State-space distribution and dynamical flow for closed and open quantum systems

We present a general formalism for studying the effects of dynamical heterogeneity in open quantum systems. We develop this formalism in the state space of density operators, on which ensembles of quantum states can be conveniently represented by probability distributions. We describe how this representation reduces ambiguity in the definition of quantum ensembles by providing the ability to explicitly separate classical and quantum sources of probabilistic uncertainty. We then derive explicit equations of motion for state space distributions of both open and closed quantum systems and demonstrate that resulting dynamics take a fluid mechanical form analogous to a classical probability fluid on Hamiltonian phase space, thus enabling a straightforward quantum generalization of Liouville's theorem. We illustrate the utility of our formalism by analyzing the dynamics of an open two-level system using the state-space formalism that are shown to be consistent with the derived analytical results

Cessation of biomechanical stretch model of C2C12 cells models myocyte atrophy and anaplerotic changes in metabolism using non-targeted metabolomics analysis

Studies of skeletal muscle disuse, either in patients on bed rest or experimentally in animals (immobilization), have demonstrated that decreased protein synthesis is common, with transient parallel increases in protein degradation. Muscle disuse atrophy involves a process of transition from slow to fast myosin fiber types. A shift toward glycolysis, decreased capacity for fat oxidation, and substrate accumulation in atrophied muscles have been reported, as has accommodation of the liver with an increased gluconeogenic capacity. Recent studies have modeled skeletal muscle disuse by using cyclic stretch of differentiated myotubes (C2C12), which mimics the loading pattern of mature skeletal muscle, followed by cessation of stretch. We utilized this model to determine the metabolic changes using non-targeted metabolomics analysis of the media. We identified increases in amino acids resulting from protein degradation (largely sarcomere) that occurs with muscle atrophy that are involved in feeding the Kreb’s cycle through anaplerosis. Specifically, we identified increased alanine/proline metabolism (significantly elevated proline, alanine, glutamine, and asparagine) and increased α-ketoglutaric acid, the proposed Kreb’s cycle intermediate being fed by the alanine/proline metabolic anaplerotic mechanism. Additionally, several unique pathways not clearly delineated in previous studies of muscle unloading were seen, including: 1) elevated keto-acids derived from branched chain amino aicds (i.e. 2-ketoleucine and 2-keovaline), which feed into a metabolic pathway supplying acetyl-CoA and 2-hydroxybutyrate (also significantly increased); and 2) elevated guanine, an intermediate of purine metabolism, was seen at 12 hours unloading. Given the interest in targeting different aspects of the ubiquitin proteasome system to inhibit protein degradation, this C2C12 system may allow the identification of direct and indirect alterations in metabolism due to anaplerosis or through other yet to be identified mechanisms using a non-targeted metabolomics approach

Synergistic Antibacterial Effects of Metallic Nanoparticle Combinations

© The Author(s) 2019.Metallic nanoparticles have unique antimicrobial properties that make them suitable for use within medical and pharmaceutical devices to prevent the spread of infection in healthcare. The use of nanoparticles in healthcare is on the increase with silver being used in many devices. However, not all metallic nanoparticles can target and kill all disease-causing bacteria. To overcome this, a combination of several different metallic nanoparticles were used in this study to compare effects of multiple metallic nanoparticles when in combination than when used singly, as single elemental nanoparticles (SENPs), against two common hospital acquired pathogens (Staphylococcus aureus and Pseudomonas. aeruginosa). Flow cytometry LIVE/DEAD assay was used to determine rates of cell death within a bacterial population when exposed to the nanoparticles. Results were analysed using linear models to compare effectiveness of three different metallic nanoparticles, tungsten carbide (WC), silver (Ag) and copper (Cu), in combination and separately. Results show that when the nanoparticles are placed in combination (NPCs), antimicrobial effects significantly increase than when compared with SENPs (P < 0.01). This study demonstrates that certain metallic nanoparticles can be used in combination to improve the antimicrobial efficiency in destroying morphologically distinct pathogens within the healthcare and pharmaceutical industry.Peer reviewe

Factors associated with depression and anxiety in the adult population of Qatar after the first COVID-19 wave: a cross-sectional study

There is limited data from Arabic-speaking countries on risk factors for depression and anxiety during the COVID-19 pandemic. Country-specific data is necessary given differences in culture, demographics, and COVID-19 infection and mortality rates. The main purpose of the study is to identify the factors associated with symptoms of depression-anxiety in the adult population of Qatar during the first year of the COVID-19 pandemic. We conducted a cross-sectional online survey in Qatar between July and December 2020 after Qatar’s first COVID-19 wave and before the beginning of the second wave. Depression-anxiety was defined as a cut-off of 20 or higher on the Patient Health Questionnaire-Anxiety Depression Scale (PHQ-ADS). Of 1138 participants, 71.0% were female, 69.0% Arabs, 70.0% Non-Qataris, and 77.0% were < 40 years (the median age in Qatar is 32 years). In a fully-adjusted model, six variables were significantly associated with moderate-to-severe levels of depression or anxiety on the PHQ-ADS; Arab ethnicity (OR = 1.67, p = 0.026), never married versus married (OR = 1.69, p = 0.015), prior history of psychiatric disorder versus no history (OR = 1.80, p = 0.009), increased worries due to social media use for COVID-related news/updates (OR = 1.72, p = 0.003), a history of COVID-19 (OR = 1.76, p = 0.039), loneliness (OR = 1.91, p < 0.001), and lower levels of religiosity (OR = 0.96, p = 0.039). These associations also pertained in the reduced model, with the exception of religiosity which was only marginally statistically significant (OR = 0.97, p = 0.055). The potential risk factors identified may assist with anxiety and depression prevention in future COVID-19 waves, and similar national events, and assist with early intervention to treat sufferers

Identification of excited states in 117Cs: Systematics of the ν(h11/2)2 alignment

Excited states have been identified in the very neutron-deficient 11755Cs62 nucleus. High-spin spectroscopy has been performed using the Gammasphere array, and the assignment of gamma-ray transitions to 117Cs has been made in a separate experiment in which gamma rays were detected in coincidence with x rays and with recoiling evaporation residues. A previously observed sequence of five gamma rays has been extended by 11 transitions, to high spin, and has been identified as the yrast π(h11/2)[550]1/2- band of 117Cs. Two additional bands have been observed and are tentatively assigned to be based on protons in the [404]9/2+ and [422]3/2+ orbitals. Alignments of pairs of h11/2 neutrons and protons are observed in all of the bands. The alignments are compared to cranked Woods-Saxon calculations, and are discussed with respect to the effects of a neutron-proton interaction. Of particular interest are the features of the ν(h11/2)2 alignment in the π[550]1/2- band and of the π(h11/2)2 alignment in the [422]3/2+ band. The frequencies of these alignments can be qualitatively explained only if a neutron-proton interaction is taken into account

Lifetime measurements and dipole transition rates for superdeformed states in 190Hg

High-precision lifetime measurements have been performed in two of the superdeformed (SD) bands of 190Hg with the Doppler-shift attenuation method. Intrinsic quadrupole moments, Q0, were extracted for the yrast and first excited SD bands in this nucleus. Dipole transition rates have been established for the inter-band transitions which connect the first excited SD band to the yrast states in the second minimum. The results support the interpretation of the excited SD band as a band based on an octupole vibration

Identification of excited states in 119Ba

Excited states have been identified in the very neutron-deficient 119Ba nucleus. Two bands have been observed, which are likely to be based on h11/2 and (g7/2d5/2) neutron orbitals. Despite this being the first observation of excited states in 119Ba, the bands extend to (75/2)ℏ and (79/2)ℏ, respectively. The bands have been assigned to 119Ba using gamma-recoil and gamma-x-ray coincidences. Several quasiparticle alignments have been identified, involving neutron (h11/2)2 and proton (h11/2)2 aligned configurations. Furthermore, the bands show features which are reasonably consistent with smooth band termination at high spin. Theoretical results for 119Ba are discussed within the framework of cranked Woods-Saxon and Nilsson-Strutinsky calculations

First observation of excited states in 118Ba: Possible evidence for octupole correlations in neutron-deficient barium isotopes

Quadrupole moments of the six known superdeformed ~SD! bands of 193Hg and the yrast SD band of 192Hg have been determined by a Doppler-shift-attenuation-method measurement utilizing the gammasphere array. The quadrupole moments of all 193Hg SD bands were found to be similar, suggesting the active single-particle orbitals in the mass-190 region exhibit only small shape-driving effects. Additionally, there is evidence for an unexpected difference in the quadrupole moments of SD bands in 192Hg and 193Hg

Excited states in 155Yb and 155,156,157 Lu from recoil-decay tagging

The 270-MeV 58Ni+ 102Pd reaction was used for the first recoil-decay tagging measurement with Gamma-sphere coupled to the Fragment Mass Analyzer at Argonne National Laboratory. Level structures of 155Yb, 156Lu, and 157Lu, as well as the excited states associated with the 25/2- isomer in 155Lu, are identified for the first time. The systematical behavior of the energy levels is compared with that of neighboring isotones and isotopes. The attractive interaction between h11/2 protons and h9/2 neutrons plays an important role in the structure of 155Yb and 155,156Lu

High-spin excitations in 158,159,160Hf from recoil-decay tagging

The 270-MeV 58Ni+ APd reaction was used for the first recoil-decay tagging measurement with Gammasphere coupled to the Fragment Mass Analyzer at Argonne National Laboratory. Level structures of 158Hf and 159Hf are identified for the first time, and that of 160Hf is extended. The systematical behavior of the energy levels in neighboring isotones and isotopes, as well as the aligned angular momenta as a function of rotational frequency, are examined