Tight Mesh Research Articles

Study of Mechanical Properties of Micron Polystyrene-Toughened Epoxy Resin

Epoxy resin has a tight three-dimensional mesh structure after curing; due to this reason, the epoxy resin is brittle and not tough enough, which becomes the main reason for the destruction of the epoxy adhesive-steel/CFRP interface under fatigue loading of CFRP-reinforced steel structures. To prepare epoxy adhesives with good performance and suitable for CFRP-reinforced steel structures, the mechanical properties of epoxy adhesives are improved by adding polystyrene (PS) microspheres. In this work, five modified adhesives with PS weight fractions of 0 wt%, 1.25 wt%, 2.50 wt%, 3.75 wt% and 5 wt% are prepared by dispersion of PS particles through an ultrasonic cell crusher using a room-temperature curing process, and the tensile, flexural and impact properties of PS adhesives with different doping are investigated. Then, the microscopic morphology of the tensile section of the colloids is observed by scanning electron microscopy (SEM). The results show that the optimum dosing of PS is 2.5 wt%, and the tensile strength, tensile modulus of elasticity, flexural strength, flexural modulus and impact strength of the adhesive are increased by 77%, 147.7%, 71%, 35% and 22%, respectively, with this dosing. SEM analysis shows that PS particles produce large deformation to absorb energy when the matrix is fractured, and crack expansion needs to bypass or shear the PS particles, thus inhibiting crack expansion and achieving the purpose of toughening. Adhesion agglomeration of PS particles in the resin is the main reason for the decrease in the mechanical properties of adhesives.

Nanotoxicology In Environment: A review article

A nanometer is one billionth of a meter, which is about 1/50,000th the width of a strand of hair. Sub-microscopic nanoparticles exhibit unique properties that are strikingly different from even slightly larger sized particles. They express quantum mechanical phenomena and are small enough to pass through the skin and even through the tight mesh cells comprising the blood-brain barrier. Nanomaterials are being extensively exploited for their unique and diverse features, to raise the utility and associated value of the existing technologies , through enhanced production or by eliminating side effects or both. Nanotoxicology, is intended to define the toxicological activities of potential nanomaterials and their products, to determine whether and to what extent these materials pose threat to environment and human health. In this context, the fate of nanoparticles in environment with reference to air, water and soil has been considered. Studies about nanomaterials shows that some nanomaterials may have cytotoxic and genotoxic effects and may pose health risks. However, there is limited knowledge about the toxicity of nanomaterials. The nanotoxicology research focuses on the relationship between nanomaterial characteristics (size, shape, surface area etc.) and their toxic responses (cytotoxicity, genotoxicity, inflammation etc.). The knowledge from nanotoxicological study will be the base for designing safe nanomaterials and nanoproducts, and also direct uses in the nanomedical sciences. The main objective of the present review is to focus on the effect of nanomaterials on health and environment and to discuss the sources, fate, impacts, pathways and mechanisms of toxicity of engineered nanomaterial.

Novel design of bandages using cotton pads, doped with chitosan, glycogen and ZnO nanoparticles, having enhanced antimicrobial and wounds healing effects

In this present work, a new design for antimicrobial wound bandages is presented. The wound dressings were prepared using cotton fibers reinforced with elastic compression straps and secured with a polyester fabric of tight mesh size. The cotton pads were doped with a wound healing biocomposite, composed of chitosan, glycogen, and ZnO nanoparticles (CG@ZnONPs) previously formulated through a green process. The size of ZnONPs in the prepared CG@ZnONPs was 30–80 nm. The cotton pads impregnated with the CG@ZnONPs nanocomposite were characterized using FTIR, SEM, EDX, TGA, and DTGA methods. Moreover, the prepared dressings were tested on a number of intentionally injured rats. In this experiment, the % contraction of the treated wounds was monitored and compared to that of a control group of wounded rats, to which only sterile gauzes were applied. The results showed a much faster and an almost complete healing of rats treated with the synthesized dressings and the results were further confirmed by histopathological examination. The dressings were also found to exert a significant antimicrobial activity against a number of pathogenic microorganisms, generally encountered in common wounds, and could therefore be recommended to be a novel biomedical application for a fast, successful, and flawless wounds healing process.

Molecular “Hozo”: Thermally Stable Yet Conformationally Flexible Self-Assemblies Driven by Tight Molecular Meshing

Abstract Various noncovalent molecular interactions have been employed as driving forces to construct well-defined discrete self-assemblies. Among them, coordination and hydrogen bonds are widely used due to their high directionality and appropriate bond strength. However, the utilization of nondirectional, week molecular interactions for this purpose still presents a key challenge in supramolecular self-assembly. To tackle this critical issue, we presented a novel design concept, molecular “Hozo”, that the components with large, indented complementary hydrophobic surfaces tightly mesh with each other driven by the hydrophobic effect in water. Based on this concept, we developed a series of water-soluble cube-shaped molecular assemblies, i.e., nanocubes, composed of six molecules of identical gear-shaped amphiphiles (GSAs) with the aid of van der Waals (vdW) and cation-π interactions as well as the hydrophobic effect. The nanocubes exhibit unique properties derived from molecular meshing of the building blocks, such as high thermal stability yet as high conformational flexibility as biological molecules and emission whose intensity is affected by the structural change of the nanocube.

Adaptive segmentation of multiconductor transmission lines in quasi-static analysis by the method of moments

The paper proposes a new algorithm for constructing an adaptive mesh for quasi-static analysis of multiconductor transmission lines by the method of moments. Its versatility in analyzing transmission lines with complex geometry is shown in comparison with well-known algorithms. The algorithm showed high accuracy of calculations, memory savings are at least 1.6 times, and calculation time savings are at least 1.7 times compared to a tight uniform mesh.

Hydrogels for 3D Neural Tissue Models: Understanding Cell-Material Interactions at a Molecular Level.

The development of 3D neural tissue analogs is of great interest to a range of biomedical engineering applications including tissue engineering of neural interfaces, treatment of neurodegenerative diseases and in vitro assessment of cell-material interactions. Despite continued efforts to develop synthetic or biosynthetic hydrogels which promote the development of complex neural networks in 3D, successful long-term 3D approaches have been restricted to the use of biologically derived constructs. In this study a poly (vinyl alcohol) biosynthetic hydrogel functionalized with gelatin and sericin (PVA-SG), was used to understand the interplay between cell-cell communication and cell-material interaction. This was used to probe critical short-term interactions that determine the success or failure of neural network growth and ultimately the development of a useful model. Complex primary ventral mesencephalic (VM) neural cells were encapsulated in PVA-SG hydrogels and critical molecular cues that demonstrate mechanosensory interaction were examined. Neuronal presence was constant over the 10 day culture, but the astrocyte population decreased in number. The lack of astrocytic support led to a reduction in neural process outgrowth from 24.0 ± 1.3 μm on Day 7 to 7.0 ± 0.1 μm on Day 10. Subsequently, purified astrocytes were studied in isolation to understand the reasons behind PVA-SG hydrogel inability to support neural network development. It was proposed that the spatially restrictive nature (or tight mesh size) of PVA-SG hydrogels limited the astrocytic actin polymerization together with a cytoplasmic-nuclear translocation of YAP over time, causing an alteration in their cell cycle. This was confirmed by the evaluation of p27/Kip1 gene that was found to be upregulated by a twofold increase in expression at both Days 7 and 10 compared to Day 3, indicating the quiescent stage of the astrocytes in PVA-SG hydrogel. Cell migration was further studied by the quantification of MMP-2 production that was negligible compared to 2D controls, ranging from 2.7 ± 2.3% on Day 3 to 5.3 ± 2.9% on Day 10. This study demonstrates the importance of understanding astrocyte-material interactions at the molecular level, with the need to address spatial constraints in the 3D hydrogel environment. These findings will inform the design of future hydrogel constructs with greater capacity for remodeling by the cell population to create space for cell migration and neural process extension.

Dróttkvætt

Dróttkvætt Roberta Frank (bio) I set myself rules in order to be totally free. —Georges Perec1 Dróttkvætt. Old Norse court poetry, the verse of scalp-tingling wordsmiths, of wanderers on the whale's mean streets, of silver-tongued advertisers ("Eiríkr Bloodaxe rules OK"). Its stanza-form, a sculpture carved into time. In dróttkvætt, all things are numbers; the shape of reality is mathematical. Once tuned in to the mystic high frequencies of the universe, skalds (poets) said things that they did not know they were capable of saying. Dróttkvætt had a long run in Scandinavia, emerging at the onset of the Viking Age and holding on, horn, tooth, and claw, for more than half a millennium. The authors of poetic treatises from twelfth- and thirteenth-century Iceland believed that this verse had a future. Perhaps W. H. Auden thought so too when he slipped an English imitation into The Age of Anxiety.2 J. R. R. Tolkien also tried his hand at the form: Winter's winds had huntedwaves as dark as ravens,their [leaden] ship laden,lightless, sea-benighted.Forth now fared they mirthlessfar from mortal [portals]in caves coldly-buildedkindled fires that dwindled.3 The rhyme-scheme, alliteration, and syllable count of dróttkvætt are represented. Missing is its poetry: the hypnotic sound and memory links, the jagged wit and suggestiveness, the sudden glory of rounded perception. The classical dróttkvætt stanza consists of eight lines; a syntactic break after the fourth line divides the whole into two symmetrical halves of twenty-four syllables each (the number of letters in the older runic alphabet). The basic metrical unit is a three-stress, six-syllable line, with [End Page 393] a prescribed trochaic ending in a long stressed syllable followed by a short unstressed one. Lines are linked in pairs by means of alliteration or initial correspondence (all vowels alliterate with each other and with most words beginning with j-). There are two stressed alliterating syllables in the odd and one in the even line (always the first syllable). In each line, the next-to-last syllable chimes with a stem in the same line. In even lines, there is full rhyme; in odd lines, half-rhyme (different vowels followed by the same consonant). Of the forty-eight syllables in a full stanza, normally twenty-four are stressed, twelve bear alliteration, eight form full rhyme, and eight form half-rhyme. There is no choice in the placement of eight rhyming and four alliterating syllables. Like a wire in a tight mesh or screen, each significant word is linked in one or more ways to others in the same or immediately adjoining line. But there is more. Skalds skewed syntax. There is no certainty in dróttkvætt until the final syllable is in. The pull of an invisible grammar dictates the meaning of a stanza: words are urged into place, drawn together into a logical structure, like iron filings above a hidden magnet. Frequently a thought begun in line one is not completed until line four. Multiple stop-signs—the caesuras or gaps between alliterating and rhyming words—slow or redirect traffic, creating deliberate delays and frustration as well as multidimensional effects. Example 1: A Skald Laments his Fallen Brother.4 Gekk, sá's óðisk ekki,jarlmanns bani, snarla,(þreklundaðr fell) Þundar—Þórólfr—í gný stórum;jörð grœr, en vér verðum,Vínu nær, of mínum,(helnauð es þat) hyljaharm, ágætum barma. Strode he, who feared nothing,the earl's slayer—quickly—the bold one fell—of Óðinn—Þórólfr—in the great din;earth grows—and I have to—near Vína—over my—deadly agony is it—hide—sorrow—noble brother. [End Page 394] The first half-stanza contains a simple kenning or poetic circumlocution ("the din of Óðinn" = battle). The opening quatrain is structured so that a warrior's striding forth and subsequent fall in battle are heard simultaneously. The dead man's name is detached from its potential appositives (he, the earl's slayer, the bold one...

A never die entrepreneurial spirit-case of a struggling entrepreneur

New Entrepreneurial ventures whether small or medium, are considered to be the backbone of any country's economy. The creation of new business ventures along with the number of existing high-growth companies is a strong indicator of a nation's present and future economic development. The Entrepreneurship Center at Miami University of Ohio defines entrepreneurship as “Entrepreneurship is the process of identifying, developing and bringing a vision to life. The vision may be an innovative idea, an opportunity or simply a better way to do something. The end result of this process is the creation of a new venture formed under conditions of risk and considerable uncertainty”. There is seeming consensus on the importance of entrepreneurship in ameliorating some socio economic problems especially poverty, unemployment and all sorts of social vices in the society. There is a need to catalyze and scale up and enrich the entrepreneurial ecosystem. An ecosystem is nothing but a system of interconnected stakeholders, institutions and individuals; whose close linkages enable efficient production, diffusion and use of new and economically useful knowledge. We need to create more linkages and strengthen the existing ones, creating a tight mesh. The case mentioned below is of a struggling entrepreneur from Kolhapur, Maharashtra. It highlights his bumpy entrepreneurial journey and his never die entrepreneurial spirit. The case also aims to highlight the importance of nurturing an entrepreneurial mindset in our society which will result in lending a helping hand to startups in their initial leap into the entrepreneurial journey.

Particle size distribution and statistic analysis of the grain size messinian bentonite from the kert bassin (northern Morocco)

Abstract This work focus about the granulometric characterization the Messinian bentonites of Kert Neogene basin located in the Moroccan Northeast region in the rif chain. It was carried out by analyzing the evolution of the granulometric behavior of the bentonites along the profiles of the deposit. To do this, a sampling campaign was carried out in the form of a tight mesh. The particle size analysis of the Messinian samples was sandy loams, and loamy sands however the clay fraction ranged from 1.665 to 9.094% while the silt fraction from 20.817 to 92.794% and the sand fraction from 1.272 to 77.518%. The results for grain size indices and their distributions as a function of morphological units have shown that they are generally very fine Sands and very coarse silt, moderately misclassified, very poorly ranked and almost symmetrical.

Semi-quantitative evaluation of molecular meshing via surface analysis with varying probe radii.

A novel method for the semi-quantitative evaluation of molecular meshing in molecular complexes and assemblies (SAVPR: surface analysis with varying probe radii) is proposed. SAVPR revealed that the extremely high stability of hexameric assemblies (nanocubes) is due to tight molecular meshing between the components in the assemblies, indicating the importance of van der Waals interactions in hydrophobic molecular assemblies.

Ciprofloxacin-loaded PLGA nanoparticles against cystic fibrosis P. aeruginosa lung infections

Current pulmonary treatments against Pseudomonas aeruginosa infections in cystic fibrosis (CF) lung suffer from deactivation of the drug and immobilization in thick and viscous biofilm/mucus blend, along with the general antibiotic resistance. Administration of nanoparticles (NPs) with high antibiotic load capable of penetrating the tight mesh of biofilm/mucus can be an advent to overcome the treatment bottlenecks. Biodegradable and biocompatible polymer nanoparticles efficiently loaded with ciprofloxacin complex offer a solution for emerging treatment strategies. NPs were prepared under controlled conditions by utilizing MicroJet Reactor (MJR) to yield a particle size of 190.4±28.6nm with 0.089 PDI. Encapsulation efficiency of the drug was 79% resulting in a loading of 14%. Release was determined to be controlled and medium-independent in PBS, PBS+0.2% Tween 80 and simulated lung fluid. Cytotoxicity assays with Calu-3 cells and CF bronchial epithelial cells (CFBE41o−) indicated that complex-loaded PLGA NPs were non-toxic at concentrations ≫ MICcipro against lab strains of the bacteria. Antibacterial activity tests revealed enhanced activity when applied as nanoparticles. NPs’ colloidal stability in mucus was proven. Notably, a decrease in mucus turbidity was observed upon incubation with NPs. Herewith, ciprofloxacin complex-loaded PLGA NPs are introduced as promising pulmonary nano drug delivery systems against P.aeruginosa infections in CF lung.

Effect of Back-side Contact on Mesh Stiffness of Spur Gear Pair by Finite Element Method

Time varying mesh stiffness is an important parameter in the study of gearbox vibration analysis. Mesh stiffness is affected by gear parameters (e.g. pressure angle, contact ratio, back-up ratio, module etc.) and due to presence of gear tooth faults (e.g. crack, pitting, spalling etc.). Back-side contact of gear tooth happens when tight meshing occurs or anti-backlash gears are used. So the effect of back-side contact becomes an important consideration for calculating mesh stiffness. In this paper, the effect of back-side contact on mesh stiffness of drive side of spur gear pair is analyzed. For this, a three dimensional model is investigated by finite element method (FEM). The results are discussed and it is found that the back-side contact affects the mesh stiffness significantly.

Thermal fluid modeling of a passive heating system

In this work, two-dimensional and three-dimensional simulations on the flow in a room coupled with a facade of passive heating system type In-In (Trombe wall) were conducted numerically to determine the temperature and velocity fields in the influence of the variation of the modified Rayleigh number, which itself depends on the characteristics of the fluid and heat flow due to sunshine. The behavior of boundary layers in natural convection is analyzed along the Trombe wall in our periodically heated imposed flow. Thermal and dynamics modeling of the problem were made by a computational fluid dynamics (CFD) calculation, based on the finite volume method to model both the fluid flow and heat transfer. To take account of the strong temperature gradient and velocity near the walls, we chose a structured tight mesh near the walls and a little wider mesh elsewhere. The results have shown that for Grh > 4 × 108, the flow regime is laminar, while for Grh > 109, the flow regime becomes turbulent.

How Egg Case Proteins Can Protect Cuttlefish Offspring?

Sepia officinalis egg protection is ensured by a complex capsule produced by the female accessory genital glands and the ink bag. Our study is focused on the proteins constituting the main egg case. De novo transcriptomes from female genital glands provided essential databases for protein identification. A proteomic approach in SDS-PAGE coupled with MS unveiled a new egg case protein family: SepECPs, for Sepia officinalis Egg Case Proteins. N-glycosylation was demonstrated by PAS staining SDS-PAGE gels. These glycoproteins are mainly produced in the main nidamental glands. SepECPs share high sequence homology, especially in the signal peptide and the three cysteine-rich domains. SepECPs have a high number of cysteines, with conserved motifs involved in 3D-structure. SDS-PAGE showed that SepECPs could form dimers; this result was confirmed by TEM observations, which also revealed a protein network. This network is similar to the capsule network, and it associates these structural proteins with polysaccharides, melanin and bacteria to form a tight mesh. Its hardness and elasticity provide physical protection to the embryo. In addition, SepECPs also have bacteriostatic antimicrobial activity on GRAM- bacteria. By observing the SepECP / Vibrio aestuarianus complex in SEM, we demonstrated the ability of these proteins to agglomerate bacteria and thus inhibit their growth. These original proteins identified from the outer egg case ensure the survival of the species by providing physical and chemical protection to the embryos released in the environment without any maternal protection.

Structural Analysis of a Specialized Type III Secretion System Peptidoglycan-cleaving Enzyme

The Gram-negative bacterium enteropathogenic Escherichia coli uses a syringe-like type III secretion system (T3SS) to inject virulence or "effector" proteins into the cytoplasm of host intestinal epithelial cells. To assemble, the T3SS must traverse both bacterial membranes, as well as the peptidoglycan layer. Peptidoglycan is made of repeating N-acetylmuramic acid and N-acetylglucosamine disaccharides cross-linked by pentapeptides to form a tight mesh barrier. Assembly of many macromolecular machines requires a dedicated peptidoglycan lytic enzyme (PG-lytic enzyme) to locally clear peptidoglycan. Here we have solved the first structure of a T3SS-associated PG-lytic enzyme, EtgA from enteropathogenic E. coli. Unexpectedly, the active site of EtgA has features in common with both lytic transglycosylases and hen egg white lysozyme. Most notably, the β-hairpin region resembles that of lysozyme and contains an aspartate that aligns with lysozyme Asp-52 (a residue critical for catalysis), a conservation not observed in other previously characterized lytic transglycosylase families to which the conserved T3SS enzymes had been presumed to belong. Mutation of the EtgA catalytic glutamate, Glu-42, conserved across lytic transglycosylases and hen egg white lysozyme, and this differentiating aspartate diminishes type III secretion in vivo, supporting its essential role in clearing the peptidoglycan for T3SS assembly. Finally, we show that EtgA forms a 1:1 complex with the building block of the polymerized T3SS inner rod component, EscI, and that this interaction enhances PG-lytic activity of EtgA in vitro, collectively providing the necessary strict localization and regulation of the lytic activity to prevent overall cell lysis.

Analytical determination of back-side contact gear mesh stiffness

Back-side gear tooth contact happens when anti-backlash (or scissor) gears are used, tooth wedging or tight mesh occurs, or vibration amplitudes are high enough that teeth separate and pass the backlash zone. An accurate description of the back-side gear tooth mesh stiffness is needed to study gear mechanics in such cases. This work studies the time-varying back-side mesh stiffness and its correlation with backlash by analyzing the relationship between the drive-side and back-side mesh stiffnesses. Results of this work yield the general form of the back-side mesh stiffness in terms of the known drive-side mesh stiffness for an arbitrary gear pair. The analytical results are confirmed by simulation results from gear contact analysis software that precisely tracks drive- and back-side gear tooth contact.

Nonlinear dynamics and stability of wind turbine planetary gear sets under gravity effects

Abstract This paper investigates the dynamics of wind turbine planetary gear sets under the effect of gravity using a modified harmonic balance method that includes simultaneous excitations. This modified method along with arc-length continuation and Floquet theory is applied to a lumped-parameter planetary gear model including gravity, fluctuating mesh stiffness, bearing clearance, and nonlinear tooth contact to obtain the dynamic response of the system. The calculated dynamic responses compare well with time domain-integrated mathematical models and experimental results. Gravity is a fundamental vibration source in wind turbine planetary gear sets and plays an important role in the system dynamic response compared to excitations from tooth meshing alone. Gravity causes nonlinear effects induced by tooth wedging and bearing-raceway contacts. Tooth wedging, also known as a tight mesh, occurs when a gear tooth comes into contact on the drive-side and back-side simultaneously and it is a source of planet-bearing failures. Clearance in carrier bearings decreases bearing stiffness and significantly reduces the lowest resonant frequencies of the translational modes. Gear tooth wedging can be prevented if the carrier-bearing clearance is less than the tooth backlash.

Accurate Substrate Analysis Based on a Novel Finite Difference Method via Synchronization Method on Layered and Adaptive Meshing

In this paper, we present a finite difference method (FDM) based on layered and adaptive meshing to extract substrate resistance. To allow adaptive meshing, a novel synchronization method is introduced which expresses the potential at other points than the centroids of panels by modifying the finite difference equations. This method makes it possible to overcome the high computational cost of the FDM due to tight uniform meshing requirements while enjoying a straightforward implementation and easy handling of irregular/arbitrary substrate structures to extract the substrate coupling of integrated circuits.

Microanatomy at Cellular Resolution and Spatial Order of Physiological Differentiation in a Bacterial Biofilm

ABSTRACTBacterial biofilms are highly structured multicellular communities whose formation involves flagella and an extracellular matrix of adhesins, amyloid fibers, and exopolysaccharides. Flagella are produced by still-dividing rod-shaped Escherichia coli cells during postexponential growth when nutrients become suboptimal. Upon entry into stationary phase, however, cells stop producing flagella, become ovoid, and generate amyloid curli fibers. These morphological changes, as well as accompanying global changes in gene expression and cellular physiology, depend on the induction of the stationary-phase sigma subunit of RNA polymerase, σS (RpoS), the nucleotide second messengers cyclic AMP (cAMP), ppGpp, and cyclic-di-GMP, and a biofilm-controlling transcription factor, CsgD. Using flagella, curli fibers, a CsgD::GFP reporter, and cell morphology as “anatomical” hallmarks in fluorescence and scanning electron microscopy, different physiological zones in macrocolony biofilms of E. coli K-12 can be distinguished at cellular resolution. Small ovoid cells encased in a network of curli fibers form the outer biofilm layer. Inner regions are characterized by heterogeneous CsgD::GFP and curli expression. The bottom zone of the macrocolonies features elongated dividing cells and a tight mesh of entangled flagella, the formation of which requires flagellar motor function. Also, the cells in the outer-rim growth zone produce flagella, which wrap around and tether cells together. Adjacent to this growth zone, small chains and patches of shorter curli-surrounded cells appear side by side with flagellated curli-free cells before curli coverage finally becomes confluent, with essentially all cells in the surface layer being encased in “curli baskets.”

Endoscopic double‐metallic stenting for malignant biliary and duodenal obstructions

Endoscopic metallic stenting is a safe, effective treatment for malignant biliary obstructions, but can be technically difficult when combined malignant biliary and duodenal obstructions exist. Available duodenal metallic stents feature a tight mesh unsuitable for transpapillary biliary stenting. We evaluated the feasibility and usefulness of new endoscopic procedures for endoscopic double-stent placement in managing such obstructions. The through-the-scope duodenal metallic stent has a central cross-wired, unfixed structure that allows insertion of the biliary stent through the mesh wall of a duodenal stent. Transpapillary endoscopic placement of a biliary stent was performed through the lumen of this duodenal stent. Endoscopic ultrasound (EUS)-guided biliary drainage was performed successfully through the duodenal bulb after puncturing with a 19G needle. Biliary metallic stenting through the choledochoduodenal tract and effective drainage were achieved. Use of a combined endoscopic biliary and duodenal stent inserted through the mesh of the new duodenal metallic stent is feasible and effective in managing the aforementioned obstructions. EUS-guided biliary metal stenting is a therapeutic option for endoscopic management when a failed transpapillary approach through the lumen of the duodenal stent occurs. The continued development of endoscopic procedures and devices should resolve issues associated with complicated strictures.