Rosendahlramos6608

65-year-old patient with a history of ischemic stroke with residual ophthalmoparesis, positive in fecal occult blood screening, pending colonoscopy, who attended the emergency room due to 3 days with pain, abdominal distension and diarrhea. In the emergency room, he presented with diffuse abdominal pain, hemodynamic instability with acute renal failure and metabolic acidosis, with severe elevation of acute phase reactants. Abdominal fluid resuscitation and CT (computed tomography) were performed, which reported dilatation of the loops of the small intestine to the distal ileum with thickening of the wall of the right colon and gas, dissecting intrahepatic portal branches and splanchnic veins. An exploratory laparotomy was indicated, showing findings of non-transmural right colitis without ischemia or perforation, significant dilation of the small intestine and intra-abdominal serous fluid, without the need for intestinal resection. Salmonella enterica, sensitive to Ciprofloxacin, was isolated in stool culture. He remained in the ICU for 23 days with a slow but favorable evolution with targeted antibiotic therapy. Acute renal failure was corrected, vasoactive drugs were suspended and non-invasive mechanical ventilation and oxygen therapy were needed He presented postoperative ileus and periumbilical laparotomy skin dehiscence with good evolution after initiating negative pressure therapy. On postoperative day 32, she was transferred to the convalescent center for rehabilitation due to myopathy of the critical patient, being discharged after 22 days of stay.The origin of the exceptional stability of molecular glasses grown by physical vapor deposition (PVD) is not well understood. Differences in glass density have been correlated with thermodynamic stability for thin films of N,N'-Bis(3-methylphenyl)-N,N'-diphenylbenzidine (TPD) grown by PVD at specific substrate temperatures below the glass transition temperature. However, the relationship between the internal conformation of glass molecules and the thermodynamic properties of molecular glasses is not well studied. We use carbon 1s near edge x-ray absorption fine structure (NEXAFS) spectroscopy to examine different TPD sample preparations in which differences in the thermodynamic stability of the glass are known. Density functional theory simulations of the NEXAFS spectra of TPD allow us to attribute spectroscopic differences to changes in the internal conformation of the TPD molecule and relate this conformation to the stability of the TPD glass. This provides a direct experimental measurement of the internal conformation of molecules forming an organic glass.Kramers' procedure for calculating the rate of activated processes involves partitioning space into reactant, barrier, and product regions by introducing two dividing surfaces. Then, a nonequilibrium steady state is established by injecting particles on one surface and removing them when they reach the other. The rate is obtained as the ratio of the steady-state flux between the surfaces and the population of the initial well. An alternative procedure that seems less artificial is to estimate the first non-zero eigenvalue of the operator that describes the dynamics and then equate its magnitude to the sum of the forward and backward rate constants. Here, we establish the relationship between these approaches for diffusive dynamics, starting with the variational principle for the eigenvalue of interest and then using a trial function involving two adjustable surfaces. We show how Kramers' flux-over-population expression for the rate constant can be obtained from our variationally determined eigenvalue in the special case where the reactant and product regions are separated by a high barrier. This work exploits the modern theory of activated rate processes where the committor (the probability of reaching one dividing surface before the other) plays a central role. Surprisingly, our upper bound for the eigenvalue can be expressed solely in terms of mean first-passage times and the mean transition-path time between the two dividing surfaces.Absorption, fluorescence, and phosphorescence spectra of single crystals of [1]benzothieno[3,2-b][1]benzothiophene (BTBT) and BTBT dispersed in frozen n-nonane, n-hexadecane, and dichloromethane matrices were studied at 5 K. Observation of a new absorption band and related changes in the fluorescence to phosphorescence intensity ratio, when the concentration of BTBT in the matrix increased above 10-4M, indicated the presence of BTBT aggregates. Quantum-chemistry calculations performed for the simplest aggregate, isolated dimer, showed that its structure is similar to the "herringbone" element in the BTBT crystal unit cell and the lowest electronic excited singlet state of the dimer has the intermolecular charge-transfer character. A qualitatively different nature of this state in dimers and in crystals, when compared with the situation in BTBT monomer [locally excited (LE) state], is associated with a decrease in the intersystem crossing yield. The structured vibronic structure of phosphorescence spectra in the studied systems indicated LE character of the triplet states.The role of water vapor (H2O) and its hydrogen-bonded complexes in the gas-phase reactivity of organic compounds with hydroxyl (OH) radicals has been the subject of many recent studies. Contradictory effects have been reported at temperatures between 200 and 400 K. For the OH + acetaldehyde reaction, a slight catalytic effect of H2O was previously reported at temperatures between 60 and 118 K. In this work, we used Laval nozzle expansions to reinvestigate the impact of H2O on the OH-reactivity with acetaldehyde between 21.7 and 135.0 K. learn more The results of this comprehensive study demonstrate that water, instead, slows down the reaction by factors of ∼3 (21.7 K) and ∼2 (36.2-89.5 K), and almost no effect of added H2O was observed at 135.0 K.A vibronic exciton model is developed to account for the spectral signatures of HJ-aggregates of oligomers and polymers containing donor-acceptor-donor (DAD) repeat units. In (DAD)N π-stacks, J-aggregate-promoting intrachain interactions compete with H-aggregate-promoting interchain interactions. The latter includes Coulombic coupling, which arises from "side-by-side" fragment transition dipole moments as well as intermolecular charge transfer (ICT), which is enhanced in geometries with substantial overlap between donors on one chain and acceptors on a neighboring chain. J-behavior is dominant in single (DAD)N chains with enhanced intrachain order as evidenced by an increased red-shift in the low-energy absorption band along with a heightened A1/A2 peak ratio, where A1 and A2 are the oscillator strengths of the first two vibronic peaks in the progression sourced by the symmetric quinoidal-aromatic vibration. By contrast, the positive H-promoting interchain Coulomb interactions operative in aggregates cause the vibronic ratio to attenuate, similar to what has been established in H-aggregates of homopolymers such as P3HT.