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Antenna requirements for software defined radio (SDR) and cognitive radio (CR) systems are reviewed and the resulting challenges are discussed. Both concepts imply capabilities for operation over very wide bandwidths, of the order of one decade in some cases. This then becomes the main challenge for antenna designers. However, as the concepts evolve, some systems will work over limited bandwidths and existing or extended bandwidth antennas will be used. In the Paper the concepts are explained. As bandwidth is a major concern, the fundamental limits of performance are restated. For handheld radio antenna bandwidth and efficiency at low frequencies is the main problem. Both in the terrestrial fixed infrastructure and in space communication the difficulty of designing very wideband arrays to give the pattern control necessary for interference minimization is significant. In defence applications external handset antennas are seen to be necessary and extension to very wide bandwidths is also seen to be challenging. It is concluded that there is steady progress towards the realization of both SDR and CR, and this is throwing up very significant antenna challenges. [ABSTRACT FROM PUBLISHER]

A neutron scattering technique was developed to measure the density of heavy water confined in a nanoporous silica matrix in a temperature-pressure range, from 300 to 130 K and from 1 to 2,900 bars, where bulk water will crystalize. We observed a prominent hysteresis phenomenon in the measured density profiles between warming and cooling scans above 1,000 bars. We interpret this hysteresis phenomenon as support (although not a proof) of the hypothetical existence of a first-order liquid-liquid phase transition of water that would exist in the macroscopic system if crystallization could be avoided in the relevant phase region. Moreover, the density data we obtained for the confined heavy water under these conditions are valuable to large communities in biology and earth and planetary sciences interested in phenomena in which nanometer-sized water layers are involved. [ABSTRACT FROM AUTHOR]

Abstract: Using incoherent quasi-elastic and inelastic neutron scattering, we have investigated the hydrogen relaxational dynamics and hydrogen vibrational modes in the polyoxomolybdate specie [Mo72Fe30O252(CH3COO)12[Mo2O7(H2O)]2[H2Mo2O8(H2O)](H2O)91]·≈150 H2O. The translational dynamics of the water molecules in the compound is profoundly different from that of bulk water at the same temperature showing a non-Debye relaxation behavior. The temperature dependence of the relaxation time can be described in terms of an Arrhenius law, indicating that the dynamics is triggered by the breaking of the bonds connecting the crystal water molecules with the hydrophilic nanocapsule surfaces. Inelastic neutron scattering spectra confirm the attenuation of water translational modes with respect to the bulk water case due to the strong destructuring effect imposed by the nanocage interface and the enhancement of the highest frequency librational mode as already found in hydrated Vycor or Gelsil matrix. Small angle X-ray scattering on freshly prepared aqueous solution evidences the presence of nanocapsule structures proper of the monomer (2.6nm in diameter) that coexist with a small amount of oligomers. After 1month the polyoxomolibdate specie self-assembles in a supramolecular structure with a polydisperse distribution of dimensions spanning from the monomer to the “blackberry” vesicular structure already reported in literature. [ABSTRACT FROM AUTHOR]

novel numerical model to simulate thermal response of human body tissues exposed to RF energy is presented in this article. It is based on a new algorithm for the construction of a realistic blood vessel network, a new model of blood flow velocity distribution and an approach to solve the bio-heat equation in human tissue with variable and initially unknown blood temperature distribution. The algorithm generates a discrete 3D representation of both arterial and venous vascular networks and a continuous blood velocity vector field for arbitrary enclosed geometries required to represent the complex anatomy of human body and blood flow. The results obtained in this article by applying the developed method to realistic exposure conditions demonstrates relative difference in thermal response of the exposed tissue compared to results obtained by conventional bio-heat equation with constant blood perfusion and temperature. The developed technique may provide more accurate and realistic modelling in thermal dosimetry studies of human body RF exposure. [ABSTRACT FROM AUTHOR]

This review article describes our neutron scattering experiments made in the past four years for the understanding of the single-particle (hydrogen atom) dynamics of a protein and its hydration water and the strong coupling between them. We found that the key to this strong coupling is the existence of a fragile-to-strong dynamic crossover (FSC) phenomenon occurring at around TL=225±5 K in the hydration water. On lowering of the temperature toward FSC, the structure of hydration water makes a transition from predominantly the high density form (HDL), a more fluid state, to predominantly the low density form (LDL), a less fluid state, derived from the existence of a liquid–liquid critical point at an elevated pressure. We show experimentally that this sudden switch in the mobility of hydration water on Lysozyme, B-DNA and RNA triggers the dynamic transition, at a temperature TD=220 K, for these biopolymers. In the glassy state, below TD, the biopolymers lose their vital conformational flexibility resulting in a substantial diminishing of their biological functions. We also performed molecular dynamics (MD) simulations on a realistic model of hydrated lysozyme powder, which confirms the existence of the FSC and the hydration level dependence of the FSC temperature. Furthermore, we show a striking feature in the short time relaxation (β-relaxation) of protein dynamics, which is the logarithmic decay spanning 3 decades (from ps to ns). The long time α-relaxation shows instead a diffusive behavior, which supports the liquid-like motions of protein constituents. We then discuss our recent high-resolution X-ray inelastic scattering studies of globular proteins, Lysozyme and Bovine Serum Albumin. We were able to measure the dispersion relations of collective, intra-protein phonon-like excitations in these proteins for the first time. We found that the phonon energies show a marked softening and at the same time their population increases substantially in a certain wave vector range when temperature crosses over the TD. Thus the increase of biological activities above TD has positive correlation with activation of slower and large amplitude collective motions of a protein. [ABSTRACT FROM AUTHOR]

The exact closed-form expression for the electromagnetic field excited by pulse-shaped and triangular line currents is presented. The analytical formulation, based on the incomplete Hankel functions, shows that the field is composed of cylindrical waves excited near the current axis and spherical waves arising from the source critical points. Spherical waves related with pulse-shaped current basis functions are shown to have stronger field singularities than for triangular basis functions because of the impulsive charges present at the current truncations. For triangular line currents, it is further shown that an additional spherical wave arises from the critical point featuring a charge jump discontinuity. Near and high-frequency asymptotic field expressions show explicitly the nature of the field singularities. Using the analytical properties of the incomplete Hankel functions, the Galerkin's impedance matrix coefficients, useful to solve radiation and scattering problems in truncated cylindrical structures using the method of moments, are finally derived in a closed-form. Numerical examples show the accuracy of the proposed field representation. [ABSTRACT FROM AUTHOR]

The spatial distribution of the electromagnetic field excited in semi-infinite open-ended circular waveguides is analyzed using a physical optics (PO) and incomplete Hankel functions formulation. Using the incomplete Hankel functions, the PO surface integral employed to compute the field quantities is reduced to a simple line integral along the waveguide contour. Such a superposition integral, which describes the elementary field contributions having spherical and cylindrical character, is then evaluated in closed analytical form along the waveguide axis. It is shown that cylindrical waves are generated by the surface currents flowing on the waveguide walls, while the spherical waves are produced by the currents and charges excited at the waveguide truncation. Cylindrical and spherical waves are responsible for the field synthesis in terms of waveguided modes and scattered fields at the waveguide mouth. Numerical examples, demonstrating the accuracy of said field representation in the near- and far-field region of truncated circular waveguides, are finally provided. [ABSTRACT FROM AUTHOR]

A study of the specific absorption rate (SAR) in an exposed body induced by canonical antennas is presented, with the aim of determining an upper bound for the antenna transmit power that demonstrates that a product is inherently compliant with internationally accepted radio frequency (RF) exposure limits. Starting from the fundamental limits in antenna quality factor (Q) and the corresponding bandwidth, several antenna sizes are selected, and their SAR distributions are computed using the method of moments (MoM) and finite-difference time domain (FDTD) method in the frequency range 309-3000 MHz. The threshold powers are then determined, below which the peak 1-g and 10-g averaged SAR would not exceed the limits specified in international exposure standards. From the data, simple expressions are derived to estimate the threshold power over a wide range of antenna sizes, frequencies, and distances from the body. It is demonstrated that the results presented in this paper are conservative in comparison with the measured SAR data of real products as well as other published data. [ABSTRACT FROM AUTHOR]

By confining water in a nanoporous structure so narrow that the liquid could not freeze, it is possible to study properties of this previously undescribed system well below its homogeneous nucleation temperature TH = 231 K. Using this trick, we were able to study, by means of a Fourier transform infrared spectroscopy, vibrational spectra (HOH bending and OH-stretching modes) of deeply supercooled water in the temperature range 183 < T < 273 K. We observed, upon decreasing temperature, the building up of a new population of hydrogen-bonded oscillators centered around 3,120 cm-1, the contribution of which progressively dominates the spectra as one enters into the deeply supercooled regime. We determined that the fractional weight of this spectral component reaches 50% just at the temperature, TL ≈ 225 K, where the confined water shows a fragile-to-strong dynamic cross-over phenomenon [Ito, K., Moynihan, C. T., Angell, C. A. (1999) Nature 398:492–494]. Furthermore, the fact that the corresponding OH stretching spectral peak position of the low-density-amorphous solid water occurs exactly at 3,120 cm-1 [Sivakumar, T. C., Rice, S. A., Sceats, M. G. (1978) J. Chem. Phys. 69:3468-3476.] strongly suggests that these oscillators originate from existence of the low-density-liquid phase derived from the occurrence of the first-order liquid-liquid (LL) phase transition and the associated LL critical point in supercooled water proposed earlier by a computer molecular dynamics simulation [Poole, P. H., Sciortino, F., Essmann, U., Stanley, H. E. (1992) Nature 360:324–328]. [ABSTRACT FROM AUTHOR]

The circuit model and the near-field behavior of a novel wide-band E-shaped microstrip patch antenna suitable for wireless communication devices are presented. A suitable locally conformal FDTD numerical procedure is employed to analyze the electromagnetic field excited by the radiator, and to derive a frequency-independent antenna equivalent circuit. Numerical results concerning the antenna parameters are in good agreement with experimental measurements. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 97–100, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22057 [ABSTRACT FROM AUTHOR]

By confining water in nanopores, so narrow that the liquid cannot freeze, it is possible to explore its properties well below its homogeneous nucleation temperature TH ≈ 235 K. In particular, the dynamical parameters of water can be measured down to 180 K, approaching the suggested glass transition temperature Tg σ 165 K. Here we present experimental evidence, obtained from Nuclear Magnetic Resonance and Quasi-Elastic Neutron Scattering spectroscopies, of a well defined decoupling of transport properties (the self-diffusion coefficient and the average translational relaxation time), which implies the breakdown of the Stokes-Einstein relation. We further show that such a non-monotonic decoupling reflects the characteristics of the recently observed dynamic crossover, at σ225 K, between the two dynamical behaviors known as fragile and strong, which is a consequence of a change in the hydrogen bond structure of liquid water. [ABSTRACT FROM AUTHOR]

Miniature probes employed for specific absorption rate (SAR) measurements are typically calibrated using a sinusoidal waveform (SW), even though they may be employed to measure a wide variety of communication signals with complex waveforms. This paper shows that the compression produced by the nonlinear response of the probe versus SAR, due to its diode detector, may introduce a significant overestimation of the SAR produced by CDMA IS-95 waveforms when the diode detector operates well into the compression region. This finding is demonstrated theoretically, verified numerically and experimentally, and physically interpreted. The effect is typically small and may be neglected in many practical circumstances involving low-power RF energy emitters, such as mobile phones or two-way dispatch radios. [ABSTRACT FROM AUTHOR]

A wideband E-shaped microstrip patch antenna for wireless communications is presented. Zig-zag slots and perturbations of the E-shaped metallic patch are employed to excite two resonant modes and achieve a wide-band frequency behavior, featuring a fractional bandwidth of about 30%, and, at the same time, to meet the occupation volume requirements of mobile wireless local-area network enabled communication devices. A locally conformal finite-difference time-domain numerical procedure has been employed to analyze the radiating structure. Numerical results concerning the antenna parameters are in good agreement with experimental measurements. [ABSTRACT FROM AUTHOR]

The specific absorption rates (SAR) determined computationally in the specific anthropomorphic mannequin (SAM) and anatomically correct models of the human head when exposed to a mobile phone model are compared as part of a study organized by IEEE Standards Coordinating Committee 34, Sub-Committee 2, and Working Group 2, and carried out by an international task force comprising 14 government, academic, and industrial research institutions. The detailed study protocol defined the computational head and mobile phone models. The participants used different finite-difference time-domain software and independently positioned the mobile phone and head models in accordance with the protocol. The results show that when the pinna SAR is calculated separately from the head SAR, SAM produced a higher SAR in the head than the anatomically correct head models. Also the larger (adult) head produced a statistically significant higher peak SAR for both the 1- and 10-g averages than did the smaller (child) head for all conditions of frequency and position. [ABSTRACT FROM AUTHOR]

A closed-form solution for the spatial distribution of the electromagnetic field excited by an electric traveling-wave current source is presented. Incomplete Hankel and modified Bessel functions are employed to represent progressive and evanescent wave fields, respectively. It is shown that these fields are expressed in terms of spherical and cylindrical waves exhibiting optical character. Using the properties of the incomplete Hankel and modified Bessel functions, the spatial regions where the fields exist in optical sense are determined. It is shown that different shadow boundaries (SBs), featuring complex shapes, identify discontinuity surfaces for the geometrical optics (GO) field. Three surfaces, one being the well-know Keller's cone, are found to describe in the general ease the SBs for both the progressive and the evanescent wave fields. It is demonstrated that these surfaces collapse to the Keller's cone surface in the limit of β → ∞. [ABSTRACT FROM AUTHOR]

A novel class of special functions for electromagnetics is presented. Formed by the incomplete Hankel and modified Bessel functions, this class allows solving electromagnetics problems concerning truncated cylindrical structures. The differential and recurrence equations of these functions feature additional terms with respect to the classical theory of the Hankel and Bessel functions, The general properties, the most important analytical characteristics, and the large argument asymptotic approximations of the incomplete functions are derived using the steepest descent path (SDP) technique, showing that each special function splits into two terms. The first one has a discontinuous character and is linked to the saddle-point(s) contribution(s), while the second one, arising from the integral end-point contribution(s), compensates exactly the said discontinuity. In the solution of electromagnetic problems, the first term describes the geometrical optics (GO) field, the diffracted field being described by the second one. The general theory is employed to find the closed form analytical solution of the field radiated from a uniform line current source. Using the properties of the incomplete Hankel functions, it is demonstrated that this source excites cylindrical fields having optical character. Finally, the shape of the spatial regions where the GO solution cannot be applied is determined and discussed in details. [ABSTRACT FROM AUTHOR]

Prediction formulae for estimating the peak equivalent power density in the near-field of cellular base-station array antennas are demonstrated. Theoretical justification stemming from a uniform asymptotic expansion of the field radiated by collinear arrays is described, and verification is carried out by means of an extensive computational analysis of different classes of base station antennas. The formulae, which depend on a few, readily available parameters, can be conveniently employed for the estimation of compliance distances with respect to RF safety guidelines issued by the International Committee on Non-Ionizing Radiation Protection (ICNIRP), which have been adopted in many countries throughout the world, without requiring necessarily extensive and expensive nearfield measurements campaigns. [ABSTRACT FROM AUTHOR]

A uniform asymptotic representation of the electromagnetic field radiated from arbitrary collinear array antennas is presented. The asymptotic field is obtained applying the saddle-point technique to the radiation integrals after expressing the current excited along the array axis by means of a Fourier spectral representation. The resulting electromagnetic field is expressed in terms of propagating and evanescent truncated Floquet Waves (FWs). The leading asymptotic term of the FWs exhibits an optical behavior and is responsible for the slow decay of the array near-field, which can be described as cylindrical in character. The transition toward the spherical wave propagation regime is due to the interference of the cylindrical field with the relevant scattered field from the array truncations, while the reactive energy storage is due to the evanescent FWs, as well as to the progressive inductive and progressive electrostatic FWs excited close the antenna axis. Using the asymptotic field representation, prediction formulas for the spatial locations where the array near-field exhibits peak deviation from the cylindrical decay, and where the transition from cylindrical to spherical wave propagation regime takes place, have been derived. The proposed analytical technique can be adopted to analyze the spatial field distributions and the radiation mechanisms of periodic and nonperiodic linear arrays. [ABSTRACT FROM AUTHOR]

Examines the effects of ear-connection modeling on the electromagnetic-energy absorption in a human-head phantom exposed in a dipole antenna field. Elaboration of the lousy pinna concentrations of phantoms; Derivation of the half-wave dipole in RF source; Details of the specific absorption rate in the wireless devices.

Analyzes the structure of polyethylene oxide solutions in tap water and heavy water with the use of small-angle neutron scattering, PCS, and Raman spectroscopy. Information on the diffusive properties of the compound; Factor affecting coil conformation; Information on the solvent quality of the types of water.

Evidence on the effectiveness of SARS-CoV-2 vaccines in nursing home (NHs) residents is limited. We examined the impact of the BNT162b2 mRNA SARS-CoV-2 vaccine on the course of the epidemic in NHs in the Florence Health District, Italy, before and after vaccination. Moreover, we assessed survival and hospitalization by vaccination status in SARS-CoV-2-positive cases occurring during the post-vaccination period. We calculated the weekly infection rates during the pre-vaccination (1 October–26 December 2020) and post-vaccination period (27 December 2020–31 March 2021). Cox analysis was used to analyze survival by vaccination status. The study involved 3730 residents (mean age 84, 69% female). Weekly infection rates fluctuated during the pre-vaccination period (1.8%–6.5%) and dropped to zero during the post-vaccination period. Nine unvaccinated (UN), 56 partially vaccinated (PV) and 35 fully vaccinated (FV) residents tested SARS-CoV-2+ during the post-vaccination period. FV showed significantly lower hospitalization and mortality rates than PV and UV (hospitalization: FV 3%, PV 14%, UV 33%; mortality: FV 6%, PV 18%, UV 56%). The death risk was 84% and 96% lower in PV (HR 0.157, 95%CI 0.049–0.491) and FV (HR 0.037, 95%CI 0.006–0.223) versus UV. SARS-CoV-2 vaccination was followed by a marked decline in infection rates and was associated with lower morbidity and mortality among infected NH residents. [ABSTRACT FROM AUTHOR]

Presents a hybrid technique in the analysis of transient emissions from microstrip interconnects. Background on microstrip technology; Derivation of space-time expression for traveling current pulse; Formation of planar structures; Current distributions.

A representation of the surface current density particularly suited for the electrodynamic characterization of arbitrarily shaped discontinuities in monolithic microwave and millimeter-wave integrated circuits (MMICs) is presented. The spectral domain approach (SDA) is adopted to carry out the analysis. Some numerical results, obtained using the proposed current representation, are compared with those available in the literature. A fast and excellent numerical convergence for the scattering parameters is achieved. [ABSTRACT FROM AUTHOR]

Copyright of Annals of Telecommunications is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Starting from a real case of a 69-year old patient affected by cholangiocarcinoma, we intend to discuss the accuracy and appropriateness of the diagnostic and therapeutic procedures adopted. This case shows in particular that a more accurate preoperative staging could probably avoid the patient unnecessary laparotomy. According to the indications in the medical literature, this patient could possibly benefit from chemotherapy, but a chemoembolization of liver metastases was performed. However in the literature no available evidence suggests that this treatment would be beneficial in this kind of clinical picture. Eventually, when the disease was already at an advanced stage and worsened due to a necrosis of the left hepatic lobe and a cholangitic infection, a repositioning of the stent on the stent was performed, despite in the literature the life expectancy cut-off for this procedure is at least 6 months. We also discuss the communication between the physician, the patient and the family, which was probably based on overly optimistic and unrealistic expectations. This led to a number of surgical procedures, which were not certainly helpful and indeed were probably even harmful for this patient. In addition, these procedures caused unnecessary costs borne by the healthcare system. In conclusion, we advocate that discussion and self-assessment must be always promoted, so that the healthcare professionals can review the process and the outcome of their treatment as well as their behavior to understand if it could have been more appropriate to offer actual benefits to the patients in terms of better quality of life and longer life expectancy. [ABSTRACT FROM AUTHOR]

Compact high-gain wideband antenna systems for through-the-wall imaging and wireless communications, featuring 160% fractional bandwidth, are presented. Each radiating system, consisting of two orthogonal Vivaldi antennas forming a cross-shaped configuration so as to excite linear (horizontal/vertical) and circular polarization (CP), is equipped with a top-mount spherical–axicon dielectric lens. The optimized shaping of the lens and of the outer edge Vivaldi arms allow achieving gain levels exceeding 15 dBi with good front-to-back-ratio. The proposed antenna features a broadside gain diagram with stable radiation pattern and wideband impedance matching in the frequency range between 650 MHz and 6 GHz. CST Microwave Studio, implementing a full-wave locally conformal finite integration technique (FIT), was employed to design and characterize the antenna and to guide its physical realization. Two-port equivalent circuits were developed to characterize parasitic coupling effects between the Vivaldi antennas ports, while a full-wave analysis allowed characterizing their frequency- and time-domain behaviors. The numerical results concerning the antennas parameters, illustrating the suitability of the proposed antennas to support narrow and ultra-wideband signal waveforms, are found to be in good agreement with the experimental measurements performed on an antenna prototype. [ABSTRACT FROM AUTHOR]

We report on incoherent quasielastic neutron scattering measurements examining a self-diffusion process in two types of glass-forming liquids, namely a molecular liquid (3-methylpentane) and an ionic liquid [1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide]. We have experimentally demonstrated that both liquids exhibit two crossovers in the momentum transfer (Q) dependence of the self-correlation function, which is basically described by the stretched exponential function, exp[-(t/τ)β]. The first crossover point (Q≈0.2Å-1) corresponds to a crossover from Fickian (β=1) to non-Fickian (β≠1) diffusion attributed to dynamical correlation. On the other hand, the second one at Q≈0.8Å-1 is associated with the crossover from Gaussian to non-Gaussian behavior. It is remarkable that the stretching exponent β gradually changes in between the two crossover points. We consider that the two crossovers are the universal feature for glass-forming liquids. [ABSTRACT FROM AUTHOR]

A correction to the article "Asymmetric polymers in bicontinuous microemulsions and their accretion to the bending of the membrane" that was published in the previous issue of the periodical.

Neutron spin echo spectroscopy is a high resolution inelastic neutron scattering method probing nanosecond dynamics. It is well suited to study the atomistic motion in polymer systems and contributes to our understanding of viscoelasticity. However, for samples under shear, or moving samples in general, Doppler scattering has to be considered. We compare the measured phase shift and depolarisation due to Doppler scattering from a rotating graphite disk to numerical and analytical calculations and find excellent agreement. This allows to take into account Doppler scattering during the data processing and makes longer Fourier times as well as higher shear rates and Q ranges possible with neutron spin echo spectroscopy, enabling for example the study of polymers under high shear. [ABSTRACT FROM AUTHOR]

EXPANSE, an EXPanded Angle Neutron Spin Echo instrument, has been proposed and selected as one of the first suite of instruments to be built at the Second Target Station of the Spallation Neutron Source at the Oak Ridge National Laboratory. This instrument is designed to address scientific problems that involve high-energy resolution (neV–μeV) of dynamic processes in a wide range of materials. The wide-angle detector banks of EXPANSE provide coverage of nearly two orders of magnitude in scattering wavenumbers, and the wide wavelength band affords approximately four orders of magnitude in Fourier times. This instrument will offer unique capabilities that are not available in the currently existing neutron scattering instruments in the United States. Specifically, EXPANSE will enable direct measurements of slow dynamics in the time domain over wide Q-ranges simultaneously and will also enable time-resolved spectroscopic studies. The instrument is expected to contribute to a diverse range of science areas, including soft matter, polymers, biological materials, liquids and glasses, energy materials, unconventional magnets, and quantum materials. [ABSTRACT FROM AUTHOR]

Bundlemer (grey cylinders) solution structure at various concentrations (C) and length scales (Q-1) is dictated by short-range attraction (green) and long-range repulsion (yellow) interactions. [Display omitted] • Bundlemers are model globular protein mimicking colloidal particles. • Bundlemers can be computationally desinged to display desired net charge and pattern. • Bundlemers display a balance of attraction and repulsion interactions. The use of isotropic potential models of simple colloids for describing complex protein–protein interactions is a topic of ongoing debate in the biophysical community. This contention stems from the unavailability of synthetic protein-like model particles that are amenable to systematic experimental characterization. In this article, we test the utility of colloidal theory to capture the solution structure, interactions and dynamics of novel globular protein-mimicking, computationally designed peptide assemblies called bundlemers that are programmable model systems at the intersection of colloids and proteins. Small-angle neutron scattering (SANS) measurements of semi-dilute bundlemer solutions in low and high ionic strength solution indicate that bundlemers interact locally via repulsive interactions that can be described by a screened repulsive potential. We also present neutron spin echo (NSE) spectroscopy results that show high- Q freely-diffusive dynamics of bundlemers. Importantly, formation of clusters due to short-range attractive, inter-bundlemer interactions is observed in SANS even at dilute bundlemer concentrations, which is indicative of the complexity of the bundlemer charged surface. The similarities and differences between bundlemers and simple colloidal as well as complex protein–protein interactions is discussed in detail. [ABSTRACT FROM AUTHOR]

Rechargeable Zn‐ion batteries (ZIBs) are widely regarded as promising candidates for large‐scale energy storage applications. Like most multivalent battery systems (based on Zn, Mg, Ca, etc.), further progress in ZIB development relies on the discovery and design of novel cathode hosts capable of reversible Zn2+ (de)intercalation. Herein, this work employs VPO4F as a ZIB cathode and explores ensuing intercalation mechanisms along with interfacial dynamics during cycling to quantify the water dynamics in concentrated electrolytes and/or hybrid aqueous‐non aqueous (HANEs) electrolyte(s). Like most oxide‐based cathode materials, proton (H+) intercalation dominates electrochemical activity during discharge of ZnxHyVPO4F in aqueous media due to the hydroxylated nature of the interface. Such H+ electrochemistry diminishes low‐rate and/or long‐term electrochemical performance of ZIBs which inhibits implementation for practical applications. Thus, quantification of the water dynamics in various electrolytes is demonstrated for the first time. Detailed investigations of water mobility in various concentrated electrolytes and HANEs systems enable the design of an electrolyte that enhances aqueous anodic stability and suppresses water/proton activity during discharge. Tuning Zn2+/H+ intercalation kinetics simultaneously allows for a high voltage (1.9 V) and long‐lasting aqueous zinc‐ion battery: Zn|Zn(OTf)2·nH2O‐PC|ZnxHyVPO4F. [ABSTRACT FROM AUTHOR]

Membrane viscosity is a fundamental property that controls molecular transport and structural rearrangements in lipid membranes. Given its importance in many cell processes, various experimental and computational methods have been developed to measure the membrane viscosity, yet the estimated values depend highly on the method and vary by orders of magnitude. Here we investigate the molecular origins of membrane viscosity by measuring the nanoscale dynamics of the lipid acyl tails using x-ray and neutron spectroscopy techniques. The results show that the membrane viscosity can be estimated from the structural relaxation times of the lipid tails. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to assess the incidence of deep vein thrombosis (DVT) of the lower limbs, using serial compression ultrasound (CUS) surveillance, in acutely ill patients with COVID-19 pneumonia admitted to a non-ICU setting. Methods: Multicenter, prospective study of patients with COVID-19 pneumonia admitted to Internal Medicine units. All patients were screened for DVT of the lower limbs with serial CUS. Anticoagulation was defined as: low dose (enoxaparin 20–40 mg/day or fondaparinux 1.5–2.5 mg/day); intermediate dose (enoxaparin 60–80 mg/day); high dose (enoxaparin 120–160 mg or fondaparinux 5–10 mg/day or oral anticoagulation). The primary end-point of the study was the diagnosis of DVT by CUS. Results: Over a two-month period, 227 consecutive patients with moderate-severe COVID-19 pneumonia were enrolled. The incidence of DVT was 13.7% (6.2% proximal, 7.5% distal), mostly asymptomatic. All patients received anticoagulation (enoxaparin 95.6%) at the following doses: low 57.3%, intermediate 22.9%, high 19.8%. Patients with and without DVT had similar characteristics, and no difference in anticoagulant regimen was observed. DVT patients were older (mean 77±9.6 vs 71±13.1 years; p = 0.042) and had higher peak D-dimer levels (5403 vs 1723 ng/mL; p = 0.004). At ROC analysis peak D-dimer level >2000 ng/mL (AUC 0.703; 95% CI 0.572–0.834; p = 0.004) was the most accurate cut-off value able to predict DVT (RR 3.74; 95%CI 1.27–10, p = 0.016). Conclusions: The incidence of DVT in acutely ill patients with COVID-19 pneumonia is relevant. A surveillance protocol by serial CUS of the lower limbs is useful to timely identify DVT that would go otherwise largely undetected. [ABSTRACT FROM AUTHOR]