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1.
J Chem Phys ; 159(14)2023 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-37811824

RESUMO

We update the Quadratic Integrand Double-Hybrid (QIDH) model [J. Chem. Phys. 141, 031101 (2014)] by incorporating the nonempirical restored-regularized Strongly Constrained and Appropriately Normed (r2SCAN) meta-generalized gradient approximation exchange-correlation functional, thus devising a robust density functional approximation free of any empirical parameter and incorporating all the constraints so far known for the exchange-correlation kernel. We assessed the new r2SCAN-QIDH expression on the GMTKN55 database and further extend its application to various types of non-covalent interactions (e.g., S66 × 8, O24 × 5). The assessment done shows that the model becomes very competitive in accuracy with respect to parent exchange-correlation functionals of any type, but without relying on any fitted parameter or numerical training.

2.
Tech Coloproctol ; 27(9): 769-774, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37133736

RESUMO

PURPOSE: Invasive surgical management of cryptoglandular perianal fistulas (PF) is challenging because of high recurrence rates and the potential for injury to the sphincter complex. In the present technical note, we introduce a minimally invasive treatment for PF using a perianal fistula implant (PAFI) comprising ovine forestomach matrix (OFM). METHODS: This retrospective observational case series highlights 14 patients who had undergone a PAFI procedure at a single center between 2020 and 2023. During the procedure, previously deployed setons were removed and tracts were de-epithelialized with curettage. OFM was rehydrated, rolled, passed through the debrided tract, and secured in place at both openings with absorbable suture. Primary outcome was fistula healing at 8 weeks, and secondary outcomes included recurrence or postoperative adverse events. RESULTS: Fourteen patients underwent PAFI using OFM with a mean follow-up period of 37.6 ± 20.1 weeks. In follow-up, 64% (n = 9/14) had complete healing at 8 weeks and all remained healed, except one at last follow-up visit. Two patients underwent a second PAFI procedure and were healed with no recurrence at the last follow-up visit. Of all patients that healed during the study period (n = 11), the median time to healing was 3.6 (IQR 2.9-6.0) weeks. No postprocedural infections nor adverse events were noted. CONCLUSIONS: The minimally invasive OFM-based PAFI technique for PF treatment was demonstrated to be a safe and feasible option for patients with trans-sphincteric PF of cryptoglandular origin.


Assuntos
Próteses e Implantes , Fístula Retal , Animais , Humanos , Canal Anal/cirurgia , Fístula Retal/cirurgia , Fístula Retal/complicações , Estudos Retrospectivos , Ovinos , Resultado do Tratamento , Cicatrização
3.
J Chem Phys ; 158(4): 044105, 2023 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-36725511

RESUMO

A family of non-empirical double-hybrid (DH) density functionals, such as Perdew-Burke-Ernzerhof (PBE)0-DH, PBE-QIDH, and their range-separated exchange (RSX) versions RSX-0DH and RSX-QIDH, all using Perdew-Burke-Ernzerhof(PBE) exchange and correlationfunctionals, is applied here to calculate the excitation energies for increasingly longer linear and cyclic acenes as part of their intense benchmarking for excited states of all types. The energies for the two lowest-lying singlet 1La and 1Lb states of linear oligoacenes as well as the triplet 3La and 3Lb states, are calculated and compared with experimental results. These functionals clearly outperform the results obtained from hybrid functionals and favorably compare with other double-hybrid expressions also tested here, such as B2-PLYP, B2GP-PLYP, ωB2-PLYP, and ωB2GP-PLYP. The study is complemented by the computation of adiabatic S0-T1 singlet-triplet energy difference for linear acenes as well as the extension of the study to strained cyclic oligomers, showing how the family of non-empirical expressions robustly leads to competitive results.

4.
Phys Chem Chem Phys ; 24(7): 4515-4525, 2022 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-35119058

RESUMO

We calculate the relative energy between the cumulene and polyyne structures of a set of C4k+2 (k = 4-7) rings (C18, C22, C26, and C30 prompted by the recent synthesis of the cyclo[18]carbon (or simply C18) compounds. Reference results were obtained by a costly Quantum Monte-Carlo (QMC) approach, providing thus very accurate values allowing to systematically compare the performance of a variety of wavefunction methods [(i.e., MP2, SCS-MP2, SOS-MP2, DLPNO-CCSD, and DLPNO-CCSD(T)] as well as DFT approaches, applying for the latter a diversity of density functionals covering global and range-separated hybrid and double-hybrid models. The influence of the use of a range-separation scheme for density functionals, for both hybrid and double-hybrid expressions, is discussed according to its key role. Overall, range-separated double-hybrid functionals (e.g., RSX-QIDH) behave very accurately and provide competitive results compared with DLPNO-CCSD(T), at a more reasonable computational cost.

5.
J Chem Phys ; 156(3): 034105, 2022 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-35065561

RESUMO

The energy difference (ΔEST) between the lowest singlet (S1) state and the triplet (T1) excited state of a set of azaphenalene compounds, which is theoretically and experimentally known to violate Hund's rule, giving rise to the inversion of the order of those states, is calculated here with a family of double-hybrid density functionals. That excited-state inversion is known to be very challenging to reproduce for time-dependent density functional theory employing common functionals, e.g., hybrid or range-separated expressions, but not for wavefunction methods due to the inclusion of higher-than-single excitations. Therefore, we explore here if the last developed family of density functional expressions (i.e., double-hybrid models) is able to provide not only the right excited-state energy order but also accurate ΔEST values, thanks to the approximate inclusion of double excitations within these models. We herein employ standard double-hybrid (B2-PLYP, PBE-QIDH, and PBE0-2), range-separated (ωB2-PLYP and RSX-QIDH), spin-scaled (SCS/SOS-B2PLYP21, SCS-PBE-QIDH, and SOS-PBE-QIDH), and range-separated spin-scaled (SCS/SOS-ωB2-PLYP, SCS-RSX-QIDH, and SOS-RSX-QIDH) expressions to systematically assess the influence of the ingredients entering into the formulation while concomitantly providing insights for their accuracy.

6.
Phys Rev Lett ; 125(21): 217401, 2020 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-33274990

RESUMO

SrRuO_{3}, a ferromagnet with an approximately 160 K Curie temperature, exhibits a T^{2}-dependent dc resistivity below ≈30 K. Nevertheless, previous optical studies in the infrared and terahertz range show non-Drude dynamics at low temperatures, which seem to contradict Fermi-liquid predictions. In this work, we measure the low-frequency THz range response of thin films with residual resistivity ratios, ρ_{300K}/ρ_{4K}≈74. At temperatures below 30 K, we find both a sharp zero frequency mode which has a width narrower than k_{B}T/ℏ as well as a broader zero frequency Lorentzian that has at least an order of magnitude larger scattering. Both features have temperature dependences consistent with a Fermi liquid with the wider feature explicitly showing a T^{2} scaling. Above 30 K, there is a crossover to a regime described by a single Drude peak that we believe arises from strong interband electron-electron scattering. Such two channel Drude transport sheds light on reports of the violation of Matthiessen's rule and extreme sensitivity to disorder in metallic ruthenates.

7.
Benef Microbes ; 11(6): 527-534, 2020 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-33032471

RESUMO

Bifidobacterium infantis NLS super strain (B. infantis NLS-SS) was previously shown to alleviate gastrointestinal symptoms in newly diagnosed coeliac disease (CD) patients consuming gluten. A high proportion of patients following a gluten-free diet experiences symptoms despite dietary compliance. The role of B. infantis in persistently symptomatic CD patients has not been explored. The aim of the study was to evaluate the effect of B. infantis NLS-SS on persistent gastrointestinal symptoms in patients with CD following a long-term GFD. We conducted a randomised, cross-over, double-blind, placebo-controlled trial in symptomatic adult CD patients on a GFD for at least two years. After one-week run-in, patients were randomised to B. infantis NLS-SS or placebo for 3 weeks with cross-over after a 2-week wash-out period. We estimated changes (Δ) in celiac symptom index (CSI) before and after treatment. Stool samples were collected for faecal microbiota analysis (16S rRNA sequencing). Gluten immunogenic peptide (GIP) excretion in stool and urine samples was measured at each study period. Eighteen patients were enrolled; six patients were excluded due violations in protocol. For patients with the highest clinical burden, CD symptoms were lower in probiotic than in placebo treatment (P=0.046). B. infantis and placebo treated groups had different microbiota profiles as assessed by beta diversity clustering. In probiotic treated groups, we observed an increase in abundance of B. infantis. Treatment with B. infantis was associated with decreased abundance of Ruminococcus sp. and Bifidobacterium adolescentis. GIP excretion in stools and urine was similar at each treatment period. There were no differences in adverse effects between the two groups. B. infantis NLS-SS improves specific CD symptoms in a subset of highly symptomatic treated patients (GFD). This is associated with a shift in stool microbiota profile. Larger studies are needed to confirm these findings. ClinicalTrials.gov: NCT03271138.


Assuntos
Bifidobacterium longum subspecies infantis , Doença Celíaca/terapia , Dieta Livre de Glúten , Microbioma Gastrointestinal , Probióticos/uso terapêutico , Adulto , Carga Bacteriana , Bifidobacterium longum subspecies infantis/crescimento & desenvolvimento , Doença Celíaca/dietoterapia , Doença Celíaca/microbiologia , Estudos Cross-Over , Método Duplo-Cego , Fezes/química , Fezes/microbiologia , Feminino , Glutens/análise , Glutens/urina , Humanos , Masculino , Pessoa de Meia-Idade , Fragmentos de Peptídeos/análise , Fragmentos de Peptídeos/urina , Ruminococcus/crescimento & desenvolvimento
8.
Surgery ; 168(3): 504-508, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32665144

RESUMO

BACKGROUND: Both frailty and older age are risk factors for adverse surgical outcomes. We hypothesized that frailty, regardless of patient age, is a predictor of poor postoperative outcome among patients with rectal cancer undergoing proctectomy. METHODS: Patients with primary rectal cancer undergoing proctectomy between 2012 to 2015 were identified in the database of the National Quality Improvement Program. The simplified, 5-item frailty index was grouped into 0, 1, 2, and ≥3. Outcomes were morbidity and 30-day mortality. RESULTS: This study involved 9,252 patients from the National Quality Improvement Program database. Increasingly frail patients had greater morbidity and mortality (P < .001). Logistic regression revealed that frailty was a predictor of morbidity (odds ratio = 6.7, P < .0001); in contrast, older age was not associated with morbidity when adjusting for frailty (odds ratio = 1.2, P = .14). Both older age and frailty were associated with greater mortality, with frailty (odds ratio = 20.8, P < .0001) more so than older age (odds ratio = 10.3, P < .0001). CONCLUSION: Frailty was more strongly associated with morbidity and mortality than older age in patients undergoing proctectomy. Surgical options can be expanded to older patients with the use of simplified, 5-item frailty index as a decision-making tool.


Assuntos
Fragilidade/epidemiologia , Avaliação Geriátrica/estatística & dados numéricos , Complicações Pós-Operatórias/epidemiologia , Protectomia/efeitos adversos , Neoplasias Retais/cirurgia , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Tomada de Decisão Clínica/métodos , Estudos de Viabilidade , Feminino , Idoso Fragilizado/estatística & dados numéricos , Fragilidade/diagnóstico , Fragilidade/etiologia , Mortalidade Hospitalar , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/etiologia , Neoplasias Retais/complicações , Estudos Retrospectivos , Medição de Risco/métodos , Medição de Risco/estatística & dados numéricos , Fatores de Risco , Resultado do Tratamento , Adulto Jovem
9.
Nat Commun ; 10(1): 786, 2019 02 19.
Artigo em Inglês | MEDLINE | ID: mdl-30783084

RESUMO

The transition temperature Tc of unconventional superconductivity is often tunable. For a monolayer of FeSe, for example, the sweet spot is uniquely bound to titanium-oxide substrates. By contrast for La2-xSrxCuO4 thin films, such substrates are sub-optimal and the highest Tc is instead obtained using LaSrAlO4. An outstanding challenge is thus to understand the optimal conditions for superconductivity in thin films: which microscopic parameters drive the change in Tc and how can we tune them? Here we demonstrate, by a combination of x-ray absorption and resonant inelastic x-ray scattering spectroscopy, how the Coulomb and magnetic-exchange interaction of La2CuO4 thin films can be enhanced by compressive strain. Our experiments and theoretical calculations establish that the substrate producing the largest Tc under doping also generates the largest nearest neighbour hopping integral, Coulomb and magnetic-exchange interaction. We hence suggest optimising the parent Mott state as a strategy for enhancing the superconducting transition temperature in cuprates.

10.
J Chem Phys ; 149(4): 041101, 2018 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-30068200

RESUMO

We apply a recently developed parameter-free double-hybrid density functional belonging to the quadratic-integrand double-hybrid model to calculate association energies (ΔE) and three-body effects (Δ3E) arising from intermolecular interactions in weakly bound supramolecular complexes (i.e., the dataset 3B-69). The model behaves very accurately for trimer association energies and is found to outperform widely used density functional approximations while approaching the accuracy of more costly ab initio methods for three-body effects. The results are further improved when we add some specific corrections for the remaining dispersion interactions, D3(BJ) or VV10 for two-body effects and Axilrod-Teller-Muto for three-body effects, leading to marginal deviations (less than 1 kcal/mol for ΔE and around 0.03-0.04 kcal/mol for Δ3E) with respect to benchmark results.

11.
Phys Chem Chem Phys ; 19(21): 13481-13487, 2017 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-28275771

RESUMO

The PBE-QIDH and SOS1-PBE-QIDH double-hybrid density functionals are merged with a pair of dispersion corrections, namely the pairwise additive D3(BJ) and the non-local correlation functional VV10, leading to the corresponding dispersion-corrected models. The parameters adjusting each of the dispersion corrections to the functionals are obtained by fitting to well-established energy datasets (e.g. S130) used as a benchmark, giving rise to functionals spanning covalent and non-covalent binding forces. The application of the models to challenging systems out of the training set, like those comprising the L7 database of large supramolecular complexes, or the S66x8 dataset of stretched and elongated intermolecular distances, reveals the high accuracy of the coupling.

12.
Phys Rev Lett ; 116(19): 197003, 2016 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-27232037

RESUMO

Here we demonstrate how the Fermi surface topology and quantum many-body interactions can be manipulated via epitaxial strain in the spin-triplet superconductor Sr_{2}RuO_{4} and its isoelectronic counterpart Ba_{2}RuO_{4} using oxide molecular beam epitaxy, in situ angle-resolved photoemission spectroscopy, and transport measurements. Near the topological transition of the γ Fermi surface sheet, we observe clear signatures of critical fluctuations, while the quasiparticle mass enhancement is found to increase rapidly and monotonically with increasing Ru-O bond distance. Our work demonstrates the possibilities for using epitaxial strain as a disorder-free means of manipulating emergent properties, many-body interactions, and potentially the superconductivity in correlated materials.

13.
J Dairy Sci ; 99(7): 5173-5179, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27157571

RESUMO

Thermal treatments are used to improve milk microbial safety, shelf life, and biological activity of some of its components. However, thermal treatments can reduce the nutritional quality of milk, affecting the molecular structure of milk proteins, such as lysozyme, which is a very important milk component due to its antimicrobial effect against gram-positive bacteria. Jenny milk is characterized by high lysozyme content. For this reason, in the last few years, it has been used as an antimicrobial additive in dairy products as an alternative to hen egg white lysozyme, which can cause allergic reactions. This study aimed to investigate the effect of pasteurization and condensation on the concentration and antimicrobial activity of lysozyme in jenny milk. Furthermore, lysozyme quantity and activity were tested in raw and pasteurized milk after condensation at 40 and 20% of the initial volume. Reversed-phase HPLC was performed under fluorescence detection to monitor lysozyme in milk samples. We evaluated the antimicrobial activity of the tested milk against Bacillus megaterium, Bacillus mojavensis, Clavibacter michiganensis, Clostridium tyrobutyricum, Xanthomonas campestris, and Escherichia coli. Condensation and pasteurization did not affect the concentration or antimicrobial activity of lysozyme in jenny milk, except for B. mojaventis, which showed resistance to lysozyme in milk samples subjected to heat treatments. Moreover, lysozyme in jenny milk showed antimicrobial activity similar to synthetic antibiotics versus some gram-positive strains and also versus the gram-negative strain X. campestris.


Assuntos
Anti-Infecciosos/análise , Leite/química , Muramidase/análise , Pasteurização , Animais , Equidae , Temperatura Alta
14.
J Phys Chem A ; 120(10): 1756-62, 2016 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-26901447

RESUMO

We assess here the reliability of orbital optimization for modern double-hybrid density functionals such as the parameter-free PBE-QIDH model. We select for that purpose a set of closed- and open-shell strongly and weakly bound systems, including some standard and widely used data sets, to show that orbital optimization improves the results with respect to standard models, notably for electronically complicated systems, and through first-order properties obtained as derivatives of the energy.

15.
J Chem Phys ; 142(22): 224105, 2015 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-26071699

RESUMO

We have systematically analyzed the performance of some representative double-hybrid density functionals (including PBE0-DH, PBE-QIDH, PBE0-2, XYG3, XYGJ-OS, and xDH-PBE0) for a recently introduced database of diene isomerization energies. Double-hybrid models outperform their corresponding hybrid forms (for example, PBE0-DH, PBE0-2, and PBE-QIDH are more accurate than PBE0) and the XYG3, XYGJ-OS, and xDH-PBE0 functionals perform excellently, providing root mean square deviation values within "calibration accuracy." XYGJ-OS and xDH-PBE0 also rival the best performing post-Hartree-Fock methods at a substantially lower cost.

16.
J Dairy Sci ; 98(8): 5133-42, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26074234

RESUMO

The occurrence of late blowing defects in cheese produces negative effects on the quality and commercial value of the product. In this work, we verified whether the addition of raw jenny milk to bulk cow milk reduced the late blowing defects in semihard cheeses. During cheesemaking, different aliquots of jenny milk were poured into 2 groups of 4 vats, each containing a fixed amount of cow milk. A group of cheeses was created by deliberately contaminating the 4 vats with approximately 3 log10 cfu/mL milk of Clostridium tyrobutyricum CLST01. The other 4 vats, which were not contaminated, were used for a second group of cheeses. After 120 d of ripening, some physical, chemical, and microbiological parameters were evaluated on the obtained semihard cheeses. Differences in sensory properties among cheeses belonging to the uncontaminated group were evaluated by 80 regular consumers of cheese. Our results showed that the increasing addition of jenny milk to cow milk led to a reduction of pH and total bacterial count in both cheese groups, as well as C. tyrobutyricum spores that either grew naturally or artificially inoculated. We observed a progressive reduction of the occurrence of late blowing defects in cheese as consequence of the increasing addition of jenny milk during cheese making. Moreover, the addition of jenny milk did not affect the acceptability of the product, as consumers found no difference among cheeses concerning sensorial aspects. In conclusion, the important antimicrobial activity of lysozyme contained in jenny milk has been confirmed in the current research. It is recommend for use as a possible and viable alternative to egg lysozyme for controlling late blowing defects in cheese.


Assuntos
Queijo/análise , Queijo/microbiologia , Leite/química , Animais , Bovinos , Equidae , Feminino , Muramidase/metabolismo
17.
Nat Nanotechnol ; 9(6): 443-7, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24705511

RESUMO

In an effort to scale down electronic devices to atomic dimensions, the use of transition-metal oxides may provide advantages over conventional semiconductors. Their high carrier densities and short electronic length scales are desirable for miniaturization, while strong interactions that mediate exotic phase diagrams open new avenues for engineering emergent properties. Nevertheless, understanding how their correlated electronic states can be manipulated at the nanoscale remains challenging. Here, we use angle-resolved photoemission spectroscopy to uncover an abrupt destruction of Fermi liquid-like quasiparticles in the correlated metal LaNiO3 when confined to a critical film thickness of two unit cells. This is accompanied by the onset of an insulating phase as measured by electrical transport. We show how this is driven by an instability to an incipient order of the underlying quantum many-body system, demonstrating the power of artificial confinement to harness control over competing phases in complex oxides with atomic-scale precision.

18.
J Chem Phys ; 139(16): 164104, 2013 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-24182001

RESUMO

The present work assesses some recently developed double-hybrid density functionals (B2π-PLYP, PBE0-DH, and PBE0-2) using linear-response Tamm-Dancoff Time-Dependent Density Functional Theory. This assessment is achieved against experimentally derived low-lying excitation energies of large organic dyes of recent interest, including some excitations dominated by charge-transfer transitions. Comparisons are made with some of the best-performing methods established from the literature, such as PBE0 or B3LYP hybrid or the recently proposed B2-PLYP and B2GP-PLYP double-hybrid models, to ascertain their quality and robustness on equal footing. The accuracy of parameter-free or empirical forms of double-hybrid functionals is also briefly discussed. Generally speaking, it turns out that double-hybrid expressions always provide more accurate estimates than corresponding hybrid methods. Double-hybrid functionals actually reach averaged accuracies of 0.2 eV, that can be admittedly considered close to any intended accuracy limit within the present theoretical framework.


Assuntos
Compostos Orgânicos/química , Teoria Quântica , Modelos Moleculares , Conformação Molecular , Termodinâmica , Fatores de Tempo
19.
Phys Chem Chem Phys ; 15(35): 14581-94, 2013 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-23907488

RESUMO

We review why and how double-hybrid density functionals have become new leading actors in the field of computational chemistry, thanks to the combination of an unprecedented accuracy together with large robustness and reliability. Similar to their predecessors, the widely employed hybrid density functionals, they are rooted in the Adiabatic Connection Method from which they emerge in a natural way. We present recent achievements concerning applications to chemical systems of the most interest, and current extensions to deal with challenging issues such as non-covalent interactions and excitation energies. These promising methods, despite a slightly higher computational cost than other typical density-based models, are called to play a key role in the near future and can thus pave the way towards new discoveries or advances.

20.
Phys Rev Lett ; 110(8): 087004, 2013 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-23473191

RESUMO

We report high-resolution angle-resolved photoemission studies of epitaxial thin films of the correlated 4d transition metal oxide ferromagnet SrRuO(3). The Fermi surface in the ferromagnetic state consists of well-defined Landau quasiparticles exhibiting strong coupling to low-energy bosonic modes which contributes to the large effective masses observed by transport and thermodynamic measurements. Upon warming the material through its Curie temperature, we observe a substantial decrease in quasiparticle coherence but negligible changes in the ferromagnetic exchange splitting, suggesting that local moments play an important role in the ferromagnetism in SrRuO(3).

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