Haze factor of silver nanowires in variable refractive index environment: experimental and simulation approaches.

While silver nanowires (Ag NWs) have been demonstrated as a highly efficient transparent conducting material, they suffer from strong light scattering, which is quantified by a large haze factor (HF) in the optical spectrum. Here we investigate the influence of the dielectric environment on the light scattering of Ag NWs by comparing experimental measurements and simulations. In air, two peaks on the HF spectra are observed experimentally at the wavelength ofλI= 350 nm andλII= 380 nm and are attributed by simulations to the influence of the Ag NWs pentagonal shape on the localized surface plasmon resonance. The relative intensity between the two peaks is found to be dependent on whether the Ag NWs are in contact with the glass substrate or not. The HF behaviour in the near IR region seems to be dominated by Rayleigh scattering following simulations results. Dielectric environments of Ag NWs with various refractive indexes were obtained experimentally by the conformal deposition of different metal oxide coatings using atomic layer deposition, including Al-doped zinc oxide, Al2O3and SiO2coatings. The HF is found to be correlated with the refractive index environment in terms of HF peaks position, intensity and broadening. This trend of HF peaks is supported by a theoretical model to understand the optical mechanism behind this phenomenon.

[Medulloblastoma : management of a usually pediatric tumour in a young adult]. / Médulloblastome : prise en charge d'une tumeur habituellement pédiatrique chez un jeune adulte.

Medulloblastoma is a cerebellar grade IV tumour according to the WHO classification, mainly seen in children under the age of 15. This cancer can nevertheless occur in adults. We report the case of a 22-year-old patient with a medulloblastoma disseminated in the spine. The patient had a type 1 Arnold-Chiari malformation causing hydrocephalus treated by ventriculoperitoneal shunt. The current condition began with perineal and lower limb hypoesthesia, ataxic gait, erectile dysfunction and urinary incontinence. Subsequently, a predominant paraparesis of the right lower limb appeared. The patient was treated according to the PNET HR+5 protocol combining two courses of conventional chemotherapy followed by two courses of high-dose chemotherapy with autograft recovery. Given the excellent response, a proton therapy was then delivered to the whole cerebrospinal axis with boosts to the primary tumour sites. The case of this young adult patient shows on the one hand an atypical presentation, and on the other hand underlines, in the absence of a specific therapeutic strategy established for adults, the importance of collaboration between the adult and pediatric oncology departments, with management integrating innovations such as proton therapy and molecular typing.

Le médulloblastome est une tumeur cérébelleuse de grade IV selon l'Organisation Mondiale de la Santé, principalement observée chez les enfants de moins de 15 ans. Ce cancer peut néanmoins survenir chez l'adulte. Nous rapportons le cas d'un patient de 22 ans présentant un médulloblastome disséminé au niveau du rachis. Le patient est porteur d'une malformation d'Arnold-Chiari de type 1 provoquant une hydrocéphalie traitée par dérivation ventriculo-péritonéale. L'affection actuelle a débuté par une hypoesthésie du périnée et des membres inférieurs, une démarche ataxique, un trouble érectile et des troubles vésico-sphinctériens. Par la suite est apparue une paraparésie prédominant au membre inférieur droit. Le patient a été traité selon le protocole pédiatrique PNET HR+5 combinant deux cures de chimiothérapie conventionnelle suivies de deux cures de chimiothérapie à haute dose avec rattrapage par autogreffe. Vu l'excellente réponse, une protonthérapie a été administrée sur l'axe cérébrospinal avec surdosages sur les sites primaires de la tumeur. Le cas de ce jeune adulte illustre, d'une part, une présentation atypique et d'autre part, souligne, en l'absence de stratégie thérapeutique spécifique établie pour l'adulte, l'importance de la collaboration entre les services d'Oncologie adulte et pédiatrique, la prise en charge intégrant les innovations telles que la protonthérapie et le typage moléculaire.

Embedded System Prototype to Fight Covid-19 Pandemic Contamination with Less Cost.

In the shadow of the coronavirus (Covid-19) pandemic, the sterilization has become a major necessity for humans to avoid exponential Infection. In order to avoid touching contaminated surfaces, we develop an embedded system prototype, which allows the bottle or any other medium to pour the sterilization product without touching it. The human hands are detected using two sensors HC-SR04 and LM35. To overcome the stability problem due to the problem of sensor noise and enhance the system performance a Kalman filter algorithm is implemented to ensure stable hands detection. The efficiency of the prototype mounted on an Arduino board is checked. After the completion of the prototype, a comprehensive cost analysis is conducted.

EM modelling of arbitrary shaped anisotropic dielectric objects using an efficient 3D leapfrog scheme on unstructured meshes.

The standard Yee algorithm is widely used in computational electromagnetics because of its simplicity and divergence free nature. A generalization of the classical Yee scheme to 3D unstructured meshes is adopted, based on the use of a Delaunay primal mesh and its high quality Voronoi dual. This allows the problem of accuracy losses, which are normally associated with the use of the standard Yee scheme and a staircased representation of curved material interfaces, to be circumvented. The 3D dual mesh leapfrog-scheme which is presented has the ability to model both electric and magnetic anisotropic lossy materials. This approach enables the modelling of problems, of current practical interest, involving structured composites and metamaterials.

[Clinical case of the month. Portal venous gas due to a hydrogen peroxide colic enema]. / Le cas clinique du mois. Aéroportie due a un lavement a l'eau oxygénée.

Portal venous gas is a worrying radiological sign that was described for the first time in 1955 among newborn children suffering from necrotizing enterocolitis. It was often related to mesenteric ischemia which mortality remains very high. Now, as radiological explorations increase, portal venous gas is more and more described in less pejorative contexts, such as hydrogen peroxide intoxication. It is what happened to our patient who underwent a hydrogen peroxide colic enema followed by a major and transient portal venous gas onset. This solved quickly and spontaneously.

[From the creation to the appreciation of a personal digital assistant-based clinical decision-support system for the management of artificial nutrition]. / De la conception à l'évaluation d'un programme d'aide à la prescription en nutrition artificielle sous Palm OS.

OBJECTIVES: The aim of our study was to assess the effect of NutriPDA, a personal digital assistant (PDA)-based clinical decision-support system (CDSS) for the management of artificial nutrition. A CDSS was developed and implemented on a handheld computer for use in the ICU after cardiovascular and thoracic surgery. STUDY DESIGN: System impact was assessed in a prospective "before/after" cohort trial. METHODS: After informed consent we studied 61 patients in the postcardiovascular and thoracic surgery ICU (age > 17 years, duration of artificial nutrition > 3 days, length of stay > 8 days). Patients were divided into two groups (before and after the use of NutriPDA: Group A: 32 patients (4-month period in 2005); group B: 29 patients (4-month period in 2006). RESULTS: There were no significant differences in anthropometric and clinical parameters between the 2 groups. Energetic intakes were < 80% of basal energetic expenditures in 21% and 1% of patients, respectively (P < 0.01). Caloric and nitrogen intakes were below international recommendation in Group A: 20+/-4 kcal/kg/d (mean+/-SD), 104+/-30 mg/kg/d, but not in Group B: 26+/-5 kcal/kg/d, 196+/-41 mg/kg/d (P < 0.01). CONCLUSION: NutriPDA was found to be able to optimize artificial nutrition by improving caloric intake in ICU. This new software has potential clinical applications.

Respiratory variations in pulse oximeter waveform amplitude are influenced by venous return in mechanically ventilated patients under general anaesthesia.

BACKGROUND AND OBJECTIVES: Respiratory variations in pulse oximetry plethysmographic waveform amplitude (DeltaPOP) are related to respiratory variations in arterial pulse pressure (DeltaPP) in the critical care setting. The aims of this study were to test the hypothesis that in mechanically ventilated patients undergoing general anaesthesia, DeltaPOP calculation is feasible and can detect changes in preload. METHODS: Twenty-five mechanically ventilated patients were studied immediately after induction of general anaesthesia. Haemodynamic data (mean arterial pressure [MAP], central venous pressure [CVP], DeltaPP and DeltaPOP) were recorded at baseline, before and after tilting the patient from anti-Trendelenburg to Trendelenburg position in order to induce preload changes. RESULTS: Change from anti-Trendelenburg to Trendelenburg position induced changes in MAP (58 +/- 9 to 67 +/- 10 mmHg, P < 0.05), CVP (4 +/- 4 to 13 +/- 5 mmHg, P < 0.05), DeltaPP (14 +/- 8 to 7 +/- 5%, P < 0.05) and DeltaPOP (17 +/- 12 to 9 +/- 5%, P < 0.05). There was a significant relationship between DeltaPOP in anti-Trendelenburg position and percent change in MAP after volume expansion (r = 0.82; P < 0.05). CONCLUSIONS: DeltaPOP can be determined in the operating room and is influenced by changes in preload. This new index has potential clinical applications for the prediction of fluid responsiveness.

Delayed rupture of traumatic aneurysm after civilian craniocerebral gunshot injury in children.

BACKGROUND: There are few published large series on civilian craniocerebral gunshot injuries in children. Traumatic intracranial aneurysms (TICAs) are rare and highly unstable lesions. They represent less than 1% of all aneurysms and can either rupture within minutes after formation or remain quiescent for several weeks or years, manifesting with delayed hemorrhage and neurologic deterioration. CASE HISTORY: We report the case of a 10-year-old girl who was referred for coma after high-velocity craniocerebral gunshot wound and neurological deterioration 7 days after the initial injury. A massive right posterior occipital hematoma caused by the rupture of an unsuspected right posterior cerebral artery TICA was discovered. TICA was treated by coil embolization, with a good neurological recovery at 6-month follow-up. DISCUSSION: We discuss the pathogenesis and the management of TICA in a child after civilian craniocerebral gunshot injuries. CONCLUSIONS: TICAs should be suspected in patients with civilian craniocerebral gunshot injuries, presenting with secondary neurological deterioration, to carry out emergent CT scan and angiographic exploration before contemplating definitive endovascular treatment. Endovascular management may be a prompt safe-to-use technique and a valuable option, especially when surgery is highly risky.

[Impact of the guidelines on clinical practice of artificial nutrition in intensive care unit after cardiovascular and thoracic surgery]. / Impact d'un protocole de nutrition artificielle en réanimation après chirurgie cardiovasculaire et thoracique.

OBJECTIVE: To analyze the impact of an artificial nutrition program in post-anaesthesia intensive care unit. STUDY DESIGN: Observational study. PATIENTS AND METHODS: Patients with length of stay greater than 8 days after cardiovascular and thoracic surgery: Group 1: 34 patients (4-month period in 2000); group 2: 15 patients (2-month period in 2001); group 3: 40 patients (4-month period in 2003). Between these 3 periods, informations of physicians and written protocol in order to improve their nutritional knowledge. After analysis of variance (P<0.05). Newman-Keuls tests to compare themselves each groups. RESULTS: Anthropometric, demographic and clinical parameters were similar in the 3 groups. Energic intakes were less than 80% of basal energetic expenditures in 33%, 33 and 22% of patient, respectively (NS). Caloric and nitrogen intakes were less than recommended, respectively 19+/-6 (mean+/-SD), 21+/-7 and 21+/-8 kcal/kg/24 h and 102+/-32, 111+/-31 and 92+/-40 mg/kg/24 h (NS). However enteral nutrition was administered in 49, 40 and 100% of patients respectively (P<0.001). The glucid/lipid ratio improved from 0.47 in group 1 up to 0.68 in group 3 (P<0.0001). Vitamins, oligoelements and clinical and biological monitoring of artificial nutrition improved (P<0.001). CONCLUSION: A clinical audit demonstrated an improvement in artificial nutrition parameters but no significant change in others.

Transient displacement induced in shear wave elastography: comparison between analytical results and ultrasound measurements.

It is now accepted that an effective way to investigate the elastic properties of soft tissues is to generate a localized transient acoustic radiation force and to follow the associated displacements in the time/space domain. Shear waves induced by this stress field are particularly interesting in this kind of medium because they are governed by the shear elastic modulus mu, which is directly linked to the Young modulus, and spatial distribution and temporal evolution of the transient motion induced must therefore be obtained in detail. We report here a model based on the elastodynamic Green's function formalism to describe these displacements. 3D simulation of radiation force in homogenous elastic media was performed and the displacement curves computed at different radial distances for different temporal force profiles. Amplitude and duration of displacement were found to be reliable parameters to characterize the elastic properties of the medium. Experimental measurements were performed in a homogeneous agar-gelatin tissue-mimicking phantom, and two transducers were used to generate the radiation force and follow the induced displacements. Displacements obtained from different lateral locations around the applied force axis were then used to reconstruct the shear-wave propagation in a scan plane as a function of time. The experimental displacements/curves agreed with the theoretical profiles obtained by the elastodynamic Green's function formalism.

[Experiences with the Shirodkar-McDonald cerclage in the treatment of cervix insufficiency]. / Erfahrungen mit der Cerclage nach Shirodkar-McDonald zur Behandlung der Zervixinsuffizienz.

A clinical-statistical study of 1040 pregnancies after cerclage between 1965 and 1982. Over the same period 28,033 births were registered. Frequency of cerclage was 3.7%. Of 1682 pregnancies in the same patients without cerclage, 47.3% of the children survived, while of the 1040 pregnancies with cerclage, 92% of the children survived. The rate of abortion sank from 44% to 5.8%, the frequency of premature birth from 17.6% to 13.1%. The mothers' course of pregnancy, delivery and puerperium were normal. The relative frequency of Caesarean sections and vacuum extractions was slightly lower than that of the whole group. An attempt is made to ascribe the high success rate of 92% to the following facts: that in 75.4% of the cases, these were prophylactic cerclages; that in all cases the bladder was displaced; that, on the day of surgery, nearly all patients received a tocolytic slow drip infusion as prophylaxis; and that the low mortality rate (10.5%) among premature infants is due to excellent collaboration with the intensive care ward for premature infants in the same hospital. As regards indication, surgical techniques, antenatal counselling and management of delivery, the homogeneity of the group observed over this 17-year period is presumably another positive factor.