Magnetic resonance imaging (MRI) has become an unrivalled medical diagnostic technique able to map tissue anatomy and physiology non-invasively. MRI measurements are meticulously engineered to ...control experimental conditions across the sample. However, residual radiofrequency (RF) field inhomogeneities are often unavoidable, leading to artefacts that degrade the diagnostic and scientific value of the images. Here we show that, paradoxically, these artefacts can be eliminated by deliberately interweaving freely varying heterogeneous RF fields into a magnetic resonance fingerprinting data-acquisition process. Observations made based on simulations are experimentally confirmed at 7 Tesla (T), and the clinical implications of this new paradigm are illustrated with in vivo measurements near an orthopaedic implant at 3T. These results show that it is possible to perform quantitative multiparametric imaging with heterogeneous RF fields, and to liberate MRI from the traditional struggle for control over the RF field uniformity.
A large number of behavioral experiments have demonstrated the existence of a magnetic sense in many animal species. Further, studies with immediate gene expression markers have identified putative ...brain regions involved in magnetic information processing. In contrast, very little is known about the physiology of the magnetic sense and how the magnetic field is neuronally encoded. In vivo electrophysiological studies reporting neuronal correlates of the magnetic sense either have turned out to be irreproducible for lack of appropriate artifact controls or still await independent replication. Thus far, the research field of magnetoreception has little exploited the power of ex vivo physiological studies, which hold great promise for enabling stringent controls. However, tight space constraints in a recording setup and the presence of magnetizable materials in setup components and microscope objectives make it demanding to generate well-defined magnetic stimuli at the location of the biological specimen. Here, we present a solution based on a miniature vector magnetometer, a coil driver, and a calibration routine for the coil system to compensate for magnetic distortions in the setup. The magnetometer fits in common physiology recording chambers and has a sufficiently small spatial integration area to allow for probing spatial inhomogeneities. The coil-driver allows for the generation of defined non-stationary fast changing magnetic stimuli. Our ex vivo multielectrode array recordings from avian retinal ganglion cells show that artifacts induced by rapid magnetic stimulus changes can mimic the waveform of biological spikes on single electrodes. However, induction artifacts can be separated clearly from biological responses if the spatio-temporal characteristics of the artifact on multiple electrodes is taken into account. We provide the complete hardware design data and software resources for the integrated magnetic stimulation system.
CuSbS2 was tested as a negative electrode material for sodium-ion batteries. The material synthesized by ball milling offers a specific charge of 730 mAh g−1, close to the theoretical value ...(751 mAh g−1), over a few cycles. The reaction mechanism was investigated by means of operando X-ray diffraction, 121Sb Mössbauer spectroscopy, and Cu K-edge X-ray absorption spectroscopy. These studies reveal a sodiation mechanism that involves an original conversion reaction in two steps, through the formation of a ternary phase, CuSb(1−x)S(2−y), as well as a NaxS alloy and Sb, followed by an alloying reaction involving the previously formed Sb. The desodiation process ends with the reformation of the ternary phase, CuSb(1−x′)S(2−y′), deficient in Sb and S; this phase is responsible for the good reversibility observed upon cycling.
•A ternary phase CuSbS2 is tested as anode material for sodium ion batteries.•Reversible specific charge of 730 mAh g−1 for few cycles without optimization.•Combination of conversion and alloying reactions mechanism.
Coronavirus disease 2019 has stretched the ability of many institutions to supply needed personal protective equipment, especially N95 respirators. N95 decontamination and re-use programmes provide ...one potential solution to this problem. Unfortunately, a comprehensive evaluation of the effects of decontamination on the fit of various N95 models using a quantitative fit test (QNFT) approach is lacking.
To investigate the effects of up to eight rounds of vaporized hydrogen peroxide (VHP) decontamination on the fit of N95 respirators currently in use in a hospital setting, and to examine if N95 respirators worn by one user can adapt to the face shape of a second user with no compromise to fit following VHP decontamination.
The PortaCount Pro+ Respirator Fit Tester Model 8038 was used to quantitatively define functional integrity, measured by fit, of N95 respirators following decontamination with VHP.
There was an observable downward trend in the functional integrity of Halyard Fluidshield 46727 N95 respirators throughout eight cycles of decontamination with VHP. Functional integrity of 3M 1870 N95 respirators was reduced significantly after the respirator was worn, decontaminated with VHP, and then quantitatively fit tested on a second user. Furthermore, inconsistencies between qualitative fit test and QNFT results were uncovered that may have strong implications on the fit testing method used by institutions.
The data revealed variability in the functional integrity of different N95 models after VHP decontamination, and exposed potential limitations of N95 decontamination and re-use programmes.
Chronic infection with the hepatitis B virus (HBV) is a major risk factor for development of end‐stage liver disease, including cirrhosis, liver failure and primary liver cancer. There are now seven ...antiviral agents approved by the United States Food and Drug Administration (FDA) for the management of chronic HBV infection. Despite the fact that there are between 1.4 and 2 million chronic HBV infections in the United States, fewer than 50 000 people per year receive prescriptions for HBV antiviral medications. This report discusses possible explanations for the disparity between the number of people who are chronically infected and the number of people who receive treatment. Explanations for this incongruence include the potentially large number of infected persons who are unscreened and thus remain undiagnosed, and lack of access, including insurance, education and referral to appropriate medical care, particularly for disproportionately infected populations.
The COVID-19 pandemic has caused a severe shortage of personal protective equipment (PPE), especially N95 respirators. Efficient, effective and economically feasible methods for large-scale PPE ...decontamination are urgently needed.
(1) to develop protocols for effectively decontaminating PPE using vaporized hydrogen peroxide (VHP); (2) to develop novel approaches that decrease set-up and take-down time while also increasing decontamination capacity; (3) to test decontamination efficiency for N95 respirators heavily contaminated by make-up or moisturizers.
We converted a decommissioned Biosafety Level 3 laboratory into a facility that could be used to decontaminate N95 respirators. N95 respirators were hung on metal racks, stacked in piles, placed in paper bags or covered with make-up or moisturizer. A VHP® VICTORY™ unit from STERIS was used to inject VHP into the facility. Biological and chemical indicators were used to validate the decontamination process. Findings: N95 respirators individually hung on metal racks were successfully decontaminated using VHP. N95 respirators were also successfully decontaminated when placed in closed paper bags or if stacked in piles of up to six. Stacking reduced the time needed to arrange N95 respirators for decontamination by approximately two-thirds while almost tripling facility capacity. Make-up and moisturizer creams did not interfere with the decontamination process.
Respirator stacking can reduce the hands-on time and increase decontamination capacity. When personalization is needed, respirators can be decontaminated in labelled paper bags. Make up or moisturizers do not appear to interfere with VHP decontamination.
The rising incidence of obesity is a major public health issue worldwide. Recent human and animal studies suggest that parental diet can influence fetal development and is implicated with risk of ...obesity and type 2 diabetes in offspring. The hypothalamus is central to body energy homoeostasis and appetite by controlling endocrine signals. We hypothesise that offspring susceptibility to obesity is programmed in the hypothalamus in utero and mediated by changes to DNA methylation, which persist to adulthood. We investigated hypothalamic genome-wide DNA methylation in Psammomys obesus diet during pregnancy to the offspring's risk of obesity.
Using methyl-CpG binding domain capture and deep sequencing (MBD-seq), we examined the hypothalamus of offspring exposed to a low-fat diet and standard chow diet during the gestation and lactation period.
Offspring exposed to a low-fat parental diet were more obese and had increased circulating insulin and glucose levels. Methylome profiling identified 1447 genomic regions of differential methylation between offspring of parents fed a low-fat diet compared with parents on standard chow diet. Pathway analysis shows novel DNA methylation changes of hypothalamic genes associated with neurological function, nutrient sensing, appetite and energy balance. Differential DNA methylation corresponded to changes in hypothalamic gene expression of Tas1r1 and Abcc8 in the offspring exposed to low-fat parental diet.
Subject to parental low-fat diet, we observe DNA methylation changes of genes associated with obesity in offspring.
The purpose of this analysis is to examine the effect of an algorithm-driven online diabetes prevention program on changes in eating habits, physical activity and wellness/productivity factors.
The ...intervention, Alive-PD, used small-step individually tailored goal setting and other features to promote changes in diet and physical activity. A 6-month randomized controlled trial was conducted among patients from a healthcare delivery system who had confirmed prediabetes (n =339). Change in weight and glycemic markers were measured in the clinic. Changes in physical activity, diet and wellness/productivity factors were self-reported. Mean age was 55 (s.d. 8.9) years, mean body mass index was 31 (s.d. 4.4) kg m(-2), 68% were white and 69% were male.
The intervention group increased fruit/vegetable consumption by 3.71 (95% confidence interval (CI) 2.73, 4.70) times per week (effect size 0.62), and decreased refined carbohydrates by 3.77 (95% CI 3.10, 4.44) times per week both significantly (P<0.001) greater changes than in the control group. The intervention group also reported a significantly greater increase in physical activity than in the control group, effect size 0.49, P<0.001. In addition, the intervention group reported a significant increase in self-rated health, in confidence in ability to make dietary changes and in ability to accomplish tasks, and a decrease in fatigue, compared with the control group. These changes paralleled the significant treatment effects on glycemic markers and weight.
In addition to promoting improvements in weight and glycemic markers, the Alive-PD program appears to improve eating habits and physical activity, behaviors important not just for diabetes prevention but for those with diagnosed diabetes or obesity. The improvements in wellness/productivity may derive from the diet and activity improvements, and from the satisfaction and self-efficacy of achieving goals.
Manganese‐iron oxide particles are a promising candidate for both chemical‐looping combustion (CLC) and thermochemical energy storage. In CLC, the ability of metal oxides to oxidize fuels in an ...oxygen‐free atmosphere and re‐oxidize in air is addressed. Whereas, reaction enthalpy is the main focus of thermochemical energy storage for, e. g. concentrated solar power or an industrial process that requires high temperature levels. Sufficient mechanical strength of the particles while they endure chemical, thermal, or mechanical stress is a crucial factor for both concepts. Particle stability is investigated here by adding 20 wt.% of TiO2, ZrO2, or CeO2 as a supportive material to (Mn0.7Fe0.3)2O3. Thermal cyclization and temperature shock tests are conducted in a packed bed reactor to identify chemical stability as well as the effect of chemical and thermal stress. A subsequent particle size distribution analysis is performed to determine the relevant breakage mechanism. Attrition resistance is tested with a customized attrition jet cup to estimate the mechanical strength of particles. It is found that the high tendency of unsupported manganese‐iron oxide particles towards agglomeration can be improved with any of the chosen additives. The particles with CeO2, and especially with ZrO2, as an additive indicate an increase in resistance towards attrition. However, adding TiO2 has a severe negative impact on the chemical reactivity of the manganese‐iron oxide.
Particle degeneration and agglomeration is one challenge for an application of metal oxides in the discipline of thermochemical storage and chemical‐looping combustion. By supporting manganese‐iron oxide granules with additives, such as e. g. ZrO2 or CeO2, the tendency towards agglomeration and attrition can be minimized tremendously.
PDF
