1,206 research outputs found
Narrow Band Imaging and High Definition Television in endoscopic evaluation of upper aero-digestive tract cancer.
Narrow band imaging and high definition television are recent innovations in upper aero-digestive tract endoscopy. Aim of this prospective,
non-randomized, unblinded study was to establish the diagnostic advantage of these procedures in the evaluation of squamous cell cancer
arising from various upper aero-digestive tract sites. Between April 2007 and January 2010, 444 patients affected by upper aero-digestive
tract squamous cell cancer, or previously treated for it, were evaluated by white light and narrow band imaging ± high definition television
endoscopy, both in the pre-/intra-operative setting and during follow-up. Tumour resection was performed taking into account narrow band
imaging and high definition television information to obtain histopathologic confirmation of their validity. Endoscopic and pathologic data
were subsequently matched to obtain sensitivity, specificity, positive, negative predictive values, and accuracy. Overall, 110 (25%) patients
showed adjunctive findings by narrow band imaging ± high definition television when compared to standard white light endoscopy. Of
these patients, 98 (89%) received histopatological confirmation. The sensitivity, specificity, positive, negative predictive values, and accuracy
for white light-high definition television were 41%, 92%, 87%, 82%, and 67%, for narrow band imaging alone 75%, 87%, 87%,
74%, and 80%, and for narrow band imaging-high definition television 97%, 84%, 88%, 96%, and 92%. The highest diagnostic gain was
observed in the oral cavity and oropharynx (25%). Narrow band imaging and high definition television were of value in the definition of
superficial tumour extension, and in the detection of synchronous lesions in the pre-/intra-operative settings. These technologies also played
an important role during post-treatment surveillance for early detection of persistences, recurrences, and metachronous tumours
Quantitative analysis of videokymography in normal and pathological vocal folds: a preliminari study.
Videokymography (VKG) captures high-speed
images of the vocal folds independently of the periodicity
of the acoustic signal. The aim of this study was to preliminarily
assess a software package that can objectively
measure specific parameters of vocal fold vibration. From
August 2009 until December 2010, we prospectively
evaluated 40 subjects (Group A, 18 normal subjects;
Group B, 14 patients with benign lesions of the middle
third of the vocal fold, such as polyps and cysts; Group C, 8
patients treated by endoscopic excision of vocal fold
benign lesions) by videoendoscopy, videolaryngostroboscopy,
and VKG. A VKG camera was coupled to a 70
telescope and video was recorded during phonation. Images
were objectively analyzed by a post-processing software
tool (VKG-Analyser) with a user-friendly interface
developed by our group. Different parameters were considered,
including the ratio between the amplitude of the
vibration of one vocal fold with respect to the contralateral
(Ramp), the ratio between the period of one vocal fold
vibration and the opposite one (Rper), and the ratio between
the duration of the open and closed phase within a glottal
cycle (Roc). Mean values for Ramp, Rper, and Roc in Group A
were 1.05, 1.04, and 1.35, respectively; in Group B were
1.63, 0.92, and 0.97, respectively; and in Group C were
1.13, 0.91, and 1.85, respectively. Quantitative analysis of
videokymograms by the herein presented tool, named VKG-Analyser, is useful for objective evaluation of the
vibratory pattern in normal and pathologic vocal folds.
Important future developments of this tool for the study of
both physiologic and pathologic patterns of vocal fold
vibration can be expected
Narrow Band Imaging and High Definition Television in the endoscopic evaluation of upper aero-digestive tract cancer
Narrow band imaging and high definition television are recent innovations in upper aero-digestive tract endoscopy. Aim of this prospective,
non-randomized, unblinded study was to establish the diagnostic advantage of these procedures in the evaluation of squamous cell cancer
arising from various upper aero-digestive tract sites. Between April 2007 and January 2010, 444 patients affected by upper aero-digestive
tract squamous cell cancer, or previously treated for it, were evaluated by white light and narrow band imaging ± high definition television
endoscopy, both in the pre-/intra-operative setting and during follow-up. Tumour resection was performed taking into account narrow band
imaging and high definition television information to obtain histopathologic confirmation of their validity. Endoscopic and pathologic data
were subsequently matched to obtain sensitivity, specificity, positive, negative predictive values, and accuracy. Overall, 110 (25%) patients
showed adjunctive findings by narrow band imaging ± high definition television when compared to standard white light endoscopy. Of
these patients, 98 (89%) received histopatological confirmation. The sensitivity, specificity, positive, negative predictive values, and accuracy
for white light-high definition television were 41%, 92%, 87%, 82%, and 67%, for narrow band imaging alone 75%, 87%, 87%,
74%, and 80%, and for narrow band imaging-high definition television 97%, 84%, 88%, 96%, and 92%. The highest diagnostic gain was
observed in the oral cavity and oropharynx (25%). Narrow band imaging and high definition television were of value in the definition of
superficial tumour extension, and in the detection of synchronous lesions in the pre-/intra-operative settings. These technologies also played
an important role during post-treatment surveillance for early detection of persistences, recurrences, and metachronous tumours
A systematic study of spin-dependent recombination in GaAsN as a function of nitrogen content
A systematic study of spin-dependent recombination (SDR) under steady-state
optical pumping conditions in dilute nitride semiconductors as a function of
nitrogen content is reported. The alloy content is determined by a fit of the
photoluminescence (PL) intensity using a Roosbroeck-Shockley relation and
verified by a study of the GaN-like LO phonon peak in a Raman spectroscopy
map. PL spectra taken from alloys of the form GaAsN where exhibit PL intensity increases when switching from a linearly- to a
circularly-polarized pump up to a factor of 5 for . This work used a
1.39 eV laser with a radius of 0.6 m. The observed SDR ratio monotonically
decreases with increasing , reaching 1.5 for . Moreover, the
excitation power required to obtain maximum SDR systematically increases with
increasing , varying from 0.6 mW for to 15 mW for .
These observations are consistent with an increase in the density of
electronically active defects with increasing nitrogen content, both those
responsible for the SDR as well as other, standard Shockley-Read-Hall (SRH)
centers.Comment: 11 pages, 5 figures; work presented at the International Conference
on the Physics of Semiconductors, Sydney, 202
Influences of dietary supplementation with Lepidium meyenii (Maca) on stallion sperm production and on preservation of sperm quality during storage at 5 °C.
Stallion semen is damaged by oxidative stress during cooling and transport. Semen processing and extenders have been tested to improve the fertilizing capacity of semen and to preserve semen during transport. Dietary supplementation with natural antioxidants has been proposed to prevent oxidative damages. In this study, for the first time, the effect of dietary supplementation with Lepidium meyenii (Maca) on the characteristics of fresh and chilled stallion semen was evaluated. Maca is a traditional Andean crop used as a nutraceutical for the fertility-enhancing properties that are linked with antioxidant activity. The diet of five stallions was supplemented with 20 g of Maca powder daily for a total of 60 days. A control group of five stallions received the same diet without Maca. Semen was collected once before the administration of Maca (D0), twice during the administration at 30 and 60 days (D30 and D60), and finally twice at 30 and 60 days after the end of the administration (D90 and D120). Ejaculates were processed for cooled shipping at 5 °C and evaluated in the laboratory for total and progressive motility, acrosome integrity, and lipid peroxidation after collection and after 24, 48, and 72 h of storage. Dietary supplementation with Maca improved sperm concentration (from 213 ± 80.4 to 447 ± 73.1 × 106 spz/mL) and total sperm count (from 10,880 ± 4377 to 24,783 ± 4419 × 106 spz). The beneficial effects of Maca supplementation on motility and acrosome integrity in the raw semen were detected from the end of treatment with Maca (D60) until the end of the study (D120). Furthermore, during cooling storage, total motility, progressive motility, and acrosome integrity declined more slowly in the Maca-treated group than in the control group. Lipid peroxidation did not change during cooling storage in either group and did not show a significant difference between the two groups. In this study, the dietary supplementation with Maca increased sperm production and stabilized semen quality during chilled storage
Ni/HZSM-5 catalyst preparation by deposition-precipitation. Part 2. Catalytic hydrodeoxygenation reactions of lignin model compounds in organic and aqueous systems
Nickel metal supported on HZSM-5 (zeolite) is a promising catalyst for lignin depolymerization. In this work, the ability of catalysts prepared via deposition-precipitation (DP) to perform hydrodeoxygenation (HDO) on two lignin model compounds in organic and aqueous solvents was evaluated; guaiacol in dodecane and 2-phenoxy-1-phenylethanol (PPE) in aqueous solutions. All Ni/HZSM-5 catalysts were capable of guaiacol HDO into cyclohexane at 523 K. The role of the HZSM-5 acid sites was confirmed by comparison with Ni/SiO2 (inert support) which exhibited incomplete deoxygenation of guaiacol due to the inability to perform the cyclohexanol dehydration step. The catalyst prepared with 15 wt% Ni, a DP time of 16 h, and a calcination temperature of 673 K (Ni(15)/HZSM-5 DP16_Cal673), performed the guaiacol conversion with the greatest selectivity towards HDO products, with an intrinsic rate ratio (HDO rate to conversion rate) of 0.31, and 90% selectivity to cyclohexane. Catalytic activity and selectivity of Ni/HZSM-5 (15 wt%) in aqueous environments (water and 0.1 M NaOH solution) was confirmed using PPE reactions at 523 K. After 30 min reaction time in water, Ni/HZSM-5 exhibited ~100% conversion of PPE, and good yield of the desired products; ethylbenzene and phenol (~35% and 23% of initial carbon, respectively). Ni/HZSM-5 in NaOH solution resulted in significantly higher ring saturation compared to the Ni/HZSM-5 in water or the NaOH solution control
Minced Umbilical Cord Fragments as a Source of Cells for Orthopaedic Tissue Engineering: An In Vitro Study
A promising approach for musculoskeletal repair and regeneration is mesenchymal-stem-cell- (MSC-)based tissue engineering. The aim of the study was to apply a simple protocol based on mincing the umbilical cord (UC), without removing any blood vessels or using any enzymatic digestion, to rapidly obtain an adequate number of multipotent UC-MSCs. We obtained, at passage 1 (P1), a mean value of 4, 2 × 106 cells (SD 0,4) from each UC. At immunophenotypic characterization, cells were positive for CD73, CD90, CD105, CD44, CD29, and HLA-I and negative for CD34 and HLA-class II, with a subpopulation negative for both HLA-I and HLA-II. Newborn origin and multilineage potential toward bone, fat, cartilage, and muscle was demonstrated. Telomere length was similar to that of bone-marrow (BM) MSCs from young donors. The results suggest that simply collecting UC-MSCs at P1 from minced umbilical cord fragments allows to achieve a valuable population of cells suitable for orthopaedic tissue engineering
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