Layers Of Wall Research Articles

Impact of flaxseed gum on the aggregate structure, pasting properties, and rheological behavior of waxy rice starch

This study examines the effects of flaxseed gum (FG) on the aggregate structure, pasting and rheological properties of waxy rice starch (WRS). Results display an increase in the ordered molecular structure (R1047/1024), relative crystallinity (RC), compactness (α), and microphase heterogeneity (ε, density degree of nanoaggregates, from 3.52 to 4.23) for WRS-FG complexes. These suggested FG facilitated the development of more organized molecular and crystalline structures of WRS, accompanied by the formation of ordered nanoaggregates with higher density (i.e., nano-aggregation structure). Also, FG addition resulted in the formation of enhanced gel network structure characterized by thicker layer walls and more uniform pores. These structural transformations contributed to a rise in gelatinization temperature (To, from 56.90 °C to 62.10 °C) and enthalpy (ΔH), as well as alterations in paste viscosities (PV, from 1285.00 mPa·s to 1734.00 mPa·s), and the rigidity of network structure (e.g., decreased loss tangent). These results indicate that FG could effectively regulate the techno-functional properties of WRS by rationally controlling the starch intrinsic structures of starch. And this study may improve the pasting and gelling properties of starch, thus driving the development of high-quality starchy foods and prolonging their shelf life, especially for glutinous rice flour products.

Efficient enzyme-free method to assess the development and maturation of the innate and adaptive immune systems in the mouse colon

Researchers who aim to globally analyze the gastrointestinal immune system via flow cytometry have many protocol options to choose from, with specifics generally tied to gut wall layers of interest. To get a clearer idea of the approach we should use on full-thickness colon samples from mice, we first undertook a systematic comparison of three tissue dissociation techniques: two based on enzymatic cocktails and the other one based on manual crushing. Using flow cytometry panels of general markers of lymphoid and myeloid cells, we found that the presence of cell-surface markers and relative cell population frequencies were more stable with the mechanical method. Both enzymatic approaches were associated with a marked decrease of several cell-surface markers. Using mechanical dissociation, we then developed two minimally overlapping panels, consisting of a total of 26 antibodies, for serial profiling of lymphoid and myeloid lineages from the mouse colon in greater detail. Here, we highlight how we accurately delineate these populations by manual gating, as well as the reproducibility of our panels on mouse spleen and whole blood. As a proof-of-principle of the usefulness of our general approach, we also report segment- and life stage-specific patterns of immune cell profiles in the colon. Overall, our data indicate that mechanical dissociation is more suitable and efficient than enzymatic methods for recovering immune cells from all colon layers at once. Additionally, our panels will provide researchers with a relatively simple tool for detailed immune cell profiling in the murine gastrointestinal tract, regardless of life stage or experimental conditions.

The effect of alcoholic extract of Citrullus colocynthis on the structural manifestations of the parasite Fasciola gigantica and its comparison with the drug pendazole

The current study aims to find out the effect of alcoholic extracts of the fruit of the Citrullus colocynthis plant, as it was during the current study during the period from 12/2/2022 to 24/4/2023 and by 206 livers for cows, including (31) infected livers and 1348 livers for sheep that did not show infection. In the current study, the incidence of giant liver Fasciola gigantica cows was 15.04%, while sheep hadn't infection during the study period. The results of the current study show that there are different effects in the tissues of the treated worms if compared to the control group, which was showing the integrity of the tissues well after 6 hours, as it is observed the layers of the body wall, spines and muscle layers that cover the wall, as well as the parenchyma tissue in which the body systems are embedded, which did not notice any changes in those tissues and structures, which include (for intestinal backfilling, testicles, mules and uterus). As noted, the damages vary according to the concentration of separation and deformation in the longitudinal and circular muscles, and a few cells are seen in the tenderloin. The thorns are still present in the cover, and the effect of the drug albendazole is little practical Clearly.

Revealing spatial distribution and accessibility of cell wall polymers in bamboo through chemical imaging and mild chemical treatments

Understanding the distribution and accessibility of polymers within plant cell walls is crucial for addressing biomass recalcitrance in lignocellulosic materials. In this work, Imaging Fourier Transform Infrared (FTIR) and Raman spectroscopy, coupled with targeted chemical treatments, were employed to investigate cell wall polymer distribution in two bamboo species at both tissue and cell wall levels. Tissue-level Imaging FTIR revealed significant disparities in the distribution and chemical activity of cell wall polymers between the fibrous sheath and fibrous strand. At the cell wall level, Imaging Raman spectroscopy delineated a distinct difference between the secondary wall and intercellular layer, with the latter containing higher levels of lignin, hydroxycinnamic acid (HCA), and xylan, and lower cellulose. Mild acidified sodium chlorite treatment led to partial removal of lignin, HCA, and xylan from the intercellular layer, albeit to a lesser extent than alkaline treatment, indicating susceptibility of these polymers to chemical treatment. In contrast, lignin in the secondary wall exhibited limited reactivity to acidified sodium chlorite but was slightly removed by alkaline treatment, suggesting stable chemical properties with slight alkaline intolerance. These findings provide valuable insights into the inherent design mechanism of plant cells and their efficient utilization.

Sound absorption performance and mechanism of aluminum foam with double-layer structures of conventional and porous cell walls

Open-cell aluminum foam exhibits sound absorption valleys in the 2500-4000 Hz range, reducing its sound absorption performance in the 800–6300 Hz range. This paper prepared a novel aluminum foam with a double-layer structure using the infiltration casting method, and its pore structure, sound absorption performance, acoustic model, and sound absorption mechanism are investigated. The double-layer structure consists of a conventional pore (CP) layer with a single pore size of 250 μm or 600 μm and a porous cell wall (PCW) layer with double pore diameters of 250 μm and 600 μm. As the thickness ratio between the CP and PCW layers decreases, the acoustic absorption valley value of the double-layer structure increases when combined with a small-pore CP layer. In contrast, it decreases slightly when combined with a large-pores CP layer. The double-layer structure reaches a sound absorption valley value and average sound absorption coefficient of 0.912 and 0.902, respectively. The double-layer structure's sound absorption valley value is better than that of a homogeneous structure, improving sound absorption performance. A Lu modified model is established to characterize the sound absorption of the double-layer structure, which closely matches the experimental results. The modified model further analyzed the vital geometrical parameters affecting the absorption valleys. Acoustic impedance analysis shows the enhanced sound absorption valleys are due to: 1) Gradient acoustic impedance reduces sound reflections at the air-structure interfaces and increases secondary reflection at the interfaces in the structure; 2) The series–parallel configuration increased the resonance peak bandwidth, while the dual-sized resonance cavities regulated the resonance peak frequency.

Optimizing FDM process parameters: predictive insights through taguchi, regression, and neural networks

Fused deposition modelling (FDM) is a popular additive manufacturing process used for rapid prototyping and the production of complex geometries. Despite its popularity, FDM’s susceptibility to variations in numerous process parameters can significantly impact the quality, design, functionality, and mechanical properties of 3D printed parts. This study explores thirteen FDM process parameters and their influence on the mechanical properties of polylactic acid (PLA) polymer, encompassing surface roughness, warpage, tensile and bending strength, elongation at break, deformation, and microhardness. The optimum parameters were identified alongside key contributors by applying the Taguchi method, signal-to-noise ratios, and analysis of variances (ANOVA). Notably, specific FDM parameters significantly affect the surface profile, with layer thickness contributing 32.65% and fan speed contributing 8.59% to the observed variations. Similarly, warping values show notable influence from nozzle temperature (29.53%), wall thickness (16.74%), layer thickness (16.56%), and retraction distance (12.80%). Tensile strength is primarily determined by wall thickness (31.83%), followed by infill percentage (26.73%) and infill pattern (16.18%). Elongation at break predominantly correlates with wall thickness (44.82%), with a supplementary contribution from nozzle temperature (10.90%). Microhardness lacks a dominant parameter. Bending strength variations primarily arise from layer thickness (38%), wall thickness (37.6%), and infill percentage (9.17%). Deformation tendencies are influenced by layer thickness (19.20%), print speed (11.37%), wall thickness, and fan speed (10.9% each). The optimized dataset of FDM process parameters was then employed in two prediction models: multiple-regression and artificial neural network (ANN). Evaluation based on the correlation coefficient (R2) and root mean squared error (RMSE) indicates that the ANN model outperforms the multiple-regression approach. The results indicate that precise control of FDM parameters, coupled with ANN predictions, facilitates the fabrication of 3D printed parts with the desired mechanical characteristics.

Relationship between histomorphology and biomechanical properties of the ascending aortic wall in the aneurysm zone

Introduction. Thoracic aortic aneurysm (TAA) ranks 17th among all causes of a death. Over the past decade, the incidence rate of TAA increased several times and occurs in about 10 out of 100 thousand people per year. The search for the causes that lead to TAA is an urgent task. Local mechanical stress on the aortic wall leads to significant molecular and cellular changes in its tissue.Aim: To investigate the relationship between biomechanical properties and histological changes in the TAA tissue.Material and Methods. Thirty patients with TAA were included in the study. During surgery, fragments of the resected ascending aorta were obtained from each patient and subjected to uniaxial biomechanical testing to failure on an Instron 3343 testing machine (Instron, USA). Ultimate tensile stress at failure (σv, MPa), ultimate strain at failure (ε, mm/mm × %) and area under stress-strain curves (S, cm2) were calculated. In addition, the intraoperative material was fixed in formalin for histological examination of cellular and tissue changes in the aneurysm area. Inflammatory changes, the severity of aortic wall fibrosis and collagen/elastin ratio were assessed.Results. Atherosclerotic changes of the thoracic aortic wall were found in 43.3% (subgroup 1), aortitis – in 3.3%, connective tissue dysplasia – in 53.3% (subgroup 2) of the patients. Patient with inflammatory changes of the aortic wall was excluded. The biomechanical properties of the aorta were not statistically different between groups. A correlation was found between age with εcirc (r = –0.49) and Scirc (r = –0.54) and Slong (r = –0.5). A correlation was also found between εcirc and the degree of fibrosis in the medial layer of the aortic wall (r = –0.5) and collagen/elastin ratio (r = –0.61).Conclusions. Atherosclerotic changes in the aortic wall do not change the biomechanical properties of the TAA. However, structural changes in the medial layer of the aortic wall in the aneurysm zone result in reduced of its mechanical strength.

Anguilla anguilla vs Contracaecum rudolphii: Granuloma allows host tolerance and parasite survival

High survival of the nematode Contracaecum rudolphii in European eel, Anguilla anguilla L. despite an extensive recruitment of immune cells in granulomas is described. A total of 39 eel specimens captured in Canneviè lagoon (Northern Adriatic Sea, Italy) was obtained from local fishermen. The fish were examined for the presence of endoparasitic helminths. Twenty-six eels (67%) harbored third-stage larvae (L3) of Contracaecum rudolphii A and the intensity of infection ranged from 1 to 100 parasites per fish (mean 11.4). A total of 296 larvae were counted and 293 were alive and encysted in the serosa (primarily on external surface of the rectum) as conspicuous granulomas, appearing as white nodules. Histological sections showed a granuloma formed around an individual larva and consisted of three concentric cell layers, containing numerous mast cells (MCs), fibroblasts, macrophages, and epithelioid cells. Encysted larvae were also present in other layers of the intestinal wall, including the mucosa, where recruitment of macrophage aggregates in lamina propria was documented. Immunohistochemical investigations, applying eight antibodies raised against immune cell markers, revealed histamine and serotonin in MCs and inducible-nitric oxide synthase and toll-like receptor-2 in macrophages surrounding the parasite larvae. The study indicates that this innate cellular response in the eel has a chronic inflammatory character and keeps the nematode larvae arrested in a state allowing both host tolerance and parasite survival. The European eel serves as prey for birds and the high survival of C. rudolphii A larvae in the eel indicates that this fish species is a good paratenic host for the parasite allowing completion of its life cycle in birds.

Females with a History of Spontaneous Coronary Artery Dissection Exhibit Greater Pressor Responses to Isometric Handgrip and Post-exercise Ischemia Compared to Healthy Females

Background: Spontaneous coronary artery dissection (SCAD) causes acute coronary syndrome via the sudden separation between the coronary arterial wall layers and/or hematoma. The SCAD patient population is >80% female who typically have few or no traditional cardiovascular disease risk factors (e.g., obesity, hypertension). Risk of a recurrent SCAD is reported as high as 19% at 3 years after an initial SCAD. Mechanisms underlying SCAD (re)occurrence are unknown. Common triggers for SCAD include sympathoexcitatory stimuli, including heavy exercise and intense Valsalva-like activities. This study tested the hypothesis that SCAD patients exhibit greater neurocardiovascular responses (e.g., blood pressure, heart rate, muscle sympathetic nerve activity) to isometric handgrip and post-exercise ischemia compared to healthy females. Methods: Eight females with a history of SCAD (age: 56±6 yrs, BMI: 28±4 kg/m2) and 6 age- and BMI-matched healthy female controls (CON, age: 55±8 yrs, BMI: 26±5 kg/m2) participated. Continuous blood pressure (finger photoplethysmography) and heart rate (3-lead ECG) were measured during rest (1 minute), isometric handgrip at 30% maximal voluntary contraction (2 minutes), and post-exercise ischemia at 220 mmHg (2 minutes) to isolate the skeletal muscle metaboreflex. Muscle sympathetic nerve activity (MSNA, peroneal microneurography) was measured in a subset of participants (5 SCAD/4 CON). Data are presented as an absolute change from rest (mean±SD). Two-way independent t-tests were used for statistical analyses. Results: Resting mean blood pressure (SCAD: 96±8 vs CON: 91±9 mmHg, p=0.354), heart rate (SCAD: 56±11 vs CON: 59±10 bpm, p=0.666), and MSNA (SCAD: 50±19 vs CON: 43±32 bursts/100 heartbeats, p=0.697) were not different between groups. Relative to healthy controls, SCAD patients elicited greater increases in mean blood pressure during isometric handgrip (SCAD: Δ9±3 vs CON: Δ4±4 mmHg, p=0.034) and post-exercise ischemia (SCAD: Δ7±4 vs CON: Δ3±3 mmHg, p=0.046). There were no group differences regarding heart rate responses during isometric handgrip (SCAD: Δ3±4 vs CON: Δ4±4 bpm, p=0.359) and post-exercise ischemia (SCAD: Δ3±4 vs CON: Δ2±3 bpm, p=0.861). Responses in MSNA during isometric handgrip (SCAD: Δ12±8 vs CON: Δ9±8 bursts/100 heartbeats, p=0.536) and post-exercise ischemia (SCAD: Δ11±2 vs CON: Δ13±10 bursts/100 heartbeats, p=0.713) also were not different between groups. Conclusion: These preliminary data suggest that compared to healthy females, female patients who experienced a SCAD exhibit greater pressor, but not chronotropic or sympathetic, responses to isometric handgrip and post-exercise ischemia. Exaggerated pressor responses to these perturbations may be a potential risk factor for SCAD (re)occurrence. NIH K23 HL155506, NIH T32 DK07352, NIH K01 HL148144, NIH UL1 TR0022377, and AHA 898649. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Augmented pressor responses to mental stress in females with spontaneous coronary artery dissection

Background: Spontaneous coronary artery dissection (SCAD) causes acute coronary syndrome or sudden cardiac death due to a separation of arterial wall layers. The majority of patients with SCAD are females (>80%) with few to no traditional cardiovascular risk factors. Though the physiological mechanisms that predispose to SCAD are unknown, common triggers for SCAD events include sympathoexcitatory stimuli, such as mental and emotional stress. Additionally, studies report high prevalence of depression and anxiety among patients with SCAD. Our study aimed to investigate cardiovascular responses to mental stress in patients with SCAD. We hypothesized that patients with SCAD would have exaggerated cardiovascular responses to mental stress compared to healthy controls. Methods: Four female patients with SCAD were age-, and BMI-matched with 4 healthy females. Participants underwent 2 minutes of baseline quiet rest, a 5-minute Stroop Color Word Test to induce mental stress, followed by 2 minutes of recovery. Continuous beat-to-beat blood pressure (BP, finger photoplethysmography) and heart rate (HR, 3-lead ECG) were recorded. Venous occlusion plethysmography was used to measure forearm blood flow (FBF). Forearm vascular conductance (FVC) was calculated as FBF/mean BP×100. Data are presented as change from baseline (Δmean±SD). Group data were compared using independent samples t-tests. Results: Resting hemodynamic parameters (Systolic [SBP], Diastolic [DBP], and Mean BP [MBP], Pulse pressure [PP], and HR) and FVC were similar between groups. Patients with SCAD had greater increases in DBP (Δ12±5 vs. Δ1±5 mmHg, p=0.02) and PP (Δ5±3 vs. Δ-7±8 mmHg, p=0.04) during the last minute of mental stress test compared to controls. Although, there were no differences in the changes of SBP (Δ17±7 vs. Δ-1±13 mmHg, p=0.05), MBP (Δ13±6 vs. Δ3±8 mmHg, p=0.08), HR (Δ8±0 vs. Δ10±2 bpm, p=0.12), or FVC (Δ1.5±1.2 vs. Δ1.8±1.3 ml/min/100 mmHg, p=0.80) between groups. During the last minute of recovery, there were no differences in hemodynamic parameters (SBP: Δ6±9 vs. Δ-4±10 mmHg, p=0.23; DBP: Δ2±7 vs. Δ-3±2 mmHg, p=0.22; MBP: Δ3±7 vs. Δ-3±5 mmHg, p=0.22; PP: Δ4±5 vs. Δ-1±8 mmHg, p= 0.35; HR: Δ-1±3 vs. Δ0±3 bpm, p=0.64), or FVC (Δ1.3±1.7 vs. Δ0.5±0.3 ml/min/100 mmHg, p= 0.35) between groups. Conclusion: These preliminary data suggest that patients with SCAD have greater increases in DBP and PP in response to mental stress compared to healthy controls. These exaggerated pressor responses might have implications for the pathophysiology of SCAD. NIH K23 HL155506, T32 DK07352, K01 HL148144, UL1 TR0022377, and AHA 898649. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Nano cells from fruit bunch residue: Nestling nanotechnology within the circular oil palm milling residue management

Nano-structured materials gain a vast market acceptance mainly due to their overarching endurance. Nanofibrillar cellulose (NFC) is one example of an augmenting agent unviable for production by small and medium enterprises (SMEs) due to the underlying process complexity. This study aims to characterise the NFC-alternative cells denoted as TRX-cellsⓇ, which is a mix of cellulose and non-cellulose components, ruling out its status as ‘cellulose nanofibers, CNF’. The aim to test-fit the TRX-cells® production process into the circularity model was executed by deliberating on the usability of the byproduct. In doing so, fibrous oil palm empty fruit bunch (EFB) was treated with dioxydanyl radicals (DIOR) and homogenised. The rapid EFB-DIOR reaction at 70°C targeting dearomatisation reaction in a 10%-solid open system was performed before refining the DIOR-treated EFB to micro-scale fibres. Subjecting the micro-fibres to 17 kWh/mt PFI-milling yielded 85–95% of nano-scale fibrous mass. Relative to the stiff micro-fibres, the nano-scale cells web exhibit 34–41% softness enhancement judged from the web tear resistance profile associated with inter-fibre space reduction. Advanced chromatographic evidence for 27% xylan amongst TRX-cells®’ total aldo-sugars was one form of the non-cellulose nano-component. High-resolution Transmission Electron Microscopy hyphenated to Energy Dispersive Analysis of X-ray (HRTEM-EDX) elemental mapping showed a 0.4 atomic percentage of nano-biominerals, confirming the presence of the redistributed dearomatised cells adjacent to cellulose held in the web of the hemicellulose. Shearing at the dearomatised inter-cell wall layers by PFI mill peeled 5 nm–100 nm thickness laminae. The smorgasbord of cellulose and non-celluloses resulted in crystallinity comparable to softwood NFC of approximately 60%, with unique preservation and precision-printing enabling properties. Given the non-recyclability of the DIOR-treated EFB microfibres, nestling the rapid waste transformation process into the circularity model shed light on circular bio-nanotechnology to the spectrum of opportunity for zero-waste, reduced emission and net zero carbon practices on top of an added value from waste transformation to a product.

Experimental investigation of electrochemical and mechanical properties of stainless steel 309L at different built orientation by cold metal transfer assisted wire arc additive manufacturing

In this article, a multi layered wall of stainless steel 309 L (ER309L) material was WAAM printed over a substrate, at optimized parameters using gas metal arc welding as heat input source assisted by cold metal transfer machine, aiming to evaluate mechanical and electrochemical properties at different built orientations i.e., 0°, 30°, 45°, 60°, and 90°. Wall samples were cut-out by wire cut electric discharge machine to compare their properties. Microstructural properties and phases were confirmed by Scanning Electron Microscopy, Energy-Dispersive Spectrometry (EDS) and X-ray diffractometry (XRD), as they change on melting and solidification along the building direction. Columnar dendrite and vertical ferritic grains were observed through an optical microscope. SEM images suggests the presence of Widmanstatten austenite laths forming δ/γ duplex phase. Element distribution by EDS was further verified by Schaeffler’s diagram. XRD pattern confirms various elements and their phase compositions. The tensile strength and yield strength of samples decreased with increase in orientation angle, which is attributed to decrease in the inter-layer length which restricts the slipping of grains and reestablishment of the residual forces., tableau software was used to theoretically predict values for 45° sample as it broke outside the gauge length. electrochemical properties and corrosion behaviour were studied by electrochemical impedance spectroscopy (EIS) and Potentiodynamic polarization (PDP) where in highest Rct=170 Ω and lowest corrosion rate, 0.56 mils per year (MPY) was observed for 45° is attributed to diffusion of chromium to the metal-solution interface forming a passive film. The corrosion rate range 0.48–2.7 MPY, advocates SS309L have a uniform passive film. The properties studied certifies that WAAM printed stainless steel component can be exploited for critical applications.

A reinterpretation of human breast anatomy includes all the layers of the anterior body wall.

Mammary glands define mammals as a group, yet a comprehensive anatomical description of the mammary gland does not exist for almost any mammalian species. In humans, the anatomical and surgical literature provide conflicting and incomplete descriptions of the gross anatomy of the breast. We dissected 9 male and 15 female human body donors to clarify this gross anatomy. We found that, like other epidermally derived glands of the body, the mammary glandular tissue is constrained to a membrane-bound, central structure referred to as the corpus mammae in the surgical literature, and not dispersed throughout the breast as typically described in the anatomical literature. The major fasciae of the human anterior body wall, including the superficial fatty Camper's fascia and the deeper membranous Scarpa's fascia, both contribute to the structure of the breast. This anatomical arrangement suggests that, as the mammary gland invaginates posteriorly from the integument during embryological development, the mammary fat pad most likely derives from Camper's fascia, and growth of Scarpa's fascia around this fat pad forms the anterior and posterior lamellae of the breast pocket. Anteriorly, Scarpa's fascia becomes a double layer that creates the surface structure of the breast. Posteriorly, Scarpa's fascia forms a circummammary ligament that (1) stabilizes the breast against the thoracic wall and (2) is continuous with Scarpa's fascia on the rest of the anterior body wall. The suspensory ligaments of the breast represent the typical retinaculae cuti found consistently throughout the human body wall, and do not directly attach to the skin. Instead, these retinaculae attach to the anterior or posterior lamella of Scarpa's fascia.

The Relevance of Surface Resistances on the Conductive Thermal Resistance of Lightweight Steel-Framed Walls: A Numerical Simulation Study

The accurate evaluation of the thermal performance of building envelope components (e.g., facade walls) is crucial for the reliable evaluation of their energy efficiency. There are several methods available to quantify their thermal resistance, such as analytical formulations (e.g., ISO 6946 simplified calculation method), numerical simulations (e.g., using finite element method), experimental measurements under lab-controlled conditions or in situ. Regarding measurements, when using the heat flow meter (HFM) method, very often, the measured value is based on surface conditions (e.g., temperature and heat flux), achieving in this way the so-called surface-to-surface or conductive thermal resistance (Rcond). When the building components are made of homogeneous layers, their Rcond values are constant, regardless of their internal and external surface boundary conditions. However, whenever this element is composed of inhomogeneous layers, such as in lightweight steel-framed (LSF) walls, their Rcond values are no longer constant, depending on their thermal surface resistance. In the literature, such systematic research into how these Rcond values vary is not available. In this study, the values of four LSF walls were computed, with different levels of thermal conductivity inhomogeneity, making use of four finite elements’ numerical simulation tools. Six external thermal surface resistances (Rse) were modelled, ranging from 0.00 up to 0.20 m2·K/W. The average temperature of the partition LSF walls is 15 °C, while for the facade LSF walls it is 10 °C. It was found that the accuracy values of all evaluated numerical software are very high and similar, the Rcond values being nearly constant for walls with homogeneous layers, as expected. However, the variation in the Rcond value depends on the level of inhomogeneity in the LSF wall layers, increasing up to 8%, i.e., +0.123 m2·K/W, for the evaluated Rse values.

Ultrastructure of silk threads of the water spider Argyroneta aquatica (Clerck, 1757) (Araneae, Cybeidae) in comparison with that of some mites

Silk of the water spider Argyroneta aquatica (Clerck, 1757) was obtained in the laboratory in the form of a capturing web irrespective of the formation of a diving bell and egg cocoon. Silk threads were examined by light microscopy, scanning (SEM), and transmission electron microscopy (TEM) as well as by atomic force (AFM) microscopy. Based on the diameter and internal organization, the silk threads have been divided into five types—a-, b-, c-, d-, and e-types interlaced freely in the thread bundles taken for examinations. Threads of all types are infinitely long, non-branched, round in shape, uniform in width through their course, and rarely found to be ruptured. Threads of the a-type are mostly straight, up to 1,000 nm in diameter, and composed of a fibrillary wall enveloping an electron-dense vacuolated core, which may be occasionally absent. The wall may also become lost, leaving a single core substance surrounded by a slightly wrinkled double membrane. Threads of the b-, c-, and d-types are organized nearly identical, being composed of a fine granular electron-light uniform material enveloped by a fine membrane. The diameter of these threads varies from max. 500 nm in the b-type and 120 nm in the c-type to around 50 nm in the d-type. Threads of these types are more convoluted and more numerous than threads of the a-type. Threads of the last kind, the e-type, occur rarely and are significantly larger with a diameter of around 3.5–4.5 µm. They possess the layered membranous wall surrounding a uniformly dense core. The silk of the water mites Limnochares aquatica (L., 1758) and Limnesia maculata (O.F. Müller, 1776) is composed of threads of only one type that closely corresponded to the a-type threads of A. aquatica. Conversely, the silk of the two-spotted spider mite Tetranychus urticae (C.L. Koch, 1836) consists of threads highly correlated with the d-type threads of A. aquatica. This finding shows that in different phylogenetic lineages of arachnids, the mechanisms of silk production are quite similar.

Акустический пограничный слой твёрдой абсолютно теплопроводной поверхности

The paper presents the analysis results of formation theoretical descriptions of an acoustic boundary layer near solid absolutely thermally conductive surface, obtained by G. Kirchhoff and L.D. Landau. In both cases, the acoustic boundary layer is formed by inhomogeneous viscous and thermal waves in the wall layer of a liquid medium in contact with the surface of a solid body, from which a plane traveling sound wave is reflected. Based on the analysis, conclusions can be drawn: the analyzed problem solutions are physically sound, independent and complementary to each other. During the formation of an acoustic boundary layer, viscous and thermal waves are excited synchronously in pairs. Inside the acoustic boundary layer, each pair of inhomogeneous waves propagates towards each other. Inhomogeneous waves originate on parallel surfaces that limit the volume of the acoustic boundary layer. The analysis of the process of transformation of heat waves into additional one-dimensional inhomogeneous waves, the appearance of which in the boundary layer was predicted by G. Kirchhoff. It is shown that when interacting with the surface of the body of a traveling sound wave in the sound frequency range, these waves do not affect the formation of the boundary layer. The expressions allowing for a numerical estimation of the heat dissipation power density in the boundary layer are refined. A formula has been obtained that allows us to determine the proportion of the energy of the sound wave that is absorbed in the acoustic boundary layer. In practice, the results obtained in the article can be used, for example, in aeroacoustics to assess the dissipative properties of solid surfaces.

Large eddy simulation of a turbulent channel flow using dynamic Smagorinsky subgrid scale model and differential equation wall model

A large eddy simulation (LES) is conducted in a plane channel flow which is turbulent. For understanding the mechanism of the turbulent motion more efficiently, the present study is an attempt to conduct the LES using a Dynamic Smagorinsky Model (DSM) and a Differential Equation Wall Model (DEWM). DSM is a subgrid-scale model and DEWM is for approximating the near wall layer. The simulation is performed in a domain of 2 π δ × 2 δ × π δwhich is discretized by 32 × 20 × 32grid points where δ is the channel half width. The discretization techniques have been used in the simulation, are the 3rd order low storage R-K method in time and 2nd order finite difference formulation in space. To assess the performance of the LES with DSM and DEWM, the simulation results are compared with direct numerical simulation (DNS) data and LES data using Standard Smagorinsky Model (SSM). Comparing the results in the essential turbulence statistical field it has been found that DSM performs better than SSM in most of the cases and shows better agreement with the DNS results. Flow structures in the turbulent flow field are compared in isosurfaces and contour plots, and found that tube-like vortical structures are randomly distributed over the entire flow field, and the number of the vortical structures are more for the DSM case than that of SSM.

High-frequency optical coherence tomography for endovascular management of cerebral aneurysms.

Endovascular management of intracranial aneurysms has become the mainstay of treatment in recent years; however, retreatment rates remain as high as 1 in 5. High-frequency optical coherence tomography (HF-OCT) is an emerging imaging modality for the assessment, treatment and follow-up of cerebral aneurysms. EMBASE and SCOPUS databases were searched for studies relating to the management of intracranial aneurysm with OCT. A combination of keywords were used including 'cerebral aneurysm', 'intracranial aneurysm', 'high-frequency optical coherence tomography', 'optical coherence tomography', and 'optical frequency domain imaging'. There were 23 papers included in this review. For the assessment of intracranial aneurysm, OCT was able to accurately assess aneurysm morphology as well as detailed analysis of arterial wall layers. During IA treatment, OCT was used to assess and troubleshoot stent placement to optimise successful isolation from the circulation. In the follow-up period, endothelial growth patterns were visualised by OCT imaging. OCT shows promise for the treatment of IAs at all stages of management. Due to the novel development of HF-OCT, there is limited longitudinal data in human studies. Further research in this area is required with a focus specifically on long-term treatment outcomes in humans.

Clinicopathologic and endoscopic characteristics of ten patients with gastric hamartomatous inverted polyp: a single center case series

BackgroundGastric hamartomatous inverted polyps (GHIPs) are not well characterized and remain diagnostically challenging due to rarity. Therefore, this study aims to investigate the clinicopathologic and endoscopic characteristics of patients with GHIP.MethodsWe retrospectively reviewed clinicopathologic and endoscopic features of ten patients with GHIP who were admitted to Beijing Friendship Hospital from March 2013 to July 2022. All patients were treated successfully by endoscopic resection.ResultsGHIPs were usually asymptomatic and found incidentally during gastroscopic examination. They may be sessile or pedunculated, with diffuse or local surface redness or erosion. On endoscopic ultrasonography, the sessile submucosal tumor-type GHIP demonstrated a heterogeneous lesion with cystic areas in the third layer of the gastric wall. Histologically, GHIPs were characterized by a submucosal inverted proliferation of cystically dilated hyperplastic gastric glands accompanied by a branching proliferation of smooth muscle bundles. Inflammatory cells infiltration was observed in the stroma, whereas only one patient was complicated with glandular low-grade dysplasia. Assessment of the surrounding mucosa demonstrated that six patients (60%) had atrophic gastritis or Helicobacter pylori–associated gastritis, and four patients (40%) had non-specific gastritis. Endoscopic resection was safe and effective.ConclusionsGHIPs often arise from the background of abnormal mucosa, such as atrophic or H.pylori-associated gastritis. We make the hypothesis that acquired inflammation might lead to the development of GHIPs. We recommend to make a full assessment of the background mucosa and H. pylori infection status for evaluation of underlying gastric mucosal abnormalities, which may be the preneoplastic condition of the stomach.

Preparation of spore-immobilized glutathione reductase and its application in inhibiting browning of pear wine.

Browning is the key problem hindering the industrialization of pear wine. The use of high-yield glutathione Saccharomyces cerevisiae in the fermentation of pear wine can inhibit browning. Glutathione reductase (GR) can ensure the reduction of glutathione. Spore immobilization of enzymes is a new technology. It is a new attempt to apply spore-immobilized GR in combination with high-yield glutathione S. cerevisiae to inhibit browning of pear wine. Saccharomyces cerevisiae spore immobilization enzyme technology was used to immobilize GR in the spores of mutant S. cerevisiae dit1∆, osw2∆ and chs3∆ and wild-type S. cerevisiae. The enzyme activity of GR immobilized by chs3∆ spores was the highest of 3.08 U mg-1 min-1. The chs3∆ spore-immobilized GR had certain resistance to ethanol, citric acid, sucrose, glucose and proteinase K. Electron microscopy analysis showed that the spore wall of chs3∆ had moderate size holes, which might be the main reason why it immobilized GR with the highest enzyme activity. And the GR was immobilized between the prespore membrane and mannoprotein layer of the spore wall. When chs3∆ spore-immobilized GR (chs3∆-GR) was added to Dangshan pear wine fermented by high-yield glutathione S. cerevisiae JN32-9, the presence of chs3∆-GR could further protect amino acids, polyphenols and glucose from oxidation, thereby reducing the browning of the pear wine during storage by 47.32%. GR immobilized by S. cerevisiae spores was effective in inhibiting the browning of pear wine. The method was simple, green and effective and did not increase the production cost of pear wine. © 2024 Society of Chemical Industry.