Multiple Defects Research Articles

The native and metastable defects and their joint density of states in hydrogenated amorphous silicon obtained from the improved dual beam photoconductivity method

In this study, undoped hydrogenated amorphous silicon (a-Si:H) thin films deposited under moderate dilution ratios of silane by radio frequency plasma-enhanced chemical vapor deposition (RF-PECVD) have been investigated using steady-state photoconductivity and improved dual beam photoconductivity (DBP) methods to identify changes in multiple gap states in annealed and light-soaked states. Four different gap states were identified in annealed state named as A, B, C, and X states. The peak energy positions of these Gaussian distributions are consistent with those recently identified by Fourier transform photocurrent spectroscopy (FTPS). After in situ light soaking, their density increases with different rates as peak energy positions and half-widths remain unaffected. The electron-occupied A and B states located below the dark Fermi level and their density and ratios in the annealed and light-soaked states correlate well with those defects detected by time-domain pulsed electron paramagnetic resonance (EPR) experiments. The A, B, and X states located closer to the middle of the bandgap anneal out at room temperature in dark and define the “fast” states. However, the C states show no sign of room temperature annealing such that they must define the “slow” states in undoped a-Si:H. The results found in this study indicate that the anisotropic disordered network is a more appropriate model than previously proposed defect models based on the continuous random network to define the nanostructure of undoped a-Si:H, where multiple defects, D0 and non-D0 defects, can be identified by using the improved DBP method.

Fibrin Glue–Coated Collagen Complex Patch: A Novel Material for Surgical Repair of Spontaneous Temporal Bone Cerebrospinal Fluid Leak and Encephalocele

To compare outcomes of surgical repair of temporal bone encephalocele and cerebrospinal fluid (CSF) leak using fibrin glue-coated collagen (FGCC) complex patch versus other materials for repair of dura. Retrospective chart review. Tertiary care hospital. Fifty-two adult patients undergoing transmastoid (TM), middle fossa (MF) or combined approach repair of spontaneous MF CSF leak between 2016 and 2020. Exposure of bony defect via TM approach, MF craniotomy, or combined TM/MF, and repair of the associated dura defect with FGCC complex patch, or other materials (acellular collagen matrix, bovine collagen, autologous fascia, fibrin tissue sealant). Successful repair without recurrent CSF leak or encephalocele throughout follow-up. Cost of materials used in duraplasty. Sixty-four percent of patients were female. Mean (standard deviation) age at repair was 61.4 (12.1) years. Mean (standard deviation) body mass index was 35.0 (8.3) kg/m 2 . Forty-nine (94%) patients had successful repair without known recurrence of CSF leak or encephalocele over a median follow-up interval of 11.7 months. Average duraplasty material cost was significantly lower with FGCC in comparison with other nonautologous materials (FGCC+: $1259.94, FGCC-: $1652.58; p = 0.004). No significant differences in recurrence risk (FGCC+: 6.9%, FGCC-: 6.9%; p > 0.999) or operative time (FGCC+: 153.7 min, FGCC-: 155.4 min; p = 0.88) were detected based on material used for duraplasty. All materials studied demonstrate effective and sustained means of repair for MF CSF leak and encephalocele, including in the presence of multiple defects. Use of FGCC for duraplasty produces noninferior surgical results to other nonautologous materials in repair of spontaneous CSF leaks of the temporal bone and may be more cost-effective.

Disease modeling of ADAMTS9-related nephropathy using kidney organoids reveals its roles in tubular cells and podocytes.

Mutations in ADAMTS9 cause nephronophthisis-related ciliopathies (NPHP-RC), which are characterized by multiple developmental defects and kidney diseases. Patients with NPHP-RC usually have normal glomeruli and negligible or no proteinuria. Herein, we identified novel compound-heterozygous ADAMTS9 variants in two siblings with NPHP-RC who had glomerular manifestations, including proteinuria. To investigate whether ADAMTS9 dysfunction causes NPHP and glomerulopathy, we differentiated ADAMTS9 knockout human induced pluripotent stem cells (hiPSCs) into kidney organoids. Single-cell RNA sequencing was utilized to elucidate the gene expression profiles from the ADAMTS9 knockout kidney organoids. ADAMTS9 knockout had no effect on nephron differentiation; however, it reduced the number of primary cilia, thereby recapitulating renal ciliopathy. Single-cell transcriptomics revealed that podocyte clusters express the highest levels of ADAMTS9, followed by the proximal tubules. Loss of ADAMTS9 increased the activity of multiple signaling pathways, including the Wnt/PCP signaling pathway, in podocyte clusters. Mutations in ADMATS9 cause a glomerulotubular nephropathy in kidney and our study provides insights into the functional roles of ADMATS9 in glomeruli and tubules.

Paternal methotrexate exposure affects sperm small RNA content and causes craniofacial defects in the offspring

Folate is an essential vitamin for vertebrate embryo development. Methotrexate (MTX) is a folate antagonist that is widely prescribed for autoimmune diseases, blood and solid organ malignancies, and dermatologic diseases. Although it is highly contraindicated for pregnant women, because it is associated with an increased risk of multiple birth defects, the effect of paternal MTX exposure on their offspring has been largely unexplored. Here, we found MTX treatment of adult medaka male fish (Oryzias latipes) causes cranial cartilage defects in their offspring. Small non-coding RNA (sncRNAs) sequencing in the sperm of MTX treated males identify differential expression of a subset of tRNAs, with higher abundance for specific 5′ tRNA halves. Sperm RNA methylation analysis on MTX treated males shows that m5C is the most abundant and differential modification found in RNAs ranging in size from 50 to 90 nucleotides, predominantly tRNAs, and that it correlates with greater testicular Dnmt2 methyltransferase expression. Injection of sperm small RNA fractions from MTX-treated males into normal fertilized eggs generated cranial cartilage defects in the offspring. Overall, our data suggest that paternal MTX exposure alters sperm sncRNAs expression and modifications that may contribute to developmental defects in their offspring.

Complete excision of giant clavicular hydatid cyst: a case report

BackgroundEchinococcosis, also known as hydatid disease, is a zoonotic parasitic disease prevalent in pastoral areas, mainly involving the liver and lungs, and less frequently the bones and surrounding soft tissues. Diagnosis and treatment of bone hydatid disease is a challenge, and because of the insidious course of the disease, the lesions are often widely disseminated by the time patients seek medical attention.Case presentationA 29-year-old woman presented with a painless mass that was gradually increasing in size in the cervical thorax. Imaging revealed an enlarged clavicle with multiple bone cortical defects and the existence of cysts in the soft tissues surrounding the clavicle, for which complete excision of the clavicle and the attached cysts was performed. There was no recurrence of the cyst within one year after the operation, and the patient felt well and had normal shoulder joint movement.ConclusionsBone hydatid may appear in bones throughout the body, and cysts that leak from the bone into the surrounding soft tissues may spread at a relatively rapid rate. Prompt surgical removal of the affected bone and surrounding cysts is necessary for treatment.

Distinct clusters of human pain gene orthologs in Caenorhabditis elegans regulate thermo-nociceptive sensitivity and plasticity.

The detection and avoidance of harmful stimuli are essential animal capabilities. The molecular and cellular mechanisms controlling nociception and its plasticity are conserved, genetically controlled processes of broad biomedical interest given their relevance to understand and treat pain conditions that represent a major health burden. Recent genome-wide association studies (GWAS) have identified a rich set of polymorphisms related to different pain conditions and pointed to many human pain gene candidates, whose connection to the pain pathways is however often poorly understood. Here, we used a computer-assisted Caenorhabditis elegans thermal avoidance analysis pipeline to screen for behavioral defects in a set of 109 mutants for genes orthologous to human pain-related genes. We measured heat-evoked reversal thermosensitivity profiles, as well as spontaneous reversal rate, and compared naïve animals with adapted animals submitted to a series of repeated noxious heat stimuli, which in wild type causes a progressive habituation. Mutations affecting 28 genes displayed defects in at least one of the considered parameters and could be clustered based on specific phenotypic footprints, such as high-sensitivity mutants, nonadapting mutants, or mutants combining multiple defects. Collectively, our data reveal the functional architecture of a network of conserved pain-related genes in C. elegans and offer novel entry points for the characterization of poorly understood human pain genes in this genetic model.

Steel Strip Defect Sample Generation Method Based on Fusible Feature GAN Model under Few Samples.

Due to the shortage of defect samples and the high cost of labelling during the process of hot-rolled strip production in the metallurgical industry, it is difficult to obtain a large quantity of defect data with diversity, which seriously affects the identification accuracy of different types of defects on the steel surface. To address the problem of insufficient defect sample data in the task of strip steel defect identification and classification, this paper proposes the Strip Steel Surface Defect-ConSinGAN (SDE-ConSinGAN) model for strip steel defect identification which is based on a single-image model trained by the generative adversarial network (GAN) and which builds a framework of image-feature cutting and splicing. The model aims to reduce training time by dynamically adjusting the number of iterations for different training stages. The detailed defect features of training samples are highlighted by introducing a new size-adjustment function and increasing the channel attention mechanism. In addition, real image features will be cut and synthesized to obtain new images with multiple defect features for training. The emergence of new images is able to richen generated samples. Eventually, the generated simulated samples can be directly used in deep-learning-based automatic classification of surface defects in cold-rolled thin strips. The experimental results show that, when SDE-ConSinGAN is used to enrich the image dataset, the generated defect images have higher quality and more diversity than the current methods do.

Pipeline condition assessment and finite element modeling of mechano-electrochemical interaction between corrosion defects with varied orientations on pipelines

Multiple corrosion defects located in varied orientations are common on pipelines, significantly impacting pipeline conditions. In this work, 3D finite element (FE) based multi-physics field coupling models were developed to model mechano-electrochemical (M−E) interaction between corrosion defects with varied orientations and its effect on pipeline conditions. The effects of the parameters, including defect geometries, operating conditions, and the relative positions and spacings between the defects, were determined. The results demonstrated that, the strongest M−E interaction occurred between defects when the longitudinal or circumferential spacing is 0, causing high-level local stress concentration and the anodic current density (i.e., corrosion rate) at the corrosion defects. As the defects gradually overlapped or separated from each other on the pipe surface, the magnitude of the M−E interaction decreased. The interaction between defects even disappeared when the longitudinal or circumferential spacing between defects reached 96 mm or 72 mm, respectively, and the defects can be assessed separately. An increased internal pressure led to local plasticity deformation and anodic current density concentration occurring at the inner edge of the defects and defect adjacent area. For example, the maximum anodic current density increased by 56.4% when the internal pressure increased from 12 MPa to 17 MPa. It was also observed that M−E interaction between defects disappeared if the defects were shorter than 48 mm or shallower than 8 mm. Sensitivity analysis demonstrated that the degree of M−E interaction was most sensitive to circumferential spacing, followed by defect depth, defect length, longitudinal spacing, and internal pressure.

Adaptive visual detection of industrial product defects.

Visual inspection of the appearance defects on industrial products has always been a research hotspot pursued by industry and academia. Due to the lack of samples in the industrial defect dataset and the serious class imbalance, deep learning technology cannot be directly applied to industrial defect visual inspection to meet the real application needs. Transfer learning is a good choice to deal with insufficient samples. However, cross-dataset bias is unavoidable during simple knowledge transfer. We noticed that the appearance defects of industrial products are similar, and most defects can be classified as stains or texture jumps, which provides a research basis for building a universal and adaptive industrial defect detection model. In this article, based on the idea of model-agnostic meta-learning (MAML), we propose an adaptive industrial defect detection model through learning from multiple known industrial defect datasets and then transfer it to the novel anomaly detection tasks. In addition, the Siamese network is used to extract differential features to minimize the influence of defect types on model generalization, and can also highlight defect features and improve model detection performance. At the same time, we add a coordinate attention mechanism to the model, which realizes the feature enhancement of the region of interest in terms of two coordinate dimensions. In the simulation experiments, we construct and publish a visual defect dataset of injection molded bottle cups, termed BC defects, which can complement existing industrial defect visual data benchmarks. Simulation results based on BC defects dataset and other public datasets have demonstrated the effectiveness of the proposed general visual detection model for industrial defects. The dataset and code are available at https://github.com/zhg-SZPT/MeDetection.

Transcatheter atrial septal defect closure late after completion of biventricular circulation in patients with pulmonary atresia intact ventricular septum or critical pulmonary stenosis.

This study aimed to explore anatomical and hemodynamic features of atrial septal defect, which was treated by transcatheter device closure late after completion of biventricular circulation in patients with pulmonary atresia and intact ventricular septum (PAIVS) or critical pulmonary stenosis (CPS). We studied echocardiographic and cardiac catheterization data, including defect size, retroaortic rim length, single or multiple defects, the presence of malalignment atrial septum, tricuspid and pulmonary valve diameters, and cardiac chamber sizes, in patients with PAIVS/CPS who underwent transcatheter closure of atrial septal defect (TCASD), and compared to control subjects. A total of 173 patients with atrial septal defect, including 8 patients with PAIVS/CPS, underwent TCASD. Age and weight at TCASD were 17.3 ± 18.3 years and 36.6 ± 13.9 kg, respectively. There was no significant difference in defect size (13.7 ± 4.0 vs. 15.6 ± 5.2 mm, p = 0.317) and the retro-aortic rim length (3.7 ± 4.3 vs. 3.6 ± 0.3.1 mm, p = 0.948) between the groups; however, multiple defects (50% vs. 5%, p < 0.001) and malalignment atrial septum (62% vs. 14%. p < 0.001) were significantly frequent in patients with PAIVS/CPS compared to control subjects. The ratio of pulmonary to systemic blood flow in patients with PAIVS/CPS was significantly lower than that in the control patients (1.2 ± 0.4 vs. 2.0 ± 0.7, p < 0.001); however, four out of eight patients with atrial septal defect associated with PAIVS/CPS had right-to-left shunt through a defect, who were evaluated by the balloon occlusion test before TCASD. The indexed right atrial and ventricular areas, the right ventricular systolic pressure, and mean pulmonary arterial pressure did not differ between the groups. After TCASD, the right ventricular end-diastolic area remained unchanged in patients with PAIVS/CPS, whereas it significantly decreased in control subjects. Atrial septal defect associated with PAIVS/CPS had more complex anatomy, which would be a risk for device closure. Hemodynamics should be individually evaluated to determine the indication for TCASD because PAIVS/CPS encompassed anatomical heterogeneity of the entire right heart.

Application of 3D Printing in Bone Grafts.

The application of 3D printing in bone grafts is gaining in importance and is becoming more and more popular. The choice of the method has a direct impact on the preparation of the patient for surgery, the probability of rejection of the transplant, and many other complications. The aim of the article is to discuss methods of bone grafting and to compare these methods. This review of literature is based on a selective literature search of the PubMed and Web of Science databases from 2001 to 2022 using the search terms "bone graft", "bone transplant", and "3D printing". In addition, we also reviewed non-medical literature related to materials used for 3D printing. There are several methods of bone grafting, such as a demineralized bone matrix, cancellous allograft, nonvascular cortical allograft, osteoarticular allograft, osteochondral allograft, vascularized allograft, and an autogenic transplant using a bone substitute. Currently, autogenous grafting, which involves removing the patient's bone from an area of low aesthetic importance, is referred to as the gold standard. 3D printing enables using a variety of materials. 3D technology is being applied to bone tissue engineering much more often. It allows for the treatment of bone defects thanks to the creation of a porous scaffold with adequate mechanical strength and favorable macro- and microstructures. Bone tissue engineering is an innovative approach that can be used to repair multiple bone defects in the process of transplantation. In this process, biomaterials are a very important factor in supporting regenerative cells and the regeneration of tissue. We have years of research ahead of us; however, it is certain that 3D printing is the future of transplant medicine.

Comparison of multimodal RGB-thermal fusion techniques for exterior wall multi-defect detection

Exterior wall inspections are critical to ensuring public safety around aging buildings in urban cities. Conventional manual approaches are dangerous, time-consuming and labor-intensive. AI-enabled drone platforms have recently become popular and provide an alternative to serving automated and intelligent inspections. However, current identification only investigates RGB image of visual defects or thermal images of thermal anomalies without considering the continuous monitoring and the conversion between multiple defects. To gain new insights with modality-specific information, this research therefore compares the performance of early, intermediate, and late multimodal RGB-Thermal images fusion techniques for multi-defect detection in facades, especially for detached tiles and missing tiles. Numerous RGB and thermals images from an ageing campus building were collected as a dataset and the classical UNet for image segmentation was modified as a benchmark. The comparative results regarding accuracy (mAP, ROC, and AUC) proved that early fusion model performed well in distinguishing detached tiles and missing tiles from complex and congested facades. Nevertheless, intermediate and late fusion models were proven to be more efficient and effective with an optimal architecture, achieving high mean average accuracy with much less parameters. In addition, the results also showed that multi-modal fusion techniques can significantly improve the performance of multi-defects detection without adding a large number of parameters to single-modal AI models.

Multiple ventricular septal defects associated to anomalous venous returns, mitral valve disease, myocardium hypertrophy, and right outflow obstruction: a multimodality imaging assessment.

We report a rare congenital heart disease characterized by multiple ventricular septal defects associated to anomalous systemic and pulmonary venous returns, marked apical myocardial hypertrophy of both ventricles and of right outflow, and hypoplastic mitral anulus. Multimodality imaging is mandatory to assess anatomical details.

Deregulated intracellular pathways define novel molecular targets for HBV-specific CD8 T cell reconstitution in chronic hepatitis B

In chronic HBV infection, elevated reactive oxygen species levels derived from dysfunctional mitochondria can cause increased protein oxidation and DNA damage in exhausted virus-specific CD8 T cells. The aim of this study was to understand how these defects are mechanistically interconnected to further elucidate T cell exhaustion pathogenesis and, doing so, to devise novel T cell-based therapies. DNA damage and repair mechanisms, including parylation, CD38 expression, and telomere length were studied in HBV-specific CD8 T cells from chronic HBV patients. Correction of intracellular signalling alterations and improvement of antiviral T cell functions by the NAD precursor nicotinamide mononucleotide and by CD38 inhibition was assessed. Elevated DNA damage was associated with defective DNA repair processes, including NAD-dependent parylation, in HBV-specific CD8 cells of chronic HBV patients. NAD depletion was indicated by the overexpression of CD38, the major NAD consumer, and by the significant improvement of DNA repair mechanisms, and mitochondrial and proteostasis functions by NAD supplementation, which could also improve the HBV-specific antiviral CD8 T cell function. Our study delineates a model of CD8 T cell exhaustion whereby multiple interconnected intracellular defects, including telomere shortening, are causally related to NAD depletion suggesting similarities between T cell exhaustion and cell senescence. Correction of these deregulated intracellular functions by NAD supplementation can also restore antiviral CD8 T cell activity and thus represents a promising potential therapeutic strategy for chronic HBV infection. Correction of HBV-specific CD8 T cell dysfunction is believed to represent a rational strategy to cure chronic HBV infection, which however requires a deep understanding of HBV immune pathogenesis to identify the most important targets for functional T cell reconstitution strategies. This study identifies a central role played by NAD depletion in the intracellular vicious circle that maintains CD8 T cell exhaustion, showing that its replenishment can correct impaired intracellular mechanisms and reconstitute efficient antiviral CD8 T cell function, with implications for the design of novel immune anti-HBV therapies. As these intracellular defects are likely shared with other chronic virus infections where CD8 exhaustion can affect virus clearance, these results can likely also be of pathogenetic relevance for other infection models.

MRI of the pelvic floor in female patients with stress urinary incontinence, pre- and postoperative and/or physiotherapy: analysis of the defect-specific approach

BackgroundStress urinary incontinence (SUI) is a common disabling pelvic floor dysfunction, particularly among aging women. Magnetic resonance imaging (MRI) with dynamic sequences has been proven reliable for detecting pelvic floor weaknesses, especially with multiple compartments defects. Since surgical and non-surgical management options exist, detailed imaging analysis and comprehension of the various surgical and non-surgical interventions are crucial for surgical planning and postoperative evaluation. However, patients often present with recurrent or new symptoms after surgery, where MR imaging is necessary to detect complications in this setting. We aimed to analyze MR images pre- and postoperative/intervention using the defect-specific approach aiming at better understanding of the underlying complication and/or the cause of recurrence.ResultsThirty female patients with SUI were included in the study; 20 underwent surgery, 6 were treated by physiotherapy only, while 3 patients underwent both surgery and physiotherapy and 1 patient was treated conservatively. According to their clinical symptoms, patients with successful surgical/physiotherapy outcome were 18 cases (60%), while unsuccessful group comprised of 12 cases (40%) is classified as follows: persistent complaints subgroup 7 patients (23.3%), de novo complaint subgroup 2 patients (6.7%), while the complicated subgroup is comprised of 2 patients (6.7%) and the persistent/de novo complaints subgroup of the unsuccessful group is composed of 1 case (3.3%). They all underwent MRI of the pelvic floor with a standardized technique, pre- and postoperative/physiotherapy. Changes in level III endopelvic fascia defects between the pre- and postoperative/physiotherapy studies were statistically significant (p = 0.045). Urinary bladder and uterine descent were also found statistically significant between the pre- and postoperative/physiotherapy studies (p = 0.001 and p = 0.029, respectively). Comparing successful and unsuccessful groups pre- and postoperative/therapy, levator plate angle (LPA) was found statistically significant as well (p = 0.039 preoperative and p = 0.001 postoperative).ConclusionsAnalysis of the pre- and postoperative static and dynamic MRI sequences along with proper understanding of the preformed intervention can pinpoint the underlying pathology leading to the recurrent or de novo symptom and/or complications. The defect-specific approach can help determine the underlying pelvic floor defect by altering the MRI techniques tailored for each patient according to their complaint.

Tumor Necrosis Factor-α Alters Maternal and Embryonic Zinc Metabolism and Is Developmentally Toxic in Mice

We tested the hypothesis that tumor necrosis factor-α (TNF-α) would be teratogenic in mice due in part to its effects on zinc metabolism. In Experiment 1, nonpregnant mice were injected with a single dose of TNF-α (40,000 U) or PBS and then received a 65Zn-labeled meal. Mice killed 10 h after TNF-α treatment had high liver 65Zn and low plasma 65Zn, compared with controls. In Experiment 2, gestation day 8 (GD 8) mice were injected with PBS or TNF-α and then received a 65Zn-labeled meal. Dams killed 10 h after TNF-α treatment had higher liver and kidney 65Zn and lower plasma and embryonic 65Zn accumulation than controls. In Experiment 3, TNF-α dosing from GD 7–12 was associated with high maternal liver Zn and metallothionein concentrations on GD 13 and a high frequency of exencephaly on GD 18. In Experiment 4, dams fed diets containing 4.5, 12.5 or 50.0 µg Zn/g were given PBS or TNF-α on GD 7–12. Gross fetal defects were not observed in the PBS-treated litters evaluated on GD 18. In contrast, TNF-α-treated litters were characterized by multiple defects, with the incidence and severity being highest in the low Zn diet group. In Experiment 5, embryos cultured in serum from TNF-α-treated animals exhibited a high frequency of defects; the developmental toxicity of this serum was ameliorated when it was supplemented with Zn. Thus, the developmental toxicity of TNF-α is due in part to its influence on Zn metabolism.

Suppression of multiple phenotypic and RNA processing defects by overexpression of oligoribonuclease in Escherichia coli

Oligoribonuclease (Orn) is an essential ribonuclease (RNase) from Escherichia coli (E.coli), which plays a critical role in the conversion of short RNA molecules (NanoRNAs) to mononucleotides. Although no additional functions have been ascribed to Orn since its discovery nearly 50years ago, it was observed in this study that the growth defects caused by a lack of two other RNases that do not digest NanoRNAs, polynucleotide phosphorylase, and RNase PH, could be suppressed by overexpression of Orn. Further analyses showed that overexpression of Orn can alleviate the growth defects caused by an absence of other RNases even when its expression was increased by a small degree, and it can carry out molecular reactions that are normally performed by RNase T and RNase PH. In addition, biochemical assays revealed that Orn can fully digest single-stranded RNAs within a variety of structural contexts. These studies provide new insights into Orn function and its ability to participate in multiple aspects of E.coli RNA metabolism.

Repair of multiple hand defects with superficial circumflex iliac artery perforator flap.

Reconstruction and repair of multiple defects in the hand is a combination of function, sensation and aesthetics. The reconstruction using the superficial circumflex iliac artery perforator flap has become popular, which overcomes the inherent shortcomings of traditional inguinal flaps by preserving the deep fascia. In this report, we present our experience in the design and clinical application of the superficial circumflex iliac artery perforator flap, which we used to repair multiple defects in the hand. From January 2015 to December 2020, 41 patients received free superficial circumflex iliac artery perforator flap to repair multiple hand defects. All flaps were carefully designed according to the hand defect including 21 single and 20 bilobed flaps. The area of ​​the donor area is 2.5cm×3.0cm∼8.0cm×6.5cm. We followed up all patients regularly and completed standardized assessments of outcomes based on post-reconstruction hand function and esthetic scores. 41 cases of flaps survived completely.3 cases of vascular crisis was relieved after surgical exploration, 1 case of mild distal necrosis was healed after dressing change, 1 case of pigmentation happened. There were 41 patients, 27 males and 14 females, with an average age of 40.5 years (4 to 59 years old). The defects included 20 cases opisthenars and 21 cases palms. The wounds were irregular, with exposed or damaged tendons, nerves or bones. All flaps were followed for a mean of 10.5 months (3 to 15 months). The functional and esthetic outcomes were satisfactory for all flaps without complications such as hand spasms, adhesions and scar contractures CONCLUSION: The superficial circumflex iliac artery perforator flap's donor site was concealed, relatively stable perforators, easy dissection. Recipient site condition was good and acceptable for the patients. It is a significant choice for multiple hand defects.

Effects of bondline defects on the bond behaviour of CFRP-steel double strap joints

Adhesive bonding is used frequently for the applications of carbon fiber-reinforced polymer (CFRP) composites in steel structures such as strengthening or joining. However, the bondline defects are inevitable and could negatively affect the bond behaviour between CFRP and steel. Thus, the bondline defects represent a critical hazard and require careful assessment. This paper presents an experimental and numerical study on the effects of bondline defects on the bond behaviour of CFRP-steel double strap joints. The variables include the defect size (up to 35% of the bonded area), number (up to 45) and locations in the bondline. Multiple defects with mixed sizes are considered in a numerical analysis to investigate the effect of the defect number in more detail. It is found that the bondline defects lead to a reduction in the joint capacity. The highest reduction in capacity (36%) is observed when multiple small-sized defects are presented in the bondline. With the increment of the defect area, the failure mode becomes a combination of steel-adhesive interface debonding and CFRP delamination. A design framework is proposed based on the experimental and numerical results for the conservative prediction of the joint capacity with consideration of bondline defects.

Multi-resolution non-contact laser-sensing damage detection technique for composite laminates

Numerous ultrasonic (UT) modalities have been developed to perform inspections of engineered structures. However, increased precision often comes at the cost of longer inspection times. As an example, guided waves propagating in plate-like structures allow fast inspection of large areas due to their long propagation distances. Damage characterization accuracy is, however, limited in this case due to relatively large wavelengths. On the other hand, local inspection with high-frequency bulk waves provides much more accurate damage characterization thanks to shorter wavelengths. The drawback of local inspection is the long scanning time necessary for large components. Here, we discuss a two-step laser-interferometer-based non-contact approach for the inspection of carbon-fiber-reinforced structures. First, a full-field screening using guided waves is performed to determine the possible damage locations. The identified hot spots are further evaluated in the second step with a high-frequency bulk wave system. A piezoceramic exciter is used for the guided wave setup, while a pulsed laser excitation source is used in the bulk wave setup. The proposed approach minimizes sample preparation time and is completely non-intrusive. The feasibility of the proposed framework is demonstrated in a complex shape, thin-walled composite structure with multiple defects.