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.

[Five-year survival and outcomes of chronic hip stump ischemia treatment]. / Piatiletniaia vyzhivaemost' i rezul'taty lecheniia khronicheskoi ishemii kul'ti bedra.

AIM: To investigate five-year survival, short- and long-term outcomes of hip stump ischemia treatment. MATERIAL AND METHODS: There were 383 patients with hip stump in 1997-2013. Critical hip stump ischemia in 3 months after amputation occurred in 45 patients. RESULTS: Two-fold decrease of 5-year survival was found. Five-year survival was higher 3 times in patients after arterial reconstruction compared with those without revascularization. The same tendency was confirmed in analysis of groups standardized by gender, age and type of arterial disease.

[Critical ischemia of hip stump. Incidence, clinical significance and diagnosis]. / Kriticheskaia ishemiia kul'ti bedra: chastota, klinicheskoe znachenie i diagnostika.

AIM: To study the incidence of hip stump ischemia, risk factors for 5-year survival after amputation, clinical features and diagnosis of this complication. MATERIAL AND METHODS: 1287 patients with peripheral artery disease followed by hip amputation were examined within 1997-2015. 50 of them had stump ischemia. RESULTS: It was found that hip stump ischemia occurs in 5.2% of cases and significantly aggravates 5-year survival. Transcutaneous oxygen tension less than 20 mm Hg is reliable hemodynamic criterion of ischemia.

Electron localizability for hexagonal element structures.

For 21 elements crystallizing in hexagonal structure density functional calculations were performed. The topology of the electron localizability indicator (ELI) allows classifying the elements as appertaining to one of six patterns. The bifurcation diagrams as well as the electron populations in ELI basins for each pattern are discussed.

New metal-rich sulfides Ni(6)SnS(2) and Ni(9)Sn(2)S(2) with a 2D metal framework: synthesis, crystal structure, and bonding.

Two new, metal-rich nickel-tin sulfides Ni(6)SnS(2) and Ni(9)Sn(2)S(2) were found by establishing phase relations in the ternary Ni-Sn-S system at 540 degrees C. Their single crystals were prepared by means of chemical vapor transport reactions. Single crystal X-ray diffraction was used for the determination of their crystal structures. Both compounds crystallize in a tetragonal system (I4/mmm, No. 139, Z = 2, a = 3.646(1) A, c = 18.151(8) A for Ni(6)SnS(2), and a = 3.678(1) A, c = 25.527(8) A for Ni(9)Sn(2)S(2)). Their crystal structures represent a new structure type and can be considered as assembled from bimetallic nickel-tin and nickel-sulfide slabs alternating along the crystallographic c axis. DFT band structure calculations showed the bonding within the bimetallic slabs to have a delocalized, multicenter nature, typical for metallic systems, and predominantly classical, pairwise bonding between nickel and sulfur.

Quasi-1D cations 1 infinity [Ni8Bi8S]n + of variable charge: infinite columns 1 infinity [Ni8Bi8S]2+ in the novel compound Ni8Bi8SI2.

The new compound Ni(8)Bi(8)SI(2) has been synthesized and its crystal structure determined by X-ray crystallography. The structure contains one-dimensional (1D) cations (1)( infinity )[Ni(8)Bi(8)S](2+) separated by iodine anions. The geometry of the columns is similar to that of the recently reported (1)( infinity )[Ni(8)Bi(8)S](+), and the main difference between them is only their formal charge. Electronic structure calculations and physical properties measurements were performed to analyze the influence of the number of valence electrons on the bonding and properties of compounds containing these 1D cations. It was shown that the removal of one electron (i.e., (1)( infinity )[Ni(8)Bi(8)S](+) --> (1)( infinity )[Ni(8)Bi(8)S](2+)) mainly affects the Ni-S bonding within the cation and essentially has no influence on the intermetallic Ni-Bi bonding. It was found that Ni(8)Bi(8)SI(2) containing double-charged columns has conductivity properties more similar to a pure 1D metal than the congener Ni(8)Bi(8)SI containing mono-charged columns.

Unique [(1)infinityNi(8)Bi(8)S] metallic wires in a novel quasi-1D compound. Synthesis, crystal and electronic structure, and properties of Ni(8)Bi(8)SI.

A new quasi-one-dimensional compound Ni(8)Bi(8)SI has been synthesized and its crystal structure determined from single-crystal X-ray diffraction data. The structure of Ni(8)Bi(8)SI consists of [(1)infinityNi(8)Bi(8)S] columns separated by iodine atoms. Conductivity and magnetic susceptibility measurements (down to 4.2 K) show that Ni(8)Bi(8)SI is a one-dimensional metal and exhibits Pauli paramagnetic properties. These observations are in good agreement with the results from electronic structure calculations. An analysis of the chemical bonding employing difference electron charge density maps reveals strong multicenter Ni-Bi bonds and pair Ni-S interactions within the [(1)infinityNi(8)Bi(8)S] columns. Only electrostatic interactions are inferred between the columns and iodine atoms.

[Surgical treatment of "difficult" gastric ulcers]. / Khirurgicheskoe lechenie "trudnykh" iazv zheludka.

In surgical treatment of "difficult" ulcers of the stomach including ulcers of the proximal part of the stomach, giant ulcers (more than 3 cm in diameter) and multiple ulcers it is expedient to use resection of the stomach with the formation of functionally active anastomosis. The choice of the operative method is determined by specific features of the ulcerous process, morphofunctional state of proximal parts of the gastrointestinal tract which determines the individual character of the operative intervention. The use of such operative interventions has reduced the postoperative lethality to 0.9%. Complex examinations have established excellent and good results (by the Visick scale) at remote terms after operation in 95.2% of the patients.

[A method for an areflux gastroduodenal anastomosis in the surgery of peptic ulcer of the duodenal bulb]. / Sposob arefliuksnogo gastroduodenoanastomoza v khirurgii iazvennoi bolezni lukovitsy dvenadtsatiperstnoi kishki.

The authors describe a new method of areflux gastroduodenal anastomosis used for prevention of reflux gastritis after a distal resection of the stomach for ulcer disease of the duodenum bulb. It can be achieved by forming a functionally active sphincter and a "value-cusp" from the mucous-submucous layers of the frontal semicircumference of the stump of the stomach and duodenum. The method described was used in 48 resections of the stomach. Complex follow-up of the patients within the terms from 2 months till 3 years after the operations has shown a reliable areflux function of the gastroduodenal anastomosis.

[A reflux-free Y-shaped gastroenteroanastomosis in the surgery of cancer of the distal portion of the stomach]. / Arefliuksnyi Y-obraznyi gastroénteroanastomoz v khirurgii raka distal'nogo otdela zheludka.

A procedure for formation of jejunal valve in addition to Y-shaped gastroenteroanastomosis following subtotal resection of the stomach is described. Surgery was performed in 44 patients with cancer of the distal part of the stomach. No anastomosis-related complications were observed. One (2.3%) patient died. Function of the anastomosis was studied early and at later periods following surgery. The valve proved reliably free from reflux. Partial return of the reservoir function of the gastric stump was observed.

[Prevention of dumping syndrome after distal gastrectomy in peptic ulcer]. / Profilaktika demping-sindroma posle distal'noi rezektsii zheludka po povodu iazvennoi bolezni.

Operations were performed on 386 patients with peptic ulcer by a method suggested by the authors for gastric resection with formation of a sphincter in the region of the anastomosis. In 18 patients a Billroth II anastomosis was reconstructed into a Billroth I anastomosis by the authors' modification in severe dumping syndrome. Complex examination was conducted in late-term postoperative periods in 324 patients after primary resection and in 18 after reconstructive operation. A mild dumping syndrome was found in 9 (2.8%) and 3 patients, respectively. The results of the study show that if the authors' requirements regarding the volume and method of gastric resection are abided by, there is no doubt that the suggested method has advantages over the classical method in that the reservoir function of the stomach is maintained, hydrochloric acid secretion reduces to a state of hypo- or normoacidity, and the peristaltic component of evacuation is preserved due to the formed functionally active anastomosis.

[Prevention of reflux gastritis after distal resection of the stomach in peptic ulcer]. / Profilaktika refliuks-gastrita posle distal'noi rezektsii zheludka po povodu iazvennoi bolezni.

A complex pre- and postoperative examination of 181 patients with ulcer disease of the stomach (86) and duodenum (95) was performed. The patients were operated on by an original authors' method with the formation of artificial sphincter in the anastomosis area. The investigations performed have shown that the method of gastric resection with the formation of functionally active anastomosis allows to considerably decrease probability of the appearance of duodenogastric reflux and reflux gastritis.

[Surgical treatment of stomach ulcer]. / Khirurgicheskoe lechenie iazvennoi bolezni zheludka.

Operated on were 168 patients with gastric ulcer disease. The preference was given to Billroth-I gastric resection with the artificial sphincter formation at the site of anastomosis and proximal gastric resection with the antireflux gastroesophageal anastomosis creation. The introduction of the developed techniques of gastric resection permitted to improve considerably the long-term functional results of treatment.