Search

A synthesized MIL-101-NH2 has been used as an adsorbent to analyze Congo red (CR), methyl orange (MO), and acid chrome blue K (AC) dye adsorption phenomena. This investigation, based on statistical physics treatment, applied the double layer model with two energies to understand dye adsorption on three samples, namely, MIL-101-NH2-1, MIL-101-NH2-2, and MIL-101-NH2-3, at T = 298 K. Modeling results indicated that dye adsorption occurred via a mixed adsorption orientation for CR and MO dyes and a non-parallel orientation for AC dye on the MIL-101-NH2 surface. Dye uptake quantities varied from 2534.4 to 3440 mg/g for CR dye, 240.4 to 490.8 mg/g for MO dye, and 277 to 293 mg/g for AC dye. Thus, the highest adsorption amount appeared in the case of CR dye. Interpretation of the calculated energies showed that adsorption of the dyes on MIL-101-NH2 is a physisorption phenomenon, which could be controlled through energetic parameters obtained via numerical findings using the statistical double layer model. Moreover, the expression of the model is exploited to investigate the thermodynamic functions, such as internal energy. [ABSTRACT FROM AUTHOR]

In this paper, a synthesized zeolite (ZSM-5) is used as an adsorbent to analyze the adsorption phenomenon of carbon dioxide. This investigation, based on the statistical physics treatment, applied the multilayer model with saturation to understand the CO2 adsorption on four samples, namely M-ZSM-5 (M = Na+, Mg2+, Zn2+, La3+), at various temperatures T = 0 °C, 30 °C and 60 °C. The modeling results indicated that CO2 adsorption occurred via a non-parallel orientation on the ZSM-5 surface. The CO2 adsorption capacities varied from 26.14 to 28.65 cm3/g for Na-ZSM-5, from 25.82 to 27.97 cm3/g for Mg-ZSM-5, from 54.82 to 68.63 cm3/g for La-ZSM-5 and from 56.53 to 74.72 cm3/g for Zn-ZSM-5. Thus, Zn-ZSM-5 exhibits the highest adsorption amount. The analysis of the adsorption energies shows that the adsorption of CO2 on ZSM-5 zeolite is a physisorption phenomenon that could be controlled thanks to the energy parameters obtained via the numerical findings using the multilayer statistical model. Finally, the distribution of site energy was determined to confirm the physical character of the interactions between adsorbate/adsorbent and the heterogeneity of the zeolite surface. [ABSTRACT FROM AUTHOR]

Experimental adsorption isotherms of hydrogen in CNT samples (CNT-A, activated CNT-A CNT-B and activated CNT-B) at T = 77, 87 and 90 K have been fitted using some theoretical model expressions treated by statistical physics through the grand canonical ensemble. The monolayer model with single energy is selected to fit and interpret the experimental data obtained with CNTs. The physico-chemical parameters, interfering in the adsorption process and implicated in the model expressions, could be directly determined from the experimental data through numerical simulation. Three parameters of the model are fitted, namely the number of hydrogen molecule per site n, the interstitial site density Nm and the energetic parameter P1/2. The evolution of these parameters as function of temperature is plotted and interpreted in relation to adsorption process. Finally, the thermo-dynamic potential functions, which involve in the adsorption mechanism like free enthalpy of Gibbs Ga, internal energy Eint and entropy Sa, are derived by statistical physics calculations from the selected model. [ABSTRACT FROM AUTHOR]

Theoretical model expressions are used in order to adjust four absorption isotherms of hydrogen on LaNi4.6Al0.4 at four different temperatures (T = 288K, 293 K, 303 K and 313 K). The development of these expressions is based on statistical physics formalism and some working hypothesis. The physicochemical parameters intervening in the absorption process and involved in the model expressions could be directly deduced from the experimental absorption isotherms by numerical simulation. The best model that shows a good correlation with the experimental data has been determined. Six parameters of the model are adjusted, namely the numbers of hydrogen atoms per site n1 and n2, the receptor site densities N1m and N2m and the energetic parameters P1 and P2. The behaviors of these parameters are discussed in relationship with temperature of absorption isotherms. Then, a dynamic investigation of the simultaneous evolution with pressure of the two α and β phases is involved in the absorption process using the adjustment parameters. Thanks to the energetic parameters, we calculated the absorption energies, which are typically ranged between 109.871 and 133.634 kJ/mol comparable to usual chemical bond energies. The calculated thermodynamic parameters, such as entropy, Gibbs free energy and internal energy from fitted parameters values showed that the absorption of hydrogen in LaNi4.6Al0.4 alloy was spontaneous and exothermic in nature. [ABSTRACT FROM AUTHOR]

Introduction: The aim of our study was to evaluate occupational reprotoxic risks in women exposed to anticancer drugs in hospitals. Method: We conducted a descriptive analytical study of 68 subjects exposed two groups of subjects: 68 exposed to anticancer drugs and 211 unexposed. The working tools used were the medical-professional questionnaire, the inspection and the semi-quantitative method. The statistical tests used were: z-test, chi-square, relative risk and multivariate analysis: multiple correspondence analysis (ACM) and logistic regression (AIC). Results: Fifteen cases of infertility and 50 abortions were recorded in exposed patients with respective RRof 3.10 and 2.09 and a statistically significant difference (p<0.001). There was no difference in congenital malformations, stillbirths, and low birth weight. These results were confirmed by ACM and AIC. Sterility and abortions have been retained after adjustment of confounding factors by AIC. Conclusion: This study emphasizes the importance of the reprotoxic risks caused by occupational exposure to cancer drugs, and emphasizes the strengthening of protective equipment and the special medical supervision of oncology staff. [ABSTRACT FROM AUTHOR]

Copyright of Environnement, Risques & Santé is the property of John Libbey Eurotext Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Introduction: A study was conducted in the oncology wards of an Algerian university hospital in order to analyse cytostatic handling conditions. Materials and methods: Working conditions were evaluated in 2014 and then re-evaluated after opening of the cancer centre in 2015, using validated tools: professional questionnaire, ward monograph support and oncology ward audit support. The results were compared to clinical practice guidelines and oncology wards were classified according to the percentage compliance: non-compliance (< 69%), partial compliance (70-79%), substantial compliance (80-94%) and high compliance (95-100%). Exposure was evaluated by calculating the Cytotoxic Contact Index (CCI). Results: Oncology wards are situated in three hospitals. Reconstitution is performed in nonspecific treatment rooms with no collective protection measures. 62% of oncology units (oncology, gynaecology and haematology wards) were classified as level 2 and 3 exposure, requiring collective prevention measures. The level of compliance was very low (28%). All wards were classified as non-compliant for all items. Compliance essentially concerned training, quality control and hygiene measures. An improvement of cytostatic handling conditions was observed in 2015, concerning personnel training, recruitment of clinical pathologists and pharmacists, floorspace and hygiene of premises, storage of cytostatic agents and individual and collective protection equipment. Conclusion: In the light of this study, it appears relevant to improve cytostatic handling conditions by setting up a medical and environmental surveillance programme with the participation of all prevention personnel.

Acute fatty liver of pregnancy (AFLP) is a rare, potentially fatal complication that occurs in the third trimester or early postpartum period. It generally appears between weeks 30 and 38. Usually the APLF symptoms start one to two weeks before hospitalization with nausea, emesis, general uneasiness, jaundice, epigastric pain and other symptoms. A careful history and physical examination, in conjunction with compatible laboratory and imaging results, are often sufficient to make the diagnosis, and liver biopsy is rarely indicated. The maternal outcome has improved enormously during the last decade. Early diagnosis, pregnancy termination and handling in special care or treating complications has lead to good maternofetal results.

Aim: Our aim was to evaluate the indications and contribution of liver biopsy (LB) in intensive care (ICU) and to compare them to those of LB in gastroenterology., Methods: We included retrospectively 37 successive LB achieved in ICU and 38 successive LB achieved in gastroenterology. All data were reviewed by three intensivists and three gastroenterologists to determine the contribution of the LB., Results: The indications of LB were different in the two units. The most frequent indications were cirrhosis (36.8%), isolated biological hepatic disruptions (26.3%) and histological classification of viral hepatitis (18.4%) in gastroenterology and isolated biological hepatic disruptions (48.6%), hepatopathy during pregnancy (27%) and fever of unknown origin (10.8%) in intensive care unit. According to the six reviewers, LB was enough contributive in the two units, (78.4% in ICU and 71.1% in gastroenterology -p=0.46-). It allowed to eliminate, to confirm, or to change a diagnosis in more than 70% of cases and allowed to modify the course of therapy in 21.6% of cases in ICU and in 26.3% of cases in gastroenterology (p-0.6)., Conclusion: The LB is a feasible technique in ICU and can be as contributive as it is in gastroenterology.

Background: A case of organophosphorus intoxication with rebounding symptoms is reported., Case Report: Case report of a 24-year-old man who poisoned himself with organophosphorus pesticide and was hospitalized in a 22-bed adult medical surgical intensive care unit at a tertiary care hospital. The patient had ingested organophosphorus pesticide after an argument and fight with his family and had presented typical clinical and biological manifestations of intoxication by this chemical. He was treated by mechanical ventilation, large fluid infusion, gastric lavage, as well as atropine and pralidoxime. After 48 hours of intensive care, the patient improved considerably, but shortly after this improvement, mental, hemodynamic, and respiratory status altered again. Gastric fibroscopy showed a small plastic bag containing powder in the stomach which was responsible for the rebounding symptoms of the intoxication., Conclusions: Gastric fibroscopy can be helpful in case of organophosphorus intoxication with persistent or rebounding symptoms.