Insights into the relationship between ferroelectric and photovoltaic properties in CsGeI3 for solar energy conversion.

Materials such as oxide and halide perovskites that simultaneously exhibit spontaneous polarization and absorption of visible light are called photoferroelectrics. They hold great promise for the development of applications in optoelectronics, information storage, and energy conversion. Devices based on ferroelectric photovoltaic materials yield an open-circuit voltage that is much higher than the band gap of the corresponding active material owing to a strong internal electric field. Their efficiency has been proposed to exceed the Shockley-Queisser limit for ideal solar cells. In this paper, we present theoretical calculations of the photovoltaic properties of the ferroelectric phase of the inorganic germanium halide perovskite (CsGeI3). Firstly, the electronic, optical and ferroelectric properties were calculated using the FP-LAPW method based on density functional theory, and the modern theory of polarization based on the Berry phase approach, respectively. The photovoltaic performance was evaluated using the Spectroscopic Limited Maximum Efficiency (SLME) model based on the results of first-principles calculations, in which the power conversion efficiency and the photocurrent density-voltage (J-V) characteristics were estimated. The calculated results show that the valence band maximum (VBM) of CsGeI3 is mainly contributed by the I-5p and Ge-4s orbitals, whereas the conduction band is predominantly derived from Ge-4p orbitals. It can be seen that CsGeI3 exhibits a direct bandgap semiconductor at the symmetric point of Z with a value of 1.53 eV, which is in good agreement with previous experimental results. The ferroelectric properties were therefore investigated. With a switching energy barrier of 19.83 meV per atom, CsGeI3 has a higher theoretical ferroelectric polarization strength of 15.82 µC cm-2. The SLME calculation also shows that CsGeI3 has a high photoelectric conversion efficiency of over 28%. In addition to confirming their established favorable band gap and strong absorption, we demonstrate that CsGeI3 exhibits a large shift current bulk photovoltaic effect of up to 40 µA V-2 in the visible region. Thus, this material is a potential ferroelectric photovoltaic absorbed layer with high efficiency.

Systemic lupus of pediatric onset in Afro-Caribbean children: a cohort study in the French West Indies and French Guiana.

BACKGROUND: Systemic diseases of pediatric onset are more frequent in the Afro-Caribbean population. We performed a study of patients followed in the French overseas departments of America (FOAD) for pediatric systemic lupus erythematosus (pSLE). The aims were to describe the clinical and biological specificities during childhood in this population. METHODS: A retrospective study was conducted between January 2000 and September 2021. Patients with pSLE were identified from multiple sources: computerized hospital archives, registry of referring pediatricians, adult specialists in internal medicine and the French National Registry for rare diseases. We studied SLE with pediatric onset defined by international criteria. RESULTS: Overall, 2148 patients were identified, of whom 54 were included. The average follow-up was 8.3 years (range: 0.3-25 years). We observed an increase in new diagnoses over time. At onset, pSLE patients had a median of 10 SLICC criteria (range: 4-12), and the median EULAR/ACR 2019 score was 38 (12-54). At onset, one third of patients had renal involvement, 15% had neurolupus and 41% cardiac involvement. During childhood, 54% had renal involvement, and 26% suffered from neurolupus. Patients suffered a median of 3 flares during childhood, and 26% had more than 5 flares. Patients with younger age at onset had worse outcomes than those who were older at diagnosis, i.e., more flares (median 5, p = 0.02) and requiring an average of 4 background therapies (p = 0.04). CONCLUSION: The outcomes of Afro-Caribbean patients were similar to those in Western population, but with worse disease activity at onset. Further studies should be performed to identify the genetic and environmental factors in this population.

User behaviour-based approach to define mobility devices needs of disabled person in Algeria: a questionnaire study.

PURPOSE: This article showcases the adaptability of existing mobility devices for the Algerian disabled population. It aims to develop a behavior model of disabled Algerian persons through (1) development of a theoretical model based on literature review and (2) improvement of this model by using local collected data from our developed questionnaire. METHODS: The majority of existing mobility devices for disabled persons are adapted developed countries context. The Algerian context (people and environment) has its own specifications and needs. Researchers does not address the disabled people behavior modelling in Algeria, due to the unavailability of data and the difficulty of their collection. In order to overcome this problem and develop adapted mobility devices for this particular population, the deployment of a questionnaire to collect local data, becomes necessary. First, a behavior model is deduced from the literature review then a questionnaire is developed and deployed to complete the missing field of this model. The deployment questionnaire panel is composed of 260 persons including users, their families and staff working in disabled person's aid organization. RESULTS: The main result of this paper consist in a specific behavior model of Algerian disabled persons. This population are looking for reliable and smart wheelchair (97%) to be able to overcome their daily mobility difficulties due to the infrastructure and the global economic context. CONCLUSION: The proposed model can generate adapted wheelchair for Algerian context. The results of the questionnaire are an important step to understand disabilities in Algeria and developing countries.Implications for RehabilitationDevelopment of a behavior model for the disabled persons displacement.Development and deployment of questionnaire for disabled persons in Algeria.Review of disabled person situation and existing wheelchair in Algeria.Identification of Algerian disabled persons requirement and demonstrate that are different from European one.Definition of recommendation set for the design of wheelchair adapted to Algerian context.

Fast Stent Retrieval during Mechanical Thrombectomy Improves Recanalization in Patients with the Negative Susceptibility Vessel Sign.

BACKGROUND AND PURPOSE: In acute ischemic stroke, the negative susceptibility vessel sign on T2*-weighted images traditionally highlights fibrin-rich clots, which are particularly challenging to remove. In vitro, fast stent retrieval improves fibrin-rich clot extraction. We aimed to evaluate whether the speed of stent retrieval influences the recanalization and clinical outcome of patients presenting with the negative susceptibility vessel sign. MATERIALS AND METHODS: Patients were identified from a registry of patients with ischemic stroke receiving mechanical thrombectomy between January 2016 and January 2020. Inclusion criteria were the following: 1) acute ischemic stroke caused by an isolated occlusion of the anterior circulation involving the MCA (Internal Carotid Artery-L, M1, M2) within 8 hours of symptom onset; 2) a negative susceptibility vessel sign on prethrombectomy T2*-weighted images; and 3) treatment with a combined technique (stent retriever + contact aspiration). Patients were dichotomized according to retrieval speed (fast versus slow). The primary outcome was the first-pass recanalization rate. RESULTS: Of 68 patients who met inclusion criteria, 31 (45.6%) were treated with fast retrieval. Patients receiving a fast retrieval had greater odds of first-pass complete (relative risk and 95% confidence interval [RR 95% CI], 4.30 [1.80-10.24]), near-complete (RR 95% CI, 3.24 [1.57-6.68]), and successful (RR 95% CI, 2.60 [1.53-4.43]) recanalization as well as greater odds of final complete (RR 95% CI, 4.18 [1.93-9.04]), near-complete (RR 95% CI, 2.75 [1.55-4.85]), and successful (RR 95% CI, 1.52 [1.14-2.03]) recanalization. No significant statistical differences in procedure-related serious adverse events, distal embolization, or symptomatic intracranial hemorrhage were reported. No differences were noted in terms of functional independence (RR 95% CI, 1.01 [0.53-1.93]) and all-cause mortality (RR 95% CI, 0.90 [0.35-2.30]) at 90 days. CONCLUSIONS: A fast stent retrieval during mechanical thrombectomy is safe and improves the retrieval of clots with the negative susceptibility vessel sign.

Screening of bacterial isolates related to olive orchard pests in Tunisia using 16S ribosomal RNA and evaluation of their biotechnological potential.

AIM: This study investigated the bacterial diversity of dead insects collected from olive tree orchards widely cultivated in Tunisia. We aimed to explore metabolic diversity, screen enzymatic activities for biotechnological applications and carry out preliminary bioassays for bio-insecticide development. METHODS AND RESULTS: A total of 50 bacteria strains were randomly isolated from four different biotopes situated in Sfax (Tunisia). 16S rRNA gene sequencing was used to identify 24 species, and isolates were evaluated for enzymatic activity and antimicrobial potential. Nineteen of the total number of Bacillus strains have enzymatic activity compared to strains from the other genera (14/50). Our bacterial collection was evaluated for antimicrobial potential against bacterial and fungal isolates. Isolates B8-2 (Bacillus subtilis) showed strong antibacterial activities and isolates B2-3 (Bacillus licheniformis) and B10-1 (Serratia marcescens) showed the highest antifungal activity. Seventeen of the total number of isolates caused greater than 50% mortality rate of second and fourth instar larvae of Ephestia kuehniella. CONCLUSION: The selected species from olive orchards represent a broad spectrum of antimicrobial and insecticidal activities and can be considered promising resources in biological control. SIGNIFICANCE AND IMPACT OF THE STUDY: Bacteria isolated from olive pests in olive orchards were investigated for detecting their potential biotechnological applications.

Nutrient recycling from the effluent of a decentralized anaerobic membrane bioreactor (AnMBR) treating fresh domestic wastewater by cultivation of the microalgae Acutodesmus obliquus.

This study investigates the feasibility of microalgae cultivation with the effluent (permeate) of a decentralized anaerobic membrane bioreactor (AnMBR) treating high strength domestic wastewater. Two experiments, consisting of three and two successive batch experiments with incubation times varying between 5 and 9 days, were conducted. Nutrient removal and growth of the microalgae species Acutodesmus obliquus were studied for the following culture media: (A) permeate, (B) permeate enriched with iron (Fe), magnesium (Mg), manganese (Mn), sulfur (S) and the chelating agent EDTA, (C) commercial fertilizer as control culture. Initial nutrient concentrations in the culture media ranged from 9.3 to 16.6 mg·L-1 total phosphorus (TP) and from 85.1 to 126.2 mg·L-1 total nitrogen (TN). TP reached an average removal of 97%, 98% and 99% in (A), (B) and (C) respectively. An average TN removal of 94% and 96% was achieved in (B) and (C). Starting from the third batch of the first experiment and the second batch of the second experiment, the culture with permeate (A) showed a decrease in TN removal. Further batch experiments showed the need to add iron to ensure an optimal TN removal from the permeate.

Closed loop obstruction: pictorial essay.

Closed loop obstruction occurs when a segment of bowel is incarcerated at two contiguous points. The diagnosis is based on multiple transitional zones. The incarcerated loops appear in U or C form or present a radial layout around the location of the obstruction. It's very important to specify the type of obstruction because, in patients with simple bowel obstruction, a conservative approach is often advised. On the other hand, a closed loop obstruction immediately requires a surgical approach because of its high morbidity and the risk of death in case of a late diagnosis.

[Contribution of the chromogenic medium CHROMagar(®)Candida in mycological diagnosis of yeasts]. / Apport du milieu chromogène CHROMagar(®)Candida dans le diagnostic mycologique des levures.

The incidence of invasive candidiasis has increased dramatically over the last decades due to a larger number of patients at risk. The diagnosis remains difficult as the clinical presentation is not specific and the biological diagnosis usually takes several days to become positive. We propose in this work through a prospective study to evaluate the contribution of a chromogenic medium CHROMagar(®) (Becton-Dickinson) in the mycological diagnosis of Candida. We selected 680 samples from patients hospitalized in the intensive care unit for epidemiological surveillance over a period of 11 weeks. We treated samples by culture on Sabouraud and on CHROMagar(®). The species identification was performed by chlamydosporulation test and carbohydrate assimilation tests. We found that the CHROMagar(®)Candida evaluated in our work was a valuable tool in the primary culture in differentiating the most frequently isolated yeast species and in better detection of mixed cultures.

[Chronic kidney disease and myocardial infarction: epidemiological, clinical, therapeutic and prognostic characteristics (about 231 cases)]. / Insuffisance rénale chronique et infarctus de myocarde : particularités épidémiologiques, cliniques, thérapeutiques et pronostiques (à propos de 231 cas).

AIMS OF THE STUDY: To study the epidemiologic, clinical, therapeutic and prognostic characteristics of the myocardial infarction (MI) in patients with chronic kidney disease (CKD). To identify the impact of CKD in hospital, mid- and long-term survival after myocardial infarction. To determine the predictive factors of hospital and midterm MACCE in patients with CKD. PATIENTS AND METHODS: The study population was 231 patients with a myocardial infarction admitted alive from January 2005 to December 2006. The population was divided into two groups. Group 1: glomerular filtration rate (GFR) ≥60 ml/min: 112 patients; group 2: GFR<60 ml/min: 119 patients. RESULTS: Patients with CKD had more history of stroke and arterial hypertension. They had received less medical therapies and urgent reperfusion. In multivariate analysis, CKD was a predictive factor of hospital (P=0.016), at 6 months (P=0.003), at 1 year (P=0.004) and at 2 years MACCE (P=0,015). The predictive factors of hospital MACCE in group 2 were: use of vasopressors (P=0.001) and primary angioplasty (P=0.043). In patients with CKD, only surgical coronary revascularization was MACCE predictive factor (P=0.03). CONCLUSION: Baseline renal function is a powerful predictor of short- and long-term events after myocardial infarction. Our results confirm the need to include the renal function in the evaluation of the level of risk among patients admitted with acute myocardial infarction.

[Supraventricular tachycardia in infants]. / Les troubles du rythme supraventriculaires chez le nourrisson et l'enfant. À propos de six cas.

Supraventricular tachycardia in infants are variable. We try to summarize clinical, electrical and treatment particularities of supraventricular arrhythmia in infants. The majority of infants with supraventricular arrhythmia have a good clinical outcome and an excellent prognosis and may not require chronic antiarrhythmic therapy if they had precocious treatment.

Left ventricular thrombus complicating tachycardia-induced cardiomyopathy.

A 45 day old new-born with arrhythmia-induced cardiomyopathy complicated by thrombus formation is presented. Drug treatment produced immediate symptomatic relief and subsequent reversion to normal cardiac function. The thrombus disappeared a few days later.

[Neurological and heart failure following an accidental intoxication by hydrogen sulphide: a case report]. / Défaillance cardiaque et neurologique secondaire à une intoxication accidentelle par l'hydrogène sulfuré : à propos d'un cas.

We report the case of a patient who was victim of a hydrogen sulphide poisoning. This poisoning took place following a fall in sewers. The initial clinical presentation was dominated by an acute respiratory failure caused by an acute pulmonary oedema. In this context, non cardiogenic pulmonary oedema is usually evoked in the literature. Our observation supports a left ventricular systolic dysfunction as a possible cause of this cardiorespiratory complication. The initial presentation was also marked by a coma which is often associated with severe poisonings by hydrogen sulphide. Evolution was favourable under symptomatic treatment. We discuss the mechanism of heart and neurological failure.

[Multiple pulmonary coronary fistulae. Apropos of a case]. / Fistules coronaro-artérielles pulmonaires multiples. A propos d'un cas.

Coronary-pulmonary fistula is a rare congenital anomaly. It is usually detected fortuitously in adulthood during a coronary angiography carried out to assess signs of myocardial ischemia. Multiple coronary fistulae are still more rare. Coronary angiography evaluates the lesions and indicates the most appropriate treatment. The congenital lesions are frequently combined with atheromatous lesions. The case described is that of a double fistula in a 61-year old man which was revealed by angina; the stenoses and occlusions which accompanied the fistulae lead to a discussion of their atheromatous nature and the nature of the pathological link between them: is this fortuitous or are they a progressive complication? Treatment involves both exclusion of the fistulae and coronary revascularization.

[Coronary angioplasty combining rotational atherectomy and balloon dilatation. Results in 67 complex stenoses]. / Angioplastie coronaire associant athérectomie rotative et ballon. Résultats sur 67 sténoses complexes.

The treatment of complex coronary stenoses by conventional angioplasty is limited by a relatively low angiographic success rate, associated with a high risk of major complications. The role of new angioplasty techniques in the treatment of these lesions has not yet been determined. The aim of this prospective study was to evaluate the systematic association of rotational atherectomy (Rotablator) with balloon angioplasty on coronary stenoses characterised by at least 2 type B criteria of the ACC/AHA classification (type B2 lesions). The procedures was begun with rotational ablation with a medium-sized burr (50 to 70% of the reference diameter of the artery) and completed systematically by balloon angioplasty (balloon/artery ratio = 1), using the lowest possible inflation pressures for successful dilatation. This technique was used in 61 patients who had 67 coronary stenoses with a primary success rate (residual stenosis < 50% and no major complications) of 93.4% (57 patients). One emergency coronary bypass procedure was necessary and another patient developed transmural infarction on the 3rd day after the procedure. There were two technical failures (3.3%). The mean inflation pressure of the balloon was 4.1 +/- 1.2 atmospheres. There were no fatalities. During atherectomy, transient conduction defects were observed in 4 patients (6.6%): severe hypotension in 2 patients (3.3%) and complete spasm in 3 stenoses (4.5%). A significant increase in cardiac enzyme levels was observed in 4 patients (6.6%). The authors conclude that rotational atherectomy with a medium-sized burr, followed by systematic low pressure balloon dilatation allows treatment of certain complex coronary stenoses with a high primary success rate and few major complications.(ABSTRACT TRUNCATED AT 250 WORDS)

[Spasm of the left main coronary artery resistant to intracoronary vasodilators. Apropos of a case]. / Spasme du tronc commun coronaire gauche, résistant aux vasodilatateurs intracoronaires. A propos d'un cas.

Coronary spasm is essentially and angiographic diagnosis. Catheter-induced spasm is frequent during coronary angiography and usually regresses after the administration of intracoronary vasodilators. The authors report a case of coronary spasm with subocclusion of the left main coronary artery: the coronary narrowing remained significant after intracoronary vasodilator therapy, suggesting an organic component. The spasm was relieved only after a prolonged intravenous infusion of isosorbide dinitrate.

[Brucella endocarditis on Starr aortic valve prosthesis]. / Endocardite brucellienne sur valve de Starr aortique.

The authors report the case of a 22 year old patient with brucella endocarditis on a Starr-Edwards aortic valve prosthesis implanted 5 years previously. Six blood cultures were positive for Brucella melitensis biovar I. Antibiotic therapy associating Rifampicin and Tetracycline and then Rifampicin and Ofloxacine did not prevent abscess formation and valve dehiscence. The poor haemodynamic status and persistent infection led to replacement of the valve prosthesis. Culture of the infected prosthesis grew a colony of brucella melitensis resistant to fluoro-quinolones. Valve replacement and antibiotic therapy led to clinical improvement and constant apyrexia with a 12 month follow-up. Brucella endocarditis on a valve prosthesis is a very rare occurrence. The combination of valve replacement and antibiotic therapy is usually required.