A Compact Array Antenna: Explicit Design for C and X Band Applications

A novel and compact design of a circularly polarized slot antenna (CPSA) is elaborated. With the aim of generating CP feature and enhancing the impedance bandwidth, four rectangular stubs are wisely embedded in the antenna feed line structure and slotted ground plane to excite two orthogonal E vectors. Subsequently, a suitable arrangement of CPSAs in the form of 2 × 2 and 4 × 4 array antennas provokes higher functionalities in C and X band applications, respectively. Sequentially rotated (SR) feed technique is adopted to excite the antenna structure in array configurations. Measured and simulated results confirm outperformance of the array antennas with respect to the previously proposed designs. Compact size, wider impedance and axial ratio (AR) bandwidth, higher gain, and suitable radiation characteristics, both in single and array configurations, confirm suitability of the proposed designs for communication systems

Dual-band magneto-electric dipole antenna with high-gain for base-station applications

The paper presents the results of a novel high-gain dual-band magneto-electric dipole (MED) antenna. The antenna comprises two pairs of horizontal metal plates of different heights that are excited by a Γ-shaped feedline structure. The antenna is entirely made of metal plates. Compared to traditional MED antennas the proposed design exhibits dual-band operation with higher radiation gain and whose frequency ratio can be modified by simply adjusting the heights of the two magneto-electric dipole segments. This feature is necessary for cellular base-station applications. The operation and characteristics of the antenna are validated by measurements. The measured results confirm the proposed antenna achieves fractional bandwidths of 13.31% (801.9-916.2 MHz) and 19.76% (1710.7-2085.7 MHz) for S11 ≤-10 dB. It has stable unidirectional radiation patterns and optimum radiation gains of 9.2 dBi and 7.8 dBi at the first and second operating bands, respectively

Increasing tumoral 5-fluorouracil concentrations during a 5-day continuous infusion: a microdialysis study

Purpose: Response to anticancer therapy is believed to be directly related to the concentration of the anticancer drug in the tumor itself. Assessment of intra-tumor drug pharmacokinetics can be helpful to gain more insight into mechanisms involved in the (in)sensitivity of tumors to anticancer therapy. We explored the pharmacokinetics of 5-fluorouracil in both plasma and tumor tissue during a 5-day continuous infusion of 5-fluorouracil in patients with cancer. Sampling for measurement of 5-fluorouracil in tumor tissue was performed using microdialysis. Experimental design: In seven patients with an accessible (sub)cutaneous tumor treated with a continuous 5-fluorouracil infusion, plasma and microdialysate samples from tumor and normal adipose tissue were collected over a period of 5 days. Results: For six patients, drug concentrations in both tumor tissue and plasma were available. Concentration-time curves of unbound 5-fluorouracil were lower in tumor tissue compared to the curves in plasma, but exposure ratios of tumor tissue versus plasma increased during the 5-day infusion period. The presence of circadian rhythmicity of 5-fluorouracil pharmacokinetics in the tumor itself was demonstrated as 5-fluorouracil concentrations in tumor extracellular fluid were higher during the night than during daytime. Conclusion: Microdialysis was successfully employed in patients with cancer during a continuous 5-day 5-fluorouracil infusion. Plasma and tumor pharmacokinetics of 5-fluorouracil differed substantially with increasing 5-fluorouracil concentrations in tumor over time, possibly resulting from a lowered interstitial fluid pressure by 5-fluorouracil itself. This microdialysis 5-fluorouracil model might be useful to monitor the effect of drug delivery modulating strategies in future studies

Do agile managed information systems projects fail due to a lack of emotional intelligence?

YesAgile development methodologies (ADM) have become a widely implemented project management approach in Information Systems (IS). Yet, along with its growing popularity, the amount of concerns raised in regard to human related challenges caused by applyingADMare rapidly increasing. Nevertheless, the extant scholarly literature has neglected to identify the primary origins and reasons of these challenges. The purpose of this study is therefore to examine if these human related challenges are related to a lack of Emotional Intelligence (EI) by means of a quantitative approach. Froma sample of 194 agile practitioners, EI was found to be significantly correlated to human related challenges in agile teams in terms of anxiety, motivation, mutual trust and communication competence. Hence, these findings offer important new knowledge for IS-scholars, project managers and human resource practitioners, about the vital role of EI for staffing and training of agile managed IS-projects

A new compact planar UWB monopole antenna

International audienc