We show that it is possible to realize significant nonlinear optical interactions at the few photon level in graphene nanostructures. Our approach takes advantage of the electric field enhancement ...associated with the strong confinement of graphene plasmons and the large intrinsic nonlinearity of graphene. Such a system could provide a powerful platform for quantum nonlinear optical control of light. As an example, we consider an integrated optical device that exploits this large nonlinearity to realize a single photon switch.
A Gram-stain-negative, nutritionally fastidious bacterium (PLS229T) causing pear leaf scorch was identified in Taiwan and previously grouped into Xylella fastidiosa. Yet, significant variations ...between PLS229T and Xylellafastidiosa were noted. In this study, PLS229T was evaluated phenotypically and genotypically against representative strains of Xylellafastidiosa, including strains of the currently known subspecies of Xylellafastidiosa, Xylella fastidiosa subsp. multiplex and 'Xylella fastidiosasubsp.pauca'. Because of the difficulty of in vitro culture characterization, emphases were made to utilize the available whole-genome sequence information. The average nucleotide identity (ANI) values, an alternative for DNA-DNA hybridization relatedness, between PLS229T and Xylellafastidiosa were 83.4-83.9 %, significantly lower than the bacterial species threshold of 95 %. In contrast, sequence similarity of 16S rRNA genes was greater than 98 %, higher than the 97 % threshold to justify if two bacterial strains belong to different species. The uniqueness of PLS229T was also evident by observing only about 87 % similarity in the sequence of the 16S-23S internal transcribed spacer (ITS) between PLS229T and strains of Xylellafastidiosa, discovering significant single nucleotide polymorphisms at 18 randomly selected housekeeping gene loci, observing a distinct fatty acid profile for PLS229T compared with Xylellafastidiosa, and PLS229T having different observable phenotypes, such as different susceptibility to antibiotics. A phylogenetic tree derived from 16S rRNA gene sequences showed a distinct PLS229T phyletic lineage positioning it between Xylellafastidiosa and members of the genus Xanthomonas. On the basis of these data, a novel species, Xylella taiwanensis sp. nov. is proposed. The type strain is PLS229T (=BCRC 80915T=JCM 31187T).
The bilayer-based Antiferroelectric Tunneling Junction (AFTJ) with ferroelectric (FE) HfZrO 2 (HZO) and dielectric (DE) Al 2 O 3 demonstrates a current ratio of <inline-formula> <tex-math ...notation="LaTeX">> 100\times </tex-math></inline-formula>, a TER (tunneling electroresistance) of <inline-formula> <tex-math notation="LaTeX">> 50\times </tex-math></inline-formula>, multilevel states, <inline-formula> <tex-math notation="LaTeX">> 10^{4} </tex-math></inline-formula> sec retention, and a cycling endurance as high as 10 8 . The concept of tunneling current through DE in an antiferroelectric (AFE) system enhances the capacity to modulate the current/TER ratio and makes the AFTJ feasible for low-power crossbar eNVM (embedded nonvolatile memory) applications.
The cross sections of e+e-→π+π-hc at center-of-mass energies from 3.896 to 4.600 GeV are measured using data samples collected with the BESIII detector operating at the Beijing Electron Positron ...Collider. The cross sections are found to be of the same order of magnitude as those of e+e-→π+π- J/ψ and e+e-→π+π-ψ (2S), but the line shape is inconsistent with the Y states observed in the latter two modes. Two structures are observed in the e+e- → π+π- hc cross sections around 4.22 and 4.39 GeV / c 2 , which we call Y ( 4220 ) and Y ( 4390 ) , respectively. A fit with a coherent sum of two Breit-Wigner functions results in a mass of (4218.4 $+5.5\atop{-4.5 ± 0.9) MeV/c2 and a width of 66.0$+12.3\atop-8.3$±0.4 MeV for the Y (4220), and a mass of (4391.5 $+6.3\atop-16.8$ ± 1.0) MeV/c2 and a width of (139.5$+16.2\atop-20.6 ± 0.6) MeV for the Y (4390), where the first uncertainties are statistical and the second ones systematic. The statistical significance of Y ( 4220 ) and Y(4390) is 10σ over one structure assumption.
Summary
Background
Case series suggest a possible association between bariatric surgery and incident IBD.
Aim
The aim of this study was to evaluate the association between bariatric surgery and ...new‐onset IBD.
Methods
We first conducted a multi‐institutional case series of patients with a history of IBD and bariatric surgery. We next conducted a matched case‐control study using medical and pharmacy claims from 2008 to 2012 in a US national database from Source Healthcare Analytics LLC. Bariatric surgery was defined by ICD‐9 or CPT code. Bariatric surgery was evaluated as recent (code in database timeframe), past (past history V code) or no history. Conditional logistic regression was used to estimate odds ratios (OR) and 95% CI for new‐onset IBD, CD and UC.
Results
A total of 15 cases of IBD (10 CD, 4 UC, 1 IBD, type unclassified) with a prior history of bariatric surgery were identified. Most cases were women, had Roux‐en‐Y surgery years prior to diagnosis and few IBD‐related complications. A total of 8980 cases and 43 059 controls were included in our database analysis. Adjusting for confounders, a past history of bariatric surgery was associated with an increased risk of new‐onset IBD (OR 1.93, 95% CI 1.34‐2.79). However, patients who had recent bariatric surgery did not appear to be at shorter term risk of IBD (OR 0.94, 95% CI 0.58‐1.52).
Conclusion
New‐onset IBD was significantly associated with a past history of bariatric surgery. This potential association needs to be confirmed in future prospective studies.
Linked ContentThis article is linked to Alukaidey and Heerasing, and Ungaro and Colombel papers. To view these articles visit https://doi.org/10.1111/apt.14611 and https://doi.org/10.1111/apt.14667.
The complicated structure of the neutron cannot be calculated using first-principles calculations due to the large colour charge of quarks and the self-interaction of gluons. Its simplest structure ...observables are the electromagnetic form factors1, which probe our understanding of the strong interaction. Until now, a small amount of data has been available for the determination of the neutron structure from the time-like kinematical range. Here we present measurements of the Born cross section of electron–positron annihilation reactions into a neutron and anti-neutron pair, and determine the neutron’s effective form factor. The data were recorded with the BESIII experiment at centre-of-mass energies between 2.00 and 3.08 GeV using an integrated luminosity of 647.9 pb−1. Our results improve the statistics on the neutron form factor by more than a factor of 60 over previous measurements, demonstrating that the neutron form factor data from annihilation in the time-like regime is on par with that from electron scattering experiments. The effective form factor of the neutron shows a periodic behaviour, similar to earlier observations of the proton form factor. Future works—both theoretical and experimental—will help illuminate the origin of this oscillation of the electromagnetic structure observables of the nucleon.Form factors encode the structure of nucleons. Measurements from electron–positron annihilation at BESIII reveal an oscillating behaviour of the neutron electromagnetic form factor, and clarify a long-standing photon–nucleon interaction puzzle.
We study the e^{+}e^{-}→γωJ/ψ process using 11.6 fb^{-1} e^{+}e^{-} annihilation data taken at center-of-mass energies from sqrts=4.008 GeV to 4.600 GeV with the BESIII detector at the BEPCII ...storage ring. The X(3872) resonance is observed for the first time in the ωJ/ψ system with a significance of more than 5σ. The relative decay ratio of X(3872)→ωJ/ψ and π^{+}π^{-}J/ψ is measured to be R=1.6_{-0.3}^{+0.4}±0.2, where the first uncertainty is statistical and the second systematic (the same hereafter). The sqrts-dependent cross section of e^{+}e^{-}→γX(3872) is also measured and investigated, and it can be described by a single Breit-Wigner resonance, referred to as the Y(4200), with a mass of 4200.6_{-13.3}^{+7.9}±3.0 MeV/c^{2} and a width of 115_{-26}^{+38}±12 MeV. In addition, to describe the ωJ/ψ mass distribution above 3.9 GeV/c^{2}, we need at least one additional Breit-Wigner resonance, labeled as X(3915), in the fit. The mass and width of the X(3915) are determined. The resonant parameters of the X(3915) agree with those of the Y(3940) in B→KωJ/ψ and of the X(3915) in γγ→ωJ/ψ observed by the Belle and BABAR experiments within errors.
To investigate the clinical pictures of patients with recurrent thunderclap headaches of unknown etiology and to field-test two relevant International Classification of Headache Disorders, 2nd ...edition (ICHD-II) criteria, i.e., primary thunderclap headache (Code 4.6) and benign (or reversible) angiopathy of the CNS (Code 6.7.3).
We prospectively recruited patients presenting with idiopathic recurrent thunderclap headaches from a hospital-based headache clinic. Detailed histories, neurologic examinations, and MRIs and magnetic resonance angiographies (MRAs) were performed in all patients to exclude secondary causes. Patients with cerebral vasoconstriction received serial MRA follow-up.
Fifty-six consecutive patients (51 female/5 male, mean age 49.6 +/- 9.8 range 22 to 76 years) were enrolled. Segmental vasoconstriction (or benign CNS angiopathy) was found in 22 patients (39%). Thunderclap headache recurred in all patients with a median frequency of 0.7 times per day for a median period of 14 days (range 6 to 86 days). The median duration for each single attack was 3 hours. Most patients (84%) reported at least one trigger. Nimodipine effectively aborted further attacks in 83% of the treated patients. Headache attacks subsided within 3 months. Four patients (7%) developed ischemic complications. Patients with and without vasoconstriction based on MRA images were similar regarding demographics and headache profile. Except for the duration criterion, our patients generally mapped well into the proposed ICHD-II criteria.
This study suggests that the two diagnostic entities proposed by the ICHD-II may present different spectra of the same disorder. The distinct headache profile may help physicians quickly recognize this disabling headache disorder with risk of stroke and provide timely treatment.
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