of Mersenius C and the Copernicus central peak on the Moon. Spectra of both bodies were measured in close temporal succession and were reduced in thesame manner with identical calibration stars to minimize differences in the reduction process. The Copernicus spectra display the expected absorption features dueto mafic minerals in the near infrared and show spectral features in the SiO combination/overtone vibrational band region above 4 $\mu$m. The spectra of Mercuryfrom longitude 170$^\circ$ and north and south midlatitudes display a 1-$\mu$m absorption band indicative of high-Ca clinopyroxene, while a spectrum from longitude 260$^\circ$ and northern midlatitudes does not. The Mercury spectra show a broad feature of low emittance over the full 3--5 $\mu$m thermal infrared region, butno narrow features in this spectral range. The longitude 260$^\circ$ spectrum shows excess thermal emission around 5 $\mu$m attributable to the existence of a thermal gradient in the insolated dayside regolith. The thermal-IR spectra suggesta significant difference in the compositional and/or structural properties of Mercury and the Moon that may be due to grain size, absorption coefficient, or the magnitude of near-surface thermal gradients. The results indicate that the composition of Mercury's surface is heterogeneous on regional scales, and that the nearinfrared wavelength range provides more discriminative information on the surfacecomposition than the 2--4 $\mu$m region, where the solar reflected and thermallyemitted radiation contribute approximately equally to the observed flux of thesebodies.

The small punch test, also known as miniature disk bend test, is a relatively new method for the creep test of specimens of small dimensions. Experiments have shown that the small punch test can be used to describe the time to failure by means of an equation of the Dorn type, in which stress is replaced by load. The activation energies calculated using such a modified equation are somewhat smaller than the activation energies calculated from the results obtained using conventional creep testing methods. However, the constant value of the activation energy and the almost constant value of the load exponent in the modified Dorn equation confirm the hypothesis about the almost iso-stress nature of the small punch creep test. A finite element analysis of the small punch test has been carried out taking into account the constitutive theta -projection concept of the law of creep of the experimental steel 14 MoV 6 3, obtained from conventional, constant load creep test data. The viscosity parameters were evaluat...

s S307 (p= 6.22e-06 for interaction) and may play a role in disease progression and impaired myocardial energetics. Conclusion: A bioinformatic analysis may identify previously unreported miRs potentially involved in HF development. This is a novel approach using public access data for identify potential biomarkers of subjects with high risk for HF development or progression. FONDAP 15130011 ACCDIS.

Observations of lunar sodium were made on November 16–18, 1997, at Asiago and Mount Lemmon Observatories. A small enhancement was observed, and we suggest that it was related to the Leonid shower. Visual observations by members of the Association of Lunar and Planetary Observers and the North American Meteor Network show a peak, a few hours wide, at about 12:50 UT on the 17th. The possible enhancement of the lunar Na appears to last at least 3 days, and must be associated with a considerably more extended cloud of particles than that responsible for the bright visual meteors. The circumstances of the 1997, 1998, and 1999 events are discussed. Large showers may occur in 1998 and 1999; the 1998 shower occurs too close to new moon for good atmospheric observations, but if the extended, faint shower is also enhanced the corresponding lunar Na should be observable for a considerably longer period.

We present and use a new rough-surface thermal model to aid in the analysis of new mid-infrared spectral measurements of Mercury from 5–12.5 μm. The model calculates spatially resolved thermal emission from slowly rotating, airless bodies. The Mercury data contain the first spectral measurements of Mercury between 5–7.5 μm, a region not accessible from ground-based telescopes, and are also the first observations of Mercury to be made while flying on the Kuiper Airborne Observatory (KAO). They were obtained with the High- efficiency Infrared Faint Object Grating Spectrometer (HIFOGS). Our rough surface thermal model which best fit the KAO data has a Hapke θ of 20°. A strong 5-μm emission feature was present during both observing periods. We suggest the 5-μm excess may be a result of near surface thermal gradients in regolith materials with a 30 to 100-μm grainsize, but cannot entirely rule out an observational artifact resulting from our instrumentation or the telescope on the KAO. Other features in the spectra are consistent with a feldspathic and feldspathoidal surface composition.

We report results of a part of an organized effort of five observing groups to simultaneously observe sodium in the lunar atmosphere. International Lunar Atmosphere Week spanned the week of September 15–22, 1995. Of the seven nights, we experienced four nights with good viewing conditions. We used the Mt. Lemmon Lunar Coronagraph (MLLC) and DARRK spectrograph. Both are especially designed for lunar atmospheric measurements from the surface extending to an altitude of approximately 1 lunar radius or ∼1700 km (860 km geopotential height). Emission rates for Na were compatible with those previously reported for relatively large phase angles (96° to 129°) with the average total of D2 and D1 emission rate ∼6.9 kRayleigh. A thermal component was observed only on the night of September 17, when the solar zenith angle at the limb was only 6°. We observed a factor of ∼2 greater column abundances over the north pole than over the sunlit equatorial limb on September 18 while on September 19, the equatorial bright limb column abundance was a factor of ∼5 higher than the north polar. Apparent geopotential scale heights varied from 279 to 435 km, indicating an extended atmosphere. If the scale heights are represented by a temperature, values are 985 to 1470 K. The data set appears to support the idea that the dominant source during this period was meteoritic impact volatilization.

We report spectroscopic measurements of sodium in Mercury's atmosphere for the period July 1985–May 1988. Na abundance varies from 10 atoms cm −2 in equatorial regions in March 1987 to as much as ∼1.5 × 10 12 atoms cm −2 in May 1988. All observations were made using a high-resolution echelle spectrograph on the 61-in. telescope on Mt. Bigelow, Arizona. Strong high-latitude enhancements are common, with the added characteristic that there is usually more at one hemisphere than the other. There is an obvious diurnal correlation, with morning abundances significantly higher than afternoon. We see notable Na emission enhancements when our spectrograph slit is placed over the radar-bright spots at 340° mercurian longitude and 55°N and 25°S latitude. We do not see any trend in column abundance with increasing radiation acceleration. We do not see a significant correlation of abundance with either solar F10.7 flux or sunspot number. Other larger variations occur and must be caused by other factors.

An inexpensive, small mass, airglow experiment consisting of a suite of airglow detectors is planned for one or more lunar landers. Solid state detectors measuring light through narrow band filters or concave gratings can integrate emissions from lunar atmospheric constituents and store the information for relay to earth when convenient. The proposed instrument is a simplified version of the Shuttle-borne Arizona Imager-Spectrograph. These zenith and near horizon viewing detectors may allow us to monitor fluctuations in atomic species of oxygen, calcium, sodium, potassium, argon, and neon and OH, if present. This choice of observations would monitor outgassing from the interior (Ar), meteoritic dust flux (Na, K) solar wind sputtering (O, Ca), and outgassing from the surface (implanted Ne, Na, K). A global network could be inexpensively deployed aboard landers carrying a variety of other selenographic instrumentation. Powered by solar cells such a field network will return data applicable to a wide variety of interplanetary medium and solar-lunar interaction problems.

Spectroscopic observations (7.3-13.5 μm) of three locations on the surface of Mercury are reported. The observed spectral radiance emanated from equatorial and low latitude regions between 12 and 32° mercurian longitude on 8 December 1990, from the longitudinal region 22-44° on 10 December 1990, and from the longitudinal region 110-130° on 12 July 1992; all locations are primarily intercrater plains. Spectra indicate compositional differences among these three locations. The emissivity maximum, or Christiansen emission peak, occurs at 8.1 μm in the 8 December 1990 spectra, but at shorter wavelengths in the data of 10 December 1990 and 12 July 1992. Emission peaks near 8 μm indicate rocks of intermediate or mafic composition. Spectra from 22 to 44° longitude resemble spectra of terrestrial basalt and diorite with SiO2 content between 49 and 55%. The Christiansen feature in spectra from near 110-130° longitude strongly suggests the presence of plagioclase, in particular labradorite, while the overall spectrum resembles anorthosite. The spectra from all three locations on Mercury show distinct and recognizable features, the principal Christiansen emission peak being the most prominent, but they also contain features that we have not yet identified. The general indication from the spectra is that Mercury's surface consists of minerals more depleted in oxidized iron than those on the Moon. We also explore the theoretical and observational complexities of ground-based mid-infrared spectroscopy of airless bodies in general and Mercury in particular. A spectroscopic study of quartzite in both reflectance and emittance illustrates the practical, spectral validity of Kirchhoff's Law.

High-resolution spectroscopic measurements of Mercury were made at 4227 A to search for neutral calcium in the atmosphere An upper limit to the intensity is 9.0 kR; the corresponding Ca column abundance is 8 atoms cm -2 with a Ca/Na ratio of

The composition and chemistry of Mercury's regolith has beets calculated from MESSENGER MASCS 0 3-1 3 mu m spectra from the first flyby, using an implementation of Hapke's radiative transfer-based photometric model for light scattering in semi-transparent porous media, and a linear spectral mixing algorithm We combine this investigation with linear spectral fitting results from mid-infrared spectra and compare derived oxide abundances with mercurian formation models and lunar samples Hapke modeling results indicate a regolith that is optically dominated by finely comminuted particles with average area weighted grain size near 20 pin Mercury shows lunar-style space weathering, with maturation-produced microphase iron present at similar to 0 065 wt% abundance, with only small variations between mature and immature sites, the amount of which is unable to explain Mercury's low brightness relative to the Moon The average modal mineralogies for the flyby 1 spectra derived from Hapke modeling are 35-70% Na-rich plagioclase or orthoclase, up to 30% Mg-rich clinopyroxene

Groundbased observations of midinfrared (7.5- to 11.4-μm) spectral radiance from five locations on the Moon are reported. We have obtained medium resolution spectra from three locations in Copernicus crater and two locations in mare basalt. Two locations in the crater walls of Copernicus show similar spectra which in turn differ from spectra from the eastermost central peak. Mineralogic interpretation of the features in the central peak spectra is consistent with the composition of the locations as determined by near-infrared reflectance (0.67- to 2.5-μm) spectroscopy. In addition to emission minima, which we attribute to olivine, there are unidentified features in the spectra which may provide additional compositional information. An emissivity maximum at shorter wavelengths than the reststrahlen bands is identified as the Christiansen feature in the Copernicus spectra. The wavelength of maximum emission shifts to longer wavelengths with increasing mafic composition as predicted by laboratory spectroscopy. The mare locations observed are of different albedos and our spectra indicate that the locations are of slightly different composition. We see a broad emission minimum centered at 8.5 μm in the Kepler ejecta spectrum but not in that from the mare east of Euler. Spectra from both mare locations have a triplet of minima at 8.1, 8.4, and 8.75 μm which are not identified. Spectra from both mare locations exhibit local maxima just longward of 9 μm and a sharp drop in emissivity at wavelengths longer than 11 μm.

Results are presented from Apollo satellite observations (from May 1988 to July 1991) of sodium and potassium in the lunar atmosphere. The observations of Na and K show a wide range of scale heights, single-component temperatures, and surface number densities, while the column abundances remain within a factor of 3. The observed trends can be explained using a model of competing release mechanisms with different dependences on solar zenith angle and resulting two-component atmospheres. The theory is applied to the budget of atomic oxygen.

Mid-infrared 2-D spectroscopic measurements from 8.0 to 12.7 gm of Mercury were taken using Boston University's Mid-Infrared Spectrometer and Imager (MIRSI) mounted on the NASA Infrared Telescope Facility (IRTF) on Mauna Kea, Hawaii, 7-11 April 2006. Measurements reported here cover radar bright region C, a dark plains region west of Caloris Basin, and the interior of Caloris Basin. By use of spectral deconvolution with a large spectral library composed of many mineral compositions and grain size separates, we fitted, or "unmixed", the Mercury spectra. We find mineral suites composed of magnesium-rich orthopyroxene and olivine, Ca-, Mg-, Na-rich clinopyroxene, potassium feldspar, and Na-bearing plagioclase feldspar. Both Ca- and Mg-rich garnet (pyrope and grossular, respectively) are apparently present in small amounts. Opaque minerals are required for spectral matching, with rutile (TiO2) repeatedly providing the "best fit". However, in the case of the radar bright region C, perovskite also contributed to a very good fit. Caloris Basin infill is rich in both potassium feldspar and Na-rich plagioclase. There is little or no olivine in the Caloris interior smooth plains. Together with the high alkali content, this indicates that resurfacing magmas were low to intermediate in SiO2. Data suggest the dark plains exterior to Caloris are highly differentiated low-iron basaltic magmas resulting in material that might be classified as oligorclase basalts. (C) 2009 Elsevier Ltd. All rights reserved

Over the 3-day period from 12 to 14 October, 1990, the sodium abundance in the lunar atmosphere at 80° South increased by 60%, while interspersed measurements at the equator showed no substantial change. The source is suggested to be an unknown meteor shower with a radiant near the south ecliptic pole. A low relative velocity of ∼20 km/sec, combined with small particle masses, would keep the shower below the detectability threshold of radar. The stream could evolve from a reasonable asteroidal or cometary orbit with perihelion somewhat greater than 1 astronomical unit (AU) and a major axis of a few AU. The short residence time of lunar sodium makes it much more favorable than the terrestrial sodium layer for detection of such an event.

Observations of neutral potassium (K) in the tenuous lunar atmosphere are described. An echelle spectrograph, CCD, and data acquisition system are used to obtain emission spectra of neutral K atoms in the lunar atmosphere as observed by the 1.54 telescope at the Catalina Observatory at first quarter the night of April 29, 1989. A table of relevant lunar atmosphere parameters summarizes the results of the investigation. It is found that the number density at the surface is 9.5 + or - 1 atoms per cu cm and that there is a large nonthermal component and a deficiency of atoms equilibrated to the surface temperature. The calculated thermalization rate of the nonthermal component through encounters with the lunar surface gives a source of strength for the thermal component factor of 7 greater than loss by photoionization. Possible explanations for the low thermalized population observed are considered.

Enhanced abundances of neutral potassium (K) in the atmosphere of Mercury have been found above the longitude range containing Caloris Basin. Results of a large data set including six elongations of the planet between June 1986 and January 1988 show typical K column abundances of approximately 5.4 x 10(8) K atoms/cm(2). During the observing period in October 1987, when Caloris Basin was in view, the typical K column was approximately 2.7 x 10(9) K atoms/cm(2). Another large value (2.1 x 10(9) K atoms/cm(2)) was seen over the Caloris antipode in January 1988. This enhancement is consistent with an increased source of K from the well-fractured crust and regolith associated with this large impact basin. The phenomenon is localized because at most solar angles, thermal alkali atoms cannot move more than a few hundred kilometers from their source before being lost to ionization by solar ultraviolet radiation.

The development approach and design solutions employed for the 380 V AC direct-input 48 V 30 A switch-mode rectifier are described. The unit achieved all design goals set out prior to development. The net result is a unit which incorporates the following characteristics: direct 380 V AC three-phase input, compact size, high efficiency and power factor, front to back cooling, stackable without baffles, ease of installation and set-up, and IEC 380 safety requirements. >

The UV-Vis and circular dichroism (CD) spectra of several mitomycin antitumor compounds and some of their derivatives were analyzed in order to attribute the proper assignment to their electronic transitions. The lowest energy pi--pi* transition was found to depend on the effect of the auxochromic group in the aromatic ring, whereas the three n--pi* transitions, present at around 240, 400 and 560 nm, are related to the C(9)==O of the carbamoyl group and to the C(8)==O and the C(5)==O of the quinone, respectively. The chirality of the C(9) is responsible for the sign of the Cotton effect (CE) at around 240 nm, whereas the substituents of the chromophore for mitosane derivatives and the conformation of the carbamoyloxymethyl group at C(9) determine the CE sign of the (1)A--(1)L(b) transition. When the aziridine ring was opened and mitosenes derivatives were obtained, CD spectra did not differ significantly among the compounds and the bands associated to the different transitions had similar Cotton effect. Our findings suggest that the differences in the CD spectra, observed between mitosanes and mitosenes, are probably related to the more rigid molecular structure of the mitosene derivatives and the different conformations in solution of the C(9) side chain.

The interaction of Fe3+ with several anthracycline antitumour antibiotics has been reinvestigated. Absorption and circular dichroism (CD) measurements were carried out (i) in aqueous solution and (ii) in semi-aqueous MeOH to avoid the stacking of the anthracycline molecules. The Fe3+ binding to anthracycline was dependent on the metal-to-ligand molar ratio, antibiotic concentration, ionic strength, and pH. The formation of two major Fe3(+)-anthracycline complexes, I and II, was observed for all the drugs. These species differed in their coordination modes to the anthracycline ligands. Complex I was a monomeric species, where Fe3+ was bound to the anthracycline through the {C(11)-O-; C(12) = O} chelating site. In complex II, Fe3+ was also bound through the {C(5) = O; C(6)-O-} coordination site. Thus, the antibiotic ligand was acting as a bridge between two metal ions, forming oligomeric (or polymeric) structures. The different degree of association of the anthracyclines could be responsible for the reactivity of the metal ion. In fact, complexes I and II could constitute mononuclear, binuclear or polynuclear Fe3+ species depending on the competitive kinetics of both coordination and hydrolysis of the metal ion.

Use of the ECG for diagnosis of ischemic heart disease is more difficult in the setting of ventricular paced rhythms (VPRs). ST-segment/T-wave configuration are changed by the altered intraventricular conduction associated with ventricular pacing. The anticipated, or expected, morphology in patients with VPRs is one of QRS-complex-ST-segment to T-wave discordance. Several strategies are available to the physician to assist in the correct interpretation of the 12-lead ECG in patients with permanent ventricular pacemakers, including: a knowledge of the anticipated ST-segment-T-wave changes of VPRs and consequently the ability to recognize acute, ischemic morphologies; the performance of serial ECGs or ST-segment trend monitoring demonstrating dynamic changes encountered in acutely ischemic patients; a comparison with previous ECGs; and, if appropriate, an analysis of the native, underlying rhythm. The first strategy, an awareness of the anticipated ST-segment morphologies of VPRs, is the most important and not dependent on additional diagnostic testing, past medical records, or additional expertise in pacemaker function. Two cases are reported in which an analysis of the ECG in the setting of VPR assisted the treating physicians in establishing the correct diagnosis of acute myocardial infarction.

Reflection of a laser beam from the free surface of a nematic liquid crystal shows that the surface is periodically deformed when a high electric field (conduction regime) is continuously applied. Walls which appear to be of the alignment-inversion type have also been observed for these fields. These results are associated with flow cells that were discussed earlier.

Summary It was the aim of our investigations to increase the antitumor activity of cyclophosphamide. Therefore we applied a combined treatment with silatranes and isoniazid in relation 1: 20: 1. The effects were directed against a transplantable sarcoma 180. The parablastomatous invasive zone and the regional lymph nodes draining an implanted tumor were taken for the histochemical and morphological studies. The doses ranged from 50 to 175 mg of body mass. The combined derivatives inhibited tumor growth by 70 % in relation to the control. The authors connect the limitation of tumor progression in the applied experimental model in mice with the active response of T dependent zone of the regional lymph nodes, the rebuilding of stroma within the borderline invasive zone and the changes within the composition of cellular immune response of the peritumor tissue.

Thrombolytic dissolution of coronary artery thrombus has added new dimensions to early myocardial infarction treatment. Reperfusion via streptokinase infusion has been shown to be beneficial; however, adverse effects are being noted. We present the case of a patient so treated who subsequently developed left ventricular free wall rupture.

The exercise stress test is one of the most useful procedures available in the management of ischemic heart disease. It can provide a good deal of information, in addition to ST segment changes, for the clinician to interpret. Analysis of test results allows more accurate diagnosis, estimation of the severity of disease, and establishment of prognosis.

Thermal infrared emission spectra of the moon and Mercury have been obtained using the Si:As photoconductor and circular variable filter at the NASA Infrared Telescope Facility on Mauna Kea, Hawaii. Lunar spectra from 7.2 to 12.2 microns for two different locations in the south polar highlands have Christiansen frequency peaks at 8.1 microns and 7.9 microns, respectively. This indicates different compositions at the two locations; mafic in the first case, more felsic in the second. Emission spectra from Mercury are not as spatially localized,; however, the longitude of maximum contribution to the spectrum can be calculated from thermal models of the earth-facing disk. Results for areas centered at two longitudes have been obtained. Two locations in the intercrater plains were observed. At 40-deg longitude (very near the crater Homer), a peak at 7.9 microns indicates mafic igneous rock type. Spectra emanating from 46-deg longitude have peaks at 7.8 microns, indicating a region borderline between mafic and intermediate composition.

The interaction of Cu(II) with the protamine scylliorhinine Z3 was studied by means of CD measurements. At a 1:1 molar ratio, three complexes are formed. (1) In the pH range 5–6.5, the results suggest the formation of a five-membered chelate ring through the coordination of two nitrogen atoms, the N-terminal and the contiguous peptide nitrogen. (2) At pH ≥ 6.4, there is involvement of the lateral NH2 group of Arg; at pH 6.5–8, the formation of a 3N cupric complex is strongly suggested. (3) At pH ≥ 8, results indicate the formation of a 4N complex as a major species in Cu(II)-Z3 solution. The transformation from a 2N to a 3N complex, and from a 3N to a 4N complex was followed with the help of the σ(αNH2) Cu(II) charge-transfer dichroic band transitions. At Cu(II):Z3 molar ratios ≥ 2 and at pH > 8, a new dichroic band appears, indicating the involvement of the tyrosine residue side chain in metal-ion complexation.

Racemic and optically active hexahydro-5-tert-butoxymethyl-2H-azepin-2-one were polymerized, and the resulting poly-4-tert-butoxymethyl-6-hexanamides were treated to remove the tert-butyl protective group. ORD and CD spectra of (–)-poly-(S)-4-tert-butoxymethyl-6-hexanamide and (–)poly-(S)-4-hydroxymethyl-6-hexanamide were compared with spectra of their low molecular weight models, (S)(–)-6-acetamido-4-tert-butoxymethyl-N-methylhexanamide and (S)( – )-6-acetamido-4-hydroxymethyl-N-methylhexanamide, in 2,2,2-trifluoroethanol, p-dioxane–water mixtures, and methanol–water mixtures.

A series of optically active hexahydro-2H-azepin-2-ones substituted at the 5 position were prepared from (S)( − ) and (R)(+)-hexahydro-5-carboxy-2H-azepin-2-one obtained via resolution of the racemic acid with brucine. Racemic hexahydro-5-carboxy-2H-azepin-2-one was synthesized from 4-oxocyclohexanecarboxylic acid. Interest in many substituted hexahydro-2H-azepin-2-ones (ϵ-caprolactams, 2-oxohexamethyleneimines) stems in part from their ability to form polymers of the nylon 6 type whose properties may be systematically modified through regulation of the nature and position of the lactam substituent. Further structural control is possible through the use of optically pure monomers. An asymmetric seven-membered lactam with a polar substituent might lead to a stereoregular polyamide where interaction between the side chain and the polymer backbone could influence the conformational properties of the polymer. A side chain such as the hydroxymethyl moiety would be expected to favor hydrogen bonding. This question is discussed in more detail in the paper which follows on the optical properties of the polymer.

Pentobarbital (PB), at dose range of 20--50 mg/kg, displays in rabbits non-linear, dose-dependent kinetics. Pharmacokinetics parameters of drug elimination depend largely upon the dose, while the distribution phase is dose-independent. The rate of disappearance of PB from the central compartment (plasma) decreases with the increase of the dose. The analysis of pharmacodynamic parameters has shown that this dose-dependent retardation of PB elimination is probably caused by an impairment of metabolic processes, resulting from disturbance of the circulatory system. A close correlation has been found between the hypotensive effect of PB and the elimination constant, k13, and also between the hypotensive effect and beta.Vd(extrap), a coefficient proportional to the rate of metabolism of PB [23, 29]. The results indicate the necessity of considering the changes in the functional state of the organism, related to the action of a drug, in pharmacokinetic studies.