Could Alfa fibers substitute glass fibers in composite materials?

In the present work polyester resin composites with Alfa fibers in the form of pulp were prepared and their properties were compared with those of polyester resin reinforced with glass fibers, the latter composites being widely used for structural applications. The composites were prepared using two manufacturing processes, namely hand lay-up and vacuum molding, to assess the influence of the process on the composites properties. Firstly, the tensile properties for the two composites were evaluated. The composites thermal properties were studied by differential scanning calorimetry and thermogravimetric analysis. Finally, the morphology of a glass fiber composite (GFC) and Alfa pulp composite (APC) was analyzed by scanning electron microscopy, to characterize the composites surface and cross-sections.The authors would like to thank CTC (Centre technique de la Chimie) for their valuable help during mechanical testing. The company Solutions Composites, especially Mr.Adel Hammami is gratefully acknowledged for financial and material support. The authors also wish to thank the members of the Department of Polymer Engineering University of Minho, Guimarães, Portugal for their valuable cooperation. This research work is carried out as part of a mobidocPhD, a program financed by the European Union within Pasri Projet. M.C Paiva acknowledges the Portuguese Foundation for Science and Technology (FCT) and the European program FEDER/COMPETE for the financial support through project PEst-C/CTM/ LA0025/2013 (LA 25-2015-2017)

Revue sur l'enlèvement des métaux des effluents par adsorption sur la sciure et les écorces de bois

Les résidus de transformation du bois tels les écorces et la sciure de bois ont été largement étudiés depuis quelques années pour leur propriété d'adsorption et d'enlèvement des métaux toxiques contenus dans les effluents contaminés. En ce qui concerne la sciure de bois, les recherches répertoriées ont porté principalement sur l'utilisation du sapin rouge, du manga, du tilleul, de l'épinette, du pin, du cèdre, du teck, de l'akamatsu et du buna. Pour ce qui est des écorces de bois, plusieurs espèces ont été étudiées, notamment les écorces de pin, de chêne et d'épinette. La présente revue fait le point sur les performances de ces différents adsorbants peu coûteux pour l'adsorption des principaux métaux contaminants (Cd, Cr, Cu, Hg, Ni, Pb et Zn). Les points discutés portent sur les méthodes de préparation (lavage, séchage et tamisage) et de traitement chimique de l'adsorbant (traitement acide ou basique, traitement à la formaldéhyde, phosphatation, carboxylation, sulfoéthylation, carboxyméthylation, etc.), les conditions opératoires utilisées lors de l'adsorption, les modèles thermodynamiques, cinétiques et autres applicables au couple adsorbant-adsorbat, l'effet des principaux paramètres opératoires (temps de contact, pH de traitement, température, concentration d'adsorbant, taille des particules, etc.), les principes et les mécanismes impliqués dans l'élimination des contaminants métalliques par les adsorbants présentés.Wood industry by-products such as barks and sawdusts have been widely studied in recent years for their property of metal adsorption and metal removal from contaminated effluents. Concerning the utilization of sawdusts, many researchers have studied metal adsorption on material from species such as red fir, mango, lime, pine, cedar, teak, Japanese red pine and Japanese beech. As regards wood barks, several species were studied, in particular pine, oak and spruce. The present review gives a progress report on the efficiency of these various inexpensive materials for the adsorption of different metals (Cd, Cr, Cu, Hg, Ni, Pb and Zn). The points discussed relate to the preparation methods (washing, drying, screening) and the chemical treatments of the adsorbents (acid or base treatment, formaldehyde treatment, phosphatation, carboxylation, sulfoethylation, carboxymethylation, etc.). We also consider the operating conditions used during adsorption, the thermodynamic, kinetic and other models applicable to the adsorbent-adsorbate couple, the effect of the operational parameters (time of contact, pH, temperature, adsorbent concentration, particle size, etc.), as well as the principles and mechanisms involved in metal removal by the adsorbents.The accumulation of organic or inorganic matter at the solid-liquid interface is the basis of almost all surface reactions. Adsorption is often a process described in terms of isotherms, which represent the relationship between the concentration of a solute in solution and the quantity adsorbed at the surface at constant temperature. The isotherms are often used to establish the maximum adsorption capacity of a given adsorbent for metals. Langmuir and Freundlich isotherms are the most frequently used and their models are presented in this review.Knowledge of adsorption parameters is essential for understanding the adsorption mechanisms involved. Usually, the maximum adsorption capacity for sawdusts and barks is reached after one hour. The pH of the ambient water is a very important parameter because it affects the metal adsorption capacities. For most of the metals studied, the adsorption capacity increases when the pH increases. The opposite effect is observed for metals involved in an anionic complex (Cr, Se, Pt, Au). Metal adsorption efficiency also improves with increases in substrate concentration because there are more available adsorption sites. Metal adsorption is affected by an another important factor, the particle size. In effect, a smaller size particle increases the specific surface and improves the adsorption capacity. The presence of anions in the effluent doesn't appear to have a great effect on adsorption results with sawdusts. However, some anions were reported to have an influence on the metal adsorption capacities of barks. In the case of a metal mixture, the presence of one metal may influence, compete or exclude the recovery of another metal from the solution.Sawdusts contain lignin, cellulose, tannin and protein. Wood tannin likely serves as a primary adsorption site for divalent cations. The application of chemical treatments on sawdusts could modify the lignin functional groups. Other studies regarding the participation of major components of barks (lignin, carbohydrate and protein) in the adsorption process revealed the involvement of amine and carboxyl functional groups. The proposed mechanism involves an ion-exchange process. This phenomenon suggests that cationic exchange is the active mechanism for some wood species, in agreement with the work of some researchers.Currently, only a few industries use plant biomass to eliminate metals in wastewater. To encourage industries to use this biotechnology, research has to be oriented towards the cheapest and most competitive process rather than the current and conventional process. Forest waste products are produced in large quantities in several countries. They constitute easily-available resources of low cost. Future research in this field should be focused on cheap new chemical treatments to apply to by-products to improve their adsorption capacities

Phytochemical evaluation and vasodilatory activity of O. elongatum, C. salviifolius and C. laurifolius

The high blood pressure is one of the main causes of death and cardiovascular diseases. Vasodilator medications are frequently used to treat arterial hypertension. The aim of this study was to evaluate vasodilator properties of three plants from North of Morocco then to quantify phenolic compounds and flavonoids in each plant extracts. The leaves of Origanum elongatum, Cistus salviifolius and Cistus laurifolius were extracted with hexane, methanol and ethyl acetate by ultrasonic apparatus. The total phenolic content, analyzed using Folin–Ciocalteu’s reagent, of the samples varied from 46.6 µg/100 mg to 153 µg/100 mg dry weight, expressed as gallic acid equivalents (GAE). The total flavonoid concentrations, detected using 2% aluminum chloride, varied from 3.63 to 5.54 µg equivalents (RE)/mg dry weight. Under different plant growth regulators induce a vasodilator effect on Wistar rat mesenteric vascular bed pre-contracted with norepinephrine. for O.elongatum, the methanolic extracts at (PP = 50 mmHg) were found to be more active than the acetylcholine with a concentration of 10-4 M taken as a reference  (PP = 40 mmHg) and The vasodilator activity of methanolic extract of Cistus laurifolius at 100 μg/ml is the same as the reference (PP=40 mmHg). the vasodilator activity found in the three plants studied is due to their antioxidant power

Profile of patients with HPV infection at the regional hospital of Saint-Louis, Senegal

Background: Objectives of current study was to define the sociodemographic characteristics of patients, to determine the frequency of HPV infection at the CHRSL and to describe factors associated with HPV infection. Methods: This was a prospective cross-sectional study conducted in the gynecology-obstetrics department of the Saint Louis Regional Hospital Center from November 11, 2019 to November 11, 2021, a period of 24 months. We studied sociodemographic, clinical and test results characteristics. Samples were taken from patients in the gynaecological position using a dedicated kit (cytobrush and tube). Viral research was carried out using the Atila Biosystems device for amplification and detection of viral DNA. This test genotypes HPV 16, 18 and 45, and detects 12 other HR HPVs (31, 33, 35, 39, 51, 52, 56, 58, 59, 66 and 68) simultaneously using three probes labelled with different fluorophores. Analysis was performed using Epi-Info software and Excel 2010. Results: The study population comprised 128 patients. The mean age of the patients was 41.95 years, with extremes of 23 and 70 years. They were married (92.97%) and housewives (46.88%). Almost all patients (77.34%) were genitally active. The average age at marriage was 21.78 years, and polygamous households predominated (53.91%). The average age at first intercourse was 20.05 years. The average age at first pregnancy was 21.78. Over (57.81%) of patients had at least two partners. Incense was used in 97.66% of cases. The viral HPV test was positive in (38.28%) of patients. High-risk papillomaviruses were the most common, at 63.27%. Colposcopy was performed in 17.19%; normal and satisfactory in (63.64%) of patients, with 22.27% of cervical biopsies, and histology showed one CIN2 and two CIN3. Therapeutically, one thermoablation and two hysterectomies were performed. Conclusions: HPV viral typing in primary screening for cervical cancer offers opportunities and remains realistic and feasible in less developed countries such as Senegal, despite modest resources

Healthcare-associated infections in a tunisian university hospital: From analysis to action

Introduction: our study was conducted, in university hospital center (UHC) Farhat Hached of Sousse (city in Tunisian center-east), within healthcare-associated infections (HAI) epidemiological surveillance (ES) program,  based, among others, on HAI regular prevalence surveys. Our objectives are to resituate HAI prevalence rate and to identify their risk factors (RF) in order to adjust, in our hospital, prevention programs.Methods: it is a transversal descriptive study, including all patients who had been hospitalized for at least 48 hours, measuring prevalence of HAI a “given day”, with only one passage by service. Risk factors were  determined using Epiinfo 6.0, by uni-varied analysis, then, logistic  regression stepwise descending for the variables whose pResults: the study focused on 312 patients. Infected patients prevalence was 12.5% and that of HAI was 14.5 %. Infections on peripheral venous catheter (PVC)  dominated (42.2%) among all HAI identified. HAI significant RF were neutropenia (p<10-4) for intrinsic factors, and PVC for extrinsic factors (p=0,003). Conclusion: predominance of infections on PVC should be subject of specific prevention actions, including retro-information strategy, prospective ES, professional practices evaluation and finally training and increasing awareness of health personnel with hygiene measures. Finally,  development of a patient safety culture with personnel ensures best adherence to hygiene measures and HAI prevention

INTERGROWTH-21st very preterm size at birth reference charts

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Historical Scientific Racism and Psychiatric Publications: A Necessary International Anti-racist Code of Ethics

Ethical aspects of publishing in scientific journals are an important issue addressed since the late 1970s by the International Committee of Medical Journal Editors (1978). Today, medical journals also benefit from other international organizations’ recommendations such as the Committee on Publication Ethics, World Association of Medical Editors, and World Health Organization (WHO). These international best practices guidelines cover various ethical issues related to integrity in research, authorship, conflicts of interest, and so on

Implementation of the INTERGROWTH-21st Project in Kenya

The African site in the INTERGROWTH-21(st) Project was Parklands, a wealthy suburb of Nairobi, Kenya, with a largely middle-to-high socio-economic status population. There are three hospitals with obstetric units in Parklands, with approximately 4300 births per year. The Newborn Cross-Sectional Study (NCSS) sample was drawn from all three hospitals, covering 100% of births in this target population. The Fetal Growth Longitudinal Study (FGLS) sample was recruited from antenatal clinics serving these hospitals, using the eligibility criteria in the INTERGROWTH-21(st) protocol. Special activities to raise awareness of the study included securing media coverage and distributing leaflets in antenatal clinic waiting rooms. FGLS required women to be recruited in the first trimester; therefore, a major challenge at this study site was the high background frequency of first antenatal consultations in the second trimester. The problem was overcome by the study awareness campaign, as a result of which more women started attending antenatal care earlier in pregnancy