scholarly journals Enhanced Thermal Conductivity and Superior Antimicrobial Activity by Cu/Ni Nanofiber Dispersed Fluids with Prolonged Stability

2019 ◽  
Vol 9 (2) ◽  
pp. 4950-4953
Keyword(s):  
Thermal Conductivity ◽  
Inhibitory Concentration ◽  
Imaging Techniques ◽  
Antibacterial Properties ◽  
Zone Of Inhibition ◽  
Visible Spectroscopy ◽  
Synthesis Parameters ◽  
Uv Visible ◽  
The Stability ◽  
Inhibition Analysis

The present study reports the synthesis, characterization and antibacterial properties of Cu/Ni nanofluids. The influence of various synthesis parameters on the stability of nano suspensions were studied and optimized. The samples were characterized using UV-Visible spectroscopy and TEM imaging techniques. The TEM images revealed the formation of nanofibers. The optimized composition of the Cu/Ni nanofluid was found to be stable for more than four months with zeta potential value of 40.4mV. The thermal conductivity studies showed 19% enhancement in comparison to the base fluid (water). The antibacterial properties of the nanosuspensions were studied by performing minimum inhibitory concentration tests (MIC) and zone of inhibition analysis.

scholarly journals Synthesis and Antimicrobial Resistant Modulatory Activity of 2,4-Dinitrophenylhydrazone Derivatives as Agents against Some ESKAPE Human Pathogens

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Alberta Ade ◽  
Cedric D. K. Amengor ◽  
Abena Brobbey ◽  
Isaac Ayensu ◽  
Benjamin K. Harley ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Klebsiella Pneumoniae ◽  
Inhibitory Concentration ◽  
Fungal Species ◽  
Human Pathogens ◽  
Visible Spectroscopy ◽  
Active Compounds ◽  
Gram Negative ◽  
Uv Visible

A library of six novel phenylhydrazones were synthesized and evaluated for their in vitro antimicrobial and resistance modulating activity against a panel of Gram-positive, Gram-negative, and fungal species. The compounds were produced in good yields of 60–92% w/w and characterized using melting point, UV-visible spectroscopy, infrared, and nuclear magnetic resonance (1H, 13C, and DEPT-Q) techniques. Mass spectroscopy was used to confirm the identity of one of the most active compounds, 5 [SA5]. The phenylhydrazones showed activity against all the six selected microorganisms with minimum inhibitory concentration (MIC) values of the most active compounds, 1 [BP1] and 5 [SA5], at 138 µM (Klebsiella pneumoniae) and 165 µM (Streptococcus pneumoniae), respectively. Compound 1 [BP1] further demonstrated a high resistance modulatory activity at 1.078 µM against Streptococcus pneumoniae and Klebsiella pneumoniae.

scholarly journals Synthesis of Eco-Friendly Silver Nanoparticles from Securidaca Longepedunculata and Artocarpus Heterophyllus Powders and Evaluation of their Antibacterial Properties

2019 ◽  
Vol 1 ◽  
pp. 114-121
Author(s):  
B A Ikyenge ◽  
I G Agbidye ◽  
F R Idoko ◽  
S O Adoga
Keyword(s):  
Silver Nanoparticles ◽  
Cardiac Glycosides ◽  
Antibacterial Properties ◽  
Colloidal Solutions ◽  
Visible Spectroscopy ◽  
Positive Bacterium ◽  
Infra Red ◽  
Uv Visible ◽  
The Fourier Transform ◽  
Securidaca Longepedunculata

Aqueous extracts of Securidacalongepedunculata and Artocarpusheterophyllus were screened for photochemicals and both were found to contain saponins, tannins, flavonoid, cardiac glycosides, anthraquinones and alkaloids. Biosynthesis of silver nanoparticles was carried out from these extracts. The formation and stability of the reduced nanoparticles in the colloidal solutions were monitored using UV-visible spectroscopy. The Fourier transform infra-red spectroscopy (FTIR), indicated the presence of bio-molecules responsible for reduction and stabilization of the nanoparticles. The morphology of the nanoparticles formed from Securidacalongepedunculata was flake like and that from Artocarpusheterophyllus was plate-like as shown by scanning electron microscopy (SEM). The nanoparticles from both plants showed potent anti-bacterial activities towards Staphylococcus aureus, a gram positive bacterium.

scholarly journals Study of the β-Cyclodextrin Imipramine Hydrochloride Inclusion Complex and Determination of its Stability Constant (K) by UV-Visible Spectroscopy

2007 ◽  
Vol 4 (4) ◽  
pp. 550-558 ◽  
Author(s):  
Alamdar Ashnagar ◽  
Nahid Gharib Naseri ◽  
Bita Khanaki
Keyword(s):  
Stability Constant ◽  
Inclusion Complex ◽  
Visible Spectroscopy ◽  
Constant Amount ◽  
A Value ◽  
Visible Spectra ◽  
Imipramine Hydrochloride ◽  
Uv Visible ◽  
The Stability

In this research, the interactions of imipramine hydrochloride drug with β- cyclodextrin and the stability constant (K) of the inclusion complex formed between them were investigated by using UV-visible spectroscopy. Solutions consisting of a known and constant amount of imipramine hydrochloride and varying amounts of β- cyclodextrin were prepared in 0.1 M phosphate buffer (pH 7.4). The final solutions had cyclodextrin concentrations between 0.0011 and 0.0153 M. UV-visible spectra of each solution was taken at λmax= 250 nm. The absorbances at this wavelength were recorded and plotted against cyclodextrin concentrations. From the graph, the concentrations of free and bound imipramine hydrochloride and free β-cyclodextrin were calculated using the Beer-Lambert law. From these data, the stability constant was calculated and a value of K=52.26±11.41 mol-1L was obtained. The magnitude of the stability constant is discussed in terms of the relative sizes and the chemical natures of β-cyclodextrin and imipramine hydrochloride.

scholarly journals An Assessment of Ethnomedicinal Use, Chemical Constituents Analysis and Bioactivity Evaluation on High Altitude Medicinal Plant Delphinium brunonianum of Manang District

2012 ◽  
Vol 12 ◽  
pp. 111-118 ◽  
Author(s):  
Hari P Tripathee ◽  
Ram P Sharma ◽  
Yagna P Timilsina ◽  
Ramayan Pathak ◽  
Krishna P Devkota
Keyword(s):  
Medicinal Plant ◽  
Inhibitory Concentration ◽  
Methanol Extract ◽  
Chemical Constituents ◽  
Antibacterial Properties ◽  
Spectroscopic Techniques ◽  
Zone Of Inhibition ◽  
Phytochemical Investigation ◽  
Escherchia Coli ◽  
Ethnomedicinal Uses

The medicinal plant Delphenium brunonianum collected from Manang district, Nepal has been selected for its study on ethnomedicinal uses, phytochemical investigation and bioactivity evaluation. This plant is found to be used extensively by the community for the treatment of fever, headache, stomachache and poison removal. From phytochemical investigation, four known compounds namely ?-amyrin (1), ?-sitosterol (2), ?-sitosterol glucoside (3) and anthriscifoldine (4) have been isolated from methanol extract of D. brunonianum. Compound 1 is triterpene, 2 and 3 are sterols, whereas, 4 is a diterpenoid alkaloid. The structures of all compounds were determined with modern spectroscopic techniques including 1D- and 2D- Nuclear Magnetic Resonance techniques and comparison with literature data. The extract and all compounds exhibited antibacterial properties with respect to the zone of inhibition and minimum inhibitory concentration against Bacillus subtilis, staphylococcus aureus, Pseudomonas aureginous, Escherchia coli and Salmonella flexinarie. Compound 4 was found to be more active than other compounds, and even than the standards ampicillin and gentamicin in most of the tested bacteria.DOI: http://dx.doi.org/10.3126/njst.v12i0.6488 Nepal Journal of Science and Technology 12 (2011) 111-118 

scholarly journals Nanoparticle Formulation of Pineapple Stem Extract (Ananas Comosus (L).(Merr) as Antimicrobial Agent

2017 ◽  
Vol 15 (2) ◽  
pp. 174
Author(s):  
Dian Eleveny Martha Flareyanti ◽  
Fahleni Fahleni ◽  
Deni Rahmat
Keyword(s):  
Inhibitory Concentration ◽  
Ph Value ◽  
Chemical Characteristic ◽  
Ananas Comosus ◽  
Flow Properties ◽  
Zone Of Inhibition ◽  
Pityrosporum Ovale ◽  
Stem Extract ◽  
Nanoparticle Formulation ◽  
The Stability

Pineapple stem contains bromelain enzyme with highest concentration compared to the other parts. The aim of the research was to formulate an anti dandruff creambath containing nanoparticles of pineapple stem which was physically and chemically stable and could inhibit the growth of Pityrosporum ovale. The pineapple stem extract was then formulated into nanoparticles prepared by cross-linking method using chitosan. The resulting nanoparticles were dried using freeze drying. The dried powder of extract was used to determine the minimum inhibitory concentration (MIC) against Pityrosporum ovale. The zone of inhibition of extract and nanoparticles were measured at the MIC. The extracts were then formulated into anti dandruff creambath. The creambath in the concentration of 3% (MIC) whereas the nanoparticles were formulated in the consentration of 1, 2, 3 fold MIC. Each formula was evaluated for its physical characteristics including organoleptics, homogenity, viscosity and flow properties, spread ability and for its chemical characteristic pH value. The stability was performed for one month at temperature of 25 oC and 40 oC. The results showed that the nanoparticles have particle size of 860.03 nm and zeta potensial of 18.63 mV. The best formula was formula IV with inhibitory zone of 17 mm, and had stable organoleptic properties, homogenity, viscosity and flow properties, and pH value, as well as capaability of spreading with diameter of 4817.53 mm. Accordingly the nanoparticlesin creambath could increase the antimicrobial activity.

Unmodified Goldnanoparticles Used as Probes for Detection of Coralyne with poly(A40)

2013 ◽  
Vol 788 ◽  
pp. 136-140 ◽  
Author(s):  
Meng Shu Han ◽  
Ji Wei Hu ◽  
Jin Luo
Keyword(s):  
Linear Response ◽  
Limit Of Detection ◽  
Duplex Structure ◽  
Visible Spectroscopy ◽  
Buffer Solution ◽  
Protoberberine Alkaloids ◽  
Double Stranded Dna ◽  
Uv Visible ◽  
The Stability ◽  
Induced Aggregation

Coralyne is a kind of protoberberine alkaloids with strong anticancer activity in animal models, which could induce single-stranded adenine rich nucleic acids (poly (dA)) to form a duplex structure. And poly (dA) could be absorbed on the surface of gold nanoparticles (AuNPs) to enhance the stability against NaCl induced aggregation. However, coralyne induced poly (dA) to form double-stranded DNA, which then left the AuNPs resulting in the arrgregation by NaCl. This paper investigated the conditions and effects of using poly (A40) as a probe for the coralyne detection. The detection of coralyne used 100 mM HEPES and 200 mM NaCl as the buffer solution. The poly (A40) was 250 nM in the experiment for the protection of AuNPs aggregation caused by buffer solution. UV-visible spectroscopy was employed to detect the colorimetric changes in the aggregated condition of AuNPs. From blank to 1000 nM of coralyne, a linear response was obtained with R2 = 0.862. The limit of detection was 100 nM. Results showed that the detection of coralyne with poly (A40) was achievable by using unmodified AuNPs.

Interaction between tetracyanoethylene and naphthalene in reverse micelles of AOT in n-hexane. The electron-donor properties of AOT

1996 ◽  
Vol 74 (9) ◽  
pp. 1603-1608 ◽  
Author(s):  
M. A. Biasutti ◽  
Juana J. Silber
Keyword(s):  
Electron Donor ◽  
Reverse Micelles ◽  
Formation Constants ◽  
Local Concentration ◽  
Micellar Media ◽  
Visible Spectroscopy ◽  
Donor Acceptor ◽  
Uv Visible ◽  
The Stability ◽  
Homogeneous Media

The electron donor–acceptor (EDA) interaction between TCNE and naphthalene (Naph) in n-hexane and reverse micelles of AOT in n-hexane was studied by UV–visible spectroscopy with the aim of determining the influence of the micellar media on the EDA interaction. The spectra of the mixtures of TCNE–Naph in n-hexane show two typical maxima at 418 and 534 nm, assigned to the formation of a π–π EDA complex. In the micellar media a new band is observed at 398 nm. When the spectra of TCNE in n-hexane are studied in the presence of AOT two new bands at 398 and 418 nm are detected. These bands are consistent with an EDA interaction between TCNE and AOT as n-donor. The stability constants of this interaction were calculated for AOT concentrations below the CMC and in the micellar media at different W(W = [H2O]/[AOT]). The results give evidence of the tendency of AOT to interact very strongly with electron acceptors. Moreover, in the system TCNE–Naph in the micellar media it is shown that Naph and AOT compete to form a complex with TCNE. The formation constants of the complexes of AOT–Naph in the micelle system were determined at W = 0 and 5. Despite the competition of AOT for TCNE the stability constant for the complex TCNE–Naph is higher than in homogeneous media, probably due to the high local concentration of the acceptor in the micelle. Key words: reverse micelles, aerosol-OT, tetracyanoethylene, naphthalene, electron donor–acceptor complexes.

Efek Antibakteri Ekstrak Aquades Buah Kurma (Phoenix dactylifera L.) Varietas Ajwa terhadap Staphylococcus aureus Secara In Vitro

2020 ◽  
Vol 2 (2) ◽  
Author(s):  
Lu'lu Ulul Albab ◽  
Usep Abdullah Husin ◽  
Buti Azfiani Azhali ◽  
Titik Respati ◽  
Ratna Dewi Indi Astuti
Keyword(s):  
Staphylococcus Aureus ◽  
Minimum Inhibitory Concentration ◽  
Inhibitory Concentration ◽  
Minimum Bactericidal Concentration ◽  
Antibacterial Properties ◽  
Phoenix Dactylifera ◽  
Diffusion Method ◽  
Zone Of Inhibition ◽  
Phoenix Dactylifera L

Penemuan antimikrob menjadi hal yang sangat penting dalam pengobatan dan kemajuan medis. Tantangan dalam pengobatan menggunakan antibiotik adalah resistensi bakteri terhadap antibiotik yang digunakan. Salah satu bakteri yang mengalami resistensi adalah Staphylococcus aureus. Oleh karena itu, diteliti alternatif pengobatan dengan menggunakan tumbuhan yang berpotensi memiliki kemampuan antibakteri. Buah kurma varietas Ajwa telah diteliti memiliki beberapa senyawa aktif yang berpotensi sebagai antibakteri dan antioksidan. Kurma Ajwa juga telah disebutkan di dalam Al-Quran dan Al-Hadits. Tujuan penelitian ini adalah mengetahui efek antibakteri ekstrak akuades buah kurma Ajwa dengan melihat luas zona hambat serta konsentrasi hambat minimum (KHM) dan konsentrasi bunuh minimum (KBM) pada Staphylococcus aureus. Penelitian ini menggunakan metode ekperimental secara in vitro dan bersifat deskriptif observasional dengan pendekatan kuantitatif. Metode yang digunakan adalah metode difusi dengan menggunakan sumuran dan metode dilusi padat. Penelitian ini dilakukan di Laboratorium Terpadu Mikrobiologi Poltekkes Bandung. Didapatkan rerata hasil zona hambat adalah 5,87 mm yang termasuk kategori sedang, KHM pada konsentrasi 50%, dan KBM belum dapat ditemukan. Berdasar atas uji statistik, hasil penelitian uji difusi menunjukkan bahwa ekstrak akuades buah kurma (Phoenix dactylifera L.) varietas Ajwa berpengaruh menghambat pertumbuhan bakteri Staphylococcus aureus. ANTIBACTERIAL EFFECT OF EXTRACT AQUADES AJWA DATE (PHOENIX DACTYLIFERA L.) AGAINST STAPHYLOCOCCUS AUREUS IN VITROThe discovery of antimicrobials has been significantly important for current treatments and the future developments in the medical field. One of the challenges faced in the usage of antibiotics is the resistance imposed by the bacteria towards the antibiotics itself. An example of such bacteria that experiences thisresistance is Staphylococcus aureus. As a result, studies regarding alternatives of treatments, specifically those utilizing various plants that may potentially have antibacterial properties are conducted. Previous studies have already shown that date palms of the Ajwa variety, known as Phoenix dactylifera, contains several active compounds that are potential antioxidants and exhibit antibacterial properties. The Ajwa date palm has also been mentioned in several scriptures of the Al-Quran and Al-Hadits. The objective of this study was to understand the antibacterial properties of aquadest-extracted Phoenix dactylifera through the measurement of the area of the zone of inhibition, the minimum inhibitory concentration (MIC), and the minimum bactericidal concentration (MBC) of Staphylococcus aureus. This study involves the use of an experimental method, known as in vitro, and is also a descriptive observational study with a quantitative approach. The methodology used consists of the well diffusion method and the solid dilution method. This study was conducted at Laboratorium Terpadu Mikrobiologi Poltekkes Bandung. The results of this study show an average zone of inhibition of 5.87 mm which is categorized as medium, a minimum inhibitory concentration of 50%, and a minimum bactericidal concentration that is yet to be found. Based on statistical tests, the result of the diffusion method shows that the aquadest-extracted Phoenix dactylifera is influential in inhibiting the growth of the Staphylococcus aureus bacteria.

scholarly journals Microfibrillated Cellulose-silver Nanocomposite Based PVA Hydrogels and Their Enhanced Physical, Mechanical and Antibacterial Properties

2022 ◽  
Author(s):  
Md. Shamsul Alam ◽  
Md. Sabbir Hasan ◽  
Jannat Al Foisal ◽  
G. M. Arifuzzaman Khan ◽  
Rownok Jahan ◽  
...  
Keyword(s):  
Antibacterial Properties ◽  
Multidrug Resistant ◽  
Microfibrillated Cellulose ◽  
Visible Spectroscopy ◽  
Silver Nanocomposites ◽  
Potential Applications ◽  
Silver Nanocomposite ◽  
Uv Visible ◽  
Thermal Stability Of ◽  
Pva Hydrogel

Abstract Modification of cellulose with silver nanoparticles produces various nanocomposites with significantly developed properties. This work aims to prepare a PVA hydrogel modified with cellulose/silver nanocomposites having potential applications in various fields including biomedical, antimicrobial inhibition, textile wears, etc. Microfibrillated cellulose/silver nanocomposites hydrogels were prepared in the aqueous medium with aid of microwave-assisted heating. Different percentages of nanocomposites were incorporated in PVA hydrogel to enhance the properties of PVA hydrogel. Prepared products were characterized by UV-Visible spectroscopy, FTIR, TGA, XRD, and SEM. The swelling (in water saline, acidic and alkaline solution), tensile, thermal, and antibacterial properties were also examined. The formation of Ag nanoparticles (AgNPs) in the (MFC-Ag) NC was confirmed by XRD and UV–Vis spectra. UV–Vis spectra showed the characteristic peaks of Ag in the UV–Vis spectra at 425 nm. Final products exhibited significant porosity and maximum swelling of 519.44%. The thermal stability of hydrogel increased with an increased percentage of (MFC-Ag)NC. Hydrogels exhibited significant antimicrobial inhibition against multidrug-resistant microorganisms, including Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa.

scholarly journals Biosynthesis and characterization of silver nanoparticles (AgNPs) using marine bacteria against certain human pathogens

2016 ◽  
Vol 2 (7) ◽  
pp. 152 ◽  
Author(s):  
J. Nasrin Begam
Keyword(s):  
Silver Nanoparticles ◽  
Marine Bacteria ◽  
Inhibitory Concentration ◽  
Bacterial Isolate ◽  
Xrd Analysis ◽  
Diffusion Method ◽  
Human Pathogens ◽  
Visible Spectroscopy ◽  
Disk Diffusion Method ◽  
Uv Visible

The present work investigates the synthesis of silver nanoparticles (AgNPs) by biological method using marine bacteria. The minimum inhibitory concentration (MIC) test was performed to find the inhibitory concentration of AgNO3 against marine bacterial isolate. After MIC study, the biogenic AgNPs was prepared through marine bacterial isolate and characterized by using UV-visible spectroscopy, Scanning Electron Microscopy (SEM), X Ray Diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). From the UV-visible spectroscopy, the absorption peak was found at 420 nm. In SEM image, it is confirmed that the sample contains spherical shaped silver nanoparticles and most of the particles were below 100 nm in size. In XRD analysis, it was confirmed that the silver nanoparticles are crystalline in nature, which was confirmed by the FTIR peak at 518 cm-1 corresponding to the Ag vibration present in crystalline structure. The antimicrobial activity of silver nanoparticles was determined by disk diffusion method, and found that silver nanoparticles have significant antibacterial activity against most of the pathogens.

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