Exploring Reversible Redox Behavior in the 6H-BaFeO3-δ (0 < δ < 0.4) System: Impact of Fe3+/Fe4+ Ratio on CO Oxidation

This work is devoted to evaluating the relationship between the oxygen content and catalytic activity in the CO oxidation process of the 6H-type BaFeO3-δ system. Strong evidence is provided about the improvement of catalytic performance with increasing Fe average oxidation state, thus suggesting the involvement of lattice oxygen in the catalytic process. The compositional and structural changes taking place in both the anionic and cationic sublattices of the catalysts during redox cycles have been determined by temperature-resolved neutron diffraction. The obtained results evidence a structural transition from hexagonal (P63/mmc) to orthorhombic (Cmcm) symmetry. This transition is linked to octahedra distortion when the Fe3+ concentration exceeds 40% (δ values higher than 0.2). The topotactical character of the redox process is maintained in the δ range 0 < δ < 0.4. This suggests that the cationic framework is only subjected to slight structural modifications during the oxygen exchange process occurring during the catalytic cycle.

The possible role of microcystin (D-Leu1 MC-LR) as an antioxidant on Microcystis aeruginosa (Cyanophyceae). In vitro and in vivo evidence

Microcystins constitute a serious threat to the quality of drinking water worldwide. However, the eco-physiological role of them is not completely known and it is suggested that toxins can play a role in the antioxidant protection. The objective of this study was to evaluate the microcystin antioxidant capacity in vitro by Electronic Paramagnetic Resonance, highly specific for the different reactive oxygen species and in vivo by 7 days exposure of Microcystis aeruginosa to high (29 °C) temperature in addition to a 26 °C control condition. An effective in vitro antioxidant activity was observed for [D-Leu¹]MC-LR against hydrosoluble radicals. As far as we know, this is the first in vitro record of the role of MC as antioxidant. In addition, a significant increase in cellular biomass was observed under 26 °C in cultures with [D-Leu¹]MC-LR supplementation in coincidence with a significant decrease of reactive species. For cultures at 29 °C, the antioxidant role of toxins was inconclusive probably due to the presence of different reactive species generated during the experiment. Thus, MC could scavenge certain reactive species associated with the antioxidant role of CAT or the OH content by SOD activity (not measured) and then CAT activity could be lower in the presence of MC. Reinforcing our hypothesis, the [D-Leu¹]MC-LR consumption after 7 days was significantly higher in cells with [D-Leu¹]MC-LR supplementation in both 26 °C and 29 °C.When the production of reactive species was controlled by the scavenger activity of antioxidants plus MC, cells avoided the potential oxidative damage and started with exponential growth.

Atomically Resolved Short-Range Order at the Nanoscale in the Ca-Mn-O System

The elucidation of the reaction mechanisms involving redox processes in functional transition-metal oxides, which usually start in areas of very few nanometers in size, is yet a challenge to be satisfactorily achieved. Atomically resolved HAADF and EELS have provided both chemical and structural information at the nanoscale, which reveal the preservation of short-range cationic order in areas of 2-3 nm length as the driving force behind the reversibility of the Ca₂Mn₃O₈-Ca₂Mn₃O₅ redox process. Oxygen evolution is accommodated by cationic diffusion along the Ca and Mn layers of the cation-deficient Ca₂Mn₃O₈ delafossite related structure, whereas Mn remains octahedrally coordinated.

[Small bowel intussusception in the adult caused by ileal submucous lipoma]

We present the case of a 68 year-old male patient with secondary intestinal intussuspection due to a submucous li-poma of the ileum. This is a rare entity in adults and is usually due to an organic lesion. The clinical manifestation is characterized by vomiting, abdominal pain and melenas. In our case the patient, following a colonoscopy and an abdominal CT-scan, was subjected to an extended resection of caecum and terminal ilium. At present, the precision of the etiological diagnosis of intussuspections has increased thanks to the development of image tests, like CT-scan. Early surgical treatment is recommended, without intraoperative deintussuspection given the high risk of presenting a malign or ischemic lesion in the adult.

Polidocanol foam stability in terms of its association with glycerin

Objectives:

Foam sclerotherapy effectiveness mainly depends on the concentration of the sclerosing agent and foam stability. The objective of this study was to determine if the addition of glycerol at different concentrations contributes to the stability of polidocanol foam.

Materials and methods:

Control Group: 3% polidocanol. Group 1: polidocanol 3% + glycerin 1.66%. Group 2: polidocanol 3% + glycerin 3.3%. Group 3: polidocanol 3% + Glycerin 5%. Tessari standard method. Five recordings were made for each mixture. Early visual liquefaction time and half liquid time decay were recorded in seconds. Microscopic measurement of the foams. Mixtures surface tension measurement (N/m).

Results:

Early visual liquefaction: Control Group: 27 (± 3.11); Group 1: 67.8 (± 6.49); Group 2:48.6 (± 8.2); and Group 3: 35.8 (± 4.49). Half-liquid time: Control: 129.2 (± 11.00); Group 1: 260.4 (±18.99); Group 2: 224.6 (±13.03); and Group 3: 189.2 (±8.52). Bubbles/mm2–diameter–wall thickness: Control: 68–98 μm-7 μm; Group 1: 189–60 μm-9 μm; Group 2: 76–92 μm-12 μm; and Group 3: 49–112 μm-20 μm. Surface tension: Control = 5.54 N/m; Group 1 = 5.45 N/m; Group 2 = 5.35 N/m; and Group 3 = 5.21 N/m.

Conclusions:

Small amounts of glycerin highly increase the stability and quality of polidocanol foam. This simple chemical method is easily reproducible and applicable.

Isolated fibrinoid vasculitis in renal angiomyolipoma

Renal angiomyolipoma is a tumor composed of a mixture of thick-walled blood vessels, smooth muscle, and mature adipose tissue. It may present as a single unilateral lesion or as a multifocal uni- or bilateral neoplasm. The histologic spectrum of angiomyolipoma is wide but as far as we know intratumoral fibrinoid vasculitis has not been described in the tumor. This is the first report of isolated intratumoral fibrinoid vasculitis observed in two nodules of a unilateral multifocal renal angiomyolipoma. The vasculitis arose in a hypertensive 62-year-old woman who presented with a history of dull right flank and low back pain of 3 months' duration. There were no signs of generalized disease. Immunophenotyping of the vascular cellular infiltrate disclosed abundant T lymphocytes, significant numbers of histiocytes, and absence of B lymphocytes. The diagnosis of isolated intratumoral arteritis depends on the exclusion of systemic disease. It is important to distinguish cases like this one to avoid misdiagnosis and to prevent unnecessary treatment.

Papillary cystic tumor of the pancreas coexisting with hairy cell leukemia

The coexistence of a pancreatic papillary cystic tumor with hairy cell leukemia is reported. To the best of our knowledge this association has never been published. A 41-year-old man diagnosed with hairy cell leukemia developed a second malignancy that corresponded to a papillary cystic pancreatic tumor. The patient underwent splenectomy and a tumoral surgical resection, and is currently well at 21 months follow-up. A pathogenetic relationship between the two malignancies was not demonstrated. Hairy cell leukemia has been reported to be associated to a great number of different second malignancies. In contrast, only two papillary cystic tumors of the pancreas have been described associated to a second neoplasm, a papillary thyroid carcinoma and a colonic carcinoma. This unusual benign or low-grade malignant pancreatic tumor more commonly occurs in the tail of the pancreas of young women. We want to stress the unusual presentation of this pancreatic tumor affecting the head of the gland in a male patient as well as its coexistence with a hairy cell leukemia.

Renal perineurioma in childhood

Perineurioma of the kidney in a 7-year-old girl is described. The tumor in the upper pole was discovered during the evaluation of a urinary tract infection. The neoplasm measured 2.6 cm and radiographically it mimicked a nephroblastoma. The diagnosis of perineurioma was confirmed with histologic, immunohistochemical, and ultrastructural studies. These revealed findings typical of perineurioma of other locations. Histopathologically, differential diagnosis may include nephroblastoma, mesoblastic nephroma, neurofibroma, schwannoma, malignant peripheral nerve sheath tumor with perineural cell differentiation, and other benign and malignant mesenchymal tumors with spindle cell pattern. To the best of our knowledge, we report a unique renal perineurioma in a child.

Diffuse expansive cavernous hemangioma of the gallbladder

Although hemangiomas are common hepatic tumors, their occurrence in the gallbladder is extremely rare. In the present report, we describe a diffuse expansive cavernous hemangioma of the gallbladder. The patient was a 50-year-old woman presenting with a 24-hour history of persistent right upper abdominal quadrant pain. The lesion caused a voluminous enlargement of the gallbladder creating a clinical impression of a cystic mesenteric tumor. The vascular origin of the tumor was confirmed by immunohistochemistry. Only 4 cases, including the present one of cavernous hemangioma involving the gallbladder have been reported in the English literature. The average age of presentation is 52.5 years (range 43-60 years), and the female to male ratio is 3:1. The lesions can be symptomatic and may have confusing radiographic appearances. Lithiasis has not been associated with the cavernous hemangioma of the gallbladder.