396 research outputs found
Construction, expression, functional characterization and practical application of fusion protein SPA-BAPmut
Aim. The creation of genetically engineered fusion protein SPA-BAPmut and its application as a secondary immunoreagent in immunoassays. Methods. Gene cloning, PCR, electrophoresis, DNA sequencing, bacteria cells culturing, protein expression and purification, ELISA, Western-blotting were used. Results. The DNA sequences encoding Staphylococcus aureus protein A (SPA) and bacterial alkaline phosphatase with enhanced catalytic activity (BAPmut) were used for construction of gene encoding fusion protein SPA-BAPmut that was expressed in the high-productive Escherichia coli system and obtained in a soluble form. Cultivation conditions to provide a high-level expression of SPA-BAPmut (> 1 g/l) were determined. The target protein was obtained with purity more than 95 % using IMAX method. SPA-BAPmut is thermostable, and both parts of fusion protein (SPA and BAPmut) retain their IgG binding and alkaline phosphatase activity for a long time. SPA-BAPmut was used as a substitute of secondary antibodies in immunoassays. As little as 5 ng of the antigen could be detected in Western blotting and 1 g/ml of IgG in ELISA. Conclusions. The possibility of using SPA-BAPmut as universal secondary immunoreagent for different types of immunoassays was shown.Мета. Створення генно-інженерного злитого білка SPA-BAPmut та його застосування як вторинного імунореагенту в імунологічних тестах. Методи. Клонування генів, ПЛР, секвенування ДНК, культивування бактерій, електрофорез, синтез і очищення білків, ELISA, вестерн-блот. Результати. З використанням послідовновностей ДНК, що кодують білок А Staphylococcus aureus (SPA) і бактерійну лужну фосфатазу з покращеними каталітичними властивостями (BAPmut), сконструйовано ген злитого білка SPA-BAPmut та забезпечено його препаративне отримання у розчинній формі внаслідок синтезу в клітинах Escherichia coli. Визначено умови ферментації, за яких вихід SPA-ВAPmut становить приблизно 1 г/л культури E. coli. Із застосуванням методу металоафінної хроматографії одержано цільовий білок з чистотою понад 95 %. SPA-ВAPmut термостабільний, а обидва його компоненти (SPA і ВAPmut) зберігають імуноглобулінзв’язувальну і фосфатазну активність тривалий час. SPA-BAPmut дозволяє виявляти щонайменше 5 нг антигену та 1 мкг/мл антитіл. Висновки. Показано можливість використання SPA-ВAPmut як універсального вторинного імунореагенту в імунохімічних тестах.Цель. Создание генно-инженерного слитого белка SPA-BAPmut и eго использование как вторичного иммунореагента в иммунологических тестах. Методы. Клонирование генов, ПЛР, секвенирование ДНК, культивирование бактерий, электрофорез, биосинтез и очистка белков, ELISA, вестерн-блот. Результаты. С использованием последовательностей ДНК, кодирующих белок А Staphylo- coccus aureus (SPA) и бактериальную щелочную фосфатазу с улучшенными каталитическими свойствами (BAPmut), сконструирован ген слитого белка SPA-BAPmut и обеспечено его препаративное получение в растворимой форме вследствие синтеза в клетках Escherichia coli. Определены условия ферментации, при которых выход SPA-ВAPmut составляет около 1 г/л культуры E. coli. С применением метода металлоаффинной хроматографии целевой белок получен с чистотой более 95 %. SPA-ВAPmut термостабилен, а оба его компонента (SPA и ВAPmut) сохраняют иммуноглобулинсвязывающую и фосфатазную активность на протяжении длительного времени. SPA-BAPmut позволяет детектировать 5 нг антигена и 1 мкг/мл антител. Выводы. Показана возможность применения SPA-ВAPmut как универсального вторичного иммунореагента в иммунохимических тестах
Monte Carlo calculations for the hard Pomeron
Starting from the same input as the standard BFKL Pomeron, we directly
calculate the ``hard'' Pomeron as a gluonic ladder by using Monte Carlo
methods. We reproduce the characteristic features of the the BFKL Pomeron and
are now also able to evaluate new observables. The applicability of the BFKL
approach under realistic kinematical conditions can be tested and the influence
of the running coupling constant examined.Comment: 9 pages and 4 figures included. To appear in Phys.Lett.
Unitarisation of the hard pomeron and black-disk limit at the LHC
Recent models of soft diffraction include a hard pomeron pole besides the
usual soft term. Such models violate the black-disk limit around Tevatron
energies, so that they need to be supplemented by a unitarisation scheme.
Several such schemes are considered in this letter, where we show that they
lead to a large uncertainty at the LHC. We also examine the impact of
unitarisation on various small-t observables, the slope in t of the elastic
cross section, or the ratio of the real to imaginary parts of the scattering
amplitude, leading to the conclusion that the existence of a hard pomeron in
soft scattering may be confirmed by LHC data.Comment: 15 pages, 12 figures, late
Enterosorption as a method to decrease the systemic toxicity of cisplatin
A perspective adsorptive method to minimize systemic toxic effects of chemotherapy is enterosorption (ES). However, the capabilities of this method are far from being completely studied. The question remains opened — should ES be initiated in the first hours on completing cytostatic infusion without the risk of their anticancer activity to be decreased. Aim: to analyze ES influence on anticancer activity and toxic reactions of cisplatin (CP) upon the use of carbon enterosorbent in 1 h after intravenous administration of cytostatic. Methods: CP at the dose of 1 mg/kg body weigh (BW) was administered to Guerin carcinoma-bearing rats each second day for two weeks. Enterosorbents on the basis of highly activated carbon fibers were administered by per os daily 1 h after CP injection. 3 days after the last CP administration the rats were weighted and blood under ether narcosis has been taken for biochemical examination. Tumors and innate organs were isolated, weighted, and fixed in 4% buffered formalin for morphologic examination. Results: In rats administered with CP at the background of ES, BW loss was in 1.6 times lower than in animals after CP session. Relative kidney weight in CP-treated rats was 33.9% higher than in normal ones (p ≤ 0.05). No significant differences were detected between relative kidney weights in the CP + ES-treated and intact animals. Introduction of ES allowed prevent an 30% increase of creatinin content observed in blood plasma after CP treatment (р ≤ 0.05). Urea content was 1.7 times lower in blood plasma of CP + ES-treated rats than after CP treatment. CP caused significant toxic injuries in kidneys, liver, and spleen tissues. Morphologic structure of organs in rats treated with CP at the background of ES was affected at much lower degree. In tumors, large areas of newly formed connective tissue and blood vessels have been fixed after the CP+ES action instead of large necrotic area observed after CP treatment. ES caused insignificant suppression of Guerin carcinoma growth and had additional impact to inhibitory action of CP. Conclusion: Active carbon enterosorbents which are administrated just 1 h after CP administration possesses detoxicating potential sufficient for significant elimination of toxic effect of the cytostatic at the background of complete preservation of its antitumor activity
Nuclear Shadowing in DIS: Numerical Solution of the Evolution Equation for the Green Function
Within a light-cone QCD formalism based on the Green function technique
incorporating color transparency and coherence length effects we study nuclear
shadowing in deep-inelastic scattering at moderately small Bjorken x_{Bj}.
Calculations performed so far were based only on approximations leading to an
analytical harmonic oscillatory form of the Green function. We present for the
first time an exact numerical solution of the evolution equation for the Green
function using realistic form of the dipole cross section and nuclear density
function. We compare numerical results for nuclear shadowing with previous
predictions and discuss differences.Comment: 21 pages including 3 figures; a small revision of the tex
Роль кальций-pH-зависимых механизмов в патогенезе воспалительных заболеваний пародонта
Comparative investigation of dynamics of pH, concentration of calcium and inorganic phosphate in mixtured saliva during testing loads in patients with healthy periodontium, susceptible to caries and with combination of caries with inflammatory periodontal diseases was performed. Close dependency between dynamics of researched parameters was revealed during sugar and urea loads as well. Inorganic phosphate disgomeostasis, role in pathogenesis of inflammatory periodontal diseases was showed.Проведено сравнительное исследование динамики рН, концентрации кальция и неорганического фосфата в смешанной слюне при тестовых нагрузках у лиц со здоровым пародонтом, кариесвоспримчивых и с сочетанием кариеса и воспалительных заболеваний пародонта. Выявлена тесная взаимосвязь динамики изучаемых параметров как при сахарной, так и при карбамидной нагрузках. Показана роль дисгомеостаза неорганического фосфата в патогенезе воспалительных заболеваний пародонта
Nonperturbative Effects in Gluon Radiation and Photoproduction of Quark Pairs
We introduce a nonperturbative interaction for light-cone fluctuations
containing quarks and gluons. The interaction squeezes the transverse
size of these fluctuations in the photon and one does not need to simulate this
effect via effective quark masses. The strength of this interaction is fixed by
data. Data on diffractive dissociation of hadrons and photons show that the
nonperturbative interaction of gluons is much stronger. We fix the parameters
for the nonperturbative quark-gluon interaction by data for diffractive
dissociation to large masses (triple-Pomeron regime). This allows us to predict
nuclear shadowing for gluons which turns out to be not as strong as
perturbative QCD predicts. We expect a delayed onset of gluon shadowing at shadowing of quarks. Gluon shadowing turns out to be nearly scale
invariant up to virtualities due to presence of a semihard
scale characterizing the strong nonperturbative interaction of gluons. We use
the same concept to improve our description of gluon bremsstrahlung which is
related to the distribution function for a quark-gluon fluctuation and the
interaction cross section of a fluctuation with a nucleon. We expect
the nonperturbative interaction to suppress dramatically the gluon radiation at
small transverse momenta compared to perturbative calculations.Comment: 58 pages of Latex including 11 figures. Shadowing for soft gluons and
Fig. 6 are added as well as a few reference
Measurement of the polarisation of W bosons produced with large transverse momentum in pp collisions at sqrt(s) = 7 TeV with the ATLAS experiment
This paper describes an analysis of the angular distribution of W->enu and
W->munu decays, using data from pp collisions at sqrt(s) = 7 TeV recorded with
the ATLAS detector at the LHC in 2010, corresponding to an integrated
luminosity of about 35 pb^-1. Using the decay lepton transverse momentum and
the missing transverse energy, the W decay angular distribution projected onto
the transverse plane is obtained and analysed in terms of helicity fractions
f0, fL and fR over two ranges of W transverse momentum (ptw): 35 < ptw < 50 GeV
and ptw > 50 GeV. Good agreement is found with theoretical predictions. For ptw
> 50 GeV, the values of f0 and fL-fR, averaged over charge and lepton flavour,
are measured to be : f0 = 0.127 +/- 0.030 +/- 0.108 and fL-fR = 0.252 +/- 0.017
+/- 0.030, where the first uncertainties are statistical, and the second
include all systematic effects.Comment: 19 pages plus author list (34 pages total), 9 figures, 11 tables,
revised author list, matches European Journal of Physics C versio
Observation of a new chi_b state in radiative transitions to Upsilon(1S) and Upsilon(2S) at ATLAS
The chi_b(nP) quarkonium states are produced in proton-proton collisions at
the Large Hadron Collider (LHC) at sqrt(s) = 7 TeV and recorded by the ATLAS
detector. Using a data sample corresponding to an integrated luminosity of 4.4
fb^-1, these states are reconstructed through their radiative decays to
Upsilon(1S,2S) with Upsilon->mu+mu-. In addition to the mass peaks
corresponding to the decay modes chi_b(1P,2P)->Upsilon(1S)gamma, a new
structure centered at a mass of 10.530+/-0.005 (stat.)+/-0.009 (syst.) GeV is
also observed, in both the Upsilon(1S)gamma and Upsilon(2S)gamma decay modes.
This is interpreted as the chi_b(3P) system.Comment: 5 pages plus author list (18 pages total), 2 figures, 1 table,
corrected author list, matches final version in Physical Review Letter
Search for displaced vertices arising from decays of new heavy particles in 7 TeV pp collisions at ATLAS
We present the results of a search for new, heavy particles that decay at a
significant distance from their production point into a final state containing
charged hadrons in association with a high-momentum muon. The search is
conducted in a pp-collision data sample with a center-of-mass energy of 7 TeV
and an integrated luminosity of 33 pb^-1 collected in 2010 by the ATLAS
detector operating at the Large Hadron Collider. Production of such particles
is expected in various scenarios of physics beyond the standard model. We
observe no signal and place limits on the production cross-section of
supersymmetric particles in an R-parity-violating scenario as a function of the
neutralino lifetime. Limits are presented for different squark and neutralino
masses, enabling extension of the limits to a variety of other models.Comment: 8 pages plus author list (20 pages total), 8 figures, 1 table, final
version to appear in Physics Letters
- …