181 research outputs found
Infrared Signature of the Superconducting State in Pr(2-x)Ce(x)CuO(4)
We measured the far infrared reflectivity of two superconducting
Pr(2-x)Ce(x)CuO(4) films above and below Tc. The reflectivity in the
superconducting state increases and the optical conductivity drops at low
energies, in agreement with the opening of a (possibly) anisotropic
superconducting gap. The maximum energy of the gap scales roughly with Tc as 2
Delta_{max} / kB Tc ~ 4.7. We determined absolute values of the penetration
depth at 5 K as lambda_{ab} = (3300 +/- 700) A for x = 0.15 and lambda_{ab} =
(2000 +/- 300) A for x = 0.17. A spectral weight analysis shows that the
Ferrell-Glover-Tinkham sum rule is satisfied at conventional low energy scales
\~ 4 Delta_{max}.Comment: 4 pages, 4 figure
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Pancreas Cancer-Associated Weight Loss.
Unintentional weight loss in patients with pancreatic cancer is highly prevalent and contributes to low therapeutic tolerance, reduced quality of life, and overall mortality. Weight loss in pancreatic cancer can be due to anorexia, malabsorption, and/or cachexia. Proper supportive care can stabilize or reverse weight loss in patients and improve outcomes. We review the literature on supportive care relevant to pancreatic cancer patients, and offer evidence-based recommendations that include expert nutritional assessment, counseling, supportive measures to ensure adequate caloric intake, pancreatic enzyme supplementation, nutritional supplement replacement, orexigenic agents, and exercise. Pancreatic Cancer Action Network-supported initiatives will spearhead the dissemination and adoption of these best supportive care practices. IMPLICATIONS FOR PRACTICE: Weight loss in pancreatic cancer patients is endemic, as 85% of pancreatic cancer patients meet the classic definition of cancer cachexia. Despite its significant prevalence and associated morbidity, there is no established approach to this disease entity. It is believed that this is due to an important knowledge gap in understanding the underlying biology and lack of optimal treatment approaches. This article reviews the literature regarding pancreas cancer-associated weight loss and establishes a new framework from which to view this complex clinical problem. An improved approach and understanding will help educate clinicians, improve clinical care, and provide more clarity for future clinical investigation
On the optical conductivity of Electron-Doped Cuprates I: Mott Physics
The doping and temperature dependent conductivity of electron-doped cuprates
is analysed. The variation of kinetic energy with doping is shown to imply that
the materials are approximately as strongly correlated as the hole-doped
materials. The optical spectrum is fit to a quasiparticle scattering model;
while the model fits the optical data well, gross inconsistencies with
photoemission data are found, implying the presence of a large, strongly doping
dependent Landau parameter
Infrared Hall conductivity of NaCoO
We report infrared Hall conductivity of
NaCoO thin films determined from Faraday rotation angle
measurements. exhibits two types of hole
conduction, Drude and incoherent carriers. The coherent Drude carrier shows a
large renormalized mass and Fermi liquid-like behavior of Hall scattering rate,
. The spectral weight is suppressed and disappears at T
= 120K. The incoherent carrier response is centered at mid-IR frequency and
shifts to lower energy with increasing T. Infrared Hall constant is positive
and almost independent of temperature in sharp contrast with the dc-Hall
constant.Comment: 5 Pages, 5 Figures. Author list corrected in metadata only, paper is
unchange
Probing pairing symmetry of Sm_{1.85}Ce_{0.15}CuO_4 via highly-sensitive voltage measurements: Evidence for strong impurity scattering
Using a highly-sensitive home-made mutual-inductance technique, temperature
profiles of the magnetic penetration depth in the optimally-doped
thin films have been extracted. The low-temperature
behavior of is found to be best-fitted by linear and quadratic laws above and below ,
respectively, which clearly indicates the presence of d-wave pairing mechanism
dominated by strong paramagnetic scattering at the lowest temperatures. The
best fits produce and
for the estimates of the nodal gap parameter and impurity scattering rate
Infrared Properties of Electron Doped Cuprates: Tracking Normal State Gaps and Quantum Critical Behavior in Pr(2-x)Ce(x)CuO(4)
We report the temperature dependence of the infrared-visible conductivity of
Pr(2-x)Ce(x)CuO(4) thin films. When varying the doping from a
non-superconducting film (x = 0.11) to a superconducting overdoped film (x =
0.17), we observe, up to optimal doping (x = 0.15), a partial gap opening. A
model combining a spin density wave gap and a frequency and temperature
dependent self energy reproduces our data reasonably well. The magnitude of
this gap extrapolates to zero for x ~ 0.17 indicating the coexistence of
magnetism and superconductivity in this material and the existence of a quantum
critical point at this Ce concentration.Comment: 5 pages 6 figures include
Assessment of needs, health-related quality of life, and satisfaction with care in breast cancer patients to better target supportive care
Background This study assessed whether breast cancer (BC) patients express similar levels of needs for equivalent severity of symptoms, functioning difficulties, or degrees of satisfaction with care aspects. BC patients who did (or not) report needs in spite of similar difficulties were identified among their sociodemographic or clinical characteristics. Patients and methods Three hundred and eighty-four (73% response rate) BC patients recruited in ambulatory or surgery hospital services completed the European Organisation for Research and Treatment of Cancer Quality of Life questionnaire (EORTC QLQ)-C30 quality of life [health-related quality of life (HRQOL)], the EORTC IN-PATSAT32 (in-patient) or OUT-PATSAT35 (out-patient) satisfaction with care, and the supportive care needs survey short form 34-item (SCNS-SF34) measures. Results HRQOL or satisfaction with care scale scores explained 41%, 45%, 40% and 22% of variance in, respectively, psychological, physical/daily living needs, information/health system, and care/support needs (P < 0.001). BC patients' education level, having children, hospital service attendance, and anxiety/depression levels significantly predicted differences in psychological needs relative to corresponding difficulties (adjusted R2 = 0.11). Medical history and anxiety/depression levels significantly predicted differences in information/health system needs relative to degrees of satisfaction with doctors, nurses, or radiotherapy technicians and general satisfaction (adjusted R2 = 0.12). Unmet needs were most prevalent in the psychological domains across hospital services. Conclusions Assessment of needs, HRQOL, and satisfaction with care highlights the subgroups of BC patients requiring better supportive care targetin
The impact of members of the Society of University Surgeons on the scholarship of American surgery
Background
A core objective of the Society of University Surgeons (SUS) is research focused: to “advance the art and science of surgery through original investigation.” This study sought to determine the current impact of the SUS on academic surgical productivity.
Methods
Individual faculty data for numbers of publications, citations, and National Institute of Health (NIH) funding history were collected for 4,015 surgical faculty at the top 55 NIH-funded departments of surgery using SCOPUS and the NIH Research Portfolio Online Reporting Tools. SUS membership was determined from membership registry data.
Results
Overall, 502 surgical faculty (12.5%) were SUS members with 92.7% holding positions of associate or full professor (versus 59% of nonmembers). Median publications (P) and citations (C) among SUS members were P: 112, C: 2,460 versus P: 29, C: 467 for nonmembers (P < .001). Academic productivity was considerably higher by rank for SUS members than for nonmembers: associate professors (P: 61 vs 36, C: 1,199 vs 591, P < .001) and full professors (P: 141 vs 81, C: 3,537 vs 1,856, P < .001). Among full professors, SUS members had much higher rates of NIH funding than did nonmembers (52.6% vs 26%, P < .05) and specifically for R01, P01, and U01 awards (37% vs 17.7%, P < .01). SUS members were 2 times more likely to serve in divisional leadership or chair positions (23.5% vs 10.2%, P < .05).
Conclusion
SUS society members are a highly productive academic group. These data support the premise that the SUS is meeting its research mission and identify its members as very academically productive contributors to research and scholarship in American surgery and medicine
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