Ultrasonic waves can be used to transfer power and data efficiently through metallic enclosures when feedthroughs are not practical due to structural or electromagnetic shielding considerations. Previous implementations of ultrasonic power transfer (UPT) used a piezoelectric transducer permanently bonded to the metal for efficient ultrasonic coupling. For portable operation, it is essential to have a detachable transmitter (charger) that is only attached to the enclosure while transferring power.
View Article and Find Full Text PDFLarge reductions in the thermal conductivity of thin silicon membranes have been demonstrated in various porous structures. However, the role of coherent boundary scattering in such structures has become a matter of some debate. Here we report on the first experimental observation of coherent phonon boundary scattering at room temperature in 2D phononic crystals formed by the introduction of air holes in a silicon matrix with minimum feature sizes >100 nm.
View Article and Find Full Text PDFA total of 278 different isolates of filamentous fungi were screened using synthetic medium for respective ability to produce kojic acid. Nineteen, six, and five isolates proved to be low, moderate, and high kojic acid producers, respectively. Levels of kojic acid produced were generally increased when shaking cultivation was used rather than those obtained using static cultivation.
View Article and Find Full Text PDFA technique based on suspended islands is described to measure the in-plane thermal conductivity of thin films and nano-structured materials, and is also employed for measurements of several samples with a single measurement platform. Using systematic steps for measurements, the characterization of the thermal resistances of a sample and its contacts are studied. The calibration of the contacts in this method is independent of the geometry, size, materials, and uniformity of contacts.
View Article and Find Full Text PDFPhys Rev E Stat Nonlin Soft Matter Phys
June 2011
The problem of designing electromagnetic metamaterials is complicated by the pseudo-infinite parameter space governing such materials. We present a general solution based on group theory for the design and optimization of the electromagnetic properties of metamaterials. Using this framework, the fundamental properties of a metamaterial design, such as anisotropy or magnetic or electrical resonances, can be elucidated based on the symmetry class into which the unit cell falls.
View Article and Find Full Text PDFToxoplasmosis is a disease affecting 500 million people worldwide. The seroprevalence varies (from 5% to 90%), depending on geographical location, age, habit of eating raw meat or unwashed fruit and vegetables, and general level of hygiene. The incidence of infections is higher in warmer and humid climate and increases with age.
View Article and Find Full Text PDFLiver fibrosis is the common consequence of chronic liver injury of any etiology, disrupting the normal architecture,and causing hepatocellular dysfunction and portal hypertension. Since the renin-angiotensin system (RAS) may be involved in chronic liver diseases, in the present study we assayed renin levels using ELISA in groups of Egyptian patients with liver cirrhosis (N=32) and hepatocellular carcinoma (HCC) (N=67), for comparison with twenty five healthy controls. The results showed significant differences between the control and liver cirrhosis patients (P<0.
View Article and Find Full Text PDFPhononic crystals (PnCs) are the acoustic wave equivalent of photonic crystals, where a periodic array of scattering inclusions located in a homogeneous host material causes certain frequencies to be completely reflected by the structure. In conjunction with creating a phononic band gap, anomalous dispersion accompanied by a large reduction in phonon group velocities can lead to a massive reduction in silicon thermal conductivity. We measured the cross plane thermal conductivity of a series of single crystalline silicon PnCs using time domain thermoreflectance.
View Article and Find Full Text PDFRheumatoid arthritis (RA) is a chronic autoimmune disease characterized by severe joint deformities due to bony erosions and tendon damage. Cytokines are protein mediators of inflammation and are produced as a result of the activation of various cellular reactions. They are the final mediators and/or regulators of the inflammatory process.
View Article and Find Full Text PDFObjectives: Several immunoassays have been established for detection of Mycobacterium tuberculosis (MTB) antigens in serum, sputum and cerebrospinal fluid of tuberculous patients using polyclonal or monoclonal antibodies raised against different mycobacterium antigens. Some of these assays display both high sensitivity and specificity for the detection of these antigens. However, these assays require special and highly expensive equipment and the procedures require long periods for their completion.
View Article and Find Full Text PDFThis Feature Article reviews recent work on an optical technique for fabricating, in a single exposure step, three-dimensional (3D) nanostructures with diverse structural layouts. The approach, which we refer to as proximity field nanopatterning, uses conformable, elastomeric phase masks to pattern thick layers of transparent, photosensitive materials in a conformal contact mode geometry. Aspects of the optics, the materials, and the physical chemistry associated with this method are outlined.
View Article and Find Full Text PDFMycobacterium tuberculosis can cause life-threatening complications in which the immune response plays an important role. This study was designed to evaluate the serum levels of interleukin-18 (IL-18), interferon-gamma (IFN-gamma) and soluble Fas (sFas) in cases with pulmonary tuberculosis due to confirmed M. tuberculosis infection.
View Article and Find Full Text PDFThis paper introduces approaches that combine micro/nanomolding, or nanoimprinting, techniques with proximity optical phase mask lithographic methods to form three dimensional (3D) nanostructures in thick, transparent layers of photopolymers. The results demonstrate three strategies of this type, where molded relief structures in these photopolymers represent (i) fine (<1 microm) features that serve as the phase masks for their own exposure, (ii) coarse features (>1 microm) that are used with phase masks to provide access to large structure dimensions, and (iii) fine structures that are used together phase masks to achieve large, multilevel phase modulations. Several examples are provided, together with optical modeling of the fabrication process and the transmission properties of certain of the fabricated structures.
View Article and Find Full Text PDFEgypt J Immunol
November 2006
Hepatitis C infection is a major public health problem worldwide. Hepatitis C virus (HCV) infection has been identified as a major causative agent of post-transfusion hepatitis. The host immune response to HCV infection is composed of both non- specific immune response, including interferon (IFN) production and natural killer (NK) cell activity and a virus-specific immune response, including humoral and cellular components.
View Article and Find Full Text PDFIntroduction: Enzyme-linked immunosorbent assay (ELISA) was used for analysis of serum mutant p53 protein, carcinoembryonic antigen (CEA), and epidermal growth factor receptor (EGFR). Serum samples were obtained from 48 patients with colorectal cancer (CRC) and a control group of twenty healthy individuals.
Results: The results demonstrated a significant increase of serum mutant p53, EGFR, and CEA levels in CRC patients compared to the control group (P<0.
J Immunoassay Immunochem
March 2006
Hepatitis C has emerged as a major worldwide public health problem. The host immune response to HCV infection is composed of both a non-specific immune response, including interferon (IFN) production and natural killer (NK) cell activity, and a virus-specific immune response, including humoral and cellular components. Susceptibility to infection has been related to immunological disturbances.
View Article and Find Full Text PDFInfection with Schistosoma mansoni causes hepatic granuloma formation and fibrosis in response to parasite eggs. The present work localized the leucine aminopeptidase (LAP) in S. mansoni eggs and in liver tissue sections from infected mice.
View Article and Find Full Text PDFSchistosoma mansoni (S. mansoni) and hepatitis C virus (HCV) coinfection is common in Egypt and other developing countries. Patients coinfected with HCV and schistosomiasis exhibit a unique clinical, virological and histological pattern manifested by viral persistence with high HCV RNA titers as well as higher necroinflammatory and fibrosis scores in their liver biopsy samples.
View Article and Find Full Text PDFSchistosoma mansoni infection is characterized by a strong T-helper type 2 (Th2) cell-associated immune response, but in the case of viral infection, it is associated with interferon-gamma (IFN-gamma) increase and induction of Th1 immune response. Few data are available about the immune response of cases infected with combined hepatitis C virus (HCV) and schistosomiasis. Thus, the investigation of the cytokine pattern in patients coinfected with both HCV and Schistosoma mansoni was our rationale.
View Article and Find Full Text PDFBackground/aim: Helicobacter pylori infection is associated with the development of atrophic gastritis and increased gastric epithelial proliferation that is important in developing gastric carcinoma. Some countries with a high prevalence of H. pylori infection have high gastric cancer rates, whereas in others these rates are low.
View Article and Find Full Text PDFA three-dimensional tungsten photonic crystal is thermally excited and shown to emit light at a narrow band, lambda = 3.3-4.25 microm.
View Article and Find Full Text PDFIntroduction: Obstructive jaundice is an important clinical problem. It may cause transient hemolysis and shortened erythrocyte life span as well as cytokine induction. An increase in lipid peroxidation has been noted as evidence of oxidative damage in red cells due to cholestasis.
View Article and Find Full Text PDFFor what is believed to be the first time, a three-dimensional tungsten photonic crystal is demonstrated to emit light effectively at wavelength lambda = 1.5 microm. At a bias of V = 7 V, the thermal emission exhibits a full width at half-maximum of delta lambda = 0.
View Article and Find Full Text PDFThree-dimensional (3D) metallic crystals are promising photonic bandgap structures: they can possess a large bandgap, new electromagnetic phenomena can be explored, and high-temperature (above 1,000 degrees C) applications may be possible. However, investigation of their photonic bandgap properties is challenging, especially in the infrared and visible spectrum, as metals are dispersive and absorbing in these regions. Studies of metallic photonic crystals have therefore mainly concentrated on microwave and millimetre wavelengths.
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