Use of hyperpolarized [1-C]pyruvate and [2-C]pyruvate to probe the effects of the anticancer agent dichloroacetate on mitochondrial metabolism in vivo in the normal rat

Development of hyperpolarized technology utilizing dynamic nuclear polarization has enabled the measurement of ¹³C metabolism in vivo at very high signal-to-noise ratio (SNR). In vivo mitochondrial metabolism can, in principle, be monitored with pyruvate, which is catalyzed to acetyl-CoA via pyruvate dehydrogenase (PDH). The purpose of this work was to determine whether the compound sodium dichloroacetate (DCA) could aid the study of mitochondrial metabolism with hyperpolarized pyruvate. DCA stimulates PDH by inhibiting its inhibitor, pyruvate dehydrogenase kinase. In this work, hyperpolarized [1-¹³C]pyruvate and [2-¹³C]pyruvate were used to probe mitochondrial metabolism in normal rats. Increased conversion to bicarbonate (+ 181±69%, P=.025) was measured when [1-¹³C]pyruvate was injected after DCA administration, and increased glutamate (+ 74±23%, P=.004), acetoacetate (+ 504±281%, P=.009) and acetylcarnitine (+ 377±157%, P=.003) were detected when [2-¹³C]pyruvate was used.     

Magic angle effect in magnetic resonance imaging of the Achilles tendon and enthesis

Collagen fibers in tendons and entheses are highly ordered. The protons within the bound water are subject to dipolar interactions whose strength depends on the orientation of the fibers to the static magnetic field B₀. Clinical pulse sequences have been employed to investigate this magic angle effect of the Achilles tendon, but only limited to imaging appearance with a signal void at many angular orientations due to its short T2. Here we investigated the magic angle effect of the Achilles tendons and entheses on a clinical 3-T scanner using clinical sequences as well as an ultrashort TE sequence with a minimal TE of 8 μs. Qualitative and quantitative investigation of the angular-dependent imaging appearance, T1 and T2* values were performed on five ankle specimens. There was a significant increase in signal intensity for all pulse sequences near the magic angle. Mean T2* for tendon increased from 1.94±0.28 ms at 0° relative to the B₀ field to 15.25±2.13 ms at 55°, and mean T1 increased from 598±37 ms at 0° to 621±44 ms at 55°. There was less magic angle effect for enthesis whose mean T2* increased from 4.12±0.37 ms at 0° to 12.46±1.78 ms at 55°, and mean T1 increased from 685±41 ms at 0° to 718±56 ms at 55°.     

Pressure Broadening of the Rotational Line of Oxygen at 425 GHz

The pressure broadening of the ¹⁶O¹⁶O rotational line (N, J)=(3, 2)-(1, 2) at 425 GHz by oxygen and nitrogen perturbers at room temperatures have been reported. A spectrometer with BWO and acoustic detector was employed with a double magnetically shielded cell. The signal-to-noise ratio on the line was about 200-250 for self-broadening and about 100 for broadening by N₂ measurements. The pressure-broadening parameters of the line at room temperature (23±0.5°C) were measured as 2.19±0.01 MHz/Torr for self-broadening and 2.215±0.02 MHz/Torr for broadening by nitrogen. Values of these parameters significantly (by about 25%) differ from ones previously measured by H. M. Pickett, E. A. Cohen, and D. E. Brinza, (Astrophys. J.248, L49-L51 (1981)). The results of the present work show the necessity for correction of broadening parameters of this line for the purpose of Earth atmosphere remote sensing. The central frequency of the transition (N, J)=(3, 2)-(1, 2) was measured as 424 763.023±0.020 MHz.     

The effect of high intensity focused ultrasound on luciferase activity on two tumor cell lines in vitro, under the control of a CMV promoter

In this study, we compared the effect of high intensity focused ultrasound (HIFU) and thermal stress on the luciferase activity, controlled by a cytomegaly virus (CMV) promoter in an in vitro model using two tumor cell lines (M21, SCCVII). HIFU was applied in a pulsed-wave mode with increasing voltage at constant pulse duration, or thermal stress was delivered over a range of temperatures (36-52 °C) for 5 min. The resulting luciferase activity was measured in live cells using a cooled CCD camera. Luciferase activity was measured at set time intervals over a total of 48 h post-stress. Compared to baseline, the luciferase activity of the M21 tumor cell line when exposed to HIFU was approximately 54.2 ± 67.5% (p < 0.01) higher at a temperature of 42 °C, and approximately 52.9±128.5% (p < 0.01) higher at 44 °C. In the SCCVII tumor cell line, the luciferase activity after HIFU application was 55.4 ± 66.6% (p < 0.01) higher compared to baseline at a temperature of 42 °C. The M21 and SCCVII tumor cell line when exposed to thermal stress alone did not increase the luciferase activity. M21 and SCCVII tumor cells exposed to HIFU showed a maximum decrease in cell viability to 45.3 ± 7.5% and 10.3 ± 7.5%, respectively, and when exposed to thermal stress to 85.3 ± 3.5% and 20.4 ± 6.5%, respectively, compared to the untreated control. In M21 and SCCVII cells exposed to HIFU, free radicals could be detected using the dichlorofluorescein dye. Our findings demonstrate that HIFU can enhance the luciferase activity controlled by a CMV promoter. However it also has a higher damaging effect on the cells.     

Reflector-based phase calibration of ultrasound transducers

Recently, the measurement of phase transfer functions (PTFs) of piezoelectric transducers has received more attention. These PTFs are useful for e.g. coding and interference based imaging methods, and ultrasound contrast microbubble research. Several optical and acoustic methods to measure a transducer’s PTF have been reported in literature. The optical methods require a setup to which not all ultrasound laboratories have access to. The acoustic methods require accurate distance and acoustic wave speed measurements. A small error in these leads to a large error in phase, e.g. an accuracy of 0.1% on an axial distance of 10 cm leads to an uncertainty in the PTF measurement of ±97° at 4 MHz. In this paper we present an acoustic pulse-echo method to measure the PTF of a transducer, which is based on linear wave propagation and only requires an estimate of the wave travel distance and the acoustic wave speed. In our method the transducer is excited by a monofrequency sine burst with a rectangular envelope. The transducer initially vibrates at resonance (transient regime) prior to the forcing frequency response (steady state regime). The PTF value of the system is the difference between the phases deduced from the transient and the steady state regimes. Good agreement, to within 7°, was obtained between KLM simulations and measurements on two transducers in a 1-8 MHz frequency range. The reproducibility of the method was ±10°, with a systematic error of 2° at 1 MHz increasing to 16° at 8 MHz. This work demonstrates that the PTF of a transducer can be measured in a simple laboratory setting.     

Investigation of in-plane orientation characteristics for Bi-2212/MgO thin films fabricated by the MOD method

We investigated the characteristics of in-plane orientation for c-axis-oriented Bi-2212 thin films on MgO substrates, fabricated by the metal–organic decomposition (MOD) method. Bi-2212/MgO films were annealed using a 2-step heat treatment. The dominant rotation angle of the Bi-2212 film was 45° ([1 0 0] of Bi-2212 // [1 1 0] of MgO) for a precursor film fabricated at 500 °C and fired at 840 °C for 0 min or 30 min. However, after firing for 1 h the ?-scanning signal indicating the 45° angle became smaller and the signal representing an angle of about ±12° ([1 0 0] of Bi-2212 // [5 1 0] of MgO) became larger. After firing for 3 h, this ±12° signal became dominant. The extent of the 45° angle’s shift to ±12° increased with increasing firing time. On the other hand, when the precursor film was fabricated at 430 °C, signals indicating angles of 0°, ∼±12°, and 45° were observed after firing for 30 min. The rotation angle depended on the precursor-fabrication temperature when the precursor film was fired at 840 °C for 0 min or 30 min.     

In-Situ Intrinsic Interface Strength Measurement at Elevated Temperatures and its Relationship to Interfacial Structure

A previously developed laser spallation technique has been modified to measure the tensile strength of thin film interfaces in-situ at temperatures up to 1100°C. Tensile strengths of Nb/A-plane sapphire, FeCrAl/A-plane sapphire and FeCrAlY/A-plane sapphire were measured up to 950°C. The measured strengths at high temperatures were substantially lower compared with their corresponding strengths at ambient temperature. For example, at 850°C, the interface tensile strength for the Nb/sapphire (151 ± 17 MPa), FeCrAl/sapphire (62 ± 8 MPa) and FeCrAlY/sapphire (82 ± 11 MPa) interface systems were lower by factors of approximately, 3, 5, and 8, respectively, over their corresponding ambient values. These results underscore the importance of using such in-situ measured values under operating conditions as the failure criterion in any life prediction or reliability models of such coated systems where local interface temperature excursions are expected. The results on alloy film interfaces also demonstrate that the presence of Y increases the strength of FeCrAl/Al₂O₃ interfaces.     

The microwave spectra of cyanamide: Conclusions from a transitions

Microwave spectra have been observed for the species NH₂CN, NHDCN, ND₂CN, ¹⁵NH₂CN, NH₂C¹⁵N, ¹⁵ND₂CN and ND₂C¹⁵N. The nonplanar nature of the molecule is confirmed and the following structural parameters obtained N₁N₂ = 2.506 ± 0.002 Å, N₁C = 1.346 ± 0.005 Å, CN₂ = 1.160 ± 0.005 Å, N₁H = 1.001 ± 0.015 Å, HN?₁H = 113°31′ ± 2°, out of plane angle (see text) = 37°58′ ± 1°. (N₁ is the amino nitrogen atom and N₂ that the cyanide group.)     

Measurements of the diffusion parameters in diphenyl at temperatures from 20 °C to 170 °C

Diffusion coefficient, mean life time of thermal neutrons, coefficient of diffusion cooling and diffusion length in diphenyl at temperatures 20°, 40°, 60°, 80°, 110°, 140° and 170° C were measured by the pulse method. Their dependence on the temperature of diphenyl was deduced in an analytic form and the change of the neutron transport length was determined experimentally. No discontinuity of the diffusion coefficient at the melting point of diphenyl apart from that caused by density change was observed. The energy exchange cross sectionM ₂ is practically independent of temperature in the range from 20 °C to 170 °C and the deduced microscopic absorption cross section for hydrogen equals 337±2 millibarns. The thermalization of neutrons in diphenyl proceeds more slowly than in water and neutrons loose their energy predominantly by interaction with the C—H group of the diphenyl molecule.We are indebted to Mr. J.Jadavan and Mr. J.Jirou for their technical assistance during the measurements and setting up the measuring apparatus.     

Electrical properties of plastically deformed n-type InSb

The conductivity and Hall effect have been measured between 78 ° and 295 ° K for n-InSb plastically deformed by uniaxial compression at 150 °, 200 °, 250 °, and 300 ° C. The sharp fall in the conductivity and the rise in the Hall coefficient are explained by trapping and scattering of carriers at dislocations and by scattering at point defects. Hole conduction occurs at low temperatures in specimens deformed 2.3% at 300 ° C. All deformed n-type specimens alter their low-temperature conductivity type after 3 hr at 300 ° C.     

Evaluation of the dosimetric characteristics of a radiophotoluminescent glass dosimeter for high-energy photon and electron beams in the field of radiotherapy

We aimed to evaluate the suitability of a glass dosimeter (GD) for high-energy photon and electron beams in experimental and clinical use, especially for radiation therapy. We examined the expanded dosimetric characteristics of GDs including dose linearity up to 500 Gy, uniformity among GD lots and for individual GDs, the angular dependence, and energy dependence of 4 therapeutic x-ray qualities. In addition, we measured the dosimetric features (dose linearity, uniformity, angular dependence, and energy dependence) of the GD for electron beams of 10 different electron energy qualities. All measurements with the exception of dose linearity for photon beam were performed in a water phantom. For high-energy photon beams, dose linearity has a linear relationship for a dose ranging from 1 to 500 Gy with the coefficient of determination; R² of 0.998. The uniformity of each GD of dose measurements was within ±0.5% for four GD lots and within ±1.2% for 80 GDs. In terms of the effects of photon beam angle, lower absorbed doses of within 1.0% were observed between 60° and 105° than at 90°. The GD energy dependence of 4 photon beam energy qualities was within ±2.0%. On the other hand, the result of the dose linearity for high-energy electron beams showed well fitted regression line with the coefficient of determination; R² of 0.999 between 6 and 20 MeV. The uniformity of GDs exposed to the nominal electron energies 6, 9, 12, 16, and 20 MeV was ±1.2%. In terms of the angular dependence to electron beams, absorbed doses were within 2.0% between 60° and 105° than at 90°. In evaluation of the energy dependence of the GD at nominal electron energies between 5 and 20 MeV, we obtained responses between 1.1% and 3.5% lower than that for a cobalt-60 beam. Our results show that GDs can be used as a detector for determining doses when a high-energy photon beam is used, and that it also has considerable potential for dose measurement of high-energy electron beam.     

Diffusion of Al in ion-implanted α-Zr and α-Hf

The diffusion of Al in the group IVa metals Zr and Hf has been studied for the first time in the temperature ranges 600°–800°C (Zr) and 750°–900°C (Hf) using ion-beam techniques. Diffusion couples were created by ion-implantation. The time-dependent diffusion profiles were monitored by the use of the Nuclear Resonance Broadening (NRB) technique. The linear Arrhenius plots extracted from the measured diffusivities indicate that the diffusivity of implanted Al in Zr and Hf can be described by the activation energyQ=2.9±0.2eV and 3.7±0.3eV and the pre-exponential factorD ₀=17±42cm²/s and 170±600cm²/s, respectively.     

Intra-operative acoustic hemostasis of liver: production of a homogenate for effective treatment

Objective: We have shown that High-Intensity Focused Ultrasound (HIFU) can effectively control bleeding from injuries to solid organs such as liver, spleen, and lung. Achievement of hemostasis was augmented when a homogenate of tissue and blood was formed. The objective of this study was to investigate quantitatively the effect of homogenate production on HIFU application time for hemostasis. Possible mechanisms involved in homogenate production were also studied.Methods: Ten anesthetized rabbits had laparotomy and liver exposure. Liver incisions, 15-25 mm long and 3-4 mm deep, were made followed immediately by HIFU application. Two electrical powers of 80 and 100 W corresponding to focal acoustic intensities of 2264 and 2829 W/cm², respectively were used. Tissue and homogenate temperatures were measured. Smear and histological tissue sample analysis using light microscopy were performed.Results: In treatments with homogenate formation, hemostasis was achieved in 76 ± 1.3 s (Mean ± Standard Error Mean: SEM) at 80 W. In treatments without homogenate formation (at 80 W), hemostasis was achieved in 106 ± 0.87 s. At 100 W, hemostasis was achieved in 46 ± 0.3 s. The time required for homogenate formation, at 80 and 100 W were 60 ± 2.5 and 23 ± 0.3 s, respectively. The homogenate temperature was 83 °C (SEM 0.6 °C), and the non-homogenate tissue temperature at the treatment site was 60 °C (SEM 0.4 °C). The smear and histological analysis showed significant blood components and cellular debris in the homogenate, with some intact cells.Conclusion: The HIFU-induced homogenate of blood and tissue resulted in a statistically significant shorter HIFU application time for hemostasis. The incisions with homogenate had higher temperatures as compared to incisions without homogenate. Further studies of the correlation between homogenate formation and temperature must be done, as well as studies on the long-term effects of homogenate in achieving hemostasis.     

Diffusion of nitrogen in ion-implanted chromium and tungsten

The diffusion of N in the group VI B metals Cr and W has been studied in the previously uninvestigated temperature ranges 300°–550 °C (Cr) and 600°–800 °C (W) using ion-beam techniques. Diffusion couples were created by ion-implantation. The timedependent diffusion profiles were monitored by the use of the Nuclear Resonance Broadening (NRB) technique. The linear Arrhenius plots extracted from the measured diffusivities indicate that the diffusivity of implanted N in Cr and W can be described by the activation energyQ=1.39±0.06 eV and 2.32±0.16 eV and the pre-exponential factorD ₀=(7.0±7.2)×10^–4cm^2/s and 4.3±8.3cm^2/s, respectively. The solubilities of N in Cr and W from the implanted distributions were found to deviate from those obtained using conventional metallographical methods.     

Measurements of long-term changes in atmospheric OCS (carbonyl sulfide) from infrared solar observations

Multi-decade atmospheric OCS (carbonyl sulfide) infrared measurements have been analyzed with the goal of quantifying long-term changes and evaluating the consistency of the infrared atmospheric OCS remote-sensing measurement record. Solar-viewing grating spectrometer measurements recorded in April 1951 at the Jungfraujoch station (46.5°N latitude, 8.0°E longitude, 3.58 km altitude) show evidence for absorption by lines of the strong ν₃ band of OCS at 2062 cm⁻¹. The observation predates the earliest previously reported OCS atmosphere remote-sensing measurement by two decades. More recent infrared ground-based measurements of OCS have been obtained primarily with high-resolution solar-viewing Fourier transform spectrometers (FTSs). Long-term trends derived from this record span more than two decades and show OCS columns that have remained constant or have decreased slightly with time since the Mt. Pinatubo eruption, though retrievals assuming different versions of public spectroscopic databases have been impacted by OCS ν₃ band line intensity differences of ∼10%. The lower stratospheric OCS trend has been inferred assuming spectroscopic parameters from the high-resolution transmission (HITRAN) 2004 database. Volume mixing ratio (VMR) profiles measured near 30°N latitude with high-resolution solar-viewing FTSs operating in the solar occultation mode over a 22 years time span were combined. Atmospheric Trace MOlecucle Spectroscopy (ATMOS) version 3 FTS measurements in 1985 and 1994 were used with Atmospheric Chemistry Experiment (ACE) measurements during 2004-2007. Trends were calculated by referencing the measured OCS VMRs to those of the long-lived constituent N₂O to account for variations in the dynamic history of the sampled airmasses. Means and 1-sigma standard deviations of VMRs (in ppbv, or 10⁻⁹ per unit air volume) averaged over 30-100 hPa from measurements at 25-35°N latitude are 0.334±0.089 ppbv from 1985 (ATMOS Spacelab 3 measurements), 0.297±0.094 ppbv from 1994 ATLAS 3 measurements, 0.326±0.074 ppbv from ACE 2004 measurements, 0.305±0.096 ppbv from ACE 2005 measurements, 0.328±0.074 from ACE 2006 measurements, and 0.305±0.090 ppbv from ACE measurements through August 2007. Assuming these parameters, we conclude that there has been no statistically significant trend in lower stratospheric OCS over the measurement time span. We discuss past measurement sets, quantify the impact of changes in infrared spectroscopic parameters on atmospheric retrievals and trend measurements, and discuss OCS spectroscopic uncertainties of the current ν₃ band parameters in public atmospheric databases.     

Loss reduction in silicon nanophotonic waveguide micro-bends through etch profile improvement

Single mode silicon photonic wire waveguides allow low-loss sharp micro-bends, which enables compact photonic devices and circuits. The circuit compactness is achieved at the cost of loss induced by micro-bends, which can seriously affect the device performance. The bend loss strongly depends on the bend radius, polarization, waveguide dimension and profile. In this paper, we present the effect of waveguide profile on the bend loss. We present waveguide profile improvement with optimized etch chemistry and the role of etch chemistry in adapting the etch profile of silicon is investigated. We experimentally demonstrate that by making the waveguide sidewalls vertical, the bend loss can be reduced up to 25% without affecting the propagation loss of the photonic wires. The bend loss of a 2 μm bend has been reduced from 0.039dB/90° bend to 0.028dB/90° bend by changing the sidewall angle from 81° to 90°, respectively. The propagation loss of 2.7 ± 0.1dB/cm and 3 ± 0.09dB/cm was observed for sloped and vertical photonic wires respectively was obtained.     

Reinvestigation of pressure broadening parameters at 60-GHz band and single 118.75 GHz oxygen lines at room temperature

Low pressure measurements of broadening parameters of the 118.75 GHz fine structure line of oxygen molecule have been made by a BWO-based spectrometer with acoustic detector (RAD) at room temperature. Pressure broadening parameters were obtained for the buffer gases O₂, N₂, Ne, He, Ar, H₂O, CO₂, and CO and have the following values 2.23 ± 0.01, 2.245 ± 0.02, 1.375 ± 0.02, 1.62 ± 0.03, 2.005 ± 0.02, 2.52 ± 0.04, 2.66 ± 0.08, and 2.31 ± 0.05 MHz/Torr, respectively. Measured central frequency is 118 750.340 ± 0.007 MHz. The central frequencies and broadenings by O₂ and N₂ of fine structure lines 1⁺, 5⁻, 7⁺, 11⁺, and 15⁻ belonging to the 60-GHz band are also measured. Comparison of previous and recent data on electronic, rotational, and fine structure lines broadenings reveals their close values (within 10%) and dependencies on corresponding rotational quantum numbers for these different oxygen spectra stretching from millimeter through submillimeter up to the optical bands. Such similarity could be used for estimation of the broadenings of not measured yet oxygen lines.     

Novel strategy in increasing stability and corrosion resistance for super-hydrophobic coating on aluminum alloy surfaces

A novel super-hydrophobic coating was prepared by chemical modification on the anodized aluminum alloy surface. The surface structure was characterized by water contact angle measurement, scanning electron microscopy (SEM), and the composition was measured by X-ray photoelectron spectroscopy (XPS). The corrosion behavior of the super-hydrophobic coating was evaluated by the polarization curve and the electrochemical impedance spectroscopy (EIS). It was found that the static water contact angle on the surface of super-hydrophobic coating was as high as 167.7 ± 1.2°, and the sliding angle was 5°. The super-hydrophobic coating resulted in excellent corrosion resistance property and the super-hydrophobic coating showed a good stability.     

The microwave spectrum and structure of chlorine isocyanate

The microwave spectra of three isotopic species of chlorine isocyanate, ClNCO, have been measured in the frequency region 8–37 GHz. Spectra have been observed for molecules in both the ground and excited vibrational states, and have yielded values for the rotational constants, inertial defects, centrifugal distortion constants, and nuclear quadrupole coupling constants for both chlorine and nitrogen. The molecule has been shown to be planar, with the following internuclear parameters: fx547-1 < (NCO) = 171° 24′ ± 1° 30′, with Cl and O trans. The principal values of the chlorine nuclear quadrupole coupling tensor were calculated, and were found to be consistent with the derived structure.     

Resolution of discrepancy between backward angle cross-section data for neutron-deuteron elastic scattering

High-accuracy differential cross-section data for neutron-deuteron elastic scattering at centre-of-mass backward angles in the range from 140° to 178° have been measured to accuracies better than ±3% for incident neutron energies of 8.0, 10.0, and 14.0 MeV. The measurements were made by detection of the recoil deuterons and protons from a mixed CD₂-CH₂ foil. The new data are compared to existing data and to three-nucleon calculations with the Bonn-B nucleon-nucleon potential. We conclude that the present measurements unambiguously resolve the discrepancies among previously reported data of the same type.