Propagation path loss modeling and coverage measurements in urban microcell in millimeter wave frequency bands

The global bandwidth deficiency facing wireless carriers has motivated the exploration of the underutilized millimeter wave (mm-wave) frequency spectrum for future broadband cellular communication networks, and mm Wave band is one of the promising candidates due to wide spectrum. This paper presents propagation path loss and outdoor coverage and link budget measurements for frequencies above 6 GHz (mm-wave bands) using directional horn antennas at the transmitter and omnidirectional antennas at the receiver. This work presents measurements showing the propagation time delay spread and path loss as a function of separation distance for different frequencies and antenna pointing angles for many types of real-world environments. The data presented here show that at 28 GHz, 38 GHz and 60 GHz, unobstructed Line of Site (LOS) channels obey free space propagation path loss while non-LOS (NLOS) channels have large multipath delay spreads and can utilize many different pointing angles to provide propagation links. At 60 GHz, there is more path loss and smaller delay spreads. Power delay profiles PDPs were measured at every individual pointing angle for each TX and RX location, and integrating each of the PDPs to obtain received power as a function of pointing angle. The result shows that the mean RMS delay spread varies between 7.2 ns and 74.4 ns for 60 GHz and 28 GHz respectively in NLOS scenario

Propagation Path Loss Modeling and Outdoor Coverage Measurements Review in Millimeter Wave Bands for 5G Cellular Communications

The global bandwidth inadequacy facing wireless carriers has motivated the exploration of the underutilized millimeter wave (mm-wave) frequency spectrum for future broadband cellular communication networks, and mmWave band is one of the promising candidates due to wide spectrum. This paper presents propagation path loss and outdoor coverage and link budget measurements for frequencies above 6 GHz (mm-wave bands) using directional horn antennas at the transmitter and omnidirectional antennas at the receiver. This work presents measurements showing the propagation time delay spread and path loss as a function of separation distance for different frequencies and antenna pointing angles for many types of real-world environments. The data presented here show that at 28 GHz, 38 GHz and 60 GHz, unobstructed Line of Site (LOS) channels obey free space propagation path loss while non-LOS (NLOS) channels have large multipath delay spreads and can utilize many different pointing angles to provide propagation links. At 60 GHz, there is more path loss and smaller delay spreads. Power delay profiles PDPs were measured at every individual pointing angle for each TX and RX location, and integrating each of the PDPs to obtain received power as a function of pointing angle. The result shows that the mean RMS delay spread varies between 7.2 ns and 74.4 ns for 60 GHz and 28 GHz respectively in NLOS scenario

Effect of Chloride Ions on the Corrosion Behavior of Al Zn Alloy in NaOH Solution at Four Different Temperatures

This research involves study effect of chloride ions in concentration range (0.01 0.50 mol.dm-3) on the corrosion behavior of Al-Zn alloy in basic media of 1x10-3 mol.dm-3 NaOH at pH=11 and four different temperatures in the range (298-313 K). Cathodic and anodic Tafel slopes (bc &ba) and transfer coefficients (αc & αa) were calculated and the results interprets according to the variation of the rate determining steps. The results also indicate that the chloride ions are bonded chemically in the interface as an initial step of formation of different mixed oxohydroxy and chloro complexes. Polarization resistance (Rp) is calculates and interprets the different polarization behavior because of addition of chloride ions to the basic media

HEREDITARYSPHEROCYTOSIS DIAGNOSED IN 16 YEAR FEMALE- ACASE REPORT

Hereditary Spherocytosis (HS) is relatively common haemolytic anemia in which basic abnormality is an intrinsic defect of red cell membrane. Clinically patients may asymptomatic to intermittent jaundice,anemia, abdominal pain and splenomegaly. Here we reporting a case of 16-year female presented as recurrent abdominal pain,jaundice ,splenomegaly and anemia. Clinical examination show pallor,jaundice and massive splenomegaly. Investigations confirmed diagnosis of HS, by the presence of peripheral blood smear spherocytes,increased MCHC,reticulocytosis,negative direct coombs test and increased osmotic fragility. She advised to undergo splenectomy and cholecystectomy as active part of management

Spectrum sharing and compatibility between the international mobile telecommunication-advanced and digital broadcasting in the digital dividend band

The International Telecommunication Union for Radiocommunication (ITU-R) became involved with the spectrum allocation for next generation mobile communication services in World Radio Communication conference 2007 (WRC- 07). The reason is to minimize the adjacent channel interference between Mobile service and DVB-T system within the same geographical area. Therefore, this paper investigates the spectrum sharing requirements such as separation distance and studies the compatibility between Mobile services (IMT-Advanced) and Digital Video Broadcasting – Terrestrial (DVB-T) in the 790 to 862 MHz frequency band. This paper also involves the studies of propagation characteristics within this band which can provide better coverage. Possibility of coexistence and sharing analysis were obtained by taking into account the detailed calculations of the path loss effect by using the practical parameters of DVB-T and Mobile service. The interference has been analyzed and simulated for suburban environment in different channel bandwidths for Mobile service at 5MHz and 20MHz, and in different transmitted power for Digital Video Broadcasting – Terrestrial. The best separation distance between these two systems found are 4.65 Km and 3.42 Km for bandwidth of 5MHz and 20 MHz respectively

Multifocal Osteolytic tuberculosis - Uncommon presentation of common disease

Tuberculosis is one of the most prevalent bacterial infection in developing country like india and it is capable of affecting almost every system in the human body. Multifocal skeletal tuberculosis is a rare condition. We report a 22-year old immunocompetent female history of backache and sternal pain for three months, associated with progressive weight loss with no fever. Computed Tomography (CT) scanning demonstrated hypodense multifocal osteolytic lesions of the thoracic spine (T12) and the manubrum sternii. CT guided fine needle aspiration cytology (FNAC) performed from both osteolytic lesions. Cytology smears from both lesions show many granulomas and few giant cells. Z-N stain for AFB was positive. Patient treated with anti-tuberculus drugs and responded well. This case reported for its rarity, unusual radiological findings & to emphasize the role of CT/CT guided FNAC in osteolytic lesions and also to stress the need for high index of suspicion in tuberculosis endemic areas to avoid delayed diagnosis in such uncommon presentation of common disease

Systematic Comparison of Retinal Organoid Differentiation from Human Pluripotent Stem Cells Reveals Stage Specific, Cell Line, and Methodological Differences

A major goal in the stem cell field is to generate tissues that can be utilized as a universal tool for in vitro models of development and disease, drug development, or as a resource for patients suffering from disease or injury. Great efforts are being made to differentiate human pluripotent stem cells in vitro toward retinal tissue, which is akin to native human retina in its cytoarchitecture and function, yet the numerous existing retinal induction protocols remain variable in their efficiency and do not routinely produce morphologically or functionally mature photoreceptors. Herein, we determine the impact that the method of embryoid body (EB) formation and maintenance as well as cell line background has on retinal organoid differentiation from human embryonic stem cells and human induced pluripotent stem cells. Our data indicate that cell line‐specific differences dominate the variables that underline the differentiation efficiency in the early stages of differentiation. In contrast, the EB generation method and maintenance conditions determine the later differentiation and maturation of retinal organoids. Of the latter, the mechanical method of EB generation under static conditions, accompanied by media supplementation with Y27632 for the first 48 hours of differentiation, results in the most consistent formation of laminated retinal neuroepithelium containing mature and electrophysiologically responsive photoreceptors. Collectively, our data provide substantive evidence for stage‐specific differences in the ability to give rise to laminated retinae, which is determined by cell line‐specific differences in the early stages of differentiation and EB generation/organoid maintenance methods at later stages

Poly(ethylene glycol) based nanotubes for tuneable drug delivery to glioblastoma multiforme

Glioblastoma multiforme (GBM) is the most aggressive type of malignant brain tumour, which is associated with a poor two-year survival rate and a high rate of fatal recurrence near the original tumour. Focal/local drug delivery devices hold promise for improving therapeutic outcomes for GBM by increasing drug concentrations locally at the tumour site, or by facilitating the use of potent anti-cancer drugs that are poorly permeable across the blood brain barrier (BBB). For inoperable tumours, stereotactic delivery to the tumour necessitates the development of nanoscale/microscale injectable drug delivery devices. Herein we assess the ability of a novel class of polymer nanotube (based on poly(ethylene glycol) (PEG)) to load doxorubicin (a mainstay breast cancer therapeutic with poor BBB permeability) and release it slowly. The drug loading properties of the PEG nanotubes could be tuned by varying the degree of carboxylic acid functionalisation and hence the capacity of the nanotubes to electrostatically bind and load doxorubicin. 70% of the drug was released over the first seven days followed by sustained drug release for the remaining two weeks tested. Unloaded PEG nanotubes showed no toxicity to any of the cell types analysed, whereas doxorubicin loaded nanotubes decreased GBM cell viability (C6, U-87 and U-251) in a dose dependent manner in 2D in vitro culture. Finally, doxorubicin loaded PEG nanotubes significantly reduced the viability of in vitro 3D GBM models whilst unloaded nanotubes showed no cytotoxicity. Taken together, these findings show that polymer nanotubes could be used to deliver alternative anti-cancer drugs for local therapeutic strategies against brain cancers

Accuracy of Multiple Pour Cast from Various Elastomer Impression Methods

The accurate duplicate cast obtained from a single impression reduces the profession clinical time, patient inconvenience, and extra material cost. The stainless steel working cast model assembly consisting of two abutments and one pontic area was fabricated. Two sets of six each custom aluminum trays were fabricated, with five mm spacer and two mm spacer. The impression methods evaluated during the study were additional silicone putty reline (two steps), heavy-light body (one step), monophase (one step), and polyether (one step). Type IV gypsum casts were poured at the interval of one hour, 12 hours, 24 hours, and 48 hours. The resultant cast was measured with traveling microscope for the comparative dimensional accuracy. The data obtained were subjected to Analysis of Variance test at significance level <0.05. The die obtained from two-step putty reline impression techniques had the percentage of variation for the height −0.36 to −0.97%, while diameter was increased by 0.40–0.90%. The values for one-step heavy-light body impression dies, additional silicone monophase impressions, and polyether were −0.73 to −1.21%, −1.34%, and −1.46% for the height and 0.50–0.80%, 1.20%, and −1.30% for the width, respectively

Circulating leukocyte telomere length is highly heritable among families of Arab descent

Background Telomere length, an indicator of ageing and longevity, has been correlated with several biomarkers of cardiometabolic disease in both Arab children and adults. It is not known, however, whether or not telomere length is a highly conserved inheritable trait in this homogeneous cohort, where age-related diseases are highly prevalent. As such, the aim of this study was to address the inheritability of telomere length in Saudi families and the impact of cardiometabolic disease biomarkers on telomere length. Methods A total of 119 randomly selected Saudi families (123 adults and 131 children) were included in this cross-sectional study. Anthropometrics were obtained and fasting blood samples were taken for routine analyses of fasting glucose and lipid profile. Leukocyte telomere length was determined using quantitative real time PCR. Results Telomere length was highly heritable as assessed by a parent-offspring regression [h2 = 0.64 (p = 0.0006)]. Telomere length was modestly associated with BMI (R2 0.07; p-value 0.0087), total cholesterol (R2 0.08; p-value 0.0033), and LDL-cholesterol (R2 0.15; p-value 3 x 10-5) after adjustments for gender, age and age within generation. Conclusion The high heritability of telomere length in Arab families, and the associations of telomere length with various cardiometabolic parameters suggest heritable genetic fetal and/or epigenetic influences on the early predisposition of Arab children to age-related diseases and accelerated ageing