A comparison of reflector antenna designs for wide-angle scanning

Conventional reflector antennas are typically designed for up to + or - 20 beamwidths scan. An attempt was made to stretch this scan range to some + or - 300 beamwidths. Six single and dual reflector antennas were compared. It is found that a symmetrical parabolic reflector with f/D = 2 and a single circular waveguide feed has the minimum scan loss (only 0.6 dB at Theta sub 0 = 8 deg, or a 114 beamwidths scan). The scan is achieved by tilting the parabolic reflector by an angle equal to the half-scan angle. The f/D may be shortened if a cluster 7 to 19 elements instead of one element is used for the feed. The cluster excitation is adjusted for each new beam scan direction to compensate for the imperfect field distribution over the reflector aperture. The antenna can be folded into a Cassegrain configuration except that, due to spillover and blockage considerations, the amount of folding achievable is small

Establishment and characterization of two human breast carcinoma cell lines by spontaneous immortalization: Discordance between Estrogen, Progesterone and HER2/neu receptors of breast carcinoma tissues with derived cell lines

Background: Breast cancer is one of the most common cancers among women throughout the world. Therefore, established cell lines are widely used as in vitro experimental models in cancer research.Methods: Two continuous human breast cell lines, designated MBC1 and MBC2, were successfully established and characterized from invasive ductal breast carcinoma tissues of Malaysian patients. MBC1 and MBC2 have been characterized in terms of morphology analysis, population doubling time, clonogenic formation, wound healing assay, invasion assay, cell cycle, DNA profiling, fluorescence immunocytochemistry, Western blotting and karyotyping.Results: MBC1 and MBC2 exhibited adherent monolayer epithelial morphology at a passage number of 150. Receptor status of MBC1 and MBC2 show (ER+, PR+, HER2+) and (ER+, PR-, HER2+), respectively. These results are in discordance with histopathological studies of the tumoral tissues, which were triple negative and (ER-, PR-, HER2+) for MBC1 and MBC2, respectively. Both cell lines were capable of growing in soft agar culture, which suggests their metastatic potential. The MBC1 and MBC2 metaphase spreads showed an abnormal karyotype, including hyperdiploidy and complex rearrangements with modes of 52-58 chromosomes per cell.Conclusions: Loss or gain in secondary properties, deregulation and specific genetic changes possibly conferred receptor changes during the culturing of tumoral cells. Thus, we hypothesize that, among heterogenous tumoral cells, only a small minority of ER+/PR+/HER2+ and ER+/PR-/HER2+ cells with lower energy metabolism might survive and adjust easily to in vitro conditions. These cell lines will pave the way for new perspectives in genetic and biological investigations, drug resistance and chemotherapy studies, and would serve as prototype models in Malaysian breast carcinogenesis investigations. © 2012 Kamalidehghan et al.; licensee BioMed Central Ltd

A comparison of reflector antenna designs for wide-angle scanning

Conventional reflector antennas are typically designed for up to + or - 20 beamwidths scan. An attempt was made to stretch this scan range to some + or - 300 beamwidths. Six single and dual reflector antennas were compared. It is found that a symmetrical parabolic reflector with f/D = 2 and a single circular waveguide feed has the minimum scan loss (only 0.6 dB at Theta sub 0 = 8 deg, or a 114 beamwidths scan). The scan is achieved by tilting the parabolic reflector by an angle equal to the half-scan angle. The f/D may be shortened if a cluster 7 to 19 elements instead of one element is used for the feed. The cluster excitation is adjusted for each new beam scan direction to compensate for the imperfect field distribution over the reflector aperture. The antenna can be folded into a Cassegrain configuration except that, due to spillover and blockage considerations, the amount of folding achievable is small

A segmented mirror antenna for radiometers

An antenna is designed for the radiometer application of the planned NASA Earth Science Geostationary Platforms in the 1990's. The antenna consists of two parts: a regular parabolic dish of 5 meters in diameter which converts the radiation from feeds into a collimated beam, and a movable mirror that redirects the beam to a prescribed scan direction. The mirror is composed of 28 segmented planar conducting plates, mostly one square meter in size. The secondary pattern of the antenna was analyzed based on a physical optics analysis. For frequencies between 50 and 230 GHz, and for a scan range of + or -8 deg (270 beamwidths scan at 230 GHz), the worst calculated beam efficiency is 95 percent. To cover such a wide frequency and scan range, each of the 28 plates is individually controlled for a tilting less than 4 deg, and for a sliding less than 0.5 cm. The sliding is done at discrete steps. At 230 GHz, a step size of 2 mil is sufficient. The plate positions must be reset for each frequency and for each scan direction. Once the position is set, the frequency bandwidth of the antenna is very narrow

SEM Analysis of MTAD Efficacy for Smear Layer Removal from Periodontally Affected Root Surfaces

Objective: Biopure® MTAD (Dentsply Tulsa Dental, USA) has been developedas a final irrigant following root canal shaping to remove intracanal smear layer.Many of the unique properties of MTAD potentially transfer to the conditioningprocess of tooth roots during periodontal therapy. The aim of this ex vivo studywas to evaluate the effect of MTAD on the removal of smear layer from root surfaces.Materials and Methods: Thirty two longitudinally sectioned specimens from 16freshly extracted teeth diagnosed with advanced periodontal disease were dividedinto four groups. In group 1 and 2, the root surfaces were scaled using Gracey curettes.In group 3 and 4, 0.5 mm of the root surface was removed using a fissurebur. The specimens in group 1 and 3 were then irrigated by normal saline. Thespecimens in groups 2 and 4 were irrigated with Biopure MTAD.All specimens were prepared for SEM and scored according to the presence ofsmear layer.Results: MTAD significantly increased (P=0.001) the smear layer removal inboth groups 2 and 4 compared to the associated control groups, in which only salinewas used.Conclusion: MTAD increased the removal of the smear layer from periodontallyaffected root surfaces. Use of MTAD as a periodontal conditioner may be suggeste

SEM analysis of MTAD efficacy for smear layer removal from periodontally affected root surfaces

Objective: Biopure® MTAD (Dentsply Tulsa Dental, USA) has been developedas a final irrigant following root canal shaping to remove intracanal smear layer.Many of the unique properties of MTAD potentially transfer to the conditioningprocess of tooth roots during periodontal therapy. The aim of this ex vivo studywas to evaluate the effect of MTAD on the removal of smear layer from root surfaces.Materials and Methods: Thirty two longitudinally sectioned specimens from 16freshly extracted teeth diagnosed with advanced periodontal disease were dividedinto four groups. In group 1 and 2, the root surfaces were scaled using Gracey curettes.In group 3 and 4, 0.5 mm of the root surface was removed using a fissurebur. The specimens in group 1 and 3 were then irrigated by normal saline. Thespecimens in groups 2 and 4 were irrigated with Biopure MTAD.All specimens were prepared for SEM and scored according to the presence ofsmear layer.Results: MTAD significantly increased (P=0.001) the smear layer removal inboth groups 2 and 4 compared to the associated control groups, in which only salinewas used.Conclusion: MTAD increased the removal of the smear layer from periodontallyaffected root surfaces. Use of MTAD as a periodontal conditioner may be suggeste

Mitochondrial DNA signals of late glacial recolonization of Europe from near Eastern refugia

Human populations, along with those of many other species, are thought to have contracted into a number of refuge areas at the height of the last Ice Age. European populations are believed to be, to a large extent, the descendants of the inhabitants of these refugia, and some extant mtDNA lineages can be traced to refugia in Franco-Cantabria (haplogroups H1, H3, V, and U5b1), the Italian Peninsula (U5b3), and the East European Plain (U4 and U5a). Parts of the Near East, such as the Levant, were also continuously inhabited throughout the Last Glacial Maximum, but unlike western and eastern Europe, no archaeological or genetic evidence for Late Glacial expansions into Europe from the Near East has hitherto been discovered. Here we report, on the basis of an enlarged whole-genome mitochondrial database, that a substantial, perhaps predominant, signal from mitochondrial haplogroups J and T, previously thought to have spread primarily from the Near East into Europe with the Neolithic population, may in fact reflect dispersals during the Late Glacial period, ?19–12 thousand years (ka) ago.<br/

A study on immunological factors in white spot vaccinated shrimp, Litopenaeus vannamei in comparison to none vaccinated groups

The aim of this study was to evaluate the efficacy of white spot virus vaccine produced by gamma irradiation in the face of Litopenaeus vannamei in comparison with Gracilaria corticata and Saccharomyces cerevisiae Seven hundred and twenty healthy shrimp SPF L. vannamei subadult with average weight of 10±1.02 g were collected and divided into 8 groups. The first group (T1) was fed with commercial pellet as control. The second group (T2) was fed with S. cerevisiae added to shrimp feed (1 g/Kg), the third group (T3) G. corticata so that algae Gracilaria were dried and added to shrimp feed at the rate of 1500 mg per kg and finally, the fourth group (T4) was vaccination group which the shrimp were exposed to the vaccine and injected intramuscularly gamma irradiant WSSV (1µl/gbw) for 10 days. The shrimps of all groups were then injected with WSSV and maintained for 25 days. Results indicated that the survival rates for groups T4, T3 T2 and T1 were 57.05±3.52%, 22.5±0.5%, 15±1.05% and 00.0±0%, respectively. Ultimately, at the end of the study the shrimp group T4 showed higher hematological data: THC, TPP, SOD, POD and PO. The study concluded that gamma irradiant WSSV is effective immunostimulants in shrimp L. vannamei and the immunity has better performances than those of the G. corticata and S. cerevisiae

Association of nuclear and mitochondrial genes with audiological examinations in Iranian patients with nonaminoglycoside antibiotics-induced hearing loss

Mitochondrial DNA mutations play an important role in causing sensorineural hearing loss. The purpose of this study was to determine the association of the mitochondrial genes RNR1, MT-TL1, and ND1 as well as the nuclear genes GJB2 and GJB6 with audiological examinations in nonfamilial Iranians with cochlear implants, using polymerase chain reaction, DNA sequencing, and RNA secondary structure analysis. We found that there were no novel mutations in the mitochondrial gene 12S rRNA (MT-RNR1) in patients with and without GJB2 mutation (GJB2+and GJB2-, respectively), but a total of six polymorphisms were found. No mutations were observed in tRNALeu(UUR) (MT-TL1). Furthermore, eight polymorphisms were found in the mitochondrial ND1 gene. Additionally, no mutations were observed in the nuclear GJB6 gene in patients in the GJB2- and GJB2+ groups. The speech intelligibility rating and category of auditory perception tests were statistically assessed in patients in the GJB2- and GJB2+ groups. The results indicated that there was a significant difference (P &lt;0.05) between the categories of auditory perception score in the GJB2- group compared to that in the GJB2+group. Successful cochlear implantation was observed among individuals with GJB2 mutations (GJB2+) and mitochondrial polymorphisms compared to those without GJB2 mutations (GJB2-). In conclusion, the outcome of this study suggests that variation in the mitochondrial and nuclear genes may influence the penetrance of deafness. Therefore, further genetic and functional studies are required to help patients in making the best choice for cochlear implants. © 2016 Balali et al