Search

BACKGROUND: Physician online ratings are ubiquitous and influential, but they also have their detractors. Given the lack of scientific survey methodology used in online ratings, some health systems have begun to publish their own internal patient-submitted ratings of physicians. OBJECTIVE: The purpose of this study was to compare online physician ratings with internal ratings from a large healthcare system. DESIGN: Retrospective cohort study comparing online ratings with internal ratings from a large healthcare system. SETTING: Kaiser Permanente, a large integrated healthcare delivery system. PARTICIPANTS: Physicians in the Southern California region of Kaiser Permanente, including all specialties with ambulatory clinic visits. MAIN MEASURES: The primary outcome measure was correlation between online physician ratings and internal ratings from the integrated healthcare delivery system. RESULTS: Of 5438 physicians who met inclusion and exclusion criteria, 4191 (77.1%) were rated both online and internally. The online ratings were based on a mean of 3.5 patient reviews, while the internal ratings were based on a mean of 119 survey returns. The overall correlation between the online and internal ratings was weak (Spearman’s rho .23), but increased with the number of reviews used to formulate each online rating. CONCLUSIONS: Physician online ratings did not correlate well with internal ratings from a large integrated healthcare delivery system, although the correlation increased with the number of reviews used to formulate each online rating. Given that many consumers are not aware of the statistical issues associated with small sample sizes, we would recommend that online rating websites refrain from displaying a physician’s rating until the sample size is sufficiently large (for example, at least 15 patient reviews). However, hospitals and health systems may be able to provide better information for patients by publishing the internal ratings of their physicians.

In this paper, we present recent results from bunch-shaping experiments using α-BBO crystal at the High Brightness Electron Beam Source Laboratory (HBESL). α-BBO crystals were used to shape the ultra-short laser pulse ( < 100fs) at HBESL to generate twin pulses at the cathode. The twin electron pulses were transported down the linac ( < 5 MeV) to a transverse deflecting mode cavity and the temporal profile recorded on the screen. The longitudinal time profile of the twin pulses show the difference between the effect of crystals and the longitudinal space charge effect. The electron beam was recorded for various position of the crystal and bunch charge.

Background This study aimed to investigate whether radiofrequency ablation (RFA) is an alternative to surgical resection for hepatocellular carcinoma (HCC) within the context of current guidelines. Methods This retrospective study included patients with normal portal pressure and serum bilirubin level who initially underwent liver resection or RFA for a single HCC of maximum size 3 cm. Between-group differences in cumulative rates of survival and recurrence specific for HCC were analysed in the entire cohort and in a propensity score-matched cohort. Results A total of 604 patients were enrolled, 273 in the liver resection group and 331 in the RFA group. The 5- and 10-year HCC-specific survival rates for the resection and RFA groups were 87·6 versus 82·1 per cent and 59·0 versus 61·2 per cent respectively (P = 0·214), whereas overall 5- and 10-year recurrence-free survival rates for the corresponding groups were 60·6 versus 39·4 per cent and 37·5 versus 25·1 per cent respectively (P < 0·001). In the propensity score-matched cohort (152 pairs), there were no differences in HCC-specific survival (hazard ratio (HR) 1·03 for RFAversus resection; P = 0·899), whereas recurrence-free survival again differed between the treatment groups (HR 1·75; P < 0·001). RFA was independently associated with poorer outcomes in terms of treatment-site recurrence-free survival (adjusted HR 1·66; P = 0·026), but not non-treatment-site recurrence-free survival (adjusted HR 1·15; P = 0·354). Conclusion Although RFA carries a higher risk of treatment-site recurrence than hepatic resection, it provides comparable overall survival in patients with a single small HCC without portal hypertension or a raised bilirubin level.

To evaluate the clinical utility of computed tomography (CT) and magnetic resonance imaging (MRI) in the diagnosis of peripheral cholangiocarcinoma of the liver, 11 patients with pathologically proven peripheral cholangiocarcinoma were examined with both CT and MRI. On CT scans in 10 cases, the tumors appeared as irregular, low-attenuation masses with a wide variation in heterogeneity. Contrast enhancement of the tumors was mild in nine cases and moderate in one case, at the periphery. Tumor was not identified in one case. On T1-weighted MRIs, the tumors showed low intensity in eight cases and isointensity in three cases. On T2-weighted images, the tumors showed high intensity in all 11 cases. Focal dilatation of the intrahepatic bile ducts around the tumor was seen in one case on MRIs and in four cases on CT scans. Portal vein invasion of the tumors was seen in one case, and lymphadenopathy was seen in four cases on both MRIs and CT scans. MRI was slightly superior to CT in detecting the tumors, was inferior to CT in delineating focal ductal dilatation around the tumors, and was equal to CT in assessing extent of the tumors.

Magnetic resonance (MR) imaging was performed on five tumors of three patients who had hepatic hemangiomas. Four tumors were given an intraarterial infusion of 3-8 ml of iodized oil, while one tumor was not. MR images were obtained at 2.0 or 0.5 T. A single spin echo sequence with TE of 30 ms and TR of 500 ms and a double echo sequence with TEs of 60 and 150 ms and TR of 2000 ms, were used to produce relatively T1-, T2-weighted, and heavily T2-weighted images, respectively. Follow-up MR imaging was done 1-5 months after infusion of iodized oil. On relatively T1-weighted images, hemangiomas showed iso- or hypointensity. On T2-weighted images, all tumors showed hyperintensity. However, on heavily T2-weighted images, tumors with iodized oil showed heterogeneous, slight hyperintensity, while tumors without iodized oil showed characteristic appearance of marked hyperintensity in hemangiomas. In hepatic cavernous hemangiomas with intraarterial infusion of iodized oil, familiarity with this unusual MR intensity of tumors on heavily T2-weighted images is useful to avoid the incorrect diagnosis and to reduce the frequency of inappropriate hepatic resection.

To design high power oversized Relativistic Backward Wave Oscillator (RBWO) which can generate GW-level Power in THz frequency, numerical studies such as finite difference time domain (FDTD) and particle in cell (PIC) were performed. 0.1GW at 0.1THz was estimated. The Oversized BWO which means relatively wide cross-section space (oversized) to decrease power density comparing with fundamental BWO is made up of slow wave structure (SWS) of rectangular type wall radius designed to generate wave on surface with strong interaction between electron beam and wave under intense fields at 500 kV-1.5kA, 100ns pulse in the relativistic range. In the meantime, the type of THz EM waves radiated antenna is COaxial Beam Rotating Antenna (COBRA). The antenna lens is designed to be matched with the W-band frequency and the thickness of lens is decided by theoretically calculation and results of numerical methods. On the basis of the results from numerical studies, it is designed and fabricated to generate radiated 0.1GW-0.1THz for 30ns, electromagnetic wave on the range of millimeter wave through these studies.

Background Miliary tuberculosis (TB) is an unusual cause of acute respiratory distress syndrome (ARDS). Objective To evaluate the clinical characteristics and outcomes of patients with ARDS caused by miliary TB admitted to the intensive care unit (ICU). Design A total of 67 patients were enrolled during the period 1999-2008. Results The median age of the patients was 56 years (range 17-81), 19 (28.4%) were aged >71 years, and 38 (56.7%) were male. All-cause mortality in the ICU and hospital were respectively 58.2% and 61.2%. Of the total number of enrolled patients, 49 (73.1%) were prescribed anti-tuberculosis medication within 3 days of hospital admission. On the day of ARDS diagnosis (10.0 ± 3.7 vs. 7.4 ± 3.5, P = 0.005), non-survivors had a significantly higher Sequential Organ Failure Assessment (SOFA) score than survivors. Multivariate analysis showed that SOFA score on the day of ARDS diagnosis was a significant predictor of survival (OR 0.809, 95%CI 0.691-0.946, P = 0.008). It was difficult to determine the efficacy of systemic corticosteroids on patient survival. Conclusion ARDS caused by miliary TB was associated with a high in-hospital mortality rate, with SOFA score on the day of ARDS diagnosis being a valuable prognostic indicator.

We report a thermionic Pierce electron gun, which has been designed, developed and experimentally tested for getting desired performance for W-band LIGA fabricated devices like folded waveguide backward-wave oscillator (FWBWO). This gun has used thermionic dispenser cathode of 1.6 mm button diameter with corresponding cathode emission loading around 2.5 A/cm2 . It is delivering 50 mA beam current at 12 kV beam voltage with 0.36 mm beam waist radius. The current density of beam is estimated at the beam waist position.

Gliomatosis cerebri is a diffuse infiltrative glial neoplasm frequently involving both cerebral hemispheres. Diagnosis and evaluation of its extent with CT are known to be difficult. The purpose of this study was to compare the MR and CT findings in gliomatosis cerebri.MR images of nine patients were reviewed retrospectively and compared with CT scans. Pathology was determined by open or stereotaxic biopsy. The MR images included sagittal T1-weighted, axial proton density-weighted, and T2-weighted images. Contrast material was administered in seven patients. Unenhanced and enhanced CT scans were obtained in eight patients.On proton density-weighted and T2-weighted MR images, the most common findings were poorly defined bilateral areas of diffuse high signal intensity in the cerebral hemisphere. On T1-weighted images, the lesions were isointense to hypointense compared with normal brain. Enhanced T1-weighted images showed focal parenchymal enhancement in three patients and meningeal enhancement in one. On CT scans, the lesions showed poorly defined areas of subtle low density or isodensity, and appeared much smaller than those on T2-weighted MR images. Enhancement was seen in only one case. The extent of disease was evaluated much better on T2-weighted MR images than on T1-weighted MR images and CT scans.In gliomatosis cerebri, MR imaging is more sensitive than CT for detecting lesions and shows the extent of disease better than CT does. Accordingly, MR imaging should be used as a primary imaging study in the evaluation of gliomatosis cerebri.

Previous work on obtaining beam centroid position information using a beam excited resonant cavity with two orthogonal TM110 modes was extended to a higher harmonic cavity. The cavity operated at a frequency of 3220 MHz, the fourth harmonic of the accelerator frequency, and was fine tuned by using the frequency shift caused by varying the size of the beam hole. As predicted by beam-cavity interaction theory, the cavity output signal was shown to be proportional both to the square of the beam centroid displacement and to the square of beam current, and to be well correlated with position information obtained by self-powered ?-ray detectors. A crystal and a singly balanced mixer were used to process this signal to give information of both magnitude and sign of the beam position. The cavity was used to observe the effects on beam position when slow (0.01 Hz) sinusoidal disturbances were applied to three accelerator parameters: forward power, frequency and phase. Corresponding changes in the beam position have been found. The preliminary results of an automatic beam centering control show that slow disturbances on beam position can be corrected by driving a steering magnet with the cavity signals.