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1.
J Chem Theory Comput ; 17(10): 5969-5991, 2021 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-34506154

RESUMO

In this paper, we discuss coupled-trajectory schemes for molecular-dynamics simulations of excited-state processes. New coupled-trajectory strategies to capture decoherence effects, revival of coherence and nonadiabatic interferences in long-time dynamics are proposed, and compared to independent-trajectory schemes. The working framework is provided by the exact factorization of the electron-nuclear wave function, and it exploits ideas emanating from various surface-hopping schemes. The new coupled-trajectory algorithms are tested on a one-dimensional two-state system using different model parameters which allow one to induce different dynamics. The benchmark is provided by the numerically exact solution of the time-dependent Schrödinger equation.

2.
J Phys Chem A ; 125(28): 6075-6088, 2021 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-34259520

RESUMO

We present a study of the O(3P) + C2H4 scattering reaction, a process that takes place in the interstellar medium and is of relevance in atmospheric chemistry as well. A comprehensive investigation of the electronic properties of the system has been carried out based on multiconfigurational ab initio CASSCF/CASPT2 calculations, using a robust and consistent active space that can deliver accurate potential energy surfaces in the key regions visited by the system. The paper discloses detailed description of the primary reaction pathways and the relevant singlet and triplet excited states at the CASSCF and CASPT2 level, including an accurate description of the critical configurations, such as minima and transition states. The chosen active space and the CASSCF/CASPT2 computational protocol are assessed against coupled-cluster calculations to further check the stability and reliability of the entire multiconfigurational procedure.

3.
Nutrition ; 90: 111264, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34004413

RESUMO

OBJECTIVES: Malnutrition negatively affects the quality of life, survival, and clinical outcome of patients with cancer. Home artificial nutrition (HAN) is an appropriate nutritional therapy to prevent death from cachexia and to improve quality of life, and it can be integrated into a home palliative care program. The choice to start home enteral nutrition (HEN) or home parenteral nutrition (HPN) is based on patient-specific indications and contraindications. The aim of this observational study was to analyze the changes that occurred in the criteria for choosing the access route to artificial nutrition during 30 y of activity of a nutritional service team (NST) in a palliative home care setting, as well as to compare indications, clinical nutritional outcomes, and complications between HEN and HPN. METHODS: The following parameters were analyzed and compared for HEN and HPN: tumor site and metastases; nutritional status (body mass index, weight loss in the past 6 mo); basal energy expenditure and oral food intake; Karnofsky performance status; access routes to HEN (feeding tubes) and HPN (central venous catheters); water and protein-calorie support; and survival and complications of HAN. RESULTS: From 1990 to 2020, HAN was started in 1014 patients with cancer (592 men, 422 women; 65.6 ± 12.7 y of age); HPN was started in 666 patients (66%); and HEN was started in 348 patients (34%). At the end of the study, 921 patients had died, 77 had suspended HAN for oral refeeding and 16 were in the progress of HAN. The oral caloric intake was <50% basal energy expenditure in all patients: 721 (71.1%) were unable to eat at all (HEN 270, HPN 451), whereas in 293 patients (28.9%), artificial nutrition was supplementary to oral intake. From 2010 to 2020, the number of central venous catheters for HPN, especially peripherally inserted central catheters, doubled compared with that in the previous 20 y, with a decrease of 71.6% in feeding tubes for HEN. At the beginning, patients on HEN and HPN had comparable nutrition and performance status, and there was no difference in nutritional outcome after 1 mo of HAN. In 215 patients who started supplemental parenteral nutrition to oral feeding, total protein-calorie intake allowed a significant increase in body mass index and Karnofsky performance status. The duration of HEN was longer than that of HPN but was similar to that of supplemental parenteral nutrition. CONCLUSIONS: Over 30 y of nutritional service team activity, the choice of central venous catheters as an access route to HAN increased progressively and significantly due to personalized patient decision-making choices. Nutritional efficacy was comparable between HEN and HPN. In patients who maintained food oral intake, supplemental parenteral nutrition improved weight, performance status, and survival better than other types of HAN.


Assuntos
Neoplasias , Nutrição Parenteral no Domicílio , Feminino , Humanos , Avaliação de Estado de Karnofsky , Masculino , Neoplasias/terapia , Cuidados Paliativos , Qualidade de Vida
4.
J Chem Phys ; 154(11): 114101, 2021 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-33752379

RESUMO

We develop a trajectory-based approach for excited-state molecular dynamics simulations of systems subject to an external periodic drive. We combine the exact-factorization formalism, allowing us to treat electron-nuclear systems in nonadiabatic regimes, with the Floquet formalism for time-periodic processes. The theory is developed starting with the molecular time-dependent Schrödinger equation with the inclusion of an external periodic drive that couples to the system dipole moment. With the support of the Floquet formalism, quantum dynamics is approximated by combining classical-like, trajectory-based, nuclear evolution with electronic dynamics represented in the Floquet basis. The resulting algorithm, which is an extension of the coupled-trajectory mixed quantum-classical scheme for periodically driven systems, is applied to a model study, exactly solvable, with different field intensities.

5.
ACS Cent Sci ; 7(1): 81-92, 2021 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-33532571

RESUMO

Organofluorine compounds are known to be toxic to a broad variety of living beings in different habitats, and chemical fluorination has been historically exploited by mankind for the development of therapeutic drugs or agricultural pesticides. On the other hand, several studies so far have demonstrated that, under appropriate conditions, living systems (in particular bacteria) can tolerate the presence of fluorinated molecules (e.g., amino acids analogues) within their metabolism and even repurpose them as alternative building blocks for the synthesis of cellular macromolecules such as proteins. Understanding the molecular mechanism behind these phenomena would greatly advance approaches to the biotechnological synthesis of recombinant proteins and peptide drugs. However, information about the metabolic effects of long-term exposure of living cells to fluorinated amino acids remains scarce. Hereby, we report the long-term propagation of Escherichia coli (E. coli) in an artificially fluorinated habitat that yielded two strains naturally adapted to live on fluorinated amino acids. In particular, we applied selective pressure to force a tryptophan (Trp)-auxotrophic strain to use either 4- or 5-fluoroindole as essential precursors for the in situ synthesis of Trp analogues, followed by their incorporation in the cellular proteome. We found that full adaptation to both fluorinated Trp analogues requires a low number of genetic mutations but is accompanied by large rearrangements in regulatory networks, membrane integrity, and quality control of protein folding. These findings highlight the cellular mechanisms behind the adaptation to unnatural amino acids and provide the molecular foundation for bioengineering of novel microbial strains for synthetic biology and biotechnology.

6.
J Chem Phys ; 154(3): 034104, 2021 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-33499611

RESUMO

We study the relaxation process through a conical intersection of a photo-excited retinal chromophore model. The analysis is based on a two-electronic-state two-dimensional Hamiltonian developed by Hahn and Stock [J. Phys. Chem. B 104 1146 (2000)] to reproduce, with a minimal model, the main features of the 11-cis to all-trans isomerization of the retinal of rhodopsin. In particular, we focus on the performance of various trajectory-based schemes to nonadiabatic dynamics, and we compare quantum-classical results to the numerically exact quantum vibronic wavepacket dynamics. The purpose of this work is to investigate, by analyzing electronic and nuclear observables, how the sampling of initial conditions for the trajectories affects the subsequent dynamics.

7.
J Chem Theory Comput ; 16(10): 6032-6048, 2020 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-32931266

RESUMO

We report an in-depth analysis of the photo-induced isomerization of the 2-cis-penta-2,4-dieniminium cation: a minimal model of the 11-cis retinal protonated Schiff base chromophore of the dim-light photoreceptor rhodopsin. Based on recently developed three-dimensional potentials parametrized on ab initio multi-state multi-configurational second-order perturbation theory data, we perform quantum-dynamical studies. In addition, simulations based on various quantum-classical methods, among which Tully surface hopping and the coupled-trajectory approach derived from the exact factorization, allow us to validate their performance against vibronic wavepacket propagation and, therefore, a purely quantum treatment. Quantum-dynamics results uncover qualitative differences with respect to the two-dimensional Hahn-Stock potentials, widely used as model potentials for the isomerization of the same chromophore, due to the increased dimensionality and three-mode correlation. Quantum-classical simulations show, instead, that three-dimensional model potentials are capable of capturing a number of features revealed by atomistic simulations and experimental observations. In particular, a recently reported vibrational phase relationship between double-bond torsion and hydrogen-out-of-plane modes critical for rhodopsin isomerization efficiency is correctly reproduced.

8.
J Phys Chem A ; 124(34): 6764-6777, 2020 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-32786992

RESUMO

In the framework of the exact factorization of the time-dependent electron-nuclear wave function, we investigate the possibility of solving the nuclear time-dependent Schrödinger equation based on trajectories. The nuclear equation is separated in a Hamilton-Jacobi equation for the phase of the wave function, and a continuity equation for its (squared) modulus. For illustrative adiabatic and nonadiabatic one-dimensional models, we implement a procedure to follow the evolution of the nuclear density along the characteristics of the Hamilton-Jacobi equation. Those characteristics are referred to as quantum trajectories, since they are generated via ordinary differential equations similar to Hamilton's equations, but including the so-called quantum potential, and they can be used to reconstruct exactly the quantum-mechanical nuclear wave function, provided infinite initial conditions are propagated in time.

9.
J Chem Theory Comput ; 16(8): 4833-4848, 2020 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-32633509

RESUMO

We present a detailed derivation of the generalized coupled-trajectory mixed quantum-classical (G-CT-MQC) algorithm based on the exact-factorization equations. The ultimate goal is to propose an algorithm that can be employed for molecular dynamics simulations of nonradiative phenomena, as the spin-allowed internal conversions and the spin-forbidden intersystem crossings. Internal conversions are nonadiabatic processes driven by the kinetic coupling between electronic states, whereas intersystem crossings are mediated by the spin-orbit coupling. In this paper, we discuss computational issues related to the suitable representation for electronic dynamics and the different natures of kinetic and spin-orbit coupling. Numerical studies on model systems allow us to test the performance of the G-CT-MQC algorithm in different situations.

10.
Cell Syst ; 11(1): 11-24.e4, 2020 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-32619549

RESUMO

The COVID-19 pandemic is an unprecedented global challenge, and point-of-care diagnostic classifiers are urgently required. Here, we present a platform for ultra-high-throughput serum and plasma proteomics that builds on ISO13485 standardization to facilitate simple implementation in regulated clinical laboratories. Our low-cost workflow handles up to 180 samples per day, enables high precision quantification, and reduces batch effects for large-scale and longitudinal studies. We use our platform on samples collected from a cohort of early hospitalized cases of the SARS-CoV-2 pandemic and identify 27 potential biomarkers that are differentially expressed depending on the WHO severity grade of COVID-19. They include complement factors, the coagulation system, inflammation modulators, and pro-inflammatory factors upstream and downstream of interleukin 6. All protocols and software for implementing our approach are freely available. In total, this work supports the development of routine proteomic assays to aid clinical decision making and generate hypotheses about potential COVID-19 therapeutic targets.


Assuntos
Proteínas Sanguíneas/metabolismo , Infecções por Coronavirus/sangue , Pneumonia Viral/sangue , Proteômica/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Betacoronavirus/isolamento & purificação , Biomarcadores/sangue , Proteínas Sanguíneas/análise , COVID-19 , Infecções por Coronavirus/classificação , Infecções por Coronavirus/patologia , Infecções por Coronavirus/virologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pandemias/classificação , Pneumonia Viral/classificação , Pneumonia Viral/patologia , Pneumonia Viral/virologia , SARS-CoV-2 , Adulto Jovem
11.
Clin Nutr ; 39(11): 3346-3353, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32143890

RESUMO

BACKGROUND AND AIMS: The prevalence of malnutrition is over 70% in advanced cancer patients and impacts negatively on survival and quality of life. Artificial nutrition can be integrated into a home palliative care program. This observational study aims to describe the criteria for identifying the cancer patients that could benefit from home artificial nutrition (HAN) and to evaluate its impact on survival and performance status. METHODS: The selection criteria for patient's eligibility to HAN were: Karnofsky Performance Status (KPS) ≥40, life expectancy ≥6 weeks, inadequate caloric intake ± malnutrition, suitable psycho-physical conditions and informed consent. The access route for nutritional therapy (home parenteral nutrition, HPN; home enteral nutrition, HEN) was chosen according to the ESPEN Guidelines. The parameters considered were: primary site of the tumor; oral food intake; nutritional status; stage of cachexia; fluid, energy and protein supplied by HAN; survival. RESULTS: From 1990 to 2019, 43,474 cancer patients were assisted at home in Bologna (Italy). HAN started in 969 patients (2.2% of total patients, 571 men and 398 women, mean age 65.7 ± 12.7 years): HPN in 629 patients (64.9%), with gastrointestinal obstruction as the main indication; HEN in 340 patients (35.1%), with dysphagia as the main indication. Considering the 890 deceased patients, the mean survival after the start of HAN was 18.3 weeks and 649 patients (72.9%) survived more than 6 weeks. The mean survival was higher in HEN (22.1 weeks) compared to HPN patients (16.1 weeks) (p < .001). After one month, KPS was unchanged in 649 (67.0%), increased in 232 (23.9%) and decreased in 88 patients (9.1%). The mean KPS increased in patients starting HAN in pre-cachexia and cachexia (p < .001). Cachexia and refractory cachexia at the entry were associated with a reduced survival [odds ratio: 1.5 and 2.3 respectively, p < .001 for both condition] respect to pre-cachexia. CONCLUSIONS: The selection criteria allow the identification of the patient who can take advantage of HAN. HAN can be effective in avoiding death from malnutrition in 73% of patients, and in maintaining or improving the KPS at one month in 90% of cases. The benefits provided by HAN on survival and performance status depend on the cachexia degree at the entry.


Assuntos
Nutrição Enteral/mortalidade , Desnutrição/terapia , Neoplasias/terapia , Cuidados Paliativos/métodos , Nutrição Parenteral no Domicílio/mortalidade , Idoso , Caquexia/etiologia , Caquexia/mortalidade , Caquexia/terapia , Nutrição Enteral/métodos , Feminino , Humanos , Itália , Avaliação de Estado de Karnofsky , Masculino , Desnutrição/etiologia , Desnutrição/mortalidade , Pessoa de Meia-Idade , Neoplasias/complicações , Neoplasias/mortalidade , Nutrição Parenteral no Domicílio/métodos , Seleção de Pacientes
12.
Phys Rev Lett ; 124(3): 033001, 2020 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-32031839

RESUMO

We investigate spin-orbit interactions in ultrafast molecular processes employing the exact factorization of the electron-nuclear wave function. We revisit the original derivation by including spin-orbit coupling, and show how the dynamics driven by the time-dependent potential energy surface alleviates inconsistencies arising from different electronic representations. We propose a novel trajectory-based scheme to simulate spin-forbidden non-radiative processes, and we show its performance in the treatment of excited-state dynamics where spin-orbit effects couple different spin multiplets.

13.
Nutrition ; 60: 212-216, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30658227

RESUMO

OBJECTIVE: The aim of this study was to evaluate kidney function outcome in adults on home parenteral nutrition (HPN) for chronic intestinal failure using the newly recommended equations for estimated glomerular filtration rate (eGFR) assessment in clinical practice. METHODS: This was an observational study with 72 patients. Clinical and biochemical parameters were collected at initiation of HPN (retrospective baseline [BL]), at inclusion in the study (cross-sectional [CS]), and at the end of a 30-mo prospective follow-up (Fup). The eGFR (mL/min/1.73 m2 body surface) was calculated by the Chronic Kidney Disease Epidemiology Collaboration creatinine and categorized as normal, mildly decreased (MDKF), and chronic kidney disease (CKD) when ≥90, 60 to 89, and <60, respectively. RESULTS: An eGFR<90 was observed in 41.7% of patients at BL, 53.4% at CS, and 56.6% at Fup. A CKD was present in all of the patients at BL, 20.1% at CS, and 35.9% at Fup. The probability of maintaining an eGFR ≥60 was 98%, 82%, and 79% at 1, 5, and 10 y after BL, respectively (Kaplan-Meier analysis). The probability was lower in patients with MDKF at BL (P = 0.039). The development of a CKD was significantly associated with aging and urologic diseases and numerically associated with the episodes of venous-catheter sepsis, short bowel syndrome, and a low volume of HPN. CONCLUSIONS: In patients on HPN for chronic intestinal failure, decreased kidney function is a frequent finding, even at HPN commencement, demanding accurate monitoring during the treatment. Prevention of CKD primarily relies on the maintenance of fluid balance and the prevention of catheter-sepsis and urologic diseases.


Assuntos
Enteropatias/fisiopatologia , Enteropatias/terapia , Nutrição Parenteral no Domicílio , Insuficiência Renal Crônica/terapia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Doença Crônica , Estudos Transversais , Feminino , Taxa de Filtração Glomerular , Humanos , Enteropatias/complicações , Estimativa de Kaplan-Meier , Rim/fisiopatologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Insuficiência Renal Crônica/etiologia , Insuficiência Renal Crônica/fisiopatologia , Estudos Retrospectivos , Resultado do Tratamento , Adulto Jovem
14.
Clin Nutr ; 38(3): 1198-1205, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-29778510

RESUMO

BACKGROUND & AIMS: Intestinal failure associated liver disease (IFALD) has been defined using numerous criteria; however the clinical relevance of these criteria has never been compared. We therefore aimed to evaluate the prevalence, incidence, evolution of IFALD diagnosed by different criteria and to assess any clinical features that may be associated with its occurrence. METHODS: A cross sectional (CS) and retrospective study were carried out on adults on home parenteral nutrition (HPN) for chronic intestinal failure (CIF) managed at a single center. Inclusion criteria at CS: age ≥18 years, benign disease. Collected data included: patient demographics, CIF and HPN characteristics, episodes of central venous catheter related bloodstream infection (CRBSI). IFALD was diagnosed by 9 criteria based on liver function tests and liver ultrasound (US) imaging. IFALD diagnoses were categorized as steatosis (2 criteria), cholestasis (3 criteria) or fibrosis (2 criteria) and unclassified (2 criteria). Prevalence was assessed at CS and at starting HPN (baseline, BS). Evolution was assessed as change of IFALD between BS and CS. Incidence was calculated as patients who developed IFALD from BS to CS. RESULTS: A total of 113 patients were included. At CS, IFALD prevalence range in each diagnostic categories was: cholestasis 5-15%; steatosis 17-43%; fibrosis 10-20%; unclassified 7-38%. A 28.5% of patients did not have IFALD according to any criteria. Two cholestasis criteria and one fibrosis criterion were significantly (P < 0.05) associated with a short bowel syndrome as the pathophysiological mechanism of CIF, HPN requirement and the number of CRBSI episodes. At BS, IFALD prevalence range was: cholestasis 13-40%; steatosis 27-90%; fibrosis 2-5%; unclassified 8-75%. The incidence range of IFALD was: cholestasis 0-7%; steatosis 0-39%; fibrosis 7-18%; unclassified 4-9%. IFALD steatosis diagnosed by US was the most frequent diagnosis at both CS prevalence and incidence assessments. Notably, IFALD criteria normalized in various percentages (2-70%), depending on the diagnostic categories, between BS and CS. CONCLUSIONS: This is the first study to systematically demonstrate that the frequency of IFALD varies greatly depending on diagnostic criteria used, confirming the need for a consensus definition to be used between different national and international IF units. IFALD can be present at HPN initiation but may resolve thereafter; further work is required to evaluate the factors associated with improvement.


Assuntos
Enteropatias , Hepatopatias , Adulto , Idoso , Estudos Transversais , Feminino , Humanos , Incidência , Enteropatias/complicações , Enteropatias/epidemiologia , Enteropatias/terapia , Hepatopatias/epidemiologia , Hepatopatias/etiologia , Masculino , Pessoa de Meia-Idade , Nutrição Parenteral no Domicílio/métodos , Nutrição Parenteral no Domicílio/estatística & dados numéricos , Prevalência , Estudos Retrospectivos , Fatores de Risco
15.
J Chem Theory Comput ; 14(9): 4513-4529, 2018 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-30063343

RESUMO

We analyze a mixed quantum-classical algorithm recently derived from the exact factorization equations [Min, Agostini, Gross, PRL 115, 073001 (2015)] to show the role of the different terms in the algorithm in bringing about decoherence and wavepacket branching. The algorithm has the structure of Ehrenfest equations plus a "coupled-trajectory" term for both the electronic and nuclear equations, and we analyze the relative roles played by the different nonadiabatic terms in these equations, including how they are computed in practice. In particular, we show that while the coupled-trajectory term in the electronic equation is essential in yielding accurate dynamics, that in the nuclear equation has a much smaller effect. A decoherence time is extracted from the electronic equations and compared with that of augmented fewest-switches surface-hopping. We revisit a series of nonadiabatic Tully model systems to illustrate our analysis.

16.
Clin Nutr ; 37(2): 728-738, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-28483328

RESUMO

BACKGROUND & AIMS: The aim of the study was to evaluate the applicability of the ESPEN 16-category clinical classification of chronic intestinal failure, based on patients' intravenous supplementation (IVS) requirements for energy and fluids, and to evaluate factors associated with those requirements. METHODS: ESPEN members were invited to participate through ESPEN Council representatives. Participating centers enrolled adult patients requiring home parenteral nutrition for chronic intestinal failure on March 1st 2015. The following patient data were recorded though a structured database: sex, age, body weight and height, intestinal failure mechanism, underlying disease, IVS volume and energy need. RESULTS: Sixty-five centers from 22 countries enrolled 2919 patients with benign disease. One half of the patients were distributed in 3 categories of the ESPEN clinical classification. 9% of patients required only fluid and electrolyte supplementation. IVS requirement varied considerably according to the pathophysiological mechanism of intestinal failure. Notably, IVS volume requirement represented loss of intestinal function better than IVS energy requirement. A simplified 8 category classification of chronic intestinal failure was devised, based on two types of IVS (either fluid and electrolyte alone or parenteral nutrition admixture containing energy) and four categories of volume. CONCLUSIONS: Patients' IVS requirements varied widely, supporting the need for a tool to homogenize patient categorization. This study has devised a novel, simplified eight category IVS classification for chronic intestinal failure that will prove useful in both the clinical and research setting when applied together with the underlying pathophysiological mechanism of the patient's intestinal failure.


Assuntos
Enteropatias/dietoterapia , Enteropatias/patologia , Nutrição Parenteral no Domicílio/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Australásia , Doença Crônica , Estudos Transversais , Europa (Continente) , Feminino , Humanos , Intestinos/patologia , Israel , Masculino , Pessoa de Meia-Idade , América do Sul , Estados Unidos , Adulto Jovem
17.
Clin Nutr ; 37(4): 1415-1422, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-28701261

RESUMO

BACKGROUND & AIM: Home parenteral nutrition (HPN) is the primary treatment for chronic intestinal failure (IF). Intestinal transplantation (ITx) is indicated when there is an increased risk of death due to HPN complications or to the underlying disease. Age, pathophysiologic conditions and underlying disease are known predictors of HPN dependency and overall survival. Although the cause of death on HPN is mostly related to underlying disease in these patients, the relationship between mortality and duration of HPN use remains unclear. The purpose of the present study is to describe factors associated with survival and HPN dependency as well as causes of death in adult patients requiring HPN for chronic intestinal failure during the first 5 years of treatment with HPN. METHODS: A multicenter international (European and USA) questionnaire-based retrospective follow-up of a cohort of 472 IF patients who started HPN was conducted between June and December 2000. Study endpoint was either end of 5-year follow-up, weaned-off HPN, ITx, or death on HPN. Data were analyzed for HPN dependence and overall survival using Kaplan-Meier models and log rank tests. RESULTS: The overall survival probability was 88%, 74% and 64% at 1, 3 and 5 years respectively. Survival was inversely related to age (p < .001) and higher in patients with Crohn's disease or chronic idiopathic pseudo-obstruction. A total of 169 (36.5%) patients were weaned-off HPN mainly (80%) within the first year and most frequently in patients with fistulae. Five of the 14 patients who underwent ITx died. By the end of the study, 104 (23%) of patients died on HPN; 65% of deaths occurred within the first 2.5 years of HPN. CONCLUSIONS: Younger ages at HPN initiation and underlying pathologies are significantly predictive of survival on HPN. Risk of death is greatest during the first 2 years of HPN.


Assuntos
Enteropatias/mortalidade , Enteropatias/terapia , Nutrição Parenteral no Domicílio/mortalidade , Adolescente , Adulto , Idoso , Doença Crônica , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto Jovem
18.
World J Gastroenterol ; 23(25): 4604-4614, 2017 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-28740349

RESUMO

AIM: To investigate the fatty acid-based functional lipidomics of patients on long-term home parenteral nutrition receiving different intravenous lipid emulsions. METHODS: A cross-sectional comparative study was carried out on 3 groups of adults on home parenteral nutrition (HPN), receiving an HPN admixture containing an olive-soybean oil-based intravenous lipid emulsion (IVLE) (OO-IVLE; n = 15), a soybean- medium-chain triacylglycerol-olive-fish oil-based IVLE (SMOF-IVLE; n = 8) or HPN without IVLE (No-IVLE; n = 8) and 42 healthy controls (HCs). The inclusion criteria were: duration of HPN ≥ 3 mo, current HPN admixtures ≥ 2 mo and HPN infusions ≥ 2/wk. Blood samples were drawn 4-6 h after the discontinuation of the overnight HPN infusion. The functional lipidomics panel included: the red blood cell (RBC) fatty acid (FA) profile, molecular biomarkers [membrane fluidity: saturated/monounsaturated FA ratio = saturated fatty acid (SFA)/monounsaturated fatty acid (MUFA) index; inflammatory risk: n-6/n-3 polyunsaturated fatty acid (PUFA) ratio = n-6/n-3 index; cardiovascular risk: sum of n-3 eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) = n-3 index; free radical stress: sum of FA trans isomers = %trans index] and FA pathway enzyme activity estimate (delta-9-desaturase = D9D; delta-6-desaturase = D6D; delta-5-desaturase = D5D; elongase = ELO). Statistics were carried out using nonparametric tests. The amount of each FA was calculated as a percentage of the total FA content (relative%). RESULTS: In the OO-IVLE group, the percentage of oleic acid in the RBCs was positively correlated with the weekly load of OO-IVLE (r = 0.540, P = 0.043). In the SMOF-IVLE cohort, the RBC membrane EPA and DHA were positively correlated with the daily amount of SMOF-IVLE (r = 0.751, P = 0.044) and the number of HPN infusions per week (r = 0.753; P = 0.046), respectively. The SMOF-IVLE group showed the highest EPA and DHA and the lowest arachidonic acid percentages (P < 0.001). The RBC membrane linoleic acid content was lower, and oleic and vaccenic acids were higher in all the HPN groups in comparison to the HCs. Vaccenic acid was positively correlated with the weekly HPN load of glucose in both the OO-IVLE (r = 0.716; P = 0.007) and the SMOF-IVLE (r = 0.732; P = 0.053) groups. The estimated activity of D9D was higher in all the HPN groups than in the HCs (P < 0.001). The estimated activity of D5D was lower in the SMOF-IVLE group than in the HCs (P = 0.013). The SFA/MUFA ratio was lower in all the HPN groups than in the HCs (P < 0.001). The n-6/n-3 index was lower and the n-3 index was higher in the SMOF-IVLE group in comparison to the HCs and to the other HPN groups (P < 0.001). The %trans index did not differ among the four groups. CONCLUSION: The FA profile of IVLEs significantly influenced the cell membrane functional lipidomics. The amount of glucose in the HPN may play a relevant role, mediated by the insulin regulation of the FA pathway enzyme activities.


Assuntos
Emulsões Gordurosas Intravenosas/metabolismo , Ácidos Graxos/metabolismo , Enteropatias/terapia , Metabolismo dos Lipídeos , Metaboloma , Nutrição Parenteral no Domicílio/métodos , Adolescente , Adulto , Idoso , Biomarcadores/sangue , Doenças Cardiovasculares , Doença Crônica , Estudos Transversais , Ácidos Docosa-Hexaenoicos , Eritrócitos/metabolismo , Emulsões Gordurosas Intravenosas/administração & dosagem , Emulsões Gordurosas Intravenosas/química , Feminino , Glucose/administração & dosagem , Glucose/química , Glucose/metabolismo , Humanos , Enteropatias/sangue , Enteropatias/metabolismo , Masculino , Metabolômica/métodos , Pessoa de Meia-Idade , Fatores de Risco , Adulto Jovem
19.
J Phys Chem Lett ; 8(13): 3048-3055, 2017 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-28618782

RESUMO

We report the first nonadiabatic molecular dynamics study based on the exact factorization of the electron-nuclear wave function. Our approach (a coupled-trajectory mixed quantum-classical, CT-MQC, scheme) is based on the quantum-classical limit derived from systematic and controlled approximations to the full quantum-mechanical problem formulated in the exact-factorization framework. Its strength is the ability to correctly capture quantum (de)coherence effects in a trajectory-based approach to excited-state dynamics. We show this by benchmarking CT-MQC dynamics against a revised version of the popular fewest-switches surface-hopping scheme that is able to fix its well-documented overcoherence issue. The CT-MQC approach is successfully applied to investigation of the photochemistry (ring-opening) of oxirane in the gas phase, analyzing in detail the role of decoherence. This work represents a significant step forward in the establishment of the exact factorization as a powerful tool to study excited-state dynamics, not only for interpretation purposes but mainly for nonadiabatic ab initio molecular dynamics simulations.

20.
J Phys Chem Lett ; 8(4): 831-837, 2017 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-28151670

RESUMO

Conical intersections represent critical topological features of potential energy surfaces and open ultrafast nonradiative deactivation channels for photoexcited molecules. In the following, we investigate how this funneling picture is transposed in the eyes of the exact factorization formalism for a 2D model system. The exact factorization of the total molecular wave function leads to the fundamental concept of time-dependent potential energy surface and time-dependent vector potential, whose behavior during a dynamics through a conical intersection has up to now remained unexplored. Despite the fact that these quantities might be viewed as time-dependent generalizations of the adiabatic potential energy surfaces and the nonadiabatic coupling vectors, characteristic quantities appearing in the Born-Oppenheimer framework, we observe that they do not exhibit particular topological features in the region of conical intersection but still reflect the complex dynamics of the nuclear wavepacket.

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