3,701 research outputs found

    The evolution of electron dispersion in the series of rare-earth tritelluride compounds obtained from their charge-density-wave properties and susceptibility calculations

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    We calculated electron susceptibility of rare-earth tritelluride compounds RTe3_3 as a function of temperature, wave vector and electron-dispersion parameters. Comparison of results obtained with the available experimental data on the transition temperature and on the wave vector of a charge-density wave in these compounds allowed us to predict values and the evolution of electron-dispersion parameters with the variation of atomic number of rare-earth element R.Comment: 6 pages, 6 figure

    Adaptive Mesh Refinement for Electromagnetic Simulation

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    We consider problems related to initial meshing and adaptive mesh refinement for the electromagnetic simulation of various structures. The quality of the initial mesh and the performance of the adaptive refinement are of great importance for the finite element solution of the Maxwell equations, since they directly affect the accuracy and the computational time. In this paper, we describe the complete meshing workflow, which allows the simulation of arbitrary structures. Test simulations confirm that the presented approach allows to reach the quality of the industrial simulation software

    Lactamomethylation of alkylphenols: synthesis and quantum-chemical study of the reaction pathway

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    Six novel lactamomethyl derivatives of 2,5-dimethylphenol and 2,3,5-trimethylphenol were prepared with moderate yields by the reaction of corresponding phenols with 1-(hydroxymethyl)lactams in the presence of an acid catalyst. In all cases, the substitution occurred at position 4 to the phenolic hydroxyl group. The structures of all synthesized compounds were confirmed by FT-IR, 1H and 13C NMR, 2D NMR and elemental analysis. The selectivity and possible pathways of the lactamomethylation reaction were studied by quantum-chemical methods. In silico calculations showed that the substitution at para-position to the hydroxyl group of the corresponding phenols was more preferable due to the higher stability of forming intermediates

    Isatuximab plus pomalidomide and dexamethasone in patients with relapsed/refractory multiple myeloma according to prior lines of treatment and refractory status: ICARIA-MM subgroup analysis.

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    SB reports honoraria from Amgen, Bristol-Myers Squibb, Celgene, and Janssen; and reports a consultancy/advisory role for Celgene, Janssen, Karyopharm, and Takeda. VV reports a consultancy/advisory role for Astellas, Biocad, Bristol-Myers Squibb, Janssen, Roche, Sanofi, and Takeda. VM reports a consultancy/advisory role for Amgen, Bristol-Myers Squibb, Celgene, Janssen, and Takeda. LK reports honoraria from Amgen, Celgene, Janssen, and Takeda; a consultancy/advisory role for Amgen, Celgene, Janssen, and Takeda; and travel support from Amgen and Janssen. MP reports honoraria from Celgene, Pfizer, and Takeda; consultancy/advisory role for Amgen, Celgene, Janssen, Roche, and Takeda; and research funding from Amgen, Celgene, Janssen, Pfizer, Roche, and Takeda. PGR reports a consultancy/advisory role for Amgen, Janssen, Karyopharm, Oncopeptides, Sanofi, and Takeda; and research funding from Bristol-Myers Squibb, Celgene, Oncopeptides, and Takeda. LP, FV, KW, LB, and YK have no disclosures. FC, SLG, FM, and HvdV are employees of Sanofi

    Colloidal associations of major and trace elements in the snow pack across a 2800-km south-north gradient of western Siberia

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    Colloidal (size 1 nm to 1 ΞΌm) transport of major and trace elements, notably micronutrients and low-solubility geochemical tracers, is a ubiquitous and well-established feature for all surface and soil waters in boreal and subarctic regions. However, little is known on the colloidal associations of organic carbon (OC) and major and trace elements in atmospheric precipitation such as snow. This is despite significant efforts devoted to distinguishing the soluble and particulate transport of trace metals and contaminants by atmospheric aerosols. To acquire a snap-shot of major and trace element size fractionation in the snow cover of western Siberia, we sampled snow cores integrated over the entire depth (0–50 cm until bottom) across a sizable (2800 km) south - north transect in the Ob River watershed (western Siberia). A number of trace metal pollutants (Cr, Ni, Zn, Cd) exhibited significant linkage, pronounced over the first 20 km, to sources of local pollution. Some elements (P, Mn, Zn, Ba) also demonstrated an increase in their colloidal fraction in the proximity of pollution centers, possibly reflecting input from industrial centers and gas flares. Following centrifuginal ultrafiltration, we analyzed total dissolved (< 0.22 ΞΌm), two colloidal (high molecular weight, HMW50 kDa ΜΆ 0.22 ΞΌm; medium molecular weight MMW3 kDa ΜΆ 50 kDa) and low molecular weight (LMW < 3 kDa) fractions in the melted snow for all major and trace elements. We discovered sizable (20 to 70%) proportion of some major (Ca, SO4) and many trace (Fe, Y, Zn, Sb, La, Ce, Yb, Pb) elements in the colloidal (3 kDa - 0.22 ΞΌm) form, without significant link to latitude, type of biome, or the concentration of possible colloidal carrier (DOC, Fe, Al, Ca, SO4). The origin of snow water colloids in snow can be hypothesized to stem from solute freezing on lake surfaces (Fe, OC), frost flowers of the Arсtic ice (Ca, SO4), clays dispersion (Al, Si) and sulphur dioxide oxidation particles (SO4, oxyanions). Via hydrochemical mass balance calculations, we demonstrate an overwhelming impact of snow melt on spring-time riverine export of Cd, Pb, Zn, As, Sb and Cs. These preliminary results call for further studies of atmospheric colloids including those originating from rainwater

    Isatuximab as monotherapy and combined with dexamethasone in patients with relapsed/refractory multiple myeloma

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    This phase 2 study evaluated isatuximab as monotherapy or combined with dexamethasone in relapsed/refractory multiple myeloma (RRMM). Patients had RRMM refractory to an immunomodulatory drug (IMiD) and a proteasome inhibitor (PI) or had received >= 3 prior lines of therapy incorporating an IMiD and PI. Patients received isatuximab either as monotherapy (20 mg/kg on days 1, 8, 15, and 22 [once weekly] of cycle 1 followed by 20 mg/kg on days 1 and 15 of subsequent cycles; Isa group) or in combination with dexamethasone (40 mg/d [20 mg/d in patients aged >= 75 years] once weekly; Isa-dex group). Treated patients (N=164) had received a median of 4 (range, 2-10) prior treatment lines. Patients received a median of 5 (1-24) and 7 (1-22) treatment cycles; at data cutoff, 13 (11.9%) of 109 and 15 (27.3%) of 55 patients remained on treatment in the Isa and Isa-dex arms, respectively. Overall response rate (primary efficacy end point) was 23.9% in the Isa arm and 43.6% in the Isa-dex arm (odds ratio, 0.405; 95% confidence interval, 0.192-0.859; P=.008). Median progression-free survival and overall survival were 4.9 and 18.9 months for Isa, and 10.2 and 17.3 months for Isa-dex. Infusion reactions (mostly grade 1/2) and hematologic abnormalities were the most common adverse events. There was a similar incidence of grade 3 or higher infections in both groups (22.0% and 21.8%). In conclusion, addition of dexamethasone to isatuximab increased response rates and survival outcomes with no detrimental effect on safety.Peer reviewe

    Seasonal dynamics of organic carbon and metals in thermokarst lakes from the discontinuous permafrost zone of western Siberia

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    Despite relatively good knowledge of the biogeochemistry of Siberian thermokarst lakes during summer base flow, their seasonal dynamics remains almost unexplored. This work describes the chemical composition of 130 thermokarst lakes ranging in size from a few m2 to several km2, located in the discontinuous permafrost zone. Lakes were sampled during spring flood, just after the ice break (early June), the end of summer (August), the beginning of ice formation (October) and during the full freezing season in winter (February). The lakes larger than 1000m2 did not exhibit any statistically significant control of the lake size on dissolved organic carbon (DOC), the major and trace element concentrations over three major open water seasons. On the annual scale, the majority of dissolved elements including organic carbon increased their concentration from 30 to 500 %, with a statistically significant (p summer>autumn>winter. The ice formation in October included several stages: first, surface layer freezing followed by crack (fissure) formation with unfrozen water from the deeper layers spreading over the ice surface. This water was subsequently frozen and formed layered ice rich in organic matter. As a result, the DOC and metal (Mn, Fe, Ni, Cu, Zn, As, Ba and Pb) concentrations were highest near the surface of the ice column (0 to 20 cm) and decreased by a factor of 2 towards the bottom. The main implications of discovered freeze-driven solute concentrations in thermokarst lake waters are enhanced colloidal coagulation and removal of dissolved organic matter and associated insoluble metals from the water column to the sediments. The measured distribution coefficients of a TE between amorphous organo-ferric coagulates and lake water (<0.45 ΞΌm) were similar to those reported earlier for Fe-rich colloids and low molecular weight (<1 kDa, or <1–2 nm) fractions of thermokarst lake waters, suggesting massive coprecipitation of TE with amorphous Fe oxyhydroxide stabilized by organic matter. Although the concentration of most elements was lowest in spring, this period of maximal water coverage of land created a significant reservoir of DOC and soluble metals in the water column that can be easily mobilized to the hydrological network. The highest DOC concentration observed in the smallest (<100m2) water bodies in spring suggests their strongly heterotrophic status and, therefore, a potentially elevated CO2 flux from the lake surface to the atmosphere

    Evidence of Ξ₯(1S)β†’J/ψ+Ο‡c1\Upsilon(1S) \to J/\psi+\chi_{c1} and search for double-charmonium production in Ξ₯(1S)\Upsilon(1S) and Ξ₯(2S)\Upsilon(2S) decays

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    Using data samples of 102Γ—106102\times10^6 Ξ₯(1S)\Upsilon(1S) and 158Γ—106158\times10^6 Ξ₯(2S)\Upsilon(2S) events collected with the Belle detector, a first experimental search has been made for double-charmonium production in the exclusive decays Ξ₯(1S,2S)β†’J/ψ(Οˆβ€²)+X\Upsilon(1S,2S)\rightarrow J/\psi(\psi')+X, where X=Ξ·cX=\eta_c, Ο‡cJ(J=Β 0,Β 1,Β 2)\chi_{cJ} (J=~0,~1,~2), Ξ·c(2S)\eta_c(2S), X(3940)X(3940), and X(4160)X(4160). No significant signal is observed in the spectra of the mass recoiling against the reconstructed J/ψJ/\psi or Οˆβ€²\psi' except for the evidence of Ο‡c1\chi_{c1} production with a significance of 4.6Οƒ4.6\sigma for Ξ₯(1S)β†’J/ψ+Ο‡c1\Upsilon(1S)\rightarrow J/\psi+\chi_{c1}. The measured branching fraction \BR(\Upsilon(1S)\rightarrow J/\psi+\chi_{c1}) is (3.90Β±1.21(stat.)Β±0.23(syst.))Γ—10βˆ’6(3.90\pm1.21(\rm stat.)\pm0.23 (\rm syst.))\times10^{-6}. The 90%90\% confidence level upper limits on the branching fractions of the other modes having a significance of less than 3Οƒ3\sigma are determined. These results are consistent with theoretical calculations using the nonrelativistic QCD factorization approach.Comment: 12 pages, 4 figures, 1 table. The fit range was extended to include X(4160) signal according to referee's suggestions. Other results unchanged. Paper was accepted for publication as a regular article in Physical Review

    Efficiency of Finding Muon Track Trigger Primitives in CMS Cathode Strip Chambers

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    In the CMS Experiment, muon detection in the forward direction is accomplished by cathode strip chambers~(CSC). These detectors identify muons, provide a fast muon trigger, and give a precise measurement of the muon trajectory. There are 468 six-plane CSCs in the system. The efficiency of finding muon trigger primitives (muon track segments) was studied using~36 CMS CSCs and cosmic ray muons during the Magnet Test and Cosmic Challenge~(MTCC) exercise conducted by the~CMS experiment in~2006. In contrast to earlier studies that used muon beams to illuminate a very small chamber area (< ⁣0.01< \! 0.01~m2^2), results presented in this paper were obtained by many installed CSCs operating {\em in situ} over an area of β‰ˆβ€‰β£23\approx \! 23~m2^2 as a part of the~CMS experiment. The efficiency of finding 2-dimensional trigger primitives within 6-layer chambers was found to be~99.93Β±0.03%99.93 \pm 0.03\%. These segments, found by the CSC electronics within 800800~ns after the passing of a muon through the chambers, are the input information for the Level-1 muon trigger and, also, are a necessary condition for chambers to be read out by the Data Acquisition System

    NAJZNAČAJNIJE OSNOVE PATOGENEZE COVID-19

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    At the end of 2019, a new coronavirus infection occurred in the People's Republic of China with an epicentre in the city of Wuhan. On February 11th, 2020, the World Health Organization assigned the official name of the infection caused by the new coronavirus – COVID-19. COVID-19 has affected people from all over the world given that the infection was noted in 200 countries resulting in annunciation of the pandemic situation. Human corona viruses cause mild to moderate respiratory infections. At the end of 2002, a new coronavirus appeared (SARS-CoV), the causal agent of atypical pneumonia, which caused acute respiratory distress syndrome (ARDS). The initial stage of COVID-19 infection is the penetration of SARS-CoV-2 into target cells that have angiotensin converting enzyme type II receptors. The virus enters the body through the respiratory tract and interacts primarily with toll-like receptors (TLRs). The events in SARS-Cov-2 induced infection follow the next scenario: epithelial cells via TLRs recognize and identify SARS-Cov-2, and after that the information is transmitted to the transcriptional NF-ΞΊB, which causes expression of the corresponding genes. Activated in this way, the epithelial cells begin to synthesize various biologically active molecules. The results obtained on preclinical material indicate that ROS generation increases and the antioxidant protection decreases, which plays a major role in the pathogenesis of SARS-CoV, as well as in the progression and severity of this respiratory diseasePublishe
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