Menstrual cycle and age: influence on parenchymal contrast medium enhancement in MR imaging of the breast

PURPOSE: To quantify how frequently mesenteric adenitis clinically mimics appendicitis and to determine its appearance at computed tomography (CT). MATERIALS AND METHODS: The medical records of 651 consecutive patients with an admission diagnosis of appendicitis were reviewed to determine how often mesenteric adenitis was the discharge diagnosis. The CT scans of a separate group of 18 patients with a discharge diagnosis of mesenteric adenitis were reviewed. These patients were part of a group of 100 consecutive patients prospectively evaluated with CT of the appendix for clinically suspected appendicitis. RESULTS: Fifty of 651 patients (7.7%) with an admission diagnosis of appendicitis had a discharge diagnosis of mesenteric adenitis. Mesenteric adenitis constituted 50 of the 252 (19.8%) discharge diagnoses other than appendicitis. All 18 CT scans of mesenteric adenitis showed three or more nodes that measured at least 5 mm in shortest axis clustered in the right lower quadrant, with a normal appendix identified. Eight patients had associated ileal or ileocecal wall thickening. CONCLUSION: Mesenteric adenitis is an important clinical mimic of appendicitis. It appears at CT as clustered, enlarged mesenteric lymph nodes with a normal appendix, and there may be associated ileitis or ileocolitis noted.     

Co-Channel Operation of Macro- and Femtocells in a Hierarchical Cell Structure

In this paper, the feasibility of user-deployed femtocells in the same frequency band as an existing macrocell network is investigated. Key requirements for co-channel operation of femtocells such as auto-configuration and public access are discussed. Methods for femtocell power auto-configuration that ensure a constant cell radius in the downlink, and a low pre-definable interference impact on co-channel macrocells in the uplink are proposed. The theoretical performance of randomly deployed femtocells in such a hierarchical cell structure and the resulting impact on existing co-channel macrocells is analysed for a cellular UMTS network using system level simulations.     

Rapid solidification in the Al2O3ZrO2 system

Eutectic compositions of Al₂O₃ and ZrO₂ have been melted and rapidly solidified by shock-wave quenching, flame-pressure atomization and high-pressure water atomization. Quenching rates > 10⁴ K/s resulted in amorphous particles which, on annealing, crystallized at 1310°C. Microcrystalline particles with tetragonal ZrO₂ distributed in an ?-Al₂O₃ matrix formed at lower quenching rates. ?-Al₂O₃ transformed into α-Al₂O₃ on annealing at 953°C.     

Phase Stability of Fine-Grained (Mg,Y)-PSZ

A fine-grained zirconia, which has been costabilized with yttria and magnesia, has been prepared. Its stability during subeutectoid annealing at 1100^deg;C, and its hydrothermal stability during hydrothermal treatment at 180^deg;C, have been determined and they are compared to those of Y-TZP and Mg-PSZ materials .     

Temporal course of perfusion in human masseter muscle during isometric contraction assessed by arterial spin labeling at 3T

Object  

Examination of blood perfusion in the masseter muscle in the course of repetitive isometric contraction by arterial spin-labeling (ASL) MR imaging and additional T2 relaxation time measurements during and after masseter muscle activation.     

Mechanisms and Kinetics of Reaction-Bonded Aluminum Oxide Ceramics

Reaction-bonded Al₂O₃ (RBAO) ceramics were fabricated starting from mechanically alloyed Al₂O₃/Al, Al₂O₃/ Al/ZrO₂, and Al₂O₃/Al/ZrO₂/Zr mixtures. Isopressed compacts were heat-treated in air up to 1550°C. Reaction-bonding mechanisms, kinetics, and the influence of ZrO₂ and Zr additions are investigated. Independent of additive, oxidation of Al proceeds both as solid/gas and liquid/gas reaction, and the reaction kinetics follow a parabolic rate law. The reaction rate depends strongly on the particle size of Al. The activation energy of the reaction depends essentially on green density. Below the melting temperature of Al, in samples containing 45 vol% Al and 55 vol% Al₂O₃, it is 112 and 152 kJ/mol at ∼64% and ∼74% TD, respectively, while above the melting temperature, it lies in the range ∼ 26–33 kJ/mol. Zr additions reduce the activation energy to some extent. Samples with only ZrO₂ additions exhibit nearly the same activation energies as ZrO₂-free samples, though ZrO₂ has a very positive effect on the microstructural development in RBAO ceramics. Microstructure evolution and some strength data of RBAO bodies are also reported.     

Validation of a Method for Quantitation of Soybean Lectin in Commercial Varieties

Soybean agglutinin (SBA) protein, also known as soybean lectin, is regarded as an anti‐nutrient due to its negative effect on the ability of monogastric animals to gain weight following consumption of raw soybean seed. Historically, SBA has been measured using a time‐consuming and cumbersome hemagglutination procedure. The objective of our research was to obtain a validated methodology that is precise and accurate in the measurement of SBA while allowing minimally equipped laboratories to effectively conduct the analysis, thus our focus was on evaluating an existing commercially available ELISA, an enzyme‐linked‐lectin‐assay (ELLA), and a hybrid ELISA/ELLA. A new ELLA technique that can detect and quantify lectins was chosen and modified specifically for the quantitation of SBA in soybean seed. The proposed ELLA methodology is similar to a standard sandwich ELISA, and uses polyacrylamide‐linked N‐acetylgalactosamine (Gal–NAc–PAA) for a capture phase and the biotinylated version (Gal–NAc–PAA–Biotin) for detection. Based upon the validation data, the ELLA method can precisely and accurately determine soybean lectin levels in soybean seed. The validated ELLA method was used to quantify SBA in nine commercial soybean varieties introduced between 1972 and 2008 and demonstrated that the natural variability of SBA is subject to the effects of genotype and environment.     

Synthesis of Novel Niobium Aluminide-Based Composites

A reactive sintering process has been used to produce almost fully dense composites with interpenetrating networks of NbAl₃ and Al₂O₃. The process involves the reaction synthesis of niobium aluminides and Al₂O₃ from compacts of intensively milled aluminum and Nb₂O₅ powder mixtures. During carefully controlled heating under an inert atmosphere, the oxide reduction by aluminum to form niobium aluminides and Al₂O₃ proceeds at temperatures below the melting point of aluminum. At temperatures of >1000°C, the reaction-formed niobium aluminides and Al₂O₃ sinter. The present paper discusses processing parameters, such as attrition milling, the heating cycle, and the metal:ceramic ratio in the starting mixture, that control microstructure development and mechanical properties.     

Interphase cytogenetic diagnosis of bladder cancer on cells from urine and bladder washing

In order to determine the value of fluorescence in situ hybridization (FISH) in the diagnosis and follow-up of bladder cancer interphase cytogenetics was performed on cells from urine and bladder washings. 50 ml of urine or bladder washings were collected. FISH was carried out using centromere probes for chromosomes 7, 8, 9 and 12 according to standard protocols. In each case 100 cell nuclei were analysed. Fifty-four samples from urine and 67 samples from bladder washing were analysed by FISH in comparison with results obtained by conventional cytology. Sensitivity of detection of tumor cells by FISH was 68.5% in urine and 63% in bladder washings regardless of tumor stage and grade. Sensitivity obtained by conventional cytology was 50% in urine and 77.3% in bladder washings. FISH on cells from urine samples is an effective complement to the standard urine cytology. Using centromere probes this approach is characterized by high specificity and sensitivity in tumors with T-category higher than pTa and grade higher than G1.