Fluorous and Organic Extraction Systems: A Comparison from the Perspectives of Coordination Structures, Interfaces, and Bulk Extraction Phases.

Microscopic structures in liquid-liquid extraction, such as structuration between extractants or extracted complexes in bulk organic phases and at interfaces, can influence macroscopic phenomena, such as the distribution behavior of solutes, including extraction efficiency and selectivity. In this study, we correlated the macroscopic behavior of the Zr(IV) extraction from nitric acid solutions with microscopic structural information to understand at the molecular level the key factors contributing to the higher metal ion extraction performance in the fluorous extraction system as compared to the analogous organic extraction system. The fluorous and organic extraction systems consist of tris(4,4,5,5,6,6,7,7,7-nonafluoroheptyl) phosphate (TFP) in perfluorohexane and tri--heptyl phosphate (THP) in -hexane, respectively.

Foam Flotation of Clay Particles Using a Bifunctional Amine Surfactant.

Understanding clay flotation mechanisms has become a major concern because of the increasing level of environmental contamination of soil and ground water by heavy metals and radionuclides. Clays are often used as sorbents for extracting metals in indirect flotation processes but can function simultaneously as defoamers. However, how foam generation and stability depend on the molecular interactions between the clays and surfactant is still controversial.

Size and structure of hexanuclear plutonium oxo-hydroxo clusters in aqueous solution from synchrotron analysis.

The size and shape of a water-soluble hexanuclear plutonium cluster were probed by combining synchrotron small-angle X-ray scattering (SAXS) and extended X-ray absorption fine structure (EXAFS). A specific setup coupling both techniques and dedicated to radioactive samples on the MARS beamline endstation at Synchrotron SOLEIL is described. The plutonium hexanuclear cores are well stabilized by the 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid ligands and this allows a good evaluation of the setup to probe the very small plutonium core.

Ultrasonically assisted conversion of uranium trioxide into uranium(vi) intrinsic colloids.

Under oxidizing conditions, the corrosion of spent nuclear fuel may lead to the leaching of radionuclides including soluble uranyl-based species. The speciation of the generated chemical forms is complex and the related potential formation of colloidal species appears surprisingly poorly reported in the literature. Their formation could however contribute significantly to the mobility of radionuclides in the environment.

Specific salt and pH effects on foam film of a pH sensitive surfactant.

Steady state foams made of a pH sensitive surfactant, nonaoxyethylene oleylether carboxylic acid, with ion complexing properties was studied using small angle neutron scattering (SANS). The effect of pH variation and salt addition on the foam film thickness was investigated and discussed in terms of the influent parameters stabilizing the foam such as surface properties and electrostatic effects determined by tensiometry and zeta potential measurements. The decrease in the film thickness by adding mono (Na(+)) and divalent (Ca(2+)) salts is classically explained by screening of the double layer in foam films (transverse interactions).

Qualitative cosmetic evaluation after root-coverage procedures.

Background: The purpose of the present study was to evaluate the esthetic outcome using four categories of root-coverage procedures (pedicle soft tissue grafts, non-submerged grafts, submerged grafts, and envelope techniques) and to identify factors associated with esthetic assessment.

Methods: A professional panel of three observers (two periodontists and one control) used a before-after panel scoring system to evaluate the esthetics of 162 root-coverage surgeries. A five-point ordinal scale was used to evaluate the overall esthetic improvement and seven variables that may be considered in the assessment.

[Myoepithelioma (or myoepithelial cell adenoma). Report of a case].

One case of myo-epithelioma occurring in the parotid gland is reported. This tumor was composed of spindle cells. The diagnosis was confirmed by ultrastructural and immunohistochemical analysis demonstrating myofilaments aggregation pattern and positive staining for S100-protein and keratin antibodies.

Keratins 6, 13 and 19. Differential expression in squamous cell carcinoma of the head and neck.

One hundred forty-one head and neck squamous cell carcinomas were analyzed for keratin (K) 6, 13 and 19. Staining was evaluated by light microscopy (with or without grading) and image analyzer and expressed as a percentage of positive versus all tumor surface (PSA). Both techniques rendered strongly correlated results.

Basaloid squamous carcinoma of the head and neck. Immunohistochemical comparison with adenoid cystic carcinoma and squamous cell carcinoma.

Basaloid squamous carcinoma (BSC) is a rare distinct variant of squamous cell carcinoma of the head and neck region. This entity may commonly pose diagnostic difficulties, especially on small biopsy material. We report the clinicopathological characteristics of 12 new cases and compare their immunohistochemical features with those of solid adenoid cystic carcinomas and conventional squamous cell carcinomas.

Histological re-evaluation of 101 intraoral salivary gland tumors by an EORTC-study group.

Tumors of the salivary glands constitute a heterogeneous group of lesions of great morphologic variation and for this reason present many difficulties in histologic classification. The histologic slides of 101 consecutive intraoral salivary gland tumors of the Department of Oral Pathology of the Free University in Amsterdam were reviewed, retrospectively, by an EORTC-study group on salivary gland tumors. Complete concurrence of diagnosis was reached in 54 cases.

Metastatic papillary endometrial carcinoma of the tongue. Case report and review of the literature.

Tongue metastases are exceptional, with a frequency of 0.1% to 0.2% in autopsy series of patients with disseminated cancer.

Adenoid cystic carcinoma of the head and neck: evaluation with MR imaging and clinical-pathologic correlation in 27 patients.

Twenty-seven adenoid cystic carcinomas (ACCs) of the head and neck in 27 patients were evaluated in a retrospective study based on findings at magnetic resonance (MR) imaging and pathologic and clinical examination. Clinical follow-up was obtained over a mean period of 6.3 years (range of follow-up, 3 months to 17 years); all patients underwent one to seven MR examinations.

Hypopharyngeal sebaceous carcinoma: a case report.

A hypopharyngeal squamous-cell carcinoma with sebaceous differentiation is reported. In the primary as well as the metastatic lymph nodes, the tumor showed basaloid, squamous, and sebaceous cells. In addition, immunostaining for S-100 protein and vimentin manifested scattered cells showing cytoplasmic processes suggesting myoepithelial cells.

Paragangliomas of the head and neck. Immunohistochemical analysis of 16 cases in comparison with neuro-endocrine carcinomas.

Sixteen cases of paragangliomas of the head and neck including 8 of the vagal body, 3 of the carotid body, 2 jugulotympanic, 2 vagal or jugulotympanic and 1 of the larynx were analysed. Clinically, 13 tumors were benign, 2 showed local aggressivity and 1 showed metastases. All tumors were tested with antisera directed against neuron-specific enolase (NSE), chromogranin A (CGA), S-100 protein, neurofilaments (NF), glial fibrillary acid protein (GFAP) and cytokeratin (CK).

Primary prostatic Wilms' tumor.

The first case of primary Wilms' tumor of the prostatic gland is described. It occurred in a 32-year-old man. Histologically, it consisted of a triphasic tumor; tubular and glomeruloid structures were identified, among prominent blastematous sheets and in an edematous stroma.

Squamous cell carcinoma of the upper aerodigestive tract associated with well-differentiated carcinoma of the thyroid gland.

The association of squamous cell carcinoma of the upper aerodigestive tract with well-differentiated thyroid carcinomas has rarely been reported in the literature. We report 10 cases illustrating this occurrence. In eight cases, the thyroid carcinoma was discovered accidentally on histological examination of a single neck node, a neck node dissection specimen, an unexpectedly found thyroid nodule, or a systematically resected thyroid lobe, all during surgical treatment of an upper aerodigestive tract carcinoma.

Papillary carcinoma in thyroglossal duct remnants.

About 100 cases of carcinoma arising in thyroglossal remnants have been reported in the world literature. Five additional cases were discovered incidentally on histopathological examinations of specimens following Sistrunk's operation for removal of thyroglossal cysts and are now reported. The possibility of preoperative clinical diagnosis and the modalities of treatment are discussed.

Oral and pharyngeal adenosquamous carcinoma. A report of four cases with immunohistochemical studies.

Four cases of adenosquamous carcinoma from the oral and pharyngeal cavities were analyzed by light microscopy and immunohistochemistry. Lymph node metastases were present in three cases. One patient died 2 years after treatment.

Analysis of the c-Ha-ras-1 gene for deletion, mutation, amplification and expression in lymph node metastases of human head and neck carcinomas.

The c-Ha-ras gene was analysed by Southern blot hybridisation in 67 specimens of lymph node metastases and in 25 specimens of primary tumours obtained from 85 untreated patients with head and neck squamous cell carcinoma. The loss of one c-Ha-ras allele was observed in 10/46 (22%) tumours from heterozygous patients for this locus. Different genes, located as the c-Ha-ras gene on the short arm of chromosome 11, were also found to be deleted suggesting that the deletion of other genes could play a role in aggressiveness of head and neck carcinomas.

So-called branchiogenic carcinoma is actually cystic metastases in the neck from a tonsillar primary.

In 1974, we reported on six patients with squamous cell carcinoma arising in the tonsillar area who presented with a characteristic form of cystic nodal metastasis. This study reports on an additional 21 patients with this entity. Treatment of these patients included removal of the cystic metastasis with or without radical neck dissection and irradiation of Waldeyer's ring.

Glutathione and cysteine levels in human tumour biopsies.

There is evidence that some human tumours could be treated with a combination of buthionine sulfoximine and hypoxic cell sensitizers. However, clinical application of this technique requires a prior knowledge of the level of non-protein bound sulfhydryl (NPSH) compounds in these tumours. The present study provides data on the levels of glutathione (GSH) and cysteine (CYS) in human tumour biopsies from the cervix and from the head and neck.

[Phalangette metastases of cancer of the mouth. An uncommon mode of propagation].

The direct propagation of a cancer of the buccal cavity or oropharynx to the bone of a distal phalanx is demonstrated in two patients suffering from onychophagy. This exceptional way of cancer propagation must be searched for if an unusual site of metastasis is encountered.