Broadband gain performance in the mid-IR using supercontinuum: 2.7 µm gain in high-purity Er3+doped tungsten tellurite glass fibers.

This paper presents an experimental study of broadband mid-IR amplification that is carried out, for the first time, to the best of our knowledge, in an erbium-doped tungsten tellurite fiber. A simple, robust supercontinuum source based on a tapered germanate fiber is developed as a seed input in the region of 1.5-3 µm. We show that gain by a factor of 5 on one pass can be achieved in the 2.7 µm range by pumping a low-cost, high-efficiency diode laser at 976 nm using high-purity tellurite glass fibers.

Dual-band Tm3+-doped tellurite fiber amplifier and laser at 1.9 µm and 2.3 µm.

Ultrabroadband amplification and two-color CW lasing simultaneously near 1.9 µm and 2.3 µm in a Tm3+-doped tellurite fiber were demonstrated experimentally, for the first time to the best of our knowledge. A low-loss Tm3+-doped core fiber from TeO2-ZnO-La2O3-Na2O glasses stable against crystallization was produced by a special technique, providing a low concentration of hydroxyl groups. Supercontinuum from a highly GeO2 doped silica fiber pumped by an Er fiber laser system was used as a seed for an amplifier. A maximum gain of 30 dB and 7 dB was measured at 1.9 µm and 2.3 µm, respectively. We report detailed experimental and theoretical studies, which are in a very good agreement, of laser amplification and generation in the manufactured fiber with carefully measured and calculated parameters. A quantitatively verified numerical model was used to predict power scalability at 2.3 µm in schemes with optimized parameters at increased pump power. The presented results show that a high-quality tellurite fiber is a promising candidate for developing lasers in the 2.3 µm atmospheric window which are particularly relevant for applications in gas sensing, eye-safe laser radars, breath analysis, remote sensing and stand-off trace gas detection.

Toward a mid-infrared femtosecond laser system with suspended-core tungstate-tellurite glass fibers.

A simple design of a fiber laser system for generating high-quality pulses with a duration of order 100 fs with ultrabroad wavelength tunability in the 2-5 µm range is discussed. This design incorporates conventional fs near-IR lasers and specially developed tungstate-tellurite fibers with two zero-dispersion wavelengths (ZDW) and relies on nonlinear wavelength conversion via either soliton self-frequency shift (SSFS) or red-shifted dispersive wave (DW) generation. The fiber parameters needed for such optical conversion have been scanned numerically and showed a possibility of SSFS beyond 4 µm and of DW generation beyond 5 µm. We have also studied and prepared tungstate-tellurite glasses and preforms that are highly stable against crystallization, exhibit extremely low level of hydroxyl groups absorption, and from which the suspended-core two-ZDW fibers can be manufactured.

[The specific clinical features of otogenic intracranial complications: the current views].

The objective of the present study was to elucidate the specific clinical features of otogenic intracranial complications (ICC) encountered in the current otorhinolaryngological practice. The work is based on the results of the retrospective analysis of 106 adult patients presenting with otogenic intracranial complications admitted for the treatment to multidisciplinary clinics of Sankt-Peterburg and Krasnoyarsk. Forty six (42.5%) patients presented with acute otitis media. 90% of them had suppurative destructive mastoiditis. In sixty (56.6%) patients, chronic suppurative otitis media (epitympanophonia) was associated with the extensive destructive process spreading toward dura mater of the medial and posterior cranial fossae and onto the sigmoid sinus. The prevalence of intracranial complications among the adult patients suffering from suppurative otitis media and treated in the otorhinolaryngological clinics amounted to 3.17%. The overall structure of otogenic intracranial complications was as follows: meningitis 42.5%, brain and cerebellum abscess 24.5%, suppurative meningoencephalitis 19.8%, sinus thrombosis 5.7%, epidural and subdural empyemas 4.7%, the combined suppurative brain lesions 2.8%. Systemic inflammatory response syndrome (sepsis) was diagnosed in 33 (31%) patients with otogenic ICC. The high intrahospital mortality rate among the patients with this condition (20.8%) is emphasized. The main causes of the fatal outcome in the patients with otogenic intracranial complications are supposed to be brain oedema with the concomitant development of dyslocation syndrome and sepsis.

Widely tunable mid-infrared fiber laser source based on soliton self-frequency shift in microstructured tellurite fiber.

A turnkey fiber laser source generating high-quality pulses with a spectral sech shape and Fourier transform-limited duration of order 100 fs widely tunable in the 1.6-2.65 µm range is presented. It is based on Raman soliton self-frequency shifting in the suspended-core microstructured TeO2-WO3-La2O3 glass fiber pumped by a hybrid Er/Tm fiber system. Detailed experimental and theoretical studies, which are in a very good agreement, of nonlinear pulse dynamics in the tellurite fiber with carefully measured and calculated parameters are reported. A quantitatively verified numerical model is used to show Raman soliton shift in the range well beyond 3 µm for increased pump energy.

First measurement of the transverse spin asymmetries of the deuteron in semi-inclusive deep inelastic scattering.

First measurements of the Collins and Sivers asymmetries of charged hadrons produced in deep-inelastic scattering of muons on a transversely polarized 6LiD target are presented. The data were taken in 2002 with the COMPASS spectrometer using the muon beam of the CERN SPS at 160 GeV/c. The Collins asymmetry turns out to be compatible with zero, as does the measured Sivers asymmetry within the present statistical errors.

Exotic meson decay to omegapi0pi-.

A partial-wave analysis of the mesons from the reaction pi(-)p --> pi(+)pi(-)pi(-)pi(0)pi(0)p has been performed. The data show b(1)pi decay of the spin-exotic states pi(1)(1600) and pi(1)(2000). Three isovector 2(-+) states were seen in the omegarho(-) decay channel. In addition to the well known pi(2)(1670), signals were also observed for pi(2)(1880) and pi(2)(1970).

[Demographic problems and reproductive health of women and children of first year of life]. / Demograficheskie problemy i reproduktivnoe zdorov'e zhenshchin i detei pervogo goda zhizni.

The authors presented comparative evaluation of general demographic situation and reproductive health of women and infants in main mining and industrial districts of Mourmansk region.

Blood concentrations of persistent toxic substances in the indigenous communities of the Russian Arctic.

OBJECTIVES: Investigation was carried out within the framework of the large-scale international project "Persistent Toxic Substances (PTS), Food Security and Indigenous People of the Russian North" under RAIPON/AMAP/GEF aegis. Objectives of the project are to obtain comprehensive information on exposure of indigenous populations to contaminants through food chains (and other sources), and to investigate the possible health effects connected to this exposure. Four regions of Russia are involved in the project: Kola Peninsula (Murmansk oblast), Nenetsk okrug (Pechora river basin), Taimyr Peninsula, Chukotka Peninsula. METHODS: Questionnaire and paired sampling of maternal/cord blood among indigenous women at childbirth (more than 250 persons) as well as among general indigenous population (more than 1,400 persons), additionally breast milk sampling of lactating women (more than 50 persons) in Chukotka was conducted. About 700 blood samples have been analyzed at the Center for Environmental Chemistry, SPA "Typhoon" (Obninsk, Russia), the Regional Center "Monitoring of the Arctic", RCMA (St. Petersburg, Russia), the Norwegian Institute for Air Research, NILU (Tromso, Norway) and at INSPQ (Sainte-Foy, Quebec, Canada). RESULTS AND CONCLUSIONS: On the whole, PTS in human blood of the Russian Arctic natives are similar to those in the coastal areas of Greenland and Canada, and for some POPs such as toxaphenes and mirex, these levels are lower.

[Health status, functional prospects and use of medical and social services by the elderly living in St. Petersburg]. / Sostoianie zdorov'ia, funktsional'nye vozmozhnosti i ispol'zovanie uslug meditsinskoi i sotsial'noi sluzhb pozhilymi litsami, prozhivaiushchimi v Sankt-Peterburge.

The sharp increase of absolute number and share of the aged population in St. Petersburg requires changes in the medico-social service provision for the elderly. IPSE survey study was realized in 2000 in St. Petersburg under support of the Tacis Bistro Facility of the European Commission (The findings, conclusions and interpretations expressed in the article are those of authors and should not be taken to reflect the policies or opinions of the Europian Commission). The aim of the survey was to analyse health status, functional ability and use of medical and social services by the 60-89 aged elderly of the city and to identify the groups of elderly population in the most need of help. According to the results of the IPSE survey study, there is a significant number of elderly people who are not able to live independently at home without other people's help (approximately 97,000 elderly people in St. Petersburg who need assistance in daily living). The group of elderly people with considerably declined functional abilities should be a priority in planning the elder care services. For this group intervention programmes need to be developed. Providing the elderly with sufficient home help services fosters their independent living and allows the elderly to live longer at own home. To live at home is often the best choice for both the elderly and also the service system due to lower costs.

Observation of exotic meson production in the reaction pi- p --> eta'pi- p at 18 GeV/c.

An amplitude analysis of an exclusive sample of 5765 events from the reaction pi- p-->eta'pi- p at 18 GeV/c is described. The eta'pi- production is dominated by natural parity exchange and by three partial waves: those with J(PC) = 1(-+), 2(++), and 4(++). A mass-dependent analysis of the partial-wave amplitudes indicates the production of the a2(1320) meson as well as the a4(2040) meson, observed for the first time decaying to eta'pi-. The dominant, exotic (non- qq) 1(-+) partial wave is shown to be resonant with a mass of 1.597+/-0.010(+0.045)(-0.010) GeV/c2 and a width of 0.340+/-0.040+/-0.050 GeV/c2. This exotic state, the pi1(1600), is produced with a t dependence which is different from that of the a2(1320) meson, indicating differences between the production mechanisms for the two states.

[State of microcirculation channel in the area of laser "welded" anastomosis of the small intestine]. / Sostoianie mikrotsirkuliatornogo rusla v oblasti lazernogo "svarnogo" tonkokishechnogo anastomoza.

Experiments were conducted with CO2 and AIG laser on neodymium to study the condition of microcirculation and the degree of its disturbance in the wall of the small intestine in formation of a laser "welded" entero-enteral and termino-terminal anastomosis. The microcirculatory disorders and their extent were found to be directly dependent on the degree of the thermal effect and the width of the coagulation zone in the region of the suture. The results of the experiment confirmed that the suggested powers of the laser effect on the intestinal wall were optimal.

[Global optimization of the conformational energy of oligopeptides using a tunnel algorithm]. / Global'naia optimizatsiia konformatsionnoi énergii oligopeptidov s pomoshch'iu tunnel'nogo algoritma.

The tunneling algorithm has been suggested as a method for the searching of the low energy conformations of the oligopeptides. The efficiency of the method has been compared with other global energy minimization methods such as grid search and molecular dynamics. It has been shown that tunneling algorithm reached global minimum of potential energy of the molecule of 3-4 residues more effectively than other methods. Experiments with oligopeptides of more than 4 residues showed that although during reasonable time tunneling algorithm does not reach the global minimum it can very effectively find the low energy minimum.

[Use of YAG-neodymium and CO2 lasers for creating small-intestinal anastomoses]. / Ispol'zovanie AIG-neodimovogo i CO2-lazerov dlia formirovaniia tonkokishechnykh anastomozov.

A method for creating laser enteric anastomoses was developed in experiments with YAG-neodymium and CO2 lasers. The properties of such anastomoses were studied in detail in the early stages after the operation. The use of serial Soviet-produced laser devices and standard surgical instruments in the experiments makes it possible to introduce the results of the work into clinical practice in the near future.

[The persistence of the distemper virus in continuous human cells]. / Persistentsiia virusa chumy plotoiadnykh v perevivaemykh kletkakh cheloveka.

Two cultures chronically infected with distemper virus (HEP-2 and L-41) were obtained. The cultures produced a small-plaque cell-associated virus and a virus-specific antigen which was demonstrated by the fluorescence antibody technique in 40%-60% of the cells. The chronically infected cells produced interferon as judged by their resistance to superinfections with heterologous viruses. The virus-carrier state was characterized by temperature sensitivity.

Comparative clinico-morphological investigations of the CNS of monkeys and of the eye teguments of guinea pigs infected with different measles virus strains.

Measles virus strains Edmonston and L-16 have been studied in 10 intracerebrally (i.c.) infected monkeys and in 155 guinea pigs infected into the anterior eye chamber. The strains appeared to differ in pathogenicity for monkeys and guinea pigs. The more pathogenic Edmonston strain caused encephalitis in monkeys, whereas in guinea pigs it caused iridocyclitis, keratoconjunctivitis and follicular conjunctivitis. Strain L-16 was not neurovirulent for monkeys, while in guinea pigs it caused follicular conjunctivitis. Specific pathohistological changes detected in the CNS of monkeys and in the eye teguments of guinea pigs were confirmed by virologic and serologic findings.

[Effectiveness of a combined live mumps-measles vaccine]. / Issledovanie éffektivnosti zhivoi assotsiirovannoi parotitno-korevoi vaktsiny.

The reactogenic and areactogenic properties of a live combined mumps-measles vaccine (MMV) prepared in primary cultures of Japanese quail embryo cells from attenuated strains of mumps (L-3) and measles (L-16) viruses were under study. The observations involved 648 infants varying in ages from 1 to 3 years, seronegative to measles and mumps viruses, without the history of the disease and vaccinations against these infections or contraindications to vaccinations. The infants were vaccinated with 5 batches of MMV with different portions of the mumps and measles components. The vaccinees and controls (placebo injections) were observed for 30 days postvaccination. The live MMV was shown to be a safe, well tolerated preparation with low reactogenicity and a high antigenic activity.