Ultra-High Capacity Optical Satellite Communication System Using PDM-256-QAM and Optical Angular Momentum Beams.

Twisted light beams such as optical angular momentum (OAM) with numerous possible orthogonal states have drawn the prodigious contemplation of researchers. OAM multiplexing is a futuristic multi-access technique that has not been scrutinized for optical satellite communication (OSC) systems thus far, and it opens up a new window for ultra-high-capacity systems. This paper presents the 4.8 Tbps (5 wavelengths × 3 OAM beams × 320 Gbps) ultra-high capacity OSC system by incorporating polarization division multiplexed (PDM) 256-Quadrature amplitude modulation (256-QAM) and OAM beams. To realize OAM multiplexing, Laguerre Gaussian (LG) transverse mode profiles such as LG00, LG140, and LG400 were used in the proposed study. The effects of the receiver's digital signal processing (DSP) module were also investigated, and performance improvement was observed using DSP for its potential to compensate for the effects of dispersion, phase errors, and nonlinear effects using the blind phase search (BPS), Viterbi phase estimation (VPE), and the constant modulus algorithm (CMA). The results revealed that the proposed OAM-OSC system successfully covered the 22,000 km OSC link distance and, out of three OAM beams, fundamental mode LG00 offered excellent performance. Further, a detailed comparison of the proposed system and reported state-of-the-art schemes was performed.

Role of ST6GAL1 and ST6GAL2 in subversion of cellular signaling during enteroaggregative Escherichia coli infection of human intestinal epithelial cell lines.

Emerging evidence have suggested that aberrant sialylation on cell-surface carbohydrate architecture may influence host-pathogen interactions. The α2,6-sialyltransferase (ST) enzymes were found to alter the glycosylation pattern of the pathogen-infected host cell-surface proteins, which could facilitate its invasion. In this study, we assessed the role of specific α2,6-ST enzymes in the regulation of enteroaggregative E. coli (EAEC)-induced cell signaling pathways in human intestinal epithelial cells. EAEC-induced expression of α2,6-ST family genes in HCT-15 and INT-407 cell lines was assessed at mRNA level by qRT-PCR. Specific esi-RNA was used to silence the target ST-gene in each of the EAEC-infected cell type. Subsequently, the role of these enzymes in regulation of EAEC-induced cell signaling pathways was unraveled by analyzing the expression of MAPkinases (ERK1/2, p38, JNK) and transcription factors (NFκB, cJun, cFos, STAT) at mRNA and protein levels by qRT-PCR and western immunoblotting, respectively, expression of selected sialoglycoproteins by western immunoblotting along with the secretory IL-8 response using sandwich ELISA. ST6GAL-1 and ST6GAL-2 were efficiently silenced in EAEC-infected HCT-15 and INT-407 cells, respectively. Significant reduction in EAEC-induced activation of MAPKs, transcription factors, sialoglycoproteins, and IL-8 secretion was noted in ST-silenced cells in comparison to the respective control cells. We propose that ST6GAL-1 and ST6GAL-2 are quintessential for EAEC-induced stimulation of MAPK-mediated pathways, resulting in activation of transcription factors, leading to an inflammatory response in the human intestinal epithelial cells. Our study may be helpful to design better therapeutic strategies to control EAEC- infection. KEY POINTS: • EAEC induces α2,6-sialyltransferase (ST) upregulation in intestinal epithelial cells • Target STs (ST6GAL-1 & ST6GAL-2) were efficiently silenced using specific esiRNAs • Expression of MAPKs, transcription factors & IL-8 was reduced in ST silenced cells.

A multidisciplinary approach in pre-pubertal child sexual assault cases - forensic evaluation and suggestions.

BACKGROUND: Child sexual assault is highly prevalent in India yet a handful cases are reported under POCSO (Protection against child sexual offenses) Act, 2012. Even though the victims' testimony alone is enough to arrest accused as regulated by the Supreme Court but forensic evidence is still critical for sentencing rapists. A systematic evaluation of such cases will estimate impact of Child sexual assault (CSA) and pinpoint important aspects required for progression of prevention strategies and provision of support. METHOD AND OBJECTIVE: Present study reviewed cases pertaining pre-pubertal victims (up to 10 years age). Study included simple descriptive analysis of data highlighting significance of different variables in sexual assault cases involving child victims- perpetration, interventions, medical examination and forensic DNA analysis with the aim to improve primary preventive strategies and identify potential setbacks obstructing road to justice. RESULT: The strengths and weaknesses of pre-pubertal sexual assault assessment were identified. This study analyzed socio-economic backgrounds, age of alleged accused and whether known to the victim. Frequently reported type of abuse was assessed and total reviewed cases that yielded DNA profile from exhibits of victims and alleged accused were determined. CONCLUSION: As emerged in present study, pre-pubertal CSA is a complicated phenomenon grounded in interplay between societal influences, family support, evidence collection, legal delays, and medical hindrances that greatly affect DNA analysis. Prevalence of CSA is evidently alarming and demands stringent measures to be taken to prevent and control it. Joint and multidisciplinary assessment is important for forensic reporting rather than solo assessment.

COVID-19: Role of Robotics, Artificial Intelligence and Machine Learning During the Pandemic.

The outbreak of COVID-19 has led to a global health emergency. Emerging from China, it has now been declared as a pandemic. Owing to the fast pace at which it spreads, its control and prevention have now become the greatest challenge. The inner structural analysis of the virus is an important area of research for the invention of the potential drug. The countries are following different strategies and policies to fight against COVID-19; various schemes have also been employed to cope up with the economic crisis. While the government is struggling to balance between the public health sector and the economic collapse, the researchers and medicine practitioners are inclined towards obtaining treatment and early detection of the deadly disease. Further, the impact of COVID-19 on Dentistry is alarming and posing severe threats to the professionals as well. Now, the technology is helping the countries fight against the disease. ML and AI based applications are substantially aiding the process of detection and diagnosis of novel coronavirus. Science of Robotics is another approach followed with an aim to improve patient care.

Hempseed (Cannabis sativa) offers effective alternative over statins in ameliorating hypercholesterolemia associated nephropathy.

A direct link between hypercholesterolemia (HC) and renal pathologies has been established. Statins, the drugs of choice for HC management, have been associated with various side effects and toxicities, including nephropathy and other renal insults. Thus, natural dietary products based-alternative strategies for HC and associated pathologies are being considered. OBJECTIVES: Based on the unique nutritional composition and numerous health benefits of Hempseeds (Cannabis sativa), currently the potential anti-inflammatory and redox modulatory effects of hempseeds lipid extract (HEMP) against HC associated renal damage were evaluated and compared with statins (Simvastatin) in HFD induced experimental model of HC in rats. DESIGN & METHODS: The hempseed lipid fractions (HEMP) were prepared and their ameliorating effects on HFD induced lipid profiles, renal function markers (RFT), histopathological/morphological changes, renal oxidative stress, and inflammation markers were studied and compared with statins (HFD + STATINS). Further, HEMP-mediated modulation of lipid metabolism mediators (APO-B/E) was studied. RESULTS: Not only, HEMP administration improved the lipid profiles and morphological signs of HC, but it also was safe compared to Simvastatin in terms of hepatic and renal function markers. Further, changes in renal histoarchitecture, biochemical markers of oxidative stress, and expression profiles of lipid metabolism and inflammatory pathways (Cox-1/2, PGDS, PGES) revealed that HEMP positively modulating the redox homeostasis activated the resolution pathways against HC associated renal insults. CONCLUSION: The outcomes of the current study indicated HEMP's ameliorative and therapeutic potential against hypercholesterolemia-associated nephropathies and other systemic effects.

Environmental Copper Sensor Based on Polyethylenimine-Functionalized Nanoporous Anodic Alumina Interferometers.

Anthropogenic copper pollution of environmental waters from sources such as acid mine drainage, antifouling paints, and industrial waste discharge is a major threat to our environment and human health. This study presents an optical sensing system that combines self-assembled glutaraldehyde-cross-linked double-layered polyethylenimine (PEI-GA-PEI)-modified nanoporous anodic alumina (NAA) interferometers with reflectometric interference spectroscopy (RIfS) for label-free, selective monitoring of ionic copper in environmental waters. Calibration of the sensing system with analytical solutions of copper shows a linear working range between 1 and 100 mg L-1, and a low limit of detection of 0.007 ± 0.001 mg L-1 (i.e., ∼0.007 ppm). Changes in the effective optical thickness (ΔOTeff) of PEI-GA-PEI-functionalized NAA interferometers are monitored in real-time by RIfS, and correlated with the amount of ionic copper present in aqueous solutions. The system performance is validated through X-ray photoelectron spectroscopy (XPS) and the spatial distribution of copper within the nanoporous films is characterized by time-of-flight-secondary ion mass spectroscopy (TOF-SIMS). The specificity and chemical selectivity of the PEI-GA-PEI-NAA sensor to Cu2+ ions is verified by screening six different metal ion solutions containing potentially interfering ions such as Al3+, Cd2+, Fe3+, Pb2+, Ni2+, and Zn2+. Finally, the performance of the PEI-GA-PEI-NAA sensor for real-life applications is demonstrated using legacy acid mine drainage liquid and tap water for qualitative and quantitative detection of copper ions. This study provides new opportunities to develop portable, cost-competitive, and ultrasensitive sensing systems for real-life environmental applications.

Copper removal from acid mine drainage-polluted water using glutaraldehyde-polyethyleneimine modified diatomaceous earth particles.

Mine waters and tailings generated from mining and mineral processing activities often have detrimental impact on the local environment. One example is acid mine drainage, in which sulphides in the mining waste react with water and oxygen to produce an acidic environment that subsequently dissolves host rock minerals from the waste containing toxic metals and trace elements. Copper is one such metal of significance, as it is mined at large volumes in sulphide containing ores. It has strong biocidal activity that greatly affects ecosystems. We have previously reported that glutaraldehyde (GA)-crosslinked polyethyleneimine (PEI) has strong affinity and selectivity for copper and that diatomaceous earth (DE) particles can be modified with the material to form a copper-extraction resin. In this study, the copper uptake of GA-PEI-DE particles was investigated from synthetic and real acid mine drainage samples under different pHs and their copper removal performance was compared with that of selected commercial resins. The results revealed that copper could effectively and preferentially bind to the material at pH 4, and that the copper could be completely eluted by lowering of the pH. In addition, effective copper uptake and elution was demonstrated using real legacy acid mine drainage water from Mount Lyell in Tasmania.

Bio-template assisted synthesis of porous glutaraldehyde-polyethyleneimine particulate resin for selective copper ion binding and recovery.

Porous ion-exchange resins with features of high selectivity, high capacity, fast adsorption kinetics and chemical stability over a wide pH range are attractive for extracting precious metals like copper and upcycling waste. In this study, porous glutaraldehyde-polyethyleneimine (GA-PEI) particulate resin was synthesised using diatomaceous earth (DE) particles as a bio-template. The crosslinking of PEI by GA was successfully conducted on the surface of DE. Removal of the template DE, merely by chemical etching with potassium hydroxide, resulted in the porous GA-PEI particulate resin. The resin showed excellent selectivity for copper ions in binding and recovery from solutions as complex as real legacy acid mine drainage liquid. The copper ion uptake capacity of the GA-PEI resin was determined to be >8 times greater than non-etched GA-PEI-DE particles. Under the investigated conditions, the GA-PEI resin showed higher selectivity to copper ions from real legacy acid mine drainage liquid compared to the commercial resins Purolite S930 Plus and Lewatit TP 220. Importantly, the absorbed copper ions could be released by simply adjusting pH of the solution to 1. For uptake from acid mine drainage liquid at pH 4 and elution at pH 1, purer copper solutions were achieved with GA-PEI compared to Purolite S930 Plus or Lewatit TP 220 following two cycles of iteration. The results indicate the great potential for using the porous GA-PEI resin in copper extraction under real-world conditions.

Unhindered copper uptake by glutaraldehyde-polyethyleneimine coatings in an artificial seawater model system with adsorbed swollen polysaccharides and competing ligand EDTA.

Shortly after a surface is submerged in the sea, a conditioning film is generally formed by adsorption of organic molecules, such as polysaccharides. This could affect transport of molecules and ions between the seawater and the surface. An artificial seawater model system was developed to understand how adsorbed polysaccharides impact copper binding by glutaraldehyde-crosslinked polyethyleneimine coatings. Coating performance was also determined when competed against copper-chelating EDTA. Polysaccharide adsorption and copper binding and distribution were investigated using advanced analytical techniques, including depth-resolved time-of-flight secondary ion mass spectroscopy, grazing incidence X-ray absorption near-edge spectroscopy, quartz crystal microbalance with dissipation monitoring and X-ray photoelectron spectroscopy. In artificial seawater, the polysaccharides adsorbed in a swollen state that copper readily penetrated and the glutaraldehyde-polyethyleneimine coatings outcompeted EDTA for copper binding. Furthermore, the depth distribution of copper species was determined with nanometre precision. The results are highly relevant for copper-binding and copper-releasing materials in seawater.