86 research outputs found
Стриктуры желчных путей при описторхозе
1170 patients with chronic opisthorchosis have been operated by surgeons of Tomsk hepatology center for 35 years, 4756 patients have been treated. In 730 operated patients different strictures of biliary tracts have been revealed, strictures of cystic duct have been observed in 372 patients (51%), strictures of choledoch distal section and major duodenal papilla (MDP) of expanded character — in 124 patients (17%), stricture combination — in 205 patients (28%) and sclerosing cholangitis — in 29 (4%). The treatment of opisthorchosis strictures of biliary tracts is surgical. In case of any its localization a cholecystectomy is necessary, in case of strictures of choledoch distal section and MDP a supraduodenal choledochoduodenostomy is necessary. In early postsurgical period it is prescribed an anthelmintic therapy with iodinol through external drainage of bile ducts. Good farther results have been marked at 79,4% of patients.За 35 лет работы сотрудниками Томского гепатологического центра были пролечены 4 756 больных с хроническим описторхозом, из них оперированы — 1 170. У 730 оперированных пациентов выявлены различные стриктуры билиарного тракта, в том числе стриктуры пузырного протока наблюдались у 372 человек (51%), стриктуры дистального отдела холедоха и большого дуоденального сосочка (БДС), носящие протяженный характер, — у 124 (17%), сочетание стриктур — у 205 (28%), склерозирующий холангит — у 29 (4%). Лечение описторхозных стриктур желчных путей — оперативное. При всех локализациях стриктур необходима холецистэктомия, при стриктурах дистального отдела холедоха и БДС — супрадуоденальная холедоходуоденостомия. В раннем послеоперационном периоде показана антигельминтная терапия йодинолом через наружный дренаж желчных протоков. Хорошие отдаленные результаты отмечены у 79,4% больных
Печеночная недостаточность при механическом холестазе паразитарного генеза
In Tomsk zonal hepatologic center 358 patients with obstructive parasitogenic jaundice have been operated (alveococcosis-based — 43, echinococcosis-based — 17, opisthorchosis-based — 298). Clinical presentations of hepatic failure before the surgery have been observed at 30,7% of patients, more often — under long and intensive cholestasis. Postsurgical hepatic failure has developed at 23,1%. Intraportal medicine infusions play an important role in prophylaxis and treatment of hepatic failure along with timely and optimal surgery. Infusions permit to decrease the hepatic failure progress probability from 60,6 to 30,5%, probability of suppurative complications from 10,3 to 3,1% and postsurgical lethality from 38,2 to 9,5%.В Томском зональном гепатологическом центре оперировано по поводу механической желтухи паразитарного генеза 358 человек (на почве альвеококкоза — 43, эхинококкоза — 17, описторхоза — 298). Клинические проявления печеночной недостаточности до операции наблюдались у 30,7% пациентов, чаще при длительном и интенсивном холестазе. Послеоперационная недостаточность печени развилась у 23,2%. В профилактике и лечении печеночной недостаточности наряду со своевременностью и оптимальностью оперативного вмешательства важную роль играют внутрипортальные инфузии лекарственных средств, позволяющие снизить вероятность прогрессирования недостаточности печени с 60,6 до 30,5%, развития гнойных осложнений с 10,3 до 3,1%, уменьшить послеоперационную летальность с 38,2 до 9,5%
Longitudinal double spin asymmetries in single hadron quasi-real photoproduction at high
We measured the longitudinal double spin asymmetries for single
hadron muo-production off protons and deuterons at photon virtuality <
1(GeV/) for transverse hadron momenta in the range 0.7
GeV/ to 4 GeV/ . They were determined using COMPASS data taken
with a polarised muon beam of 160 GeV/ or 200 GeV/ impinging on
polarised or targets. The experimental
asymmetries are compared to next-to-leading order pQCD calculations, and are
sensitive to the gluon polarisation inside the nucleon in the range
of the nucleon momentum fraction carried by gluons
Interplay among transversity induced asymmetries in hadron leptoproduction
In the fragmentation of a transversely polarized quark several left-right
asymmetries are possible for the hadrons in the jet. When only one unpolarized
hadron is selected, it exhibits an azimuthal modulation known as Collins
effect. When a pair of oppositely charged hadrons is observed, three
asymmetries can be considered, a di-hadron asymmetry and two single hadron
asymmetries. In lepton deep inelastic scattering on transversely polarized
nucleons all these asymmetries are coupled with the transversity distribution.
From the high statistics COMPASS data on oppositely charged hadron-pair
production we have investigated for the first time the dependence of these
three asymmetries on the difference of the azimuthal angles of the two hadrons.
The similarity of transversity induced single and di-hadron asymmetries is
discussed. A new analysis of the data allows to establish quantitative
relationships among them, providing for the first time strong experimental
indication that the underlying fragmentation mechanisms are all driven by a
common physical process.Comment: 6 figure
Interplay among transversity induced asymmetries in hadron leptoproduction
In the fragmentation of a transversely polarized quark several left-right
asymmetries are possible for the hadrons in the jet. When only one unpolarized
hadron is selected, it exhibits an azimuthal modulation known as Collins
effect. When a pair of oppositely charged hadrons is observed, three
asymmetries can be considered, a di-hadron asymmetry and two single hadron
asymmetries. In lepton deep inelastic scattering on transversely polarized
nucleons all these asymmetries are coupled with the transversity distribution.
From the high statistics COMPASS data on oppositely charged hadron-pair
production we have investigated for the first time the dependence of these
three asymmetries on the difference of the azimuthal angles of the two hadrons.
The similarity of transversity induced single and di-hadron asymmetries is
discussed. A new analysis of the data allows to establish quantitative
relationships among them, providing for the first time strong experimental
indication that the underlying fragmentation mechanisms are all driven by a
common physical process.Comment: 6 figure
Resonance Production and S-wave in at 190 GeV/c
The COMPASS collaboration has collected the currently largest data set on
diffractively produced final states using a negative pion
beam of 190 GeV/c momentum impinging on a stationary proton target. This data
set allows for a systematic partial-wave analysis in 100 bins of three-pion
mass, GeV/c , and in 11 bins of the reduced
four-momentum transfer squared, (GeV/c) . This
two-dimensional analysis offers sensitivity to genuine one-step resonance
production, i.e. the production of a state followed by its decay, as well as to
more complex dynamical effects in nonresonant production. In this paper,
we present detailed studies on selected partial waves with , , , , and . In these waves, we observe
the well-known ground-state mesons as well as a new narrow axial-vector meson
decaying into . In addition, we present the results
of a novel method to extract the amplitude of the subsystem with
in various partial waves from the
data. Evidence is found for correlation of the and
appearing as intermediate isobars in the decay of the known
and .Comment: 96 page
The Spin Structure Function of the Proton and a Test of the Bjorken Sum Rule
New results for the double spin asymmetry and the proton
longitudinal spin structure function are presented. They were
obtained by the COMPASS collaboration using polarised 200 GeV muons scattered
off a longitudinally polarised NH target. The data were collected in 2011
and complement those recorded in 2007 at 160\,GeV, in particular at lower
values of . They improve the statistical precision of by
about a factor of two in the region . A next-to-leading order
QCD fit to the world data is performed. It leads to a new determination
of the quark spin contribution to the nucleon spin, ranging
from 0.26 to 0.36, and to a re-evaluation of the first moment of .
The uncertainty of is mostly due to the large uncertainty in
the present determinations of the gluon helicity distribution. A new evaluation
of the Bjorken sum rule based on the COMPASS results for the non-singlet
structure function yields as ratio of the axial and
vector coupling constants , which validates the sum rule to an accuracy of about
9\%.Comment: 19 pages, 8 figures and table
Leading-order determination of the gluon polarisation from semi-inclusive deep inelastic scattering data
Using a novel analysis technique, the gluon polarisation in the nucleon is
re-evaluated using the longitudinal double-spin asymmetry measured in the cross
section of semi-inclusive single-hadron muoproduction with photon virtuality
. The data were obtained by the COMPASS experiment at
CERN using a 160 GeV/ polarised muon beam impinging on a polarised LiD
target. By analysing the full range in hadron transverse momentum ,
the different -dependences of the underlying processes are separated
using a neural-network approach. In the absence of pQCD calculations at
next-to-leading order in the selected kinematic domain, the gluon polarisation
is evaluated at leading order in pQCD at a hard scale of . It is determined in three intervals
of the nucleon momentum fraction carried by gluons, , covering the
range ~ and does not exhibit a significant
dependence on . The average over the three intervals, at
, suggests that the gluon polarisation
is positive in the measured range.Comment: 14 pages, 6 figure
Multiplicities of charged pions and unidentified charged hadrons from deep-inelastic scattering of muons off an isoscalar target
Multiplicities of charged pions and unidentified hadrons produced in
deep-inelastic scattering were measured in bins of the Bjorken scaling variable
, the relative virtual-photon energy and the relative hadron energy .
Data were obtained by the COMPASS Collaboration using a 160 GeV muon beam and
an isoscalar target (LiD). They cover the kinematic domain in the photon
virtuality > 1(GeV/c, , and . In addition, a leading-order pQCD analysis was performed using the
pion multiplicity results to extract quark fragmentation functions
Transverse-momentum-dependent Multiplicities of Charged Hadrons in Muon-Deuteron Deep Inelastic Scattering
A semi-inclusive measurement of charged hadron multiplicities in deep
inelastic muon scattering off an isoscalar target was performed using data
collected by the COMPASS Collaboration at CERN. The following kinematic domain
is covered by the data: photon virtuality (GeV/), invariant
mass of the hadronic system GeV/, Bjorken scaling variable in the
range , fraction of the virtual photon energy carried by the
hadron in the range , square of the hadron transverse momentum
with respect to the virtual photon direction in the range 0.02 (GeV/ (GeV/). The multiplicities are presented as a
function of in three-dimensional bins of , , and
compared to previous semi-inclusive measurements. We explore the
small- region, i.e. (GeV/), where
hadron transverse momenta are expected to arise from non-perturbative effects,
and also the domain of larger , where contributions from
higher-order perturbative QCD are expected to dominate. The multiplicities are
fitted using a single-exponential function at small to study
the dependence of the average transverse momentum on , and . The power-law behaviour of the
multiplicities at large is investigated using various
functional forms. The fits describe the data reasonably well over the full
measured range.Comment: 28 pages, 20 figure
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