High-Q trenched aluminum coplanar resonators with an ultrasonic edge microcutting for superconducting quantum devices

Dielectric losses are one of the key factors limiting the coherence of superconducting qubits. The impact of materials and fabrication steps on dielectric losses can be evaluated using coplanar waveguide (CPW) microwave resonators. Here, we report on superconducting CPW microwave resonators with internal quality factors systematically exceeding 5 × 106 at high powers and 2 × 106 (with the best value of 4.4 × 106) at low power. Such performance is demonstrated for 100-nm-thick aluminum resonators with 7-10.5 um center trace on high-resistivity silicon substrates commonly used in Josephson-junction based quantum circuit. We investigate internal quality factors of the resonators with both dry and wet aluminum etching, as well as deep and isotropic reactive ion etching of silicon substrate. Josephson junction compatible CPW resonators fabrication process with both airbridges and silicon substrate etching is proposed. Finally, we demonstrate the effect of airbridges' positions and extra process steps on the overall dielectric losses. The best quality factors are obtained for the wet etched aluminum resonators and isotropically removed substrate with the proposed ultrasonic metal edge microcutting.

[Laparoscopic subtotal distal gastrectomy for distal gastric cancer]

OBJECTIVE

To analyze the primary results of laparoscopic distal gastrectomy in patients with distal gastric cancer.

MATERIAL AND METHODS

There were 21 laparoscopic distal gastrectomies in patients with distal gastric cancer. Mean age of patients was 63.7±6.3 years. According to TNM staging system, cancer stage 1 was detected in 90% of patients (n=19), stage 2a - in 10% (n=2) of patients.

RESULTS

Time of distal gastrectomy was 190.4±51.6 min, blood loss - 90.3±51.2 ml. The number of excised lymph nodes was 21.2±5.1. We were able to achieve R0 resection edge in all patients. Length of hospital-stay was 7.6±2.3 days, incidence of postoperative complications - 23.8%. Complications Clavien-Dindo grade IIIb-V were observed in 9.5% of patients (n=2). Overall postoperative mortality was 4.7% (n=1). No progression of the underlying disease has been revealed in any patient throughout the follow-up period (since May 2018). To date, the maximum median follow-up is 25 months of overall and disease-free survival.

CONCLUSION

Laparoscopic subtotal distal resection is an appropriate intervention ensuring R0 resection edge in most cases.

[Laparoscopic subtotal distal resection for distal gastric cancer]

OBJECTIVE

To analyze the primary experience of laparoscopic distal gastrectomy in patients with distal gastric cancer.

MATERIAL AND METHODS

There were 21 laparoscopic distal gastrectomies in patients with antrum malignancies. Mean age of patients was 63.7±6.3 years. According to TNM staging system, cancer stage I was detected in 90% of patients (n=19), stage IIa - in 10% (n=2) of patients.

RESULTS

Duration of distal gastrectomy was 190.4±51.6 minutes, blood loss - 90.3±51.2 ml. The number of harvested lymph nodes was 21.2±5.1. We were able to reach R0 resection edge in all patients. Length of hospital-stay was 7.6±2.3 days, incidence of postoperative complications - 23.8%. Complications Clavien-Dindo grade IIIb-V were observed in 9.5% of patients (n=2). Overall postoperative mortality was 4.7% (n=1). No progression of the underlying disease has been revealed in any patient throughout the follow-up period (since May 2018). To date, the maximum median follow-up is 25 months of overall and disease-free survival.

CONCLUSION

Laparoscopic subtotal distal resection is appropriate intervention ensuring R0 resection edge in most cases.

The circadian dynamics of the hippocampal transcriptome and proteome is altered in experimental temporal lobe epilepsy

Gene and protein expressions display circadian oscillations, which can be disrupted in diseases in most body organs. Whether these oscillations occur in the healthy hippocampus and whether they are altered in epilepsy are not known. We identified more than 1200 daily oscillating transcripts in the hippocampus of control mice and 1600 in experimental epilepsy, with only one-fourth oscillating in both conditions. Comparison of gene oscillations in control and epilepsy predicted time-dependent alterations in energy metabolism, which were verified experimentally. Although aerobic glycolysis remained constant from morning to afternoon in controls, it increased in epilepsy. In contrast, oxidative phosphorylation increased in control and decreased in epilepsy. Thus, the control hippocampus shows circadian molecular remapping, which is altered in epilepsy. We suggest that the hippocampus operates in a different functioning mode in epilepsy. These alterations need to be considered when studying epilepsy mechanisms, designing drug treatments, and timing their delivery.

Electrochemical preparation of standard gas mixtures using solid-state electrolyte membrane

A novel electrochemical method of preparation of standard gas mixtures for calibration of gas-analytical equipment with O₂, H₂ and CO was elaborated. Utilization of solid state electrolyte membrane allows to perform a nearly 100%-efficient electrochemical generation or conversion of the analyte and avoid some problems typical for liquid electrolytes, such as solvent evaporation and condensation at the inner walls of the gas tubes or deviations from the Faraday's law. Analysis of uncertainties associated with the calibration procedure showed that the lowest systematic errors are achieved when the calibrant is generated during the electrolysis (i.e. anodic evolution of oxygen or cathodic generation of CO), and the major uncertainties are associated with operation of the flow controllers. For calibration with H₂, where the calibrant is partially converted during the electrochemical process, the total uncertainty is essentially determined by molar fractions of the components in H₂-Ar mixture, instrumental errors of the equipment, primarily by precision of mass-flow controllers or stability of the gas flow, and the initial flow rate of the calibrant-containing gas mixture. The relative total errors of calibration with oxygen are assessed to be 5-6%; similar uncertainties were calculated for analysis of oxygen content in standard gas mixtures by chromatography using the electrochemical method of calibration.

Metabolic correction by pyruvate halts acquired epilepsy in multiple rodent models

Metabolic intervention strategy of epilepsy treatment has been gaining broader attention due to accumulated evidence that hypometabolism, manifested in humans as reduced brain glucose consumption, is a principal factor in acquired epilepsy. Therefore, targeting deficient energy metabolism may be an effective approach for treating epilepsy. To confront this pathology we utilized pyruvate, which besides being an anaplerotic mitochondrial fuel possesses a unique set of neuroprotective properties as it: (i) is a potent reactive oxygen species scavenger; (ii) abates overactivation of Poly [ADP-ribose] polymerase 1 (PARP-1); (iii) facilitates glutamate efflux from the brain; (iv) augments brain glycogen stores; (v) is anti-inflammatory; (vi) prevents neuronal hyperexcitability; and (vii) normalizes the cytosolic redox state. In vivo, chronic oral pyruvate administration completely abolished established epileptic phenotypes in three accepted and fundamentally different rodent acquired epilepsy models. Our study reports metabolic correction by pyruvate as a potentially highly effective treatment of acquired epilepsies.

Two-layer and composite films based on oxidized and fluorinated graphene

This study is devoted to the production and investigation of dielectric films, based on oxidized and fluorinated graphene suspensions.

[ANESTHESIA FOR AIRWAY ENDOSCOPIC RECANALISATION WITH SELFEXPANDED STENTS]

Tracheal and bronchial endoscopic stenting can give a quick therapeutic result or delay surgiCal treatment of patients with stenosis. It also can improve quality of life, create conditions for palliative therapy and increase survival of incur- able oncological patients. This paper contains description of our experience in anesthesia for tracheal stenting with re- spiratory support.

MATERIALS AND METHODS

23 patients were investigated retrospectively (15 males, 8females). They had 28 interventions under general anesthesia. 14 patients had malignant and 9 had non-malignant lesions. Complicated somatic status, stenosis extention and localization, type of laryngoscope. unprotected airways determined choice of in- travenous anesthesia with high-frequency ventilation and muscle relaxation.

RESULTS

Improvement (dyspnea decreasing) was mentioned in 78,3% (18/23) cases after stenting, in 8,7% (2/23) cases improvement was slight; in 4,3% (1/23) cases - no change; in 8,7% (2/23) cases patients died complications after stenting occurred in 10 cases (43,5%). In 4 cases (17,4%) - stent displacement; in 2 cases (8,7%) - purulent tracheobronchitis; in 1 case (4,35%) - paroxysmal cough with pain. In 1 case loss of stent during paroxysmal cough and vocal cords edema occurred. In 2 cases (8,7%) operation was failed and patients died due to the lesion progression and respiratory insufficiency.

CONCLUSIONS

Anesthetic pro- tection is an important component at endoscopic recanalization with selfexpanded stents. Management is difficult due to complicated somatic status, and unprotected airways. Significant health enhancement, dyspnea decreasing even by exercise stress justified high anesthetics risks.

[EXPERIMENTAL TESTING OF THE OPERATOR'S PERCEPTION OF SYMBOLIC INFORMATION ON THE HELMET-MOUNTED DISPLAY DEPENDING ON THE STRUCTURAL COMPLEXITY OF VISUAL ENVIRONMENT]

The experiments showed that pilot's perception of symbolic information on the helmet-mounted display (HMD) depends on type of HMD (mono- or binocular), and structural complexity of the background image. Complex background extends time and increases errors in perception, particularly when monocular HMD is used. In extremely complicated visual situations (symbolic information on a background intricately structured by supposition of a TV image on real visual environment) significantly increases time and lowers precision of symbols perception no matter what the HMD type.

[SOME ASPECTS OF DIAGNOSIS AND COMPREHENSIVE TREATMENT OF BARRETT'S ESOPHAGUS]

OBJECTIVE

Assess the value of routine endoscopy in the diagnosis of Barrett's esophagus (BE) in patients with gastroesophageal reflux disease (GERD) and to show the feasibility of a comprehensive treatment algorithm that includes antireflux surgery as an essential component.

MATERIALS AND METHODS

The study was conducted on a sample of 171 patients with Barrett's esophagus who underwent antireflux surgery. In evaluating the operating characteristics of endoscopy were recruited another 675 patients with GERD without BE. On the diagnostic phase was used endoscopy with double chromoscopy and biopsy followed by histological examination. At the stage of treatment, patients received conservative therapy by PPl after which underwent antireflux surgery and argon-plasma coagulation (in some cases).

RESULTS

Endoscopy of the esophagus with a double chromoscopy in identification BE in patients with GERD, has a moderate sensitivity (71.9%, 95% Cl 64.6%-78.5%) and high specificity (100%, 95% Cl 99.5%-100%). A comprehensive treatment approach that includes antireflux surgery as an essential component has allowed to achieve excellent and satisfactory immediate results of treatment in 88.9% of patients (95% Cl 83.2%-93.2%). Excellent and satisfactory long-term results were achieved in 89.5 % of patients (95% Cl 83.9%-93.6 %).

CONCLUSION

The results indicate the need for biopsy and histological examination in all patients with GERD, who has no suspicion of BE according to endoscopy, and prove high efficiency of complex treatment algorithm that includes antireflux surgery as an essential component.

[Experimental studies of reliability of symbolic information perception from the aviation LCD panel]

Results of tachistiscopic experiments on reliability of symbol recognition on LCD panel as a function of screen definition (640 x 480, 800 x 600 and 1024 x 768 pixels), angular size of a picture element (10, 15, 20 and 30 angular min) and luminance contrast (LC) with the background (0.2 to 1.4 standard units) are presented. The obtained quantitative relations indicate significance of the above parameters for recognition reliability. Symbols with the size of 30 angular min and LC of 0.5 were recognizable irrespective of screen definition in the study. Recognition of symbols 20 and 15 angular min of size was much dependent on screen definition and LC of symbols. For symbols of size 10 angular min and LC ≥ 1.0 the recognition probability did not exceed 0.59-0.7.

[Study of speech characteristics in hearing-impaired pilots for creation of voice-activated system operating airborne equipment]

Comparative experimental study covered speech characteristics in speakers with normal hearing and pilot speakers with neurosensory deafness. Evaluation criteria were duration, speech volume, spectral characteristics of words. Main difference of speach in pilot speakers with hearing disorders was higher variability of its characteristics.

[Peculiarities of pilot's perception of flight information presented on on-board liquid crystal displays]

The article deals with results of experimental studies conducted on flight testing desk and covering peculiarities of pilot's perception of flight information presented on on-board liquid crystal display in dependence on changes speed and update rate of the screen. The authors determine frequency characteristics of information update rate, that achieve acceptable quality of the flight parameters perception in accordance with the changes speed. Vigorous maneuvering with high angular velocities of changed parameters of roll and pitch causes visual distortions that are connected with poor frequency of information update rate, deteriorate piloting quality and can cause flight unsafety.

[Optimizing visual work of pilot wearing night vision glasses]

The article deals with results of experimental studies on optimizing visual work conditions of pilot in night vision glasses. Prevention of visual fatigue during work in night vision glasses was proved to be contributed mostly by the image brightness (in range of 0.7-1.8 candle/m2) adjustable by the pilot, precise individual settings of optic system in night vision glasses (by viewer's eye base) and regulation of the work duration.

[Oxygen consumption by resting humans at different Elbrus altitudes]

The purpose of the work was to test experimentally the "hypoxic paradox" of growing or constant oxygen consumption by normal humans exposed to O2-deficient environments. The objective was to perform thorough statistical analysis of O2 consumption at two altitudes above sea level under the conditions of close to basic metabolism, and to develop an analytical expression for adequate description of O2 consumption dependence on altitude above seal level. The investigation was fulfilled in August, 2009 at the altitudes of 2224 and 4200 m on Elbrus flanks with participation of 4 volunteers. It was shown that O2 consumption by resting humans decreases with altitude, i.e. the "hypoxic paradox" is invalid. An analytical expression was proposed to describe change in O2 consumption in the interval of altitudes from 0 to 4200 m above sea level.

[Mathematical model of carbon oxide in pressurized chamber during long-term human habitation]

A new approach to quantitative assessment of CO measurements in atmosphere of continuously operating pressurized module GVK-250 has been proposed. It was established that implementation of scheduled operations in the module transform nonstationary CO laws to low-ergodic. The total amount of atmospheric CO decreases substantially as soon as gas emission reaches a low-ergodic condition. Results of the investigation have been brought up to computational procedures and can be instrumental in the course of long-term run of pressurized modules and experimental works.

[Endoscopic diagnosis and complex treatment of Barrett's esophagus complicated by hernia of esophageal foramen of the diaphragm]

A protocol is suggested of complex diagnosis and treatment of Barrett's esophagus using sparing endoscopic removal of Barrett's epithelium in combination with surgery and medicinal antireflux therapy. Eighty-three patients were diagnosed and treated for hernia of esophageal foramen of the diaphragm and gastro-esophageal reflux complicated by Barrett's esophagus. Ninety-two percent of patients receiving our four-component treatment were cured; no recurrent esophageal adenocarcinoma was reported during the 56.7 +/- 2.4 month follow-up. Conversely, in patients receiving three-component treatment, efficacy was 56%; esophageal adenocarcinoma was reported in 3 (12%).

Void Closure in Complex Plasmas under Microgravity Conditions

We describe the first observation of a void closure in complex plasma experiments under microgravity conditions performed with the Plasma-Kristall (PKE-Nefedov) facility on board the International Space Station. The void--a grain-free region in the central part of the discharge where the complex plasma is generated--has been formed under most of the plasma conditions and thought to be an inevitable effect. However, we demonstrate in this Letter that an appropriate tune of the discharge parameters allows the void to close. This experimental achievement along with its theoretical interpretation opens new perspectives in engineering new experiments with large quasi-isotropic void-free complex plasma clouds in microgravity conditions.

[Extended D3 lymphadenectomy in surgical treatment of stomach cancer]

Results of 178 operations with extended D3 lymphadenectomy (study group) performed at the patients with stomach cancer are analyzed. Control groups consisted of 175 patients undergone operations with D2 lymphadenectomy, and 266 patients undergone surgery of typical extension. Study and control groups were similar according to prognostic factors. Indications for extended lymphadenectomy are formulated. It was demonstrated that short-term results in both group were equal. Safety of extended D3 lymphadenectomies wasalso confirmed. Extended D3 lymphadenectomies permitted to increase the respectability on 6.7%.

[Visual efficiency of pilot using of the night vision glasses]

Questionnaires filled out by 24 helicopter pilots using the night vision glasses (NVG) showed that minimization of the risk of visual discomfort was, first of all achieved through proper adjustment of image brightness and setting NVG time limits. The experiments enabled determination of the most favorable range of brightness (0.67-1.79 cd/m2) and rationalization of the necessity of individual adjustment depending on the light conditions and flight objectives, and NVG usage regulations to preclude visual fatigue.

Force field inside the void in complex plasmas under microgravity conditions

Observations of complex plasmas under microgravity conditions onboard the International Space Station performed with the Plasma-Kristall experiment-Nefedov facility are reported. A weak instability of the boundary between the central void (region free of microparticles) and the microparticle cloud is observed at low gas pressures. The instability leads to periodic injections of a relatively small number of particles into the void region (by analogy this effect is called the "trampoline effect"). The trajectories of injected particles are analyzed providing information on the force field inside the void. The experimental results are compared with theory which assumes that the most important forces inside the void are the electric and the ion drag forces. Good agreement is found clearly indicating that under conditions investigated the void formation is caused by the ion drag force.