Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 184
Filtrar
Más filtros

País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Climacteric ; 26(5): 489-496, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37288958

RESUMEN

OBJECTIVE: Risk-reducing salpingo-oophorectomy (RRSO) is advised before 40-45 years of age for BRCA1/2 mutation carriers. This study describes the effect of RRSO on lipid determinants, hemoglobin A1c (HbA1c) and C-reactive protein (CRP). METHODS: A total of 142 women with increased risk of ovarian cancer were included, 92 premenopausal and 50 postmenopausal. Serum levels of low-density lipoprotein (LDL)-cholesterol, high-density lipoprotein (HDL)-cholesterol and total cholesterol, triglycerides, HbA1c and CRP were determined at three points in time: before (T0) and 6 weeks (T1) and 7 months (T2) following RRSO. The Hot Flush Rating Scale was administered at the same time points. RESULTS: In premenopausal women, levels of HDL-cholesterol, the cholesterol ratio and HBA1c increased significantly over time, although still staying within the reference range. In this group, hot flushes increased over time (p < 0.001). In postmenopausal women, no significant changes were observed following RRSO. At T2, serum LDL-cholesterol, triglycerides, HbA1c and CRP were significantly lower in premenopausal women compared to postmenopausal women, whereas HDL was increased. CONCLUSIONS: Seven months after RRSO, the lipid profile in premenopausal women had changed, although still staying within the reference range. For postmenopausal women, we did not observe any significant changes. Our results do not suggest a worsening of cardiovascular risk within 7 months of RRSO.


Asunto(s)
Neoplasias de la Mama , Neoplasias Ováricas , Femenino , Humanos , Salpingooforectomía/efectos adversos , Hemoglobina Glucada , Proteína BRCA1/genética , Proteína C-Reactiva , Proteína BRCA2/genética , Colesterol , Triglicéridos , Lípidos , Neoplasias Ováricas/genética , Ovariectomía , Mutación , Neoplasias de la Mama/etiología
2.
Opt Lett ; 47(13): 3163-3166, 2022 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-35776576

RESUMEN

We show that 13-fs laser pulses associated with 225 TW of peak power can be used to produce laser wakefield acceleration (LWFA) and generate synchrotron radiation. To achieve this, 130-TW high-power laser pulses (3.2 J, 24 fs) are efficiently compressed down to 13 fs with the thin film compression (TFC) technique using large chirped mirrors after propagation and spectral broadening through a 1-mm-thick fused silica plate. We show that the compressed 13-fs laser pulse can be properly focused even if it induces a 10% degradation of the Strehl ratio. We demonstrate the usability of such a laser beam. We observe both an increase of the electron energy and of the betatron radiation critical energy when the pulse duration is reduced to 13 fs compared with the 24-fs case.

3.
J Synchrotron Radiat ; 27(Pt 2): 558-566, 2020 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-32153298

RESUMEN

New calibration tools in the pyFAI suite for processing scattering experiments acquired with area detectors are presented. These include a new graphical user interface for calibrating the detector position in a scattering experiment performed with a fixed large area detector, as well as a library to be used in Jupyter notebooks for calibrating the motion of a detector on a goniometer arm (or any other moving table) to perform diffraction experiments.

4.
Opt Express ; 28(9): 13978-13990, 2020 Apr 27.
Artículo en Inglés | MEDLINE | ID: mdl-32403862

RESUMEN

We demonstrate that a laser-based synchrotron X-ray source can be used to image and characterize in a single laser shot spherical capsules similar to ICF targets. Thus, we establish this source potential for real-time ultrafast imaging of the ICF laser driver interaction with the target. To produce the X-ray beam we used a 160 TW high power laser system with 3.2 J and 20 fs incident on a supersonic gas jet target at 2.5 Hz repetition rate. We produced 2.7 × 109 photons/0.1% BW/sr/shot at 10 keV with a critical energy Ec = 15.1 keV. In our experimental conditions the spatial resolution was 4.3 µm in the object plane. We show that it is feasible to image the capsule structure and experimentally retrieve the phase information.

5.
Opt Express ; 28(3): 3147-3158, 2020 Feb 03.
Artículo en Inglés | MEDLINE | ID: mdl-32121988

RESUMEN

We review the results obtained in several experimental campaigns with the INRS high-power laser system and determine the X-ray emission scaling from synchrotron radiation produced during laser wakefield acceleration (LWFA) of electrons. The physical processes affecting the generation of intense and stable X-ray beams during the propagation phase of the high-intensity ultrashort pulse in the gas jet target are discussed. We successfully produced stable propagation in the gas jet target of a relativistic laser pulse through self-guiding on length larger than the dephasing and depletion lengths, generating very intense beams of hard X-rays with up to 200 TW on target. The experimental scaling law obtained for the photon yield in the 10-40 keV range is presented and the level of X-ray emission at the 1 PW laser peak power level, now available at several laser facilities, is estimated.

6.
Fish Physiol Biochem ; 45(3): 1167-1175, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-30874954

RESUMEN

The Saint John River (SJR) is home to the only Canadian population of shortnose sturgeon, Acipenser brevirostrum. Adult shortnose sturgeon routinely enter saltwater to forage, yet less is known about how juveniles cope with the associated osmoregulatory pressures. Recently, it has been shown that short-term (24 h) exposure to saltwater causes significant changes to ion and water levels in juvenile shortnose. In some species of fish, notably salmonids, it has been shown that shifts in fluid and ion levels following saltwater challenges reduce the swimming capacity. The relationship between ion concentration and swimming capacity is not well understood for sturgeon species. Our research aimed to determine whether short-term salt exposure affects swimming ability in juvenile shortnose sturgeon. Juvenile, SJR, hatchery-raised shortnose sturgeon (< 1 year old) were exposed to salinities of 0 (control), 16, or 24‰ for 24 h and then subjected to a critical swimming speed test (Ucrit) to quantify swimming ability. Following the test, the fish were weighed and blood samples were drawn to be analyzed for plasma ion and cortisol levels. While ion levels and weight loss were significantly higher in salt exposed fish, there were no significant differences in critical swimming speed or cortisol concentrations. This is in contrast to what has been observed in salmonids and Adriatic sturgeon. This suggests the hydromineral imbalance caused by moderate salt exposure is not sufficient to affect the swimming performance of shortnose sturgeon. Shortnose sturgeon are not thought to enter the saline stretches of the SJR until roughly 8 years of age, yet this research shows that much younger juveniles withstand moderate salinity for short periods, with little whole-animal ramifications.


Asunto(s)
Peces/fisiología , Salinidad , Tolerancia a la Sal , Natación/fisiología , Agua/química , Animales
7.
J Synchrotron Radiat ; 25(Pt 2): 612-617, 2018 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-29488943

RESUMEN

Diffraction imaging is an X-ray imaging method which uses the crystallinity information (cell parameter, orientation) as a signal to create an image pixel by pixel: a pencil beam is raster-scanned onto a sample and the (powder) diffraction signal is recorded by a large area detector. With the flux provided by third-generation synchrotrons and the speed of hybrid pixel detectors, the acquisition speed of these experiments is now limited by the transfer rate to the local storage as the data reduction can hardly be performed in real time. This contribution presents the benchmarking of a typical data analysis pipeline for a diffraction imaging experiment like the ones performed at ESRF ID15a and proposes some disruptive techniques to decode CIF binary format images using the computational power of graphics cards to be able to perform data reduction in real time.

8.
Climacteric ; 21(6): 574-580, 2018 12.
Artículo en Inglés | MEDLINE | ID: mdl-30295077

RESUMEN

OBJECTIVES: The aim of this study was to investigate whether serum anti-Müllerian hormone (AMH) predicts symptom burden after risk-reducing salpingo-oophorectomy (RRSO) in order to individualize counseling. METHODS: Patient-reported menopausal symptoms, sexual functioning, and psychological distress (depression and anxiety) were assessed 1 day before (T0) and 6 weeks (T1) and 7 months (T2) after RRSO. AMH was assessed before RRSO. Multivariable regression analysis was used to investigate the association between AMH and short-term and long-term change in symptom burden following RRSO. RESULTS: Ninety-one premenopausal women at high risk of ovarian cancer were included. Presurgical AMH was not related significantly to change in symptoms post RRSO. As a secondary outcome we found that regular menses before RRSO was associated specifically with long-term increase in hot flushes (sr = 0.40, p = 0.001; total R2 = 0.171) and depression (sr = 0.29, p = 0.012; total R2 = 0.132). Earlier receipt of chemotherapy was associated with long-term improvement in sexual functioning (sr = 0.24, p = 0.041; total R2 = 0.348). CONCLUSION: In this cohort, AMH was not a significant predictor of change in symptoms following RRSO. Regular menses prior to RRSO and earlier receipt of chemotherapy were significantly, but relatively weakly, associated with changes in outcomes 6 weeks and/or 7 months after RRSO.


Asunto(s)
Hormona Antimülleriana/sangre , Neoplasias de la Mama/complicaciones , Menopausia/sangre , Neoplasias Ováricas/prevención & control , Salpingooforectomía/efectos adversos , Adulto , Femenino , Humanos , Persona de Mediana Edad , Análisis Multivariante , Países Bajos , Neoplasias Ováricas/sangre , Estudios Prospectivos , Calidad de Vida , Análisis de Regresión , Conducta de Reducción del Riesgo , Encuestas y Cuestionarios
9.
J Fish Biol ; 90(1): 185-200, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-27723098

RESUMEN

The swimming performance and associated swimming behaviour (i.e. substratum-skimming, station-holding and free swimming) were assessed in shortnose sturgeon Acipenser brevirostrum during critical swimming and endurance swimming tests over a rough and a smooth substratum. It was hypothesized that the addition of a rough substratum in the swimming flume may provide a surface for the A. brevirostrum to grip and offer an energetic advantage. Substratum type did not affect the critical swimming performance, but A. brevirostrum consistently performed more bottom behaviours (i.e. substratum-skimming and station-holding) while on a smooth substratum. Acipenser brevirostrum had little contact with the rough substratum until the velocity was >1 body length s-1 . Endurance swimming time was significantly lower for A. brevirostrum over the rough bottom at the highest velocity (30 cm s-1 ) which may be attributed to the observed increase in free swimming and decrease in bottom behaviours. During endurance swimming, the rough substratum was mainly used at intermediate velocities, suggesting that there may be a stability cost associated with being in contact with the rough substratum at certain velocities.


Asunto(s)
Conducta Animal/fisiología , Peces/fisiología , Natación/fisiología , Animales , Vivienda para Animales , Condicionamiento Físico Animal , Resistencia Física
10.
Phys Chem Chem Phys ; 16(47): 25760-4, 2014 Dec 21.
Artículo en Inglés | MEDLINE | ID: mdl-25354544

RESUMEN

(PhSiO1.5)8,10,12 cages are bulky, electron withdrawing like CF3; yet self-brominate (60 °C), favoring ortho substitution: PhT8 (≈85%), PhT10 (≈75%) and PhT12 (60%). First-principles calculations suggest bromination initiates when Br2 is "trapped" via H-bonding to ortho-H's, followed by polarization via strong interactions with cage faces, possibly cage LUMOs.

11.
J Fish Biol ; 84(4): 1117-35, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24628001

RESUMEN

This study focused on the acute physiological responses to saltwater exposure in juvenile shortnose sturgeon Acipenser brevirostrum. In two separate laboratory experiments, 2 year-old A. brevirostrum were exposed to either full (32) or half-strength (16) seawater for up to 24 h. First, oxygen consumption rates were used to estimate the metabolic costs over 24 h. Secondly, blood and muscle samples were analysed at 6, 12 and 24 h for water loss, various measures of osmoregulatory status (plasma osmolality and ions) and other standard haematological variables. Juveniles exposed to full-strength seawater showed significant decreases in oxygen consumption rates during the 24 h exposure. Furthermore, seawater-exposed fish had significantly increased plasma osmolality, ions (Na(+) and Cl(-)) and a 17% decrease in total wet mass over the 24 h exposure period. To a lesser extent, increases in osmolality, ions and mass loss were observed in fish exposed to half-strength seawater but no changes to oxygen consumption. Cortisol was also significantly increased in fish exposed to full-strength seawater. While plasma protein was elevated following 24 h in full-strength seawater, haemoglobin, haematocrit and plasma glucose levels did not change with increased salinity. These results imply an inability of juvenile A. brevirostrum to regulate water and ions in full-strength seawater within 24 h. Nonetheless, no mortality occurred in any exposure, suggesting that juvenile A. brevirostrum can tolerate short periods in saline environments.


Asunto(s)
Peces/fisiología , Consumo de Oxígeno , Salinidad , Estrés Fisiológico , Animales , Glucemia/análisis , Peso Corporal , Hematócrito , Hemoglobinas/análisis , Hidrocortisona/sangre , Concentración Osmolar , Agua de Mar , Equilibrio Hidroelectrolítico/fisiología
13.
J Cancer Surviv ; 2024 Apr 26.
Artículo en Inglés | MEDLINE | ID: mdl-38664296

RESUMEN

PURPOSE: Breast cancer patients receiving chemotherapy can develop cognitive impairment. There is no gold standard for defining cognitive impairment. We applied the National Institute on Aging-Alzheimer's Association (NIA-AA) criteria for mild cognitive impairment (MCI) to determine its prevalence in breast cancer patients receiving adjuvant chemotherapy and examine differences between patients with and without MCI. METHODS: We used pre-existing cognitive data on 5 neuropsychological test outcomes (verbal memory, processing speed, executive functioning, and verbal fluency) gathered from 240 breast cancer patients who received adjuvant conventional (n = 154) or high-dose chemotherapy (n = 86). Assessments occurred 6 or 12 months post-chemotherapy and results were compared with data from 66 women without cancer. MCI was defined by the following: (i) presence of concern regarding a change in cognition, (ii) impairment in one or more cognitive tests (1.5 standard deviation below a normative mean), (iii) preservation of independence in functional abilities, and (iv) the absence of dementia. RESULTS: Twenty percent (n = 49) of breast cancer patients who received chemotherapy (conventional therapy n = 29 (12%), high-dose therapy = 20 (8.3%)) met the criteria for MCI, compared with 7.6% (n = 5) of controls. Prevalence was significantly different between patients and controls (P = 0.020, and corrected for IQ P < 0.001). Patients with MCI had significant lower education levels (P < 0.002) and premorbid IQ (P = 0.001) compared with patients without MCI. CONCLUSIONS: Twenty percent of breast cancer patients treated with chemotherapy met NIA-AA criteria for MCI, compared with 7.6% of the controls. IMPLICATIONS FOR CANCER SURVIVORS: These criteria, which include formal test performance as well as a person's symptoms and functional status, can be useful in clinical practice and scientific research.

14.
Theriogenology ; 218: 79-88, 2024 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-38301510

RESUMEN

The aim of the present study was to evaluate: 1) the association between AMH, AFC, superovulatory response and embryo yield in sheep; and 2) the effect of FSH treatment length during superstimulation of the first follicular wave on ovarian response and embryo yield, particularly in ewes with low and high AMH. The experiment was performed on 63 Polled Dorset ewes that received an ovarian superstimulatory treatment during the first follicular wave (Day 0 protocol). Ewes were administered a total dose of 240 mg of FSH distributed in six (6-dose regimen, n = 30) or eight (8-dose regimen, n = 33) decreasing doses administered 12 h apart. On Day -9 (random stage of the estrous cycle) and Day 0 (day of the first FSH dose) ovarian ultrasonography was performed and blood samples were collected for AFC and AMH determinations, respectively. A weak positive correlation between AMH and small AFC (follicles <4 mm) was observed (r = 0.23; P = 0.07), and AMH concentration was positively correlated (r = 0.29; P < 0.05) with the number of corpora lutea (CL) determined at embryo collection (i.e., 6 d after insemination). The length of FSH treatment tended (P = 0.06) to affect the ovarian response, such that the number of CL was greater in 8-dose than 6-dose treated ewes, while no differences (P > 0.10) in embryo yield outcomes were observed. For further analysis, ewes were classified into low (<7 ng/mL) and high (>10 ng/mL) serum AMH. In high AMH ewes, there were no differences (P > 0.05) in the number of CL nor embryo yield between the 6-dose and 8-dose treatment (e.g., 7.8 ± 2.4 and 8.3 ± 2.5 transferable embryos, respectively; P = 0.92). Conversely, for low AMH ewes, fertilized ova and embryo yield were greater (P ≤ 0.05) for ewes receiving the 8-dose than the 6-dose superstimulatory treatment (e.g., 8.4 ± 2.8 vs. 2.7 ± 0.9 transferable embryos, respectively, P ≤ 0.05). In conclusion, embryo production in poor responding ewes with low low circulating AMH is improved by extending the superstimulatory treatment length from 6 to 8 FSH doses.


Asunto(s)
Hormona Folículo Estimulante , Folículo Ovárico , Femenino , Animales , Ovinos , Folículo Ovárico/fisiología , Hormona Folículo Estimulante/farmacología , Ovario , Cuerpo Lúteo , Superovulación
15.
Transl Anim Sci ; 8: txae071, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38863594

RESUMEN

Cull cows represent a significant percentage of revenue received from the U.S. beef industry; however, cull cows are heavily price discounted at time of slaughter. This experiment's objective is to evaluate different feeding strategies and their effects on body condition score, subcutaneous fat color, and carcass yield and quality traits in cull cows. The central hypothesis is feeding a high-energy diet, with low levels of vitamin A, for 56 d will improve animal performance, carcass yield, and quality traits in addition to capturing the point (rate) of the conversion of yellow to white subcutaneous fat. In the present experiment 98 Angus crossbreed cows were utilized. Cows were fed either low vitamin A (LVA) diet consisting of whole shelled corn, soybean hulls, soybean meal, and a mineral-vitamin supplement or high vitamin A (HVA) diet, formulated using whole shelled corn, fescue hay, dry distiller grains with soluble, and a mineral-vitamin supplement for 56 d. During the 56 d feeding period, body weights and condition scores, and subcutaneous adipose samples were collected every 14 d. On day 56, cattle were slaughtered; 48 h postmortem carcass characteristics and objective color scores (subcutaneous adipose tissue) were recorded and a sample of the longissimus dorsi lumborum was collected. Subcutaneous adipose tissue samples were utilized to record subjective color scores and then ground to be analyzed for ß-carotene concentration. The longissimus dorsi lumborum samples (2.54 cm slices) were removed for Warner-Bratzler shear force (WBSF) and pH testing. Data were analyzed using the MIXED procedure of SAS. Feeding cull cows LVA resulted in differences in subcutaneous carcass fat color (P = 0.01) as well as b* values (P < 0.01) on day 56 compared with HVA. Subjective fat color scores were not different (P > 0.10) on day 0 or 14 but were different (P ≤ 0.05) on days 28, 42, and 56. Additionally, 9-cis-ß-carotene concentration on day 56 were different (P = 0.05) between treatments. A trend was noticed for all-trans-ß-carotene concentration (P = 0.10) on day 56 as well. Cull cow body weights were greater (P ≤ 0.04) when fed the LVA diet starting on days 14, 28, and 42; and a trend was noticed on day 56 (P = 0.09). Overall, cows fed the LVA treatment for 56 d exhibited decreased adipose yellowness and ß-carotene concentrations as well as increased live weights.

16.
Artículo en Inglés | MEDLINE | ID: mdl-36657229

RESUMEN

In comparison to most modern teleost fishes, sturgeons generally display muted stress responses. While a muted stress response appears to be ubiquitous across sturgeon species, the mechanisms unpinning this muted response have not been fully described. The objective of this study was to determine the patterns of hematological and transcriptomic change in muscle tissue following an acute high temperature stress (critical thermal maxima; CTmax) in two locally co-occurring but evolutionarily distant sturgeon species (Atlantic and shortnose sturgeon). The most striking pattern found was that Atlantic sturgeon launched a vigorous transcriptomic response at CTmax, whereas shortnose sturgeon did not. In contrast, shortnose sturgeon have significantly higher cortisol than Atlantics at CTmax, reconfirming that shortnose have a less muted cortisol stress response. Atlantic sturgeon downregulated a number of processes, included RNA creation/processing, methylation and immune processes. Furthermore, a number of genes related to heat shock proteins were differentially expressed at CTmax in Atlantic sturgeon but none of these genes were significantly changed in shortnose sturgeon. We also note that the majority of differentially expressed genes of both species are undescribed and have no known orthologues. These results suggest that, while sturgeons as a whole may show muted stress responses, individual sturgeon species likely use different inducible strategies to cope with acute high temperature stress.


Asunto(s)
Hidrocortisona , Transcriptoma , Animales , Peces/metabolismo , Respuesta al Choque Térmico/genética , Perfilación de la Expresión Génica
17.
Anim Reprod Sci ; 250: 107210, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36913895

RESUMEN

The objective of the present study was to evaluate the effect of GnRH dose administered at initiation (GnRH-1) of a 5-day CO-Synch + P4 protocol on ovulatory response, expression of estrus, and fertility in suckled beef cows. Suckled beef cows (n = 1101) at four locations were randomized to receive either 100 or 200 µg of gonadorelin acetate at initiation (D-8) of a 5-day CO-Synch + P4 protocol concurrently with insertion of an intravaginal progesterone (P4) device. On D-3 the P4 device was removed, two doses of prostaglandin F2α were administered concurrently and a patch was applied to evaluate expression of estrus. Artificial insemination was performed 72 h after P4 device removal (D0) simultaneously with the administration of 100 µg of gonadorelin acetate (GnRH-2). Increasing GnRH dose at initiation of a 5-day CO-Synch + P4 did not enhance ovulatory response (P = 0.57) to GnRH-1, expression of estrus (P = 0.79), nor pregnancies per AI (P/AI; P = 0.91). Both follicle size (quadratic) and circulating P4 (linear) affected (P < 0.01) ovulatory response to GnRH-1 independent of dose. Cows that had ovulation to GnRH-1 had smaller (P < 0.001) follicle size on D-3 and reduced (P = 0.05) expression of estrus compared to cows that did not have ovulation to GnRH-1, however, P/AI did not differ (P = 0.75). In conclusion, increasing the dose of GnRH-1 in the 5-day CO-Synch + P4 protocol did not enhance ovulatory response, expression of estrus, or P/AI in suckled beef cows.


Asunto(s)
Sincronización del Estro , Progesterona , Embarazo , Femenino , Bovinos , Animales , Sincronización del Estro/métodos , Progesterona/farmacología , Hormona Liberadora de Gonadotropina/farmacología , Estro/fisiología , Dinoprost , Inseminación Artificial/veterinaria , Inseminación Artificial/métodos
18.
Qual Life Res ; 21(7): 1241-7, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-21964947

RESUMEN

PURPOSE: The present study examined the internal responsiveness of the short-form Oral Health Impact Profile (OHIP-14) and its ability to differentiate between patients with and without pre- and postoperative complaints as well as other clinical variables. METHODS: The sample consisted of 97 patients undergoing surgical third molar removal. The OHIP-14 was filled in preoperatively, on each postoperative day for a week and once more after 1 month. In addition, pre- and postoperative status was measured along with other clinical variables. RESULTS: The OHIP-14 is able to differentiate between the first preoperative day (M = 16.85, SD = 5.35) and all the days within the postoperative week (first day M = 29.46, SD = 9.32). One month postoperatively, mean OHIP scores are reduced to preoperative levels. In addition, differences could be shown between patients with and without pre- (M = 18.9, SD = 8.1 vs. M = 16.2, SD = 3.9) and postoperative complaints (M = 18.9, SD = 8.1 vs. M = 16.2, SD = 3.9), partial (preop; M = 17.8, SD = 6.8, postoperative; M = 27.4, SD = 7.7) and complete mucosa coverage (preop; M = 15.9, SD = 3.2, postoperative; M = 29.5, SD = 10.6) and the level of impaction (Pell and Gregory classification) of the third molar (3B showing the highest increase in the mean OHIP score). CONCLUSIONS: The OHIP-14 can be considered internally responsive to changes in impacts of oral conditions as a result of surgical third molar removal and is able to differentiate the effect of several clinical variables.


Asunto(s)
Tercer Molar/cirugía , Complicaciones Posoperatorias , Perfil de Impacto de Enfermedad , Extracción Dental , Adulto , Femenino , Estado de Salud , Humanos , Masculino , Salud Bucal , Reproducibilidad de los Resultados , Adulto Joven
19.
Opt Express ; 19(15): 14093-8, 2011 Jul 18.
Artículo en Inglés | MEDLINE | ID: mdl-21934771

RESUMEN

We demonstrated the generation of infrared radiation by filamentation of a spectrally shaped femtosecond laser beam. The spectrum is divided in two distinctive parts using an acousto-optic programmable dispersive filter (AOPDF) as a pulse shaper, resulting in two pulses of different colors. One pulse is frequency doubled and the beams are then focused to produce an optical filament. Efficient infrared generation occurred in the filament zone through the four-wave mixing interaction. This in-line setup allowed perfect spatial overlap of the pulses, fine control of the relative delay and the remote control of the infrared spectral distribution through spectral shaping of the initial femtosecond laser beam via the AOPDF.

20.
Opt Express ; 19(1): 230-40, 2011 Jan 03.
Artículo en Inglés | MEDLINE | ID: mdl-21263561

RESUMEN

We report measurements of crater diameter and surface ablation threshold as a function of laser fluence in porcine corneal stroma and fused silica with pulse durations of 7 fs (2.7 optical cycles), 30 fs and 100 fs at 800 nm. For laser pulses with Gaussian radial intensity profile, we show experimentally that the square of the crater diameter is a linear function of the logarithm of the fluence in fused silica, while it is closer to a linear function of the fluence in corneal stroma. Extrapolating these relations to zero diameter indicates that for both media the minimum fluence required for surface ablation is reduced with shorter pulse duration. A simple theoretical model suggests that this effect is due to a more significant contribution of photoionization as the laser pulse duration shortens.


Asunto(s)
Córnea/cirugía , Cirugía Laser de Córnea/métodos , Animales , Cirugía Laser de Córnea/instrumentación , Diseño de Equipo , Técnicas In Vitro , Modelos Teóricos , Dispositivos Ópticos , Fenómenos Ópticos , Dióxido de Silicio , Porcinos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA