A
bstract
For any state in a
D
-dimensional Hilbert space with a choice of basis, one can define a discrete version of the Wigner function — a quasi-probability distribution which represents the ...state on a discrete phase space. The Wigner function can, in general, take on negative values, and the amount of negativity in the Wigner function has an operational meaning as a resource for quantum computation. In this note, we study the growth of Wigner negativity for a generic initial state under time evolution with chaotic Hamiltonians. We introduce the Krylov-Wigner function, i.e., the Wigner function defined with respect to the Krylov basis (with appropriate phases), and show that this choice of basis minimizes the early time growth of Wigner negativity in the large
D
limit. We take this as evidence that the Krylov basis (with appropriate phases) is ideally suited for a dual, semi-classical description of chaotic quantum dynamics at large
D
. We also numerically study the time evolution of the Krylov-Wigner function and its negativity in random matrix theory for an initial pure state. We observe that the negativity broadly shows three phases: it rises gradually for a time of
O
D
, then hits a sharp ramp and finally saturates close to its upper bound of
D
.
Various polycarbonate ‐ poly(butylene terephthalate) polyester (PC‐PBT) blend prepared by reactive melt blending primarily in extruder with range of temperature and time are discussed in this review ...article. In the melt blended PC‐PBT blend system, transesterification plays a major role in formation of PC‐PBT blend. Transesterification reactions between these two polymers have been analyzed by proper polymer sample, end‐capped or having reactive chain end group. The kinetics of mechanism is a function of temperature and PC‐PBT ratio. Trace catalyst residue present in PBT catalyzes the transesterification reaction. As the extent of transesterification is increased, it forms various composition of copolymer. Inhibition in the transesterification reaction of PC‐PBT blend has been observed when different type of alkyl, aryl, and alkyl‐aryl group of phosphite are introduced into it, otherwise there has been collateral change in the morphology, thermal, and mechanical property of blend. Therefore, this PC‐PBT blend has been an interesting topic of research in academia and industries.
Schematic representation of chronology of transesterification reaction between polycarbonate and poly(butylene terephthalate)
Immune checkpoint blockade (ICB) has emerged as a novel therapeutic tool for cancer therapy in the last decade. Unfortunately, a small number of patients benefit from approved immune checkpoint ...inhibitors (ICIs). Therefore, multiple studies are being conducted to find new ICIs and combination strategies to improve the current ICIs. In this review, we discuss some approved immune checkpoints, such as PD-L1, PD-1, and CTLA-4, and also highlight newer emerging ICIs. For instance, HLA-E, overexpressed by tumor cells, represents an immune-suppressive feature by binding CD94/NKG2A, on NK and T cells. NKG2A blockade recruits CD8+ T cells and activates NK cells to decrease the tumor burden. NKG2D acts as an NK cell activating receptor that can also be a potential ICI. The adenosine A2A and A2B receptors, CD47-SIRPα, TIM-3, LAG-3, TIGIT, and VISTA are targets that also contribute to cancer immunoresistance and have been considered for clinical trials. Their antitumor immunosuppressive functions can be used to develop blocking antibodies. PARPs, mARTs, and B7-H3 are also other potential targets for immunosuppression. Additionally, miRNA, mRNA, and CRISPR-Cas9-mediated immunotherapeutic approaches are being investigated with great interest. Pre-clinical and clinical studies project these targets as potential immunotherapeutic candidates in different cancer types for their robust antitumor modulation.
The neuropeptide substance P (SP) contributes to neurogenic inflammation through the activation of human mast cells via Mas-related G protein-coupled receptor-X2 (MRGPRX2). Using pertussis toxins and ...YM-254890, we demonstrated that SP induces Ca
mobilization and degranulation via both the Gαi and Gαq family of G proteins in rat basophilic leukemia (RBL-2H3) cells stably expressing MRGPRX2. To determine the roles of MRGPRX2's transmembrane (TM) and intracellular domains on SP-induced responses, we utilized information obtained from both structural modeling and naturally occurring MRGPRX2 missense variants. We found that highly conserved residues in TM6 (I225) and TM7 (Y279) of MRGPRX2 are essential for SP-induced Ca
mobilization and degranulation in transiently transfected RBL-2H3 cells. Cells expressing missense variants in the receptor's conserved residues (V123F and V282M) as well as intracellular loops (R138C and R141C) failed to respond to SP. By contrast, replacement of all five Ser/Thr residues with Ala and missense variants (S325L and L329Q) in MRGPRX2's carboxyl-terminus resulted in enhanced mast cell activation by SP when compared to the wild-type receptor. These findings suggest that MRGPRX2 utilizes conserved residues in its TM domains and intracellular loops for coupling to G proteins and likely undergoes desensitization via phosphorylation at Ser/Thr residues in its carboxyl-terminus. Furthermore, identification of gain and loss of function MRGPRX2 variants has important clinical implications for SP-mediated neurogenic inflammation and other chronic inflammatory diseases.
Oxidative stress in the insulin target tissues has been implicated in the pathophysiology of type 2 diabetes. The study has examined the oxidative stress parameters in the mitochondria of ...subcutaneous white adipose tissue from obese and non-obese subjects with or without type 2 diabetes. An accumulation of protein carbonyls, fluorescent lipid peroxidation products, and malondialdehyde occurs in the adipose tissue mitochondria of obese type 2 diabetic, non-diabetic obese, and non-obese diabetic subjects with the maximum increase noticed in the obese type 2 diabetes patients and the minimum in non-obese type 2 diabetics. The mitochondria from obese type 2 diabetics, non-diabetic obese, and non-obese type 2 diabetics also produce significantly more reactive oxygen species (ROS) in vitro compared to those of controls, and apparently the mitochondrial ROS production rate in each group is proportional to the respective load of oxidative damage markers. Likewise, the mitochondrial antioxidant enzymes like superoxide dismutase and glutathione peroxidase show decreased activities most markedly in obese type 2 diabetes subjects and to a lesser degree in non-obese type 2 diabetes or non-diabetic obese subjects in comparison to control. The results imply that mitochondrial dysfunction with enhanced ROS production may contribute to the metabolic abnormality of adipose tissue in obesity and diabetes.
Design of low power receiver of orthogonal frequency division multiplexing (OFDM) systems in small low power battery operated wireless devices can be tackled with analog DFT front-end. The radix-2 ...fast Fourier transform algorithm has not been very efficient with device level non-idealities. Analog DFT with higher radix such as radix-4 claimed to offer better performances while device level non-idealities are concerned. But its circuit level performance in OFDM receiver is yet to be explored. This work presents complete VLSI architecture of the DFT front-end in QAM–OFDM receiver. The DFT processor consists of MOS current mirror. Geometrical variations of transistor sizes result in significant error during coefficient multiplication. This issue has been addressed using gain programmable current mirror with drain switches. Analysis of non-ideal effects are also observed on the QAM–OFDM system performance. All the circuit level simulations are carried out using SPICE with 65 nm CMOS process and demaping of QAM symbols were done using behavioral QAM demapper designed in MATLAB.
Alzheimer's disease (AD), the major cause of dementia among the elderly world-wide, manifests in familial and sporadic forms, and the latter variety accounts for the majority of the patients affected ...by this disease. The etiopathogenesis of sporadic AD is complex and uncertain. The autopsy studies of AD brain have provided limited understanding of the antemortem pathogenesis of the disease. Experimental AD research with transgenic animal or various cell based models has so far failed to explain the complex and varied spectrum of AD dementia. The review, therefore, emphasizes the importance of AD related risk factors, especially those with metabolic implications, identified from various epidemiological studies, in providing clues to the pathogenesis of this complex disorder. Several metabolic risk factors of AD like hypercholesterolemia, hyperhomocysteinemia and type 2 diabetes have been studied extensively both in epidemiology and experimental research, while much less is known about the role of adipokines, pro-inflammatory cytokines and vitamin D in this context. Moreover, the results from many of these studies have shown a degree of variability which has hindered our understanding of the role of AD related risk factors in the disease progression. The review also encompasses the recent recommendations regarding clinical and neuropathological diagnosis of AD and brings out the inherent uncertainty and ambiguity in this area which may have a distinct impact on the outcome of various population-based studies on AD-related risk factors.
Alzheimer’s disease (AD), the major cause of dementia worldwide, is characterized by progressive loss of memory and cognition. The sporadic form of AD accounts for nearly 90% of the patients ...developing this disease. The last century has witnessed significant research to identify various mechanisms and risk factors contributing to the complex etiopathogenesis of AD by analyzing postmortem AD brains and experimenting with animal and cell culture based models. However, the treatment strategies, as of now, are only symptomatic. Accumulating evidences suggested a significant association between vitamin D deficiency, dementia, and AD. This review encompasses the beneficial role of vitamin D in neurocognition and optimal brain health along with epidemiological evidence of the high prevalence of hypovitaminosis D among aged and AD population. Moreover, disrupted signaling, altered utilization of vitamin D, and polymorphisms of several related genes including vitamin D receptor (VDR) also predispose to AD or AD-like neurodegeneration. This review explores the relationship between this gene-environmental influence and long term vitamin D deficiency as a risk factor for development of sporadic AD along with the role and rationale of therapeutic trials with vitamin D. It is, therefore, urgently warranted to further establish the role of this potentially neuroprotective vitamin in preventing and halting progressive neurodegeneration in AD patients.
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