Simultaneous Determination of Chlorothalonil and Hexachlorobenzene in Technical and Formulated Materials by Capillary Gas Chromatography

Abstract A capillary gas chromatographic method using flame ionization detection was developed for simultaneous assay of chlorothalonil and hexachlorobenzene in technical material and formulated products. Method precision is excellent, and the method allows simultaneous determination of one chemical impurity. The method uses an internal normalization reagent (n-butyl phthalate). Modification and extension of the method to formulated products, including wettable powders, water-based flowables, and dispersible (or dry flowable) granular formulations, are discussed. Preliminary statistical analysis of intra- and interlaboratory comparisons was performed to evaluate method ruggedness. Average relative standard deviations for technical materials were 0.34 and 0.17% from 2 laboratories. Additional method validation studies were conducted to examine the influence of pH, solvent systems, gas chromatographic systems, and temperature conditions on different formulations.</jats:p

Simultaneous Determination of Chlorothalonil and Hexachlorobenzene in Technical and Formulated Materials by Capillary Gas Chromatography: Collaborative Study

Abstract A collaborative study was conducted for the capillary gas chromatographic (GC) method for the simultaneous determination of the fungicide chlorothalonil (CTL) and the accompanying impurity, hexachlorobenzene (HCB), in technical and formulated materials. The method calls for the dissolution of technical and dry formulations of CTL and HCB from the aqueous flowable formulation. The 10 participating laboratories were asked to analyze the samples by adhering to the method as closely as their instrumentation and data systems allowed, and to note any deviations from the method. Collaborators were asked to prepare the standards and samples, set up the capillary GC systems, analyze the samples, and calculate the results. CTL produced reproducibility relative standard deviations (RSDR) of 0.4–2.5 (active ingredient concentrations ranged from approximately 52 to 98% by weight). HCB produced RSDR values of 5.2–22% (HCB concentrations were 0.02–0.04% by weight). The method was adopted First Action by AOAC INTERNATIONAL.</jats:p

The medical management of abnormal uterine bleeding in reproductive-aged women

In the treatment of women with abnormal uterine bleeding, once a thorough history, physical examination, and indicated imaging studies are performed and all significant structural causes are excluded, medical management is the first-line approach. Determining the acuity of the bleeding, the patient\u27s medical history, assessing risk factors, and establishing a diagnosis will individualize their medical regimen. In acute abnormal uterine bleeding with a normal uterus, parenteral estrogen, a multidose combined oral contraceptive regimen, a multidose progestin-only regimen, and tranexamic acid are all viable options, given the appropriate clinical scenario. Heavy menstrual bleeding can be treated with a levonorgestrel-releasing intrauterine system, combined oral contraceptives, continuous oral progestins, and tranexamic acid with high efficacy. Nonsteroidal antiinflammatory drugs may be utilized with hormonal methods and tranexamic acid to decrease menstrual bleeding. Gonadotropin-releasing hormone agonists are indicated in patients with leiomyoma and abnormal uterine bleeding in preparation for surgical interventions. In women with inherited bleeding disorders all hormonal methods as well as tranexamic acid can be used to treat abnormal uterine bleeding. Women on anticoagulation therapy should consider using progestin-only methods as well as a gonadotropin-releasing hormone agonist to treat their heavy menstrual bleeding. Given these myriad options for medical treatment of abnormal uterine bleeding, many patients may avoid surgical intervention

Anisotropic flow in Xe-Xe collisions at root s(NN)=5.44 TeV

CNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFINEP - FINANCIADORA DE ESTUDOS E PROJETOSFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOThe first measurements of anisotropic flow coefficients v(n) for mid-rapidity charged particles in Xe-Xe collisions at root s(NN)=5.44TeV are presented. Comparing these measurements to those from Pb-Pb collisions at root s(NN)=5.02 TeV, v(2) is found to be suppressed for mid-central collisions at the same centrality, and enhanced for central collisions. The values of v(3) are generally larger in Xe-Xe than in Pb-Pb at a given centrality. These observations are consistent with expectations from hydrodynamic predictions. When both v(2) and v(3) are divided by their corresponding eccentricities for a variety of initial state models, they generally scale with transverse density when comparing Xe-Xe and Pb-Pb, with some deviations observed in central Xe-Xe and Pb-Pb collisions. These results assist in placing strong constraints on both the initial state geometry and medium response for relativistic heavy-ion collisions.7848295CNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFINEP - FINANCIADORA DE ESTUDOS E PROJETOSFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFINEP - FINANCIADORA DE ESTUDOS E PROJETOSFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOSem informaçãoSem informaçãoSem informaçãoAgências de fomento estrangeiras apoiaram essa pesquisa, mais informações acesse artig

Linear and non-linear flow mode in Pb–Pb collisions at √sNN = 2.76 TeV

The second and the third order anisotropic flow, V2 and V3, are mostly determined by the corresponding initial spatial anisotropy coefficients, ε2 and ε3, in the initial density distribution. In addition to their dependence on the same order initial anisotropy coefficient, higher order anisotropic flow, Vn (n > 3), can also have a significant contribution from lower order initial anisotropy coefficients, which leads to mode-coupling effects. In this Letter we investigate the linear and non-linear modes in higher order anisotropic flow Vn for n = 4, 5, 6 with the ALICE detector at the Large Hadron Collider. The measurements are done for particles in the pseudorapidity range |η| < 0.8 and the transverse momentum range 0.2 < pT < 5.0 GeV/c as a function of collision centrality. The results are compared with theoretical calculations and provide important constraints on the initial conditions, including initial spatial geometry and its fluctuations, as well as the ratio of the shear viscosity to entropy density of the produced system

Functional biogeography: Stoichiometry and thresholds for interpreting nutrient limitation in aquatic plants

Atmospheric N pollution may shift nutrient limitations in aquatic autotrophs from N to P or cause an intensification of P limitation in formerly pristine areas. Small changes in nutrient supply in oligotrophic lakes and rivers could lead to large changes in relative plant growth and yield with possible knock on effects on ecosystem carbon cycling through changes in the decomposition rate of their tissue. Previous biogeographical studies have shown inconsistent responses of plant nutrient tissue content and stoichiometry (functional traits) to external nutrient availability. Here we used a single species, Juncus bulbosus, to test the interplay between plant tissue nutrient (content and stoichiometry) and external environmental factors (local and catchment scale). We developed a comparative approach applicable globally to assess the thresholds for nutrient limitation in aquatic plants in the wild. Phosphorus in Juncus bulbosus tissue was negatively related to sediment organic matter (Fe root plaque limiting P uptake) and catchment vegetation cover (less P leaching to lakes). Our comparative approach revealed that the lack of increase in N plant tissue along the strong gradient in external N concentration may be explained by P limitation and strict plant tissue N:P ratio. Our comparative approach further showed that the nutrient content and stoichiometry of Juncus bulbosus was similar to other submerged aquatic plants growing in nutrient poor aquatic ecosystems. In southern Norway, mass development of Juncus bulbosus may be primarily triggered by changes in P availability, rather than CO2 or inorganic N, as previously thought, although co-limitations are also possible. If so, the mass development of Juncus bulbosus in oligotrophic aquatic ecosystems could be an early indicator of increasing P fluxes through these ecosystems which are less limited by N due to high atmospheric N deposition

Anisotropic flow in Xe–Xe collisions at sNN=5.44 TeV

The first measurements of anisotropic flow coefficients vn for mid-rapidity charged particles in Xe–Xe collisions at sNN=5.44 TeV are presented. Comparing these measurements to those from Pb–Pb collisions at sNN=5.02 TeV, v2 is found to be suppressed for mid-central collisions at the same centrality, and enhanced for central collisions. The values of v3 are generally larger in Xe–Xe than in Pb–Pb at a given centrality. These observations are consistent with expectations from hydrodynamic predictions. When both v2 and v3 are divided by their corresponding eccentricities for a variety of initial state models, they generally scale with transverse density when comparing Xe–Xe and Pb–Pb, with some deviations observed in central Xe–Xe and Pb–Pb collisions. These results assist in placing strong constraints on both the initial state geometry and medium response for relativistic heavy-ion collisions

Freeze-out radii extracted from three-pion cumulants in pp, p–Pb and Pb–Pb collisions at the LHC

In high-energy collisions, the spatio-temporal size of the particle production region can be measured using the Bose–Einstein correlations of identical bosons at low relative momentum. The source radii are typically extracted using two-pion correlations, and characterize the system at the last stage of interaction, called kinetic freeze-out. In low-multiplicity collisions, unlike in high-multiplicity collisions, two-pion correlations are substantially altered by background correlations, e.g. mini-jets. Such correlations can be suppressed using three-pion cumulant correlations. We present the first measurements of the size of the system at freeze-out extracted from three-pion cumulant correlations in pp, p–Pb and Pb–Pb collisions at the LHC with ALICE. At similar multiplicity, the invariant radii extracted in p–Pb collisions are found to be 5–15% larger than those in pp, while those in Pb–Pb are 35–55% larger than those in p–Pb. Our measurements disfavor models which incorporate substantially stronger collective expansion in p–Pb as compared to pp collisions at similar multiplicity

Precision measurement of the mass difference between light nuclei and anti-nuclei

The measurement of the mass differences for systems bound by the strong force has reached a very high precision with protons and anti-protons1,2. The extension of such measurement from (anti-)baryons to (anti-)nuclei allows one to probe any difference in the interactions between nucleons and anti-nucleons encoded in the (anti-)nuclei masses. This force is a remnant of the underlying strong interaction among quarks and gluons and can be described by effective theories3, but cannot yet be directly derived from quantum chromodynamics. Here we report a measurement of the difference between the ratios of the mass and charge of deuterons (d) and anti-deuterons (), and 3He and nuclei carried out with the ALICE (A Large Ion Collider Experiment)4 detector in Pb–Pb collisions at a centre-of-mass energy per nucleon pair of 2.76 TeV. Our direct measurement of the mass-over-charge differences confirms CPT invariance to an unprecedented precision in the sector of light nuclei5,6. This fundamental symmetry of nature, which exchanges particles with anti-particles, implies that all physics laws are the same under the simultaneous reversal of charge(s) (charge conjugation C), reflection of spatial coordinates (parity transformation P) and time inversion (T)

Measurement of electrons from semileptonic heavy-flavour hadron decays at midrapidity in pp and Pb–Pb collisions at √sNN = 5.02 TeV

The differential invariant yield as a function of transverse momentum (pT) of electrons from semileptonic heavy-flavour hadron decays was measured at midrapidity in central (0–10%), semi-central (30–50%) and peripheral (60–80%) lead–lead (Pb–Pb) collisions at √sNN = 5.02 TeV in the pT intervals 0.5–26 GeV/c (0–10% and 30–50%) and 0.5–10 GeV/c (60–80%). The production cross section in proton–proton (pp) collisions at √s = 5.02 TeV was measured as well in 0.5 < pT < 10 GeV/c and it lies close to the upper band of perturbative QCD calculation uncertainties up to pT = 5 GeV/c and close to the mean value for larger pT. The modification of the electron yield with respect to what is expected for an incoherent superposition of nucleon–nucleon collisions is evaluated by measuring the nuclear modification factor RAA. The measurement of the RAA in different centrality classes allows in-medium energy loss of charm and beauty quarks to be investigated. The RAA shows a suppression with respect to unity at intermediate pT, which increases while moving towards more central collisions. Moreover, the measured RAA is sensitive to the modification of the parton distribution functions (PDF) in nuclei, like nuclear shadowing, which causes a suppression of the heavy-quark production at low pT in heavy-ion collisions at LHC