Model of light collimation by photonic crystal surface modes

We propose a quantitative model explaining the mechanism of light collimation by leaky surface modes that propagate on a corrugated surface around the output of a photonic crystal waveguide. The dispersion relation of these modes is determined for a number of surface terminations. Analytical results obtained on the basis of the model are compared to those of rigorous numerical simulations. Maximum collimation is shown to occur at frequency values corresponding to excitation of surface modes whose wave number retains a nonzero real part.Comment: 6 pages, 7 figures. Version 2: corrected sign of k_x' (sections 4-6, fig. 2), minor clarifications in section 2. Version 3: significant changes, including reformulation of the model using the theory of aperture antennas, as well as extended discussion of the accuracy of the mode

A numerical study of Bi-periodic binary diffraction gratings for solar cell applications

In this paper, a numerical study is made of simple bi-periodic binary diffraction gratings for solar cell applications. The gratings consist of hexagonal arrays of elliptical towers and wells etched directly into the solar cell substrate. The gratings are applied to two distinct solar cell technologies: a quantum dot intermediate band solar cell (QD-IBSC) and a crystalline silicon solar cell (SSC). In each case, the expected photocurrent increase due to the presence of the grating is calculated assuming AM1.5D illumination. For each technology, the grating period, well/tower depth and well/tower radii are optimised to maximise the photocurrent. The optimum parameters are presented. Results are presented for QD-IBSCs with a range of quantum dot layers and for SSCs with a range of thicknesses. For the QD-IBSC, it is found that the optimised grating leads to an absorption enhancement above that calculated for an ideally Lambertian scatterer for cells with less than 70 quantum dot layers. In a QD-IBSC with 50 quantum dot layers equipped with the optimum grating, the weak intermediate band to conduction band transition absorbs roughly half the photons in the corresponding sub-range of the AM1.5D spectrum. For the SSC, it is found that the optimised grating leads to an absorption enhancement above that calculated for an ideally Lambertian scatterer for cells with thicknesses of 10 ?m or greater. A 20um thick SSC equipped with the optimised grating leads to an absorption enhancement above that of a 200um thick SSC equipped with a planar back reflector

Mitochondria Death/Survival Signaling Pathways in Cardiotoxicity Induced by Anthracyclines and Anticancer-Targeted Therapies

Anthracyclines remain the cornerstone of treatment in many malignancies but these agents have a cumulative dose relationship with cardiotoxicity. Development of cardiomyopathy and congestive heart failure induced by anthracyclines are typically dose-dependent, irreversible, and cumulative. Although past studies of cardiotoxicity have focused on anthracyclines, more recently interest has turned to anticancer drugs that target many proteins kinases, such as tyrosine kinases. An attractive model to explain the mechanism of this cardiotoxicity could be myocyte loss through cell death pathways. Inhibition of mitochondrial transition permeability is a valuable tool to prevent doxorubicin-induced cardiotoxicity. In response to anthracycline treatment, activation of several protein kinases, neuregulin/ErbB2 signaling, and transcriptional factors modify mitochondrial functions that determine cell death or survival through the modulation of mitochondrial membrane permeability. Cellular response to anthracyclines is also modulated by a myriad of transcriptional factors that influence cell fate. Several novel targeted chemotherapeutic agents have been associated with a small but worrying risk of left ventricular dysfunction. Agents such as trastuzumab and tyrosine kinase inhibitors can lead to cardiotoxicity that is fundamentally different from that caused by anthracyclines, whereas biological effects converge to the mitochondria as a critical target

Involvement of Mitochondrial Disorders in Septic Cardiomyopathy

Sepsis is defined as a life-threatening organ dysfunction caused by a dysregulated host response to infection. It remains a leading cause of death worldwide, despite the development of various therapeutic strategies. Cardiac dysfunction, also referred to as septic cardiomyopathy, is a frequent and well-described complication of sepsis and associated with worse clinical outcomes. Recent research has increased our understanding of the role of mitochondrial dysfunction in the pathophysiology of septic cardiomyopathy. The purpose of this review is to present this evidence as a coherent whole and to highlight future research directions

Mitochondria death/ survival signaling pathways in cardiotoxicity induced by anthracyclines and anticancer-targeted therapies. Biochem Res Int

Anthracyclines remain the cornerstone of treatment in many malignancies but these agents have a cumulative dose relationship with cardiotoxicity. Development of cardiomyopathy and congestive heart failure induced by anthracyclines are typically dosedependent, irreversible, and cumulative. Although past studies of cardiotoxicity have focused on anthracyclines, more recently interest has turned to anticancer drugs that target many proteins kinases, such as tyrosine kinases. An attractive model to explain the mechanism of this cardiotoxicity could be myocyte loss through cell death pathways. Inhibition of mitochondrial transition permeability is a valuable tool to prevent doxorubicin-induced cardiotoxicity. In response to anthracycline treatment, activation of several protein kinases, neuregulin/ErbB2 signaling, and transcriptional factors modify mitochondrial functions that determine cell death or survival through the modulation of mitochondrial membrane permeability. Cellular response to anthracyclines is also modulated by a myriad of transcriptional factors that influence cell fate. Several novel targeted chemotherapeutic agents have been associated with a small but worrying risk of left ventricular dysfunction. Agents such as trastuzumab and tyrosine kinase inhibitors can lead to cardiotoxicity that is fundamentally different from that caused by anthracyclines, whereas biological effects converge to the mitochondria as a critical target

Case Report: Acute myocarditis and cerebral infarction following Bothrops lanceolatus envenomation in Martinique: a case series

Bothrops lanceolatus (Bl), a snake endemic to Martinique, is responsible for numerous envenomations annually, leading to severe complications such as thrombosis, necrosis, and hemorrhage. This case series investigates the link between Bothrops lanceolatus envenomation and acute myocarditis, utilizing cardiac magnetic resonance imaging (MRI) to enhance management strategies. In both cases, cardiac MRI confirmed myocarditis with edema, and subsequent cerebral MRI revealed bilateral infarcts. Elevated troponin levels further supported the myocarditis diagnosis. Multiple doses of Bothrofav® antivenom facilitated recovery without clinical after effects.These cases represent the first documented instances of myocarditis due to Bl envenomation confirmed via cardiac MRI. Prompt administration of antivenom and the use of advanced imaging techniques were crucial in achieving favorable outcomes

Numerical optimization of grating-enhanced second-harmonic generation in optical waveguides

Rigorous electromagnetic theory is combined with a phenomenological approach to permit optimization of grating-enhanced second-harmonic generation (SHG) in optical waveguides. Provided that the absorption losses in the optically nonlinear layer are not high, maximum SHG is observed when phase matching occurs between the incident wave at the pump frequency and guided waves at both the pump and the signal frequencies. Different coupling mechanisms are considered, and a procedure for determining the optimal groove depth and period of the grating is discussed. The phenomenological approach permits deeper physical insight into the problem and a considerable saving of computation time. Direct phase matching is shown to result in stronger SHG than indirect phase matching ( performed through the grating vector), even if the former includes coupling between waveguide modes of different orders

Case report: Musculoskeletal metastastic inflammatory myofibroblastic tumor (IMT) treated by sequential ALK-TKI with longterm response

Inflammatory myofibroblastic tumors (IMTs) are known to be associated with rearrangements of the anaplastic lymphoma kinase (ALK) gene. The treatment of this type of tumor includes systemic therapies such as chemotherapies or anti-inflammatories; in recent years, targeted anti-ALK therapies have emerged and became the standard of care in ALK rearranged patients. We aimed to present a rare case of musculoskeletal IMT with ALK rearrangement, characterized by metastatic evolution and enhanced responses to sequential treatment with all ALK-TKI. We have outlined a potential treatment pathway involving sequential ALK-TKI targeted therapies and successive local interventions to control the cancer