Outcome of alimentary tract duplications operated on by minimally invasive surgery: a retrospective multicenter study by the GECI (Groupe d'Etude en Coeliochirurgie Infantile).

BACKGROUND: Alimentary tract duplications (ATD) are a rare cause of intestinal obstruction in childhood. There are many case reports but few series about laparoscopy or thoracoscopy for ATD. The aim of our study was to report the outcome of minimally invasive surgery (MIS) for ATD. METHODS: This was a retrospective multicenter study from the GECI (Groupe d\u27Etude en Coeliochirurgie Infantile). We reviewed the charts of 114 patients operated on by MIS for ATD from 1994 to 2009. RESULTS: Sixty-two patients (54 %) had a prenatal diagnosis. Forty-nine patients (43 %) were symptomatic before surgery: 33 of those patients (63 %) with postnatal diagnosis compared to 16 (25 %) with prenatal diagnosis (P < 0.01). In this last group, the median age at onset of symptoms was 16 days (range = 0-972). One hundred and two patients had laparoscopy (esophageal to rectal duplications) and 12 patients had thoracoscopy for esophageal duplications. The mean operative time was 90 min (range = 82-98). There were 32 (28 %) resection anastomoses, 55 (48 %) enucleations, and 27 (24 %) unroofings. The conversion rate was 32 %, and in a multivariate analysis, it was significantly higher, up to 41 % for patients weighing <10 kg (P < 0.01). Ten patients (8 %) had unintentional perioperative opening of the digestive tract during the dissection. Eight patients had nine postoperative complications, including six small bowel obstructions. The median length of hospital stay was 4 days (range = 1-21) without conversion and 6 days (range = 1-27) with conversion (P = 0.01). The median follow-up was 3 months (range = 1-120). Eighteen of the 27 patients who underwent partial surgery had an ultrasound examination during follow-up. Five (18 %) of them had macroscopic residue. CONCLUSION: This study showed that MIS for ATD is feasible with a low rate of complications. Patients with prenatal diagnosis should have prompt surgery to prevent symptoms, despite a high rate of conversion in small infants

In vitro phosphorylation as tool for modification of silk and keratin fibrous materials

An overview is given of the recent work on in vitro enzymatic phosphorylation of silk fibroin and human hair keratin. Opposing to many chemical "conventional" approaches, enzymatic phosphorylation is in fact a mild reaction and the treatment falls within "green chemistry" approach. Silk and keratin are not phosphorylated in vivo, but in vitro. This enzyme-driven modification is a major technological breakthrough. Harsh chemical chemicals are avoided, and mild conditions make enzymatic phosphorylation a real "green chemistry" approach. The current communication presents a novel approach stating that enzyme phosphorylation may be used as a tool to modify the surface charge of biocompatible materials such as keratin and silk

Antimicrobial lubricant formulations containing poly(hydroxybenzene)-trimethoprim conjugates synthesized by tyrosinase

Poly(hydroxybenzene)-trimethoprim conjugates were prepared using methylparaben as substrate of the oxida- tive enzyme tyrosinase. MALDI-TOF MS analysis showed that the enzymatic oxidation of methylparaben alone leads to the poly(hydroxybenzene) formation. In the presence of tri- methoprim, the methylparaben tyrosinase oxidation leads poly(hydroxybenzene)-trimethoprim conjugates. All of these compounds were incorporated into lubricant hydroxyethyl cellulose/glycerol mixtures. Poly(hydroxybenzene)-trimetho- prim conjugates were the most effective phenolic structures against the bacterial growth reducing by 96 and 97 % of Escherichia coli and Staphylococcus epidermidis suspen- sions, respectively (after 24 h). A novel enzymatic strategy to produce antimicrobial poly(hydroxybenzene)-antibiotic conjugates is proposed here for a wide range of applications on the biomedical field.The authors Idalina Gonçalves and Cláudia Botelho would like to acknowledge the NOVO project (FP7-HEALTH- 2011.2.3.1- 5) for funding. Loïc Hilliou acknowledges the financial support by FCT – Foundation for Science and Technology, Portugal (501100001871), through Grant PEst-C/CTM/LA0025/2013 - Strategic Project - LA 25 - 2013–2014, and by Programa Operacional Regional do Norte (ON.2) through the project BMatepro – Optimizing Materials and Processes^, with reference NORTE-07-0124-FEDER-000037 FEDER COMPETE

Precise measurement of the differential cross section from the 16O (α,α) 16O elastic reaction at 165° and 170° between 2.4 and 6.0 MeV

Non-Rutherford cross section for elastic scattering of α particles from oxygen has been measured for energies between 2.4 and 6.0 MeV at commonly used backscattering angles of 165° and 170°. High precision in energy has been obtained with a 2 MV Tandetron accelerator, with precise and stable energy calibration. The choice of a thin Ta2 O5 TaC standard increased the sensitivity and reduced systematic errors due to the geometry. Precise data for energy, width, and ratio to Rutherford of the resonances have been extracted from nuclear shell models, and excitation levels of Ne20 have been deduced. The well-known resonance ER =3031.7±0.5 keV and the narrow and intense resonance ER =5375.5±0.5 keV, not included in cross-section libraries, have been applied for surface oxygen analysis in thin WCNSi O2 Si multilayer samples, with improved depth resolution by optimizing the measuring geometry. © 2006 American Institute of Physics

Depth-profiling of implanted 28Si by (α,α) and (α,p0) reactions

Silicon nanocrystals enclosed in thin films (Si quantum dots or Si QDs) are regarded to be the cornerstone of future developments in new memory, photovoltaic and optoelectronic products. One way to synthesize these Si QDs is ion implantation in SiO2 layers followed by thermal annealing post-treatment. Depth-profiling of these implanted Si ions can be performed by reactions induced by α-particles on 28Si. Indeed, for high incident energy, nuclear levels of 32S and 31P can be reached, and cross-sections for (α,α) and (α,p0) reactions are more intense. This can help to increase the signal for surface silicon, and therefore make distinguishing more easy between implanted Si and Si coming from the SiO2, even for low fluences. In this work, (α,α) and (α,p0) reactions are applied to study depth distributions of 70 keV 28Si+ ions implanted in 200 nm SiO2 layers with fluences of 1 × 1017 and 2 × 1017 cm-2. Analysis is performed above ER = 3864 keV to take advantage of resonances in both (α,α) and (α,p0) cross-sections. We show how (α,p0) reactions can complement results provided by resonant backscattering measurements in this complex case. © 2010 Elsevier B.V. All rights reserved

Depth-profiling of implanted 28Si by (α,α) and (α,p0) reactions

Silicon nanocrystals enclosed in thin films (Si quantum dots or Si QDs) are regarded to be the cornerstone of future developments in new memory, photovoltaic and optoelectronic products. One way to synthesize these Si QDs is ion implantation in SiO2 layers followed by thermal annealing post-treatment. Depth-profiling of these implanted Si ions can be performed by reactions induced by α-particles on 28Si. Indeed, for high incident energy, nuclear levels of 32S and 31P can be reached, and cross-sections for (α,α) and (α,p0) reactions are more intense. This can help to increase the signal for surface silicon, and therefore make distinguishing more easy between implanted Si and Si coming from the SiO2, even for low fluences. In this work, (α,α) and (α,p0) reactions are applied to study depth distributions of 70 keV 28Si+ ions implanted in 200 nm SiO2 layers with fluences of 1 × 1017 and 2 × 1017 cm-2. Analysis is performed above ER = 3864 keV to take advantage of resonances in both (α,α) and (α,p0) cross-sections. We show how (α,p0) reactions can complement results provided by resonant backscattering measurements in this complex case. © 2010 Elsevier B.V. All rights reserved

Ionoluminescence induced by low-energy proton excitation of Si nanocrystals embedded in silica

Silicon nanocrystals (Si-nc) can be synthesized into a silica matrix by ion implantation of silicon excess, followed by thermal annealing in N 2 or Ar atmosphere. In this work, ionoluminescence (IL) measurements have been performed on fused silica samples containing Si-nc using a 18 keV proton beam for the IL excitation. This low energy irradiation has allowed us to reduce the IL probing range to the first 300 nm of the studied materials, thus enhancing the contribution to the IL signal of the sample region where the Si-nc are located. A transmission optical detection set-up has been developed to ensure the collection of a strong IL signal. Comparison of the data recorded between 300 and 800 nm shows that the IL intensity decreases for long excitation times in Si-nc samples, whereas the IL signal intensity remains remarkably stable in pure SiO 2 sample. The variations observed for samples with Si-nc are attributed to the damaging effects induced by the impinging protons. The sample annealed under N 2 exhibits a stronger IL emission than the sample annealed under Ar, where both the concentration of residual defects and the excitation efficiency of the radiative centers could be lower. The results make the IL measurements a promising tool for in situ monitoring of ion implantation with pure fused silica samples, as well as a promising technique for novel characterizations of Si-nc embedded within SiO 2. © 2011 Elsevier B.V. All rights reserved

Ionodeterioration of the silicon nanocrystal photoluminescence

The photoluminescence (PL) of Si nanocrystals (Si-nc) embedded in fused silica has been investigated under simultaneous excitations by laser and low energy proton beam. Ionodegradation of the sample, characterized by a rapid decrease and a spectral blueshift of the PL emission has been observed. These effects are associated with the creation of non-radiative centers in the Si-nc. Micro-Raman spectroscopy analysis shows that the proton beam has not changed the average size of Si-nc, but has disturbed a fraction of Si-Si bonds inside the Si-nc, which is consistent with both simulations and direct measurements. A post-annealing performed at 400 C for 1 h can restore the structural properties of the Si-nc, but only a part of their nominal PL emission intensity is recovered. Characterization of the damage induced by low energy proton irradiation reported in this paper makes the use of light ion beams relevant for the experimental investigation of nanostructured systems, such as ionoluminescence measurements. © 2011 American Institute of Physics

Ionodeterioration of the silicon nanocrystal photoluminescence

The photoluminescence (PL) of Si nanocrystals (Si-nc) embedded in fused silica has been investigated under simultaneous excitations by laser and low energy proton beam. Ionodegradation of the sample, characterized by a rapid decrease and a spectral blueshift of the PL emission has been observed. These effects are associated with the creation of non-radiative centers in the Si-nc. Micro-Raman spectroscopy analysis shows that the proton beam has not changed the average size of Si-nc, but has disturbed a fraction of Si-Si bonds inside the Si-nc, which is consistent with both simulations and direct measurements. A post-annealing performed at 400 C for 1 h can restore the structural properties of the Si-nc, but only a part of their nominal PL emission intensity is recovered. Characterization of the damage induced by low energy proton irradiation reported in this paper makes the use of light ion beams relevant for the experimental investigation of nanostructured systems, such as ionoluminescence measurements. © 2011 American Institute of Physics

Ionoluminescence induced by low-energy proton excitation of Si nanocrystals embedded in silica

Silicon nanocrystals (Si-nc) can be synthesized into a silica matrix by ion implantation of silicon excess, followed by thermal annealing in N 2 or Ar atmosphere. In this work, ionoluminescence (IL) measurements have been performed on fused silica samples containing Si-nc using a 18 keV proton beam for the IL excitation. This low energy irradiation has allowed us to reduce the IL probing range to the first 300 nm of the studied materials, thus enhancing the contribution to the IL signal of the sample region where the Si-nc are located. A transmission optical detection set-up has been developed to ensure the collection of a strong IL signal. Comparison of the data recorded between 300 and 800 nm shows that the IL intensity decreases for long excitation times in Si-nc samples, whereas the IL signal intensity remains remarkably stable in pure SiO 2 sample. The variations observed for samples with Si-nc are attributed to the damaging effects induced by the impinging protons. The sample annealed under N 2 exhibits a stronger IL emission than the sample annealed under Ar, where both the concentration of residual defects and the excitation efficiency of the radiative centers could be lower. The results make the IL measurements a promising tool for in situ monitoring of ion implantation with pure fused silica samples, as well as a promising technique for novel characterizations of Si-nc embedded within SiO 2. © 2011 Elsevier B.V. All rights reserved