Two Dimensions Simulation of a Magnetotactic Bacteria Cell Exposed to an Electromagnetic Field at 3 GHz

The effect of the presence of magnetite nanoparticles inside biological objects when they are exposed to microwaves has not yet been investigated completely. Microwaves magnetic hyperthermia is a field under development, and the use of biogenic magnetite is a relatively new vista. In this regard, the present approach presents a first step in a modeling-simulation process focused on the computation of the absorbed power distribution in bacteria cells containing native magnetite nanoparticles in the form of chains (magnetosomes). The presented simulations’ results refer to the simplest case of two-dimensional computation, which doesn’t take into consideration the geometric and magnetic anisotropy characteristics of the real magnetosomes.

Multi-talented Microbots

The microbot/xenobot designs focused on in this paper have applications both inside and outside the body. What you need to know about xenobots, since they are a very new invention, is that they are layered heart and skin tissue robots built from frog stem cells. The observed tasks that have been pub- lished are organizing microplastics, self-healing, and chemical communication with pheromones. There has never been an invention similar to xenobots, which is why they are paving a revolution as the first “Living Robots”[1]. These ap- plications include micro-sculpting nerve tissue inside the body and virus detec- tion/monitoring outside the body.Inside the body, microbots and xenobots working together can represent an effective new treatment against peripheral and diabetic neuropathy, preventing paralysis. Bolstering the body’s response to neural damage by clearing the restrictions of natural neural growth would allow neurons to regrow and connect much faster[2]; xenobots[1] alone can be injected into the traumatized area to decompose myelin sheath if this process is accessible within a few hours of serious nerve damage. In the long-term, after several months/years, xenobots and microbots[3] will come together, carrying neural stem cells, and following an external electromagnetic field to regenerate neurons and micro-sculpt nerve tissue in a three-step process. First, the xenobots (with biogenic magnetite) carry the cargo of neural progenitors, dropping them off at the dorsal root ganglion (also infected with biogenic magnetite). Then, axons of the neurons growing from the neural progenitor would grow in the direction of the microbot pulling it. The infrared light would power the twisted graphene bilayer and direct the microbot, pulling neurons to invoke growth and reconnecting the network of neurons near muscles.[5]Outside the body, xenobots will monitor virus concentrations with a virus stimulus and fluorescent light indication. After the coronavirus pandemic, virus destruction products such as the MAP-1 spray for coronavirus (distributed by Germagic) have proven successful. Determining exactly when a virus has resided in a particular area has not been proven, but would greatly aid in contact trac- ing. Microbots[3] and xenobots[1] are essential for determining how long a particular virus has resided on a surface, giving information about when peo- ple could have been infected. Horizontal gene integration from synthetic RNA and DNA origami mechanisms give xenobots sensitivity to viruses. Xenobots coming in contact with viruses can indicate surface virus contact by gradually increasing/decreasing the green color that they illuminate as the Green Fluo- rescent Protein goes through a positive feedback loop as viruses increase and decrease in contact with the xenobot. [8] This half-life of fluorescence is modeled by a differential equation in Attenuation of green fluorescent protein half-life in mammalian cells.[4]

A novel authigenic magnetite source for sedimentary magnetization

We report a novel authigenic nanoscale magnetite source in marine methane seep sediments. The magnetite occurs in large concentrations in multiple horizons in a 230 m sediment core with gas hydrate–bearing intervals. In contrast to typical biogenic magnetite produced by magnetotactic bacteria and dissimilatory iron-reducing bacteria, most particles have sizes of 200–800 nm and many are aligned in distinctive structures that resemble microbial precipitates. The magnetite is interpreted to be a byproduct of microbial iron reduction within methanic sediments with rapidly changing redox conditions. Iron sulfides that accumulated at a shallow sulfate-methane transition zone were oxidized after methane seepage intensity decreased. The alteration process produced secondary iron (oxyhydr)oxides that then became a reactive iron source for magnetite authigenesis when methane seepage increased again. This interpretation is consistent with 13C depletion in coexisting carbonate nodules. The authigenic magnetite will record younger paleomagnetic signals than surrounding sediments, which is important for paleomagnetic interpretations in seep systems. The microbial and possibly abiotic processes that caused these magnetic minerals to form at moderate burial depths remain to be determined.

Reductive dissolution of biogenic magnetite

Reductive dissolution of magnetite is known to occur below the Fe-redox boundary in sediments. In this study, detailed processes associated with biogenic magnetite dissolution are documented. A sediment core from the Japan Sea was used for this purpose, in which reductive dissolution of magnetic minerals is known to start at depths of about 1.15 m and is mostly complete within a depth interval of about 0.35 m. Using first-order reversal curve diagrams, preferential dissolution of biogenic magnetite within this interval is estimated from the observation that a narrow peak that extends along the coercivity axis (central ridge), which is indicative of biogenic magnetite, diminishes downcore. Transmission electron microscopy is used to demonstrate that the sediments contain three magnetofossil morpho-types: octahedra, hexagonal prisms, and bullet-shaped forms. Within the reductive dissolution zone, partially etched crystals are commonly observed. With progressive dissolution, the proportion of bullet-shaped magnetofossils decreases, whereas hexagonal prisms become more dominant. This observation can be explained by the differences in resistance to dissolution among crystal planes of magnetite and the differences in surface area to volume ratios. Magnetofossil morphology may reflect the preference of magnetotactic bacterial lineages for inhabiting specific chemical environments in sediments. However, it could also reflect alteration of the original morphological compositions during reductive diagenesis, which should be considered when using magnetofossil morphology as a paleoenvironmental proxy.

Reductive dissolution of biogenic magnetite

Reductive dissolution of magnetite is known to occur below the Fe-redox boundary in sediments. In this study detailed processes associated with biogenic magnetite dissolution are documented. A sediment core from the Japan Sea was used for this purpose, in which reductive dissolution of magnetic minerals is known to start at depths of about 1.15 m and is mostly complete within a depth interval of about 0.35 m. Using first-order reversal curve diagrams, preferential dissolution of biogenic magnetite within this interval is estimated from the observation that a narrow peak that extends along the coercivity axis (central ridge), which is indicative of biogenic magnetite, diminishes downcore. Transmission electron microscopy is used to demonstrate that the sediments contain three magnetofossil morpho-types: octahedra, hexagonal prisms, and bullet-shaped forms. Within the reductive dissolution zone, partially etched crystals are commonly observed. With progressive dissolution, the proportion of bullet-shaped magnetofossils decreases, whereas hexagonal prisms become more dominant. This observation can be explained by the differences in resistance to dissolution among crystal planes of magnetite and the differences in surface area to volume ratios. Magnetofossil morphology may reflect the preference of magnetotactic bacterial lineages for inhabiting specific chemical environments in sediments. However, it could also reflect alteration of the original morphological compositions during reductive diagenesis, which should be considered when using magnetofossil morphology as a paleoenvironmental proxy.

Reductive dissolution of biogenic magnetite

Reductive dissolution of magnetite is known to occur below the Fe-redox boundary in sediments. In this study detailed processes associated with biogenic magnetite dissolution are documented. A sediment core from the Japan Sea was used for this purpose, in which reductive dissolution of magnetic minerals is known to start at depths of about 1.15 m and is mostly complete within a depth interval of about 0.35 m. Using first-order reversal curve diagrams, preferential dissolution of biogenic magnetite within this interval is estimated from the observation that a narrow peak that extends along the coercivity axis (central ridge), which is indicative of biogenic magnetite, diminishes downcore. Transmission electron microscopy is used to demonstrate that the sediments contain three magnetofossil morpho-types: octahedra, hexagonal prisms, and bullet-shaped forms. Within the reductive dissolution zone, partially etched crystals are commonly observed. With progressive dissolution, the proportion of bullet-shaped magnetofossils decreases, whereas hexagonal prisms become more dominant. This observation can be explained by the differences in resistance to dissolution among crystal planes of magnetite and the differences in surface area to volume ratios. Magnetofossil morphology may reflect the preference of magnetotactic bacterial lineages for inhabiting specific chemical environments in sediments. However, it could also reflect alteration of the original morphological compositions during reductive diagenesis, which should be considered when using magnetofossil morphology as a paleoenvironmental proxy.