Large Protrusions Research Articles

Evaluation of Surface Finishing Efficiency of Titanium Alloy Grade 5 (Ti-6Al-4V) After Superfinishing Using Abrasive Films.

Ti-6Al-4V is the most commonly used alpha-beta titanium alloy, making it the most prevalent among all titanium alloys. The processed material is widely employed in aerospace, medical, and other industries requiring moderate strength, a good strength-to-weight ratio, and favorable corrosion resistance. A microfinishing process on the titanium alloy surface was conducted using abrasive films with grain sizes of 30, 12, and 9 μm. Superfinishing with abrasive films is a sequential process, where finishing operations are performed with tools of progressively smaller grains. The surface topography measurements of the workpiece were taken after each operation. The experiment was in the direction of developing a new surface smoothness coefficient considering the number and distribution of contact points so as to properly evaluate the quality of the surface finishing. The results showed that the finest-grain films gave the most uniform contact points, thus offering the best tribological characteristics; the 9 LF (micron lapping film) tools gave the smoothest surfaces (Sz = 2 µm), while the biggest-grain films, such as the 30 FF (micron microfinishing film), were less effective since large protrusions formed. This is a suitable study to explore the optimization paths for the superfinishing of titanium alloys, with implications for improving the performance and longevity of components in critical industrial applications.

Analysis of Processes Accompanying Cylindrical Cumulation

Flow contraction within cylindrical samples causes instability in motion, leading to the formation of circumferential compression stress. This then results in perturbations in the form of Mach three-shock configurations (protrusions) at the shock front. The area at the front of the perturbed shock wave increases due to these protrusions. Furthermore, the protrusions are amplified as a consequence of the absorption of smaller perturbations, which are continuously generated at the shock front. The shock front undergoes sharp growth at the final stage, giving rise to several large protrusions that divide it into separate sectors. These sectors undergo oscillatory movements. As the counter configurations collide, a high-pressure zone is generated, which propels some of the compressed material forward. The protrusions reach their maximum height when they become equal to the distance of the front to the axis. The near-axis region is taken up by the frontal protrusions, and the consequent rarefaction shock wave decelerates the incoming flow.

Organization of a cytoskeletal superstructure in the apical domain of intestinal tuft cells.

Tuft cells are a rare epithelial cell type that play important roles in sensing and responding to luminal antigens. A defining morphological feature of this lineage is the actin-rich apical "tuft," which contains large fingerlike protrusions. However, details of the cytoskeletal ultrastructure underpinning the tuft, the molecules involved in building this structure, or how it supports tuft cell biology remain unclear. In the context of the small intestine, we found that tuft cell protrusions are supported by long-core bundles that consist of F-actin crosslinked in a parallel and polarized configuration; they also contain a tuft cell-specific complement of actin-binding proteins that exhibit regionalized localization along the bundle axis. Remarkably, in the sub-apical cytoplasm, the array of core actin bundles interdigitates and co-aligns with a highly ordered network of microtubules. The resulting cytoskeletal superstructure is well positioned to support subcellular transport and, in turn, the dynamic sensing functions of the tuft cell that are critical for intestinal homeostasis.

How do multiple active cellular forces co-regulate wound shape evolution?

Wound closure is a fundamental procedure in many physiological and pathological processes, driven by multiple active cellular forces. In the closure process the wound shape can evolve into round, oval, or slit. However, the underlying mechanisms that determine the mechanical strategies of wound shape evolution are unclear. To understand how these active forces co-regulate wound shapes, we constructed a novel complex variable method-based mechanical model and obtained the stress field and free energy of cell layer with arbitrary wound shape. Our results revealed that there was a stress-driven cell polarization and arrangement around the wound under the cooperative regulation of the tissue pretension, cell protrusion stress and actomyosin ring tension that drove the direction of cell polarization and arrangement for the wound closure. In addition, a 3D phase diagram was obtained from minimizing the free energy of the cell layer that illustrates how the different active cellular forces co-regulate the wound shape evolution. In general, large cellular protrusion induces the evolution of the wound toward slit shape, and strong and medium contractions of the actomyosin ring correspond to the evolution toward oval shape and round shape, respectively. This study reveals a critical mechanism by which living organisms actively control complex processes via the coordination of multiple active cellular forces in tissue repair and development.

Further description of the poorly known zooparasitic nematode Abbreviata baltazardi Chabaud, 1953 (Spirurida: Physalopteridae).

Abbreviata baltazardi Chabaud, 1953 (Nematoda: Physalopteridae) is a hitherto poorly known parasitic nematode species reported from Phrynocephalus helioscopus Pallas (Squamata: Agamidae) in Iran. The current knowledge on the morphology of A. baltazardi is still very limited. In the present study, the detailed morphology of A. baltazardi was studied using light microscopy and, for the first time, scanning electron microscopy, based on newly collected specimens from the yarkand toad-headed agama P. axillaris Blanford Pallas (Squamata: Agamidae) in China. Some erroneous or previously unreported morphological features of A. baltazardi were observed using SEM, which include the presence of one large semicircular protrusion and 20-30 denticles on each pseudolabium, the absence of precloacal medioventral papilla in some individuals and the presence of 4-5 postcloacal medioventral papillae in males. SEM observations also clearly showed the detailed morphology of deirids, cloacal ornamentation, caudal papillae, vulva and egg. Abbreviata baltazardi represents the first species of Abbreviata Travassos, 1920 reported in China.

Urban life and sunshine: Equitable sunlight resource allocation among different consumer groups?

Owing to the significant role of sunlight hours in human survival, it is crucial to assess the fairness of sunlight resource allocation among different socioeconomic classes, which is essential for the overall harmonious development of a society. This study focused on selected residential communities in Fuzhou, China, and conducted a simulation analysis of sunlight hours using a Solar Grid Model. Additionally, based on the transaction prices of residential properties in the area, this study employs regression analysis to discuss the current supply and demand of sunlight hours for residences with different price ranges. This study found that properties belonging to the lower-spending group may experience excessive sunlight hours during summer. An increase of one hour in sunlight hours on the summer solstice is associated with a decrease of approximately 45,000 RMB in the total property price. In contrast, the higher-spending group is more likely to face insufficient sunlight during winter, and an increase of one hour in sunlight hours on the winter solstice is associated with an approximate 28,000 RMB rise in the total property price. Furthermore, the study found that controlling the size of the property area for medium- to low-priced residential properties within a range of 113 m2 enables better utilization of sunlight resources. In contrast, high-priced residences, if designed with large protrusions, are prone to wasting sunlight resources. This study employed a novel approach to simulate and replicate the current sunlight conditions in urban architectural clusters. For the first time, this study systematically analyzed variations in the demand for sunlight hours across different socioeconomic groups, using property prices as references. Finally, this study summarizes the typical characteristics of sunlight design issues related to residential sample variations and proposes corresponding solutions.

The possible transport and exclusion mode of lipofuscin in rat myocardium under electron microscopy

Lipofuscin accumulation has been observed in human coronary arteries but whether or not myocardial tissue can release lipofuscin generated within cardiomyocytes must be clarified, as this may provide indicators for future anti-ageing research. The hearts of Sprague Dawley rats, aged 6–24 months, were embedded in resin and ultrathin sections cut for electron microscopy. Lipofuscin granules were abundant in cardiomyocytes. Cardiomyocytes were seen to release lipofuscin granules into the myocardial interstitium as cytoplasmic fragments with irregular protrusions on the sarcolemma surface. The cytoplasmic fragments entering the stroma fused directly with the endothelial cells of adjacent capillaries, delivering lipofuscin to the vessel wall. These fragments were also seen to be engulfed by stromal macrophages or fused with fibroblasts, which then combined with capillary endothelial cells to deliver lipofuscin to the vessel wall. Some cytoplasmic fragments disaggregated and formed membrane-like waste, which travelled to the vessel wall from the myocardial stroma as soluble fine particles via diffusion or pinocytosis of capillary endothelial cells. Lipofuscin entered the vascular wall and endothelial cells, forming large and small protrusions or folds that transported the lipofuscin to the vascular lumen and bloodstream.

Intestinal Tuft Cells: Morphology, Function, and Implications for Human Health.

Tuft cells are a rare and morphologically distinct chemosensory cell type found throughout many organs, including the gastrointestinal tract. These cells were identified by their unique morphologies distinguished by large apical protrusions. Ultrastructural data have begun to describe the molecular underpinnings of their cytoskeletal features, and tuft cell-enriched cytoskeletal proteins have been identified, although the connection of tuft cell morphology to tuft cell functionality has not yet been established. Furthermore, tuft cells display variations in function and identity between and within tissues, leading to the delineation of distinct tuft cell populations. As a chemosensory cell type, they display receptors that are responsive to ligands specific for their environment. While many studies have demonstrated the tuft cell response to protists and helminths in the intestine, recent research has highlighted other roles of tuft cells as well as implicated tuft cells in other disease processes including inflammation, cancer, and viral infections. Here, we review the literature on the cytoskeletal structure of tuft cells. Additionally, we focus on new research discussing tuft cell lineage, ligand-receptor interactions, tuft cell tropism, and the role of tuft cells in intestinal disease. Finally, we discuss the implication of tuft cell-targeted therapies in human health and how the morphology of tuft cells may contribute to their functionality.

Preparation and characterization of Ni-Co-TiN/CeO2 composite coating by jet electrodeposition for improved mechanical and anti-corrosion properties

The Ni-Co alloy was coated with Ni-Co-TiN/CeO2 by Jet electrodeposition to enhance the properties of Nickel-Cobalt (Ni-Co) alloy. The morphologies, texture orientation, microhardness, coating adhesion, wear resistance, and corrosion resistance of Ni-Co-TiN/CeO2 composite coatings were characterized. The influences of concentration of mixed particles (micron-TiN and nano- CeO2) on microstructural, surface properties, mechanical properties and anti-corrosion performance of the composite coatings were studied. The addition of nano-mixed particles changed the morphology of Ni-Co-TiN/CeO2 composite coating from large cellular protrusion structures to fine granular structures, the mechanical properties and anti-corrosion performance of Ni-Co-TiN/CeO2 composite coatings were improved. The composite coating exhibited superior microhardness, bonding force, wear resistance and anti-corrosion performance, when the concentration of mixed particles was 4 g l−1. This work contributed to the development of a variety of micro- and nanoparticle phase-enhanced metal-based composite coatings.

Successful fiberoptic orotracheal intubation by lifting large thyroid mass and tongue protrusion in left lateral position: a case report

Abstract Introduction Awake fiberoptic bronchoscopy has long been considered the criterion standard for the management of difficult airways because of large thyroid malignancies. After an unsuccessful attempt to intubate with a fiberoptic bronchoscope in the supine position, the decision to switch to the left lateral position was made. We present this case to propose the utilization of the lateral position for awake intubation. Case presentation We report a rare case of a patient with a large papillary carcinoma of the thyroid planned for surgical excision. The patient presented to our hospital with complaints of difficulty breathing while lying down in the supine position and oozing blood from the necrotic tissue. The breathing difficulties subsided in the lateral position. Conclusion We demonstrated how the left lateral position with an adjunct maneuver facilitates intubation in large thyroid malignancies.

Preparation, characterization and performance analysis of fosthiazate/expanded perlite sustained-release pesticides

The development of a pesticide-loading system that combines high drug loading and good sustained-release performance is an effective way to reduce pesticide losses and improve utilization of pesticides. In this study, modified waste soybean oil (MSO) and polymethylene polyphenyl polyisocyanate (PM200) were used as raw materials to prepare PM200-MSO. Then, coated fosthiazate/expanded perlite sustained-release pesticides (cFOS/EP) were prepared by disc granulation principle with expanded perlite (EP) as carrier, fosthiazate (FOS) as model pesticide and PM200-MSO as coating material. The results showed that, in PM200-MSO, the –OH of MSO reacted with the –NCO group of PM200 to form carbamate. The surface contact angle of PM200-MSO decreased as the amount of MSO increased. When the amount of PM200 was not less than 50%, FOS leakage from EP was prevented. The pesticide loading (PL) of four pesticides (FOS/EP, cFOS/EP-0, cFOS/EP-1, cFOS/EP-3) was greater than 365.00 mg/g, and kinetic studies showed that FOS release from four pesticides was controlled by diffusion. cFOS/EP-1 had the best sustained-release performance, and its stability at pH5 was better than that at pH7, and the FOS release rate was pH5>pH7, the cumulative release rate (Ri) at 200 h were 58.22% and 46.99%, respectively. The FOS release from cFOS/EP-1 belonged to Fickian diffusion at pH5. When pH = 7, it belonged to non-Fickian diffusion, which was dominated by diffusion and complementary by dissolution. SEM observation confirmed the presence of large protrusions and depressions on the surface of cFOS/EP-1, internal cracks, and slight dissolution of its film structure at pH7.

Size rather than complexity of sexual ornaments prolongs male metamorphosis and explains sexual size dimorphism in sepsid flies.

Male sexual ornaments often evolve rapidly and are thought to be costly, thus contributing to sexual size dimorphism. However, little is known about their developmental costs, and even less about costs associated with structural complexity. Here, we quantified the size and complexity of three morphologically elaborate sexually dimorphic male ornaments that starkly differ across sepsid fly species (Diptera: Sepsidae): (i) male forelegs range from being unmodified, like in most females, to being adorned with spines and large cuticular protrusions; (ii) the fourth abdominal sternites are either unmodified or are converted into complex de novo appendages; and (iii) male genital claspers range from small and simple to large and complex (e.g. bifurcated). We tracked the development of 18 sepsid species from egg to adult to determine larval feeding and pupal metamorphosis times of both sexes. We then statistically explored whether pupal and adult body size, ornament size and/or ornament complexity are correlated with sex-specific development times. Larval growth and foraging periods of male and female larvae did not differ, but the time spent in the pupal stage was ca 5% longer for sepsid males despite emerging 9% smaller than females on average. Surprisingly, we found no evidence that sexual trait complexity prolongs pupal development beyond some effects of trait size. Evolving more complex traits thus does not incur developmental costs at least in this system.

Nano mixed particles enhanced Nickel-Cobalt composite coatings by scanning jet electrodeposition

Jet electrodeposition has the characteristics of rapid deposition with high current density, but faces the problem of tip discharge, which causes a decrease in coating surface uniformity and flatness. In this paper, scanning jet electrodeposition was adopted to optimize the tip discharge. The different nanoparticles were mixed as the reinforcing phase of Ni-Co alloy coating. Nano-CeO2/Nip mixed particles enhanced Nickel-Cobalt composite coatings on 304 stainless steel by scanning jet electrodeposition. The morphologies, texture orientation, microhardness, coating adhesion, and corrosion resistance of Ni-Co-CeO2/Ni composite coatings were characterized. The addition of nano-mixed particles (CeO2/Nip) changed the morphology of Ni-Co-CeO2/Nip composite coating from large cellular protrusion structures to fine granular structures and improved the uniformity of the composite coating. Compared with Ni-Co alloy coating, the microhardness increased from 467.8 to 524.7 HV, the adhesion between the substrate and the coating increased from 20.6 to 28.9 N, and the corrosion current density decreased from 2.413 × 10−5 to 5.598 × 10−6 A·cm−2 in Ni-Co-CeO2/Nip (4 g/L) composite coating, indicating that nano-mixed particles (CeO2/Nip) improved the mechanical properties and corrosion resistance of Ni-Co alloy coating in scanning jet electrodeposition.

Simulation of dieless clinching process considering the limit of blank holder

The low strength and large protrusion of the traditional dieless clinched joint hindered its application. To improve the mechanical properties of the dieless clinched joint, a novel dieless clinching process considering the limitation of the blank holder was proposed. The finite element model of the dieless clinching process was established by DEFORM-2D, the influences of the blank holder spring stiffness, the blank holder limit height, and the punch diameter on the mechanical interlock of the joint were analyzed, and the influence laws of blank holder spring stiffness and blank holder limit height on material flow and mechanical interlock were obtained. Then, the influence of these three die parameters and their interaction on the joint interlock were analyzed using the response surface method. The results show that the blank holder displacement plays a key role in the formation of mechanical interlock in the dieless clinching process. Reasonable limit height and spring stiffness of the blank holder can control the flow direction of materials, so as to improve the mechanical interlock and the strength of dieless clinched joints. It provides a new idea for improving the dieless clinching process.

Degenerative Cervical Myelopathy: A Case Report of Delayed Diagnosis in a Younger Man

BACKGROUND: Degenerative cervical myelopathy is most caused by degenerative cervical stenosis in an over 55-year age group. However, it may occur in younger ages, most commonly due to large cervical disc protrusions. CASE PRESENTATION: The case report describes a 42-year-old male, who presented with progressive ataxia and upper limb discoordination over a 4-year period. He was initially diagnosed and treated for bilateral carpal tunnel releases. Following his persistent symptoms, cervical magnetic resonance imaging was performed, which confirmed a large cervical C4/5 disc protrusion. OUTCOME AND FOLLOW-UP: Although initially managed with observation, his continuing decline resulted in emergency cervical decompression. Surgery for myelopathy aims to prevent further deterioration, and timely treatment is therefore critical to restoring function. DISCUSSION: This case highlights the difficulties faced by people with degenerative cervical myelopathy to obtain a diagnosis and treatment, and the consequences. Myelopathy is an important differential diagnosis to consider irrespective of age. Where suspected, a cervical spine MRI should be requested. JOSPT Cases 2022;2(4):220–225. Epub: 12 October 2022. doi:10.2519/josptcases.2022.11088

S2361 Pancreatic Protrusion: A Rare Case of Grade IV Hiatal Hernia With Complete Pancreatic Herniation

Introduction: Hiatal hernias are commonly described as herniation of abdominal contents through the esophageal hiatus of the diaphragm. With this, classification systems exist to define hernias as either sliding or type one, or to consider types 2, 3 and 4 as paraesophageal which also present with other sequelae. While most commonly, hiatal hernias are type one and less severe in nature, 5 percent of cases become more involved and severe. The current prevalence of hernias ranges between 10 to 80 percent of North Americans. In this case, we shed light on the diagnosis and imaging of a rare sequelae of hiatal hernia which included not only small and large protrusion, but also herniation of the pancreas. Case Description/Methods: The patient is a 95 year old woman with a past medical history of abdominal aortic aneurysm as well as a large hiatal hernia presenting with a chief complaint of poor oral intake over the last several days prior to presentation. The patient was found to be significantly lethargic compared to baseline and reported decreased oral intake due to discomfort after eating. The patient’s initial vitals demonstrated a mild tachycardia with initial lab findings within normal ranges. A CT chest and abdomen was performed which demonstrated a large hiatal hernia, which now contained loops of small and large bowel as well as the pancreas. During the hospital course, interdisciplinary rounds were conducted in regards to the patient case with surgical and gastroenterology recommendations. The uniqueness of presentation of pancreatic protrusion was discussed as well as the current treatment and monitoring modalities of a Grade 4 hiatal hernia, now presenting with complications. Ultimately, the discussions were conducted with the patient who reported she was most amenable to comfort focused care with a pleasure based diet in an attempt to avoid any medical and surgical intervention. Discussion: In emergent cases, such as with respiratory distress and bowel strangulation, emergent surgical intervention is considered in cases of hiatal hernia. However, lesser defined and established are the findings and management as well as treatment modalities of more severe hernias involving protrusion of pancreatic contents. Here, we add to imaging the unique presentation of a common diagnosis with rare sequelae. We also hope to add to a growing body of literature on the imaging, and potential stepwise approach to management of type 4 hiatal hernias with severe and emergent treatment considerations.

Fatigue behavior and tribological properties of laser additive manufactured aluminum alloy/boron nitride nanosheet nanocomposites

Laser additive manufacturing is a promising approach to prepare near-neat shape parts from Al nanocomposites with high mechanical and tribological properties. Owing to its lubricious nature, boron nitride nanosheets (BNNSs) were added into AlSi10Mg alloy via high-speed ball milling and laser metal deposition (LMD) to manufacture self-lubricating Al alloy nanocomposites with outstanding wear resistance and fatigue performance. The study shows that number of cycles-to-failure due to tensile fatigue increased from 103 for pure AlSi10Mg to 106 upon adding only 0.1 wt% of BNNSs. At 0.2 wt% BNNSs, the friction coefficient and wear-out volume of AlSi10Mg alloy decrease by 58% and 57%, respectively. Scanning electron microscopy micrographs show that pure AlSi10Mg has a worn surface of grooves, wide ridges, debris and large protrusions of worn material along the groove edges. The wear mechanism is mainly plastic deformation, delamination and adhesion in pure AlSi10Mg. On the other hand, the LMD-built AlSi10Mg/BNNS composites exhibit less rough surface with clear wear trails due to the thin lubricant layer formed from the extruded BNNSs during the test. An extended finite element model for the crack propagation during fatigue testing is developed, where the obtained results are in accord with the experimental measurements. The present study shows that additive manufacturing technology is capable to fabricate Al matrix composites with tailored properties for various design applications.

Thermal ridges – Formation of hillock-like structures in deformed bulk nickel

The effect of surface topography on grain boundary migration has been the focus of numerous studies due to its importance for microstructure evolution in thin films. In this work we have studied grain boundaries in samples of pure bulk Ni after mild cold deformation and a subsequent anneal. The surface topography in the vicinity of grain boundaries featured large protrusions formed during the anneal with a striking resemblance to downscaled terrestrial mountains. We coined the term 'thermal ridges' to describe these protrusions. Their size decreases with increasing annealing time and degree of deformation. We developed a kinetic model of ridges based on the original Mullins’ model of mobile grain boundary grooves modified to account for high surface anisotropy. The combination of our experimental and modeling results sheds new light on the phenomenon of hillock formation in thin polycrystalline films.

Numerical Simulation and Deep Neural Network Revealed Drag Reduction of Microstructured Three-Dimensional Square Cylinders at High Reynolds Numbers

Square cylinders are widely used in various fields. For example, they are common structures in fishways. The flow around square cylinders has been a common problem in various fields. However, reducing the flow drag of the square cylinder is a problem that remains unexplored. Many previous studies have reported the drag reduction of 2D square cylinders, which failed to reflect the drag of real structures. Also, some studies focus on the drag force of the inner wall of the square cylinder modified by the microstructure. Achieving drag reduction by microstructuring the surface of the 3D square cylinder is a challenging problem. This study applied a 3D numerical simulation and deep neural network to study the drag reduction performance of the square cylinder under different patch sizes. We studied the drag reduction performance of protrusion and pit-patched square cylinders and tried to find the rule between drag reduction performance and patch configuration. The results show that the square cylinder has better drag reduction performance in some cases. However, its drag reduction performance is greatly affected by the protrusion structure. Also, too large protrusions will increase the drag force of the structure. When the surface protrusion accounts for 10% of the total area of the square cylinder, the drag reduction performance is the best (22.1%). The pit patch structure demonstrated an insignificant drag reduction performance and even increased the drag in most cases. The DNN prediction model demonstrated the robustness of the numerical simulation data.

Effect of surface irregularities on diamond Schottky barrier diode with threading dislocations

Pyramidal and flat-type hillocks, both known for having a threading dislocation in the center, are utilized to examine the effect of surface irregularities on the characteristics of Schottky barrier diodes (SBDs). By performing RAMAN mapping on both hillocks, crystalline imperfections in three dimensions with clear strain are observed. Surface scanning images obtained via atomic force microscopy show an extremely large surface protrusion with a maximum height of approximately 15 nm in the pyramidal hillock. Owing to crystalline imperfections in the threading dislocation region, the SBDs fabricated on the dislocations exhibit inferior forward characteristics. However, high reverse leakage currents are only observed in dislocations on pyramidal hillocks with surface protrusions, whereas low reverse currents are observed in the flat hillock region without surface irregularities. The phenomenon above is consistent with the characteristics of wide bandgap semiconductors such as silicon carbide.