The structure of the agrochemical fungicidal 4-Chloro-3-(3,5-dichloropheny)-1H-pyrazole, RPA 406194 and related compounds

The difficulties to obtain convenient monocrystals of the important fungicide RPA 406194 have been overcome by a combination of solid state 13C NMR, X-ray powder diffraction and molecular modeling. The compound, a 3-aryl tautomer, crystallizes forming infinite chains of molecules bonded by N–H· · ·N hydrogen bonds, leading to needle-shaped crystals. The tautomerism (equilibrium constant and energy barrier) of this compound in solution has been studied

p16INK4A expression is frequently increased in periorbital and ocular squamous lesions

Backgroundp16 expression is a well established biomarker of cervical dysplasia and carcinoma arising from high risk human papilloma virus infection. Increased p16 expression is also seen in squamous neoplasms arising at other sites, including head, neck, and oropharyngeal tract. Squamous lesions are also frequently encountered at ocular surface and peri-orbital skin sites, but the prevalence of increased p16 expression in these lesions has been poorly studied.MethodsWe retrospectively surveyed 13 ocular surface and 16 orbital squamous lesions biopsied at UC San Diego Healthcare System and VA San Diego Healthcare System for p16 expression by immunohistochemistry. These cases included ocular surface lesions with diagnoses of conjunctival intraepithelial neoplasm (CIN) and squamous cell carcinoma in situ. Peri-orbital eyelid biopsies included lesions with diagnoses of SCCis and invasive squamous cell carcinoma. We performed multivariate logistic regression, followed by student's T-test or Fisher's exact test to determine if there were statistically significant associations between p16 immunoreactivity and patient age, gender, diagnosis, and ethnicity. Statistical significance was defined as p < 0.05.ResultsWe found an unexpectedly large prevalence of strong nuclear and cytoplasmic p16 immunoreactivity in our cases. Almost all of the ocular surface squamous lesions were diffusely positive for p16 expression (12/13). All of the periorbital lesions showed diffuse p16 immunoreactivity (16/16). Altogether, 28/29 lesions tested showed strong and diffuse p16 expression. We found no statistically significant correlation between p16 expression and patient age, gender, ethnicity, or diagnosis. In 6 of the peri-orbital biopsies, we had sufficient tissue to assess high-risk HPV expression by in situ hybridization. Interestingly, all of these cases were negative for HPV, despite strong p16 expression.ConclusionStrong p16 expression was observed in virtually all of the ocular surface and peri-orbital squamous neoplasms in our study. The relationship between p16 expression and HPV infection in ocular surface and peri-orbital sites requires further investigation

Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

A stabilized bi-grid method for Allen-Cahn equation in finite elements

International audienceIn this work, we propose a bi-grid scheme framework for the Allen-Cahn equation in finite element method. The new methods are based on the use of two FEM spaces, a coarse one and a fine one, and on a decomposition of the solution into mean and fluctuant parts. This separation of the scales, in both space and frequency, allows to build a stabilization on the high-mode components: the main computational effort is concentrated on the coarse space on which an implicit scheme is used while the fluctuant components of the fine space are updated with a simple semi-implicit scheme; they are smoothed without damaging the consistency. The numerical examples we give show the good stability and the robustness of the new methods. An important reduction of the computation time is also obtained when comparing our methods with fully implicit ones

Stabilized bi-grid projection methods in finite elements for the 2D incompressible Navier-Stokes equations

We introduce a family of bi-grid schemes in finite elements for solving 2D incompressible Navier-Stokes equations in velocity and pressure (u; p). The new schemes are based on projection methods and use two pairs of FEM spaces, a sparse and a fine one. The main computational e ortis done on the coarsest velocity space with an implicit and unconditionally time scheme while itscorrection on the finer velocity space is realized with a simple stabilized semi-implicit scheme whosethe lack of stability is compensated by a high mode stabilization procedure; the pressure is updatedusing the free divergence property. The new schemes are tested on the lid driven cavity up to Re =7500. An enhanced stability is observed as respect to classical semi-implicit methods and an importantgain of CPU time is obtained as compared to implicit projection schemes

Comment les enseignants en formation initiale utilisent les technologies informatiques dans leurs classes

International audienceThe research presented here deals with the way French pre-service teachers assimilate the working of technology tools and the effects on professional practice of integrating these tools into classes. We focused on the professional writings of pre-service teachers regarding the use of technology in their teaching. The results show that, besides official instructions, the motivations put forward by pre-service teachers who integrated technology in their classes are mainly their students' interest in computers and how powerful this tool is. They also show that in such an environment teachers tend to keep in the background and to leave the students to interact chiefly with the computer. We also noticed that the specificities of managing a classroom in computer environment are not taken into account unless they generate problems.La recherche présentée ici porte sur l'appropriation des outils informatiques par les enseignants français en formation initiale et les effets de leur intégration dans les classes sur les pratiques professionnelles. Nous avons pris comme objet d'étude des écrits professionnels, élaborés par ces professeurs stagiaires, portant sur l'utilisation des TIC dans leur enseignement. Les résultats obtenus font apparaître qu'outre les injonctions institutionnelles, les motivations invoquées par les stagiaires pour recourir à l'informa-tique concernent surtout l'attrait de leurs élèves pour l'ordinateur et la puissance de cet outil. Dans le cadre des usages en classe, nos résultats montrent que l'enseignant a tendance à s'effacer devant l'ordinateur, considéré comme l'interlocuteur privilégié de l'élève. Nous avons aussi pu constater que les spécificités de la gestion de la classe en environnement informatique ne sont prises en compte que lorsqu'elles se révèlent sources de problèmes

The Stability of Bridgehead Carbocations

The gas-phase stability of bridgehead carbocations has been determined by Fourier transform ion cyclotron resonance spectroscopy (FT ICR) based on dissociative proton attachment (DPA) of bridgehead bromides, chlorides, and alcohols. When appropriate leaving group corrections are applied, the relative ion stabilities obtained from these precursors are identical. The relative rate constants (log k) for solvolysis of bridgehead derivatives correlate with the stabilities of the cations over the entire reactivity range. Theoretical calculations of the stabilities of the ions relative to those of the respective hydrocarbons at the MP2/6-311G** level agree fully with the experimental data