68 research outputs found

    Pulmonary Vascular Thrombosis in COVID-19: Clinical and Morphological Parallels

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    Aim. We aimed to study the histological and thrombotic changes in lung vessels in patients who died with COVID-19, to access the correlation between anticoagulation therapy (ACT) and thrombotic events (TE), treatment results, clinical and laboratory patients' characteristics.Material and Methods. We retrospectively analyzed treatment results of patients hospitalized with COVID-19 and lung vessel samples of the deceased patients. Dynamic changes and highest levels of D-dimer and fibrinogen were studied in its correlation with the disease severity according to SOFA score, computer tomographic (CT) results, lung, renal and hepatic dysfunction. The association between different doses of ACT and treatment results, laboratory indicators and thrombotic events was accessed. The histological lung vessels examination was performed using Martius Scarlet Blue (MSB)staining.Results. 313 patients were included in the study (61 patients died). The median age of hospitalized patients was 60 years (IQR 51-66 years). The frequency of the intravitallyconfirmed TE was 4,8%. The strong statistical association was revealed between D-dimer level and 3-4 points SOFA score, patients' mortality, oxygen support requirement, CT3-CT4 pneumonia, glomerular filtration rate and TE. There was no mortality in patients with D-dimer normal references, but in cases with three times elevation reached 13%, 48,5% - in cases with 3-6 times elevation and 64,6% - in cases with more than 6 times elevation. The strong statistical association was registered between fibrinogen and SOFA score, CT 3-4 pneumonia, patients' mortality. D-dimer and fibrinogen levels demonstrated weak correlation. There was no statistical correlation between prophylactic, intermediate and therapeutic ACT and D-dimer and fibrinogen levels, CT results, patients' mortality. MSBstaining was used in 36 deceased patients tissue samples. 1394 lung vessels were analyzed. Lung vessels thrombi persisted in samples of all 36 patients (100%). Vessels with the diameter 3,5-30 mm were thrombosed in 7%, with the diameter 0,034-0,84 mm - in 48%, with the diameter 0,85-3,4 mm - in 45%. The frequency of thrombi persisted 06 hours, 6-12 hours, 12-18hours, 18-24 hours and more than 24 hours was12%, 14%, 62%, 5% and 7% respectively.Conclusion. Thrombi of different ages from fresh to organized were observed in one third of lung vessels in all deceased patients. Lung vessels thrombosis plays an important role in pathogenesis and thanatogenesis of COVID-19. The D-dimer level correlates with lung, renal dysfunction, patients' mortality and doesn't show any correlation with ACT and can be accepted as a criterion of lung vessel thrombotic progression

    The ATLAS Transition Radiation Tracker (TRT) proportional drift tube: design and performance

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    A straw proportional counter is the basic element of the ATLAS Transition Radiation Tracker (TRT). Its detailed properties as well as the main properties of a few TRT operating gas mixtures are described. Particular attention is paid to straw tube performance in high radiation conditions and to its operational stability

    The ATLAS TRT electronics

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    The ATLAS inner detector consists of three sub-systems: the pixel detector spanning the radius range 4cm-20cm, the semiconductor tracker at radii from 30 to 52 cm, and the transition radiation tracker (TRT), tracking from 56 to 107 cm. The TRT provides a combination of continuous tracking with many projective measurements based on individual drift tubes (or straws) and of electron identification based on transition radiation from fibres or foils interleaved between the straws themselves. This paper describes the on and off detector electronics for the TRT as well as the TRT portion of the data acquisition (DAQ) system

    Treatment and Secondary Prevention of Venous Thromboembolism in Real Clinical Practice Based on Health Care Professional Survey

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    Aim. To assess the duration of the anticoagulant treatment of venous thromboembolism (VTE) in various categories of patients in real clinical practice through survey of practitioners, as well as correspondence of the duration with current clinical guidelines.Material and methods. Data obtained from electronic survey of practicing surgeons as part of a commercial brand assessment (Brand Adoption Monitor) was studied. Survey was carried out by the "Validata” analytical agency at the request and with the financial support of Bayer. Inpatient and outpatient vascular surgeons, as well as general outpatient surgeons were invited to complete the electronic questionnaire. The number of interviewed specialists was 100: 50 inpatient vascular surgeons and 50 outpatient specialists, among whom the share of vascular surgeons (phlebologists, angi-ologists) was about 20%. The study was completed in 20 cities of Russia with a population of at least 200,000 people from all federal districts except the North Caucasus and the Republic of Crimea. The selection criteria for participants were: work experience in the specialty ≥3 years, work experience at the current organization >6 months, ≥5 patients with VTE during in the last month.Results. In total, 104 doctors were surveyed during the period from December 11, 2019 to January 20, 2020, of which 50 were inpatient vascular surgeons and 54 were from outpatient setting. According to the survey of vascular surgeons in hospitals, 75% (6 [5;10]) of patients were hospitalized with a primary episode of VTE and 25% (2 [1;4]) with a recurrent thrombotic event. In an outpatient surgeon, 27.5% (3 [2;5]) of patients were treated in an outpatient setting without hospitalization, 34.7% (3 [2;5]) came to an appointment immediately after discharge from the hospital and 38.8% (2 [1;4]) were a repeat visit regarding a previous VTE. Most often, surgeons observed episodes of clinically unprovoked VTE in 27.3% of cases, thrombotic events provoked by major transient risk factors were 12.2%, event provoked by small transient risk factors were 13.3% and events provoked by small persistent risk factors were 12.6%, while cancer-associated thrombosis represented 13.5%. Most surgeons chose to prescribe anticoagulant therapy beyond 3 months. About half of the specialists prescribed therapy for a year or longer for cancer-associated thrombosis and recurrent VTE. When treating the first episode of clinically unprovoked VTE, about half of the respondents chose anticoagulation for a period of 3 to 6 months. About 60% of specialists prescribed anticoagulant therapy for a period of 3 to 6 months to patients with minor transient or persistent risk factors and patients with VTE provoked by major transient risk factor (trauma or surgery).Conclusion. Correspondence of the duration of anticoagulant therapy in real clinical practice with the international clinical guidelines varies within 450% range and, on average, does not exceed 30%. This discrepancy was both in situations when the duration of therapy was lower than recommended, but also in situations when treatment extension would not have been recommended

    Atypical Mineralization Involving Pd-Pt, Au-Ag, REE, Y, Zr, Th, U, and Cl-F in the Oktyabrsky Deposit, Norilsk Complex, Russia

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    Highly atypical mineralization involving Pd-Pt, Au-Ag, REE, Y, Zr, U, Th, and Cl-F-enriched minerals is found in zones with base metal sulfides (BMS; ~5 vol.% to 20 vol.%) in the eastern portion of the Oktyabrsky deposit in the Norilsk complex (Russia). The overall variations in Mg# index, 100 Mg/(Mg + Fe2+ + Mn), in host-rock minerals are 79.8 → 74.1 in olivine, 77.7 → 65.3 in orthopyroxene, 79.9 → 9.2 in clinopyroxene, and An79.0 → An3.7. The span of clinopyroxene and plagioclase compositions reflects their protracted crystallization from early magmatic to late interstitial associations. The magnesian chromite (Mg# 43.9) trends towards Cr-bearing magnetite with progressive buildups in oxygen fugacity; ilmenite varies from early Mg-rich to late Mn-rich variants. The main BMS are chalcopyrite, pyrrhotite, troilite, and Co-bearing pentlandite, with less abundant cubanite (or isocubanite), rare bornite, Co-bearing pyrite, Cd-bearing sphalerite (or wurtzite), altaite, members of the galena-clausthalite series and nickeline. A full series of Au-Ag alloy compositions is found with minor hessite, acanthite and argentopentlandite. The uncommon assemblage includes monazite-(Ce), thorite-coffinite, thorianite, uraninite, zirconolite, baddeleyite, zircon, bastnäsite-(La), and an unnamed metamict Y-dominant zirconolite-related mineral. About 20 species of PGM (platinum group minerals) were analyzed, including Pd-Pt tellurides, bismuthotellurides, bismuthides and stannides, Pd antimonides and plumbides, a Pd-Ag telluride, a Pt arsenide, a Pd-Ni arsenide, and unnamed Pd stannide-arsenide, Pd germanide-arsenide and Pt-Cu arseno-oxysulfide. The atypical assemblages are associated with Cl-rich annite with up to 7.54 wt.% Cl, Cl-rich hastingsite with up 4.06 wt.% Cl, ferro-hornblende (2.53 wt.% Cl), chlorapatite (>6 wt.% Cl) and extensive solid solutions of chlorapatite, fluorapatite and hydroxylapatite, Cl-bearing members of the chlorite group (chamosite; up to 0.96 wt.% Cl), and a Cl-bearing serpentine (up to 0.79 wt.% Cl). A decoupling of Cl and F in the geochemically evolved system is evident. The complex assemblages formed late from Cl-enriched fluids under subsolidus conditions of crystallization following extensive magmatic differentiation in the ore-bearing sequences

    Atypical Mineralization Involving Pd-Pt, Au-Ag, REE, Y, Zr, Th, U, and Cl-F in the Oktyabrsky Deposit, Norilsk Complex, Russia

    No full text
    Highly atypical mineralization involving Pd-Pt, Au-Ag, REE, Y, Zr, U, Th, and Cl-F-enriched minerals is found in zones with base metal sulfides (BMS; ~5 vol.% to 20 vol.%) in the eastern portion of the Oktyabrsky deposit in the Norilsk complex (Russia). The overall variations in Mg# index, 100 Mg/(Mg + Fe2+ + Mn), in host-rock minerals are 79.8 → 74.1 in olivine, 77.7 → 65.3 in orthopyroxene, 79.9 → 9.2 in clinopyroxene, and An79.0 â†’ An3.7. The span of clinopyroxene and plagioclase compositions reflects their protracted crystallization from early magmatic to late interstitial associations. The magnesian chromite (Mg# 43.9) trends towards Cr-bearing magnetite with progressive buildups in oxygen fugacity; ilmenite varies from early Mg-rich to late Mn-rich variants. The main BMS are chalcopyrite, pyrrhotite, troilite, and Co-bearing pentlandite, with less abundant cubanite (or isocubanite), rare bornite, Co-bearing pyrite, Cd-bearing sphalerite (or wurtzite), altaite, members of the galena-clausthalite series and nickeline. A full series of Au-Ag alloy compositions is found with minor hessite, acanthite and argentopentlandite. The uncommon assemblage includes monazite-(Ce), thorite-coffinite, thorianite, uraninite, zirconolite, baddeleyite, zircon, bastnäsite-(La), and an unnamed metamict Y-dominant zirconolite-related mineral. About 20 species of PGM (platinum group minerals) were analyzed, including Pd-Pt tellurides, bismuthotellurides, bismuthides and stannides, Pd antimonides and plumbides, a Pd-Ag telluride, a Pt arsenide, a Pd-Ni arsenide, and unnamed Pd stannide-arsenide, Pd germanide-arsenide and Pt-Cu arseno-oxysulfide. The atypical assemblages are associated with Cl-rich annite with up to 7.54 wt.% Cl, Cl-rich hastingsite with up 4.06 wt.% Cl, ferro-hornblende (2.53 wt.% Cl), chlorapatite (>6 wt.% Cl) and extensive solid solutions of chlorapatite, fluorapatite and hydroxylapatite, Cl-bearing members of the chlorite group (chamosite; up to 0.96 wt.% Cl), and a Cl-bearing serpentine (up to 0.79 wt.% Cl). A decoupling of Cl and F in the geochemically evolved system is evident. The complex assemblages formed late from Cl-enriched fluids under subsolidus conditions of crystallization following extensive magmatic differentiation in the ore-bearing sequences
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