An overview of green synthesized silver nanoparticles towards bioactive antibacterial, antimicrobial and antifungal applications.

Present review emphatically introduces the synthesis, biocompatibility, and applications of silver nanoparticles (AgNPs), including their antibacterial, antimicrobial, and antifungal properties. A comprehensive discussion of various synthesis methods for AgNPs, with a particular focus on green chemistry mediated by plant extracts has been made. Recent research has revealed that the optical properties of AgNPs, including surface plasmon resonance (SPR), depend on the particle size, as well as the synthesis methods, preparation synthesis parameters, and used reducing agents. The significant emphasis on the use of synthesized AgNPs as antibacterial, antimicrobial, and antifungal agents in various applications has been reviewed. Furthermore, the application areas have been thoroughly examined, providing a detailed discussion of the underlying mechanisms, which aids in determining the optimal control parameters during the synthesis process of AgNPs. Furthermore, the challenges encountered while utilizing AgNPs and the corresponding advancements to overcome them have also been addressed. This review not only summarizes the achievements and current status of plant-mediated green synthesis of AgNPs but also explores the future prospects of these materials and technology in diverse areas, including bioactive applications.

Preparation of cross-linked enzyme aggregates of lipase from Aspergillus niger: process optimization, characterization, stability, and application for epoxidation of lemongrass oil.

Cross-linked enzyme aggregates (CLEAs) of lipase were prepared after fractional precipitation with 40-50% ammonium sulfate and then cross-linking with glutaraldehyde. The process variables for the preparation of lipase-CLEAs such as glutaraldehyde concentration, cross-linking period, and initial pH of medium were optimized. The optimized conditions for the preparation of lipase-CLEAs were 25 mM/80 min/pH 7.0, and 31.62 mM/90 min/pH 6.0 with one factor at a time approach and numerical optimization with central composite design, respectively. Lipase-CLEAs were characterized by particle size analysis, SEM, and FTIR. Cross-linking not only shifted the optimal pH and temperature from 7.0 to 7.5 and 40-45 to 45-50 °C, but also altered the secondary structure. Lipase-CLEAs showed an increase in Km by 7.70%, and a decrease in Vmax by 16.63%. Lipase-CLEAs presented better thermostability than free lipase as evident from thermal inactivation constants (t1/2, D and Ed value), and thermodynamic parameters (Ed, ΔH°, ΔG°, and ΔS°) in the range of 50-70 °C. Lipase-CLEAs retained more than 65% activity up to four cycles and showed good storage stability for 12 days when stored at 4 ± 2 °C. They were successfully utilized for the epoxidation of lemongrass oil which was confirmed by changes in iodine value, epoxide value, and FTIR spectra.

Craniofacial reconstruction of the Indus Valley Civilization individuals found at 4500-year-old Rakhigarhi cemetery.

Despite academic efforts to study the Indus Valley Civilization (IVC), there have as yet been no successful attempts to unveil the IVC people's craniofacial appearance. We investigated the IVC cemetery area of Rakhigarhi site, which was estimated to be of 2273 ± 38 and 2616 ± 73 years BCE. By craniofacial reconstruction (CFR) procedure using computed tomography (CT) data of two Rakhigarhi skulls (A1 BR02 and A2 BR36), we successfully reconstructed the faces of the IVC individuals who were buried about 4500 years ago. This is the first attempt to unveil scientifically accurate representations of IVC people's actual facial morphology.

An Ancient Harappan Genome Lacks Ancestry from Steppe Pastoralists or Iranian Farmers.

We report an ancient genome from the Indus Valley Civilization (IVC). The individual we sequenced fits as a mixture of people related to ancient Iranians (the largest component) and Southeast Asian hunter-gatherers, a unique profile that matches ancient DNA from 11 genetic outliers from sites in Iran and Turkmenistan in cultural communication with the IVC. These individuals had little if any Steppe pastoralist-derived ancestry, showing that it was not ubiquitous in northwest South Asia during the IVC as it is today. The Iranian-related ancestry in the IVC derives from a lineage leading to early Iranian farmers, herders, and hunter-gatherers before their ancestors separated, contradicting the hypothesis that the shared ancestry between early Iranians and South Asians reflects a large-scale spread of western Iranian farmers east. Instead, sampled ancient genomes from the Iranian plateau and IVC descend from different groups of hunter-gatherers who began farming without being connected by substantial movement of people.

A young couple's grave found in the Rakhigarhi cemetery of the Harappan Civilization.

The Harappan Civilization, one of the earliest complex societies in the world, flourished on the Indian subcontinent. Although many additional Harappan settlements and cemeteries have been discovered and investigated, no coupled burials at Harappan cemeteries have been reported to date. In 2013-2016, we excavated the cemetery of the Rakhigarhi site (Haryana), the largest city of the Harappan Civilization. At the site, we found a grave that turned out to be a coupled (joint) burial of the primary type. This report is the first anthropologically confirmed case of coupled burial from a Harappan cemetery.

Archaeological and anthropological studies on the Harappan cemetery of Rakhigarhi, India.

An insufficient number of archaeological surveys has been carried out to date on Harappan Civilization cemeteries. One case in point is the necropolis at Rakhigarhi site (Haryana, India), one of the largest cities of the Harappan Civilization, where most burials within the cemetery remained uninvestigated. Over the course of the past three seasons (2013 to 2016), we therefore conducted excavations in an attempt to remedy this data shortfall. In brief, we found different kinds of graves co-existing within the Rakhigarhi cemetery in varying proportions. Primary interment was most common, followed by the use of secondary, symbolic, and unused (empty) graves. Within the first category, the atypical burials appear to have been elaborately prepared. Prone-positioned internments also attracted our attention. Since those individuals are not likely to have been social deviants, it is necessary to reconsider our pre-conceptions about such prone-position burials in archaeology, at least in the context of the Harappan Civilization. The data presented in this report, albeit insufficient to provide a complete understanding of Harappan Civilization cemeteries, nevertheless does present new and significant information on the mortuary practices and anthropological features at that time. Indeed, the range of different kinds of burials at the Rakhigarhi cemetery do appear indicative of the differences in mortuary rituals seen within Harappan societies, therefore providing a vivid glimpse of how these people respected their dead.

Energy efficient room temperature synthesis of cardanol-based novolac resin using acoustic cavitation.

The present study deals with synthesis of cardanol-cased novolac (CBN) resin by the condensation reaction between cardanol and formaldehyde using acoustic cavitation. It is a step-growth polymerization which occurs in the presence of an acid catalyst such as adipic acid, citric acid, oxalic acid, sulphuric acid and hydrochloric acid. CBN was also synthesised by a conventional method for the sake of comparison of techniques. The effect of molar ratio, effect of catalyst, effect of different catalyst and effect of power on the conversion to CBN has been studied. The synthesised CBN was characterized using the Fourier Transform Infra Red Spectroscopy (FTIR), Gel Permeation Chromatography (GPC), Nuclear Magnetic Resonance (NMR) Spectroscopy and Thermogravimetric Analysis (TGA). The reaction was monitored by the Acid value, free formaldehyde content and viscosity of the synthesised product. The reaction time required for the conventionally synthesised CBN was 5 h (300 min) with 120 °C as an operating temperature while sonochemically the time reduced to 30 min at room temperature. The amount of time and energy saved can be quantified. Ultrasound facilitated synthesis was found to be an energy efficient and time-saving method for the synthesis of novolac resin.