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1.
Ren Fail ; 46(1): 2344651, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38655865

RESUMO

Background: Symptoms of dyspepsia are usually encountered by chronic kidney disease patients. Abdominal discomfort is commonly seen in CKD patients with no other causes of organic affection. Aim: to determine the prevalence of functional dyspepsia in CKD patients, and which subtype is predominant in them. Materials and patients: This observational study included 150 CKD patients. Clinical and laboratory data were recorded for every patient. All the patients were interviewed using the ROME IV questionnaire of functional dyspepsia. Patients fulfilling criteria for functional dyspepsia were exposed to upper GI endoscopy. Results: Overall, 73 (48.7%) of CKD patients were males and 77 (51.3%) were females with mean age of (45.71 ± 9.59) and mean BMI (26.58 ± 5.39). The frequency of functional dyspepsia among CKD patients was determined to be 14.7% (22 out of 150 patients). Among those affected by functional dyspepsia, the most prevalent subtype was found to be Epigastric Pain Syndrome (EPS), accounting for 59% (13 out of 22 cases). The most common predictor of FD in CKD patients was chronic HCV infection, hemodialysis, stage of CKD and eGFR as revealed by Univariate regression analysis. Conclusion: The prevalence of FD amongst CKD patients is 14.7% with EPS the predominant subtype. Male patients, HCV patients, patients with higher CKD stages and highly impaired eGFR (low eGFR) are more probable to have FD.


Assuntos
Dispepsia , Insuficiência Renal Crônica , Humanos , Masculino , Dispepsia/epidemiologia , Dispepsia/complicações , Feminino , Pessoa de Meia-Idade , Insuficiência Renal Crônica/epidemiologia , Insuficiência Renal Crônica/complicações , Prevalência , Adulto , Inquéritos e Questionários , Dor Abdominal/epidemiologia , Dor Abdominal/etiologia
2.
BMC Ophthalmol ; 23(1): 266, 2023 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-37312088

RESUMO

BACKGROUND AND PURPOSE: Collagen cross-linking (CXL) has evolved as an essential therapeutic approach for corneal infections, allowing for rapidly eliminating the infecting microorganism while reducing inflammation. This study aims to evaluate the efficacy of CXL as a monotherapy for managing infectious keratitis caused by Fusarium solani and Pseudomonas aeruginosa. MATERIALS AND METHODS: Forty-eight white New Zealand rabbits weighing approximately 1.5-2 KG were included. The cornea of one eye of each rabbit was inoculated with either Fusarium solani or Pseudomonas aeruginosa. Group A served as a control and was subdivided into two subgroups, A1 and A2; each subgroup consisted of 8 eyes and was injected with either Fusarium solani or Pseudomonas aeruginosa, respectively. Group B (16 eyes) was inoculated with Fusarium solani, while group C (16 eyes) were inoculated with Pseudomonas aeruginosa. All animals in Group B and C received CXL treatment one week after inoculation of the organisms and after corneal abscess formation was confirmed. At the same time, animals in Group A were left untreated. RESULTS: There was a statistically significant reduction in the number of colony-forming units (CFU) in Group B following CXL. No growth existed in any samples at the end of the 4th week. There was a statistically significant difference in the number of CFU between group B and the control group (p < 0.001). In group C, there was a statistically significant reduction in the CFU at the end of the first week after CXL. However, there was regrowth in all samples afterward. All 16 models in Group C showed uncountable and extensive growth during the subsequent follow-ups. There was no statistically significant difference between the number of CFU in Group C and the control group. Histopathology showed lesser corneal melting in CXL-treated Pseudomonas aeruginosa. CONCLUSIONS: Collagen cross-linking is promising monotherapy and alternative treatment in managing infective keratitis caused by Fusarium solani but is less effective in Pseudomonas aeruginosa as monotherapy.


Assuntos
Abscesso , Ceratite , Animais , Coelhos , Abscesso/tratamento farmacológico , Colágeno , Córnea , Ceratite/tratamento farmacológico , Ceratite/microbiologia , Pseudomonas aeruginosa
3.
Clin Exp Hepatol ; 8(2): 125-131, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36092754

RESUMO

Aim of the study: Occult hepatitis C virus (HCV) infection (OCI) is a potential source of relapse after liver transplantation with subsequent graft damage. The aim of the study was to detect OCI in patients with living donor liver transplantation (LDLT) who achieved sustained virological response (SVR) after sofosbuvir-based antiviral treatment, and to detect risk factors associated with the development of OCI as well as to determine the effect of direct acting antiviral (DAA) therapy after liver transplantation. Material and methods: 41 patients with living donor liver transplantation who did not receive DAAs before with recurrent HCV infection who achieved a SVR with sofosbuvir-based therapy for 12-24 weeks were recruited. These patients were tested for OCI by HCV-RNA in peripheral blood mononuclear cells (PBMNCs). Those patients with OCI were followed up every 6 months with alanine aminotransferase (ALT), aspartate aminotransferase (AST), and serum HCV-RNA by PCR for 2 years. Results: 92.7% of treated patients achieved HCV SVR 12 weeks. OCI was detected in 4 patients. After follow-up for 18 months, 3 patients continued to have OCI, but one patient presented with progressive elevation of liver enzymes and developed overt HCV infection with positive HCV-RNA PCR in the serum. This patient was retreated with sofosbuvir 400 mg + ledipasvir 90 mg for 12 weeks with resultant negative HCV-RNA PCR in both serum and PBMNCs in addition to normalization of liver enzymes. Conclusions: Occult HCV infection is a potential source of HCV relapse after liver transplantation which should be investigated for in PBMNCs or liver biopsy.

4.
Graefes Arch Clin Exp Ophthalmol ; 260(1): 363-369, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34427739

RESUMO

PURPOSE: To compare the postoperative alignment, degree of improvement of abduction, and complications of the Hummelsheim procedure to the Jensen procedure in chronic sixth nerve palsy, and to calculate the dose-response of both procedures. METHODS: A retrospective study was done on patients who either had Hummelsheim or Jensen procedure for chronic sixth nerve palsy. Demographic characteristics, details of surgical procedure, ductions, versions, and angles of misalignment before and after surgery were analyzed. RESULTS: A total of 79 patients were identified: 38 Jensen and 41 Hummelsheim. There were no statistically significant differences in baseline characteristics of both groups. Medial rectus recession was performed in 35 patients in the Jensen group and in 30 patients in the Hummelsheim group. Success defined as orthotropia within 8 PD was achieved in 25 (66%) patients in the Jensen group and in 24 (59%) patients in the Hummelsheim group (P = 0.51). The mean improvement in the angle of deviation in the primary position was 42 ± 12 PD in the Jensen group and 42 ± 16 PD in the Hummelsheim group (P = 0.89). The mean improvement in abduction was slightly better in the Hummelsheim group (1.8 vs 1.5, P = 0.32). A new vertical deviation occurred in three patients in the Jensen group and in 4 patients in the Hummelsheim group. Anterior segment ischemia occurred in one patient in the Jensen group. CONCLUSIONS: There was no difference in the success rate between the Hummelsheim and Jensen procedures in cases of chronic sixth nerve palsy. Strabismus surgeons can choose between the two procedures according to their preference.


Assuntos
Doenças do Nervo Abducente , Esotropia , Doenças do Nervo Abducente/diagnóstico , Doenças do Nervo Abducente/cirurgia , Esotropia/cirurgia , Movimentos Oculares , Humanos , Músculos Oculomotores/cirurgia , Procedimentos Cirúrgicos Oftalmológicos , Estudos Retrospectivos
5.
Middle East J Dig Dis ; 14(2): 214-221, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36619155

RESUMO

BACKGROUND: Patients with chronic hepatitis C virus (HCV) usually have different abdominal complaints without any organic lesions. The functional cause of these complaints is claimed in most patients. This study aimed to evaluate functional gastrointestinal disorders (FGIDs) in patients with chronic hepatitis C using Rome IV diagnostic criteria. METHODS: This study included 1506 participants (1006 patients with chronic HCV, and 500 controls). All individuals were subjected to taking thorough medical history, basic investigations (complete blood counts, liver and renal functions tests), international normalized ratio (INR), alpha-fetoprotein, HCV RNA PCR (polymerase chain reaction), abdominal ultrasonography, and upper gastrointestinal tract (GIT) endoscopy for patients only), and Rome IV diagnostic questionnaire. RESULTS: Patients with HCV had symptoms of FGIDs including functional dyspepsia (FD) (P=0.009), early satiety (P=0.002), postprandial distress (P=0.02), epigastric pain (P=0.03), Inflammatory bowel syndrome (IBS) (P<0.001), IBS predominant constipation (P<0.001), IBS predominant diarrhea (P<0.001), and IBS mixed (P<0.001). There were multiple factors for the prediction of FD in patients with HCV, including high body mass index (BMI), education level, positive polymerase chain reaction (PCR), and fibrosis stage. Also, there were multiple factors for the prediction of IBS in patients with HCV, including male gender, high BMI, urban residence, education level, positive PCR, and fibrosis stage. CONCLUSIONS: FD is a prevalent finding in obese patients with HCV and with higher fibrosis scores. IBS is also prevalent in male patients with HCV.

6.
Biomolecules ; 10(7)2020 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-32679821

RESUMO

A new biorefinery approach has been developed in the present study, and applied on cumin (Cuminum cyminum) seeds as a potential source of phytochemicals of interest. Cumin is a popular spice used widely for its distinctive aroma. It is a rich reserve of both vegetable and essential oils. The biorefinery approach here focused on the evaluation of the influence of four different geographical origins (i.e., Lebanon, France, Algeria and Syria) on oil yield and quality in cumin seed, and on the valorization of remaining by-products by investigating their nutritional content and biological activity for the first time. Vegetable and essential oils were extracted, and their compositions were determined. Nutritional traits were also assessed. The delipidated and hydrodistillated cakes just as aromatic water were characterized for their fiber, sugar, protein, phenol and flavonoid contents. Antibacterial and antioxidant activities were also determined. Cumin seeds showed high contents in both vegetable and essential oils, proteins and sugars regardless their origin. Moreover, this Apiaceae species exhibited high levels of petroselinic fatty acid (an isomer of oleic acid) and sterols. Cakes and aromatic water also presented high levels of proteins, fibers, sugars and phenols. These residues revealed interesting antioxidant and antibacterial activities. These results emphasized the potential use of cumin in a biorefinery concept, with a multi-purpose industrial process. In addition, large differences were observed between the four geographical origins for phytochemical contents and compositions. These findings highlight the perspectives for developing selection programs for nutritional traits and industrial interests. All obtained results validate the health promoting effect of cumin composition as well as its industrial importance along with the residues.


Assuntos
Cuminum/química , Óleos Voláteis/análise , Compostos Fitoquímicos/análise , Argélia , Cuminum/classificação , França , Líbano , Valor Nutritivo , Filogeografia , Extratos Vegetais/química , Óleos de Plantas/análise , Sementes/química , Síria
7.
Life Sci ; 253: 117725, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32348835

RESUMO

AIMS: Non-alcoholic fatty liver disease (NAFLD) is a common liver disease. This study aimed to evaluate the role of exenatide compared with metformin in halting the progression of fatty liver stimulated by a high-fat diet (HiFD) in rats. MAIN METHODS: Thirty male Wistar rats were allocated into 6 groups, 5 rats per each group. Group I: maintained on normal diet (normal group) for fourteen weeks. The other five groups were kept on HiFD throughout the experiment, HiFD was administered beside pharmacological treatments/or vehicle. Group II: (NAFLD control group), group III: received metformin (60 mg/kg/day, P.O.), group IV-VI: received exenatide (10, 20, and 40 µg/kg/day, S.C.) respectively for 7 weeks. At the end of the therapeutic period, fasting blood glucose was determined, and body weight was registered. Rats were sacrificed, and blood samples were taken to measure serum insulin, lipids, and liver enzymes. The liver index and homeostasis model of insulin resistance (HOMA-IR) index were calculated. Further, livers were dissected for histopathological examination and Western blot analysis. KEY FINDINGS: NAFLD control group showed hyperglycemia, hyperinsulinemia, increased liver enzymes, hypertriglyceridemia, elevated hepatic lipid peroxides, and inflammatory mediators (interlukin 6, nuclear factor-κB, tumor necrosis factor-α and Toll-like receptor4) in addition to hepatic fatty degeneration. In a dose-dependent manner, exenatide significantly improved most of the above mentioned markers in comparsion with NAFLD at P≤0.05. SIGNIFICANCE: The current results suggest that exenatide is equivalent to metformin in controlling insulin resistance, body weight gain, improving liver function, suppressing inflammation, and attenuating NAFLD progression in male rats.


Assuntos
Exenatida/farmacologia , Hipoglicemiantes/farmacologia , Inflamação/tratamento farmacológico , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Animais , Peso Corporal/efeitos dos fármacos , Dieta Hiperlipídica , Progressão da Doença , Relação Dose-Resposta a Droga , Exenatida/administração & dosagem , Hipoglicemiantes/administração & dosagem , Inflamação/patologia , Resistência à Insulina , Masculino , Metformina/farmacologia , NF-kappa B/metabolismo , Hepatopatia Gordurosa não Alcoólica/patologia , Ratos , Ratos Wistar , Transdução de Sinais/efeitos dos fármacos , Receptor 4 Toll-Like/metabolismo
8.
Foods ; 7(9)2018 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-30200180

RESUMO

The aim of this study was to investigate and compare the effect of wheat bread fortification with varied levels (2%, 4%, and 6%) of chia seed powder (full fat) and cakes (defatted, residue after oil extraction). Chia flour was added to whole wheat bread rich in vital wheat gluten for the first time. The breadcrumbs were assessed for their antioxidant activity, nutritional content, textural properties, color, and sensory profiles. The addition of chia seed powder, particularly in high levels, was more effective in improving antioxidant activity compared to bread fortified with chia cakes. Bread supplementation with chia flour improves its nutritional value, especially in the case of chia cakes. A higher moisture content and lower hardness were observed after bread fortification, the influence was more evident with the defatted cake than with seed powder. Fortification with chia flour led to darker breads without significantly affecting their global acceptability. However, the fortified bread showed better values than control in terms of sensory profile. These results suggest that the addition of chia seed powder and defatted cake can enhance the overall whole wheat bread quality. Our results also highlight that bread making could be an unconventional alternative for the exploitation of defatted chia seed.

9.
Foods ; 7(3)2018 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-29495324

RESUMO

Malnutrition continues to be a key health problem in developing regions. The valorization of food waste appears as an ideal way to prevent malnutrition and improve people's access to food. Cumin (Cuminum cyminum L.) and caraway (Carum carvi L.) oilseeds are commonly used for cuisine and medicinal purposes. However, remaining cakes after oil extraction are usually underutilized. In order to assess the usefulness of these by-products in food applications, this study investigated the effect of their addition to protein bread formulations. Different levels (2, 4 and 6%) of whole seeds and cakes flour were used in the study. Fortified protein bread samples were compared to control protein bread and evaluated for their sensory, color, moisture, hardness properties, nutritional values as well as their biological activity. Results indicated that bread fortification shows a significant effect on bread properties depending on fortification level. A higher acceptability was observed specially for bread fortified with by-products flour. Increased tendencies of color darkness, moisture content, bread hardness, nutritional values as well as total phenolic content and radical scavenging activity compared to control bread were observed as the percentage of fortification increased in both cases. The overall results showed that the addition of cumin and caraway seeds and by-product flour can improve the antioxidant potential and overall quality of protein bread.

10.
Inorg Chem ; 56(17): 10655-10663, 2017 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-28832136

RESUMO

The preparation of a binuclear Ni(II) complex with a pentacoordinate environment using a cryptand organic ligand and the imidazolate bridge is reported. The coordination sphere is close to trigonal bipyramidal (tbp) for one Ni(II) and to square pyramidal (spy) for the other. The use of the imidazolate bridge that undergoes π-π stacking with two benzene rings of the chelating ligand induces steric hindrance that stabilizes the pentacoordinate environment. Magnetic measurements together with theoretical studies of the spin states energy levels allow fitting the data and reveal a large Ising-type anisotropy and a weak anti-ferromagnetic exchange coupling between the metal ions. The magnitude and the nature of the magnetic anisotropy and the difference in anisotropy between the two metal ions are rationalized using wave-function-based calculations. We show that a slight distortion of the coordination sphere of Ni(II) from spy to tbp leads to an Ising-type anisotropy. Broken-symmetry density functional calculations rationalize the weak anti-ferromagnetic exchange coupling through the imidazolate bridge.

11.
J Environ Manage ; 197: 571-581, 2017 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-28431370

RESUMO

Water scarcity and increasing water demand require the development of water management plans such as establishing artificial lakes and dams. Plans to meet water needs are faced by uprising challenges to improve water quality and to ensure the sustainability of hydro-projects. Environmental isotopes coupled to water physicochemical characteristics were investigated over a biennial cycle to assess both geomorphological and environmental impacts on the water quality of a reservoir situated in an intensively used agricultural watershed under a Mediterranean semi-arid climate. The particularity of the semi-arid climate and the diverse topography generate a continental and orographic rain effect on the isotopic composition of precipitation and the water recharged sources. The studied reservoir responds quickly to land-use activities and climatic changes as reflected by temporal and spatial variations of water chemistry and isotopic composition. Increasing changes in precipitation rate and dry periods significantly modified the water isotopic composition in the reservoir. During the first year, hydrogen (δD) and oxygen (δ18O) isotopes are depleted by 6 and 2‰ between dry and wet season, respectively. While a shift of -2‰ for δD and -1‰ for δ18O was detected during the second annual cycle. Environmental isotopic compositions demonstrate for the first time the occurrence of groundwater inflow to the central (Cz) and dam (Dz) zones of the Qaraaoun reservoir. The Cz and Dz can be considered as open water bodies subjected to dilution by groundwater inflow, which induces vertical mixing and reverse isotopic stratification of the water column. In the contrary, the river mouth zone acts as a closed system without groundwater intrusion, where heavy water accumulates and may act as a sink for contaminants during dry season. Groundwater influx acts as a dilution factor that renews the hypolimnion, and minimizes the perturbations induced by both internal biogeochemical reactions and external hydrological variations. Attention should be devoted to the hydrogeological location of planned reservoirs, which should take into account the vicinity of shallow water table to insure good water quality and water sustainability.


Assuntos
Água Subterrânea , Hidrodinâmica , Monitoramento Ambiental , Hidrologia , Rios
12.
Inorg Chem ; 56(8): 4602-4609, 2017 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-28375018

RESUMO

The preparations of related mononuclear and binuclear Co(II) complexes with a quasi-identical local C3v symmetry using a cryptand organic ligand are reported. The mononuclear complex behaves as a single molecule magnet (SMM). A relatively weak antiferromagnetic exchange coupling (J) of the same order of magnitude as the local magnetic anisotropy (D) is determined experimentally and theoretically for the binuclear complex. The weak magnitude of the antiferromagnetic exchange coupling, analyzed using a combination of broken-symmetry density functional theory and wave function based calculations, is ascribed to the weak overlap between the singly occupied orbitals because of the local C3v symmetry of the Co(II) ions; the organic ligand was found to contribute to the exchange coupling as the azido bridge that directly links the Co(II) ions. Calculation of the energy and wave functions of the spin states for the binuclear complex, in the general case, allows analysis of the effect of the |J/D| ratio on the magnetic behavior of the binuclear complex and prediction of the optimum range of values for the complex to behave as two weakly interacting SMMs.

13.
J Environ Manage ; 178: 20-29, 2016 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-27131954

RESUMO

Column leaching tests were conducted to investigate the effects of soil physicochemical characteristics on metal mobility in the subsurface. The metals investigated originated from disposed industrial waste byproducts and from agrochemicals spread over the farmlands. Soil column tests can provide insights into leaching of metals to underlying water compartments. The findings of this study can be used for prevention strategies and for setting risk assessment approaches to land-use and management, and soil and water quality and sustainability. Soils collected from an industrial (IS) watershed and an agricultural (AQ) hydrographic basin were used in soil column leaching experiments. The soil samples were characterized for mineralogy, functional groups, grain size, surface charge, soil type, porosity, and cation exchange capacity (CEC) along with elemental composition. Varying concentrations of phosphogypsum industrial waste or agrochemical (NPK fertilizer) was then added to the surface of the packed columns (n = 28). The columns were subjected to artificial rain over a period of 65 days. Leachates were collected and analyzed for dissolved Na(+), K(+), and Cd(2+) throughout the experimental period, whereas residual Cd content in the subsurface soil was measured at the end of the experiment. Physicochemical characterization indicated that the AQ soil has a higher potential for metal retention due to its fine clay texture, calcareous pH, high organic matter content and CEC. Metal release was more prominent in the IS soil indicating potential contamination of the surrounding soil and water compartments. The higher metal release is attributed to soil physicochemical characteristics. High calcium concentrations of phosphogypsum origin is expected to compete for adsorbed bivalent elements, such as Cd, resulting in their release. The physicochemical characteristics of the receiving media should be taken into consideration when planning land-use in order to achieve sustainable development. Soil physiochemical characteristics play a key role in determining the behavior and fate of elements upon application of amendments. Sandy soils should not be assigned to industrial zones or landfills due to their high permeability, unlike fine clay soils. Furthermore, application of fertilizers on sandy soils can threaten groundwater quality, whereas their extensive use on clayey soil can cause soil salinisation.


Assuntos
Sulfato de Cálcio/química , Fertilizantes/análise , Metais Pesados/química , Fósforo/química , Solo/química , Adsorção , Humanos , Resíduos Industriais , Líbano , Poluentes do Solo/química , Gerenciamento de Resíduos
14.
Environ Monit Assess ; 187(9): 579, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26293891

RESUMO

This study delineates the physical, chemical, and biological effects resulting from anthropogenic and endogenic activities in a sensitive dammed reservoir situated in a semi-arid region. The reservoir is characterized by two major flow regimes: a wet fill hydrologic regime and a dry spill one. A seasonal sampling campaign was carried out over a period of 2 years (2011-2013) where water samples were collected across the water column and from piezometers just outside the perimeter of the reservoir. Similarly, sediments were collected from the corresponding areas beneath the water column. The water samples were analyzed for environmental isotopic ratios, elemental composition, and physical, biological and chemical parameters, whereas the sediment and algal samples were subjected to physical, mineralogical, spectroscopic, and microscopic analyses. This investigation indicated that the dam had resulted in the alteration of the biogeochemical cycle of nutrients as well as the degradation of the sediment and water quality. The hydrological and biogeochemical processes were found to induce vertical downward transport of chemicals towards the fine grained calcareous sediments during the fill mode, whereas the sediments acted as a source of a chemical flux upward through the water column and downward towards the groundwater during the spill mode. The geomorphological characteristics of the reservoir enhanced the strong hydrological connectivity between the surface water and the groundwater where the reservoir responded quickly to natural and anthropogenic changes in the upper watershed. The water and sediments in the sensitive spill mode were of poor quality and should receive more attention due to the potential hazard for the associated hydro-project and the sustainability of the agricultural soil in the long term. Thus, a safe water and sediment management plan should be implemented in order to improve the dam functionality and to safeguard the precious water resources.


Assuntos
Água Doce/química , Sedimentos Geológicos/química , Água Subterrânea/química , Abastecimento de Água , Monitoramento Ambiental
15.
Inorg Chem ; 52(18): 10264-74, 2013 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-23987215

RESUMO

Based on nickel hexacyanidochromate and cobalt hexacyanidoferrate Prussian blue analogues, two series of photomagnetic/ferromagnetic sub-50 nm core multishell coordination nanoparticles have been synthesized in a surfactant-free one-pot multistep procedure with good control over the dispersity (10% standard deviation) and good agreement with the targeted size at each step. The composition and the valence state of each shell have been probed by different techniques that have revealed the predominance of Co(II)-NC-Fe(III) pairs in a series synthesized without alkali while Co(III)-NC-Fe(II) photoswitchable pairs have been successfully obtained in the photoactive coordination nanoparticles by control of Cs(+) insertion. When compared, the photoinduced behavior of the latter compound is in good agreement with that of the model one. Exchange coupling favors a uniform reversal of the magnetization of the heterostructured nanoparticles, with a large magnetization brought by a soft ferromagnetic shell and a large coercivity due to a harder photomagnetic shell. Moreover, a persistent increase of the photoinduced magnetization is observed for the first time up to the ordering temperature (60 K) of the ferromagnetic component because of a unique synergy.

16.
Environ Sci Pollut Res Int ; 20(12): 9014-25, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23764982

RESUMO

One of the most important sources of solid waste in the Mediterranean Basin ecosystem originated from the phosphate fertilizer industries, which discharge phosphogypsum (PG) directly into aquatic environments or are stacked on stockpiles. The present study investigates metal release from PG under the influence of variable pH, increasing PG mass content, and complexing organic matter ligands. Major ions from PG leachates, grain size and charge, main functional groups along with metal leachability (Pb, Cd, Cr, Cu, and Zn) were determined using ion chromatography, laser diffraction, zetameter, Fourier transform infrared spectroscopy, and atomic absorption spectroscopy, respectively. The complete dissolution of PG recorded is at 2 g/L. Saturation and supersaturation with respect to PG may occur at concentrations of 3 and 4 g/L, respectively, revealing a clustering phenomenon leading to heavy metal encapsulation within the aggregates. Organic ligands such as citrate may trigger the cationic exchange within the PG suspension leading to ion release. As these factors are considered as specific process involving the release of contaminants from PG during storage under natural conditions, this study could set the foundations for PG remediation in aquatic environment. Organic ligands under controlled pH conditions could be utilized in treating fertilizer industrial wastes by taking into consideration the particularity of the receiving area, thus decreasing metal hazardous impact on natural media.


Assuntos
Sulfato de Cálcio/química , Recuperação e Remediação Ambiental/métodos , Metais Pesados/química , Fósforo/química , Poluentes Químicos da Água/química , Sulfato de Cálcio/análise , Fertilizantes/análise , Fertilizantes/estatística & dados numéricos , Resíduos Industriais/análise , Resíduos Industriais/estatística & dados numéricos , Metais Pesados/análise , Fosfatos/análise , Fosfatos/química , Fósforo/análise , Espectrofotometria Atômica , Poluentes Químicos da Água/análise
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