Total Dissociation Research Articles

Physical outcome and quality of life after total esophagogastric dissociation in children with severe neurodisability and gastroesophageal reflux, from the caregiver's perspective

Background/Purpose The objective of this study is to retrospectively assess the surgical outcome and the quality of life (QOL) from the caregiver's perspective after total esophagogastric dissociation in neurologically impaired (NI) children with gastroesophageal reflux (GOR). Methods Based on O'Neill questionnaire, a QOL questionnaire was designed, which was completed by the caregivers recording the child's well being and caregiver's satisfaction preprocedure, immediately (6 months), and long-term postprocedure (median, 21 months; range, 4-38). Statistical analysis was done using Kruskal-Wallis Test and Dunn's multiple comparisons test. Results Twenty-three children underwent surgery between 2003 and 2008; 19 families participated. Ease of feeding improved significantly both immediately and long term. Statistically significant improvements were also seen in comfort and ability of the child to enjoy life, frequency of medical visits, vomiting, retching, and choking. Postoperatively, caring for the child became easier, and the caregiver's frustration in caring improved statistically, but the caregiver's overall QOL did not improve significantly. Conclusions Total esophagogastric dissociation has huge positive impact on the physical well being of the NI children experiencing GOR. The overall view of the procedure is one of success surpassing all expectations. Therefore, it should be considered alongside other antireflux procedures in NI children.

ChemInform Abstract: Dissociative Single and Double Photoionization of CH3F in the Region 20-110 eV Studied by Mass Spectrometry and the Photoion-Photoion Coincidence Method.

Dissociative single and double photoionization of methyl fluoride (CH3F) has been studied in the photon energy region of 20–110 eV by use of synchrotron radiation, a time‐of‐flight (TOF) mass spectrometer, and the photoion–photoion coincidence (PIPICO) method. The TOF mass spectrometer facilitates relatively efficient extraction of energetic ions, which is essential for quantitative measurements. Photoion branching ratios are reported for the observed 11 singly charged ions, H+, H+2, CH+n (n=0–3), F+, CHnF+ (n=0–3). Stable CH3F2+ is not observed in all of the energy region studied in a μs time scale. The double photoionization threshold is measured to be 35.0±0.5 eV. PIPICO spectra measured at higher photon energies show the following five types of dissociation processes:(1) CH3F2+→H++CHnF+ (n=0–2), (2) H+2+CHnF+ (n=0–1), (3) H++CH+n (n=0–2), (4) H+2+CH+, (5) H++F+, with ten total dissociation channels. These processes are characteristic in regard to bond breakage involved, whether a rearrangement reactio...

Water as a source for oxygen incorporation into acceptor doped SrTiO 3 single crystals

The possibility of the incorporation of oxygen and deuteron stemming from the dissociation of water into iron doped strontium titanate single crystals with two different iron concentrations (0.13 and 0.013 at.% Fe) has been investigated. Double labeled water ( 2H 2 18O) was used for Isotope Exchange Depth Profiling. It acts as an incorporation source of 18O into Fe-doped SrTiO 3(100) single crystals. Total dissociation of the water takes place in the vicinity of the SrTiO 3 surface and both oxygen and deuteron incorporate into the SrTiO 3. The results of the diffusion profile evaluation confirm that oxygen and deuteron migrate independently in the bulk. Oxygen incorporates into the material at high incorporation rates, practically comparable with the ones resulting from an O 2 atmosphere. The interaction of H 2O with SrTiO 3(100) surfaces was further studied with Metastable Induced Electron Spectroscopy and Ultraviolet Photoelectron Spectroscopy. Neither partial dissociation of water molecules nor any significant formation of surface OD groups was observed.

Photoinduced intramolecular charge shift reaction in ammonium N-(3,5-dinitrobenzoyl)-α-phenylglycinate adducts

Ammonium N-(3,5-dinitrobenzoyl)-α-phenylglycinate adducts were synthesized and characterized by using different protonated amines as counter-ion: NH 4 +, (CH 3–CH 2–) 2NH 2 +, (CH 3–CH 2–CH 2)NH 3 +, (CH 3–CH 2–CH 2–CH 2–)NH 3 + and (CH 3–CH 2–) 3NH +. A photochemical process was observed under ultraviolet ( λ exc, 254 nm) or solar irradiation, both in solid state and in solution: DMSO, acetone or acetonitrile. 3,5-Dinitrobenzene and carboxylate groups, separated by an N-benzylamide bridge, are present in these adducts, acting as electron acceptor and electron donor, respectively. Spectroscopic analyses (NMR, IR and UV–vis) suggest a photoinduced intramolecular electron transfer. A first-order photochemical kinetics was proposed in DMSO/(n-propylammonium N-(3,5-dinitrobenzoyl)-α-phenylglycinate) solution; such behavior was similar for all adducts studied, probably due to total salt dissociation in solution. In the solid state, however, electron transfer process efficiency is directly proportional to Lewis base (amine) strength of the adduct counter-ion. Decarboxylation is observed after the irradiation process, giving rise to a σ-adduct intermediate, and subsequent formation of benzaldehyde and 3,5-dinitrobenzamide degradation products.

Relative reactivities of amino and ethenyl groups in allylamine on Si(100)2 × 1: Temperature-dependent X-ray photoemission and thermal desorption studies of a common linker molecule

The room-temperature adsorption and thermal evolution of allylamine on Si(100)2 × 1 have been investigated by using temperature-dependent X-ray photoelectron spectroscopy (XPS) and thermal desorption spectrometry (TDS). The presence of a broad N 1 s feature at 398.9 eV, attributed to a N―Si bond, indicates N―H dissociative adsorption. On the other hand, the presence of C 1 s features at 284.6 eV and 286.2 eV, corresponding to C═C and C―N, respectively, and the absence of the Si―C feature expected at 283.2 eV shows that [2 + 2] C═C cycloaddition does not occur at room temperature. These XPS data are consistent with the unidentate staggered and eclipsed allylamine conformer adstructures arising from N―H dissociation and not [2 + 2] C═C cycloaddition. The apparent conversion of the N 1 s feature for Si―N(H)―C ▪ at 398.9 eV to that for Si―N(H) at 397.7 eV and the total depletion of C 1 s feature for C―N at 286.2 eV near 740 K indicates cleavage of the C―N bond, leaving behind a Si―N(H) radical. Furthermore, the C═C C 1 s feature at 284.6 eV undergoes steep intensity reduction between 740 K and 825 K, above which a new C 1 s feature at 283.2 eV corresponding to SiC is found to emerge. These spectral changes suggest total dissociation of the ethenyl fragment and the formation of SiC. Moreover, while the total N 1 s intensity undergoes a minor reduction (24%) upon annealing up to 1090 K, a considerable reduction (43%) is found in the overall C 1 s intensity. This observation is consistent with our TDS data, which shows the desorption of C-containing molecules including propene and ethylene at 580 K and of acetylene at 700 K. The lack of N-containing desorbates suggests that the dissociated N species are likely bonded to multiple surface Si atoms or diffused into the bulk. Interestingly, both the staggered and eclipsed N―H dissociative adstructures are found to have a less negative adsorption energy than the [N, C, C] tridentate or the [2 + 2] C═C cycloaddition adstructures by our DFT calculations, which suggests that the observed formation of N―H dissociative adstructures is kinetically favored on the Si(100)2 × 1 surface.

Prolonged Enteral Feeding Is Often Required to Avoid Long‐term Nutritional and Metabolic Complications After Esophagogastric Dissociation

Total esophagogastric dissociation (TED) was first described in 1997 by Bianchi as a new surgical procedure to treat severe gastroesophageal reflux disease (GERD) in children with neurological impairment. Recently, TED has been proposed in other conditions, such as esophageal atresia, esotracheal cleft, or caustic esophageal lesions. Although the long-term results in terms of GERD control have been previously reported, those regarding the nutritional and metabolic status have never been documented. All patients without neurological impairment with TED between 1999 and 2004 at Robert Debre Hospital and Jeanne de Flandre Hospital, France, were prospectively investigated, paying particular attention to their metabolic and nutritional status (blood concentration of iron and vitamins A, D, E, and B12; lipid malabsorption; and hyperglycemia test) and growth. Seventeen children underwent TED. Six received primary procedures, whereas 11 were operated on because of severe respiratory diseases or failure to thrive. The mean follow-up was 6 years (range 3-8 years). Two children died (12%). Seven children were weaned from enteral nutrition support, but 5 of them had failure to thrive, steatorrhea, and/or malabsorption of vitamin B12 and/or fat-soluble vitamins. Eight patients had dumping syndrome, which was symptomatic in 6 cases. TED is an effective procedure for treatment of GERD. However, nutritional and metabolic complications including dumping syndrome and chronic digestive malabsorption are frequent after TED, especially after enteral nutrition weaning. A long-term follow-up of these patients is thus necessary and prolonged enteral nutrition support is recommended.

The Quest for Appropriate Remedies in the Microsoft Antitrust EU Cases: A Comparative Appraisal

The Microsoft cases in the United States and in Europe have been influential in determining the contours of the substantive liability standards for dominant firms in US antitrust law and in EC Competition law. The competition law remedies that were adopted, following the finding of liability, seem, however, to constitute the main measure for the “success” of the case(s). An important disagreement exists between those arguing that the remedies put in place failed to address the roots of the competition law violation identified in the liability decision and others who advance the view that the remedies were far-reaching and that their alleged failure demonstrates the weakness of the liability claim. This study evaluates these claims by examining the variety of remedies that were finally imposed in the European Microsoft cases, from a comparative perspective. The study begins with a discussion of the roots of the Microsoft issues in Europe and the consequent choice of a remedial approach by the Commission and the Court. It then explores the effectiveness of the remedies in achieving the aims that were set. The non-consideration of the structural remedy in the European case and the pros and cons of developing such a remedy in the future are briefly discussed before more emphasis is put on alternative remedies (competition and non-competition law ones) that have been suggested in the literature. The study concludes by discussing the fit between the remedy and the theory of consumer harm that led to the finding of liability and questions a total dissociation between the two. We believe that it is important to think seriously about potential remedies before litigation begins. However, we do not require an ex ante identification of an appropriate remedy by the plaintiffs, since this could lead to underenforcement or overenforcement.

Laparoscopic Proximal Roux-en-Y Gastrojejunal Diversion in Children: Preliminary Experience from a Single Center

Neurologically impaired children (NIC) have a high risk of recurrence of gastroesophageal reflux (GER) following fundoplication. A postpyloric feeding tube may be useful when gastric emptying disorders occur; however, dislocation and difficulty in feeding management often require more aggressive procedures. Total esophagogastric dissociation (Bianchi's TEGD) is an alternative to the classic fundoplication procedure, whereas laparoscopic gastric bypass is a frequently performed procedure in morbid obesity, improving gastric outlet. The aim of this paper is to present a preliminary experience on the laparoscopic Roux-en-Y gastrojejunal bypass, associated with Nissen fundoplication and gastrostomy, to treat and prevent GER in NIC with gastric emptying disorders. Eight neurologically impaired children underwent surgical treatment because of feeding problems and pulmonary complications. The procedure included: 1) hiatoplasty, 2) Nissen fundoplication, 3) 20-cm Roux-en-Y gastrojejunal anastomosis and jejuno-jejunal anastomosis, and 4) gastrostomy. All cases were fed on postoperative day 3 without any intraoperative complications. One case developed an obstruction of the distal anastomosis due to adhesion and needed reoperation. Outcome was clinically evaluated with serial upper gastrointestinal contrast studies and endoscopies. Laparoscopic proximal Roux-en-Y gastrojejunal diversion, without gastric resection, is a safe, feasible procedure that improves gastric emptying and reduces the risk of GER recurrence. Yet, long-term results still have to be evaluated.

Resonance enhancement of two-frequency multiphoton dissociation ofHD+

The angular distribution of photofragments resulting from two-frequency multiphoton dissociation of ${\text{HD}}^{+}$ and their branching ratios to different photon absorption channels have been calculated by the time-independent close-coupling method within the framework of two lowest electronic state model. It is shown that when one of the frequencies, ${\ensuremath{\omega}}_{1}$, is close to an allowed rovibrational transition caused by the permanent dipole moment, the total dissociation linewidth, detailed pattern of angular distribution, and branching ratios to different photon absorption channels vary with the second frequency ${\ensuremath{\omega}}_{2}$. We have varied ${\ensuremath{\omega}}_{1}$ over a narrow range around $11\text{ }000\text{ }{\text{cm}}^{\ensuremath{-}1}$, which is close to the energy of the $v=0\ensuremath{\rightarrow}7$ transition, while ${\ensuremath{\omega}}_{2}$ was varied by about $2500\text{ }{\text{cm}}^{\ensuremath{-}1}$ up to the dissociation threshold. The branching ratios can be explained in terms of the shape resonances on two different adiabatic potentials caused by the permanent dipole moment and the nonadiabatic couplings with other potentials. Prominent rings in the angular distribution are obtained when the resonance condition is satisfied. They are shown to arise from the mixing of various rotational states due to multiphoton interactions.

Laparoscopic total esophagogastric dissociation

The total esophagogastric dissociation (Bianchi's procedure) is used to control the severe gastroesophageal reflux in patients after failure of the fundoplication techniques. The laparoscopic approach can be usefully performed in patients with impaired respiratory function. We report here 2 patients in whom the total esophagogastric dissociation has been entirely performed by laparoscopy. The laparoscopic examination of the proximal esojejunal anastomosis is made feasible using an intestinal clamp placed to avoid the esophageal retraction up into the posterior mediastinum. The principal complication after this surgery is the risk of internal hernia.

Density functional for van der Waals forces accounts for hydrogen bond in benchmark set of water hexamers

A recent extensive study has investigated how various exchange-correlation (XC) functionals treat hydrogen bonds in water hexamers and has shown traditional generalized gradient approximation and hybrid functionals used in density-functional (DF) theory to give the wrong dissociation-energy trend of low-lying isomers and van der Waals (vdW) dispersion forces to give key contributions to the dissociation energy. The question raised whether functionals that incorporate vdW forces implicitly into the XC functional predict the correct lowest-energy structure for the water hexamer and yield accurate total dissociation energy is here answered affirmatively for the vdW-DF [M. Dion et al., Phys. Rev. Lett.92, 246401 (2004)].

Bunsen section thermodynamic model for hydrogen production by the sulfur–iodine cycle

Abstract A model for the Bunsen section of the Sulfur–Iodine thermo-chemical cycle is proposed, where sulfur dioxide reacts with excess water and iodine to produce two demixing liquid aqueous phases (H 2 SO 4 rich and HI rich) in equilibrium. Considering the mild temperature and pressure conditions, the UNIQUAC activity coefficient model combined with Engels' solvation model is used. The complete model is discussed, with HI solvation by water and by iodine as well as H 2 SO 4 solvation by water, leading to a very high complexity with almost hundred parameters to be estimated from experimental data. Taking into account the water excess, a successful reduced model with only 15 parameters is proposed after defining new apparent species. Acids total dissociation and total H + solvation by water are the main assumptions. Results show a good agreement with published experimental data between 25 °C and 120 °C.

Ground states of linear molecules: Dissociation energies and dipole moments in the hartree-fock approximation

Computations of total molecular energies, dissociation energies, and electric dipole moments for the ground states of the molecules LiF, BeO, BF, CO, MgO, AlF, SiO, PN, CaO, SrO, HCN, FHF–, CO2, N2O, OCN–, FCN, SCO, SCN–, C1CN, FCCH, C1CCH, NCCCH are reported. The results come close to the Hartree-Fock limit, and their accuracy is critically discussed. A detailed discussion of the Slater-type orbital (STO) basis sets used for the computations is given.

The role of mass in the carrier–envelope phase effect for H+2 dissociation

The carrier–envelope phase (CEP) dependence of the dissociation of H+2 is studied with special emphasis on the role of the nuclear mass. We find that the total dissociation probability displays a CEP effect that grows with increasing mass, while the difference between dissociating to p+H and H+p displays an effect that shrinks. Insight into the physical processes involved is given by an analytic description that casts CEP effects as interferences between pathways requiring different numbers of photons.

Generators and Interpretors in a Performing Arts Population: Dissociation, Trauma, Fantasy Proneness, and Affective States

An international sample of 130 working artists was divided into two domains: generators (writers, designers, choreographers, one composer) and interpreters (directors, actors, opera singers, dancers). The correlations between dissociation, trauma experiences, fantasy proneness, and affective states were examined, followed by a regression analysis to predict elevated levels of dissociation. Artists, regardless of creative domain, scored in the moderate range for dissociation and fantasy proneness. Both groups endorsed lower levels of affective variability than a normed group. Interpreters scored significantly higher than generators on total dissociation, absorption/imagination, absorption/changeability, and depersonalization/derealization. Additive factors of younger age, affective states of anger, sadness and spirituality, and higher scores on fantasy proneness and traumatic experiences predicted elevated levels of dissociation, with only sadness predicting pathological dissociative levels on the taxometric Dissociative Experiences Scale-II (DES-II) subscale. Given these findings, greater awareness about dissociation and the need for an elaborated model of affect regulation is recommended.

Dislocation of an S-ROM Total Hip Arthroplasty Secondary to Traumatic Femoral Stem Dissociation from the Metaphyseal Sleeve

Modular total hip arthroplasty component dissociation has been reported. We describe a case of recurrent instability secondary to femoral stem dissociation from the proximal metaphyseal sleeve and resultant traumatic retroversion of the neck. Femoral stem revision was necessary for treatment of this rare complication.

Vibrational densities of states for large anharmonic molecules: An analytic representation

The analytical method based on the Airy function approximation and applicable for the calculation of vibrational densities of states of polyatomic molecules has been developed. The result is a smooth function accurate over a wide energy range from the zero-point energy to the total dissociation energy of the entire molecule.

Total esophagogastric dissociation in adult neurologically impaired patients with severe gastroesophageal reflux: an alternative approach

Patients with neuromuscular impairment, such as cerebral palsy or myotonic dystrophy, often suffer from oropharyngeal neuromuscular incoordination and severe gastresophageal reflux (GER). In 1997, Bianchi proposed total esophagogastric dissociation (TEGD) as an alternative to fundoplication and gastrostomy to eliminate totally the risk of recurrence of GER in neurologically impaired children. Little information exists about the best management for adult patients with severe neurological impairment in whom recurrent GER develops after failed fundoplication. We present our experience in three adult patients with neurological impairment in whom TEGD with Roux-en-Y esophagojejunostomy and feeding gastrostomy was performed for permanent treatment of GER.

Fatty acid monolayer dissociation and collapse: Effect of pH and cations

Surface pressure versus specific molecular area ( π– A) isotherms of stearic acid monolayers have been studied by varying the pH of the aqueous subphase containing monovalent (Na) or different divalent (Mg, Ca, Ba, Zn and Cd) cations. The lowering of the tilted to untilted phase transition pressure ( π t) with increasing pH of the subphase is correlated with an increase of the headgroup dissociation of the acid monolayer. On pure water, the surface pressure drops after the collapse point ( π c) to a lower pressure value ( π l). The pressure-gap Δ π = π c − π l changes with increasing dissociation, depending upon the particular cation. After a certain pH, no pressure gap is observed and π remains constant or increases slowly after π c. This transition from constant area collapse to constant pressure collapse of the monolayer is observed for all monovalent and divalent cations near total monolayer dissociation.

Strong system–bath interactions and the control of the photodissociation of CH3I

We present a time-dependent theory of system–bath interactions resulting in a reduced set of readily solvable integro-differential equations for the exact description of the multi-level system dynamics. We apply the method to the strong-field laser-induced dynamics of bound states interacting with multiple electronic states and multiple nuclear continua, and in particular to the bichromatic control of the photodissociation of methyl iodide, CH3 + I*(2P1/2) ← CH3I → CH3 + I(2P3/2). We have computed the complete strong-field control-map ‘landscapes’, depicting the yield of the I(2P3/2) ground atomic state as a function of external laser parameters. Employing pulses of 50–75 fs durations and 10–100 TW cm−2 intensities, we find yields which range between ∼10% and ∼45%, as compared to the natural value of ∼30%. These values should be contrasted with the weak-field control case where the yields vary over the much larger range of ∼0–80%, though with a much lower total dissociation yield per pulse. In addition to the above, we demonstrate the validity of the Markov approximation for strong laser-mediated system–bath interactions involving ‘slowly varying’ continua.