2,052 research outputs found
Application of a modified complementary filtering technique for increased aircraft control system frequency bandwidth in high vibration environment
A modified complementary filtering technique for estimating aircraft roll rate was developed and flown in a research helicopter to determine whether higher gains could be achieved. Use of this technique did, in fact, permit a substantial increase in system frequency bandwidth because, in comparison with first-order filtering, it reduced both noise amplification and control limit-cycle tendencies
ΠΠ½ΠΆΠ΅Π½Π΅ΡΠ½ΠΎ-Π³Π΅ΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΈΠ΅ ΡΡΠ»ΠΎΠ²ΠΈΡ ΠΠ°ΠΉΠΌΠΈΠ½ΡΠΊΠΎΠ³ΠΎ ΡΠ°ΠΉΠΎΠ½Π° ΠΈ ΠΏΡΠΎΠ΅ΠΊΡ ΠΈΠ½ΠΆΠ΅Π½Π΅ΡΠ½ΠΎ-Π³Π΅ΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΈΡ ΠΈΠ·ΡΡΠΊΠ°Π½ΠΈΠΉ ΠΏΠΎΠ΄ ΡΠ΅ΠΊΠΎΠ½ΡΡΡΡΠΊΡΠΈΡ Π°ΡΡΠΎΠ²ΠΎΠΊΠ·Π°Π»ΡΠ½ΠΎΠ³ΠΎ ΠΊΠΎΠΌΠΏΠ»Π΅ΠΊΡΠ° Π°ΡΡΠΎΠΏΠΎΡΡΠ° (Π Π΅ΡΠΏΡΠ±Π»ΠΈΠΊΠ° ΠΠ»ΡΠ°ΠΉ)
ΠΠ°ΡΡΠΎΡΡΠ°Ρ ΡΠ°Π±ΠΎΡΠ° ΠΏΡΠ΅Π΄ΡΡΠ°Π²Π»ΡΠ΅Ρ ΡΠΎΠ±ΠΎΠΉ ΠΏΡΠΎΠ΅ΠΊΡ ΠΈΠ½ΠΆΠ΅Π½Π΅ΡΠ½ΠΎ-Π³Π΅ΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΈΡ
ΠΈΠ·ΡΡΠΊΠ°Π½ΠΈΠΉ ΠΏΠΎΠ΄ ΡΠ΅ΠΊΠΎΠ½ΡΡΡΡΠΊΡΠΈΡ Π°ΡΡΠΎΠ²ΠΎΠΊΠ·Π°Π»ΡΠ½ΠΎΠ³ΠΎ ΠΊΠΎΠΌΠΏΠ»Π΅ΠΊΡΠ° Π°ΡΡΠΎΠΏΠΎΡΡΠ° ΠΠΎΡΠ½ΠΎ-ΠΠ»ΡΠ°ΠΉΡΠΊ. Π¦Π΅Π»ΡΡ ΠΏΡΠΎΠ΅ΠΊΡΠΈΡΠΎΠ²Π°Π½ΠΈΡ ΡΠ²Π»ΡΠ΅ΡΡΡ ΠΈΠ·ΡΡΠ΅Π½ΠΈΠ΅ ΠΈΠ½ΠΆΠ΅Π½Π΅ΡΠ½ΠΎ-Π³Π΅ΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΈΡ
ΡΡΠ»ΠΎΠ²ΠΈΠΉ ΡΡΠ°ΡΡΠΊΠ° ΠΈ ΡΠ°Π·ΡΠ°Π±ΠΎΡΠΊΠ° ΠΏΡΠΎΠ΅ΠΊΡΠ° ΠΈΠ½ΠΆΠ΅Π½Π΅ΡΠ½ΠΎ-Π³Π΅ΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΈΡ
ΠΈΠ·ΡΡΠΊΠ°Π½ΠΈΠΉ ΠΏΠΎΠ΄ ΡΠ΅ΠΊΠΎΠ½ΡΡΡΡΠΊΡΠΈΡ Π°ΡΡΠΎΠ²ΠΎΠΊΠ·Π°Π»ΡΠ½ΠΎΠ³ΠΎ ΠΊΠΎΠΌΠΏΠ»Π΅ΠΊΡΠ° Π°ΡΡΠΎΠΏΠΎΡΡΠ° ΠΠΎΡΠ½ΠΎ-ΠΠ»ΡΠ°ΠΉΡΠΊ.This work is a project of engineering and geological surveys for the reconstruction of the airport terminal complex Gorno-Altaysk. The purpose of the design is to study the engineering and geological conditions of the site and develop a project of engineering and geological surveys for the reconstruction of the airport terminal complex Gorno-Altaysk
Identification of new omeprazole metabolites in wastewaters and surface waters
Omeprazole is one of the world-wide most consumed pharmaceuticals for treatment of gastric diseases. As opposed to other frequently used pharmaceuticals, omeprazole is scarcely detected in urban wastewaters and environmental waters. This was corroborated in a previous research, where parent omeprazole was not detected while four transformation products (TPs), mainly resulting from hydrolysis, were found in effluent wastewaters and surface waters. However, the low abundance of omeprazole TPs in the water samples together with the fact that omeprazole suffers an extensive metabolism, with a wide range of excretion rates (between 0.01 and 30%), suggests that human urinary metabolites should be investigated in the water environment. In this work, the results obtained in excretion tests after administration of a 40 mg omeprazole dose in three healthy volunteers are reported. Analysis by liquid chromatography coupled to hybrid quadrupole time-of-flight mass spectrometry (LC-QTOF MS) reported low concentrations of omeprazole in urine. Up to twenty-four omeprazole metabolites (OMs) were detected and tentatively elucidated. The most relevant OM was an omeprazole isomer, which obviously presented the same exact mass (m/z 346.1225), but also shared a major common fragment at m/z 198.0589. Subsequent analyses of surface water and effluent wastewater samples by both LC-QTOF MS and LC-MS/MS with triple quadrupole revealed that this metabolite (named as OM10) was the compound most frequently detected in water samples, followed by OM14a and OM14b. Up to our knowledge, OM10 had not been used before as urinary biomarker of omeprazole in waters. On the contrary, parent omeprazole was never detected in any of the water samples. After this research, it seems clear that monitoring the presence of omeprazole in the aquatic environment should be focused on the OMs suggested in this article instead of the parent compound
Time spent with cats is never wasted: Lessons learned from feline acromegalic cardiomyopathy, a naturally occurring animal model of the human disease
<div><p>Background</p><p>In humans, acromegaly due to a pituitary somatotrophic adenoma is a recognized cause of increased left ventricular (LV) mass. Acromegalic cardiomyopathy is incompletely understood, and represents a major cause of morbidity and mortality. We describe the clinical, echocardiographic and histopathologic features of naturally occurring feline acromegalic cardiomyopathy, an emerging disease among domestic cats.</p><p>Methods</p><p>Cats with confirmed hypersomatotropism (IGF-1>1000ng/ml and pituitary mass; n = 67) were prospectively recruited, as were two control groups: diabetics (IGF-1<800ng/ml; n = 24) and healthy cats without known endocrinopathy or cardiovascular disease (n = 16). Echocardiography was performed in all cases, including after hypersomatotropism treatment where applicable. Additionally, tissue samples from deceased cats with hypersomatotropism, hypertrophic cardiomyopathy and age-matched controls (n = 21 each) were collected and systematically histopathologically reviewed and compared.</p><p>Results</p><p>By echocardiography, cats with hypersomatotropism had a greater maximum LV wall thickness (6.5mm, 4.1β10.1mm) than diabetic (5.9mm, 4.2β9.1mm; Mann Whitney, p<0.001) or control cats (5.2mm, 4.1β6.5mm; Mann Whitney, p<0.001). Left atrial diameter was also greater in cats with hypersomatotropism (16.6mm, 13.0β29.5mm) than in diabetic (15.4mm, 11.2β20.3mm; Mann Whitney, p<0.001) and control cats (14.0mm, 12.6β17.4mm; Mann Whitney, p<0.001). After hypophysectomy and normalization of IGF-1 concentration (n = 20), echocardiographic changes proved mostly reversible. As in humans, histopathology of the feline acromegalic heart was dominated by myocyte hypertrophy with interstitial fibrosis and minimal myofiber disarray.</p><p>Conclusions</p><p>These results demonstrate cats could be considered a naturally occurring model of acromegalic cardiomyopathy, and as such help elucidate mechanisms driving cardiovascular remodeling in this disease.</p></div
Increased epidermal thickness and abnormal epidermal differentiation in keloid scars
Background: The pathogenesis underlying keloid formation is still poorly understood. Research has focused mostly on dermal abnormalities, while the epidermis has not yet been studied.
Objectives: To identify differences within the epidermis of mature keloid scars compared with normal skin and mature normotrophic and hypertrophic scars.
Methods: Rete ridge formation and epidermal thickness were evaluated in tissue sections. Epidermal proliferation was assessed using immunohistochemistry (Ki67, keratins 6, 16 and 17) and with an in vitro proliferation assay. Epidermal differentiation was evaluated using immunohistochemistry (keratin 10, involucrin, loricrin, filaggrin, SPRR2, SKALP), reverse-transcriptase polymerase chain reaction (involucrin) and transmission electron microscopy (stratum corneum).
Results: All scars showed flattening of the epidermis. A trend of increasing epidermal thickness correlating to increasing scar abnormality was observed when comparing normal skin, normotrophic scars, hypertrophic scars and keloids. No difference in epidermal proliferation was observed. Only the early differentiation marker involucrin showed abnormal expression in scars. Involucrin was restricted to the granular layer in healthy skin, but showed panepidermal expression in keloids. Normotrophic scars expressed involucrin in the granular and upper spinous layers, while hypertrophic scars resembled normotrophic scars or keloids. Abnormal differentiation was associated with ultrastructural disorganization of the stratum corneum in keloids compared with normal skin.
Conclusions: Keloids showed increased epidermal thickness compared with normal skin and normotrophic and hypertrophic scars. This was not due to hyperproliferation, but possibly caused by abnormal early terminal differentiation, which affects stratum corneum formation. Our findings indicate that the epidermis is associated with keloid pathogenesis and identify involucrin as a potential diagnostic marker for abnormal scarring
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Contains research objectives and reports on three research projects.National Science Foundation (Grant G-16526)National Institutes of Health (Grant MH-04737-03)National Aeronautics and Space Administration (Grant NsG-496)Lincoln Laboratory, Purchase Order DDL BB-107U.S. Air Force under Contract AF 19(628)-50
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