Sleeve gastrectomy reveals the plasticity of the human gastric epithelium.

Gastrin is secreted following a rise in gastric pH, leading to gastric acid secretion. Sleeve gastrectomy (SG), a bariatric surgery where 80% of the gastric corpus is excised, presents a challenge for gastric pH homeostasis. Using histology, and single-cell RNA sequencing of the gastric epithelium in 12 women, we observed that SG is associated with an increase in a sub-population of acid-secreting parietal cells that overexpress respiratory enzymes and an increase in histamine-secreting enterochromaffin-like cells (ECLs).

The Role of Aqueous Solvation on the Intersystem Crossing of Nitrophenols.

The photochemistry of nitrophenols is a source of smog as nitrous acid is formed from their photolysis. Nevertheless, computational studies of the photochemistry of these widespread toxic molecules are scarce. In this work, the initial photodeactivation of -nitrophenol and -nitrophenol is modeled, both in gas phase and in aqueous solution to simulate atmospheric and aerosol environments.

A Local Diabatisation Method for Two-State Adiabatic Conical Intersections.

A methodology to locally characterize conical intersections (CIs) between two adiabatic electronic states for which no nonadiabatic coupling (NAC) vectors are available is presented. Based on the Hessian and gradient at the CI, the branching space coordinates are identified. The potential energy surface around the CI in the branching space is expressed in the diabatic representation, from which the NAC vectors can be calculated in a wave-function-free, energy-based approach.

Spin-Orbit Couplings for Nonadiabatic Molecular Dynamics at the ΔSCF Level.

A procedure for the calculation of spin-orbit coupling (SOC) at the delta self-consistent field (ΔSCF) level of theory is presented. Singlet and triplet excited electronic states obtained with the ΔSCF method are expanded into a linear combination of singly excited Slater determinants composed of ground electronic state Kohn-Sham orbitals. This alleviates the nonorthogonality between excited and ground electronic states and introduces a framework, similar to the auxiliary wave function at the time-dependent density functional theory (TD-DFT) level, for the calculation of observables.

The ΔSCF method for non-adiabatic dynamics of systems in the liquid phase.

Computational studies of ultrafast photoinduced processes give valuable insights into the photochemical mechanisms of a broad range of compounds. In order to accurately reproduce, interpret, and predict experimental results, which are typically obtained in a condensed phase, it is indispensable to include the condensed phase environment in the computational model. However, most studies are still performed in vacuum due to the high computational cost of state-of-the-art non-adiabatic molecular dynamics (NAMD) simulations.

The photodissociation of solvated cyclopropanone and its hydrate explored non-adiabatic molecular dynamics using ΔSCF.

The decay of cyclopropanone is a typical example of a photodecomposition process. Ethylene and carbon monoxide are formed following the excitation to the first singlet excited state through a symmetrical or asymmetrical pathway. The results obtained with non-adiabatic molecular dynamics (NAMD) using the delta self-consistent field (ΔSCF) method correspond well to previous experimental and multireference theoretical studies carried out in the gas phase.

ΔSCF with Subsystem Density Embedding for Efficient Nonadiabatic Molecular Dynamics in Condensed-Phase Systems.

An approach combining subsystem density embedding with the variational delta self-consistent field is presented, which extends current capabilities for excited-electronic-state calculations. It was applied on full-atomic nonadiabatic dynamics of a solvated diimide system, demonstrating that comparable accuracy can be achieved for this system for the investigated configuration space and with a shorter simulation time than the computationally more expensive conventional Kohn-Sham density functional theory-based method. This opens a new pragmatic technique for efficient simulation of nonadiabatic processes in the condensed phase, in particular, for liquids.

Trajectory Surface Hopping Nonadiabatic Molecular Dynamics with Kohn-Sham ΔSCF for Condensed-Phase Systems.

We present an efficient approach for surface hopping-based nonadiabatic dynamics in the condensed phase. For the systems studied, a restricted Kohn-Sham orbital formulation of the delta self-consistent field (ΔSCF) method was used for efficient calculation of excited electronic states. Time-dependent density functional theory (DFT) is applied to aid excited-state SCF convergence and provide guess electronic state densities.

Reliability of the bicaudate parameter in the revealing of the enlarged lateral Ventricles in schizophrenia patients.

Introduction: In schizophrenia patients the lateral ventricle enlargement has mostly been reported in relationship with smaller cortical and/or subcortical brain volumes; and it has been observed that ventricular system growth may be a consequence of the smaller caudate nucleus volume. Bicaudate parameters have been used in the Alzheimer dementia and Huntington's chorea diagnosing in order to evaluate brain changes and the enlargement of the lateral ventricles.

Subjects And Methods: This study has been carried out on 140 patients out of which 70 patients (30 men and 40 women) who met the ICD 10 criteria for schizophrenia and 70 healthy controls (30 men and 40 women) matched on sex and age with the studied group.

Clinical Significance of the Cerebral Perforating Arteries.

There is scarce data in the contemporary literature regarding the correlation of the microanatomy of the perforating arteries, their atherosclerosis, and the ischemia in their territory. In order to examine, at least partially, those parameters, the perforating arteries of 12 brains were microdissected or their vascular casts were obtained. In addition, 30 specimens of the perforators were used for a histological and immunohistochemical study.

Mechanism of ultrafast non-reactive deactivation of the retinal chromophore in non-polar solvents.

The photoisomerization of the all-trans protonated Schiff base of retinal (SBR) in solution is highly inefficient. The present theoretical and experimental investigation aims at disclosing the mechanisms of ultrafast, non-reactive relaxation of SBR that lead to the drastic decrease in the isomerization yield in non-polar solvents. Our pump-probe measurements demonstrate the sensitivity of the all-trans SBR excited-state dynamics on the electrostatic interaction with the surrounding counterions and the crucial importance of the chromophore microenvironment.

Nonradiative Relaxation Mechanisms of UV Excited Phenylalanine Residues: A Comparative Computational Study.

The present work is directed toward understanding the mechanisms of excited state deactivation in three neutral model peptides containing the phenylalanine residue. The excited state dynamics of theγL(g+)folded form of N-acetylphenylalaninylamide (NAPA B) and its amide-N-methylated derivative (NAPMA B) is reviewed and compared to the dynamics of the monohydrated structure of NAPA (NAPAH). The goal is to unravel how the environment, and in particular solvation, impacts the photodynamics of peptides.

Kinematic magnetic resonance imaging study of the brain stem and cervical cord by dynamic neck motion.

Background: The aim was to examine the position of the brain stem and cervical cord following the neck flexion and extension.

Materials And Methods: The serial sagittal T2-weighted magnetic resonance imaging (MRI) sections of the cervical cord and brain stem were made in 6 volunteers. The images were mainly used to measure certain distances and angles of the brain stem and cervical cord in the neutral position, and then following the head and neck flexion and extension.

Long-term Effects of Maternal Deprivation on the Volume, Number and Size of Neurons in the Amygdala and Nucleus Accumbens of Rats.

Background: Maternal deprivation (MD) in rodents is an important neurodevelopmental model for studying a variety of behavioral changes which closely resemble the symptoms of schizophrenia in humans.

Subjects And Methods: To determine whether early-life stress leads to changes in the limbic system structures: the amygdala and the nucleus accumbens, 9-day-old Wistar rats were exposed to 24 hour MD. On P60 the rats were sacrificed for morphometric analysis and their brains were compared to the control group.

Timescales of N-H bond dissociation in pyrrole: a nonadiabatic dynamics study.

The excitation wavelength dependent photodynamics of pyrrole are investigated by nonadiabatic trajectory-surface-hopping dynamics simulations based on time dependent density functional theory (TDDFT) and the algebraic diagrammatic construction method to the second order (ADC(2)). The ADC(2) results confirm that the N-H bond dissociation occurring upon excitation at the origin of the first excited state, S1(πσ*), is driven by tunnelling [Roberts et al., Faraday Discuss.

Calculating CD Spectra of Flexible Peptides: An Assessment of TD-DFT Functionals.

Calculations of CD spectra can provide important structural information for peptide systems. Although TD-DFT is an attractive method for these calculations, recent studies have pointed to problems with modeling charge transfer excitations. Motivated by these problems, we benchmarked the performances of CAM-B3LYP, ωB97X-D, M06-2X, B3LYP, and PBE0 against high level ab initio RICC2 calculations for selected peptide structures.

Mechanisms of photostability in kynurenines: a joint electronic-structure and dynamics study.

Kynurenines are UV filters found in the human ocular lens which protect the retina from radiation damage. We report on ab initio investigations of the photochemistry of the cis and trans conformers of kynurenine and of an intramolecularly hydrogen-bonded conformer of 3-hydroxykynurenine O-β-D-glucoside. We have explored the excited-state reaction paths for several radiationless excited-state deactivation processes in kynurenines.

Alternative method for direct measurement of tibial slope.

Background/aim: The tibial slope is one of the most frequently cited anatomical causes of anterior cruciate ligament trauma. The aim of this study was to determine the possibility of direct measuring of the tibial slope of the knee without prior soft tissue dissection in cadavers.

Methods: Measurement was performed on the two groups of samples: osteological and cadaveric.

Non-radiative relaxation of UV photoexcited phenylalanine residues: probing the role of conical intersections by chemical substitution.

A conformation-selective photophysics study in phenylalanine model peptides, combining pump-probe gas phase experiments and excited state calculations, highlights for the first time the quenching properties of a primary amide group (through its nπ* excited state) along with the effect of vibrational energy that facilitates access to the conical intersection area.

[Surgical anatomy of the initial segment of the lateral circumflex femoral artery].

Introduction: The lateral circumflex femoral artery usually originates from the lateral side of the initial part of the deep femoral artery, or less frequently from the femoral artery. If it is a branch of the femoral artery, it arises directly above the point of origin of the deep femoral artery. The aim of this study was to determine the origin of the lateral circumflex femoral artery, its origin distance from the midpoint of the inguinal ligament and the topographical relations of the origin, which have a great significance in clinical work.

Origin of the medial circumflex femoral artery--a cadaver study.

Aim: To determine the pattern of origin of medial circumflex femoral artery (MCFA), its origin distance from the midpoint of the inguinal ligament and the topographical relations of the origin, which have great significance in clinical work.

Methods: Dissections on the autopsy group of 42 thighs were performed, and anatomical relationships of MCFA was analyzed. All data were entered into a scheme of the protocol which was designed for this research containing the case number, age and sex, side, topographical-anatomical relations of MCFA, artery dimensions and variations, and the distance between the place of origin of MCFA and the midpoint of the inguinal ligament.

[The importance of cytology in diagnosing rare breast carcinoma--two case reports].

Introduction: This paper presents two cases of very rare tumors of breast: breast sebaceos carcinoma, which has rarely been described in medical literature, and breast carcinosarcoma. Morphological characteristics and biological behavior of sebaceos carcinoma are still rather vague. Carcinosarcoma of the breast is a rare malignancy with distinct cell lines described as a breast carcinoma of ductal type with a sarcoma-like component.

Unraveling the mechanisms of nonradiative deactivation in model peptides following photoexcitation of a phenylalanine residue.

The mechanisms of nonradiative deactivation of a phenylalanine residue after near-UV photoexcitation have been investigated in an isolated peptide chain model (N-acetylphenylalaninylamide, NAPA) both experimentally and theoretically. Lifetime measurements at the origin of the first ππ* state of jet-cooled NAPA molecules have shown that (i) among the three most stable conformers of the molecule, the folded conformer NAPA B is ∼50-times shorter lived than the extended major conformer NAPA A and (ii) this lifetime is virtually insensitive to deuteration at the NH(2) and NH sites. Concurrent time-dependent density functional theory (TDDFT) based nonadiabatic dynamics simulations in the full dimensionality, carried out for the NAPA B conformer, provided direct insights on novel classes of ultrafast deactivation mechanisms, proceeding through several conical intersections and leading in fine to the ground state.

Photoinduced dynamics of formic acid monomers and dimers: the role of the double hydrogen bond.

Nonadiabatic dynamics in the framework of time-dependent density functional theory was used to simulate gas-phase relaxation dynamics of pairs of conformations of formic acid monomers (cis and trans FAM) and dimers (acyclic aFAD and cyclic cFAD). In the early phase of the excited state dynamics, elongation of the C═O bond and pyramidalization of the carbon atom is observed in both FAM and FAD. Subsequently, the photodynamics of FAM is shown to be dominated by fragmentation processes occurring mostly in the excited state and resulting in HCO and OH radicals.

[The influence of the morphometric parameters of the intercondylar notch on rupture of the anterior cruciate ligament].

Background/aim: Morpohometric parameters of the intercondylar notch of femur present one of the substantial risk factors for rupture of the anterior cruciate ligament (ACL). In morphometric studies of the knee the most often referred indexes are notch width index and notch shape index. The aim of this study was to identificate the morphometric parameters of the intercondylar notch as risk factors for ACL rupture.