Analysis and Design of a Diplexing Power Divider for Ku-Band Satellite Applications.

In dual-band RF front-end systems, to transmit different frequency signals in different paths, each path requires the power to be divided along two transmission channels. In such systems, a circuit is created in which the input ports of power dividers with different frequency bands are connected to the output ports of a diplexing circuit in a cascade form. These circuits often contain different band filters in their schemes and have a complicated design. In this paper, an innovative technique for designing a diplexing power divider for Ku-band applications is presented. The proposed structure is designed on multilayer printed circuit boards (PCBs) and the utilization of a transition based on an extended SMA connector. The extended SMA connector provides two separate paths for the transmission of the RF signals. Hence, the proposed structure eliminates the need for intricate and bulky bandpass filters, allowing seamless integration with other planar devices and components within Ku-band satellite subsystems. In fact, the proposed architecture channelizes the divided output electromagnetic signals into two separate frequency spectrums. With the presented technique, two frequency ranges are envisaged, covering Ku-band applications at 13-15.8 GHz and 16.6-18.2 GHz. With the proposed structure, an insertion loss as low as 1.5 dB was achieved. A prototype of the proposed power-divider diplexing device was fabricated and measured. It exhibits a good performance in terms of return loss, isolation, and insertion losses.

Repetitive transcranial magnetic stimulation for early-onset Alzheimer's disease - A case report.

Background: Early-onset Alzheimer's Disease (AD) is a rare form of AD defined as exhibiting signs and symptoms before age 65. Several studies have shown high frequency repetitive transcranial magnetic stimulation (rTMS) to be an effective treatment for individuals with mild cognitive impairment (MCI) and AD when applied to the left and/or right dorsolateral prefrontal cortex (DLPFC) with clear improvements found on standardized assessments of cognitive function. Case report: Here, we present a case report of a 44-year-old patient with clinical and laboratory characteristics of definite early-onset AD. Findings: rTMS led to marked cognitive improvements. We hope to inspire more clinical interest in exploring rTMS for treatment of dementia.

Talent acquisition and technology: A step towards sustainable development.

Purpose: The purpose of the research is to highlight the use of social media and information technology in employee recruitment by providing a conceptual recruitment model in the aspects of theoretical foundations and empirical evidence on the factors and outcomes leading to the use of social media recruiting technology (SMART). Design/methodology/approach: A total of 4,481 organizations are listed as the population of the study, and a total of 589 responses are used in the study for data analysis. Selection of the sample is done based on the simple random sampling technique. Appropriateness of sample size is confirmed with the help of G*Power (3.1.9.2) software, which calculated a sample size of 326 with 99% power, a multiple correlation (R) of 0.30, and at a significance level of 0.05. Findings: The paper provides empirical insights into the elements of the extended unified theory of acceptance and use of technology; i.e., performance expectancy, effort expectancy, social influence, facilitating conditions, hedonic motivation, habit, and price value have positive relations with the intention to adopt social media recruiting technology, and the intention impacts use of social media recruiting technology. Furthermore, the use of social media recruiting technology impacts outcome variables, i.e., social media recruiting time, cost, and recruitment quality, which establish the extension of the recruitment model with all factors and outcomes. Originality: This study provides a model of employee recruitment to win the battle of acquiring human capital using social media recruiting technology as a step toward sustainable development, which has been conceptually defined and empirically tested. The comprehensiveness of the model has never been discussed in earlier studies. Practical implications: Through this research, organizations will get an opportunity to experience enhancement in the scope of recruitment as a whole instead of considering recruitment as a traditional procedure, and the use of information technology can be expanded for progressive measures for future purposes and pandemic situations.

Developing Broadband Microstrip Patch Antennas Fed by SIW Feeding Network for Spatially Low Cross-Polarization Situation.

A stacked multi-layer substrate integrated waveguide (SIW) microstrip patch antenna with broadband operating bandwidth and low cross-polarization radiation is provided. A complete study on the propagating element bandwidth and cross polarization level is presented to demonstrate the importance of the design. The proposed antenna includes three stacked printed circuit board (PCB) layers, including one layer for the radiating 2 × 2 rectangular patch elements and two SIW PCB layers for the feeding network. There are two common methods for excitation in cavity-backed patch antennas: probe feeding (PF) and aperture coupling (AC). PF can be used to increase the bandwidth of the antenna. Although this method increases the antenna's bandwidth, it produces a strong cross-polarized field. The AC method can be used to suppress cross-polarized fields in microstrip patch antennas. As microstrip patch antennas are inherently narrowband, the AC method has little effect on their bandwidth. This paper proposes an antenna that is simultaneously fed by AC and PF. As a result of this innovation, the operating bandwidth of the antenna has increased, and cross-polarization has been reduced. Actually, the combination of probe feeding and aperture coupling schemes leads to achieving a broadband operating bandwidth. The arrangement of radiator elements and cavities implements a mirrored excitation technique while maintaining a low cross-polarization level. In both numerical and experimental solutions, a less than −30 dB cross-polarization level has been achieved for all of the main directions. A fractional impedance bandwidth of 29.8% (10.55−14.25 GHz) for S11 < −10-dB is measured for the proposed array. Simulated and measured results illustrate good agreement. Having features like low cost, light weight, compactness, broadband, integration capabilities, and low cross-polarization level makes the designed antenna suitable for remote-sensing and satellite applications.

Relationship between XPD Lys 751 Gln polymorphism and colorectal cancer risk: a case-control study in a population-based study.

AIM: In our study, we analyzed the allelic frequency of XPD Lys751Gln polymorphism of the XPD gene and the correlation between its variant alleles with colorectal cancer in patients and control groups. BACKGROUND: Human cells are routinely exposed to mutagenic and carcinogenic aromatic amines via smoking, pollution areas and other sources. These chemicals can form DNA adducts in vivo and thus lead to DNA damage. Amongst the known genetic polymorphisms of the DNA-repair genes the xeroderma pigmentosum group D (XPD, also known as ERCC2) has been the most extensively studied most commonly. PATIENTS AND METHODS: This study has examined the relationship between the XPD Lys 751 Gln polymorphism and colorectal cancer in 88 patients and their 88 age and sex-matched controls. Genomic DNA from peripheral whole blood was extracted using Miller method to determine the genotype of subjects with RFLP-PCR analysis. RESULTS: This study shows cancer patients have more of the heterozygous genotype (XPD Lys 751 Gln) compared to control group. However the results are not statistically significant. Furthermore, colorectal cancer was less common in individuals with recessive homozygous genotype (P< 0.0001). CONCLUSION: This study suggests that individuals with heterozygous polymorphism (Lys/Gln) may have an increased susceptibility to colorectal cancer compared to other polymorphisms (Lys/Lys and Gln/Gln).

Posterior reversible encephalopathy syndrome as the initial manifestation of Guillain-Barré Syndrome.

BACKGROUND: Guillain-Barré Syndrome (GBS) frequently affects autonomic nerves with subsequent fluctuations in blood pressure. Posterior reversible encephalopathy syndrome (PRES) is a descriptive radiological term for hypertensive encephalopathy. This article describes a unique case in which autonomic neuropathy led to marked elevations in blood pressure with subsequent PRES prior to the significant motor weakness and diagnosis of GBS. METHODS: To describe a patient who presented with PRES and GBS. RESULTS: A 58-year-old female presented to the local emergency room with complaints of acute sharp thoracolumbar back pain. Within the following 2 days, her blood pressure showed marked elevation with sudden episodic falls. She subsequently became encephalopathic and had a tonic-clonic seizure. Brain MRI was consistent with PRES. By day 5 of her initial presentation, she had developed weakness and areflexia with the electrophysiological findings of GBS. Her sensorium recovered, and MRI changes reversed with control of blood pressure. She was treated with intravenous immunoglobulin with full recovery back to baseline over the next 4 to 5 months. CONCLUSION: The autonomic effects of GBS may cause hypertensive encephalopathy or PRES prior to the motor manifestations.