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The Moebius strip, as a fascinating loop structure with one-sided topology, provides a rich playground for manipulating the non-trivial topological behavior of spinning particles, such as electrons, polaritons, and photons in both real and parameter spaces. For photons resonating in a Moebius-strip cavity, the occurrence of an extra phase, known as Berry phase, with purely topological origin is expected due to its non-trivial evolution in the parameter space. However, despite numerous theoretical investigations, characterizing optical Berry phase in a Moebius-strip cavity has remained elusive. Here we report the experimental observation of Berry phase generated in optical Moebius-strip microcavities. In contrast to theoretical predictions in optical, electronic, and magnetic Moebius-topology systems where only Berry phase {\pi} occurs, we demonstrate that variable Berry phase smaller than {\pi} can be acquired by generating elliptical polarization of resonating light. Moebius-strip microcavities as integrable and Berry-phase-programmable optical systems are of great interest in topological physics and emerging classical or quantum photonic applications.

Our main goal is to study the formation of rocky planets and the first $100~\textrm{Myr}$ of their dynamical evolution around a star with mass $0.08 M_\odot$ close to the substellar mass limit. We developed two sets of $N$-body simulations assuming an embryo population affected by tidal and general relativistic effects refined by the inclusion of the spin-up and contraction of the central star, and immerse in a gas disk during the first 10 Myr. Each set of simulations incorporates a different prescription from literature to calculate the interaction between the gas-disk and the embryos: one widely used prescription based on results from hydrodynamics simulations, and a recent prescription based on the analytic treatment of dynamical friction. We found that given a standard disk model, the dynamical evolution and the final architectures of the resulting rocky planets is strongly related with the prescription used to treat the interaction within the gas and the embryos, having a big impact on the resulting close-in planet population and particularly on those located inside the habitable zone. We found a good agreement within the distribution of period ratio of adjacent confirmed exoplanets observed around very low mass stars and brown dwarfs and those obtained from our simulations only when the prescription based on dynamical friction for gas-embryo interaction is used. Our results also reproduce a close-in planet population of interest located inside the habitable zone. A fraction of those planets will be exposed for a long period of time to the stellar irradiation inside the inner edge of the evolving habitable zone until the zone reaches them., Comment: 16 pages, 14 figures, accepted for publication in A&A

Different propulsion mechanisms have been suggested for describing the motion of a variety of chemical micromotors, including the bubble-recoil mechanism, which has attracted great attention in the last decades due to its high efficiency and thrust force, enabling several applications in the fields of environmental remediation and biomedicine. Bubble-induced motion has been modeled including three different phenomena: capillarity, bubble growth, and bubble expulsion. However, most of those models have been suggested independently based on a single influencing factor (i.e. viscosity), limiting the understanding of the overall micromotor performance. In this work, we study the combined influence of medium viscosity, surface tension and fuel concentration on the switching behavior between different propulsion mechanisms in the same micromotor. Furthermore, we propose a holistic theoretical model that explains the three propulsion mechanisms, obtaining good agreement with the recorded experimental data., Comment: 29 pages, 5 figures

Recent observational results show that very low mass stars and brown dwarfs are able to host close-in rocky planets. Low-mass stars are the most abundant stars in the Galaxy and the formation efficiency of their planetary systems is relevant in the computation of a global probability of finding Earth-like planets inside habitable zones. Tidal forces and relativistic effects are relevant in the latest dynamical evolution of planets around low-mass stars and their effect on the planetary formation efficiency still needs to be addressed. Our goal is to evaluate the impact of tidal forces and relativistic effects on the formation of rocky planets around a star close to the substellar mass limit, in terms of the resulting planetary architectures and its distribution according to the corresponding evolving habitable zone. Thus, we performed a set of $N$-body simulations spanning the first 100~Myr of the evolution of two systems composed respectively by 224 embryos with a total mass 0.25M$_\oplus$ and 74 embryos with a total mass 3 M$_\oplus$ around a central object of 0.08~M$_\odot$. For these two scenarios, we compared the planetary architectures that result from simulations that are purely gravitational with those from simulations that include the early contraction and spin-up of the central object, the distortions and dissipation tidal terms and general relativistic effects. We found that including these effects allows the formation and survival of a close-in population located in the habitable zone of the system. This means that both effects are relevant during the formation of rocky planets and their early evolution around stars close to the substellar mass limit, in particular when low-mass planetary embryos are involved., Comment: 16 pages, 17 figures

Bone conduction is the transmission of acoustic energy to the inner ear by different paths involving the bones of the skull. In this work, we use the path the hand provides in order to transmit the sound coming from the cell phone using Bluetooth system. The aim of this work was to study the vibrations produced by a sound transmitted through bone conduction between a mobile phone and the hand analyzed with the DSP Logger MX equipment., Comment: 7 pages, 7 figures, 1 table, conference paper

Cellular micromotors are attractive for locally delivering high concentrations of drug and targeting hard-to-reach disease sites such as cervical cancer and early ovarian cancer lesions by non-invasive means. Spermatozoa are highly efficient micromotors perfectly adapted to traveling up the female reproductive system. Indeed, bovine sperm-based micromotors have recently been reported as a potential candidate for the drug delivery toward gynecological cancers of clinical unmet need. However, due to major differences in the molecular make-up of bovine and human sperm, a key translational bottleneck for bringing this technology closer to the clinic is to transfer this concept to human sperm. Here, we successfully load human sperm with a chemotherapeutic drug and perform treatment of relevant 3D cervical cancer and patient-representative 3D ovarian cancer cell cultures, resulting in strong anti-cancer effects. Additionally, we show the subcellular localization of the chemotherapeutic drug within human sperm heads and assess drug effects on sperm motility and viability over time. Finally, we demonstrate guidance and release of human drug-loaded sperm onto cancer cell cultures by using streamlined microcap designs capable of simultaneously carrying multiple human sperm towards controlled drug dosing by transporting known numbers of sperm loaded with defined amounts of chemotherapeutic drug.

Medical imaging plays an important role in diagnosis and treatment of multiple diseases. It is a field under continuous development which seeks for improved sensitivity and spatiotemporal resolution to allow the dynamic monitoring of diverse biological processes that occur at the micro- and nanoscale. Emerging technologies for targeted diagnosis and therapy such as nanotherapeutics, micro-implants, catheters and small medical tools also need to be precisely located and monitored while performing their function inside the human body. In this work, we show for the first time the real-time tracking of moving single micro-objects below centimeter thick tissue-mimicking phantoms, using multispectral optoacoustic tomography (MSOT). This technique combines the advantages of ultrasound imaging regarding depth and resolution with the molecular specificity of optical methods, thereby facilitating the discrimination between the spectral signatures of the micro-objects from those of intrinsic tissue molecules. The resulting MSOT signal is further improved in terms of contrast and specificity by coating the micro-objects surface with gold nanorods, possessing a unique absorption spectrum, which will allow their discrimination from surrounding biological tissues when translated to in vivo settings.

In the present research, we study the effects of a single giant planet in the dynamical evolution of water-rich embryos and planetesimals, located beyond the snow line of systems around Sun-like stars, in order to determine what kind of terrestrial-like planets could be formed in the habitable zone (hereafter HZ) of these systems. To do this, we carry out N-body simulations of planetary accretion, considering that the gas has been already dissipated from the disk and a single giant planet has been formed beyond the snow line of the system, at 3 au. We find that a giant planet with a value of mass between Saturn-mass and Jupiter-mass, represents a limit from which the amount of water-rich embryos that moves inward from beyond the snow line starts to decrease. From this, our research suggests that giant planets more massive than one Jupiter-mass become efficient dynamical barriers to inward-migrating water-rich embryos. Moreover, we infer that the number of these embryos that survive in the HZ significantly decreases for systems that host a giant planet more massive than one Jupiter-mass. This result has important consequences concerning the formation of terrestrial-like planets in the HZ with very high water contents and could provide a selection criteria in the search of potentially habitable exoplanets in systems that host a gaseous giant around solar-type stars., Comment: 10 pages, 8 figures

A sperm-driven micromotor is presented as cargo-delivery system for the treatment of gynecological cancers. This particular hybrid micromotor is appealing to treat diseases in the female reproductive tract, the physiological environment that sperm cells are naturally adapted to swim in. Here, the single sperm cell serves as an active drug carrier and as driving force, taking advantage of its swimming capability, while a laser-printed microstructure coated with a nanometric layer of iron is used to guide and release the sperm in the desired area by an external magnet and structurally imposed mechanical actuation, respectively. The printed tubular microstructure features four arms which release the drug-loaded sperm cell in situ when they bend upon pushing against a tumor spheroid, resulting in the drug delivery, which occurs when the sperm squeezes through the cancer cells and fuses with cell membrane. Sperms also offer higher drug encapsulation capability and carrying stability compared to other nano and microcarriers, minimizing toxic effects and unwanted drug accumulation. Moreover, sperms neither express pathogenic proteins nor proliferate to form undesirable colonies, unlike other cells or microorganisms do, making this bio-hybrid system a unique and biocompatible cargo delivery platform for various biomedical applications, especially in gynecological healthcare.