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Proton-induced straining of two-dimensional crystals
No full textTransition-metal dichalcogenides are an emergent class of semiconducting materials with extraordinary opto-electronic properties when reduced to few layers. In the monolayer limit, they emit light efficiently in the visible/infrared region and their flexibility and robustness allow to exploit mechanical deformations to
change their inherent properties. Here, we discuss the effect of proton irradiation of bulk WS2, WSe2, WTe2, MoS2, MoSe2 and MoTe2 crystals with low-energy beams.
Protons penetrate through the crystal top layer and molecular hydrogen forms. The trapped gas coalesces to create micro-/nano-domes, leading to the blistering of onelayer-thick domes filled with highly pressurised hydrogen, that locally turns the dark bulk material into an efficient light emitter. These domes are robust and stable, and host strong, non-trivial strain fields that cause unprecedented major changes in the band structure of the material
Field-effect–induced superconductivity in surfaces of tetrahedrally coordinated semiconductors: The case of (111) hydrogenated silicon
No full textWe show the possibility of inducing a superconductive phase transition in tetrahedrally coordinated semiconductors via field-effect (FET) doping by taking as an example the hydrogenated (111) silicon surface. We perform density functional theory computations of the electronic and vibrational properties of the system in the proper FET geometry, by taking into account the applied electric field and the induced charge density. Using a simplified superconductive model at q = Γ and the McMillan/Allen-Dynes formula, we get an estimate of the superconductive critical temperature. We observe that, by heavily doping with holes at ndop = 6·1014 cm−2, we get an electron-phonon coupling constant of λSi = 0.98 and a superconductive phase transition at Tc ∈ [8.94; 10.91] K, with μ∗ ∈ [0.08; 0.12]
Nuclear reaction modeling of 52gMn production for multimodal imaging
No full textThe present work is a theoretical investigation of nuclear reactions for the production of 52gMn that, with 51Mn and 52mMn, is the only radionuclide that can be used for MultiModal Imaging PET-MRI. A comparison of different reactions is presented considering the reaction natV(α,x)52gMn and the standard production routes with chromium targets. To optimize the production of the radionuclide of interest, an analysis of the cross sections is performed using three nuclear reaction codes (Talys, Fluka and Empire) to select the energy window corresponding to the maximum production of 52gMn and minimum of its contaminants. Numerical computations of the production rate and the time evolution of the produced nuclides are performed, leading to the calculation of the integral yield and of the isotopic and radionuclidic purities for each reaction. The result is that the reaction with natV is very promising and competitive with the investigated standard production routes. Indeed, this reaction shows a radionuclidic purity high enough for clinical applications and an integral yield value even higher than that of the reaction with natural chromium target
Recensioni: Intelligenza artificiale e diritto. Perché le tecnologie di IA sono una grande opportunità per il diritto
Get PDFLa collana "Scienza e Filosofia", diretta da Armando Massarenti, si arricchisce di un nuovo titolo con la pubblicazione di un volume, che affronta un tema di particolare rilevanza e attualità, quello del rapporto fra l'intelligenza artificiale e il diritto
Fusobacterium Nucleatum Empyema: An Atypical Presentation
Get PDFA 40-year-old man presented to the emergency room and was evaluated in the internal medicine department for unexplained weight loss, asthenia, anorexia and night sweats over the previous 2 months. After a loculated pleural effusion was identified on thoracic computed tomography, purulent fluid was drained from the lung and Fusobacterium nucleatum was isolated. The patient was successfully treated for 27 days with amoxicillin-clavulanic acid. This was an atypical presentation of a common micro-organism implicated in lung infections
Abdominal Pain Relieved By A Warm Hot Water Bottle: An Atypical Presentation Of Eosinophilic Gastroenteritis
Get PDFA 26-year-old woman presented with a 3-month history of worsening episodic abdominal pain, which was associated with frequent passage of watery stools, nausea and dyspepsia. Her peripheral eosinophil count was markedly elevated. This responded well to a reducing regimen of corticosteroids. Her symptoms completely resolved with a corresponding fall in eosinophil count. The patient was diagnosed with eosinophilic gastroenteritis. We have not considered steroid-sparing agents at this point, but should she have future exacerbations then this will be considered
Primary Aortoesophageal Fistula: Is a High Level of Suspicion Enough?
Get PDFAortoenteric fistula (AEF) is a rare condition with a high mortality rate. AEFs are classified according to their primary and secondary causes, the former being less frequent. Primary AEFs occur in a native aorta and their causes include aneurysms, foreign bodies, tumours, radiotherapy and infection. The classic triad of aortoesophageal fistulas, a subtype of AEFs, are mid-thoracic pain and sentinel haemorrhage, followed by massive bleeding after a symptom-free interval.We present the case of a 41-year-old male patient who presented in the emergency room after successive episodes of abundant haematemesis. He was hypovolemic, hypothermic and acidotic at presentation. His medical history included an emergency room visit the week before with chest pain but no relevant anomalies on work-up, active intravenous drug use and chronic hepatitis.Esophagogastroduodenoscopy (EGD) showed a bulging ulcerated lesion suspicious for aortoesophageal fistula, confirmed by computed tomography (CT) angiography, which revealed a saccular aortic aneurysm with a bleeding aortoesophageal fistula. The patient underwent urgent thoracic endovascular aortic repair.The sentinel chest pain, leucocytosis and CT findings hinted at the presence of a mycotic aneurysm, despite the negative blood cultures. It was most likely caused by a septic embolus due to the patient’s risk factors. While a high level of suspicion for aortoesophageal fistula is needed to prompt a fast diagnosis, EGD and CT findings were crucial to establish it and allow a life-saving intervention. We conclude that chest pain cannot be disregarded in a patient aged 41 years with multiple comorbidities, despite normal work-up, to prevent a fatal outcome
Intermittent Pacemaker Malfunction Caused by Continuous Compression of the Lead by the Clavicle (Subclavian Crush Syndrome)
Get PDFSubclavian vein access is still one of the most favoured access options for cardiac implantable electronic device (CIED) implantation. For the physician, the technique is reasonably familiar and easy to carry out. However, this has several potential complications. In this case, we present a late complication of subclavian access. The patient presented with intermittent loss of pacemaker output, which caused him to experience several syncopal events. In the acute setting, we changed the lead polarity and achieved a good outcome. Further management of this situation consisted of removal and replacement of the damaged lead
When the Treatment is the Cause: Disseminated Bacille Calmette–Guérin Infection
Get PDFBacille Calmette–Guérin (BCG) administration for superficial bladder cancer is a well-tolerated and very effective therapy. However, unpredictable systemic complications may occur on rare occasions. We present the case of a patient who attended for consultation because of fever, asthenia and weight loss following BCG immunotherapy. The clinical response to treatment and computed tomography scanning were key to diagnosis
A Fatal Case of Ciprofloxacin-induced Fulminant Hepatitis
Get PDFFatal hepatotoxicity associated with ciprofloxacin is extremely rare. This is the second fully investigated case of fulminant hepatotoxicity due to ciprofloxacin in a male patient previously ciprofloxacin tolerant. The patient’s medical history included stable Waldenstrom’s macroglobulinaemia, inguinal hernia repair, prostate cancer (radiotherapy in 2006) and idiopathic Parkinson’s disease. Extensive investigation for progressive liver failure confirmed drug-induced liver injury