457 research outputs found
Calculation of pure dephasing for excitons in quantum dots
Pure dephasing of an exciton in a small quantum dot by optical and acoustic
phonons is calculated using the ``independent boson model''. Considering the
case of zero temperature the dephasing is shown to be only partial which
manifests itself in the polarization decaying to a finite value. Typical
dephasing times can be assigned even though the spectra exhibits strongly
non-Lorentzian line shapes. We show that the dephasing from LO phonon
scattering, occurs on a much larger time scale than that of dephasing due to
acoustic phonons which for low temperatures are also a more efficient dephasing
mechanism. The typical dephasing time is shown to strongly depend on the
quantum dot size whereas the electron phonon ``coupling strength'' and external
electric fields tend mostly to effect the residual coherence. The relevance of
the dephasing times for current quantum information processing implementation
schemes in quantum dots is discussed
Live demonstration: a public engagement platform for invasive neural interfaces
Neural interfaces, and more specifically ones ofthe invasive/implantable variety, today are a topic of muchcontroversy, often making the general public uncomfortable andintimidated. We have thus devised a bespoke interactive demoto help people understand brain implants and their need inthe age of wearable devices, with the secondary objective ofintroducing the wireless cortical neural probe that we, at NGNI(Next Generation Neural Interfaces) lab, are developing
Porencephaly in an Italian neonate with foetal alcohol spectrum disorder: A case report
INTRODUCTION: Foetal alcohol spectrum disorder (FASD) is a complex malformative disease caused by the teratogenic effect of alcohol consumed during pregnancy. Mothers are frequently reluctant to admit alcohol consumption during pregnancy. During infancy and particularly during neonatal period, differential diagnosis is difficult. PATIENT CONCERNS: This case is represented by an Italian neonate boy small for gestational age, born by caesarean section at a gestational age of 37 weeks + 6 days by neglect and single-parent pregnancy. On physical examination, he presented particular facial features: microcephaly, epicanthal folds, flat midface, low nasal bridge, indistinct philtrum, and thin upper lip; moreover, examination revealed a macro-penis and recurvation without evidence of glans. DIAGNOSIS: Echocardiogram showed an inter-ventricular defect of medium-muscular type and brain magnetic resonance imaging showed asymmetry of the cerebral hemispheres with hypoplasia of the left cerebral hemisphere, dilatation of the left ventricle, cerebrospinal fluid cavity, and porencephaly. INTERVENTIONS: We investigated the ethylglucuronide (EtG) concentration in the neonate's hair by liquid chromatography-tandem mass spectrometry and we detected EtG in the infant's hair (normal value, 30 pg/mg), demonstrating prenatal alcohol exposure. OUTCOMES: In this neonate, EtG measure in hairs permitted the diagnosis of FASD, so allowing to exclude genetic diseases associated with similar clinical findings. After this result the mother admitted that she drunk alcohol during pregnancy (she declared 3 glasses of wine every day). At the age of 6 months, the child showed a moderate neurodevelopmental delay. CONCLUSION: This case shows that FAD should be considered in neonates with rare neurological diseases as porencephaly. In neonates and infants born to a mother who did not report alcohol use, EtG measure in hairs can significantly improve diagnosis of FASD, so allowing to exclude genetic diseases associated with similar clinical findings
Agregados al catálogo de las plantas naturalizadas y adventicias de la provincia de La Pampa, Argentina
In this contribution 23 species of naturalized and adventive plants, are cited for first time tor La Pampa. The synonymy, a short description, the distribution, and the dispersal forms are given. The iconography and a boucher are included. A Iist of 13 species who were cited for J. Williamson (1967) with the iconography and a voucher, is attached.En esta contribución se enumeran 23 especies que se citan por primera vez como plantas naturalizadas o adventicias, que viven en la Provincia de La Pampa. Se da sinonimia, una breve descripción, la distribución y la forma de dispersión. Se incluye además la iconografía y se cita un ejemplar de herbario. Se agrega un listado de 13 especies que fueron citadas por J. Williamson (1967) con su iconografía y un ejemplar de referencia
Comparación de los contenidos de oxalatos y nitratos en amaranto, acelga y espinaca
Comparación de los contenidos de oxalatos y nitratos en amaranto, acelga y espinac
Time-resolved spectroscopy of multi-excitonic decay in an InAs quantum dot
The multi-excitonic decay process in a single InAs quantum dot is studied
through high-resolution time-resolved spectroscopy. A cascaded emission
sequence involving three spectral lines is seen that is described well over a
wide range of pump powers by a simple model. The measured biexcitonic decay
rate is about 1.5 times the single-exciton decay rate. This ratio suggests the
presence of selection rules, as well as a significant effect of the Coulomb
interaction on the biexcitonic wavefunction.Comment: one typo fixe
Incidencia del fluor soluble en el rendimiento de materia seca en plántulas pertenecientes a seis cultivares de Amaranthus
During the months of november-december 1987, the produtive result of dry matter was observed in six cultivars of Amaranthus by means of using pots placed in greenhouse, adding the followiyg quantities of fluorine as of sodium fluorine: 8 mg kg ,12 mg Kg and 16 mg Kg. The yield result of dry matter, obtained 35 days after having been sown , proved that Amaranthus hypochondriacus L. type "Mercado" (Rodale 81S -1024) showed a highly superior result with the addition 12 mg Kg and 16 mg Kg of soluble fluorine. The rest of the cultivars did not present important differences.Se estudió el rendimiento de materia seca en seis cultivares de Amaranthus, mediante ensayo en macetas dispuestas en invernáculo, durante los meses de noviembre-diciembre de 1987, aplicándose las siguientes dosis de fluor como fluoruro de sodio: 8 mg Kg, 12 mg kg y 16 mg kg. Los rendimientos de materia seca obtenidos a los treinta y cinco días de la siembra mostraron que Amaranthus hypochondriacus L. tipo "Mercado" (Rodale 81S - 1024). Presentó un rendimiento significativamente superior con el agregado de 12 mg Kg y 16 mg Kg de fluor soluble. Los cultivares restantes no presentan diferencias significativas
Implementing anti-epidermal growth factor receptor (EGFR) therapy in metastatic colorectal cancer: challenges and future perspectives
Epidermal growth factor receptor (EGFR) inhibitors are valuable therapeutics in metastatic colorectal cancer (mCRC). Anti-EGFR monoclonal antibodies (MoAbs), such as cetuximab or panitumumab, in combination with chemotherapy are effective treatment options for patients with RAS and BRAF wild-type mCRC. Nevertheless, several issues are still open concerning the optimal use of anti-EGFR drugs in the continuum of care of mCRC. Novel approaches for increasing the efficacy of anti-EGFR therapies include better molecular selection of EGFR-dependent mCRC, intensification of chemotherapy, combination of anti-EGFR MoAbs and immune checkpoint inhibitors, and reintroduction of EGFR blockade or 'rechallenge' in selected patients who have previously responded to anti-EGFR MoAb therapy. An extensive translational research program was conducted in the Cetuximab After Progression in KRAS wIld-type colorectal cancer patients-Gruppo Oncologico dell' Italia Meridionale (CAPRI-GOIM) study with the aims of determining which subgroups of patients could benefit from the continuous inhibition of EGFR, from evaluating the role of liquid biopsy-based and its concordance with tissue-based molecular testing, and from investigating novel potential mechanisms of resistance to anti-EGFR therapies. In this review, we summarize the translational and clinical findings of the CAPRI-GOIM program in the context of the current knowledge of therapeutic strategies and of ongoing research on more appropriate uses of anti-EGFR therapies in RAS and BRAF wild-type mCRC patients
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