The Role of Biosynthesized Metallic and Metal Oxide Nanoparticles in Combating Anti-Microbial Drug Resilient Pathogens

Because of their high efficiency, antibiotics have long been the primary treatment for infections, but the rise of drug-resistant pathogens has become a therapeutic concern. Nanoparticles, as novel biomaterials, are currently gaining global attention to combat them. Drug-resistant diseases may need the use of nanoparticles as a viable therapeutic option. By altering target locations and enzymes, decreasing cell permeability, inactivating enzymes, and increasing efflux by overexpressing efflux pumps, they can bypass conventional resistance mechanisms. Therefore, understanding how metal and metal oxide nanoparticles affect microorganisms that are resistant to antimicrobial drugs is the main objective of this review. Accordingly, the uses of metal and metal oxide nanoparticles in the fight against drug-resistant diseases appear promising. However, their mechanism of action, dose, and possible long-term effects require special attention and future research. Furthermore, repeated use of silver nanoparticles may cause gram-negative microorganisms to acquire resistance, necessitating additional study.

Toxicity and Molecular Mechanisms of Actions of Silver Nanoparticles

Silver nanoparticles (AgNPs) have gained popularity due to their antibacterial properties, and are therefore widely used in several applications such as wound dressings, food packaging, and water purification. However, the toxicity of AgNPs to humans and the environment is a growing concern. This review aims to summarize the current knowledge on the toxicity and molecular mechanisms of action of AgNPs. The toxicity of AgNPs can be attributed to their small size, which allows them to enter cells and interact with cellular components. Reports suggest that AgNPs can induce cell death, DNA damage, and oxidative stress in various cell types. The toxic effects of AgNPs differ based on their size, shape, surface charge, and coating. The molecular mechanisms behind the toxicity of AgNPs involve the production of reactive oxygen species, disruption of cellular membranes, and activation of proinflammatory cytokines. Overall, the toxicity of AgNPs is dependent on various factors, and more research is needed to fully understand the mechanisms behind their toxicity. This review highlights the need for proper risk assessments and regulations to minimize the adverse effects of AgNPs on human health and the environment.

Angular Dependence of Lateral and Levitation Forces in Asymmetric Small Magnet/Superconducting Systems

The dipole-dipole interaction model is used to calculate the angular dependence of lateral and levitation forces on a small permanent magnet and a cylindrical superconductor in the Meissner state lying laterally off the symmetric axis of the cylinder. Under the assumption that the lateral displacement of the magnet is small compared with the physical dimensions of the system, we obtain analytical expressions for the lateral and levitation forces as functions of geometrical parameters of the superconductor as well as the height, the lateral displacement and the orientation of magnetic moment of the magnet. The effect of thickness and radius of the superconductor on the levitation force is similar to that for a symmetric magnet/superconducting cylinder system, but within the range of lateral displacement. The splitting in the levitation force increases with the increasing angle of orientation of the magnetic moment of the magnet. For a given lateral displacement of the magnet, the lateral force vanishes when the magnetic moment is perpendicular to the surface of the superconductor and has a maximum value when the moment is parallel to the surface. For a given orientation of the magnetic moment, the lateral force has a linear relationship with the lateral displacement. The stability of the magnet above the superconducting cylinder is discussed in detail.

First Principles Study of Atomic Adsorption on (111) and (100) Surfaces of Iridium

We have investigated the adsorption of nine different adatoms on the(111)and(100)surfaces of Iridium(Ir)using first principles density functional theory.The study explores surface functionalization of Ir which would provide important information for further study of its functionality in catalysis and other surface applications.The adsorption energy,stable geometry,density of states and magnetic moment are some of the physical quantities of our interest.The study reveals that the three-/four-fold hollow site is energetically the most favorable adsorption site on the(111)/(100)surface of Ir.The investigation on a wide range of coverages(from 0.04 to 1 monolayer)reveals the strong coverage dependence of adsorption energy of the adsorbate atoms.The adsorption energy is found to increase as the coverage increases,implying a repulsive interaction between the adsorbates.Strong hybridization between the adsorbates and the substrate electronic states is revealed to impact the adsorption,while the magnetic moment of the adsorbates is found to be suppressed.The Bader analysis reveals significant amount of charge transfers between the adsorbate atoms and the substrate.The binding of adsorbate atoms on the(100)surface is observed to be moderately stronger as compared to that on the(111)surface.

Phytogenic Synthesis of Metal/Metal Oxide Nanoparticles for Degradation of Dyes

Now-a-days nanotechnology is one of the booming fields for the researchers.With the increase in industrialization mainly textile,paper,medicine,plastic industry,there is an increase in concentration of organic dyes as pollutant.Release of harmful dyes in water bodies has become a serious issue,as most of the dyes are carcinogenic and mutagenic in nature and causes various diseases.Therefore,there is a requirement to find out new approaches for efficient treatment of effluent containing dyes.Nanoparticles are one of the potential solutions to this problem.They can be synthesized from different methods,however synthesis of nanoparticles from different plant parts(leaf,root or stem extract)is economical as well as ecofriendly.Phytogenic nanoparticles have various environmental applications and one of them is remediation of dyes.The aim of this review is to provide an overview of last five years studies about catalytic and photocatalytic degradation of various harmful dyes by plant synthesized nanoparticles,mechanism of degradation and advantages and disadvantages of phytogenic synthesis.

Prevalence of Multidrug Resistant <i>Mycobacterium tuberculosis</i>among Tuberculosis Patients Admitted to Adama Hospital Medical College, Adama, Ethiopia: A Retrospective Study

Multidrug resistant tuberculosis (MDR-TB) is an emerging challenge for TB control programs globally. Ethiopia ranks 7th among the world’s 22 high TB burden countries. According to report of WHO (2017), TB is one of the leading infectious causes of death in Ethiopia claiming the life of more than 30 thousand people annually. The surge of MDR-TB has been compounding the problem further. Facility-based MDR-TB researches have not been generated in equal pace with community-based ones. The aim of this study was to assess the prevalence of MDR-TB using clinical records of MDR-TB patients in Adama Hospital Medical College (AHMC) from 2014 to 2018. All clinical data of MDR-TB from 2014-2018 was collected from AHMC TB department. Socio-demographic and risk factor data were collected from patients using semi-structured questionnaire. Data were analyzed using Microsoft excel and SPSS version 20. Out of a total 2332 TB suspected cases admitted to AHMC from 2014 to 2018, 175 (7.5%) were confirmed MDR-TB cases or confirmed Rifampicin resistant cases. In particular, 97 (4.2%) presented presumptive MDR-TB alone and 78 (3.3%) showed confirmed Rifampicin resistance alone. Comparison among age groups showed the highest prevalence for 24 - 44 years with 1.8% and 1.5% confirmed MDR-TB and Rifampicin resistance. The overall prevalence of MDR-TB was moderate indicating for possible rise of the problem due to course of time. Further study combining both community and health facility based is recommended to highlight the need to make useful strategies for testing, surveillance and effective clinical management of MDR-TB cases.

Nonlinear Dynamics of Nervous Stomach Model Using Supervised Neural Networks

The purpose of the current investigations is to solve the nonlinear dynamics based on the nervous stomach model(NSM)using the supervised neural networks(SNNs)along with the novel features of Levenberg-Marquardt backpropagation technique(LMBT),i.e.,SNNs-LMBT.The SNNs-LMBT is implemented with three different types of sample data,authentication,testing and training.The ratios for these statistics to solve three different variants of the nonlinear dynamics of the NSM are designated 75%for training,15%for validation and 10%for testing,respectively.For the numerical measures of the nonlinear dynamics of the NSM,the Runge-Kutta scheme is implemented to form the reference dataset.The attained numerical form of the nonlinear dynamics of the NSM through the SNNs-LMBT is implemented in the reduction of the mean square error(MSE).For the exactness,competence,reliability and efficiency of the proposed SNNs-LMBT,the numerical actions are capable using the proportional arrangements through the features of the MSE results,error histograms(EHs),regression and correlation.

Analysis of the Promoter Region, Motif and CpG Islands in AraC Family Transcriptional Regulator ACP92 Genes of <i>Herbaspirillum seropedicae</i>

Identification of promoters and their regulatory elements are the most important phases in bioinformatics. To understand the regulation of gene expression, identification, and analysis of promoters region, motif and CpG islands are the most important steps. The accurate prediction of promoter’s is basic for proper interpretation of gene expression patterns, construction and understanding of genetic regulatory system. Therefore, the objective of this study was to analyze the promoter region, motif such as a transcription factor and CpG islands in AraC family transcriptional regulator ACP92 genes of Herbaspirillum seropedicae. The analysis was carried out by identifying transcription start sites in ACP92 genome sequences taken from the H. seropedicae assembly of NCBI genome browser, and 29 ACP92 genes sequences. Accordingly, transcription start sites (TSS) were identified, and the result indicated that 37.9% had more than one TSS whereas only 62.1% had one TSS. In the analysis, seven motifs were identified from the thought sequences and MV6 was revealed the common promoter motif for all (100%) in H. seropedicae ACP92 gene that serves as binding sites for transcription factors which shared a minimum of 48.27%. Based on a common motif MV6 to find out similar motifs using TOMTOM from the databases of prokaryotes DNA, most of them are transcription factors of fur family. The others are bacterial histone-like protein family, matp and sigma-54 factor family also transcription factor families that are binding candidate to MV6. H. seropedicae ACP92 genes are CpG Island which implies that the regulation of gene expression plays an important role.

Copernicrinus zamorae gen.et sp.nov.,the oldest thiolliericrinid crinoid(Crinoidea,Echinodermata) from the Bajocian strata of Algeria,Africa

The thiolliericrinids(Thiolliericrinidae) are comatulids(Comatulida),which retained their stalks as adults.Here,we report a centrodorsal from the Bajocian strata(Middle Jurassic) of the Djebel Kérdacha area,northwestern Algeria(Africa).It is the first thiolliericrinid report from outside of Europe and also the oldest representative of the Thiolliericrinidae whose first occurrence is from the Oxfordian.The crinoid is assigned to Copernicrinus zamorae gen.et sp.nov.The reported new taxon shows strong similarities with the stemless ‘true’comatulids,Solanocrinites;the only difference is the presence of a facet to the stem in Copernicrinus.The closest comparable thiolliericrinid to Copernicrinus is the Oxfordian Thiolliericrinus,interpreted as a descendant of the latter.The origin and overview of all thiolliericrinid representatives are also discussed herein.

Vibrations in Magnet/Superconductor Levitation Systems

The problem of a small magnet levitating above a very thin superconducting disc in the Meissner state is analysed. The dipole-dipole interaction model is employed to derive analytical expressions for the interaction energy, levitation force, magnetic stiffness and frequency of small vibrations about the equilibrium position in two different configurations, i.e. with the magnetic moment parallel and perpendicular to the superconductor. The results show that the frequency of small vibrations decreases with the increasing levitation height for a particular radius of the superconducting disc, which is in good agreement with the experimental results. However, the frequency increases monotonically up to saturation by increasing the radius of the disc for a particular height of the magnet. In addition, the frequency of vibrations is higher when the system is in the vertical configuration than that when the system is in the horizontal configuration.

Summary on Adsorption and Photocatalysis for Pollutant Remediation: Mini Review

Adsorption and photo catalysis are the most popular methods applied for the reduction of amount of pollutants that enter water bodies. The main challenge in the process of adsorption is the demonstration of the experimental data obtained from sorption processes. For many decades most of the researchers used adsorption and kinetic of adsorption as a repetitive work to describe the adsorption data by using common models such as, Langmuir and Freundlich for adsorption isotherms;PFO and PSO models for kinetics. This has been done without careful evaluation of the characteristics of adsorption process. It has been well understood that adsorption does not degrade the pollutant to eco-friendly products and photo catalysis will not degrade without adsorption of the pollutant on the catalyst. Therefore, understanding the detailed mechanism of adsorption, as well as, photo catalysis has been presented in this paper. During photo catalysis: modification towards suppression of electron-hole recombination, improving visible light response, preventing agglomeration, controlling the shape, size, morphology, etc. are the most important steps. This mini review also widely discusses the key points behind adsorption and photo catalysis.

Fe-Oxide Nanomaterial: Synthesis, Characterization and Lead Removal

Organic solvent free iron oxide nanomaterial used for lead removal was synthesized by co-precipitation method. Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopic with energy dispersive X-ray analysis (SEM-EDX), X-ray diffraction (XRD) and thermo gravimetric-differential thermal (TG-DTA) analysis were used to determine the surface characteristics and analysis of iron oxide. Optimization of solution pH, adsorbent dosage, contact time, agitation speed and initial lead ion concentration were conducted for further adsorption isotherm, kinetics, thermodynamics and desorption study. Langmuir sorption isotherm model fits the adsorption data better than Freundlich, Dubinin-Radushkevich (D-RK) and Flory-Huggins (FH) models. The mean adsorption energy and free energy obtained from D-RK and FH models guides that the mechanism was under control of physical adsorption and actuality of spontaneous reaction, respectively. From kinetics of adsorption pseudo second (PSO) model fits well than pseudo first (PFO) and Elovich adsorption-reaction models. And to test whether the reaction is under control of adsorption-diffusion or not the intra particle diffusion (IPD) model was tested, but it fails to pass through the origin. This indicates that the reaction mechanism only under control of adsorption-reaction. The maximum adsorption capacity (qmax) of the adsorbent was 70.422 mg/g.

Sheltered preservation of cyrtocrinid crinoids from the Lower Cretaceous of Madagascar and their palaeogeographic significance

Sheltered preservation,in which organisms are trapped within shells of cephalopods,is a wellknown phenomenon.This preservational style constitutes an important source of paleontological data.Here,we report the first crinoid preserved inside the early Albian ammonite Cleoniceras besairiei Collignon from Madagascar.This crinoid is assigned to the aspidocrinid phyllocrinid(Apsidocrinus,Phyllocrinidae),and constitutes the first phyllocrinid from the African continent,the second from the southern margin of the Tethys(after New Zealand),and also from the southern hemisphere.This specimen represents the youngest occurrence of a phyllocrinid in the world as well,and constitutes one of the youngest occurrences of cyrtocrinids from shallow sea environments,before predation-induced migration of the stalked crinoids to the deep sea refugia due to the so-called Mesozoic Marine Revolution.This finding highlights that ammonite shells may also be a convenient material for studying echinoderms.

Zircon Trace Element Constraints on the Evolution of the Paleoproterozoic Birimian Granitoids of the West African Craton(Ghana)

The Paleoproterozoie Birimian granitoids of the West African Craton （WAC） in the northwestern part of Ghana, have been studied for their zircon trace elements concentrations to infer the source characteristics, origin, and magmatic evolution. The zircons in the granitoids have Th/U ratios ranging from 0.03 to 1.55, and display depleted light rare earth elements 0LREE） and enriched heavy rare earth elements （HREE） contents, characterized by pronounced positive to negative anomalies of Eu （Eu/Eu＊=0.14-0.98 and 1.01-6.06, respectively） and Ce （Ce/Ce＊=0.08-0.98 and 1.02-116, respectively）, which may imply that they were derived from both magmatic and hydrothermal sources. The geochemical plots of U/Yb vs. Y and Hf, the positive correlation between Hf and the other high field strength elements 0tFSE） and high rare earth elements （REE） contents, with enrichment in Ce and depletion in Eu, indicate that the granitoids possibly formed from partial melting of the crust. The trace elements characteristics （i.e., wide range of Hf, Ce/Ce＊, Th/U and Zr/Hf values） of the zircons suggest that crystallization of the magma occurred under variable oxidation states, which spanned over a longer period, implying that our data corroborate interpretations from studies of whole-rock geochemistry and geochronology on the granitoids of northwestern Ghana. This further indicates that the evolution of the Birimian granitoids in this part of the WAC occurred earlier than what had been reported in the literature.

Short-term application of biochar increases the amount of fertilizer required to obtain potential yield and reduces marginal agronomic efficiency in high phosphorus-fixing soils

There is little understanding as to whether the addition of biochar requires less fertilizer to obtain the potential yield.Furthermore,the additional yield ascribed to the non-nutrient effects of biochar is ambiguously quantified.Therefore,this study is aimed to elucidate the influence of biochar application rate and production temperature on(i)marginal agronomic efficiency(AELN),(ii)potential yield(Yopt),(iii)the amount of mineral fertilizer required to obtain the potential yield(Fopt);and(iv)nutrient use efficiency.AELN,Yopt and Fopt were calculated after fitting the yield response at different levels of mineral fertilizer with a second-degree polynomial.Application of biochar reduced marginal agronomic efficiency,implying that the plant utilized the applied nutrient more efficiently without biochar at a low dose of mineral fertilizer.Biochar increased potential yield but required more mineral fertilizer to obtain the optimum yield.The non-nutrient associated effect of biochar reached to 39% and is mainly attributed to its liming effect.The effect of biochar on AELN,Yopt,Fopt,fertilizer use efficiency and soil pH were more pronounced at the higher application rate.Addition of biochar,however,increased soil Mehlich-P and carbon content,irrespective of production temperature and application rate.This study demonstrated that the short-term effect of biochar application on fertilizer utilization should be examined with caution in low-input cropping systems because the biochar effects were dependent on fertilizer level,biochar application rate,production temperature and their interactions.Further manipulative experiments are recommended to identify the mechanisms that explain the non-nutrient effect of biochar on yield.

Nd^(3+)-sensitized upconversion nanoparticle coated with antimony shell for bioimaging and photothermal therapy in vitro using single laser irradiation

Combining treatment and diagnosis,called theranostics,which is achieved within single nanoparticle is an ultimate goal of many studies.Herein,we developed a new nanotheranostic agent-Nd^(3+)-sensitized upconversion nanoparticles core for dual modal imaging(i.e.,upconversion luminescence imaging and magnetic resonance imaging) and antimony nanoshell for photothermal therapy(PTT).The core-shellshell upconversion nanoparticles(NaYF_(4):Yb,Er@NaYF_(4):Yb,Nd@NaGdF_(4):Nd,named as UCNP) were firstly synthesized using thermal decomposition method and then were coated by antimony shell over the surface of UCNP using simple cost and time effective new method.Furthermore,the surface of UCNP@Sb nanostructures was modified with DSPE-PEG in order to enhance the water solubility and biocompatibility.The final nanotheranostic agent,named as UCNP@Sb-PEG,exhibits very low toxicity,good biocompatibility,very good photothermal therapeutic effect,and efficient upconversion luminescence(UCL) imaging of HeLa cells under only one laser(808 nm) irradiation.The antimony shell is quenching the upconversion emission in pristine nanotheranostic agent,but interestingly,the UCL intensity of the agent recovers progressively under 808 nm laser irradiation due to light induced degradability of antimony shell.Besides,high longitudinal relaxivity(r_(1)) obtained from the experiment approves excellent potential of the nanotheranostic agent for T_(1)-weighted magnetic resonance imaging application.

Multiresidue pesticide analysis in tomato using GC-MS/MS using modified QuEChERS method with titanium-coated graphite with CNT-ABS nanocomposite as dispersive solid-phase extraction materials

The presence of pesticide residues in food and vegetables is a growing concern for consumers.To monitor these residues reliably,a selective and sensitive multiresidue system has been developed and validated in tomato by gas chromatography–tandem mass spectrometry(GC-MS/MS).Titanium-coated graphite with carbon nanotube(CNT)in acrylonitrile–butadiene–styrene(ABS)used as reversed-dispersive solid-phase extraction materials with modified QuEChERS(Quick,Easy,Cheap,Effective,Rugged,and Safe)method.Titanium-coated graphite with CNT-ABS is synthesized,characterized by X-ray diffraction and scanning electron microscopy.The clean-up performance of titanium-coated graphite with CNT-ABS was demonstrated to be better to primary secondary amine and graphitized carbon black cartridges.The processing of two multiple reaction monitoring transformations for each analyte is done using GC-MS/MS in electron impact mode.Satisfactory purification and recovery effects(74%–100%)of 35 pesticides were achieved in tomato matrices when using 5 mg of titanium-coated graphite ABS-CNT nanocomposite.It was observed that quinolphos and deltamethrin are present above the maximum residue limit.The technique proved to be reliable and sensitive in tomato samples for the routine testing of 35 pesticides.