Gamma-ray dose threshold for MAPbI3 solar cells.

In this work, we report on the effects observed in MAPbI3 polycrystalline films and solar cells under moderate gamma-ray doses of 3-21 kGy. We applied several instrumental techniques such as photoluminescence spectroscopy, time-resolved photoluminescence, Suns-VOC measurement, and impedance spectroscopy to characterize exposed samples. We observed a nonlinear dependency of such characteristics as PL intensity, career lifetime, ideality factor, and recombination resistance on the exposure dose. Small doses of 3-5 kGy annihilate some of the defect centers in the material, which results in improved carrier extraction and prolonged carrier lifetime, while with larger doses of 10 kGy and above, nonradiative recombination becomes predominant. In this way, we revealed a gamma-ray threshold for MAPbI3 films of around 10 kGy, above which it is not recommended to exploit this material. In space environment, yearly doses rarely exhibit 0.1 kGy (10 krad), and the MAPbI3 material has a sufficient margin of safety for space applications. Moreover, this unusual behaviour opens up the opportunity to use gamma-ray sources as an effective method to improve the quality of defective polycrystalline perovskite films before actual exploitation in an ionizing radiation-free environment.

Sorption behaviour of neptunium in marine and fresh water bottom sediments in Far East area of Russia (Lake Khanka and Amur Bay).

The concentration and sorption behavior of 237Np on the bottom sediments of water bodies in the Far East region of Russia (Lake Khanka and Peter the Great Bay) were studied for the first time. The 237Np concentrations vary from 1.06 × 10-6 to 4.43 × 10-5 mBq g-1 in the bottom sediments of Lake Khanka and from 1.05 × 10-4 to 2.52 × 10-3 mBq g-1 for Amur Bay. The experiment on the adsorption of Np on marine and lake sediment showed that it is sorbed through complexation with silicates (albite, leucite). The Np sorption isotherm on marine sediments is described by the Langmuir equation; the distribution coefficients (Kd) of Np vary from 57 to 588 mL g-1. For lake sediments, the isotherm is described by the Henry equation; the Kd value reaches 935 mL g-1.

Structural Insight into Complexation Ability and Coordination of Uranyl Nitrate by 1,10-Phenanthroline-2,9-diamides.

Reprocessing of spent nuclear fuel (SNF) is an important task in a frame of ecology and rational use of natural resources. Uranium, as the main component of SNF (>95%), can be recovered for further use as fresh nuclear fuel. To minimize an amount of solid radioactive waste generated during SNF reprocessing, new extractants are under investigation. Diamides of 1,10-phenanthroline-2,9-dicarboxylic acid are perspective tetradentate N-donor ligands that form strong complexes with f-elements, which are soluble in polar organic solvents. As an example of three ligands of this class, we conducted a comparative study and showed how the substituent in the amide functional group affects the extraction ability toward uranyl nitrate from nitric acid media. We have performed a careful study (NMR, FT-IR, XRD, RMC-EXAFS) of the structures of synthesized complexes of new ligands with uranyl nitrate and used quantum mechanical calculations to explain the discovered regularities through.

A first phosphine oxide-based extractant with high Am/Cm selectivity.

A new phosphine oxide ligand demonstrates high selectivity for the Am-Cm pair with SF = 2.9-3.5 and the Am-Eu pair with SF = 7.3-8.5 in a range of 0.1-3 M nitric acid. Thermodynamic measurements show that the entropy factor is responsible for selectivity observed in the extraction experiment. The most prevalent complexes of all three metal ions were (Ph2PyPO)2M(NO3)3. According to their DFT modelling, the M-N distances for the Cm ion were larger than those for Am, so the last ion enters deeper into the pseudo-cavity of the ligand, which causes the observed selectivity.

Measurements of electron density profile by frequency modulated continuous wave reflectometer in the T-10 tokamak using high magnetic field side probing and extraordinary mode lower cutoff.

A new, previously unused combination of the high magnetic field side probing and the lower extraordinary mode cutoff was used in the T-10 tokamak for the electron density profile measurements by using a frequency modulation continuous wave reflectometer. This scheme has a significant advantage for large fusion machines where flat electron density profiles and high electron temperatures are expected. The reflectometer design is based on a common scheme with voltage controlled oscillators, active multipliers, and in-phase/quadrature signal detection. Iterative procedures were applied to calibrate a microwave source frequency and compensate the dispersion of probing signals in the conventional rectangular waveguides used as the transmission lines. About 0.2% stability of the beating frequency was reached after the calibration procedure had been finished. An advanced finite-difference scheme was proposed for the reconstruction of the electron density profile to reduce errors and improve the overall performance of the algorithm. Reconstructed electron density profiles demonstrate good agreement with conventional T-10 diagnostic data. Some specific technical and physical aspects of the diagnostic were also discussed on the basis of T-10 operation experience.

[Hyperthermic intraperitoneal chemotherapy combined with cytoreductive procedure in patients with peritoneal pseudomyxoma].

AIM: To study the results of intraperitoneal chemoperfusion combined with cytoreductive procedure in patients with peritoneal pseudomyxoma. MATERIAL AND METHODS: For the period 2006--2015 seven patients with peritoneal pseudomyxoma underwent aggressive treatment using hyperthermic intraperitoneal chemoperfusion combined with cytoreductive procedure at the Department of General Oncology of N.N. Petrov Research Institute of Oncology. RESULTS: Two patients had postoperative complications. One of them died after 12 days postoperatively. Features of postoperative complications were predominantly determined by volume of cytoreduction. Advanced tumoral process caused death in 2 patients additionally. Other patients are still alive during 4--28 months after surgery. CONCLUSION: Hyperthermic intraperitoneal chemoperfusion combined with cytoreductive procedure is advisable for peritoneal pseudomyxoma to improve survival. Optimal cytoreduction should be developed in researches with large number of patients to decrease incidence of complications.

[PERFUSION TECHNOLOGIES IN TREATMENT OF PATIENTS WITH SKIN MELANOMA AND SOFT TISSUE SARCOMAS OF EXTREMITIES].

A steady increase of incidence of skin melanoma and soft tissue sarcomas of the extremities currently continues to be observed. Taking into account the high probability of developing of locally disseminated forms of skin melanoma and soft tissue sarcomas of extremities, the need to use combined methods in their treatment is quite high. In the 21st century the possibility of a use of isolated regional chemoperfusion provides a high objective response of tumor to chemotherapy without their systemic impact and improves the quality of life through preservation of the limb. This review describes the currently used drugs, and the results of ongoing clinical research in the world, as well as the results of our own study.

[Melphalan pharmacokinetics during isolated limb regional perfusion in patients with skin melanoma and soft tissue sarcoma].

The study of pharmacokinetics of melphalan in the perfusate and blood plasma during isolated limb regional perfusion (ILRP) was carried out in patients with melanoma (n=21) and soft tissue sarcoma (n = 24). Melphalan was administered as 10 mg/l for a lower extremity and 13 mg/l for a upper extremity. Quantification of melphalan in perfusate and blood samples was performed by means of liquid chromatography/tandem mass spectrometry. 30 samples of the perfusate and 27 venous blood samples were analyzed. During the first 5 minutes of ILRP concentration of melphalan in the perfusate decreased to 13.2% of the initial value, and by the end of perfusion (60 minutes) it was 3.3%. The amount of melphalan in the blood plasma of the patients by the end of ILRP wasn't higher than 1.6% from the administered dose. That demonstrates minor systemic absorption of the drug during ILRP. Moreover melphalan concentration in the blood plasma during the perfusion was in average 0.015-0.223 mg/l which is significantly lower compared to the blood plasma concentrations after intravenous administration of melphalan. Thus ILRP procedure provided 97% of the melphalan dose accumulation in the soft tissues of a limb and in tumor tissues. Also pharmacokinetic advantage of melphalan over systemic administration of the drug was shown.

[Organ-preserving interventions in combined therapy of children and adolescents with osteosarcoma].

An analyzed cohort consists of 50 pediatric patients with osteosarcoma receiving combined therapy in N. N. Petrov Research Institute for Oncology (1999-2010). Thirty nine of them had localized disease, 11 patients had distant metastases. The treatment scheme included neoadjuvant therapy with cisplatin and doxorubicin, surgical treatment and adjuvant therapy depended on initial response and could include cisplatin, doxorubicin, high-dose methotrexate, ifosfamide, etoposide. Four-year overall and relapse-free survival in children with localized disease was 74.3% and 69.2% accordingly. In 62% of patients were performed organ-preserving surgical interventions, in 22 patients was performed endoprosthetics, in 4 patients the defect was replaced by a bone autograft on a vascular bundle. The effectiveness of initial treatment and secondary endoprosthetics were analyzed. Six patients with lung metastases received normotermic lung chemoperfusion, 4 of them are alive and disease-free for 8 to 24 months.

[Reconstructive osteoplastic operations after amputation of the shoulder increasing the functional ability for prosthesis].

The article presents 3 methods of operative reconstruction of the shoulder stump for improving the conditions of prosthesis without fixation of the prosthesis at the level of the shoulder joint. The methods were used in 42 patients and gave good functional results.

[Postoperative recurrence of a nodular goiter].

Long-term results were followed up from 3 to 15 years in 649 patients with different morphological forms of the nodular goiter. Postoperative recurrent nodular goiter was diagnosed in 26.8% of the patients. The greater part of recurrences (87.4%) was nodular colloid goiter that was shown morphologically. Main part of the recurrences (69.1%) appeared after operations if the greater part of the thyroid gland was left--resection of a lobe and enucleation of the nodes. No recurrences were registered after thyroidectomy. The results of the investigation suggest that such operations as enucleation of a node and resection of a lobe with a node are thought to be inadequate.

[Urgent resection of the colon with compressive anastomosis and afferent colostoma].

Thirty patients with colon disease in need of urgent surgery have undergone resection of the colon with formation of terminal afferent colostomy and compressive colon-colon anastomosis using oval and linear nikelid-titanium implants. Complications were seen in 6 (20%) patients, lethality was 6,7% due to multiorgan failure in the presence of generalized peritonitis. There were no complications due to colon-colon anastomosis. The above method permits one to reduce surgical trauma of future reconstructive surgeries.

Rheodynamic model of cardiac pressure pulsations.

To analyse parametrically (in terms of the qualitative theory of dynamical systems) the mechanical influence of inertia, resistance (positive and negative), elasticity and other global properties of the heart-muscle on the left ventricular pressure, an active rheodynamic model based on the Newtons's principles is proposed. The equation of motion of the heart mass centre is derived from an energy conservation law balancing the rate of mechanical (kinetic and potential) energy variation and the power of chemical energy influx and dissipative energy outflux. A corresponding dynamical system of two ordinary differential equations is obtained and parametrically analysed in physiological conditions. As a result, the following main conclusion is made: in physiological norm, because of the heart electrical activity, its equilibrium state is unstable and around it, mechanical self-oscillations emerge. In case the electrical activity ceases, an inverse phase reconstruction occurs during which the unstable equilibrium state of the system becomes stable and the self-oscillations disappear.

Determination of erythrocyte aggregation.

One of the most common health criteria--erythrocyte sedimentation rate (ESR)--is considered in the paper. It is shown that the simple model presented, based on the generalized Stokes formula, the blood volume conservation law, and the Smoluchowski theory of particles coagulation, makes it possible, on the basis of experimentally recorded sedimentation curves, to identify quantitatively the values of the essential physical parameters of the coupled processes of erythrocyte aggregation and sedimentation. The analytical solution of Smoluchowski equation is used to evaluate the sedimentation and aggregation rate constants. The problem of determining the erythrocyte aggregation rate (EAR) is transformed to a minimization task in which only the experimental results for ESR are needed. Experimentally ESR is measured accurately enough by using an equipment set up just for the purpose. This method of identification could be used as a diagnostic test in hematological laboratories.

[Surgical treatment of soft tissue sarcomas of the pelvic girdle]. / Osobennosti khirurgicheskogo lecheniia sarkom miagkikh tkanei tazovogo poiasa.

Wide excision of neoplasm is most frequently used in surgery for soft tissue tumors, on appropriate sites and whenever the "envelope" can be preserved. The most frequent site of pelvic girdle soft-tissue tumors was the glutal area (39.0 +/- 4.8%). Out of 100 patients with such sarcomas, wide excision of tumor was performed in 82, and tumor excision + bone resection--18. The former procedure was mostly used in the management of liposarcomas (26.5 +/- 4.2%), while the latter--in synovial sarcoma (33.3 +/- 4.9%).

The role of aggregation kinetics in the sedimentation of erythtocytes.

The well-known S-shaped settling curves are obtained as solutions of an autonomic dynamical system deduced mathematically from the generalized Stokes formula, the blood volume conservation law, and the Smoluchowski theory of particle coagulation. Numerical computations and parametric analysis of the deduced two nonlinear differential equations for the plasma zone thickness and aggregate size are given. It is shown that the model presented makes it possible, on the basis of experimentally recorded sedimentation curves and aggregate size growth, to identify quantitatively the values of the essential physical parameters of the coupled processes of erythrocyte aggregation and sedimentation. This method of identification could be used as a diagnostic test in hematological laboratories.

[Organ-sparing treatment of finger injuries caused by a punching]. / Sberegatel'noe lechenie pri povrezhdenii pal'tsev kisti shtampom.

There have been studied 1037 cases of hand and finger punch injuries, observed in 786 victims. An analysis of the trauma causes allowed to carry out the complex of preventive measures. The efficiency of these measures is testified by 3-fold decrease of occupational traumatism at Lysvensk metal works during 5 recent years. It has been stated that 496 (52.6%) of 945 finger and hand wounds were tissue avulsion and crush. These damages are typical ones in case of finger injuries with a punch. There have been analysed the results of treatment of 341 patient with scalped wounds, open fractures, finger and hand avulsions and crushes (482 wounds). It has been stated that careful surgical treatment of a wound with edge dissection, removal of damaged fatty tissue and free fractured fragments is a reliable method of infectious complication prophylaxis when the wound has been stitched without intention and the skin defects closed by means of the first skin plasty. The first skin plasty has been used for treatment of 62 wounds. Complete graft survival has been noted in 70.9% cases. In 85% of cases there have been obtained good functional results. A special section of sparing treatment presents finger replantation in case of their avulsion. Microsurgical technique has been applied with 9 patients. There have been replanted 13 fingers and 1 hand (survived 10 fingers and the hand). There have been revascularized 3 fingers (2 of them have survived).