Solar photodegradation of Rhodamine B dye by Cu2O/TiO2 heterostructure: experimental and computational studies of degradation and toxicity.

CONTEXT AND RESULTS: In this study, the heterojunction Cu2O/TiO2 is used for the degradation of a cationic dye, Rhodamine B, under solar light irradiation over a wide pH range. The physical and optical properties of both semiconductors Cu2O and TiO2 are correlated with the photo-electrochemical characterization to establish the energy diagram of the heterojunction Cu2O/TiO2. X-ray diffraction, UV-visible, SEM, EDX, and BET analyses are conducted for both photocatalysts. The band gap (Eg) of 3.26 eV is obtained for TiO2 with an indirect optical transition. In the case of Cu2O, the transition is directly allowed at 2.05 eV. According to the BET analysis, the specific surface area of TiO2 particles is higher (82.65 m2 g-1) than that of Cu2O (29.81 m2 g-1). The flat band potentials, determined from the Mott-Schottky plots, are 0.3 and - 0.32 VSCE for TiO2 and Cu2O, respectively. The photocatalytic activity is directly proportional to the mass ratio, and the best result is obtained for the mass ratio 1:1 of Cu2O/TiO2. COMPUTATIONAL AND THEORETICAL TECHNIQUES: Furthermore, a theoretical study is conducted by using density functional theory to optimize the structure, reactivity sites of the RhB molecule, and physical parameters like the energy of the frontier molecular orbitals and electronegativity and to predict the proposed mechanism of RhB degradation as well as its intermediates. Also, molecular dynamics simulation is used to determine the adsorption behavior of RhB on TiO2 (101) and Cu2O (111) surfaces. The ecotoxicity evaluation showed that degradation products have significantly lower acute toxicity than RhB.

Cephalexin degradation initiated by OH radicals: theoretical prediction of the mechanisms and the toxicity of byproducts.

In this work, the density functional theory is used to study the local reactivity of cephalexin (CLX) to radical attack and explain the mechanism of the reaction between CLX and hydroxyl radical attack leading to degradation byproducts. The reaction between •OH and CLX is supposed to lead to either an addition of a hydroxyl radical or an abstraction of a hydrogen. The results showed that the affinity of cephalexin for addition reactions increases as it passes from the gas to the aqueous phase and decreases as it passes from the neutral to the ionized form. Thermodynamic data confirmed that OH addition radicals (Radd) are thermodynamically favored over H abstraction radicals (Rabs). The ecotoxicity assessments of CLX and its byproducts are estimated from the acute toxicities toward green algae, Daphnia, and fish. The formation of byproducts is safe for aquatic organisms, and only one byproduct is harmful to Daphnia.

[Temperament and alcoholic behavior in medical students]. / Tempérament et conduites alcooliques chez l'étudiant en médecine.

BACKGROUND AND AIMS: The Tunisian medical student population is very heterogeneous. This heterogeneity is based among other things on temperamental differences between different students and their behavior and strategies to cope with the requirements and constraints of medical studies. We conducted this study aiming: to determine the prevalence of alcohol use in a student population at Sfax Medical School and to evaluate the factors associated with this use; to study the relationship between affective temperament and alcohol consumption among medical students. METHODS: We conducted a descriptive and analytical cross-sectional study in the form of a survey between July 2018 and January 2019 among students (aged between 19 and 30) recruited from the University of Medicine of Sfax during their internship in the psychiatric department "A" at CHU HédiChaker of Sfax. We used a pre-established survey sheet based on data from the substance use and affective temperament literature in medical students that was completed by the participants after obtaining their consent and having explained the anonymity and confidentiality of the questionnaire. This sheet included a section on student sociodemographic characteristics, a second part describing the history and characteristics of alcohol consumption and the evaluation of alcohol consumption through the Alcohol Use Disorders Identification Test (AUDIT), and a third part for temperament evaluation by TIME-A, and Temperament Evaluation of Memphis Pisa Paris and San Diego Auto-questionnaire. RESULTS: We recruited 136 students with an average age of 21.63 years (SD 2 years) and a sex ratio (H/F) of 0.66. Alcohol consumption was observed among 19.8 % of students surveyed, 19.1 % of whom were occasional consumers. The mean age of onset of alcohol consumption was 18.48 years (SD 1.76 years). All consumer students had started using alcohol with their friends. The desired effect was euphoric in 74 % of cases, sleeping for 14.8 % of them. Among consumers, the average score at AUDIT was 6.44 (SD 5.3). Among them 70.4 % had a risk-free consumption (score of 8 or less); 14.8% were at risk (score 9-12) and 11.1 % were likely alcohol dependent (score>12). The evaluation of affective temperament according to TIME-A showed that the cyclothymic and hyperthymic temperament scores were the highest among the students (respectively 5.5 and 4). The analytical study showed that alcohol dependence was significantly more common among male students (p=0.048). Alcohol use was significantly more common among students who smoke (p<0.001) and those who consume cannabis (p<0.001). The bivariate correlation showed that more students had a high score of depressive temperaments (r=0.18, p=0.032), irritable (r=0.2, P=0.018) and hyperthymic (r=0.27, p=0.001). The higher their scores on the AUDIT scale, the more alcohol-dependent they were. CONCLUSION: The implementation of preventive measures is an obvious emergency. In the same way, taking into account the difference in affective temperaments in this very particular population could have a grandiose importance and an interesting impact both in the screening and in the care of these students.

[Female sexual dysfunction and multiple sclerosis: A case-control study]. / Dysfonction sexuelle féminine et sclérose en plaques : étude cas-témoins.

OBJECTIVES: To compare the scores of the different dimensions of sexual function of women with multiple sclerosis to a group of control women and to identify possible factors associated with sexual dysfunction in women with multiple sclerosis. METHODS: This is a descriptive and analytical case-control study. Twenty-six women with multiple sclerosis were compared to 26 control women matched for age and socioeconomic status. The evaluation focused on demographic and clinical data. Patients with multiple sclerosis were evaluated by Expanded Disability Status Scale (EDSS) for functional status, by Female Sexual Function Inventory (FSFI) for sexual function and by Beck Depression Inventory-Short Form (BDI-DF) for severity of depression. RESULTS: Our results confirmed the high prevalence of sexual dysfunction among patients with multiple sclerosis (69.2%) compared to controls (26.9%) (P=0.002). Sexual desire, arousal and orgasm were the most altered sexual phases in our study. Total FSFI, and FSFI subscale scores (sexual desire, arousal, lubrication, orgasm and satisfaction) were lower in women with multiple sclerosis compared with controls. The analytical study showed that in women with multiple sclerosis, the total FSFI score was correlated with age (rs=-0.68; P<0.001), duration of marriage (rs=-0.57; P=0.002), level of disability (rs=-0.45; P=0.021) and BDI-SF score (rs=-0.51; P=0.008). FSFI score was also associated to low education level (P=0.02) and urinary dysfunction (P=0.04). CONCLUSION: Our study highlighted the importance of sexual dysfunction in women with multiple sclerosis. The inclusion of this aspect in the clinical assessment will improve the quality of life of these patients. LEVEL OF EVIDENCE: 3.

Ridge augmentation with titanium mesh: A case report.

Insufficient bone volume for dental implant placement in the maxillary anterior segment is a constant challenge in oral surgery. Several techniques have been suggested to reconstruct deficient alveolar ridges and to facilitate dental implant placement. These techniques include bone splitting osteotomy, distraction osteogenesis, inlay and onlay bone grafting. Guided bone regeneration (GBR) is also a promising alternative that increases the bone volume by the use of a subperiosteal barrier. AIM: The aim of this case was to demonstrate that the use of rigid titanium occlusive barrier is a reliable alternative to perform a lateral alveolar bone augmentation and treat localized ridge deformities before reaching an ideal implant placement. OBSERVATION: A 25-year-old healthy male was referred for implant placement in the maxillary central incisor. The alveolar bone width at the implant site 21 was less than 5mm. Hard tissue augmentation was accomplished using guided bone regeneration. A rigid titanium occlusive barrier was customized to desired shape of future alveolar ridge then secured with tent and fixing screws. Autogenous bone graft harvested with an auto-chip-maker adjacent to the surgical site were mixed with a xenograft and putted under the barrier. The wound was closed using a vestibular mucoperiosteal flap. At 4 months, the rigid barrier was removed, and a 7mm crestal width transversal bone was observed. At the same time, a fixture (4×10mm) was placed. A definitive ceramometal crown was completed after full osseointegration with periodical clinical maintenance. The exposure of the titanium mesh occurred in this case and was visible with a circular flap dehiscence at 1-month follow-up visit. This exposure did not affect the successful regenerative outcomes. After removal of the titanium mesh from the grafted defects, the space beneath the membrane enclosure was seen to be almost completely filled with new hard tissue covered by a thin layer of soft tissue. The postoperative follow-ups revealed that the implant was stable with excellent osseointegration and the buccal depression of the surgical area was reconstructed. CONCLUSION: The use of rigid titanium occlusive screwed barrier with autogenous and bovine bone graft might be a reliable technique for alveolar ridge reconstruction. This approach achieve excellent final esthetic outcome of the implant-supported restoration.

Risk factors for heat related death during the August 2003 heat wave in Paris, France, in patients evaluated at the emergency department of the Hôpital Européen Georges Pompidou.

OBJECTIVES: This study sought to determine the risk factors for short term mortality in the victims of the heat wave of August 2003 in France from among patients evaluated in our emergency department (ED). It was hypothesised that age, temperature, and some long term therapies and pre-existing pathologies were factors associated with short term mortality. METHODS: A retrospective analysis of a seven day period. Four experts decided blindly, in pairs, whether a patient had presented with a heat related problem. Inclusion criteria were: core temperature > or =38 degrees C and/or clinical signs of dehydration. Comparisons were made between the survivors and one month non-survivors for 57 different items. Short term mortality was defined as death in the ED or within the first month of the ED visit. RESULTS: Of 841 patients attending the ED in the study period, 165 were included in the study, of which most were elderly women. Thirty one (18.8%) died within one month. Factors associated with short term mortality were: a greater degree of dependent living; more severe clinical condition on admission (higher temperature and heart rate, lower blood pressure, hypoxia, and altered mental status); higher values of blood glucose, troponin, and white blood cell count; lower values of serum protein and prothrombin levels; pre-existing ischaemic cardiomyopathy; pneumonia as associated infection; and previous psychotropic treatment. The total number of survivors at one year was 91. CONCLUSIONS: Although this study is limited because of the small sample size, the results have helped determine factors useful for future identification of patients at greatest risk of death in order to implement a more efficient patient care protocol.

An optimised protocol for plant regeneration from embryogenic suspension cultures of date palm, Phoenix dactylifera L., cv. Deglet Nour.

An improved protocol is described for the large-scale micropropagation of an elite date palm ( Phoenix dactylifera L.) cultivar, Deglet Nour. Clonal plants were regenerated from somatic embryos derived from highly proliferating suspension cultures. Friable embryogenic calli were initiated from both leaf and inflorescence explants. Suspension cultures consisting of pro-embryonic masses were established from calli showing a high competency for somatic embryogenesis. The subculture of suspensions in liquid medium enriched with low amounts of plant growth regulators (1 mg l(-1) 2,4-dichlorophenoxyacetic acid with 300 mg l(-1) charcoal) resulted in the differentiation of large numbers of somatic embryos. The productivity of the cultures increased 20-fold (from 10 to 200 embryos per month per 100 mg fresh weight of embryogenic callus) when embryogenic suspensions were used instead of standard cultures on solid media. The overall production of somatic embryos reached 10,000 units per litre per month. Partial desiccation of the mature somatic embryos, corresponding to a decrease in water content from 90% to 75%, significantly improved germination rates (from 25% to 80%). The cutting back of the cotyledonary leaf was also found to stimulate embryo germination. Flow cytometric analysis showed that the micropropagation protocol followed here did not affect the ploidy level of somatic embryo-derived plantlets.

Pneumococcal cellulitis in an HIV-infected adult.

Streptococcus pneumoniae is an uncommon cause of cellulitis. In almost all of the reported cases, the infection occurred in immunosuppressed patients, especially in those with connective tissue diseases. We report a case of cervical cellulitis associated with septicemia which occurred in an HIV-infected adult.

Primary sternal osteomyelitis and septicaemia due to Staphylococcus aureus.

Primary sternal osteomyelitis is rare in these recent decades. Only scattered cases have been reported, most of them in intravenous drug users. We report the case of an 88-y-old woman who presented a primary sternal infection due to Staphylococcus aureus associated with secondary septicaemia. The only predisposing factor was radiotherapy for a malignant tumour of the right mammary gland 20 y ago. Diagnostic evaluation and therapeutic management are briefly discussed.

[Hepatic amebiasis: an unusual clinical presentation]. / Amibiase hépatique: une présentation clinique inhabituelle.

BACKGROUND: Painful liver enlargement with fever are common signs of hepatic ambiasis. Exceptionally, atypical signs may also occur including symptoms suggesting renal sepsis. CASE REPORT: An 18-year-old woman from the New Caledonia was hospitalized in metropolitan France for suspected right-sided acute pyelonephritis. Urinalysis was normal and the kidney ultrasound suggested the need for an abdominal CT-scan which evidenced a voluminous 10-cm abscess pus. Serology for amebia was positive, confirming the diagnosis of hepatic amebic abscess. Outcome was rapidly favorable with intravenous anti-parasite treatment amebic abscess. Outcome was rapidly favorable with intravenous anti-parasite treatment and percutaneous drainage. DISCUSSION: Atypical signs of hepatic ambiasis may mislead diagnosis. The absence of a fetid odor at puncture helps guide diagnosis, confirmed by serology. Percutaneous drainage can hbe proposed for voluminous abscesses or if the risk of extrahepatic complications is eminent.

Adult respiratory distress syndrome and pancytopenia associated with miliary tuberculosis in a HIV-infected patient.

Adult respiratory distress syndrome (ARDS) is a rare but severe complication of miliary tuberculosis, which may appear even after introduction of antituberculosis therapy. Mortality has been reported to be as high as 100% if there is associated pancytopenia. We report a case of a patient infected with the human immunodeficiency virus who presented with miliary tuberculosis associated with pancytopenia and adult respiratory distress syndrome.

[Acute respiratory distress syndrome and pancytopenia during miliary tuberculosis in a HIV positive patient]. / SDRA et pancytopénie au cours d'une miliaire tuberculeuse chez un patient VIH positif.

Acute respiratory distress syndrome (ARDS) is a rare but severe complication of miliary tuberculosis, which may occur even under antituberculous therapy. Even with adequate treatment, its mortality is close to 70%, and if associated with pancytopenia, it may reach 100%. Underlying diseases, delayed diagnosis and additional complications are factors of poor prognosis. We report a case of a patient infected with the human immunodeficiency virus who experienced pancytopenia and ARDS associated with miliary tuberculosis. The patient recovered under antituberculous chemotherapy.