ADMM-based Detector for Large-scale MIMO Code-domain NOMA Systems

Large-scale multi-input multi-output (MIMO) code domain non-orthogonal multiple access (CD-NOMA) techniques are one of the potential candidates to address the next-generation wireless needs such as massive connectivity, and high reliability. This work focuses on two primary CD-NOMA techniques: sparse-code multiple access (SCMA) and dense-code multiple access (DCMA). One of the primary challenges in implementing MIMO-CD-NOMA systems is designing the optimal detector with affordable computation cost and complexity. This paper proposes an iterative linear detector based on the alternating direction method of multipliers (ADMM). First, the maximum likelihood (ML) detection problem is converted into a sharing optimization problem. The set constraint in the ML detection problem is relaxed into the box constraint sharing problem. An alternative variable is introduced via the penalty term, which compensates for the loss incurred by the constraint relaxation. The system models, i.e., the relation between the input signal and the received signal, are reformulated so that the proposed sharing optimization problem can be readily applied. The ADMM is a robust algorithm to solve the sharing problem in a distributed manner. The proposed detector leverages the distributive nature to reduce per-iteration cost and time. An ADMM-based linear detector is designed for three MIMO-CD-NOMA systems: single input multi output CD-NOMA (SIMO-CD-NOMA), spatial multiplexing CD-NOMA (SMX-CD-NOMA), and spatial modulated CD-NOMA (SM-CD-NOMA). The impact of various system parameters and ADMM parameters on computational complexity and symbol error rate (SER) has been thoroughly examined through extensive Monte Carlo simulations

Pushing the Boundary of Covalency in Lanthanoid-Tellurium Bonds: Insights from the Synthesis, Molecular and Electronic Structures of Low-Coordinate, Monomeric Europium(II) and Ytterbium(II) Tellurolates

Owing to the strict hard/soft dichotomy between the lanthanoids and tellurium atoms, and the strong affinity of lanthanoid ions for high coordination numbers, low-coordinate, monomeric lanthanoid tellurolate complexes have remained elusive as compared to the lanthanoid complexes with lighter group 16 elements (O, S, and Se). This makes the development of suitable ligand systems for low-coordinate, monomeric lanthanoid tellurolate complexes an appealing endeavor. In a first report, a series of low-coordinate, monomeric lanthanoid (Yb, Eu) tellurolate complexes were synthesized by utilizing hybrid organotellurolate ligands containing N-donor pendant arms. The reaction of bis[2-((dimethylamino)methyl)phenyl] ditelluride, 1 and 8,8′diquinolinyl ditelluride, 2 with Ln0 metals (Ln=Eu, Yb) resulted in the formation of monomeric complexes [LnII(TeR)2(Solv)2] [R=C6H4-2-CH2NMe2] [3: Ln=Eu, Solv=tetrahydrofuran; 4: Ln=Eu, Solv=acetonitrile; 5: Ln=Yb, Solv=tetrahydrofuran; 6: Ln=Yb, Solv=pyridine] and [EuII(TeNC9H6)2(Solv)n] (7: Solv=tetrahydrofuran, n=3; 8: Solv=1,2-dimethoxyethane, n=2), respectively. Complexes 3–4 and 7–8 represent the first sets of examples of monomeric europium tellurolate complexes. The molecular structures of complexes 3–8 are validated by single–crystal X-ray diffraction studies. The electronic structures of these complexes were investigated using Density Functional Theory (DFT) calculations, which revealed appreciable covalency between the tellurolate ligands and lanthanoids

LEPTOTROMBIDIUM DELIENSE INFESTATION IN DOMESTIC DOGS FROM INDIA, A VECTOR OF SCRUB TYPHUS: A CASE REPORT

Scrub typhus is a vector-borne, zoonotic disease caused by Orientia tsutsugamushi. Several members of the genus Leptotrombidium have gained importance due to their potential role as vectors as well as reservoirs for O. tsutsugamushi. The larvae of Leptotrombidium species are primary parasites of ground-dwelling rodents. However, changes in climate, and host specificity makes them adapt to other animals and play a role in the perpetuation of various (re)- emerging pathogens between animals and humans. Two male mongrel dogs aged six months were presented to the College of Veterinary Sciences and Animal Husbandry, Central Agricultural University, Mizoram, India with a history of skin lesions and intense pruritus. Routine skin scraping examination of samples revealed the presence of Leptotrombidium deliense larvae. Considering the public health importance of L. deliense infestation, an attempt was made to screen the dogs for O. tsutsugamushi and other haemoprotozoans. Microscopic and molecular tests were negative for haemoprotozoan parasites and O. tsutsugamushi, respectively. Both the dogs were successfully treated with parenteral ivermectin and topical fipronil spra

Genetic determinants of telomere length from 109,122 ancestrally diverse whole-genome sequences in TOPMed

Genetic studies on telomere length are important for understanding age-related diseases. Prior GWAS for leukocyte TL have been limited to European and Asian populations. Here, we report the first sequencing-based association study for TL across ancestrally-diverse individuals (European, African, Asian and Hispanic/Latino) from the NHLBI Trans-Omics for Precision Medicine (TOPMed) program. We used whole genome sequencing (WGS) of whole blood for variant genotype calling and the bioinformatic estimation of telomere length in n=109,122 individuals. We identified 59 sentinel variants (p-value OBFC1indicated the independent signals colocalized with cell-type specific eQTLs for OBFC1 (STN1). Using a multi-variant gene-based approach, we identified two genes newly implicated in telomere length, DCLRE1B (SNM1B) and PARN. In PheWAS, we demonstrated our TL polygenic trait scores (PTS) were associated with increased risk of cancer-related phenotypes

Carbene chemistry of arsenic, antimony, and bismuth : origin, evolution and future prospects

The discovery of the first isolable N-heterocyclic carbene in 1991 ushered in a new era in coordination chemistry. The remarkable bonding properties of carbenes have led to their rapid proliferation as auxiliary ligands for a wide range of transition metals and main group elements. In the case of group 15, while carbene-stabilized nitrogen and phosphorus compounds are extensively studied, the scope of research has shrunk significantly from arsenic to bismuth. This is essentially attributed to the decrease in stability of the C-E bond upon descending the group. Even so, modulating the carbene backbone or introducing alternative synthetic strategies not only alleviates the stability issues but also offers promising results in terms of the bonding and reactivities of these compounds. The purpose of the present perspective is to provide a comprehensive overview of the origins and development of carbene chemistry of arsenic, antimony, and bismuth, as well as to highlight the future prospects of this field

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An insight into the redox activity of Ru and Os complexes of the N,N′-bis(2-pyridyl)benzene-1,2-diamine ligand: structural, electrochemical and electronic structure analysis by density functional theory calculations

The synthesis of Ru and Os complexes of the ligand, N,N′-bis(2-pyridyl)benzene-1,2-diamine namely, [Ru-¹¹¹(acac)₂(Py-bqdi)], (9), (Ru-¹¹(Ph-trpy)(Py-bqdi)Cl], (10) and (Os-¹¹(bpy)₂(Py-bqdi)](ClO₄), ([11]ClO₄) [where Py-bqdi = N,N′-dipyridyl-o-benzoquinonediimine, acac = 2,4-pentanedionate, Ph-trpy = 4'-phenyl-2,2′:6′,2″ -terpyridine, bpy = 2,2′-bipyridine] is reported. The molecular structures of complexes 9-[11]ClO₄ are authenticated by single crystal X-ray diffraction studies. The electronic structural properties of the complexes, in particular, the accessible oxidized/reduced forms of the complexes, are examined by using an array of analytical techniques (magnetic resonance, UV-Vis-NIR spectroscopy and electrochemistry). Comprehensive Density Functional Theory (DFT) calculations have also been carried out to provide additional support to the experimental work

Synthesis, characterization, and theoretical studies of cis-Dichloridobis(8-quinolinethiolato)tin(IV) and bis(8-Sulfanylquinolinium) Hexachloridostannate(IV) derivatives

The structural characterisation of bis(8-sulfanylquinolinium) hexachloridostannate(IV) (2) is reported and the variable reaction behaviour of this compound in different solvents has been explored. In particular, attempted recrystallization of 2 from chloroform and dichloromethane affords two polymorphs of cis-dichloridobis(8-quinolinethiolato)tin(IV), 3m and 3t, respectively. Attempted recrystallization of 2 from methanol gives crystals of 8,8'-dithiodiquinolinium hexachloridostannate(IV) 4. When 2 is dissolved in dimethyl sulfoxide in the presence of air, it undergoes oxidation to afford diquinolinyl-8,8'-disulfide 5. The molecular structures of the isolated compounds 2-4 are unambiguously authenticated by single crystal X-ray diffraction studies. The electronic structure properties of all the isolated compounds 2-4 are thoroughly studied by DFT calculations

Isolation of homoleptic dicationic tellurium and monocationic bismuth analogues of non-N-heterocyclic carbene derivatives

The first examples of Te analogues of non-N-heterocyclic carbene (non-NHC) derivatives, [(ppy)₂Te]·2ClO₄, [4]·2ClO₄, and [(ppy)₂Te]·2OTf, [5]·2OTf [where ppy = 2-(2'pyridyl)phenyl and Tf = O₂SCF₃] are reported by the metathesis reaction of diorganoiodotelluronium(IV) cation, [(ppy)₂TeI]·I₃, [3]·I₃, with AgClO₄ and AgOTf, respectively. The metathesis reaction of ppyTeCl₃, 6, with an excess of AgClO₄ resulted in the isolation of [ppyTe(μ-O)]₂·2ClO₄, [8]·2ClO₄. The reaction of triorganotelluronium(IV) cation [(ppy)₃Te]·Br, [10]Br, with K₂PdCl₄ afforded [(ppy)₂TeCl]·[(ppy)PdCl₂], 11. The generality of the "ppy" group on stabilizing other main-group non-NHC analogues has been further established by synthesizing the second example of a Bi analogue of a non-NHC derivative, namely, bismuthenium ion, [(ppy)₂Bi]·Cl, [12]·Cl, using the same aryl group. All of the synthesized compounds are unambiguously authenticated by single-crystal X-ray diffraction studies. DFT calculations [natural bond orbital (NBO), atoms in molecules (AIM), and electron localization function (ELF)] indicate that the stability of the non-NHC carbenoids relies on the a-hole participation of the Te/Bi atom with the strong intramolecular coordination ability of the pyridyl N atom of the aryl substituent