Hollow Space Research Articles

Scaling of the extended phenotype: convergent energetics from diverse spider web geometries.

Organisms capture energy to support growth, survival and reproduction in diverse ways. Larger metazoans require less energy per unit time and mass than smaller ones. Thus, structures animals build to capture energy need not scale isometrically with body size. Web-building spiders use silk structures of diverse geometries to capture energy, including two-dimensional orbs in some families or three-dimensional tangles or sheet-and-tangles, in others. Despite this diversity, we show that energy consumption rate per unit mass scaled identically with body size across all web geometries with a less than 1 : 1 relationship to body size, as expected for metazoans from metabolic theory. Spiders thus appear to adjust the size and shape of their webs in precise ways to attain this relationship, including, as we show here, creating a hollow space within certain three-dimensional web types to maintain a constant prey capture surface area per unit spider mass as they grow in size without requiring more silk. Our findings show how the allometric relationship between energetic traits and body size can be mediated by extended phenotypes and suggest an equivalence paradigm akin to the equal fitness paradigm whereby the diverse adaptive strategies of organisms allow them to perform equally well in supplying a unit of mass the energy needed across a lifetime.

Energetics and Raman spectroscopy of organic molecules encapsulated in single-walled boron nitride nanotubes: The example of π-conjugated oligothiophenes

The instability of organic electronic devices under environmental conditions narrowly related to the unstable aggregate state of organic semiconductors is one key obstacle to practical application. Herein, we highlight a promising strategy to overcome these drawbacks consisting to make use of the hollow space within single-walled boron nitride nanotubes (SWBNNTs). As a prototypical system of organic π-conjugated molecules encapsulated in SWBNNTs, we investigate the energetic stability and Raman spectra of a series of oligothiophene molecules (nT) (n = 2, 4, and 6) inside SWBNNTs through a combination of molecular dynamics (MD), density functional theory (DFT), bond polarisability model (BPM), and spectral moments method (SMM). The structural stability of these nanohybrids are explored initially. The optimal SWBNNTs diameters in which the resulting nanohybrids are stable with either one molecule (nT@SWBNNTs) and two encapsulated molecular chains (nT-nT@SWBNNTs) are computed. Then, the computed Raman spectra of the oligothiophenes and SWBNNTs before and after filling are reported. The energetic stability and the possible appearance or not of charge transfer in such nanohybrids are investigated by attentive analysis of the nanoconfinement effect on Raman features of oligothiophenes and SWBNNTs. The present results provide benchmark theoretical data to efficiently probe the interactions subsisting in such nanohybrids based on SWBNNTs templates that can serve as a new stable component for organic electronic devices.

Nanotechnology-Driven Delivery of Caffeine Using Ultradeformable Liposomes-Coated Hollow Mesoporous Silica Nanoparticles for Enhanced Follicular Delivery and Treatment of Androgenetic Alopecia.

Androgenetic alopecia (AGA) is caused by the impact of dihydrotestosterone (DHT) on hair follicles, leading to progressive hair loss in men and women. In this study, we developed caffeine-loaded hollow mesoporous silica nanoparticles coated with ultradeformable liposomes (ULp-Caf@HMSNs) to enhance caffeine delivery to hair follicles. Caffeine, known to inhibit DHT formation, faces challenges in skin penetration due to its hydrophilic nature. We investigated caffeine encapsulated in liposomes, hollow mesoporous silica nanoparticles (HMSNs), and ultradeformable liposome-coated HMSNs to optimize drug delivery and release. For ultradeformable liposomes (ULs), the amount of polysorbate 20 and polysorbate 80 was varied. TEM images confirmed the mesoporous shell and hollow core structure of HMSNs, with a shell thickness of 25-35 nm and a hollow space of 80-100 nm. SEM and TEM analysis showed particle sizes ranging from 140-160 nm. Thermal stability tests showed that HMSNs coated with ULs exhibited a Td10 value of 325 °C and 70% residue ash, indicating good thermal stability. Caffeine release experiments indicated that the highest release occurred in caffeine-loaded HMSNs without a liposome coating. In contrast, systems incorporating ULp-Caf@HMSNs exhibited slower release rates, attributable to the dual encapsulation mechanism. Confocal laser scanning microscopy revealed that ULs-coated particles penetrated deeper into the skin than non-liposome particles. MTT assays confirmed the non-cytotoxicity of all HMSN concentrations to human follicle dermal papilla cells (HFDPCs). ULp-Caf@HMSNs promoted better cell viability than pure caffeine or caffeine-loaded HMSNs, highlighting enhanced biocompatibility without increased toxicity. Additionally, ULp-Caf@HMSNs effectively reduced ROS levels in DHT-damaged HFDPCs, suggesting they are promising alternatives to minoxidil for promoting hair follicle growth and reducing hair loss without increasing oxidative stress. This system shows promise for treating AGA.

Axial compressive behavior and capacity prediction of concrete-filled cold-formed lipped channel PEC stub columns

The stability and capacity of thin-walled steel columns can be considerably upgraded by filling concrete into hollow spaces surrounded by cold-formed lipped channel (CLC) and external battens. However, there is limited experimental data available, especially for the axial compression behavior of concrete-filled CLC partially encased composite (PEC) columns. This paper aims to investigate the compressive behavior of CLC-PEC short columns and presents an analytical model for predicting the axial capacity of the column. The study explores the influences of cross-sectional dimensions and external batten plate configurations on the compressive performance of CLC-PEC columns through axial compression tests conducted on 12 short column specimens. The results indicate that the failure modes of the specimens involve localized concrete spalling on the exposed side at the lower part of the column, along with a elephant foot-shaped buckling of the cold-formed steel lipped channel. The damage surface of the confined concrete was obtained by circumferential cutting of the buckling location. The findings highlight the significant influence of the character of the CLC section on the ineffectively confined area at the failure surface, with a dumbbell-shaped effective confinement zone revealing the presence of a highly confined area. Based on the calibrated failure surfaces, a numerical model-based study of the axial stress distribution in the concrete core was then carried out to estimate the confinement effect of the columns under peak loading. The study employed multiple regression analysis to quantify the area ratio of the confined zone to the concrete core based on finite element analysis (FEA) results from 143 CLC-PEC columns. The proposed model was evaluated against test results and found to be more reliable than axial compression loads based on the superposition strength method. The proposed axial capacity of short columns takes into account the slenderness ratio of each member.

Top-down fabrication of Si nanotube arrays using nanoimprint lithography and spacer patterning for electronic and optoelectronic applications

Silicon (Si) nanotube arrays are expected to be a promising material for application in electronics and optoelectronics due to their large specific surface area with axially hollow spaces, whereas realizing smooth surfaces, high aspect ratios, and controlled dimensions remains a challenge. Moreover, it is also necessary to estimate various aspects of Si nanotubes such as their surface damage and anti-reflective properties. Here, we demonstrate a top-down fabrication of Si nanotube arrays with wall thicknesses of ∼40 to ∼10 nm using nanoimprint lithography (NIL) and spacer patterning. The Bosch process yields the nanotubes with smooth surfaces, long lengths (∼1000 nm), and no noticeable distortion or deformation. Raman scattering and electron spin resonance (ESR) measurements show their high crystal quality with a low density of surface dangling-bond defects. Furthermore, a significant enhancement of the anti-reflection effect of nanotubes and its dimension dependence is demonstrated and investigated by UV–Vis–NIR spectrophotometry as well as numerical simulations.

Modelling Mucus Clearance in Sinuses: Thin-Film Flow Inside a Fluid-Producing Cavity Lined with an Active Surface

The paranasal sinuses are a group of hollow spaces within the human skull, surrounding the nose. They are lined with an epithelium that contains mucus-producing cells and tiny hairlike active appendages called cilia. The cilia beat constantly to sweep mucus out of the sinus into the nasal cavity, thus maintaining a clean mucus layer within the sinuses. This process, called mucociliary clearance, is essential for a healthy nasal environment and disruption in mucus clearance leads to diseases such as chronic rhinosinusitis, specifically in the maxillary sinuses, which are the largest of the paranasal sinuses. We present here a continuum mathematical model of mucociliary clearance inside the human maxillary sinus. Using a combination of analysis and computations, we study the flow of a thin fluid film inside a fluid-producing cavity lined with an active surface: fluid is continuously produced by a wall-normal flux in the cavity and then is swept out, against gravity, due to an effective tangential flow induced by the cilia. We show that a steady layer of mucus develops over the cavity surface only when the rate of ciliary clearance exceeds a threshold, which itself depends on the rate of mucus production. We then use a scaling analysis, which highlights the competition between gravitational retention and cilia-driven drainage of mucus, to rationalise our computational results. We discuss the biological relevance of our findings, noting that measurements of mucus production and clearance rates in healthy sinuses fall within our predicted regime of steady-state mucus layer development.

Mesoporous carbon hollow spheres based sensitive SPME probes for in vivo sampling analysis of selected plant hormones in Chinese aloes

Phytohormones are a class of endogenous substances that separately or synergistically regulate the growth, development, and differentiation of plants. Accurately and efficiently detecting and monitoring the concentration of plant hormones in living plants is of significant importance. Herein, a novel mesoporous carbon hollow spheres (MCHS)-based in vivo solid phase microextraction (SPME) probe was designed for in vivo sampling of plant hormones. The designed MCHS features the advantages of high surface area, porous shells, and large hollow spaces, facilitating the dynamic adsorption and enrichment of target phytohormone. In addition, a cationic polyelectrolyte, (poly (diallyl dimethyl ammonium chloride) (PDDA), was further modified onto the MCHS to expedite the extraction process by electrostatic interaction. Utilizing the MCHS@PDDA probe in combination with HPLC-MS/MS facilitated the continuous monitoring of three plant hormones (abscisic acid (ABA), indole-3-acetic acid (IAA), and gibberellin (GA3)) in Chinese aloe. The detection limit of this method was 0.016–0.090 μg/L, the linear range was 10–1000 μg/L, and both the RSD of the single probe (n = 6) and probe-to-probe test (n = 6) were less than 7.2 %. This method had excellent accuracy and good reproducibility comparable to the traditional sample pretreatment method. Ultimately, this established in-vivo SPME method was successfully adopted to quantify three selected plant hormones in living Chinese Aloes, providing a new method for the long-term monitoring of endogenous active substances in living system.

Reaction mechanism of Ca(OH)2-based carbon storage suitable for the production of building materials

The development of CaCO3 oxyfuel combustion and calcium looping techniques offers opportunities for Ca(OH)2 production with near-zero CO2 emissions. This study investigated the viability of Ca(OH)2-based CO2 storage for use in the production of building materials. To resolve the deficient strength gain of Ca(OH)2 carbonation, siliceous materials, using fly ash as a model compound, were introduced into the raw mixture, and hydrothermal curing was applied to promote the pozzolanic reaction. Two microstructural features, i.e., inner and outer CaCO3 formations, were identified during Ca(OH)2 carbonation via backscattered electron imaging. Inner CaCO3 formation is characterized by Ca(OH)2–CaCO3 conversion within the edge of Ca(OH)2 particles. Outer CaCO3 formation is characterized by the dissolution of Ca(OH)2 and the precipitation of CaCO3 in capillary pores, which generates hollow microstructures. The hollow space can be further filled by Al-tobermorite during hydrothermal curing. The prepared materials are capable of storing up to 16 % CO2 by the mass of the raw mixture. Furthermore, the pore structure influenced by inner and outer CaCO3 formation demonstrates the feasibility of adjusting the material's mechanical and CO2 storing properties by controlling the carbonation and hydrothermal curing schemes.

Design and theoretical analysis of near-infrared multiband metamaterial absorber with concentric sub-resonators for solar applications

Metamaterial absorbers with multiple frequency bands can be designed by stacking sub-resonators vertically or arranging them co-planarly. However, to increase the number of absorption peaks, we often need more sub-resonators. Therefore, a study explores dynamic infrared multiband metamaterial absorbers to enhance electromagnetic wave absorption and addresses tunability challenges by utilizing a periodic sub-wavelength structure-based unit cell. The novel design comprises a concentric triangular strip within a central hollow of a square patch, with four hollow cylindrical spaces at the patch corners, each containing four small square pillars. The design comprises a metal–dielectric–metal architecture, with silver as the top patch and the ground metal layer separated by a thin magnesium fluoride dielectric layer. A temperature-controlled material vanadium dioxide layer is introduced below the upper metal layer to enhance the absorbance. Moreover, extensive parametric investigations have been conducted involving the manipulation of shape while keeping other dimensions constant. The goal is achieving perfect multiple absorptions within the 90–300 THz frequency range, ensuring impedance match and exhibiting plasmonic resonance characteristics. The study also investigates unit cell behavior regarding polarization and incident angle variations. Simulations are conducted using CST Microwave Studio Suite® with finite integration technology and validated with COMSOL Multiphysics® using the finite element method in the frequency domain. The simulated results reveal multiple absorption peaks in the terahertz range, averaging 98.32% with a maximum absorption of up to 99.99% and exhibiting high absorption coefficients at discrete resonance frequencies, suggesting promising applications in terahertz technology-related fields.

Core-shell carbon@Ni2(CO3)(OH)2 particles as advanced cathode materials for hybrid supercapacitor: The key role of carbon for enhanced electrochemical properties

Three-dimensional porous Ni2(CO3)(OH)2 compounds were grown on carbon nanopowder using a facile hydrothermal method for the production of core-shell carbon@Ni2(CO3)(OH)2 compounds. This work successfully overcame the shortcomings related to the low electrical conductivity and poor electrical stability caused by the presence of hollows in the Ni2(CO3)(OH)2 structure. The hollow spaces were filled with carbon powder, which acted as a seed material, yielding an ideal electrode material with a large specific surface area, high electrical conductivity, and good stability. A Ni2(CO3)(OH)2 electrode containing 50 mg of carbon powder could store more energy than a Ni2(CO3)(OH)2 electrode without carbon seed materials. The Ni2(CO3)(OH)2 electrode comprising 50 mg of carbon powder has a considerably high specific capacity (181.7 mAh g−1 at 3 A g−1) and excellent cycling stability (77.9 % capacity retention after 5000 cycles), which is 1.5 times higher than that of the Ni2(CO3)(OH)2 electrode without carbon powder. Moreover, an asymmetric supercapacitor using Ni2(CO3)(OH)2 containing 50 mg of carbon powder as the positive electrode and graphene as the negative electrode exhibits a high energy density of 34.2 Wh kg−1 and a power density of 176.1 W kg−1 at a current density of 2 A g−1. Using a combination of carbon and a Ni2(CO3)(OH)2 nanowire compound to increase the electrochemical property and specific surface area, respectively, a suitable synergistic effect can be obtained, which may pave the way for efficient electrode design for high-performance supercapacitors.

Cemani chicken: characteristics of fresh semen, testes morphometric, and the relationship between the two traits

Abstract The monitoring of the reproductive performance of roosters can be conducted by examining the characteristics of fresh semen, the morphometric approach of the testes, and the correlation between these two traits. To analyze the semen traits, a total of ten rooster heads were utilized, while the morphometric analysis of the testes was performed on five rooster heads. Descriptive methods were employed to assess the shape and characteristics of the fresh semen. The average length, width, weight, and circumference of the testes were evaluated using a T-test with a confidence level of 95%. Furthermore, Pearson’s correlation was employed to investigate the association between the traits of the semen and the morphology of the testes. The effects confirmed that the testes of Cemani chickens had been no extraordinary from chickens in general, placed inside the frame hollow space close to the spine, connected to the dorsal belly hollow space, or simply in the back of the lungs and the front of the kidneys and testes, elongated and oval. Typically, the left testes were relatively longer, wider, and heavier than the right testes. The semen exhibited a creamy white color, with a thick consistency and an acidity level of seven. Furthermore, it displayed a satisfactory mass movement with an average value of 2.80 ± 0.92. The motility and viability of the spermatozoa were within the normal range (70.50 ± 5.50 and 80.90 ± 4.58, respectively) at a concentration of 1402 ± 382 x 106/ml. The characteristics of the semen and the size of the testes (both left and right) demonstrated a correlation with motility. This observation concluded was that Cemani chickens exhibit remarkably accurate semen characteristics and testicular morphometrics.

An innovative approach for lid design for rehabilitation of maxillary oncological defect using hollow bulb obturator

BackgroundPost Maxillectomy, prosthodontic treatment modalities include surgical obturator, interim obturator and followed by definitive obturator. The surgical and interim obturator serves the purpose of providing a matrix on which surgical packing can be placed, reduces the contamination during wound healing, facilitates speech and permits deglutition and lessens the psychological impact of surgery. Local drug delivery techniques at the surgical site and the fabricated prosthesis have an impact on the targeted tissue. ObjectivesTo design a hollow bulb obturator with a detachable lid with attachments in the palatal surface of the obturator and to facilitate local drug delivery. MethodsDuplication of patient's maxillectomy cast, pre-shaped plaster bolus was incorporated inside the defect space to create the hollow space. After which a wax pattern was fabricated and acrylized. Wax template of the lid design was made and acrylized incorporating pins. ResultThe weight of the prosthesis is reduced. Due to the lesser weight of the prosthesis retention and physiologic function increases. The decrease in pressure to the surrounding tissue aids in deglutition and encourages the regeneration of tissue. The fabricated lid appears stable and retentive, which can be easily removed and placed back according to the need. ConclusionLocal drug delivery techniques at the surgical site and the fabricated prosthesis has an impact on the targeted tissue.The ability of the drug to reach the appropriate anatomic region will always be important, and has been the subject of much research in the past 5 years. Modified hollow bulb of the obturator in this research can aid in local drug delivery in surgical and interim obturators avoiding the removal of the obturator as the whole.

ANALISIS FAKTOR PERILAKU ANAK SD KELAS 4 – 5 DALAM PERAWATAN KESEHATAN GIGI TERHADAP KEJADIAN KARIES PADA SISWA SD SWASTA PARULIAN 2 KOTA MEDAN TAHUN 2022

Dental caries is a first-rate problem in children's oral hollow space to date. school-age youngsters, especially primary faculty youngsters, are a set this is liable to dental and oral sicknesses because generally those kids still have behaviors or conduct that don't aid dental health.The cause of this reasearch to analyze the behavioral factors of basic faculty youngsters in grades IV–Vin dental health care for the occurrence of caries in students of private standard faculty Parulian 2 Medan city in 2022.This form of research is an observational analytic survey look at with a Case control examine design, to evaluate the case institution and the control institution based totally on their exposure reputation.The population in this look at had been all 38 college students in grades IV-V at Parulian 2 personal standard school in 2022 who had dental caries on their permanent tooth. The effects confirmed that there was a massive relationship between age (p=0.001), gender (p=0.022), socioeconomic (p=0.022), and the incidence of dental caries. there is a extensive relationship among knowledge (p=0.028) and attitude (p=0.010) with the occurrence of dental caries. there's a big dating among how to brush your teeth (p=zero.001), frequency of brushing your enamel (p=0.039), time of brushing your enamel (p=zero.021), frequency of going to the dentist (p=zero.000), and the occurrence of dental caries (p=0.039 ), teeth brushing gear (p=zero.031) with the occurrence of dental caries.Multivariate outcomes showed that the maximum dominant variable influencing the threat of dental caries turned into the variable frequency of going to the dentist with Exp B = 14.609 (ninety five% CI: 2.824-seventy five.592). it is for the government and software holders on the puskesmas, specifically UKGS, to in addition growth the provision of education approximately dental caries to faculties, as well as carry out ongoing dental care for simple college youngsters.

Encapsulation of cytochrome c in hollow mesoporous silica spheres by denaturation

Cytochrome c (Cyt-c) was encapsulated in hollow mesoporous silica spheres as a support for immobilization. Cyt-c was denatured by an aqueous solution of guanidine hydrochloride to increase the flexibility of Cyt-c structure by unfolding and subsequently passed through the mesopores into the hollow spaces by diffusion. After incorporation, the refolding of Cyt-c was carried out by removing the guanidine hydrochloride using dialysis. Considering that the mesopore size was slightly smaller than the native Cyt-c size, Cyt-c was immobilized inside the hollow spheres. Modification of encapsulated Cyt-c with 18-crown-6 showed catalytic activity for the asymmetric oxidation of methyl 4-tolyl sulfoxide. The encapsulated catalyst could be reused to achieve almost the same catalytic activity.

Multifunctional Nanofibrous Hollow Microspheres for Enhanced Periodontal Bone Regeneration.

Destructive periodontitis destroys alveolar bone and eventually leads to tooth loss. While guided bone regeneration, which is based on creating a physical barrier to hinder the infiltration of epithelial and connective tissues into defect sites, has been widely used for alveolar bone regeneration, its outcomes remain variable. In this work, a multifunctional nanofibrous hollow microsphere (NFHMS) is developed for enhanced alveolar bone regeneration. The NFHMS is first prepared via combining a double emulsification and a thermally induced phase separation process. Next, E7, a short peptide with high specific affinity to bone marrow-derived stem cells (BMSCs), is conjugated onto the surface of NFHMS. After that, bone forming peptide (BFP), a short peptide derived from bone morphology protein 7 isloaded in calcium phosphate (CaP) nanoparticles, which are further encapsulated in the hollow space of the NFHMS-E7 to form NFHMS-E7-CaP/BFP. The NFHMS-E7-CaP/BFP selectively promoted the adhesion of BMSCs and expelled the adhesion of fibroblasts and epithelial cells. In addition, the BFP is sustainedly released from the NFHMS-E7-CaP/BFP to enhance the osteogenesis of BMSCs. A rat challenging fenestration defect model showed that the NFHMS-E7-CaP/BFP significantly enhanced alveolar bone tissue regeneration. This work provides a novel bioengineering approach for guided bone regeneration.

3-D woven honeycomb structures and their composites

Honeycomb is regarded as a valuable structural material because of its high strength, shear stiffness, high impact strength, low weight, high crushing stress, and nearly constant force to crush. It is a cellular solid, well-known as a core in creating sandwich structures for use in structural composites. Honeycombs are often utilized in the aircraft sector as the core of sandwich panels and in the automotive industry as effective impact attenuators because of their superior mechanical performance. The hollow spaces in the honeycomb structure not only reduce weight but also ensure the required strength, provided they are designed correctly. In lightweight application areas, because they offer structural integrity, 3-D woven honeycomb composites have a bright future and possess the potential to replace aluminum and other metal alloys. This issue of Textile Progress focuses on the manufacturing of 3-D woven honeycomb fabrics, their mechanical characterization, application areas, different ways of weaving honeycomb cells, and some innovations related to honeycomb-like auxetic and 3-D printed honeycomb structures.

Polymer Binder-Free aqueous spinning of biomimetic CNT based hierarchical hollow fiber for structural and energy storage application

Assembly of functional nanomaterials into structural–functional integrated materials, such as structural-energy storage materials, are highly desirable for lightweight, high-performance wearable electronics, automobiles, and aviation/aerospace vehicles, yet extremely challenging due to the paradox between functional properties and the maintenance of mechanical properties. Herein, inspired by wheat-straw structures, we reported a polymer binder-free aqueous spinning strategy to manufacture biomimetic hollow carbon nanotube-based fibers (H-CNTF), where two-dimensional graphene oxide (GO) nanosheets are employed as an alternative to polymer binder for assisting the formation of hollow structures by rapid interaction with cations in coagulation, forming strong interaction with CNTs and tunning rheological property of spinning dope. The hierarchical hollow structure consisting of micron-scale hollow tubular space and porous walls endows H-CNTF with large surface area and abundant loading sites for guest materials, and the good CNT orientation and the absence of polymer binder enable H-CNTF excellent electrical and mechanical properties. As a proof of concept, the resulting H-CNTF supercapacitor electrodes exhibit high electrochemical energy storage performance with a specific capacity of 163 F/cm3 and high tensile strength of 0.35 N/tex. In addition, the polymer composite based on H-CNTF is about 100 % stronger than that based on solid fiber owing to the more uniform composite structure. The combination of outstanding electrochemical and mechanical properties makes this hollow fiber a promising material for future structural and energy storage applications.

Titanium Multi-Topology Metamaterials with Exceptional Strength.

Additively manufactured metamaterials are architectured cellular materials that can be engineered through structural innovations to achieve unusual mechanical and multifunctional properties. Among these, hollow-strut lattice (HSL) metamaterials have proven to allow outstanding structural efficiency, with a multifunctional architecture ideal for lightweight, biomedical, microfluidic, and thermal engineering. To capitalize on their structural efficiency and significantly extend their mechanical envelope, a thin-plate lattice topology is seamlessly integrated into the inner hollow space of an HSL topology. This integration serves a dual purpose: to radically enhance the resistance of the irregular HSL nodes to deformation and to uniformly distribute the applied stresses in the new topology for unparalleled strength. Fabricated in titanium alloy Ti-6Al-4V with densities of 1.0-1.8g cm-3 , this thin-plate integrated hollow-strut lattice (TP-HSL) metamaterials achieve relative yield strength that well surpasses the empirical upper limit of all cellular metals, including HSL and solid-strut lattice (SSL) metamaterials made from various metallic alloys. Furthermore, their absolute yield strength drastically exceeds that of magnesium alloys with comparable densities while inheriting the high corrosion resistance, biocompatibility, heat resistance, and other unique attributes of Ti-6Al-4V. Titanium multi-topology metamaterials expand the boundaries of lightweight multifunctional metallic materials.

Possible formation of H2 hydrates in different nanotubes and surfaces using molecular dynamics simulation.

In this work, we simulated water molecules confined in carbon, boron nitride (BN), and silicon carbide (SiC) nanotubes with similar sizes. We also simulated water molecules confined between parallel graphene, BN, and SiC surfaces in two cases: (a) a similar geometric surface density of water of 0.177/Å2, in which the number of gas molecules was 18% of the total water molecules, and (b) a similar density profile of water of 0.04-0.05 dalton per Å3. To examine H2 hydrate formation, we added guest H2 molecules to the confined water molecules in the nanotube and surface systems. We analyzed the formed shapes, adsorption energies, radial distribution functions (RDFs), and self-diffusion coefficients of the confined molecules in gas hydrate formation. Our results showed that a more ordered heptagonal ice nanotube was formed in the BN nanotube than that in the other systems. After the addition of H2 molecules in the different nanotubes, some of the H2 molecules occupied the wall of the ice nanotube and some of them positioned in the hollow space. Although gas hydrates were created in all surface systems, ordered gas hydrate shapes were formed only in the graphene system. The adsorption energy for guest H2 molecules between the different surfaces was negative, which means that the formation of H2 hydrates between these surfaces is a spontaneous process (unlike that in the nanotube systems). According to RDF results, the BN nanotube and graphene surfaces are proper systems to form more ordered H2 hydrate structures. The confined water molecules have much higher diffusion coefficients in the BN nanotube and graphene surfaces than in the other systems. The F 4 parameter also substantiated hydrate formation in the different nanostructures. In a new configuration of BN and SiC systems with density profiles similar to that of the graphene system, the H2 hydrate was not formed completely as in the case of the graphene system. H2 hydrates formed in the new BN and SiC surfaces were less than those formed in the primary structures (with a geometrical density similar to that of the graphene system) and the graphene system.

A Modified Eggshell Technique for Sclerosing Thoracic Disc Herniation.

Sclerosing thoracic disc herniation refers to a condition in which the intervertebral disc in the thoracic region protrudes and becomes calcified, causing compression on the spinal cord and/or nerve roots. Sclerosing herniation of the thoracic disc poses a significant danger as it can lead to serious complications like paraplegia during or after surgery. Iatrogenic spinal cord injury is a common risk for individuals diagnosed with sclerosing thoracic disc herniation due to the inflexible protrusion of the sclerosing disc into the spinal canal and its adhesion to the ventral side of the dural sac. The challenging and crucial aspect of the surgery is how to safely and efficiently eliminate the hardened tissue. The eggshell method is a surgical procedure that addresses the kyphosis abnormality of the spinal column by excavating the vertebral body via the pedicles and subsequently inserting the kyphotic fracture block into the excavated vertebral body. In this article, a revised surgical method using the eggshell technique will be presented for the treatment of sclerosing thoracic disc herniation. The surgical procedure briefly involves hollowing out the anterior intervertebral space of the hardened disc tissue to create an eggshell-like structure, with the sclerotic tissue forming the posterior wall. Subsequently, the sclerotic disc tissue is pushed into the hollow intervertebral space to achieve complete decompression of the ventral spinal cord. The safety and effectiveness of this approach for treating sclerosing thoracic disc herniation have been confirmed.