1,113 research outputs found

    Benchmarking Vision-Language Contrastive Methods for Medical Representation Learning

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    We perform a comprehensive benchmarking of contrastive frameworks for learning multimodal representations in the medical domain. Through this study, we aim to answer the following research questions: (i) How transferable are general-domain representations to the medical domain? (ii) Is multimodal contrastive training sufficient, or does it benefit from unimodal training as well? (iii) What is the impact of feature granularity on the effectiveness of multimodal medical representation learning? To answer these questions, we investigate eight contrastive learning approaches under identical training setups, and train them on 2.8 million image-text pairs from four datasets, and evaluate them on 25 downstream tasks, including classification (zero-shot and linear probing), image-to-text and text-to-image retrieval, and visual question-answering. Our findings suggest a positive answer to the first question, a negative answer to the second question, and the benefit of learning fine-grained features. Finally, we make our code publicly available

    EGFR Kinase Promotes Acquisition of Stem Cell-Like Properties: A Potential Therapeutic Target in Head and Neck Squamous Cell Carcinoma Stem Cells

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    Members of the EGFR/ErbB family of tyrosine kinases are found to be highly expressed and deregulated in many cancers, including head and neck squamous cell carcinoma (HNSCC). The ErbB family, including EGFR, has been demonstrated to play key roles in metastasis, tumorigenesis, cell proliferation, and drug resistance. Recently, these characteristics have been linked to a small subpopulation of cells classified as cancer stem cells (CSCs) which are believed to be responsible for tumor initiation and maintenance. In this study, we investigated the possible role of EGFR as a regulator of “stemness” in HNSCC cells. Activation of EGFR by the addition of EGF ligand or ectopic expression of EGFR in two established HNSCC cell lines (UMSCC-22B and HN-1) resulted in the induction of CD44, BMI-1, Oct-4, NANOG, CXCR4, and SDF-1. Activation of EGFR also resulted in increased tumorsphere formation, a characteristic ability of cancer stem cells. Conversely, treatment with the EGFR kinase inhibitor, Gefinitib (Iressa), resulted in decreased expression of the aforementioned genes, and loss of tumorsphere-forming ability. Similar trends were observed in a 99.9% CD44 positive stem cell culture derived from a fresh HNSCC tumor, confirming our findings for the cell lines. Additionally, we found that these putative cancer stem cells, when treated with Gefitinib, possessed a lower capacity to invade and became more sensitive to cisplatin-induced death in vitro. These results suggest that EGFR plays critical roles in the survival, maintenance, and function of cancer stem cells. Drugs that target EGFR, perhaps administered in combination with conventional chemotherapy, might be an effective treatment for HNSCC

    Global injury morbidity and mortality from 1990 to 2017 : results from the Global Burden of Disease Study 2017

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    Correction:Background Past research in population health trends has shown that injuries form a substantial burden of population health loss. Regular updates to injury burden assessments are critical. We report Global Burden of Disease (GBD) 2017 Study estimates on morbidity and mortality for all injuries. Methods We reviewed results for injuries from the GBD 2017 study. GBD 2017 measured injury-specific mortality and years of life lost (YLLs) using the Cause of Death Ensemble model. To measure non-fatal injuries, GBD 2017 modelled injury-specific incidence and converted this to prevalence and years lived with disability (YLDs). YLLs and YLDs were summed to calculate disability-adjusted life years (DALYs). Findings In 1990, there were 4 260 493 (4 085 700 to 4 396 138) injury deaths, which increased to 4 484 722 (4 332 010 to 4 585 554) deaths in 2017, while age-standardised mortality decreased from 1079 (1073 to 1086) to 738 (730 to 745) per 100 000. In 1990, there were 354 064 302 (95% uncertainty interval: 338 174 876 to 371 610 802) new cases of injury globally, which increased to 520 710 288 (493 430 247 to 547 988 635) new cases in 2017. During this time, age-standardised incidence decreased non-significantly from 6824 (6534 to 7147) to 6763 (6412 to 7118) per 100 000. Between 1990 and 2017, age-standardised DALYs decreased from 4947 (4655 to 5233) per 100 000 to 3267 (3058 to 3505). Interpretation Injuries are an important cause of health loss globally, though mortality has declined between 1990 and 2017. Future research in injury burden should focus on prevention in high-burden populations, improving data collection and ensuring access to medical care.Peer reviewe

    Search for new particles in events with energetic jets and large missing transverse momentum in proton-proton collisions at root s=13 TeV

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    A search is presented for new particles produced at the LHC in proton-proton collisions at root s = 13 TeV, using events with energetic jets and large missing transverse momentum. The analysis is based on a data sample corresponding to an integrated luminosity of 101 fb(-1), collected in 2017-2018 with the CMS detector. Machine learning techniques are used to define separate categories for events with narrow jets from initial-state radiation and events with large-radius jets consistent with a hadronic decay of a W or Z boson. A statistical combination is made with an earlier search based on a data sample of 36 fb(-1), collected in 2016. No significant excess of events is observed with respect to the standard model background expectation determined from control samples in data. The results are interpreted in terms of limits on the branching fraction of an invisible decay of the Higgs boson, as well as constraints on simplified models of dark matter, on first-generation scalar leptoquarks decaying to quarks and neutrinos, and on models with large extra dimensions. Several of the new limits, specifically for spin-1 dark matter mediators, pseudoscalar mediators, colored mediators, and leptoquarks, are the most restrictive to date.Peer reviewe

    Probing effective field theory operators in the associated production of top quarks with a Z boson in multilepton final states at root s=13 TeV

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    Observation of γγ → ττ in proton-proton collisions and limits on the anomalous electromagnetic moments of the τ lepton

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    The production of a pair of τ leptons via photon–photon fusion, γγ → ττ, is observed for the f irst time in proton–proton collisions, with a significance of 5.3 standard deviations. This observation is based on a data set recorded with the CMS detector at the LHC at a center-of-mass energy of 13 TeV and corresponding to an integrated luminosity of 138 fb−1. Events with a pair of τ leptons produced via photon–photon fusion are selected by requiring them to be back-to-back in the azimuthal direction and to have a minimum number of charged hadrons associated with their production vertex. The τ leptons are reconstructed in their leptonic and hadronic decay modes. The measured fiducial cross section of γγ → ττ is σfid obs = 12.4+3.8 −3.1 fb. Constraints are set on the contributions to the anomalous magnetic moment (aτ) and electric dipole moments (dτ) of the τ lepton originating from potential effects of new physics on the γττ vertex: aτ = 0.0009+0.0032 −0.0031 and |dτ| < 2.9×10−17ecm (95% confidence level), consistent with the standard model

    Search for an exotic decay of the Higgs boson to a pair of light pseudoscalars in proton-proton collisions at 13 TeV and Luminosity measurement in Pb-Pb collisions at 5.02 TeV

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    In the first part of the thesis, we report the results of a search for exotic decay of a Higgs boson with mH_{H} = 125 GeV to a pair of new light bosons, a1_{1}, where one of the light bosons decays to a pair of muons and the other to a pair of b quarks. Such signatures are predicted in a number of well-motivated extensions of the standard model, including the next-to-minimal supernumerary and generic two-Higgs-doublet models with an additional scalar singlet. A data sample corresponding to an integrated luminosity of 138 fb1^{-1} recorded with the CMS detector during 2016-2018 is exploited in μ\muμ\mubb final state where no statistically significant excess is observed with respect to the standard model backgrounds for different ma1_{a1} hypotheses above 15 GeV and below mH_{H}/2. Upper limits on BB(HHaa1aa1 → μ\muμ\mubb) are obtained to be (0.17 − 3.3) × 104^{−4} depending on the ma1_{a1} values. The second part of the thesis includes a study of luminosity measurement using lead-lead (PbPb) collisions at 5.02 TeV in 2015

    Bovine subclinical mastitis-associated methicillin-resistant Staphylococcus aureus, selective genotyping and antimicrobial susceptibility profile of the isolates in Kurdistan province of Iran

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    Background and Objectives: Staphylococcus aureus is frequently involved in bovine subclinical mastitis worldwide. Besides, the methicillin-resistant S. aureus (MRSA) carrier state of animals is a matter of worrisome. This study aimed to evaluate the frequency of MRSA, discriminatory geno-analysis and antibiotic resistance scheme of the strains isolated from bovine subclinical mastitis in Kurdistan province of Iran.&#x0D; Materials and Methods: A total of 283 samples were collected and analyzed for S. aureus phenotypically and molecularly. SCCmec and coa types, and pvl gene were evaluated using polymerase chain reaction (PCR). Finally, the restriction fragment length polymorphism (RFLP) patterns of coa types and the antimicrobial susceptibility profile of the isolates were assessed.&#x0D; Results: Among the 95 isolates of S. aureus, 11 (11.57%) strains were recognized as MRSA. Six, one, and four SCCmec types represented for IVa, IVc, and V were determined, respectively, among which an individual IVa and V determinant harboured pvl gene. Restriction digestion products of 490 bp, 680 bp, and 730 bp of coa bands were generated. Tobramycin, mupirocin, fusidic acid, clindamycin, and chloramphenicol were the most effective drugs against the MRSA isolates.&#x0D; Conclusion: The detrimental involvement of S. aureus in bovine subclinical mastitis is proved herein. Besides, the contribution of MRSA and potential contamination of milk and dairy products with the bacterium may impose a serious public health risk. This demands serious and long-lasting efforts to control the infection. The results may be effective in the implementation of accurate controlling strategies.</jats:p
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