On the topology of adiabatic passage

We examine the topology of eigenenergy surfaces characterizing the population transfer processes based on adiabatic passage. We show that this topology is the essential feature for the analysis of the population transfers and the prediction of its final result. We reinterpret diverse known processes, such as stimulated Raman adiabatic passage (STIRAP), frequency-chirped adiabatic passage and Stark-chirped rapid adiabatic passage (SCRAP). Moreover, using this picture, we display new related possibilities of transfer. In particular, we show that we can selectively control the level which will be populated in STIRAP process in Lambda or V systems by the choice of the peak amplitudes or the pulse sequence

Counterintuitive transitions between crossing energy levels

We calculate analytically the probabilities for intuitive and counterintuitive transitions in a three-state system, in which two parallel energies are crossed by a third, tilted energy. The state with the tilted energy is coupled to the other two states in a chainwise linkage pattern with constant couplings of finite duration. The probability for a counterintuitive transition is found to increase with the square of the coupling and decrease with the squares of the interaction duration, the energy splitting between the parallel energies, and the tilt (chirp) rate. Physical examples of this model can be found in coherent atomic excitation and optical shielding in cold atomic collisions

European Schottky-Diode Based Receiver Technology

Acces full text: https://doi.org/10.1109/IRMMW-THz.2019.8873877This contribution summarizes recent achievements of European MM- and SubMM-Wave receiver technology using Schottky diodes and THz-MICs fabricated by so-called Film-Diode (FD) process. The FD-process has particularly been developed for applications at MM-Waves and THz frequencies and targets at ultimate performance at high frequencies. This technology is extensively employed for modern space missions but also finds terrestrial applications

High Power Discrete Schottky Diodes Based 275-305 GHz Transceiver for FMCW-Rada

A heterodyne 275-305 GHz transceiver intended for frequency modulated continuous wave radar applications is presented here. A commercial E-band active multiplication chain is used to provide the required power and frequency band of the transceiver. All modules beyond E-band are solid-state discrete Schottky diodes based developed by ACST GmbH. The transceiver consists of a 135-160 GHz and a 270-320 GHz doublers to increase the frequency up to Y-band for the transmitter part. The receiver part consists of a 270-320 GHz sub-harmonic mixer pumped by the 135-160 GHz doubler. A Dband directional coupler distributes the power at 137.5 GHz to 152.5 GHz between the transmitter and receiver part. The transmitted power is higher than 20 mW in band and 8.5 dB average doubler side band noise figure is performed by the receiver

Single-Chip 135-160 GHz Doubler with more than 150 mW Output Power based on Discrete Schottky Diodes

Single chip doubler based on novel diamond-based discrete Schottky diodes is presented here. CVD Diamond technology has been integrated by ACST GmbH in the discrete diode structure to implement in high power multipliers development. A single chip 135-160 GHz doubler able to handle up to 400 mW input power and provide more than 150 mW output power is reported. Conversion efficiency higher than 30 % is performed in band and up to 40% at some frequencies point

Subnormal vitamin B12 concentrations and anaemia in older people: a systematic review

<p>Abstract</p> <p>Background</p> <p>Pernicious anaemia is undeniably associated with vitamin B12 deficiency, but the association between subnormal vitamin B12 concentrations and anaemia in older people is unclear. The aim of this systematic review was to evaluate the association between subnormal vitamin B12 concentrations and anaemia in older people.</p> <p>Methods</p> <p>Clinical queries for aetiology and treatment in bibliographic databases (PubMed [01/1949-10/2009]; EMBASE [01/1980-10/2009]) were used. Reference lists were checked for additional relevant studies. Observational studies (≥50 participants) and randomized placebo-controlled intervention trials (RCTs) were considered.</p> <p>Results</p> <p>25 studies met the inclusion criteria. Twenty-one observational cross-sectional studies (total number of participants n = 16185) showed inconsistent results. In one longitudinal observational study, low vitamin B12 concentrations were not associated with an increased risk of anaemia (total n = 423). The 3 RCTs (total n = 210) were well-designed and showed no effect of vitamin B12 supplementation on haemoglobin concentrations during follow-up in subjects with subnormal vitamin B12 concentrations at the start of the study. Due to large clinical and methodological heterogeneity, statistical pooling of data was not performed.</p> <p>Conclusions</p> <p>Evidence of a positive association between a subnormal serum vitamin B12 concentration and anaemia in older people is limited and inconclusive. Further well-designed studies are needed to determine whether subnormal vitamin B12 is a risk factor for anaemia in older people.</p

Primary biliary cirrhosis

Primary biliary cirrhosis (PBC) is a chronic and slowly progressive cholestatic liver disease of autoimmune etiology characterized by injury of the intrahepatic bile ducts that may eventually lead to liver failure. Affected individuals are usually in their fifth to seventh decades of life at time of diagnosis, and 90% are women. Annual incidence is estimated between 0.7 and 49 cases per million-population and prevalence between 6.7 and 940 cases per million-population (depending on age and sex). The majority of patients are asymptomatic at diagnosis, however, some patients present with symptoms of fatigue and/or pruritus. Patients may even present with ascites, hepatic encephalopathy and/or esophageal variceal hemorrhage. PBC is associated with other autoimmune diseases such as Sjogren's syndrome, scleroderma, Raynaud's phenomenon and CREST syndrome and is regarded as an organ specific autoimmune disease. Genetic susceptibility as a predisposing factor for PBC has been suggested. Environmental factors may have potential causative role (infection, chemicals, smoking). Diagnosis is based on a combination of clinical features, abnormal liver biochemical pattern in a cholestatic picture persisting for more than six months and presence of detectable antimitochondrial antibodies (AMA) in serum. All AMA negative patients with cholestatic liver disease should be carefully evaluated with cholangiography and liver biopsy. Ursodeoxycholic acid (UDCA) is the only currently known medication that can slow the disease progression. Patients, particularly those who start UDCA treatment at early-stage disease and who respond in terms of improvement of the liver biochemistry, have a good prognosis. Liver transplantation is usually an option for patients with liver failure and the outcome is 70% survival at 7 years. Recently, animal models have been discovered that may provide a new insight into the pathogenesis of this disease and facilitate appreciation for novel treatment in PBC