5,174 research outputs found
Изучение терапевтических эффектов излучения с длиной волны 670 нм при различных типах диабетического макулярного отека
The purpose of this study was to investigate the therapeutic effects of 670 nm irradiation in patients with diabetic macular edema. In several studies, positive effects of red/near-infrared irradiation showed in a range of ocular diseases such as macular degeneration, macular edema, and retinitis pigmentosa. This study was conducted on forty five eyes of 26 diabetic patients with macular edema between the ages of 51 and 80.Measurement of visual acuity and slit lamp examination, funduscopy, and optical coherence tomography were performed in all subjects. None of the patients had proliferative retinopathy. We used a portable LED device (Warp 10, Quantum Devices) for treatment. Patients held this device at a distance of 3 cm from their eyes for 240 seconds for three months. Full ophthalmic examinations were repeated 1, 2, and 3 months after treatment.After 3 months, the mean visual acuity improved from 0.44 ± 0.38 log MAR to 0.27 ± 0.24 log MAR and vision increased by 1.52 ± 1.16 lines post treatment (р<0.001). The mean central macula thickness decreased from 381.49 ± 144.40 μm to 359.72 ± 128.84 μm (р=0.050). In patients with mild and moderate nonproliferative diabetic retinopathy, the mean central retinal thickness decreased 52.06 ± 67.78 μm and 39.27 ± 44.69 μm, respectively, but patients with severe type showed an increase of 34.93 ± 65.65 μm in the mean central retinal thickness (р<0.001). Also, the severity of macular edema had no effect on final outcomes (р>0.05). Photobiomodulation can positively affect diabetic macular edema, especially in patients with mild to moderate diabetic retinopathy.Целью данной исследовательской работы являлось изучение терапевтических эффектов излучения с длиной волны 670 нм у пациентов с диабетическим макулярным отеком. Ряд предыдущих исследований свидетельствует о положительном эффекте красного инфракрасного излучения при некоторых заболеваниях глаз, таких как макулодистрофия (дегенерация желтого пятна), макулярный отек и пигментный ретинит. Наше исследование было проведено на 45 глазах у 26 больных сахарным диабетом в возрасте от 51 до 80 лет с макулярным отеком. Всем пациентам были проведены определение остроты зрения, осмотр глаз щелевой лампой, фундоскопия и оптическая когерентная томография. Ни у одного из пациентов не было пролиферативной ретинопатии. Для лечения нами был применен портативный светодиодный прибор (Warp 10, Quantum devices). Пациенты держали светодиод на расстоянии 3 см от глаза в течение 240 сек в течение 3 мес. Все офтальмологические исследования были повторены через 1, 2 и 3 мес после проведения лечебной процедуры. Через 3 мес средняя острота зрения улучшилась с показателем логарифма минимального угла разрешения 0,44 ± 0,38 до 0,27 ± 0,24, что показало увеличение показателя остроты зрения на 1,52 ± 1,16 после лечения (р<0,001). Средняя центральная толщина сетчатки в области макулы уменьшилась с 381,49 ± 144,40 мкм до 359,72 ± 128,84 мкм (р=0,050). У пациентов с легкой и умеренной непролиферативной диабетической ретинопатией средняя толщина сетчатки уменьшилась до 52,06 ± 67,78 и 52,06 ± 67,78 мкм, соответственно, а у пациентов с тяжелой ретинопатией наблюдалось увеличение на 34,93 ± 65,65 мкм (р<0,001). Помимо того, степень макулярного отека не повлияла на окончательный результат лечения (р>0,05). Фотобиомодуляция была эффективной при диабетическом макулярном отеке, в частности, у пациентов с легкой и умеренной диабетической ретинопатией
Time-ordering and a generalized Magnus expansion
Both the classical time-ordering and the Magnus expansion are well-known in
the context of linear initial value problems. Motivated by the noncommutativity
between time-ordering and time derivation, and related problems raised recently
in statistical physics, we introduce a generalization of the Magnus expansion.
Whereas the classical expansion computes the logarithm of the evolution
operator of a linear differential equation, our generalization addresses the
same problem, including however directly a non-trivial initial condition. As a
by-product we recover a variant of the time ordering operation, known as
T*-ordering. Eventually, placing our results in the general context of
Rota-Baxter algebras permits us to present them in a more natural algebraic
setting. It encompasses, for example, the case where one considers linear
difference equations instead of linear differential equations
Design of integrated pitch axis for autopilot/autothrottle and integrated lateral axis for autopilot/yaw damper for NASA TSRV airplane using integral LQG methodology
Two designs are presented for control systems for the NASA Transport System Research Vehicle (TSRV) using integral Linear Quadratic Gaussian (LQG) methodology. The first is an integrated longitudinal autopilot/autothrottle design and the second design is an integrated lateral autopilot/yaw damper/sideslip controller design. It is shown that a systematic top-down approach to a complex design problem combined with proper application of modern control synthesis techniques yields a satisfactory solution in a reasonable period of time
Renormalization: a quasi-shuffle approach
In recent years, the usual BPHZ algorithm for renormalization in perturbative
quantum field theory has been interpreted, after dimensional regularization, as
a Birkhoff decomposition of characters on the Hopf algebra of Feynman graphs,
with values in a Rota-Baxter algebra of amplitudes. We associate in this paper
to any such algebra a universal semi-group (different in nature from the
Connes-Marcolli "cosmical Galois group"). Its action on the physical amplitudes
associated to Feynman graphs produces the expected operations: Bogoliubov's
preparation map, extraction of divergences, renormalization. In this process a
key role is played by commutative and noncommutative quasi-shuffle bialgebras
whose universal properties are instrumental in encoding the renormalization
process
Glass Transition Temperature of Cross-Linked Epoxy Polymers: a Molecular Dynamics Study
Recently, epoxy polymers have been used in different applications and research fields due to their superior properties. In this study, the classical molecular dynamics (MD) was used to simulate formation of
the epoxy polymer from cross linking of the EPON 828 with DETA curing agent, and calculate the glass
transition temperature (Tg) of the material. A series of MD simulations were independently carried out on
the cross-linked epoxy polymer in a range of temperatures from 600 K down to 250 K, and the density of
the materials was calculated at the end of each run. Through the linear fitting between temperature and
density above and below the glass transition temperature, Tg was estimated. The glass transition temperature of the pure DGEBA were also estimated through the same procedure and compared with those of the
cross-linked polymer. Molecular simulations revealed significant increase in Tg of the cross-linked epoxy
polymer as a result of newly created covalent bonds between individual chains.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3510
Comparison of N-acetylcysteine, ascorbic acid, and normal saline effect in prevention of contrast-induced nephropathy
BACKGROUND: Considering the crucial role of appropriate preventative strategies in reducing the rate of contrast-induced nephropathy (CIN) occurrence and its related morbidity and mortality, the effect of N-acetylcysteine (NAC), ascorbic acid (AA), and normal saline (NS) was investigated in the patient's undergone coronary angiography. METHODS: In this clinical trial, 120 patients scheduled for elective coronary angiography with serum creatinine (Cr) level > 1.5 mg/dl or glomerular filtration rate (GFR) >= 60 selected by convenience method. Selected patients were allocated in three treatment groups randomly to receive oral NAC (600 mg/twice daily) plus NS (100 ml/hour) (Group A), oral AA (250 mg/twice daily) plus NS (100 ml/hour) (Group B) and NS (100 ml/hour) (Group C), respectively. The occurrence of CIN was evaluated based on serum Cr and GFR in three studied groups, before and after angiography procedure. The analysis of variance and paired t-test were used for data analysis by SPSS. RESULTS: The serum Cr increased and GFR decreased significantly during the intervention in three groups (P 0.050). CONCLUSION: The study showed that nor the addition of NAC neither the addition of AA to sodium chloride infusion has more beneficial effect than hydration with sodium chloride, in the prevention of CIN
Use of Α-Interferon, Amantadin and Isoprinosine in Subacute Sclerosing Panencephalitis (Sspe): Comparing the Effectiveness
ObjectiveSub acute Sclerosing Pan Encephalitis (SSPE), a progressive neurological disorder characterized by inflammation of the brain (encephalitis), is the result of an inappropriate immune response to the measles virus or measles vaccination.SSPE usually develops 2 to 10 years after the original viral attack. Some of the major signs and symptoms are mental deterioration, jerky movements, and seizures specially myoclonic type, involuntary movements, and/or behavioral changes, difficulty in walking, speech, and loss of cognition, respiratory distress and death.Materials and MethodsDuring the ten years, from July 1991 to July 2001, we admitted 45 cases of (SSPE), at different stages of the disorder. Regardless of their stage of disease, for intervention, randomly, we used one of three drugs; Amantadin, Interferon alfa and Isoprinosine, administered to the patients, for between one month to one year. Fourteen cases received Amantadin, 15 Alfa interferon, and 16 were given Isoprinosine.ResultsWhile the results show all three drugs to be relatively effective, Isoprinosine showed four times more effectiveness than Amantadin and twice as much as Interferon.ConclusionThe results showed Isoprinosine to be much more effective than Amantadin and Alfa interferon in treating the condition
A Study of Swelling Behaviour in a Tunnel Using Finite Element Methods
The aim of this research is to show swelling behaviour in a tunnel excavated through rocks by modeling them and using laboratory results. The engineering challenge is how to design a tunnel which contains swelling rocks such as marl. This aim is achieved through two methods. In the first method, the Field System Solution program (FISS) is calibrated using experimentally obtained laboratory graphs of the saturated rocks around the tunnel, and the parameters are applied to the geometry of the tunnel. Comparing a critical state model with stresses around the tunnel, stability of the rocks was examined. In the second method, stability of the rocks around the tunnel was investigated by using the Nisa-II program, adjusting the laboratory swelling graphs with the creep function to the program and, finally, drawing Von Mises stresses around the tunnel
Genetic algorithm-based pore network extraction from micro-computed tomography images
A genetic-based pore network extraction method from micro-computed tomography (micro-CT) images is proposed in this paper. Several variables such as the number, radius and location of pores, the coordination number, as well as the radius and length of the throats are used herein as the optimization parameters. Two approaches to generate the pore network structure are presented. Unlike previous algorithms, the presented approaches are directly based on minimizing the error between the extracted network and the real porous medium. This leads to the generation of more accurate results while reducing required computational memories. Two different objective functions are used in building the network. In the first approach, only the difference between the real micro-CT images of the porous medium and the sliced images from the generated network is selected as the objective function which is minimized via a genetic algorithm (GA). In order to further improve the structure and behavior of the generated network, making it more representative of the real porous medium, a second optimization has been used in which the contrast between the experimental and the predicted values of the network permeability is minimized via GA. We present two case studies for two different complex geological porous media, Clashach sandstone and Indiana limestone. We compare porosity and permeability predicted by the GA generated networks with experimental values and find an excellent match
- …