Search results for " Phase"

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…

Geometric factors in the adiabatic evolution of classical systems

1992

Abstract The adiabatic evolution of the classical time-dependent generalized harmonic oscillator in one dimension is analyzed in detail. In particular, we define the adiabatic approximation, obtain a new derivation of Hannay's angle requiring no averaging principle and point out the existence of a geometric factor accompanying changes in the adiabatic invariant.

Revealing Anisotropy in a Paul Trap Through Berry Phase

2006

When an ion confined in an anisotropic bidimensional Paul trap is subjected to a laser beam oriented along an arbitrary direction, the interaction between its electronic and vibrational degrees of freedom is described by a time-dependent Hamiltonian model as a consequence of the lack of symmetry. Appropriately choosing the laser frequency, the Hamiltonian model turns out to be sinusoidally oscillating at the difference between the proper frequencies of the center of mass of the ion. Thus, if the anisotropy of the trap is sufficiently small, the evolution of the system can be considered as adiabatic. In the context of this physical situation we have calculated the Berry phase acquired in a c…

Magnetic In-Tube Solid Phase Microextraction

2012

We report a new in-tube solid phase microextraction approach named magnetic in-tube solid phase microextraction, magnetic-IT-SPME. Magnetic-IT-SPME has been developed, taking advantage of magnetic microfluidic principles with the aim to improve extraction efficiency of IT-SPME systems. First, a magnetic hybrid material formed by Fe(3)O(4) nanoparticles supported on SiO(2) was synthesized and immobilized in the surface of a bared fused silica capillary column to obtain a magnetic adsorbent extraction phase. The capillary column was placed inside a magnetic coil that allowed the application of a variable magnetic field. Acetylsalicylic acid, acetaminophen, atenolol, diclofenac, and ibuprofen …

Outcomes of single versus double hormone receptor–positive breast cancer. A GEICAM/9906 sub-study

2018

Abstract Background Retrospective data suggest better outcomes for patients with double hormonal receptor (oestrogen [ER] and progesterone receptor [PgR])–positive (dHR+) early breast cancer, compared with single hormonal receptor–positive, sHR+, (ER+/PgR– or ER–/PgR+) disease. Here, we evaluate the classification according to intrinsic subtypes and clinical outcomes of sHR+ versus dHR+ in HER2-negative breast cancer patients enrolled in GEICAM/9906 study ( NCT00129922 ). Methods Archival tumours were retrieved retrospectively for the analysis of ER, PgR and HER2 status and classified into intrinsic subtypes using the PAM50 gene expression assay. Disease-free survival (DFS) and overall surv…

Emotional interference and attentional processing in premenstrual syndrome

2017

Abstract Background and objectives Premenstrual syndrome (PMS) is characterized by menstrual cycle-related affective, behavioral, and/or somatic symptoms. By applying the emotional Stroop task (EST) the current study examined if changes in processing emotional information, which have been demonstrated in affective disorders, are also present in PMS. Methods Via online screening, telephone interviews, and daily records over two months 55 women for the PMS group (on the basis of the specific inclusion criteria and a prospectively confirmed PMS) and 55 ‘non-PMS’ controls were recruited. All participants completed three emotional Stroop tasks (EST) with neutral and negative word, picture, and f…

Biological parameters in breast cancer.

1996

Flow cytometric DNA analysis and lysosomal cathepsins B and L in locally advanced laryngeal cancer. Relationship with clinicopathologic parameters an…

1995

Background. The traditional factors of locally advanced laryngeal squamous cell carcinoma (LSCC) have limited predictive value for the identification of high risk patients. Therefore, it is extremely important to define prognostic factors that identify the more aggressive types. Reliable and reproducible prognostic indicators are being investigated to help clinicians identify high risk groups and address more rational treatment. Methods. Flow cytometric DNA ploidy and S‐phase fraction (SPF) measurements were performed on frozen tumor tissues from a consecutive series of 71 patients with Stage III and IV LSCC. Lysosomal cathepsin B and L activity levels were determined biochemically in match…

Does Preoperative Treatment with a Gonadotropin-Releasing Hormone Agonist Improve the Outcome of Endometrial Resection?

1998

Abstract Study Objective. To verify if more favorable long-term results of endometrial resection can be obtained with preoperative gonadotropin-releasing hormone (GnRH) agonist treatment. Design. Multicenter, randomized, controlled trial (Canadian Task Force classification I). Setting. Tertiary care academic department. Patients. Sixty-three premenopausal women with established menorrhagia. Intervention. Eight weeks of goserelin depot treatment before endometrial resection or immediate surgery in the early proliferative phase of the cycle. Measurements and Main Results. Variations in menstrual patterns and bleeding scores as well as overall degree of satisfaction with treatment were determi…

New spectrophotometric procedure for determining cefotaxime based on derivatization with 1,2-naphthoquinone-4-sulphonate into solid-phase extraction …

1998

Cefotaxime was derivatised with 1,2-naphthoquinone-4-sulphonate (NQS), extracted into solid-phase cartridges (C18) and detected using a UV-visible detection system. Optimum conditions for this new procedure were: hydrogencarbonate-carbonate buffer, pH 10.5, 5-min reaction time at 25 degrees C and an NQS concentration of 7.1x10(-3) mol l(-1). The accuracy and the precision of the liquid-solid procedure were tested. The procedure was used to measure cefotaxime in pharmaceutical and urine samples. The results obtained were contrasted with those reported for a HPLC method for urine samples. The generalized H-point standard additions method was used to measure cefotaxime in urine samples.