Facile one-pot synthesis of amoxicillin-coated gold nanoparticles and their antimicrobial activity

Nanomaterials have been the object of intense study due to promising applications in a number of different disciplines. In particular, medicine and biology have seen the potential of these novel materials with their nanoscale properties for use in diverse areas such as imaging, sensing and drug vectorisation. Gold nanoparticles (GNPs) are considered a very useful platform to create a valid and efficient drug delivery/carrier system due to their facile and well-studied synthesis, easy surface functionalization and biocompatibility. In the present study, stable antibiotic conjugated GNPs were synthesised by a one-step reaction using a poorly water soluble antibiotic, amoxicillin. Amoxicillin, a member of the penicillin family, reduces the chloroauric acid to form nanoparticles and at the same time coats them to afford the functionalised nanomaterial. A range of techniques including UV-vis spectroscopy, dynamic light scattering (DLS), transmission electron microscopy (TEM) and thermogravimetric analysis (TGA) were used to ascertain the gold/drug molar ratio and the optimum temperature for synthesis of uniform monodisperse particles in the ca. 30-40 nm size range. Amoxicillin-conjugated gold showed an enhancement of antibacterial activity against Escherichia coli compared to the antibiotic alone

Back reaction effects on the dynamics of heavy probes in heavy quark cloud

We holographically study the effect of back reaction on the hydrodynamical properties of $\mathcal{N} = 4$ strongly coupled super Yang-Mills (SYM) thermal plasma. The back reaction we consider arises from the presence of static heavy quarks uniformly distributed over $\mathcal{N} = 4$ SYM plasma. In order to study the hydrodynamical properties, we use heavy quark as well as heavy quark-antiquark bound state as probes and compute the jet quenching parameter, screening length and binding energy. We also consider the rotational dynamics of heavy probe quark in the back-reacted plasma and analyse associated energy loss. We observe that the presence of back reaction enhances the energy-loss in the thermal plasma. Finally, we show that there is no effect of angular drag on the rotational motion of quark-antiquark bound state probing the back reacted thermal plasma.Comment: 29 pages, 21 figure

Gauge fields in (A)dS within the unfolded approach: algebraic aspects

It has recently been shown that generalized connections of the (A)dS space symmetry algebra provide an effective geometric and algebraic framework for all types of gauge fields in (A)dS, both for massless and partially-massless. The equations of motion are equipped with a nilpotent operator called $\sigma_-$ whose cohomology groups correspond to the dynamically relevant quantities like differential gauge parameters, dynamical fields, gauge invariant field equations, Bianchi identities etc. In the paper the $\sigma_-$-cohomology is computed for all gauge theories of this type and the field-theoretical interpretation is discussed. In the simplest cases the $\sigma_-$-cohomology is equivalent to the ordinary Lie algebra cohomology.Comment: 59 pages, replaced with revised verio

Inferring stabilizing mutations from protein phylogenies : application to influenza hemagglutinin

One selection pressure shaping sequence evolution is the requirement that a protein fold with sufficient stability to perform its biological functions. We present a conceptual framework that explains how this requirement causes the probability that a particular amino acid mutation is fixed during evolution to depend on its effect on protein stability. We mathematically formalize this framework to develop a Bayesian approach for inferring the stability effects of individual mutations from homologous protein sequences of known phylogeny. This approach is able to predict published experimentally measured mutational stability effects (ΔΔG values) with an accuracy that exceeds both a state-of-the-art physicochemical modeling program and the sequence-based consensus approach. As a further test, we use our phylogenetic inference approach to predict stabilizing mutations to influenza hemagglutinin. We introduce these mutations into a temperature-sensitive influenza virus with a defect in its hemagglutinin gene and experimentally demonstrate that some of the mutations allow the virus to grow at higher temperatures. Our work therefore describes a powerful new approach for predicting stabilizing mutations that can be successfully applied even to large, complex proteins such as hemagglutinin. This approach also makes a mathematical link between phylogenetics and experimentally measurable protein properties, potentially paving the way for more accurate analyses of molecular evolution

Molecular characterization and phylogenetic analysis of betasatellite molecules associated with okra yellow vein mosaic disease in Sri Lanka

Okra production in Sri Lanka has been severely affected by okra yellow vein mosaic disease (OYVMD), which is caused by begomoviruses and associated betasatellites. These betasatellite molecules commonly determine the development and severity of the disease. Therefore, knowledge about the genetic variability of betasatellites associated with OYVMD could assist okra breeding programs in the selection of resistant varieties. The present study aimed to characterize the betasatellite DNA sequences associated with OYVMD in Sri Lanka and to determine their phylogenetic relationships. Betasatellite DNA of six virus isolates from widely separated geographical locations were sequenced and compared with already reported begomovirus betasatellites. The betasatellite molecules have features common to other betasatellite DNAs: a conserved nonanucleotide TAATATTAC, a coding sequence for the protein βC1, an adenine rich region and a satellite conserved region. Nucleotide diversity among the isolates was relatively low (π = 0.034). A recombination event was detected at a specific region in the genome of all isolates. The isolates shared >96% sequence identity with bhendi yellow vein betasatellites reported from India and phylogenetic analysis confirmed their genetic relationship

Multiplicity Distributions and Charged-neutral Fluctuations

Results from the multiplicity distributions of inclusive photons and charged particles, scaling of particle multiplicities, event-by-event multiplicity fluctuations, and charged-neutral fluctuations in 158$\cdot A$ GeV Pb+Pb collisions are presented and discussed. A scaling of charged particle multiplicity as $N_{part}^{1.07\pm 0.05}$ and photons as $N_{part}^{1.12\pm 0.03}$ have been observed, indicating violation of naive wounded nucleon model. The analysis of localized charged-neutral fluctuation indicates a model-independent demonstration of non-statistical fluctuations in both charged particles and photons in limited azimuthal regions. However, no correlated charged-neutral fluctuations are observed.Comment: Talk given at the International Symposium on Nuclear Physics (ISNP-2000), Mumbai, India, 18-22 Dec 2000, Proceedings to be published in Pramana, Journal of Physic

In silico mining of micro-RNAs from Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae)

MicroRNAs (miRNAs) are small, endogenously, non-coding genes that regulate protein production either by mRNA cleavage or by translational repression in eukaryotes and viruses. miRNAs plays a key role in biological processes including growth, development and physiology of an organism. In this study, we employed insilico approaches to identify the miRNAs from Spodoptera frugiperda, a major pest of small grain crops. A total of seven miRNAs were identified and characterized from 67,360 expressed sequence tags (ESTs) of S. frugiperda with: 1) mature and pre-miRNAs sizes vary from 19 to 25 ans 61 to 95 nucleotides respectively; 2) minimum free energy ranged from -31.70 to -21.00 kcal/mol; and 3) (A + U) content varied from 27 to 60. The functional annotation of these miRNAs were identified as regulation of transcription factors, catalytic activities and signal transduction pathways. Further studies of these miRNAs will help to carryout functional analyses, which promises more towards insect pest management free of insecticides and pesticides.Keywords: MicroRNAs, translational repression, Spodoptera frugiperda, expressed sequence tags, minimum free energy, insect pest managementAfrican Journal of Biotechnology, Vol. 13(1), pp. 32-43, 1 January, 201

A Comparative study on Postoperative Pain among Laparoscopic guided Transversus Abdominis Plane (TAP) Block vs Port site Infiltration of Local Anaesthetic in Laparoscopic Cholecystectomy

Background: Postoperative pain management is a critical aspect of recovery following laparoscopic cholecystectomy. Various analgesic techniques, including transversus abdominis plane block (TAPB) and port-site infiltration (PILA), have been utilized to alleviate pain. Objective: To evaluate the role of laparoscopic-guided TAPB in comparison to port-site infiltration with 0.25% bupivacaine in managing postoperative pain in patients undergoing laparoscopic cholecystectomy. Methods: This was a single centre, hospital based comparative study conducted in the inpatient wards of the Department of General Surgery, JSS Medical College, Mysuru, Karnataka, India for a duration of 18 months (between June 2023 and December 2024) among patients with symptomatic cholelithiasis undergoing elective laparoscopic cholecystectomy. Results: A total of 120 patients were enrolled, with 60 in each group. Baseline characteristics, including age, gender, duration of pain, and body mass index, were comparable between the two groups. The mean duration of surgery did not differ significantly between the groups (TAPB: 52.9 minutes, PILA: 55.1 minutes; p = 0.181). However, the TAPB group had a significantly shorter hospital stay (1.5 days vs 2.0 days, p < 0.001) and a lower need for rescue analgesia. At 48 hours postoperatively, 53.3% of TAPB patients required two doses of analgesia, compared to 45.0% of PILA patients, and none in the TAPB group required three doses, unlike 38.3% in the PILA group. Pain scores, assessed using the Visual Analog Scale (VAS), were significantly lower in the TAPB group at all postoperative time points. On the day of surgery, pain scores were comparable between the groups, but by 3 hours postoperatively, the TAPB group reported significantly lower pain (p < 0.001). These differences persisted at 6, 12, 24, and 48 hours. Conclusion: The TAPB group experienced superior pain control, reduced analgesic requirements, and a quicker recovery, suggesting that laparoscopic-guided TAPB is a more effective option for postoperative pain management in laparoscopic cholecystectomy

Lac repressor mediated DNA looping: Monte Carlo simulation of constrained DNA molecules complemented with current experimental results

Tethered particle motion (TPM) experiments can be used to detect time-resolved loop formation in a single DNA molecule by measuring changes in the length of a DNA tether. Interpretation of such experiments is greatly aided by computer simulations of DNA looping which allow one to analyze the structure of the looped DNA and estimate DNA-protein binding constants specific for the loop formation process. We here present a new Monte Carlo scheme for accurate simulation of DNA configurations subject to geometric constraints and apply this method to Lac repressor mediated DNA looping, comparing the simulation results with new experimental data obtained by the TPM technique. Our simulations, taking into account the details of attachment of DNA ends and fluctuations of the looped subsegment of the DNA, reveal the origin of the double-peaked distribution of RMS values observed by TPM experiments by showing that the average RMS value for anti-parallel loop types is smaller than that of parallel loop types. The simulations also reveal that the looping probabilities for the anti-parallel loop types are significantly higher than those of the parallel loop types, even for loops of length 600 and 900 base pairs, and that the correct proportion between the heights of the peaks in the distribution can only be attained when loops with flexible Lac repressor conformation are taken into account. Comparison of the in silico and in vitro results yields estimates for the dissociation constants characterizing the binding affinity between O1 and Oid DNA operators and the dimeric arms of the Lac repressor. © 2014 Biton et al

Organic-Inorganic Nanostructure Architecture via Directly Capping Fullerenes onto Quantum Dots

A new form of fullerene-capped CdSe nanoparticles (PCBA-capped CdSe NPs), using carboxylate ligands with [60] fullerene capping groups that provides an effective synthetic methodology to attach fullerenes noncovalently to CdSe, is presented for usage in nanotechnology and photoelectric fields. Interestingly, either the internal charge transfer or the energy transfer in the hybrid material contributes to photoluminescence (PL) quenching of the CdSe moieties.open2