The quest to realize strongly interacting photons remains an outstanding challenge both for fundamental science and for applications. Here, we explore mediated photon-photon interactions in a highly ...imbalanced two-component mixture of exciton polaritons in a semiconductor microcavity. Using a theory that takes into account nonperturbative correlations between the excitons as well as strong light-matter coupling, we demonstrate the high tunability of an effective interaction between quasiparticles formed by minority component polaritons interacting with a Bose-Einstein condensate (BEC) of a majority component polaritons. In particular, the interaction, which is mediated by sound modes in the BEC can be made strong enough to support a bound state of two quasiparticles. Since these quasiparticles consist partly of photons, this in turn corresponds to a dimer state of photons propagating through the BEC. This gives rise to a new light transmission line where the dimer wave function is directly mapped onto correlations between the photons. Our findings open new routes for highly nonlinear optical materials and novel hybrid light-matter quantum systems.
Micro-ornamentations characterize the surface of scales in lepidosaurians and are summarized in four main patterns, i.e., spinulated, lamellated, lamellate-dentate, and honeycomb, although variations ...of these patterns are present in different species. Although geckos are known to possess a spinulated pattern derived from the Oberhautchen layer, also other pattern variations of the spinulated micro-ornamentation are present such as those indicated as dendritic ramification, corneous belts, and small bare patches. The present study mainly describes the variation of micro-ornamentations present in scales of different skin regions in the Mediterranean gecko
Tarentula mauritanica
using scannig and transmission electron microscopy. The study reports that the accumulation of corneous material in Oberhautchen cells is not homogenous in different areas of body scales and, when mature, this process gives rise to different sculpturing on the epidermal surface generating not only spinulae but also transitional zones leading to the other main patterns. It is hypothesized that spinulae formation derives from the vertical and lateral symmetric growth of tubercolate, non-overlapped scales of geckos. Sparse areas also result smooth or with serpentine-ridges likely revealing the beta-layer located underneath and merged with the Oberhautchen. The eco-functional role of this variable micro-ornamentation in the skin of lizards however remains largely speculative.
KRAS codons 12 and 13 mutations predict resistance to anti-EGFR monoclonal antibodies (moAbs) in metastatic colorectal cancer. Also, BRAF V600E mutation has been associated with resistance. ...Additional KRAS mutations are described in CRC.
We investigated the role of KRAS codons 61 and 146 and BRAF V600E mutations in predicting resistance to cetuximab plus irinotecan in a cohort of KRAS codons 12 and 13 wild-type patients.
Among 87 KRAS codons 12 and 13 wild-type patients, KRAS codons 61 and 146 were mutated in 7 and 1 case, respectively. None of mutated patients responded vs 22 of 68 wild type (P=0.096). Eleven patients were not evaluable. KRAS mutations were associated with shorter progression-free survival (PFS, HR: 0.46, P=0.028). None of 13 BRAF-mutated patients responded vs 24 of 74 BRAF wild type (P=0.016). BRAF mutation was associated with a trend towards shorter PFS (HR: 0.59, P=0.073). In the subgroup of BRAF wild-type patients, KRAS codons 61/146 mutations determined a lower response rate (0 vs 37%, P=0.047) and worse PFS (HR: 0.45, P=0.023). Patients bearing KRAS or BRAF mutations had poorer response rate (0 vs 37%, P=0.0005) and PFS (HR: 0.51, P=0.006) compared with KRAS and BRAF wild-type patients.
Assessing KRAS codons 61/146 and BRAF V600E mutations might help optimising the selection of the candidate patients to receive anti-EGFR moAbs.
Magnetic particle imaging (MPI) is a new medical imaging approach that is based on the nonlinear magnetization response of super-paramagnetic iron oxide nanoparticles (SPIOs) injected into the blood ...stream. To date, real-time MPI of the bolus passage of an approved MRI SPIO contrast agent injected into the tail vein of living mice has been demonstrated. However, nanoparticles are rapidly removed from the blood stream by the mononuclear phagocyte system. Therefore, imaging applications for long-term monitoring require the repeated administration of bolus injections, which complicates quantitative comparisons due to the temporal variations in concentration. Encapsulation of SPIOs into red blood cells (RBCs) has been suggested to increase the blood circulation time of nanoparticles. This work presents first evidence that SPIO-loaded RBCs can be imaged in the blood pool of mice several hours after injection using MPI. This finding is supported by magnetic particle spectroscopy performed to quantify the iron concentration in blood samples extracted from the mice 3 and 24 h after injection of SPIO-loaded RBCs. Based on these results, new MPI applications can be envisioned, such as permanent 3D real-time visualization of the vessel tree during interventional procedures, bleeding monitoring after stroke, or long-term monitoring and treatment control of cardiovascular diseases.
Oxysterols are bioactive lipids that act as regulators of lipid metabolism, inflammation, cell viability and are involved in several diseases, including atherosclerosis. Mounting evidence linked the ...atherosclerosis to endothelium dysfunction; in fact, the endothelium regulates the vascular system with roles in processes such as hemostasis, cell cholesterol, hormone trafficking, signal transduction and inflammation. Several papers shed light the ability of oxysterols to induce apoptosis in different cell lines including endothelial cells. Apoptotic endothelial cell and endothelial denudation may constitute a critical step in the transition to plaque erosion and vessel thrombosis, so preventing the endothelial damaged has garnered considerable attention as a novel means of treating atherosclerosis. Endoplasmic reticulum (ER) is the site where the proteins are synthetized and folded and is necessary for most cellular activity; perturbations of ER homeostasis leads to a condition known as endoplasmic reticulum stress. This condition evokes the unfolded protein response (UPR) an adaptive pathway that aims to restore ER homeostasis. Mounting evidence suggests that chronic activation of UPR leads to cell dysfunction and death and recently has been implicated in pathogenesis of endothelial dysfunction. Autophagy is an essential catabolic mechanism that delivers misfolded proteins and damaged organelles to the lysosome for degradation, maintaining basal levels of autophagic activity it is critical for cell survival. Several evidence suggests that persistent ER stress often results in stimulation of autophagic activities, likely as a compensatory mechanism to relieve ER stress and consequently cell death. In this review, we summarize evidence for the effect of oxysterols on endothelial cells, especially focusing on oxysterols-mediated induction of endoplasmic reticulum stress.
Display omitted
•Endothelial cells dysfunction is critical in the process of atherothrombosis.•Endoplasmic reticulum stress is a key component in endothelial cell dysfunction.•Oxysterols are oxidation products of cholesterol found in atherosclerosis lesions.•Oxysterols are potential modulators of endoplasmic reticulum stress.
We compare the entire classical and quantum evolutions of the Dicke model in its regular and chaotic domains. This is a paradigmatic interacting spin-boson model of great experimental interest. By ...studying the classical and quantum survival probabilities of initial coherent states, we identify features of the long-time dynamics that are purely quantum and discuss their impact on the equilibration times. We show that the ratio between the quantum and classical asymptotic values of the survival probability serves as a metric to determine the proximity to a separatrix in the regular regime and to distinguish between two manifestations of quantum chaos: scarring and ergodicity. In the case of maximal quantum ergodicity, our results are analytical and show that quantum equilibration takes longer than classical equilibration.
Cell-based drug delivery Pierigè, F.; Serafini, S.; Rossi, L. ...
Advanced drug delivery reviews,
01/2008, Volume:
60, Issue:
2
Journal Article
Peer reviewed
Drug delivery has been greatly improved over the years by means of chemical and physical agents that increase bioavailability, improve pharmacokinetic and reduce toxicities. At the same time, cell ...based delivery systems have also been developed. These possesses a number of advantages including prolonged delivery times, targeting of drugs to specialized cell compartments and biocompatibility. Here we'll focus on erythrocyte-based drug delivery. These systems are especially efficient in releasing drugs in circulations for weeks, have a large capacity, can be easily processed and could accommodate traditional and biologic drugs. These carriers have also been used for delivering antigens and/or contrasting agents. Carrier erythrocytes have been evaluated in thousands of drug administration in humans proving safety and efficacy of the treatments. Erythrocyte-based delivery of new and conventional drugs is thus experiencing increasing interests in drug delivery and in managing complex pathologies especially when side effects could become serious issues.
In November 2013, a series of earthquakes began along a mapped ancient fault system near Azle, Texas. Here we assess whether it is plausible that human activity caused these earthquakes. Analysis of ...both lake and groundwater variations near Azle shows that no significant stress changes were associated with the shallow water table before or during the earthquake sequence. In contrast, pore-pressure models demonstrate that a combination of brine production and wastewater injection near the fault generated subsurface pressures sufficient to induce earthquakes on near-critically stressed faults. On the basis of modelling results and the absence of historical earthquakes near Azle, brine production combined with wastewater disposal represent the most likely cause of recent seismicity near Azle. For assessing the earthquake cause, our research underscores the necessity of monitoring subsurface wastewater formation pressures and monitoring earthquakes having magnitudes of ∼M2 and greater. Currently, monitoring at these levels is not standard across Texas or the United States.
Abstract
Stable walking relies critically on motor responses to signals of head motion provided by the vestibular system, which are phase-dependent and modulated differently within each muscle. It is ...unclear, however, whether these vestibular contributions also vary according to the stability of the walking task. Here we investigate how vestibular signals influence muscles relevant for gait stability (medial gastrocnemius, gluteus medius and erector spinae)—as well as their net effect on ground reaction forces—while humans walked normally, with mediolateral stabilization, wide and narrow steps. We estimated local dynamic stability of trunk kinematics together with coherence of electrical vestibular stimulation (EVS) with muscle activity and mediolateral ground reaction forces. Walking with external stabilization increased local dynamic stability and decreased coherence between EVS and all muscles/forces compared to normal walking. Wide-base walking also decreased vestibulomotor coherence, though local dynamic stability did not differ. Conversely, narrow-base walking increased local dynamic stability, but produced muscle-specific increases and decreases in coherence that resulted in a net increase in vestibulomotor coherence with ground reaction forces. Overall, our results show that while vestibular contributions may vary with gait stability, they more critically depend on the stabilization demands (i.e. control effort) needed to maintain a stable walking pattern.
Big Data Seismology Arrowsmith, S. J.; Trugman, D. T.; MacCarthy, J. ...
Reviews of geophysics (1985),
June 2022, Volume:
60, Issue:
2
Journal Article
Peer reviewed
Open access
The discipline of seismology is based on observations of ground motion that are inherently undersampled in space and time. Our basic understanding of earthquake processes and our ability to resolve ...4D Earth structure are fundamentally limited by data volume. Today, Big Data Seismology is an emergent revolution involving the use of large, data‐dense inquiries that is providing new opportunities to make fundamental advances in these areas. This article reviews recent scientific advances enabled by Big Data Seismology through the context of three major drivers: the development of new data‐dense sensor systems, improvements in computing, and the development of new types of techniques and algorithms. Each driver is explored in the context of both global and exploration seismology, alongside collaborative opportunities that combine the features of long‐duration data collections (common to global seismology) with dense networks of sensors (common to exploration seismology). The review explores some of the unique challenges and opportunities that Big Data Seismology presents, drawing on parallels from other fields facing similar issues. Finally, recent scientific findings enabled by dense seismic data sets are discussed, and we assess the opportunities for significant advances made possible with Big Data Seismology. This review is designed to be a primer for seismologists who are interested in getting up‐to‐speed with how the Big Data revolution is advancing the field of seismology.
Plain Language Summary
Seismology is the scientific discipline by which vibrational waves that travel through the Earth are used to study a range of natural processes, from the structure and layering of the subsurface to the dynamics of earthquake rupture. Long propelled by advances in instrumentation and the availability of waveform observations, seismology has entered an era of Big Data where new opportunities come hand in hand with new challenges. This review article gives an overview of recent scientific advances powered by Big Data Seismology, along with emerging trends, potential challenges, and future opportunities. The review encompasses a range of subjects from seismic imaging and earthquake source physics to education and outreach, and is designed to be a jumping off point for readers interested in how big data is changing the face of seismology research.
Key Points
Big Data Seismology is an emergent subdiscipline that uses “big data” inquiries to explore fundamental science questions in seismology
Three drivers of Big Data Seismology are the growth of large data volumes, the development of new algorithms, and advances in computing
Big Data Seismology is being applied to study earthquakes, to better resolve Earth structure, and to open new frontiers in seismology
PDF
