Extra-long and taper-free germanium nanowires: use of an alternative Ge precursor for longer nanostructures.

One of the challenges in the development of germanium nanowires (Ge NWs) is to increase their length beyond the 10 µm limit without enlarging the NW diameter, i.e. minimizing the tapering. Here we report how it is possible to overcome this hurdle by using isobutyl germane (iBuGe) as a metal organic precursor during MOCVD growth, instead of the commonly used germane. We have grown and characterized by transmission electron microscopy, scanning electron microscopy and Raman various samples and we have analyzed the effect of growth time, precursor flux and growth temperature on the NW length. The use of iBuGe coupled to optimized growth conditions permitted to obtain Ge NWs with lengths up to 30 µm with minimal tapering. To explain why a new precursor has this impact on the morphology of the NWs we consider two possible causes: (i) the role of carbon radicals produced by isobutyl decomposition and (ii) the reduced growth rate of Ge on the sidewalls. On the basis of Raman characterization and temperature-dependence of tapering, we conclude that the reduced tapering is probably due to lower growth rates on the sidewalls.

The Jacopo Tintoretto "Wedding Feast at Cana": A non-invasive and multi-technique analytical approach for studying painting materials.

This paper presents the results of a fully non-invasive photographic and spectroscopic study on a masterpiece by the famous Venetian painter Jacopo Tintoretto (1518-1594): "The Wedding feast at Cana" (1561), located inside the sacristy of the Santa Maria della Salute Basilica in Venice. A restoration campaign was carried out on the painting between 2016 and 2017. Various techniques were chosen to characterize in detail the materials used by the painter, especially pigments: Near Infrared Reflectography (NIR) to identify preparatory sketch and also allowing formulating hypothesis on some pigments; Raman and Fiber Optics Reflectance Spectroscopy (FORS) applied directly to the surface of the object, avoiding sample collection, to identify the pigments palette applied by Tintoretto. Information about binders was also obtained in a totally non-invasive way by using NIR spectroscopy. All analysis points were precisely (±2 mm) registered on a painting virtual map in order to recover them in a future possible conservation project.

[Diagnosis of thoracic outlet syndrome. Value of angiography in the sitting position]. / Diagnostic des syndromes du défilé cervico-thoraco-brachial: apport de l'artériographie réalisée en position assise.

PURPOSE: Thoracic outlet syndrome includes arterial, venous or neurological symptoms. Frequently difficult to diagnose clinically, confirmatory imaging studies are usually required. The purpose of this study is to review the diagnostic work-up during management of patients with thoracic outlet syndrome and demonstrate the value of angiography in the sitting position. MATERIALS AND METHODS: Retrospective study of 81 surgical procedures for thoracic outlet syndrome, between 1997 and 2005, in 56 patients aged 17-57 years. Surgery was bilateral in 26 cases, with bilateral surgery in a single setting for 1 patient. All patients presented clinical symptoms confirmed on US, angiography, venogram or EMG. Angiography, from a transfemoral approach, was initially performed in the supine position, without and with dynamic maneuver, and in the sitting position with dynamic maneuver when needed. RESULTS: In 48 patients, supine rest angiography showed stenosis in 6% of cases and supine dynamic angiography showed stenosis in 81% of cases, with severe stenosis in only 35% of cases (stenosis>80% or arterial occlusion). Angiography in the sitting position was performed in 33 patients, showing worsening of stenosis in 91% of cases, with severe stenosis in 87%. CONCLUSION: Angiography in the sitting position with dynamic maneuver improves the sensitivity for detection of thoraci coutlet syndrome. This procedure may be considered in addition to other imaging modalities routinely used including Doppler US, CT and MRI.

[Echographic aspects of collections of fluid in the gallbladder space following cholecystectomy. Apropos of 11 cases]. / Aspect échographique des collections liquidiennes de la loge vésiculaire après cholécystectomie. A propos de 11 observations.

Fifty seven patients (51 women and 6 men) undergoing cholecystectomy had ultra-sound evaluation on the 3rd, 5th, 7th and 9th post-operative days. In all the cases, the right upper quadrant has been observed correctly with a phased array 3.5 MHg transducer. Eleven of the fifty seven patients (19%) were found to have fluid collection in the gallbladder fossa. The collection has a rounded or an oval configuration, in the proportion of 11 and 55 mm, surrounded by an echogenic area. These fluid collections were of no clinical and biological significance and disappeared in 2 or 4 days time. The authors discuss the relationship between the presence of fluid and the use of drains or different surgical techniques.

[Rectal localisation of carcinoid tumour by radiography (author's transl)]. / Tumeur carcinoïde de localisation rectale de découverte radiologique.

Carcinoid tumors of the rectum are rare and their radiologic visualization is exceptional. In the series we report about an incidental finding during double contrast enema which takes the form of an expanding tumor developing inside the intestinal lumen and showing no signs of malignity. Standard investigation in the follow up of rectal carcinoid tumors showed no hepatic mestastisis, no other foci in the digestive tract and no biologic anomalies. The patient did not complain of carcinoid syndrome. Double contrast enema is the only process enabling the discovery of rectal masses so small with non negligible frequency (2% of our explorations). Whatever the radiologic aspect and localization, fibroscopic and histologic examinations are necessary in order to make an accurate diagnosis of their nature.

[Aneurysm of the pancreaticoduodenal arteries and stenosis of the celiac trunk. Apropos of a case]. / Anévrisme de l'arcade pancréatico-duodénale et sténose du tronc coelique. A propos d'une observation.

The authors describe the different imaging techniques and their interest. They discuss their etiology. The association with stenosis of the coeliac axis incites to think at a hemodynamic theory.

[Ileal carcinoid tumors. Value of small intestine transit]. / Tumeurs carcinoïdes de l'lléon. Intérêt du transit de l'intestin grêle.

The authors describe two personnel observations of ileal carcinoid tumors, demonstrated by double contrast small bowel examination. Confirmation came from operation and histology. Small bowel examination can demonstrate limited carcinoid tumors giving no angiographic traduction.

[Post-traumatic osteolysis of the distal end of the clavicle]. / Ostéolyse post-traumatique de l'extrémité distale de la clavicule.

Osteolysis of the distal clavicular shaft is an uncommon sequel to trauma. The clinical and radiological aspects are described. The pathogenesis and the early manifestations of osteolysis are discussed.

[Inferior vena cava injury. X-ray computed tomographic and angiographic aspect]. / Traumatisme de la veine cave inférieure. Aspect tomodensitométrique et angiographique.

We report one case of traumatic rupture of the inferior vena cava. CT was performed during the acute phase and showed retroperitoneal hematoma near the inferior vena cava with extravasation of contrast agent. After stabilization angiography showed pseudo-aneurysmal picture of inferior vena cava.

[Kahler's disease of the stomach. A case report]. / Maladie de Kahler à localisation gastrique. A propos d'une observation.

The authors report a case of a gastric involvement by a multiple myeloma, suspected on ultrasonography although the gastric endoscopy was normal. The barium examination and the CT scan agreed with the ultrasound hypothesis confirmed by histology.

[Intramedullary metastases and syringomyelic cavities]. / Métastases médullaires et cavités syringomyéliques.

Intramedullary metastases from a non neurogenic cancer are relatively rare, representing approximately 1-2,1% of metastatic sites according to published autopsy reports. Their association with syrinx is extremely rare. Four cases have been described in the last 30 years. We report the case of a 60 year old female with past medical history of Peutz-Jeghers disease, who presented with clinical signs suggestive of medullary lesions of the cervical spine. MR imaging showed tumoral lesions at different levels associated with syrinx. Surgical biopsy confirmed the intramedullary lesions which, by pathology, were found to be of metastatic origin.

[Acute intestinal invagination. Ultrasonic aspects]. / Invagination intestinale aiguë. Aspect échotomographique.

The sonographic pattern of an intussusception in a 21 months old child is reported. The value and the meaning of this pattern is discussed according clinical and anatomical presentation of intussusception.

[Nodular lymphoid hyperplasia. Diffuse form extending from the duodenal bulb to the rectum, associated with agammaglobulinemia]. / Hyperplasie lymphoïde nodulaire. Forme diffuse étendue du bulbe duodénal au rectum, associée à une agammaglobulinémie.

The authors study a case of nodular lymphoid hyperplasia, extending from the duodenal bulb to the rectum, associated to an agammaglobulinemia; they observe the variations of the roentgenology appearance and the distribution of the elementary pictures; they discuss the meaning of the disease, the association or the evolution to a lymphoid carcinoma.

[Pseudo-aneurysm of the internal carotid artery]. / Pseudo-anévrysme de la carotide interne.

The authors recall the anatomy of the deep neck spaces and report the case of a 3-year-old girl with a parapharyngeal abscess followed by a pseudo-aneurism of the carotide artery. Ultrasonography, CT scan and angiography findings are described. This case puts in mind of the seriousness of neck abscesses. Each specific anatomical location must be definite for a better therapeutic approach on account of hemorrhagic risks of parapharyngeal abscesses.

[Acute immune epiduritis in a child]. / Epidurite aiguë d'origine immunologique chez un enfant.

Acute epiduritis is an uncommon disease especially in children. We report an unusual case of acute epiduritis in a child, revealed by characteristic clinical signs and Magnetic Resonance Imaging (MRI). Given the absence of identified infectious or tumoral cause, and the ineffectiveness of antimicrobial treatment, a therapeutic test with polyvalent immunoglobulins was implemented. Rapid clinical improvement led to the retrospective diagnosis of probable immunological acute epiduritis.

Raman and micro-thermometric investigation of the fluid inclusions in quartz in a gold-rich formation from Lepaguare mining district (Honduras, Central America).

Fluid inclusions in the quartz crystals present in gold-rich veins from central Honduras have been studied by means of micro-thermometry and micro-Raman spectroscopy in order to provide information on the physico-chemical conditions and chemical composition of the mineralizing fluids. The use of a confocal micro-Raman apparatus allowed to obtain information on the fluid composition, in particular on the gas phase, minimizing the contributions of the host matrix to the Raman signal. The samples studied were collected from an area (Lepaguare mining district, Northern-Central Honduras) rich in ore deposits due to the Cenozoic magmatic activity, where the gold and sulphide mineralization is connected with a system of quartz veins (few decimetres thick) occurring in low-grade metamorphic rocks and produced by hydrothermal fluids. The quartz crystals present in the gold-rich veins often contain fluid inclusions. Four types of fluid inclusions have been observed, but their assemblage in the same clusters and fracture systems, as well as their comparable salinity and homogenization data, suggest that they have the same origin. Micro-thermometry and Raman spectroscopy provide a composition of the mineralizing fluids attributable to the system H(2)O-NaCl-KCl-CO(2)-CH(4), with temperature and pressure intervals of 210-413 degrees C and 1050-3850 bar, respectively. These data agree with an epigenetic origin of the gold deposit (depth < 6 km) related to granitoid or granodiorite intrusions associated to orogenic environments.

Spectroscopic study of the degradation products in the holy water fonts in Santa Maria della Steccata Church in Parma (Italy).

Two holy water fonts (dated at the beginning of the XVII century) in the Santa Maria della Steccata Church in Parma (Italy) have recently been restored. Before the intervention, a detailed investigation on their degradation products was carried out to understand the mechanisms of alteration of the materials and to suggest appropriate restoration procedures. The analyses were performed by means of powder X-ray diffraction (XRD), micro-Fourier transform infrared (FTIR) and micro-Raman spectroscopies. Calcite, iron oxides, silicates and sodium chloride (from salted holy water) were found in the red coloured calcarenite. On and under the lead coverings, different lead oxides (mainly massicot), other lead salts (lead basic carbonate, cerussite, plumbonacrite Pb10O(OH)6(CO3)6 and lead-chlorine compounds as laurionite PbOHCl and phosgenite Pb2CO3Cl2) were identified by Raman spectroscopy and XRD. Haematite alpha-Fe2O3, goethite alpha-FeO(OH) and lepidocrocite gamma-FeO(OH) were found on and around the iron hinges. Lead compounds and sodium chloride, through crystallization and solubilization cycles, were responsible for the stone's degradation, whereas the iron corrosion materials on the hinges produced mechanical stress and cracks in the stone. Various suggestions have been given on how to restore these fonts and to remove the causes of damage.