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International Journal of Molecular... Jul 2023Graphene is the first two-dimensional material that becomes the center material in various research areas of material science, chemistry, condensed matter, and... (Review)
Review
Graphene is the first two-dimensional material that becomes the center material in various research areas of material science, chemistry, condensed matter, and engineering due to its advantageous properties, including larger specific area, lower density, outstanding electrical conductivity, and ease of processability. These properties attracted the attention of material researchers that resulted in a large number of publications on EMI shielding in a short time and play a central role in addressing the problems and challenges faced in this modern era of electronics by electromagnetic interference. After the popularity of graphene, the community of material researchers investigated other two-dimensional materials like MXenes, hexagonal boron nitride, black phosphorous, transition metal dichalcogenides, and layered double hydroxides, to additionally enhance the EMI shielding response of materials. The present article conscientiously reviews the current progress in EMI shielding materials in reference to two-dimensional materials and addresses the future challenges and research directions to achieve the goals.
Topics: Graphite; Electric Conductivity; Electronics; Phosphorus
PubMed: 37569645
DOI: 10.3390/ijms241512267 -
Biomedical Physics & Engineering Express Oct 2023To show the considerations followed for MR-linac in shielding design for the first MR-linac in Mexico following the national clinical necessities.The National Council on...
To show the considerations followed for MR-linac in shielding design for the first MR-linac in Mexico following the national clinical necessities.The National Council on Radiation Protection and Measurements (NCRP) 151 recommendations were followed for the shielding design for primary and secondary barriers and the door design. The calculations were made considering the clinical demands in the country, that is, intensity modulated (IMRT) and 3D conformal radiotherapy (3DC-RT) in 80%-20% proportion.The values obtained in the level survey fully comply with the limits established by the national regulatory authority and with those recommended by the International Commission on Radiological Protection (ICRP) for public and occupational exposures.It is remarkable that the workload may increase or that the doses per patient may increase considering occupancy factors, which would allow the introduction of hypofractionated techniques with the same number of patients considered in this work without the need to make modifications in the bunker design.
Topics: Humans; Particle Accelerators; Radiotherapy, Conformal; Protective Devices; Radiation Protection
PubMed: 37857281
DOI: 10.1088/2057-1976/ad04e9 -
Molecules (Basel, Switzerland) Nov 2023Electromagnetic shielding materials are special materials that can effectively absorb and shield electromagnetic waves and protect electronic devices and electronic... (Review)
Review
Electromagnetic shielding materials are special materials that can effectively absorb and shield electromagnetic waves and protect electronic devices and electronic circuits from interference and damage by electromagnetic radiation. This paper presents the research progress of intrinsically conductive polymer materials and conductive polymer-based composites for electromagnetic shielding as well as an introduction to lightweight polymer composites with multicomponent systems. These materials have excellent electromagnetic interference shielding properties and have the advantages of electromagnetic wave absorption and higher electromagnetic shielding effectiveness compared with conventional electromagnetic shielding materials, but these materials still have their own shortcomings. Finally, the paper also discusses the future opportunities and challenges of intrinsically conductive polymers and composites containing a conductive polymer matrix for electromagnetic shielding applications.
PubMed: 38005369
DOI: 10.3390/molecules28227647 -
The Review of Scientific Instruments Mar 2024Achieving micro-kelvin (µK) temperature stability is critical for many calorimetric applications. For example, sub-nanowatt resolution biocalorimetry requires...
Achieving micro-kelvin (µK) temperature stability is critical for many calorimetric applications. For example, sub-nanowatt resolution biocalorimetry requires stabilization of the temperature of the calorimeter to µK levels. Here, we describe how µK temperature stability can be accomplished in a prototypical calorimetric system consisting of two nested shields and a suspended capillary tube, which is well suited for biocalorimetry applications. Specifically, we show that by employing nested shields with µTorr-levels of vacuum in the space between them as well as precise feedback control of the temperature of the shields (performed using high-resolution temperature sensors), the effect of ambient temperature fluctuations on the inner shield and the capillary tube can be attenuated by ∼100 dB. We also show that this attenuation is key to achieving temperature stabilities within ±1 and ±3 µK (amplitude of oscillations) for the inner shield and the capillary tube sensor, respectively, measured in a bandwidth of 1 mHz over a period of 10 h at room temperature (∼20.9 ± 0.2 °C). We expect that the methods described here will play a key role in advancing biocalorimetry.
PubMed: 38446002
DOI: 10.1063/5.0188285 -
Dermatologic Clinics Oct 2023The reality of dermatology practice in the 21st century includes the potential for lawsuits and liability. While medical malpractice may be top-of-mind, there are a host... (Review)
Review
The reality of dermatology practice in the 21st century includes the potential for lawsuits and liability. While medical malpractice may be top-of-mind, there are a host of liability risks beyond malpractice-from employee claims and fiduciary liability for the practice retirement plan to premises liability and HIPAA violations-as well as potential personal liability for rental properties, car accidents (for self and children), outside businesses, personal guarantees and more. This article outlines the leading tools dermatologists can utilize to better shield their assets from potential liability-including exempt assets, co-ownership forms, and legal tools, such as limited liability companies and trusts.
Topics: Child; Humans; Dermatologists; Ownership
PubMed: 37718020
DOI: 10.1016/j.det.2023.05.008 -
Ecology and Evolution Sep 2023Males of many insects, including butterflies, produce mate-guarding devices, such as mating plugs, to prolong guarding and prevent future female matings in the male's...
Males of many insects, including butterflies, produce mate-guarding devices, such as mating plugs, to prolong guarding and prevent future female matings in the male's absence. In a few butterflies, large external mate-guarding devices, that is, sphragides, occur. Gór et al. (, 160, 2023 and 515-557) found conspicuously large size and morphological variation of mate-guarding devices within a single population of the potentially polyandrous Clouded Apollo (, L.) butterfly. They termed the externally visible male-produced devices as Copulatory opening APpendices (CAP) consisting of small devices, termed small CAPs and the much larger shield (i.e. sphragis). Our aim was to reveal CAP replacement dynamics within females during their lifetime and to understand how male investment into small CAPs or shields was (i) related to CAP persistence on the female, that is securing paternity, (ii) associated with female quality, measured as size and (iii) with actual adult sex ratio. We investigated a univoltine Clouded Apollo population to estimate CAP replacement risks, using multistate survival models, in an extensive observational study through 6 years based on mark-recapture. Shields were the most frequent mate-guarding devices and were more persistent than small CAPs, often lasting for life, excluding future matings. Thus, most females bearing a shield were deprived of postcopulatory female choice, and the genetic variance in their offspring could be reduced compared to those bearing small CAPs, thus mating more often. The ratio of shields to all CAPs gradually decreased towards the end of the flight period. Males were more prone to produce a shield when mating females with wider thoraces and when the ratio of males (i.e. competition) was higher in the population. To our best knowledge, this is the first quantitative study to investigate potential factors on which male investment in mate-guarding devices may depend, and how the variation in these devices impacts CAP persistence on females.
PubMed: 37727777
DOI: 10.1002/ece3.10533 -
Angewandte Chemie (International Ed. in... Mar 2024We report soluble tetrakis-biphenylyl substituted pentacenes comprised of sp carbons and synthesized from pentacene-5,7,12,14-tetraone. Intramolecular Yamamoto coupling...
We report soluble tetrakis-biphenylyl substituted pentacenes comprised of sp carbons and synthesized from pentacene-5,7,12,14-tetraone. Intramolecular Yamamoto coupling of two tetrakis(chlorobiphenylyl)pentacenes yields helical, doubly wrapped pentacenes, in which the quaterphenylene units solubilize the pentacenes and shield their central anthracene units to an unprecedented degree. The criss-cross-bridged pentacenes resist (photo)oxidation, Diels-Alder reactions and are much less reactive than TIPS-ethynylated pentacene. Extension of this concept might provide access to the larger acenes.
PubMed: 38180106
DOI: 10.1002/anie.202316902 -
Frontiers in Cardiovascular Medicine 2023Magnetocardiography (MCG), which is nowadays 60 years old, has not yet been fully accepted as a clinical tool. Nevertheless, a large body of research and several... (Review)
Review
Magnetocardiography (MCG), which is nowadays 60 years old, has not yet been fully accepted as a clinical tool. Nevertheless, a large body of research and several clinical trials have demonstrated its reliability in providing additional diagnostic electrophysiological information if compared with conventional non-invasive electrocardiographic methods. Since the beginning, one major objective difficulty has been the need to clean the weak cardiac magnetic signals from the much higher environmental noise, especially that of urban and hospital environments. The obvious solution to record the magnetocardiogram in highly performant magnetically shielded rooms has provided the ideal setup for decades of research demonstrating the diagnostic potential of this technology. However, only a few clinical institutions have had the resources to install and run routinely such highly expensive and technically demanding systems. Therefore, increasing attempts have been made to develop cheaper alternatives to improve the magnetic signal-to-noise ratio allowing MCG in unshielded hospital environments. In this article, the most relevant milestones in the MCG's journey are reviewed, addressing the possible reasons beyond the currently long-lasting difficulty to reach a clinical breakthrough and leveraging the authors' personal experience since the early 1980s attempting to finally bring MCG to the patient's bedside for many years thus far. Their nearly four decades of foundational experimental and clinical research between shielded and unshielded solutions are summarized and referenced, following the original vision that MCG had to be intended as an unrivaled method for contactless assessment of the cardiac electrophysiology and as an advanced method for non-invasive electroanatomical imaging, through multimodal integration with other non-fluoroscopic imaging techniques. Whereas all the above accounts for the past, with the available innovative sensors and more affordable active shielding technologies, the present demonstrates that several novel systems have been developed and tested in multicenter clinical trials adopting both shielded and unshielded MCG built-in hospital environments. The future of MCG will mostly be dependent on the results from the ongoing progress in novel sensor technology, which is relatively soon foreseen to provide multiple alternatives for the construction of more compact, affordable, portable, and even wearable devices for unshielded MCG inside hospital environments and perhaps also for ambulatory patients.
PubMed: 37636301
DOI: 10.3389/fcvm.2023.1232882 -
Nature Communications Nov 2023Janus structures have unique properties due to their distinct functionalities on opposing faces, but have yet to be realized with flowing liquids. We demonstrate such...
Janus structures have unique properties due to their distinct functionalities on opposing faces, but have yet to be realized with flowing liquids. We demonstrate such Janus liquids with a customizable distribution of nanoparticles (NPs) throughout their structures by joining two aqueous streams of NP dispersions in an apolar liquid. Using this anisotropic integration platform, different magnetic, conductive, or non-responsive NPs can be spatially confined to opposite sides of the original interface using magnetic graphene oxide (mGO)/GO, TiCT/GO, or GO suspensions. The resultant Janus liquids can be used as templates for versatile, responsive, and mechanically robust aerogels suitable for piezoresistive sensing, human motion monitoring, and electromagnetic interference (EMI) shielding with a tuned absorption mechanism. The EMI shields outperform their current counterparts in terms of wave absorption, i.e., SE ≈ 51 dB, SE ≈ 0.4 dB, and A = 0.91, due to their high porosity ranging from micro- to macro-scales along with non-interfering magnetic and conductive networks imparted by the Janus architecture.
PubMed: 38016959
DOI: 10.1038/s41467-023-43319-7 -
ACS Applied Bio Materials Jun 2024The increasing demand for biodegradable and environmentally friendly materials is shifting the focus from traditional polymer composites to biocomposites in various... (Review)
Review
The increasing demand for biodegradable and environmentally friendly materials is shifting the focus from traditional polymer composites to biocomposites in various applications, especially in electromagnetic shielding. Effective utilization of biopolymers demands improved properties and can be achieved to a certain extent by functionalization. Biopolymers such as cellulose, polylactic acid, and starch are some of the potential candidates for mitigating electromagnetic pollution in next-generation electronic devices because of their high aspect ratio, flexibility, light weight, high mechanical strength, thermal stability, and tunable microwave absorption to the electromagnetic interference (EMI) shielding composites. This Review provides an overview of the current advancements in EMI shielding materials and outlines recent research on EMI shielding composites that utilize various biodegradable polymer structures.
Topics: Biopolymers; Biocompatible Materials; Materials Testing; Particle Size; Electromagnetic Fields
PubMed: 38768373
DOI: 10.1021/acsabm.4c00421