Low-optical-loss, low-resistance Ag/Ge based ohmic contacts to n-type InP for membrane based waveguide devices

We present the development of Ag/Ge based ohmic contacts to n-type InP with both low contact resistances and relatively low optical losses. A specific contact resistance as low as 1.5×10-6 O cm2 is achieved by optimizing the Ge layer thickness and annealing conditions. The use of Ge instead of metal as the first deposited layer results in a low optical absorption loss in the telecommunication wavelength range. Compared to Au based contacts, the Ag based metallization also shows considerably reduced spiking effects after annealing. Contacts with different lengths are deposited on top of InP membrane waveguides to characterize the optical loss before and after annealing. A factor of 5 reduction of the propagation loss compared to the conventional Au/Ge/Ni contact is demonstrated. This allows for much more optimized designs for membrane photonic devices

Contribution of 24-h Blood Pressure Variability to Dementia-Related Disorders in Hispanics

Introduction: As the number of people living with dementia is increasing at alarming rates worldwide, there is an urgent need to understand the physiopathology of dementia syndromes. Among the most important preventable risk factors, treatment of vascular risk factors such as high blood pressure (BP) decreases the risk of Alzheimer’s disease and related dementias (ADRD). Recent evidence suggests that examining BP variability provides additional physiopathological and predictive information above the mean BP level. However, studies examining the relationship between 24-h BP variability and ADRD are limited, and evidence of the association with dementia has not been documented yet. Therefore, we aimed in this study to assess the association of 24-h ambulatory BP variability with brain imaging and cognitive markers of ADRD. Methods: A cross-sectional observational study was conducted using a subset of 420 individuals from the Maracaibo Aging Study aged ≥40 years. Study participants underwent brain MRI scanning and 24-h ambulatory BP monitoring assessments. Markers of ADRD included 1) cerebral small vessel disease (CSVD, defined as white matter hyperintensities, presence of lacunes, cerebral microbleeds, and enlarged perivascular spaces, and hippocampal volume), 2) cognitive functioning addressed with the mini-mental state exam (EMEMS), and 3) diagnose of dementia at baseline. 24-h ambulatory BP variability was studied as the average real variability index. Adjusted linear and logistic regression models were used to analyze the association between 24-h BP and ADRD and accounted for age, sex, education level, body mass index (BMI), current smoking, alcohol intake, hypertension treatment, diabetes mellitus, serum total cholesterol, previous cardiovascular diseases, and cephalic circumference and 24-h mean BP level. Results: The mean age was 57.1±11.8 years old and 73.2% were women (n=303). In adjusted analysis, each unit increase in the 24-h systolic BP variability was significantly associated with lower hippocampus volume (β, -0.036; 95% confidence interval [CI], -0.064, -0.008, P=0.011), greater white matter hyper intensities volume (β, 0.026; 95% CI, 0.008, 0.044; P=0.006), lower cognitive scores (β, -0.370; 95% CI, -0.729, -0.011; P=0.044), greater presence of lacunes (Odds ratios [OR], 1.38; 95% CI, 1.10, 1.71; P=0.004), enlarged perivascular spaces (OR,1.34; 95% CI, 1.08, 1.67; P=0.007), and dementia prevalence (OR, 1.41; 95% CI, 1.07, 1.85; P=0.014). 24-hour diastolic blood pressure variability was only significantly associated with lacunes (OR, 1.42; 95% CI, 1.06, 1.90; P=0.017). In exploratory analysis, we found that neither daytime nor nighttime variability in BP significantly relate with ADRD. Conclusions: Excessive 24-h BP variability associates with ADRD independently of the mean BP level. Understanding the physiological mechanisms explaining the relationship between excessive 24-h BP variability and ADRD may be clinically relevant in the prevention of ADRDs

"Validity of a scale of Latin American perception of fear and concern transmitted by the media during the pandemic (MED-LAT-COVID-19)"

"Introduction: The pandemic has caused fear, especially due to the daily disseminated news; however, there is not an instrument to measure this fear in multiple realities. Objective: To validate a scale for Latin American perception of fear and concern transmitted by the media during the pandemic. Methodology: This is an instrumental study. The survey was based on an instrument which was pre-validated in Peru and submitted to 15 experts in almost 10 countries. Subsequently, thousands of people were surveyed in 13 Latin American countries, whose answers were used for descriptive statistics for validation. Results: Confirmatory Factor Analysis (CFA) generated two re-specifications, where four items were eliminated from the original scale. With these changes, the global goodness of fit (absolute and incremental) were satisfactory (CFI ¼ 0.978; TLI ¼ 0.964; GFI ¼ 0.976; AGFI ¼ 0.949; RMSEA ¼ 0.075 and RMR ¼ 0.029). The first factor measures the media exaggeration (three questions); the second, the fear transmitted by the media (three questions); and the third, the fear transmitted by others different from the media (two questions). The Cronbach’s alpha coefficient was higher than 0.70 for the scale and its factors. Conclusion: The MED-LAT-COVID-19 scale reported a good adjustment. It has eight items in three factors, which could be measured in an isolated way, or along with other tests that assess mental health in the current pandemic context.

Differential branching fraction and angular analysis of the decay B0→K∗0μ+μ−

The angular distribution and differential branching fraction of the decay B 0→ K ∗0 μ + μ − are studied using a data sample, collected by the LHCb experiment in pp collisions at s√=7 TeV, corresponding to an integrated luminosity of 1.0 fb−1. Several angular observables are measured in bins of the dimuon invariant mass squared, q 2. A first measurement of the zero-crossing point of the forward-backward asymmetry of the dimuon system is also presented. The zero-crossing point is measured to be q20=4.9±0.9GeV2/c4 , where the uncertainty is the sum of statistical and systematic uncertainties. The results are consistent with the Standard Model predictions

Src activation by β-adrenoreceptors is a key switch for tumor metastasis

Norepinephrine (NE) can modulate multiple cellular functions important for cancer progression; however, how this single extracellular signal regulates such a broad array of cellular processes is unknown. Here, we identify Src as a key regulator of phosphoproteomic signaling networks activated in response to beta-adrenergic signaling in cancer cells. These results also identify a new mechanism of Src phosphorylation that mediates beta-adrenergic/PKA regulation of downstream networks, thereby enhancing tumor cell migration, invasion and growth. In human ovarian cancer samples, high tumoral NE levels were correlated with high pSrcY419 levels. Moreover, among cancer patients, the use of beta blockers was significantly associated with reduced cancer-related mortality. Collectively, these data provide a pivotal molecular target for disrupting neural signaling in the tumor microenvironment

Measurement of the CKM angle γ from a combination of B±→Dh± analyses

A combination of three LHCb measurements of the CKM angle γ is presented. The decays B±→D K± and B±→Dπ± are used, where D denotes an admixture of D0 and D0 mesons, decaying into K+K−, π+π−, K±π∓, K±π∓π±π∓, K0Sπ+π−, or K0S K+K− final states. All measurements use a dataset corresponding to 1.0 fb−1 of integrated luminosity. Combining results from B±→D K± decays alone a best-fit value of γ =72.0◦ is found, and confidence intervals are set γ ∈ [56.4,86.7]◦ at 68% CL, γ ∈ [42.6,99.6]◦ at 95% CL. The best-fit value of γ found from a combination of results from B±→Dπ± decays alone, is γ =18.9◦, and the confidence intervals γ ∈ [7.4,99.2]◦ ∪ [167.9,176.4]◦ at 68% CL are set, without constraint at 95% CL. The combination of results from B± → D K± and B± → Dπ± decays gives a best-fit value of γ =72.6◦ and the confidence intervals γ ∈ [55.4,82.3]◦ at 68% CL, γ ∈ [40.2,92.7]◦ at 95% CL are set. All values are expressed modulo 180◦, and are obtained taking into account the effect of D0–D0 mixing

Search for the decay Bs0→D*∓π±

A search for the decay Bs0→D*∓π± is presented using a data sample corresponding to an integrated luminosity of 1.0  fb-1 of pp collisions collected by LHCb. This decay is expected to be mediated by a W-exchange diagram, with little contribution from rescattering processes, and therefore a measurement of the branching fraction will help us to understand the mechanism behind related decays such as Bs0→π+π- and Bs0→DD- . Systematic uncertainties are minimized by using B0→D*∓π± as a normalization channel. We find no evidence for a signal, and set an upper limit on the branching fraction of B(Bs0→D*∓π±)<6.1(7.8)×10-6 at 90% (95%) confidence level

Measurements of the branching fractions of B+→ppK+ decays

The branching fractions of the decay B+ → pp̄K+ for different intermediate states are measured using data, corresponding to an integrated luminosity of 1.0 fb-1, collected by the LHCb experiment. The total branching fraction, its charmless component Mpp̄ < 2.85 GeV/c2 and the branching fractions via the resonant cc̄ states η c(1S) and ψ(2S) relative to the decay via a J/ψ intermediate state are [Equation not available: see fulltext.] Upper limits on the B + branching fractions into the η c(2S) meson and into the charmonium-like states X(3872) and X(3915) are also obtained

Study of DJ meson decays to D+π−, D0π+ and D∗+π− final states in pp collisions

A study of D+π−, D0π+ and D∗+π− final states is performed using pp collision data, corresponding to an integrated luminosity of 1.0 fb−1, collected at a centre-of-mass energy of 7 TeV with the LHCb detector. The D1(2420)0 resonance is observed in the D∗+π− final state and the D∗2(2460) resonance is observed in the D+π−, D0π+ and D∗+π− final states. For both resonances, their properties and spin-parity assignments are obtained. In addition, two natural parity and two unnatural parity resonances are observed in the mass region between 2500 and 2800 MeV. Further structures in the region around 3000 MeV are observed in all the D∗+π−, D+π− and D0π+ final states

Measurement of B meson production cross-sections in proton-proton collisions at √s= 7 TeV

The production cross-sections of B mesons are measured in pp collisions at a centre-of-mass energy of 7 TeV using data collected with the LHCb detector corresponding to a integrated luminosity of 0.36fb−1. The B+, B0 and B0s mesons are reconstructed in the exclusive decays B+→J/ψK+, B0→J/ψK∗0 and B0s→J/ψϕ, with J/ψ→μ+μ−, K∗0→K+π− and ϕ→K+K−. The differential cross-sections are measured as functions of B meson transverse momentum pT and rapidity y, in the range 0 < pT<40GeV/c2 and 2.0<y<4.5. The integrated cross-sections in the same pT and y ranges, including charge-conjugate states, are measured to be σ(pp→B++X)=38.9±0.3(stat.)±2.5(syst.)±1.3(norm.)μb, σ(pp→B0+X)=38.1±0.6(stat.)±3.7(syst.)±4.7(norm.)μb, σ(pp→B0s+X)=10.5±0.2(stat.)±0.8(syst.)±1.0(norm.)μb, where the third uncertainty arises from the pre-existing branching fraction measurements