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Background: Efforts have been made to combine radiographic biomarkers such as bronchiectasis or bronchial wall thickness (BWT) for the purpose of identifying asthma subphenotypes and their clinical implications. Objective: Our aim was to assess whether a composite triple radiologic phenotype measured by high-resolution computed tomography comprising BWT, mucus plug score (MPS), and mediastinal lymph node (MLN) size might provide a better insight into subphenotypes in persistent asthma. Methods: A total of 112 patients with moderate-to-severe asthma were included in this retrospective observational study. A binary method was used to classify patients according to median values for the following: a pooled mediastinal lymph node size of 3.6 mm or more; a BWT as a pooled wall area of at least 50% of the total airway area; and a mucus plug score of 1 or higher, with a mucus plug considered positive if complete bronchial obstruction was imaged more than 2 cm from a pleural surface. Results: Patients with the triple imaging phenotype exhibited significantly worse Asthma Control Questionnaire scores, with their scores exceeding minimal clinical important difference, a higher prevalence of concomitant chronic rhinosinusitis with nasal polyps, and a greater total IgE level. Conclusion: We have demonstrated an association between poorer symptom control and the triple radiologic asthma phenotype.
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Magnetic resonance imaging (MRI) is widely used in clinical diagnosis as a safe, non-invasive, high-resolution medical imaging technology, but long scanning time has been a major challenge for this technology. The undersampling reconstruction method has become an important technical means to accelerate MRI by reducing the data sampling rate while maintaining high-quality imaging. However, traditional undersampling reconstruction techniques such as compressed sensing mainly rely on relatively single sparse or low-rank prior information to reconstruct the image, which has limitations in capturing the comprehensive features of images, resulting in the insufficient performance of the reconstructed image in terms of details and key information. In this paper, we propose a deep plug-and-play multiple complementary priors MRI reconstruction model, which combines traditional low-rank matrix recovery model methods and deep learning methods, and integrates global, local and nonlocal priors to improve reconstruction quality. Specifically, we capture the global features of the image through the matrix nuclear norm, and use the deep convolutional neural network denoiser Swin-Conv-UNet (SCUNet) and block-matching and 3-D filtering (BM3D) algorithm to preserve the local details and structural texture of the image, respectively. In addition, we utilize an efficient half-quadratic splitting (HQS) algorithm to solve the proposed model. The experimental results show that our proposed method has better reconstruction ability than the existing popular methods in terms of visual effects and numerical results.
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Bacterial magnetosomes ("MAGs") represent a promising class of magnetic iron oxide nanoparticles with exceptional material characteristics and high application potential in the biomedical and biotechnological field. For the surface functionalization of MAGs with different protein cargos, their enveloping membrane can be addressed by genetic means. However, the expression of foreign polypeptides as translational fusion to magnetosome membrane proteins is still laborious and lacks versatility as the generated particles are monospecific and thus restricted to predetermined functions. Utilizing the SpyTag-SpyCatcher (ST-SC) bioconjugate system, we here establish a flexible platform for the targeted nanoassembly of multifunctional MAGs that combines the rapidity of chemical coupling (e.g., by cross-linking reactions) and the unmatched selectivity and controllability of in vivo functionalization. MAGs genetically engineered to display either SC- or ST-connectors are shown to efficiently bind a variety of complementary tagged (protein) cargo. Specifically, we cover a broad spectrum of representative functional moieties and foreign cargo (such as enzymes, antibodies, fluorophores, and silica beads) with relevance in biotechnology and biomedicine and demonstrate the interchangeability of the MAGs-adapted ST-SC system. For the controlled generation of artificial shells surrounding the particles, SC-MAGs are effectively coated by protein-corona proteins. The potential of the here-provided toolkit is even more enhanced by using SC-MAGs as an affinity tool for selective protein pulldown in vitro and in vivo. Overall, this innovative technology turns bacterial MAGs into a flexible magnetic nanoscaffold for the targeted plug-and-play display of virtually unlimited additional functionalities, thereby generating a multitude of magnetic hybrid materials that can be used in many applications.
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Magnetossomos , Magnetospirillum , Magnetossomos/metabolismo , Magnetossomos/química , Magnetossomos/genética , Magnetospirillum/metabolismo , Magnetospirillum/genética , Magnetospirillum/química , Nanopartículas Magnéticas de Óxido de Ferro/química , Química Click , Nanopartículas de Magnetita/química , Peptídeos/química , Peptídeos/metabolismoRESUMO
Symptoms of patulous Eustachian Tube (PET) were first described by Jago in 1858 and reported by Schwartze in 1864, recognizing PET as a clinical entity. This review summarizes the causes, epidemiology, diagnosis, and treatment of PET, with a particular emphasis on diagnosis and treatment, detailing the diagnostic criteria and silicone plug (Kobayashi plug) surgery proposed or developed in Japan. PET is often linked to weight loss from chronic illnesses, dieting, anorexia nervosa, hemodialysis, and bariatric surgery. It is also associated with pregnancy, oral contraceptive use, nasopharyngeal and muscular atrophy or scarring, and neuromuscular diseases. Interestingly, many PET cases lack an identifiable cause. The prevalence of PET ranges from 0.3 % to 7.0 %, with a higher incidence in females and typically occurring in adolescents and adults. Diagnosis relies on a combination of clinical history, physical examination, ET function test, and imaging. The Japan Otological Society (JOS) proposed standardized diagnostic criteria, where a "definite PET" diagnosis requires all three criteria (aural symptoms, tubal obstruction procedures, and objective findings), while "possible PET" requires two. Treatment includes conservative and surgical interventions. For persistent and severe cases that do not improve with conservative treatments, surgical options are explored. These surgical procedures are classified by the type of intervention, which includes tympanic membrane manipulation (such as tympanostomy tube insertion and mass loading of the tympanic membrane), plug surgery, ET injection, shim surgery, tuboplasty, and ET closure. The Kobayashi plug, a 23 mm long silicone plug, is specifically designed for PET treatment. Indications for its use include "definite PET," a PHI-10 score of 26 or higher, and lack of improvement after six months of conservative treatment. Preoperative evaluations include CT scans to assess ET patency and confirm the bony portion. Surgery, mostly performed under local anesthesia, involves inserting the plug into the ET via a myringotomy, ensuring the correct size and position with endoscopic guidance. In conclusion, PET is a challenging condition with diverse etiologies and symptoms. Effective management requires a comprehensive diagnostic approach and tailored treatment plans, with the Kobayashi plug offering a promising solution for refractory cases. Further research and advancements in diagnostic techniques and therapeutic interventions will continue to enhance the management of PET.
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BACKGROUND: Transcatheter patent ductus arteriosus closure in premature infants is gaining attention with rapidly growing experience. The KA micro plug device poses many favourable features for ductus arteriosus closure in premature infants. The study aimed to describe the technique and outcomes of a KA micro plug in closing the ductus arteriosus in premature infants weighing less than 1500 g. METHODS: This is a single-centre retrospective study in premature infants with patent ductus arteriosus weighing less than 1500 g who underwent off-label use of a KA micro plug at the Stead Family Children's Hospital from February 2022 to December 2023. RESULTS: Eighteen premature infants weighing less than 1500 g underwent attempted transcatheter ductus arteriosus closure using a KA micro plug device. Median weight, age, and corrected gestational age at the procedure were 943 g (682-1225), 26 days (9-79), and 28.5 weeks (25.6-32), respectively. The procedure was successful with complete closure achieved in all patients. No major haemodynamic instabilities were encountered. No catheterization-related complications were encountered. On a median follow-up of 10.9 months (0.1-19), all patients are alive with the device in a good position without residual shunt or abnormal findings. CONCLUSION: KA micro plug device for patent ductus arteriosus in infants weighing less than 1500 g is feasible, safe, and effective. We recommend that manufacturers of devices used to close the ductus arteriosus in small infants enhance both the devices and their delivery systems to simplify the procedure and mitigate the risk of haemodynamic instability.
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BACKGROUND: To evaluate the benefits of omalizumab treatment in patients through real-world follow-up and assess the impact of omalizumab treatment on airway remodeling using chest CT. METHODS: This is a single-center prospective, observational study included Chinese patients with refractory asthma who received omalizumab treatment from May 2021 to December 2022. We collected real-world clinical data, including their hospitalization information, pulmonary function, FENO, laboratory assessment, ACT scores, chest CT at baseline and every follow-up month. A comparison was made between the pre-treatment and post-treatment laboratory indicators, pulmonary function, airway parameters, and mucous plug scores under chest CT. RESULTS: This study included a total of 61 patients with refractory asthma treated with omalizumab. The study found that: â regardless of whether the treatment lasted for a full four months or not, it significantly improved patient asthma control scores and reduced hospitalization costs and length of stay (p < 0.05). â¡After four months of treatment, pulmonary ventilation function examination revealed significant improvements (p < 0.05) in MEF75, MEF50, MEF75/25, PEF, and FEV1/FVC. â¢After four months of omalizumab treatment, the ratio of wall thickness and outer radius (T/D) and wall area percentage (WA%) of the bronchial wall decreased significantly (p < 0.05). â£After medication, the expression of airway mucous plugs decreased. CONCLUSIONS: Omalizumab treatment can reduce airway wall thickness, decrease the percentage of airway wall area, and the expression of airway mucous plugs, thereby improving airflow limitation. Utilizing chest CT provides a novel and intuitive assessment of the efficacy of omalizumab treatment. TRIAL REGISTRATION: This study was registered in Chinese Clinical Trial Registry, the number is ChiCTR2100046343.
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OBJECTIVES: Coronary artery fistulas (CAFs) are rare congenital anomalies with an occurrence rate of 0.002-0.3%. The right coronary artery (RCA) is reportedly the most common site of origin of CAFs, but fistulas draining to the left atrium (LA) are rare. We presented a three-year-old boy with a symptomatic congenital RCA-to-LA fistula, which was successfully percutaneously occluded with an Amplatzer vascular plug 4 (AVP4). CASE REPORT: The diagnosis was made by echocardiography when he was two months old. During the follow-up period of 2 years, a progressive dilatation of the RCA and enlargement of the left ventricle was detected, so treatment for congestive heart failure was initiated. At the age of three, the patient presented with a history of occasional mild central chest pain and discomfort and mild dyspnea on exertion. On a 24 h ECG Holter monitor, the depression of ST segments was registered. CT angiography highlighted a large type B RCA fistula to the LA, which extended along the atrioventricular sulcus. The proximal RCA diameter was 7 mm. The fistula was tortuous, with segmental narrowing and three curves. Cardiac catheterization was performed across the right femoral artery on the three-year-old boy (body weight: 13 kg). Across the 4F Judkins right guiding catheter, an AVP4 of 5 mm was placed in the distal part of the CAF connected with the delivery cable. After 15 min, ECG changes were not registered, so the device was released. Immediate post-deployment angiography demonstrated complete CAF occlusion, with satisfying flow in the distal coronary artery. The patient was discharged after four days. In the short-term follow-up period, the boy was symptom-free. CONCLUSIONS: In our experience, given the existence of the left-to-left shunt and the more pronounced exercise-induced coronary steal phenomenon that occurs in medium-sized and large CAFs, occlusion is necessary to prevent the further progression of clinical signs and symptoms.
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Roxarsone (ROX) is widely used as a feed addictive for livestock and poultry. ROX promotes angiogenesis, which can lead to health problems, and it is necessary to identify methods to counter this angiogenic effect of ROX. The VEGF/VEGFR2 signaling pathway is involved in the growth and reconstruction of new blood vessels during angiogenesis. In this study, a recombinant lentiviral vector encoding Vegfr2 shRNA was transfected into rat vascular endothelial cells and used in mouse matrigel plug and melanoma xenograft models to investigate its potential to regulate ROX-induced angiogenesis and tumor growth. Treating endothelial cells with ROX increased cell proliferation, migration, and a tube-like structure of growth relative to the control group. The addition of the lentiviral Vegfr2-silencing vector significantly attenuated the effects of ROX on endothelial cells. The hemoglobin content of mouse matrigel plugs treated with ROX was increased significantly. This effect was dramatically attenuated by the co-administration of shRNA targeting Vegfr2. The volume, weight and CD34 staining of the melanoma xenograft tumors increased by ROX were also attenuated by Vegfr2 silence. These results indicate that the down-regulation of VEGFR2 protein plays an inhibitory role in the ROX-promoted angiogenesis in vivo and in vitro. These data support the targeting of Vegfr2 gene as an effective means to treat ROX-induced angiogenesis and tumor growth.
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BACKGROUND: Recently, there has been a surge of literature utilizing the human amniotic membrane (hAM) to manage cases of macular holes. In this scoping review, we aimed to systematically narrate the literature to identify cases of macular holes that are managed using hAM and explore the visual and anatomical outcomes to inform future research questions. METHODS: This scoping review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A detailed database search strategy (Scopus, Embase, Medline, and Cochrane Central) was developed to identify English-language published articles that reported using hAM to manage macular holes. All human clinical studies were included for a narrative data synthesis divided across study types. RESULTS: The database search identified 82 articles, of which 34 were eligible for full-text review (0 randomized controlled trials (RCTs), 12 non-RCTs, 10 retrospective reviews, ten published case reports, and two clinical trial registries). The non-RCTs included patients with macular holes related to a wide range of retinal diseases, including retinal detachment, recurrent holes, and high myopia. Only two non-RCTs reported comparative data with a control group, but the study characteristics differed, and quantitative synthesis was impossible. Most retrospective interventional series and individual case reports reported a success rate of 93 -100% in hole closure and improvement in best-corrected visual acuity. None of the studies reported adverse effects after a hAM transplantation. CONCLUSION: The hAM effectively seals macular holes without any safety concerns, improving anatomical and visual outcomes in all macular holes.
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Background: Multiple techniques exist for the preoperative localization of small, deeply located solid or subsolid pulmonary nodules to guide limited thoracoscopic resection. This study aims to conduct a multi-institutional comparison of three different tomography-guided tracers' methods. Methods: A retrospective multicenter cross-sectional study was conducted. All patients suitable for CT-guided tracers with microcoil (GROUP1, n = 58), hook wire (GROUP2, n = 86), or bioabsorbable hydrogel plug (GROUP3, n = 33) were scheduled for video-assisted thoracoscopic wedge resection. Outcome variables: successful nodule localization, safety, and the feasibility of the tracers' placement. A χ2 test or Fisher's test for expected numbers less than five and a Kruskal-Wallis test were used to analyze the categorical and continuous variables, respectively. For the power calculations, we used G*Power version 3.1.9.6. Results: One hundred seventy-seven patients underwent the localization and resection of 177 nodules detected with three different CT-guided tracers. A significant difference was recorded for cancer history (p = 0.030), respiratory function, Charlson comorbidity index (p = 0.018), lesion type (p < 0.0001), distance from pleura surface (p < 0.0001), and time between preoperative CT-guided tracers and surgical procedures (p < 0.0001). Four post-procedural complications were recorded and in GROUP2, four cases of tracer dislocations occurred. Finally, hook wire group was associated with the shortest surgical time (93 min, p = 0.001). Conclusions: All methods were feasible and efficient, resulting in a 100% success rate for the microcoils and the bioabsorbable hydrogel plugs and a 94.2% success rate for the hook wires. Our results highlight the need to choose a technique that is less stressful for the patient and helps the surgeon by extending the approach to deep nodules and resecting over the course of several days from deployment.
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This preliminary study evaluated the biocompatibility of a novel degradable intravaginal plug contraceptive composed of PEG 4000 and chitosan in cats using haematological profiling and vaginal cytology. Five healthy, non-pregnant female cats were fully anaesthetised and fitted with an intravaginal plug (10 × 0.3 mm) using an applicator, following oestrogen administration 3 h prior. Blood samples were collected from the cephalic vein on days 0 (pre-insertion) and 3 and 7 (post-insertion). Vaginal cytology examinations were conducted on day 0 (pre- and post-oestrogen injection) and days 1, 3 and 7 post-insertion. Haematological parameters, including red blood cell count, haemoglobin levels, haematocrit values, total white blood cell count and differentiation, showed no significant changes after contraceptive insertion (p > 0.05). Vaginal cytology indicated an acute inflammatory response in one out of five subjects on day three post-insertion. The distribution of vaginal epithelial cells (parabasal, intermediate and superficial) remained unaffected by contraception. Oestrogen injection resulted in the dominance of superficial cells up to day 7 of observation (p < 0.05). Overall, PEG 4000 and chitosan-based intravaginal plug contraceptives demonstrated sufficient biocompatibility, indicating their potential as viable contraceptive options for feline use.
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Quitosana , Polietilenoglicóis , Vagina , Animais , Gatos , Feminino , Vagina/citologia , Administração Intravaginal , Materiais Biocompatíveis , Estrogênios/administração & dosagem , Anticoncepção/veterinária , Anticoncepção/métodos , Anticoncepcionais Femininos/administração & dosagem , Anticoncepcionais Femininos/farmacologia , Dispositivos Anticoncepcionais FemininosRESUMO
A self-degradable rubber plug (SDRP) was developed to address issues in existing crosslinked polymer temporary plugging technology, such as poor self-degradation properties. The synthesis formula was optimized using response surface analysis, resulting in an optimized composition of the SDRP: 13 wt% monomer, 0.02 wt% initiator, 0.7 wt% crosslinker, and 1.8 wt% degradation catalyst. Under the condition of 70-120 °C, the SDRP was transformed from a liquid to a solid gel in 30-110 min; the degradation time was 3-10 days, and the viscosity of the completely degraded solution was lower than 20 mPa·s. At an injection volume of 1 PV SDPR, a breakthrough pressure of 8.34 MPa was achieved. The hydrolysis of the unstable crosslinker was found to have caused the breakage of the SDRP. Over time, the functional groups within the unstable crosslinker underwent hydrolysis due to the combined effects of temperature and the degradation catalyst. This process led to the disruption of crosslinking points, resulting in a gradual deterioration of the network structure. As a consequence, some immobile water was converted into free water. The mobility of water molecules increased until the plug was completely degraded into a viscous liquid. This study enriches the temporary plugging gel system.
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Given the high toxicity of N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (6PPD) derivatives, such as 6PPD quinone (6PPDQ) to salmon, as well as their ubiquitous presence in the environment, the contaminant of aquatic food products has drawn significant attention. However, analytical methods for p-Phenylenediamines (PPDs) and their transformation products (TPs) in aquatic products remain underdeveloped. In particular, the degradation of some compounds and strong matrix effects complicate detection. In this study, we present a stable, rapid, and sensitive method combining salt-out assisted extraction, antioxidant protection, and multi-plug filtration clean-up (m-PFC) to detect two PPDs and five TPs in aquatic products. Crucially, the appropriate selection of antioxidants prevented the degradation of the easily oxidized target compounds. Further, the m-PFC method significantly enhanced the purification efficiency, achieving satisfactory recoveries (62.1-115 %), and method detection limits (MDLs) ranging from 0.00300 to 0.400 µg/kg. Subsequently, the method was applied to monitor PPDs and their TPs in aquatic products systematically, revealing the presence of 6PPD and N-isopropyl-N'-phenyl-1,4-phenylenediamine (IPPD) in white shrimp from aquafarms, whereas none of the seven target analytes were detected in fish and crab samples. These findings contribute to the detection of PPDs, their TPs and other unstable chemicals in aquatic products, thereby providing insights into their concentrations in these products.
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PURPOSE: To evaluate the effect of punctal plugs combined with cyclosporine eye drops on dry eye disease (DED) and ocular surface inflammation. METHODS: In a clinical trial, 73 patients were randomly allocated into three groups: punctal plug group, combination therapy group, and cyclosporine group. At the baseline and four weeks after treatment, the Schirmer I test score, fluorescein tear film break-up time (FBUT), ocular surface staining score and dry eye symptoms were assessed. Tear samples were collected to detect the level of inflammatory factors (interleukins, matrix metalloproteinase 9 (MMP-9) and tumor necrosis factor alpha (TNF-α)). In an animal experiment, a New Zealand rabbit dry eye model was induced. The rabbits were randomly divided into control group, punctal plug group, and combination therapy group (n = 6). Conjunctival goblet cell density, protein level of MMP-9 in conjunctiva and mRNA levels of inflammatory factors in conjunctiva and cornea were measured before and after treatment. RESULTS: In combination therapy group of the clinical trial, the following results were observed: significant improvement in Schirmer I test scores and FBUT compared to the cyclosporine group and punctal plug group, respectively; a decrease in the tear levels of IL-6, IL-1, and MMP-9 compared to the punctal plug group; and a decrease in the tear levels of IL-1α, IL-6, and IL-17 compared to the baseline (all p < 0.05). In the animal experiment, rabbits in combination therapy group had a higher goblet cell density (p < 0.01) and lower mRNA levels of IL-16 (p < 0.05), IL-17 (p < 0.05), and MMP-9 (p < 0.01) in conjunctiva and that of MMP-9 (p < 0.01) in cornea compared to punctal plug group. CONCLUSION: Cyclosporine eye drops combined with degradable punctal plugs is a more optimized clinical treatment strategy for DED compared with degradable punctal plugs or cyclosporine eye drops alone, considering the influence of comprehensive clinical efficacy and ocular surface inflammation.
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The reduction of greenhouse gas emissions and the effort of carbon neutrality require the improvement of spark-ignition engines in terms of efficiency and capability to operate on renewable fuels. The electrode wear of spark plugs, used for ignition of novel fuels and lean mixtures, emerges as a significant challenge in this transition. Understanding the physical mechanism and influence of spark operation parameters of the wear process is thus important. Compared to the conventional methodology of performing long-term wear tests, laser-based optical diagnostics methods are capable of assessing electrode wear during one single or a few spark discharges. In this work, the necessary initial steps required for performing optical investigations using laser-induced fluorescence (LIF) are presented. Several excitation pathways of nickel atoms were investigated, and 336.96 nm was identified as the optimal one. This excitation approach yielded emissions between 338.75 and 353.58 nm, effectively avoiding the major interference from N2 plasma emission in spark discharges. Additionally, a linear relationship in fluorescence signal intensity with excitation energy up to 400 µJ was observed. These findings indicate the potential of LIF for in situ diagnostics of electrode wear, contributing to engine development in both efficiency and compatibility with sustainable fuels.
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Glaucoma is one of the world's leading causes of blindness, and its management is challenging. The main objective is to lower intraocular pressure through medical, para-surgical, and surgical therapy. Medical therapy often represents the first line of treatment. Although effective in many cases, the eye drops are accompanied by significant problems. They require high patient compliance and can be associated with various side effects, limiting their efficacy. Consequently, the research for new drug delivery systems trying to overcome these limitations is ongoing: numerous devices are developing and gradually entering clinical practice. These new therapeutic options may offer better control of the intraocular pressure, with fewer side effects, and are less dependent on patients' compliance. Hence, the research in this field continues to flourish. This review summarizes the most recent findings in the scientific literature, underlines the role and possible limitations of the new glaucoma drug delivery systems in clinical practice, and recognizes their new horizons and perspectives.
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Streptococci are well-known opportunistic bacterial abortifacients in mares. Colonization of the pregnant uterus is considered to happen after transcervical migration of bacteria from the lower genital tract mucosa. Streptococcus ovis is a pathogen mainly associated with inflammatory lesions in sheep. This species has not been reported in association with disease in horses. In the present case, S. ovis was isolated in monoculture from the lung of an 8-months-old equine fetus and was associated with development of acute suppurative bronchopneumonia, umbilical cord cellulitis and placentitis in the cervical star region of the allantochorion. The mare had been in a pasture together with sheep. One week prior to abortion, a double-guarded uterine swab had been inserted into the cervical canal by a veterinarian, who was unaware of the mare being pregnant. This probably damaged the cervical mucus plug thus allowing S. ovis bacteria to pass the cervical canal and colonize the placenta.
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Patent ductus arteriosus (PDA) is a deadly congenital disease in dogs if left untreated. Occlusion of the defect is the treatment of choice and can be achieved by surgical ligation or interventional closure. In this retrospective study of 16 dogs, an alternative to the classically used canine device which is placed by an arterial route is described. The Amplatzer Vascular Plug II® (AVPII) can be deployed by a transvenous approach, using a modified and simplified technique using a single catheter to perform angiography and device delivery. This allows the percutaneous treatment of smaller dogs <3 kg and the concomitant treatment of pulmonic stenosis if present. Successful and complete closure was achieved in all dogs with a mean device/ampulla diameter ratio of 1.28 and a mean device/ostium ratio of 3.6. Embolization into the pulmonary artery was observed in one dog where the device/ampulla diameter ratio was <1.1 and device/ostium ratio was <2.1. In conclusion, our study confirms that PDA transvenous closure using the AVPII appears to be a viable alternative to transarterial closure, allowing the treatment of smaller dogs and a fully percutaneous approach. Care should be taken in patients with very large ducti where undersizing might result in device embolization.
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Doenças do Cão , Permeabilidade do Canal Arterial , Embolização Terapêutica , Dispositivo para Oclusão Septal , Animais , Cães , Permeabilidade do Canal Arterial/veterinária , Permeabilidade do Canal Arterial/terapia , Permeabilidade do Canal Arterial/cirurgia , Embolização Terapêutica/veterinária , Embolização Terapêutica/métodos , Embolização Terapêutica/instrumentação , Doenças do Cão/terapia , Doenças do Cão/cirurgia , Estudos Retrospectivos , Masculino , Feminino , Dispositivo para Oclusão Septal/veterináriaRESUMO
The efficiency of current GaN-based blue laser diodes (LDs) is limited by the high resistance of a thick p-AlGaN cladding layer. To reduce the operation voltage of InGaN blue LDs, we investigated optimum LD structures with an indium tin oxide (ITO) partial cladding layer using numerical simulations of LD device characteristics such as laser power, forward voltage, and wall-plug efficiency (WPE). The wall-plug efficiency of the optimized structure with the ITO layer was found to increase by more than 20% relative to the WPE of conventional LD structures. In the optimum design, the thickness of the p-AlGaN layer decreased from 700 to 150 nm, resulting in a significantly reduced operation voltage and, hence, increased WPE. In addition, we have proposed a new type of GaN-based blue LD structure with a dielectric partial cladding layer to further reduce the optical absorption of a lasing mode. The p-cladding layer of the proposed structure consisted of SiO2, ITO, and p-AlGaN layers. In the optimized structure, the total thickness of the ITO and p-AlGaN layers was less than 100 nm, leading to significantly improved slope efficiency and operation voltage. The WPE of the optimized structure was increased relatively by 25% compared to the WPE of conventional GaN-based LD structures with a p-AlGaN cladding layer. The investigated LD structures employing the ITO and SiO2 cladding layers are expected to significantly enhance the WPE of high-power GaN-based blue LDs.
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Percutaneous closure of coronary fistulas can be a challenge, given the tortuosity and the small caliber of the anomalous vessel. The microvascular plugs (MVP) are polytetrafluoroethylene-coated nitinol devices designed to perform embolization of small peripheral vessels. Its reduced profile allows the release of the device through microcatheters, facilitating the intervention. We present three cases of coronary fistulas in adults, percutaneously closed through radial access using these devices.