Observation of the screening signature in the lateral photovoltage of electrons in the Quantum Hall regime

The lateral photovoltage generated in the plane of a two-dimensional electron system (2DES) by a focused light spot, exhibits a fine-structure in the quantum oscillations in a magnetic field near the Quantum Hall conductivity minima. A double peak structure occurs near the minima of the longitudinal conductivity oscillations. This is the characteristic signature of the interplay between screening and Landau quantization.Comment: 4 pages, 4 figures, to be published in Phys. Rev.

Dipeptidyl peptidase-1 inhibition in patients hospitalised with COVID-19: a multicentre, double-blind, randomised, parallel-group, placebo-controlled trial

Background Neutrophil serine proteases are involved in the pathogenesis of COVID-19 and increased serine protease activity has been reported in severe and fatal infection. We investigated whether brensocatib, an inhibitor of dipeptidyl peptidase-1 (DPP-1; an enzyme responsible for the activation of neutrophil serine proteases), would improve outcomes in patients hospitalised with COVID-19. Methods In a multicentre, double-blind, randomised, parallel-group, placebo-controlled trial, across 14 hospitals in the UK, patients aged 16 years and older who were hospitalised with COVID-19 and had at least one risk factor for severe disease were randomly assigned 1:1, within 96 h of hospital admission, to once-daily brensocatib 25 mg or placebo orally for 28 days. Patients were randomly assigned via a central web-based randomisation system (TruST). Randomisation was stratified by site and age (65 years or ≥65 years), and within each stratum, blocks were of random sizes of two, four, or six patients. Participants in both groups continued to receive other therapies required to manage their condition. Participants, study staff, and investigators were masked to the study assignment. The primary outcome was the 7-point WHO ordinal scale for clinical status at day 29 after random assignment. The intention-to-treat population included all patients who were randomly assigned and met the enrolment criteria. The safety population included all participants who received at least one dose of study medication. This study was registered with the ISRCTN registry, ISRCTN30564012. Findings Between June 5, 2020, and Jan 25, 2021, 406 patients were randomly assigned to brensocatib or placebo; 192 (47·3%) to the brensocatib group and 214 (52·7%) to the placebo group. Two participants were excluded after being randomly assigned in the brensocatib group (214 patients included in the placebo group and 190 included in the brensocatib group in the intention-to-treat population). Primary outcome data was unavailable for six patients (three in the brensocatib group and three in the placebo group). Patients in the brensocatib group had worse clinical status at day 29 after being randomly assigned than those in the placebo group (adjusted odds ratio 0·72 [95% CI 0·57–0·92]). Prespecified subgroup analyses of the primary outcome supported the primary results. 185 participants reported at least one adverse event; 99 (46%) in the placebo group and 86 (45%) in the brensocatib group. The most common adverse events were gastrointestinal disorders and infections. One death in the placebo group was judged as possibly related to study drug. Interpretation Brensocatib treatment did not improve clinical status at day 29 in patients hospitalised with COVID-19

Synthesis and characterisation of magnesium substituted calcium phosphate bioceramic nanoparticles made via continuous hydrothermal flow synthesis

Continuous hydrothermal flow synthesis (CHFS) technology has been used as an efficient and direct route to produce a range of largely crystalline magnesium substituted calcium phosphate bioceramics. Initially, magnesium substituted hydroxyapatite, Mg-HA, according to the formula [Ca 10-xMgx(PO4)6(OH)2] was prepared in the CHFS system for x = 0.2 [where x:(10 - x) is the Mg:Ca ratio used in the reagents]. Biphasic mixtures of Mg-HA and Mg-whitlockite were obtained corresponding to x values in the range x = 0.4-1.6. The direct synthesis of phase pure crystalline Mg-whitlockite [based on the formula (Ca3-yMgy(HPO4)z(PO 4)2-2z/3] was also achieved using the CHFS system for the range y = 0.7-1.6 (this corresponds to the range x = 1.6-5.3). With increasing substitution of magnesium for calcium, the material became ever more amorphous and the BET surface area generally increased. All the as-precipitated powders (without any additional heat treatments) were analyzed using techniques including X-ray powder diffraction, Raman spectroscopy and Fourier transform infra-red spectroscopy. Transmission electron microscopy (TEM) images revealed that in the case of y = 1.2, the Mg-whitlockite material comprised of ca. 28 nm sized spheres. The use of the CHFS system in this context facilitated rapid production of combinations of particle properties (crystallinity, size, shape) that were hitherto unobtainable in a single step process. © The Royal Society of Chemistry 2008

Does advanced access improve access to primary health care? Questionnaire survey of patients

Background: General practices in England have been encouraged to introduce Advanced Access, but there is no robust evidence that this is associated with improved access in ways that matter to patients.Aim: To compare priorities and experiences of patients consulting in practices which do or do not operate Advanced Access.Design of study: Patient questionnaire survey.Setting: Forty-seven practices in 12 primary care trust areas of England.Method: Questionnaire administered when patients consulted.Results: Of 12 825 eligible patients, 10 821 (84%) responded. Most (70%) were consulting about a problem they had had for at least 'a few weeks'. Patients obtained their current appointment sooner in Advanced Access practices, but were less likely to have been able to book in advance. They could usually see a doctor more quickly than those in control practices, but were no more satisfied overall with the appointment system. The top priority for patients was to be seen on a day of choice rather than to be seen quickly, but different patient groups had different priorities. Patients in Advanced Access practices were no more or less likely to obtain an appointment that matched their priorities than those in control practices. Patients in both types of practice experienced problems making contact by telephone.Conclusion: Patients are seen more quickly in Advanced Access practices, but speed of access is less important to patients than choice of appointment; this may be because most consultations are about long-standing problems. Appointment systems need to be flexible to accommodate the different needs of different patient groups

Impact of Advanced Access on access, workload, and continuity: controlled before-and-after and simulated-patient study

Background: Case studies from the US suggest that Advanced Access appointment systems lead to shorter delays for appointments, reduced workload, and increased continuity of care.Aim: To determine whether implementation of Advanced Access in general practice is associated with the above benefits in the UK.Design of study: Controlled before-and-after and simulated-patient study.Setting: Twenty-four practices that had implemented Advanced Access and 24 that had not.Method: Anonymous telephone calls were made monthly to request an appointment. Numbers of appointments and patients consulting were calculated from practice records. Continuity was determined from anonymised patient records.Results: The wait for an appointment with any doctor was slightly shorter at Advanced Access practices than control practices (mean 1.00 day and 1.87 days respectively, adjusted difference ?0.75; 95% confidence interval [CI] = ?1.51 to 0.004 days). Advanced Access practices met the NHS Plan 48-hour access target on 71% of occasions and control practices on 60% of occasions (adjusted odds ratio 1.61; 95% CI = 0.78 to 3.31; P = 0.200). The number of appointments offered, and patients seen, increased at both Advanced Access and control practices over the period studied, with no evidence of differences between them. There was no difference between Advanced Access and control practices in continuity of care (adjusted difference 0.003; 95% CI = ?0.07 to 0.07).Conclusion: Advanced Access practices provided slightly shorter waits for an appointment compared with control practices, but performance against NHS access targets was considerably poorer than officially reported for both types of practice. Advanced Access practices did not have reduced workload or increased continuity of care