Potential of using cultivated dermal fibroblasts on the biodegradable polymeric matrices for treating skin damages in the experiment

ФИБРОБЛАСТЫЭКСПЕРИМЕНТЫ НА ЖИВОТНЫХБИОМЕДИЦИНСКИЕ ИССЛЕДОВАНИЯБИОДЕГРАДАЦИЯСОЕДИНИТЕЛЬНОЙ ТКАНИ КЛЕТКИКРЫСЫ ЛИНИИ WISTARКОЖА /ПОВРЕЖДДЕКСТРАНА ФОСФАТПОЛИЛАКТИДРАНЫ ЗАЖИВЛЕНИЕКЛЕТОК ТРАНСПЛАНТАЦИЯКЛЕТОЧНАЯ ТЕРАПИЯЦель. Оценить возможность применения культивированных дермальных фибробластов на полимер- ных биодеградируемых матрицах для лечения повреждений кожного покрова в эксперименте. Материал и методы. Исследование выполнено на 90 крысах линии Wistar массой тела 180-200 г, с чистыми ранами диаметром 2,5 см. Было сформировано 6 групп – по животных в каждой. Культуру дер- мальных фибробластов выделяли из кожи новорожденных крыс; для накопления необходимой биомассы клеток проводили субпассирование. В 1 группе (контроль) клеточные биопрепараты не применялись. В группах 2-6 для лечения экспериментальных ран были использованы биодеградируемые матрицы (фосфат декстрана либо полилактид) как без клеточного биопрепарата, так и с содержанием культивированных фибробластов в количестве от 250?103 до 700?103 клеток на один раневой дефект. Выводы о влиянии дермаль- ных фибробластов на полимерных биодеградируемых матрицах на раневой процесс делали на основании сравнительного анализа результатов компьютерной планиметрии и морфологического исследования. Результаты. На всех этапах (7, 14, 21, 28 сутки) эксперимента минимальная скорость заживления была зарегистрированы в группе 1. Шестая группа, в которой в рану вносили полилактид, содержащий 700?103 клеток, характеризовалась максимальными – относительно остальных групп – значениями скоро- сти заживления. В микропрепаратах 6 группы на 21 сутки эксперимента отмечена полная эпителизация ра- невого дефекта. Выявлено наличие сильной прямой корреляционной связи между количеством трансплан- тированных клеток и скоростью заживления раневых дефектов на 7 сутки (?=0,923), 14 сутки (?=0,924), а также 21 сутки эксперимента (?=0,914). Заключение. В условиях эксперимента установлено, что локальное применение культивированных дермальных фибробластов на полимерных биодеградируемых матрицах (фосфат декстрана и полилактид) ведет к достоверному сокращению сроков эпителизации раневых дефектов.Objectives. To evaluate the possibility of using of cultivated dermal fibroblasts on the biodegradable polymeric matrices for treating skin damages in the experiment. Methods. The study was performed on 90 rats of Wistar line (180-200 g weight) with pure wounds (D-2,5cm). Six groups were formed, 15 animals per each group. The culture of dermal fibroblasts was isolated from the skin of newborn rats; to accumulate the required biomass of cells subpassage was carried out. The cellular biological products were not applied in group 1 (control). Biodegradable matrices (dextran phosphate or polylactide) were used for treating wounds in the groups 2-6 as matrices without cellular biological product and matrices with cultured fibroblasts (250?103 to 700?103 cells per wound). Conclusion about the impact of biodegradable polymeric matrices with dermal fibroblasts on the wound healing was made on the basis of a comparative analysis of the results of digital planimetry and morphological studies. Results. At all stages (7, 14, 21, 28 days) minimal rate of healing was registered in the first group. The sixth group, where polylactide containing 700?103 cells was added in the wound, is characterized by the biggest values of the healing rate – with respect to other groups. Complete epithelization of the wound defects in the micropreparations of the sixth group was marked by the 21st day of the experiment. The strong direct correlation between the number of transplanted cells and wound rate healing was detected on the 7th day (?=0,923), the 14th day (?=0,924), and the 21st day of the experiment (?=0,914). Conclusion. In the experiment it has been found out, that local application of the cultivated dermal fibroblasts on biodegradable polymer matrices (dextran phosphate and polylactide) results in a significant reduction of terms of the wound epithelization

New search for correlated e+e- pairs in the alpha decay of 241Am

A new search for production of correlated e+e- pairs in the alpha decay of 241Am has been carried out deep underground at the Gran Sasso National Laboratory of the I.N.F.N. by using pairs of NaI(Tl) detectors of the DAMA/LIBRA set-up. The experimental data show an excess of double coincidences of events with energy around 511 keV in faced pairs of detectors, which are not explained by known side reactions. This measured excess gives a relative activity lambda = (4.70 \pm 0.63) \times 10^{-9} for the Internal Pair Production (IPP) with respect to alpha decay of 241Am; this value is of the same order of magnitude as previous determinations. In a conservative approach the upper limit lambda < 5.5 \times 10^{-9} (90% C.L.) can be derived. It is worth noting that this is the first result on IPP obtained in an underground experiment, and that the lambda value obtained in the present work is independent on the live-time estimate.Comment: 18 pages, 5 figures, 3 tables; version accepted for publication on Eur. Phys. J.

Recent advances in neutrinoless double beta decay search

Even after the discovery of neutrino flavour oscillations, based on data from atmospheric, solar, reactor, and accelerator experiments, many characteristics of the neutrino remain unknown. Only the neutrino square-mass differences and the mixing angle values have been estimated, while the value of each mass eigenstate still hasn't. Its nature (massive Majorana or Dirac particle) is still escaping. Neutrinoless double beta decay ($0\nu$-DBD) experimental discovery could be the ultimate answer to some delicate questions of elementary particle and nuclear physics. The Majorana description of neutrinos allows the $0\nu$-DBD process, and consequently either a mass value could be measured or the existence of physics beyond the standard should be confirmed without any doubt. As expected, the $0\nu$-DBD measurement is a very difficult field of application for experimentalists. In this paper, after a short summary of the latest results in neutrino physics, the experimental status, the R&D projects, and perspectives in $0\nu$-DBD sector are reviewed.Comment: 36 pages, 7 figures, To be publish in Czech Journal of Physic

Spectral modeling of scintillator for the NEMO-3 and SuperNEMO detectors

We have constructed a GEANT4-based detailed software model of photon transport in plastic scintillator blocks and have used it to study the NEMO-3 and SuperNEMO calorimeters employed in experiments designed to search for neutrinoless double beta decay. We compare our simulations to measurements using conversion electrons from a calibration source of $\rm ^{207}Bi$ and show that the agreement is improved if wavelength-dependent properties of the calorimeter are taken into account. In this article, we briefly describe our modeling approach and results of our studies.Comment: 16 pages, 10 figure

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 6-LiD 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.Comment: 6 pages, 2 figure

The Majorana neutrino masses, neutrinoless double beta decay and nuclear matrix elements

The effective Majorana neutrino mass is evaluated by using the latest results of neutrino oscillation experiments. The problems of the neutrino mass spectrum,absolute mass scale of neutrinos and the effect of CP phases are addressed. A connection to the next generation of the neutrinoless double beta decay (0nbb-decay) experiments is discussed. The calculations are performed for 76Ge, 100Mo, 136Xe and 130Te by using the advantage of recently evaluated nuclear matrix elements with significantly reduced theoretical uncertainty. An importance of observation of the 0nbb-decay of several nuclei is stressed.Comment: 29 pages, 5 figures, EXO (10 t) experiment considere

Measurement of the 2νββ decay half-life of 150Nd and a search for 0νββ decay processes with the full exposure from the NEMO-3 detector

We present results from a search for neutrinoless double-β (0νββ) decay using 36.6 g of the isotope 150Nd with data corresponding to a live time of 5.25 y recorded with the NEMO-3 detector. We construct a complete background model for this isotope, including a measurement of the two-neutrino double-β decay half-life of T2ν 1=2 ¼ ½9.34 0.22ðstatÞ þ0.62 −0.60 ðsystÞ × 1018 y for the ground state transition, which represents the most precise result to date for this isotope. We perform a multivariate analysis to search for 0νββ decays in order to improve the sensitivity and, in the case of observation, disentangle the possible underlying decay mechanisms. As no evidence for 0νββ decay is observed, we derive lower limits on half-lives for several mechanisms involving physics beyond the standard model. The observed lower limit, assuming light Majorana neutrino exchange mediates the decay, is T0ν 1=2 > 2.0 × 1022 y at the 90% C.L., corresponding to an upper limit on the effective neutrino mass of hmνi < 1.6–5.3 eV

Development of methods for the preparation of radiopure ⁸²Se sources for the SuperNEMO neutrinoless double-beta decay experiment

A radiochemical method for producing 82Se sources with an ultra-low level of contamination of natural radionuclides (40K, decay products of 232Th and 238U) has been developed based on cation-exchange chromatographic purification with reverse removal of impurities. It includes chromatographic separation (purification), reduction, conditioning (which includes decantation, centrifugation, washing, grinding, and drying), and 82Se foil production. The conditioning stage, during which highly dispersed elemental selenium is obtained by the reduction of purified selenious acid (H2SeO3) with sulfur dioxide (SO2) represents the crucial step in the preparation of radiopure 82Se samples. The natural selenium (600 g) was first produced in this procedure in order to refine the method. The technique developed was then used to produce 2.5 kg of radiopure enriched selenium (82Se). The produced 82Se samples were wrapped in polyethylene (12 μm thick) and radionuclides present in the sample were analyzed with the BiPo-3 detector. The radiopurity of the plastic materials (chromatographic column material and polypropylene chemical vessels), which were used at all stages, was determined by instrumental neutron activation analysis. The radiopurity of the 82Se foils was checked by measurements with the BiPo-3 spectrometer, which confirmed the high purity of the final product. The measured contamination level for 208Tl was 8-54 μBq/kg, and for 214Bi the detection limit of 600 μBq/kg has been reached.</p

Final results on the 0νββ decay half-life limit of 100^{100} Mo from the CUPID-Mo experiment

The CUPID-Mo experiment to search for 0νββ decay in $^{100}$Mo has been recently completed after about 1.5 years of operation at Laboratoire Souterrain de Modane (France). It served as a demonstrator for CUPID, a next generation 0νββ decay experiment. CUPID-Mo was comprised of 20 enriched Li$_2^{100}$MoO$_4$ scintillating calorimeters, each with a mass of ∼0.2 kg, operated at ∼20 mK. We present here the final analysis with the full exposure of CUPID-Mo ($^{100}$Mo exposure of 1.47 kg×year) used to search for lepton number violation via 0νββ decay. We report on various analysis improvements since the previous result on a subset of data, reprocessing all data with these new techniques. We observe zero events in the region of interest and set a new limit on the $^{100}$Mo 0νββ decay half-life of T$^{0ν}_{1/2}$ >1.8×10$^{24}$ year (stat. + syst.) at 90% CI. Under the light Majorana neutrino exchange mechanism this corresponds to an effective Majorana neutrino mass of ⟨m$_{ββ}$⟩ < (0.28−0.49) eV, dependent upon the nuclear matrix element utilized