Attempts to create quantum degenerate gases without evaporative cooling have been pursued since the early days of laser cooling, with the consensus that polarization gradient cooling (PGC, also known as "optical molasses") alone cannot reach condensation. In the present work, we report that simple PGC can generate a small Bose-Einstein condensate (BEC) inside a corrugated micrometer-sized optical dipole trap. The experimental parameters enabling BEC creation were found by machine learning, which increased the atom number by a factor of 5 and decreased the temperature by a factor of 2.
View Article and Find Full Text PDFQuantum scrambling describes the spreading of information into many degrees of freedom in quantum systems, such that the information is no longer accessible locally but becomes distributed throughout the system. This idea can explain how quantum systems become classical and acquire a finite temperature, or how in black holes the information about the matter falling in is seemingly erased. We probe the exponential scrambling of a multiparticle system near a bistable point in phase space and utilize it for entanglement-enhanced metrology.
View Article and Find Full Text PDFState-of-the-art atomic clocks are based on the precise detection of the energy difference between two atomic levels, which is measured in terms of the quantum phase accumulated over a given time interval. The stability of optical-lattice clocks (OLCs) is limited both by the interrupted interrogation of the atomic system by the local-oscillator laser (Dick noise) and by the standard quantum limit (SQL) that arises from the quantum noise associated with discrete measurement outcomes. Although schemes for removing the Dick noise have been recently proposed and implemented, performance beyond the SQL by engineering quantum correlations (entanglement) between atoms has been demonstrated only in proof-of-principle experiments with microwave clocks of limited stability.
View Article and Find Full Text PDFFree radical driven lipid peroxidation is a chain reaction which can lead to oxidative degradation of biological membranes. Propagation vs. termination rates of peroxidation in biological membranes are determined by a variety of factors including fatty acyl chain composition, presence of antioxidants, as well as biophysical properties of mono- or bilayers.
View Article and Find Full Text PDFHepatocellular carcinoma and cholangiocarcinoma are the most common primary malignant liver tumors. Since the liver plays a key role in lipid metabolism, the study of serum phospholipid (PL) profiles may provide a better understanding of alterations in hepatic lipid metabolism. In this study, we used a high-resolution HILIC-LC-MS lipidomic approach to establish the serum phospholipidome profile of patients with liver cancer before (T0) and after tumor resection (T1) and a control group (CT) of healthy individuals.
View Article and Find Full Text PDFFront Neurosci
December 2019
Epidemiological studies show increasing prevalence rates of cognitive decline and hearing loss with age, particularly after the age of 65 years. These conditions are reported to be associated, although conclusive evidence of causality and implications is lacking. Nevertheless, audiological and cognitive assessment among elderly people is a key target for comprehensive and multidisciplinary evaluation of the subject's frailty status.
View Article and Find Full Text PDFIEEE Trans Med Imaging
April 2020
We introduce a Magnetic Particle Imaging Susceptometer (MPIS) that uses a high-sensitivity atomic magnetometer (AM) for recording the spatial distribution of fluid-suspended magnetic nanoparticles. We have evaluated the MPIS performance by one-dimensional scans of structured nanoparticle phantoms, demonstrating, in particular, resolutions of ≈2.5 mm prior to deconvolution and << 1 mm after deconvolution.
View Article and Find Full Text PDFObesity is a public health problem and a risk factor for pathologies such type 2 diabetes mellitus, cardiovascular diseases, and nonalcoholic fatty liver disease. Given these clinical implications, there is a growing interest to understand the pathophysiological mechanism of obesity. Changes in lipid metabolism have been associated with obesity and obesity-related complications.
View Article and Find Full Text PDFSpin squeezing can improve atomic precision measurements beyond the standard quantum limit (SQL), and unitary spin squeezing is essential for improving atomic clocks. We report substantial and nearly unitary spin squeezing in ^{171}Yb, an optical lattice clock atom. The collective nuclear spin of ∼10^{3} atoms is squeezed by cavity feedback, using light detuned from the system's resonances to attain unitarity.
View Article and Find Full Text PDFFree Radic Biol Med
November 2019
Oxidized LDL (oxLDL) has been shown to play a crucial role in the onset and development of cardiovascular disorders. The study of oxLDL, as an initiator of inflammatory cascades, led to the discovery of a variety of oxidized phospholipids (oxPLs) responsible for pro-inflammatory actions. Oxidized 1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphocholine (PAPC) is frequently used by the scientific community as a representative oxPL mixture to study the biological effects of oxidized lipids, due to the high abundance of PAPC in human tissues and the biological activities of oxidized arachidonic acids derivatives.
View Article and Find Full Text PDFThis manuscript described a dynamic simulation of uranyl nitrate crystallization in a linear crystallizer. Furthermore, a mathematical model of the crystallizer supply system was developed with a related control algorithm; the model contained two piston feeders. The results showed the crystallization process's sensitivity to the solution level in the crystallizer.
View Article and Find Full Text PDFThe aminophospholipids (APL), phosphatidylethanolamine (PE) and phosphatidylserine (PS) are widely present in cell membranes and lipoproteins. Glucose and reactive oxygen species (ROS), such as the hydroxyl radical (OH), can react with APL leading to an array of oxidised, glycated and glycoxidised derivatives. Modified APL have been implicated in inflammatory diseases and diabetes, and were identified as signalling molecules regulating cell death.
View Article and Find Full Text PDFRecent evidence suggests that phosphatidylserine (PS) and its oxidized species drive the clearance of apoptotic cells by macrophages with putative immune response modulation. However, it is not clear whether PS and oxidized PS differentially modulate at molecular level the functional responses of macrophages. Therefore, we proposed in this work to explore this question by evaluating the influence of PS oxidation products on the macrophages inflammatory status.
View Article and Find Full Text PDFMass Spectrom Rev
August 2019
The biological functions of modified aminophospholipids (APL) have become a topic of interest during the last two decades, and distinct roles have been found for these biomolecules in both physiological and pathological contexts. Modifications of APL include oxidation, glycation, and adduction to electrophilic aldehydes, altogether contributing to a high structural variability of modified APL. An outstanding technique used in this challenging field is mass spectrometry (MS).
View Article and Find Full Text PDFAminophospholipids (APL), phosphatidylethanolamine (PE) and phosphatidylserine (PS), can be oxidized upon oxidative stress. Oxidized PE and PS have been detected in clinical samples of different pathologies and may act as modulators of the inflammatory response. However, few studies have focused on the effects of oxidized APL (ox-APL) esterified with arachidonic acid, even though a considerable number of studies have assessed the modulation of the immune system by oxidized 1-palmitoyl-2-arachidonoyl-sn-3-glycerophosphocholine (OxPAPC).
View Article and Find Full Text PDFEndothelial dysfunction has been widely associated with oxidative stress, glucotoxicity and lipotoxicity and underlies the development of cardiovascular diseases (CVDs), atherosclerosis and diabetes. In such pathological conditions, lipids are emerging as mediators of signalling pathways evoking key cellular responses as expression of proinflammatory genes, proliferation and apoptosis. Hence, the assessment of lipid profiles in endothelial cells (EC) can provide valuable information on the molecular alterations underlying CVDs, atherosclerosis and diabetes.
View Article and Find Full Text PDFVinyl sulfones are used for drug design of irreversible inhibitors of cysteine proteases since they are able to alkylate cysteine thiols inside the catalytic pocket of this class of enzymes. Some authors have reported the lack of reactivity towards glutathione as sufficient evidence of the selectivity of such a mechanism. Herein, we demonstrate that some simple molecules containing a vinyl sulfone moiety are not thiol-specific alkylants since they react with some albumin nucleophiles including side chains of Cys34 and His146.
View Article and Find Full Text PDFInteract Cardiovasc Thorac Surg
July 2014
Objectives: Aortic valvuloplasty could represent an alternative to valve replacement resulting in optimal haemodynamic conditions, avoiding anticoagulation and allowing, in young people, normal aortic annulus growth. We analysed our results of aortic valve repair for incompetence due to leaflets and root pathology.
Methods: From January 2003 to January 2013, 235 patients affected by aortic valve regurgitation, pure or associated with aortic dilatation, were treated with a combination of the principal leaflet repair techniques and, when necessary, sparing procedures.