Patch Defects Research Articles

Pavement maintenance and surface treatment: Evaluation and prevention towards road safety aspect along Ampang Jaya road

Abstract The severity of road damage, such as surface cracking or potholes putting drivers of moving vehicles at greater risk of collisions. This study aims to determine and propose the maintenance procedure and surface treatment activity carried out along Jalan Taman Putra, Jalan Bunga Raya and Jalan Perdana Utama in Ampang Jaya, Selangor. From a visual inspection, Jalan Bunga Raya and Jalan Perdana Utama was rated as B and required immediate repairs, while Rating C required to be fixed for user comfort on Jalan Taman Putra. Patch defects account for 45 % and 46 % of all defects on Jalan Taman Putra and Jalan Bunga Raya routes, respectively. Meanwhile, most defects on Jalan Perdana Utama were delamination, accounting for 38 % of all defects. The statistics on the number of road accidents show that pavement restoration work is effective when it results in a decrease in accidents between 2015 and 2021 by 42 % in Jalan Taman Putra, 33 % in Jalan Bunga Raya, and 12 % in Jalan Perdana Utama. Rehabilitating the roads had a favourable impact on Ampang Jaya, Selangor's low traffic accidents rate and raised levels of road safety. To improve road safety features, efficient supervision and maintenance efficiency are required.

Study of Brown Patch Defect in Automotive Grade Interstitial Free Steel

Study of Brown Patch Defect in Automotive Grade Interstitial Free Steel

Study of White Patch Defect in Automotive Grade Interstitial Free Steel

Surface of cold-rolled steel intended for automotive body panel applications is expected to be defect free. The presence of surface defects hampers the aesthetics and average surface roughness and thereby deteriorates the paintability of the steel sheet. This study aims to investigate the source of white patch defect in cold-rolled and skin-passed interstitial free steel sheets. Macroscopic observations of as-received white patch sample revealed the presence of blackish deposit having cracks inside the deposits, suggesting that these deposits were heated up possibly during annealing process. Further during macroscopic observation, it was revealed that the black deposits were of near round shape. If deposit is present before rolling, then it is expected that it will elongate during rolling and will not retain round shape. Round shape of the deposits under investigation suggested that it is not before rolling. Electrolytic cleaning line (ECL) is the only in-between process. Surface characterization techniques such as SEM–EDS, Raman spectroscopy, Fourier transform infrared spectroscopy were used to analyze the defect and good region of the steel sheet. Overall analysis indicated grease contamination on cold-rolled steel sheet at the entry of ECL caused generation of white patch defect. Regular cleaning and preventive maintenance of plant machinery were recommended to avoid such leakages to arrest the defect generation in the future.

Multi-Disciplinary Surgical Approach to Esophageal Reconstruction: The Role of the Plastic Surgeon

Reconstruction of the esophagus is a highly interdisciplinary undertaking that involves a wide range of specialties in all phases of care. Esophageal reconstruction may be indicated for a number of reasons, which range from oncologic resection to traumatic injuries to congenital defects. The ultimate goals of esophageal reconstruction are to provide soft tissue coverage of the defect, restore continuity of the gastrointestinal (GI) tract, create a functional conduit, and allow for oral intake. This can be achieved through a number of different surgical techniques, which depend on the extent of the defect. For non-circumferential patch defects of the esophagus, local muscle flaps from the neck and trunk are commonly used. For shorter segmental defects, interposition small intestine free flaps or tubularized fasciocutaneous flaps from the extremities are employed. For longer segmental defects, sections of the native GI tract (such as stomach, colon, or jejunum) are recruited to reconstruct the esophagus. The most common complications of esophageal reconstruction include fistula formation, which can typically be managed conservatively, and conduit strictures, which may require serial dilation. Long-term outcomes are typically favorable, with good restoration of swallowing and speech and overall high quality of life in long-term survivors. New developments in tissue engineering involving the use of biological substitutes have also shown promise in esophageal reconstruction. These methods involve the placement of biologic matrices, autologous cells and/or growth factors to restore continuity of the esophagus. In this review, we discuss the role of plastic surgery in the reconstruction of the esophagus.

Laser-Assisted Lattice Recovery of Graphene by Carbon Nanodot Incorporation.

Producing highly oriented graphene is a major challenge that constrains graphene from fulfilling its full potential in technological applications. The exciting properties of graphene are impeded in practical bulk materials due to lattice imperfections that hinder charge mobility. A simple method to improve the structural integrity of graphene by utilizing laser irradiation on a composite of carbon nanodots (CNDs) and 3D graphene is presented. The CNDs attach themselves to defect sites in the graphene sheets and, upon laser-assisted reduction, patch defects in the carbon lattice. Spectroscopic experiments reveal graphitic structural recovery of up to 43% and electrical conductivity four times larger than the original graphene. The composites are tested as electrodes in electrochemical capacitors and demonstrate extremely fast RC time constant as low as 0.57 ms. Due to their low defect concentrations, the reduced graphene oxide-carbon nanodot (rGO-CND) composites frequency response is sufficiently fast to operate as AC line filters, potentially replacing today's electrolytic capacitors. Using this methodology, demonstrated is a novel line filter with one of the fastest capacitive responses ever reported, and an aerial capacitance of 68.8 mF cm-2 . This result emphasizes the decisive role of structural integrity for optimizing graphene in electronic applications.

Evaluation of Acellular Bilayer Silk Fibroin Grafts for Onlay Tracheoplasty in a Rat Defect Model.

To assess the efficacy of acellular bilayer silk fibroin (BLSF) grafts to repair full-thickness tracheal defects and to compare the performance with conventional porcine small intestinal submucosa (SIS) implants. A prospective controlled animal trial in a rat model of onlay tracheoplasty. Pediatric medical center. Tracheal reconstruction of adult Sprague-Dawley rats was performed with BLSF (n = 38) or SIS (n = 32) matrices for up to 3 months of implantation. Functional evaluations of repaired conduits as well as histologic, immunohistochemical, and histomorphometric analyses of neotissues were assessed. Prior to scheduled euthanasia, survival rates of rats receiving BLSF or SIS grafts were ≥94%, with no clinical signs of airway obstruction observed over the course of the study. Micro-computed tomography analysis revealed that the mean percentage of stenosis was <20% in both implant groups. BLSF and SIS grafts supported formation of pseudostratified ciliated columnar epithelium by 1 week postoperatively; however, each matrix failed to promote de novo chondrogenesis by 3 months following repair. BLSF scaffolds can be used for reconstruction of rat tracheal patch defects with functional outcomes comparable to those of SIS matrices.

Defect characterisation from limited view pipeline radiography

This work presents a method of characterising pipeline defects using a small number of radiographs taken at different angles around the pipe. The method relies on knowledge of the setup geometry and use of multiple images, and does not require calibration objects to be included in the setup. It is aimed at use in situations where access is difficult such as in subsea pipeline inspections. Given a set of radiographs, a background subtraction method is used to extract defects in the images. Using a ray tracing algorithm and knowledge of the experimental setup, the range of possible locations of the defect in 3D space is then calculated. Constraints are applied on potential defect shapes and positions to further refine the defect range. The method is tested on simulated and experimental flat bottomed hole defects and simulated corrosion patch defects with lateral and axial sizes ranging from 12.5 to 33.8mm and thickness between 3mm and 16mm. Results demonstrate a good, consistent ability to calculate lateral and axial defect dimensions to within ±3mm of the true size. Defect thickness calculations are more difficult and as such errors are more significant. In most cases defect thickness is calculated to within 4mm of the actual value, often closer. Errors in thickness are due to overestimation, meaning the calculation could be used to place a maximum limit on potential defect size rather than as an actual estimate of the thickness. This would still be useful, for example in deciding whether a defect requires further investigation.

PP-360 Unusual History of a Patient with Subsequent Giant Left Ventricular Aneurisms

Left ventricular (LV) aneurysm is usually defined as a segment of the ventricular wall that exhibits paradoxical (dyskinetic) systolic expansion. A large LV aneurysm in a patient with symptoms of heart failure, particularly if angina pectoris is also present, is an indication for surgery. We reported a case with left ventricular aneurysm and low ejection fraction who had previously advocated coronary revascularization, ischemic Ventricular Septal Defect (VSD) repair with subsequent patch defect and reoperation and inferoposterior aneurysmectomy.

Y Chromosome–Linked B and NK Cell Deficiency in Mice

There are no primary immunodeficiency diseases linked to the Y chromosome, because the Y chromosome does not contain any vital genes. We have established a novel mouse strain in which all males lack B and NK cells and have Peyer's patch defects. By 10 wk of age, 100% of the males had evident immunodeficiencies. Mating these immunodeficient males with wild-type females on two different genetic backgrounds for several generations demonstrated that the immunodeficiency is linked to the Y chromosome and is inherited in a Mendelian fashion. Although multicolor fluorescence in situ hybridization analysis showed that the Y chromosome in the mutant male mice was one third shorter than that in wild-type males, exome sequencing did not identify any significant gene mutations. The precise molecular mechanisms are still unknown. Bone marrow chimeric analyses demonstrated that an intrinsic abnormality in bone marrow hematopoietic cells causes the B and NK cell defects. Interestingly, fetal liver cells transplanted from the mutant male mice reconstituted B and NK cells in lymphocyte-deficient Il2rg(-/-) recipient mice, whereas adult bone marrow transplants did not. Transducing the EBF gene, a master transcription factor for B cell development, into mutant hematopoietic progenitor cells rescued B cell but not NK cell development both in vitro and in vivo. These Y chromosome-linked immunodeficient mice, which have preferential B and NK cell defects, may be a useful model of lymphocyte development.

Esophagus and regenerative medicine

In addition to squamous cell carcinoma, the incidence of Barrett's esophagus with high-grade dysplasia and esophageal adenocarcinoma is rapidly increasing worldwide. Unfortunately, the current standard of care for esophageal pathology involves resection of the affected tissue, sometimes involving radical esophagectomy. Without exception, these procedures are associated with a high morbidity, compromised quality of life, and unacceptable mortality rates. Regenerative medicine approaches to functional tissue replacement include the use of biological and synthetic scaffolds to promote tissue remodeling and growth. In the case of esophageal repair, extracellular matrix (ECM) scaffolds have proven to be effective for the reconstruction of small patch defects, anastomosis reinforcement, and the prevention of stricture formation after endomucosal resection (EMR). More so, esophageal cancer patients treated with ECM scaffolds have shown complete restoration of a normal, functional, and disease-free epithelium after EMR. These studies provide evidence that a regenerative medicine approach may enable aggressive resection of neoplastic tissue without the need for radical esophagectomy and its associated complications.

Incorporation of Integra® in tissue defects: a pilot study in the rat model

Integra has been shown to be very useful in accelerating the growth of neodermis. It has found extensive use in case of burns as a primary dressing immediately after a burn, after release of contractures and following scar revision. It has been used to achieve cover after the debridement of extensive infective processes involving the skin. Encouraged by these results we have assessed the application of Integra to augment and/or patch defects of the urinary bladder, diaphragm and the abdominal wall in the rat model. This was a pilot study and involved the incorporation of Integra in the diaphragm, the urinary bladder (extramucosal) and the muscle layer of the abdominal wall. Eight adult Wistar rats were given general anaesthesia and Integra was implanted with absorbable sutures at the sites mentioned. The omentum was hitched to the collagen matrix surface to revascularise the graft. The silicone was left in situ. The operative period was covered with antibiotics. The anaesthesia was then reversed. Postoperatively the rats were given analgesia and feeds started immediately. The rats were sacrificed after 3 weeks. The abdominal cavity was examined for adhesions. The Integra implant along with adjacent tissue was harvested and examined histologically. There were no visible intra-abdominal adhesions. The histology revealed good degree of neovascularisation and fibrosis in and adjacent to the implant. This was comparable to the changes seen in the skin. This pilot study has shown that implanting Integra invokes a similar response in deeper tissues and it can develop neovascularisation from the omentum. Hence, this could find some application in treating congenital conditions such as diaphragmatic hernias, abdominal wall defects and for bladders requiring augmentation. Our initial results are quite encouraging and we feel that this field should be further explored.

Regeneration of the esophagus using gastric acellular matrix: an experimental study in a rat model

Recently, tissue engineering of the autologous esophagus has been thought to provide a promising strategy for esophageal substitution. In this study, gastric acellular matrix (GAM) was used as a scaffold for regeneration of the esophagus in a rat model. Usage of GAM has an advantage that naturally derived extracellular matrix autograft can be prepared less invasively in a clinical setting. Twenty-seven F344 female rats were used as recipients. Patch defects created in the abdominal esophagus were replaced by GAM patch grafts. The rats were sacrificed 1 week to 18 months after implantation. The specimen was examined macroscopically as well as microscopically. 5'-Bromo-2'-deoxyuridine (BrdU) proliferation assay was performed in six rats that were sacrificed 1, 2, and 4 weeks after implantation. Twenty-four rats survived without complications. The graft site did not show esophageal stenosis or dilatation in any rat. Keratinized stratified squamous esophageal mucosa was regenerated in the entire graft 2 weeks after implantation. Regeneration of the muscle layer or lamina muscularis mucosae in the graft site was not observed even 18 months after implantation. Marked incorporation of BrdU was observed only in the mucosal layer but not in the muscle layer. GAM patch graft provided satisfactory mucosal regeneration of the esophagus without stenosis or dilatation, although muscle regeneration was still a future challenge.

Defect Identification and Repair Algorithm for Polymer Light Emitting Diodes

The innate character of ink jet instability sometimes causes device defects in polymer light emitting diodes (PLED). This study develops an image-processing method to identify defects by methods such as filtering, color processing, background subtraction, dilation, etc. Based upon the defect information and the pre-built ink jet print head library, the amount of ink volume and the location to print on can be appropriately estimated to patch defects. In addition, an optimal printing route can be determined with a specially designed head driving waveform, consisting of pre-oscillations during motion intermission. By this methodology a 60 pL sized drop from ink jet nozzles can approximately patch the PLED panel with pixel resolution of 240x73 μm, the QCIF standard. The results demonstrated good accuracy in landing while patching unfilled pixels. However, there are some satellite drop occurrences observed due to the sensitivity of image data threshold level setting. Overall, the confidence level of successful defect identification is larger than 95%. In this paper, an optimal repair route and a strategy about thin film morphology control were also discussed. These approaches are helpful to repair defects and, consequently, increase the yield rate for PLED or other applications by ink jet technology.

Apical localization of actin patches and vacuolar dynamics in Ashbya gossypii depend on the WASP homolog Wal1p.

Analysis of the Ashbya gossypii Wiskott-Aldrich syndrome-like gene AgWAL1 indicates that it is required for the maintenance of polarized hyphal growth. Growth and organelle dynamics of the wild type and of wal1 and other mutant strains were monitored by in vivo (fluorescence) time-lapse microscopy. Loss of WAL1 led to slow growth and defects in polarized growth that produced swellings in subapical regions, whereas formation of hyphal tips and dichotomous tip branching occurred as in the wild-type. Few actin cables in Agwal1 cells were found to insert into the hyphal tip, but specific clustering of cortical actin patches was observed in subapical regions of hyphal tips instead of at the hyphal apex. Distribution and movement of vacuoles was observed in vivo using FM4-64. In the wild type and in the slowly growing mutant strains bem2 and cla4, which lack a Rho-GTPase-activating protein and a PAK kinase, respectively, early endosomes appeared in the hyphal tip, whereas very few early endosomes and small vacuoles were found in the wal1 mutant hyphal tips, thus linking the cortical patch defect of wal1 hyphae with the distribution of endosomes. Vivid movement of vacuoles seen in the wild type and in the bem2 mutant in subapical regions was largely reduced in the wal1 and cla4 mutants. The tubular structure of mitochondria (as visualized by DIOC6 in vivo) was similar in the wild type and the wal1 mutant, although wal1 mitochondria appeared to be larger. Interestingly, mitochondria were found to insert into the hyphal tips in both strains. Our results indicate a function for Wal1p in filamentous fungi in coordinating actin patch distribution with polarized hyphal tip growth.

Method of Patching Element Defects by Ink-Jet Printing for Polymer Light Emitting Diodes

The innate character of ink-jet instability causes the device defect in manufacturing for polymer light emitting diodes (PLED). This study develops image process skill to identify defect location; these skills include the filtering, color processing, background subtraction, dilation etc. Combination with the defect information and the predetermined head library, the ink-jet amount to patch defects can be appropriately estimated. Besides, an optimal printing route has designed with a special head driving of pre-oscillation during motion intermission. By this methodology, a 60 pL drop size from ink jet nozzle can precisely patch the PLED panel with pixel resolution of 240*73 &#x3BC;m, the QCIF standard. This ink-jet manufacture skill use for patch defects can increase the yield rate on line.

Mesenchymal expression of Foxl1, a winged helix transcriptional factor, regulates generation and maintenance of gut-associated lymphoid organs

The Foxl1 gene, which encodes a winged helix transcriptional regulator, is expressed in the mesenchymal layer of developing and mature gastrointestinal tract. Foxl1-deficient mice exhibit various defects not only in the epithelial layer of the gastrointestinal tract but also in gut-associated lymphoid tissues. In the small intestine of Foxl1-deficient mice, the formation of Peyer’s patches is affected, particularly in the caudal region. This alteration is shown to be due to the delayed formation of Peyer’s patches organizing centers as revealed by the expressions of VCAM1 and IL-7 receptor α-chain at 17.5 days postcoitus. Peyer’s patch defects are concordant with the significantly decreased expression of Lymphotoxin β-receptor in the caudal region of fetal intestine. Foxl1 is suggested to regulate the responsiveness of fetal intestinal mesenchymal cells to inductive signals mediated by Lymphotoxins during Peyer’s patch organogenesis. In addition, constitutive outgrowth of colonic patches due to defects in radioresistant stromal components of colonic patches are seen in Foxl1-deficient mice. Because of the functional similarities of hypertrophic colonic patches to those seen in hapten-induced experimental colitis, this hypertrophy is suggested to involve Lymphotoxin β-receptor signaling. Together, the data suggest that Foxl1 might be involved in cellular responses of gut-associated lymphoid tissues dependent upon the Lymphotoxins/Lymphotoxin β-receptor axis.

Device closure of ventricular septal defects

The vast majority of ventricular septal defects can be closed surgically with little morbidity or mortality. There is a small subset of defects (muscular defects, patch margin defects, fenestrated patch defects and post-infarct ventricular septal ruptures) in which surgical closure carries a significantly higher morbidity and mortality. For these defects, transcatheter closure techniques have been developed to close or significantly reduce shunting with low morbidity and mortality. Currently, two devices are available for defect closure, the CardioSEAL™ Starflex septal occluder and the Amplatzer™ ventricular septal defect occluder. Techniques for closure and current results are discussed.

Pathology of ALY Mice: Congenital Immunodeficiency with Lymph Node and Peyer's Patch Defects

The ALY-aly/aly mouse is a new and unique animal model of primary immunodeficiency with autosomal recessive inheritanceThe ALY mouse is devoid of superficial and profound lymph nodes and Peyer's patchesFurthermore, the lymphoid follicles and marginal zones are not clearly identified in the spleenIn addition to these structural defects, in the present study, we show that some B subpopulations are defectiveFirstly, the thymic B lymphocytes are very rareSecondly, the B220 hi sIg hi B subpopulation in the bone marrow is not detected as a clear cluster on FACS analysesThirdly, the B220 – cells in the bone marrow are very rare in both ALY- aly/aly and ALY- aly/+ miceBy contrast, the NK activity is normalTaken together, the ALY mouse is an invaluable model to elucidate the immunological networks between the lymphoid structures (lymph nodes, Peyer's patches, lymphoid follicles, etc.) and functions.

Resorbable bioscaffold for esophageal repair in a dog model

Purpose: Porcine-derived, xenogeneic extracellular matrix (ECM) derived from either the small intestinal submucosa (SIS) or urinary bladder submucosa (UBS) was used as a tissue scaffold for esophageal repair in a dog model. Methods: Patch defects measuring approximately 5 cm in length and encompassing 40% to 50% of the circumference of the esophagus or complete circumferential segmental defects measuring 5 cm in length were created by surgical resection in healthy adult female dogs. The defects were repaired with ECM scaffolds derived from either SIS or UBS. The animals were kept alive for periods ranging from 4 days to 15 months. Results: The xenogeneic scaffolds used for repair of the patch defects were resorbed completely within 30 to 60 days and showed replacement by skeletal muscle, which was oriented appropriately and contiguous with adjacent normal esophageal skeletal muscle, organized collagenous connective tissue, and a complete and intact squamous epithelium. No signs of clinical esophageal dysfunction were seen in any of the animals with the patch defect repair. The xenogeneic scaffolds configured into tubes for repair of the segmental defects all showed stricture within 45 days of surgery. Conclusion: These ECMs show promise as a treatment option for esophageal repair, but stricture remains problematic for complete tube grafts. J Pediatr Surg 35:1097-1103. Copyright © 2000 by W.B. Saunders Company.

Fresh Osteochondral Allografts for Treatment of Articular Defects in Osteochondritis Dissecans of the Lateral Femoral Condyle in Adults

Fresh osteochondral allografts were used to patch defects in the lateral femoral condyle in 17 patients with osteochondritis dissecans. The patients included 12 males and five females, ages 16 to 46 years. All had previously undergone other procedures including pinning (4), primary removal of osteochondral fragments (16), and abrasion arthroplasty (14). Defects up to 3 cm in diameter were treated with isotopic grafts and fixed with Herbert screws. Larger defects were treated with crescent-shaped grafts fixed with multiple Herbert screws. Follow-up time ranged from two to nine years. Pain, stiffness, swelling, buckling, and locking were ablated in 16 of the 17 patients. No graft collapse has been noted in these individuals. Verification of graft viability was achieved at periods from six weeks to six years, typically at the time of hardware removal. The only failure occurred in an individual with a 3- x 4.5-cm defect who suffered gross fragmentation which left a large crater. Osteochondritis dissecans of the lateral femoral condyle provides an ideal opportunity for evaluating osteochondral grafts. Sixteen of 17 grafts were a success at two to nine years after surgery.