Antibacterial, antifungal and antioxidant activity of Dichapetalum gelonioides (Roxb.) Engl. (Dichapetalaceae)

Objectives: Dichapetalum gelonioides (Roxb.) Engl. belongs to the family Dichapetalaceae. In the present study, we investigated antibacterial, antifungal and antioxidant activity of methanolic extract of leaf and fruit of D. gelonioides. Methods: Maceration process was carried out for extraction of leaf and fruit of D. gelonioides. Agar well diffusion method was employed to evaluate antibacterial activity of extracts against gram positive and gram negative bacteria. Poisoned food technique was performed to investigate antifungal activity of extracts against two seed-borne fungi. Antioxidant activity was evaluated by DPPH radical scavenging and ferric reducing assays.  Results: Both leaf and fruit extracts were effective in causing inhibition of all test bacteria. Highest and least inhibitory activity was observed against Bacillus cereus and Escherichia coli respectively. Both Aspergillus niger and Bipolaris sp. were inhibited to >50% by leaf and fruit extracts. Extent of inhibition of Bipolaris sp. was slightly higher when compared to A. niger. Both leaf and fruit extracts showed a dose dependent scavenging of DPPH radicals with high activity being showed by leaf extract. Leaf extract was shown to exhibit marked reducing potential than fruit extract. Conclusions: Overall, leaf extract was shown to be more effective in displaying antioxidant activity and causing inhibition of bacteria and fungi when compared to fruit extract. The results indicate that the plant possess active principles which are to be purified, characterized and subjected for antimicrobial and antioxidant assays in further studies. Keywords: Dichapetalum gelonioides, Maceration, Agar well diffusion, Poisoned food technique, DPPH, Ferric reducin

In-vitro antimicrobial and antioxidant activity of Argyreia cuneata (Willd.) Ker Gawl. (Convolvulaceae)

Objectives: Argyreia cuneata (Willd.) Ker Gawl. belongs to the family Convolvulaceae. The present study was performed to screen the potential of crude extract of various parts of A. cuneata to exhibit antimicrobial activity. Methods: Extraction of shade dried and powdered leaf, stem and flower of A. cuneata was carried out by maceration technique. Antibacterial and antifungal activity of extracts was evaluated by Agar well diffusion and Poisoned food technique respectively. Antioxidant activity was determined by DPPH radical scavenging, ABTS radical scavenging and ferric reducing assays. Results:  All extracts were effective in inhibiting test bacteria and the susceptibility of bacteria to extracts was in the order: Bacillus cereus > Shigella flexneri > Escherichia coli > Salmonella typhimurium. Leaf extract and stem extract exhibited highest and least antibacterial activity, respectively. Extracts were effective in causing inhibition of seed-borne fungi viz. Aspergillus niger and Bipolaris sp to >50%. Leaf extract exhibited marked antifungal activity followed by flower extract and stem extract. All extracts were shown to exhibit concentration dependent scavenging and reducing activity. Antioxidant activity of extracts observed was in the order: leaf extract > flower extract > stem extract.  Conclusion: Among various parts of A. cuneata, leaf extract exhibited marked antimicrobial and antioxidant activity. The plant can be employed as an effective antimicrobial and antioxidant agent in suitable form. Further studies may be undertaken to recover phytochemicals from the plant and to investigate the antimicrobial and antioxidant activity of isolated components. Keywords: Argyreia cuneata, Maceration, Antimicrobial, Agar well diffusion, Poisoned food technique, Antioxidan

Phytochemical analysis, antimicrobial and antioxidant activity of Lophopetalum wightianum Arn. (Celastraceae)

Objectives: Lophopetalum wightianum Arn. (Celastraceae) is a lofty evergreen tree reaching around 40m in height. The present study was carried out to investigate antimicrobial and antioxidant activity of leaf and bark extract of L. wightianum. Methods: The shade dried and powdered leaf and bark were extracted by maceration process using methanol. Extracts were screened for phytoconstituents present by standard protocols. Antibacterial and antifungal activity of extracts was evaluated by agar well diffusion and poisoned food technique respectively. Antioxidant activity was determined by DPPH radical scavenging and ferric reducing assays. Results: Phytochemicals viz. alkaloids, flavonoids, sterols, saponins and triterpenoids were detected in both leaf and bark extracts. Inhibitory activity against test bacteria of bark extract was marked than leaf extract. Bark extract displayed more or less similar activity against test bacteria while leaf extract was more effective against Escherichia coli. In antifungal activity, leaf extract showed highest inhibitory against Bipolaris sp. than A. niger. Bark extract showed more or less similar antifungal activity against A. niger and Bipolaris sp. Bark extract scavenged DPPH radicals more efficiently with IC50 value 7.03µg/ml than leaf extract which scavenged radicals with IC50 value of 24.64µg/ml. Reducing potential exhibited by bark extract was higher when compared to leaf extract. Conclusion: Overall, bark extract displayed marked antimicrobial and antioxidant potential. The plant is shown to contain bioactive principles with activity against pathogenic microorganisms and free radicals that cause oxidative damage. Keywords: Lophopetalum wightianum, Maceration, Phytochemical, Antimicrobial, Antioxidan

Search for long-lived particles decaying to a pair of muons in proton-proton collisions at s \sqrt{s} = 13 TeV

An inclusive search for long-lived exotic particles decaying to a pair of muons is presented. The search uses data collected by the CMS experiment at the CERN LHC in proton-proton collisions at $\sqrt{s}$ = 13 TeV in 2016 and 2018 and corresponding to an integrated luminosity of 97.6 fb$^{−1}$. The experimental signature is a pair of oppositely charged muons originating from a common secondary vertex spatially separated from the pp interaction point by distances ranging from several hundred μm to several meters. The results are interpreted in the frameworks of the hidden Abelian Higgs model, in which the Higgs boson decays to a pair of long-lived dark photons Z$_{D}$, and of a simplified model, in which long-lived particles are produced in decays of an exotic heavy neutral scalar boson. For the hidden Abelian Higgs model with m(Z$_{D}$) greater than 20 GeV and less than half the mass of the Higgs boson, they provide the best limits to date on the branching fraction of the Higgs boson to dark photons for cτ(Z$_{D}$) (varying with m(Z$_{D}$)) between 0.03 and ≈0.5 mm, and above ≈0.5 m. Our results also yield the best constraints on long-lived particles with masses larger than 10 GeV produced in decays of an exotic scalar boson heavier than the Higgs boson and decaying to a pair of muons.[graphic not available: see fulltext

Search for pair production of vector-like quarks in leptonic final states in proton-proton collisions at s \sqrt{s} = 13 TeV

A search is presented for vector-like T and B quark-antiquark pairs produced in proton-proton collisions at a center-of-mass energy of 13 TeV. Data were collected by the CMS experiment at the CERN LHC in 2016–2018, with an integrated luminosity of 138 fb$^{−1}$. Events are separated into single-lepton, same-sign charge dilepton, and multi-lepton channels. In the analysis of the single-lepton channel a multilayer neural network and jet identification techniques are employed to select signal events, while the same-sign dilepton and multilepton channels rely on the high-energy signature of the signal to distinguish it from standard model backgrounds. The data are consistent with standard model background predictions, and the production of vector-like quark pairs is excluded at 95% confidence level for T quark masses up to 1.54 TeV and B quark masses up to 1.56 TeV, depending on the branching fractions assumed, with maximal sensitivity to decay modes that include multiple top quarks. The limits obtained in this search are the strongest limits to date for $\textrm{T}\overline{\textrm{T}}$ production, excluding masses below 1.48 TeV for all decays to third generation quarks, and are the strongest limits to date for $\textrm{B}\overline{\textrm{B}}$ production with B quark decays to tW.[graphic not available: see fulltext

Search for CPCP violation in ttH and tH production in multilepton channels in proton-proton collisions at s\sqrt{s} = 13 TeV

International audienceThe charge-parity (CP) structure of the Yukawa interaction between the Higgs (H) boson and the top quark is measured in a data sample enriched in the t$\overline{\textrm{t}}$H and tH associated production, using 138 fb$^{−1}$ of data collected in proton-proton collisions at $\sqrt{s}$ = 13 TeV by the CMS experiment at the CERN LHC. The study targets events where the H boson decays via H → WW or H → ττ and the top quarks decay via t → Wb: the W bosons decay either leptonically or hadronically, and final states characterized by the presence of at least two leptons are studied. Machine learning techniques are applied to these final states to enhance the separation of CP -even from CP -odd scenarios. Two-dimensional confidence regions are set on κ$_{t}$ and $\overset{\sim }{\kappa } _{t}$, which are respectively defined as the CP -even and CP -odd top-Higgs Yukawa coupling modifiers. No significant fractional CP -odd contributions, parameterized by the quantity |${f}_{CP}^{\textrm{Htt}}$| are observed; the parameter is determined to be |${f}_{CP}^{\textrm{Htt}}$| = 0.59 with an interval of (0.24, 0.81) at 68% confidence level. The results are combined with previous results covering the H → ZZ and H → γγ decay modes, yielding two- and one-dimensional confidence regions on κ$_{t}$ and $\overset{\sim }{\kappa } _{t}$, while |${f}_{CP}^{\textrm{Htt}}$| is determined to be |${f}_{CP}^{\textrm{Htt}}$| = 0.28 with an interval of |${f}_{CP}^{\textrm{Htt}}$| < 0.55 at 68% confidence level, in agreement with the standard model CP -even prediction of |${f}_{CP}^{\textrm{Htt}}$| = 0.[graphic not available: see fulltext

Search for a charged Higgs boson decaying into a heavy neutral Higgs boson and a W boson in proton-proton collisions at s=\sqrt{s} = 13 TeV

A search for a charged Higgs boson ${\mathrm{\tilde{H}^{\pm}}}$ decaying into a heavy neutral Higgs boson H and a W boson is presented. The analysis targets the H decay into a pair of tau leptons with at least one of them decaying hadronically and with an additional electron or muon present in the event. The search is based on proton-proton collision data recorded by the CMS experiment during 2016-2018 at $\sqrt{s} =$ 13 TeV, corresponding to an integrated luminosity of 138 fb$^{-1}$. The data are consistent with standard model background expectations. Upper limits at 95% confidence level are set on the product of the cross section and branching fraction for an ${\mathrm{\tilde{H}^{\pm}}}$ in the mass range of 300-700 GeV, assuming an H with a mass of 200 GeV. The observed limits range from 0.085 pb for an ${\mathrm{\tilde{H}^{\pm}}}$ mass of 300 GeV to 0.019 pb for a mass of 700 GeV. These are the first limits on ${\mathrm{\tilde{H}^{\pm}}}$ production in the ${\mathrm{\tilde{H}^{\pm}}} \to \mathrm{H} \mathrm{W^{\pm}}$ decay channel at the LHC.A search for a charged Higgs boson H$^{±}$ decaying into a heavy neutral Higgs boson H and a W boson is presented. The analysis targets the H decay into a pair of tau leptons with at least one of them decaying hadronically and with an additional electron or muon present in the event. The search is based on proton-proton collision data recorded by the CMS experiment during 2016–2018 at $\sqrt{s}$ = 13 TeV, corresponding to an integrated luminosity of 138 fb$^{−1}$. The data are consistent with standard model background expectations. Upper limits at 95% confidence level are set on the product of the cross section and branching fraction for an H$^{±}$ in the mass range of 300–700 GeV, assuming an H with a mass of 200 GeV. The observed limits range from 0.085 pb for an H$^{±}$ mass of 300 Ge V to 0.019 pb for a mass of 700 GeV. These are the first limits on H$^{±}$ production in the H$^{±}$→ HW$^{±}$ decay channel at the LHC.[graphic not available: see fulltext]A search for a charged Higgs boson H$^\pm$ decaying into a heavy neutral Higgs boson H and a W boson is presented. The analysis targets the H decay into a pair of tau leptons with at least one of them decaying hadronically and with an additional electron or muon present in the event. The search is based on proton-proton collision data recorded by the CMS experiment during 2016-2018 at $\sqrt{s}$ = 13 TeV, corresponding to an integrated luminosity of 138 fb$^{-1}$. The data are consistent with standard model background expectations. Upper limits at 95% confidence level are set on the product of the cross section and branching fraction for an H$^\pm$ in the mass range of 300-700 GeV, assuming an H with a mass of 200 GeV. The observed limits range from 0.085 pb for an H$^\pm$ mass of 300 GeV to 0.019 pb for a mass of 700 GeV. These are the first limits on H$^\pm$ production in the H$^\pm$ $\to$ HW$^\pm$ decay channel at the LHC

Measurement of the Higgs boson inclusive and differential fiducial production cross sections in the diphoton decay channel with pp collisions at s \sqrt{s} = 13 TeV

The measurements of the inclusive and differential fiducial cross sections of the Higgs boson decaying to a pair of photons are presented. The analysis is performed using proton-proton collisions data recorded with the CMS detector at the LHC at a centre-of-mass energy of 13 TeV and corresponding to an integrated luminosity of 137 fb$^{−1}$. The inclusive fiducial cross section is measured to be ${\sigma}_{\textrm{fid}}={73.4}_{-5.3}^{+5.4}{\left(\textrm{stat}\right)}_{-2.2}^{+2.4}\left(\textrm{syst}\right)$ fb, in agreement with the standard model expectation of 75.4 ± 4.1 fb. The measurements are also performed in fiducial regions targeting different production modes and as function of several observables describing the diphoton system, the number of additional jets present in the event, and other kinematic observables. Two double differential measurements are performed. No significant deviations from the standard model expectations are observed.[graphic not available: see fulltext