60 research outputs found

    Ability of the National Surgical Quality Improvement Program Risk Calculator to Predict Complications Following Total Laryngectomy

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    Importance The accuracy of the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) risk calculator has been assessed in multiple surgical subspecialties; however, there have been no publications doing the same in the head and neck surgery literature. Objective To evaluate the accuracy of the calculator’s predictions in a single institution’s total laryngectomy (TL) population. Design, Setting, and Participants Total laryngectomies performed between 2013 and 2014 at a tertiary referral academic center were evaluated using the risk calculator. Predicted 30-day outcomes were compared with observed outcomes for return to operating room, surgical site infection, postoperative pneumonia, length of stay, and venous thromboembolism. Main Outcomes and Measures Comparison of the NSQIP risk calculator’s predicted postoperative complication rates and length of stay to what occurred in this patient cohort using percent error, Brier scores, area under the receiver operating characteristic curve, and Pearson correlation analysis. Results Of 49 patients undergoing TL, the mean (SD) age at operation was 59 (9.3) years, with 67% male. The risk calculator had limited efficacy predicting perioperative complications in this group of patients undergoing TL with or without free tissue reconstruction or preoperative chemoradiation or radiation therapy with a few exceptions. The calculator overestimated the occurrence of pneumonia by 165%, but underestimated surgical site infection by 7%, return to operating room by 24%, and length of stay by 13%. The calculator had good sensitivity and specificity of predicting surgical site infection for patients undergoing TL with free flap reconstruction (area under the curve, 0.83). For all other subgroups, however, the calculator had poor sensitivity and specificity for predicting complications. Conclusions and Relevance The risk calculator has limited utility for predicting perioperative complications in patients undergoing TL. This is likely due to the complexity of the treatment of patients with head and neck cancer and factors not taken into account when calculating a patient’s risk

    Opportunistic Detection of Type 2 Diabetes Using Deep Learning From Frontal Chest Radiographs

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    Deep learning (DL) models can harness electronic health records (EHRs) to predict diseases and extract radiologic findings for diagnosis. With ambulatory chest radiographs (CXRs) frequently ordered, we investigated detecting type 2 diabetes (T2D) by combining radiographic and EHR data using a DL model. Our model, developed from 271,065 CXRs and 160,244 patients, was tested on a prospective dataset of 9,943 CXRs. Here we show the model effectively detected T2D with a ROC AUC of 0.84 and a 16% prevalence. The algorithm flagged 1,381 cases (14%) as suspicious for T2D. External validation at a distinct institution yielded a ROC AUC of 0.77, with 5% of patients subsequently diagnosed with T2D. Explainable AI techniques revealed correlations between specific adiposity measures and high predictivity, suggesting CXRs\u27 potential for enhanced T2D screening

    Linearized esculentin-2EM shows pH dependent antibacterial activity with an alkaline optimum

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    Here the hypothesis that linearized esculentin 2EM (E2EM-lin) from Glandirana emeljanovi possesses pH dependent activity is investigated. The peptide showed weak activity against Gram-negative bacteria (MLCs ≥ 75.0 μM) but potent efficacy towards Gram-positive bacteria (MLCs ≤ 6.25 μM). E2EM-lin adopted an α-helical structure in the presence of bacterial membranes that increased as pH was increased from 6 to 8 (↑ 15.5 to 26.9 %), while similar increases in pH enhanced the ability of the peptide to penetrate (↑ 2.3 to 5.1 mN m-1) and lyse (↑ 15.1 to 32.5%) these membranes. Theoretical analysis predicted that this membranolytic mechanism involved a tilted segment, that increased along the α-helical long axis of E2EM-lin (1-23) in the N → C direction, with - increasing overall from circa - 0.8 to - 0.3. In combination, these data showed that E2EM-lin killed bacteria via novel mechanisms that were enhanced by alkaline conditions and involved the formation of tilted and membranolytic, α-helical structure. The preference of E2EM-lin for Gram-positive bacteria over Gram-negative organisms was primarily driven by the superior ability of phosphatidylglycerol to induce α-helical structure in the peptide as compared to phosphatidylethanolamine. These data were used to generate a novel pore-forming model for the membranolytic activity of E2EM-lin, which would appear to be the first, major reported instance of pH dependent AMPs with alkaline optima using tilted structure to drive a pore-forming process. It is proposed that E2EM-lin has the potential for development to serve purposes ranging from therapeutic usage, such as chronic wound disinfection, to food preservation by killing food spoilage organisms

    Mechanisms underlying the autonomic modulation of ventricular fibrillation initiation—tentative prophylactic properties of vagus nerve stimulation on malignant arrhythmias in heart failure

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    Fabry-Perot interferometer using curved plates

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    Fabry-Perot interferometer with curved plates is described. It is found that the partially reflecting surfaces of the Fabry-Perot interferometer need not be necessarily flat. The pair of Fabry-Perot plates may be curved but the surfaces must be well matched with an accuracy better than λ/100

    Non-destructive thickness measurement of dichromated gelatin films deposited on glass plates

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    A quick estimation of the thickness of thin films deposited on glass plates is described in this paper. The principle of the method is based on the measurement of the Haidinger fringes generated by the film. For ease of observation and measurement, a commercial Fizeau-type interferometer such as a Zygo interferometer using a large angle of illumination has been used. The simple modification to observe the Haidinger fringes with the Fizeau-type interferometer is also described. The thickness of the film is related to the diameters of the Haidinger fringes. It is possible to estimate the thickness quickly by counting the number of fringes. A more accurate estimate can be obtained by the measurement of the diameters of the fringes and using these data in a formula that relates these two to the thickness of the film. The method is found to be useful for measuring the thickness of dichromated gelatin films (DCG) coated on a substrate to make holographic optical elements. The accuracy in estimating the thickness of the film is of the order ±1 μm. The method is entirely non-destructive and works well in the thickness range of 5-150μm

    Design and fabrication of a variable frequency grating and its application as a lateral-shear interferometer having a variable shear

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    The design and fabrication of holographic gratings of frequency variable from 50 to 750 lines/mm over length of 75 mm have been described. An application of these variable frequency gratings as a lateral-shear interferometer has also been suggested. The variable shear interferometer is found to be useful for testing of lenses with a maximum sensitivity in the detection of wavefront aberrations. Comparison of single-frequency grating having uniform pitch of 100 lines/mm with a grating of frequency variable from 59 to 220 lines/mm using an average pitch of 100 lines/mm over a small area as a lateral-shear interferometer have been made. Our experimental observations show that a small area of average pitch of 100 lines/mm on the grating having a variable frequency of 59-220 lines/mm over a distance of 75 mm behaves as a lateral-shear interferometer in the same way as any area of pitch of 100 lines/mm on the grating of uniform pitch of 100 lines/mm

    Proliferative Activity and Aneuploidy in Pleomorphic Adenomas of the Salivary Glands

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    We used flow cytometry in a retrospective study of pleomorphic adenoma and carcinoma arising in pleomorphic adenoma, using paraffin-embedded tissue, to assess the relationship among proliferative activity, ploidy, and recurrence or malignant transformation. Twenty-four specimens obtained from 22 tumors were acceptable for analysis (co-efficient of variation, \u3c or = 7.0), including multiple samples from two tumors. Fourteen tumors (13 benign and one malignant) were diploid. Six tumors were aneuploid: four benign pleomorphic adenomas and two carcinomas arising in pleomorphic adenoma. Two tetraploid tumors were malignant recurrences from the same patient. Of the recurrent tumors (nine benign and four malignant), 54% were aneuploid. The highest S-phase fractions were observed in recurrent and malignant pleomorphic adenomas. Immunostaining with p105, a nuclear proliferation antigen, revealed increased proliferative activity in a majority of pleomorphic adenomas. Increased proliferative activity and aneuploidy occurred in benign pleomorphic adenomas

    Wedge-plate shearing interferometers for collimation testing: use of a moire technique

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    Various optical arrangements of a double-wedge-plate shearing interferometer are presented for checking laser beam collimation. The use of moire fringes is found to be advantageous for setting the shear fringes parallel to the direction of shear in order to obtain a well-collimated laser beam. The experimental procedure and various details of the interferometer are discussed. A brief summary of a few methods for collimation testing that use a wedge plate is also given. The accuracies achievable with shearing interferometers that use a parallel plate, a wedge plate of small angle, a double wedge having a large wedge angle, a wedge plate of large angle along with two flat mirrors, and a wedge plate having a large angle are compared and summarized
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