This work demonstrates the feasibility of a hybrid radiofrequency (RF) applicator that supports magnetic resonance (MR) imaging and MR controlled targeted RF heating at ultrahigh magnetic fields ...(B0≥7.0T). For this purpose a virtual and an experimental configuration of an 8-channel transmit/receive (TX/RX) hybrid RF applicator was designed. For TX/RX bow tie antenna electric dipoles were employed. Electromagnetic field simulations (EMF) were performed to study RF heating versus RF wavelength (frequency range: 64 MHz (1.5T) to 600 MHz (14.0T)). The experimental version of the applicator was implemented at B0 = 7.0T. The applicators feasibility for targeted RF heating was evaluated in EMF simulations and in phantom studies. Temperature co-simulations were conducted in phantoms and in a human voxel model. Our results demonstrate that higher frequencies afford a reduction in the size of specific absorption rate (SAR) hotspots. At 7T (298 MHz) the hybrid applicator yielded a 50% iso-contour SAR (iso-SAR-50%) hotspot with a diameter of 43 mm. At 600 MHz an iso-SAR-50% hotspot of 26 mm in diameter was observed. RF power deposition per RF input power was found to increase with B0 which makes targeted RF heating more efficient at higher frequencies. The applicator was capable of generating deep-seated temperature hotspots in phantoms. The feasibility of 2D steering of a SAR/temperature hotspot to a target location was demonstrated by the induction of a focal temperature increase (ΔT = 8.1 K) in an off-center region of the phantom. Temperature simulations in the human brain performed at 298 MHz showed a maximum temperature increase to 48.6C for a deep-seated hotspot in the brain with a size of (19×23×32)mm(3) iso-temperature-90%. The hybrid applicator provided imaging capabilities that facilitate high spatial resolution brain MRI. To conclude, this study outlines the technical underpinnings and demonstrates the basic feasibility of an 8-channel hybrid TX/RX applicator that supports MR imaging, MR thermometry and targeted RF heating in one device.
The formation of dendrites and other protrusions on lithium metal anodes is a subject of continued interest due to the potential to incorporate these anodes in next-generation rechargeable batteries ...with increased energy densities. Solid polymer electrolytes show improved stability against lithium metal compared to liquid carbonate electrolytes. We have studied the effect of salt concentration on the formation of protrusions formed on electrodeposited lithium through a rigid block copolymer electrolyte, polystyrene-block-poly(ethylene oxide) (PS-b-PEO or SEO), in a lithium‑lithium symmetric cell. The cell lifetime decreases by a factor of 100 when salt concentration is increased by a factor of 5. Our main objective is to understand the reason for this observation. We show that this decrease is not due to a salt-induced change of the morphology of the block-copolymer electrolyte, nor is it due to a salt-induced change of mechanical properties. We use an approach based on Newman's concentrated solution theory to fully characterize ion transport in the block-copolymer electrolyte, and report the conductivity, salt diffusion coefficient, cation transference number, and thermodynamic factor. Neither cell lifetime nor protrusion density in failed cells correlate with any of these electrochemical parameters. However, the electrochemical parameters can be used to predict salt concentration profiles in our symmetric cells. We posit that an important parameter in protrusion growth is the magnitude of the salt concentration gradient, ∆. We observe a direct correlation between ∆ and lithium protrusion growth.
•The lifetime of lithium-lithium symmetric cells decreases by a factor of 100 when salt concentration is increased by a factor of 5.•The decrease of cell lifetime is not due to salt-induced morphological change nor salt-induced mechanical change.•Concentrated solution theory was used to fully characterize ion-transport in the block copolymer electrolyte.•Prediction of salt concentration profiles in the lithium-lithium symmetric cells were made.•We observe a direct correlation between the magnitude of the salt concentration gradient and lithium protrusion growth.
Introduction
The effects of spending time in forests have been subject to investigations in various countries around the world. Qualitative comparisons have been rarely done so far.
Methods
Sixteen ...healthy highly sensitive persons (SV12 score ≥ 18) aged between 18 and 70 years were randomly assigned to groups spending 1 h in the forest and in the field at intervals of one week. Semi-structured interviews were conducted after each intervention and analyzed using a mixed-methods approach of content analysis and grounded theory.
Results
Both natural environments induced feelings of inner calmness, inner cleansing, joy, freedom, connectedness, strengthening qualities, and heightened body awareness. The forest environment additionally offered emotional shelter, and showed advantages in promoting inner strength and self-concentration.
Discussion
People with previous negative experiences in the forest may feel safer in fields because of the wider view and better overview. Important preconditions are enough time and the absence of a judgmental authority. The two environments induced in part different but also similar emotions which might be useful to promote psychological well-being differentially.
Purpose
The Vibrant Soundbridge (VSB) was introduced in 1996, and the fourth generation of the audio processor recently released. This clinical study evaluates the audiological performance and ...subjective satisfaction of the new SAMBA 2 audio processor compared to its predecessor, SAMBA.
Method
Fifteen VSB users tested both audio processors for approximately 3 weeks. Air conduction and bone conduction thresholds and unaided and aided sound field thresholds were measured with both devices. Speech performance in quiet (Freiburg monosyllables) and noise (OLSA) was evaluated as well as subjective listening effort (ACALES) and questionnaire outcomes (SSQ12 and APSQ). In addition, data from 16 subjects with normal hearing were gathered on sound field tests and ACALES.
Results
Both audio processors showed substantial improvement compared to the unaided condition. The SAMBA and SAMBA 2 had comparable performance in sound filed thresholds, while the SAMBA 2 was significantly better in speech in quiet, speech in noise, reduced listening effort, and improved subjective satisfaction compared with the SAMBA.
Conclusion
The SAMBA 2 audio processor, compared to its predecessor SAMBA, offers improved performance throughout the parameters investigated in this study. Patients with a VSB implant would benefit from an upgrade to SAMBA 2.
This consensus statement has been compiled on behalf of the International Society for Holter and Noninvasive Electrophysiology. It reviews the topic of heart rate turbulence (HRT) and concentrates on ...technologies for measurement, physiologic background and interpretation, and clinical use of HRT. It also lists suggestions for future research. The phenomenon of HRT refers to sinus rhythm cycle-length perturbations after isolated premature ventricular complexes. The physiologic pattern of HRT consists of brief heart rate acceleration (quantified by the so-called turbulence onset) followed by more gradual heart rate deceleration (quantified by the so-called turbulence slope) before the rate returns to a pre-ectopic level. Available physiologic investigations confirm that the initial heart rate acceleration is triggered by transient vagal inhibition in response to the missed baroreflex afferent input caused by hemodynamically inefficient ventricular contraction. A sympathetically mediated overshoot of arterial pressure is responsible for the subsequent heart rate deceleration through vagal recruitment. Hence, the HRT pattern is blunted in patients with reduced baroreflex. The HRT pattern is influenced by a number of factors, provocations, treatments, and pathologies reviewed in this consensus. As HRT measurement provides an indirect assessment of baroreflex, it is useful in those clinical situations that benefit from baroreflex evaluation. The HRT evaluation has thus been found appropriate in risk stratification after acute myocardial infarction, risk prediction, and monitoring of disease progression in heart failure, as well as in several other pathologies.
Due to their rarity and radioactive nature, comparatively little is known about the actinides, particularly those with atomic numbers higher than that of plutonium, and their compounds. In this work, ...we describe how transmission electron microscopy can provide comprehensive, safe, and cost-effective characterization using only single nanogram amounts of highly-radioactive, solid compounds. Chlorides of the rare elements berkelium and californium are dropcast and then converted in situ to oxides using the electron beam. The f-band occupancies are probed using electron energy loss spectroscopy and an unexpectedly weak spin-orbit-coupling is identified for berkelium. In contrast, californium follows a jj coupling scheme. These results have important implications for the chemistries of these elements and solidify the status of californium as a transitional element in the actinide series.
To investigate the safety and feasibility of 3 nonconsecutive days of intermittent fasting (IF) per week over 12 weeks in participants with insulin-treated type 2 diabetes.
Forty-six people were ...randomized to an IF or control group. Dietary counseling and continuous glucose monitoring was provided. Coprimary end points were the change in HbA1c from baseline to 12 weeks and a composite end point (weight reduction ≥2%, insulin dose reduction ≥10%, and HbA1c reduction ≥3 mmol/mol).
The IF group showed a significant HbA1c reduction (-7.3 ± 12.0 mmol/mol) compared with the control group (0.1 ± 6.1 mmol/mol) over 12 weeks (P = 0.012). The coprimary end point was achieved by 8 people in the IF and none in the control group (P < 0.001). No severe hypoglycemia occurred.
IF is a safe and feasible dietary option to ameliorate glycemic control while reducing total daily insulin dose and body weight in insulin-treated people with type 2 diabetes.
The introduction of lockdowns and other containment measures during the COVID-19 pandemic substantially altered people's lifestyle and dietary behavior. Several studies evaluated the short-term ...effects of these measures; yet reports on long-term consequences are scarce. We sought to address this gap in the literature by analyzing dietary and lifestyle data collected at an obesity center in Rome, Italy. The Italian region of Lazio was hit hard by the pandemic. To evaluate the potential health impacts, we compared the pre- and post-lockdown data of 118 individuals. Contrary to the common belief that lockdown had adverse effects solely on people's dietary habits, we observed a significantly increased consumption of raw vegetables, whole grains, and water in our study sample. Favorable effects, however, were also accompanied by adverse trends, such as a higher prevalence of sleeping difficulties. Our data emphasize that the lockdowns associated with the pandemic also influenced participants' social behavior, with less individuals reporting eating out or in company. Our study highlights the substantial impact of lockdowns on many dimensions of life. As such, it is of utmost importance in the critical evaluation of such stringent containment measures.
Aims
To investigate the seroconversion following first and second COVID‐19 vaccination in people with type 1 and type 2 diabetes in relation to glycaemic control prior to vaccination and to analyse ...the response in comparison to individuals without diabetes.
Materials and methods
This prospective, multicentre cohort study analysed people with type 1 and type 2 diabetes and a glycated haemoglobin level ≤58 mmol/mol (7.5%) or >58 mmol/mol (7.5%), respectively, and healthy controls. Roche's Elecsys anti‐SARS‐CoV‐2 S immunoassay targeting the receptor‐binding domain was used to quantify anti‐spike protein antibodies 7 to 14 days after the first and 14 to 21 days after the second vaccination.
Results
A total of 86 healthy controls were enrolled in the study, as well as 161 participants with diabetes, of whom 150 (75 with type 1 diabetes and 75 with type 2 diabetes) were eligible for the analysis. After the first vaccination, only 52.7% of participants in the type 1 diabetes group and 48.0% of those in the type 2 diabetes group showed antibody levels above the cut‐off for positivity. Antibody levels after the second vaccination were similar in participants with type 1 diabetes, participants with type 2 diabetes and healthy controls after adjusting for age, sex and multiple testing (P > 0.05). Age (r = −0.45, P < 0.001) and glomerular filtration rate (r = 0.28, P = 0.001) were significantly associated with antibody response.
Conclusions
Anti‐SARS‐CoV‐2 S receptor‐binding domain antibody levels after the second vaccination were comparable in healthy controls and in participants with type 1 and type 2 diabetes, irrespective of glycaemic control. Age and renal function correlated significantly with the extent of antibody levels.
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