Conductivitylike Gilbert Damping due to Intraband Scattering in Epitaxial Iron.

Confirming the origin of Gilbert damping by experiment has remained a challenge for many decades, even for simple ferromagnetic metals. Here, we experimentally identify Gilbert damping that increases with decreasing electronic scattering in epitaxial thin films of pure Fe. This observation of conductivitylike damping, which cannot be accounted for by classical eddy-current loss, is in excellent quantitative agreement with theoretical predictions of Gilbert damping due to intraband scattering. Our results resolve the long-standing question about a fundamental damping mechanism and offer hints for engineering low-loss magnetic metals for cryogenic spintronics and quantum devices.

The prevalence and correlates of syphilis and HIV among homosexual and bisexual men in Shijiazhuang, China.

Bisexual men (men who have sex with men and women) are potential epidemiological bridges responsible for the spread of HIV and other sexually transmitted infections from men who have sex with men only to the heterosexual population. We aimed to estimate the prevalence of syphilis and HIV and the factors associated with syphilis infection among men who have sex with men and women and men who have sex with men only from Shijiazhuang, China. In 2011-2013, a cross-sectional cohort of 427 men who have sex with men was recruited by a snowball sampling method and tested for syphilis and HIV. Chi square and logistic regression were performed to identify syphilis risk factors. Among the 427 men who have sex with men, 71 (16.6%) cases were syphilis-positive and 16 cases (3.7%) were HIV-positive. The proportions of men who have sex with men and women and men who have sex with men only in the total sample were 31.4% and 68.6%, respectively. Men who have sex with men and women exhibited double the syphilis prevalence of men who have sex with men only and were more likely to practice insertive anal sex. Higher education level, being married, having more male partners, and both receptive and insertive anal sex roles were associated with syphilis among men who have sex with men and women. Residing in suburban areas, being married, being HIV positive, and an absence of desire to change sexual orientation were associated with syphilis among men who have sex with men only. Therefore, men who have sex with men and women represent an important sub-group in the syphilis epidemic and further interventions should be developed to reduce risk among different sub-sets of men who have sex with men.

Does a smaller tract in percutaneous nephrolithotomy contribute to less invasiveness? A prospective comparative study.

OBJECTIVES: To determine the systemic response to percutaneous nephrolithotomy (PCNL) and mini-PCNL (MPCNL) and evaluate whether MPCNL is less invasive than PCNL, as experimental studies suggest that the acute-phase reaction is proportional to surgery-induced tissue damage. METHODS: In all, 165 consecutive patients who had undergone MPCNL (93) or PCNL (72) were prospectively assessed. Blood samples were collected 24 hours before; during surgery; at the end of anesthesia; and 12, 24, and 36 hours after surgery. The extent of the systemic response to surgery-induced tissue trauma was measured, by assessing the levels of acute-phase markers tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), IL-10, C-reactive protein (CRP), and serum amyloid A (SAA), at all sampling times in all patients. RESULTS: No significant differences were observed between the 2 groups in preoperative variables. Baseline levels of TNF-alpha, IL-6, IL-10, CRP, and SAA were comparable in both groups. An increase was noted in TNF-alpha, IL-6, CRP, and SAA after surgery but no significant differences were assessed between MPCNL and PCNL during the entire period. IL-10 did not change at the different sampling times. CONCLUSIONS: Our data fail to demonstrate significant advantages of MPCNL in terms of reduced surgical trauma and associated invasiveness compared with standard PCNL based on the variables objectively measured in this study.

Tunable features of magnetoelectric transformers.

We have found that magnetostrictive FeBSiC alloy ribbons laminated with piezoelectric Pb(Zr,Ti)O(3) fiber can act as a tunable transformer when driven under resonant conditions. These composites were also found to exhibit the strongest resonant magnetoelectric voltage coefficient of 750 V/cm-Oe. The tunable features were achieved by applying small dc magnetic biases of -5

Prospective comparison of five mediators of the systemic response after high-intensity focused ultrasound and targeted cryoablation for localized prostate cancer.

OBJECTIVE: To evaluate whether high-intensity focused ultrasound (HIFU) is less invasive than targeted cryoablation of the prostate (TCAP), as experimental studies suggest that the acute-phase reaction is proportional to surgery-induced tissue damage. PATIENTS AND METHODS: Between May 2004 and December 2007, 127 consecutive patients undergoing HIFU (71) or TCAP (56) in our departments were assessed prospectively. Blood samples were collected 24 h before (T0), during surgery (T1), at the end of anaesthesia (T2), and at 12 (T3), 24 (T4) and 36 h after surgery (T5). The extent of the systemic response to surgery-induced tissue trauma was measured by assessing the levels of acute-phase markers tumour necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), IL-10, C-reactive protein (CRP) and serum amyloid A (SAA), at all sampling times in all patients. RESULTS: The median (interquartile range) age in the HIFU and TCAP groups was 70 (62-77) and 68 (59-75) years, respectively (P = 0.4). Baseline levels (T0) of TNF-alpha, IL-6, IL-10, CRP and SAA were comparable in both groups. The levels of all four markers increased during both procedures; the median values were higher for TCAP at T2 (P = 0.02, 0.001, <0.001 and 0.06), T3 (P < 0.001, 0.009, 0.003 and 0.001), T4 (P = 0.007, <0.001, 0.005 and <0.001) and T5 (P < 0.001, 0.004, <0.001 and 0.02), respectively. IL-6 was also higher for TCAP at T1 (P = 0.03). IL-10 did not change at the different sampling times. CONCLUSION: The tissue trauma and associated invasiveness of HIFU is less than that of TCAP, based on the variables objectively measured in this study.

Longitudinal and transverse magnetoelectric voltage coefficients of magnetostrictive/piezoelectric laminate composite: experiments.

Magnetostrictive Terfenol-D (Tb(x)Dy(1-x)Fe2) and piezoelectric (Pb(Zr(1-x)Ti(x))O3) magnetoelectric (ME) laminate composites have been investigated experimentally for various modes of operation: longitudinal magnetized/longitudinal polarized (L-L mode), transverse magnetized/longitudinal polarized (T-L mode), and transverse magnetized/transverse polarized (T-T mode) ME modes. We report their experimentally determined performance characteristics based on our previously developed equivalent circuits for these various modes. Predicted and experimental results are in agreement that the L-L mode laminates have enhanced ME effects, and that, under low or zero magnetic bias, the L-L mode ME voltage coefficients are up to a factor of 5-20x higher than those of the T-L mode or T-T mode laminates. The maximum ME voltage coefficient of the L-L mode laminates is over 86 mV/Oe under a bias of 500 Oe.

Giant magneto-electric effect in laminate composites.

It has been discovered that laminate composites of longitudinally magnetized magnetostrictive and transversely poled piezoelectric layers (a L-T laminate composite) have a giant magneto-electric (ME) effect under a low magnetic bias. The ME voltage coefficient is over 110 mV/Oe at a magnetic bias H = 500 Oe. This value is 5-10 times higher than that previously reported for transverse magnetized/transverse polarized (T-T) laminates of the same layer compositions at the same bias. In this paper, we also report the magneto-elasto-electric bieffect equivalent circuit of the L-T laminate composite and the corresponding theoretical formula of the magneto-electric voltage coefficient.

Longitudinal and transverse magnetoelectric voltage coefficients of magnetostrictive/piezoelectric laminate composite: theory.

This paper presents a novel, long-type of magnetostrictive and piezoelectric laminate composite design in which the layers are, respectively, magnetized/poled along their length axes, and a theory for modeling its behavior. Using piezoelectric and magnetostrictive constitutive equations, and an equation of motion, a magneto-elastoelectric bieffect equivalent circuit is developed. The circuit is used to predict the longitudinal and transverse magnetoelectric (ME) voltage coefficients of our Terfenol-D/Pb(Zr1-xTix)O3 laminate design. It is found that the longitudinal ME voltage coefficient is significantly higher (approximately 5x) than the transverse one, and that our new laminate design has significantly higher ME voltage coefficients under small applied direct current (DC) magnetic bias fields than designs reported previously by other groups. Experimental values were found to be coincidental with predicted ones.

A piezoelectric-sound-resonance cavity for hydrogen gas detection.

A new concept for hydrogen gas (H2) detection has been developed. This concept is based on a piezoelectric-sound-resonance cavity (PSRC). Detection uses sound resonance and the acoustic property differences of gases as a sensing mechanism in which there is a significant difference in the sound velocity and acoustic impedance between H2 and air. The PSRC sensor consists of two thin piezoelectric discs, separated by a small cavity. One disc excites a weak acoustic standing wave in the cavity, and the second senses the wave by monitoring the acoustic impedance characteristics of the cavity. Changes in H2 concentration result in a shift of the sound resonance state. Investigations of a PSRC prototype have demonstrated a sensitivity limit of <10 ppm, a fast response time approximately 1 second, and a signal (phase and voltage) in proportion to the change in H2 concentration (n) over the range of 10(-5) < n < 0.2. These performance characteristics are far superior to those of other methods.