Folding Technique Research Articles

Management of incisional cerebrospinal fluid leak in open cranial surgeries and the "folding technique" in duraplasty.

The aim of this study was to review a series of patients who underwent open cranial surgeries to evaluate the incidence of iatrogenic incisional CSF leaks and discuss its prevention and management. The authors also discuss the utility of the "folding technique" used in duraplasty as an alternative to conventional dural reconstruction techniques. All patients undergoing open cranial surgery were reviewed, and those with incisional CSF leak were included in this study. CSF leakage was managed using either conservative nonsurgical methods or surgical interventions. When the conservative nonsurgical methods failed to curb the leak, surgical procedures such as lumbar external drainage (LED) using lumbar subarachnoid drainage, external ventricular drainage (EVD), a lumboperitoneal or ventriculoperitoneal shunt (VPS), and reexploration of the surgical site were considered. Between 2019 and 2024, 2149 patients underwent open cranial surgeries at our hospital for any cranial pathology; 39 (1.8%) of these patients experienced postoperative incisional CSF leakage. The majority of the pathologies requiring surgeries were located in the supratentorial region (76.9%). Patients were classified according to the type of dural closure technique used. Primary stitching, the patient's fascia, or synthetic dura (resorbable, nonresorbable, or both) were used for dural reconstruction. The median interval between the surgery and the start of the leakage was 19 (IQR 1-79) days in patients with no history of radiotherapy; however, this duration was longer in patients who received radiotherapy (median 45 [IQR 10-540] days). The surgical interventions for CSF leakage were classified as wound resuturing (combined with other conservative approaches such as tightened dressing and elevating the head end of the bed), LED or EVD, or surgical reexploration. The folding technique in duraplasty is a simple way to achieve watertight duraplasty even with autograft or synthetic material. Incisional CSF leakage is a potentially preventable complication with high morbidity. Such cases could be managed via conservative approaches including wound resuturing, LED or EVD, and surgical reexploration. However, the management strategy is beyond any strict algorithm. This folding technique for duraplasty is a worthy replacement for conventional primary suturing for dural repair or reconstruction in cranial and even spinal defects. This study highlights the importance of regaining the watertight nature of the dura in the primary surgery to prevent any further intervention and lower the overall morbidity.

Achieving Creative Values in Interior Design Inspired by Folding Techniques

Achieving Creative Values in Interior Design Inspired by Folding Techniques

Origami-Inspired Biosensors: Exploring Diverse Applications and Techniques for Shape-Changing Sensor Platforms

Biosensors are widely used across industries such as healthcare, food safety, and environmental monitoring, offering high stability and sensitivity compared to conventional methods. Recently, origami—the art of folding 2D structures into 3D forms—has emerged as a valuable approach in biosensor development, enabling the creation of shape-changing devices. These origami-based biosensors are particularly useful in precision medicine, rapid diagnostics, and resource-limited settings, offering affordable, highly precise, and portable solutions with diverse applications. Paper and biological substrates like DNA have been integrated with origami techniques to develop biosensors with enhanced functionality. The incorporation of aptamer origami into both paper and DNA biosensors further increases sensitivity and specificity for target detection. The concept of paper-based origami biosensors originated from using paper as a platform for biological assays, leading to significant advancements in design and functionality. These devices employ folding techniques to create channels and wells for manipulating samples and detecting target molecules through reactions with specific reagents. Similarly, DNA origami, introduced in 2006, has revolutionized biosensors by enabling the creation of precise molecular systems with tunable properties. Paper-based and DNA origami biosensors have immense potential to transform biosensing technologies in healthcare, food safety, and environmental monitoring. This review explores diverse origami-based biosensor techniques and their applications, including the role of aptamer origami in paper and DNA biosensors.

Tracking the long-term timing accuracy of the X-Ray Telescope on board the Neil Gehrels Swift Observatory

Context. The Neil Gehrels Swift Observatory has been operational since November 2004. Its X-ray Telescope (XRT), operating in the 0.3–10.0 keV range, is designed to provide detailed position, timing, and spectroscopic information. Aims. The calibration procedure for assessing the absolute timing accuracy of XRT was described in a previous paper. Here we update the past analysis using the complete data set of the Crab pulsar observations up to October 2022 and using a new version of the data-processing software package that includes corrections to several issues that could have affected the previous results. Methods. We evaluate the accuracy of the Crab pulse period determination using the folding technique and the pulse-phase analysis and compare our results with the values derived from radio observations. We also check the absolute time reconstruction, measuring the phase position of the main peak in the Crab profile and comparing it with the value reported in the literature, which is based on Rossi X-Ray Timing Explorer (RXTE) observations. Results. We find that the accuracy in period determination for the Crab pulsar is of the order of a few picoseconds for the observations with the largest data time span. The absolute time reconstruction, measured using the position of the main pulse peak, shows that the main peak precedes the phase of the position reported in the literature for RXTE by ~263 µs on average. This corresponds to 0.982 in phase, with an observed dispersion of ±0.02 in phase values. We also find that observations very close in time (down to ~1 day separation) show a significant variation in absolute phase.

Retinal imaging based glaucoma detection using modified pelican optimization based extreme learning machine

Glaucoma is defined as progressive optic neuropathy that damages the structural appearance of the optic nerve head and is characterized by permanent blindness. For mass fundus image-based glaucoma classification, an improved automated computer-aided diagnosis (CAD) model performing binary classification (glaucoma or healthy), allowing ophthalmologists to detect glaucoma disease correctly in less computational time. We proposed learning technique called fast discrete curvelet transform with wrapping (FDCT-WRP) to create feature set. This method is entitled extracting curve-like features and creating a feature set. The combined feature reduction techniques named as principal component analysis and linear discriminant analysis, have been applied to generate prominent features and decrease the feature vector dimension. Lastly, a newly improved learning algorithm encompasses a modified pelican optimization algorithm (MOD-POA) and an extreme learning machine (ELM) for classification tasks. In this MOD-POA+ELM algorithm, the modified pelican optimization algorithm (MOD-POA) has been utilized to optimize the parameters of ELM’s hidden neurons. The effectiveness has been evaluated using two standard datasets called G1020 and ORIGA with the \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$10 \ imes 5$$\\end{document}-fold stratified cross-validation technique to ensure reliable evaluation. Our employed scheme achieved the best results for both datasets obtaining accuracy of 93.25% (G1020 dataset) and 96.75% (ORIGA dataset), respectively. Furthermore, we have utilized seven Explainable AI methodologies: Vanilla Gradients (VG), Guided Backpropagation (GBP ), Integrated Gradients ( IG), Guided Integrated Gradients (GIG), SmoothGrad, Gradient-weighted Class Activation Mapping (GCAM), and Guided Grad-CAM (GGCAM) for interpretability examination, aiding in the advancement of dependable and credible automation of healthcare detection of glaucoma.

Trapping light in air with membrane metasurfaces for vibrational strong coupling

Optical metasurfaces can manipulate electromagnetic waves in unprecedented ways at ultra-thin engineered interfaces. Specifically, in the mid-infrared (mid-IR) region, metasurfaces have enabled numerous biochemical sensing, spectroscopy, and vibrational strong coupling (VSC) applications via enhanced light-matter interactions in resonant cavities. However, mid-IR metasurfaces are usually fabricated on solid supporting substrates, which degrade resonance quality factors (Q) and hinder efficient sample access to the near-field electromagnetic hotspots. Besides, typical IR-transparent substrate materials with low refractive indices, such as CaF2, NaCl, KBr, and ZnSe, are usually either water-soluble, expensive, or not compatible with low-cost mass manufacturing processes. Here, we present novel free-standing Si-membrane mid-IR metasurfaces with strong light-trapping capabilities in accessible air voids. We employ the Brillouin zone folding technique to excite tunable, high-Q quasi-bound states in the continuum (qBIC) resonances with our highest measured Q-factor of 722. Leveraging the strong field localizations in accessible air cavities, we demonstrate VSC with multiple quantities of PMMA molecules and the qBIC modes at various detuning frequencies. Our new approach of fabricating mid-IR metasurfaces into semiconductor membranes enables scalable manufacturing of mid-IR photonic devices and provides exciting opportunities for quantum-coherent light-matter interactions, biochemical sensing, and polaritonic chemistry.

Potential of Non-flat Solar Sail for Higher Characteristic Acceleration

Solar sails offer a promising means of propelling spacecraft by harnessing Solar Radiation Pressure. Although non-flat solar sails have traditionally been considered less efficient in generating thrust, altering the sails’ design to a non-flat configuration can enhance structural stability, allowing for thinner sail films and reducing overall mass. Consequently, non-flat sails could enable the use of larger sails for future space exploration without excessive mass. This study comprehensively explores non-flat solar sails using three folding techniques: Miura-Ori, Iso-area flasher by Palmer-Shafer, and Parachute-folded. The main goal is to optimize the characteristic acceleration while maintaining its structural integrity. Using Finite Element Analysis (FEA), we analyze deformation patterns and thrust generation to identify the most effective folding technique for a non-flat solar sail. The Parachute-folded sail with five support points demonstrated significantly improved the characteristic acceleration while maintaining a lower deformation than the other two folded configurations and the flat sail counterpart. Further, an enhancement was achieved by strategically integrating a polyimide reinforcement layer along its outer borders, resulting in a sail model with a higher structural resistance to deformation and decreased moment reaction compared to the uniform thickness Parachute-folded sail. Due to computational limitations, the thickness evaluated for this analysis was made in the interval of 30 μm to 400 μm. Investigating new solar sail designs can make large sails more feasible for future missions that are capable of shorter transfer times.

The Utility of Folding Technique in Duraplasty

The Utility of Folding Technique in Duraplasty

From theory to practice: Truchet tile as a computational visual coding approach for facade visualization

The study presents unique teaching approach for generating a parametric modular facade fabrication for first-year students in visual design module using a computational visual coding method based on Truchet Tiles. The method followed four main phases: exploring tiling, testing connectivity, fabrication, and assembly. Shape grammar was considered during the design principles implementation to respond to climatic behavior. Space-filling shapes method known as the “Generalized Abeille Tiles” was followed to ensure tiling connectivity. The experimentation involves manual folding techniques without any software. A survey was conducted among first-year and fourth-year students post-introduction to computational software. The results showed a wide range of alternative geometries with different self-shading patterns generated. It highlighted that facade fabrication aided students in comprehending computational logic, easing the understanding of computational software complexity. This pilot study emphasizes the effectiveness of teaching computational concepts in early curricula.

Detection of a cyclotron line in the Be X-ray pulsar IGR J06074+2205

Context. IGR J0607.4+2205 is a transient Be X-ray binary discovered two decades ago. IGR J0607.4+2205 underwent an outburst in 2023 during which it was observed twice with NuSTAR. Aims. The main goal of this work is to model the broadband X-ray spectrum of IGR J0607.4+2205 during the outburst and to study the variations of the spectral and timing features at different intensities. Methods. We extracted the light curve and spectrum of the source from the two NuSTAR observations carried out during the recent outburst in the energy range of 3−78 keV. We used the epoch folding technique to find pulsation from the source and to study the changes in emission characteristics from the source with energy across an order of magnitude variation in source luminosity. Results. IGR J0607.4+2205 shows pulsations with a period of ∼347.6 s during both the observations, with a pulse fraction of ≥50%. The broadband spectrum of the source was modelled using a power-law continuum with a high-energy cutoff. During the first observation, a cyclotron absorption line at ∼51 keV was also present in the source with an optical depth of ∼1.3. However, no cyclotron line feature was detected in the second observation when the source was an order of magnitude fainter. Additionally, soft excess was detected in the second observation, which was modelled with a black body component emerging from close to the neutron star (NS). Conclusions. We report the first ever detection of a cyclotron line in the broadband spectrum of IGR J0607.4+2205 centred at 51 ± 1 keV. The magnetic field strength of the NS is estimated to be ∼4 × 1012 G from the centroid energy of the absorption line. A significant change is observed in the pulse profile with luminosity during the decay of the outburst, indicating an associated change in the beaming pattern.

Numerical modelling of different airbag folding patterns and their influence on occupant responses in frontal vehicle impact

This paper presented a procedure for airbag folding for the application in occupant safety studies and analysed the influence of different airbag folding patterns on the occupant severity in frontal impact. Airbags were folded in two patterns: zig-zag and top-roll, using two folding techniques: Initial Metric Method and Explicit Folding. The explicit folding was found to be more expensive in terms of preparation time. However, this approach provided more control over the whole folding process. The Initial Metric Method was more robust, however, it’s hard to apply for complex folding patterns. Deployments of airbags were validated against experimental data of pendulum tests. Those airbag models were applied to 2006 Ford F250 pickup truck. This vehicle was used for simulations of frontal vehicle impact where the 50th male Hybrid III crash test dummy was an occupant. Results of this simulation were compared with an actual test with a similar vehicle, under the same impact conditions. Results showed the head and chest accelerations were lower for top-roll folded airbag cases, however neck normal forces were higher compared to zig-zag folded airbag. The internal pressure in the early stage of deployment was 33% higher for the top-roll folded airbags.

Percutaneous Removal of Migrated Gastrointestinal Stents Using Gastrostomy Access

This report describes the experience of removing migrated gastrointestinal (GI) stents using a gastrostomy (G) access. Four male patients aged 23–62 years (mean, 42 years) had 6 migrated stents removed using an existing (n = 3) or new (n = 1) G access. Removed stents included 5 covered esophageal stents that migrated into the stomach and 1 distal noncovered duodenal stent that migrated into the proximal duodenum. One patient had 2 stents removed during the same session. All stents were removed successfully without adverse events. Techniques used included the folding technique using a wire in 3 stents and forceps in 2 stents. Eversion technique was used in the duodenal stent. The G or gastrojejunostomy tubes were replaced after stent removal and used for enteral feedings. In conclusion, removing migrated GI stents using an existing or new G access was technically successful and safe.

PELATIHAN KETERAMPILAN DAN PENGETAHUAN HANDUK LEMBAB (OSHIBORI)

Moist towel (osihibori) skills and knowledge training aims to increase knowledge and skills in making and managing it. Oshibori is wet towel used to clean hands in hotels, restaurants and other public places. This training was carried out with the aim of improving service quality and guest satisfaction. Skills and knowledge training consists of understanding, folding techniques and presentation techniques. Training is carried out using lecture, demonstration and direct practice methods. The results show that participants can improve their knowledge and skills in managing oshibori well.

Ultra-thin amphiphilic hydrogel electrolyte for flexible zinc-ion paper batteries

The paper-like ZIBs can be folded and unfolded using the Miura folding technique, enhancing the areal energy density by a factor of 18.

Cross-domain growth and angle-dependent interlayer coupling of twisted bilayer MoS2

Twisted 2D transition metal dichalcogenides (TMDCs) play a significant role in the development of twistronics. However, it is still challenging to prepare high-quality twisted TMDCs by current stacking or folding techniques. Herein, we propose a cross-domain chemical vapor deposition method to synthesize twisted bilayer MoS2 through precisely controlling the supply of molybdenum precursor. It is found that the top layer of a bilayer MoS2 grain maintains its original orientation even when it crosses over to neighboring monolayer MoS2 grain. This suggests that the van der Waals epitaxy can be prevented with the assistance of covalent bonds. Furthermore, the interlayer coupling strength reaches a maximum value at the twisted angle (θ) of 0° or 60° and a minimum at θ = 30°. Moreover, the evolution of in-plane shear mode and out-of-plane breathing mode obtained from low-frequency Raman spectroscopy reveals atomic reconstructions of the moiré pattern. Meanwhile, the shift of the indirect bandgap exhibits an angle dependence consistent with the interlayer coupling strength, which likely comes from the mixing of pz orbitals. The change in A−/A intensity ratio is not mainly originated from the trion binding energy, but the excess electron concentration. Our results offer a feasible approach to prepare high-quality twisted TMDCs and provide a good platform for studying twistronics and related phenomena.

Approximating complex 3D curves using origami spring structures

Origami provides a versatile platform for creating intricate three-dimensional (3D) reconfigurable structures through folding techniques. However, the applications of origami patterns are restricted due to limited deformation modes and complex actuation. Here we explore origami spring structures as a solution to address these limitations by approximating complex 3D curves with an underactuated scheme. By doing so, we showcase the reconfigurability and versatility of origami springs while tackling control complexity. Through the introduction of virtual creases, we simplify non-rigid deformations and enable accurate descriptions of their 3D configurations. Furthermore, we develop inverse kinematics optimization algorithms to determine optimal configurations closely approximating given 3D curves with full actuation and underactuated situations. Experimental realization of various 3D curves demonstrates the feasibility and effectiveness of our proposed approach. This research could find practical utility in soft robotics, flexible mechanisms, and deployable structures.

Compact folded‐shorted patch array offering dual‐band operation and dual‐circularly polarized radiation for picosatellites and other small satellites

AbstractThe development of a dual‐band folded shorted patch (FSP) antenna array is presented which offers dual‐circularly polarized radiation. Applications include small satellites like CubeSats and picosatellites. The proposed 2 × 2 FSP array design operates at 1.1 and 2.4 GHz and offers good radiation performance in terms of minimal reflection coefficient losses, broad beamwidths (which is generally required for low gain antenna structures ensuring link connectivity), as well as low cross‐polarization levels. The antenna array consists of a meandered layer defining the top of the FSPs. The shorting and folding technique as well as the noted meandering allows further size reduction of the quarter‐wavelength patch. In particular, the proposed antenna array is compact with a total size of 50 mm by 50 mm (or 0.18λ by 0.18λ at the lower operational frequency). An eight‐port coaxial and microstrip feed system is integrated onto the backside of the antenna ground plane, two ports for each element, and with external phase feeding of 90°, dual‐circularly polarized is made possible for the compact antenna unit. To the best knowledge of the authors, no similar antenna structure has been designed, manufactured and tested being useful for picosatellites and other small satellites.

Design and Development of Morphological Analyzer for Tigrigna Verbs using Hybrid Approach

Morphological analyzer is the base for various high-level NLP applications such as information retrieval, spell checking, grammar checking, machine translation, speech recognition, POS tagging and automatic sentence construction. This paper is carefully designed for design and analysis of morphological analyzer Tigrigna verbs using hybrid of memory learning and rules based approaches. The experiment have conducted using Python 3 where TiMBL algorithms IB2 and TRIBL2, and Finite State Transducer rules are used. The performance of the system has been evaluated using 10 fold cross validation technique. Testing was conducted using optimized parameter settings for regular verbs and linguistic rules of the Tigrigna language allomorph and phonology for the irregular verbs. The accuracy of the memory based approach with optimized parameters of TiMBL algorithm IB2 and TRIBL2 was 93.24% and 92.31%, respectively. Finally, the hybrid approach had an actual performance of 95.6% using linguistic rules for handling irregular and copula verbs.

The teaching of geometry in mathematics and sciences applying symmetry with folding techniques

This work offers students the use of geometry in a simpler and more practical way, providing the teaching of Symmetry and based on this assumption, the use of folding techniques, combining this work with the practical and logical field of use of concepts, providing students with a effective understanding of the geometric proposal used, in addition to putting the student in front of numerous questions required in the ENEM test, which are often seen in this exam. This activity was applied to a seventh grade class of elementary school II in a Federal Public School in the metropolitan region of Belém, showing its effectiveness and harmonization with the content of Plane Geometry, corroborating for a better teaching with an effective learning of the contents of the proposed teaching.

“Mamuli” Pattern in East Sumba Woven Fabric as Inspiration For “Kandunnu” Standing Lamp Using the IMOE Method

Inspiration is a crucial factor in the conception and development of innovative design products. In the contemporary creative world, an innovative product transcends mere aesthetic factors, encompassing intrinsic values. This study investigates a framework for transforming Mamuli pattern, found in East Sumba woven fabric, into a contemporary and innovative product, in the form of a standing lamp. This effort aimed to guide designers and design students in the precise and effective transformation of local culture. Innovation was done through materialization, observation and experimentation (IMOE). They were applied to cultural artifacts, structured across four levels, namely the inner, middle, outer, and experimental. The experimental element assumed a central role in the methodology. The inner level encompassed the meanings and symbols of the cultural artifact (Mamuli pattern), while the middle level involved its creative process. The outer level represented the physical appearance, including materials, colors, and ornaments. The experimental element involved the creative process of transforming the cultural artifact into a contemporary form. The experiment targeted designers and design students, facilitating the creation of contemporary products through a culturally-sensitive transformation, fostering innovations. Developed through an ethno-mathematical theory and experimental folding techniques, it generated experimental innovative product designs. It transformed Mamuli pattern from East Sumba woven fabric into Kandunnu standing lamp, drawing inspiration from both the outer and inner levels.