Localization Mechanisms of Radiopharmaceuticals

Scintigraphic techniques have opened a new era of developments in the localization of infectious and cancerous foci. Diseases area targeting mechanisms of radiopharmaceuticals encompasses visualization, characterization, and measurement of physiological and biological functioning at targeted sites in addition to measure the area and density of the disease. The accumulation of a radiopharmaceutical at specific organ is based upon numerous processes such as enzymatic interactions, receptor binding site, transport of chemical species and elimination of damaged cells from circulation by a normal metabolic process. PET and SPECT are developing scanning techniques that provides effective diagnostic tool to identify pathophysiology of diseased cells. In this chapter, we are exploring and explaining different mechanisms of radiopharmaceutical localization for imaging and therapeutic processes. The knowledge of these mechanisms will help to develop target based new radiopharmaceuticals using variety of medically used radioisotopes either for imaging or therapy of diseased cells

UWB circular metal mesh transparent antenna

This paper presents the design of a novel co-planar waveguide (CPW)-fed circular metal mesh (MM) transparent antenna (TA) for ultra-wideband (UWB) applications. To achieve transparency, the MM technique is utilized on both the conductor and the dielectric substrate. To achieve broadband impedance matching in the band of interest, the corners of the CPW ground are truncated in a curved pattern. It is observed from the simulation results that the proposed UWB MM TA is resonating from 2.88 to 20 GHz, offering an impedance bandwidth of 17.12 GHz. In addition, acceptable radiation characteristics are observed in the proposed design, which makes it suitable for indoor wireless infrastructure

Frequency of ABO and Rhesus blood groups among blood donors of the Twin cities

More than 20 distinct blood group systems have been characterized; but the ABO and Rh blood groups remain the most important. The frequencies exhibit considerable variation in different geographic locations, reflecting the underlying genetic and ethnic diversity of the human population. The primary objective to carry out this study was to explore the frequency of ABO and Rh blood groups among the donors in the region of Islamabad and Rawalpindi, Pakistan. This cross-sectional study was carried out in the twin cities of Rawalpindi and Islamabad including data from 6th April 2019 to 15th September 2019. Data were collected retrospectively from the records of donors of all the registered blood banks in the mentioned localities during the last 5 years. Informed consent was gained and a total of 46363 participants were included with 25030 males and 21333 females. All participants were selected without any bias via the online patient record of the blood banks. All blood groups were identified using the slide agglutination method with commercially prepared anti-sera. The frequency of each blood group in order of its prevalence was found to be: B +ive (31.8%) > O +ive (28.5%) > A +ive (22.1%) > AB +ive (9%) > B -ive (3%) > O -ive (2.5%) > A -ive (2.1%) > AB -ive (0.9%). Overall blood group B +ive was the most common blood group, and Rh +ive groups were generally more common than Rh -ive blood groups. The results of our study provide useful data regarding frequencies of ABO and Rhesus blood groups among blood donors of the twin cities. It will in the future help create an inventory of blood banks, study disease patterns, and heredity in this region. [J Med Allied Sci 2023; 13(1):41-45

Miniaturized Wideband Antenna Prototype Operating over the Ku-Band

A wideband antenna is proposed based on three-dimensional printing technology. The antenna was designed using the PREPERM 10 material, with permittivity ϵr = 10, where the overall height of the proposed prototype was maintained as 12.83 mm (0.51λ), having a lateral dimension of 60 mm × 60 mm, at an operating frequency of 12 GHz (λ = 25 mm). The proposed antenna achieved a wide frequency bandwidth with a voltage standing-wave ratio (VSWR) of less than two, from 10 GHz to 15 GHz in the Ku-band, where the maximum directivity was 20 dBi over a reflection coefficient bandwidth of 50%. It showed a miniaturized non-uniform metasurface of 2.4λ × 2.4λ × 0.51λ that was placed at 16.5 mm (0.66λ) above the ground plane, which was 2.4λ × 2.4λ × 0.04λ in dimension. Thus, the overall height of the proposed antenna system from the feed source was 29.33 mm (1.17λ). The total weight of the system including the designed structures made of PREPERM 10 and ABS with copper-painted prototypes was 96 g and 79 g, respectively. The measured results were consistent with the simulated results, demonstrating the feasibility and effectiveness of the proposed method

Generation of Beam Tilt through Three-Dimensional Printed Surface

In this paper, 3D printed surfaces are presented to study this technology’s application in generating beam tilt for the electromagnetic waves in the Ku-band. Additionally, the input source is maintained by a feed horn that is additively manufactured and is coated with copper spray paint to add conductivity, which is fed by a WR-75 waveguide. The proposed beam tilt generating surface is also referred to as a Beam Deviating Surface (BDS). There is no relative gap between the BDS and the aperture of the horn, which eventually decreased the overall antenna height. The BDS layer is able to deviate the beam for a fixed elevation angle of 22.5∘ and could be consequently rotated along with the rotation of the BDS prototype. The voltage standing wave ratio value is less than two over the operating frequency range, which depicts the wideband behavior. The measured and simulated radiation patterns show that we can tilt the electromagnetic waves in ranges of up to +/−22.5∘ with a minimum side lobe level of −5 dB at frequencies from 10 to 15 GHz. This signifies the wideband characteristic of the proposed prototype, which is achieved by Vero material from Multijet Printing that is a low-cost and rapid manufacturing 3D printing technology

Increasing the directivity of resonant cavity antennas with nearfield transformation meta-structure realized with stereolithograpy

A simple, nearfield transformation meta-structure is proposed to increase the directivity of resonant cavity antennas (RCA). The meta-structure is comprised of 14 × 14 meta-atoms or so called “unit-cells”, adding localized phase delays in the aperture of the RCA and thus increasing its broadside directivity. A prototype of the meta-structure is additively manufactured using the stereolithograpy process and has a profile of 0.56λ. With the meta-structure integrated with the RCA, it demonstrates a measured broadside directivity of 20.15 dBi without affecting its half-power directivity bandwidth. Benefiting from additive manufacturing, the proposed approach is a simple, light-weight, low-cost, and planar approach that can be tailored to achieve medium-to-high gains with RCAs

Generation of Beam Tilt through Three-Dimensional Printed Surface

In this paper, 3D printed surfaces are presented to study this technology’s application in generating beam tilt for the electromagnetic waves in the Ku-band. Additionally, the input source is maintained by a feed horn that is additively manufactured and is coated with copper spray paint to add conductivity, which is fed by a WR-75 waveguide. The proposed beam tilt generating surface is also referred to as a Beam Deviating Surface (BDS). There is no relative gap between the BDS and the aperture of the horn, which eventually decreased the overall antenna height. The BDS layer is able to deviate the beam for a fixed elevation angle of 22.5∘ and could be consequently rotated along with the rotation of the BDS prototype. The voltage standing wave ratio value is less than two over the operating frequency range, which depicts the wideband behavior. The measured and simulated radiation patterns show that we can tilt the electromagnetic waves in ranges of up to +/−22.5∘ with a minimum side lobe level of −5 dB at frequencies from 10 to 15 GHz. This signifies the wideband characteristic of the proposed prototype, which is achieved by Vero material from Multijet Printing that is a low-cost and rapid manufacturing 3D printing technology

A 28 GHz Broadband Helical Inspired End-Fire Antenna and Its MIMO Configuration for 5G Pattern Diversity Applications

In this paper, an end-fire antenna for 28 GHz broadband communications is proposed with its multiple-input-multiple-output (MIMO) configuration for pattern diversity applications in 5G communication systems and the Internet of Things (IoT). The antenna comprises a simple geometrical structure inspired by a conventional planar helical antenna without utilizing any vias. The presented antenna is printed on both sides of a very thin high-frequency substrate (Rogers RO4003, εr = 3.38) with a thickness of 0.203 mm. Moreover, its MIMO configuration is characterized by reasonable gain, high isolation, good envelope correlation coefficient, broad bandwidth, and high diversity gain. To verify the performance of the proposed antenna, it was fabricated and verified by experimental measurements. Notably, the antenna offers a wide −10 dB measured impedance ranging from 26.25 GHz to 30.14 GHz, covering the frequency band allocated for 5G communication systems with a measured peak gain of 5.83 dB. Furthermore, a performance comparison with the state-of-the-art mm-wave end-fire antennas in terms of operational bandwidth, electrical size, and various MIMO performance parameters shows the worth of the proposed work

Slotted Antenna Array with Enhanced Radiation Characteristics for 5G 28 GHz Communications

This paper presents a 1 × 4 linear antenna array working at 28 GHz for 5G communication systems. The proposed array employs four rectangular slotted antenna elements fed by a 1 × 4 T-power divider. An artificial magnetic conductor (AMC) layer is placed below the array for increasing the radiation intensity and improving overall array gain. The measured impedance bandwidth of the proposed array with (|S11| < −10 dB) is extended from 25.36 to 26.03 GHz (with a bandwidth of 0.67 GHz) and from 26.75 to 28.81 GHz (with a bandwidth of 2.06 GHz). The proposed array design exhibits a measured gain value that varies between 11.8 dBi and 13.1 dBi within the operating bands and reaches 13.1 dBi at 28 GHz. The proposed array achieves a radiation efficiency of 83.05%, and a front-to-back ratio ranging between 15 and 20 dB across the operating frequency band. The array is fabricated and tested with good matching between the simulated and tested outcomes. The improved performance of the array makes it a suitable candidate for 5G new radio (NR) communications