Search results for "COLUMN"

Hexagonal-columnar mesophases of acylated azacrowns with enhanced stabilities

1992

A series of discotic liquid crystals based on completely acylated macrocyclic oligoamines (azacrowns) has been synthesized. Discotic mesophases could be very highly stabilized by making use of an increased steric hindrance, caused by supplemental lateral meta-substituents which were introduced into the cinnamic acids used as the acylation agents. Employing this method yields compounds exhibiting hexagonal mesophases over a very broad range of more than 300°. Even if very large macrocycles are used as the core of such disc-shaped compounds, enantiotropic mesophases are achieved. Themeta-substituents as well as the size of the azacrowns were varied and their influence on the mesomorphic behav…

Los fantasmas del Parlamento

1980

Zeolithe als Adsorbentien für die Trennung, Reinigung und Konzentrierung von organischen Wertprodukten in der präparativen Säulen-Flüssig-Chromatogra…

1995

Comparative column chromatographic estimations of phenylalanine in plasma, whole blood, native and paper-dried capillary blood of healthy children an…

1984

The concentration of phenylalanine in plasma, whole venous and capillary blood, and paper-dried blood of 75 probands (25 healthy adults, 27 healthy children, and 23 patients with hyperphenylalaninaemia) were measured by use of a sensitive short column chromatography method. The comparison of the values in each group of probands by several statistic methods showed an excellent correlation of the phenylalanine concentration in paper-dried whole blood to those measured in venous plasma. Evaluation of the analytical method revealed a high sensitivity and accuracy by use of a sample volume of 50 microliter. We would therefore suggest that the estimation of phenylalanine for the diagnosis and the…

Changes in cytokeratin expression accompany squamous metaplasia of the human respiratory epithelium.

1992

To determine the characteristics of metaplastic changes of the nasal respiratory epithelium, the distribution of individual cytokeratins (CKs) was studied immunohistochemically and by two-dimensional gel electrophoresis. The authors define four types of changes of the normal pseudostratified columnar epithelium: (1) transitional pseudostratified epithelium (first unusual CK.: no. 13); (2) stratified columnar epithelium (increased expression of CKs 4 and 13; CKs 7, 8, 18 and 19 reduced); (3) stratified squamous epithelium, non-keratinized (appearance of CK 16); and (4) stratified squamous epithelium, keratinized (expression of CKs 1 and 10, variable CK5 and 14 patterns in basal cells). These…

Automated Determination of Fluvoxamine in Plasma by Column-Switching High-Performance Liquid Chromatography

1992

Abstract A column-switching system with high-performance liquid-chromatographic separation and ultraviolet detection is described for automated determination of fluvoxamine in human plasma or serum. Samples were injected and the drug was retained in a clean-up column [20 x 4.6 mm (i.d.)] filled with C8 reversed-phase material (10-micron particles). After unwanted material was washed out, the drug was eluted and separated with an analytical chromatography column, 4.6 x 250 mm (i.d.), filled with Nucleosil 100 CN (5-micron particles) with an acetonitrile:methanol:0.01 mol/L phosphate buffer eluent (188:578:235 by vol) at a flow rate of 1.5 mL/min for < 20 min and detected by spectromet…

Automated Determination of Ziprasidone by HPLC With Column Switching and Spectrophotometric Detection

2005

An isocratic high-performance liquid chromatography (HPLC) method with column switching and ultraviolet (UV) detection is described for quantitative analysis of the new antipsychotic drug ziprasidone. After centrifugation of serum or plasma samples and addition of fluperlapine as internal standard, the samples were injected into the HPLC system. On-line sample clean-up was conducted on a column (10 x 4.0 mm ID) filled with silica C8 material (20-microm particle size) using 8% (vol/vol) acetonitrile in deionized water as eluent. Ziprasidone was eluted and separated on ODS Hypersil C18 material (5 microm; column size 250 x 4.6 mm ID) using acetonitrile-water-tetramethylethylendiamine (50:49.6…

Short-term changes in median nerve neural tension after a suboccipital muscle inhibition technique in subjects with cervical whiplash: A randomised c…

2014

Abstract Objectives To assess the immediate effect of a suboccipital muscle inhibition (SMI) technique on: (a) neck pain, (b) elbow extension range of motion during the upper limb neurodynamic test of the median nerve (ULNT-1), and (c) grip strength in subjects with cervical whiplash; and determine the relationships between key variables. Design Randomised, single-blind, controlled clinical trial. Setting Faculty of Nursing, Physiotherapy and Podiatry, University of Seville, Spain. Participants Forty subjects {mean age 34 years [standard deviation (SD) 3.6]} with Grade I or II cervical whiplash and a positive response to the ULNT-1 were recruited and distributed into two study groups: inter…

The value of nuclear medicine for the diagnosis of spine diseases.

1993

Nuclear medicine examinations hold an important position in the diagnosis of diseases of the spine. During the last decade, decisive progress has been made in the field of instrumentation and radiopharmaceutical techniques: the use of high resolution collimators and the introduction of emission computer tomography as examples of improved instrumentation as well as 99m-Technetium red blood cell labelling as a new radiopharmaceutical technique. These present some of the developments responsible for the growing importance of scintigraphical diagnosis. Inflammatory processes of the vertebrae and the surrounding soft tissues can be detected or excluded with high reliability by the use of radionu…

Aurora-A overexpression as an early marker of reflux-related columnar mucosa and Barrett's oesophagus.

2007

Abstract BACKGROUND: The development of oesophageal adenocarcinoma is generally closely associated with the presence of a specialised intestinal-type epithelium such as that found in Barrett's oesophagus (BO). A particular histological condition is when the distal oesophagus showing cardiac and/or fundic mucosa without intestinal metaplasia cannot be defined as 'Barrett's mucosa' [condition that we call 'columnar-lined oesophagus' (CLO)] and up till now, there has been no agreement in literature about the management of this condition. Aurora-A overexpression leads to centrosome amplification, chromosomal instability and aneuploidy in mammalian cells. PATIENTS AND METHODS: A prospective stud…