Climate change, in the framework of the Constructal Law

Here we present a simple and transparent alternative to the complex models of earth’s thermal behaviour under time-changing conditions. We show the one-to-one relationship between changes in atmospheric properties and time-dependent changes in temperature and its distribution on earth. The model accounts for convection and radiation, thermal inertia and changes in albedo (ρ) and greenhouse factor (γ). The constructal law is used as the principle that governs the evolution of fl ow confi guration on earth. The model showed that for two time-dependent scenarios, (δρ = 0.002; δγ = 0.011) and (δρ = 0.002; δγ = 0.005) the predicted equatorial and polar temperature increases and the time scales are (ΔTH = 1.16 K; ΔTL = 1.11 K; 104 years) and (0.41 K;0.41 K; 57 years), respectively. A continuous model of temperature variation was used to predict the thermal response of the Earth’s surface to changes bounded by δρ = δγ and δρ = −δγ. The poleward heat current reaches its maximum in the vicinity of 35° latitude,accounting for the position of the Ferrel cell between the Hadley and Polar Cells

Finite element 3-D model of a double quantum ring: effects of electric and laser fields on the interband transition

In this work, the changes in the energy of electrons and holes, oscillator strength and interband transition time when external fields are applied to a GaAs/AlGaAs semiconductor double ring grown by the droplet epitaxy technique are theoretically analyzed. We consider a static electric field and an intense laser field nonresonant with the quantum structure, with variable intensities and orientations with respect to the symmetry axis of the quantum ring. In the formalism of the effective mass approximation for electrons and holes, the energies and wavefunctions were numerically computed using the finite element method implemented with an accurate three-dimensional model of the real quantum ring. Laser dressing of the confining potential was performed using the exact integration formula at each point. Our results show major differences between the effects of the two types of applied fields, caused mainly by the static electric-field-induced strong polarizability of the confined electron-hole pair. In addition, the effects of both fields exhibit strong anisotropy in the electronic properties as a result of the particular flattened geometry of the quantum ring. Proper combinations of field strengths and orientations are helpful in designing accurate tools for the sensitive manipulation of interband radiative properties.Comment: 23 pages, 15 figures, 3 table

Методы пренатальной диагностики: QF-PCR, Кариотип, FISH, NIFTY

Centrul Medical „Repromed”Contemporary cytogenetic and molecular genetic technologies offer a solid basis for an accurate and early diagnosis of genetic diseases. Because of the rapid progress in both areas, the prenatal diagnosis became an efficient instrument both for medical geneticists and gynecologists. The development of complex techniques of prenatal molecular diagnosis has produced a real burst of information, which requires an appropriate interpretation and application by the clinician for the benefit of the patient. Our purpose is to make a brief analysis of the classical and newest methods of prenatal genetic diagnosis and to evaluate the risks and benefits of each method both for pregnant and fetus.Современная цитогенетика совместно с прогрессом молекулярно-генетических технологий проложили путь к более точному и значительно более раннему диагностированию генетических заболеваний, которые сделали пренатальную диагностику весьма эффективным инструментом для врача гинеколога и генетика. Разработка более сложных молекулярных методов пренатальной диагностики привела к взрыву информации, которая должна быть применена врачами для блага пациентов. С помощью этой статьи мы хотим сделать краткий анализ классических и новейших методов для пренатальной диагностики генетических заболеваний, взвесить пользу и риск каждого метода как для беременной, так и для плода

Методы пренатального генетического скрининга. Двойной, тройной и четверной тесты

Centrul Medical „Repromed”Antenatal screening of hereditary diseases and congenital malformations during the first and second trimester of pregnancy is an important tool for the evaluation of the intrauterine fetal condition. Special attention is paid to the principles of antenatal screening organization, echographic markers, and biochemical methods of fetal development assessment. Antenatal genetic screening includes fetal ultrasound and biochemical screening (estimation of certain plasmatic markers, which fluctuate in cases of certain fetal diseases). There are several types of screening (depending on the number of performed biochemical tests): double test (combined test), triple test, and quadruple test. Screening tests are not pretending to be the source of the final diagnosis. They rather give a possibility to identify the group of pregnant with an increased risk of certain fetal pathologies, which require specific diagnostic methods. The current recommendations are presented for general practitioners, gynecologists, specialists in genetics, and patients.Пренатальный скрининг наследственных и врожденных заболеваний в первом и втором триместре беременности способствует получению дополнительной информации относительно здоровья плода. Особое внимание уделено принципам организации пренатального скрининга, ультразвуковым маркерам и биохимическим методам диагностики развития плода. Пренатальный генетический скрининг включает в себя ультразвуковой и биохимический скрининг, то есть определение серологических маркеров, изменяющихся при некоторых патологиях. Есть несколько типов скрининга: двойной тест (комбинированный тест), тройной тест и четверной тест – в зависимости от количества биохимических показателей. Скрининговые тесты предназначены не для окончательного диагноза, а для выявления беременных женщин, имеющих высокий риск при некоторых патологиях плода, которым рекомендуется диагностические исследования. Статья содержит рекомендации как для семейных врачей, гинекологов и генетиков, так и для пациентов