Ion detector of time-of-flight mass spectrometer with registration of leading and trailing edges.

The accuracy of the ion flight time measurement in the time-of-flight mass spectrometer is critical to achieving high resolution. The pulse amplitude variation of the detector pulses leads to the registration time spread at a given pulse detection threshold. This time spread can be eliminated by determining the position of the pulse apex. To determine the position of the pulse apex, the output of the ion detector is fed simultaneously to the two channels of the time-to-digital converter. In this case, the first channel is set to register the leading edge, and the second channel is set to register the trailing edge of the pulse. Using a simple processing of the received data, the position of the pulse tip is determined. Thus, the dependence of the temporal position of the peak on the pulse amplitude is largely eliminated. Examples are given, and the efficiency of using this algorithm to increase the resolution of time-of-flight mass spectral peak registration is demonstrated.

Nonlinear Generation of Vorticity by Surface Waves.

We demonstrate that waves excited on a fluid surface produce local surface rotation owing to hydrodynamic nonlinearity. We examine theoretically the effect and obtain an explicit formula for the vertical vorticity in terms of the surface elevation. Our theoretical predictions are confirmed by measurements of surface motion in a cell with water where surface waves are excited by vertical and harmonic shaking the cell. The experimental data are in good agreement with the theoretical predictions. We discuss physical consequences of the effect.

[Substitution of an extensive defect of tissues after resection of the sternum in tumors]. / Zameshchenie obshirnogo defekta tkanei posle rezektsii grudiny po povodu opukholi.

An original method of substitution of great defect of the soft tissues and osteochondral part of the chest wall after resection of the sternum for a malignant tumor is described. Operations were made on 4 patients. Favorable results were noted in all the patients. The terms of follow-up were from 6 to 25 months.

[Polypous ethmoiditis]. / Polipoznyi étmoidit.

Investigations of etiology, pathogenesis and treatment of polypous ethmoiditis show the role of chronic inflammation, sensitization and autoimmune reactions in mechanisms of nasal polyposis (NP). The development of postoperative recurrences of NP depends on the microflora, defective microcirculation, permeability of the histohematic barriers of the nasal and labyrinthine mucosa and metabolism of glycosaminoglycanes in the above mucosa. Adequate treatment methods are suggested: He-Ne laser radiation, UV blood radiation, cryotherapy, corticosteroids. Promising are also autovaccine, autovaccine with tissue (polypous) antigen, ozone solutions.

[Bactericidal and bacteriostatic properties of Acryloxide copolymer in articular endoprosthesis]. / Bakteritsidnye i bakteriostaticheskie svoistva sopolimera "Akriloksid" pri éndoprotezirovanii sustavov.

Based upon bacteriological investigations the authors have proved bacteriostatic and sometimes bactericidal effects of the polymer material "Acryloxide". Endoprostheses made of it do not require sterilization which was demonstrated in operations of endoprosthesis of joints on 225 patients.

[Role of hospital infection in the occurrence of suppurative complications in children with the use of compression-distraction osteosynthesis]. / Rol' gospital'noi infektsii v vozniknovenii gnoinykh oslozhnenii u detei pri primenenii kompressionno-distraktsionnogo osteosinteza.

The authors have performed clinico-bacteriological investigations in 100 patients. Compressional-distractional osteosynthesis was used to correct deformities of the extremities. In 56 children purulent-inflammatory complications were observed. The main pathogenic agent of purulent complications was staphylococcus. The same phagotypes of staphylococcus were isolated from the skin around the wire, rhinopharynx of the children and medical personnel as well as the air of the hospital rooms.