Wound Infection After Excision and Primary Midline Closure for Pilonidal Disease: Risk Factor Analysis to Improve Patient Selection

Background: Excision and primary midline closure for pilonidal disease (PD) is a simple procedure; however, it is frequently complicated by infection and prolonged healing. The aim of this study was to analyze risk factors for surgical site infection (SSI) in this context. Methods: All consecutive patients undergoing excision and primary closure for PD from January 2002 through October 2008 were retrospectively assessed. The end points were SSI, as defined by the Center for Disease Control, and time to healing. Univariable and multivariable risk factor analyses were performed. Results: One hundred thirty-one patients were included [97 men (74%), median age=24 (range 15-66) years]. SSI occurred in 41 (31%) patients. Median time to healing was 20days (range 12-76) in patients without SSI and 62days (range 20-176) in patients with SSI (P<0.0001). In univariable and multivariable analyses, smoking [OR=2.6 (95% CI 1.02, 6.8), P=0.046] and lack of antibiotic prophylaxis [OR=5.6 (95% CI 2.5, 14.3), P=0.001] were significant predictors for SSI. Adjusted for SSI, age over 25 was a significant predictor of prolonged healing. Conclusion: This study suggests that the rate of SSI after excision and primary closure of PD is higher in smokers and could be reduced by antibiotic prophylaxis. SSI significantly prolongs healing time, particularly in patients over 25year

Neurologic complications of sickle cell disease in Africa A systematic review and meta-analysis

To summarize prevalence data on the neurologic complications of sickle cell disease (SCD) in Africa

Déficits cognitifs chez les enfants et adolescents souffrant de drépanocytose

La drépanocytose compte parmi les maladies génétiques les plus répandues dans le monde. Comme les accidents vasculaires cérébraux (AVC) constituent l'une des complications les plus handicapantes de cette maladie, les drépanocytaires sont particulièrement à risque de présenter des déficits cognitifs. L'objectif de ce travail était de mettre en place un examen neuropsychologique systématique pour les enfants et adolescents souffrant de drépanocytose au Cameroun, où la drépanocytose constitue un problème majeur de santé publique. Une batterie de 10 tests psychométriques évaluant 4 domaines cognitifs (fonctions exécutives, attention, mémoire et dextérité manuelle) a été adaptée au contexte socio-culturel camerounais et des données normatives ont été récoltées à Yaoundé auprès de 125 sujets en bonne santé. La batterie a ensuite été administrée à 96 enfants et adolescents souffrant de drépanocytose. Les principaux résultats indiquent que 1) la prévalence des déficits cognitifs chez les drépanocytaires au Cameroun est élevée, même chez les patients n'ayant pas souffert d'AVC; 2) la maladie a un impact négatif sur le fonctionnement exécutif et attentionnel, alors que la mémoire et la dextérité manuelle sont relativement préservées; 3) les déficits exécutifs augmentent avec l'âge; 4) l'anémie a un effet négatif sur les fonctions exécutives, alors que l'hémoglobine fœtale exerce un effet "protecteur" sur les fonctions exécutives et attentionnelles. L'ensemble de ce travail suggère que l'examen neuropsychologique peut contribuer à l'amélioration de la prise en charge des drépanocytaires et qu'il constitue un instrument particulièrement bien adapté pour les pays en voie de développement. Ce projet a permis d'établir les premières bases de l'utilisation de l'examen neuropsychologique au Cameroun. Dans la continuité de ce travail, nous projetons de développer dans ce pays un programme de réhabilitation cognitive pour les enfants drépanocytaires

Real-time usage forecasting for bike-sharing systems ::a study on random forest and convolutional neural network applicability

In this paper, we present a system that has been developed to facilitate the collection and use of Bike-Sharing Systems data for research, notably to develop and compare bike usage forecasting algorithms. We collected internal and external data for six different European cities and developed a system providing short and long-term predictions of bikes and slots availabilities for bike-sharing stations in real-time. In order to provide the best predictions, we developed and compared the performances of two types of algorithm; the first one is based on the state-of-the-art Random Forest algorithm and the second one is based on Convolutional Neural Networks. Our study demonstrates their applicability, showing better accuracy for short-term predictions with the Random Forest algorithm and better long-term prediction accuracy with the Convolutional Neural Networks algorithm

Inducing Open-Shell Character in Porphyrins through Surface-Assisted Phenalenyl π-Extension

Organic open-shell compounds are extraordinarily attractive materials for their use in molecular spintronics thanks to their long spin-relaxation times and structural flexibility. Porphyrins (Pors) have widely been used as molecular platforms to craft persistent open-shell structures through solution-based redox chemistry. However, very few examples of inherently open-shell Pors have been reported, which are typically obtained through the fusion of non-Kekulé polyaromatic hydrocarbon moieties to the Por core. The inherent instability and low solubility of these radical species, however, requires the use of bulky substituents and multistep synthetic approaches. On-surface synthesis has emerged as a powerful tool to overcome such limitations, giving access to structures that cannot be obtained through classical methods. Herein, we present a simple and straightforward method for the on-surface synthesis of phenalenyl-fused Pors using readily available molecular precursors. In a systematic study, we examine the structural and electronic properties of three surface-supported Pors, bearing zero, two (PorA2), and four (PorA4) meso-fused phenalenyl moieties. Through atomically resolved real-space imaging by scanning probe microscopy and high-resolution scanning tunneling spectroscopy combined with density functional theory calculations, we unambiguously demonstrate a triplet ground state for PorA2 and a charge-transfer-induced open-shell character for the intrinsically closed-shell PorA4

Inducing Open-shell Character in Porphyrins through Surface-assisted Phenalenyl π−Extension

Herein, we present a simple and straightforward method for the synthesis of phenalenyl-fused Pors (Por A0, PorA2 and PorA4) through readily available molecular precursors. While PorA0 was prepared by “wet” synthesis, the two- and four-fold phenalenyl-fused Por derivatives PorA2 and PorA4 were fabricated through a surface-assisted cyclodehydrogenation reaction from meso-2,6-dimethylphenyl(dmp) substituted precursors Por(dmp)2 and Por(dmp)4, respectively. In a systemat-ic way, we examined the structural and electronic properties of three surface-supported Pors.<br /

Bottom‐up Fabrication and Atomic‐Scale Characterization of Triply Linked, Laterally π‐Extended Porphyrin Nanotapes**

Porphyrin nanotapes (Por NTs) are highly promising structures for their use as molecular wires thanks to their high degree of π‐conjugation, low HOMO‐LUMO gaps, and exceptional conductance. Such structures have been repeatedly reported in solution‐based approaches, but their on‐surface synthesis, which allows an atomically‐resolved characterization, remains unreported to this date. Here, we report the first example of meso‐meso triply‐fused Por NTs, which are prepared from a readily available Por precursor through a two‐step synthesis on Au(111). The diradical character of the on‐surface formed building block PorA2, a phenalenyl π‐extended ZnIIPor, facilitates intermolecular homocoupling and allows for the formation of laterally π‐extended tapes. The structural and electronic properties of individual Por NTs are addressed, both on Au(111) and on a thin insulating NaCl layer, by high‐resolution scanning probe microscopy/spectroscopy complemented by density functional theory calculations. Remarkably, the triply‐linked, laterally π‐extended Por NTs carry one unpaired electron at each end, which leads to magnetic end states. Our study provides an alternative and versatile route to the fabrication of Por NTs and the atomic‐scale characterizations of their structural and electronic properties

Bottom-up Fabrication and Atomic-scale Characterization of Triply-linked, Laterally π-Extended Porphyrin Nanotapes

Porphyrin nanotapes (Por NTs) have attracted vast interest as potential molecular wires thanks to their exceptional electronic properties. Recently, Por NTs have been synthesized by solution-based methods, demonstrating high versatility and great potential for technological applications. However, their synthesis is tedious and their characterization limited by low solubility and stability. Here, we report the first example of meso-meso triply-fused Por NTs, which are prepared from a readily available Por precursor through a two-step synthesis on Au(111). The structural and electronic properties of individual Por NTs are addressed, both on Au(111) and on a thin insulating NaCl layer, by high-resolution scanning probe microscopy/spectroscopy complemented by density functional theory calculations.</p

Differentiation of focal liver lesions: usefulness of parametric imaging with contrast-enhanced US.

Purpose: To evaluate whether parametric imaging with contrast material-enhanced ultrasonography (US) is superior to visual assessment for the differential diagnosis of focal liver lesions (FLLs). Materials and Methods: This study had institutional review board approval, and verbal patient informed consent was obtained. Between August 2005 and October 2008, 146 FLLs in 145 patients (63 women, 82 men; mean age, 62.5 years; age range, 22-89 years) were imaged with real-time low-mechanical-index contrast-enhanced US after a bolus injection of 2.4 mL of a second-generation contrast agent. Clips showing contrast agent uptake kinetics (including arterial, portal, and late phases) were recorded and subsequently analyzed off-line with dedicated image processing software. Analysis of the dynamic vascular patterns (DVPs) of lesions with respect to adjacent parenchyma allowed mapping DVP signatures on a single parametric image. Cine loops of contrast-enhanced US and results from parametric imaging of DVP were assessed separately by three independent off-site readers who classified each lesion as benign, malignant, or indeterminate. Sensitivity, specificity, accuracy, and positive and negative predictive values were calculated for both techniques. Interobserver agreement (κ statistics) was determined. Results: Sensitivities for visual interpretation of cine loops for the three readers were 85.0%, 77.9%, and 87.6%, which improved significantly to 96.5%, 97.3%, and 96.5% for parametric imaging, respectively (P &lt; .05, McNemar test), while retaining high specificity (90.9% for all three readers). Accuracy scores of parametric imaging were higher than those of conventional contrast-enhanced US for all three readers (P &lt; .001, McNemar test). Interobserver agreement increased with DVP parametric imaging compared with conventional contrast-enhanced US (change of κ from 0.54 to 0.99). Conclusion: Parametric imaging of DVP improves diagnostic performance of contrast-enhanced US in the differentiation between malignant and benign FLLs; it also provides excellent interobserver agreement

Neuropsychology in Cameroon: First Normative Data for Cognitive Tests among School-Aged Children

Introduction: Very few normative data on psychometric tests are available in sub-Saharan African countries, in spite of the obvious needs and potential benefits from psychological and neuropsychological examination in these contexts. The goal of the ongoing overall project is to assess the cognitive functioning of Cameroonian school-aged children suffering from Sickle Cell Disease. For this purpose, normative data on psychometric tests adapted to the Cameroonian cultural context had to first be established. Method: 125 “healthy” school-aged Cameroonian children were recruited from public schools in the city of Yaoundé and were given a battery of 14 cognitive tests assessing executive functions and memory. Criteria for tests inclusions were: simplicity of administration, few verbal demand, and broad cross-cultural applicability. Results allow concluding that the battery is appropriate for neuropsychological evaluation in Cameroon, with the exception of the Block Design test (WISC-IV) and a Verbal Phonemic Fluency test. A factor analysis shows a division of the tests in a four-factors model that is very consistent with the expected measures of the tests. Effects of gender, age, and education are also discussed. Conclusion: this study is the first to report normative data on neuropsychological tests among children in Cameroon and constitutes an initial step for the advancement of neuropsychology in this country in particular and in sub-Saharan Africa in general. The battery is currently used in Cameroon with children suffering from Sickle Cell Disease as an aid to detect cerebrovascular complications