365 research outputs found
A Novel Thin NIPAM Gel Cassette Dosimeter for Photon-Beam Radiotherapy
The response of thin polymer gel cassettes (called NIPAM gels) to ionizing radiation was investigated in this study. The NIPAM gels were prepared from gelatin, N-isopropyl acrylamide, tetrakis (hydroxymethyl) phosphoniumchloride, and N,N′-methylene-bis-acrylamide. Gel cassettes were irradiated in a phantom using a linear accelerator, and the polymerization morphology of irradiated NIPAM gel was characterized using scanning electron microscopy. The dose-response sensitivity of the NIPAM gels was evaluated using the differences in optical densities. The optical densities were obtained using a computer-controlled CCD camera that was connected to a planar illumination source for acquisition of optical transmission images. The central axis depth dose profiles of the phantom were extracted, and a comparison with ionization chamber measurements demonstrated similarities in profiles. The sensitivity, linearity of the response, accuracy, and reproducibility of the polymer gel cassettes were acceptable. However, the profiles of the half-blocked field irradiation showed no significant dispersion in the visible region. This study also extensively investigated the spatial stability of the NIPAM gel. The results showed that the gel cassette response remains stable for up to three months after irradiation
Mixed-state long-range order and criticality from measurement and feedback
We propose a general framework for using local measurements, local unitaries,
and non-local classical communication to construct quantum channels which can
efficiently prepare mixed states with long-range quantum order or quantum
criticality. As an illustration, symmetry-protected topological (SPT) phases
can be universally converted into mixed-states with long-range entanglement,
which can undergo phase transitions with quantum critical correlations of local
operators and a logarithmic scaling of the entanglement negativity, despite
coexisting with volume-law entropy. Within the same framework, we present two
applications using fermion occupation number measurement to convert (i) spinful
free fermions in one dimension into a quantum-critical mixed state with
enhanced algebraic correlations between spins and (ii) Chern insulators into a
mixed state with critical quantum correlations in the bulk. The latter is an
example where mixed-state quantum criticality can emerge from a gapped state of
matter in constant depth using local quantum operations and non-local classical
communication.Comment: 25 pages, 11 figure
Measurement as a shortcut to long-range entangled quantum matter
The preparation of long-range entangled states using unitary circuits is
limited by Lieb-Robinson bounds, but circuits with projective measurements and
feedback (``adaptive circuits'') can evade such restrictions. We introduce
three classes of local adaptive circuits that enable low-depth preparation of
long-range entangled quantum matter characterized by gapped topological orders
and conformal field theories (CFTs). The three classes are inspired by distinct
physical insights, including tensor-network constructions, multiscale
entanglement renormalization ansatz (MERA), and parton constructions. A large
class of topological orders, including chiral topological order, can be
prepared in constant depth or time, and one-dimensional CFT states and
non-abelian topological orders with both solvable and non-solvable groups can
be prepared in depth scaling logarithmically with system size. We also build on
a recently discovered correspondence between symmetry-protected topological
phases and long-range entanglement to derive efficient protocols for preparing
symmetry-enriched topological order and arbitrary CSS (Calderbank-Shor-Steane)
codes. Our work illustrates the practical and conceptual versatility of
measurement for state preparation.Comment: 22 pages, 9 figures, restructured, relation to Ref. [7, 8] clarifie
The effectiveness of different health education strategies in people with pre-diabetes: A randomized controlled trial
Background. People with pre-diabetes often lack knowledge of their risks of developing diabetes. In one of our previous study, Multi-Approach Health Education was shown evidence to be effective on health behavior of reducing risks of developing diabetes. However, which one approach is really effective and efficient need further investigation. Purpose. To examine the effects of different intervention strategies on diabetes prevention knowledge, exercise, dietary behavior, and physiological indicators for people with pre-diabetes. Methods. This was a randomly controlled trial. People who received health examination and were found fasting blood glucose higher than normal, between 100 - 125 mg/dl in 2011 were recruited. Three types of intervention were randomly assigned to 3 groups respectively. The control group (n=51) received a health education lecture. One experimental group (n=48) received the identical lecture plus telephone encouragement. The second experimental group (n=41) received the identical lecture plus a health reminder poster in their daily life. The outcomes were evaluated for the change in knowledge of diabetes prevention, exercise behavior, dietary behavior, and physiological outcomes at 6 and 12 weeks after the lecture of three groups, respectively. Results. Three intervention strategies were equally efficacious at inducing positive behavioral changes but overall the magnitudes of physiological changes were the same. In general, the maximum change in parameters was achieved after 6 weeks and maintained in the second 6 weeks of the study. Conclusions. Educating people with pre-diabetes about their condition can have a positive effect upon their health behaviors. However, education lecture coupled with a telephone follow up or plus educational posters were found no more effective than lecture alone. The lecture alone of health education may be enough for people with pre-diabetes, but the long term effect needs further investigation
Effects of mycophenolate mofetil on cutaneous lupus erythematosus in (NZBÂ Ă—Â NZW) F1 mice
AbstractBackgroundFew studies have evaluated the effects and precise molecular mechanism of mycophenolate mofetil (MMF) in the treatment of human cutaneous lupus erythematosus (CLE). Our findings shed light on the therapeutic effects of MMF in a UVB-induced NZB × NZW (NZBW) F1 CLE mouse model.MethodsContinuous MMF treatment (60 mg/kg/day) was administered up to Day 50 from the beginning of UVB induction (Day 0; 20 weeks old), as the pathologic features of CLE are present after 50 days. The therapeutic effects of MMF treatment in NZBW lupus mice were examined by comparing histopathological changes, lupus band test (deposition of immune complexes at the dermal–epidermal junction) and colocalization of autoantibodies with a dermal autoantigen Dsg3, and by evaluating the associations of local matrix metalloprotease activities.ResultsMMF improved survival in the NZBW lupus mice from 35.7% to 81.8%. The proteinuria, blood urea nitrogen, and interleukin 6 levels were significantly reduced after MMF treatment. The dermal lymphocytic infiltration, deposition of immune complexes at the dermal–epidermal junction, colocalized autoantibodies with Dsg3, and epidermal matrix metalloprotease activity were also attenuated in MMF-treated NZBW F1 mice.ConclusionThe results confirmed that MMF could substantially attenuate skin damage due to CLE in the NZBW F1 mouse model
The relations between 3-year changes in physical fitness and academic performance in nationally representative sample of junior high school students
Abstract The objective of the current study was to examine the relationship between different components of physical fitness across 3 years of junior high school with academic performance assessed at the end of the period. Two nationwide representative datasets were used. The first was the physical fitness profile assessed at the beginning of each of the three school years. The second contained the scores on a standardized test administered at the end of the third year. All data were standardized by calculating percentile rank (PR). Students were classified as “High-fit” if their fitness scores ≧ top 25% PR on the age- and sex-adjusted norms. All other students were classified as “not high-fit”. The relationships between fitness and exam performance were tested adjusting for sex, body mass index, and level of urbanization. Students who were in the high-fit group in both years 1 and 3 academically outperformed those who were outside this classification during both assessments. The degree of outperformance was greatest for those who were aerobically fit, followed by those who were high-fit in terms of muscular endurance, muscular strength, and flexibility, respectively. It is therefore concluded that the relationship between physical fitness and academic performance in Taiwanese junior high school students is strongest in the case of aerobic fitness
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