Treatment-refractory heart failure as a manifestation of aortic arch atresia.

BACKGROUND: Distal segment atresia (isthmus) is an extremely rare anatomical variant of obstructive aortic arch anomalies. CASE REPORT: We present the case of a newborn who, at 48 hours of life, presented a clinical picture of heart failure. The initial echocardiogram showed a congenital interrupted aortic arch type A, patent ductus arteriosus, and ventricular septal defect. Prostaglandins were initially indicated. Subsequently, a second echocardiogram showed the absence of ductus arteriosus; the CT angiography study confirmed this finding and revealed blood flow to the descending aorta through small intercostal blood vessels. The possibility of atresia of the distal segment (isthmus) of the aortic arch was considered and confirmed at the time of surgery. CONCLUSIONS: Aortic atresia should be considered a diagnostic possibility in the presence of type A interrupted aortic arch since the hemodynamic behavior between them is similar. Surgical medical treatment should be individualized since this condition is frequently an emergency in the neonatal period. However, this is not always the case, as other cases have been reported in schoolchildren and adults.

INTRODUCCIÓN: La atresia de segmento distal (istmo) de arco aórtico es una variante anatómica extremadamente rara de las anomalías obstructivas del arco aórtico. CASO CLÍNICO: Se presenta el caso de un recién nacido que a las 48 horas de vida presentó un cuadro clínico de insuficiencia cardiaca. El estudio de ecocardiograma inicial mostró una anomalía congénita de interrupción de arco aórtico tipo A, conducto arterioso y comunicación interventricular. De inicio se indicaron prostaglandinas. Posteriormente, el segundo ecocardiograma mostró la ausencia del conducto arterioso; el estudio de angiotomografía confirmó este hallazgo y también reveló flujo sanguíneo hacia aorta descendente a través de pequeños vasos sanguíneos intercostales. Se consideró la posibilidad de atresia del segmento distal (istmo) de arco aórtico y se confirmó al momento del acto quirúrgico. CONCLUSIONES: La atresia aórtica debe ser considerada como posibilidad diagnóstica en presencia de interrupción de arco aórtico tipo A, ya que el comportamiento hemodinámico entre ellos es similar. El tratamiento médico quirúrgico debe individualizarse, ya que es frecuente que sea una urgencia en el periodo neonatal. Sin embargo, no sucede así siempre, ya que se han reportado casos en escolares y adultos.

Treatment-refractory heart failure as a manifestation of aortic arch atresia / Falla cardiaca refractaria a tratamiento como manifestación de atresia de arco aórtico

Abstract Background: Distal segment atresia (isthmus) is an extremely rare anatomical variant of obstructive aortic arch anomalies. Case report: We present the case of a newborn who, at 48 hours of life, presented a clinical picture of heart failure. The initial echocardiogram showed a congenital interrupted aortic arch type A, patent ductus arteriosus, and ventricular septal defect. Prostaglandins were initially indicated. Subsequently, a second echocardiogram showed the absence of ductus arteriosus; the CT angiography study confirmed this finding and revealed blood flow to the descending aorta through small intercostal blood vessels. The possibility of atresia of the distal segment (isthmus) of the aortic arch was considered and confirmed at the time of surgery. Conclusions: Aortic atresia should be considered a diagnostic possibility in the presence of type A interrupted aortic arch since the hemodynamic behavior between them is similar. Surgical medical treatment should be individualized since this condition is frequently an emergency in the neonatal period. However, this is not always the case, as other cases have been reported in schoolchildren and adults.

Resumen Introducción: La atresia de segmento distal (istmo) de arco aórtico es una variante anatómica extremadamente rara de las anomalías obstructivas del arco aórtico. Caso clínico: Se presenta el caso de un recién nacido que a las 48 horas de vida presentó un cuadro clínico de insuficiencia cardiaca. El estudio de ecocardiograma inicial mostró una anomalía congénita de interrupción de arco aórtico tipo A, conducto arterioso y comunicación interventricular. De inicio se indicaron prostaglandinas. Posteriormente, el segundo ecocardiograma mostró la ausencia del conducto arterioso; el estudio de angiotomografía confirmó este hallazgo y también reveló flujo sanguíneo hacia aorta descendente a través de pequeños vasos sanguíneos intercostales. Se consideró la posibilidad de atresia del segmento distal (istmo) de arco aórtico y se confirmó al momento del acto quirúrgico. Conclusiones: La atresia aórtica debe ser considerada como posibilidad diagnóstica en presencia de interrupción de arco aórtico tipo A, ya que el comportamiento hemodinámico entre ellos es similar. El tratamiento médico quirúrgico debe individualizarse, ya que es frecuente que sea una urgencia en el periodo neonatal. Sin embargo, no sucede así siempre, ya que se han reportado casos en escolares y adultos.

Influence of Microalgae Diets on the Biological and Growth Parameters of Oithona nana (Copepoda: Cyclopoida).

Several species of the planktonic free-living genus Oithona have been successfully used in the larviculture of marine fish and shrimp. However, few studies have been published that allow us to estimate the potential of Oithona nana culture under controlled conditions. This work evaluated the effect of the microalgae Isochrysis galbana and Chaetoceros calcitrans as single (200,000 cells/mL) and mixed diets (100,000 + 100,000 cells/mL) on population and individual growth, ingestion rate, number of spawnings, fertility, development time by stage, and sex ratio of O. nana. We cultured this copepod at 28 ± 0.5 °C, 35 PSU salinity, 125 lux, and 12:12 photoperiod. Results showed that diet had no effect on the final population level (6273-7966 ind/L) or on individual growth, nor on sex ratio, with less males than females. With C. calcitrans, O. nana had a higher filtration rate (57 ng C/ind/day). On the other hand, a mixed diet induced a higher number of spawns (0.4 events/day) and nauplii per spawn (23 ind). Similarly, a single or mixed diet, containing I. galbana, accelerated the development rate by 6.33-7.00 days. We concluded that O. nana can be cultured with both microalgae, indicating its potential use in an intensive system for production. However, more research is required to improve the productivity of O. nana rearing.

A novel approach to assessing environmental disturbance based on habitat selection by zebra fish as a model organism.

Aquatic ecotoxicity assays used to assess ecological risk assume that organisms living in a contaminated habitat are forcedly exposed to the contamination. This assumption neglects the ability of organisms to detect and avoid contamination by moving towards less disturbed habitats, as long as connectivity exists. In fluvial systems, many environmental parameters vary spatially and thus condition organisms' habitat selection. We assessed the preference of zebra fish (Danio rerio) when exposed to water samples from two western Ecuadorian rivers with apparently distinct disturbance levels: Pescadillo River (highly disturbed) and Oro River (moderately disturbed). Using a non-forced exposure system in which water samples from each river were arranged according to their spatial sequence in the field and connected to allow individuals to move freely among samples, we assayed habitat selection by D. rerio to assess environmental disturbance in the two rivers. Fish exposed to Pescadillo River samples preferred downstream samples near the confluence zone with the Oro River. Fish exposed to Oro River samples preferred upstream waters. When exposed to samples from both rivers simultaneously, fish exhibited the same pattern of habitat selection by preferring the Oro River samples. Given that the rivers are connected, preference for the Oro River enabled us to predict a depression in fish populations in the Pescadillo River. Although these findings indicate higher disturbance levels in the Pescadillo River, none of the physical-chemical variables measured was significantly correlated with the preference pattern towards the Oro River. Non-linear spatial patterns of habitat preference suggest that other environmental parameters like urban or agricultural contaminants play an important role in the model organism's habitat selection in these rivers. The non-forced exposure system represents a habitat selection-based approach that can serve as a valuable tool to unravel the factors that dictate organisms' spatial distribution in connected ecosystems.

Output-Feedback Control for Discrete-Time Spreading Models in Complex Networks.

The problem of stabilizing the spreading process to a prescribed probability distribution over a complex network is considered, where the dynamics of the nodes in the network is given by discrete-time Markov-chain processes. Conditions for the positioning and identification of actuators and sensors are provided, and sufficient conditions for the exponential stability of the desired distribution are derived. Simulations results for a network of N = 10 6 corroborate our theoretical findings.

Alcohol-based solutions for bovine testicular tissue fixation.

Tissue fixation, a central element in histotechnology, is currently performed with chemical compounds potentially harmful for human health and the environment. Therefore, alternative fixatives are being developed, including alcohol-based solutions. We evaluated several ethanol-based mixtures with additives to study fixative penetration rate, tissue volume changes, and morphologic effects in the bovine testis. Fixatives used were Bouin solution, 4% formaldehyde (F4), 70% ethanol (E70), E70 with 1.5% glycerol (E70G), E70 with 5% acetic acid (E70A), E70 with 1.5% glycerol and 5% acetic acid (E70AG), and E70 with 1.5% glycerol, 5% acetic acid, and 1% dimethyl sulfoxide (DMSO; E70AGD). Five-millimeter bovine testicular tissue cubes could be completely penetrated by ethanol-based fixatives and Bouin solution in 2-3 h, whereas F4 required 21 h. Bouin solution produced general tissue shrinkage, whereas the other fixatives (alcohol-based and F4) caused tissue volume expansion. Although Bouin solution is an excellent fixative for testicular tissue, ethanol-based fixatives showed good penetration rates, low tissue shrinkage, and preserved sufficient morphology to allow identification of the stages of the seminiferous epithelium cycle, therefore representing a valid alternative for histotechnology laboratories. Common additives such as acetic acid, glycerol, and DMSO offered marginal benefits for the process of fixation; E70AG showed the best preservation of morphology with excellent nuclear detail, close to that of Bouin solution.

Distinction of Ecuadorian varieties of fermented cocoa beans using Raman spectroscopy.

Cocoa (Theobroma cacao) is a crop of economic importance. In Ecuador, there are two predominant cocoa varieties: National and CCN-51. The National variety is the most demanded, since its cocoa beans are used to produce the finest chocolates. Raman measurements of fermented, dried and unpeeled cocoa beans were performed using a handheld spectrometer. Samples of the National and CCN-51 varieties were collected from different provinces and studied in this work. For each sample, 25 cocoa beans were considered and each bean was measured at 4 different spots. The most important Raman features of the spectra were assigned and discussed. The spectroscopic data were processed using chemometrics, resulting in a distinction of varieties with 91.8% of total accuracy. Differences in the average Raman spectra of cocoa beans from different sites but within the same variety can be attributed to environmental factors affecting the cocoa beans during the fermentation and drying processes.

Dimers of perhaloacetyl cyanides: CClF2C(O)OC(CN)2CClF2 and CF3C(O)OC(CN) 2CF3. preparation, properties, and spectroscopy.

The vapor of the new compound 1,1-dicyano-2-chloro-2,2-difluoroethyl chlorodifluoroacetate, CClF2C(O)OC(CN)2CClF2 and of the known 1,1-dicyano-2,2,2-trifluoroethyl trifluoroacetate, CF3C(O)OC(CN)2CF3, were investigated using vibrational spectroscopy tools. The existence of rotational isomerism was confirmed for CClF2C(O)OC(CN)2CClF2 when the matrix isolated compound was examined in combination with the computational results applying quantum chemical models. From the four conformers gauche-syn-gauche, gauche-syn-anti, syn-syn-anti, syn-syn-gauche (the used nomenclature is with respect to the ϕ(ClC-C(O)), ϕ((O)C-OC), and ϕ(OC-CCl) torsion angles, respectively) predicted for CClF2C(O)OC(CN)2CClF2 the first two forms can be evidenced using Ar-matrix IR spectroscopy, with the first one being the most abundant at room temperature. On the other side, the results obtained for CF3C(O)OC(CN)2CF3 reveals the existence of only one syn-syn-anti form. CClF2C(O)OC(CN)2CClF2 melts at -40 °C and its vapor pressure was fitted by the equation ln p = -4732.6 (1/T) + 10.75 (p [Atm], T [K]) in the range -20 to 20 °C. Its extrapolated boiling point is 167 °C. The first ionization potentials occur for CClF2C(O)OC(CN)2CClF2 and CF3C(O)OC(CN)2CF3 at 12.13 and 12.43 eV, respectively, and were attributed to the ejection of electrons formally located at the carbonylic oxygen lone-pair electrons (nO). The proposed interpretation of the photoelectron spectrum is consistent with related molecules reported previously, and also with the prediction of Outer Valence Green's Functions (OVGF).

Matrix photochemical study and conformational analysis of CH3C(O)NCS and CF3C(O)NCS.

The vapor of acetyl isocyanide, CH3C(O)NCS, and trifluoroacetyl isocyanide, CF3C(O)NCS, were isolated in solid Ar at 15 K. The existence of rotational isomerism was confirmed when the matrixes were irradiated with broad-band UV-vis light (200 ≤ λ ≤ 800 nm) and also by temperature-dependent Ar-matrix IR spectroscopy. The initial spectra showed the vapor of CH3C(O)NCS and CF3C(O)NCS consist of two conformers syn-syn and syn-anti (with the C═O bond syn with respect to the C-H or C-F bond and syn or anti with respect to the N═C double bond). When CH3C(O)NCS is irradiated, simultaneously with the randomization process, H2CCO and HSCN are produced. In the case of the photolysis of CF3C(O)NCS, the main products are CF3NCS and CO. The assignment of the IR bands to the different photoproducts was made on the basis of the usual criteria, taking account reported antecedents in the literature.

Chlorodifluoroacetyl isothiocyanate, ClF2CC(O)NCS: preparation and structural and spectroscopic studies.

Chlorodifluoroacetyl isothiocyanate, ClF2CC(O)NCS, was synthesized by the reaction of ClF2CC(O)Cl with an excess of AgNCS. The colorless product melts at -85 °C, and its vapor pressure follows the equation ln p = -4471.1 (1/T) + 11.35 (p [atm], T [K]) in the range -38 to 22 °C. The compound has been characterized by IR (gas phase, Ar matrix, and matrix photochemistry), by liquid Raman, by (19)F and (13)C NMR, gas UV-vis, and photoelectron spectroscopy (PES), by photoionization mass spectrometry (PIMS), and by gas electron diffraction (GED). The conformational properties of ClF2CC(O)NCS have been analyzed by joint application of vibrational spectroscopy, GED and quantum chemical calculations. The existence of two conformers has been detected in the gas and liquid phases, in which the C-Cl bond adopts a gauche orientation with respect to the C═O group; the C═O group is in syn- or anti-position with respect to the N═C double bond of the NCS group. The computed ΔG° difference between these two gauche-syn and gauche-anti forms is ΔG° = 0.63 kcal mol(-1) in the B3LYP/6-31G(d) approximation. The most significant gas-phase structural parameters for gauche-syn ClF2CC(O)NCS are re(NC═S) 1.559(2) Å, re(N═CS) 1.213(2) Å, re(N-C) 1.399(7) Å, re(C═O) 1.199(2) Å, and ∠e(CNC) 134.7(13)°. Photolysis of ClF2CC(O)NCS using an ArF excimer laser (193 nm) mainly yields ClF2CNCS, CO, and ClC(O)CF2NCS. The valence electronic properties of the title compound were studied using PES and PIMS. The experimental first vertical ionization energy of 10.43 eV corresponds to the ejection primarily of the sulfur lone-pair electrons of the in-plane nonbonding orbital on the NCS group.

Spectroscopic characterization and constitutional and rotational isomerism of ClC(O)SCN and ClC(O)NCS.

Chlorocarbonylthio- and isothiocyanate (ClC(O)SCN and ClC(O)NCS) have been isolated and characterized by IR (Ar matrix, gas), Raman (liquid), (13)C NMR and UV-visible spectroscopies. Vibrational and quantum chemical studies suggest the presence of the syn and anti conformers (SCN group with respect to the C═O bond) in the gas phase for both constitutional isomers. syn-ClC(O)SCN is preferred by ΔH° (anti/syn) = 1.3(0.3) kcal mol(-1). The solid-state structure of ClC(O)SCN has been determined by single crystal X-ray diffraction analysis at low temperature. The crystalline solid consists exclusively of molecules in the syn conformation. On the other hand, the anti form is more stable for the ClC(O)NCS isomer. The structure of ClC(O)NCS and its conformational composition were determined by gas electron diffraction. An unusual low syn → anti interconversion energy barrier of 0.98 (0.15) kcal mol(-1) was detected for ClC(O)NCS at cryogenic temperatures. The photochemistry of both constitutional isomers isolated in solid argon at 15 K was studied. Rearrangement of ClC(O)SCN to ClC(O)NCS was observed in the neat liquid and under UV-vis irradiation of ClC(O)SCN isolated in solid argon. Properties have been discussed in terms of the valence electronic structure, including the analysis of the He(I) photoelectron spectrum of ClC(O)SCN.

Chlorodifluoroacetyl isocyanate, ClF2CC(O)NCO: preparation and structural and spectroscopic studies.

Chlorodifluoroacetyl isocyanate, ClF2CC(O)NCO, was prepared by the reaction of ClF2CC(O)Cl with excess of AgNCO. The colorless compound melts at −83 °C and the vapor pressure follows the equation ln p = −3868.3 (1/T) + 10.89 (p [Atm], T [K]) in the range −38 to +22 °C, extrapolated bp ca. 82 °C. It has been characterized by IR (gas phase, Ar matrix), liquid Raman, 19F and 13C NMR, gas UV­vis spectrum, photoelectron spectroscopy (PES), photoionization mass spectrometry (PIMS), and gas electron diffraction (GED). The matrix photochemistry has been studied and the conformational properties of ClF2CC(O)NCO have been analyzed by joint application of vibrational spectroscopy, GED, and quantum chemical calculations. Two conformers were detected in gaseous and liquid phases, in which the C­Cl bond adopts a gauche orientation with respect to the C═O group, whereas this group can be in syn or anti orientation with respect to the N═C bond of the NCO group. An enthalpy difference ΔH(exp)° = 1.3 ± 0.2 kcal mol(­1) between the most stable syn­gauche and the less stable anti-gauche form was derived using the van't Hoff equation, which is in reasonable agreement with the computed difference of ΔH° = 0.8 kcal mol(­1) (B3LYP/6-311+G(3df) approximation). The most significant gas phase structural parameters for gauche­syn ClF2CC(O)NCO are r(e)(NC═O) = 1.157(1) Å, r(e)(N═CO) = 1.218(1) Å, r(e)(N­C) = 1.378(9) Å, r(e)(C═O) = 1.195(1) Å, angle(e)(CNC) = 128.6(19)°. Photolysis of ClF2CC(O)NCO using an ArF excimer laser (193 nm) mainly yield ClF2CNCO along with some ClF2CC(O)N nitrene. The valence electronic properties of the title compound were studied using the PES and PIMS. The experimental first vertical ionization energy of 11.54 eV corresponds to the ejection of a carbonylic oxygen lone pair electron.

Chlorodifluoroacetyl azide, ClF2CC(O)N3: preparation, properties, and decomposition.

Chlorodifluoroacetyl azide, ClF(2)CC(O)N(3), was prepared and characterized by IR (gas, Ar matrix), Raman (liquid), UV-vis (gas), and (19)F, (13)C NMR spectroscopy. The vibrational spectra were analyzed in terms of a single conformer, gauche-syn, where the Cl-C and the N(α)═N(ß) bonds are gauche and syn to the C═O bond, respectively. The photo and thermal decomposition reactions of the azide were studied with the aid of matrix isolation. In both cases, a new isocyanate species ClF(2)CNCO was produced and characterized by matrix IR spectroscopy. The conformational properties and the Curtius rearrangement pathways of this new carbonyl azide were theoretically explored, which suggest the preference of a concerted over stepwise decomposition for the global minimum gauche-syn conformer.

Chlorodifluoroacetyl cyanide, ClF2CC(O)CN: synthesis, structure, and spectroscopic characterization.

The novel molecule difluorochloroacetyl cyanide, ClF(2)CC(O)CN, has been characterized by IR (gas phase, Ar matrix), Raman (liquid), (19)F and (13)C NMR, and photoelectron (PES) spectroscopies; photoionization mass spectrometry (PIMS); and gas electron diffraction (GED). The conformational properties of ClF(2)CC(O)CN have been studied by joint application of vibrational spectroscopy, GED, and quantum chemical calculations. The existence of two conformers is detected in the gas and liquid phases, in which the C-Cl bond adopts gauche and syn orientations with respect to the C═O group. The computed enthalpy difference is in harmony with the experimental results of the gauche being more stable than the syn conformer by ΔH° = 1.3 kcal mol(-1) (MP2/cc-pVTZ). The valence electronic properties and the possible ionization and dissociation processes of the title compound are studied using the PES and PIMS. The experimental first vertical ionization energy of 12.0 eV corresponds to the ejection of an electron of the oxygen lone pairs. Taking into account the properties and broad applications of acyl cyanides, ClF(2)CC(O)CN is a promising new precursor in preparative chemistry.

2-Chloroethylisocyanate. Thermal decomposition and spectroscopic properties.

2-Chloroethylisocyanate has been studied in a thorough way. NMR, Raman, FTIR, and Ar-matrix vibrational spectra of the molecule are presented and discussed with the complement of ab initio and DFT methods. The spectroscopic results reveal the existence of anti and gauche conformers that are equally populated in the gas phase. Thermal decomposition between 393 and 648 K shows two different pathways depending on the temperature, which can be interpreted in terms of simple second- and first-order mechanisms, respectively. Quantum mechanical calculations reproduce the experimental results.

Vibrational spectra, crystal structures, constitutional and rotational isomerism of FC(O)SCN and FC(O)NCS.

Fluorocarbonyl thio- and isothiocyanate, FC(O)SCN and FC(O)NCS, were fully characterized by IR (gas, Ar and N(2) matrixes), Raman (liquid and solid), UV (gas), and (13)C NMR (liquid) spectroscopy, as well as single-crystal X-ray diffraction. Their vibrational and conformational properties were analyzed using matrix isolation techniques guided by quantum chemical calculation at the ab initio [MP2 and CCSD(T)], density functional theory B3LYP, and CBS-QB3 levels of theory. A complete assignment of the fundamental modes of FC(O)SCN was performed. In both the gas and liquid states, FC(O)SCN and FC(O)NCS were found to exist as two conformers (C(s) symmetry), in which the carbonyl double bond (C═O) adopts a synperiplanar (syn) and an antiperiplanar (anti) orientation with respect to either the SCN or NCS group. For FC(O)SCN, the conformational enthalpy difference, ΔH° = H°(anti) - H°(syn), was determined by matrix IR experiments to be 0.9 ± 0.2 kcal mol(-1). The conformational equilibria were evaluated by fast-cooling gaseous samples highly diluted in argon at different temperatures as cryogenic matrixes. The conformational properties of both molecules were analyzed in terms of the hyperconjugative electronic effect applying the natural bond orbital method. The kinetics of the thermal conversion of the high-energy anti into the syn FC(O)NCS conformer was studied in Ar and N(2) matrixes at cryogenic temperatures. The reversed syn → anti photoisomerization was observed using UV-vis light. Rearrangement of FC(O)SCN into FC(O)NCS was observed in the neat liquid and in solution. Under 193 nm (ArF excimer laser) irradiation, FC(O)NCS isolated in cryogenic Ar matrixes forms FC(O)SCN. At low temperature, single crystals of the two constitutional isomers were obtained using a miniature zone melting procedure. According to X-ray diffraction, they exclusively crystallize in their syn forms (C(s) symmetry) in the orthorhombic crystal system.

Acute abdominal manifestations in patients with ventriculo-peritoneal shunts

Five patientes with acute abdominal maifestations after revision of ventriculo-peritoneal shunt were identified. abdominal pain, nausea, vomiting and distention propted surgical intervention. Clinical evidence of increased intracranial pressure or shunt malfunction were not prominent findings. Exteriorization of the distal (peritoneal catherer resolved tha cute abdominal findings promptly