Synthesis of Metallic Nanoparticles Based on Green Chemistry and Their Medical Biochemical Applications:Synthesis of Metallic Nanoparticles

Nanoparticles have distinct properties that make them potentially valuable in a variety of industries.As a result,emerging approaches for the manufacture of nanoparticles are gaining a lot of scientific interest.The biological pathway of nanoparticle synthesis has been suggested as an effective,affordable,and environmentally safe method.Synthesis of nanoparticles through physical and chemical processes uses unsafe materials,expensive equipment and adversely affects the environment.As a result,in order to support the increased utilization of nanoparticles across many sectors,nanotechnology research activities have shifted toward environmentally safe and cost-effective techniques that outperform chemical and/or biological procedures.The use of organisms to produce metal nanoparticles is among the most frequently discussed methods.Plants appear to be the best candidates among these organisms for large-scale nanoparticle biosynthesis.Medicinal plants have been employed as reducing agents and NP stabilizers to minimize the toxicity of NPs in both the environment and the human body.Furthermore,the presence of certain functional components in plant extracts may be extremely useful and effective for the human body.Polyphenol,for example,which may have antioxidant properties,might intercept free radicals before they interact with other biomolecules and cause considerable damage.The current article analyzes the most recent developments and improvements in the green synthesis of metal nanoparticles by different plants and the use of these nanoparticles for various biomedical applications and hopes to provide insights into this exciting research frontier.

The Blue Water Footprint of Extensive Beef Production on Semi-Arid Rangeland over a Full Production Cycle in South Africa

Water plays a critical role in beef cattle production. Current methods used to estimate the blue water footprint of beef cattle are largely based on generic values that do not make provision for different production systems within different regions. Total production cycle measurements should therefore be considered to accurately assess the blue water footprint of beef cattle grazing natural rangeland. The aim of the study was to measure water intake of extensive Bonsmara cattle grazing Marikana Thornveld over a full production cycle at the ARC-Roodeplaat Research Station. Measurements commenced at weaning (June 2017) and continued until the heifers weaned their first calves at approximately 210 days of age (July 2019). Water consumption differed between 21.4 litre per animal per day when the heifers were still growing to 54.3 litres during lactation, relating to between 6.7% and 12.0% of live weight. The blue water footprint over the total production cycle was calculated to be 27,147 litres.

Influence of Flow Regime on the Vegetation Zonation along Mountain Streams in the Western Cape, South Africa

Zonation patterns of riparian vegetation have been sampled and described in mountain streams in two catchments in the Hottentots-Holland Mountains, Western Cape, South Africa. Six main vegetation types that differ in structure and species composition, are dominant along these river banks: Aquatic vegetation, Wetbanks, Palmiet, Scrub, Forest and Shrubland(Fynbos). The study aims to correlate the vegetation patterns to flooding patterns, in particular the inundation frequency and stream power. A problem arises: because these catchments are ungauged, like most mountain catchments, with the only weirs at the downstream end of the catchment. Discharge data at the weirs are extrapolated to the sites upstream by multiplication with a factor based on the size of the subcatchment that drains through a sample site. In this way, recurrence intervals for floods in mountain streams are derived. Discharges at sites are also calculated using bed roughness(Manning's n) and slope in straight sections with uniform flow conditions. Stream power is derived from the discharges calculated in this manner. The combination of stream power and recurrence intervals explains the occurrence of most vegetation types occurring on the banks, except for one type: Afromontane Forest. This type is probably more dependent on other factors, such as protection from fire and the depth of the groundwater table.

An in vitro evaluation of the antioxidant and antidiabetic potential of Sutherlandia montana E. Phillips & R.A. Dyer leaf extracts

Objective: To evaluate the antioxidant and antidiabetic activities of Sutherlandia montana E. Phillips & R.A. Dyer leaf extracts using the in vitro model.Methods: The antioxidant activities of aqueous, decoction, ethanol and hydro-ethanol extracts of the plant were determined using seven different assays; the antidiabetic potential was evaluated through the inhibition of key carbohydrate hydrolysing enzymes(aamylase and a-glucosidase), while the modes of the enzymes inhibition were assessed using enzyme kinetic analysis.Results: The ethanol extract exhibited the best scavenging activity(IC_(50): 0.47, 0.36,0.20, 0.29 and 0.01 mg/m L) against the tested radicals like 1,1-diphenyl-2-picrylhydrazyl,2, 20-azinobis(3-ethylbenzothiazoline-6-sulfonic acid), nitric oxide, hydroxyl and superoxide anion, respectively. It also showed the best reducing power efficiency when compared with the standard(silymarin), while the decoction extract displayed the strongest metal chelating potential(IC_(50): 0.71 mg/m L). The ethanol(IC_(50): 5.52 mg/m L)and decoction(IC_(50): 0.05 mg/m L) extracts exhibited mild and strong inhibitory effects on the specific activities of a-amylase and a-glucosidase respectively, through an uncompetitive and non-competitive mode of action.Conclusions: The observed properties might be linked to the presence of active principles as shown by the results of the phytochemical analyses of the extracts. This research has validated the folkloric application of Sutherlandia montana as a potential antidiabetic agent, which is evident from the inhibition of specific activities of key enzymes involved in carbohydrate metabolism.

Chemical constituents, in vitro antimicrobial and cytotoxic potentials of the extracts from Macaranga barteri Mull-Arg

Objectives: To investigate antimicrobial and cytotoxic potentials as well as chemical constituents of extracts from Macaranga barteri(M. barteri).Methods: Antimicrobial activity was carried out using micro-dilution, cell culture and GC–MS methods were employed to determine the cytotoxicity and chemical constituents of the extracts respectively.Results: Marked activity was observed in methanol(ME) fraction [MIC_(50):(0.097 7–6.250 0) mg/mL] compared to hexane and ethyl acetate fractions. Aeromonas hydrophila(environmental strain) and Shigella sonnei(ATCC 29930) were the most susceptible pathogens to ME and ciprofloxacin(Cl) at MIC_(50) value of 0.097 7 and < 0.019 5 mg/mL respectively. Cryptococcus neoformans(ATCC 66031) was susceptible to ME at 0.195 3 mg/mL compared to fluconazole at 10.000 0 mg/mL. Decreased viability of the Vero cells was observed at the concentrations of 0.1–1.0 mg/mL. The lethal dose(LC_(50))of hexane, ethyl acetate and methanol fractions were recorded at(0.30 ± 0.07),(0.52 ± 0.05) and(0.22 ± 0.04) mg/mL, respectively. Some of the compounds identified from ME were caryophyllene(25.21%), neophytadiene(11.90%), a-humulene(7.67%),phytol(4.40%), ethyl ester hexadecanoic acid(4.04%) and nerolidol(2.83%) which were known to have various antimicrobial activities.Conclusions: Methanol fraction of M. barteri is a potent and safe antimicrobial and antifungal alternative which can be useful in the search for new antimicrobial drugs. The study also confirmed the orthodox usage of M. barteri in combating infectious diseases.

Synthesis and Crystal Structure of an Anionic Linear Trinuclear Copper(Ⅱ) Complex Containing 2-Thenoyltrifluoroacetonato and Acetato Ligands

A novel anionic trinuclear linear copper（II） complex {[Et3NH][Cul.5（CH3COO）- （TTA）3] } 2 （1, TTA = 2-thenoyltrifluoroacetonate） has been synthesized in a direct reaction involving copper（]l） acetate monohydrate, TTA and excess triethylamine base in dichloromethane solvent. Green colored X-ray quality crystals of 1 were grown from n-hexane solvent at room temperature. The data were collected at 100 K. Compound I crystallizes in the monoclinic P21/n space group （a = 11.2141（8）, b = 19.0965（13）, c = 17.3680（14） A, β = 90.225（2）°, V= 3719.3（5） A3, Mr = 1840.14, Dc = 1.643 Mg/m3, F（000） = 1866, μ = 1.129 mm^-1 and Z = 2）. The asymmetric unit of 1 contains two copper atoms, one of which lies on a crystallographic inversion center with 50% occupancy.

Commissioning and Optimization of a Total Skin Electron Therapy Technique Using a High Dose Rate Electron Facility

Total skin electron therapy (TSET) is used for the treatment of Mycosis Fungoides. Several tech-niques have been developed, in order to achieve homogeneous dose distribution over the complete body surface. To implement a TSET technique, one has to optimize a variety of parameters. Monte Carlo simulation of TSET can facilitate this optimization. The aim of this study was to commission and optimize a TSET technique using the 4 and 6 MeV electron and the high dose rate facility on the Elekta Precise accelerator. The EGS4nrc/BEAMnrc Monte Carlo code was used. The beam data were calculated and measured at two different scoring planes for a single beam. The Model was validated by comparing the simulation with measurements. Two different vertical angles were used to obtain a uniform dose. The angle was optimized for best dose uniformity. The Rando phantom is placed on a rotating platform and rotates 60 degrees apart to facilitate the six patient position orientations. The doses delivered in a phantom by complete treatment were measured with Kodak EDR2 films and TLDs. The dose distribution varied among various scanning directions by 2 - 3 mm and 3 - 4 mm for 4 and 6 MeV respectively. The composite percentage depth dose of all six dual fields for the 4 and 6 MeV yielded an R80 of ~4 mm and ~6 mm, respectively. Dose uniformity was ±6% for 4 MeV and ±5% for 6 MeV. The bremsstrahlung contamination was 0.9% - 1.3%. Good agreements were found with published literature and inline with international protocols.

Modeling the Spread of Tuberculosis with Piecewise Differential Operators

Very recently,a new concept was introduced to capture crossover behaviors that exhibit changes in patterns.The aimwas tomodel real-world problems exhibiting crossover from one process to another,for example,randomness to a power law.The concept was called piecewise calculus,as differential and integral operators are defined piece wisely.These behaviors have been observed in the spread of several infectious diseases,for example,tuberculosis.Therefore,in this paper,we aim at modeling the spread of tuberculosis using the concept of piecewise modeling.Several cases are considered,conditions under which the unique system solution is obtained are presented in detail.Numerical simulations are performed with different values of fractional orders and density of randomness.

A Practical Solution to the Small Sample Size Bias and Uncertainty Problems of Model Selection Criteria in Two-Input Process Multiple Response Surface Methodology Datasets

Multiple response surface methodology (MRSM) most often involves the analysis of small sample size datasets which have associated inherent statistical modeling problems. Firstly, classical model selection criteria in use are very inefficient with small sample size datasets. Secondly, classical model selection criteria have an acknowledged selection uncertainty problem. Finally, there is a credibility problem associated with modeling small sample sizes of the order of most MRSM datasets. This work focuses on determination of a solution to these identified problems. The small sample model selection uncertainty problem is analysed using sixteen model selection criteria and a typical two-input MRSM dataset. Selection of candidate models, for the responses in consideration, is done based on response surface conformity to expectation to deliberately avoid selection of models using the problematic classical model selection criteria. A set of permutations of combinations of response models with conforming response surfaces is determined. Each combination is optimised and results are obtained using overlaying of data matrices. The permutation of results is then averaged to obtain credible results. Thus, a transparent multiple model approach is used to obtain the solution which gives some credibility to the small sample size results of the typical MRSM dataset. The conclusion is that, for a two-input process MRSM problem, conformity of response surfaces can be effectively used to select candidate models and thus the use of the problematic model selection criteria is avoidable.

Comparison of slow freezing and vitrification methods for Venda cockerel’s spermatozoa

An improvement in avian semen cryopreservation is essential and has the potential to improve the cryo-gene banking efficiency. This study compared two cryopreservation methods (slow freezing and vitrification) and the effect of different thawing/warming temperatures (5℃, 25℃ and 41℃) on Venda cockerel’s spermatozoa. Semen samples from Venda cockerels were diluted with modified Kobidil+ extender supplemented with 8% dimethyl sulfoxide. Semen from each ejaculate was stained with nigrosin/eosin for viability examination. The cryopreserved samples were either slow cooled in 0.25 mL straw or vitrified in a solid surface vitrification (SSV) device. Semen straw or cryovial was stored in liquid nitrogen container. The straw or cryovial with sperm was thawed or warmed at 5?C, 25?C and 41℃ and analysed by a Computer-Aided Sperm Analysis (CASA). There was a significant difference in live/normal sperm between the semen donors. Cockerels spermatozoa cryopreserved by slow freezing (43%) and thawed at 5?C had a significantly higher survival and motility rate compared to vitrification (2.5%) method. In conclusion, there was higher rate of live/normal morphology sperm. Cryopreservation process reduces sperm motility and velocity rate regardless of cryoprevervation method and thawing or warming temperatures. However, slow freezing was a better method to maintain motility of spermatozoa following cryopreservation.

The Syntax and Morphology of the Negative Morphemes/s a/in Sesotho

Sesotho is one of the African Languages where sentence negation is expressed by means of bound negative morphemes. It has only three negative morphemes which arespread across the Sesotho matrix and subordinate clauses. They are the negative morphemes /ha/, /sa/ and /se/.These morphemes are bound verbal morphemes that negate various predicate forms and only appear in restricted sentence types. The central aim of this paper is to examine sentence constructions that realize negation by means of the negative morpheme /sa/ and its syntactic distribution within copulative verbs, non - copulative verbs, deficient verbs and aspect morphemes over a full range of inflectional categories such as tense, aspect and mood. This morpheme will be examined within the general framework of the Minimalist Programme, which holds that inflectional categories occur as heads of phrasal categories. This paper will further illustrate the morphological representations of these morphemes within Beard’s (1995) Lexeme-Morpheme Base Morphology, which defines morphology as the sum of all the phonological means of expressing the relations of constituents in words, of words in phrases and of phrasal constituents in sentences. It distinguishes lexemes from bound morphemes.

Negation of the Object in Sesotho

This article examines constituent negation in Sesotho. It investigates negation of the object argument in clauses with non-copulative verbs. In the case of non-copulative verbs, transitive and di-transitive constructions will be considered. The article argues that Sesotho does not have a direct means of negating clausal constituents but employs clauses such as cleft sentences and clauses with AGRS [ho] as well as contrastive clauses to effect negation. It further examines negation in terms of Haegeman5s (1995) Neg-Criterion, the well-formedness condition that determines the distribution and interpretation of negative elements. It gives a brief overview of grammatical concepts regarding negation and the notion object argument in its focus and post verbal positions, and explains how constituent negation, [the object argument] is realized in Sesotho.

Comparative effects of xylitol and erythritol on modulating blood glucose;inducing insulin secretion;reducing dyslipidemia and redox imbalance in a type 2 diabetes rat model

Xylitol and erythritol have been reported in numerous previous and recent studies as potential antidiabetic sweeteners,however,it is not certain which one is most effective in this regard.In the present study,the effects of xylitol and erythritol were comparatively investigated on blood glucose,insulin level,dyslipidemia,pancreatic islet morphology andβ-cell function,and redox imbalance in a type 2 diabetes(T2D)model of rats.Seven-week-old male Sprague-Dawley rats were randomly divided into 8 groups:Normal Control(NC),Diabetic Control(DC),Diabetic Xylitol 5%(DX5),Diabetic Xylitol 10%(DX10),Diabetic Xylitol 20%(DX20),Diabetic Erythritol 5%(DE5),Diabetic Erythritol 10%(DE10),and Diabetic Erythritol 20%(DE20).T2D was induced in the diabetic groups initially by feeding 10%fructose solution to induce insulin resistance followed by an intraperitoneal injection of streptozotocin(40 mg/kg body weight)dissolved in citrate buffer(pH 4.5)to induce partial pancreaticβ-cells dysfunctions.The animals in NC group were fed with normal drinking water and injected with citrate buffer only.After the confi rmation of diabetes,the xylitol and erythritol with above-mentioned concentrations were supplied to the respective animal groups when the animals in NC and DC groups were supplied with normal drinking water.After 8 weeks intervention period,the body weight,fl uid and water intake,blood glucose,serum alanine aminotransferase,aspartate aminotransferase,CK-MB and creatinine were signifi cantly decreased,while the serum insulin level,serum lipids,glucose tolerance ability,pancreatic islet morphology andβ-cell function,pancreatic and serum redox imbalance were improved in the most xylitol and erythritol fed groups compared to the DC group,when effects were better for xylitol compared to erythritol.The data of this study suggests that xylitol has better antioxidant and antidiabetic effects compared to erythritol.Therefore,xylitol can be used as a preferrable dietary anti-diabetic sweetener or supplement over erythritol for the management of diabetes and its associated complications.

Molecular evidence and phylogenetic delineation of spotted fever group Rickettsia species in Amblyomma ticks from cattle in Gauteng and Limpopo Provinces,South Africa

Objective:To determine the prevalence of tick-borne pathogens with a particular focus on Rickettsia spp.in ticks collected from cattle in Gauteng and Limpopo Provinces,South Africa.Methods:A total of 200 ticks were collected from cattle within the Madala livestock,Pretoria,Gauteng Province and in Mankweng Township,Polokwane,Limpopo Province in 2019.The ticks were morphologically identified and processed individually for a total genomic DNA extraction.Specific primers targetting ompA,ompB,and the 17KDa genes were used for a molecular screening and delineation of Rickettsia from the extracted genetic materials using polymerase chain reaction(PCR)technique.PCR amplicons of positive samples were sequenced bidirectionally using the Sanger sequencing method.Sequences generated were processed and analysed using appropriate bioinformatics software.Results:The ticks were morphologically identified as Amblyomma spp.PCR profiling of the genomic DNA samples revealed the presence of the Rickettsia pathogen in 42(21%)of the ticks collected from both Provinces.Out of the genes profiled,14(7%)were positive for 17KDa,42(21%)for ompA and 32(16%)were positive for ompB genes respectively.The nucleotide blast of the sequenced genomes showed high similarity,as high as 100% with other reference Rickettsia(R.)africae in the GenBank.The phylogenetic analysis of the sequences further validated them as R.africae with their characteristic clustering pattern with related reference sequences.Conclusions:There is an abundance of R.africae in Amblyomma ticks collected from cattle in the study areas.This has serious public health implications as individuals who accidentally get infested with the ticks could acquire R.africae.Hence,adequate precautions in terms of sensitization of farmers about the risk and mass mobilization drive to control the vectors in the areas are highly recommended to safeguard public health.

The effect of global warming on beef production in developing countries of the southern hemisphere

Developing countries from the southern hemisphere will be confronted by the same beef production challenges caused by global warming, because these countries are at the same geographical positions in southern latitudes. Global warming is expected to have a more extreme effect on the southern hemisphere than on other continents and will have a negative effect on the beef production environments in these countries. The negative effects will include high ambient temperatures, nutritional stress and altered patterns of animal diseases. Heat stress in beef cattle on veld/savannah is expected to increase as a result of changing weather patterns on a global and regional scale. This may negatively influence food production from beef cattle for the human food chain. Negative effects of increased temperatures and thus heat stress can include lower reproductive rates and weaning weights. The effect of heat stress can be partly addressed by nutritional strategies, such as replacing rapid fermentable carbohydrates with saturated fatty acids and the feeding of more by-pass protein and dietary electrolytes. Global warming will also alter the distribution pattern of animal diseases and the vectors of some of these diseases. This may even include the spread to South American countries. Likewise the nutritional value of natural pastures may be influenced. The effect of global warming on the quality of pastures will depend on whether the global warming is a result of increased carbon dioxide levels or not. An improved understanding of the adaptation of beef cattle to their production environments is important, but adaptation is complex and thus difficult to measure. Fortunately, several proxy-indicators for adaptation such as reproductive, production and health traits are available. The selection of animals and genotypes that are better adapted to the production system, including heat stress, is possible and should be persuade to ensure sustainable beef production in hotter climates.

Low-dose immunotherapy as a potentiator to increase the response with neo-adjuvant chemotherapy in oral cancers

Neo-adjuvant chemotherapy(NACT)is utilized in locally advanced oral cancers to reduce the tumor burden and downstage the tumor to be amenable for definitive surgical management.Its long-term results compared to upfront surgical resection was not encouraging.Immunotherapy has now been used not only in recurrence and metastatic setting but also in the locally advanced tumor management regimens.The purpose of this concept paper is to bring forward the rationale to use a fixed low-dose immunotherapy agent as a potentiator to the standard NACT regimen and recommend their future investigation in oral cancer management.

Impact of Commercial Organic Ameliorants on Nitrogen and Phosphorus Concentrations of Maize Biomass at Ninth Leaf and Silking Growth Stages

The response of grain yield, biomass yield and harvest index of maize to the application of commercial organic ameliorants was inconsistent and poor. Hence it was hypothesized that the supply of N and P to maize plants was inadequate during vegetative growth, resulting in low concentrations of the two nutrients in maize biomass. The effects of nine ameliorants on the N and P concentrations of maize plants at ninth leaf (V9) and silking (R1) stages of maize were studied over three years at Bothaville (8% clay), Ottosdal (12% clay) and Potchefstroom (34% clay). All ameliorants were applied as prescribed by manufacturers. The N and P concentrations in maize biomass of the ameliorants at V9 and R1 were lower, comparable or higher, showing that the inconsistent and poor response of yield parameters can not be ascribed to inadequate uptake of N and P. A matter of concern that justifies thorough investigation, is the prescribed use of Crop care and Growmor with partial and of Montys and Promis with no NPK fertilization, an unsustainable practice over the long term. Characterization of the active ingredient(s) of the ameliorants is deemed also of importance for better insight.