Difference-frequency generation of optical radiation from two-color x-ray pulses.

We describe the process of difference-frequency generation of short optical pulses from two-color X-ray pulses. By assuming 10¹¹ photons per X-ray pulse, we predict that the optical count rate can exceed 10⁷ photons per pulse. Similar to other effects involving nonlinear interactions of X-rays and optical radiation, the effect we describe can be used for microscopic studies of chemical bonds and as a probe for light-matter interactions on the atomic scale.

Lack of association of G-protein subunit gene C825T polymorphism with left ventricular hypertrophy in essential hypertension.

Background: The aim of the present study was to determine if there is an association of G-protein b3 subunit (GNB3) gene polymorphisms and left ventricular hypertrophy (LVH) in patients with essential hypertension (EH) in a St. Petersburg population.

Material/methods: We examined 135 patients (mean age 48 +/- 7 yrs) with mild to moderate EH recruited from the general population of an outpatient hypertension clinic.

Lack of association of the renin-angiotensin system genes polymorphisms and left ventricular hypertrophy in hypertension.

Objective: The aim of the present study was to determine if there is an association of different gene polymorphisms of renin-angiotensin system and left ventricular hypertrophy (LVH) in patients with essential hypertension (EH) in St Petersburg population.

Patients And Methods: We examined 156 patients (the mean age 49+/-8 years) with mild-to-moderate EH recruited from the general population of the outpatient clinic. Left ventricular mass was measured by echocardiography and left ventricular mass index (LVMI) was calculated.