ABSTRACT
We measured the FIR (Far Infrared) absorbance of a series of organic hydrated sub-nanopores (i.e. pores of the size of several A) containing confined water. Our results show that the FIR frequency region between 400 and 570 cm(-1) is sensitive to the differences in water mobility. The absorbance of these compounds was significantly higher than that of chemically similar anhydrous or non-porous hydrated compounds in the same region. Moreover, changes in the water dynamics inside the hydrated pores were found and characterized by their temperature dependent studies in the range from -5 to 20 degrees C. Upon increasing the temperature, water confined in narrow pores shows a small increase in FIR absorbance, while less confined water molecules inside larger pores exhibit a higher increase in absorbance, resembling more what has been observed for bulk water.
Subject(s)
Water/chemistry , Hydrogen Bonding , Porosity , Spectroscopy, Fourier Transform Infrared , TemperatureABSTRACT
The behavior of water confined near nonpolar surfaces has important implications for a number of biological phenomena. In this type of confined environment the properties of "hydrophobicity" and "hydrophilicity" are closely related to the structure of the interfacial water, which in turn can depend on temperature in a very subtle way. Although the physical-chemical consequences of this fact have been theoretically addressed to a great extent, the underlying thermodynamic question is still widely discussed. Accordingly we performed thermogravimetric analysis and variable-temperature powder X-ray diffraction studies on representative hydrogen bonding organic pores occupied by water. The results indicate that a hydrophilic-to-hydrophobic transition of the inner surface of the pores occurs upon increasing temperature, which may be attributed to a strong influence of the dynamics and thermodynamics of local water molecules on the surface affinity of the pores. The relevance of our findings to the understanding of the phenomenon of water transport in natural pores is discussed.
Subject(s)
Organic Chemicals/chemistry , Water/chemistry , Hydrogen Bonding , Hydrophobic and Hydrophilic Interactions , Models, Chemical , Porosity , Temperature , Thermodynamics , X-Ray DiffractionABSTRACT
Water molecules confined inside narrow pores are of great importance in understanding the structure, stability, and function of water channels. Here we report that besides the H-bonding water that structures the pore, the permanent presence of a significant, fast-moving fraction of incompletely H-bonded water molecules inside the pore should control the free entry and exit of water. This is achieved by means of complementary DSC and solid-state NMR studies. We also present compelling evidence from X-ray diffraction data that the cluster formed by six water molecules in the most stable cage-like structure is sufficiently hydrophobic to be stably adsorbed in a nonpolar environment.
Subject(s)
Water/chemistry , Crystallography, X-RayABSTRACT
The open-ended hollow tubular structure formed by inclusion of water molecules in the packing of the hydroxyl acid 1 (R1 = CH2OH, R2 = ethyl groups) led to the synthesis and structural study of their unsaturated analogues. In this article we report on a general and practical large-scale synthesis of hydroxyl acids that possess alkenyl and alkynyl appendages. Substitution of the ethyl groups in 1 with unsaturated two-carbon appendages has a different effect on the molecular structure and on the hydrogen-bonding pattern. No variation has been induced by substitution of only one ethyl group with a vinyl one, although the substitution of both ethyl groups with vinyl or acetylene appendages has the greatest effect on the molecular structure and results in different hydrogen-bonding motifs.
ABSTRACT
Se realizó el presente estudio a partir de un problema social de la ciencia, que se refiere al rechazo por parte de los creyentes cristianos, a los tratamientos que se aplican en la Medicina Tradicional China (MTC). Se desconocen las causas que provocan que los creyentes rechacen esta terapéutica, ya que durante la entrevista médica no se logró que dieran una explicación válida, solamente dijeron que tenían referencias que el símbolo del Tao es demoníaco. Por lo tanto, nos propusimos descifrar las causas. Se comprobó que existen contradicciones teórico filosóficas, ya que la filosofía del Tao se basa en un Materialismo Dialéctico primitivo en contraposición con la filosofía religiosa que es Idealista.Los especialistas consultados argumentaron que los fundamentos teóricos de la Medicina Tradicional China parten de la filosofía del Tao y no están relacionados con ninguna religión. Sin embargo, se encontró que la filosofía del Tao que comenzó como una escuela filosófica pura, se convirtió en una Religión donde usan sellos mágicos o talismanes como el símbolo del Ying y del Yang. En los países asiáticos, su práctica está relacionada con la religión Taoísta. También se constató que muchos creyentes y líderes religiosos desconocen que existe la religión Taoista y su relación con la MTC(AU)
It was carried out a study from of a social problem of the science that refers to the rejection from the Christian believers to the treatments that are applied in the Chinese Traditional Medicine (CTM). We didn't know why the believers rejected this therapy because we didnt get any explanation from them about it. Therefore, we intended to settle down the causes. In our study, we checked that philosophical theoretical contradictions were existed, because the Tao's philosophy is based on a primitive Dialectical Materialism instead of the religious philosophy, which is Idealist. The consulted specialists said that the theoretical foundations of the Traditional Medicine, are based on the Tao's philosophy and they are not related with any religion. However, we found in the investigation that the Tao's philosophy, which began like a pure philosophical school, became a Religion where they use magic symbols, as the Ying Yang symbol. In the Asian countries, the Traditional Medicine is related with the Taoist religion. We also verify that many believers ignore about the Taoist religion and their relationship with the CTM(AU)
Subject(s)
Humans , Medicine, Chinese Traditional , Religion , Religious PhilosophiesABSTRACT
La necesidad de conocer el estado de desarrollo de la competencia y el desempeño de los profesionales en el nivel primario de atención, nos estimuló a su determinación mediante actividades docentes de Discusión de casos adultos fallecidos, en el Policlínico No. 2 del poblado de La Fe, en la Isla de la Juventud, en 13 de estas reuniones celebradas mensualmente por un Grupo Básico de Trabajo durante el curso 2001-2002 (Octubre/01-Julio/02), aplicando como instrumento de valoración la Metodología para Análisis en el Nivel Primario de Salud de Casos Adultos Fallecidos, creada por el autor principal de esta investigación, y validada convenientemente, que permitió extraer los datos que fueron luego analizados y expresados porcentualmente, y que nos llevaron a los resultados siguientes: los encuentros medico-pacientes fueron considerados como adecuados en cantidad y calidad, al igual que las historias clínicas individuales en cuanto a su información. Sin embargo, se evidenciaron serias deficiencias en relación con el conocimiento y prácticas del método clínico y las acciones de salud, por lo que llegamos a la conclusión de que la atención de salud ofrecida en estos casos, necesita de aprendizaje y adiestramiento, pues se evidenciaron insuficiencias en la competencia y desempeño de los profesionales en este nivel de atención.
The need to know the state of development of the competence and performance of professionals at the primary health care level encouraged us to determine it by carrying out teaching activities of Discussion of dead adult cases at the Polyclinic no. 2, in La Fe village, Isle of Youth, in 13 of these meetings held monthly by a Basic Working Group during the course 2001-2002 (October/01-July/02). The Methodology for Analysis at the Primary Health Care Level of Dead Adult Cases was applied as an evaluation tool. It was created by the main author of this research and conveniently validated, and made possible to obtain the data that were later analyzed and expressed by percentage and that led us to the following results: the quantity and quality of the doctor-patient meetings were considered suitable, as well as the information found in the medical histories. However, serious deficiencies were observed in connection with the knowledge and practice of the clinical method and the health actions that made us conclude that the health care provided in these cases require learning and training, since insufficiencies were evidenced in the competence and performance of the professionals at this health care level.
ABSTRACT
La necesidad de conocer el estado de desarrollo de la competencia y el desempeño de los profesionales en el nivel primario de atención, nos estimuló a su determinación mediante actividades docentes de Discusión de casos adultos fallecidos, en el Policlínico No 2 del poblado de La Fe, en la Isla de la Juventud, en 13 de estas reuniones celebradas mensualmente por un Grupo Básico de Trabajo durante el curso 2001-2002 (Octubre/01-Julio/02), aplicando como instrumento de valoración la Metodología para Análisis en el Nivel Primario de Salud de Casos Adultos Fallecidos, creada por el autor principal de esta investigación, y validada convenientemente, que permitió extraer los datos que fueron luego analizados y expresados porcentualmente, y que nos llevaron a los resultados siguientes: los encuentros medico-pacientes fueron considerados como adecuados en cantidad y calidad, al igual que las historias clínicas individuales en cuanto a su información. Sin embargo, se evidenciaron serias deficiencias en relación con el conocimiento y prácticas del método clínico y las acciones de salud, por lo que llegamos a la conclusión de que la atención de salud ofrecida en estos casos, necesita de aprendizaje y adiestramiento, pues se evidenciaron insuficiencias en la competencia y desempeño de los profesionales en este nivel de atención(AU)
Subject(s)
Primary Health Care , Clinical Competence , Professional CompetenceABSTRACT
[reaction: see text] The unique solid-state hydration/dehydration properties of the diacid (+/-)-1e in comparison with other homologues of the same family are studied. Hydrophobic enhancement, which is a consequence of the loss of water molecules from (+/-)-1e chains, is a property that can be exploited to achieve organic condensed systems for nonpolar molecules by interstitial van der Waals confinement.
ABSTRACT
In a model formed by hydroxy acids with a general structure (+/-)-1, we found that solid-state structures depend on steric interactions. Thus, with the exception of molecules 1b and 1e, compounds (+/-)-1a-(+/-)-1m, which possess bulky and conformationally rigid substituents, aggregate by forming tapes and sheets by alternating (+) and (-) subunits held together via carboxylic acid to alcohol hydrogen bonds. Homologue (+/-)-1n with conformationally flexible substituents, which allow conformational deformation gives, by way of the incorporation of water molecules, an efficient hexagonal assembly, which extends to the third-dimension to form tubular H-bonding networks. Each puckered channel can be described as being interconnected by closely packed hexagons in chair-like conformations. The ethyl groups presented in (+/-)-1n provided the volume required to lock the inner hexagonal wall into a rigid structure.
Subject(s)
Hydrogen Bonding , Hydroxy Acids/chemistry , Molecular Conformation , Water/chemistry , Carboxylic Acids/chemistry , Carboxylic Acids/metabolism , Hydrophobic and Hydrophilic Interactions , Lipid Bilayers , Models, MolecularSubject(s)
Humans , Nursing , Nursing, Practical/methods , Medical Records , Evaluation Studies as TopicABSTRACT
The incorporation of water molecules into the hydrogen-bonded pattern of condensed organic materials implies an unfavorable entropic tradeoff resulting from water ordering. Here we show for a family of diacids of general structure (+/-)-1 that extended chains of anhydrous or hydrated structures can be prepared by controlling the steric factors that lead to the closest packing of individual components.
ABSTRACT
La introducción acelerada de las técnicas y equipos de computación es hoy una realidad en nuestro país. Dicha tendencia está en estrecha relación con las expectativas de desarrollo de la producción, la técnica y el progreso científico que debemos lograr en años venideros. Las leyes fundamentales de la dialéctica se ponen de manifiesto, de forma evidente, en el avance histórico de la computación y es un elemento básico para dar cumplimiento a los objetivos generales educativos de los programas de las asignaturas de Informática que se imparten en los distintos niveles de enseñanza, en lo referido a la consolidación de la concepción científica del mundo. La sustitución constante de la nueva tecnología por la vieja, el cambio tecnológico que experimenta el perfeccionamiento del hardware y la utilización, cada vez más marcada, de elementos nuevos y novedosos del software, crean la premisa para comprender el papel que juegan las leyes fundamentales de la dialéctica en el desarrollo histórico de la computación(AU)
The quick introduction of the techniques and computer teams are today a reality in our country. This tendency is in narrow relationship with the expectations of the production development, the technique and the scientific development that we should achieve in coming years. The main dialectics laws are in an evident way in the historical development of the computing and it is a basic element to give execution to the educational general objectives of the programs of Computing science subjects that are imparted in the different teaching levels, referring to the consolidation of the scientific conception of the world. The constant substitution of the new technology for the old one, the technological change that experiences the development of the hardware and the use, more and more marked, of new and novel elements of the software, create the premise to understand the main dialectics laws rall in the historical development of the computing(AU)
Subject(s)
Humans , Computer Systems , JurisprudenceABSTRACT
El trabajo contiene una revisión bibliográfica sobre los aspectos más novedosos del método científico aplicado a la universidad médica, como certera guía que permite evitar el error filosófico, en las ciencias particulares, en el momento de la interpretación de resultados, además abarca una reseña histórica del método científico desde su surgimiento hasta el presente(AU)
Subject(s)
Humans , Research/methods , Methodology as a Subject , Health Sciences , Philosophy , Scientific DomainsABSTRACT
This paper deals with the effects of elenoside, (3-hidroxymethyl-1-methoxy-5,6-methylene-dioxy-4-(3,4-methylenedioxyphenyl)-2-naftoic acid lactone-beta-D-glucoside) an arylnaphthalene lignan with broad spectrum cytotoxicity in a human tumor cell line panel, isolated from Justicia hyssopifolia (Acanthaceae) grown in the Canary Islands (Spain), on isolated cardiac auricle of rabbits, urinary excretion of rats, and on isolated rat ileum. These effects, using a vehicle (propylene glycol-ethanol-plant oil-Tween 80 (40:10:50:2) as a standard, are presented. Elenoside at concentrations of 3.2x10(-4), 6.4 x 10(-4), and 1.2 x 10(-3) M produced an increase in the contraction force of auricles in a concentration-dependent way. At doses of 25 and 50 mg/kg, an antidiuretic effect and a decrease in sodium excretion were observed. Elenoside at concentrations of 3.2 x 10(-4), 6.4 x 10(-4) and 1.2 x 10(-3) M produced an increase in the contraction force of ileum in a concentration-dependent manner. Elenoside produced the concentration dependent inhibition of 86Rb uptake. These results indicate that elenoside has digitalis-like activity similar to mammalian lignans. Moreover, this lignan has an irritant effect on the gastrointestinal tract.
Subject(s)
Acanthaceae , Heart Rate/drug effects , Ileum/drug effects , Lignans/pharmacology , Animals , Dose-Response Relationship, Drug , Erythrocytes/metabolism , Heart Rate/physiology , Humans , Ileum/physiology , In Vitro Techniques , Lignans/isolation & purification , Male , Plant Extracts/isolation & purification , Plant Extracts/pharmacology , Plant Leaves , Rabbits , Rats , Rats, Sprague-Dawley , Urination/drug effects , Urination/physiologyABSTRACT
Se ha realizado una revisión bibliográfica sobre como evitar el error filosófico en las ciencias particulares, sobre elementos filosóficos que deben estar presentes en las valoraciones teóricas de las ciencias particulares, que están directamente relacionadas con la actividad práctica transformadora. Los componentes estructurales con que cuentan las ciencias particulares, como son, el componente empírico que permite conocer las características fenoménicas del objeto, y el componente teórico que penetra hasta la esencia de la realidad objetiva, y las bases y deducciones filosóficas que permiten arribar a la materialidad y cognocibilidad del mundo y una comprensión filosófica materialista dialéctica de la realidad objetiva(AU)
Subject(s)
Humans , Science , Philosophy , Philosophy, Medical , Review Literature as TopicABSTRACT
El proyecto de intervención permite introducir acciones en el objeto de estudio que será seleccionado. Los estudiantes de pregrado y postgrado cuentan con una guía segura para poder confeccionar sus proyectos de investigación, los profesores son los más beneficiados con el uso de esta herramienta metodológica en la práctica científica(AU)
The intervention project allows to introduce actions in the study object that will be selected. The pregrado students and graduate degree have a sure guide to be able to make their investigation projects, the professors are those more beneficiaries with the use of this methodological tool in the scientific practice(AU)
