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1.
Georgian Med News ; (340-341): 217-226, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37805901

RESUMEN

Although mitochondrial DNA respiration circuit abnormalities are among the most common metabolic diseases to manifest in children, identification can be difficult due to their medical variability. Given the multisystem nature of the condition and its diverse and generalized manifestations, making a final diagnosis often takes a long time. Within this summary, they give an in-depth account of the physical signs of adolescent Mitochondrial Respiratory Chain Disorders (MRCDs),analyze the available diagnostics and treatment possibilities, and emphasize current developments in this field of study. During the discovery of fresh biomarkers and the development of next generation sequencing (NGS) technology, extensive research over the years has considerably enhanced the regularity that precise diagnoses are produced. Given the intricate nature of mitochondrial DNA biology and its double genomic investments, Sequencing has made significant progress in identifying the genetic basis of Mitochondrial Respiratory Chain Disorders (MRCDs). Research studies have been created employing a variety of various methods of therapy in an effort to shift the goal on therapy that is mainly curative to possibly having a positive impact on the natural course of the trouble. That's because there is gained a greater awareness of the underlying causes of this category of ailments.


Asunto(s)
Enfermedades Mitocondriales , Niño , Adolescente , Humanos , Enfermedades Mitocondriales/diagnóstico , Enfermedades Mitocondriales/genética , Enfermedades Mitocondriales/terapia , Medicina Genómica , Transporte de Electrón/genética , Mitocondrias/genética , ADN Mitocondrial/genética , ADN Mitocondrial/metabolismo
2.
J Biomol Struct Dyn ; : 1-29, 2023 Jul 04.
Artículo en Inglés | MEDLINE | ID: mdl-37403335

RESUMEN

A structural and spectroscopic study of 5-chloroorotic acid (5-ClOA) biomolecule was carried out by IR and FT-Raman and the results obtained were compared to those achieved in 5-fluoroorotic acid and 5-aminoorotic acid compounds. The structures of all possible tautomeric forms were determined using DFT and MP2 methods. To know the tautomer form present in the solid state, the crystal unit cell was optimized through dimer and tetramer forms in several tautomeric forms. The keto form was confirmed through an accurate assignment of all the bands. For this purpose, an additional improvement in the theoretical spectra was carried out using linear scaling equations (LSE) and polynomic equations (PSE) deduced from uracil molecule. Base pairs with uracil, thymine and cytosine nucleobases were optimized and compared to the natural Watson-Crick (WC) pairs. The counterpoise (CP) corrected interaction energies of the base pairs were also calculated. Three nucleosides were optimized based on 5-ClOA as nucleobase, and their corresponding WC pairs with adenosine. These modified nucleosides were inserted in DNA:DNA and RNA:RNA microhelices, which were optimized. The position of the -COOH group in the uracil ring of these microhelices interrupts the DNA/RNA helix formation. Because of the special characteristic of these molecules they can be used as antiviral drugs.Communicated by Ramaswamy H. Sarma.

3.
J Biomol Struct Dyn ; 41(10): 4444-4466, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35583120

RESUMEN

Base pairs of 4-amino-3-nitrobenzonitrile (4A-3NBN) molecule with uracil, thymine and cytosine nucleobases were optimized and compared to natural Watson-Crick (WC) pairs. The slightly greater flexibility of the -NO2 group of 4A-3NBN than the N3-H group of the natural nucleobases together with a noticeable higher dipole moment of its pairs can facilitate disruption of the DNA/RNA helix formation. Several new mutagenic modified nucleosides with 4A-3NBN and 3-amino-2-nitrobenzonitrile (3A-2NBN) were proposed as antiviral prodrugs and their base pairs optimized. The special characteristics of these prodrugs appear appropriated for their clinical use. The counterpoise (CP) corrected interaction energies of the base pairs were calculated and compared to the natural ones. The M06-2X DFT method was used for this purpose. The molecular structure of 4A-3NBN was analyzed in detail and the crystal unit cell was simulated by a tetramer form and eight dimer forms. The performance of the B3LYP, X3LYP and M06-2X methods was tested on the vibrational wavenumbers in the monomer, dimer and tetramer forms of 4A-3NBN. The observed IR and Raman bands were assigned according to the optimum dimer II form determined by B3LYP and by the tetramer form calculated by M06-2X, which is the expected unit cell that forms the crystal net. The two best scaling procedures were used.Communicated by Ramaswamy H. Sarma.


Asunto(s)
Nucleósidos , Profármacos , Modelos Moleculares , Espectrometría Raman , Espectroscopía Infrarroja por Transformada de Fourier , Emparejamiento Base
4.
Med J Armed Forces India ; 77(2): 125-128, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33867626

RESUMEN

India was certified free of polio in 2014. Until now, the oral polio vaccine (OPV) was being used in India. As the OPV is a live vaccine, vaccine-associated paralytic poliomyelitis may occur after its use. The aim is to replace the OPV with injectable polio vaccine. The Polio Eradication and Endgame Strategic Plan 2013-2018 has been made to eradicate polio. A switch from the trivalent OPV (tOPV) to bivalent OPV (bOPV) has been undertaken in all countries since April 2016. tOPV vials have been withdrawn and replaced by bOPV. In addition, the inactivated polio vaccine (IPV) has been introduced. The next step would be to remove the type 3 virus component followed by complete cessation of the OPV and a final switch to the IPV. The timeline has been fixed as 2018-2019. Replacement of a vaccine may raise fears in the community that need to be addressed. Re-emergence of circulating vaccine-derived poliovirus after withdrawal of the tOPV may occur. Proper disposal of vaccine vials needs to be ensured. Proper training of vaccinators is important. All stakeholders need to be incorporated, and focus should be more on deprived populations. The switch marks a significant step towards the final goal of polio eradication. Finally, the importance of community participation cannot be overemphasized. Sustained surveillance is the key to prevent occurrence of cases in polio-free countries through importation.

5.
J Appl Microbiol ; 131(5): 2257-2269, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32692423

RESUMEN

AIMS: To obtain quantitative efficacy data of two ultraviolet light (UVC) technologies for surface inactivation of Bacillus anthracis Ames and Bacillus atrophaeus spores. METHODS AND RESULTS: Spores were deposited onto test coupons and controls of four different materials, via liquid suspension or aerosol deposition. The test coupons were then exposed to UVC light from either a low-pressure mercury vapor lamp or a system comprised of light emitting diodes, with a range of dosages. Positive controls were held at ambient conditions and not exposed to UVC light. Following exposure to UVC, spores were recovered from the coupons and efficacy was quantified in terms of log10 reduction (LR) in the number of viable spores compared to that from positive controls. CONCLUSIONS: Decontamination efficacy varied by material and UVC dosage (efficacy up to 5·7 LR was demonstrated). There was no statistical difference in efficacy between the two species or between inoculation methods. Efficacy improved for the LED lamp at lower relative humidity, but this effect was not observed with the mercury vapor lamp. SIGNIFICANCE AND IMPACT OF THE STUDY: This study will be useful in determining whether UVC could be used for the inactivation of B. anthracis spores on different surface types.


Asunto(s)
Bacillus anthracis , Mercurio , Bacillus , Descontaminación , Esporas Bacterianas , Rayos Ultravioleta
6.
J Biomol Struct Dyn ; 38(18): 5443-5463, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31838954

RESUMEN

This study focuses on the effects of the bromine atom on the molecular structure parameters in the main tautomeric forms of 5-bromouracil (5BrU), and as well, its effect on hydration and on the Watson-Crick (WC) pairs as compared to uracil molecule. The influence of the bromine atom was studied in several environments. The hydration effect on the molecular structure and energies of the main tautomeric forms of 5BrU was analyzed by considering a variable number of water molecules in explicit form up to 30 to simulate the first and second hydration shells. The 'mutagenic' 2-hydroxy-4-oxo (U2) enol tautomer of 5BrU, but not of uracil, was absolutely favored over the keto form in clusters with more than 20 water molecules. For all calculations, B3LYP and M06-2X Methods were used. The effect of the bromine atom when it was inserted into the natural and reverse WC pairs uridine-adenosine was also determined, and counterpoise (CP) corrected interaction energies were calculated. The effect of the bromine atom was analyzed in several DNA:RNA hybrid microhelices. Different backbone and helical parameters were calculated and compared. The bromine atom destabilizes its base pair, with a remarkable increase in the rise parameter (Dz) corresponding to the microhelix, and to a slight increase in the diameter (d). Molecular docking calculations were also carried out with 5BrU for targeted proteins associated with diabetes, hepatocellular carcinoma and breast and lung cancers. The molecular docking analysis confirms that the 5BrU molecule may play an important role as a promising inhibitor against breast cancer.Communicated by Ramaswamy H. Sarma.


Asunto(s)
Bromouracilo , ADN , Simulación del Acoplamiento Molecular , ARN , Bromo , Bromouracilo/química , Humanos
7.
Int J Mol Sci ; 20(14)2019 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-31311161

RESUMEN

The molecular structure of 2-thiouracil, 4-thiouracil and 2,4-dithiouracil was analyzed under the effect of the first and second hydration shell by using the B3LYP density functional (DFT) method, and the results were compared to those obtained for the uracil molecule. A slight difference in the water distribution appears in these molecules. On the hydration of these molecules several trends in bond lengths and atomic charges were established. The ring in uracil molecule appears easier to be deformed and adapted to different environments as compared to that when it is thio-substituted. Molecular docking calculations of 2-thiouracil against three different pathogens: Bacillus subtilis, Escherichia coli and Candida albicans were carried out. Docking calculations of 2,4-dithiouracil ligand with various targeted proteins were also performed. Different DNA: RNA hybrid microhelixes with uridine, 2-thiouridine, 4-thiouridine and 2,4-dithiouridine nucleosides were optimized in a simple model with three nucleotide base pairs. Two main types of microhelixes were analyzed in detail depending on the intramolecular H-bond of the 2'-OH group. The weaker Watson-Crick (WC) base pair formed with thio-substituted uracil than with unsubstituted ones slightly deforms the helical and backbone parameters, especially with 2,4-dithiouridine. However, the thio-substitution significantly increases the dipole moment of the A-type microhelixes, as well as the rise and propeller twist parameters.


Asunto(s)
Antiinfecciosos/química , Simulación del Acoplamiento Molecular , Tiouracilo/química , Animales , Antiinfecciosos/farmacología , Bacillus subtilis/efectos de los fármacos , Candida albicans/efectos de los fármacos , ADN/química , Escherichia coli/efectos de los fármacos , Humanos , Interacciones Hidrofóbicas e Hidrofílicas , Unión Proteica , ARN/química , Tiouracilo/farmacología
8.
Spectrochim Acta A Mol Biomol Spectrosc ; 188: 418-435, 2018 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-28756258

RESUMEN

The laser Raman and IR spectra of 5-chlorocytosine have been recorded and accurately assigned in the solid state using Density functional calculations (DFT) together with the linear scaling equation procedure (LSE) and the solid state simulation of the crystal unit cell through a tetramer form. These results remarkably improve those reported previously by other authors. Several new scaling equations were proposed to be used in related molecules. The six main tautomers of the biomolecule 5-chlorocytosine were determined and optimized at the MP2 and CCSD levels, using different basis sets. The relative stabilities were compared with those obtained in cytosine and their 5-halo derivatives. Several relationships between energies, geometric parameters and NBO atomic charges were established. The effect of the chlorine substitution in the fifth position was evaluated through the stability of the Watson-Crick (WC) base pair of 5-chlorodeoxycytidine with deoxyguanosine, and through their vibrational spectra.


Asunto(s)
Emparejamiento Base , Cloro/química , Simulación por Computador , Citosina/análogos & derivados , Desoxicitidina/análogos & derivados , Desoxiguanosina/química , Espectrometría Raman , Cristalización , Citosina/química , Desoxicitidina/química , Enlace de Hidrógeno , Conformación Molecular , Espectroscopía Infrarroja por Transformada de Fourier , Estereoisomerismo , Termodinámica , Vibración
9.
J Biomol Struct Dyn ; 36(5): 1225-1254, 2018 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-28537217

RESUMEN

The effect of the sulphur atom on 2-thiouracil (2TU) and 2-thiouridine molecules, as compared with uracil and uridine molecules, respectively, was carried out in several environments. The predicted IR spectrum of 2TU in the isolated state was compared with that obtained for uracil molecule and with those reported experimentally in matrix isolation. Its crystal unit cell in the solid state was simulated through a tetramer form using DFT methods for the first time. The calculated Raman spectrum was compared to the experimental ones in the solid state. A linear scaling procedure was used for this task. The first hydration shell was simulated by explicit number of water molecules surrounding 2TU up to 30 and was compared with that obtained in uracil molecule. Water molecules 'distributed' around 2TU was preferred over that 'clustering', because it can better reproduce the hydration and their effects on different parameters of the molecular structure of 2TU and uracil. The total atomic charges and several calculated thermodynamic parameters were discussed. The effect of the sulphur atom on the Watson-Crick (WC) and reverse WC base pair uridine-adenosine was estimated, and the CP corrected interaction energies were calculated. 2-thiouridine has a weaker WC pair than that with uridine, although its slight higher dipole moment (µ) facilitates the interaction with the water molecules. Several helical parameters were determined.


Asunto(s)
Adenosina/química , Modelos Moleculares , Ácidos Nucleicos/química , Análisis Espectral , Azufre/química , Tiouracilo/química , Algoritmos , Emparejamiento Base , Simulación por Computador , Enlace de Hidrógeno , Modelos Teóricos , Conformación Molecular , Agua/química
10.
Med J Armed Forces India ; 73(3): 287-289, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-28790788

RESUMEN

Resistance to standard antimalarials has led to the need for newer options. Artemisinin-based combination therapies (ACTs), which require a tedious three-day treatment schedule, have been introduced for the treatment of drug-resistant malaria. Of late, the new generation artemisinin-naphthoquine (ANQ) combination has been developed, which requires a single dose treatment. Artemisinin initiates the action through the cleavage of the endoperoxide bridge while naphtoquine maintains the process by getting concentrated in the digestive vacuole of the parasite. One ANQ tablet contains 50 mg naphthoquine and 125 mg of artemisinin in the ratio of 1:2.5. The optimal dosage in adults is 400 mg of naphthoquine and 1000 mg artemisinin; which amounts to 8 tablets in a single dose. The dosage for children is adjusted based on the body-weight. The combination has been found to be quite effective with and safe. Studies have demonstrated an adequate clinical and parasitologic response of 98.1-100% in both adults and children. However, further trials are required to confirm its non-inferiority with other ACTs. Adverse reactions with ANQ have been mild. Further studies are needed before safety can be established during pregnancy. ANQ increases the compliance rates because of single dosage. It may be administered by the peripheral health workers as a directly observed therapy, which would be of special benefit to troops in the North-Eastern Sector.

11.
Med J Armed Forces India ; 72(4): 373-376, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-27843186

RESUMEN

Dengue fever has re-emerged as a major public health challenge. Of late, several promising attempts have been made to control the disease with limited success. An innovative method of biological control of dengue is the use of the bacterium Wolbachia. Selected strains of Wolbachia have been introduced into Aedes aegypti to prevent transmission of dengue viruses by the vector. Wolbachia prevents dengue transmission by either directly blocking the virus or by decreasing the lifespan of the vector. The mechanism by which it causes these effects is not clearly understood. The main concern of this technique is the emergence of a new dengue virus serotype which may evade the protection offered by Wolbachia. The technique is environment friendly and holds promise for control of other vector borne diseases.

12.
J Appl Microbiol ; 121(6): 1603-1615, 2016 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-27569380

RESUMEN

AIMS: To evaluate the use of relatively low levels of hydrogen peroxide vapour (HPV) for the inactivation of Bacillus anthracis spores within an indoor environment. METHODS AND RESULTS: Laboratory-scale decontamination tests were conducted using bacterial spores of both B. anthracis Ames and Bacillus atrophaeus inoculated onto several types of materials. Pilot-scale tests were also conducted using a larger chamber furnished as an indoor office. Commercial off-the-shelf (COTS) humidifiers filled with aqueous solutions of 3 or 8% hydrogen peroxide (H2 O2 ) were used to generate the HPV inside the mock office. The spores were exposed to HPV for periods ranging from 8 h up to 1 week. CONCLUSIONS: Four- to seven-day exposures to low levels of HPV (average air concentrations of approx. 5-10 parts per million) were effective in inactivating B. anthracis spores on multiple materials. The HPV can be generated with COTS humidifiers and household H2 O2 solutions. With the exception of one test/material, B. atrophaeus spores were equally or more resistant to HPV inactivation compared to those from B. anthracis Ames. SIGNIFICANCE AND IMPACT OF THE STUDY: This simple and effective decontamination method is another option that could be widely applied in the event of a B. anthracis spore release.


Asunto(s)
Antibacterianos/farmacología , Bacillus anthracis/efectos de los fármacos , Descontaminación/métodos , Peróxido de Hidrógeno/farmacología , Bacillus/efectos de los fármacos , Esporas Bacterianas/efectos de los fármacos
13.
J Clin Pharm Ther ; 41(3): 365-367, 2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-27060706

RESUMEN

WHAT IS KNOWN AND OBJECTIVE: Endovascular embolization of basilar tip aneurysms (BTA) is performed to prevent rupture, but little is known regarding post-procedural vasospasm and its consequences. We relate management of post-procedural vasospasm found in cardiovascular literature on this rare post-procedural intracranial complication. CASE DESCRIPTION: A 52-year-old man develops ischaemic strokes after undergoing posterior cerebral artery (PCA) stent-assisted coil embolization of BTA. Work-up suggested that vasospasm was the cause of his strokes. WHAT IS NEW AND CONCLUSION: Vasospasm after intracranial stenting may share similar pathophysiological features to coronary stenting, resulting in ischaemia. Verapamil should be considered an empiric therapy in prevention of stent-related vasospasm.

14.
Middle East J Anaesthesiol ; 23(1): 105-10, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26121902

RESUMEN

Trigeminal neuralgia (TN) is characterized by unilateral, lancinating, paroxysmal pain in the dermatomal distribution area of trigeminal nerve. Percutaneous balloon compression (PBC) of Gasserian ganglion is an effective, comparatively cheaper and simple therapeutic modality for treatment of TN. Compression secondary to PBC selectively injures the large myelinated A-alfa (afferent) fibers that mediate light touch and does not affect A-delta and C-fibres, which carry pain sensation. Balloon compression reduces the sensory neuronal input, thus turning off the trigger to the neuropathic trigeminal pain. In this current case series, we are sharing our experience with PBC of Gasserian Ganglion for the treatment of idiopathic TN in our patients at an academic university-based medical institution in India. During the period of August 2012 to October 2013, a total of twelve PBCs of Gasserian Ganglion were performed in eleven patients suffering from idiopathic TN. There were nine female patients and two male patients with the age range of 35-70 years (median age: 54 years). In all patients cannulation of foramen ovale was done successfully in the first attempt. In eight out of eleven (72.7%) patients ideal 'Pear-shaped' balloon visualization could be achieved. In the remaining three patients (27.3%), inflated balloon was 'Bullet-shaped'. In one patient final placement of Fogarty balloon was not satisfactory and it ruptured during inflation. This case was deferred for one week when it was completed successfully with 'Pear-shaped' balloon inflation. During the follow up period of 1-13 months, there have been no recurrences of TN. Eight out of eleven patients (72.7%) are completely off medicines (carbamazepine and baclofen) and other two patients are stable on very low doses of carbamazepine. All patients have reported marked improvement in quality of life. This case series shows that percutaneous balloon compression is a useful minimally invasive intervention for the treatment of trigeminal neuralgia.


Asunto(s)
Cateterismo/métodos , Ganglio del Trigémino/cirugía , Neuralgia del Trigémino/cirugía , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad
15.
Spectrochim Acta A Mol Biomol Spectrosc ; 136 Pt B: 464-72, 2015 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-25448947

RESUMEN

The experimental FT-IR and FT-Raman spectra of 2,5-dichlorobenzonitrile molecule were recorded at room temperature, and the results compared with quantum chemical theoretical values using MP2 and DFT methods. Molecular geometry, vibrational wavenumbers and thermodynamic parameters were calculated. With the help of specific scaling procedures for the computed wavenumbers, the experimentally observed FTIR and FT-Raman bands were analyzed and assigned to different normal modes of the molecule. Most of the modes have wavenumbers in the expected range and the error obtained was in general very low. Several general conclusions were deduced. The NBO analysis has been done and Molecular Electrostatic Potential (MEP) has been plotted.


Asunto(s)
Electrones , Modelos Moleculares , Nitrilos/química , Teoría Cuántica , Espectrometría Raman , Electricidad Estática , Conformación Molecular , Espectroscopía Infrarroja por Transformada de Fourier , Vibración
16.
Spectrochim Acta A Mol Biomol Spectrosc ; 138: 723-35, 2015 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-25544188

RESUMEN

Density Functional Theory (DFT) calculations at B3PW91 level with 6-311G (d) basis sets were carried out for 2,3-Pyrazinedicarboxylic acid (PDCA) to analyze in detail the equilibrium geometries and vibrational spectra. Calculations reveal that the optimized geometry closely resembles the experimental XRD data. Vibrational spectra were analyzed on the basis of potential energy distribution (PED) of each vibrational mode, which provides quantitative as well as qualitative interpretation of IR and Raman spectra. Information about size, shape, charge density distribution and site of chemical reactivity of the molecule were obtained by mapping electron density isosurface with the electrostatic potential surface (ESP). Based on optimized ground state geometries, NBO analysis was performed to study donor-acceptor (bond-antibond) interactions. TD-DFT analysis was also performed to calculate energies, oscillator strength of electronic singlet-singlet transitions and the absorption wavelengths. The (13)C and (1)H nuclear magnetic resonance (NMR) chemical shifts of the molecule in the ground state were calculated by gauge independent atomic orbital (GIAO) method and compared with the experimental values. PDCA was screened for its antimicrobial activity and found to exhibit antifungal and antibacterial effects. Molecular docking was also performed for the different receptors.


Asunto(s)
Antiinfecciosos/farmacología , Ácidos Dicarboxílicos/farmacología , Modelos Moleculares , Pirazinas/farmacología , Teoría Cuántica , Espectrometría Raman , Vibración , Bacterias/efectos de los fármacos , Espectroscopía de Resonancia Magnética con Carbono-13 , Ácidos Dicarboxílicos/química , Análisis Diferencial Térmico , Dimerización , Electrones , Hongos/efectos de los fármacos , Enlace de Hidrógeno , Pruebas de Sensibilidad Microbiana , Conformación Molecular , Simulación del Acoplamiento Molecular , Espectroscopía de Protones por Resonancia Magnética , Pirazinas/química , Solventes/química , Espectrofotometría Ultravioleta , Espectroscopía Infrarroja por Transformada de Fourier , Electricidad Estática , Termogravimetría
18.
Spectrochim Acta A Mol Biomol Spectrosc ; 132: 430-45, 2014 Nov 11.
Artículo en Inglés | MEDLINE | ID: mdl-24887505

RESUMEN

FT-Raman and FT-IR studies of the biomolecule 5-fluoroorotic acid in the solid state were carried out. The unit cell found in the crystal was simulated as a tetramer form by density functional calculations. They were performed to clarify wavenumber assignments of the experimental observed bands in the spectra. Correlations with the molecule of uracil were made, and specific scale equations were employed to scale the wavenumbers of 5-fluoroorotic acid. Good reproduction of the experimental wavenumbers is obtained and the % error is very small in the majority of the bands. This fact confirms our simplified solid state model. The molecular structure was fully optimized using DFT and MP2 methods. The relative stability of both the syn and anti conformations was investigated, and the anti-form was found to be slightly more stable, by 7.49 kJ/mol at the MP2 level. The structures of all possible tautomeric forms were determined. The keto-form appeared as the most stable one. The NBO atomic charges and several thermodynamic parameters were also calculated.


Asunto(s)
Simulación por Computador , Modelos Moleculares , Ácido Orótico/análogos & derivados , Teoría Cuántica , Espectrometría Raman , Dimerización , Isomerismo , Conformación Molecular , Ácido Orótico/química , Espectroscopía Infrarroja por Transformada de Fourier , Termodinámica , Vibración
19.
Spectrochim Acta A Mol Biomol Spectrosc ; 130: 653-68, 2014 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-24856263

RESUMEN

A Raman and IR study of the biomolecule 6-chlorouracil was carried out in the solid state. The unit cell found in the crystal was simulated as a tetramer form by density functional calculations. Specific scale factors and scaling equations deduced from uracil molecule were employed in the predicted wavenumbers of 6-chlorouracil. The scaled wavenumbers were used in the reassignment of the IR and Raman experimental bands. Good reproduction of the experimental wavenumbers is obtained and the % error is very small in the majority of cases. A comparison between the molecular structure and charge distribution of 6-chlorouracil and 5-chlorouracil molecules was presented. The effect of the hydration with the PCM model in the molecular structure and charges was discussed. The optimum tautomers of 6-chlorouracil were optimized and analyzed. Six of them were related to those of uracil molecule. The effect of the halogen substitution in the sixth position of the pyrimidine ring in the stability of the different tautomers was evaluated. HOMO and LUMO orbital energy analysis were carried out.


Asunto(s)
Espectrofotometría Infrarroja , Espectroscopía Infrarroja por Transformada de Fourier , Espectrometría Raman , Uracilo/análogos & derivados , Uracilo/química , Algoritmos , Simulación por Computador , Cristalización , Dimerización , Enlace de Hidrógeno , Modelos Moleculares , Conformación Molecular , Distribución Normal
20.
J Appl Microbiol ; 117(1): 40-9, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24690070

RESUMEN

AIMS: To evaluate a standard aerosolization method for uniformly depositing threat-representative spores onto surfaces. METHODS AND RESULTS: Lyophilized Bacillus anthracis ΔSterne spores, coated in silica, were aerosolized into a containment chamber and deposited onto nine surface types by two independent laboratories. Laboratory A produced a mean loading concentration of 1·78 × 10(5) CFU cm(-2) ; coefficient of variation (CV) was <40% for 96% of samples. Laboratory B produced a mean loading concentration of 7·82 × 10(6) CFU cm(-2) ; 68% of samples demonstrated CV <40%. CONCLUSIONS: This method has been shown to meet the goal of loading threat-representative spores onto surfaces with low variability at concentrations relevant to the Department of Defense. SIGNIFICANCE AND IMPACT OF THE STUDY: As demonstrated in 2001, a biological attack using anthrax disseminated as a dry powder is a credible threat. This method will provide a means to load spores onto surfaces that mimic a 'real-world' scenario of an aerosolized anthrax attack. The method has utility for evaluating sporicidal technologies and for nondecontamination studies, for example fate and transport or reaerosolization.


Asunto(s)
Bacillus anthracis/química , Armas Biológicas , Dióxido de Silicio/química , Esporas Bacterianas/química , Aerosoles , Adhesión Bacteriana , Liofilización , Humanos , Polvos/química , Electricidad Estática
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