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The structural, electronic and thermoelectric properties of ZrP2 monolayer is studied using density functional theory and Boltzmann transport theory. The electronic band structure calculations demonstrate that this monolayer is a direct band gap semiconductor (Eg= 0.78 eV). The ZrP2 monolayer has hexagonal lattice structure, having a lattice constant 3.04 Å. The energetic, mechanical and dynamic stability of the ZrP2 monolayer is checked and it is found to be stable. The transport coefficients are calculated using Boltztrap code. The lattice thermal conductivity is calculated using Slack’s equation and found to be very low at room temperature. High value of power factor and low value of thermal conductivity play an essential role in boosting the thermoelectric efficiency of the ZrP2 monolayer. The n-type (p-type) monolayerhas a ZT value of 0.78 (1.12) at 500 K. The ZrP2 monolayer is an ideal candidate to be used in the manufacturing of thermoelectric devices.

With the advent of the Internet and other digital technologies, contemporary businesses from all sectors are using social media for communication with consumers to engage them meaningfully with a brand. However, the use of social media for corporate social responsibility (CSR) communication is relatively new to the existing literature. Likewise, the impact of CSR communication through social media (CSR-S) on consumer emotions and behavior is, to date, underexplored. To address this, the present research aims to test the relationship of CSR-S on brand admiration and consumer purchase intention. The study proposes a direct relationship between CSR-S and purchase intention with a mediating effect of brand admiration. The data were collected from the banking consumers of Pakistan through a self-administered questionnaire. The authors distributed 800 questionnaires and received 463 questionnaires useful for data analysis, so the present research study response rate was around 59%. The data were analyzed using the structural equation modeling (SEM) technique in AMOS. The results revealed that CSR-S is positively related to purchase intention (β = 0.233). The results further showed that brand admiration partially mediates this relationship (β = 0.079). The survey respondents confirmed that their bank’s CSR communication helps enhance their purchase likelihood and their feelings of admiration for their bank. These findings will help policymakers at banking institutions better understand the importance of CSR communication on different social media platforms to achieve consumer-related outcomes.

Oxygen and hydrogen evolutions are the two fundamental processes involved in electrocatalytic water splitting. Two dimensional (2D) transition metal dichalcogenides (TMDCs) and graphene-based materials are regarded as the emergent catalysts for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Herein, doped graphene and molybdenum dichalcogenide heterostructures are evaluated for their catalytic activity using density functional theory (DFT). The Janus MoSSe and P-doped graphene heterostructure is found to have the best electrocatalytic activities with smaller overpotential values (ηOER = 1.67 V and ηHER = 0.10 V) as compared to those of the parent monolayers graphene (ηOER = 1.85 V and ηHER = 1.80 V) and MoS2 (ηOER = 2.99 V and ηHER = 1.72 V).

By performing the Density functional theory based first principle calculations, we investigate the effect of z-axial (compressive and tensile) strain on the electronic band structure and transport coefficients of Janus MoSSe monolayer. The unstrained Janus MoSSe monolayer is a direct band gap semiconductor having an energy gap of 1.63 eV. The electronic band structure is very sensitive to the application of z-axial strain. Because of which the electronic transport coefficients get modulated. We found out that z-axial tensile strain enhances the power factor of n-type Janus MoSSe monolayer, however no enhancement is predicted for p-type Janus MoSSe monolayer

Two dimensional (2D) chalcogenide monolayers have diversified applications in optoelectronics, piezotronics, sensors and energy harvesting. The group-IV tellurene monolayer is one such emerging material in the 2D family owing to its piezoelectric, thermoelectric and optoelectronic properties. In this paper, the mechanical and piezoelectric properties of 2D tellurene in centrosymmetric β and non-centrosymmetric β′ phases are investigated using density functional theory. β′-Te has shown a negative Poisson's ratio of −0.024 along the zigzag direction. Giant in-plane piezoelectric coefficients of −83.89 × 10−10 C m−1 and −42.58 × 10−10 C m−1 are observed for β′-Te under biaxial and uniaxial strains, respectively. The predicted values are remarkably higher, that is 23 and 12 times the piezoelectric coefficient of a MoS2 monolayer with biaxial and uniaxial strain in the zigzag direction, respectively. A large thermal expansion coefficient of tellurene is also estimated using quasi harmonic approximation. High piezoelectricity combined with exotic mechanical and thermal properties makes tellurene a very promising candidate in nanoelectronics.

The first-principles calculations based on Density Functional Theory are performed in order to investigate the effect of strain on the electronic structure and transport properties of the p-type GaS monolayer. Our calculations show that unstrained GaS monolayer is semiconducting in nature having an indirect energy band gap of 2.35 eV. The application of compressive or tensile strain modifies the electronic band structure and energy band gap which further modifies the electronic transport coefficients of GaS monolayers. The energy band gap of GaS monolayer increases (decreases) under the application of compressive (tensile) strain. The Seebeck coefficient of p-type GaS monolayer is increased by applying strain, giving rise to the increase in the power factor.

International trade plays a vital role in the Indian economy. As the country need to import diverse products so International trade is extremely important to country. India exports vast number of products and also imports an equal amount of other products. Although India has steadily opened up its economy, its tariffs continue to be high when compared with other countries, and its investment norms are still restrictive. This leads some to see India as a ‘rapid globalizer’ while others still see it as a ‘highly protectionist’ economy. Nonetheless, in recent years, the government’s stand on trade and investment policy has displayed a marked shift from protecting ‘producers’ to benefiting ‘consumers’. India is now aggressively pushing for a more liberal global trade regime, especially in services. This paper is an attempt to analyse the major changes in volume, composition and direction of International Trade of India.

We investigate the effect of adsorbed gold atom on phonon dispersion curves of a graphene sheet and calculate various thermodynamic properties of pure and gold-adsorbed graphene using Ab initio density functional perturbation theory (DFPT). The phonon frequencies have been calculated using Vienna ab initio Simulation Package (VASP) software in combination with phonopy code in the harmonic approximation. The variation of concentration of gold has been simulated by placing one and two gold atoms on graphene sheets containing successively 8 C-atoms (G8) and 32 C-atoms (G32). From phonon dispersion curves, it is clear that the change in the phonon frequencies of graphene with 3.125% Au adsorbent (G32) is negligible as compared to 12.5% of Au adsorbent (G8). An increase in the variation of entropy as well as specific heat with temperature is also observed upon Au adsorption in both graphene sheets as compared to pure graphene. But reverse trend is observed for the case of variation of free energy with temperature. Here, it decreases upon Au adsorption.

Binding of four DNA nucleotide units with (ZnO)3 cluster in an aqueous phase has been investigated using density functional theory (DFT) and time dependent-density functional theory (TDDFT) method and the stability order for (ZnO)3-nucleobases/sugar/phosphate systems is predicted as phosphate > C > A > S > T ∼ G. The order of binding energy for (ZnO)3-nucleotide hybrid systems is observed to be (ZnO)3 + nuc-C ˃ (ZnO)3 + nuc-A ˃ (ZnO)3 + nuc-G ˃ (ZnO)3 + nuc-T. The binding of nucleotide units with the cluster has been explained on the basis of molecular electrostatic potential (MEP) plots, hydrogen bonding, glycosidic torsion angles, density of state (DOS) plots. The photophysical properties of (ZnO)3-nucleotide complexes have been studied using TDDFT approach. Among all (ZnO)3-nucleotide complexes, the absorption spectra of (ZnO)3 + nuc-A and (ZnO)3 + nuc-C complexes are seen to undergo red shift with respect to their bare nucleotide units that would be useful in the optical sensing of the respective nucleotides of DNA. It is interesting to note that binding of the nucleotide unit with the cluster makes it fluorescent, the study reports the fluorescence activity of (ZnO)3 + nuc-T complex.

Modeling of a graphene nanoribbon field effect transistor (GNRFET) as a frequency doubler has been extensively explored for developing future communication applications. For its analysis, different types of modifications are applied to the GNRFET model simulated in a Hewlett simulation program with an integrated circuit. The model is demonstrated for its frequency response and conversion gain. It uses an intrinsic GNRFET for frequency doubling which clearly shows a distortionless sinusoidal output at a peak frequency of 20.6 MHz for an applied input of 10.3 MHz. However, after applying doping at different fractions of 0.3%, 3% and 30% in the transistor model, signal decay appears at 30% doping fractions. Results are also shown for increasing the number of dimers (N), increasing the number of channels for conduction and the impact of changing the dielectric constant on the doubler model performance. It is found that as the channel width increases, an increase in the conversion gain from − 26.05 dB to − 20 dB results from an increase in N from 8 to 20 dimer lines. Further, if four graphene nanoribbon (GNR) channels are used in the doubler operation instead of one GNR channel, then a high conversion gain of − 16.47 dB as compared to − 26.05 dB for an individual GNR channel is also calculated. Regarding the impact of different dielectrics, it is revealed that, similar to a conventional transistor, a graphene transistor with a high-K-value dielectric presents the highest gain, but with a high distortion in the output signal. However, using a conventional silicon dioxide (SiO2) dielectric having a low K value gives lower conversion gain, but ideal frequency doubling in the output is attained.

Density Functional Theory (DFT) and Time Dependent (TD)-DFT studies predict substantial modifications in optical properties of Transition Metal Oxides (TMOs) of Ti, V and Zn by complexing them with conjugated polymer polythiophene (PTh). The TMO nanostructures were synthesized and their complexes with polymers were fabricated using a chemical oxidative polymerization method. Coating of the TMOs with PTh and the nano-dimensional nature of the samples was confirmed by various morphological investigations such as infrared (IR), X-ray diffractographs (XRD), High Resolution Transmission Electron Microscopy (HR-TEM) and field emission scanning electron microscopy (FE-SEM) techniques. The prepared samples were found to be a visible light driven photocatalyst. The sensitization of the complexes has been explained in terms of relative ordering of frontier orbitals of PTh and the TMO, and PTh qualified as an efficient photosensitizer for all three metal oxides on the basis of its electronic characteristics. Since the Highest Occupied Molecular Orbital (HOMO) of PTh lies well between the band gap of all three TMOs, the electron transfer from donor (PTh) to acceptor (TMO) is facilitated. The appreciable red shift in the absorption spectrum and decrease in the optical band gap calculated by Tauc's plot confirmed substantial reduction in the band gap of the formed complex in comparison to their bare counterparts. The isodensity plots established the PTh–TMO complexes as donor acceptor complexes and intermolecular charge transfer quantified the electron transfer from PTh (donor) to the TMOs (acceptor).

The Oxygen Evolution Reaction (OER) is one of the major roadblocks for electrocatalytic oxidation of water (water splitting) and for designing efficient metal-air batteries. Herein, we present a comprehensive study to design graphene based efficient electrocatalyst, modified by doping with main group elements Al, Si, P, S and co-doping with B and N, for OER using DFT computations. Four elementary steps in the OER reaction have been traced, free energy change for each elementary step was calculated considering thermodynamic corrections. Out of all the doped models, S doped graphene shows maximum efficiency that was further enhanced by adjusting the concentration of codopants B and N around the active dopant site. Our results show that synergy between codopants B and N and dopant S atom leads to high electrocatalytic efficiency of modified graphene towards OER and brings down the overpotential to as low as 0.44 V.

Social media has emerged as a flexible and interactive communication medium in the present digital era. Contemporary businesses use social media to achieve different communication objectives. However, using social media as a communication medium for corporate social responsibility (CSR) communication with stakeholders like, consumers is not well-explored in the existing literature. Furthermore, prior studies have also failed to consider the blend of CSR communication and social media to achieve consumer-related outcomes, for example, their loyalty and purchase likelihood. To this end, the objective of this study is to examine the relationship of the CSR communication of a bank through social media with consumer loyalty and purchase intention. The current study also proposes brand admiration as a potential mediator between this relationship. The data were collected from the banking consumers through a self-administered questionnaire in a developing economy. The data were analyzed through the structural equation modeling (SEM) technique using AMOS software. The results of the current survey confirmed that CSR communication of a bank on social media has direct and indirect, via brand admiration, relations with consumer loyalty, and purchase intentions. The outcomes of this survey will be helpful for the policymakers to understand the importance of CSR communication on social media to enhance the loyalty, and purchase intention of banking consumers.

The agency problem strikes as an ethical, practical, and economic issue in equal measures. The principal objective of the current research is to trace the nature of the agency conflicts in the family-owned pyramidal business groups of corporate Malaysia and how they affect the firm value. It is argued that the principa͐l-principal (PP) conflict is more severe in family-owned business firms. To achieve the objectives of the current study, the GMM and the fixed effect estimates are used. In addition, to find the difference between family-owned firms and family-owned firms in the pyramidal business, we have employed the Mann-Whitney test. The null hypothesis is accepted which indicates that the impact of the PP conflict among family firms is different from those in pyramidal business groups. The final sample of 420 firms listed on the Bursa Malaysia is chosen for the analysis. The results of the current study provide support to the hypothesized results that the PP conflict is severe in family-owned groups and has a significant effect on firm value. The findings of the current study also provide support that the PP conflict is prevalent in Malaysia, supporting the earlier evidence regarding the expropriation of minority shareholders rights reported in the studies carried out on samples of Malaysian non-financial firms. This is also in line with our measure of PP conflict severity, which is high in pyramidal family firms. Overall, the results provided support to the expropriation hypothesis. Thus, the findings of this study also confirm the view that in family-owned Malaysian firms, the ethical dilemmas of wealth expropriations do exist and are more intense in the pyramidal family-owned business structures. Instead of relying on traditional methods, the current study employed a synthetic measure to gauge the PP conflict. The study which is among the pioneer on the expropriation of minority shareholders will be helpful for policymakers, researchers and finance professionals in understanding the issues related to principal-principal conflict, and firm value in family-owned pyramidal business groups of Malaysia.

Platelets are best known for their vasoprotective responses to injury and inflammation. Here, we have asked whether they also support vascular integrity when neither injury nor inflammation is present. Changes in vascular barrier function in dermal and meningeal vessels were measured in real time in mouse models using the differential extravasation of fluorescent tracers as a biomarker. Severe thrombocytopenia produced by two distinct methods caused increased extravasation of 40-kDa dextran from capillaries and postcapillary venules but had no effect on extravasation of 70-kDa dextran or albumin. This reduction in barrier function required more than 4 h to emerge after thrombocytopenia was established, reverting to normal as the platelet count recovered. Barrier dysfunction was also observed in mice that lacked platelet-dense granules, dense granule secretion machinery, glycoprotein (GP) VI, or the GPVI signaling effector phospholipase C (PLC) γ2. It did not occur in mice lacking α-granules, C type lectin receptor-2 (CLEC-2), or protease activated receptor 4 (PAR4). Notably, although both meningeal and dermal vessels were affected, intracerebral vessels, which are known for their tighter junctions between endothelial cells, were not. Collectively, these observations 1) highlight a role for platelets in maintaining vascular homeostasis in the absence of injury or inflammation, 2) provide a sensitive biomarker for detecting changes in platelet-dependent barrier function, 3) identify which platelet processes are required, and 4) suggest that the absence of competent platelets causes changes in the vessel wall itself, accounting for the time required for dysfunction to emerge.

Graphene-based photodetectors have shown responsivities up to 10$^8$A/W and photoconductive gains up to 10$^{8}$ electrons per photon. These photodetectors rely on a highly absorbing layer in close proximity of graphene, which induces a shift of the graphene chemical potential upon absorption, hence modifying its channel resistance. However, due to the semi-metallic nature of graphene, the readout requires dark currents of hundreds of $\mu$A up to mA, leading to high power consumption needed for the device operation. Here we propose a novel approach for highly responsive graphene-based photodetectors with orders of magnitude lower dark current levels. A shift of the graphene chemical potential caused by light absorption in a layer of colloidal quantum dots, induces a variation of the current flowing across a metal-insulator-graphene diode structure. Owing to the low density of states of graphene near the neutrality point, the light-induced shift in chemical potential can be relatively large, dramatically changing the amount of current flowing across the insulating barrier, and giving rise to a novel type of gain mechanism. This readout requires dark currents of hundreds of nA up to few $\mu$A, orders of magnitude lower than other graphene-based photodetectors, while keeping responsivities of $\sim$70A/W in the infrared, almost two orders of magnitude higher compared to established germanium on silicon and indium gallium arsenide infrared photodetectors. This makes the device appealing for applications where high responsivity and low power consumption are required., Comment: 14 pages, 7 figures

Recent approaches to develop infrared photodetectors characterized by high sensitivities, broadband spectral coverage, easy integration with silicon electronics and low cost have been based on hybrid structures of transition metal dichalcogenides (TMDCs) and PbS colloidal quantum dots (CQDs). However, to date, such photodetectors have been reported with high sensitivity up to 1.5 $\mu$m. Here we extend the spectral coverage of this technology towards 2 $\mu$m demonstrating for the first time compelling performance with responsivities 1400 A/W at 1.8 $\mu$m with 1V bias and detectivities as high as $10^{12}$ Jones at room temperature. To do this we studied two TMDC materials as a carrier transport layer, tungsten disulfide (WS$_2$) and molybdenum disulfide (MoS$_2$) and demonstrate that WS$_2$ based hybrid photodetectors outperform those of MoS$_2$ due to a more adequate band alignment that favors carrier transfer from the CQDs., Comment: 24 pages including Supporting Information

Optical sensing in the mid- and long-wave infrared (MWIR, LWIR) is of paramount importance for a large spectrum of applications including environmental monitoring, gas sensing, hazard detection, food and product manufacturing inspection, and so forth. Yet, such applications to date are served by costly and complex epitaxially grown HgCdTe quantum-well and quantum-dot infrared photodetectors. The possibility of exploiting low-energy intraband transitions make colloidal quantum dots (CQD) an attractive low-cost alternative to expensive low bandgap materials for infrared applications. Unfortunately, fabrication of quantum dots exhibiting intraband absorption is technologically constrained by the requirement of controlled heavy doping, which has limited, so far, MWIR and LWIR CQD detectors to mercury-based materials. Here, we demonstrate intraband absorption and photodetection in heavily doped PbS colloidal quantum dots in the 5-9 µm range, beyond the PbS bulk band gap, with responsivities on the order of 10-4 A/W at 80 K. We have further developed a model based on quantum transport equations to understand the impact of electron population of the conduction band in the performance of intraband photodetectors and offer guidelines toward further performance improvement. I.R. acknowledges support from the Ministerio de Economiá , Industria y Competitividad of Spain via a Juan de la Cierva fellowship. The authors acknowledge financial support from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (Grant Agreement 725165), the Spanish Ministry of Economy and Competitiveness (MINECO), and the “Fondo Europeo de Desarrollo Regional” (FEDER) through Grant TEC2017- 88655-R. The authors also acknowledge financial support from Fundacio Privada Cellex, the program CERCA and from the Spanish Ministry of Economy and Competitiveness, through the “Severo Ochoa” Programme for Centres of Excellence in R&D (SEV-2015-0522). S.C. acknowledge support from a Marie Curie Standard European Fellowship (“NAROBAND”, H2020-MSCA-IF-2016-750600).

In this work, we systematically investigate the effect of biaxial strain on the electronic transport coefficients of monolayer MoSe2 (n-type and p-type) by using the DFT formalism. The application of strain modifies the electronic band structure by changing the energy band gap and also makes the transition from direct to indirect, which in turn directly modulates the transport coefficients of the material i.e. Seebeck coefficients and electrical conductivity. The compressive strain is found to enhance the power factor of n-type MoSe2 monolayer and in case of p-type tensile strain improves power factor but only slightly. In particular, the application of strain enhances the various transport parameters which further help in increasing the efficiency of monolayer MoSe2 as a thermoelectric material.

The first principles calculations have been performed for the ferroelectric β-phase of the semi-crystalline polymer Polyvinylidene fluoride (PVDF). The electronic structure and the dielectric properties have been investigated using density functional theory (DFT). Hybrid functionals give better results for band gap as compared to generalized gradient approximation (GGA) and local density approximation (LDA). It is found that β-phase has a band gap of 6.5 eV at the Γ-point which is in good agreement with the experimental results. The dielectric properties of polar form (I) and (II) have been analyzed using density functional perturbation theory (DFPT). An anisotropy has been observed in the dielectric permittivity of crystalline PVDF. The microscopic investigation of these properties helps in better understanding and hence improving the energy density in energy storage devices.

The effect of biaxial strain on the electronic transport coefficients of monolayer MoS2 (both p and n-type) are studied. The electronic band structure calculations are done by Density Functional Theory based Quantum Espresso software and transport coefficients are calculated using BoltzTrap code. The electronic band structure is sensitive to biaxial strain which leads to the modulation of transport coefficients under strain. This variation of transport coefficients with respect to carrier concentration are investigated at room temperature on application of biaxial strain. It is found that for n-type monolayer, compressive strain enhances the Seebeck coefficient which further improves the power factor. However, for p-type monolayer, the Seebeck coefficient and power factor decrease on applying both types of strain. In both types of monolayer, the electrical conductivity changes by a very small amount under strain. These results show that, n-type monolayer MoS2 could be used as an efficient thermoelectric materialunder compressive strain.

The electronic structure and transport properties of GaN-MoS2 heterostructure have been theoretically investigated using first principles calculations. Among the various possibilities of stacking MoS2 over GaN monolayers to form heterostructure, we studied the case in which the S atom is directly placed over the Ga atom. This type of stacking is energetically favourable. The GaN-MoS2 heterostructure preserves the direct band gap nature of MoS2 monolayer i.e. it has direct band gap of 0.97 eV. The valence bands and conduction bands adjoining the fermi level are mostly contributed by N and Mo atoms. To study the performance of both n-type and p-type GaN-MoS2 heterostructure in thermoelectric applications, we investigate the transport coefficients on which the ZT parameter depends. We found that p-type heterostructure has high electrical conductivity as compared to n-type heterostructure. Due to which it has a high magnitude of power factor which is one of the deciding factors in the evaluation of ZT parameter.

Two dimensional materials based on chalcogenides are showing exciting thermoelectric efficiency. Recent experimental synthesisation of several Janus monolayers inspire investigation of novel materials. In this paper, we study the thermoelectric performance of the novel Janus Al2STe monolayer using Density Functional theory. We found that Janus Al2STe monolayer is an indirect band gap semiconductor with an energy gap of 1.17 eV and is dynamically stable. The transport coefficients such as Seebeck coefficient, electrical conductivity, power factor, and electronic thermal conductivity are evaluated using BoltzTraP2 code based on Boltzmann transport theory within constant relaxation time approximation. The dependence of relaxation time on temperature has been approximated with the deformation potential theory. Further, the lattice component of thermal conductivity has been obtained using ShengBTE code. The calculated value of ZT shows that both n-type and p-type Janus monolayer have outstanding thermoelectric performance. From the evaluated results, we conclude that Janus Al2STe monolayer can be used as a propitious candidate in the fabrication of thermoelectric devices.

Adsorption of small gas molecules (such as CO, O2, NO and NO2) on pristine graphene (PG) and Li-adsorbed graphene (PG-Li) have been investigated using first principles methods within density functional theory (DFT). The adsorption energy, equilibrium graphene-molecule distance, density of states (DOS) and PDOS of small gas molecules adsorbed on PG and PG-Li have been calculated. We find that electronic properties of PG are sensitive to the adsorption of O2 and NO2 molecules while it remains insensitive to the adsorption of O2 and NO2 molecules. We also notice that PG-Li, with Li atom adsorbed on hollow site(H-site) of graphene, has a higher chemical reactivity towards the gas molecules as compared to PG and these molecules have higher adsorption energy on this surface. Simultaneous adsorption of Li at mixed sites has a higher chemical reactivity towards the NO/CO gas molecules and shows higher adsorption energy as compared to its adsorption at single site. Moreover, the strong interactions between PG-Li and the adsorbed molecules (as compared to PG and gas molecules) induce dramatic changes to the electronic properties of PG adsorbed with Li and make PG-Li a promising candidate as sensing material for CO, O2, NO and NO2 gases.

Integrated circuits based on complementary metal-oxide–semiconductors (CMOS) are at the heart of the technological revolution of the past 40 years, enabling compact and low-cost microelectronic circuits and imaging systems. However, the diversification of this platform into applications other than microcircuits and visible-light cameras has been impeded by the difficulty to combine semiconductors other than silicon with CMOS. Here, we report the monolithic integration of a CMOS integrated circuit with graphene, operating as a high-mobility phototransistor. We demonstrate a high-resolution, broadband image sensor and operate it as a digital camera that is sensitive to ultraviolet, visible and infrared light (300–2,000 nm). The demonstrated graphene–CMOS integration is pivotal for incorporating 2D materials into the next-generation microelectronics, sensor arrays, low-power integrated photonics and CMOS imaging systems covering visible, infrared and terahertz frequencies. Graphene–quantum dots on CMOS sensor offers broadband imaging.

Complement plays a key role in host defense, but its dysregulation can cause autologous tissue injury. Complement activation is normally controlled by regulatory proteins, including factor H (FH) in plasma and membrane cofactor protein (MCP) on the cell surface. Mutations in FH and MCP are linked to atypical hemolytic uremic syndrome, a type of thrombotic microangiopathy (TMA) that causes renal failure. We describe here that disruption of FH function on the cell surface can also lead to disseminated complement-dependent macrovascular thrombosis. By gene targeting, we introduced a point mutation (W1206R) into murine FH that impaired its interaction with host cells but did not affect its plasma complement-regulating activity. Homozygous mutant mice carrying this mutation developed renal TMA as well as systemic thrombophilia involving large blood vessels in multiple organs, including liver, lung, spleen, and kidney. Approximately 30% of mutant mice displayed symptoms of stroke and ischemic retinopathy, and 48% died prematurely. Genetic deficiency of complement C3 and factor D prevented both the systemic thrombophilia and renal TMA phenotypes. These results demonstrate a causal relationship between complement dysregulation and systemic angiopathy and suggest that complement activation may contribute to various human thrombotic disorders involving both the micro- and macrovasculature.

To explore communication applications, a study towards achieving linearity in the I–V characteristics through increasing concentrations of Boron (B) / Nitrogen (N) doping on pristine graphene sheet is investigated. Individual B/N doping of 6.25, 12.50, 18.75 and 25% has been done in the same sub lattice using Density Functional Theory (DFT) along with Non Equilibrium Greens Function (NEGF) calculations. The modification in the electronic and transport properties of graphene sheet are also investigated. In comparison to the variation of band gap from 0.35 to 1.183 eV and 0.36 to 1.149 eV for B and N respectively, an insignificant variation in effective mass is reported. Apart from linearity, variation in conductance in doped structures is seen. B doping increases conductivity and yields ON current of 610 µA while N doping gives ON current of 310 µA for maximum doping concentrations. In this work, the sustained carrier mobility and high gain linear characteristics of doped graphene obtained will help to utilise a graphene channel for different communication device applications.

Metal catalyzed asymmetric oxidation of prochiral sulfides is one of the prevailing strategies to produce enantiopure sulfoxides. Keeping in view the reported reactivity of peroxo vanadium complexes towards asymmetric oxidation reactions, this study explores the reactivity of vanadia represented as a VO

Computations have been performed on VxOy clusters (with x = 1–8, y = 1–21) to explore their structure, stability, and reactivity based on local and global reactivity descriptors defined within the formalism of density functional theory (DFT). The vertical and adiabatic ionization energies and electron affinities are in accordance with Franck–Condon principle and suggest that the VxOy clusters are more likely to be electron acceptors than donors. The structure and reactivity of VxOy clusters delicately depend on their oxygen content and environment. Distinct active sites have been identified for each cluster species on the basis of coordination, symmetry, and charge distribution. The propensity of all the reactive sites towards an approaching electrophile and/or nucleophile has been studied using local reactivity descriptor. In oxygen-poor clusters, the vanadium atoms are more prone to nucleophilic attack. With an increase in oxygen concentration, the coordination number of vanadium increases and reaches four-fold, the site for nucleophilic attack shifts to terminal oxygens. We conclude that of all the stoichiometries, the stable VxOy clusters have the (VO3)a(V2O5)b formula unit. The localization of positive charge density in cubic cage structure of V8O20 successfully traps halide ions (F−, Cl−, and Br−). In view of increasing use of metal oxide clusters in heterogeneous catalysis, the understanding of structure-activity relationship in vanadium oxides’ clusters provided in the current study is highly desirable.

G protein–coupled receptors are critical mediators of platelet activation whose signaling can be modulated by members of the regulator of G protein signaling (RGS) family. The 2 most abundant RGS proteins in human and mouse platelets are RGS10 and RGS18. While each has been studied individually, critical questions remain about the overall impact of this mode of regulation in platelets. Here, we report that mice missing both proteins show reduced platelet survival and a 40% decrease in platelet count that can be partially reversed with aspirin and a P2Y12 antagonist. Their platelets have increased basal (TREM)-like transcript-1 expression, a leftward shift in the dose/response for a thrombin receptor–activating peptide, an increased maximum response to adenosine 5′-diphosphate and TxA2, and a greatly exaggerated response to penetrating injuries in vivo. Neither of the individual knockouts displays this constellation of findings. RGS10−/− platelets have an enhanced response to agonists in vitro, but platelet count and survival are normal. RGS18−/− mice have a 15% reduction in platelet count that is not affected by antiplatelet agents, nearly normal responses to platelet agonists, and normal platelet survival. Megakaryocyte number and ploidy are normal in all 3 mouse lines, but platelet recovery from severe acute thrombocytopenia is slower in RGS18−/− and RGS10−/−18−/− mice. Collectively, these results show that RGS10 and RGS18 have complementary roles in platelets. Removing both at the same time discloses the extent to which this regulatory mechanism normally controls platelet reactivity in vivo, modulates the hemostatic response to injury, promotes platelet production, and prolongs platelet survival.

Flexible and transparent graphene photodetector technology allows non-invasive monitoring of vital signs., Wearable health and wellness trackers based on optical detection are promising candidates for public health uses due to their noninvasive tracking of vital health signs. However, so far, the use of rigid technologies hindered the ultimate performance and form factor of the wearable. Here, we demonstrate a new class of flexible and transparent wearables based on graphene sensitized with semiconducting quantum dots (GQD). We show several prototype wearable devices that are able to monitor vital health signs noninvasively, including heart rate, arterial oxygen saturation (SpO2), and respiratory rate. Operation with ambient light is demonstrated, offering low-power consumption. Moreover, using heterogeneous integration of a flexible ultraviolet (UV)–sensitive photodetector with a near-field communication circuit board allows wireless communication and power transfer between the photodetectors and a smartphone, offering battery-free operation. This technology paves the way toward seamlessly integrated wearables, and empowers the user through wireless probing of the UV index.

Computations have been performed on V

Colloidal quantum dot (CQD) light-emitting diodes (LEDs) deliver a compelling performance in the visible, yet infrared CQD LEDs underperform their visible-emitting counterparts, largely due to their low photoluminescence quantum efficiency. Here we employ a ternary blend of CQD thin film that comprises a binary host matrix that serves to electronically passivate as well as to cater for an efficient and balanced carrier supply to the emitting quantum dot species. In doing so, we report infrared PbS CQD LEDs with an external quantum efficiency of ~7.9% and a power conversion efficiency of ~9.3%, thanks to their very low density of trap states, on the order of 1014 cm−3, and very high photoluminescence quantum efficiency in electrically conductive quantum dot solids of more than 60%. When these blend devices operate as solar cells they deliver an open circuit voltage that approaches their radiative limit thanks to the synergistic effect of the reduced trap-state density and the density of state modification in the nanocomposite. PbS quantum dot ternary blends enable the realization of high-efficiency colloidal quantum dot infrared light-emitting diodes