Double-layer Mesh Research Articles

Surgical management of costal margin rupture associated with intercostal hernia: Evolution of techniques

INTRODUCTION Costal margin rupture (CMR) injuries in association with intercostal hernia (IH) are rare and symptomatic and provide a significant surgical challenge. Surgical failure rates up to 60% are reported, and optimal techniques are unclear. We have characterized these injuries and describe the evolution of our surgical management techniques. METHODS Patients characterized by the Sheffield Classification where CMR and IH were both present, either CMR-IH or transdiaphragmatic intercostal hernia (TDIH), were identified prospectively, and injury characteristics, patient management, and follow-up data were recorded. Surgical techniques evolved according to patient outcomes from suture repair without and then with extrathoracic mesh, to three iterations of double-layer mesh repair (DLMR). The third iteration involved DLMR with biologic mesh, titanium buttress plates applied to the ribs adjacent to the IH with intercostal nerve-sparing suture placement. Associated surgical stabilization of rib fractures, or surgical stabilization of nonunited rib fractures, was performed when required, with costal margin plate fixation where possible. RESULTS Of 25 patients with CMR-IH and 11 with TDIH, 25 patients underwent surgery, with 6 reoperations in 5 patients. There were 8 suture repairs and 3 extrathoracic mesh repairs: DLMR was performed in 14 patients (3 Mark [Mk] 1, 5 Mk 2, and 6 Mk 3) with 2, 1, and 0 reoperations, respectively. Costal margin stabilization with titanium plates was successful twice at the level of the seventh but failed twice out of three times at the ninth costal cartilage. Reoperation after a failed mesh repair is particularly challenging and may require the placement of titanium buttress plates, surgical stabilization of rib fractures, and the use of stainless steel wire sutures. CONCLUSION Repair of CMR-IH/TDIH is challenging, but experience-based evolution of techniques has led to a durable and reproducible Mk 3 repair. LEVEL OF EVIDENCE Observational; Level III.

A double-layer mesh-driven robust topology optimization strategy for mechanical metamaterials under size uncertainty

With the increasingly stringent functional requirement of advanced equipment, it is crucial to design materials and structures with special properties. Improving optimization efficiency and shortening the design cycle are widely concerned as important scientific issues. This paper proposes a novel double-layer mesh-driven robust topology optimization strategy for mechanical metamaterials under size uncertainty. A double-layer mesh technology that establishes a mapping relationship between structural response and sensitivity information is developed, which greatly improves computational efficiency. The influence of size uncertainty is considered in topology optimization, and the robust design of mechanical metamaterials is realized. Various metamaterial designs are realized by solving optimization models based on sensitivity information. These can provide technical support and design references for the engineering application of mechanical metamaterials.

Robust Zero Level-Set Extraction from Unsigned Distance Fields Based on Double Covering

In this paper, we propose a new method, called DoubleCoverUDF, for extracting the zero level-set from unsigned distance fields (UDFs). DoubleCoverUDF takes a learned UDF and a user-specified parameter r (a small positive real number) as input and extracts an iso-surface with an iso-value r using the conventional marching cubes algorithm. We show that the computed iso-surface is the boundary of the r -offset volume of the target zero level-set S , which is an orientable manifold, regardless of the topology of S. Next, the algorithm computes a covering map to project the boundary mesh onto S , preserving the mesh's topology and avoiding folding. If S is an orientable manifold surface, our algorithm separates the double-layered mesh into a single layer using a robust minimum-cut post-processing step. Otherwise, it keeps the double-layered mesh as the output. We validate our algorithm by reconstructing 3D surfaces of open models and demonstrate its efficacy and effectiveness on synthetic models and benchmark datasets. Our experimental results confirm that our method is robust and produces meshes with better quality in terms of both visual evaluation and quantitative measures than existing UDF-based methods. The source code is available at https://github.com/jjjkkyz/DCUDF.

Complex uncertainty-oriented robust topology optimization for multiple mechanical metamaterials based on double-layer mesh

With the continuous improvement of structural performance requirements of advanced equipment, the multiscale design of materials and structures is increasingly developing towards refinement and multi-function. Metamaterials have broad application prospects due to their superior mechanical properties. In this paper, a robust topology optimization design strategy for mechanical metamaterials with multiple properties including modulus and Poisson's ratio is proposed. This method considers the manufacturing size uncertainty on properties of metamaterials and adopts a double-layer mesh technology to improve the efficiency of topology optimization. In addition, a topology optimization model for metamaterials with different mechanical properties is established, and mechanical metamaterials with various properties and configurations have been designed and validated. These can provide technical support and design references for the engineering application of mechanical metamaterials.

Costal margin injuries and trans-diaphragmatic intercostal hernia: Presentation, management and outcomes according to the Sheffield classification.

Costal margin rupture (CMR) injuries are under-diagnosed and inconsistently managed, while carrying significant symptomatic burden. We hypothesized that the Sheffield Classification system of CMR injuries would relate to injury patterns and management options. Data were collected prospectively between 2006 and 2023 at a major trauma center in the United Kingdom. Computed tomography scans were interrogated and injuries were categorized according to the Sheffield Classification. Clinical, radiologic, management and outcome variables were assessed. Fifty-four patients were included in the study. Intercostal hernia (IH) was present in 30 patients and associated with delayed presentation ( p = 0.004), expulsive mechanism of injury (i.e. such as occurs with coughing, sneezing, or retching), higher body mass index ( p < 0.001), and surgical management ( p = 0.02). There was a bimodal distribution of the level of the costal margin rupture, with IH Present and expulsive mechanism injuries occurring predominantly at the ninth costal cartilage, and IH Absent cases and other mechanisms at the seventh costal cartilage ( p < 0.001). There were correlations between the costal cartilage being thin at the site of the CMR and the presence of IH and expulsive etiology ( p < 0.001). Management was conservative in 23 and surgical in 31 cases. Extrathoracic mesh IH repairs were performed in 3, Double Layer Mesh Repairs in 8, Suture IH repairs in 5, CMR plating in 8, CMR sutures in 2, and associated Surgical Stabilization of Rib Fractures in 11 patients. There was one postoperative death. There were seven repeat surgical procedures in five patients. The Sheffield Classification is associated statistically with presentation, related chest wall injury patterns, and type of definitive management. Further collaborative data collection is required to determine the optimal management strategies. Therapeutic/Care Management; Level III.

Comparison of the Outcome and Efficacy of Single-Layer versus Dual-Layer Mesh Stent among Carotid Stenosis Patients Attending a Tertiary Care Setting—A Prospective Observational Study

Abstract Introduction The effect of stent design whether single-layer or double-layer on long-term durability of carotid artery stenting (CAS) is unknown. The aim of this article was to compare the clinical outcome and efficacy of single-layer versus dual-layer mesh stent for CAS among carotid stenosis patients. Methods A prospective observational study was conducted among 41 consecutive patients, who underwent CAS procedures between November 2019 and November 2021. Procedural data and outcomes for patients treated with the single-layer stent (n = 19patients) and double-layer stent (n = 22) were compared. Procedural efficacy and complications were considered as primary outcome variable. SPSS version 22 was used for statistical analysis. Results Mean age of study population in dual-layer stents group was 63.86 ± 11.08 years and it was 61.47 ± 8.26 years in single-layer stent group. There was no statistically significant difference between two groups with age, stenosis, side of stenosis, prestenting angioplasty, and poststenting angioplasty (p-value &gt;0.05). Out of 22 participants with dual-layer stent, only one (4.5%) participant experienced five episodes of transient ischemic attack in last 1 month. Both clinical and associated complaints were more in dual-layer group compared with single layer. One (5.26%) participant in single-layer group had reclusion/restenosis at 30 days. Majority in single-(57.8%) and double-layer (63.64%) stents group showed modified Rankin Scale score of 0. Conclusion Restenosis after CAS occurred less frequently in patients treated with double-layer mesh when compared with single-layer stent. However, both stents were equally effective at preventing peri procedural complications.

V-048 EXPANDING INDICATION OF LAPAROSCOPIC INTRACORPOREAL RECTUS APONEUROPLASTY (LIRA) TO SUPRAPUBIC AREA: LIRA &amp; TAPE

Abstract Aim LIRA-technique is a minimally invasive technique described to repair M2–M4 primary and incisional hernias. Defects below this area (M5 –Suprapubic area) could be treated using the concept associated to LIRA, expanding the indication of this technique in combination with a transabdominal partially extraperitoneal (TAPE) repair. The aim of this video is to show the surgical steps combining LIRA &amp; TAPE for M2–M5 ventral hernias. Material &amp; Methods 75-years-old-female patient with clinical examination and CT-scan showed a 9 cm width incisional hernia(W2), including the supraumbilical(M3), infraumbilical(M4) and suprapubic area(M5) with a total longitudinal length of 18 cm. Results The first step of the procedure is to open the peritoneum and posterior rectus sheath at 1–2 cm from the edge of the defect over the arcuate line. This flap allows following the dissection below arcuate line. At the suprapubic area, a bilateral peritoneal flap was done as indicated during the TAPE-repair until both Cooper ligaments are identified. Loop sutures were used for closing the defect, using the rectus muscle below the arcuate line, as well as the posterior rectus sheath above this line. A double-layer mesh is used in this case, being placed intraperitoneally. Conclusions The combination of LIRA &amp; TAPE techniques provides an extension of the indication of concept associated to the LIRA for the repair of M5/W2 hernias, which could not be achieved using a conventional technique. Our initial experience with this technique, expanding the concept of LIRA to the suprapubic area, shows no recurrences and no postoperative morbidity.

A Novel Micro-Pressure Graphene Sensor Array With Double-Layer Mesh Structure

In this work, a novel micro-pressure graphene sensor array with double-layer mesh structure is designed in order to effectively realize the multi-point measurement of micro-pressure. A <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$4\times 4$ </tex-math></inline-formula> sensor array could form 16 pressure-sensing pixels with good multi-point measurement capability. The double-layer mesh graphene with interconnected porous microstructure is fabricated with a cheap and convenient laser direct writing (LDW) technique. Based on the excellent microstructure and the double-layer mesh structure, this graphene pressure sensor array demonstrates high sensitivity in the low-pressure range (0.339 kPa <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−1</sup> , < 200 Pa), ultra-fast response time (< 30 ms), and prominent repeatability (>200 cycles), which meets the requirements of micro-pressure measurement. In addition, a full-automatic micro-pressure demodulation system equipped with human-computer interaction interface is designed to realize the two-dimensional shape recognition. Therefore, it could open broad applications in the fields of micro-pressure measurement, two-dimensional shape recognition and wearable electronic devices.

Results of Angioplasty With Double-Layer Mesh Stent and Protection Systems of the Extra- and Intracranial Dissection of Cephalic Arteries

Purpose: Although a majority of cervical artery dissections can be managed conservatively, patients presenting with cerebral embolization or significant stenosis require a more aggressive approach. However, complications associated with endovascular repair are quite frequent and optimal interventional technique still remains to be established. Materials and methods: The aim of this post hoc survey was to analyze results of endovascular treatments for symptomatic dissections of the internal carotid and vertebral arteries, which were performed under protection and with the use of double-layer mesh stents. During endovascular procedure catheters, stents and protection systems were tailored according to the angioarchitecture of dissection, particularly to its location, length and coexisting stenotic or aneurysmatic lesions. We evaluated retrospectively midterm and late results of endovascular treatment of 25 patients presenting with symptomatic dissection of cervical arteries, including 11 patients with dissections of intracranial segments of the internal carotid artery. Follow-ups were scheduled 1, 3 and 6 after the procedure, and then every 6 months. Control computed tomography (CT) or digital subtraction angiography (DSA) arteriographies were performed 1–6 months and 12 months after endovascular repair. Results: There were no periprocedural major adverse events. All patients completed the 12-month follow-up. There were neither fatalities nor new neurologic adverse events at the 30-day follow-up, and no such adverse events during long-term follow-up. At 12-month follow-up, in all patients, angiographies revealed patent stents, full coverage of lesions by stents and complete thrombotic closure of the pseudoaneurysms. Conclusions: A tailored endovascular management of symptomatic dissection of cervical arteries is safe and efficient, also in a long run.

Сравнение эффективности "оnlay" пластики больших и гигантских грыж пищеводного отверстия диафрагмы полипропиленовым сетчатым имплантатом и двухслойным биокарбоновым сетчатым имплантатом

This article is a continuation of a series of studies on the optimization of techniques and methods of surgical operations for hernias of the esophageal aperture of the diaphragm and is based on the use of the author’s development of a model of a two-layer biocarbon mesh implant. The purpose of this study is to highlight the immediate and long-term results of using a double-layer biocarbon mesh implant in comparison with the standard method of using a polypropylene implant when operating patients with large and giant hiatal hernia. All patients were split into 2 research groups that underwent alloplasty with various implants: Group I of 221 patients who underwent alloplasty with a polypropylene mesh implant (171 patients with large hernias of 10-20 cm2) and 50 patients with giant hernias of the esophageal orifice with the area of the hernial defect exceeding 20 cm2); Group II of 79 patients who underwent an original alloplasty with a bi-layer biocarbon mesh implant (50 patients with large hernias and 29 patients with giant hernia of the esophageal orifice). Postoperative complications were classified according to the Clavien-Dindo scale. De Meester index was used as a comparison criterion. The article discusses the results of operations of 300 patients for large and giant hernias of the esophageal aperture of the diaphragm, of which 79 were operated on using a prototype biocarbon double-layer mesh implant according to the author's patent. The paper presents immediate and long-term results. The results of surgical treatment are pilot and representative, which determine the further tactics and direction of improving operations to remove large and giant hernias of the esophageal opening of the diaphragm. For the first time, data on the use of the author's development of a bi-layer biocarbon mesh implant are presented and compared with a polypropylene mesh implant during an "on-line" plastic repair of large and giant hiatal hernia. Significant differences were obtained in relapses of all types in favor of a biocarbon mesh implant (5,6 versus 22,8%; p &lt; 0,0001; Fisher's exact test).

Design and Experiment of Vibrating Screen Millet Cleaning Devise with Double-fan

HighlightsAccording to the physical characteristics of the millet, the double-layer mesh vibrating screen was used as the cleaning screen to prolong the cleaning time of the millet in the cleaning room, prevent the blocking of the vibrating screen, and improve the cleaning performance of the millet cleaning device.As the air flow produced by centrifugal fan was continuously attenuated on the screen surface, the draft chaser cannot completely discharge the chaffs, stalks and other sundries outside the machine. The cross-flow fan designed at the tail of the vibrating screen worked well for increasing the air flow field, improving the cleaning performance.In order to reduce the unthreshed grain-codes in the threshed mixture, a re-threshing device was installed for the millet cleaning device that transported sundries at the end of the screen to the main threshing roller for re-threshing, which improved the cleaning rate and reduced the loss rate effectively.The mathematical model of four factors quadric regression between the rotating speed of centrifugal fan, cross-flow fan, frequency of vibrating screen, width of sundry outlet and the cleaning performance of the device was established, which was meaningful and had high fitting degree. The results of indoor test shown that the cleaning rate was 98.8% and the loss rate was 1.3%.The results of bench test and field test shown that when the size of the upper screen was 12×12 mm, the size of the lower screen was 6×6 mm, the diameter of the suction port of the cross-flow fan was 15 mm, the rotating speed of the centrifugal fan was 1406 r/min, the rotating speed of the cross-flow fan was 713 r/min, the frequency of the vibrating screen was 5.9 Hz, and the width of the sundry outlet was 178 mm, the cleaning rate of the millet cleaning device was 98.75%, and the loss rate was 1.34%.Abstract. The cleaning device is an important part of the millet combine harvester, which directly affects the performance of the whole machine. Aiming at the problems of low cleaning rate and high loss rate in the traditional air-and-screen cleaning device, a vibrating screen millet cleaning device with double-fan was designed. The structure and relevant parameters of the vibrating screen millet cleaning device with double-fan were analyzed and determined. The effects of the rotating speed of centrifugal fan, the rotating speed of cross-flow fan, the vibrating frequency of vibrating screen and the width of the sundry outlet on the millet cleaning rate and the loss rate were studied by single factor test and the orthogonal combination test of four element quadratic rotation. The regression equation between the rotating speed of centrifugal fan, the rotating speed of cross-flow fan, the vibrating frequency of vibrating screen and the width of the sundry outlet and the millet cleaning rate and the loss rate are constructed was used to optimize and obtain the operation parameters of the cleaning device. The indoor test results showed that when the centrifugal fan speed was 1406 r/min, the cross-flow fan speed was 726 r/min, the vibrating screen frequency was 5.9 Hz, and the width of the sundry outlet was 178 mm, the millet cleaning rate was 98.8%, and the loss rate was 1.3%. The result of field test showed that the cleaning rate and loss rate of the vibrating screen millet cleaning device with double-fan were 98.75% and 1.34%, respectively. Keywords: Double-fan, Double-layer mesh vibrating screen, Field test, Millet.

On the aerodynamic fog collection efficiency of fog water collectors via three-dimensional numerical simulations

Fog water collection gained interest in recent years as an emerging solution for water scarcity in arid and semi-arid areas. During a fog event, a porous mesh screen of plastic polymer retains the water through droplet impaction, where the droplets coalesce and trickle into a gutter for collection. This type of collecting system has existed since the 1960s; however, a substantial lack of understanding remains as to the aerodynamics that dominates the collection phenomena. The Aerodynamic Collection Efficiency (ηa) is the determining factor in the overall performance of such systems. This paper aims to further the fundamental knowledge on the aerodynamic behavior during fog collection. For this, a three-dimensional computational fluid dynamics model was developed, where the collector's mesh was modeled as a porous medium, which simulates a conventional two-dimensional double layer mesh. A parametric study was carried out varying the mesh's geometric characteristics (flat and concave), mesh-to-ground distance, and wind speed. The effect of wind speed on aerodynamic collection efficiency is mainly determined by the relative relationship between the viscous and inertial pressure drop in the porous medium. A greater curvature reduces the mesh's airflow impedance, leading to a significant improvement of the aerodynamic collection efficiency. Within the parameter range of our study, we found a maximum aerodynamic collection efficiency of 35% for the largest curvature (1.1 m), the highest mesh-to-ground distance (2 m), and the maximum wind speed (5 to 7 m s−1).

Durability and Performance of Ferrocement Infill Wall Panel

Ferrocement is composed of cement mortar reinforced with small diameter closely spaced steel wire mesh to form a thin section conforming high performance of serviceability. The present study investigates the performance of ferrocement panels focused on the mechanical properties, water absorption and durability. A series of specimens were cast with single and double mesh layers. Flexural performance was carried out following sixty days in temperature cycle and in corrosion cell. These results was compared with the controlled sample. The test results shows that the flexural strength performance was reduced by 52% and 35% for single and double layer wire mesh samples respectively followed by corrosion environment. First crack load also changed after completion of sixty temperature cycles. This load is 27.3%, 42.3% and 31.8% of failure load for controlled sample, sample in room air after every temperature cycle and samples in room air following quenching after every temperature cycle respectively for single mesh layer sample, and for double mesh layer sample these values are 38.9%, 30.1% and 17.7%. Early first crack is found for the samples following quenching and cooled in room air; however, both types of samples are in low absorption level. This data represents that double layer mesh specimen exhibits better when compared to single layer mesh specimen in strength and corrosion parameters.

Short-Term Double Layer Mesh Stent Patency for Emergent or Elective Carotid Artery Stenting.

Background and Purpose- Novel double layer micromesh stents have recently been introduced for treatment of patients with significant carotid stenosis. Strict evaluation of safety and patency of such novel devices is required both in elective and in emergency interventions. We report a single center experience with double layer mesh stents for carotid artery revascularization. Methods- Consecutive patients who underwent carotid artery stenting with a double layer mesh stent between June 2015 and September 2018 in our tertiary vascular referral center were included. Treatment indications were emergent carotid artery stenting for intracranial or extracranial carotid stenosis in patients undergoing intraarterial thrombectomy for acute ischemic stroke in the anterior circulation, or elective carotid artery stenting for significant symptomatic or asymptomatic stenosis. End points were postprocedural thrombotic stent occlusion and procedural stroke or death. Results- Fifty-four patients were included; 27 were treated for acute stroke with intracranial and extracranial (tandem) lesions and 27 for elective stenting. Follow-up imaging was available for 9/27 (33%) patients with acute stroke, and 19/27 (70%) electively treated patients. Five stent occlusions occurred, of which 2 were symptomatic with clinical deterioration within one day. Another patient deteriorated on postprocedural day one, but imaging of the carotids was not performed, and the stent turned out occluded on the 30-day duplex. All stent occlusions occurred in patients treated for acute stroke. Conclusions- This study suggests that occlusion of novel double layer mesh stents occurs in a considerable proportion of carotid artery stenting procedures performed in the emergency setting for acute stroke, with occlusion-related symptoms in half the cases. Future prospective studies should clarify the role of double layer mesh stents in this high-risk patient population.

Grafting with double-layered polypropylene mesh for gap healing of mid-metacarpal superficial digital flexor tendon in Equus asinus: clinical and pathological evaluations

Tendon injury is one of the most common causes of wastage in equine. The superficial digital flexor tendon (SDFT) gets affected the most, especially in the mid-metacarpal region. Several studies have focused on the grafting of severed SDFT, but no ideal grafting material has been approved for clinical application. The present study aimed to evaluate the grafting of the mid-metacarpal SDFT in donkeys with a double-layered polypropylene mesh clinically, ultrasonically, macro/microscopically. Clinically healthy adult donkeys (n = 24) were divided randomly and equally into two groups: control (C) and study (S) groups. Tenotomy was performed on all animals by excising a full-thickness segment from the mid-metacarpal SDFT. In the C group, a suture tenorrhaphy was performed. While in the S group, SDFT was grafted with the double-layered polypropylene mesh. The S group showed faster clinical improvements, and earlier appearance of normal newly formed tendinous tissue ultrasonically compared with the C group. Macroscopically, the grafted tendons showed a rapid restoration of normal color and consistency. Moreover, they had minimal peri-tendinous adhesions compared with the non-grafted tendons. Microscopically, the grafted tendons showed earlier vascularization and more mature collagen fibers compared with the non-grafted tendons. In the present study, we have succeeded to graft the gap of the mid-metacarpal SDFT of a donkey using the double-layered polypropylene mesh. This method is an economical way to accelerate the healing process of the SDFT and enhance the clinical recovery in donkeys.

Unifying classification for transdiaphragmatic intercostal hernia and other costal margin injuries.

Taxonomy of injuries involving the costal margin is poorly described and surgical management varies. These injuries, though commonly caused by trauma, may also occur spontaneously, in association with coughing or sneezing, and can be severe. Our goal was to describe our experience using sequential segmental analysis of computed tomographic (CT) scans to perform accurate assessment of injuries around the costal margin. We propose a unifying classification for transdiaphragmatic intercostal hernia and other injuries involving the costal margin. We identify the essential components and favoured techniques of surgical repair. Patients presenting with injuries to the diaphragm or to the costal margin or with chest wall herniation were included in the study. We performed sequential segmental analysis of CT scans, assessing individual injury patterns to the costal margin, diaphragm and intercostal muscles, to create 7 distinct logical categories of injuries. Management was tailored to each category, adapted to the individual case when required. Patients with simple traumatic diaphragmatic rupture were considered separately, to allow an estimation of the relative incidence of injuries to the costal margin compared to those of the diaphragm alone. We identified 38 patients. Of these, 19 had injuries involving the costal margin and/or intercostal muscles (group 1). Sixteen patients in group 1 underwent surgery, 2 of whom had undergone prior surgery, with 4 requiring a novel double-layer mesh technique. Nineteen patients (group 2) with diaphragmatic rupture alone had a standard repair. Sequential analysis of CT scans of the costal margin, diaphragm and intercostal muscles defines accurately the categories of injury. We propose a 'Sheffield classification' in order to guide the clinical team to the most appropriate surgical repair. A variety of surgical techniques may be required, including a single- or double-layer mesh reinforcement and plate and screw fixation.

Double-layer metal mesh etched by femtosecond laser for high-performance electromagnetic interference shielding window.

An excellent transparent electromagnetic interference (EMI) shielding window is proposed and demonstrated theoretically and experimentally. The window is composed of double layers of Au–Ni composite mesh, separated by the quartz-glass substrate. The simulation exhibits that the shielding effectiveness (SE) of the double-layer mesh can be improved by increasing the thickness of the substrate in the low frequency range far below the first interfere valley. The measured SE of the proposed structure reaches over 37.61 dB covering an ultra-wide frequency ranging from 150 MHz to 5 GHz, with a maximal SE of 75.84 dB at 3.58 GHz, while the average optical transmittance of the double-layer mesh maintains ∼76.35% at 400–900 nm. Moreover, femtosecond laser direct writing processing technology is used to manufacture the double-layer metal grids, the fabricated grids are not easy to be scuffed off and has a longer operating life. Such a high-performance EMI shielding window has great potential applications in precision optical monitoring instrument and military devices.

The effects of Light Intensity on Seedling Growth of Annona muricata Linn.

This study was carried out to investigate seedlings growth performance of Annona muricata Linn. as influenced by different light intensities. Seedlings of A. muricata were subjected to three (3) treatments via; growth in direct sunlight (control), in single layered mesh net and in double layered mesh net. Each of the experiment was replicated three (3) times in a Complete Randomized Design (CRD). The variables assessed were plant height, number of leaves, stem girth and leaf area. The data collected were subjected to one way analysis of variance (ANOVA). The results showed that there were significant differences among the treatments at 5% level of probability. Seedlings under direct sunlight had the highest mean height of 13.63cm, number of leaves (17.50cm), stem girth of 1.20cm and had the least leaf area of 11.30cm2 at three month after transplantation. This was followed by the seedlings under single layered mesh net with mean height of 11.05cm, number of leaves (7.00), stem girth (0.78cm) and highest leaf area of 17.06cm2 while the least plant height, number of leaves and stem girth was recorded in seedlings under double layered mesh net with mean values of 10.03cm, 5.83 and 0.68cm respectively. It is concluded that seedlings of Annona muricata under direct sunlight has better growth performance than those under single and double layered mesh net. Though, it had the least leaf area, it recorded the highest mean values in other parameters considered. Therefore, direct sunlight might be required in raising seedlings of this species.

Double layered stents for carotid angioplasty: A meta-analysis of available clinical data.

The objective of this meta-analysis is to evaluate clinical efficacy of double layered mesh covered carotid stent systems in the clinical practice. The need for an increase plaque coverage to decrease the risk of debris dislodgement through the stent struts, following carotid artery stenting (CAS), has brought to the design of a new generation of double layered carotid stents. Several small sized clinical studies evaluating two different devices have been recently published, unfortunately these are not sufficiently powered to test for device related and clinical endpoints and no comparison, between the two available devices, has been reported yet. Ten studies, enrolling 635 patients, were included in the present meta-analysis. Our study analyzed a composite endpoint of 30-day stroke and death and the occurrence of procedural unsuccess after CAS with the use of two different double layered carotid stent systems. Thirty-day stroke and death rate was quite low (patients 635, event rate 0.02, 95% CI: 0.01-0.04, P < 0.0001). The incidence of procedural unsuccess with these devices was relatively low (patients 635, event rate 0.03, 95% CI: 0.01-0.08, P < 0.0001). When a subgroup analysis was performed, according to the specific subtype of carotid stent, no differences in the occurrence of 30-day death and stroke rate and procedural unsuccess were observed (P = 0.979). This meta-analysis suggests that dual layered carotid stents could be safely used for the treatment of extracranial carotid artery stenosis, with a relatively low rate of procedural unsuccess, and allow achieving a quite low rate of postprocedural adverse events.

Fabrication of multiple-layered gradient cellular metal scaffold via electron beam melting for segmental bone reconstruction

The triple- and double-layered mesh Ti-based alloy scaffolds were successfully fabricated using electron beam melting (EBM). In this study Ti-based alloy cylindrical scaffolds with different 3D architectures intended for the segmental bone defect treatment were systematically compared. All lattice-like scaffolds were additively manufactured using EBM technology from Ti6Al4V to mimic the structures of human trabecular bone. Cylindrically-shaped lattice scaffolds (outer diameter of 15mm and length of 35mm) of five different types were designed and manufactured. Four types were tubular with inner hole diameter of 5mm and two lattice layers of different density. Fifth type was cylindrical with three lattice layers of different density. In all samples outer lattice layer was most dense, and inner layers- least dense. Mechanical properties of scaffolds were determined by conducting uniaxial compression testing. The strain-stress curves for all samples with gradient porosities showed considerable ductility.