Indian Institute of Technology Palakkad&nbsp;(IIT Palakkad or IIT PKD) is a public autonomous&nbsp;engineering&nbsp;and&nbsp;research&nbsp;institute located in&nbsp;Palakkad,&nbsp;Kerala. It was&nbsp;one of the five new&nbsp;IITs&nbsp;proposed in the&nbsp;2014 Union budget of India. The campus was inaugurated on 3 August 2015. The institute has 94 faculty, 978 students, and 63 non-teaching staffs.

IT Palakkad currently offers four-year Bachelor of Technology (B.Tech) and two years MS programmes in 8 different engineering disciplines including&nbsp;Computer Science, Electrical, Mechanical, Civil among others.

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IIT Palakkad

In humans, maternal IgGs are transferred to the fetus from the second trimester of pregnancy onwards. The transplacental delivery of maternal IgG is mediated by its binding to the neonatal Fc receptor (FcRn) after endocytosis by the syncytiotrophoblast. IgGs present in the maternal milk are also transferred to the newborn through the digestive epithelium upon binding to the FcRn. Importantly, the binding of IgGs to the FcRn is also responsible for the recycling of circulating IgGs that confers them with a long half-life. Maternally delivered IgG provides passive immunity to the newborn, for instance by conferring protective anti-flu or anti-pertussis toxin IgGs. It may, however, lead to the development of autoimmune manifestations when pathological autoantibodies from the mother cross the placenta and reach the circulation of the fetus. In recent years, strategies that exploit the transplacental delivery of antigen/IgG complexes or of Fc-fused proteins have been validated in mouse models of human diseases to impose antigen-specific tolerance, particularly in the case of Fc-fused factor VIII (FVIII) domains in hemophilia A mice or pre-pro-insulin (PPI) in the case of preclinical models of type 1 diabetes (T1D). The present review summarizes the mechanisms underlying the FcRn-mediated transcytosis of IgGs, the physiopathological relevance of this phenomenon, and the repercussion for drug delivery and shaping of the immune system during its ontogeny. © Copyright © 2020 Mimoun, Delignat, Peyron, Daventure, Lecerf, Dimitrov, Kaveri, Bayry and Lacroix-Desmazes.

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Biological Sciences and Engineering

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Frontiers in Immunology

Relevance of the Materno-Fetal Interface for the Induction of Antigen-Specific Immune Tolerance

An overreactive immune response, cytokine storm, and development of acute respiratory distress syndrome characterize severe cases of COVID-19. Bonam et al. present a Perspective on diverse immunotherapeutic approaches based on the neutralization of inflammatory cytokines, immunomodulation, and passive viral neutralization for treating severely ill COVID-19 patients. © 2020 The Author(s) Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). It has infected millions, with more than 275,000 fatal cases as of May 8, 2020. Currently, there are no specific COVID-19 therapies. Most patients depend on mechanical ventilation. Current COVID-19 data clearly highlight that cytokine storm and activated immune cell migration to the lungs characterize the early immune response to COVID-19 that causes severe lung damage and development of acute respiratory distress syndrome. In view of uncertainty associated with immunosuppressive treatments, such as corticosteroids and their possible secondary effects, including risks of secondary infections, we suggest immunotherapies as an adjunct therapy in severe COVID-19 cases. Such immunotherapies based on inflammatory cytokine neutralization, immunomodulation, and passive viral neutralization not only reduce inflammation, inflammation-associated lung damage, or viral load but could also prevent intensive care unit hospitalization and dependency on mechanical ventilation, both of which are limited resources. © 2020 The Author(s)

Cell Reports Medicine

Adjunct Immunotherapies for the Management of Severely Ill COVID-19 Patients

Therapeutic normal IgG intravenous immunoglobulin (IVIG) is a well-established first-line immunotherapy for many autoimmune and inflammatory diseases. Though several mechanisms have been proposed for the anti-inflammatory actions of IVIG, associated signaling pathways are not well studied. As β-catenin, the central component of the canonical Wnt pathway, plays an important role in imparting tolerogenic properties to dendritic cells (DCs) and in reducing inflammation, we explored whether IVIG induces the β-catenin pathway to exert anti-inflammatory effects. We show that IVIG in an IgG-sialylation independent manner activates β-catenin in human DCs along with upregulation of Wnt5a secretion. Mechanistically, β-catenin activation by IVIG requires intact IgG and LRP5/6 co-receptors, but FcγRIIA and Syk are not implicated. Despite induction of β-catenin, this pathway is dispensable for anti-inflammatory actions of IVIG in vitro and for mediating the protection against experimental autoimmune encephalomyelitis in vivo in mice, and reciprocal regulation of effector Th17/Th1 and regulatory T cells. © 2020, The Author(s).

Communications Biology

Therapeutic normal IgG intravenous immunoglobulin activates Wnt-β-catenin pathway in dendritic cells

Even though both cellular and humoral immunities contribute to host defense, the role played by humoral immunity against the airborne opportunistic fungal pathogen Aspergillus fumigatus has been underexplored. In this study, we aimed at deciphering the role of the complement system, the major humoral immune component, against A. fumigatus. Mass spectrometry analysis of the proteins extracted from A. fumigatus conidial (asexual spores and infective propagules) surfaces opsonized with human serum indicated that C3 is the major complement protein involved. Flow cytometry and immunolabeling assays further confirmed C3b (activated C3) deposition on the conidial surfaces. Assays using cell wall components of conidia indicated that the hydrophobin RodAp, B-(1,3)-glucan (BG) and galactomannan (GM) could efficiently activate C3. Using complement component-depleted sera, we showed that while RodAp activates C3 by the alternative pathway, BG and GM partially follow the classical and lectin pathways, respectively. Opsonization facilitated conidial aggregation and phagocytosis, and complement receptor (CR3 and CR4) blockage on phagocytes significantly inhibited phagocytosis, indicating that the complement system exerts a protective role against conidia by opsonizing them and facilitating their phagocytosis mainly through complement receptors. Conidial opsonization with human bronchoalveolar lavage fluid (BALF) confirmed C3 to be the major complement protein interacting with conidia. Nevertheless, complement C2 and mannose-binding lectin (MBL), the classical and lectin pathway components, respectively, were not identified, indicating that BALF activates the alternative pathway on the conidial surface. Moreover, the cytokine profiles were different upon stimulation of phagocytes with serum- and BALF-opsonized conidia, highlighting the importance of studying interaction of conidia with complement proteins in their biological niche. Copyright © 2020 American Society for Microbiology. All Rights Reserved.

Infection and Immunity

Differential interactions of serum and bronchoalveolar lavage fluid complement proteins with conidia of airborne fungal pathogen aspergillus fumigatus

Herein, renewable and uniform nanospheres based on chitosan (CS) and lignosulfonate (LS): (CS@LS) were designed for the first time through a simple one-step covalent cross-linking protocol. Experimental and theoretical pieces of evidence have proven the self-assembled structure of the nanospheres as a binary network between CS and LS. The optimum composite structure was formed at CS@LS 1 : 1 ratio, with a characteristic domain size in the range of 150-200 nm. The amphiphilic nanospheres demonstrated high thermal, mechanical and bactericidal properties. The CS@LS-1 : 1 nanosphere demonstrated high growth inhibition towards aerobic Gram (-) E. coli and Gram (+) B. subtilis and anaerobic sulfate-reducing bacteria (SRB) making them ideal biocides for water disinfection. This work provides an important synthesis guideline for the development of green biomimetic nanomaterials for a plethora of applications, where a uniform size and shape are crucial success criteria.

Green Chemistry

One-step synthesis of an antimicrobial framework based on covalently cross-linked chitosan/lignosulfonate (CS@LS) nanospheres

In this work, uniform cross-linked chitosan/lignosulfonate (CS/LS) nanospheres with an average diameter of 150-200 nm have been successfully used as a novel, environmentally friendly biocide for the inhibition of mixed sulfate-reducing bacteria (SRB) culture, thereby controlling microbiologically influenced corrosion (MIC) on carbon steel. It was found that 500 $\mu$g{\textperiodcentered}mL-1 of the CS/LS nanospheres can be used efficiently for the inhibition of SRB-induced corrosion up to a maximum of 85% indicated by a two fold increase of charge transfer resistance (Rct) on the carbon steel coupons. The hydrophilic surface of CS/LS can readily bind to the negatively charged bacterial surfaces and thereby leads to the inactivation or damage of bacterial cells. In addition, the film formation ability of chitosan on the coupon surface may have formed a protective layer to prevent the biofilm formation by hindering the initial bacterial attachment, thus leading to the reduction of corrosion.

Materials

Chitosan/lignosulfonate nanospheres as "green" biocide for controlling the microbiologically influenced corrosion of carbon steel

Intravenous immunoglobulin (IVIG) is one of the widely used immunotherapeutic molecules in the therapy of autoimmune and inflammatory diseases. Previous reports demonstrate that one of the anti-inflammatory actions of IVIG implicates suppression of macrophage activation and release of their inflammatory mediators. However, macrophages are highly plastic and depending on the microenvironmental signals, macrophages can be polarized into pro-inflammatory classic (M1) or anti-inflammatory alternative (M2) type. This plasticity of macrophages raised additional questions on the role of IVIG towards macrophage polarization. In the present report, we show that IVIG affects the polarization of both classically and alternatively activated macrophages and this process is F(ab’)2-independent. Our data thus indicate the lack of reciprocal regulation of inflammatory and non-inflammatory macrophages by IVIG. © 2019, © 2019 Taylor & Francis Group, LLC.

Human Vaccines and Immunotherapeutics

Intravenous immunoglobulin suppresses the polarization of both classically and alternatively activated macrophages

Objective: This paper presents a simple automated method to estimate respiration rate (RR) from the photoplethysmography (PPG) signals. Methods: The method consists of preprocessing, extremely low-frequency two-pole digital resonator, fast Fourier transform, spectral magnitude computation, prominent spectral peak identification and respiration rate computation. Validation Dataset: The proposed RR estimation method is evaluated using standard PPG databases including MIMIC-II and CapnoBase. Results: The proposed method had estimation accuracy with absolute error value (median, 25th–75th percentiles) of 0.522 (0, 1.403) and 0.2746 (0, 0.475) breaths/minute for the PPG recordings from the MIMIC-II and CapnoBase databases, respectively for the 30 s segment. Results showed that the proposed method outperforms the existing methods such as the empirical mode decomposition and principal component analysis (EMD-PCA), ensemble EMD-PCA, and improved complete EEMD with adaptive noise-PCA methods. Conclusion: Results demonstrate that the proposed method is more accurate in estimating RR with less processing time of 0.0296 s as compared to that of the existing methods. This study further demonstrate that the two-pole digital resonator with extremely low-frequency can be simple method to estimate the RR from the PPG signals. © 2020, Springer Nature Singapore Pte Ltd.

Department of Electrical Engineering

Communications in Computer and Information Science

An Automated Algorithm for Estimating Respiration Rate from PPG Signals

This work presents a novel antipodal endfire broadband antenna incorporating paddle like shape and a frustum shaped dielectric for microwave imaging applications. Ten paddle shaped stubs with different lengths are attached to the feed structure, and their dimensions are optimized to obtain the optimum performances. Seven frustum shaped dielectrics of same dimensions are loaded to the structure to improve the gain at higher frequencies. The proposed structure demonstrates simulated return loss of <10 dB over 3.1-14 GHz with a simulated peak gain of 12.2 dBi. © 2020 IEEE.

Asia-Pacific Microwave Conference Proceedings, APMC

Novel UWB Antipodal Antenna with Paddle Shaped Stubs and Frustum Shaped Dielectric Loading for Microwave Imaging Applications

Conventional predictive controller selects the optimal switching state out of the available switching states by appropriate cost function optimisation. The direct application of the optimal switching state without a modulator restricts the use of carrier interleaving techniques with predictive control of parallel converters. The paper proposes a constant switching frequency predictive controller for parallel AC/DC converters with an intermediate modulation stage. The paper combines the generalised discontinuous pulse width modulation (GDPWM) technique with carrier interleaving for reducing both the switching losses of the converter and the harmonic distortion of grid currents. The parallel converter operate with separate DC loads for mitigating the flow of circulating currents. The controller guarantees good and quick dynamic response. The performance of the proposed controller-modulation is evaluated using MATLAB/SIMULINK. The paper analyses the performance of the parallel rectifier with individual converters operating at different DC load voltages and different power factor angles. © 2020 IEEE.