Accessible and reliable neurometric testing in humans using a smartphone platform.

Tests of human brain circuit function typically require fixed equipment in lab environments. We have developed a smartphone-based platform for neurometric testing. This platform, which uses AI models like computer vision, is optimized for at-home use and produces reproducible, robust results on a battery of tests, including eyeblink conditioning, prepulse inhibition of acoustic startle response, and startle habituation. This approach provides a scalable, universal resource for quantitative assays of central nervous system function.

Hydrogen passivation of the n-GaN nanowire/p-Si heterointerface.

The influence of hydrogen plasma treatment on the electrical and optical properties of vertical GaN nanowire (NW)/Si heterostructures synthesized via plasma assisted molecular beam epitaxy is studied. The effect of the treatment is thoroughly studied via variation of the passivation duration. Photoluminescence investigation demonstrates that the passivation affects the doping of the GaN NWs. The samples were processed as photodiodes with a top transparent electrode to obtain detailed information about the n-GaN NWs/p-Si heterointerface under illumination. The electron beam induced current measurements demonstrated the absence of potential barriers between the active parts of the diode and the contacts, indicating ohmic behavior of the latter. I-V characteristics obtained in the dark and under illumination show that hydrogen can effectively passivate the recombination centers at the GaN NWs/Si heterointerface. The optimum passivation duration, providing improved electrical properties, is found to be 10 min within the studied passivation regimes. It is demonstrated that longer treatment causes degradation of the electrical properties. The discovered phenomenon is discussed in detail.

Effects of the surface preparation and buffer layer on the morphology, electronic and optical properties of the GaN nanowires on Si.

The role of Si (111) substrate surface preparation and buffer layer composition in the growth, electronic and optical properties of the GaN nanowires (NWs) synthesized via plasma-assisted molecular beam epitaxy is studied. A comparison study of GaN NWs growth on the bare Si (111) substrate, silicon nitride interlayer, predeposited AlN and GaO x buffer layers, monolayer thick Ga wetting layer and GaN seeding layer prepared by the droplet epitaxy is performed. It is demonstrated that the homogeneity and the morphology of the NW arrays drastically depend on the chosen buffer layer and surface preparation technique. An effect of the buffer and seeding layers on the nucleation and desorption is also discussed. The lowest NWs surface density of 14 µm-2 is obtained on AlN buffer layer and the highest density exceeding the latter value by more than an order of magnitude corresponds to the growth on the 0.3 ML thick Ga wetting layer. It is shown, that the highest NWs mean elongation rate is obtained with AlN buffer layer, while the lowest elongation rate corresponds to the bare Si (111) surface and it is twice as lower as the first case. It is found, that use of AlN buffer layer corresponds to the most homogeneous NWs array with the smallest length dispersion while the least homogeneous array corresponds to the bare Si substrate. Vertically aligned GaN NWs array on the wide bandgap GaO x semiconductor buffer layer grown by plasma-enhanced chemical vapor deposition demonstrates its potential for electronic applications. Photoluminescence (PL) study of the synthesized samples is characterized by an intense optical response related to the excitons bound to neutral donors. The highest PL intensity is obtained in the sample with AlN buffer layer.

[The dynamics of contamination of Kozhanovskoe lake with 137Cs in the post-Chernobyl period].

The paper presents the dynamics and the current state of radioactive contamination with 137Cs of low--running Kozhanovskoe lake situated in Bryansk region. Semi-empiric assessment of the current radiation state based on the analysis of dynamics of contamination of Kozhanovskoe lake with 137Cs corresponds satisfactory to experimental data. Integral 137Cs inventories were estimated for the main components of the lake, including water, bottom sediments and aquatic vegetation for the period of 2005-2007.

Effect of nonselective beta-adrenoblockers on the state of sympathoadrenal system and ratio of neuroactive amino acids in rat medulla oblongata.

Experiments on rats showed that injection of propranolol into the medulla oblongata increased the contents of epinephrine, norepinephrine, dopamine, and L-DOPA by 3.76, 1.4, 2.0, and 1.7 times, respectively. These propranolol-induced changes in the levels and ratio of neurotransmitters were not accompanied by variations in serotonin content. Propranolol had no significant effects on the content of excitatory amino acids, except marked increase in aspartate content. The level of inhibitory amino acids increased mainly due to an increase in GABA content. The balance between excitatory and inhibitory amino acids was shifted towards inhibitory compounds.

Effects of verapamil and amiodarone on sympathoadrenal system and balance of excitatory and inhibitory amino acids in rat medulla oblongata.

Local injection of verapamil into ventrolateral region of the medulla oblongata triggered the release of epinephrine. Verapamil increased the total content of norepinephrine and epinephrine by 560% and decreased the content of serotonin by 46%. Verapamil had no effect on norepinephrine/epinephrine and norepinephrine/(norepinephrine+epinephrine) ratios in normal rats. Blockade of K+-channels in the medulla oblongata by local injection of 0.001 mg amiodarone did not change the levels of epinephrine and norepinephrine and norepinephrine/epinephrine and norepinephrine/(norepinephrine+epinephrine) ratios. In the medulla oblongata, verapamil proportionally increased the levels of norepinephrine, dopamine, and L-DOPA. Similarly, amiodarone increased the levels of L-DOPA and dopamine by 2.6 and 3.2 times, respectively. Amiodarone shifted the ratio of neuroactive amino acids towards inhibitory transmitters.

Effects of bradysole and dibasole on cerebral bloodflow under experimental conditions.

Bradysole (1 mg/kg intravenously) induced a moderate increase in cerebral bloodflow and a minor decrease in systemic blood pressure in narcotized rats. These effects were less pronounced compared to the effects of dibasole (bradysole structural analog) in the same dose.

Effect of imidazobenzoimidazole derivatives RU-353, RU-563, and lidocaine on cerebral circulation in rats.

We demonstrated a dose-dependent inhibitory effect of novel imidazobenzoimidazole derivatives RU-353 and RU-563 on cerebral blood flow and systemic blood pressure in narcotized rats. The effects of RU-353 increased, while the effect of RU-563 decreased with increasing the dose.

Effect of cyclic GABA derivative TZ-146 on the content of neurotransmitters in rat brain stem.

The effect of cyclic GABA derivative TZ-146 on the content of catecholamines, serotonin, their metabolites, and neurotransmitter amino acids in rat hypothalamus and brain stem was studied by high-performance liquid chromatography with electrochemical detection. Opposite changes in the content of homovanillic acid, aspartate, glutamate, and glycine in the examined structures were accompanied by inhibition of dopamine metabolism. Possible participation of cerebral glutamatergic system in the effect of TZ-146 is discussed.

[Differential diagnosis of B-cell lymphoma rich in T cells and peripheral T-cell lymphomas]. / O differentsial'noi diagnostike B-kletochnoi limfomy, bogatoi T-kletkami, i perifericheskikh T-kletochnykh limfom.

Clinicomorphological analysis of T-cell-rich B-cell lymphoma in a 50-year-old female and literature data revealed objective difficulties in morphological diagnosis using cytological and histological methods. Large number of epithelioid histiocytes and tumor cells polymorphism resembled Lennert's lymphoma (peripheral T-cell lymphoma). Immunohistochemical study confirmed B-cell origin of tumor cells and large number of reactive T-cells. It is suggested that it would be more correctly to use the term "Lennert-like areas" in such cases with subsequent immunohistochemical study.

[Results of organ-preserving and reconstructive surgery of the mandible in patients with cancer of the oral cavity]. / Rezul'taty organosokhraniaiushchikh i rekonstruktivnykh operatsii na nizhnei cheliusti u bol'nykh rakom polosti rta.

Surgery is the basic procedure of combined therapy for locally-advanced carcinoma of the oral mucosa. It is intended to excise involved mucosa and soft tissues of the oral cavity and to resect the mandible. Rim resection (55) produces good functional and cosmetic results and was followed by 5-year survival in 76.4%. Due to median mandibulotomy (24), optimal access was provided to tumor involving the whole tongue and sitting at the back of the oral cavity (5-year survival--58.3%). Postoperative complication incidence was significantly lowered when titanium miniplates were used for mandibular arch reconstruction. When these miniplates and osteomyocutaneous flaps were used for mandibular reconstruction, following segmental resection, good cosmetic and functional results were recorded in 5 out of 8 cases (5-year survival--75%).