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1.
Artículo en Inglés | MEDLINE | ID: mdl-38331669

RESUMEN

The training, competency requirements and scope of practice of professionals within a radiation oncology department vary across countries. The purpose of this review is to shed light on the current status of radiotherapy training in the USA by discussing current benchmarks for medical residency, physics residency, radiation therapy and dosimetry training programmes. Although there are notable strengths, the US radiotherapy workforce training system also faces several challenges when it comes to standardising education to develop a competent workforce that meets societal needs. Continued efforts are needed at a systemic level to improve training in areas such as brachytherapy and proton therapy, promote research involvement and develop trainees who are equipped to form a competent radiation therapy workforce.

2.
Gynecol Oncol ; 159(1): 23-29, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-32718729

RESUMEN

OBJECTIVES: A pooled analysis of PORTEC-1 & 2 identified substantial lymphovascular space invasion (LVSI) in 4.8% of patients, which predicted for pelvic recurrence, distant metastasis, and overall survival. Our institution implemented the PORTEC three-tier system of LVSI reporting (absent, focal, or substantial). We aimed to quantify the incidence of substantial LVSI in a North American population and to correlate extent of LVSI with lymph node (LN) involvement. METHODS: A retrospective review was conducted on patients with clinically uterine-confined, endometrioid type endometrial cancer who underwent surgical staging and were found to have pT1a-b disease. Binary logistic regression was used to assess predictors of LN involvement (defined as ITC, micrometastases, or macrometastases). RESULTS: In total, 438 patients with pT1a-b disease were identified. In the overall cohort and in the subset meeting PORTEC-1 inclusion criteria (n = 195), no LVSI was present in 67.4% and 50.8%; focal LVSI was present in 16.7% and 24.1%; and substantial LVSI was present in 16.0% and 25.1%, respectively. Among patients who underwent surgical LN assessment (79.2%, n = 347), LNs were involved in 3.3% without LVSI, 7.5% with focal LVSI (OR 2.4), and 15.2% with substantial LVSI (OR 5.3) (p = .005), with a similar trend in the PORTEC-1 cohort. Extent of LVSI correlated with disease burden in LN metastases. CONCLUSION: Our incidence of substantial LVSI was three to five times higher than reported by PORTEC and correlated with LN involvement. This questions the reproducibility of the three-tier LVSI reporting system and emphasizes the need for multi-institutional data outside PORTEC for confirmation of our findings.


Asunto(s)
Neoplasias Endometriales/patología , Metástasis Linfática/patología , Vasos Linfáticos/patología , Recurrencia Local de Neoplasia/epidemiología , Anciano , Neoplasias Endometriales/diagnóstico , Neoplasias Endometriales/cirugía , Endometrio/patología , Endometrio/cirugía , Femenino , Humanos , Histerectomía , Incidencia , Escisión del Ganglio Linfático/estadística & datos numéricos , Ganglios Linfáticos/patología , Metástasis Linfática/terapia , Vasos Linfáticos/cirugía , Persona de Mediana Edad , Invasividad Neoplásica/patología , Recurrencia Local de Neoplasia/patología , Estadificación de Neoplasias , Pronóstico , Reproducibilidad de los Resultados , Estudios Retrospectivos , Medición de Riesgo/estadística & datos numéricos , Factores de Riesgo , Estados Unidos/epidemiología
3.
Sci Rep ; 9(1): 8235, 2019 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-31160646

RESUMEN

We implement a logic switch by using a graphene acoustoelectric transducer at room temperature. We operate two pairs of inter-digital transducers (IDTs) to launch surface acoustic waves (SAWs) on a LiNbO3 substrate and utilize graphene as a channel material to sustain acoustoelectric current Iae induced by SAWs. By cooperatively tuning the input power on the IDTs, we can manipulate the propagation direction of Iae such that the measured Iae can be deliberately controlled to be positive, negative, or even zero. We define the zero-crossing Iae as [Formula: see text], and then demonstrate that Iae can be switched with a ratio [Formula: see text] at a rate up to few tens kHz. Our device with an accessible operation scheme provides a means to convert incoming acoustic waves modulated by digitized data sequence onto electric signals with frequency band suitable for digital audio modulation. Consequently, it could potentially open a route for developing graphene-based logic devices in large-scale integration electronics.

4.
Oral Oncol ; 61: 41-6, 2016 10.
Artículo en Inglés | MEDLINE | ID: mdl-27688103

RESUMEN

OBJECTIVE: It has been postulated that treatment outcomes are similar between transoral robotic surgery (TORS) and definitive chemoradiation (CRT) for oropharyngeal squamous cell carcinomas (OPSCC). We compared oncologic and quality of life (QOL) outcomes between definitive CRT and definitive TORS. MATERIALS AND METHODS: An observational comparison study was performed on 92 patients treated with TORS±adjuvant therapy and 46 patients treated with definitive CRT between July 2005 and January 2016. The Kaplan Meier method was used for survival analyses, and the Mann-Whitney test was used to compare QOL scores between groups. RESULTS: All patients had T0-T2 and N0-N2 disease, although CRT patients had higher clinical staging (p<0.001). HPV+ disease was present in 79% (n=73) of TORS patients and 91% (n=19) of tested CRT patients. Median follow-up was 22.1months (range: 0.33-83.4). There were no significant differences in locoregional control or overall survival between CRT and TORS groups. Definitive TORS resulted in better saliva-related QOL than definitive CRT at 1, 6, 12, and 24months (p<0.001, p=0.025, p=0.017, p=0.011). Among TORS patients, adjuvant therapy was associated with worse QOL in the saliva domain at 6, 12, and 24months (p<0.001, p<0.001, p=0.007), and taste domain at 6 and 12months (p=0.067, p=0.008). CONCLUSION: Definitive CRT and definitive TORS offer similar rates of locoregional control, overall survival, and disease-free survival in patients with early stage OPSCC. TORS resulted in significantly better short and long-term saliva-related QOL, whereas adjuvant therapy was associated with worse saliva and taste-related QOL compared to TORS alone.


Asunto(s)
Carcinoma de Células Escamosas/terapia , Neoplasias Orofaríngeas/terapia , Calidad de Vida , Procedimientos Quirúrgicos Robotizados , Adulto , Anciano , Carcinoma de Células Escamosas/patología , Carcinoma de Células Escamosas/cirugía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Neoplasias Orofaríngeas/patología , Neoplasias Orofaríngeas/cirugía , Resultado del Tratamiento
5.
Rev Sci Instrum ; 85(8): 083707, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25173276

RESUMEN

We have constructed a scanning probe microscope for magnetic imaging, which can function as a scanning Hall probe microscope (SHPM) and as a scanning SQUID microscope (SSM). The scanning scheme, applicable to SHPM and SSM, consists of a mechanical positioning (sub) micron-XY stage and a flexible direct contact to the sample without a feedback control system for the Z-axis. With the interchangeable capability of operating two distinct scanning modes, our microscope can incorporate the advantageous functionalities of the SHPM and SSM with large scan range up to millimeter, high spatial resolution (⩽4 µm), and high field sensitivity in a wide range of temperature (4.2 K-300 K) and magnetic field (10(-7) T-1 T). To demonstrate the capabilities of the system, we present magnetic images scanned with SHPM and SSM, including a RbFeB magnet and a nickel grid pattern at room temperature, surface magnetic domain structures of a La(2/3)Ca(1/3)MnO3 thin film at 77 K, and superconducting vortices in a striped niobium film at 4.2 K.

7.
J Phys Condens Matter ; 20(46): 465105, 2008 Nov 19.
Artículo en Inglés | MEDLINE | ID: mdl-21693839

RESUMEN

Fe and Y K-edge extended x-ray absorption fine structure, Fe(Y) L(3,2)-edge (L(3)-edge) x-ray absorption near-edge structure (XANES) and valence-band photoemission spectroscopy (VB-PES) measurements have been carried out to study soft magnetic ternary Fe(78-x)Y(x)B(22) bulk metallic glasses (BMGs). The combined XANES and VB-PES results do not show broadening of the Fe 3d band to support the previous interpretation of the reduction of the magnetic moment in BMGs by Y-induced decrease of exchange splitting of Fe 3d orbitals. Instead, the density of delocalized/itinerant Fe 3d states in the vicinity of the Fermi level is found to be reduced by Y substitution, which reduces the strength of itinerant-states-mediated ferromagnetic coupling between local spins on the Fe ions and the total magnetic moment of the Fe-based BMGs.

8.
J Phys Condens Matter ; 20(27): 275238, 2008 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-21694399

RESUMEN

We report x-ray powder diffraction and temperature-dependent infrared reflectivity measurements of (Na(0.5)La(0.5))Cu(3)Ti(4)O(12) and (Na(0.5)Bi(0.5))Cu(3)Ti(4)O(12) in order to investigate the origin of their lower room-temperature dielectric constants in comparison with the giant value of CaCu(3)Ti(4)O(12). Substituting Ca with Na/La or Na/Bi is found to decrease all Ti-O-Ti angles by the TiO(6) octahedra tilts, resulting in an increase of the local structural disorder on the Na/La and Na/Bi compounds. Further, several infrared-active phonon modes show a broadening in their linewidths, reflecting that the coherency in these vibrational modes is degraded by disorder. Additionally, the lowest-frequency mode of the Ca material is observed to strengthen dramatically at low temperatures, but to a lesser extent in the Na/La and Na/Bi compounds. These results suggest the important role of the local structural disorder on the anomalous low-frequency dielectric response in these materials.

9.
Sex Transm Infect ; 82(2): 127-30, 2006 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-16581737

RESUMEN

OBJECTIVES: To explore the characteristics and issues specific to HIV related risk behaviours among men who have sex with men (MSM) in rural China. METHOD: Qualitative study using semistructured in-depth interviews in Dali prefecture, Yunnan. 24 informants recruited through a local MSM network, snowballing and by word of mouth. The main outcome measures were themes identified as increased exposures and risks to HIV. RESULTS: Risk behaviour, social stigma, one child policy and concepts of traditional Chinese medicine (TCM) had significant roles in the spread of HIV in rural China. Many MSM lead a life with double identities in China and condom use was found to be variable with attempts to "rationalise" the risky behaviour being its major determining factor. Health seeking behaviours of genitourinary problems were infrequent and illogical, which were further held back by the existing healthcare system and lack of sensitivity expressed by the health professionals. CONCLUSIONS: Clear education messages to the general public while raising awareness among health professionals of the health risks and needs in MSM are essential in the prevention of the current HIV epidemic.


Asunto(s)
Infecciones por VIH/epidemiología , Homosexualidad Masculina/estadística & datos numéricos , Sexo Inseguro , Adulto , Anciano , China/epidemiología , Condones/estadística & datos numéricos , Infecciones por VIH/psicología , Conocimientos, Actitudes y Práctica en Salud , Humanos , Masculino , Persona de Mediana Edad , Aceptación de la Atención de Salud , Factores de Riesgo , Salud Rural , Parejas Sexuales
10.
Phys Rev Lett ; 96(9): 096401, 2006 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-16606287

RESUMEN

We report experimental evidence for the charge-orbital ordering in magnetite below the Verwey transition temperature T(V). Measurements of O K-edge resonant x-ray scattering on magnetite reveal that the O 2p states in the vicinity of the Fermi level exhibit a charge-orbital ordering along the c axis with a spatial periodicity of the doubled lattice parameter of the undistorted cubic phase. Such a charge-orbital ordering vanishes abruptly above T(V) and exhibits a thermal hysteresis, correlating closely with the Verwey transition in magnetite.

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