Effect of acylation on the interaction of the N-Terminal segment of pulmonary surfactant protein SP-C with phospholipid membranes.

AbstractSP-C, the smallest pulmonary surfactant protein, is required for the formation and stability of surface-active films at the air–liquid interface in the lung. The protein consists of a hydrophobic transmembrane α-helix and a cationic N-terminal segment containing palmitoylated cysteines. Recent evidence suggests that the N-terminal segment is of critical importance for SP-C function. In the present work, the role of palmitoylation in modulating the lipid–protein interactions of the N-terminal segment of SP-C has been studied by analyzing the effect of palmitoylated and non-palmitoylated synthetic peptides designed to mimic the N-terminal segment on the dynamic properties of phospholipid bilayers, recorded by spin-label electron spin resonance (ESR) spectroscopy. Both palmitoylated and non-palmitoylated peptides decrease the mobility of phosphatidylcholine (5-PCSL) and phosphatidylglycerol (5-PGSL) spin probes in dipalmitoylphosphatidylcholine (DPPC) or dipalmitoylphosphatidylglycerol (DPPG) bilayers. In zwitterionic DPPC membranes, both peptides have a greater effect at temperatures below than above the main gel-to-liquid-crystalline phase transition, the palmitoylated peptide inducing greater immobilisation of the lipid than does the non-palmitoylated form. In anionic DPPG membranes, both palmitoylated and non-palmitoylated peptides have similar immobilizing effects, probably dominated by electrostatic interactions. Both palmitoylated and non-palmitoylated peptides have effects comparable to whole native SP-C, as regards improving the gel phase solubility of phospholipid spin probes and increasing the polarity of the bilayer surface monitored by pK shifts of fatty acid spin probes. This indicates that a significant part of the perturbing properties of SP-C in phospholipid bilayers is mediated by interactions of the N-terminal segment. The effect of SP-C N-terminal peptides on the chain flexibility gradient of DPPC and DPPG bilayers is consistent with the existence of a peptide-promoted interdigitated phase at temperatures below the main gel-to-liquid-crystalline phase transition. The palmitoylated peptide, but not the non-palmitoylated version, is able to stably segregate interdigitated and non-interdigitated populations of phospholipids in DPPC bilayers. This feature suggests that the palmitoylated N-terminal segment stabilizes ordered domains such as those containing interdigitated lipids. We propose that palmitoylation may be important to promote and facilitate association of SP-C and SP-C-containing membranes with ordered lipid structures such as those potentially existing in highly compressed states of the interfacial surfactant film

Parámetros reproductivos y distribución geográfica potencial de las áreas de anidación de Grus canadensis nesiotes (Aves, Gruidae) en Cuba: implicaciones para su conservación

Grus canadensis nesiotes (grulla cubana) es una subespecie endémica de Cuba que se encuentra en peligro de extinción. A pesar de estar directamente relacionada con los humedales, no existen estudios que contribuyan a su gestión y conservación. Por ello, se registraron parámetros reproductivos de la subespecie durante ocho temporadas reproductivas entre 2005 y 2015 en un humedal de Cuba; asimismo, se modeló y caracterizó la distribución geográfica potencial de las áreas de anidación, y se analizó su representación dentro de las áreas protegidas (AP). Para elaborar el modelo, se utilizaron el algoritmo de máxima entropía y variables de hábitat (100  m de tamaño de píxel). Para caracterizar la distribución potencial, se calculó la superficie ocupada por cada uso de suelo y tipo de vegetación dentro de dicha área de distribución. Se empleó el mismo procedimiento para calcular la superficie de la distribución que está protegida. Se localizaron 151  nidos en herbazales de ciénaga. Se trataba de plataformas simples sobre suelo húmedo o agua; los más grandes se observaron en 2006. El 70% de los nidos tuvieron dos huevos (1,7 huevos/nido) y el 63,5% fueron exitosos con 1,6 polluelos/nido exitoso. El hábitat potencial de anidación es estrecho (242 km2) y se localiza en el centro del humedal. De la distribución prevista, la superficie con alta probabilidad de presencia es del 13,8%. El 60% del herbazal de ciénaga de la zona del estudio estaba comprendido dentro de la distribución potencial, mientras que la proporción de cultivos (1,2%) y pastizales (2,1%) era baja. Las AP gestionadas solo protegen el 39,1% de la distribución potencial de los sitios de anidación y el 12% de las zonas con alta probabilidad. Se proponen tres sitios prioritarios para estudiar la anidación de la subespecie y hacer un seguimiento de la misma. Las medidas de conservación de la subespecie deberían considerar la distribución geográfica potencial de los sitios de anidación dentro y fuera de las AP.Grus canadensis nesiotes (grulla cubana) es una subespecie endémica de Cuba que se encuentra en peligro de extinción. A pesar de estar directamente relacionada con los humedales, no existen estudios que contribuyan a su gestión y conservación. Por ello, se registraron parámetros reproductivos de la subespecie durante ocho temporadas reproductivas entre 2005 y 2015 en un humedal de Cuba; asimismo, se modeló y caracterizó la distribución geográfica potencial de las áreas de anidación, y se analizó su representación dentro de las áreas protegidas (AP). Para elaborar el modelo, se utilizaron el algoritmo de máxima entropía y variables de hábitat (100  m de tamaño de píxel). Para caracterizar la distribución potencial, se calculó la superficie ocupada por cada uso de suelo y tipo de vegetación dentro de dicha área de distribución. Se empleó el mismo procedimiento para calcular la superficie de la distribución que está protegida. Se localizaron 151  nidos en herbazales de ciénaga. Se trataba de plataformas simples sobre suelo húmedo o agua; los más grandes se observaron en 2006. El 70% de los nidos tuvieron dos huevos (1,7 huevos/nido) y el 63,5% fueron exitosos con 1,6 polluelos/nido exitoso. El hábitat potencial de anidación es estrecho (242 km2) y se localiza en el centro del humedal. De la distribución prevista, la superficie con alta probabilidad de presencia es del 13,8%. El 60% del herbazal de ciénaga de la zona del estudio estaba comprendido dentro de la distribución potencial, mientras que la proporción de cultivos (1,2%) y pastizales (2,1%) era baja. Las AP gestionadas solo protegen el 39,1% de la distribución potencial de los sitios de anidación y el 12% de las zonas con alta probabilidad. Se proponen tres sitios prioritarios para estudiar la anidación de la subespecie y hacer un seguimiento de la misma. Las medidas de conservación de la subespecie deberían considerar la distribución geográfica potencial de los sitios de anidación dentro y fuera de las AP.Reproductive parameters and potential geographical distribution of nesting areas of Grus canadensis nesiotes (Aves, Gruidae) in Cuba: conservation implications Grus canadensis nesiotes (Cuban sandhill crane) is an endemic and endangered subspecies from Cuba. Protection of wetland habitats is essential for survival of this species, but studies that could contribute to its management and conservation are lacking. In this study we recorded the reproductive parameters of Grus canadensis nesiotes in eight breeding seasons between 2005 and 2015 in a wetland of Cuba. We modeled and characterized the potential geographical distribution of the nesting areas, analyzing its representation within protected areas. Maximum entropy algorithm and habitat variables were used for modeling (100 m of pixel size). To characterize the potential distribution we calculated each land–use–vegetation within the potential distribution. We used the same procedure to determine the extent of the protected area. A hundred and fifty–one nests were located in marsh grasslands. These nests were simple platforms built on wet soil/water; the largest nests were observed in 2006. Seventy percent of nests had two eggs (1.7 eggs/nest) and 63.5% were successful with 1.6 chicks per successful nest. The potential nesting habitat is a narrow stretch (242 km2) located in the center of the wetland. The area with high probability of presence makes up 13.8% of the predicted distribution. Sixty percent of marsh grassland of the study area was included in the potential distribution, while the proportion of crops (1.2%) and pastures (2.1%) was low. Managed protected areas cover only 39.1% of the potential distribution of the nesting sites and 12% of the high probability areas. We propose three priority sites to study and monitor nesting of the subspecies. Species conservation actions should consider the potential geographical distribution of nesting sites both inside and outside the protected areas

Checklist for the Multidisciplinary Approach to United Airway in Patients with Chronic Rhinosinusitis with Nasal Polyps (CRSwNP) and asthma

Dear Editor, The united airways concept calls for a multidisciplinary approach to asthma and/or chronic rhinitis/rhinosinusitis (CRS), aimed at integral airway treatment1, 2 and better coordination among specialists.3 Failure to treat rhinitis/rhinosinusitis is associated with poor asthma control, especially of severe asthma.4, 5 Biological treatments targeting type 2 (T2) inflammatory mediators in severe respiratory diseases offer a new therapeutic option directed against the pathophysiological mechanism of these difficult-to-control united airways diseases (UAD)..

Heating ventilation and air-conditioned configurations for hotels an approach review for the design and exploitation

The tourism sector is one of the main worldwide economic sectors with sustained growth, demonstrating its strength and resilience. In this sector, energy uses have increased to ensure quality, guest comfort, and rate level requirements being a building with great energy consumption. Several factors influence and can produce a significant variation in hotel consumption even in facilities located in the same region; the difference in a four-star hotel can reach 114 kWh/m2 /year. This paper deals with related aspects such as hotel design, operation, type of service, occupancy patterns, operating point and efficiency of a heating, ventilation, and air conditioning (HVAC) system where 30 to 50% of the energy is consumed. Also, previous works based on the implementation of non-conventional energy resources such as photovoltaics projects to replace fuel dependence and high costs in electricity bills were reviewed. where there are savings of up to 30% in electricity and 60% in gas consumption. However, the initial capital investment and payback period are high and require new features to be considered in these facilities

Integrating dual C and N isotopic approach to elemental and mathematical solutions for improving the PM source apportionment in complex urban and industrial cities: Case of Tarragona - Spain

Identification of dominant airborne Particulate Matter (PM) sources is essential for maintaining high air quality standards and thus ensuring a good public health. In this study, different approaches were applied for source apportionment of three PM fractions (PM1, PM2.5 and PM10) at the outdoor of 14 schools of a coastal city with a significant land use interweaving such as Tarragona (Spain). PM were collected in 24h-quartz microfiber filters in two seasonal campaigns (cold and warm), together with nine local potential sources, so a total of 84 samples were chemically, mineralogically, and isotopically characterised. Source apportionment was assessed by (i) main chemical components, (ii) Principal Component Analysis (PCA), (iii) dual C and N isotope approach, and (iv) a Bayesian isotope mixing model. When chemical concentrations were grouped into marine, crustal, secondary inorganic aerosols and organic matter + elemental carbon categories, the unaccounted component reached 45% of PM mass. The PCA allowed to identify also traffic and industrial contributions, reducing the unaccounted mass to about 25%. Adding δ13C and δ15N values, secondary organic aerosol could be estimated and a continuous contribution of diesel combustion was identified together with a remarkable use of natural gas in winter. Isotopic values were better understood when considering air masses back trajectories and a possible long-distance contribution from coal-fired electric generating units (EGUs). Finally, using Bayesian dual isotope mixing models, the unaccounted PM mass was reduced up to 5% when adding these EGUs to marine-carbonate related, road traffic, domestic heating, waste incinerator and livestock waste contributions. The added value of the dual isotope approach combined with a Bayesian isotope mixing model, in comparison with conventional chemical approaches, was thus demonstrated for PM source apportionment in an urban and industrial site where many sources and processes converge and can then be applied to other complex cities

Brote nosocomial de COVID-19 en una planta de medicina interna: probable transmisión aérea

Transmissió aèria; Brot; COVID-19Transmisión aérea; Brote; COVID-19Airborne transmission; Outbreak; COVID-19Background and objectives: Despite the increasing evidence supporting the importance of airborne transmission in SARS-CoV-2 infection, it has not been considered relevant in the vast majority of reported nosocomial outbreaks of COVID-19. The aim of this study is to describe a nosocomial outbreak of SARS-CoV-2 infection whose features suggest that aerosol transmission had an important role. Methods: This is a descriptive analysis of a nosocomial outbreak of SARS-CoV-2 infection in an internal medicine ward that occurred in December 2020. All cases were confirmed by a positive PCR test for SARS-CoV-2. Results: From December 5 to December 17, 21 patients and 44 healthcare workers (HCWs) developed a nosocomial SARS-CoV-2 infection. Fifty-one of the 65 cases (78.5%) were diagnosed between December 6 and 9. The attack rate in patients was 80.8%. Among HCWs, the attack rate was higher in those who had worked at least one full working day in the ward (56.3%) than in those who had occasionally been in the ward (25.8%; p = 0.005). Three days before the first positive case was detected, two extractor fans were found to be defective, affecting the ventilation of three rooms. Sixteen cases were asymptomatic, 48 cases had non-severe symptoms, and 2 cases required admission to the intensive care unit. All patients eventually recovered. Conclusion: The high attack rate, the explosive nature of the outbreak, and the coincidence in time with the breakdown in air extractors in some rooms of the ward suggest that airborne transmission played a key role in the development of the outbreak.Antecedentes y objetivos A pesar de los datos cada vez mayores que respaldan la importancia de la transmisión aérea en la infección por el SARS-CoV-2, en la inmensa mayoría de los brotes nosocomiales descritos de COVID-19 no se ha considerado relevante. El objetivo de este estudio consiste en describir un brote nosocomial de infección por el SARS-CoV-2 cuyas características indican que la transmisión por aerosoles desempeñó un papel importante. Métodos Se trata de un análisis descriptivo de un brote nosocomial de infección por el SARS-CoV-2 en una planta de Medicina Interna que tuvo lugar en diciembre de 2020. Todos los casos se confirmaron mediante una PCR positiva para SARS-CoV-2. Resultados Entre el 5 y el 17 de diciembre, 21 pacientes y 44 profesionales sanitarios contrajeron una infección nosocomial por el SARS-CoV-2. De los 65 casos, 51 (78,5%) se diagnosticaron entre el 6 y el 9 de diciembre. La tasa de ataque en los pacientes fue del 80,8%. Entre los profesionales sanitarios, la tasa de ataque fue mayor en los que habían trabajado al menos una jornada laboral completa en la planta (56,3%) que en los que habían estado ocasionalmente en ella (25,8%; p = 0,005). Tres días antes de detectar el primer caso positivo se identificó una avería en dos extractores de aire, que afectó a la ventilación de tres habitaciones. Dieciséis casos cursaron de forma asintomática, 48 manifestaron síntomas leves y 2 precisaron ingreso en la unidad de cuidados intensivos. Todos los casos se recuperaron finalmente. Conclusiones La elevada tasa de ataque, la naturaleza explosiva del brote y la coincidencia en el tiempo con la avería de los extractores de aire en algunas habitaciones de la planta indican que la transmisión aérea desempeñó un papel fundamental en el desarrollo del brote

Non-Full Sbox Linearization: Applications to Collision Attacks on Round-Reduced Keccak

The Keccak hash function is the winner of the SHA-3 competition and became the SHA-3 standard of NIST in 2015. In this paper, we focus on practical collision attacks against round-reduced Keccak hash function, and two main results are achieved: the first practical collision attacks against 5-round Keccak-224 and an instance of 6-round Keccak collision challenge. Both improve the number of practically attacked rounds by one. These results are obtained by carefully studying the algebraic properties of the nonlinear layer in the underlying permutation of Keccak and applying linearization to it. In particular, techniques for partially linearizing the output bits of the nonlinear layer are proposed, utilizing which attack complexities are reduced significantly from the previous best results

Cryptanalysis of 1-Round KECCAK

In this paper, we give the first pre-image attack against 1- round KECCAK-512 hash function, which works for all variants of 1- round KECCAK. The attack gives a preimage of length less than 1024 bits by solving a system of 384 linear equations. We also give a collision attack against 1-round KECCAK using similar analysis

Human embryonic mesenchymal lung-conditioned medium promotes differentiation to myofibroblast and loss of stemness phenotype in lung adenocarcinoma cell lines

Background: When genes responsible for normal embryonic development are abnormally expressed in adults, it can lead to tumor development. This can suggest that the same mechanism that controls embryonic differentiation can also control tumor differentiation. We hypothesize that the malignant phenotype of lung cancer cells could acquire benign characteristics when in contact with an embryonic lung microenvironment. We cultured two lung cancer cell lines in embryonic lung mesenchyme-conditioned medium and evaluated morphological, functional and molecular changes. Methods: The human embryonic mesenchymal lung-conditioned medium (hEML-CM) was obtained by culturing lung cells from embryos in the pseudoglandular stage of development. The NSCLC cell lines A549 and H1299 we cultured in the hEML-CM and in a tumor-conditioned medium. Morphological changes were analyzed with optical and transmission electron microscopy. To evaluate the functional effect of conditioned medium in tumor cells, we analyzed cell proliferation, migration, colony formation capacity in 2D and 3D and in vivo tumor growth capacity. The expression of the pluripotency genes OSKM, the adenocarcinoma marker NKX2-1, the lung surfactant proteins SFTP, the myofibroblast marker MYH and DNMT3A/3B was analyzed with qRT-PCR and the presence of the myofibroblast markers vimentin and α-SMA with immunofluorescence. Transcriptomic analysis was performed using Affymetrix arrays. Results: The A549 and H1299 cells cultured in hEML-CM lost their epithelial morphology, acquired mesodermal characteristics, and decreased proliferation, migration, and colony formation capacity in 2D and 3D, as well as reduced its capacity to growth in vivo. The expression of OSKM, NKX2-1 and SFTP decreased, while that of DNMT3A/3B, vimentin, α-SMA and MYH increased. Distant matrix analysis based on transcriptomic profile showed that conditioned cells were closer to myoblast and human lung fibroblast than to normal epithelial immortalized lung cells. A total of 1631 for A549 and 866 for H1299 differentially expressed genes between control and conditioned cells were identified. Conclusions: To the best of our knowledge, this is the first study to report that stimuli from the embryonic lung can modulate the malignant phenotype of lung cancer cells, control their growth capacity and activate their differentiation into myofibroblasts. These findings could lead to new strategies for lung cancer management