Phytogenic nanoparticles: synthesis, characterization, and their roles in physiology and biochemistry of plants

Researchers are swarming to nanotechnology because of its potentially game-changing applications in medicine, pharmaceuticals, and agriculture. This fast-growing, cutting-edge technology is trying different approaches for synthesizing nanoparticles of specific sizes and shapes. Nanoparticles (NPs) have been successfully synthesized using physical and chemical processes; there is an urgent demand to establish environmentally acceptable and sustainable ways for their synthesis. The green approach of nanoparticle synthesis has emerged as a simple, economical, sustainable, and eco-friendly method. In particular, phytoassisted plant extract synthesis is easy, reliable, and expeditious. Diverse phytochemicals present in the extract of various plant organs such as root, leaf, and flower are used as a source of reducing as well as stabilizing agents during production. Green synthesis is based on principles like prevention/minimization of waste, reduction of derivatives/pollution, and the use of safer (or non-toxic) solvent/auxiliaries as well as renewable feedstock. Being free of harsh operating conditions (high temperature and pressure), hazardous chemicals and the addition of external stabilizing or capping agents makes the nanoparticles produced using green synthesis methods particularly desirable. Different metallic nanomaterials are produced using phytoassisted synthesis methods, such as silver, zinc, gold, copper, titanium, magnesium, and silicon. Due to significant differences in physical and chemical properties between nanoparticles and their micro/macro counterparts, their characterization becomes essential. Various microscopic and spectroscopic techniques have been employed for conformational details of nanoparticles, like shape, size, dispersity, homogeneity, surface structure, and inter-particle interactions. UV-visible spectroscopy is used to examine the optical properties of NPs in solution. XRD analysis confirms the purity and phase of NPs and provides information about crystal size and symmetry. AFM, SEM, and TEM are employed for analyzing the morphological structure and particle size of NPs. The nature and kind of functional groups or bioactive compounds that might account for the reduction and stabilization of NPs are detected by FTIR analysis. The elemental composition of synthesized NPs is determined using EDS analysis. Nanoparticles synthesized by green methods have broad applications and serve as antibacterial and antifungal agents. Various metal and metal oxide NPs such as Silver (Ag), copper (Cu), gold (Au), silicon dioxide (SiO2), zinc oxide (ZnO), titanium dioxide (TiO2), copper oxide (CuO), etc. have been proven to have a positive effect on plant growth and development. They play a potentially important role in the germination of seeds, plant growth, flowering, photosynthesis, and plant yield. The present review highlights the pathways of phytosynthesis of nanoparticles, various techniques used for their characterization, and their possible roles in the physiology of plants.

Utility of preoperative labs in posterior spinal fusions for idiopathic scoliosis

PURPOSE

Review of 216 consecutive idiopathic scoliosis (IS) patients undergoing posterior spinal fusion (PSF) demonstrated 94.9% having abnormal lab values, but only 3.9% were referred for further evaluation. A limited set of preoperative laboratory testing costing $234/patient, and thorough, adjunct review of patient/family history could identify potentially significant comorbidities preoperatively in this study. A savings of $1556/patient from current laboratory testing was identified.

METHODS

The laboratory tests routinely obtained preoperatively were investigated: abnormal preoperative laboratory outcomes were identified and further documented if additional action was taken defined as a referral to another medical provider, performance of additional lab testing or counseling, or if there was alteration of the surgical plan.

RESULTS

Overall, 94.9% (n = 205) of patients had one or more abnormal pre-operative lab values. Further actions occurred in 11.7% (n = 24) of all abnormal lab values with 3.9% (n = 8) of these being referred to other healthcare providers. Sixteen abnormal lab values underwent further testing or treatment: 11 nicotine tests, two UCx, one UA, one PT/PTT, and one bovine gelatin RAST. Eight abnormal tests prompted referral to another provider: three CBC, three platelet function tests, one UCx, and one UA. Based on these data, standard preoperative Hgb/Hct, platelet function tests, and bovine RAST (If the surgical plan involves use of bovine gelatin products) appear to be adequate to identify potential significant comorbidities in IS patients undergoing PSF for only $234/patient, a cost savings of $1556/patient from current protocol.

CONCLUSION

Based on this study of 216 patients, a limited preoperative laboratory testing and thorough, adjunct review of patient/family history appears to be adequate to identify potential comorbidities preoperatively in this study.

LEVEL OF EVIDENCE

II.

Conformational & spectroscopic characterization, charge analysis and molecular docking profiles of chromone-3-carboxylic acid using a quantum hybrid computational method

The Spectroscopic profile of Chromone-3-Carboxylic Acid (abbreviated as C3CA) was examined using FT-IR, FT-Raman, UV, ¹H and ¹³C NMR techniques. The geometrical parameters and energies attained from DFT/B3LYP method with 6-311++G (d,p) basis sets calculations. The geometry of the molecule was fully optimized, vibrational spectra were calculated and assigned the fundamental vibrations on the basis of the total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanics (SQM) method. The XRD data obtained from the computed geometric parameters shows that there is little deviation in the structure due to the substitution of the COOH group in the molecule. Using NBO study, the delocalization of the electron and the corresponding attraction between the orbitals shows that the lone pair transition has higher stabilization energy when compared with remaining atoms. The ¹H and ¹³C NMR chemical shifts are calculated using GIAO method and the experimental chemical shifts were analysed with theoretical values which reflects better coincidence. The electronic properties, HOMO and LUMO energies, are performed with TD-DFT reproduces good with the experimental findings. Besides, frontier molecular orbitals (FMO), the high reactive nature of the molecule is identified with MEP and global reactivity descriptor analysis are performed. In addition, the molecular docking study was conducted, and results of the docking study identified the sugar phosphatase inhibitor activity of the target molecule (C3CA).

Reactivity, vibrational spectroscopy, internal rotation and thermochemical aspects of methylarsine

The aim of this investigation was to perform a characterization of the spectroscopic and thermodynamic properties of methylarsine (CH₃AsH₂). Post-Hartree-Fock, 29 DFT methods and eight different composite methodologies were employed in these analyses. A comparison between harmonic and anharmonic frequency accuracies in reproducing the observable frequencies was performed here. In addition, the CH₃AsH₂→CH₂AsH₃ isomerization barrier energy was estimated in 100kcalmol^-1, whereas the H₂-release routes barrier heights were in the 45-107kcalmol^-1 range. A rate constant of 10^-66s^-1 was predicted regarding the isomerization route, while the CH₂AsH₃ hydrogen elimination mechanism is faster than the methylarsine one. The transition state structure of the CH₃AsH₂ internal rotational barrier energy varied between 1.0 and 1.4kcalmol^-1. For the CH₂AsH₃ internal rotation the estimated barrier heights varied 0.6-2.5kcalmol^-1. The adiabatic ionization energy and the heat of formation each structure was also calculated here.