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AbstractThe octanol-water partition coefficient of 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC) was investigated using atomistic molecular dynamics simulations via thermodynamic integration and multistate Bennett acceptance ratio methods. The GAFF and CHARMM36 force fields were used with six water models widely used in molecular dynamics simulations. The OPC4 water model provided the best agreement with the experimental octanol-water partition coefficient of DPPC using the two force fields. However, there is still plenty of room for improvement in water models with correct estimation of surface tension that uses better and suitable non-bonded interaction parameters between water-water and water-DPPC. The Gibbs free energy of transferring DPPC from octanol to water phase was calculated to be 19.8 ± 0.3 and 20.2 ± 0.3 kcal mol−1, giving a partition coefficient of 14.5 ± 0.4 and 14.8 ± 0.3 for the GAFF and CHARMM36 force fields, respectively. This study reinforces the importance of developing new water models that reproduce experimental surface tensions to reconcile the water-water and water-DPPC non-bonded interactions and the existing discrepancy between experimental measurements of amphiphilic molecules that are important in many areas of scientific applications and industry such as biophysics, surfactant, colloids, membranes, medicine, nanotechnology, and food and pharmaceutical industries, and so on. It raises two important open questions: Is the experimental octanol-water partition coefficient of DPPC reliable? Or is its calculation accurate using the OPC4 water model? With respect to the experimental measurements, there may be non-treated aspects such as the formation of aggregates in aqueous phase and limit of detection of the applied method. And, in the calculation, some effects are not possible to be considered in a correct way or viable time such as calculating quantum effects, sampling all conformations, considering phase transitions, and correctly evaluating the intermolecular forces to estimate an accurate surface tension.Communicated by Ramaswamy H. Sarma

AbstractThe interactions of the antiviral pentapeptide ATN-161 with the closed and open conformations of the α5β1 integrin, the SARS-CoV-2 major protease, and the omicron variant spike protein complexed with hACE2 were studied using molecular docking and molecular dynamics simulation. Molecular docking was performed to obtain ATN-161 binding poses with these studied protein targets. Subsequently, molecular dynamics simulations were performed to verify the ligand stability at the binding site of each protein target. Pulling simulations, umbrella sampling, and weighted histogram analysis method were used to obtain the potential of mean force of each system and calculate the Gibbs free energy of binding for the ATN-161 peptide in each binding site of these protein targets. The results showed that ATN-161 binds to α5β1 integrin in its active and inactive form, binds weakly to the omicron variant spike protein complexed with hACE2, and strongly binds to the main protease target.Communicated by Ramaswamy H. Sarma

Purpose: This paper addresses the evaluation of traditional wooden floors, based on (1) visual strength grading (VSG) techniques adopted for ancient wooden structures; (2) a new approach to biological damage and (3) structural safety analysis. This assessment includes complex concepts. Therefore, the study presents a highly needed practical tool to help technicians make a preliminary assessment whereby many of the timber elements in our heritage can be saved from removal. Design/methodology/approach: A simple and effective procedure was developed for each step. An inspection and diagnosis datasheet was drawn up, and the structural analysis presented by the Eurocodes was summarized. This methodology was then applied in a case study to demonstrate the complete procedure. During the assessment of this sort of structures, the drilling technique was a relevant method utilized as it provided essential and clear information about the beams' conservation. Findings: The case study results indicate that 70% of the beams of the analysed structure exceed strict minimum performance criteria. This shows that other similar buildings can have their wooden elements saved from demolition, which is not the current regular refurbishment approach. Originality/value: The current reality shows that the technicians' lack of capacity for a pragmatic assessment of the timber members’ structural capacity promotes their disinterest in them. To avoid that, this text presents a process for evaluating wooden floors using a simple and clear approach. This will prevent the demolition of wooden elements and instead encourage their preservation.

This work describes a novel hybrid polymer composite made from sugarcane bagasse and discarded rubber particles. A 25full factorial design is performed to identify the effects of bagasse fibres and rubber particles on the physical and mechanical properties of the composites. The mechanical properties are evaluated by tensile and compression tests, and the physical properties by apparent porosity, water absorption and bulk density. The mechanical and physical properties are substantially affected by the amount and size of the rubber particles. The length and treatment of bagasse fibres affect the stiffness and strength of the composites with less contribution. The presence of sugarcane bagasse increases the compressive toughness of hybrid composites.

This viewpoint intends to show recent open issues of using coarse grained models in molecular dynamics simulation. It reviews the current knowledge of the comparison between experimental and simulation data of structural and physical chemical properties that depend on the hydrophilic and hydrophobic behavior of the molecule.

O presente trabalho teve como objetivo identificar parâmetros de segurança para realização da via de acesso cirúrgico posterior da escápula por meio de um estudo transversal em cadáveres.

In neonatal units, a significant number of newborns and their respective parents and families are hospitalized, each with culturally distinct practices and perspectives that require specialized knowledge. However, the literature lacks comprehensive evidence depicting culturally competent nursing care that concurrently promotes parental empowerment in the neonatal units.

As lesões da cabeça longa do tendão bicipital (CLB) são comuns na prática clínica e podem ter causas degenerativas, inflamatórias, instabilidades (subluxação ou luxação) ou traumáticas. Geralmente, elas estão associadas a outras doenças do ombro, principalmente a lesões do manguito rotador. Atualmente, existem controvérsias quanto às indicações dos tratamentos cirúrgicos e à escolha da melhor técnica para cada caso, devido à possibilidade de deformidade estética, perda da força muscular e dor residual.

Os autores fizeram o acesso posterossuperior do ombro usado no tratamento cirúrgico da luxação acromioclavicular, a partir da dissecção de 20 ombros de 10 cadáveres adultos recém‐resfriados, e analisaram as distâncias da via às estruturas neurovasculares próximas.

Correlacionar os resultados funcionais e os índices radiográficos das fraturas do úmero proximal tratadas com placa anatômica bloqueada para úmero proximal.

A fratura impactada em valgo do úmero proximal é considerada um tipo especial de fratura, pois a impactação metafisária da cabeça umeral, com manutenção do periósteo póstero‐medial, melhora seu prognóstico quanto à ocorrência de necrose avascular. Essa característica pode, ainda, facilitar a manobra de redução e aumentar o índice de consolidação dessas fraturas, mesmo nos casos mais complexos. Os estudos incluídos foram pesquisados nas bases de dados Bireme, Medline, PubMed, Cochrane Library e Google Scholar publicados de 1991 a 2013. O objetivo deste estudo foi identificar a definição, classificação e os métodos de tratamento dessas fraturas mais usados na literatura médica ortopédica.

Avaliar a evolução do resultado funcional da hemiartroplastia CTA®no tratamento cirúrgico da artropatia degenerativa do manguito rotador com um seguimento médio de 5,4 anos.

Estabelecer uma zona de segurança neurovascular no acesso cirúrgico do terço médio da clavícula por dissecção em cadáveres.

Avaliar os resultados funcionais do reparo artroscópico da lesão SLAP pelo portal descrito por O’Brien.

Avaliar radiologicamente a cicatrização dos ligamentos coracoclaviculares após o tratamento cirúrgico para luxação acromioclavicular.

Fractures of the facial skeleton are relatively uncommon in children and adolescents, and only a few reports review a significant number of patients. The authors performed a retrospective study to analyze the different characteristics of such fractures in the pediatric population of Portugal.

Containing the global severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has been an unprecedented challenge due to high horizontal transmissivity and asymptomatic carriage rates. Lateral flow device (LFD) immunoassays were introduced in late 2020 to detect SARS-CoV-2 infection in asymptomatic or presymptomatic individuals rapidly. While LFD technologies have been used for over 60 years, their widespread use as a public health tool during a pandemic is unprecedented. By the end of 2020, data from studies into the efficacy of the LFDs emerged and showed these point-of-care devices to have very high specificity (ability to identify true negatives) but inadequate sensitivity with high false-negative rates. The low sensitivity (<50%) shown in several studies is a critical public health concern, as asymptomatic or presymptomatic carriers may wrongly be assumed to be noninfectious, posing a significant risk of further spread in the community. Here, we show that the direct visual readout of SARS-CoV-2 LFDs is an inadequate approach to discriminate a potentially infective viral concentration in a biosample. We quantified significant immobilized antigen–antibody-labeled conjugate complexes within the LFDs visually scored as negative using high-sensitivity synchrotron X-ray fluorescence imaging. Correlating quantitative X-ray fluorescence measurements and quantitative reverse transcription-polymerase chain reaction (qRT-PCR) determined numbers of viral copies, we identified that negatively scored samples could contain up to 100 PFU (equivalent here to ∼10 000 RNA copies/test). The study demonstrates where the shortcomings arise in many of the current direct-readout SARS-CoV-2 LFDs, namely, being a deficiency in the readout as opposed to the potential level of detection of the test, which is orders of magnitude higher. The present findings are of importance both to public health monitoring during the Coronavirus Disease 2019 (COVID-19) pandemic and to the rapid refinement of these tools for immediate and future applications.

The article discusses the detection of water transitions in space, noting a study published in "Astronomy & Astrophysics" journal in which the Atacama Large Millimeter Array was used and detected the molecules in a neary spiral galaxy.