Heat dissipation after nonanatomical lung resection using a laser is mainly due to emission to the environment: an experimental ex vivo study

Laser-directed resection of lung metastases is performed more frequently in recent years. The energy-loaded laser rays heat up the lung tissue, considerably. It is still unclear which mechanism is more important for tissue heat dissipation: the lung perfusion or the tissue emission. Therefore, we created a special experimental model to investigate the spontaneous heat dissipation after nonanatomical lung resection using a diode-pumped laser with a high output power. Experiments were conducted on paracardiac pig lung lobes (n = 12) freshly dissected at the slaughterhouse. Nonanatomical resection of lung parenchyma was performed without lobe perfusion in group 1 (n = 6), while group 2 (n = 6) was perfused at a physiological pressure of 25 cm H(2)O at 37 °C with saline via the pulmonary artery. For this, we used a diode-pumped neodymium-doped yttrium aluminum garnet (Nd:YAG) LIMAX® 120 laser (Gebrüder Martin GmbH & Co. KG, Tuttlingen, Germany) with a wavelength of 1,318 nm and a power output of 100 W. Immediately after completing laser resection, the lungs were monitored with an infrared camera (Type IC 120LV; Trotec, Heinsberg, Germany) while allowed to cool down. The resection surface temperature was taken at 10-s intervals and documented in a freeze-frame until a temperature of 37 °C had been reached. The temperature drop per time unit was analyzed in both groups. Immediately after laser resection, the temperature at the lung surface was 84.33 ± 8.08 °C in group 1 and 76.75 ± 5.33 °C in group 2 (p = 0.29). Group 1 attained the final temperature of 37 °C after 182.95 ± 53.76 s, and group 2 after 121.70 ± 16.02 s (p = 0.01). The temperature drop occurred exponentially in both groups. We calculated both groups’ decays using nonlinear regression, which revealed nearly identical courses. The mean time of tissue temperature of >42 °C, as a surrogate marker for tissue damage, was 97.14 ± 26.90 s in group 1 and 65.00 ± 13.78 s in group 2 (p = 0.02). Heat emission to the environment surpasses heat reduction via perfusion in nonanatomically laser-resected lung lobes. In developing a cooling strategy, a topical cooling method would be promising

Constraining Galaxy Haloes from the Dispersion and Scattering of Fast Radio Bursts and Pulsars

Fast radio bursts (FRBs) can be scattered by ionized gas in their local environments, host galaxies, intervening galaxies along their lines-of-sight, the intergalactic medium, and the Milky Way. The relative contributions of these different media depend on their geometric configuration and the internal properties of the gas. When these relative contributions are well understood, FRB scattering is a powerful probe of density fluctuations along the line-of-sight. The precise scattering measurements for FRB 121102 and FRB 180916 allow us to place an upper limit on the amount of scattering contributed by the Milky Way halo to these FRBs. The scattering time $\tau\propto(\tilde{F} \times {\rm DM}^2) A_\tau$, where ${\rm DM}$ is the dispersion measure, $\tilde{F}$ quantifies electron density variations with $\tilde{F}=0$ for a smooth medium, and the dimensionless constant $A_\tau$ quantifies the difference between the mean scattering delay and the $1/e$ scattering time typically measured. A likelihood analysis of the observed scattering and halo DM constraints finds that $\tilde{F}$ is at least an order of magnitude smaller in the halo than in the Galactic disk. The maximum pulse broadening from the halo is $\tau\lesssim12$ $\mu$s at 1 GHz. We compare our analysis of the Milky Way halo with other galaxy haloes by placing limits on the scattering contributions from haloes intersecting the lines-of-sight to FRB 181112 and FRB 191108. Our results are consistent with haloes making negligible or very small contributions to the scattering times of these FRBs.Comment: 14 pages, 6 figures, accepted to Ap

Mothers of Men: the A&M Mothers' Clubs and coeducation

Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to [email protected], referencing the URI of the item.Includes bibliographical references (leaves 36-38).In 1933 the Texas A&M Mothers' Clubs sent petitions and letters to the Board of Advisors requesting that Texas A&M University retain its all-male status. While most studies of women opposed to equal rights center on the women maintaining power through their feminine sphere of influence, the mothers of the A&M Mothers' Clubs at this time were more concerned with being defined as good mothers by maintaining their sons' power. My research of the action of the A&M Mothers' Clubs focuses on two main aspects: a historical perspective and the social construction of motherhood. In 1933, the United States faced the worst of the Great Depression, with no end in sight. Every spot a woman had in either education or the workforce was considered one less spot for a man. Gender, or the social construct defining roles for men and women, at the time dictated that men become wage earners and support a family. It was very important in a time of high unemployment that men find a way to fulfill their roles. Men spent most of their time outside of the home, and mothers stayed home with their children. Society feared that males raised by mothers would become too feminine, so mothers were advised to teach their sons masculinity, or their proper gender role. The social construction of motherhood also greatly changed during the 1910s when these women were raising their sons. Society began to treat motherhood as a profession, and like all professions of the times, there was a right way and a wrong way to perform your job. Known as scientific motherhood, mothers during this time were advised exactly how to raise a child. Direct participation in a child's education was also common, with Parent Teachers' Associations springing up across the country. Psychologically, mothers began to bear the brunt of disorders. More and more problems were attributed to the effects of bad mothering upon a child, and mothers strove to earn the label of good mother. The Victorian era glorification of the mother was slowly disappearing when these women entered motherhood. When these forces combined to work on mothers from the 1910s to 1930s, women cared about the status of their sons. In an effort to maintain their sons' gender role of provider, secure him a spot in education, and be an involved mother, the mothers of the Texas A&M Mothers' Clubs worked to maintain the all-male status of Texas A&M University. Like other women opposed to equal rights, these women organized themselves into an effective group, but unlike those women, the mothers of the A&M Mothers' Clubs strove to maintain their sons' power, and not their own

Radio Scattering Horizons for Galactic and Extragalactic Transients

Radio wave scattering can cause severe reductions in detection sensitivity for surveys of Galactic and extragalactic fast ($\sim$ms duration) transients. While Galactic sources like pulsars are subject to scattering in the Milky Way interstellar medium (ISM), extragalactic fast radio bursts (FRBs) can also experience scattering in their host galaxies and other galaxies intervening their lines-of-sight. We assess Galactic and extragalactic scattering horizons for fast radio transients using a combination of NE2001 to model the dispersion measure (DM) and scattering time ($\tau$) contributed by the Milky Way, and independently constructed electron density models for other galaxies' ISMs and halos that account for different galaxy morphologies, masses, densities, and strengths of turbulence. For FRB source redshifts $z_{\rm s} \lesssim 1$, an all-sky, isotropic FRB population has values of $\tau$ ranging between $\sim 1\ \mu$s and$\sim 2$ms at 1 GHz (observer frame) that are dominated by host galaxies. For a hypothetical, high-redshift ($z_{\rm s}\sim5$) FRB population,$\tau$ranges from$\sim 0.01 - 100$s of ms at 1 GHz, and is largely dominated by intervening galaxies. About$20\%$of these high-redshift FRBs are predicted to have$\tau > 5$ms at 1 GHz (observer frame), and$\gtrsim 40\%$of FRBs between$z_{\rm s} \sim 0.5 - 5$are predicted to have$\tau \gtrsim 1$ms for$\nu\leq 800$ MHz. The percentage of FRBs selected against from scattering may be substantially larger because our scattering predictions are conservative compared to localized FRBs, and if circumgalactic turbulence causes density fluctuations larger than those observed from nearby halos.Comment: 24 pages, 14 figures, submitted to Ap

Investigation of the Dzyaloshinskii-Moriya interaction and room temperature skyrmions in W/CoFeB/MgO thin films and microwires

Recent studies have shown that material structures, which lack structural inversion symmetry and have high spin-orbit coupling can exhibit chiral magnetic textures and skyrmions which could be a key component for next generation storage devices. The Dzyaloshinskii-Moriya Interaction (DMI) that stabilizes skyrmions is an anti-symmetric exchange interaction favoring non-collinear orientation of neighboring spins. It has been shown that material systems with high DMI can lead to very efficient domain wall and skyrmion motion by spin-orbit torques. To engineer such devices, it is important to quantify the DMI for a given material system. Here we extract the DMI at the Heavy Metal (HM) /Ferromagnet (FM) interface using two complementary measurement schemes namely asymmetric domain wall motion and the magnetic stripe annihilation. By using the two different measurement schemes, we find for W(5 nm)/Co20Fe60B20(0.6 nm)/MgO(2 nm) the DMI to be 0.68 +/- 0.05 mJ/m2 and 0.73 +/- 0.5 mJ/m2, respectively. Furthermore, we show that this DMI stabilizes skyrmions at room temperature and that there is a strong dependence of the DMI on the relative composition of the CoFeB alloy. Finally we optimize the layers and the interfaces using different growth conditions and demonstrate that a higher deposition rate leads to a more uniform film with reduced pinning and skyrmions that can be manipulated by Spin-Orbit Torques