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We report on a large-area, high-aspect-ratio, carbon nanotube (CNT) forest structure produced at BYU acting as a window/separator for a hollow cathode EUV lamp. The structure has large-surface-area, high light trans-mission, and differential pumping. CNT fabrication allows for variable dimensions, which allows various EUV distributions and pressure gradients to be possible. Theory is presented for predicting such distributions and gradients. Several structures have been fabricated; their dimensions, properties, and predicted distributions and gradients are given.

Inflammatory bowel disease is a complex collection of disorders. Microbial dysbiosis as well as exposure to toxins including xenoestrogens are thought to be risk factors for inflammatory bowel disease development and relapse. Bisphenol-A has been shown to exert estrogenic activity in the colon and alter intestinal function, but the role that xenoestrogens, such as bisphenol-A , play in colonic inflammation has been previously described but with conflicting results. We investigated the ability of bisphenol-A to exacerbate colonic inflammation and alter microbiota metabolites derived from aromatic amino acids in an acute dextran sulfate sodium-induced colitis model. Female C57BL/6 mice were ovariectomized and exposed to bisphenol-A daily for 15 days. Disease activity measures include body weight, fecal consistency, and rectal bleeding. Colons were scored for inflammation, injury, and nodularity. Alterations in the levels of microbiota metabolites derived from aromatic amino acids known to reflect phenotypic changes in the gut microbiome were analyzed. Bisphenol-A exposure increased mortality and worsened disease activity as well as inflammation and nodularity scores in the middle colon region following dextran sulfate sodium exposure. Unique patterns of metabolites were associated with bisphenol-A consumption. Regardless of dextran sulfate sodium treatment, bisphenol-A reduced levels of tryptophan and several metabolites associated with decreased inflammation in the colon. This is the first study to show that bisphenol-A treatment alone can reduce microbiota metabolites derived from aromatic amino acids in the colon which may be associated with increased colonic inflammation and inflammatory bowel disease. Impact statement As rates of inflammatory bowel disease rise, discovery of the mechanisms related to the development of these conditions is important. Environmental exposure is hypothesized to play a role in etiology of the disease, as are alterations in the gut microbiome and the metabolites they produce. This study is the first to show that bisphenol-A alone alters tryptophan and microbiota metabolites derived from aromatic amino acids in a manner consistent with autoimmune diseases, specifically inflammatory bowel diseases, regardless of dextran sulfate sodium treatment. These findings indicate a potential mechanism by which bisphenol-A negatively affects gut physiology to exacerbate inflammation.

Background A major toxicity concern in radioembolization therapy of hepatic malignancies is radiation-induced pneumonitis and sclerosis due to hepatopulmonary shunting of 90Y microspheres. Currently, 99mTc macroaggregated albumin (99mTc-MAA) imaging is used to estimate the lung shunt fraction (LSF) prior to treatment. The aim of this study was to evaluate the accuracy/precision of LSF estimated from 99mTc planar and SPECT/CT phantom imaging, and within this context, to compare the corresponding LSF and lung-absorbed dose values from 99mTc-MAA patient studies. Additionally, LSFs from pre- and post-therapy imaging were compared. Results A liver/lung torso phantom filled with 99mTc to achieve three lung shunt values was scanned by planar and SPECT/CT imaging with repeat acquisitions to assess accuracy and precision. To facilitate processing of patient data, a workflow that relies on SPECT and CT-based auto-contouring to define liver and lung volumes for the LSF calculation was implemented. Planar imaging-based LSF estimates for 40 patients, obtained from their medical records, were retrospectively compared with SPECT/CT imaging-based calculations with attenuation and scatter correction. Additionally, in a subset of 20 patients, the pre-therapy estimates were compared with 90Y PET/CT-based measurements. In the phantom study, improved accuracy in LSF estimation was achieved using SPECT/CT with attenuation and scatter correction (within 13% of the true value) compared with planar imaging (up to 44% overestimation). The results in patients showed a similar trend with planar imaging significantly overestimating LSF compared to SPECT/CT. There was no correlation between lung shunt estimates and the delay between 99mTc-MAA administration and scanning, but off-target extra hepatic uptake tended to be more likely in patients with a longer delay. The mean lung absorbed dose predictions for the 28 patients who underwent therapy was 9.3 Gy (range 1.3–29.4) for planar imaging and 3.2 Gy (range 0.4–13.4) for SPECT/CT. For the patients with post-therapy imaging, the mean LSF from 90Y PET/CT was 1.0%, (range 0.3–2.8). This value was not significantly different from the mean LSF estimate from 99mTc-MAA SPECT/CT (mean 1.0%, range 0.4–1.6; p = 0.968), but was significantly lower than the mean LSF estimate based on planar imaging (mean 4.1%, range 1.2–15.0; p = 0.0002). Conclusions The improved accuracy demonstrated by the phantom study, agreement with 90Y PET/CT in patient studies, and the practicality of using auto-contouring for liver/lung definition suggests that 99mTc-MAA SPECT/CT with scatter and attenuation corrections should be used for lung shunt estimation prior to radioembolization.

Approximately 10–40% of strokes are cryptogenic (CS). Long-term electrocardiographic (ECG) monitoring has been recommended in these patients to search for atrial fibrillation (AF). An unresolved issue is whether ambulatory ECG (AECG) monitoring should be performed first, followed by an implantable loop recorder (ILR) if AECG monitoring is non-diagnostic, or whether long-term ECG monitoring should be initiated using ILRs from the onset. The purpose of this study was to assess, using an ILR, AF incidence in the first month after CS. We enrolled consecutive CS patients referred for an ILR. All patients were monitored via in-hospital continuous telemetry from admission until the ILR (Medtronic [Minneapolis, MN] LINQ™) was implanted. The duration and overall burden of all AF episodes ≥ 2 min was determined. The cohort included 343 patients (68 ± 11 years, CHA2DS2-VASc 3.5 ± 1.7). The time between stroke and ILR was 3.7 ± 1.5 days. During the first 30 days, only 18 (5%) patients had AF. All episodes were paroxysmal, lasting from 2 min to 67 h and 24 min. The median AF burden was 0.85% (IQR 0.52, 10.75). During 1 year of follow-up, 67 (21%) patients had AF. The likelihood of AF detection by an ILR in the first month post-CS is low. Thus, the diagnostic yield of 30 days of AECG monitoring is likely to be limited. These data suggest a rationale for proceeding directly to ILR implantation prior to hospital discharge in CS patients, as many have AF detected during longer follow-up.

An optical fiber thermometer consists of an optical fiber whose tip is coated with a highly conductive, opaque material. When heated, this sensing tip becomes an isothermal cavity that emits like a blackbody. This emission is used to predict the sensing tip temperature. In this work, analytical and experimental research has been conducted to further advance the development of optical fiber thermometry. An inexpensive optical fiber thermometer is developed by applying a thin coating of a high-temperature cement onto the tip of a silica optical fiber. An FTIR spectrometer is used to detect the spectral radiance exiting the fiber. A rigorous mathematical model of the irradiation incident on the detection system is developed. The optical fiber thermometer is calibrated using a blackbody radiator and inverse methods are used to predict the sensing tip temperature when exposed to various heat sources.

Premenopausal women exhibit enhanced insulin sensitivity and reduced incidence of type 2 diabetes compared with age-matched men, but this advantage disappears after menopause with disrupted glucose homeostasis, in part, owing to a reduction in circulating 17β-estradiol (E2). Fasting hyperglycemia, a feature of diabetes mellitus, is largely derived from dysregulation of hepatic glucose production (HGP), in which hyper-activated Foxo1 induces transcription of genes coding gluconeogenic enzymes. We investigated the E2 action on the regulation of glucose hemostasis in male and ovariectomized (OVX) female of control and liver-specific Foxo1 knockout (L-F1KO) mice, and sought to understand the mechanism by which E2 regulates gluconeogenesis via the interaction with liver Foxo1. E2 subcutaneous implant led to decreased fasting blood glucose and improvement of insulin sensitivity in both male and OVX female mice in parallel with the suppression of gluconeogenesis and hepatic gluconeogenic gene expression, including glucose 6-phosphatase (G6pase) and phosphoenolpyruvate carboxykinase 1 (Pck1). Importantly, these effects of E2 were only observed in control mice but disrupted in L-F1KO mice. Moreover, suppression of HGP and gluconeogenesis by E2 only occurred in hepatocytes isolated from control mice and we confirmed that Foxo1 was required for the E2 action on gluconeogenesis. E2 suppressed Foxo1 via activation of ERα and phosphorylation of Akt, while inhibition of both ERα and Akt signaling abolished the effect of E2 on gluconeogenesis. Collectively we demonstrated that the activation of ERα-Akt-Foxo1 signaling serves as an important mechanism of estrogen in control of glucose homeostasis. These results may help explain the gender difference in the incidence of type 2 diabetes and suggest an approach to target ERα to modulate glucose metabolism in diabetic patients. Disclosure H. Yan: None. F. Zhou: None. W. Yang: None. Q. Pan: None. Z. Shen: None. G. Han: None. K. Allred: None. C. Allred: None. Y. Xu: None. S. Guo: None.

Flaxseed and its bioactive components have been associated with a decreased risk of colorectal cancer incidence and progression. This review aims to summarize recent research regarding the role of flaxseed and each of its major dietary bioactive components in reducing colorectal cancer. In both human and animal model experiments, flaxseed consumption had beneficial effects on colon physiology associated with reduction in colorectal cancer risk or occurrence. Considered separately, each of flaxseed’s major bioactive components, including fiber, alpha-linolenic acid, lignans, and other phytochemicals, is also associated with decreased risk of colonic neoplasms and regulation of cell growth through several potential mechanisms. Collectively, experimental data suggests that consumption of flaxseed and/or its bioactive components may reduce colorectal cancer risk by a variety of mechanisms. Future studies should focus on the mechanisms by which whole flaxseed can prevent colorectal cancer.

Protective layers on aluminum mirror surfaces which can be removed via the use of atomic hydrogen or hydrogen plasmas at the point of use in space may allow an expansion of broad-band mirrors into the EUV. LUVOIR (large, UV-optical-IR telescope) is a potential NASA flagship space-based observatory of the 2020’s or 30’s. It would utilize the largest mirrors ever flown1 . Their reflective coating will almost certainly be aluminum, since such telescopes would profit from truly broad-band mirrors. To achieve reflectance over the broadest band, the top surface of such aluminum mirrors, however, needs to be bare, without the oxide layers that naturally form in air. This will open the 11 to 15 eV band. Since thin aluminum films are largely transparent between 15 and 70 eV an EUV mirror under the aluminum could make EUV bands such as 30.4 nm available for space-based astrophysics without sacrificing mirror IR, visible and UV reflectance. The local space environment for the observatory is sufficiently oxygen-free that the surface should remain bare for decades. We discuss protecting as-deposited aluminum mirrors with robust, oxygenimpenetrable, barrier layers applied in vacuo to the aluminum immediately after deposition and before air contact. The goal is that the barrier could also be cleanly, and relatively easily, removed once the mirror is in space. We propose hydrogen atoms as the means for removing the overcoat, since they can be expected to meet the criteria that the means is gentle enough to not roughen the mirror surface, and does not redeposit material on the mirror or other spacecraft components. We have investigated both organic and inorganic (such as, a-Si) hydrogen-removable films that can be applied to the aluminum immediately after its deposition have been investigated. We also examined the REVAP technique, using Cd and Zn. Agglomeration limited their effectiveness as barrier layers. That and dealing with the reevaporated atoms may limit their utility as barrier materials.

The aging process is characterized by increased chronic low-grade inflammation, aka inflamm-aging, which offend is accompanied by ‘leaky gut’ syndrome. Inflamm-aging is a highly significant risk factor for both morbidity and mortality in the older adult population (>65 years of age). In addition, there is a growing prevalence of inflammatory bowel disease (IBD), a chronic inflammatory condition of the gastrointestinal tract in the older adult population. The pathogenesis of late-onset IBD is suggested to be more complex compared with younger IBD patients; the causes determining the age of IBD onset remain unexplained. Ghrelin is a 28-amino-acid peptide hormone mainly produced by X/A-like cells of the stomach, with well-characterized functions in growth hormone secretion, food intake, adiposity and insulin resistance. Ghrelin’s biological relevant receptor is Growth Hormone Secretagogue Receptor (GHS-R). Ghrelin and ghrelin mimetics have been considered viable candidates for treating cachexia, sarcopenia, and gastrointestinal disorders. As expected, we observed that the expression of tight junction proteins in colon mucosal layer decreases with age. When challenged with dextran sulfate sodium (DSS) to induce experimental ulcerative colitis, 18-months old male C57BL/6 mice exhibited exacerbated disease activity scores compared to young male mice (5-months), showing worsened pathology such as rectal bleeding and difficulty in defecation. DSS-induced colitis was exacerbated in both ghrelin-deficient (Ghrl-/-) and ghrelin receptor-deficient (Ghsr-/-) mice. Together, these data suggest endogenous ghrelin signaling contributes to susceptibility to colitis, and ghrelin signaling pathway may present a novel target for prevention and treatment of leaky gut syndrome in aging.

Introduction Heart failure (HF) hospitalizations are of growing concern for patients and payers. Cardiac resynchronization therapy patients that achieve high CRT pacing (>90%) are at lower risk of HF hospitalization. There has been no way to identify patients with suboptimal CRT pacing outside of routine office or remote follow up. Analytic software has been developed to identify programming optimization opportunities at a clinic level. Hypothesis Cardiac device analytic software can identify opportunities for programming optimization and enable improvements in CRT pacing percentage. Methods Cardiac device analytic software (Medtronic PaceartTM Analytics) was used to identify CRT patients with suboptimal CRT pacing at a single center. Patients actively followed within the clinic were included. Patients with CRT pacing programmed off, LV leads off due to diaphragmatic stimulation, or who declined further procedures or more aggressive medical therapy were not included. Reduction in HF related healthcare utilization was modeled based on expected reduction in the risk of HF hospitalizations with increased CRT pacing percentage. Cost savings were estimated using national claims payment data. Results A total of 88 out of 642 patients were identified with suboptimal CRT pacing through the analytic tool. There were 42 patients not eligible for improvement for reasons outlined above; 46 patients were considered eligible for intervention. The mean (standard error) baseline CRT pacing was 71.6% (5.5%). With intervention, 21 patients (45.6%) improved CRT pacing to 94.1% (0.6%). 11 patients improved with control of atrial fibrillation, 9 with treatment of PVC's, and 1 with device reprogramming. This improvement of 22.5% was modeled to prevent 7 HF hospitalizations in 1 year, equating to $117,268 in potential savings to the healthcare system from a payer perspective. Conclusions Analytics data can be used to successfully identify patients that have suboptimal CRT pacing and may lead to cost savings through reducing unnecessary HF hospitalizations

We report optical constants of e-beam evaporated yttrium oxide Y2O3 thin films as determined from angle-dependent reflectance measurements at wavelengths from 5 to 50 nm. Samples were measured using synchrotron radiation at the Advanced Light Source. The experimental reflectance data were fit to obtain values for the index of refraction and thin film roughness. We compare our computed constants with those of previous researchers and those computed using the independent atom approximation from the CXRO website. We found that the index of refraction near 36 nm is much lower than previous data from Tomiki as reported by Palik. The real part of the optical constants is about 10% to 15% below CXRO values for wavelengths between 17 nm and 30 nm. Films were also characterized chemically, structurally, and optically by ellipsometry and atomic force microscopy.

A 62-year-old man with idiopathic ventricular tachycardia (VT) exhibiting left bundle branch block and left inferior axis QRS morphology with a Qr in lead III underwent electrophysiological testing. Successful ablation was achieved in the left ventricle (LV) at a site with an excellent pace map, adjacent to the His bundle electrogram recording site. At that site, the sequence of the ventricular electrogram and late potential recorded during sinus rhythm reversed during spontaneous premature ventricular contractions with the same QRS morphology as the VT. This case shows that VT can arise from the LV ostium adjacent to the membranous septum.

Single-walled carbon nanotubes (SWCNT) were prepared using iron catalysts deposited by indirect evaporation on silicon substrate covered with 500 nm-thick thermal oxide. Diode SWCNT devices have been fabricated using Au and Al, as the asymmetric metal contacts, and a random network of metallic and semiconducting nanotubes as the device channel. No effort was made to align the SWCNTs or to eliminate metallic nanotubes in our devices. Asymmetric voltage–current behavior was seen. Current rectification was observed in the source–drain bias range of − 3 V to + 3 V. Rectification was somewhat surprising since, although metallic tubes are in the minority (∼ 1/3), they could potentially act as shunts and mask the electric properties of the semiconducting majority. No correlation between electrode spacing and current rectification was observed. The lowest leakage current measured was 1% of the maximum current carrying capacity. Maximum forward-biased current capacities range between 8 μA and 841 μA.

Atrial fibrillation (AF) is the most commonly diagnosed arrhythmia in the US and can result in Emergency Room (ER) visits. We describe an ER pathway for patients with AF to facilitate early discharge rather than admission. An AF treatment algorithm was implemented in a hospital ER. This pathway

IVTs Arising from the LV Anterior Papillary Muscle. Introduction: Focal ventricular arrhythmias (VAs) have been reported to arise from the posterior papillary muscle in the left ventricle (LV). We report a distinct subgroup of idiopathic VAs arising from the anterior papillary muscle (APM) in the LV. Methods and Results: We studied 432 consecutive patients undergoing catheter ablation for VAs based on a focal mechanism. Six patients were identified with ventricular tachycardia (VT, n = 1) or premature ventricular contractions (PVCs, n = 5) with the earliest site of ventricular activation localized to the base (n = 3) or middle portion (n = 3) of the LV APM. No Purkinje potentials were recorded at the ablation site during sinus rhythm or the VAs. All patients had a normal baseline electrocardiogram and normal LV systolic function. The VAs exhibited a right bundle branch block (RBBB) and right inferior axis (RIA) QRS morphology in all patients. Oral verapamil and/or Na + channel blockers failed to control the VAs in 4 patients. VT was not inducible by programmed electrical stimulation in any of the patients. In 4 patients, radiofrequency current with an irrigated or conventional 8-mm-tip ablation catheter was required to achieve a lasting success. Two patients had recurrent PVCs after a conventional radiofrequency ablation with a 4-mm-tip ablation catheter had initially suppressed the arrhythmia. Conclusions: VAs may arise from the base or middle portion of the APM and are characterized by an RBBB and RIA QRS morphology and focal mechanism. Catheter ablation of APM VAs is typically challenging, and creation of a deep radiofrequency lesion may be necessary for long-term success.

Estrogen receptor (ER) and progesterone receptor (PR) status in breast carcinomas are considered validated predictive factors for selecting patients for antihormonal therapy. Published surveys have shown a significant rate of disagreement and lack of reproducibility of immunohistochemistry (IHC) results from laboratories around the world. To address these limitations IHC assays for ER and PR were developed using characterized reagents, after careful calibration of the sensitivity and specificity to match established assays previously validated in large clinical studies. The ER assay uses a cocktail of 2 mouse monoclonal antibodies (1D5 and ER-2-123) and the PR assay uses 1 mouse monoclonal antibody (PgR 1294); both are followed by a polymer-peroxidase-based detection system. All antibodies were tested for specificity by epitope mapping. The sensitivity of the new assays was calibrated to be equivalent to previously validated IHC assays followed by a comparison with the validated assays in a concordance study involving over 200 specimens. All slides were scored with the "Allred Score," also used for scoring of the original validated assays. The overall concordance between the new and the established IHC assays was nearly perfect (99%). The concordance study demonstrated greater than 98% positive agreement and 100% negative agreement of the new IHC assays with the previously validated IHC assays. This equivalence establishes the clinical validation of the assays and, as they are based on newer generation reagents and are produced and tested under stringent quality control conditions to ensure their consistency, they add additional advantages to the user and patients.

To the Editor: Although the pathogenesis of Takotsubo cardiomyopathy (TC) remains unclear, physical or emotional stress is common in the majority of reported cases ([1–3][1]). The central role for sympathetic stimulation in TC is suggested by elevations in plasma catecholamines ([1–3][1])

Thin films of Silicon–Germanium (SiGe) were deposited by plasma enhanced chemical vapor deposition (PECVD) for use in high speed devices, Micro-electrical mechanical systems (MEMS) and bolometric infrared detectors. SiGe films grown by PECVD typically have lower stress, lower deposition temperatures and higher growth rates (200 A/min) compared with other deposition techniques. The samples were deposited at temperatures from 500 °C to 580 °C and doped using either diborane (B 2 H 6 ) or phosphine (PH 3 ). As-deposited films had predominantly (1 1 1) and (2 2 0) texture determined by X-ray diffraction (XRD). Annealing produced crystalline material with no evidence of cracking as determined by resistivity measurements. It also produced variations of crystallite orientations with predominantly (1 1 1) texture. As-grown films exhibited compressive stresses as low as 18 MPa. Stress in annealed samples increased with increasing annealing temperature and time.

w l T a w i a a c t c T a e w In most detective stories, the sleuth attempts to identify he incriminating evidence that proves the criminal is guilty. herlock Holmes frequently took the opposite approach and earched for evidence that would eliminate a possible exlanation of the crime. In the Sign of Four, he states, Eliminate all other factors, and the one which remains must e the truth.” Similarly, most investigators have attempted o identify risk factors that identify individuals at increased isk for sudden cardiac death (SCD). In this issue of Heart hythm, Rashba et al, like Sherlock Holmes, take an oposite approach and attempt to identify individuals in a igh-risk group who are not likely to have SCD. Specifially, among patients with nonischemic dilated cardiomypathy (NIDCM) and left ventricular ejection fraction LVEF) 36%, they found that none of the one in three atients (top tertile) with the highest standard deviation of ormal RR intervals (SDNN) in a Holter recording had CD. SCD accounts for 30% to 50% of all deaths of patients ith nonischemic dilated cardiomyopathy. For some time, fforts have been made to identify patients at highest risk of CD who might benefit from placement of a prophylactic mplantable cardioverter-defibrillator (ICD). Tools for isk stratification include Holter monitors looking for nonustained ventricular tachycardia or a high incidence of remature ventricular contractions, LVEF, signal-averged ECG, electrophysiologic study, QRS duration, eart rate variability (HRV) parameters, and microvolt -wave alternans. The Defibrillators in Non-Ischemic ardiomyopathy Treatment Evaluation (DEFINITE) trial howed that patients with nonischemic dilated cardiomyopthy, LVEF 36%, and “ambient arrhythmias” (an episode f nonsustained ventricular tachycardia on Holter or telemtry or an average of 10 premature ventricular contractions PVCs) per hour on a 24-hour Holter recording) receive ortality benefit from ICDs. The recently reported Sudden ardiac Death in Heart Failure Trial (SCD-HeFT) showed a imilar benefit of ICDs in patients with New York Heart ssociation (NYHA) class II or III congestive heart failure

Postmenopausal women on estrogen replacement therapy (ERT) have a reduced risk of developing colon cancer compared with postmenopausal women not on ERT, suggesting a role for estradiol (E2) in protection against this disease. To determine whether E2protects against inflammation-associated colon cancer when administered following the initiation of colonic DNA damage, in this study, we implanted E2-containing pellets into mice after co-treatment with azoxymethane and two rounds of dextran sulfate sodium (DSS). Wild-type (WT) E2-treated mice had reduced numbers and average area of adenocarcinomas compared with the control mice. These effects were lost in estrogen receptor-β (Erβ(Esr2)) knockout mice. Surprisingly, apoptosis was reduced and cell proliferation was increased in sections from tumors of the WT E2mice compared with the WT control mice. These findings are probably due, in part, to a reduction in ERβ expression in colonic epithelial cells as the cells progressed from a non-malignant to a cancerous state as enhanced apoptosis was observed in normal colonocytes expressing higher levels of ERβ. Furthermore, epithelial cells within the tumors had dramatically increased ERα mRNA and protein expression compared with the non-diseased mice. We conclude that while E2treatment resulted in an overall suppression of colonic adenocarcinoma formation, reduced ERβ expression accompanied by enhanced ERα expression caused an altered colonocyte response to E2treatment compared with the earlier stages of colon cancer development. These data are the first examples of decreased ERβ expression concurrent with increased ERα expression as a disease develops and highlight the importance of understanding the timing of E2exposure with regard to the prevention of inflammation-associated colon cancer.

We have fabricated arrays of silicon field emitters using semiconductor lithography techniques. The density of the tips was 105/cm2. The maximum current that can be extracted from each emitter is limited by resistive heating. We have investigated how the electron current emitted changes under constant applied voltage. We found that the current is very sensitive to the vacuum conditions. We attribute this to sputtering of the emitters due to ionized residual gas molecules. The poorer the vacuum, the higher the instability in the current. We studied this phenomenon at 10−6 and 10−8 Torr. The model of two concentric spherical shells is used to obtain the ion energy distribution. This is then used to calculate the rate of ion bombardment and the rate of atoms sputtered. A lifetime of the tip can be deduced from these calculations.

Scanning electron microscopy, atomic force microscopy, and Raman spectroscopy were used to characterize the microstructure of photoluminescent porous silicon (PS) layers formed by the anodic etching (HF:H2O:ethanol), at various current densities, of p‐type (100) silicon wafers possessing resistivity in the range 1–2 Ω cm. Existing models for the origin of luminescence in PS are not supported by our observations. Cross‐sectional as well as surface atomic force micrographs show the material to be clumpy rather than columnar; rodlike structures are not observed down to a scale of 40 nm. A three‐dimensional model of the mesostructure of porous silicon is discussed. Room‐temperature Raman scattering measurements show no evidence for a‐Si:H or polysilanes and the material reported here is composed of 10 nm roughly spherical Si nanocrytallites rather than 3 nm wires postulated in standard quantum confinement models.

Temporal and lateral resolution of seismic data is principally determined by the shape and duration of the propagating wavelet. Accurate wavelet estimation and the ability to change its shape are both of paramount importance to achieve the maximum resolution afforded by the available bandwidth.

Infection of a prosthetic graft after replacement of the ascending aorta is an uncommon but life-threatening complication of surgery. We report the use of antibiotic-impregnated calcium sulfate beads in a patient with ascending aortic graft infection to provide localized, high-dose therapy to the infected region. Perigraft placement of antibiotic beads provides an alternative method for the treatment of aortic graft infection.

We have produced arrays of 10,000 sharp p-type silicon points using an etch plus oxidation method. These points were used as electron emitters. No high vacuum cesiation or high temperature cleaning was needed to observe the electron emission. These are seen to be photosensitive sources of electrons at 200 K and 300 K. They were also used to produce AlKα x-rays. This constitutes the first use of etched, point arrays for generating electrons for x-ray sources.

We use laser high-order harmonics and a polarization-ratio-reflectance technique to determine the optical constants of copper and oxidized copper in the wavelength range 10-35 nm. This measurement resolves previously conflicting data sets, where disagreement on optical constants of copper in the extreme ultraviolet most likely arises from inadvertent oxidation of samples before measurement.

We are studying the possibility of producing precision, aspherical mirrors for X-rays and visible light. Our study examines the use of ultrastructure processing to replace mechanical methods of material removal. The method starts with a chemically-mechanically polished, flat silicon wafer. The aim is to preserve atomic scale smoothness of the surface wafer while the wafer is bent to a desired figure. We report measurements of the mechanical properties of various stressing layers. This involves measuring the deformation of several thin silicon wafers coated with chemically vapor deposited nickel and boron films of known thickness. We have found that, under normal conditions, the film does not add to the microroughness of the substrate on either the front or the back surfaces. Film and substrate thicknesses, however, vary by as much as 10%. This is the present limit on figure accuracy. We have developed a model that describes bending of B/Si and Ni/Si structures. The model relates stress and Young's modulus to the measured thickness of the film, and the thickness and curvature of the substrate. This approach is used to measure the stress and Young's modulus for boron and nickel films. The Young's modulus Ef was 3.05 x 1012 Pa for the boron films and 1.4 x 1010 Pa for the nickel films. From the relationship developed and verified for predicting the radii of curvature of the substrate, if may be possible to define a film thickness pattern which would provide a desired optical figure.

Raman spectra are reported from MoSi2 polycrystalline powder and soft x-ray Mo/Si multilayers. The sharp lines at 323 and 438 cm-1 are all due to crystalline MoSi2. These lines in the powder sample intensify with annealing. The Raman spectra of as-deposited multilayers shows a broad asymmetric peak, highest at about 480 cm-1. We attribute this to α-Si which is highly disordered. In contrast to α-Si in semiconductor/semiconductor and semiconductor/dielectric multilayers, in the Mo/Si samples the Raman signal can vanish after modest heating. This provides evidence that the composition of the silicon component of the multilayer changes even with 200°C annealing. Further annealing also produces the signature for crystalline MoSi2 in the multilayer samples. This is the first report of the characterization of Mo/Si soft x-ray multilayers by Raman spectroscopy, and it indicates that Raman spectroscopy may be an effective technique for characterizing these soft x-ray multilayers and may be useful in studying their interfaces.

A 73-year-old man with idiopathic premature ventricular contractions (PVCs) underwent electrophysiological testing. Left ventricular activation mapping revealed a focal mechanism of the PVCs with the earliest activation on the anterior papillary muscle (APM). Irrigated radiofrequency (RF) current delivered at that site induced a cluster of non-sustained ventricular tachycardia episodes with the same QRS morphology as the PVCs, followed by ventricular fibrillation (VF). The APM might have served as an abnormal automatic trigger and driver for the VF occurrence. Ventricular fibrillation may occur as a complication during RF catheter ablation of papillary muscle ventricular arrhythmias even if the clinical arrhythmia is limited to PVCs.

We describe an extreme-ultraviolet (EUV) polarimeter that employs laser-generated high-order harmonics as the light source. The polarimeter is designed to characterize materials and thin films for use with EUV light. Laser high harmonics are highly directional with easily rotatable linear polarization, not typically available with other EUV sources. The harmonics have good wavelength coverage, potentially spanning the entire EUV from a few to a hundred nanometers. Our instrument is configured to measure reflectances from 14 to 30 nm and has approximately 180 spectral resolution (lambda/Delta lambda). The reflection from a sample surface can be measured over a continuous range of incident angles (5 degrees-75 degrees). A secondary 14 cm gas cell attenuates the harmonics in a controlled way to keep signals within the linear dynamic range of the detector, comprised of a microchannel plate coupled to a phosphorous screen and charge coupled device camera. The harmonics are produced using approximately 10 mJ, approximately 35 fs, and approximately 800 nm laser pulses with a repetition rate of 10 Hz. Per-shot energy monitoring of the laser discriminates against fluctuations. The polarimeter reflectance data agree well with data obtained at the Advanced Light Source Synchrotron (Beamline 6.3.2).

A 32-year-old woman with a history of nonischemic dilated cardiomyopathy, left bundle branch block, left ventricular ejection fraction of 0.15, and New York Heart Association Class III congestive heart failure, despite optimal medical treatment, was referred for cardiac resynchronization therapy with implantation of an implantable cardioverter defibrillator. The patient had prior chemotherapy for non-Hodgkin's lymphoma and was shown to have chronic total occlusion of the superior vena cava (SVC) by magnetic resonance imaging. Cardiac resynchronization was accomplished with an iliofemoral approach without complications resulting in marked clinical improvement. We conclude that the iliofemoral approach allows transvenous implantation of cardiac resynchronization therapy in patients with superior vena cava occlusion.

Background Knowledge of the shock potential gradient (∇V) and postshock activation is limited to internal defibrillation of short-duration ventricular fibrillation (SDVF). Objective The purpose of this study was to determine these variables after external defibrillation of long-duration VF (LDVF). Methods In six pigs, 115–20 plunge needles with three to six electrodes each were inserted to record throughout both ventricles. After the chest was closed, the biphasic defibrillation threshold (DFT) was determined after 20 seconds of SDVF with external defibrillation pads. After 7 minutes of LDVF, defibrillation shocks that were less than or equal to the SDVF DFT strength were given. Results For DFT shocks (1632 ± 429 V), the maximum minus minimum ventricular voltage (160 ± 100 V) was 9.8% of the shock voltage. Maximum cardiac ∇V (28.7 ± 17 V/cm) was 4.7 ± 2.0 times the minimum ∇V (6.2 ± 3.5 V/cm). Although LDVF did not increase the DFT in five of the six pigs, it significantly lengthened the time to earliest postshock activation following defibrillation (1.6 ± 2.2 seconds for SDVF and 4.9 ± 4.3 seconds for LDVF). After LDVF, 1.3 ± 0.8 episodes of spontaneous refibrillation occurred per animal, but there was no refibrillation after SDVF. Conclusion Compared with previous studies of internal defibrillation, during external defibrillation much less of the shock voltage appears across the heart and the shock field is much more even; however, the minimum ∇V is similar. Compared with external defibrillation of SDVF, the biphasic external DFT for LDVF is not increased; however, time to earliest postshock activation triples. Refibrillation is common after LDVF but not after SDVF in these normal hearts, indicating that LDVF by itself can cause refibrillation without requiring preexisting heart disease.

We developed an extreme ultraviolet polarimeter, which employs laser-generated high-order harmonics as the light source. Reflection scans made with this instrument show agreement over three orders of magnitude with data obtained at the advanced light source.

Background: Humans are more similar in transmural Purkinje and cardiac ion channel distributions to dogs than pigs. The Purkinje network in pigs is transmural but confined to the endocardium in dogs. Little is known about intramural activation during long-duration ventricular fibrillation (LDVF) given these differences. We tested the hypothesis that the transmural activation sequence is similar in sinus rhythm (SR) and LDVF in dogs as well as pigs, but different between species. Methods and Results: In six pigs and seven dogs, 50–60 plunge needles (six electrodes, 2-mm spacing) were placed throughout the left ventricle. Unipolar recordings were made for >10 minutes of LDVF. SR and LDVF activation times were grouped into waves by linking activations along each needle. Origin (earliest activation) and propagation direction were determined for each wave. The mean wave origin was significantly more endocardial in dogs than pigs for SR and 1 through 10 minutes of LDVF. Predominant propagation direction in LDVF and SR was endocardial to epicardial in dogs, but the opposite or equal in both directions in pigs. Fastest activation rate was epicardial in pigs, but endocardial in dogs with an increasing endocardial-to-epicardial activation rate gradient as LDVF progressed in dogs but not pigs. Conclusions: The transmural activation sequence in SR and LDVF is markedly different between pigs and dogs. These differences may be related to differences in Purkinje fiber and ion channel distributions and suggest that dogs are a better model for investigating activation sequences during LDVF, given the similarities with humans.

Multilayer mirrors for 30.4nm can image the earth's magnetosphere using light from the sun's corona scattered off He+. Neutral He atoms scatter at 58.4nm. We will discuss the latest work in minimizing 58.4 reflection.

High-order harmonic generation is utilized as a source of extreme ultraviolet light for polarization sensitive reflectometry.

We have measured the reflectance and transmittance of thorium dioxide thin films from 50-280 eV. We have developed several methods for fitting this data that gives the most reliable values for the complex index of refraction, n = 1 - δ + iβ. These fitting methods included fitting film thickness using interference fringes in highly transmissive areas of the spectrum and fitting reflectance and transmittance data simultaneously. These techniques give more consistent optical constants than solitary unconstrained fitting of reflectance as a function of angle. Using these techniques, we have found approximate optical constants for thorium dioxide in this energy range. We found that the absorption edges of thoria were shifted 4 eV and 2 eV to lower energies from those of thorium. We also found that the peak in δ was shifted by 3 eV to lower energy from that of thorium.

We used spectroscopic ellipsometry to determine the optical constants of seven thin-film ThO2 samples deposited by radio-frequency sputtering, thickness ranging between 24 and 578 nm, for the spectral range of 1.2 to 6.5. We used a hollow-cathode light source and vacuum monochromator to measure constants at 10.2 eV. None of the deposition parameters studied including DC-bias voltages successfully increase the n of (that is, densify) thoria films. 1, 2 The value of n at 3.0 eV is 1.86 ± 0.04. We find compelling evidence to conclude that the direct band gap is at ~5.9 eV, clarifying the results of others, some of whom observed the absorption edge below 4 eV. The edge in the two thickest films is of a narrow feature (FWHM=0.4 eV) with modest absorption (α~ 6µm -1 , k~0.1). Absorption may go down briefly with increasing energy (from 6.2 to 6.5 eV). But at 10.2 eV absorption is very high and index low as measured by variableangle reflectometry, α= 47.3 ± 5.5 µm -1 and k= 0.48 ±0.05, and n=0.87 ±0.12.

Plunge needle recording techniques have provided valuable insights into transmural activation in cardiac tissue. Construction of plunge needles has been a costly and time intensive endeavor. Plunge needles constructed with standard printed circuit board (PCB) technology and methods are outlined. PCB plunge needles are less expensive in terms of raw materials and time required for construction than hypodermic stock or epoxy plunge needles. Tested PCB plunge needles recorded signals comparable to signals recorded by other plunge needles. PCB plunge needles provide an economical and rapid alternative to previously published techniques for plunge needle design.

This paper discusses the proposal to use an intermediate Martian atmospheric (IMA) structure as a partial solution to the difficulties associated with current full pressure spacesuit (FPS) designs. An IMA is similar to a regular pressurized space structure, except that its pressurant is carbo n dioxide from the Martian atmosphere instead of Earth standard air. Astronauts can work in such a structure needing only breathing gear for EVA equipment. Large volumes for workspace can be created in this manner without having to meet the exacting cons truction standards of a regular manned space vehicle. Design options for the assembly and pressurization of such large structures are considered. We explain the construction of a small intermediate atmospheric demonstrator that operates inside of a simul ated Martian atmosphere.

We have demonstrated that genistein (GEN) stimulates growth of estrogen-dependent breast tumors in vivo. In this study, we evaluated whether dietary GEN can act in an additive manner with low circulating levels of 17β-estradiol (E 2 ). We developed an E 2 delivery system using silastic implants that yield low circulating plasma E 2 levels similar to those observed in postmenopausal women. We inserted various concentrations of E 2 silastic implants (1:127, 1:63, 1:31, 1:15 and 1:7 = E 2 :cholesterol) and injected estrogen-dependent human breast cancer (MCF-7) cells into ovariectomized athymic mice. The E 2 implants tested (1:127-1:7) generated 30.1-101.6 pM E 2 in plasma, which is comparable to the E 2 levels observed in postmenopausal women. The E 2 implants stimulated MCF-7 tumor growth in a dose-dependent manner. We selected the 1:31 ratio of E 2 implant to evaluate if dietary GEN acts in an additive manner with low E 2 levels to influence the growth of MCF-7 tumors. Ovariectomized mice were divided into four groups: MCF-7 control, 500 ppm GEN, 1:31 E 2 , and 1:31 E 2 + 500 ppm GEN. At week 17, the average tumor sizes were 7.6, 32.1, 67.4 and 106.8 mm 2 for these groups, respectively (P < 0.05), demonstrating that 500 ppm GEN additively stimulated MCF-7 tumor growth in the presence of low levels of E 2 . In summary, we established a preclinical mouse model that results in E 2 blood concentrations similar to those found in postmenopausal women. Further, we observed that these concentrations regulate the growth rate of MCF-7 breast tumors. Using this model, we demonstrated that dietary GEN in the presence of low levels of circulating E 2 act in an additive manner to stimulate estrogen-dependent tumor growth in vivo. Results from this study suggest that consumption of products containing GEN may not be safe for postmenopausal women with estrogen-dependent breast cancer.

As applications for extreme ultraviolet (EUV) radiation have been identified, the demand for better optics has also increased. Thorium and thorium oxide thin films (19 to 61 nm thick) were RF-sputtered and characterized using atomic force microscopy (AFM), spectroscopic ellipsometry, low-angle x-ray diffraction (LAXRD), x-ray photoelectron spectroscopy (XPS), and x-ray absorption near edge structure (XANES) in order to assess their capability as EUV reflectors. Their reflectance and absorption at different energies were also measured and analyzed at the Advanced Light Source in Berkeley. The reflectance of oxidized thorium is reported between 2 and 32 nm at 5, 10, and 15 degrees from grazing. The imaginary component of the complex index of refraction, β, is also reported between 12.5 and 18 nm. Thin films of thorium were found to reflect better between 6.5 and 9.4 nm at 5 degrees from grazing than all other known materials, including iridium, gold, nickel, uranium dioxide, and uranium nitride. The measured reflectance does not coincide with reflectance curves calculated from the Center for X-Ray Optics (CXRO) atomic scattering factor data. We observe large energy shifts of up to 20 eV, suggesting the need for better film characterization and possibly an update of the tabulated optical constants.

elvin J Silverstein, MD, FACS, Abram Recht, MD, FASTRO, Michael D Lagios, MD, Ira J Bleiweiss, MD, eter W Blumencranz, MD, FACS, Terri Gizienski, MD, Steven E Harms, MD, FACR, Jay Harness, MD, FACS, oger J Jackman, MD, V Suzanne Klimberg, MD, FACS, Robert Kuske, MD, Gary M Levine, MD, ichael N Linver, MD, FACR, Elizabeth A Rafferty, MD, Hope Rugo, MD, Kathy Schilling, MD, ebu Tripathy, MD, Pat W Whitworth, MD, FACS, Shawna C Willey, MD, FACS

Uranium oxide and uranium nitride thin films reflect significantly more than all previously known/standard reflectors (e.g., nickel, gold, and iridium) for most of the 4-10 nm range at low angles of incidence. This work includes measurements of the EUV/soft x-ray (2-20 nm) reflectance of uranium-based thin films (~20 nm thick) and extraction of their optical constants (δ and β). We report the reflectances at 5, 10, and 15 degrees grazing incidence of air-oxidized sputtered uranium, reactively sputtered (O2) uranium oxide, and reactively sputtered (N2) uranium nitride thin films measured at Beamline 6.3.2 at the Advanced Light Source (ALS) at Lawrence Berkeley National Laboratory (LBNL). Additionally, we report optical constants of reactively sputtered uranium oxide at nine wavelengths from 4.6 to 17.5 nm derived from ALS angle-scan reflectance measurements. We also report optical constants of uranium nitride at 13 and 14 nm. We compare the reflectance of these uranium-compound thin films to gold, nickel (and nickel oxide), and iridium thin films from 2.5 to 11.6 nm. These metal thin films were chosen for comparison due to their wide use in EUV/soft x-ray applications as low-angle, thin-film reflectors. The uranium compounds can exhibit some surface oxidation in ambient air. There are important discrepancies between UO2’s and UN’s actual thin-film reflectance with those predicted from tabulated optical constants of the elemental constituents of the compounds. These differences are also demonstrated in the optical constants we report. Uranium-based optics applications have important advantages for zone plates, thin-film reflectors, and filters.