Transport of indirect excitons in ZnO quantum wells.

We report on spatially- and time-resolved emission measurements and observation of transport of indirect excitons in ZnO/MgZnO wide single quantum wells.

Nondestructive measurement of nuclear magnetization by off-resonant Faraday rotation.

We report on the nondestructive measurement of nuclear magnetization in n-GaAs via cavity enhanced Faraday rotation. In contrast with the existing optical methods, this detection scheme does not require the presence of detrimental out-of-equilibrium electrons. Specific mechanisms of the Faraday rotation are identified for (i) nuclear spins situated within the localized electron orbits, these spins are characterized by fast dynamics, (ii) all other nuclear spins in the sample characterized by much slower dynamics. Our results suggest that even in degenerate semiconductors nuclear spin relaxation is limited by the presence of localized electron states and spin diffusion, rather than by Korringa mechanism.

Spin currents in a coherent exciton gas.

We report the observation of spin currents in a coherent gas of indirect excitons. The realized long-range spin currents originate from the formation of a coherent gas of bosonic pairs--a new mechanism to suppress the spin relaxation. The spin currents result in the appearance of a variety of polarization patterns, including helical patterns, four-leaf patterns, spiral patterns, bell patterns, and periodic patterns. We demonstrate control of the spin currents by a magnetic field. We also present a theory of coherent exciton spin transport that describes the observed exciton polarization patterns and indicates the trajectories of the spin currents.

Optical pump-probe detection of manganese hyperfine beats in (Cd,Mn)Te crystals.

Optical pump-probe experiments reveal spin beats of manganese ions in (Cd,Mn)Te, due to hyperfine and crystal fields. At "magic" orientations of the magnetic field, the effect of local crystal field is strongly suppressed. In this case, the spin precession of Mn(2+) embedded in the lattice approaches the precession expected for the free ion. Following optical excitation, regular spin pulses show up, revealing the one-to-one correspondence between precession frequency and Mn(2+) nuclear spin state. The period of the spin pulses accurately determines the hyperfine constant |A|=705 neV. The manganese spin coherence time up to T(2)(Mn)≃15 ns is measured for a manganese concentration x=0.0011.

[Exenatide stimulated solute-free water excretion by human kidney].

Exenatide effect was studied in 55 human including 38 patients with type 2 diabetes mellitus without signs of diabetic nephropathy and primary renal diseases. Preliminary study with water load in volume from 0.5 to 1% b.w. showed that water load equal to 0.7% b.w. caused significant increase in urine excretion. The rise of diuresis after 10 microg Byetta (exenatide) injection and simultaneous water load of 0.7% of b.w. depended on increase in solute-free water clearance. Thus, exenatide (mimetic of GLP-1) action let us to consider its possible role as component of osmoregulation system in human. This peptide provides high efficiency of renal function in osmotic homeostasis.

Photon BLOCH oscillations in porous silicon optical superlattices.

We report the first observation of oscillations of the electromagnetic field in an optical superlattice based on porous silicon. These oscillations are an optical equivalent of well-known electronic Bloch oscillations in crystals. Elementary cells of our structure are composed by microcavities whose coupling gives rise to the extended collective modes forming optical minigaps and minibands. By varying thicknesses of the cavities along the structure axis, we have created an effective electric field for photons. A very high quality factor of the confined optical state of the Wannier-Stark ladder may allow lasing in porous silicon-based superlattices.

[Analysis of the inheritance of taillessness in the Baikuzino population of cats from Udmurtia]. / Analiz nasledovaniia "beskhvostosti" u baikuzinskoi populiatsii udmurtskikh koshek.

A new mutation of taillessness was found in its extreme form in an isolated cat population from a Russian region. The mutation was expressed as the absence of tail or its shortening. Genetic analysis gives grounds to suppose that this trait is controlled by a dominant gene with a probable recessive lethal effect at an early embryogenetic stage.

Scaling and universality of self-organized patterns on unstable vicinal surfaces.

We propose a unified treatment of the step bunching instability during epitaxial growth. The scaling properties of the self-organized surface pattern are shown to depend on a single parameter, the leading power in the expansion of the biased diffusion current in powers of the local surface slope. We demonstrate the existence of universality classes for the self-organized patterning appearing in models and experiments.

[Phenotypic and genotypic characteristics of russian hairless cats]. / Fenotipicheskie i genotipicheskie osobennosti russkikh bessherstnykh koshek.

A novel mutation that causes the loss of hair was found in Russian cats. In contrast to hairless cats known in other countries (Sphinx cats of Canada, Great Britain, France, and Germany, etc.), in which the loss of hair is inherited as a monogenic recessive trait, in Russian hairless cats this trait is determined by a semidominant gene with the participation of other genes.

Neurologic evaluation of the rat during sciatic nerve block with lidocaine.

BACKGROUND: Quantitative behavioral testing is necessary to establish a reproducible measure of differential functional blockade during regional anesthesia. Methods for assessment of the neurologic status (mental status, posture, gait, proprioception, motor function, autonomic function, and nociception) in veterinary neurology were adapted for the rat and used to monitor functional changes separately during a sciatic nerve block. METHODS: Sprague-Dawley rats were acclimated to laboratory routine before the study so that lidocaine (0.1 ml, 1%) could be injected near the sciatic notch without any chemical restraint. The onset, duration, and magnitude of functional losses were monitored. Proprioceptive integrity was evaluated by assessing the response to tactile placing and the hopping response. Extensor postural thrust, a test for postural reactions in small animals, was assessed on a digital balance and found adequate for quantifying motor function. Analgesia was assessed by measuring withdrawal response latencies to noxious thermal stimulation (51 degrees C) and to superficial and deep noxious pinches. Autonomic function was monitored by measuring skin temperature. Contralateral limb function was used as an internal control, and injection of saline was used as an external control in separate, control animals. RESULTS: Onset of postural and gait abnormalities were observed as early as 40 s after injection. On each occasion proprioceptive impairment was detected first, followed by impairment of motor function and nociception. Complete absence of proprioception occurred from 10 to 30 min (n = 9) and of motor function at 30 min after injection (n = 10); both functions were fully recovered by 120 min. A unilateral increase in skin temperature on the foot was detected by 1 min; had reached its maximum change, 5.3 +/- 0.7 degrees C, at 10 min; and had returned to control levels at 60 min after injection (n = 12). Withdrawal response to cutaneous or superficial pain was absent in all ten animals from 5 to 30 min whereas the response to deep pain was absent in all ten animals at 20 min only. The response to noxious stimulation recovered at 90 min. Attention was paid to the temporal relation of the impairment of various functions. CONCLUSIONS: Quantitative observations of the onset, offset, and intensity of differential functional impairment or block over time will make it possible to establish the doses and conditions for local anesthetics that result in differential nerve block and will permit comparison of these changes among different drugs and "clinical" protocols.

[Clinical course of infiltrative tuberculosis in adolescents]. / Klinicheskoe techenie infil'trativnogo tuberkuleza u podrostkov.

The course of infiltrative tuberculosis making up 53.2% in the pattern of clinical forms was investigated in 64 adolescents. Infiltrative tuberculosis morbidity among the girls is 3 times higher. The main detection method is represented by a planned roentgenofluorographic examination, since in the region in question infiltrative tuberculosis tends to have limited symptoms in 56.2% of the adolescents, including 30.5% of them even with disseminated process. In 60.9% of the cases, infiltrative tuberculosis is observed to have a decomposition phase which is 4.5 times more frequently traced in patients living in contact with a bacillary ++carrier . In 8% of the patients, infiltrative tuberculosis was complicated by hemoptysis. Infiltrative tuberculosis in 32.8% of the adolescents manifests itself in a pulmonary form of primary tuberculosis. Due to a complex treatment hemodynamic indices are normalized by the end of the first month in addition to the removal of the intoxication signs by the third month. Cavity closure was achieved in 71.8% of the patients. Despite the given therapy, transformation into the destructive forms of tuberculosis took place.

[Clinical course, treatment and outcome of tuberculous meningitis in children]. / Klinicheskoe techenie, lechenie i iskhody tuberkuleznogo meningita u detei.

Data are given on the follow-up of 108 children between the ages of 6 months and 15 years who had tuberculous meningitis. A basilar form of meningitis was diagnosed in 70.4% of the children and meningo-encephalitic form in 29.6%. In most of the children meningitis developed in the presence of specific changes in the lungs; the course was typical in 74.1% and acute in 25.9%. Superinfection was seen in 64% of the children, late diagnosis and untimely hospitalization of children were noted in 31.5%. A clear relationship was revealed between disappearance of clinical signs and liquor cleansing and hospitalization terms. Treatment currently applied is effective. Cure was seen in 86.1% of the cases in the presence of significant residual changes (in meningoencephalitis) in 13.9%. The disease had a fatal outcome in 13.9% of the cases of late diagnosis.

[The clinical aspects of tuberculosis of the respiratory organs in adolescents]. / Klinicheskie aspekty tuberkuleza organov dykhaniia u podrostkov.

Investigation of the tuberculous process of the respiratory organs in 120 adolescents showed that the disease was more frequent in female persons (61.7 per cent). Schoolchildren amounted to 52.6 per cent. Prophylactic examinations revealed 50 per cent of the patients. 38.3 per cent of the patients were detected on their taking medical advice. With the Mantoux test with 2 TU of PPD-L only 5 per cent of the patients were detected. Infiltrative tuberculosis in 53.3 per cent of the patients was recorded. In the majority of the patients, the signs of tuberculosis were insignificant. However, in 44.2 per cent of the adolescents, the process was accompanied by destructions. In 86.7 per cent of the patients the process was primary by its genesis. Pronounced clinical signs of tuberculosis in 36.7 per cent of the adolescents were due to extended processes in 68 per cent of the cases. The phase of destruction in them reached 86.6 per cent. 39.7 per cent of the patients were from tuberculosis foci with insufficient prophylactic and antiepidemic measures. To lower the incidence of tuberculosis in adolescents it is necessary to increase the measures for tuberculosis detection in them and to improve the quality of prophylaxis in tuberculosis foci.

[Glutamate dehydrogenases of unicellular green algae: effects of nitrate and ammonium in vivo]. / Glutamatdegidroginazy odnokletochnykh zelenykh vodorosleí vliianie nitrata i ammoniia in vivo.

The constitution and control by the inorganic nitrogen source of glutamate dehydrogenases of some unicellular green algae have been studied. The Ankistrodesmus braunii and Scenedesmus obliquus cells contain two different glutamate dehydrogenases, one of which is NADP-specific, the other is active with both NAD and NADP. Their synthesis does not depend on the nitrogen source. The activity of NADP-specific glutamate dehydrogenase increases sharply during nitrogen starvation. In Chlorella pyrenoidosa 82 and Ch. ellipsoidea only one constitutive double specific glutamate dehydrogenase is observed. Its activity does not change depending on the nitrogen nutrition conditions. In the cells of the thermophylic Chlorella strain Chlorella sp. K. ammomium induces a de novo synthesis of NADP-specific glutamate dehydrogenase in addition to the constitutive double specific glutamate dehydrogenase. Thus, the algae tested contain constitutive double specific glutamate dehydrogenase. The NADP-specific enzyme is absent in two Chlorella strains, is constitutive in A. braunii and S. obliquus, and is ammonium-inducible in three thermophylic Chlorella strains.