761 research outputs found

    Chemical Composition of the Essential Oil ofSatureja myrtifolia(Boiss. & Hohen.) from Lebanon

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    Satureja myrtifolia (Boiss. & Hohen.) Greuter & Burdeta medicinal plant belonging to the Lamiaceae family was collected from south of Lebanon and hydro-distilled by Clevenger method. Essential oil composition from aerial parts was analyzed by GC-MS technique. The odor of essential oil is characteristic, and clear yellow liquid oil was obtained after hydro-distillation. The yield of the essential oil was 1.25±0.02 % of dry matter (w/w). Thirty nine volatile components were identified in the Satureja myrtifolia oil, which shows a high amount of hydrocarbons class (57.82±0.1 %). Other classes were also identified such assesquiterpene hydrocarbons (12.96±0.1 %), oxygenated sesquiterpenes (10.65±0.2 %), phenolic compounds (10.32±0.1 %), acids (5.53±0.1 %), and monoterpenes hydrocarbons (2.21±0.1 %).In addition, a comparison with the unique study performed on Satureja myrtifolia was also carried out

    Investigation of Origanum libanoticum Essential Oils Chemical Polymorphism by Independent Components Analysis (ICA)

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    International audienceThe essential oils obtained from Origanum libanoticum Boiss., a plant endemic to Lebanon, were analyzed by GC/MS. Seventy compounds were identified, covering till 99.8% of the total oil composition. All samples were p-cymene and/or β-caryophyllene chemotype, with variable percentage of other compounds such as α-pinene, myrcene, α-phellandrene, limonene, etc. Compared to traditional drying method, lyophilized samples provided the highest essential oil (EO) yields and yields were higher at flowering stage (Chouwen: 0.33% in 2013 and 0.32% in 2014; Qartaba: 0.27% in 2013 and 0.37% in 2014). According to independent components analysis (ICA), date and site of harvest, altitude and drying technique had no effect on the variation of O. libanoticum EO chemical composition. An annual variation of EOs composition was observed since a particular variation in some major components concentration was revealed monthly and annually between 2013 and 2014

    EFFECTS OF OLIVE DRYING AND STORAGE ON THE OXIDATIVE STATUS, AROMA, CHLOROPHYLL AND FATTY ACIDS COMPOSITION OF OLIVE OIL

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    Objective: In this study, we thoroughly investigate the effect of drying and storage of olives from four Tunisian cultivars (Chetoui, Chemlali, Oueslati and Picholine) on the final composition of olive oil.Methods: Olives were dried using three different methods: ambient air, infrared radiation and oven heating. Oven-dried olives were stored during six months. Extraction was conducted using a soxhlet apparatus. Its quality was assessed by analyzing the fatty acid and aroma composition on one hand, and on the other hand by evaluating the total chlorophyll content and measuring specific extinctions at 232 and 270 nm.Results: The main results show that air dried fruits (Chetoui cultivar) gave the most pigmented oil (3.32 ppm of total chlorophylls) followed by oven dried olives (1.12 ppm), whereas infra-red dried olives had the least amount of chlorophylls (0.98 ppm). Furthermore, the highest amount of total aroma was found in oven dried fruits whereas the lowest one characterized infrared dried olives. Fatty acid composition of our oils wasn't affected by drying techniques. Also, oven dried and stored olives showed an insignificant change in chlorophyll contents and aroma composition (Chetoui variety), coupled with a decreased level of total fatty acid amount as of the third month of preservation.Conclusion: Drying techniques and storage affected aroma compounds, while oil oxidation, chlorophyll and fatty acid composition were unaffected. A better control for drying and storage should be developed to insure a better quality of olive oil. A comparison should be done between the current study and salt and dried olive preservation in order to offer hypertensive patients fruits with preserved nutritional values and the peculiar delicate flavour characteristic of olive oilÂ

    Hippocampal Automatic Recognition and 3D Segmentation Based on Active Appearance Model in Brain MR Images for Early Diagnosis ofAlzheimer's Disease

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    目的:研究磁共振(MAgnETIC rESOnAnCE,Mr)脑图像中海马的自动分割方法及海马的形态学分析方法,为阿尔茨海默病(AlzHEIMEr'S dISEASE,Ad)的早期诊断提供依据。方法:对20例Ad患者和60名正常对照者行MrI T1 WI 3d容积扫描,建立海马的三维主动表观模型,并以此模型对每个个体脑部磁共振图像上的海马进行自动识别和三维分割,分别建立正常对照组和Ad组的海马统计形状模型,比较Ad组与正常对照组间海马形状的差异性。结果:海马三维分割方法与手动分割方法在海马体积测量上无统计学差别(P>0.05);Ad患者海马头部发生萎缩(P0.05).Hippocampal head atrophy was found in AD patients(P<0.05).Conclusions: Hippocampal three-dimensional segmentation and automatic identification method based on active appearance model in brain MR image is accurate and reliable;the feature of hippocampal head atrophy can be used as a basis for diagnosis of AD.哈尔滨医科大学研究生创新基金(HCXB2010019);国家自然科学基金(81071219

    Combined searches for the production of supersymmetric top quark partners in proton-proton collisions at root s=13 TeV

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    A combination of searches for top squark pair production using proton-proton collision data at a center-of-mass energy of 13 TeV at the CERN LHC, corresponding to an integrated luminosity of 137 fb(-1) collected by the CMS experiment, is presented. Signatures with at least 2 jets and large missing transverse momentum are categorized into events with 0, 1, or 2 leptons. New results for regions of parameter space where the kinematical properties of top squark pair production and top quark pair production are very similar are presented. Depending on themodel, the combined result excludes a top squarkmass up to 1325 GeV for amassless neutralino, and a neutralinomass up to 700 GeV for a top squarkmass of 1150 GeV. Top squarks with masses from 145 to 295 GeV, for neutralino masses from 0 to 100 GeV, with a mass difference between the top squark and the neutralino in a window of 30 GeV around the mass of the top quark, are excluded for the first time with CMS data. The results of theses searches are also interpreted in an alternative signal model of dark matter production via a spin-0 mediator in association with a top quark pair. Upper limits are set on the cross section for mediator particle masses of up to 420 GeV

    Search for new particles in events with energetic jets and large missing transverse momentum in proton-proton collisions at root s=13 TeV

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    A search is presented for new particles produced at the LHC in proton-proton collisions at root s = 13 TeV, using events with energetic jets and large missing transverse momentum. The analysis is based on a data sample corresponding to an integrated luminosity of 101 fb(-1), collected in 2017-2018 with the CMS detector. Machine learning techniques are used to define separate categories for events with narrow jets from initial-state radiation and events with large-radius jets consistent with a hadronic decay of a W or Z boson. A statistical combination is made with an earlier search based on a data sample of 36 fb(-1), collected in 2016. No significant excess of events is observed with respect to the standard model background expectation determined from control samples in data. The results are interpreted in terms of limits on the branching fraction of an invisible decay of the Higgs boson, as well as constraints on simplified models of dark matter, on first-generation scalar leptoquarks decaying to quarks and neutrinos, and on models with large extra dimensions. Several of the new limits, specifically for spin-1 dark matter mediators, pseudoscalar mediators, colored mediators, and leptoquarks, are the most restrictive to date.Peer reviewe

    Probing effective field theory operators in the associated production of top quarks with a Z boson in multilepton final states at root s=13 TeV

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    Measurements of the Electroweak Diboson Production Cross Sections in Proton-Proton Collisions at root s=5.02 TeV Using Leptonic Decays

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    The first measurements of diboson production cross sections in proton-proton interactions at a center-of-mass energy of 5.02 TeV are reported. They are based on data collected with the CMS detector at the LHC, corresponding to an integrated luminosity of 302 pb(-1). Events with two, three, or four charged light leptons (electrons or muons) in the final state are analyzed. The WW, WZ, and ZZ total cross sections are measured as sigma(WW) = 37:0(-5.2)(+5.5) (stat)(-2.6)(+2.7) (syst) pb, sigma(WZ) = 6.4(-2.1)(+2.5) (stat)(-0.3)(+0.5)(syst) pb, and sigma(ZZ) = 5.3(-2.1)(+2.5)(stat)(-0.4)(+0.5) (syst) pb. All measurements are in good agreement with theoretical calculations at combined next-to-next-to-leading order quantum chromodynamics and next-to-leading order electroweak accuracy

    Search for lepton-flavor violating decays of the Higgs boson in the mu tau and e tau final states in proton-proton collisions at root s=13 TeV

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    A search is presented for lepton-flavor violating decays of the Higgs boson to mu t and et. The dataset corresponds to an integrated luminosity of 137 fb(-1) collected at the LHC in proton-proton collisions at a center-of-mass energy of 13 TeV. No significant excess has been found, and the results are interpreted in terms of upper limits on lepton-flavor violating branching fractions of the Higgs boson. The observed (expected) upper limits on the branching fractions are, respectively, B(H -> mu t) e tau) < 0.22(0.16)% at 95% confidence level.Peer reviewe

    Measurements of Higgs boson production cross sections and couplings in the diphoton decay channel at root s=13 TeV

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    Measurements of Higgs boson production cross sections and couplings in events where the Higgs boson decays into a pair of photons are reported. Events are selected from a sample of proton-proton collisions at root s = 13TeV collected by the CMS detector at the LHC from 2016 to 2018, corresponding to an integrated luminosity of 137 fb(-1). Analysis categories enriched in Higgs boson events produced via gluon fusion, vector boson fusion, vector boson associated production, and production associated with top quarks are constructed. The total Higgs boson signal strength, relative to the standard model (SM) prediction, is measured to be 1.12 +/- 0.09. Other properties of the Higgs boson are measured, including SM signal strength modifiers, production cross sections, and its couplings to other particles. These include the most precise measurements of gluon fusion and vector boson fusion Higgs boson production in several different kinematic regions, the first measurement of Higgs boson production in association with a top quark pair in five regions of the Higgs boson transverse momentum, and an upper limit on the rate of Higgs boson production in association with a single top quark. All results are found to be in agreement with the SM expectations.Peer reviewe
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