Medication-Related Osteonecrosis of the Jaw with Spontaneous Hemimaxilla Exfoliation: Report of a Case in Metastatic Renal Cancer Patient under Multidrug Therapy.

Medication-related osteonecrosis of the jaw (MRONJ) is a well-recognized complication of drug therapies for bone metabolic disorders or cancer related to administration of antiresorptive (bisphosphonates and denosumab) and antiangiogenic drugs. This report describes an advanced and unusual case of stage III peri-implantitis-induced MRONJ involving the right upper jaw which was attempting to self-exfoliate. A 61-year-old male patient, rehabilitated with the placement of two implants when he was still healthy, was suffering from metastatic renal cancer previously treated with bevacizumab, interleukin-2, zoledronic acid, denosumab, cabozantinib and nivolumab. He had been under treatment of nonsurgical therapy over a year, based on antibiotic and antiseptic mouth rinse, without improvement of oral conditions. Surgical treatment consisted of massive sequestrectomy and complete surgical debridement of necrotic bone tissues. The specimen was sent for histopathologic analysis, which confirmed bone tissue necrosis with no evidence of metastatic disease. Two-month follow-up revealed a considerable life quality improvement. Although this complication is well known, the uniqueness of this case is given by its severity, related to the administration of multiple antiresorptive and antiangiogenic drugs, by the natural response of the oral cavity with the almost complete self-exfoliation of the massive necrotic zone. This case is emblematic in highlighting the controversies in the management of MRONJ, which certainly require effective collaboration of the multidisciplinary health care team that could improve patient safety and reduce the risk of developing MRONJ.

Strain-controlled ferromagnetism in BiFeO3 nanoparticles.

Multiferroic materials are at the core of voltage-controlled spintronic devices. Therefore, an understanding of the underlying electronic correlations and their effects associated with their complex energy landscape is an important and ongoing task. One key parameter in oxide-based perovskite multiferroics is their sensitivity to strain effects under confinement. Here, we report on the ferromagnetism induced by strain-engineering at the nanoscale on BiFeO3 (BFO) nanoparticles. By controlling synthesis parameters, we were able to modify the BFO lattice parameters up to 0.15% and as a consequence, induce ferromagnetism in otherwise antiferromagnetic bulk BFO. In order to understand the driving mechanisms behind such an effect, we performed density functional theory calculations (DFT) using the BFO parameters obtained from the experiment. We found that small distortions of the structural lattice parameters of the order of 0.01% are sufficient to induce a significant spin imbalance close to the Fermi energy at the Fe sites. This may explain the appearance of weak ferromagnetism in strained BFO thin films reported earlier and offers a new route to novel voltage-controlled spintronic devices based on multiferroic materials.

Nanoclusters of crystallographically aligned nanoparticles for magnetic thermotherapy: aqueous ferrofluid, agarose phantoms and ex vivo melanoma tumour assessment.

Magnetic hyperthermia is an oncological therapy where magnetic nanostructures, under a radiofrequency field, act as heat transducers increasing tumour temperature and killing cancerous cells. Nanostructure heating efficiency depends both on the field conditions and on the nanostructure properties and mobility inside the tumour. Such nanostructures are often incorrectly bench-marketed in the colloidal state and using field settings far off from the recommended therapeutic values. Here, we prepared nanoclusters composed of iron oxide magnetite nanoparticles crystallographically aligned and their specific absorption rate (SAR) values were calorimetrically determined in physiological fluids, agarose-gel-phantoms and ex vivo tumours extracted from mice challenged with B16-F0 melanoma cells. A portable, multipurpose applicator using medical field settings; 100 kHz and 9.3 kA m-1, was developed and the results were fully analysed in terms of nanoclusters' structural and magnetic properties. A careful evaluation of the nanoclusters' heating capacity in the three milieus clearly indicates that the SAR values of fluid suspensions or agarose-gel-phantoms are not adequate to predict the real tissue temperature increase or the dosage needed to heat a tumour. Our results show that besides nanostructure mobility, perfusion and local thermoregulation, the nanostructure distribution inside the tumour plays a key role in effective heating. A suppression of the magnetic material effective heating efficiency appears in tumour tissue. In fact, dosage had to be increased considerably, from the SAR values predicted from fluid or agarose, to achieve the desired temperature increase. These results represent an important contribution towards the design of more efficient nanostructures and towards the clinical translation of hyperthermia.

Edge phonons in black phosphorus.

Black phosphorus has recently emerged as a new layered crystal that, due to its peculiar and anisotropic crystalline and electronic band structures, may have important applications in electronics, optoelectronics and photonics. Despite the fact that the edges of layered crystals host a range of singular properties whose characterization and exploitation are of utmost importance for device development, the edges of black phosphorus remain poorly characterized. In this work, the atomic structure and behaviour of phonons near different black phosphorus edges are experimentally and theoretically studied using Raman spectroscopy and density functional theory calculations. Polarized Raman results show the appearance of new modes at the edges of the sample, and their spectra depend on the atomic structure of the edges (zigzag or armchair). Theoretical simulations confirm that the new modes are due to edge phonon states that are forbidden in the bulk, and originated from the lattice termination rearrangements.

Influence of silver concentrations on structural and magnetic properties of Ag-Fe3O4 heterodimer nanoparticles.

In the present work, we have reported the effect of Ag NPs seeds on the growth and magnetic properties of Ag-Fe3O4 heterodimer nanoparticles prepared using a two step chemical approach. Three different Ag NPs concentrations have been tried and thoroughly characterized using small angle X-ray scattering (SAXS), transmission electron microscopy (TEM), X-ray diffraction (XRD), dc magnetization, and X-ray absorption near edge spectroscopy (XANES). It is observed that at low concentration, the "flower" types of nanoparticles are more favorable whereas the higher concentration of Ag NPs seeds promotes the growth of dimer type of structures. Our dc magnetization results are well correlated to the structural ones. The sample with lower amount of starting Ag NPs seeds possesses highest blocking and irreversibility temperature. On the other hand, the sample with highest concentration of Ag NPs seeds, the blocking temperature is lowered.

Universal behavior of the coefficients of the continuous equation in competitive growth models.

The competitive growth models (CGM) involving only one kind of particles, are a mixture of two processes, one with probability p and the other with probability 1-p. The p dependence produce crossovers between two different regimes. We demonstrate that the coefficients of the continuous equation, describing their universality classes, are quadratic in p (or 1-p ). We show that the origin of such dependence is the existence of two different average time rates. Thus, the quadratic p dependence is a universal behavior of all the (CGM). We derive analytically the continuous equations for two CGM, in 1+1 dimensions, from the microscopic rules using a regularization procedure. We propose generalized scalings that reproduce the scaling behavior in each regime. In order to verify the analytic results and the scalings, we perform numerical integrations of the derived analytical equations. The results are in excellent agreement with those of the microscopic CGM presented here and with the proposed scalings.