The enormous growth of wireless data traffic in recent years has made the millimeter-wave (mm-wave) technology as a good fit for high-speed communication systems. Extensive works are continuing from the device to system, to the radio architecture, to the network to support the communication in mm-wave frequency ranges. To support this extensive high data rate, beam forming is found to be the key-enabling technology. Hence, an array antenna design is an extremely important issue. The beam-forming arrays are chosen to achieve the desired link capacity considering the high path loss and atmospheric loss at mm-wave frequencies and also to increase the coverage of the mm-wave communication system. There are diverse design challenges of the array due to the small size, use of large numbers of antennas in close vicinity, integration with radio-frequency (RF) front ends, hardware constraints, and so on. This paper focuses on the evolution and development of mm-wave array antenna and its implementation for wireless communication and numerous other related areas. The scope of the discussion is extended on the reported works in every sphere of mm-wave antenna array design, including the selection of antenna elements, array configurations, feed mechanism, integration with front-end circuitry to understand the effects on system performance, and the underlying reason of it. The new design aspects and research directions are unfolded as a result of this discussion.INDEX TERMS Mm-wave communication, antenna array design, array configuration, feed mechanism, RF circuit. SASWATI GHOSH received the Ph.D. degree from IIT Kharagpur, India, where she is currently a Postdoctoral Research Fellow with G. S. Sanyal School of Telecommunications. She is involved in active research in the area of antenna design for 60-GHz communication, RF energy harvesting, EMI/EMC measurements and EMI sensors, estimation of EMC of high-frequency electronic systems, and EMI/EMC/ESD on spacecraft bodies. She has 15 international journal publications, three book chapters, and more than 60 publications, including national journals and national/international conference proceedings. She serves as a Reviewer for several international journals. She had received the Young Scientist Fellowship twice and the Women Scientist Fellowship from the Department of Science and Technology, Government of India. DEBARATI SEN received the Ph.D. degree in telecommunication engineering from IIT Kharagpur, Kharagpur, India, where she is currently an Assistant Professor. Her research interests include wireless and optical communication systems, mostly on MB-OFDM, synchronization, equalization, UWB, BAN, green communications, 60-GHz communications, and baseband algorithm design for coherent optical communications.
BackgroundVisceral leishmaniasis (VL) is distinguished by a complex interplay of immune response and parasite multiplication inside host cells. However, the direct association between different immunological correlates and parasite numbers remains largely unknown.Methodology/Principal FindingsWe examined the plasma levels of different disease promoting/protective as well as Th17 cytokines and found IL-10, TGFβ and IL-17 to be significantly correlated with parasite load in VL patients (r = 0.52, 0.53 and 0.51 for IL-10, TGFβ and IL-17, respectively). We then extended our investigation to a more antigen-specific response and found leishmanial antigen stimulated levels of both IL-10 and TGFβ to be significantly associated with parasite load (r = 0.71 and 0.72 for IL-10 and TGFβ respectively). In addition to cytokines we also looked for different cellular subtypes that could contribute to cytokine secretion and parasite persistence. Our observations manifested an association between different Treg cell markers and disease progression as absolute numbers of CD4+CD25+ (r = 0.55), CD4+CD25hi (r = 0.61) as well as percentages of CD4+CD25+FoxP3+ T cells (r = 0.68) all correlated with parasite load. Encouraged by these results, we investigated a link between these immunological components and interestingly found both CD4+CD25+ and CD4+CD25+FoxP3+ Treg cells to secrete significantly (p<0.05) higher amounts of not only IL-10 but also TGFβ in comparison to corresponding CD25- T cells.Conclusions/SignificanceOur findings shed some light on source(s) of TGFβ and suggest an association between these disease promoting cytokines and Treg cells with parasite load during active disease. Moreover, the direct evidence of CD4+CD25+FoxP3+ Treg cells as a source of IL-10 and TGFβ during active VL could open new avenues for immunotherapy towards cure of this potentially fatal disease.
-Natural vinegar is one of the fermented products which has some potentiality with respect to a nutraceutical standpoint. The present study is an optimization of the fermentation conditions for palm juice vinegar production from palm juice (Borassus flabellifer) wine, this biochemical process being aided by Acetobacter aceti (NCIM 2251). The physical parameters of the fermentation conditions such as temperature, pH, and time were investigated by Response Surface Methodology (RSM) with 2 3 factorial central composite designs (CCD). The optimum pH, temperature and time were 5.5, 30 °C and 72 hrs for the highest yield of acetic acid (68.12 g / L). The quadratic model equation had a R 2 value of 0.992. RSM played an important role in elucidating the basic mechanisms in a complex situation, thus providing better process control by maximizing acetic acid production with the respective physical parameters. At the optimized conditions of temperature, pH and time and with the help of mathematical kinetic equations, the Monod specific growth rate ( μ max = 0.021 h -1 ), maximum Logistic specific growth rate ( μ ' max = 0.027 h -1 ) and various other kinetic parameters were calculated, which helped in validation of the experimental data. Therefore, the established kinetic models may be applied for the production of natural vinegar by fermentation of low cost palm juice.
A 'green' methodology for the convenient synthesis of specific regioisomers of polysubstituted oxazoles through iodine catalyzed, water-mediated, aerobic oxidative C(sp 3 )À H functionalization of primary amines has been developed. This mild and regioselective domino procedure does not require toxic peroxides, transition metals and organic solvents. The versatility of this methodology was demonstrated by preparing a natural product, texaline. It is also scalable and has a wide substrate scope. This methodology opens up a simple avenue for the synthesis of polyarylated oxazoles from various readily available amines as well as 1,2-diketones and acyloins (α-hydroxyl ketones) in moderate to excellent yields. Furthermore, these highly substituted oxazole molecules showed excellent fluorescence properties and thus have enormous potential to be a new type of fluorescent probe for use in medicinal applications and materials science.
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