Key for a Hidden Quantum State.

Quantum trajectories are crucial to understanding the evolution of open systems. We consider an open cavity mode undergoing up and down multistate quantum jumps due to the emission and absorption of photons. We prove that among all subtrajectories, starting simultaneously from different photon number states, only one survives a long single-run evolution. A random Fock state terminating the subtrajectory becomes known for the ergodic case via the key-the processed record of the input and output photocounts, and the trajectory duration. Based on this result, we propose a robust protocol to infer the Fock state, a valuable resource for quantum applications.

Do twisted laser beams evoke nuclear hyperpolarization?

The hyperpolarization of nuclear spins promises great advances in chemical analysis and medical diagnosis by substantially increasing the sensitivity of nuclear magnetic resonance (NMR). Current methods to produce a hyperpolarized sample, however, are arduous, time-consuming or costly and require elaborate equipment. Recently, a much simpler approach was introduced that holds the potential, if harnessed appropriately, to revolutionize the production of hyperpolarized spins. It was reported that high levels of hyperpolarization in nuclear spins can be created by irradiation with a laser beam carrying orbital angular momentum (twisted light). Aside from these initial reports however, no further experimental verification has been presented. In addition, this effect has so far evaded a critical theoretical examination. In this contribution, we present the first independent attempt to reproduce the effect. We exposed a sample of immersion oil or a fluorocarbon liquid that was placed within a low-field NMR spectrometer to Laguerre-Gaussian and Bessel laser beams at a wavelength of 514.5nm and various topological charges. We acquired (1)H and (19)F NMR free induction decay data, either during or alternating with the irradiation that was parallel to B0. We observed an irregular increase in NMR signal in experiments where the sample was exposed to beams with higher values of the topological charge. However, at no time did the effect reach statistical significance of 95%. Given the measured sensitivity of our setup, we estimate that a possible effect did not exceed a hyperpolarization (at 5mT) of 0.14-6%, depending on the assumed hyperpolarized volume. It should be noted though, that there were some differences between our setup and the previous implementation of the experiment, which may have inhibited the full incidence of this effect. To approach a theoretical description of this effect, we considered the interaction of an electron with a plane wave, which is known to be able to induce electronic (e.g. in rubidium) and subsequent nuclear hyperpolarization. Compared to the plane wave, the additional transitions caused by a twisted wave are of the order of 10(-3) less. This suggests that the twist of the laser is unlikely to be responsible for the hyperpolarization of nuclear spins, unless a new mechanism of momentum transfer is identified.

Coherent inelastic backscattering of intense laser light by cold atoms.

We present a nonperturbative treatment of coherent backscattering of intense laser light from cold atoms and predict a nonvanishing backscattering signal even at very large intensities, due to the constructive (self-)interference of inelastically scattered photons.

[Radionuclide studies of reparative osteogenesis during modeling the shape of the leg]. / Radionuklidnye issledovaniia reparativnogo kosteobrazovaniia pri modelirovanii formy goleni.

The time course of metabolic processes in the osseous tissue and the capillary blood circulation in the forming osseous regenerate and the bone as a whole were studied in 16 patients using pyrophosphate and DTPA. The results of radiometry made it possible to give a quantitative evaluation of regeneration intensity: during intensive osteogenesis the accumulation of labeled pyrophosphate increased up to 720%, and the capillary blood circulation speeded up to 380%. Before the completion of osteogenesis the drug accumulation decreased considerably up to 250%.

[Cerebral blood-filling, tonus of cerebral vessels and intracranial pressure in epileptic patients during a single seizure]. / Krovenapolnenie mozga, tonus mozgovykh sosudov i vnutricherepnoe davlenie u bol'nykh épilepsiei vo vremia odinochnogo pripadka.

On the basis of simultaneous measurement of the rheosubcorticogram, polarogram, intracerebral pressure (ICP), ECoG and subcorticogram in patients with electrodes and sensors implanted in the brain, it was established that with the development of the seizure a rapidly reversible growth in the amplitude of deep rheoencephalogram, pO2 and ICP occurs beginning from the subclinical phase of epileptogenesis augmentation. According to the findings of deep rheoencephalography, the values of the tonic-elastic properties of the cerebral vessels undergo two-phase changes with the development of stable vasoparesis. The results of the study show that reactive hyperemia of the brain is the cause of the increased ICP; the cerebral perfusion pressure decreases in this case. A close correlation has been established between the values that were studied, particularly in the period of post-seizure coma.

[Radiotelemetric EEG and EKG studies of epilepsy patients]. / Radiotelemetricheskie issledovaniia EEG i EKG bol'nykh épilepsiei.

In 17 epileptic patients the EEGs and ECGs were recorded in clinical conditions using a 7-channel bioradiotelemetric system designed at the Sverdlovsk Institute of National Economy. The recording was performed under various physical, mental, and emotional loads, as well as during the seizures. This method of examination made it possible to specify in a number of cases the localization of the pathological focus, to differentiate the forms of unconscious motions, to disclose a number of the factors provoking or inhibiting the pathological activity of the brain.

[Dynamics of cerebral blood filling in epileptic patients during seizure activation]. / Dinamika mozgovogo krovenapolneniia u bol'nykh épilepsiei pri aktivatsii paroksizmov.

The interrelationship of cerebral hemodynamics and cerebral vascular tonus was studied in 36 patients with epilepsy during activation of discharges and provocation of epileptic seizures by hyperventilation and intravenous corazol infusion by simultaneous EEG and REG recording. It was found that regional functional hyperemia in the brain corresponding to the side of the epileptogenic focus increases during activation of the discharges despite a certain increase in the tonus of the cerebral vessels. During and immediately after an epileptic seizure angiospasm is replaced by vasodilation with further growth in blood filling of the brain. The possible mechanisms of the vascular reaction are discussed.

[Effect of thyroxine and insulin on nitrogen metabolism in the gastrointestinal system and mammary glands of lactating cows]. / Deistvie tiroksina i insulina na azotistyi metabolizm v pishchevaritel'noi sisteme i molochnoi zheleze u laktiruiushchikh korov.

In 9 cows giving 6-10 kg of milk daily and fed with 4 kg of combined food, administration of 50 mg of thyroxin increased extraction of some serum proteins from the blood by the digestive system (alpha- and beta-globulin factions in particular). Apsorption of amino-nitrogen from the blood by the mammary gland was increased by 3.5 times, and of ammonia by 5 times. Excretion of urine into the blood displayed a three-fold increase. Insulin in dosage 1 unit per 1 kg of body weight increased excretion of serum proteins and urine from the digestive system into the blood. Excretion of gamma-globulins into the lactic vein's blood increased by 3 times, and 0.17% of albumins were exctracted by the mammary gland from the coming blood. Subcutaneous administration of thyroxin and insulin obviously increases the amount of protein, casein and nitrogen substances in the milk.