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1.
Geophys Res Lett ; 49(3): e2021GL096069, 2022 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-35859568

RESUMEN

Water storage plays an important role in mitigating heat and flooding in urban areas. Assessment of the water storage capacity of cities remains challenging due to the inherent heterogeneity of the urban surface. Traditionally, effective storage has been estimated from runoff. Here, we present a novel approach to estimate effective water storage capacity from recession rates of observed evaporation during precipitation-free periods. We test this approach for cities at neighborhood scale with eddy-covariance based latent heat flux observations from 14 contrasting sites with different local climate zones, vegetation cover and characteristics, and climates. Based on analysis of 583 drydowns, we find storage capacities to vary between 1.3 and 28.4 mm, corresponding to e-folding timescales of 1.8-20.1 days. This makes the urban storage capacity at least five times smaller than all the observed values for natural ecosystems, reflecting an evaporation regime characterized by extreme water limitation.

2.
Genet Mol Res ; 15(1)2016 Jan 29.
Artículo en Inglés | MEDLINE | ID: mdl-26909934

RESUMEN

Genetic studies of multiple paternity are a valuable tool to gain information on the reproductive biology of turtles. We analyzed paternity type in Podocnemis sextuberculata and related number of fathers per nest to nesting period (beginning, middle, or end of nesting season); clutch size (number of eggs); female size; and hatchling success. Females were captured and maximum linear carapace lengths measured during the 60 days that encompass the nesting season at Rio Trombetas Biological Reserve (Pará, Brazil). Nests were marked and blood samples collected from hatchlings. Six heterologous loci were used: five from Podocnemis unifilis and one from Podocnemis expansa. Hatchlings were analyzed from 23 nests, and the rate of multiple paternity was 100%. The mean number of fathers per nest was six (± 0.9), and no significant difference between number of fathers in a nest and nesting period. Similarly there was no significant relationship between number of fathers in a nest and female size or hatchling success rate. Number of fathers was, however, positively correlated with clutch size (Spearman correlation rho = 0.47; P > 0.05). To our knowledge, this is the first study to test the relationship between multiple paternity and ecological aspects of the reproductive ecology of turtles in the genus Podocnemis.


Asunto(s)
Tortugas/genética , Animales , Brasil , Femenino , Masculino , Paternidad , Reproducción , Ríos
3.
Acta Anaesthesiol Scand ; 59(5): 586-97, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25782165

RESUMEN

BACKGROUND: Brain dysfunction is common in sepsis. We aimed to assess whether cerebral perfusion, oxygenation, and/or metabolism are abnormal during early endotoxemia, and how they may relate to potential neurohistological changes. METHODS: In this prospective animal study, we included 12 pigs (weight: 42 ± 4 kg; mean ± SD) that were exposed to Escherichia coli lipopolysaccharide (E. coli LPS B0111 : B4, 0.4 µg/kg/h) or saline infusion (n = 6, each) for 10 h. Systemic hemodynamics, cerebral blood flow, intracranial pressure, and brain tissue oxygen tension were continuously measured. At the end of the experiment, formalin-fixed brains were cut in coronal sections and embedded in paraffin. Afterwards, the sections were cut at 5 microns and stained with hematoxylin and eosin. RESULTS: Stable systemic hemodynamics in both groups were associated with higher carotid arterial blood flow after 10 h of endotoxemia (9.0 ± 2.2 ml/kg/min) compared to controls (6.6 ± 1.2 ml/kg/min; time-group interaction: P = 0.014). Intracranial pressure, cerebral perfusion pressure, brain oxygen consumption, and brain tissue oxygen tension were similar in both groups. In four of the six endotoxemic animals but in none of the controls, cerebral tissue lesions were found (encephalomalacia with spongy degeneration of white matter, axonal swelling, and ischemic neuronal thalamic necrosis), including significant venous vascular alterations, predominantly in the brainstem, in three of the four animals. CONCLUSIONS: Early endotoxemia seems to be associated with histological signs of brain damage unrelated to systemic or cerebral hemodynamics or oxygenation.


Asunto(s)
Endotoxemia/complicaciones , Endotoxemia/patología , Enfermedades del Sistema Nervioso/etiología , Enfermedades del Sistema Nervioso/patología , Animales , Encéfalo/patología , Circulación Cerebrovascular , Endotoxemia/inducido químicamente , Femenino , Hemodinámica , Presión Intracraneal , Lipopolisacáridos , Masculino , Consumo de Oxígeno , Estudios Prospectivos , Mecánica Respiratoria , Porcinos
4.
Photochem Photobiol Sci ; 12(8): 1341-50, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23529277

RESUMEN

2-Aminopurine is a fluorescent probe widely used to study local dynamics as well as charge and energy transfer reactions in DNA/RNA. Despite its broad utilization, the nonradiative relaxation pathways responsible for the variation in its fluorescence quantum yield and fluorescence lifetime in different solvents are still under scrutiny. In this work we use steady-state absorption and emission spectroscopy and broad-band transient absorption covering the time scale from femtoseconds to microseconds to investigate the excited-state dynamics of 2-aminopurine 2'-deoxyriboside (2APdr) in acetonitrile, ethanol, and aqueous buffer solution at pH 7. It is shown that up to ~40% of the initial excited-state population decays by intersystem crossing to the triplet state depending on the solvent used, thus competing effectively with fluorescence emission. Furthermore, the rate of formation and yield of the triplet state depend sensitively on the hydrogen-donor ability and polarity of the solvent.


Asunto(s)
2-Aminopurina/química , Desoxirribonucleósidos/química , Colorantes Fluorescentes/química , Acetonitrilos/química , Etanol/química , Fluorescencia , Concentración de Iones de Hidrógeno , Modelos Moleculares , Teoría Cuántica , Soluciones , Solventes/química , Espectrometría de Fluorescencia
5.
J Phys Chem A ; 117(30): 6580-8, 2013 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-23845162

RESUMEN

Femtosecond transient absorption experiments and density functional calculations are presented for 2-methyl-1-nitronaphthalene, 2-nitronaphthalene, and 1-nitronaphthalene in cyclohexane and acetonitrile solutions. Excitation of 2-methyl-1-nitronaphthalene at 340 nm populates the Franck-Condon singlet state, which bifurcates into two barrierless decay channels with sub-200-fs lifetimes. The primary decay channel connects the Franck-Condon singlet excited state with a receiver triplet state, whereas the second, minor channel involves conformational relaxation to populate an intramolecular charge-transfer state, as previously reported for 1-nitronaphthalene (J. Chem. Phys. 2009, 113, 224518). Conversely, the experimental and computational data for 2-nitronaphthalene shows that almost the entire Franck-Condon singlet excited-state population intersystem crosses to the triplet state in less than 200 fs due to a sizable energy barrier of ca. 5 kcal/mol that must be surmounted to access the intramolecular charge-transfer state. Our results lend support to the idea that the probability of population transfer to the triplet manifold in these nitronaphthalene derivatives is controlled not only by the small energy gap between the Franck-Condon singlet excited state and the receiver triplet state but also by the region of configuration space sampled in the singlet excited-state potential energy surface at the time of excitation. It is proposed that the ultrafast intersystem crossing dynamics in these nitronaphthalene molecules most likely occurs between nonequilibrated excited states in the strongly nonadiabatic regime.

6.
J Phys Chem A ; 117(51): 14100-8, 2013 Dec 27.
Artículo en Inglés | MEDLINE | ID: mdl-24283295

RESUMEN

Nitronaphthalene derivatives (NNDs) are among the most abundant volatile nitro-polycyclic aromatic hydrocarbons found in the Earth's atmosphere. Investigations of the atmospheric degradation processes show that photolysis is the major degradation pathway under ambient conditions. In this contribution, we present photochemical measurements and quantum-chemical calculations of three major NNDs. It is shown that the magnitude of the photodegradation and triplet quantum yields in 1-nitronaphthalene (1NN), 2-methyl-1-nitronaphthalene (2M1NN), and 2-nitronaphthalene (2NN) are inversely related to each other. In accord with a recent time-resolved and computation study (J. Phys. Chem. A 2013, 117, 6580) and in order to explain this striking observation we propose that these photochemical yields are largely controlled by (1) the conformational heterogeneity of the nitro-aromatic torsion angle, (2) the energy gap (spin-orbit coupling interaction) between the excited singlet state and the receiver triplet state, and (3) the topology of the excited singlet state in the Franck-Condon region of configuration space sampled at the time of excitation. A distribution of torsion angles closer to 90° leads to a higher photoreactivity. Methylation of the ortho position in 1NN to give 2M1NN increases the photoreactivity by 97%, while 2NN is largely photoinert. Conversely, the triplet yield decreases as the distribution of torsion angles gets closer to 90°: 0.93 ± 0.15 in 2NN, 0.64 ± 0.12 in 1NN, and 0.33 ± 0.05 in 2M1NN. These results suggest an important relationship between conformational heterogeneity and the photochemical fate of these NNDs. This structure-photoreactivity relationship is of relevance to current efforts aimed at modeling and understanding the distribution patterns of NNDs in the atmosphere and their overall contribution to air quality.

7.
J Am Chem Soc ; 134(36): 14808-17, 2012 Sep 12.
Artículo en Inglés | MEDLINE | ID: mdl-22909171

RESUMEN

Femtosecond-to-microsecond broadband transient absorption experiments are reported for Cy(3)PAu(2-naphthyl) (1), (Cy(3)PAu)(2)(2,6-naphthalenediyl) (2), and (Cy(3)PAu)(2)(2,7-naphthalenediyl) (3), where Cy = cyclohexyl. Global and target analyses of the data, based on a sequential kinetic model, reveal four spectral components. These components are assigned to (1) excited state absorption (ESA) of the ligand-centered S(1) state; (2) ESA of a receiver ligand-to-metal or metal-to-ligand charge transfer triplet state (τ(1) ≤ 300 fs); (3) ESA of the vibrationally excited, ligand-centered T(1) state (τ(3) = 7-10 ps); and (4) ESA of the relaxed T(1) state. Intersystem crossing (ISC) occurs in hundreds of femtoseconds, while internal conversion (IC) in the triplet manifold is slow (τ(2) ≈ 2 ps). The relaxed T(1) state shows biphasic decay kinetics in 2 and 3 with lifetimes of hundreds of picoseconds and hundreds of nanoseconds in air-saturated conditions, while only monophasic decay is observed in 1 under identical conditions. The primary decay pathway of the T(1) state is assigned to quenching by O(2), while the secondary channel is tentatively assigned to self-quenching or triplet-triplet annihilation. The ISC rate in 1 is not modulated significantly by the incorporation of a second heavy-atom group effecter. Instead, the position at which the second Au(I)-phosphine group is attached plays a noticeable role in the ISC rate, showing a 3-fold decrease in that of 2 compared to that of 3. The results challenge the conventional view that the rate of IC is larger than that of ISC, lending further support to the emerging kinetic model proposed for other transition-metal complexes. Gold(I) now joins the exclusive group of transition metals known to form organometallic complexes exhibiting excited-state nonequilibrium dynamics.


Asunto(s)
Oro/química , Naftalenos/química , Compuestos Orgánicos de Oro/química , Fosfinas/química , Teoría Cuántica , Soluciones , Factores de Tiempo
8.
Genet Mol Res ; 10(3): 1393-402, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21823088

RESUMEN

The chelonians are, in general, important for the economy of the traditional populations of the Amazon region, especially as a source of animal protein. Furthermore, sub-products, such as eggs and fat, are utilized in the manufacture of cosmetics, and the plastron and carapace are used in the manufacture of adornments. The freshwater turtle species Podocnemis sextuberculata, locally known as "iaçá" or "pitiú", is widely distributed in the Amazon Basin in Brazil and also in Colombia and Peru. This species is on the International Union for Conservation of Nature Red List in the category of vulnerable species. We examined the genetic variability and population structure of three populations represented by 64 individuals sampled from Reserva Federal de Abufari, Tapauá, Amazonas State; Reserva de Desenvolvimento Sustentável Mamirauá, Tefé, Amazonas State, and Terra Santa, Pará State. All of these are over 1000 km from each other. A partial 415-bp sequence of the mitochondrial gene ND1 was utilized as a molecular marker. Seven haplotypes were observed; the most common haplotype was shared by all the areas sampled, while the rarest haplotypes were represented by a single individual and were thus restricted to a single locality. The sharing of the most common haplotype, the high number of migrants (Nm) and the AMOVA results indicate a lack of genetic structure among the sampling localities. The levels of genetic variability observed were homogeneous among the sampling localities. These results (Ó¨(ST) and Nm) are compatible with what is known about the ecology of this species, which has a great migratory capacity.


Asunto(s)
Genética de Población/métodos , Animales , Brasil , Colombia , ADN Mitocondrial/genética , Haplotipos/genética , Perú , Tortugas/clasificación , Tortugas/genética
9.
Science ; 206(4423): 1186-8, 1979 Dec 07.
Artículo en Inglés | MEDLINE | ID: mdl-505003

RESUMEN

The sex of hatchling map turtles is determined by incubation temperature of eggs in the laboratory as well as in nature. Temperature controls sex differentiation rather than causing a differential mortality of sexes. Temperature has no effect on sex determination in a soft-shelled turtle.


Asunto(s)
Análisis para Determinación del Sexo , Tortugas/fisiología , Animales , Femenino , Genotipo , Masculino , Especificidad de la Especie , Temperatura
10.
Science ; 212(4491): 231-4, 1981 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-17783835

RESUMEN

Voyager 1 provided the first look at Saturn's magnetotail and magnetosphere during relatively quiet interplanetary conditions. This report discusses the energetic particle populations of the outer magnetosphere of Saturn and absorption features associated with Titan and Rhea, and compares these observations with Pioneer 11 data of a year earlier. The trapped proton fluxes had soft spectra, represented by power laws E(-gamma) in kinetic energy E, with gamma approximately 7 in the outer magnetosphere and gamma approximately 9 in the magnetotail. Structure associated with the magnetotial was observed as close as 10 Saturn radii (R(s)) on the outbound trajectory. The proton and electron fluxes in the outer magnetosphere and in the magnetotail were variable and appeared to respond to changes in interplanetary conditions. Protons with energies >/= 2 million electron volts had free access to the magnetosphere from interplanetary space and were not stably trapped outside approximately 7.5 R(s).

11.
Science ; 206(4421): 984-7, 1979 Nov 23.
Artículo en Inglés | MEDLINE | ID: mdl-17733919

RESUMEN

The Voyager 2 encounter has enhanced our understanding of earlier results and provided measurements beyond 160 Jupiter radii (R(J)) in the magnetotail. Significant fluxes of energetic sulfur and oxygen nuclei (4 to 15 million electron volts per nucleon) of Jovian origin were observed inside 25 R(J), and the gradient in phase space density at 12 R(J) indicates that the ions are diffusing inward. A substantially longer time delay versus distance was found for proton flux maxima in the active hemisphere in the magnetotail at Jovicentric longitudes lambda(III), = 260 degrees to 320 degrees than in the inactive hemisphere at lambda(III), = 85 degrees to l10 degrees . These delays can be related to the radial motion of plasma expanding into the magnetotail, and differences in the expansion speeds between the active and inactive hemispheres can produce rarefaction regions in trapped particles. It is suggested that the 10-hour modulation of interplanetary Jovian electrons may be associated with the arrival at the dawn magnetopause of a rarefaction region each planetary rotation.

12.
Science ; 204(4396): 1003-7, 1979 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-17800440

RESUMEN

The observations of the cosmic-ray subsystem have added significantly to our knowledge of Jupiter's magnetosphere. The most surprising result is the existence of energetic sulfur, sodium, and oxygen nuclei with energies above 7 megaelectron volts per nucleon which were found inside of Io's orbit. Also, significant fluxes of similarly energetic ions reflecting solar cosmic-ray composition were observed throughout the magnetosphere beyond 11 times the radius of Jupiter. It was also found that energetic protons are enhanced by 30 to 70 percent in the active hemisphere. Finally, the first observations were made of the magnetospheric tail in the dawn direction out to 160 Jupiter radii.

13.
Science ; 215(4532): 577-82, 1982 Jan 29.
Artículo en Inglés | MEDLINE | ID: mdl-17771281

RESUMEN

Results from the cosmic-ray system on Voyager 2 in Saturn's magnetosphere are presented. During the inbound pass through the outer magnetosphere, the >/= 0.43-million-electron-volt proton flux was more intense, and both the proton and electron fluxes were more variable, than previously observed. These changes are attributed to the influence on the magnetosphere of variations in the solar wind conditions. Outbound, beyond 18 Saturn radii, impulsive bursts of 0.14- to > 1.0- million-electron-volt electrons were observed. In the inner magnetosphere, the charged particle absorption signatures of Mimas, Enceladus, and Tethys are used to constrain the possible tilt and offset of Saturn's internal magnetic dipole. At approximately 3 Saturn radii, a transient decrease was observed in the electron flux which was not due to Mimas. Characteristics of this decrease suggest the existence of additional material, perhaps another satellite, in the orbit of Mimas.

14.
Science ; 256(5055): 325-33, 1992 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-17743108

RESUMEN

The goal of the Laser Interferometer Gravitational-Wave Observatory (LIGO) Project is to detect and study astrophysical gravitational waves and use data from them for research in physics and astronomy. LIGO will support studies concerning the nature and nonlinear dynamics of gravity, the structures of black holes, and the equation of state of nuclear matter. It will also measure the masses, birth rates, collisions, and distributions of black holes and neutron stars in the universe and probe the cores of supernovae and the very early universe. The technology for LIGO has been developed during the past 20 years. Construction will begin in 1992, and under the present schedule, LIGO's gravitational-wave searches will begin in 1998.

15.
Epidemiol Infect ; 137(11): 1651-4, 2009 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-19426570

RESUMEN

Tri-County Health Department investigated an outbreak of cryptosporidiosis linked to a community swimming pool. A cohort study was conducted in 37 persons who were invited to the pool party; 12 (57%) of 21 attendees had primary cryptosporidiosis infection. Risk factors for illness included swimming, getting water in mouth, and swallowing water. The pool met chlorination guidelines and used UV light irradiation, a supplemental disinfection technology that inactivates Cryptosporidium. A follow-up survey of the cohort was completed 7-8 weeks after the pool party; four (25%) of 16 non-attendees had secondary cryptosporidiosis infection. The median duration of illness, including patients with recurring symptoms, was 26 days. Clinical response rate to nitazoxanide, a therapeutic agent, was 67%. This study is unique because it describes a cryptosporidiosis outbreak from a well-maintained community swimming pool using supplemental disinfection. It also reports information on disease burden and treatment response.


Asunto(s)
Criptosporidiosis/epidemiología , Brotes de Enfermedades , Piscinas , Adolescente , Adulto , Niño , Preescolar , Colorado/epidemiología , Estudios de Seguimiento , Humanos , Incidencia , Adulto Joven
16.
J Chem Phys ; 131(22): 224518, 2009 Dec 14.
Artículo en Inglés | MEDLINE | ID: mdl-20001068

RESUMEN

The electronic energy relaxation of 1-nitronaphthalene was studied in nonpolar, aprotic, and protic solvents in the time window from femtoseconds to microseconds. Excitation at 340 or 360 nm populates the Franck-Condon S(1)(pipi( *)) state, which is proposed to bifurcate into two essentially barrierless nonradiative decay channels with sub-200 fs lifetimes. The first main decay channel connects the S(1) state with a receiver T(n) state that has considerable npi( *) character. The receiver T(n) state undergoes internal conversion to populate the vibrationally excited T(1)(pipi( *)) state in 2-4 ps. It is shown that vibrational cooling dynamics in the T(1) state depends on the solvent used, with average lifetimes in the range from 6 to 12 ps. Furthermore, solvation dynamics competes effectively with vibrational cooling in the triplet manifold in primary alcohols. The relaxed T(1) state undergoes intersystem crossing back to the ground state within a few microseconds in N(2)-saturated solutions in all the solvents studied. The second minor channel involves conformational relaxation of the bright S(1) state (primarily rotation of the NO(2)-group) to populate a dissociative singlet state with significant charge-transfer character and negligible oscillator strength. This dissociative channel is proposed to be responsible for the observed photochemistry in 1-nitronaphthalene. Ground- and excited-state calculations at the density functional level of theory that include bulk and explicit solvent effects lend support to the proposed mechanism where the fluorescent S(1) state decays rapidly and irreversibly to dark excited states. A four-state kinetic model is proposed that satisfactorily explains the origin of the nonradiative electronic relaxation pathways in 1-nitronaphthalene.

17.
Arch Intern Med ; 142(3): 545-7, 1982 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-7065789

RESUMEN

Two male maintenance workers contracted legionellosis while cleaning the interior of a cooling tower contaminated with Legionella pneumophila. In one man severe, life-threatening Legionnaires' disease developed, whereas the other experienced a comparatively mild, self-limiting illness that was consistent with previous descriptions of cases of Pontiac fever. This report represents the first documentation of the development of both of these syndromes following exposure to a common source of the organism. The implications of this observation for the pathogenetic mechanisms that underly the different clinical manifestations of legionellosis are discussed.


Asunto(s)
Enfermedad de los Legionarios/diagnóstico , Enfermedades Profesionales/transmisión , Antibacterianos/uso terapéutico , Humanos , Legionella/aislamiento & purificación , Enfermedad de los Legionarios/terapia , Enfermedad de los Legionarios/transmisión , Masculino , Persona de Mediana Edad , Oxígeno/uso terapéutico , Respiración Artificial
18.
Ophthalmologe ; 112(1): 61-3, 2015 Jan.
Artículo en Alemán | MEDLINE | ID: mdl-24942220

RESUMEN

Ophthalmomyiasis refers to infestation of the eye by fly larvae. Although rare, cases have been reported from all over the world. Patients with ophthalmomyiasis suffer from itching, foreign body sensation and epiphora. Ophthalmomyiasis is mostly caused by larvae of Oestrus ovis, the common sheep botfly. Larvae of Oestrus ovis are photophobic and hide in the upper and lower fornix. First line treatment consists of mechanical removal of the larvae.


Asunto(s)
Infecciones Parasitarias del Ojo/patología , Infecciones Parasitarias del Ojo/terapia , Miasis/patología , Miasis/terapia , Adulto , Antiprotozoarios/uso terapéutico , Terapia Combinada , Diagnóstico Diferencial , Infecciones Parasitarias del Ojo/parasitología , Gentamicinas/uso terapéutico , Humanos , Masculino , Miasis/parasitología , Resultado del Tratamiento
19.
Ophthalmologe ; 112(12): 1002-5, 2015 Dec.
Artículo en Alemán | MEDLINE | ID: mdl-25755026

RESUMEN

BACKGROUND: Pseudotumor cerebri is an idiopathic increase in intracranial pressure, which commonly affects obese women of fertile age. The diagnostic criteria according to the guidelines of the German Society for Neurology are increased cerebrospinal fluid (CSF) pressure, symptoms of increased CSF pressure, normal results of CSF examination, no relevant medication and a lack of structural and vascular lesions in magnetic resonance imaging (MRI). CASE REPORT: This article presents the case of a 39-year-old male patient who presented at hospital with visual obscuration and recently occurred double vision. Except for a recently diagnosed thrombosis of the left jugular vein of unknown origin, there was nothing else of note in the medical history. Biomicroscopic examination showed papilledema with hemorrhages and cotton wool spots. The CSF opening pressure was initially > 50 cmH2O. During therapy by lumbar puncture (three times), oral carbonic anhydrase inhibitors and loop diuretics, the abducens nerve palsy and papilledema receded. Anticoagulation therapy (initially with coumarin derivatives, then with low molecular weight heparins) was unsuccessful in eliminating the thrombosis of the jugular vein. Surgical intervention was not recommended by the vascular surgeons. CONCLUSION: This case report demonstrates the unusual combination of (idiopathic) intracranial hypertension and thrombosis of the jugular vein, which occurred spontaneously and without any detectable coagulation disorders.


Asunto(s)
Venas Yugulares/patología , Enfermedades del Nervio Óptico/diagnóstico , Enfermedades del Nervio Óptico/etiología , Seudotumor Cerebral/complicaciones , Seudotumor Cerebral/diagnóstico , Trombosis de la Vena/tratamiento farmacológico , Acetazolamida/administración & dosificación , Adulto , Anticoagulantes/administración & dosificación , Inhibidores de Anhidrasa Carbónica/administración & dosificación , Cumarinas/administración & dosificación , Diagnóstico Diferencial , Diplopía/diagnóstico , Diplopía/etiología , Diplopía/prevención & control , Humanos , Venas Yugulares/efectos de los fármacos , Masculino , Enfermedades del Nervio Óptico/tratamiento farmacológico , Seudotumor Cerebral/tratamiento farmacológico , Resultado del Tratamiento , Trombosis de la Vena/complicaciones , Trombosis de la Vena/diagnóstico
20.
Chemosphere ; 137: 157-65, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26183822

RESUMEN

In the course of the development of a new and reliable analytical method for the PCT, a group of environmental contaminants, six coplanar terphenyl congeners were synthesized and characterized by means of spectroscopic methods. These congeners are 3,3″,4,4″,5-pentachloro-p-terphenyl, 3,3″,4,5,5″-pentachloro-p-terphenyl, 3,3″,4,5″-tetrachloro-m-terphenyl, 3,3″,4,4″,5-pentachloro-m-terphenyl, 3,3″,5,5',5″-pentachloro-m-terphenyl, and 3,3″,4,4″,5,5″-hexachloro-m-terphenyl. A combination of silica gel column chromatography and preparative NP-HPLC was successfully applied for the first time for the isolation of especially the asymmetrically chlorinated target compounds from product mixtures of the syntheses. For the 29 coplanar, tetra- to heptachlorinated meta- and para-indicator congeners which are envisaged to be used within the analytical method, a simplified systematic nomenclature is suggested. Furthermore, calculation results for all torsion angles of the preferred conformations of the substances are given. The practical relevance of the calculated conformation optima is exemplarily demonstrated by the chromatographic behavior of the PCT compounds.


Asunto(s)
Contaminantes Ambientales/análisis , Contaminantes Ambientales/síntesis química , Compuestos de Policloroterfenilo/análisis , Compuestos de Policloroterfenilo/síntesis química , Contaminantes Ambientales/química , Cromatografía de Gases y Espectrometría de Masas , Espectroscopía de Resonancia Magnética , Estructura Molecular , Compuestos de Policloroterfenilo/química , Estándares de Referencia , Relación Estructura-Actividad
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