Integrated photon pair source based on a silicon nitride micro-ring resonator for quantum memories.

We report the design of an integrated photon pair source based on spontaneous four-wave mixing (SFWM), implemented in an integrated micro-ring resonator in the silicon nitride platform (Si3N4). The signal photon is generated with emission at 606 nm and bandwidth of 3.98 MHz, matching the spectral properties of praseodymium ions (Pr), while the idler photon is generated at 1430.5 nm matching the wavelength of a CWDM channel in the E-band. This novel, to the best of our knowledge, device is designed to interact with a quantum memory based on a Y2SiO5 crystal doped with Pr3+ ions, in which we used cavity-enhanced SFWM along with dispersion engineering to reach the required wavelength and the few megahertz signal photon spectral bandwidth.

Design and fabrication of Mach-Zehnder interferometers in soda-lime glass for temperature sensing applications.

High sensitivity represents one of the main goals that sensing devices need to satisfy for their applications. This work presents to the best of our knowledge the first integrated Mach-Zehnder interferometer (MZI) embedded in soda-lime glass with comparable sensitivity to silicon-on-insulator (SOI) devices. We manufactured the MZIs by the femtosecond direct laser writing (FDLW) technique and characterized them with temperature. Four buried MZIs were manufactured by slightly increasing the optical path due to separation between the arms of the interferometer (Δ s). We achieved a fringe shift of ∼8n m for an increase of 0.18 µm. We have characterized one of these devices with temperature from 30°C to 70°C obtaining a sensitivity of ∼28p m/ ∘ C. We improved the sensitivity of the device to ∼54p m/ ∘ C due to the advantage of the unique three-dimensional (3D) capabilities that FDLW provides, overcoming the characteristically low thermo-optic coefficient of soda-lime glass just by rotating the MZI structure 11°.

Measurement of the Charge-Averaged Elastic Lepton-Proton Scattering Cross Section by the OLYMPUS Experiment.

We report the first measurement of the average of the electron-proton and positron-proton elastic scattering cross sections. This lepton charge-averaged cross section is insensitive to the leading effects of hard two-photon exchange, giving more robust access to the proton's electromagnetic form factors. The cross section was extracted from data taken by the OLYMPUS experiment at DESY, in which alternating stored electron and positron beams were scattered from a windowless gaseous hydrogen target. Elastic scattering events were identified from the coincident detection of the scattered lepton and recoil proton in a large-acceptance toroidal spectrometer. The luminosity was determined from the rates of Møller, Bhabha, and elastic scattering in forward electromagnetic calorimeters. The data provide some selectivity between existing form factor global fits and will provide valuable constraints to future fits.

First Observation of P-odd γ Asymmetry in Polarized Neutron Capture on Hydrogen.

We report the first observation of the parity-violating gamma-ray asymmetry A_{γ}^{np} in neutron-proton capture using polarized cold neutrons incident on a liquid parahydrogen target at the Spallation Neutron Source at Oak Ridge National Laboratory. A_{γ}^{np} isolates the ΔI=1, ^{3}S_{1}→^{3}P_{1} component of the weak nucleon-nucleon interaction, which is dominated by pion exchange and can be directly related to a single coupling constant in either the DDH meson exchange model or pionless effective field theory. We measured A_{γ}^{np}=[-3.0±1.4(stat)±0.2(syst)]×10^{-8}, which implies a DDH weak πNN coupling of h_{π}^{1}=[2.6±1.2(stat)±0.2(syst)]×10^{-7} and a pionless EFT constant of C^{^{3}S_{1}→^{3}P_{1}}/C_{0}=[-7.4±3.5(stat)±0.5(syst)]×10^{-11} MeV^{-1}. We describe the experiment, data analysis, systematic uncertainties, and implications of the result.

Measurement of the Vector and Tensor Asymmetries at Large Missing Momentum in Quasielastic (e[over →],e

We report the measurement of the beam-vector and tensor asymmetries A_{ed}^{V} and A_{d}^{T} in quasielastic (e[over →],e^{'}p) electrodisintegration of the deuteron at the MIT-Bates Linear Accelerator Center up to missing momentum of 500 MeV/c. Data were collected simultaneously over a momentum transfer range 0.1

Hard Two-Photon Contribution to Elastic Lepton-Proton Scattering Determined by the OLYMPUS Experiment.

The OLYMPUS Collaboration reports on a precision measurement of the positron-proton to electron-proton elastic cross section ratio, R_{2γ}, a direct measure of the contribution of hard two-photon exchange to the elastic cross section. In the OLYMPUS measurement, 2.01 GeV electron and positron beams were directed through a hydrogen gas target internal to the DORIS storage ring at DESY. A toroidal magnetic spectrometer instrumented with drift chambers and time-of-flight scintillators detected elastically scattered leptons in coincidence with recoiling protons over a scattering angle range of ≈20° to 80°. The relative luminosity between the two beam species was monitored using tracking telescopes of interleaved gas electron multiplier and multiwire proportional chamber detectors at 12°, as well as symmetric Møller or Bhabha calorimeters at 1.29°. A total integrated luminosity of 4.5 fb^{-1} was collected. In the extraction of R_{2γ}, radiative effects were taken into account using a Monte Carlo generator to simulate the convolutions of internal bremsstrahlung with experiment-specific conditions such as detector acceptance and reconstruction efficiency. The resulting values of R_{2γ}, presented here for a wide range of virtual photon polarization 0.456<ε<0.978, are smaller than some hadronic two-photon exchange calculations predict, but are in reasonable agreement with a subtracted dispersion model and a phenomenological fit to the form factor data.

Precision Measurement of the Radiative ß Decay of the Free Neutron.

The standard model predicts that, in addition to a proton, an electron, and an antineutrino, a continuous spectrum of photons is emitted in the ß decay of the free neutron. We report on the RDK II experiment which measured the photon spectrum using two different detector arrays. An annular array of bismuth germanium oxide scintillators detected photons from 14 to 782 keV. The spectral shape was consistent with theory, and we determined a branching ratio of 0.00335±0.00005[stat]±0.00015[syst]. A second detector array of large area avalanche photodiodes directly detected photons from 0.4 to 14 keV. For this array, the spectral shape was consistent with theory, and the branching ratio was determined to be 0.00582±0.00023[stat]±0.00062[syst]. We report the first precision test of the shape of the photon energy spectrum from neutron radiative decay and a substantially improved determination of the branching ratio over a broad range of photon energies.

rs3918242 MMP9 gene polymorphism is associated with myocardial infarction in Mexican patients.

Several studies have demonstrated that matrix metalloproteinases (MMPs) play a major role in atherosclerotic plaque disruption and lead to myocardial infarction (MI). We investigated the association between the MMP1 -1607 1G/2G (rs1799750), MMP3 -1612 5A/6A (rs3025058), and MMP9 -1562 C/T (rs3918242) polymorphisms and the risk of developing MI in a Mexican mestizo cohort. The genotype analysis was performed using the restriction fragment length polymorphism-polymerase chain reaction technique in a group of 236 patients with a history of MI and 285 healthy controls. Similar distributions of rs1799750 and rs3025058 were observed in both groups; however, the MMP9 rs3918242 T allele and the CT genotype were associated with the risk of developing MI (OR = 2.32, pC = 0.02 and OR = 2.40, pC = 0.02, respectively). Multiple logistic analysis was performed between MI patients and controls to estimate the risk, and after adjusting for identified risk factors, the CT + TT genotypes of MMP9 rs3918242 were found to be significantly associated with increased risk of developing MI than those with the CC genotype (OR = 2.88, P < 0.01). In summary, our results reveal that the rs3918242 polymorphism of the MMP9 gene plays a major role in the risk of developing MI.

Integrated photon pairs source in silicon carbide based on micro-ring resonators for quantum storage at telecom wavelengths.

We present the design of an on-chip integrated photon pair source based on Spontaneous Four Wave Mixing (SFWM), implemented on a ring resonator in the 4H Silicon Carbide On Insulator (4H-SiCOI) platform, compatible with a solid state quantum memory in the telecommunications band. Through careful engineering of the waveguide dispersion and micro-ring resonator dimensions, we found solutions where the signal photons are emitted at 1536.48 nm with a bandwidth of ∼ 150 MHz, enabling the interaction with the hyperfine structure of Er 3 + ions. Simultaneously, the idler photons are generated at 1563.86 nm, matching the central wavelength of a specific channel in a commercial dense wavelength division multiplexing system. The proposed device fulfill all the spectral requirements in a simple ring-bus coupled waveguide configuration with design parameters within the range of reported values for similar resonators, making feasible its manufacturing with current fabrication capabilities.

Transmission of megawatt relativistic electron beams through millimeter apertures.

High-power, relativistic electron beams from energy-recovering linacs have great potential to realize new experimental paradigms for pioneering innovation in fundamental and applied research. A major design consideration for this new generation of experimental capabilities is the understanding of the halo associated with these bright, intense beams. In this Letter, we report on measurements performed using the 100 MeV, 430 kW cw electron beam from the energy-recovering linac at the Jefferson Laboratory's Free Electron Laser facility as it traversed a set of small apertures in a 127 mm long aluminum block. Thermal measurements of the block together with neutron measurements near the beam-target interaction point yielded a consistent understanding of the beam losses. These were determined to be 3 ppm through a 2 mm diameter aperture and were maintained during a 7 h continuous run.

Spray-driven halide exchange in solid-state CsPbX3 nanocrystal films.

CsPbI3 perovskite nanocrystals (NCs) are promising building blocks for photovoltaics and optoelectronics. However, they exhibit an essential drawback in the form of phase stability: α-phase, with a ∼1.80 eV bandgap, can easily experience a phase transition to a non-radiative orthorhombic δ-phase in an ambient environment. This leads to the need to carry out the CsPbI3-based device fabrication in an inert atmosphere, which is technologically inconvenient and expensive. One of the most successful approaches proposed to overcome this problem is synthesizing mixed halide CsPbBr3-xIx NCs to improve the stability of the α-phase perovskite structure. However, the formation of high-quality thin films of CsPbBr3-xIx NCs with high PLQY is challenging owing to the degradation of their optical properties after deposition on a substrate. This work presents spray coating to carry out a solid-state anion exchange in CsPbBr3 NCs thin films at ambient conditions with low-demanding reaction conditions. This constitutes a novel open-air and annealing-free technology to manufacture CsPbBr3-xIx NC thin films with high optical quality and record high photoluminescence quantum yields (PLQY) based on spray-driven halide (Br- to I-) anion exchange in a solid-state phase. Besides, tunable emission wavelengths between 520 and 670 nm can be obtained from CsPbBr3-xIx NC films using accurate tuning volumes of HI solution sprayed over the initial surface of CsPbBr3 film to provide the halide exchange. The optical quality of the halide-exchanged PNCs films remains practically identical to that of initial Br-containing layers, with a remarkable PLQY enhancement after anion exchange, from ∼61% for CsPbBr3 thin films emitting at 520 nm to ∼84% for mixed halide CsPbBr3-xIx film emitting at 640 nm. The huge potential of the system is confirmed by demonstrating a low-threshold amplified spontaneous emission.

Precise measurement of deuteron tensor analyzing powers with BLAST.

We report a precision measurement of the deuteron tensor analyzing powers T(20) and T(21) at the MIT-Bates Linear Accelerator Center. Data were collected simultaneously over a momentum transfer range Q=2.15-4.50 fm(-1) with the Bates Large Acceptance Spectrometer Toroid using a highly polarized deuterium internal gas target. The data are in excellent agreement with calculations in a framework of effective field theory. The deuteron charge monopole and quadrupole form factors G(C) and G(Q) were separated with improved precision, and the location of the first node of G(C) was confirmed at Q=4.19±0.05 fm(-1). The new data provide a strong constraint on theoretical models in a momentum transfer range covering the minimum of T(20) and the first node of G(C).

Exposure to xenoestrogens alters the expression of key morphoregulatory proteins of oviduct adenogenesis in the broad-snouted caiman (Caiman latirostris).

Endocrine disrupting compounds (EDCs) are contaminants ubiquitously found in the environment, which pose a potential threat to aquatic and wetland ecosystems. Caiman latirostris, a crocodilian species that inhabits South American wetlands, is highly sensitive to EDC exposure. Previously, we reported that early postnatal exposure to EDCs such as Bisphenol A (BPA) and 17ß-Estradiol (E2) alters C. latirostris oviduct differentiation. The aim of this work was to elucidate the molecular mechanisms behind this alteration. To accomplish this, we established the ontogenic changes in histological features and the expression of Wnt-7a, Wnt-5a, ß-catenin, FoxA2, desmin, and alpha smooth muscle actin (α-SMA) in the oviduct of C. latirostris. Then, we evaluated the effects of BPA and E2 exposure on these histological features and protein expressions. Our results showed that during the postnatal differentiation of the oviduct the presence of histological features related to adenogenesis is associated with the levels of expression of FoxA2, ß-catenin, Wnt-5a and Wnt-7a. Early postnatal exposure to BPA and E2 decreased the presence of histological features related to adenogenesis and altered the levels of expression of FoxA2, ß-catenin, Wnt-5a and Wnt-7a, as well as the desmin/α-SMA ratio. These findings suggest that altered levels of Wnt-7a, Wnt-5a, ß-catenin and FoxA2 could play a role in the BPA and E2-induced alteration in oviduct differentiation in C. latirostris. Thus, impaired adenogenesis and, probably, impaired reproduction in wildlife naturally exposed to BPA and other estrogenic agonists cannot be completely ruled out.

Increased chromosome damage in systemic sclerosis skin fibroblasts.

OBJECTIVE: To evaluate chromosome damage, by means of micronucleus frequency, in dermal fibroblasts from affected and non-affected skin from systemic sclerosis (SSc) patients and from controls. METHODS: Primary fibroblast cultures were obtained by biopsy from affected and non-affected skin from SSc patients. Control fibroblasts were derived from skin remnants from plastic surgery in healthy adults. The number of micronuclei-bearing cells per 1000 binucleated cells (MN+ cells/1000 BN) was determined in cultures with and without clastogenic stimulus (bleomycin 3 µg/mL). RESULTS: Primary cultures from 10 SSc patients (affected and non-affected skin) and nine controls were analysed by two blinded examiners. In the absence of bleomycin, the frequency of MN+ cells was higher in cultures from affected (14.01 ± 11.96 MN+ cells/1000 BN; p = 0.004) and non-affected (15.41 ± 13.58 MN cells/1000 BN; p = 0.005) skin from SSc patients as compared to fibroblasts from healthy controls (4.74 ± 3.30 MN cells/1000 BN). In bleomycin-treated cultures, the frequency of MN cells was higher in SSc affected (38.03 ± 26.14 MN cells/1000 BN; p = 0.041) and non-affected skin (38.47 ± 17.88 MN cells/1000 BN; p = 0.034) as compared to healthy control fibroblasts (20.54 ± 13.09 MN cells/1000 BN). There was no difference in the frequency of MN cells in cultures from affected and non-affected skin of SSc patients. CONCLUSIONS: This is the first demonstration that dermal fibroblasts from SSc patients present an increased frequency of spontaneous and clastogen-induced micronuclei. Increased clastogenesis seems to be a widespread phenomenon in SSc because fibroblasts from clinically affected and non-affected skin presented the equivalent increased micronuclei counts.

Apaf-1 and caspase-9 in p53-dependent apoptosis and tumor inhibition.

The ability of p53 to promote apoptosis in response to mitogenic oncogenes appears to be critical for its tumor suppressor function. Caspase-9 and its cofactor Apaf-1 were found to be essential downstream components of p53 in Myc-induced apoptosis. Like p53 null cells, mouse embryo fibroblast cells deficient in Apaf-1 and caspase-9, and expressing c-Myc, were resistant to apoptotic stimuli that mimic conditions in developing tumors. Inactivation of Apaf-1 or caspase-9 substituted for p53 loss in promoting the oncogenic transformation of Myc-expressing cells. These results imply a role for Apaf-1 and caspase-9 in controlling tumor development.

Psychotic symptoms following oxycodone withdrawal, case report and update.

Opiate withdrawal-induced psychosis is an uncommon clinical manifestation. We present a 36-year-old male patient, with no prior personal or familiar psychiatric history, in treatment with several analgesic drugs (including oxycodone) for non-inflammatory chronic rachialgia. The patient is hospitalized after exhibiting psychotic symptomatology (delusions of harm and contamination, olfactory hallucinations, and aberrant behavior). This psychotic symptomatology first manifested after abruptly interrupting his prescribed oxycodone intake. It had a fluctuating course over time (alternating between lucid states and delusional ones) and eventually subsided after the prescription of antipsychotic drugs. In this case report, we describe the follow-up of the patient and discuss the influence and relevance of oxycodone withdrawal on the psychotic symptomatology.

Assessment of an educational program for adolescents about organ donation and transplantation.

The aim of this study is to determine the effectiveness of an educational program in 157 students with a mean age of 15.36 years at three schools in Malaga. The program included the evaluation of two tests before and after four sessions in an intervention group as compared with a control group. The educational program on organ donation and transplantation led to very positive changes, raising the level of awareness and the number of persons prepared to donate their organs and those of their relatives, as well as the number of participants who discussed the matter at home. Finally, evaluation of this experience showed that inclusion of education about organ donation and transplantation in secondary education can be considered positive.

Suitability of a rapid DNA isolation and amplification for detection of Trypanosoma cruzi in Triatoma infestans dry fecal spots collected on filter paper.

A rapid DNA extraction was used for T. cruzi detection in triatomines dry fecal spots collected on filter paper and analyzed by PCR. Fifty T. infestans were fed on experimentally infected Balb/C mice with high T. cruzi parasitemia and divided into five groups of ten triatomines, and 100 triatomines were infected with lower parasitemia and divided into five groups of 20 triatomines. One dry fecal spot was analyzed per group on days 1, 2, 3, 4 and 5 post feeding. Amplification targeted T. cruzi TCZ sequence and resulted positive from day 4 after bugs feeding in the two models (high and lower parasitemial. The rapid DNA isolation and PCR proposed are suitable for detection of T. cruzi DNA in filter paper and should be considered in field research.