ABSTRACT
Manufacturing aircraft components through 3D printing has become a widespread concept with proven applicability for serial production of certain structural parts. The main objective of the research study is to determine whether a chlorinated polyethylene material reinforced with milled carbon fibers has the potential of replacing the current 5052 NIDA aluminum alloy core of the IAR330 helicopter tail rotor blade, under the form of a honeycomb structure with hexagonal cells. Achieving this purpose implied determining the tensile and compression mechanical properties of the material realized by fused deposition modeling. The tensile tests have been conducted on specimens manufactured on three printing directions, so that the orthotropic nature of the material may be taken into account. The bare compression tests were realized on specimens manufactured from both materials, with similar honeycomb characteristics. All the mechanical tests have been performed on the Instron 8872 servo hydraulic testing system and the results have been evaluated with the Dantec Q400 Digital Image Correlation system. The experimental tests have been reproduced as finite element analyses which have been validated by results comparison, in order to determine if the compression model is viable for more complex numerical analysis.
ABSTRACT
Mycobacteria identification is crucial to diagnose tuberculosis. Since the bacillus is very small, finding it in Ziehl-Neelsen (ZN)-stained slides is a long task requiring significant pathologist's effort. We developed an automated (AI-based) method of identification of mycobacteria. We prepared a training dataset of over 260,000 positive and over 700,000,000 negative patches annotated on scans of 510 whole slide images (WSI) of ZN-stained slides (110 positive and 400 negative). Several image augmentation techniques coupled with different custom computer vision architectures were used. WSIs automatic analysis was followed by a report indicating areas more likely to present mycobacteria. Our model performs AI-based diagnosis (the final decision of the diagnosis of WSI belongs to the pathologist). The results were validated internally on a dataset of 286,000 patches and tested in pathology laboratory settings on 60 ZN slides (23 positive and 37 negative). We compared the pathologists' results obtained by separately evaluating slides and WSIs with the results given by a pathologist aided by automatic analysis of WSIs. Our architecture showed 0.977 area under the receiver operating characteristic curve. The clinical test presented 98.33% accuracy, 95.65% sensitivity, and 100% specificity for the AI-assisted method, outperforming any other AI-based proposed methods for AFB detection.
ABSTRACT
AIM: To analyze the demographic characteristics and surgical outcomes of the largest series of patients with pediatric aneurysms reported in Romania, in consideration of the primary factors that lead to good long-term outcomes. Given that all cases involved ruptured aneurysms, we also investigated the ability of microsurgical clipping to prevent massive hemorrhage andaggravation of neurological deficits. MATERIAL AND METHODS: This multicenter retrospective study included 47 pediatric patients ( < 16 years old) who underwent operation over the 20-year period between January 1999 and January 2019. We analyzed medical records and imaging findings in each patient. Treatment consisted of open microsurgical dissection (clipping) and endovascular embolization (coiling). RESULTS: Mean patient age was 14.3 years, ranging from 5 months to 16 years, with 28 boys (59.5%) and 19 girls (40.4%). In our series, pediatric aneurysms represented 6.1% of all intracranial aneurysms (771 cases). Clinical features were dominated by headache (45 cases, 95.7%), neck stiffness (43 cases, 91.4%) and vomiting (42 cases, 89.3%). The most frequently involved locations were the anterior communicating artery (17 cases, 36.1%), middle cerebral artery (12 cases, 25.5%), and internal carotid artery bifurcation (9 cases, 19.1%). Glasgow Outcome Scale scores at 6 months indicated good recovery in 36 patients (76.5%), moderate disability in ninepatients (19.1%), severe disability in one patient (2.1%), and (preoperative) death in one patient (2.1%). CONCLUSION: Intracranial aneurysms in children are very rare. Early diagnosis based on brain imaging and microsurgical treatment is essential for attaining excellent results.Primary factors such as preoperative status, child profile, aneurysm size, treatment choice, and timing of the operation influence both short and long-term outcomes.
