Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 359
Filter
1.
Biomed Tech (Berl) ; 2024 Jun 04.
Article in English | MEDLINE | ID: mdl-38826069

ABSTRACT

OBJECTIVES: The objective of this study is to develop a system for automatic sign language recognition to improve the quality of life for the mute-deaf community in Egypt. The system aims to bridge the communication gap by identifying and converting right-hand gestures into audible sounds or displayed text. METHODS: To achieve the objectives, a convolutional neural network (CNN) model is employed. The model is trained to recognize right-hand gestures captured by an affordable web camera. A dataset was created with the help of six volunteers for training, testing, and validation purposes. RESULTS: The proposed system achieved an impressive average accuracy of 99.65 % in recognizing right-hand gestures, with high precision value of 95.11 %. The system effectively addressed the issue of gesture similarity between certain alphabets by successfully distinguishing between their respective gestures. CONCLUSIONS: The proposed system offers a promising solution for automatic sign language recognition, benefiting the mute-deaf community in Egypt. By accurately identifying and converting right-hand gestures, the system facilitates communication and interaction with the wider world. This technology has the potential to greatly enhance the quality of life for individuals who are unable to speak or hear, promoting inclusivity and accessibility.

2.
J Phys Chem A ; 128(20): 4068-4082, 2024 May 23.
Article in English | MEDLINE | ID: mdl-38728207

ABSTRACT

The thermo-kinetic aspects of 3-hydroxybutyric acid (3-HBA) pyrolysis in the gas phase were investigated using density functional theory (DFT), specifically the M06-2X theoretical level in conjunction with the cc-pVTZ basis set. The obtained data were compared with benchmark CBS-QB3 results. The degradation mechanism was divided into 16 pathways, comprising 6 complex fissions and 10 barrierless reactions. Energy profiles were calculated and supplemented with computations of rate coefficients and branching ratios over the temperature range of 600-1700 K at a pressure of 1 bar using transition state theory (TST) and Rice-Ramsperger-Kassel-Marcus (RRKM) methods. Thermodynamics results indicated the presence of six stable conformers within a 4 kcal mol-1 energy range. The estimated chemical kinetics results suggested that TST and RRKM approaches are comparable, providing confidence in our calculations. The branching ratio analysis reveals that the dehydration reaction pathway leading to the formation of H2O and CH3CH═CHCO2H dominates entirely at T ≤ 650 K. At these temperatures, there is a minor contribution from the simple homolytic bond fission reaction, yielding related radicals [CH3•CHOH + •CH2CO2H]. However, at T ≥ 700 K, this reaction becomes the primary decomposition route. At T = 1700 K, there is a minor involvement of a reaction pathway resulting in the formation of CH3CH(OH)•CH2 + •CHO(OH) with an approximate contribution of 16%, and a reaction leading to [•CH3 + •CH2OHCH2CO2H] with around 9%.

3.
Front Pharmacol ; 15: 1388784, 2024.
Article in English | MEDLINE | ID: mdl-38751787

ABSTRACT

Introduction: The synthetic pyrethroid derivative fenpropathrin (FNE), a commonly used insecticide, has been associated with various toxic effects in mammals, particularly neurotoxicity. The study addressed the hallmarks of the pathophysiology of Parkinson's disease upon oral exposure to fenpropathrin (FNE), mainly the alteration of dopaminergic markers, oxidative stress, and molecular docking in rat models. In addition, the protective effect of curcumin-encapsulated chitosan nanoparticles (CRM-Chs-NPs) was also assessed. Methods: In a 60-day trial, 40 male Sprague Dawley rats were divided into 4 groups: Control, CRM-Chs-NPs (curcumin-encapsulated chitosan nanoparticles), FNE (15 mg/kg bw), and FNE + CRM-Chs-NPs. Results: FNE exposure induced reactive oxygen species generation, ATP production disruption, activation of inflammatory and apoptotic pathways, mitochondrial function and dynamics impairment, neurotransmitter level perturbation, and mitophagy promotion in rat brains. Molecular docking analysis revealed that FNE interacts with key binding sites of dopamine synthesis and transport proteins. On the other hand, CRM-Chs-NPs mitigated FNE's toxic effects by enhancing mitochondrial dynamics, antioxidant activity, and ATP production and promoting anti-inflammatory and antiapoptotic responses. Conclusion: In summary, FNE appears to induce dopaminergic degeneration through various mechanisms, and CRM-Chs-NPs emerged as a potential therapeutic intervention for protecting the nervous tissue microenvironment.

4.
Life (Basel) ; 14(5)2024 Apr 23.
Article in English | MEDLINE | ID: mdl-38792560

ABSTRACT

We show that the nucleic acid bases adenine, cytosine, guanine, thymine, and uracil, as well as 2,6-diaminopurine, and the "core" nucleic acid bases purine and pyrimidine, are stable for more than one year in concentrated sulfuric acid at room temperature and at acid concentrations relevant for Venus clouds (81% w/w to 98% w/w acid, the rest water). This work builds on our initial stability studies and is the first ever to test the reactivity and structural integrity of organic molecules subjected to extended incubation in concentrated sulfuric acid. The one-year-long stability of nucleic acid bases supports the notion that the Venus cloud environment-composed of concentrated sulfuric acid-may be able to support complex organic chemicals for extended periods of time.

5.
Nat Prod Res ; : 1-7, 2024 Apr 02.
Article in English | MEDLINE | ID: mdl-38563220

ABSTRACT

Recently, the world faced many epidemics which were caused by viral respiratory pathogens. Marine creatures including Asteroidea class have been one of the recent research topics due to their diverse and complex secondary metabolites. Some of these constituents exhibit antiviral activities. The present study aimed to extract and identify the potential antiviral compounds from Pentaceraster cumingi, Astropecten polyacanthus and Pentaceraster mammillatus. The results showed that promising activity of the methanolic extract of P. cumingi with 50% inhibitory concentration (IC50) of 3.21 mg/ml against MERS-CoV with a selective index (SI) of 13.975. The biochemical components of the extracts were identified by GC/MS analysis. The Molecular docking study highlighted the virtual mechanism of binding the identified compounds towards three PDB codes of MERS-CoV non-structural protein 10/16. Interestingly, 2-mono Linolein showed promising binding energy of -14.75 Kcal/mol with the second PDB code (5YNI) and -15.22 Kcal/mol with the third PDB code (5YNQ).

6.
Sci Rep ; 14(1): 8434, 2024 Apr 10.
Article in English | MEDLINE | ID: mdl-38600208

ABSTRACT

The study investigates the molecular structure of 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) and its derivatives in the gas phase using B3LYP and M06-2X functional methods. Intermolecular interactions are analyzed using natural bond orbital (NBO) and atoms in molecules (AIM) techniques. NO2-substituted TEMPO displays high reactivity, less stability, and softer properties. The study reveals that the stability of TEMPO derivatives is mainly influenced by LP(e) → σ∗ electronic delocalization effects, with the highest stabilization observed on the oxygen atom of the nitroxide moiety. This work also considers electron density, atomic charges, and energetic and thermodynamic properties of the studied NO radicals, and their relative stability. The proton affinity and gas-phase basicity of the studied compounds were computed at T = 298 K for O-protonation and N-protonation, respectively. The studied DFT method calculations show that O-protonation is more stable than N-protonation, with an energy difference of 16.64-20.77 kcal/mol (22.80-25.68 kcal/mol) at the B3LYP (M06-2X) method. The AIM analysis reveals that the N-O…H interaction in H2O complexes has the most favorable hydrogen bond energy computed at bond critical points (3, - 1), and the planar configurations of TEMPO derivatives exhibit the highest EHB values. This indicates stronger hydrogen bonding interactions between the N-O group and water molecules.

8.
J Genet Eng Biotechnol ; 22(1): 100334, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38494269

ABSTRACT

BACKGROUND: One of the most dangerous problems that the world faced recently is viral respiratory pathogens. Marine creatures, including Echinodermata, specially Asteroidea class (starfish) have been extensively studied due to their miscellaneous bioactivities, excellent pharmacological properties, and complex secondary metabolites, including steroids, steroidal glycosides, anthraquinones, alkaloids, phospholipids, peptides, and fatty acids. These chemical constituents show antiviral activities against a wide range of viruses, including respiratory viruses. RESULTS: The present study aimed at the identification of potential antiviral compounds from some starfish species. The bioactive compounds from Pentaceraster cumingi, Astropecten polyacanthus, and Pentaceraster mammillatus were extracted using two different solvents (ethyl acetate and methanol). The antiviral activity against influenza A/H1N1 virus showed that ethyl acetate extract from Pentaceraster cumingi has the highest activity, where the selective index was 150.8. The bioactive compounds of this extract were identified by GC/MS analysis. The molecular docking study highlighted the virtual mechanism of binding of the identified compounds towards polymerase basic protein 2 and neuraminidase for H1N1 virus. Interestingly, linoleic acid showed promising binding energy of -10.12 Kcal/mol and -24.20 Kcal/mol for the selected two targets, respectively, and it formed good interactive modes with the key amino acids inside both proteins. CONCLUSION: The molecular docking analysis showed that linoleic acid was the most active antiviral compound from P. cumingi. Further studies are recommended for in-vitro and in-vivo evaluation of this compound against influenza A/H1N1 virus.

9.
ACS Omega ; 9(9): 10391-10399, 2024 Mar 05.
Article in English | MEDLINE | ID: mdl-38463322

ABSTRACT

σ-Hole site-based interactions in the trigonal bipyramidal geometrical structure of hypervalent pnicogen, halogen, and aerogen-bearing molecules with pyridine and NCH Lewis bases (LBs) were comparatively examined. In this respect, the ZF5···, XF3O2···, and AeF2O3···LB complexes (where Z = As, Sb; X = Br, I; Ae = Kr, Xe; and LB = pyridine and NCH) were investigated. The electrostatic potential (EP) analysis affirmations outlined the occurrence of σ-holes on the systems under consideration with disparate magnitudes that increased according to the following order: AeF2O3 < XF3O2 < ZF5. In line with EP outcomes, the proficiency of σ-hole site-based interactions increased as the atomic size of the central atom increased with a higher favorability for the pyridine-based complexes over NCH-based ones. The interaction energy showed the most favorable negative values of -35.97, -44.53, and -56.06 kcal/mol for the XeF2O3···, IF3O2···, and SbF5···pyridine complexes, respectively. The preferentiality pattern of the studied interactions could be explained as a consequence of (i) the dramatic rearrangement of ZF5 molecules from the trigonal bipyramid geometry to the square pyramidal one, (ii) the significant and tiny deformation energy in the case of the interaction of XF3O2 molecules with pyridine and NCH, respectively, and (iii) the absence of geometrical deformation within the AeF2O3···pyridine and ···NCH complexes other than the XeF2O3···pyridine one. Quantum theory of atoms in molecules and noncovalent interaction index findings reveal the partially covalent nature of most of the investigated interactions. Symmetry-adapted perturbation theory affirmations declared that the electrostatic component was the driving force beyond the occurrence of the considered interactions. The obtained findings will help in improving our understanding of the effect of geometrical deformation on intermolecular interactions.

10.
Sensors (Basel) ; 24(2)2024 Jan 12.
Article in English | MEDLINE | ID: mdl-38257582

ABSTRACT

Rehabilitation robotics has seen growing popularity in recent years due to its immense potential for improving the lives of people with disabilities. However, the complex, uncertain dynamics of these systems present significant control challenges, requiring advanced techniques. This paper introduces a novel adaptive control framework integrating modified function approximation (MFAT) and double-integral non-singular terminal sliding mode control (DINTSMC). The goal is to achieve precise tracking performance, high robustness, a fast response, a finite convergence time, reduced chattering, and effective handling of unknown system dynamics. A key feature is the incorporation of a higher-order sliding mode observer, eliminating the need for velocity feedback. This provides a new solution for overcoming the inherent variations and uncertainties in robot manipulators, enabling improved accuracy within fixed convergence times. The efficacy of the proposed approach was validated through simulations and experiments on an exoskeleton robot. The results successfully demonstrated the controller's effectiveness. Stability analysis using Lyapunov theory proved the closed-loop system's uniform ultimate boundedness. This contribution is expected to enable enhanced control for rehabilitation robots and improved patient outcomes.

11.
Peptides ; 173: 171139, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38142817

ABSTRACT

The recent COVID-19 pandemic shows the critical need for novel broad spectrum antiviral agents. Scorpion venoms are known to contain highly bioactive peptides, several of which have demonstrated strong antiviral activity against a range of viruses. We have generated the first annotated reference transcriptome for the Androctonus amoreuxi venom gland and used high performance liquid chromatography, transcriptome mining, circular dichroism and mass spectrometric analysis to purify and characterize twelve previously undescribed venom peptides. Selected peptides were tested for binding to the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein and inhibition of the spike RBD - human angiotensin-converting enzyme 2 (hACE2) interaction using surface plasmon resonance-based assays. Seven peptides showed dose-dependent inhibitory effects, albeit with IC50 in the high micromolar range (117-1202 µM). The most active peptide was synthesized using solid phase peptide synthesis and tested for its antiviral activity against SARS-CoV-2 (Lineage B.1.1.7). On exposure to the synthetic peptide of a human lung cell line infected with replication-competent SARS-CoV-2, we observed an IC50 of 200 nM, which was nearly 600-fold lower than that observed in the RBD - hACE2 binding inhibition assay. Our results show that scorpion venom peptides can inhibit the SARS-CoV-2 replication although unlikely through inhibition of spike RBD - hACE2 interaction as the primary mode of action. Scorpion venom peptides represent excellent scaffolds for design of novel anti-SARS-CoV-2 constrained peptides. Future studies should fully explore their antiviral mode of action as well as the structural dynamics of inhibition of target virus-host interactions.


Subject(s)
Animals, Poisonous , COVID-19 , Scorpion Venoms , Spike Glycoprotein, Coronavirus , Animals , Humans , SARS-CoV-2/metabolism , Scorpions/chemistry , Transcriptome , Proteomics , Pandemics , Peptides/metabolism , Antiviral Agents/pharmacology , Scorpion Venoms/chemistry , Protein Binding
12.
R Soc Open Sci ; 10(12): 231362, 2023 Dec.
Article in English | MEDLINE | ID: mdl-38094266

ABSTRACT

σ-Hole and lone-pair (lp)-hole interactions of aerogen oxides with Lewis bases (LB) were comparatively inspected in terms of quantum mechanics calculations. The ZOn ⋯ LB complexes (where Z = Kr and Xe, n = 1, 2, 3 and 4, and LB = NH3 and NCH) showed favourable negative interaction energies. The complexation features were explained in light of σ-hole and lp-hole interactions within optimum distances lower than the sum of the respective van der Waals radii. The emerging findings outlined that σ-hole interaction energies generally enhanced according to the following order: KrO4 ⋯ < KrO⋯ < KrO3⋯ < KrO2⋯LB and XeO4⋯ < XeO⋯ < XeO2⋯ < XeO3⋯LB complexes with values ranging from -2.23 to -12.84 kcal mol-1. Lp-hole interactions with values up to -5.91 kcal mol-1 were shown. Symmetry-adapted perturbation theory findings revealed the significant contributions of electrostatic forces accounting for 50-65% of the total attractive forces within most of the ZOn⋯LB complexes. The obtained observations would be useful for the understanding of hole interactions, particularly for the aerogen oxides, with application in supramolecular chemistry and crystal engineering.

13.
Cureus ; 15(8): e44306, 2023 Aug.
Article in English | MEDLINE | ID: mdl-37779803

ABSTRACT

The integration of artificial intelligence (AI) and robotics in regional anesthesia has brought about transformative changes in acute pain management for surgical procedures. This review explores the evolving landscape of AI and robotics applications in regional anesthesia, outlining their potential benefits, challenges, and ethical considerations. AI-driven pain assessment, real-time guidance for needle placement during nerve blocks, and predictive modeling solutions for nerve blocks have the potential to enhance procedural precision and improve patient outcomes. Robotic technology aids in accurate needle insertion, reducing complications and improving pain relief. This review also highlights the ethical and safety considerations surrounding AI implementation, emphasizing data security and professional training. While challenges such as costs and regulatory hurdles exist, ongoing research and clinical trials demonstrate the practical utility of these technologies. In conclusion, AI and robotics have the potential to reshape regional anesthesia practice, ultimately improving patient care and procedural accuracy in pain management.

14.
RSC Adv ; 13(41): 29023-29034, 2023 Sep 26.
Article in English | MEDLINE | ID: mdl-37799306

ABSTRACT

The potentiality of the 6-mercaptopurine (MP) and 6-thioguanine (TG) expired drugs toward the corrosion inhibition of the aluminium (Al) (111) surface was widely investigated using a series of density functional theory (DFT) calculations. A competition between the anti-corrosive features of the studied drugs in the gas and aqueous phases was conducted on both neutral and protonated forms by means of quantum mechanical descriptors. The results of the electrostatic potential analysis demonstrated the prominent nucleophilic nature of the sulfur and nitrogen atoms over the structures of the examined drugs. The frontier molecular orbital theory findings outlined the higher preferability of TG over MP as a corrosion inhibitor. Upon determining the most beneficial configurations of the MP/TG⋯Al (111) complexes, first-principles molecular dynamics simulations were executed. Interestingly, the competence of the TG drug in the corrosion inhibition process of Al (111) was more extensive than that of the MP one, which was confirmed by the interaction energy values of -1.79 and -1.64 eV, respectively. Upon obtaining the relaxed complexes, the effect of the presence of water solvent on the adsorption process was studied. These findings provide a foundation for developing green anti-corrosive inhibitors for the aluminium surface.

15.
Asian Pac J Cancer Prev ; 24(9): 3165-3168, 2023 09 01.
Article in English | MEDLINE | ID: mdl-37774068

ABSTRACT

OBJECTIVE: Study the frequency of codon 7 (c.747 G>T, p. R249S) mutation associated with Aflatoxin B1 (AFB1) exposure in Egyptian patients with hepatocellular carcinoma (HCC). METHODS: We utilized restriction fragment polymorphism and direct sequencing to assess codon 7 mutations in 104 hepatocellular carcinomas. The expression of TP53 protein in the tumors were assessed in 44 tumors by a monoclonal rabbit antibody. RESULTS: We identified a single 1/104 (1%) with c.747 G>T, p. R249S variant. 28/44 (63.6%) tumors showed no or occasional (less than < 5%) nuclear staining; 9/44 (20.4%) showed mild to moderate (5-49%) and 7/44 (15.9%) showed strong ≥ 50% staining. CONCLUSION: We observed much lower frequency of TP53 gene than previously published results suggesting geographical alterations in AFB1 exposure in Egypt.


Subject(s)
Aflatoxins , Carcinoma, Hepatocellular , Liver Neoplasms , Humans , Rabbits , Animals , Carcinoma, Hepatocellular/chemically induced , Carcinoma, Hepatocellular/genetics , Carcinoma, Hepatocellular/pathology , Aflatoxins/adverse effects , Genes, p53 , Egypt/epidemiology , Liver Neoplasms/chemically induced , Liver Neoplasms/genetics , Liver Neoplasms/pathology , Mutation , Aflatoxin B1/adverse effects , Codon/genetics , Tumor Suppressor Protein p53/genetics
16.
ACS Omega ; 8(36): 32828-32837, 2023 Sep 12.
Article in English | MEDLINE | ID: mdl-37720791

ABSTRACT

For the first time, sigma (σ)- and lone-pair (lp)-hole site-based interactions of SF4 and SeF4 molecules in seesaw geometry with NH3 and FH Lewis bases were herein comparatively investigated. The obtained findings from the electrostatic potential analysis outlined the emergence of sundry holes on the molecular entity of the SF4 and SeF4 molecules, dubbed the σ- and lp-holes. The energetic viewpoint announced splendid negative binding energy values for σ-hole site-based interactions succeeded by lp-hole analogues, which were found to be -9.21 and -0.50 kcal/mol, respectively, for SeF4···NH3 complex as a case study. Conspicuously, a proper concurrence between the strength of chalcogen σ-hole site-based interactions and the chalcogen's atomic size was obtained, whereas a reverse pattern was proclaimed for the lp-hole counterparts. Further, a higher preference for the YF4···NH3 complexes with elevated negative binding energy was promulgated over the YF4···FH ones, indicating the eminent role of Lewis basicity. The indications of the quantum theory of atoms in molecules generally asserted the closed-shell nature of all the considered interactions. The observation of symmetry-adapted perturbation theory revealed the substantial contributing role of the electrostatic forces beyond the occurrence of σ-hole site-based interactions. In comparison, the dispersion forces were specified to govern the lp-hole counterparts. Such emerging findings would be a gate for the fruitful forthcoming applications of chalcogen bonding interactions in crystal engineering and biological systems.

17.
ACS Omega ; 8(30): 27553-27565, 2023 Aug 01.
Article in English | MEDLINE | ID: mdl-37546583

ABSTRACT

Structural aspects of molnupiravir complexed with the RNA of the SARS-CoV-2 virus have been recently resolved inside the RNA-dependent RNA polymerase (RdRp), demonstrating the interactions of molnupiravir with purine nucleosides. However, the preference of molnupiravir to interact with one purine nucleoside over another has not been clearly investigated. Herein, the complexation of molnupiravir in its active form with guanosine and adenosine was compared, using sundry density functional theory calculations. The plausible tautomeric structures of the molnupiravir drug in complex with guanosine/adenosine were minutely scrutinized. The relative energy findings outlined the favorability of amino-molnupiravir···keto-amino-guanosine and imino-molnupiravir···amino-adenosine optimized complexes. According to the interaction (Eint) and binding (Ebind) energy values, higher preferential base-pairing of molnupiravir with guanosine over the adenosine one was recognized with Eint/Ebind values of -31.16/-21.81 and -13.93/-12.83 kcal/mol, respectively. This could be interpreted by the presence of three and two hydrogen bonds within the former and latter complexes, respectively. Observable changes in the electronic properties and global indices of reactivity of the studied complexes also confirmed the preferential binding within the studied complexes. The findings from the quantum theory of atoms in molecules and the noncovalent interaction index also support the partially covalent nature of the investigated interactions. For both complexes, changes in thermodynamic parameters outlined the spontaneous, exothermic, and nonrandom states of the inspected interactions. Inspecting the solvent effect on the studied interactions outlined more observable amelioration within the water medium compared with the gas one. These results would be a durable ground for the forthcoming studies concerned with the interactions of the molnupiravir drug with purine nucleosides.

18.
Heliyon ; 9(8): e18690, 2023 Aug.
Article in English | MEDLINE | ID: mdl-37560653

ABSTRACT

Adsorption amplitude of the aluminum phosphide (Al12P12) nanocage toward the 2-Mercaptopyridine (MCP) drug was herein monitored based on density functional theory (DFT) calculations. The adsorption process through MCP⋅⋅⋅Al12P12 complex in various configurations was elucidated by means of adsorption (Eads) energies. According to the energetic affirmations, the Al12P12 nanocage demonstrated potential versatility toward adsorbing the MCP drug within the investigated configurations and exhibited significant negative adsorption energies up to -27.71 kcal/mol. Upon the results of SAPT analysis, the electrostatic forces showed the highest contributions to the overall adsorption process with energetic values up to -74.36 kcal/mol. Concurrently, variations of molecular orbitals distribution along with alterations in the energy gap (Egap) and Fermi level (EFL) of the studied nanocage were denoted after adsorbing the MCP drug. The favorable impact of water solvent within the MCP⋅⋅⋅Al12P12 complexes was unveiled and confirmed by negative solvation energy (ΔEsolv) values up to -17.75 kcal/mol. According to thermodynamic parameters, the spontaneous and exothermic natures of the considered adsorption process were proclaimed by negative values of ΔG and ΔH parameters. Significant changes in the IR and Raman peaks, along with the appearance of new peaks, were noticed, confirming the occurrence of the targeted adsorption process. Furthermore, the adsorption features of the MCP drug on the Al12N12 nanocage were elucidated and compared to the Al12P12 analog. The obtained results demonstrated the higher preferability of Al12P12 nanocage than the Al12N12 candidate towards adsorbing the MCP drug without structural distortion.

19.
Sci Rep ; 13(1): 11792, 2023 07 21.
Article in English | MEDLINE | ID: mdl-37479792

ABSTRACT

An in-line smartphone connected to a screen-printed selective electrode hand-held device was used to determine the concentration of distigmine bromide (DB) in its pure and dosage forms as well as its degradation kinetics by continuously measuring the change in the produced emf over time. The main objective, supported by the data presented, is to produce a highly reliable smartphone integrated selective sensor as a portable analyzer with potential high cloud connectivity combining a wide linear dynamic range, the fastest response time with the lowest limits of detection and quantitation while best integrating green analytical chemistry principles. The choice of ionophore used in this approach was guided by computation and the data obtained was compared with traditional analytical techniques. DB, for which there are no previously reported stability-indicating methods and for which four novel such methods are proposed here, was selected as a model drug for this work. At-line UV-spectrophotometry DB assay was obtained by measuring the difference between the spectra of the degradation product and the same concentration of intact drug. The degradation kinetics were studied by this method through tracking the decrease of DB absorbance and/or the increase of a generated degradation product signal over time. Off-line separation based HPLC and TLC stability-indicating methods for DB were also presented. All methods employed in this work were validated for accuracy, precision, specificity, repeatability, linearity, range, detection and quantification limits according to the ICH guidelines and were applied to the analysis of laboratory prepared mixtures as well as commercial products. While all methods proposed were shown to be highly reliable, the smartphone integrated selective sensor is highlighted as a portable analyzer with potential high cloud connectivity and was shown to combine a wide linear dynamic range, the fastest response time with the lowest limits of detection and quantitation while best integrating green analytical chemistry principles.


Subject(s)
Biological Assay , Chemistry, Analytic , Kinetics , Electrodes , Pharmaceutical Preparations
20.
Molecules ; 28(14)2023 Jul 18.
Article in English | MEDLINE | ID: mdl-37513348

ABSTRACT

The potentiality of the ß12 borophene (ß12) and pristine graphene (GN) nanosheets to adsorb tetrahalomethanes (CX4; X = F, Cl, and Br) were investigated using density functional theory (DFT) methods. To provide a thorough understanding of the adsorption process, tetrel (XC-X3∙∙∙ß12/GN)- and halogen (X3C-X∙∙∙ß12/GN)-oriented configurations were characterized at various adsorption sites. According to the energetic manifestations, the adsorption process of the CX4∙∙∙ß12/GN complexes within the tetrel-oriented configuration led to more desirable negative adsorption energy (Eads) values than that within the halogen-oriented analogs. Numerically, Eads values of the CBr4∙∙∙Br1@ß12 and T@GN complexes within tetrel-/halogen-oriented configurations were -12.33/-8.91 and -10.03/-6.00 kcal/mol, respectively. Frontier molecular orbital (FMO) results exhibited changes in the EHOMO, ELUMO, and Egap values of the pure ß12 and GN nanosheets following the adsorption of CX4 molecules. Bader charge transfer findings outlined the electron-donating property for the CX4 molecules after adsorbing on the ß12 and GN nanosheets within the two modeled configurations, except the adsorbed CBr4 molecule on the GN sheet within the tetrel-oriented configuration. Following the adsorption process, new bands and peaks were observed in the band structure and density of state (DOS) plots, respectively, with a larger number in the case of the tetrel-oriented configuration than in the halogen-oriented one. According to the solvent effect affirmations, adsorption energies of the CX4∙∙∙ß12/GN complexes increased in the presence of a water medium. The results of this study will serve as a focal point for experimentalists to better comprehend the adsorption behavior of ß12 and GN nanosheets toward small toxic molecules.

SELECTION OF CITATIONS
SEARCH DETAIL
...