306 research outputs found

    Autofluorescence lifetime augmented reality as a means for real-time robotic surgery guidance in human patients.

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    Due to loss of tactile feedback the assessment of tumor margins during robotic surgery is based only on visual inspection, which is neither significantly sensitive nor specific. Here we demonstrate time-resolved fluorescence spectroscopy (TRFS) as a novel technique to complement the visual inspection of oral cancers during transoral robotic surgery (TORS) in real-time and without the need for exogenous contrast agents. TRFS enables identification of cancerous tissue by its distinct autofluorescence signature that is associated with the alteration of tissue structure and biochemical profile. A prototype TRFS instrument was integrated synergistically with the da Vinci Surgical robot and the combined system was validated in swine and human patients. Label-free and real-time assessment and visualization of tissue biochemical features during robotic surgery procedure, as demonstrated here, not only has the potential to improve the intraoperative decision making during TORS but also other robotic procedures without modification of conventional clinical protocols

    Just noticeable differences for pitch direction, height, and slope for Mandarin and English listeners

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    Previous studies on tones suggest that Mandarin listeners are more sensitive to pitch direction and slope while English listeners primarily attend to pitch height. In this study, just noticeable differences were established for pitch discrimination using a three-interval, forced-choice procedure with a two-down, one-up staircase design. A high rising and a high falling Mandarin tone were manipulated in terms of pitch direction, height, and slope. Results indicate that, overall, Mandarin listeners are more sensitive to pitch slope and English listeners to pitch height. However, these effects are modulated by both the direction (falling/rising) and slope of the pitch contours

    Training American listeners to perceive Mandarin tones

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    This is the publisher's version, also available electronically from http://scitation.aip.org/content/asa/journal/jasa/106/6/10.1121/1.428217.Auditory training has been shown to be effective in the identification of non-native segmental distinctions. In this study, it was investigated whether such training is applicable to the acquisition of non-native suprasegmentalcontrasts, i.e., Mandarin tones. Using the high-variability paradigm, eight American learners of Mandarin were trained in eight sessions during the course of two weeks to identify the four tones in natural words produced by native Mandarin talkers. The trainees’ identification accuracy revealed an average 21% increase from the pretest to the post-test, and the improvement gained in training was generalized to new stimuli (18% increase) and to new talkers and stimuli (25% increase). Moreover, the six-month retention test showed that the improvement was retained long after training by an average 21% increase from the pretest. The results are discussed in terms of non-native suprasegmental perceptual modification, and the analogies between L2 acquisition processes at the segmental and suprasegmental levels

    Transition-state vibrational analysis and isotope effects for COMT-catalyzed methyl transfer

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    Isotopic partition-function ratios (IPFRs) computed for transition structures (TSs) of the methyl-transfer reaction catalyzed by catechol O-methyltransferase and modeled by hybrid QM/MM methods are analyzed. The ability of smaller Hessians to reproduce trends in α-3H3 and 14Cα IPFRs as obtained using the much larger subset QM/MM Hessians from which they are extracted is investigated critically. A 6-atom-extracted Hessian reproduces perfectly the α-T3 IPFR values from the full-subset Hessians of all the TSs but not the α-14CIPFRs. Average AM1/OPLS-AA harmonic frequencies and mean-square amplitudes are presented for the 12 normal modes of the α-CH3 moiety within the active site of several enzymic transition structures, together with QM/MM potential energy scans along each of these modes to assess the degree of anharmonicity. A novel investigation of ponderal effects upon IPFRs suggests that the value for α-14C tends toward a limiting minimum whereas that for α-T3 tends toward a limiting maximum as the mass of the rest of the system increases. The transition vector is dominated by motions of atoms within the donor and acceptor moieties and is very well described as a simple combination of Walden-inversion “umbrella” bending and asymmetric stretching of the SCα and CαO bonds. The contribution of atoms of the protein residues Met40, Tyr68, and Asp141 to the transition vector is extremely small. Average valence force constants for the COMT TS show significant differences from early BEBOVIB estimates which were used in support of the compression hypothesis for catalysis. There is no correlation between TS IPFRs and the nonbonded distances for close contacts between the S atom of SAM and Tyr68 or between any of the H atoms of the transferring methyl group and either Met40 or Asp141

    Deep Functional and Molecular Characterization of a High-Risk Undifferentiated Pleomorphic Sarcoma.

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    Nonrhabdomyosarcoma soft-tissue sarcomas (STSs) are a class of 50+ cancers arising in muscle and soft tissues of children, adolescents, and adults. Rarity of each subtype often precludes subtype-specific preclinical research, leaving many STS patients with limited treatment options should frontline therapy be insufficient. When clinical options are exhausted, personalized therapy assignment approaches may help direct patient care. Here, we report the results of an adult female STS patient with relapsed undifferentiated pleomorphic sarcoma (UPS) who self-drove exploration of a wide array of personalized Clinical Laboratory Improvement Amendments (CLIAs) level and research-level diagnostics, including state of the art genomic, proteomic

    Expression of interleukin 6 (IL-6) correlates with oestrogen receptor in human breast carcinoma

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    Multifunctional cytokines play important and only partially defined roles in mammary tumour development and progression. Normal human mammary epithelial cells constitutively produce interleukin 6 (IL-6), IL-8 and a non-secreted form of tumour necrosis factor. Transformation of mammary epithelial cells by different oncogenes is frequently associated with alterations of cytokine/growth factor production and responsiveness. In the present study we analysed the expression of IL-6 in 149 cases of invasive breast carcinoma and the data have been correlated with clinico-pathological variables including tumour size, histological grade, nodal status, and oestrogen and progesterone receptors, Ki67 and p53, protein expression. Though the majority of breast carcinomas expressed at least low levels of immunoreactive IL-6, we found that expression of this cytokine was inversely associated with histological tumour grade (P = 0.0017), but not with tumour size and nodal status. Ki67 positivity was inversely correlated with IL-6 expression (P = 0.027). Among biological parameters analysed, a direct association was found between the percentage of IL-6-positive cells and that of oestrogen (P = 0.00005) and progesterone (P = 0.025) receptor-positive cells. No correlation was observed between IL-6 and p53 protein expression. These data indicate that down regulation of IL-6 is associated with highly malignant mammary carcinomas. It will be of interest to evaluate whether alterations of cytokines that are constitutively produced by mammary cells are also associated with high-grade tumours

    Effect of intonation on Cantonese lexical tones

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    In tonal languages, there are potential conflicts between the F0-based changes due to the coexistence of intonation and lexical tones. In the present study, the interaction of tone and intonation in Cantonese was examined using acoustic and perceptual analyses. The acoustic patterns of tones at the initial, medial, and final positions of questions and statements were measured. Results showed that intonation affects both the F0 level and contour, while the duration of the six tones varied as a function of positions within intonation contexts. All six tones at the final position of questions showed rising F0 contour, regardless of their canonical form. Listeners were overall more accurate in the identification of tones presented within the original carrier than of the same tones in isolation. However, a large proportion of tones 33, 21, 23, and 22 at the final position of questions were misperceived as tone 25 both within the original carrier and as isolated words. These results suggest that although the intonation context provided cues for correct tone identification, the intonation-induced changes in F0 contour cannot always be perceptually compensated for, resulting in some erroneous perception of the identity of Cantonese tone. © 2006 Acoustical Society of America.published_or_final_versio

    Lack of correlation between Ki-67 labelling index and tumor size of anterior pituitary adenomas

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    AIMS AND BACKGROUND: The Ki-67 is a nuclear antigen detected by the monoclonal antibody MIB-1 and its Labeling Index (LI) is considered a marker of normal and abnormal cell proliferation. Pituitary adenomas are generally well differentiated neoplasms, even if in about one third of cases they are invasive of surrounding tissues. The aim of this study is to evaluate the correlation between Ki-67 labelling index and tumor size of pituitary adenomas extimated by means CT and MRI and confirmed at operation. METHODS: Using the monoclonal antibody MIB-1, we evaluated the expression of Ki-67 in 121 anterior pituitary adenomas consecutively operated on in a 48-month period. RESULTS: In relation to neuroradiological (CT and MRI) and surgically verified tumor size, we identified 24 microadenomas, 27 intrasellar macroadenomas, 34 intra-suprasellar macroadenomas, and 36 intra-supra-parasellar macroadenomas. The adenomas were non-infiltrating (76 cases) and infiltrating (45 cases) adenomas. The wall of the cavernous sinus (CS) was infiltrated in 18 cases. Forty-eight adenomas were non-functioning and 73 functioning. The overall mean ± SD Ki-67 LI was 2.72 ± 2.49% (median 1.6). It was 2.59 ± 1.81 in microadenomas, 2.63 ± 3.45 in intrasellar macroadenomas, 1.91 ± 2.11 in intra-suprasellar macroadenomas, and 3.29 ± 5.45 in intra-supra-parasellar macroadenomas (p = 0.27). It was 3.73 ± 5.13% in infiltrating and 2.03 ± 2.41% in non-infiltrating adenomas (p = 0.02), and 5.61 ± 7.19% in CS-infiltrating versus 2.09 ± 2.37% in CS-non-infiltrating adenomas (p = 0.0005). CONCLUSIONS: Our preliminary results seem to exclude significative correlations between Ki-67 LI and tumor size of anterior pituitary adenomas, even if this index can be considered a useful marker in the determination of the infiltrative behaviour of these tumors
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