Envelope Structure Research Articles

Status of treatment strategies for Hutchinson-Gilford progeria syndrome with a focus on prelamin: A posttranslational modification.

Hutchinson-Gilford progeria syndrome (HGPS) is a rare genetic disorder characterized by premature ageing and early death at a mean age of 14.7years. At the molecular level, HGPS is caused by a de novo heterozygous mutation in LMNA, the gene encoding A-type lamins (mainly lamin A and C) and nuclear proteins, which have important cellular functions related to structure of the nuclear envelope. The LMNA mutation leads to the synthesis of a truncated prelamin A protein (called progerin), which cannot undergo normal processing to mature lamin A. In normal cells, prelamin A processing involves four posttranslational processing steps catalysed by four different enzymes. In HGPS cells, progerin accumulates as a farnesylated and methylated intermediate in the nuclear envelope where it is toxic and causes nuclear shape abnormalities and senescence. Numerous efforts have been made to target and reduce the toxicity of progerin, eliminate its synthesis and enhance its degradation, but as of today, only the use of farnesyltransferase inhibitors is approved for clinical use in HGPS patients. Here, we review the main current strategies that are being evaluated for treating HGPS, and we focus on efforts to target the posttranslational processing of progerin.

Cross-Frequency Coupling in Cortical Processing of Speech.

This study examines power-power cross-frequency coupling (CFC) between different frequency bands of cortical activity in normal-hearing (NH) listeners and its association to the processing temporal envelope (ENV) and temporal fine structure (TFS) of speech. CFC between alpha and theta bands and between gamma and theta bands was investigated when only ENV or TFS or the original speech itself were processed. Comparing the cortical activity in response to ENV and original speech, there was an increase in alpha-theta CFC and in gamma-theta CFC when listening to ENV alone. However, when comparing the response when to listening TFS alone, there was a reduction in gamma-theta CFC compared to the original speech and the alpha-theta CFC was comparable to the equivalent observed with original speech. The increase in CFC may suggest that there is more synchrony across different bands of cortical activity in processing ENV than TFS. These measures can serve as indicators when either ENV or TFS is perceived.

Application of Smart Phone in On-Site Test of Heat Transfer Coefficient of Building Envelope

With the increasing demand for on-site test of heat transfer coefficient of building envelope, a new test method is proposed aiming at the problems of common detection methods. According to the one-dimensional steady-state heat transfer theory of the envelope structure, the formula for calculating the heat transfer coefficient of the building envelope is derived based on the air temperature on both sides of the enclosure, the inner surface temperature and the inner surface heat transfer resistance. After turning the formula into a calculation program and loading the program into a smart phone, the heat transfer coefficient at the corresponding position can be obtained as long as the corresponding temperature and surface heat transfer resistance are input into the program. Comparing with the existing on-site detection methods of heat transfer coefficient and analyzing the detection results, it can be seen that the heat transfer coefficient obtained by this detection method is reliable, and that the method meets the needs of engineering detection. It is an economical, convenient, fast and reliable detection method to test the heat transfer coefficient of building envelope using smart phone and thermo detector.

Lipases secreted by a gut bacterium inhibit arbovirus transmission in mosquitoes.

Arboviruses are etiological agents of various severe human diseases that place a tremendous burden on global public health and the economy; compounding this issue is the fact that effective prophylactics and therapeutics are lacking for most arboviruses. Herein, we identified 2 bacterial lipases secreted by a Chromobacterium bacterium isolated from Aedes aegypti midgut, Chromobacterium antiviral effector-1 (CbAE-1) and CbAE-2, with broad-spectrum virucidal activity against mosquito-borne viruses, such as dengue virus (DENV), Zika virus (ZIKV), Japanese encephalitis virus (JEV), yellow fever virus (YFV) and Sindbis virus (SINV). The CbAEs potently blocked viral infection in the extracellular milieu through their lipase activity. Mechanistic studies showed that this lipase activity directly disrupted the viral envelope structure, thus inactivating infectivity. A mutation in the lipase motif of CbAE-1 fully abrogated the virucidal ability. Furthermore, CbAEs also exert lipase-dependent entomopathogenic activity in mosquitoes. The anti-arboviral and entomopathogenic properties of CbAEs render them potential candidates for the development of novel transmission control strategies against vector-borne diseases.

Ultrastructural Damages to H1N1 Influenza Virus Caused by Vapor Essential Oils.

Influenza viruses are transmitted from human to human via airborne droplets and can be transferred through contaminated environmental surfaces. Some works have demonstrated the efficacy of essential oils (EOs) as antimicrobial and antiviral agents, but most of them examined the liquid phases, which are generally toxic for oral applications. In our study, we describe the antiviral activity of Citrus bergamia, Melaleuca alternifolia, Illicium verum and Eucalyptus globulus vapor EOs against influenza virus type A. In the vapor phase, C. bergamia and M. alternifolia strongly reduced viral cytopathic effect without exerting any cytotoxicity. The E. globulus vapor EO reduced viral infection by 78% with no cytotoxicity, while I. verum was not effective. Furthermore, we characterized the EOs and their vapor phase by the head-space gas chromatography–mass spectrometry technique, observing that the major component found in each liquid EO is the same one of the corresponding vapor phases, with the exception of M. alternifolia. To deepen the mechanism of action, the morphological integrity of virus particles was checked by negative staining transmission electron microscopy, showing that they interfere with the lipid bilayer of the viral envelope, leading to the decomposition of membranes. We speculated that the most abundant components of the vapor EOs might directly interfere with influenza virus envelope structures or mask viral structures important for early steps of viral infection.

Comparison of SARS-CoV-2 (Coronavirus) with other Similar Viruses Based on Current Evidence

The rapid spread and high mortality rate of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) have recently received worldwide attention. Understanding the pathologic features and behavior of this new virus can help control its spread. The present study aimed to compare SARS-CoV-2 with other similar viruses.
 This study is a systematic review of current evidence conducted in September 2020. A search was carried out utilizing the keywords in the online databases, including Google Scholar, PubMed, Scopus, Science Direct, and Web of Science. The original peer-reviewed papers written in English that met the eligibility criteria were included in the final report.
 In this study, we compared SARS-CoV-2 with similar viruses such as influenza, Zika, Ebola, HIV, SARS-COV, and Middle East Respiratory Syndrome Coronaviruses (MERS-COV) in the features such as envelope structure, risk factors, duration of the disease, common symptoms, and treatments. Moreover, Coronavirus Disease 2019 (COVID-19) has many similarities with the other viruses explained in the present study. However, there are still controversies about the virus’s behavior.
 Although there are similarities between the abovementioned viruses, the scientific community should also pay special attention to distinct features of SARS-CoV-2, particularly the high probability of transmission in the human population, which causes substantial morbidity and mortality worldwide. Future studies are needed further to explore the biological and epidemiological behavior of this virus.

Rational solutions to the cylindrical nonlinear Schrödinger equation: Rogue waves, breathers, and Jacobi breathers solutions

The exact cylindrical rational solutions including cylindrical rogue waves (RWs), cylindrical Kuznetsov–Ma breathers (KMBs), cylindrical Akhmediev breathers (ABs), and cylindrical Jacobi breathers solutions to the cylindrical nonlinear Schrödinger equation (CNLSE) are derived. Also, the criteria for the cylindrical modulational instability and the existence of cylindrical rational solutions are discussed. The obtained solutions could be used for studying the characteristic behavior of all time evolution cylindrical modulated envelope structures in different branches of science such as oceans, seas, water tanks, optical fiber, Veins, capillary tubes, plasma physics, and so on.

Application research of solar heating technology in rural buildings in Western Sichuan Plateau

Rural buildings in Western Sichuan Plateau mainly rely on traditional experience, which lacks professional knowledge guidance. Unreasonable peripheral protection structure design, extremely low thermal comfort and high heating energy consumption, backward indoor heating facilities such as simple stoves burning firewood or cow and sheep dung, they make the indoor environment very bad. In view of these problems existing in rural buildings in Western Sichuan Plateau, this paper selects the typical buildings in HARAMA village, Anqu Town, Western Hongyuan County, and carries out the thermal calculation of outer envelope structure and indoor thermal environment test in winter. According to the calculated data, the heat transfer coefficients of exterior walls and roof are 2.94 w/(m2 K) and 3.23 w/ (m2 K) respectively, and that of window is 4.7 w/(m2 K). The heat transfer coefficients of peripheral protective structure are far higher than the specification limit. The thermal environment test data shows that the two bedrooms BR1-1 and BR1-2 facing south on the first floor have a maximum temperature of 4.77 °C and a minimum temperature of 0.51 °C. The north-facing room on the first floor is uninhabited all year round, and the indoor temperature is BR1 The range of −3 is −2.61–0.62 °C. The residents of LR1 in the living room on the first floor use a simple earthen furnace for intermittent heating, and the indoor temperature is 3.25–5.36 °C. −0.03–1.26 °C and −0.05–1.36 °C, the indoor temperature of LR2 in the living room on the second floor is −0.05–1.27 °C, and the temperature of all rooms in the room is much lower than 10 °C. Combined with the characteristics of abundant solar energy resources in this area, it is proposed to design the south facing outer wall of the building as a solar heat collection and storage wall, the exterior walls and roofs in other directions are designed as EPS insulation board insulation structure, and the windows are designed as insulating glass insulation windows. At the same time, the solar heating building scheme with additional sunshine room is added to the south of the building. Finally, DeST-h software is used to simulate the indoor basic temperature of typical buildings and solar heating buildings and the energy consumption when the indoor temperature is 10 °C, 16 °C and 18 °C. The simulation results show that the indoor basic temperature of typical buildings is −1.92 °C∼2.11 °C, while the indoor basic temperature of solar heating buildings is above 10 °C, and the minimum temperature difference is about 11.7 °C higher than that of typical buildings. The minimum indoor basic temperature of additional sunshine room is close to the minimum indoor temperature, and the maximum temperature reaches 21.85 °C, which is much higher than that of other rooms. When the indoor temperature is 10 °C, 16 °C and 18 °C, the building heating energy consumption decreases from 25.4 w/m2, 29.4 w/m2 and 36.8 w/m2 to 0 w/m2, 6.88 w/m2 and 9.38 w/m2 respectively. The indoor thermal comfort of the solar heating building is significantly improved and the energy-saving effect is remarkable, which provides a good foundation for the direct use of solar heating design in this area.

Environmental and Energy-Efficiency Considerations for Selecting Building Envelopes

Life cycle assessments in the construction industry reveal that 70–80% of all CO2 emissions occur precisely at the stage of material production (stages A1–A3 of the life cycle). Therefore, not only does the strength and thermal properties of the material selected for construction have major importance, but also the environmental impact of the material and the amount of energy spent to extract, manufacture and transport the materials. The paper presents the thermal calculations for envelope structures, assessing their environmental impact with respect to three parameters: carbon dioxide emissions, total energy consumption and amount of waste generated during material production. The research method used was an analysis of documents from real manufacturers and calculations of the main environmental parameters. Our investigation has led us to conclude that the largest amount of carbon dioxide emissions is produced by structures containing reinforced concrete, since the weight fraction of concrete is significantly greater than that of all other compared materials. The largest amount of non-renewable energy is consumed by structures containing clay bricks and reinforced concrete, since they consist of natural sources. The largest amount of waste is generated by structures containing expanded polystyrene and reinforced concrete consisting of cement, whose production in turn generates a large amount of waste.

Theory and Diagnostics of Hot Star Mass Loss

Massive stars have strong stellar winds that direct their evolution through the upper Hertzsprung–Russell diagram and determine the black hole mass function. Furthermore, wind strength dictates the atmospheric structure that sets the ionizing flux. Finally, the wind directly intervenes with the stellar envelope structure, which is decisive for both single-star and binary evolution, affecting predictions for gravitational wave events. Key findings of current hot star research include: ▪ The traditional line-driven wind theory is being updated with Monte Carlo and comoving frame computations, revealing a rich multivariate behavior of the mass-loss rate [Formula: see text] in terms of M, L, Eddington Γ, Teff, and chemical composition Z. Concerning the latter, [Formula: see text] is shown to depend on the iron (Fe) opacity, making Wolf–Rayet populations, and gravitational wave events dependent on host galaxy Z. ▪ On top of smooth mass-loss behavior, there are several transitions in the Hertzsprung–Russell diagram, involving bistability jumps around Fe recombination temperatures, leading to quasi-stationary episodic, and not necessarily eruptive, luminous blue variable and pre-SN mass loss. ▪ Furthermore, there are kinks. At 100 [Formula: see text] a high Γ mass-loss transition implies that hydrogen-rich, very massive stars have higher mass-loss rates than commonly considered. At the other end of the mass spectrum, low-mass stripped helium stars no longer appear as Wolf–Rayet stars but as optically thin stars. These stripped stars, in addition to very massive stars, are two newly identified sources of ionizing radiation that could play a key role in local star formation as well as at high redshift.

Contribution to research on ground heat storages as part of building energy systems using RES

Contribution to research on ground heat storages as part of building energy systems using RES

Caulobacter lipid A is conditionally dispensable in the absence of fur and in the presence of anionic sphingolipids.

SUMMARYLipid A, the membrane-anchored portion of lipopolysaccharide (LPS), is an essential component of the outer membrane (OM) of nearly all Gram-negative bacteria. Here we identify regulatory and structural factors that together render lipid A nonessential in Caulobacter crescentus. Mutations in the ferric uptake regulator fur allow Caulobacter to survive in the absence of either LpxC, which catalyzes an early step of lipid A synthesis, or CtpA, a tyrosine phosphatase homolog we find is needed for wild-type lipid A structure and abundance. Alterations in Fur-regulated processes, rather than iron status per se, underlie the ability to survive when lipid A synthesis is blocked. Fitness of lipid A-deficient Caulobacter requires an anionic sphingolipid, ceramide phosphoglycerate (CPG), which also mediates sensitivity to the antibiotic colistin. Our results demonstrate that, in an altered regulatory landscape, anionic sphingolipids can support the integrity of a lipid A-deficient OM.

Peptidoglycan from Akkermansia muciniphila MucT: chemical structure and immunostimulatory properties of muropeptides.

Akkermansia muciniphila is an intestinal symbiont known to improve the gut barrier function in mice and humans. Various cell envelope components have been identified to play a critical role in the immune signaling of A. muciniphila, but the chemical composition and role of peptidoglycan (PG) remained elusive. Here, we isolated PG fragments from A. muciniphila MucT (ATCC BAA-835), analyzed their composition and evaluated their immune signaling capacity. Structurally, the PG of A. muciniphila was found to be noteworthy due of the presence of some nonacetylated glucosamine residues, which presumably stems from deacetylation of N-acetylglucosamine. Some of the N-acetylmuramic acid (MurNAc) subunits were O-acetylated. The immunological assays revealed that muropeptides released from the A. muciniphila PG could both activate the intracellular NOD1 and NOD2 receptors to a comparable extent as muropeptides from Escherichia coli BW25113. These data challenge the hypothesis that non-N-acetylattion of PG can be used as a NOD-1 evasion mechanism. Our results provide new insights into the diversity of cell envelope structures of key gut microbiota members and their role in steering host-microbiome interactions.

Performance-Oriented Passive Design Strategies for Shape and Envelope Structure of Independent Residential Buildings in Yangtze River Delta Suburbs

The Yangtze River Delta is a relatively developed area with many detached houses in the suburbs. Such detached houses are usually 1–3 stories high, mostly self-built by local people. Due to the lack of passive design guidance in the design and construction process, these houses’ energy consumption is usually high. At present, residents in the area use air conditioners, fans, and other electrical equipment in their daily lives. This paper takes detached houses in the suburbs of Ningbo as the research objects, through performance simulation and big data mining of a large number of generated samples, and proposes a passive design strategy suitable for the local building form and envelope structure, which can guide local housing construction.

Research on energy saving of small public building envelope system

Recently, energy saving of small public buildings is gaining more and more attention. The envelope system takes the most important and fundamental part of reducing building energy consumption. In this study, a community center in Shanghai is used as an example to analyze the envelope of small public buildings. The structural design of walls, roofs, thermal bridges and shading measures is carried out. Comsol multi-physics simulation software is applied to perform two-dimensional simulation analysis on the heat transfer of the outer envelope structure of the community center to verify the energy saving effect of the outer envelope structure. This study indicates that small public buildings with additional rock wool thermal insulation panels could optimize energy performance in both winter and summer. The difference between the roof inner surface temperature of the building before and after retrofitting in winter is 26.96 °C, a difference of 1.95 °C; while in summer it is 2.26 less than before retrofitting when the temperature is cooled to °C 28 °C. The result of this study provides a new perspective for the research of energy saving in small public buildings.

Changes in Envelope Structure and Cell-Cell Communication during Akinete Differentiation and Germination in Filamentous Cyanobacterium Trichormus variabilis ATCC 29413.

Planktonic freshwater filamentous cyanobacterium Trichormus variabilis ATCC 29413 (previously known as Anabaena variabilis) can differentiate heterocysts and akinetes to survive under different stress conditions. Whilst heterocysts enable diazotrophic growth, akinetes are spore-like resting cells that make the survival of the species possible under adverse growth conditions. Under suitable environmental conditions, they germinate to produce new vegetative filaments. Several morphological and physiological changes occur during akinete formation and germination. Here, using scanning electron microscopy (SEM), we found that the mature akinetes had a wrinkled envelope, and the surface of the envelope smoothened as the cell size increased during germination. Thereupon, the akinete envelope ruptured to release the short emerging filament. Focused ion beam–scanning electron microscopy (FIB/SEM) tomography of immature akinetes revealed the presence of cytoplasmic granules, presumably consisting of cyanophycin or glycogen. In addition, the akinete envelope architecture of different layers, the exopolysaccharide and glycolipid layers, could be visualized. We found that this multilayered envelope helped to withstand osmotic stress and to maintain the structural integrity. Furthermore, by fluorescence recovery after photobleaching (FRAP) measurements, using the fluorescent tracer calcein, we found that intercellular communication decreased during akinete formation as compared with the vegetative cells. In contrast, freshly germinating filaments restored cell communication.

A 16 au Binary in the Class 0 Protostar L1157 MMS

Abstract We present Very Large Array observations toward the Class 0 protostar L1157 MMS at 6.8 and 9 mm with a resolution of ∼0.″04 (14 au). We detect two sources within L1157 MMS and interpret these sources as a binary protostar with a separation of ∼16 au. The material directly surrounding the binary system within the inner 50 au radius of the system has an estimated mass of 0.11 M ☉, calculated from the observed dust emission. We interpret the observed binary system in the context of previous observations of its flattened envelope structure, low rates of envelope rotation from 5000 to 200 au scales, and an ordered, poloidal magnetic field aligned with the outflow. Thus, L1157 MMS is a prototype system for magnetically regulated collapse, and the presence of a compact binary within L1157 MMS demonstrates that multiple star formation can still occur within envelopes that likely have dynamically important magnetic fields.

Modeling thermal and wind processes in the near-wall layer of building envelopes subjected to insolation

Introduction. Insolation patterns play a decisive role in creating a comfortable microclimatic environment in building spaces. This is a relevant problem of thermal safety assurance for modern construction projects and better sanitary and hygienic conditions of indoor environments. The radiant energy of the sun is a priority in the architectural and structural design and the design of thermal shells of buildings.
 Materials and methods. Theoretical, full-scale microclimatic and thermophysical field studies on structural envelopes of buildings were conducted to identify the contribution of insolation to thermal and wind patterns in the near-wall layer of building envelopes. These methods were verified using the analysis of research techniques, developed by domestic and foreign authors specializing in thermal physics of energy-efficient buildings. The authors developed a set of methods allowing to conduct new experimental studies of physical processes in the thermal air shell of the near-wall layer of envelope structures of real buildings.
 Results. As a result of the field studies of thermal and wind processes underway near the structural envelope of buildings subjected to prolonged insolation, the authors learned that the microclimate turns uncongenial in the near-wall air layer of buildings and in building spaces. This microclimate has unique thermal conditions. The extent of impact, made by the external walls of buildings on the generation and regulation of thermal and wind patterns of the near-wall microclimate was identified. A model of convective flows of the near-wall microclimatic layer of multi-storied residential buildings was developed. These convective flows demonstrate high capacity and vertical mobility and cause the air mass to travel through the space of a building floor that has columns due to the thermal contrast between the opposite walls of buildings.
 Conclusions. The authors have identified the contribution of solar energy to thermal and wind conditions in the air layer of thermal protective shells of buildings subjected to insolation. The mechanism, underlying the thermophysical processes arising in the course of interaction between insolation and the active surface of the thermal protective shell, is identified. The authors have formulated the preconditions for adjusting the design air temperature when assessing the thermal stability of building envelopes, taking into account the insolation conditions of facade systems of buildings. The preconditions for the relationship between outdoor and indoor air environments, as well as methods of natural aeration of premises have been demonstrated.

Laboratory Testing of Small Scale Solar Facade Module with Phase Change Material and Adjustable Insulation Layer

Active building envelopes that act as energy converters—gathering on-site available renewable energy and converting it to thermal energy or electricity—is a promising technological design niche to reduce energy consumption in the building sector, cut greenhouse gas emissions, and thus tackle climate change challenges. This research adds scientific knowledge in the field of composite building envelope structures containing phase-change materials for thermal energy storage. In this study, the focus lies on the cooling phase of the diurnal gain and release of solar energy. The experimental setup imitates day and night environment. Six alterations of small-scale solar facade modules are tested in two different configurations—with and without the adjustable insulation layer on their outer surface during the discharging phase. Modules explore combinations of aerogel, air gap, and Fresnel lenses for solar energy concentration. The results allow us to compare the impact of the application of an additional insulation layer at “night” for different designs of solar facade modules. The results show that modules with an air gap provide higher heat gains but do not take full advantage of the latent heat capacity of phase-change materials.

CHARMM-GUI mycobacterial lipid modeler and its incorporation into membrane builder

Mycobacteria are gram-positive bacteria with uncharacteristically complex cell envelopes that continue to elude our efforts to uncover their structures and properties. Understanding the structure and dynamics of the cell envelope is an essential prerequisite in creating antibiotics to combat the various diseases associated with mycobacteria, such as tuberculosis. However, the unusual complexity of the cell envelope components presents a challenge to both experimental and computational studies. To address this, we have been developing an easy-to-use website interface Mycobacterial Lipid Modeler in CHARMM-GUI and its incorporation into Membrane Builder to provide the essential components of the mycobacterial cell envelope lipids for modeling and simulation of mycobacterial inner and outer membranes with or without associated proteins.