Synthesis and comparative study of the structural and optical properties of binary ZnO-based composites for environmental applications

The development of photoactive systems to solve serious environmental problems is a key objective of researchers and remains a real challenge. Herein, n-p heterojunction ZnO-based composites were developed to achieve better photocatalytic performance in methylene blue (MB) degradation under natural solar irradiation. The hydrothermal technique was used to synthesize zinc oxide (ZnO)/metal oxide (MO) composites, with a molar ratio of 1 : 1 (MO = Mn₃O₄; Fe₃O₄; CuO; NiO). Various characterization techniques were used for the analysis of the structural, morphological and optical properties. X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDX) Diffuse Reflectance Spectroscopy analysis (DRS), and Diffuse Reflectance Spectroscopy analysis (DRS) validated the presence of two phases for each sample, excluding any impurities. Indeed, the ZnO structure was not affected by the coupling with MO, confirming that MO was well dispersed on the surface of the ZnO crystalline lattice for each composite. Eventually, the photocatalytic performance evaluation test of the synthesized photocatalysts was carried out on aqueous MB solution. According to the results, the ZnO/Fe₃O₄ nano-catalyst showed the best photodegradation efficiency. This result suggests that the formation of Fe₃O₄/ZnO as a p/n heterojunction reduces the recombination of photo-generated electron/hole pairs and broadens the solar spectral response range, resulting in significant photocatalytic efficiency. Meanwhile, the possible mechanism for degradation of the MB was discussed.

Enhanced photocatalytic activity against crystal violet dye of Co and In doped ZnO thin films grown on PEI flexible substrate under UV and sunlight irradiations

This work is focused on the photocatalytic activities of undoped ZnO, Co (1%) doped ZnO (CZO) and In (1%) doped ZnO (IZO) thin films grown on flexible PEI (Polyetherimide) substrate by spray pyrolysis. The photodegradation of crystal violet dye was investigated under UV and sunlight irradiations. Doping and excitation energy effects on photocatalytic efficiencies are discussed. All ZnO thin films show high photocatalytic efficiency up to 80% under either UV or sunlight irradiations for 210 min. However, CZO has the higher photocatalytic performance under UV irradiation. While, the photodegradation efficiency of IZO was enhanced under sunlight irradiation due to the narrowing of its optical gap. These results are discussed based on structural, morphological and optical investigations. The photocatalytic stability of ZnO films was studied as well. So, after three photocatalysis cycles, all ZnO thin films still effective. The obtained results are promising for the use of doped ZnO/PEI as talented photocatalysts for applications in large surfaces with various geometries for photodegradation of hazardous pollutants.

Fulminant mulch pneumonitis in a previously healthy child

Chronic granulomatous disease (CGD) is associated with multiple and recurrent infections. In patients with CGD, invasive pulmonary infection with aspergillus species remains the greatest cause of mortality. Acute fulminant presentations of fungal pneumonia are catastrophic. It is a medical emergency, and currently the treatment is based on association of corticosteroids and antifungal therapy. We describe the case of an 11-year-old boy, with late initial presentation of CGD, which was revealed by fulminant aspergillus pneumonia. He was successfully treated with an association of high doses of steroids and voriconazole.

Management of cholestatic pruritus in children with Alagille syndrome: Case report and literature review

Alagille syndrome causes intractable pruritus and disfiguring xanthomas because of retained bile acids and cholesterol. Drug therapy in addition to surgical intervention may be effective in many patients in reducing serum bile acids, cholesterol levels, pruritus, and skin xanthomas. In this report, we describe a child with Alagille syndrome who presented with severe pruritus and xanthomas as a consequence of severe hypercholesterolemia and discuss the treatment modalities.

Transient neonatal diabetes mellitus and activating mutation in the KCNJ11 gene in two siblings

Transient neonatal diabetes mellitus is a rare disease usually associated with chromosome 6 abnormalities. Mutations of the genes encoding the potassium channel are rarely associated with these transitional forms. Herein, we report the clinical features of two siblings with a heterozygous mutation C679 G>A in the KCNJ11 gene.

Familial haemophagocytosis lymphohisticytosis type 3: A case report

Familial hemophagocytic lymphohistiocytosis (FHL) is a rare autosomal recessive disorder of immune regulation. Here, we report on a fatal case of type 3 FHL (FHL3) in a 45-day-old boy. Clinically, the infant presented with fever and hepatosplenomegaly. Biology showed pancytopenia, elevated ferritin, and decreased fibrinogen. Images of hemophagocytosis were found at the bone morrow examination. The diagnosis of FHL type 3 was made by the identification of homozygous mutation in the Munc13-4 gene (UNC13D) located in exon 20: 1822 del 12bp (V608fs). This mutation was previously observed in a Tunisian and in Moroccan families.

Macrophagic activation syndrome related to an infection by Rickettsia conorii in a child

Since the Arab Spring, a resurgence of zoonotic diseases such as rickettsiosis, endemic in the Mediterranean basin, has been observed. It preferentially infects microvascular endothelial cells of mammalian hosts inducing vasculitis with endothelial injury. Rickettsioses are considered benign infectious diseases. Severe systemic manifestations have been reported and are often explained by a delay in diagnosis. We present a case of hemophagocytic syndrome occurring in a 4-year-old Libyan girl as a complication of Mediterranean spotted fever. Rickettsial infection was confirmed by serology and the patient was treated with clarithromycin, with a favorable outcome.

[Unilateral to bilateral pleurisy: Pleural tuberculosis?]

Pleural tuberculosis is the first or second most common form of extrapulmonary tuberculosis as well as the main cause of pleural effusion in many countries. It is rare in young infants and is more common in children over 10 years of age. We report the case of a 19-month-old girl admitted for prolonged fever with unilateral pleural effusion. The mother reported a history of lymph node tuberculosis 6 years previously. Intravenous antibiotics with cefotaxime and vancomycin were started. Thoracocentesis yielded a serosanguinous exudate fluid with a lymphocyte predominance. The tuberculin skin test and PCR GeneXpert(©) on pleural fluid were negative. The initial outcome was favorable, but the chest X-rays 10 days after discharge showed bilateral pleural effusion. Pleural biopsy was proposed but the culture of pleural fluid was positive for Mycobacterium tuberculosis. The child was put under standard treatment for tuberculosis. The outcome was favorable.

Unusual intraatrial thrombus in a neonate with coarctation of the aorta

Left atrial thrombus in neonates is uncommon. We describe a newborn with coarctation of the aorta, in whom a thrombus confined to the left appendage was discovered on the first day of life and was thought to be a myxoma.

[Neonatal renal candidiasis: a case report]

Neonatal renal candidiasis is an increasingly common condition affecting predominantly premature infants receiving neonatal intensive care or term infants with urogenital tract anomalies.

CASE REPORT

a female infant was born by cesarian section at 30 weeks' gestation to a mother whose pregnancy had been complicated by rupture of membranes for 5 days. The infant was admitted at birth, maternofetal bacterial infection was suspected, and intravenous antibiotics were prescribed. The patient developed sepsis caused by Klebsiella pneumoniae at the age of 13 days. She was referred to our hospital at the age of 50 days because of renal abscess. At admission, the baby presented with hypothermia and abdominal distention. Renal ultrasonography findings were compatible with fungal disease. Blood, urine, and cerebrospinal fluid cultures were negative for fungi; however, galactomannan antigen blood levels were increased. Amphotericin B was administered for 6 weeks. End-organ evaluation of the heart, brain, and eyes did not demonstrate disseminated infection. The patient was discharged with a prescription for oral fluconazole and remained well at follow-up.

Effect of estradiol and tamoxifen on brain membranes: investigation by infrared and fluorescence spectroscopy

Nongenomic effects of steroids on rat brain neurotransmitter transporters and receptors have been reported in several laboratories. In the present study, we have investigated possible membrane effects of 17alpha- and 17beta-estradiol, as well as tamoxifen, by studying their interactions with synthetic phospholipid membranes using Fourier transform infrared spectroscopy. We have also used the fluidity of rat striatal and frontal cortex membranes, as determined by fluorescence depolarization of the probe 1,6-diphenyl-1,3,5-hexatriene (DPH), to probe the effects of these drugs on membranes. Our results show that tamoxifen induces conformational disorder along the acyl chains of deuterated dimirystoylphosphatidylcholine and decreases the gel to liquid-crystalline phase transition temperature by approximately 10 degrees C. Similar effects, although less pronounced, were observed with 17beta-estradiol, whereas 17alpha-estradiol had no significant effect. The DPH fluorescence anisotropy of striatum and frontal cortex membranes was decreased in vitro with 17beta-estradiol or tamoxifen and also with 17alpha-estradiol, but to a lesser extent. These results suggest a stereospecific estradiol effect on membranes and that the effects of these compounds are not related to their activity on estrogen receptors. These observations support a different mechanism of action of steroids that could be implicated in their neuroprotective activity.