Coupling between counterpropagating cladding modes in fiber Bragg gratings

We present an experimental demonstration of energy transfer between counterpropagating cladding modes in a fiber Bragg grating (FBG). A strong FBG written in a standard photosensitive optical fiber is illuminated with a single cladding mode, and the power transferred between the forward propagating cladding mode and different backward propagating cladding modes is measured by using two auxiliary long period gratings. Resonances between cladding modes having 30 pm bandwidth and 8 dB rejection have been observed

Direct-Write Fabrication of Integrated, Multilayer Ceramic Components

The need for advanced (electronic) ceramic components with smaller size, greater functionality, and enhanced reliability requires the ability to integrate electronic ceramics in complex 3-D architectures. For rapid prototyping and small-lot manufacturing, traditional tape casting and screen printing approaches are poorly suited. To address this need, we are developing a direct-write approach for fabricating highly integrated, multilayer components using a micropen to deposit slurries in precise patterns. With this technique, components can be constructed layer by layer, simplifying fabrication. It can also be used to produce structures combining several materials in a single layer. The parts are either cofired or sequentially fired, after each layer is deposited. Since differential shrinkage can lead to defects in these multilayer structures, we are characterizing the sintering behavior ofindividua1layers. This technique has been used to fabricate devices such integrated RC filters, multilayer voltage transformers, and other passive components. The direct-write approach provides the ability to fabricate multifunctional, multimaterial integrated ceramic components (MMICCs) in an agile and rapid way.Mechanical Engineerin

Development of a single tube multiplex real-time PCR to detect the most clinically relevant Mucormycetes species

AbstractMucormycetes infections are very difficult to treat and a delay in diagnosis could be fatal for the outcome of the patient. A molecular diagnostic technique based on Real Time PCR was developed for the simultaneous detection of Rhizopus oryzae, Rhizopus microsporus and the genus Mucor spp. in both culture and clinical samples. The methodology used was Molecular beacon species-specific probes with an internal control. This multiplex real-time PCR (MRT-PCR) was tested in 22 cultured strains and 12 clinical samples from patients suffering from a proven mucormycosis. Results showed 100% specificity and a detection limit of 1 fg of DNA per microlitre of sample. The sensitivity was 100% for clinical cultured strains and for clinical samples containing species detected by the PCR assay. Other mucormycetes species were not detected in clinical samples. This technique can be useful for clinical diagnosis and further studies are warranted

Using the Resected Kidney for Transplantation After Nephrectomy for Nutcracker Syndrome

Nutcracker syndrome (NCS) is the clinical manifestation of unilateral renal venous hypertension. It develops secondary to the nutcracker phenomenon caused by compression of the left renal vein between the superior mesenteric artery and the aorta. We present the case of a 43-year-old female with a history of left flank pain, pelvic congestion, and hematuria secondary to NCS. The patient frequently required high-dose non-steroidal anti-inflammatory medications with minimal relief. She initiated a kidney donor evaluation after electing to undergo a nephrectomy for the possible long-term resolution of NCS symptoms. If diagnosed early, NCS does not generate pathology within the kidney. This finding allows an individual with medically refractory NCS to avoid the morbidity of a complex surgical procedure by instead donating their kidney. Attention to this treatment modality could provide individuals with NCS resolution of symptoms while providing someone with end-stage renal disease with a life-saving organ

Gender differences in human immunodeficiency virus (HIV) RNA and CD4 cell counts among new entrants to HIV care

ABSTRACTClinic database extraction identified 806 new entrants to human immunodeficiency virus (HIV) care in Cleveland, OH, USA. At entry, women had higherCD4 counts and lower HIVRNAlevels than men (mean, 388 vs. 310 cells/µL, and 8.94 × 104 vs. 1.27 × 105 copies/mL, respectively), but the proportion of entrants with category C illnesses, category B conditions, sexually transmitted diseases and CD4 counts < 200 µL did not differ between genders. Hepatitis B seroprevalence was higher in men (8.7% vs. 0.6%), but there was no difference in hepatitis C prevalence. Whether women in Cleveland seek HIV care earlier, or whether early markers of HIV disease differ between the genders, remains to be determined

Mandelbrot set in coupled logistic maps and in an electronic experiment

We suggest an approach to constructing physical systems with dynamical characteristics of the complex analytic iterative maps. The idea follows from a simple notion that the complex quadratic map by a variable change may be transformed into a set of two identical real one-dimensional quadratic maps with a particular coupling. Hence, dynamical behavior of similar nature may occur in coupled dissipative nonlinear systems, which relate to the Feigenbaum universality class. To substantiate the feasibility of this concept, we consider an electronic system, which exhibits dynamical phenomena intrinsic to complex analytic maps. Experimental results are presented, providing the Mandelbrot set in the parameter plane of this physical system.Comment: 9 pages, 3 figure

Welfare of rainbow trout at slaughter: integrating behavioural, physiological, proteomic and quality indicators and testing a novel fast-chill stunning method

A critical point in the life of a captive fish is the final stages of production, not only in welfare terms but also due to effects on meat quality, carcass appearance and derived economic impacts. The most common method to slaughter fish is by asphyxia either in ice-water or in the open air. In humane slaughter procedures, however, a stunning method needs to be implemented to render the fish immediately unconscious (within one second) until death. The objective of this research was to evaluate and compare the effectiveness and welfare effects of four types of stunning methods in rainbow trout (O. mykiss): cold shock by fast-chilling as a novel method, where the fish were immersed in liquid water at −8 °C, asphyxia (as the currently used method), electrical stunning, and anaesthesia with MS-222. We used a total of 176 trout (mean weight 524 ± 138 g), combining behavioural (individual swimming activity, equilibrium, opercular movement and eye-roll), physiological (heart rate and electrocardiogram amplitude) and circulating (plasma cortisol and osmolality) indicators with brain proteomic signatures. We also analysed the effects on fillet shelf-life and quality in each method (rigor mortis, water content, fillet colour, pH and ATP degradation). Anaesthesia effectively induced unconsciousness, with regular and strong heartbeat and low cortisol. Quality indicators were the best among all the methods assessed. Electric shock was found to be an effective and irreversible method for inducing unconsciousness, with strong heartbeat and large variation in cortisol response and quality indicators similar to anaesthesia. On the contrary, asphyxia presented indicators of poor welfare (e.g., long-lasting consciousness throughout the slaughter process, high cortisol levels), with very low flesh quality parameters. Fast-chilling also resulted in extreme signs of stress (intense mucus release, haemorrhage and no loss of consciousness), low ATP content and the worst proteomic signatures, along with an early onset and resolution of rigor mortis (6 and 48 h, respectively). Our results reinforce the idea that electric stunning is a promising humane method to stun farmed trout. In contrast, the fast-chilling method showed very poor results both in welfare and in quality, indicating that it is not a viable humane alternative to asphyxia. Moreover, the proteome analysis provided valuable insights into the brain mechanisms of rainbow trout at slaughter, offering potential fine-scale biomarkers of welfare.Provincia Autonoma di Trento; Fundação para a Ciência e a Tecnologiainfo:eu-repo/semantics/acceptedVersio

Direct and sequential radiative three-body reaction rates at low temperatures

We investigate the low-temperature reaction rates for radiative capture processes of three particles. We compare direct and sequential capture mechanisms and rates using realistic phenomenological parametrizations of the corresponding photodissociation cross sections.Energy conservation prohibits sequential capture for energies smaller than that of the intermediate two-body structure. A finite width or a finite temperature allows this capture mechanism. We study generic effects of positions and widths of two- and three-body resonances for very low temperatures. We focus on nuclear reactions relevant for astrophysics, and we illustrate with realistic estimates for the $\alpha$-$\alpha$-$\alpha$ and $\alpha$-$\alpha$-$n$ radiative capture processes. The direct capture mechanism leads to reaction rates which for temperatures smaller than 0.1 GK can be several orders of magnitude larger than those of the NACRE compilation.Comment: To be published in European Physical Journal

Induction of TIMP-1 expression in rat hepatic stellate cells and hepatocytes: a new role for homocysteine in liver fibrosis

Elevated plasma levels of homocysteine have been shown to interfere with normal cell function in a variety of tissues and organs, such as the vascular wall and the liver. However, the molecular mechanisms behind homocysteine effects are not completely understood. In order to better characterize the cellular effects of homocysteine, we have searched for changes in gene expression induced by this amino acid. Our results show that homocysteine is able to induce the expression and synthesis of the tissue inhibitor of metalloproteinases-1 (TIMP-1) in a variety of cell types ranging from vascular smooth muscle cells to hepatocytes, HepG2 cells and hepatic stellate cells. In this latter cell type, homocysteine also stimulated alpha 1(I) procollagen mRNA expression. TIMP-1 induction by homocysteine appears to be mediated by its thiol group. Additionally, we demonstrate that homocysteine is able to promote activating protein-1 (AP-1) binding activity, which has been shown to be critical for TIMP-1 induction. Our findings suggest that homocysteine may alter extracellular matrix homeostasis on diverse tissular backgrounds besides the vascular wall. The liver could be considered as another target for such action of homocysteine. Consequently, the elevated plasma levels of this amino acid found in different pathological or nutritional circumstances may cooperate with other agents, such as ethanol, in the onset of liver fibrosis