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1.
Arch. Soc. Esp. Oftalmol ; 99(4): 173-176, abr. 2024. ilus
Article in Spanish | IBECS | ID: ibc-232139

ABSTRACT

Este manuscrito presenta un caso de un leiomioma orbitario de larga evolución en un joven de 14años. El tumor era inusualmente grande y causaba una proptosis severa y una afectación importante de la musculatura ocular. El paciente presentaba amaurosis, una oftalmoplejía completa, dolor ocular espontáneo e incapacidad para cerrar los párpados. Debido al tamaño del tumor y a su progresión, se realizó una exenteración orbitaria derecha para eliminar todo el contenido orbitario, incluyendo el tumor y el globo ocular. El procedimiento quirúrgico tenía como objetivo prevenir la recurrencia del tumor y mejorar la calidad de vida del paciente. El análisis histopatológico confirmó el diagnóstico de leiomioma orbitario. Este caso presenta un interés particular por el grado de evolución que ha alcanzado. La extirpación completa del tumor y un seguimiento a largo plazo son necesarios para prevenir la recurrencia y garantizar resultados óptimos para el paciente. Además, este caso refleja las grandes diferencias en el acceso a la sanidad en las diferentes regiones del mundo. (AU)


This manuscript describes an exceptional case of a long-standing orbital leiomyoma in a 14-year-old male. The tumor was unusually large, causing severe proptosis and significant involvement of the ocular muscles. The patient presented with amaurosis, complete ophthalmoplegia, spontaneous eye pain, and the inability to close the eyelids, leading to psychological distress. Due to the tumor's size and progression, a right orbital exenteration was performed to remove all orbital contents, including the tumor and the eyeball. The surgical procedure aimed to prevent tumor recurrence and improve the patient's quality of life. The histopathological analysis confirmed the diagnosis of orbital leiomyoma. This case presents a particular interest due to the degree of evolution it has reached. Complete tumor excision and long-term follow-up are necessary to prevent recurrence and ensure optimal patient outcomes. This report underscores global healthcare disparities and the complexity of managing rare orbital neoplasms in diverse country settings. (AU)


Subject(s)
Humans , Male , Adolescent , Leiomyoma , Exophthalmos , Ophthalmoplegia , Orbit Evisceration
2.
Arch Soc Esp Oftalmol (Engl Ed) ; 99(4): 173-176, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38309659

ABSTRACT

This manuscript describes an exceptional case of a long-standing orbital leiomyoma in a 14-year-old male. The tumor was unusually large, causing severe proptosis and significant involvement of the ocular muscles. The patient presented with amaurosis, complete ophthalmoplegia, spontaneous eye pain, and the inability to close the eyelids, leading to psychological distress. Due to the tumor's size and progression, a right orbital exenteration was performed to remove all orbital contents, including the tumor and the eyeball. The surgical procedure aimed to prevent tumor recurrence and improve the patient's quality of life. The histopathological analysis confirmed the diagnosis of orbital leiomyoma. This case presents a particular interest due to the degree of evolution it has reached. Complete tumor excision and long-term follow-up are necessary to prevent recurrence and ensure optimal patient outcomes. This report underscores global healthcare disparities and the complexity of managing rare orbital neoplasms in diverse country settings.


Subject(s)
Exophthalmos , Leiomyoma , Muscle Neoplasms , Orbital Neoplasms , Male , Humans , Child , Adolescent , Orbital Neoplasms/diagnostic imaging , Orbital Neoplasms/surgery , Quality of Life , Neoplasm Recurrence, Local , Exophthalmos/etiology , Muscle Neoplasms/complications , Leiomyoma/diagnostic imaging , Leiomyoma/surgery , Leiomyoma/complications
3.
Neurología (Barc., Ed. impr.) ; 38(8): 530-540, Oct. 20232. tab, graf, ilus
Article in Spanish | IBECS | ID: ibc-226320

ABSTRACT

Introducción: Se desconoce la incidencia de la distrofia miotónica tipo 1 (DM1), enfermedad con gran variedad fenotípica, en nuestra región. El objetivo de nuestro trabajo es estimar la incidencia de DM1 en nuestro centro (referencia en Aragón) e identificar las características propias de nuestra población (correlación genotipo-fenotipo). Métodos: Estudio descriptivo retrospectivo de 459 pacientes clasificados según número de repeticiones CTG en: normal (5-35), premutado (36-50), protomutado (51-80), pequeñas expansiones (81-150), intermedias (151-1.000) y grandes (> 1.000). Además, según el fenotipo mostrado, se categorizaron como: no afectos (5-50 CTG), forma leve o asintomática (51-150 CTG), clásica (151-1.000 CTG) y severa (> 1.000 CTG). Resultados: La incidencia de DM1 fue de 20,61 (IC 95%: 19,59-21,63) casos por millón de individuos-año. Se evidenció una correlación inversa entre el número de CTG y la edad al diagnóstico genético (ρ = −0,547; IC 95%: −0,610 a −0,375; p < 0,001). El CTG5 fue el alelo polimórfico más frecuente en sanos. Del total de afectos, el 28,3% presentaron la forma leve o asintomática, el 59,1% la forma clásica y el 12,6% la forma severa. El 35,1% presentaron herencia materna, el 59,4% herencia paterna y el 5,5% herencia incierta. En las formas leves la calvicie frontal en varones fue el rasgo fenotípico más prevalente, junto con miotonía y cataratas, mientras que en la clásica predominó la ptosis palpebral, la debilidad facial, las alteraciones en la voz y la pronunciación, la miotonía y la sensación de cansancio/somnolencia. Conclusiones: La incidencia de DM1 es relevante en Aragón. La revisión multidisciplinar del fenotipo de pacientes con DM1 es clave para un diagnóstico precoz y medicina personalizada.(AU)


Introduction: The incidence of myotonic dystrophy type 1 (DM1), a disease with great phenotypic variety, in our region is unknown. This study aims to estimate the incidence of DM1 at our hospital (a reference centre in Aragon, Spain) and to identify the characteristics of our population (genotype-phenotype correlation). Methods: Retrospective, descriptive study of 459 patients classified according to the number of CTG repeats, as follows: normal (5-35), premutation (36-50), protomutation (51-80), small expansions (81-150), intermediate expansions (151-1000), and large expansions (> 1000). Furthermore, according to clinical phenotype, patients were categorised as unaffected (5-50 CTG repeats), mild form or asymptomatic (51-150), classical form (151-1000), and severe form (> 1000). Results: The incidence of DM1 was 20.61 cases per million person-years (95% CI: 19.59-21.63). An inverse correlation was observed between the number of CTG repeats and the age at genetic diagnosis (ρ = −0.547; 95% CI: −0.610 to −0.375; P < .001). CTG5 was the most frequent polymorphic allele in healthy individuals. Of all patients with DM1, 28.3% presented the mild or asymptomatic form, 59.1% the classical form, and 12.6% the severe form. Inheritance was maternal in 35.1% of cases, paternal in 59.4%, and uncertain in 5.5%. In mild forms, frontal balding in men was the most prevalent phenotypic trait, as well as myotonia and cataracts, while in the classical form, ptosis, facial weakness, voice and pronunciation alterations, myotonia, and fatigue/sleepiness were most frequent. Conclusions: The incidence of DM1 in Aragon is significant. Multidisciplinary study of the phenotype of patients with DM1 is key to early diagnosis and personalised management.(AU)


Subject(s)
Humans , Male , Female , Myotonic Dystrophy/classification , Myotonic Dystrophy/diagnosis , Biological Variation, Population , Polymerase Chain Reaction , Incidence , Neurology , Nervous System Diseases , Retrospective Studies
4.
Neurologia (Engl Ed) ; 38(8): 530-540, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37437658

ABSTRACT

INTRODUCTION: The incidence of myotonic dystrophy type 1 (DM1), a disease with great phenotypic variety, in our region is unknown. This study aims to estimate the incidence of DM1 at our hospital (a reference centre in Aragon, Spain) and to identify the characteristics of our population (genotype-phenotype correlation). METHODS: Retrospective, descriptive study of 459 patients classified according to the number of CTG repeats, as follows: normal (5-35), premutation (36-50), protomutation (51-80), small expansions (81-150), intermediate expansions (151-1000), and large expansions (> 1000). Furthermore, according to clinical phenotype, patients were categorised as unaffected (5-50 CTG repeats), mild form or asymptomatic (51-150), classical form (151-1000), and severe form (> 1000). RESULTS: The incidence of DM1 was 20.61 cases per million person-years (95% CI, 19.59-21.63). An inverse correlation was observed between the number of CTG repeats and the age at genetic diagnosis (ρ = -0.547; 95% CI, -0.610 to -0.375; P < .001). CTG5 was the most frequent polymorphic allele in healthy individuals. Of all patients with DM1, 28.3% presented the mild or asymptomatic form, 59.1% the classical form, and 12.6% the severe form. Inheritance was maternal in 35.1% of cases, paternal in 59.4%, and uncertain in 5.5%. In mild forms, frontal balding in men was the most prevalent phenotypic trait, as well as myotonia and cataracts, while in the classical form, ptosis, facial weakness, voice and pronunciation alterations, myotonia, and fatigue/sleepiness were most frequent. CONCLUSIONS: The incidence of DM1 in Aragon is significant. Multidisciplinary study of the phenotype of patients with DM1 is key to early diagnosis and personalised management.

5.
Neurologia (Engl Ed) ; 2021 May 07.
Article in English, Spanish | MEDLINE | ID: mdl-33972121

ABSTRACT

INTRODUCTION: The incidence of myotonic dystrophy type1 (DM1), a disease with great phenotypic variety, in our region is unknown. This study aims to estimate the incidence of DM1 at our hospital (a reference centre in Aragon, Spain) and to identify the characteristics of our population (genotype-phenotype correlation). METHODS: Retrospective, descriptive study of 459 patients classified according to the number of CTG repeats, as follows: normal (5-35), premutation (36-50), protomutation (51-80), small expansions (81-150), intermediate expansions (151-1000), and large expansions (>1000). Furthermore, according to clinical phenotype, patients were categorised as unaffected (5-50 CTG repeats), mild form or asymptomatic (51-150), classical form (151-1000), and severe form (>1000). RESULTS: The incidence of DM1 was 20.61 cases per million person-years (95%CI: 19.59-21.63). An inverse correlation was observed between the number of CTG repeats and the age at genetic diagnosis (ρ=-0.547; 95%CI: -0.610 to -0.375; P<.001). CTG5 was the most frequent polymorphic allele in healthy individuals. Of all patients with DM1, 28.3% presented the mild or asymptomatic form, 59.1% the classical form, and 12.6% the severe form. Inheritance was maternal in 35.1% of cases, paternal in 59.4%, and uncertain in 5.5%. In mild forms, frontal balding in men was the most prevalent phenotypic trait, as well as myotonia and cataracts, while in the classical form, ptosis, facial weakness, voice and pronunciation alterations, myotonia, and fatigue/sleepiness were most frequent. CONCLUSIONS: The incidence of DM1 in Aragon is significant. Multidisciplinary study of the phenotype of patients with DM1 is key to early diagnosis and personalised management.

6.
Phys Chem Chem Phys ; 20(39): 25518-25530, 2018 Oct 10.
Article in English | MEDLINE | ID: mdl-30277488

ABSTRACT

Different force fields for the graphene-CH4 system are proposed including pseudo-atom and full atomistic models. Furthermore, different charge schemes are tested to evaluate the electrostatic interaction for the CH4 dimer. The interaction parameters are optimized by fitting to interaction energies at the DFT level, which were themselves benchmarked against CCSD(T) calculations. The potentials obtained with both the pseudo-atom and full atomistic approaches describe accurately enough the average interaction in the methane dimer as well as in the graphene-methane system. Moreover, the atom-atom potentials also correctly provide the energies associated with different orientations of the molecules. In the atomistic models, charge schemes including small charges allow for the adequate representation of the stability sequence of significant conformations of the methane dimer. Additionally, an intermediate charge of -0.63e on the carbon atom in methane leads to bond energies with errors of ca. 0.07 kcal mol-1 with respect to the CCSD(T) values for the methane dimer. For the graphene-methane interaction, the atom-atom potential model predicts an average interaction energy of 2.89 kcal mol-1, comparable to the experimental interaction energy of 3.00 kcal mol-1. Finally, the presented force fields were used to obtain self-diffusion coefficients that were checked against the experimental value found in the literature. The no-charge and Hirshfeld charge atom-atom models perform extremely well in this respect, while the cheapest potential considered, a pseudo-atom model without charges, still performs reasonably well.

7.
J Phys Chem A ; 120(27): 4951-60, 2016 Jul 14.
Article in English | MEDLINE | ID: mdl-27045203

ABSTRACT

We use large-scale MP2 calculations to investigate the physisorption of molecular hydrogen on (9,0) defective carbon nanotubes (CNTs) of C72H18. These large (supra)molecular systems are typically studied using conventional DFT methods, which do not describe well the van der Waals interactions responsible for this process. Here we use CCSD(T)-calibrated MP2 calculations to estimate binding energies by considering four defective structures (hydrogenated divacancy, octagon-pentagon, and two Stone-Wales defects). The largest physisorption energies for the nondefective CNT are for configurations in which H2 points toward the center of one ring. The computed interaction energies for defect-free CNT are in the range 5.7 to 5.9 kJ/mol, in good agreement with the experimental value of 5.98 kJ/mol. The defects introduced in the (9,0)-CNT increase the surface area of the nanotube, such that the largest surface in found in the 55-77 Stone-Wales defective CNT that furthermore is the most aromatic. Only that defect enlarges the physisorption binding energy, which can become >25% larger. Moreover, a cooperative effect in the adsorption of H2 not appearing in the regular structure is found.

8.
J Chem Phys ; 135(21): 214304, 2011 Dec 07.
Article in English | MEDLINE | ID: mdl-22149789

ABSTRACT

The aim of the present theoretical work is to provide data necessary for a better understanding of the electronic spectrum of the silane molecule, which is affected by the Jahn-Teller effect. By selecting an adequate distorted C(2v) geometry of SiH(4), the three lower Koopmans ionization potentials are evaluated with the equation of motion coupled cluster of singles and doubles method. Vertical excitation energies for the different Rydberg series converging to the three Jahn-Teller components are inferred from ab initio coupled cluster linear response calculations. Absorption oscillator strengths for dipole-allowed electronic transitions are also determined with the molecular-adapted quantum defect orbital methodology. Predictions of new spectroscopic data on SiH(4) are reported.

9.
J Phys Chem A ; 113(25): 7155-60, 2009 Jun 25.
Article in English | MEDLINE | ID: mdl-19489599

ABSTRACT

Theoretical absorption oscillator strengths for transitions involving Rydberg states in molecular formaldehyde as well as cross sections for photoionization Rydberg channels associated with the production of the lowest parent ion electronic state are reported. The calculations have been performed with the molecular quantum defect orbital (MQDO) method. A test on the MQDO f values has been its comparison with previous experiments and calculations and its compliance with the expected systematic trends along the Rydberg series. The use of the MQDO method as an alternative to ab initio methods, which find serious difficulties in calculating spectral intensities in formaldehyde, is proposed. We hope that the spectroscopic data, many of them reported here for the first time, may be useful for the interpretation of the vacuum ultraviolet spectrum of this molecule.


Subject(s)
Formaldehyde/chemistry , Quantum Theory
10.
J Chem Phys ; 129(5): 054310, 2008 Aug 07.
Article in English | MEDLINE | ID: mdl-18698903

ABSTRACT

An all-electron full configuration interaction (FCI) calculation of the adiabatic potential energy curves of some of the lower states of BeH molecule is presented. A moderately large ANO basis set of atomic natural orbitals (ANO) augmented with Rydberg functions has been used in order to describe the valence and Rydberg states and their interactions. The Rydberg set of ANOs has been placed on the Be at all bond distances. So, the basis set can be described as 4s3p2d1f3s2p1d(BeH)+4s4p2d(Be). The dipole moments of several states and transition dipole strengths from the ground state are also reported as a function of the R(Be-H) distance. The position and the number of states involved in several avoided crossings present in this system have been discussed. Spectroscopic parameters have been calculated from a number of the vibrational states that result from the adiabatic curves except for some states in which this would be completely nonsense, as it is the case for the very distorted curves of the 3s and 3p (2)Sigma(+) states or the double-well potential of the 4p (2)Pi state. The so-called "D complex" at 54 050 cm(-1) (185.0 nm) is resolved into the three 3d substates ((2)Sigma(+),(2)Pi,(2)Delta). A diexcited valence state is calculated as the lowest state of (2)Sigma(-) symmetry and its spectroscopic parameters are reported, as well as those of the 2 (2)Delta (4d) state The adiabatic curve of the 4 (2)Sigma(+) state shows a swallow well at large distances (around 4.1 A) as a result of an avoided crossing with the 3 (2)Sigma(+) state. The probability that some vibrational levels of this well could be populated is discussed within an approached Landau-Zerner model and is found to be high. No evidence is found of the E(4ssigma) (2)Sigma(+) state in the region of the "D complex". Instead, the spectroscopic properties obtained from the (4ssigma) 6 (2)Sigma(+) adiabatic curve of the present work seem to agree with those of the experimental F(4psigma) (2)Sigma(+) state. The FCI calculations provide benchmark results for other correlation models for the open-shell BeH system and evidence both the limitations and capabilities of the basis set.

11.
J Phys Chem A ; 112(14): 3275-80, 2008 Apr 10.
Article in English | MEDLINE | ID: mdl-18307330

ABSTRACT

Vertical excitation energies belonging to some different Rydberg series of hydrogen chloride have been determined with a coupled-cluster theoretical approach. These excitation energies have allowed us to calculate electric dipole transition intensities in HCl and allow additional assessment of the calculation approach presently used to provide an adequate description of the valence and Rydberg states of HCl. The molecular quantum defect orbital has been applied to the calculation of oscillator strengths. In particular, new insight is given on the assignment of states as the R1Pi, the 1Delta(4dpi and 5ppi), the 1Sigma+(4dpi), and the nddelta(1Pi, 1Phi) and 4f states.

12.
J Comput Chem ; 29(4): 523-32, 2008 Mar.
Article in English | MEDLINE | ID: mdl-17722010

ABSTRACT

The all-electron full configuration interaction (FCI) vertical excitation energies for some low lying valence and Rydberg excited states of BeH are presented in this article. A basis set of valence atomic natural orbitals has been augmented with a series of Rydberg orbitals that have been generated as centered onto the Be atom. The resulting basis set can be described as 4s2p1d/2s1p (Be/H) + 4s4p3d. It allows to calculate Rydberg states up to n= {3,4,5} of the s, p, and d series of Rydberg states. The FCI vertical ionization potential for the same basis set and geometry amounts to 8.298 eV. Other properties such as FCI electric dipole and quadrupole moments and FCI transition dipole and quadrupole moments have also been calculated. The results provide a set of benchmark values for energies, wave functions, properties, and transition properties for the five electron BeH molecule. Most of the states have large multiconfigurational character in spite of their essentially single excited nature and a number of them present an important Rydberg-valence mixing that is achieved through the mixed nature of the particle MO of the single excitations.


Subject(s)
Beryllium/chemistry , Hydrogen/chemistry , Computers
13.
J Chem Inf Model ; 47(3): 1271-7, 2007.
Article in English | MEDLINE | ID: mdl-17492830

ABSTRACT

Ab initio quantum-chemistry programs produce and use large amounts of data, which are usually stored on disk in the form of binary files. A FORTRAN library, named Q5Cost, has been designed and implemented in order to allow the storage of these data sets in a special data format built with the HDF5 technology. This data format allows the data to be represented as tree structures and is portable between different platforms and operating systems, making code interoperability and communication much easier. The libraries have been used to build many interfaces among different quantum chemistry codes, and the first scientific applications have been realized. This activity was carried out within the COST in Chemistry D23 project "MetaChem", in the Working Group "A meta-laboratory for code integration in ab initio methods".

14.
J Phys Chem A ; 111(17): 3321-5, 2007 May 03.
Article in English | MEDLINE | ID: mdl-17417829

ABSTRACT

Vertical excitation energies of the CF(3)Cl molecule have been obtained from a response function approach with a CC reference function to determine absolute photoabsorption oscillator strengths in the molecular-adapted quantum defect orbital formalism (MQDO). The present work covers more highly excited Rydberg states than have been experimentally reported. Assessing of the reliability of the present calculations is provided through a comparative analysis between the results of the molecule and the Cl atom. This can be used to allow for predictions of the same type of properties in other analogous systems.

15.
J Chem Phys ; 124(12): 124313, 2006 Mar 28.
Article in English | MEDLINE | ID: mdl-16599680

ABSTRACT

Vertical excitation energies as well as related absolute photoabsorption oscillator strength data are very scarce in the literature for methane. In this study, we have characterized the three existing series of low-lying Rydberg states of CH4 by computing coupled cluster linear response (CCLR) vertical excitation energies together with oscillator strengths in the molecular-adapted quantum defect orbital formalism from a distorted Cs geometry selected on the basis of outer valence green function calculations. The present work provides a wide range of data of excitation energies and absolute oscillator strengths which correspond to the Rydberg series converging to the three lower ionization potential values of the distorted methane molecule, in energy regions for which experimentally measured data appear to be unavailable.

16.
J Comput Chem ; 26(12): 1254-62, 2005 Sep.
Article in English | MEDLINE | ID: mdl-15965970

ABSTRACT

A recently developed algorithm to generate localized molecular orbitals (LMO) is applied to the study of excited states along a photodissociation process. The LMOs allow for the selection of a consistent complete active space (CAS) for the simultaneous description of all the electronic states involved in a multistate process on the basis of simple chemical criteria. The local nature of the orbitals is used to label them in a unique way that does not depend on the molecular geometry. The selection of the electronic configurations of interest for the set of target states on only the basis of the dominant excitations required by the simplest configuration interaction (CI) descriptions for both ground and excited states is fairly simplified. The following of the changes in the nature of the states along cuts in the set of potential energy surfaces (PES) is also simpler. The C--F bond breaking and the states involved in the photodissociation of the HFCO system, together with another geometrical path along the PES of the same previous states, are studied by way of examples in this work. The local nature of the MOs warrants that this small system is representative enough to show the advantages of the procedure and that its application to larger systems (R-FCO systems) would be straightforward.

17.
J Mol Graph Model ; 16(2): 57-71, 1998 Apr.
Article in English | MEDLINE | ID: mdl-9879056

ABSTRACT

We have selected fullerene-60 and -70 cavities as model systems in order to test several methods for characterizing inclusion molecules. The methods are based on different technical foundations such as a square and triangular tessellation of the molecule taken as a unitary sphere, spherical tessellation of the molecular surface, numerical integration of the atomic volumes and surfaces, triangular tessellation of the molecular surface, and a cubic lattice approach to a molecular space. Accurate measures of the molecular volume and surface area have been performed with the pseudo-random Monte Carlo (MCVS) and uniform Monte Carlo (UMCVS) methods. These calculations serve as a reference for the rest of the methods. The SURMO2 and MS methods have not recognized the cavities and may not be convenient for intercalation compounds. The programs that have detected the cavities never exceed 5% deviation relative to the reference values for molecular volume and surface area. The GEPOL algorithm, alone or combined with TOPO, shows results in good agreement with those of the UMCVS reference. The uniform random number generator provides the fastest convergence for UMCVS and a correct estimate of the standard deviations. The effect of the internal cavity on the accessible surfaces has been calculated.


Subject(s)
Algorithms , Carbon/chemistry , Computer Simulation , Fullerenes , Models, Molecular , Software , Monte Carlo Method
18.
J Mol Graph ; 14(5): 245-59, 277, 1996 Oct.
Article in English | MEDLINE | ID: mdl-9097231

ABSTRACT

We outline a method for the calculation of multipole moments and molecular dipole-dipole (alpha), dipole-quadrupole (A), and quadrupole-quadrupole (C) polarizabilities, which we have successfully applied to benzothiazole (A)-benzobisthiazole (B) oligomer A-B13-A. Three model rotational isomers have been characterized: (1) the fully planar (000) rotational isomer; (2) a conformation with each unit rotated 10 degrees in the alternate direction (+(-)+), and (3) a rotational isomer with each unit rotated 10 degrees in the same direction (+3). The dipole moment, mu, is smaller for isomers 000 and +(-)+ than for isomer +3. The calculation of alpha A, and C has been performed by use of the interacting induced dipoles polarization model, which calculates tensor effective anisotropic point polarizabilities (method of Applequist). The values of alpha, A, and C are in the same order of magnitude as reference calculations (PAPID) program). The values of A are rather sensitive to mu, which varies under rotation, explaining the greatest value of magnitude of Ax,xx for polar isomer +3. This rotational isomer has the maximum hydrophilic accessible surface, which would improve solubility in water. It is found that small torsional changes can enhance solubility by increasing the hydrophilic accessible surface without too much affecting the values of alpha and C. However, the torsion of the oligomer can vary the value of mu and so modify A.


Subject(s)
Thiazoles/chemistry , Benzothiazoles , Computer Graphics , Computer Simulation , Models, Chemical , Molecular Conformation , Polymers/chemistry , Solubility , Static Electricity
19.
J Mol Graph ; 9(4): 254-6, 1991 Dec.
Article in English | MEDLINE | ID: mdl-1772851

ABSTRACT

Program AMYR, originally written by S. Fraga (University of Alberta, Canada), allows for the calculation of molecular associations using a pair-wise atom-atom potential. The interaction energy is evaluated through a 1/R expansion. Our improved version includes a dispersion energy term in the potential corrected by damping functions, the possibility of carrying out energy minimizations through variable metric methods, as well as the optional calculation of geometrical and topological indices. Program AMYR has been adapted also for high-performance computing and vectorization. An interactive version of the program carries out real-time molecular graphics showing simultaneously the energy profile of the calculations.


Subject(s)
Algorithms , Models, Molecular , Azides/chemistry , Benzene/chemistry , Indoles/chemistry , Isoindoles
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