A high sensitivity ultra-low temperature RF conductance and noise measurement setup

We report on the realization of a high sensitivity RF noise measurement scheme to study small current fluctuations of mesoscopic systems at milliKelvin temperatures. The setup relies on the combination of an interferometric ampli- fication scheme and a quarter-wave impedance transformer, allowing the mea- surement of noise power spectral densities with GHz bandwith up to five orders of magnitude below the amplifier noise floor. We simultaneously measure the high frequency conductance of the sample by derivating a portion of the signal to a microwave homodyne detection. We describe the principle of the setup, as well as its implementation and calibration. Finally, we show that our setup allows to fully characterize a subnanosecond on-demand single electron source. More generally, its sensitivity and bandwith make it suitable for applications manipulating single charges at GHz frequencies.Comment: The following article has been submitted to Review of Scientific Instrument

An On-Demand Coherent Single Electron Source

We report on the electron analog of the single photon gun. On demand single electron injection in a quantum conductor was obtained using a quantum dot connected to the conductor via a tunnel barrier. Electron emission is triggered by application of a potential step which compensates the dot charging energy. Depending on the barrier transparency the quantum emission time ranges from 0.1 to 10 nanoseconds. The single electron source should prove useful for the implementation of quantum bits in ballistic conductors. Additionally periodic sequences of single electron emission and absorption generate a quantized AC-current

Stereotactic body radiation therapy for abdominal oligometastases: a biological and clinical review

Advances in imaging and biological targeting have led to the development of stereotactic body radiation therapy (SBRT) as an alternative treatment of extracranial oligometastases. New radiobiological concepts, such as ceramide-induced endothelial apoptosis after hypofractionated high-dose SBRT, and the identification of patients with oligometastatic disease by microRNA expression may yet lead to further developments. Key factors in SBRT are delivery of a high dose per fraction, proper patient positioning, target localisation, and management of breathing–related motion. Our review addresses the radiation doses and schedules used to treat liver, abdominal lymph node (LN) and adrenal gland oligometastases and treatment outcomes. Reported local control (LC) rates for liver and abdominal LN oligometastases are high (median 2-year actuarial LC: 61 -100% for liver oligometastases; 4-year actuarial LC: 68% in a study of abdominal LN oligometastases). Early toxicity is low-to-moderate; late adverse effects are rare. SBRT of adrenal gland oligometastases shows promising results in the case of isolated lesions. In conclusion, properly conducted SBRT procedures are a safe and effective treatment option for abdominal oligometastases

Le Mesnil-Amelot – La Pièce du Gué

C’est dans le cadre d’un projet d’aménagement d’infrastructures sportives piloté par le district de la Plaine-de-France, qu’une opération d’évaluation a été conduite en deux temps sur ce site en 1998 : une première approche par un diagnostic en tranchées en mars-avril, puis un décapage exhaustif entre août et octobre. Une occupation antique avait été reconnue lors de prospections pédestres par la JPGF. Deux indices permettaient de pressentir une occupation médiévale : d’une part, l’existence,..

Système multi-antennaires bi-fréquence miniaturisé pour liaison MIMO 4X4

National audienceUn dispositif multi-antennaires pour systèmes MIMO est présenté dans cet article. L'antenne élémentaire utilisée est bi-fréquence afin de couvrir les différentes bandes de la norme WiFi. Les performances du dispositif sont présentées et également évaluées dans un contexte MIMO

Subnanosecond single electron source in the time-domain

International audienceWe describe here the realization of a single electron source similar to single photon sources in optics. On-demand single electron injection is obtained using a quantum dot connected to the conductor via a tunnel barrier of variable transmission (quantum point contact). Electron emission is triggered by a sudden change of the dot potential which brings a single energy level above the Fermi energy in the conductor. A single charge is emitted on an average time ranging from 100 ps to 10 ns ultimately determined by the barrier transparency and the dot charging energy. The average single electron emission process is recorded with a 0.5 ns time resolution using a real-time fast acquisition card. Single electron signals are compared tosimulation based on scattering theory approach adapted for finite excitation energies

Plasma ceramide, a real-time predictive marker of pulmonary and hepatic metastases response to stereotactic body radiation therapy combined with irinotecan

AbstractBackground and purposesEarly biomarkers of tumour response are needed to discriminate between responders and non-responders to radiotherapy. We evaluated the ability of ceramide, a bioactive sphingolipid, to predict tumour sensitivity in patients treated by hypofractionated stereotactic body radiation therapy (SBRT) combined with irinotecan chemotherapy.Materials and methodsPlasma levels of total ceramide and of its subspecies were measured before and during treatment in 35 patients with liver and lung oligometastases of colorectal cancer included in a phase II trial. Cer levels were quantified by LC–ESI-MS/MS and compared to tumour volume response evaluated one year later by CT-scan.ResultsPretreatment plasma ceramide levels were not indicative of tumour response. Nevertheless, the levels of total ceramide and of its 4 main subspecies were significantly higher at days 3 and 10 of treatment in objective responders than in non-responders. According to Kaplan–Meier curves, almost complete tumour control was achieved at 1year in patients with increased total ceramide levels whereas 50% of patients with decreased levels experienced an increase in tumour volume.ConclusionsTotal plasma ceramide is a promising biomarker of tumour response to SBRT combined with irinotecan that should enable to segregate patients with high risk of tumour escape

Awareness of venous thromboembolism among patients with cancer: Preliminary findings from a global initiative for World Thrombosis Day

BACKGROUND Cancer-associated venous thromboembolism (CAT) has detrimental impact on patients' clinical outcomes and quality of life. Data on CAT education, communication, and awareness among the general cancer population are scanty. METHODS We present the preliminary results of an ongoing patient-centered survey including 27 items covering major spheres of CAT. The survey, available in 14 languages, was promoted and disseminated online through social networks, email newsletters, websites, and media. RESULTS As of September 20, 2022, 749 participants from 27 countries completed the survey. Overall, 61.8% (n = 460) of responders were not aware of their risk of CAT. Among those who received information on CAT, 26.2% (n = 56) were informed only at the time of CAT diagnosis. Over two thirds (69.1%, n = 501) of participants received no education on signs and symptoms of venous thromboembolism (VTE); among those who were educated about the possible clinical manifestations, 58.9% (n = 119) were given instructions to seek consultation in case of VTE suspicion. Two hundred twenty-four respondents (30.9%) had a chance to discuss the potential use of primary thromboprophylaxis with health-care providers. Just over half (58.7%, n = 309) were unaware of the risks of bleeding associated with anticoagulation, despite being involved in anticoagulant-related discussions or exposed to anticoagulants. Most responders (85%, n = 612) valued receiving CAT education as highly relevant; however, 51.7% (n = 375) expressed concerns about insufficient time spent and clarity of education received. CONCLUSIONS This ongoing survey involving cancer patients with diverse ethnic, cultural, and geographical backgrounds highlights important patient knowledge gaps. These findings warrant urgent interventions to improve education and awareness, and reduce CAT burden