Hi-Z Technology (United States)

Vascular smooth muscle cells (VSMCs) undergo phenotypic changes during the development of aortic aneurysm and dissection (AAD). Metabolism shifts from oxidative phosphorylation to glycolysis. Recent studies suggest that epigenetics plays a crucial role in AAD. The epigenetic regulation of histone lactylation was analyzed in the aorta of patients with aortic aneurysm and in a murine model of AAD. Histone lactylation was also studied in VSMCs treated with angiotensin II. The epigenetic pathway involving H4K16 lactylation (H4K16la) was explored in vitro and in vivo. To examine the role of H4K16la in AAD formation, mice lacking Pdk1 or Kat7 in VSMCs were created. Mice were treated with pharmacological inhibitors of Pdk1 or Kat7. The levels of blood lactate, aortic lactate, and aortic H4K16la were compared between patients with aortic aneurysm and controls. Histone lactylation (H4K16la) was increased in the aortic tissues of patients with AAD and mice. Enhanced histone lactylation was linked to increased pyruvate dehydrogenase kinase 1 (PDK1) transcription, which accelerated lactate production in VSMCs. A positive feedback loop was identified involving H4K16la, PDK1, and lactate; this pathway alters the metabolism and phenotype of VSMCs. KAT7 (lysine acetyltransferase 7) was found to be a histone lactyltransferase for histone lactylation in VSMCs. Genetic or pharmacological inhibition of PDK1 or KAT7 decreased AAD injury by disrupting the H4K16la/PDK1/lactate pathway. Patients with AAD have elevated lactate in blood and aortic tissues and elevated H4K16la in aortic tissues compared with control patients. Histone lactylation changes the metabolism and phenotype of VSMC in AAD. Inhibition of PDK1 or KAT7 may be a novel approach to treat or prevent AAD.

(Abstracted from Lancet 2024;403:1341–1350) Prognosis for locally advanced cervical cancer is poor, with 5-year progression-free survival (PFS) and overall survival ranging from 47% to 80%. For the past several decades, treatment has included external beam radiotherapy with concurrent chemotherapy followed by brachytherapy, and novel therapeutic options are needed.

<p>Studying the amount, variety, and distribution of microscale particles and plankton at the global scale at different times and seasons is very important to understand ocean environments, and by reference, the global environment. It is important to image them in their natural habitats. Many optical techniques have been developed to meet this requirement. Most techniques suffer from one or another drawbacks, such as limited depth-of-field or low volume. Digital holography is an advanced optical imaging technique to image micro-objects, and it provides high-resolution recording, large depth-of-field and recording volume, and 3D viewing and tracking. This paper describes basic principles of in-line digital holography and provides common image processing methods. Four submersible digital holographic cameras, eHoloCam, RamaCam, weeHoloCam, and LISST-Holo, are introduced, as well as their image processing software. At the end, some limitations and challenges in the underwater holographic imaging systems are mentioned, and some possible solutions are discussed. </p>

Retinal parameters could reflect systemic vascular changes. With the advances of deep learning technology, we have recently developed an algorithm to predict retinal age based on fundus images, which could be a novel biomarker for aging and mortality. Therefore, we aim to investigate associations of retinal age gap with arterial stiffness index and incident cardiovascular disease (CVD). A deep learning model was trained based on 19 200 fundus images of 11 052 participants without any medical history at baseline to predict the retinal age. Retinal age gap (retinal age predicted minus chronological age) was generated for the remaining 35 917 participants. Regression models were used to assess the association between retinal age gap and arterial stiffness index. Cox proportional hazards regression models and restricted cubic splines were used to explore the association between retinal age gap and incident CVD. We found each 1-year increase in retinal age gap was associated with increased arterial stiffness index (β=0.002 [95% CI, 0.001-0.003]; P<0.001). After a median follow-up of 5.83 years (interquartile range: 5.73-5.97), 675 (2.00%) developed CVD. In the fully adjusted model, each 1-year increase in retinal age gap was associated with a 3% increase in the risk of incident CVD (hazard ratio=1.03 [95% CI, 1.01-1.06]; P=0.014). In the restricted cubic splines analysis, the risk of incident CVD increased significantly when retinal age gap reached 1.21 (hazard ratio=1.05 [95% CI, 1.00-1.10]; P-overall <0.0001; P-nonlinear=0.0681). We found that retinal age gap was significantly associated with arterial stiffness index and incident CVD events, supporting the potential of this novel biomarker in identifying individuals at high risk of future CVD events.

The interpretation of the radiologic response of bevacizumab-treated patients with recurrent high-grade gliomas represents a unique challenge. Delayed-contrast MR imaging was recently introduced for calculating treatment-response-assessment maps in patients with brain tumors, providing clear separation between active tumor and treatment effects. We studied the application of standard and delayed-contrast MR imaging for assessing and predicting the response to bevacizumab. Twenty-four patients with recurrent high-grade gliomas were scanned before and during bevacizumab treatment by standard and delayed-contrast MR imaging. The mean change in lesion volumes of responders (overall survival, ≥1 year) and nonresponders (overall survival, <1 year) was studied. The lesion volumes at baseline and the changes in lesion volumes 1 month after treatment initiation, calculated from standard and delayed-contrast MRIs, were studied as possible predictors of outcome. In scans acquired at progression, the average change in lesion volume from previous follow-up in standard and delayed-contrast MRIs was compared. Response and progression patterns were identified from the mean change in lesion volumes, depicted from conventional T1WI, delayed contrast-enhanced MR imaging, and DSC MR imaging. Thresholds for early prediction of response were calculated by using these sequences. For each predictor, sensitivity, specificity, positive predictive values, and negative predictive values were calculated, reaching 85.7%, 87.5%, 75%, and 93.3% for conventional T1WI; 100%, 87.5%, 77.8%, and 100% for delayed-contrast MR imaging; and 75%, 78.6%, 50%, and 91.7% for DSC MR imaging. The benefit of delayed-contrast MR imaging in separating responders and nonresponders was further confirmed by using log-rank tests (conventional T1WI, P = .0022; delayed-contrast MR imaging, P < .0001; DSC MR imaging, P = .0232) and receiver operating characteristic analyses. At progression, the increase in lesion volumes in delayed-contrast MR imaging was 37.5% higher than the increase in conventional T1WI (P < .01); these findings suggest that progression may be depicted more effectively in treatment-response-assessment maps. The benefit of contrast-enhanced MR imaging for assessing and predicting the response to bevacizumab was demonstrated. The increased sensitivity of the treatment-response-assessment maps reflects their potential contribution to the management of bevacizumab-treated patients with recurrent high-grade glioma.

The Electron Beam Ion Source particle-in-cell code (EBIS-PIC) tracks ions in an EBIS electron beam while updating electric potential self-consistently and atomic processes by the Monte Carlo method. Recent improvements to the code are reported in this paper. The ionization module has been improved by using experimental ionization energies and shell effects. The acceptance of injected ions and the emittance of extracted ion beam are calculated by extending EBIS-PIC to the beam line transport region. An EBIS-PIC simulation is performed for a Cs charge-breeding experiment at BNL. The charge state distribution agrees well with experiments, and additional simulation results of radial profiles and velocity space distributions of the trapped ions are presented.

Temperature-dependent Hall-effect measurements have been used to determine donor and acceptor concentrations and energies in n-type and p-type ZnO. Commonly observed donor energies in n-type material grown from the vapor phase (VP) are 35 and 65 meV, with the 35-meV donor identified as H, and the 65-meV donor, probably Al. Total donor concentrations in VP-grown material are as low as mid-1016 cm−3. The only acceptors unambiguously identified so far in this material are the Zn vacancy, at the low-1015-cm−3 level, and substitutional NO, at a higher level but evidently passivated with H. Acceptors that have been successfully used to create p-type ZnO by doping include N, P, and As, and resistivities as low as 0.1 Ω-cm have been obtained. The acceptor energy for N is about 90 meV for [N] ∼ 1019 cm−3, and can be estimated to be about 130 – 150 meV at low concentrations of N.

The stability and resonant field response of current driven resistive wall modes are numerically studied for DIII-D [J. L. Luxon, Nucl. Fusion 42, 614 (2002)] low pressure plasmas. The resonant field response of the feedback-stabilized resistive wall mode is investigated both analytically and numerically, and compared with the response from intrinsically stable or marginally stable modes. The modeling qualitatively reproduces the experimental results. Furthermore, based on some recent results and on the indirect numerical evidence in this work, it is suggested that the mode stability behavior observed in DIII-D experiments is due to the kink-peeling mode stabilization by the separatrix geometry. The phase inversion radius of the computed plasma displacement does not generally coincide with the radial locations of rational surfaces, also supporting experimental observations.

New and more efficient thermoelectric (TE) materials that make use of nanotechnology have been developed. These new materials, called quantum wells (QW), are composed of alternating layers of 10 nm thick silicon and SiGe films. They can be deposited by various techniques and magnetron sputtering was used to obtain uniform layered structures that exhibited no degradation of the TE properties or microstructure after thermal aging. For QW thin films, the heat and current flow are “in plane” and in this orientation all of the thermoelectric properties (the Seebeck coefficient, electrical resistivty, and the thermal conductivity) are improved to increase the TE Figure of Merit, ZT (see equation 3, p. 4, for the definition of Z). From the most recent QW test data, ZTs greater than 3 at room temperature have been obtained which constitutes a significant improvement over the state-of-the-art (SOTA) bulk thermoelectrics which have ZTs less than 1. QW materials have the best measured TE power factor (Seebeck coefficient squared divided by electrical resistivity) and, combined with low thermal conductivity substrates, should provide very high efficiency TE modules. The QW TE materials with ZTs greater than 3 lead to conversion efficiencies greater than 20 percent, which allows for much wider commercial applications, particularly in the applications such as the waste-heat recovery from truck engines, refrigeration, and air conditioning, where the SOTA bulk TE modules were shown to be technically feasible but economically unjustified due to low conversion efficiencies. With higher efficiency QW materials, these applications become economically attractive. For the refrigeration and air conditioning applications, the QW TE materials are predicted to have higher coefficients of performance (COP) than the SOTA vapor compression systems, with the additional advantages of having no compressors, no moving parts, no refrigerants, no vibrations, no noise, and practically no maintenance. With such significant advantages, it is very important to have independent confirmation of the QW TE properties that lead to such improved performance. Three independent researchers have confirmed the previously measured QW TE properties using conventional test techniques, and a totally new test technique was developed to measure the TE properties and performance and the results provided yet another confirmation of the superior TE performance of the QW materials versus the SOTA bulk thermoelectrics. The temperature range for the applications is anticipated to be as low as −150C to the upper temperature of 1000C, with the power generation capacity ranging from milliwatts to kilowatts and cooling capacity ranging from watts to several tons of refrigeration.

Summary form only given. We present the progress on the development of a new idea of using high-Mach number high-density composite plasma jets from coaxial plasma guns for disruption mitigation in tokamak1 and magneto-inertial fusion2 (MIF). The key element of the idea is the solid state pulsed power source with TiH2 (or TiDT) grains and C6o micron size powder3. Very fast injection of the molecular gas mixture provided by hydrogen release and sublimation of Cgo into the plasma gun is achieved by a special filter grid with supersonic Laval nozzles. The estimations based on the physical models of TiH2 grains heating, C6o powder sublimation, molecular gas injection, mass separation, and plasma slug acceleration will be detailed. For disruption mitigation, our calculations show that the plasma gun is able to provide the required impurity mass1 (~l-2 g) and the ram pressure to penetrate the tokamak hot plasma and to overcome the confining magnetic field pressure. Core tokamak plasma penetration can be achieved and impurity mass delivered in less than 1 ms, as required by ITER tokamak. The magnetized target fusion (MTF) plasma for MIF is created by injecting two high-Mach number (M>5) high-density (>1017 cm"3) plasma jets composed of fuel (D-T) and "pusher" (C6o/C) along the axis of a pulsed magnetic (~l-2 T) mirror into a metallic cylindrical liner. The high-density (~1018 cm"3) cylindrical MTF created by head- on collision and stagnation in the magnetic field is compressed radially by the Z-pinch of the liner and prevented to expand axially by the incoming C6o/C end-plugs. We estimated that, due to the much longer MTF axial dimension (~30 cm) as compared to other inertial confinement fusion plasmas, the electron thermal conduction time to the Cgo/C end-plugs is longer than liner implosion time.