The impact of heart valve and partial heart transplant models on the development of banking methods for tissues and organs: A concise review.

Cryopreserved human heart valves fill a crucial role in the treatment for congenital cardiac anomalies, since the use of alternative mechanical and xenogeneic tissue valves have historically been limited in babies. Heart valve models have been used since 1998 to better understand the impact of cryopreservation variables on the heart valve tissue components with the ultimate goals of improving cryopreserved tissue outcomes and potentially extrapolating results with tissues to organs. Cryopreservation traditionally relies on conventional freezing, employing cryoprotective agents, and slow cooling to sub-zero centigrade temperatures; but it is plagued by the formation of ice crystals and cell damage upon thawing. Researchers have identified ice-free vitrification procedures and developed a new rapid warming method termed nanowarming. Nanowarming is an emerging method that utilizes targeted application of energy at the nanoscale level to rapidly rewarm vitrified tissues, such as heart valves, uniformly for transplantation. Vitrification and nanowarming methods hold great promise for surgery, enabling the storage and transplantation of tissues for various applications, including tissue repair and replacement. These innovations have the potential to revolutionize complex tissue and organ transplantation, including partial heart transplantation. Banking these grafts addresses organ scarcity by extending preservation duration while preserving biological activity with maintenance of structural fidelity. While ice-free vitrification and nanowarming show remarkable potential, they are still in early development. Further interdisciplinary research must be dedicated to exploring the remaining challenges that include scalability, optimizing cryoprotectant solutions, and ensuring long-term viability upon rewarming in vitro and in vivo.

Revolutionizing Airborne Virus Defense: Electromagnetic MXene-Coated Air Filtration for Superior Aerosol Viral Removal.

The COVID-19 pandemic sparked public health concerns about the transmission of airborne viruses. Current methods mainly capture pathogens without inactivation, leading to potential secondary pollution. Herein, we evaluated the inactivation performance of a model viral species (MS2) in simulated bioaerosol by an electromagnetically enhanced air filtration system under a 300 kHz electromagnetic induction field. A nonwoven fabric filter was coated with a 2D catalyst, MXene (Ti3C2Tx), at a coating density of 4.56 mg·cm-2 to absorb electromagnetic irradiation and produce local heating and electromagnetic field for microbial inactivation. The results showed that the MXene-coated air filter significantly enhanced the viral removal efficiency by achieving a log removal of 3.4 ± 0.15 under an electromagnetic power density of 369 W·cm-2. By contrast, the pristine filter without catalyst coating only garnered a log removal of 0.3 ± 0.04. Though the primary antimicrobial mechanism is the local heating as indicated by the elevated surface temperature of 72.2 ± 4 °C under the electromagnetic field, additional nonthermal effects (e.g., dielectrophoresis) on enhanced viral capture during electromagnetically enhanced filtration were investigated by COMSOL simulation to delineate the potential transmission trajectories of bioaerosol. The results provide unique insights into the mechanisms of pathogen control and thus promote alternative solutions for preventing the transmission of airborne pathogens.

Fundamentals and Recent Progress in Magnetic Field Assisted CO2 Capture and Conversion.

CO2 capture and conversion technology are highly promising technologies that definitely play a part in the journey towards carbon neutrality. Releasing CO2 by mild stimulation and the development of high efficiency catalytic processes are urgently needed. The magnetic field, as a thermodynamic parameter independent of temperature and pressure, is vital in the enhancement of CO2 capture and conversion process. In this review, the recent progress of magnetic field-enhanced CO2 capture and conversion is comprehensively summarized. The theoretical fundamentals of magnetic field on CO2 adsorption, release and catalytic reduction process are discussed, including the magnetothermal, magnetohydrodynamic, spin selection, Lorentz forces, magnetoresistance and spin relaxation effects. Additionally, a thorough review of the current progress of the enhancement strategies of magnetic field coupled with a variety of fields (including thermal, electricity, and light) is summarized in the aspect of CO2 related process. Finally, the challenges and prospects associated with the utilization of magnetic field-assisted techniques in the construction of CO2 capture and conversion systems are proposed. This review offers a reference value for the future design of catalysts, mechanistic investigations, and practical implementation for magnetic field enhanced CO2 capture and conversion.

Direct Polyphenol Attachment on the Surfaces of Magnetite Nanoparticles, Using Vitis vinifera, Vaccinium corymbosum, or Punica granatum.

This study presents an alternative approach to directly synthesizing magnetite nanoparticles (MNPs) in the presence of Vitis vinifera, Vaccinium corymbosum, and Punica granatum derived from natural sources (grapes, blueberries, and pomegranates, respectively). A modified co-precipitation method that combines phytochemical techniques was developed to produce semispherical MNPs that range in size from 7.7 to 8.8 nm and are coated with a ~1.5 nm thick layer of polyphenols. The observed structure, composition, and surface properties of the MNPs@polyphenols demonstrated the dual functionality of the phenolic groups as both reducing agents and capping molecules that are bonding with Fe ions on the surfaces of the MNPs via -OH groups. Magnetic force microscopy images revealed the uniaxial orientation of single magnetic domains (SMDs) associated with the inverse spinel structure of the magnetite (Fe3O4). The samples' inductive heating (H0 = 28.9 kA/m, f = 764 kHz), measured via the specific loss power (SLP) of the samples, yielded values of up to 187.2 W/g and showed the influence of the average particle size. A cell viability assessment was conducted via the MTT and NRu tests to estimate the metabolic and lysosomal activities of the MNPs@polyphenols in K562 (chronic myelogenous leukemia, ATCC) cells.

Nanowarming of vitrified pancreatic islets as a cryopreservation technology for transplantation.

Biobanking of pancreatic islets for transplantation could solve the shortage of donors, and cryopreservation of vitrified islets is a possible approach. However, a technological barrier is rewarming of large volumes both uniformly and rapidly to prevent ice formation due to devitrification. Here, we describe successful recovery of islets from the vitrified state using a volumetric rewarming technology called "nanowarming," which is inductive heating of magnetic nanoparticles under an alternating magnetic field. Convective warming using a 37°C water bath as the gold standard for rewarming of vitrified samples resulted in a decrease in the viability of mouse islets in large volumes (>1 ml) owing to devitrification caused by slow warming. Nanowarming showed uniform and rapid rewarming of vitrified islets in large volumes. The viability of nanowarmed islets was significantly improved and islets transplanted into streptozotocin-induced diabetic mice successfully lowered serum glucose. The results suggest that nanowarming will lead to a breakthrough in biobanking of islets for transplantation.

Bio-Inspired Magnetically Controlled Reversibly Actuating Multimaterial Fibers.

Movements in plants, such as the coiling of tendrils in climbing plants, have been studied as inspiration for coiling actuators in robotics. A promising approach to mimic this behavior is the use of multimaterial systems that show different elastic moduli. Here, we report on the development of magnetically controllable/triggerable multimaterial fibers (MMFs) as artificial tendrils, which can reversibly coil and uncoil on stimulation from an alternating magnetic field. These MMFs are based on deformed shape-memory fibers with poly[ethylene-co-(vinyl acetate)] (PEVA) as their core and a silicone-based soft elastomeric magnetic nanocomposite shell. The core fiber provides a temperature-dependent expansion/contraction that propagates the coiling of the MMF, while the shell enables inductive heating to actuate the movements in these MMFs. Composites with mNP weight content ≥ 15 wt% were required to achieve heating suitable to initiate movement. The MMFs coil upon application of the magnetic field, in which a degree of coiling N = 0.8 ± 0.2 was achieved. Cooling upon switching OFF the magnetic field reversed some of the coiling, giving a reversible change in coiling ∆n = 2 ± 0.5. These MMFs allow magnetically controlled remote and reversible actuation in artificial (soft) plant-like tendrils, and are envisioned as fiber actuators in future robotics applications.

Inductive heating and flow chemistry - a perfect synergy of emerging enabling technologies.

Inductive heating has developed into a powerful and rapid indirect heating technique used in various fields of chemistry, but also in medicine. Traditionally, inductive heating is used in industry, e.g., for heating large metallic objects including bending, bonding, and welding pipes. In addition, inductive heating has emerged as a partner for flow chemistry, both of which are enabling technologies for organic synthesis. This report reviews the combination of flow chemistry and inductive heating in industrial settings as well as academic research and demonstrates that the two technologies ideally complement each other.

Radiosurgery imaging.

The most important imaging technology for GKNS continues to be magnetic resonance. The introduction of 3 Tesla machines permits quicker studies with better signal to noise ratio. The more powerful magnet increases the chances of heating the points of contact between patient and frame, but this has been solved with non-conducting nuts. There are several sequences for special functions. CISS studies are optimal for demonstrating cranial nerves in their passage through the subarachnoid space. FLAIR studies facilitate the distinction between CSF and edema due to inflammation. DTI permits the visualization of nerve fiber tracts. This has at least two current applications. In treatment planning of visible lesions, DTI permits a more efficient avoidance of important tracts. In functional work, tracts can be used to improve the definition of functional targets. Non stereotactic MRI can be imported into GammaPlan and co-registered to a non-distorted CT image.

Development and Evaluation of an Improved Apparatus for Measuring the Emissivity at High Temperatures.

An improved apparatus for measuring the spectral directional emissivity in the wavelength range between 1 µm and 20 µm at temperatures up to 2400 K is presented in this paper. As a heating unit an inductor is used to warm up the specimen, as well as the blackbody reference to the specified temperatures. The heating unit is placed in a double-walled vacuum vessel. A defined temperature, as well as a homogenous temperature distribution of the whole surrounding is ensured by a heat transfer fluid flowing through the gap of the double-walled vessel. Additionally, the surrounding is coated with a high-emitting paint and serves as blackbody-like surrounding to ensure defined boundary conditions. For measuring the spectral directional emissivity at different emission angles, a movable mirror is installed in front of the specimen, which can be adjusted by a rotatable arrangement guiding the emitted radiation into the attached FTIR-spectrometer. The setup of the emissivity measurement apparatus (EMMA) and the measurement procedure are introduced, and the derived measurement results are presented. For evaluating the apparatus, measurements were performed on different materials. The determined emissivities agree well with values published in literature within the derived relative uncertainties below 4% for most wavelengths.

Soft Tooling-Friendly Inductive Mold Heating-A Novel Concept.

In order to economize injection molded prototypes, additive manufacturing of, e.g., curable plastics based tools, can be employed, which is known as soft tooling. However, one disadvantage of such tools is that the variothermal process, which is needed to produce polymeric parts with small features, can lead to a shorter lifespan of the tooling due to its thermally impaired material properties. Here, a novel concept is proposed, which allows to locally heat the mold cavity via induction to circumvent the thermal impairment of the tooling material. The developed fabrication process consists of additive manufacturing of the tooling, PVD coating the mold cavity with an adhesion promoting layer and a seed layer, electroplating of a ferromagnetic metal layer, and finally patterning the metal layer via laser ablation to enhance the quality and efficiency of the energy transfer as well as the longevity by geometric measures. This process chain is investigated on 2D test specimens to find suitable fabrication parameters, backed by adhesion tests as well as environmental and induction tests. The results of these investigations serve as proof of concept and form the base for the investigation of such induction layers in actual soft tooling cavities.

Research on a New Localized Induction Heating Process for Hot Stamping Steel Blanks.

Localized induction heating with one magnetizer was experimentally analyzed in order to investigate the altering effect of the magnetizer on the magnetic field. A 22MnB5 blank for tailored property was locally heated to produce the parts of a car body in white, such as the B-pillars. A lower-temperature region with a temperature in the two-phase zone and a full-austenitic high-temperature region were formed on the steel blank after 30 s. After water-quenching, the mixture microstructure (F + M) and 100% fine-grained lath martensite were obtained from the lower- and high-temperature regions, respectively. Moreover, the ultimate tensile stress (UTS) of the parts from the lower- and high-temperature regions was 977 and 1698 MPa, respectively, whereas the total elongations were 17.5% and 14.5%, respectively. Compared with the parts obtained by conventional furnace heating⁻water quenching (UTS: 1554 MPa, total elongation: 12%), the as-quenched phase developed a tensile strength over 100 MPa greater and a higher ductility. Thus, the new heating process can be a good foundation in subsequent experiments to arbitrarily tailor the designable low-strength zone with a higher ductility by using magnetizers.

In situ synchrotron research of phase formation in mechanically activated 3Ti†+†Al powder composition during high-temperature synthesis under the condition of heating with high-frequency electromagnetic fields.

An in situ synchrotron study of the specific features of the phase formation dynamics in mechanically activated 16 wt% Al + Ti powder composition is described, the high-temperature synthesis being carried out under the condition of high volume inflammation by means of inductive heating. The kinetics of the phase formation were registered with an experimental complex, especially designed, constructed and adjusted for the method of dynamic diffraction analysis in synchrotron radiation beams. It has been experimentally in situ shown that increasing the time of mechanical activation of the initial powder mixture reduces the temperature at which components start to react and the time of realization of the high-temperature synthesis. With the latter set at 1 min of mechanical activation, the temperature of the reaction in the mixture is T = 603°C; at 3 min of mechanical activation, T = 442°C; and at 7 min, T = 359°C. The maximum burning temperatures are: for 1 min of mechanical activation, Tmax = 1080°C; for 3 min, Tmax = 1003°C; and for 7 min, Tmax = 820°C. It was found that formation of both stable compounds Ti3Al, TiAl3, TiAl2, TiAl and metastable phases Ti9Al23, Ti5Al11, Ti2Al5, Ti3Al5 occurs at the stage of primary structure formation, before the system goes to thermal explosion. High-temperature synthesis of a mixture of the studied composition takes place without formation of a liquid phase, in the solid-phase combustion mode. It was found that the increase in the time of mechanical activation of the initial powder mixture contributes to the formation of a product with a dominant content of intermetallic compound Ti3Al. By synthesis of the powder mixture of composition 16 wt% Al + Ti, mechanically activated for 7 min, the content of Ti3Al in the final product was found to be 68%.

Healing of Early Stage Fatigue Damage in Ionomer/Fe3O4 Nanoparticle Composites.

This work reports on the healing of early stage fatigue damage in ionomer/nano-particulate composites. A series of poly(ethylene-co-methacrylic acid) zinc ionomer/Fe3O4 nanoparticle composites with varying amounts of ionic clusters were developed and subjected to different levels of fatigue loading. The initiated damage was healed upon localized inductive heating of the embedded nanoparticles by exposure of the particulate composite to an alternating magnetic field. It is here demonstrated that healing of this early stage damage in ionomer particulate composites occurs in two different steps. First, the deformation is restored by the free-shrinkage of the polymer at temperatures below the melt temperature. At these temperatures, the polymer network is recovered thereby resetting the fatigue induced strain hardening. Then, at temperatures above the melting point of the polymer phase, fatigue-induced microcracks are sealed, hereby preventing crack propagation upon further loading. It is shown that the thermally induced free-shrinkage of these polymers does not depend on the presence of ionic clusters, but that the ability to heal cracks by localized melting while maintaining sufficient mechanical integrity is reserved for ionomers that contain a sufficient amount of ionic clusters guaranteeing an acceptable level of mechanical stability during healing.

Effect of inductive heating on drug release of tetrandrine-loaded PLGA magnetic nanoparticles / 中国药学杂志

OBJECTIVE: To prepare PLGA magnetic nanoparticles loaded with tetrandrine, heat the nanoparticles by inductive heating system, and study the particle size, morphology and drug release before and after heating. METHODS: Co-loaded PLGA NPs were prepared by emulsion solvent diffusion method; the physicochemical and magnetic characteristics of co-loaded PLGA NPs were investigated by DLS, SEM, TEM and VSM; RP-HPLC and ICP-MS analysis were used to measure the tetrandrine and Fe3O4 loading and entrapment efficiency. The EASYHEAT system was applied to heat the nanoparticles and further investigate the changes of particle size, morphology and drug release after inductive heating. RESULTS: Tetrandrine-loaded PLGA magnetic nanoparticles showed spherical shape with smooth surface and the Fe3O4 NPs were homogeneously distributed inside the polymeric nanoparticles; VSM result indicated that the co-loaded PLGA NPs were superparamagnetic; both tetrandrine and Fe3O4 showed good loading and entrapment efficiency. After being heated to 45℃, the diameter of co-loaded PLGA NPs increased; the morphology changed from a spherical shape into a nondefined, irregular shape; arrangement or aggregation of the incorporated Fe3O4 NPs were found. In addition, the drug release amount was also increased. CONCLUSION: With superparamagnetic property, the tetrandrine loaded-PLGA magnetic nanoparticles can effectively control the drug release behavior by inductive heating.

[3 + 2]-Cycloadditions of nitrile ylides after photoactivion of vinyl azides under flow conditions.

The photodenitrogenation of vinyl azides to 2H-azirines by using a photoflow reactor is reported and compared with thermal formation of 2H-azirines. Photochemically, the ring of the 2H-azirines was opened to yield the nitrile ylides, which underwent a [3 + 2]-cycloaddition with 1,3-dipolarophiles. When diisopropyl azodicarboxylate serves as the dipolarophile, 1,3,4-triazoles become directly accessible starting from the corresponding vinyl azide.

Multistep flow synthesis of vinyl azides and their use in the copper-catalyzed Huisgen-type cycloaddition under inductive-heating conditions.

The multistep flow synthesis of vinyl azides and their application in the synthesis of vinyltriazoles is reported. The synthesis relies on a stable polymer-bound equivalent of iodine azide that serves to carry out 1,2-functionalization of alkenes in a telescope flow protocol. The intermediate 2-iodo azides are subjected to a DBU-mediated polymer-supported elimination step yielding vinyl azides in good yield. The third step involves the formation of vinyl triazoles by a copper-catalyzed Huisgen-"click" cycloaddition. The required heat is generated by electromagnetic induction based on copper. Copper serves both as heatable as well as catalytically active packed-bed material inside the flow reactor.

Thermoseed Inductive Heating in vivo and in vitro and Its Impact on Immune Function of Tumor Bearing Rats / 中国微创外科杂志

Objective To evaluate the heating ability of thermoseeds in alternating magnetic field and its therapeutic effects on tumor bearing rats with simultaneously detected immune function. Methods To monitor the temperature increase of thermoseeds in vitro,of which the Curie point was 57 ℃ or 70 ℃.Forty Wistar rats implanted with Walker-256 cells were randomly divided into five groups: C group(control group,10 rats),M group(magnetic control group,5 rats),T group(thermoseeds control group,5 rats) and two heating treatment groups(H1 group,10 rats and H2 group,10 rats).In the H1 group,two thermoseeds with a Curie point at 57 ℃ were implanted into the tumor tissues in each rat with a heating time of 30 minutes,while in the H2 group,two thermoseeds with a Curie point at 70 ℃ were used with a heating time of 6 minutes.Five rats from each group were killed 9 days after the heating therapy to evaluate the volume and weight of the tumor tissues.The peripheral blood T-cells were counted in the rest rats in the H1,H2,and C groups. Results Magnetic inductive heating of the thermoseeds in vitro can reach the Curie point.The median tumor volume in the H2 group was 0.50 cm3(0.00-26.54),which was significantly lower than that in the M group(36.18 cm3,0.96-39.90,Z=2.21,P=0.032).And the weight of the tumors in the H1 and H2 groups was significantly lower than that in the M group [0.96 g(0.00-21.18) in H1 and 0.41 g(0.00-23.40) in H2 vs 31.45 g(1.09-36.09) in M group,Z=2.21 and P=0.032 for both].In the peripheral blood,the percentage of CD4+ T-cells was(22.39?5.27)% in H1 group,and(24.76?5.19)% in H2 group,which were significantly higher than that in C group [(12.07?4.45)%,P=0.01 and 0.003 respectively];and the percentage of CD8+ T-cells in the H2 group was significantly higher than that in the C group [(19.58?4.63)% vs(12.72?3.96)%,P=0.04].Conclusions Thermoseed had a good heating ability in alternating magnetic field and its inductive heating can inhibit tumor growth in Wistar rats and improve the immune function of the rats.

Heating of Isolated Tissues by Self-Regulating Thermoseeds / 中国微创外科杂志

Objective To examine the heating capability of thermoseeds in isolated hepatic tissues.Methods Isolated hepatic tissues were heated uniformly to 37 ℃,meanwhile the thermoseeds and thermocouples were planted using a template paralleling with the magnetic line.Afterwards,the tissues were treated in an extracorporeal magnetic field of 120-123 gauss at a frequency of 113-116 kHz for 30 minutes.At the meantime,the temperature was recorded by a computer through thermocouples. Results The temperature of the tissues raised markedly with a largest change of 14 ℃.The heating area became hard and showed a gradual change of color(white-yellow-brown).The final temperature was negatively correlated with distance when using same number of the thermoseeds(r=-0.96017 to-0.99767,P=0.0023 to 0.0398),and positively correlated with the number of thermoseeds when measuring at a same point(r=0.93775 to 0.99270,P=0.0007 to 0.0185)except for the center group(r=0.93936,P=0.0606).Conclusions Thermoseeds inductive heating technology can achieve an appropriate temperature in isolated hepatic tissues.In certain extent,the temperature increase the number of thermoseeds and heating distance.