457 research outputs found
Svojstva spoja u dvokovinskim motkama Cu-Al i Cu-čeliku nakon platiranja eksplozivom i valjanja
In the paper the microhardness, the microstructure and the bond strength of interface of bimetallic joint on the cross sections of the test bar have been investigated. For the experimental analysis, a bimetallic bar was manufactured using an explosive technique method and the process of rolling. For tests, 23 sets of specimens were prepared each consisting of copper tubes (grade M1-E), rolled steel rods (grade St3S), drawn rods (grade 55) and aluminium rods (grade PA6). The copper tubes and the steel and aluminium rods had different diameters, owing to which different distances between the rods and the internal tube walls were obtained. The results of the research show a significant deviation in microhardness distribution in the both layers near the joining border.U radu su prikazani rezultati istraživanja mikrotvordoće, mikrostrukture i čvrstoće sljubljivanja dvokovinskog spoja na presijeku ispitne šipke. Za potrebe eksperimentalne analize dvokovinska šipka je izrađena metodom primjene eksploziva i naknadnog valjanja. Za ispitivanja su pripremljena 23 kompleta uzoraka od kojih se svaki sastoji iz kompleta cijevi (kvaliteta M1-E), valjanih čeličnih šipki (kvalitete St35), vučenih šipki (kvaliteta 55) i aluminijskih šipki (kvaliteta PA6). Bakarne cijevi i čelične i aluminijske šipke su imale su imale različite promjere zbog kojih su dobivene različite udaljenosti između šipki i unutrašnjih stijenki cijevi. Rezultat ispitivanja pokazuje u oba sloja značajnu odstupanja u raspodjeli mikrotvrdoće uz granicu spoja
BASIS: High-performance bioinformatics platform for processing of large-scale mass spectrometry imaging data in chemically augmented histology
Mass Spectrometry Imaging (MSI) holds significant promise in augmenting digital histopathologic analysis by generating highly robust big data about the metabolic, lipidomic and proteomic molecular content of the samples. In the process, a vast quantity of unrefined data, that can amount to several hundred gigabytes per tissue section, is produced. Managing, analysing and interpreting this data is a significant challenge and represents a major barrier to the translational application of MSI. Existing data analysis solutions for MSI rely on a set of heterogeneous bioinformatics packages that are not scalable for the reproducible processing of large-scale (hundreds to thousands) biological sample sets. Here, we present a computational platform (pyBASIS) capable of optimized and scalable processing of MSI data for improved information recovery and comparative analysis across tissue specimens using machine learning and related pattern recognition approaches. The proposed solution also provides a means of seamlessly integrating experimental laboratory data with downstream bioinformatics interpretation/analyses, resulting in a truly integrated system for translational MSI
Epithelial ovarian carcinoma diagnosis by desorption electrospray ionization mass spectrometry imaging
Ovarian cancer is highly prevalent among European women, and is the leading cause of gynaecological cancer death. Current histopathological diagnoses of tumour severity are based on interpretation of, for example, immunohistochemical staining. Desorption electrospray mass spectrometry imaging (DESI-MSI) generates spatially resolved metabolic profiles of tissues and supports an objective investigation of tumour biology. In this study, various ovarian tissue types were analysed by DESI-MSI and co-registered with their corresponding haematoxylin and eosin (H&E) stained images. The mass spectral data reveal tissue type-dependent lipid profiles which are consistent across the n = 110 samples (n = 107 patients) used in this study. Multivariate statistical methods were used to classify samples and identify molecular features discriminating between tissue types. Three main groups of samples (epithelial ovarian carcinoma, borderline ovarian tumours, normal ovarian stroma) were compared as were the carcinoma histotypes (serous, endometrioid, clear cell). Classification rates >84% were achieved for all analyses, and variables differing statistically between groups were determined and putatively identified. The changes noted in various lipid types help to provide a context in terms of tumour biochemistry. The classification of unseen samples demonstrates the capability of DESI-MSI to characterise ovarian samples and to overcome existing limitations in classical histopathology
Mass spectrometry: from imaging to metabolic networks
A deeper understanding of inter-tumorand intra-tumorheterogeneity is a critical factor for the advancement of next generation strategies against cancer. Under the hypothesis that heterogeneous progression of tumorsis mirrored by their metabolic heterogeneity, detection of biochemical mechanisms responsible of the local metabolism becomes crucial.We show that network analysis of co-localized ions from mass spectrometry imaging data provides a detailed chemo-spatial insightinto the metabolic heterogeneity of tumor. Furthermore, module preservation analysis between colorectal cancer patients with and without metastatic recurrence suggests hypotheses on the nature of the different local metabolic pathways
Epidemiology and Outcomes of Vertebral Artery Injury in 16 582 Cervical Spine Surgery Patients: An AOSpine North America Multicenter Study.
STUDY DESIGN: A multicenter retrospective case series was compiled involving 21 medical institutions. Inclusion criteria included patients who underwent cervical spine surgery between 2005 and 2011 and who sustained a vertebral artery injury (VAI).
OBJECTIVE: To report the frequency, risk factors, outcomes, and management goals of VAI in patients who have undergone cervical spine surgery.
METHODS: Patients were evaluated on the basis of condition-specific functional status using the Neck Disability Index (NDI), modified Japanese Orthopaedic Association (mJOA) score, the Nurick scale, and the 36-Item Short-Form Health Survey (SF-36).
RESULTS: VAIs were identified in a total of 14 of 16 582 patients screened (8.4 per 10 000). The mean age of patients with VAI was 59 years (±10) with a female predominance (78.6%). Patient diagnoses included myelopathy, radiculopathy, cervical instability, and metastatic disease. VAI was associated with substantial blood loss (770 mL), although only 3 cases required transfusion. Of the 14 cases, 7 occurred with an anterior-only approach, 3 cases with posterior-only approach, and 4 during circumferential approach. Fifty percent of cases of VAI with available preoperative imaging revealed anomalous vessel anatomy during postoperative review. Average length of hospital stay was 10 days (±8). Notably, 13 of the 14 (92.86%) cases resolved without residual deficits. Compared to preoperative baseline NDI, Nurick, mJOA, and SF-36 scores for these patients, there were no observed changes after surgery (P = .20-.94).
CONCLUSIONS: Vertebral artery injuries are potentially catastrophic complications that can be sustained from anterior or posterior cervical spine approaches. The data from this study suggest that with proper steps to ensure hemostasis, patients recover function at a high rate and do not exhibit residual deficits
Optimal Plastic Design for Partially Preassigned Strength Distribution
BRIEF NOTES 2iP 2,P 2iP | T T i £ tistically admissible stress field M(X) can only be optimal if at moment values M i (i = 1, 2, . . ., n) the rotations given by equations (l)-(3) result in a kinematically admissible displacement field (necessary condition). Example. For a clamped beam with three point loads, Since the slope of the moment diagram in the outer half of the beam is three times that in the inner half, equation The foregoing theorem admits an infinite number of solutions corresponding to 2.625 aP < x -3.25 aP. The moment diagrams for the limiting cases are shown in Remark. The proposed theorem is not related directly to Foulkes' theorem [2] and its extensions [6] because the latter preassign a specified strength distribution to given subsets of the structure. In the problem considered, the cost function is discontinuous but the subsets of the structure over which various regimes of the cost function apply are not preassigned. Hence the proposed extension of the Prager-Shield theory gives a more economical design than Foulkes' method
Benchmark datasets for 3D MALDI- and DESI-imaging mass spectrometry
BACKGROUND: Three-dimensional (3D) imaging mass spectrometry (MS) is an analytical chemistry technique for the 3D molecular analysis of a tissue specimen, entire organ, or microbial colonies on an agar plate. 3D-imaging MS has unique advantages over existing 3D imaging techniques, offers novel perspectives for understanding the spatial organization of biological processes, and has growing potential to be introduced into routine use in both biology and medicine. Owing to the sheer quantity of data generated, the visualization, analysis, and interpretation of 3D imaging MS data remain a significant challenge. Bioinformatics research in this field is hampered by the lack of publicly available benchmark datasets needed to evaluate and compare algorithms. FINDINGS: High-quality 3D imaging MS datasets from different biological systems at several labs were acquired, supplied with overview images and scripts demonstrating how to read them, and deposited into MetaboLights, an open repository for metabolomics data. 3D imaging MS data were collected from five samples using two types of 3D imaging MS. 3D matrix-assisted laser desorption/ionization imaging (MALDI) MS data were collected from murine pancreas, murine kidney, human oral squamous cell carcinoma, and interacting microbial colonies cultured in Petri dishes. 3D desorption electrospray ionization (DESI) imaging MS data were collected from a human colorectal adenocarcinoma. CONCLUSIONS: With the aim to stimulate computational research in the field of computational 3D imaging MS, selected high-quality 3D imaging MS datasets are provided that could be used by algorithm developers as benchmark datasets
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