Beam investigations of D2 adsorption on Si(100): On the importance of lattice excitations in the reaction dynamics

The adsorption of D2 on Si(100) has been investigated by means of supersonic molecular beam techniques. We have succeeded in measuring the dependence of the molecular D2 sticking coefficient S on surface temperature Ts and nozzle temperature Tn. The sticking coefficient increases gradually in the range 300≤Tn≤1040 K. The influence of increased v=1 population has not been deconvoluted from the effects of translational energy alone. The dependence on Ts is more interesting. With an incident translational energy of 65 meV, S rises from a value insignificantly different from the background level to a maximum value of (1.5±0.1)×10−5 at Ts=630 K. The decrease in the effective sticking coefficient beyond this Ts is the result of desorption during the experiment. Having established that S increases with both increasing molecular energy and increasing sample temperature, we have demonstrated directly for the first time that the adsorption of molecular hydrogen on Si is activated and that lattice vibrational excitations play an important role in the adsorption process

Hydrogen adsorption on and desorption from Si: Considerations on the applicability of detailed balance

The translational energy of D2 desorbed from Si(100) and Si(111) surfaces was measured and found roughly equal to the thermal expectation at the surface temperature Ts. Combining these results with previously measured internal state distributions, the total energy of the desorbed molecules is approximately equal to the equilibrium expectation at Ts. Thus adsorption experiments, which suggest a large energetic barrier, are at variance with desorption experiments, which exhibit a trivial adsorption barrier, and the applicability of detailed balance for this system needs to be reexamined

Isotope and Quantum Effects in Vibrational State Distributions of Photodesorbed Ammonia

A marked quantum effect has been observed in the vibrational state distribution of photodesorbed ammonia. Namely, for quantum numbers larger than zero, symmetric and antisymmetric levels in the ν2 mode of the desorbed ammonia molecule are unequally populated. A strong propensity for symmetric levels is observed for NH3, whereas the reverse is found for ND3. Model calculations reproduce this effect. Moreover, it is found that the actual ratios probe the binding energy in the energetically less favorable inverted geometry with the H atoms pointing towards the surface

Androgen receptor protein is down-regulated by basic fibroblast growth factor in prostate cancer cells

Interactions between polypeptide growth factors and the androgen receptor (AR) are important for regulation of cellular events in carcinoma of the prostate. Basic fibroblast growth factor (bFGF), the prototype of heparin-binding growth factors, and the AR are commonly expressed in prostate cancer. bFGF diminished prostate-specific antigen protein in the supernatants of androgen-stimulated human prostate cancer cells LNCaP by 80%. In the present study, we asked whether the bFGF effect on prostate-specific antigen is preceded by action on AR expression. LNCaP cells were treated with bFGF and AR protein expression was determined by immunoblotting and ligand binding assay. bFGF down-regulated AR protein in a dose-dependent manner showing a maximal effect at 50 ng ml−1both in the presence or absence of dihydrotestosterone. Down-regulation of AR protein expression occurred already after 8 h of bFGF treatment and a maximal inhibition was observed 24 h after addition of bFGF to culture media. As AR expression can be reduced by an increase in intracellular calcium levels, we investigated whether the bFGF effect on AR protein is mediated by this mechanism. Calcium release from intracellular stores and store-operated calcium influx after treatment with either bFGF or calcium ionophore A 23187 were measured by single cell fluorescence technique. The ionophore A 23187 was able to induce calcium influx and an increase in cytoplasmic calcium concentration in LNCaP cells. In contrast, bFGF was incapable of eliciting a similar effect. In contrast to AR protein, AR mRNA levels were not affected by bFGF as shown by semiquantitative reverse transcription polymerase chain reaction. In summary, these studies show that bFGF is a potent negative regulator of AR protein expression in the human prostate cancer cell line LNCaP. © 2000 Cancer Research Campaig

Absence Seizures as a Feature of Juvenile Myoclonic Epilepsy in Rhodesian Ridgeback Dogs

Myoclonic epilepsy in Rhodesian Ridgeback (RR) dogs is characterized by myoclonic seizures occurring mainly during relaxation periods, a juvenile age of onset and generalized tonic-clonic seizures in one-third of patients. An 8-month-old female intact RR was presented for myoclonic seizures and staring episodes that both started at 10 weeks of age. Testing for the DIRAS1 variant indicated a homozygous mutant genotype. Unsedated wireless video-electroencephalography (EEG) identified frequent, bilaterally synchronous, generalized 4 Hz spike-and-wave complexes (SWC) during the staring episodes in addition to the characteristic myoclonic seizures with generalized 4-5 Hz SWC or 4-5 Hz slowing. Photic stimulation did not evoke a photoparoxysmal response. Repeat video-EEG 2 months after initiation of levetiracetam treatment disclosed a >95% decrease in frequency of myoclonic seizures, and absence seizures were no longer evident. Absence seizures represent another seizure type in juvenile myoclonic epilepsy (JME) in RR dogs, which reinforces its parallels to JME in humans.Peer reviewe

Many-body Effects in Angle-resolved Photoemission: Quasiparticle Energy and Lifetime of a Mo(110) Surface State

In a high-resolution photoemission study of a Mo(110) surface state various contributions to the measured width and energy of the quasiparticle peak are investigated. Electron-phonon coupling, electron-electron interactions and scattering from defects are all identified mechanisms responsible for the finite lifetime of a valence photo-hole. The electron-phonon induced mass enhancement and rapid change of the photo-hole lifetime near the Fermi level are observed for the first time.Comment: RevTEX, 4 pages, 4 figures, to be published in PR

Cardiac rehabilitation in real life

Participation in cardiac rehabilitation programs (CRPs) improves prognosis in patients with coronary artery disease (CAD). However, not much is known about the effectiveness of CRP in real life. The aim of this analysis was to identify factors related to the referral to CRP following hospitalization for CAD and estimate the effectiveness of the programs in real life. Medical records of 1061 consecutive patients aged ≤80 years, hospitalized due to an acute coronary syndrome or for a myocardial revascularization procedure in 5 hospitals serving the city and surrounding counties, were reviewed and 611 patients were interviewed 6–18 months posthospitalization. Of 611 patients participating in the interview, 212 (34.7%) were referred following the hospitalization to a center providing CRP. Age, hospitalization in a teaching hospital, and index diagnosis were independently related to being granted a referral. Among the referred patients, 86.3% participated in the CRP. Participation in CRP was related to the lower probability of having high total cholesterol (23% vs 32%, P < 0.05), fasting glucose (11% vs 18%, P = 0.05), Hb(A1c) (8% vs 16%, P = 0.05), and body mass index (27% vs 37%, P < 0.05). Generally, the effect of the CRP was significant in participants with a higher education, but not in those with a low education level. Other factors were not significantly related to the effectiveness of CRP. This study shows that CRPs are effective, but underused in Poland. The participant's education level may influence the effectiveness of CRP. Therefore, in order to increase the impact of CRP, the content of such programs should vary depending on the education level of the participants

Secondary prevention of coronary artery disease in contemporary clinical practice

Background: The highest priority in preventive cardiology was given to patients with estab-lished coronary artery disease (CAD). The aim of the study was to assess the implementation of guidelines for secondary prevention in everyday clinical practice by evaluating control of the main risk factors and the cardioprotective medication prescription rates for patients, following their hospitalization for CAD. Methods: Five hospitals with cardiology departments serving the city and its surround-ing districts in southern part of Poland participated in the study. Consecutive patients aged ≤ 80 years, hospitalized from January 1 2010 to April 31 2012 due to an acute coronary syndrome or for a myocardial revascularization procedure were recruited and interviewed 6–18 months after hospitalization. Results: The medical records of 595 patients (mean age: 62.8 ± 9.0 years, 397 men and 198 women) were reviewed and included in the analyses. Proportions of medical records with available information on risk factors were high with the exception of total cholesterol levels as well as weight and height measurements, which were available in less than 80 % of the hospita

Digital maturity and its determinants in General Practice: a cross- sectional study in 20 countries

Background: The extent to which digital technologies are employed to promote the delivery of high-quality healthcare is known as Digital Maturity. Individual and systemic digital maturity are both necessary to ensure a successful, scalable and sustainable digital transformation in healthcare. However, digital maturity in primary care has been scarcely evaluated. Objectives: This study assessed the digital maturity in General Practice (GP) globally and evaluated its association with participants' demographic characteristics, practice characteristics and features of Electronic Health Records (EHRs) use. Methods: GPs across 20 countries completed an online questionnaire between June and September 2020. Demographic data, practice characteristics, and features of EHRs use were collected. Digital maturity was evaluated through a framework based on usage, resources and abilities (divided in this study in its collective and individual components), interoperability, general evaluation methods and impact of digital technologies. Each dimension was rated as 1 or 0. The digital maturity score was calculated as the sum of the six dimensions and ranged between 0 to 6 (maximum digital maturity). Multivariable linear regression was used to model the total score, while multivariable logistic regression was used to model the probability of meeting each dimension of the score. Results: One thousand six hundred GPs (61% female, 68% Europeans) participated. GPs had a median digital maturity of 4 (P25–P75: 3–5). Positive associations with digital maturity were found with: male gender [B = 0.18 (95% CI 0.01; 0.36)], use of EHRs for longer periods [B = 0.45 (95% CI 0.35; 0.54)] and higher frequencies of access to EHRs [B = 0.33 (95% CI 0.17; 0.48)]. Practicing in a rural setting was negatively associated with digital maturity [B = −0.25 (95%CI −0.43; −0.08)]. Usage (90%) was the most acknowledged dimension while interoperability (47%) and use of best practice general evaluation methods (28%) were the least. Shorter durations of EHRs use were negatively associated with all digital maturity dimensions (aOR from 0.09 to 0.77). Conclusion: Our study demonstrated notable factors that impact digital maturity and exposed discrepancies in digital transformation across healthcare settings. It provides guidance for policymakers to develop more efficacious interventions to hasten the digital transformation of General Practice