ABSTRACT
Time of flight mass spectrometry, electron-ion coincidence, and ion yield spectroscopy were employed to investigate for the first time the thiazole (C3 H3 NS) molecule in the gas phase excited by synchrotron radiation in the soft X-ray domain. Total ion yield (TIY) and photoelectron-photoion coincidence (PEPICO) spectra were recorded as a function of the photon energy in the vicinity of the carbon K edge (C1s). The C1s resonant transitions as well as the core ionization thresholds have been determined from the profile of TIY spectrum, and the features were discussed. The corresponding partial ion yields were determined from the PEPICO spectra for the cation species produced upon the molecular photodissociation. Additional ab initio calculations have also been performed from where relevant structural and electronic configuration parameters were obtained for this molecule.
ABSTRACT
Photoelectron photoion coincidence measurements have been performed for the thiazole (C3H3NS) molecule in gas phase, using time-of-flight mass spectrometry in the electron-ion coincidence mode and vacuum ultraviolet synchrotron radiation. photoelectron photoion coincidence spectra have been recorded as a function of the photon energy covering the valence range from 10 to 21 eV. The resulting photoionization products as well as the dissociation pathways leading to the ionic species were proposed and discussed. We have also performed density functional theory and ab initio calculations for the neutral molecule, its cation and the ion fragments produced in order to determine their electronic and structural parameters.
Subject(s)
Photoelectron Spectroscopy/methods , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/methods , Thiazoles/chemistry , Models, Molecular , PhotolysisABSTRACT
We present a series of photoabsorption and partial-ion-yield experiments on thionyl chloride, SOCl(2), at both the sulfur and chlorine K edges. The photoabsorption results exhibit better resolution than previously published data, leading to alternate spectral assignments for some of the features, particularly in the Rydberg-series region. Based on measured fragmentation patterns, we suggest the LUMO, of a(') character, is delocalized over the entire molecular skeleton. Unusual behavior of the S(2 +) fragment hints at a relatively localized bond rupture (the S-O bond below the S K edge and the S-Cl bonds below the Cl K edge) following excitation to some of the higher lying intermediate states.
ABSTRACT
The main adipogenic transcription factor PPARγ possesses high affinity to 2,4-TZD, a member of the Thiazolidinedione family of insulin-sensitizing compounds used as adipogenic agents. We evaluated 2,4-TZD's effect on bovine growth and PPAR tissue expression. Seventeen Limousin bulls (18 month-old; 350 kg body weight (BW)) were assigned into 2 treatments: control and 2,4-TZD (8 mg/70 kg BW) and were fed until bulls reached 500 kg BW. They were weighed and their blood was sampled. DNA, RNA, and protein were determined in liver; skeletal muscle; subcutaneous (SC), omental, perirenal adipose tissues (AT) to determine protein synthesis rate and cellular size. Expression of PPAR mRNA was measured in liver and muscle (PPARα, -δ, and -γ) and SC adipose tissue (γ) by real-time PCR. No significant differences were found (P > 0.1) in weight gain, days on feed, and carcass quality. Muscle synthesis was greater in controls (P < 0.05); cell size was larger with 2,4-TZD (P < 0.05). PPARα, -δ, and -γ expressions with 2,4-TZD in liver were lower (P < 0.01) than in muscle. No differences were found for PPARγ mRNA expression in SCAT. The results suggest the potential use of 2,4-TZD in beef cattle diets, because it improves AT differentiation, liver, and muscle fatty acid oxidation that, therefore, might improve energy efficiency.
ABSTRACT
We have investigated the thermochemistry and ion energetics of the oxybenzone (2-hydroxy-4-methoxy-benzophenone, C14H12O3, 1H) molecule. The following parameters have been determined for this species: gas-phase enthalpy for the of neutral molecule at 298.15K, (Delta(f)H0(m)(g) = -303.5 +/- 5.1 kJ x mol-1), the intrinsic (gas-phase) acidity (GA(1H) = 1402.1 +/- 8.4 kJ x mol-1), enthalpy of formation for the oxybenzone anion (Delta(f)H0(m)(1-,g) = -402.3 +/- 9.8 kJ x mol-1). We also have obtained the enthalpy of formation of, 4-hydroxy-4'-methoxybenzophenone (Delta(f)H0(m)(g) = -275.4 +/- 10 kJ x mol-1) and 3-methoxyphenol anion (Delta(f)H0(m)(C7H7O2-,g) = -317.7 +/- 8.7 kJ x mol-1). A reliable experimental estimation of enthalpy related to intramolecular hydrogen bonding in oxybenzone has also been obtained (30.1 +/- 6.3 kJ x mol-1) and compared with our theoretical calculations at the B3LYP/6-311++G** level of theory, by means of an isodesmic reaction scheme. In addition, heat capacities, temperature, and enthalpy of fusion have been determined for this molecule by differential scanning calorimetry.
ABSTRACT
Las enfermedades renales son frecuentes, perjudiciales y tratables. Las jornadas internacionales por el Día del Riñón en su segundo año de celebración llama a la acción no sólo a los nefrólogos y pacientes renales, sino a médicos de todas las especialidades, enfermeras, científicos, expertos, administradores, gobiernos, para que estén conscientes de los desafíos que representa la Enfermedad Renal Crónica (ERC). En este artículo, se analiza el desarrollo de la Nefrología en Cuba y la relación de la ERC a otras enfermedades crónicas no transmisibles caracterizadas por el daño endotelial. Su prevención, diagnóstico y tratamiento es la vía común para contribuir a disminuir la morbimortalidad cardiovascular internacionalmente(AU)
Subject(s)
Kidney DiseasesABSTRACT
The cationic and anionic fragmentation of dichloromethane (CH2Cl2) molecule have been investigated in the energy range of the Cl K shell by using synchrotron radiation, ion yield spectroscopy, and electron-ion coincidence spectroscopy. Total and partial ion-yield and mass spectra have been recorded as a function of the photon energy. We were able to identify several singly and multiply charged cationic fragments and the following anionic species: H-; C-; Cl-. The present results provide the first experimental report of negative ion formation from a molecule excited at the Cl 1s edge. In addition, our electron-ion coincidence data provide strong evidence of the preservation of molecular alignment for the photodissociation of CH2Cl2 after deep core-electron resonant excitation.
ABSTRACT
To understand the differences in conformational behavior and reactivity of oxygen- and sulfur-containing 1,3,5-heterocyclohexanes, the enthalpies of formation and sublimation of 1,3,5-trithiane, 1, have been measured. The numerical value of the enthalpy of formation for this compound in the solid state is -8.6 +/- 2.6 kJ mol(-1), while the corresponding value in the gaseous state is 84.6 +/- 2.6 kJ mol(-1). The value for the enthalpy of sublimation is 93.2 +/- 0.2 kJ mol(-1). Standard ab initio molecular orbital calculations at the G2(MP2), G2, and G3 levels were performed, and the calculated enthalpies of formation are compared with the experimental data. These experimental and theoretical studies support the relevance of through-space lone pair-lone pair electronic repulsion in the sulfur heterocycle.
Subject(s)
Professional Practice , Schools, Veterinary , Veterinary Medicine , Canada , Curriculum , Latin America , Models, Educational , Research , United StatesABSTRACT
We report on linkage analysis and haplotype characterization in 12 Cuban families with autosomal dominant polycystic kidney disease (ADPK) using PKD1-linked markers. They included both standard restriction fragment length polymorphisms (26.6., BLu24, and pGGG1) as well as microsatellite polymorphisms (CW2, 16AC2.5, and SM6). All of the examined families were fully informative for genetic diagnosis and no evidence of unlinked families was found. Analysis of two recombination events places PKD1 distal to the marker BLu24 and reduces the size of the region likely to contain the disease gene by approximately 300 kb. The allele frequencies of each marker were similar in the ADPKD and normal populations.
Subject(s)
DNA, Satellite/genetics , Genetic Linkage , Polycystic Kidney, Autosomal Dominant/genetics , Polymorphism, Restriction Fragment Length , Alleles , Cuba , Humans , Lod Score , Pedigree , Polymorphism, GeneticABSTRACT
It is possible that the mucosal damage in congestive gastropathy of portal hypertensive patients may have an ischemic basis, since rewarming time in other sites correlates with local blood flow, a method was designed to assess the capacity of the gastric mucosa to rewarm the stomach after a cold challenge, as an index of ischemia. Eleven control subjects and 15 patients with portal hypertension (10 treated with sclerotherapy) were studied with an integrated circuit temperature transducer connected to a digital display. A balloon containing the temperature transducer inside was reversibly fixed 10 cm. proximally to the distal end of a panendoscope. Once upper endoscopy was completed, the balloon placed in the antrum was infused with cooled water (2 degrees C) through a polyethylene tube. The time elapsed for the water to be rewarmed from 20 degrees C to 25 degrees C to 30 degrees C and 20 degrees C to 30 degrees C was measured. Reproducibility of repeated measurements, gave a coefficient of variation of 6%. Total rewarming time was (-mean +/- SD) 178 +/- 51.3 seconds, significantly higher in Portal hypertensive patients as compared to 114 +/- 34.7 seconds in Controls (P < 0.001). (95% Confidence Interval: -X = 63.4 seconds Cl 45.02 to 81.78). 60% of Sensitivity and 100% of Specificity The slower rewarming time in patients with portal hypertension may be the result of mucosal ischaemia, but oedema and cellular infiltration could also affect the heat flow.
Subject(s)
Gastric Mucosa/blood supply , Hypertension, Portal/complications , Ischemia/complications , Rewarming , Adolescent , Adult , Aged , Case-Control Studies , Female , Humans , Male , Middle Aged , Sensitivity and Specificity , Time FactorsABSTRACT
It is possible that the mucosal damage in congestive gastropathy of portal hypertensive patients may have an ischemic basis, since rewarming time in other sites correlates with local blood flow, a method was designed to assess the capacity of the gastric mucosa to rewarm the stomach after a cold challenge, as an index of ischemia. Eleven control subjects and 15 patients with portal hypertension (10 treated with sclerotherapy) were studied with an integrated circuit temperature transducer connected to a digital display. A balloon containing the temperature transducer inside was reversibly fixed 10 cm. proximally to the distal end of a panendoscope. Once upper endoscopy was completed, the balloon placed in the antrum was infused with cooled water (2 degrees C) through a polyethylene tube. The time elapsed for the water to be rewarmed from 20 degrees C to 25 degrees C to 30 degrees C and 20 degrees C to 30 degrees C was measured. Reproducibility of repeated measurements, gave a coefficient of variation of 6
. Total rewarming time was (-mean +/- SD) 178 +/- 51.3 seconds, significantly higher in Portal hypertensive patients as compared to 114 +/- 34.7 seconds in Controls (P < 0.001). (95
Confidence Interval: -X = 63.4 seconds Cl 45.02 to 81.78). 60
of Sensitivity and 100
of Specificity The slower rewarming time in patients with portal hypertension may be the result of mucosal ischaemia, but oedema and cellular infiltration could also affect the heat flow.
ABSTRACT
By means of fiberendoscopic injection sclerotherapy, it was possible to achieve eradication of esophageal varices in 18 patients. At the onset of treatment 9 patients had small varices (grade II) and other 9 had big varices (grade III). It was found in the big varices group there was needed more courses (p less than 0.01) and a greater amount of sclerosing agent (p less than 0.001) than in the group with small varices. Since those patients with big varices required more courses and more volume of sclerosing agent, and in fact they have more risk to rebleed during the pre-eradication period. It is proposed as a solution during this period, the use of a B receptor blocking agent (Propranolol) simultaneously with sclerotherapy.
Subject(s)
Esophageal and Gastric Varices/therapy , Sclerosing Solutions/administration & dosage , Adult , Aged , Esophageal and Gastric Varices/pathology , Esophagoscopy , Female , Gastrointestinal Hemorrhage/therapy , Humans , Male , Middle AgedABSTRACT
By means of fiberendoscopic injection sclerotherapy, it was possible to achieve eradication of esophageal varices in 18 patients. At the onset of treatment 9 patients had small varices (grade II) and other 9 had big varices (grade III). It was found in the big varices group there was needed more courses (p less than 0.01) and a greater amount of sclerosing agent (p less than 0.001) than in the group with small varices. Since those patients with big varices required more courses and more volume of sclerosing agent, and in fact they have more risk to rebleed during the pre-eradication period. It is proposed as a solution during this period, the use of a B receptor blocking agent (Propranolol) simultaneously with sclerotherapy.
ABSTRACT
Mediante tratamiento esclerosante fibroendoscopico, se logro en 18 pacientes la erradicacion de sus varices esofagicas.Nueve pacientes presentaban al inicio de la terapeutica varices pequenas (grado III) y otros nueve varices grandes (grado III). Se comprueba que el grupo con varices grandes, requieren en forma estadisticamente significativa (p <0,01) mayor cantidad de sesiones y (p < 0.001) mayor volumen de esclerosante que el grupo con varices pequenas. Al requerir estos pacientes con varios esofagicas grandes mas sesiones y volumen de agente esclerosante, y ser al mismo tiempo los que tienen mayor riesgo de presentar recidivas hemorragicas durante el periodo preerradicatorio, se propone como solucion durante este lapso el empleo de los bloqueantes de los receptores B adrenergicos (propanolol) en forma simultanea a la escleroterapia
Subject(s)
Adult , Middle Aged , Aged , Humans , Male , Female , Sclerosing Solutions , Esophageal and Gastric Varices , EsophagoscopyABSTRACT
Mediante tratamiento esclerosante fibroendoscopico, se logro en 18 pacientes la erradicacion de sus varices esofagicas.Nueve pacientes presentaban al inicio de la terapeutica varices pequenas (grado III) y otros nueve varices grandes (grado III). Se comprueba que el grupo con varices grandes, requieren en forma estadisticamente significativa (p <0,01) mayor cantidad de sesiones y (p < 0.001) mayor volumen de esclerosante que el grupo con varices pequenas. Al requerir estos pacientes con varios esofagicas grandes mas sesiones y volumen de agente esclerosante, y ser al mismo tiempo los que tienen mayor riesgo de presentar recidivas hemorragicas durante el periodo preerradicatorio, se propone como solucion durante este lapso el empleo de los bloqueantes de los receptores B adrenergicos (propanolol) en forma simultanea a la escleroterapia
