284 research outputs found

    Pentagon-Match (PMatch): Identification of View-Invariant Planar Feature for Local Feature Matching-Based Homography Estimation

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    In computer vision, finding correct point correspondence among images plays an important role in many applications, such as image stitching, image retrieval, visual localization, etc. Most of the research works focus on the matching of local feature before a sampling method is employed, such as RANSAC, to verify initial matching results via repeated fitting of certain global transformation among the images. However, incorrect matches may still exist. Thus, a novel sampling scheme, Pentagon-Match (PMatch), is proposed in this work to verify the correctness of initially matched keypoints using pentagons randomly sampled from them. By ensuring shape and location of these pentagons are view-invariant with various evaluations of cross-ratio (CR), incorrect matches of keypoint can be identified easily with homography estimated from correctly matched pentagons. Experimental results show that highly accurate estimation of homography can be obtained efficiently for planar scenes of the HPatches dataset, based on keypoint matching results provided by LoFTR. Besides, accurate outlier identification for the above matching results and possible extension of the approach for multi-plane situation are also demonstrated.Comment: arXiv admin note: text overlap with arXiv:2211.0300

    A Geometrically Constrained Point Matching based on View-invariant Cross-ratios, and Homography

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    In computer vision, finding point correspondence among images plays an important role in many applications, such as image stitching, image retrieval, visual localization, etc. Most of the research worksfocus on the matching of local feature before a sampling method is employed, such as RANSAC, to verify initial matching results via repeated fitting of certain global transformation among the images. However, incorrect matches may still exist, while careful examination of such problems is often skipped. Accordingly, a geometrically constrained algorithm is proposed in this work to verify the correctness of initially matched SIFT keypoints based on view-invariant cross-ratios (CRs). By randomly forming pentagons from these keypoints and matching their shape and location among images with CRs, robust planar region estimation can be achieved efficiently for the above verification, while correct and incorrect matches of keypoints can be examined easily with respect to those shape and location matched pentagons. Experimental results show that satisfactory results can be obtained for various scenes with single as well as multiple planar regions

    Shape Representation Using a Generalized Potential Field Model

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    Abstract-This paper is concerned with efficient derivation of the medial axis transform of a two-dimensional polygonal region. Instead of using the shortest distance to the region border, a potential field model is used for computational efficiency. The region border is assumed to be charged and the valleys of the resulting potential field are used to estimate the axes for the medial axis transform. The potential valleys are found by following force field, thus, avoiding twodimensional search. The potential field is computed in closed form using the equations of the border segments. The simple Newtonian potential is shown to be inadequate for this purpose. A higher order potential is defined which decays faster with distance than as inverse of distance. It is shown that as the potential order becomes arbitrarily large, the axes approach those computed using the shortest distance to the border. Algorithms are given for the computation of axes, which can run in linear parallel time for part of the axes having initial guesses. Experimental results are presented for a number of examples

    Investigating the maxillary buccal vestibule

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    AbstractBackground/purposeImproper assessment of the maxillary buccal vestibular space can contribute to the fabrication of maxillary dentures with inadequate buccal flange extensions. The purpose of this study was to determine whether a significant difference existed between the anatomic dimensions of the buccal vestibules and the corresponding buccal flanges of maxillary complete dentures in an edentulous population.Materials and methodsThe anterior, middle, and posterior depth and width of the maxillary buccal vestibules in 100 randomly selected subjects were measured with a periodontal probe. Corresponding measurements of the buccal flanges of the subjects' existing dentures were recorded. The differences between buccal vestibule widths and depths and denture flange widths and lengths were statistically compared according to site.ResultsThe difference in the mean depth between the vestibules and the flanges in the posterior area (6.4 mm and 10.3 mm, respectively) was approximately 38% (P < 0.001). The difference in the mean width between the vestibules and the flanges in the posterior area (3.3 mm and 7.9 mm, respectively) was approximately 58% (P < 0.001).ConclusionThe study revealed statistically significant differences between the anatomic depth and width of the buccal vestibules and the corresponding flange dimensions of the existing dentures

    Impact of ovarian preservation in women with endometrial cancer

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    AbstractBackgroundBilateral salpingo-oophorectomy (BSO) is standardly performed in the treatment of endometrial cancer. The purpose of this study was to evaluate the impact of ovarian preservation on the outcome of patients with endometrial cancer.MethodsA retrospective cohort study was performed using the 2000–2010 database of endometrial cancer patients who were treated at Taipei Veterans General Hospital. Information regarding patient age, pathologic reports, and follow-up results was abstracted from medical records.ResultsFive hundred and twenty-nine patients were reviewed in this study. Mean age and follow-up duration were 55.7 ± 11.4 years and 37.5 ± 30.1 months, respectively. The median disease-free survival was 31.2 months (range 0.2–126.9 months). There were no significant differences in disease-free survival between stage I patients with ovarian preservation versus those with oophorectomy (p = 0.473). In a multivariate Cox model, ovarian preservation had no effect on disease-free survival [hazard ratio (HR) = 2.72; 95% confidence interval (CI), 0.48–15.59]; however, it was not significantly related to stage and para-aortic lymph node involvement.ConclusionOvarian preservation may be considered in premenopausal women with early-stage low-risk endometrial cancer

    Inhibition of FAK Signaling Elicits Lamin A/C-Associated Nuclear Deformity and Cellular Senescence

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    Focal adhesion kinase (FAK) is a non-receptor kinase that facilitates tumor aggressiveness. The effects of FAK inhibition include arresting proliferation, limiting metastasis, and inhibiting angiogenesis. PF-573228 is an ATP-competitive inhibitor of FAK. Treating lung cancer cells with PF-573228 resulted in FAK inactivation and changes in the expressions of lamin A/C and nuclear deformity. Since lamin A/C downregulation or deficiency was associated with cellular senescence, the senescence-associated β-galactosidase (SA-β-gal) assay was used to investigate whether PF-573228 treatment drove cellular senescence, which showed more SA-β-gal-positive cells in culture. p53 is known to play a pivotal role in mediating the progression of cellular senescence, and the PF-573228-treated lung cancer cells resulted in a higher p53 expression level. Subsequently, the FAK depletion in lung cancer cells was employed to confirm the role of FAK inhibition on cellular senescence. FAK depletion and pharmacological inhibition of lung cancer cells elicited similar patterns of cellular senescence, lamin A/C downregulation, and p53 upregulation, implying that FAK signaling is associated with the expression of p53 and the maintenance of lamin A/C levels to shape regular nuclear morphology and manage anti-senescence. Conversely, FAK inactivation led to p53 upregulation, disorganization of the nuclear matrix, and consequently cellular senescence. Our data suggest a new FAK signaling pathway, in that abolishing FAK signaling can activate the senescence program in cells. Triggering cellular senescence could be a new therapeutic approach to limit tumor growth

    Antimicrobial Activity of Lactobacillus Species Against Carbapenem-Resistant Enterobacteriaceae

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    ObjectiveThis study aims to identify suitable lactobacilli that have anti-carbapenem-resistant Enterobacteriaceae (CRE) activity with in vitro tolerance to pepsin and bile salts.MethodsFifty-seven Lactobacillus spp. strains encompassing nine species were collected for investigation. Their viabilities in the presence of pepsin and bile salts were tested using tolerance tests. Their anti-CRE effects were assessed by agar well diffusion and broth microdilution assay, as well as time-kill test.ResultsOf the 57 Lactobacillus isolates collected, 31 had a less than 2-log reduction in their viability in both pepsin and bile salt tolerance tests. Of these 31 isolates, 5 (LUC0180, LUC0219, LYC0289, LYC0413, and LYC1031) displayed the greatest anti-CRE activity with a CRE zone of inhibition greater than 15 mm in agar well diffusion assays. The minimal inhibitory percentages of supernatants from these five strains against CREs ranged from 10 to 30%. With the exception of LUC0180, which had a minimal bactericidal percentage ≥ 40%, the bactericidal percentage of all the strains ranged from 20 to 40%. The inhibitory effect of the cell-free culture supernatants from these Lactobacillus strains did not change after heating but was abolished as the pH changed to 7.0. After a 24-h incubation, five of the Lactobacillus strains at a concentration of 108 CFU/ml totally inhibited the growth of carbapenem-resistant Escherichia coli (CRE316) and Klebsiella pneumoniae (CRE632). After a 48-h incubation, the growth of CRE316 was completely inhibited under each concentration of lactobacilli based on time-kill test. Furthermore, when the concentration of lactobacilli was at 108 CFU/ml, the decline in pH was faster than at other concentrations.ConclusionSome Lactobacillus strains exhibit anti-CRE activity, which suggests potential applications for controlling or preventing CRE colonization or infection

    High levels of serum macrophage migration inhibitory factor and interleukin 10 are associated with a rapidly fatal outcome in patients with severe sepsis

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    SummaryObjectivesThe aim of this study was to delineate the association between high macrophage migration inhibitory factor (MIF) and interleukin 10 (IL-10) levels in the early phase of sepsis and rapidly fatal outcome.MethodsOne hundred and fifty-three adult subjects with the main diagnosis of severe sepsis (including septic shock) admitted directly from the emergency department of two tertiary medical centers and one regional teaching hospital between January 2009 and December 2011, were included prospectively. MIF and IL-10 levels were measured and outcomes were analyzed by Cox regression analysis according to the following outcomes: rapidly fatal outcome (RFO, death within 48h), late fatal outcome (LFO, death between 48h and 28 days), and survival at 28 days.ResultsAmong the three outcome groups, IL-10 levels were significantly higher in the RFO group (p < 0.001) and no significant differences were seen between the LFO and survivor groups. After Cox regression analysis, each incremental elevation of 1000 pg/ml in both IL-10 and MIF was independently associated with RFO in patients with severe sepsis. Each incremental elevation of 1000 pg/ml in IL-10 increased the RFO risk by a factor of 1.312 (95% confidence interval 1.094–1.575; p=0.003); this was the most significant factor leading to RFO in patients with severe sepsis.ConclusionsPatients with RFO exhibited simultaneously high MIF and IL-10 levels in the early phase of severe sepsis. Incremental increases in both IL-10 and MIF levels were associated with RFO in this patient group, and of the two, IL-10 was the most significant factor linked to RFO

    Comparison of single-incision mini-slings (Ajust) and standard transobturator midurethral slings (Align) in the management of female stress urinary incontinence: A 1-year follow-up

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    AbstractObjectiveTo investigate the effectiveness and safety of a new single-incision mini-sling (SIMS)—Ajust—compared with the standard transobturator midurethral sling (SMUS)—Align—for the treatment of female stress urinary incontinence (SUI).Materials and MethodsA retrospective cohort study was conducted between January 1, 2010 and August 31, 2012. Women with SUI who underwent either SMUS-Align or SIMS-Ajust were recruited. The primary outcomes included operation time, estimated operative blood loss, postoperative pain, and complications. The secondary outcomes included subjective and objective success, defined as an International Consultation on Incontinence Questionnaire (ICIQ) score of 0 or improvement as felt by the patient and a long-term complication, such as dyspareunia and mesh erosion after 6 months and 12 months of follow-up.ResultsA total of 136 patients were enrolled, including 76 receiving SMUS-Align and 60 receiving SIMS-Ajust. Baseline characteristics of the patients in both groups were similar, without a statistically significant difference. Primary outcomes between both groups were similar, except that women treated with SIMS-Ajust had statistically significantly shorter operation time (p = 0.003), less intent to treat (p < 0.05), and earlier postoperative discharge (p = 0.001) than women treated with SMUS-Align. Secondary outcomes were similar without a significant difference between the two groups (93% vs. 88% success rate in each group).ConclusionOur results showed that SIMS-Ajust was not inferior to SMUS-Align with respect to success rate, and might have a slight advantage in early discharge. A long-term follow-up or prospective study is needed to confirm the above findings
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