2,573 research outputs found
Sharp Global Bounds for the Hessian on Pseudo-Hermitian Manifolds
We find sharp bounds for the norm inequality on a Pseudo-hermitian manifold,
where the L^2 norm of all second derivatives of the function involving
horizontal derivatives is controlled by the L^2 norm of the sub-Laplacian.
Perturbation allows us to get a-priori bounds for solutions to sub-elliptic PDE
in non-divergence form with bounded measurable coefficients. The method of
proof is through a Bochner technique. The Heisenberg group is seen to be en
extremal manifold for our inequality in the class of manifolds whose Ricci
curvature is non-negative.Comment: 13 page
Advance directive and preference of old age home residents for community model of end-of-life care in Hong Kong
Key Messages:
1. Among 1600 cognitively normal elderly persons living in old age homes in Hong Kong, 88% preferred palliative treatments that could keep them comfortable and free from pain, and 88% agreed to have advance directives. Factors that favour having advance directives among Chinese elders included the practice of asking for relatives’ advice in medical decisions, wishing to be informed of their terminal illness diagnoses, absence of a stroke history, and having no problems in self-care.
2. Approximately one third of old age home residents would accept dying in place. Older age, religion (Catholic or non-believer of traditional Chinese religion), having a better mood score (Geriatric Depression Scale), having no siblings, not receiving an old age allowance, and being a resident of subvented old age homes were independent predictors of preference for community end-of-life care and dying in place.
3. End-of-life care in the hospital was expensive. The total bed-day costs for the 2084 deaths in the two clusters for the index death episode, cumulative 3, 6, and 12 months of hospitalisation were HK82 543 510, HK108 960 348, respectively. The annual cost-savings in hospitalisation bed-days would be HK$177 million when about 30% of elders accepted dying in their old age homes.
4. Elderly residents were willing to pay an additional fee for community end-of-life care services in old age homes. Both the services of the doctor and old age home staff were important attributes. Hence, elderly people were prepared to use more community end-of-life care if better staff and doctor services were provided.published_or_final_versio
Advance directive and end-of-life care preferences among Chinese nursing home residents in Hong Kong
OBJECTIVES: The objectives of the present study were to describe the knowledge and preferences of Hong Kong Chinese older adults regarding advance directives and end-of-life care decisions, and to investigate the predictors of preferences for advance directive and community end-of-life care in nursing homes. METHODS: This was a cross-sectional survey conducted in 140 nursing homes in Hong Kong. A total of 1600 cognitively normal Chinese older adults were recruited. Information on demographics, social, medical diseases, preferences of end-of-life care decisions, and advance directives were collected by face-to-face questionnaire interviews. RESULTS: The mean age of the participants was 82.4 years; 94.2% of them would prefer to be informed of the diagnosis if they had terminal diseases and 88.0% preferred to have their advance directives regarding medical treatment in the future. Approximately 35% would prefer to die in their nursing homes. The significant independent predictors for the preference of advance directive included asking for relatives' advice, wishing to be informed of their terminal illness diagnoses, absence of stroke, and having no problems in self-care in European Quality of Life-5 Dimensions. For the preference for community end-of-life care and dying in nursing homes, the independent predictors included older age, not having siblings in Hong Kong, Catholic religion, nonbeliever of traditional Chinese religion, not receiving any old age allowance, lower Geriatric Depression Scale score, and being residents of government-subsidized nursing homes. CONCLUSIONS: Most of our cognitively normal Chinese nursing home older adults prefer having an advance directive, and one-third of them would prefer to die in nursing homes.postprin
Mesenchymal stem cells and immunomodulation: current status and future prospects
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Direct photon production with effective field theory
The production of hard photons in hadronic collisions is studied using
Soft-Collinear Effective Theory (SCET). This is the first application of SCET
to a physical, observable cross section involving energetic partons in more
than two directions. A factorization formula is derived which involves a
non-trivial interplay of the angular dependence in the hard and soft functions,
both quark and gluon jet functions, and multiple partonic channels. The
relevant hard, jet and soft functions are computed to one loop and their
anomalous dimensions are determined to three loops. The final resummed
inclusive direct photon distribution is valid to next-to-next-to-leading
logarithmic order (NNLL), one order beyond previous work. The result is
improved by including non-logarithmic terms and photon isolation cuts through
matching, and compared to Tevatron data and to fixed order results at the
Tevatron and the LHC. The resummed cross section has a significantly smaller
theoretical uncertainty than the next-to-leading fixed-order result,
particularly at high transverse momentum.Comment: 42 pages, 9 figures; v2: references added, minor changes; v3: typos;
v4: typos, corrections in (16), (47), (72
Role of domain walls in the abnormal photovoltaic effect in BiFeO3
Recently, the anomalous photovoltaic (PV) effect in BiFeO3 (BFO) thin
films, which resulted in open circuit voltages (V-oc) considerably
larger than the band gap of the material, has generated a revival of the
entire field of photoferroelectrics. Here, via temperature-dependent PV
studies, we prove that the bulk photovoltaic (BPV) effect, which has
been studied in the past for many non-centrosymmetric materials, is at
the origin of the anomalous PV effect in BFO films. Moreover, we show
that irrespective of the measurement geometry, V-oc as high as 50V can
be achieved by controlling the conductivity of domain walls (DW). We
also show that photoconductivity of the DW is markedly higher than in
the bulk of BFO
Insensitivity of Human iPS Cells-derived Mesenchymal Stem Cells to Interferon-γ -induced HLA Expression Potentiates Repair Efficiency of Hind Limb Ischemia in Immune Humanized NOD Scid Gamma Mice
published_or_final_versio
A Formalism for the Systematic Treatment of Rapidity Logarithms in Quantum Field Theory
Many observables in QCD rely upon the resummation of perturbation theory to
retain predictive power. Resummation follows after one factorizes the cross
section into the rele- vant modes. The class of observables which are sensitive
to soft recoil effects are particularly challenging to factorize and resum
since they involve rapidity logarithms. In this paper we will present a
formalism which allows one to factorize and resum the perturbative series for
such observables in a systematic fashion through the notion of a "rapidity
renormalization group". That is, a Collin-Soper like equation is realized as a
renormalization group equation, but has a more universal applicability to
observables beyond the traditional transverse momentum dependent parton
distribution functions (TMDPDFs) and the Sudakov form factor. This formalism
has the feature that it allows one to track the (non-standard) scheme
dependence which is inherent in any scenario where one performs a resummation
of rapidity divergences. We present a pedagogical introduction to the formalism
by applying it to the well-known massive Sudakov form factor. The formalism is
then used to study observables of current interest. A factorization theorem for
the transverse momentum distribution of Higgs production is presented along
with the result for the resummed cross section at NLL. Our formalism allows one
to define gauge invariant TMDPDFs which are independent of both the hard
scattering amplitude and the soft function, i.e. they are uni- versal. We
present details of the factorization and resummation of the jet broadening
cross section including a renormalization in pT space. We furthermore show how
to regulate and renormalize exclusive processes which are plagued by endpoint
singularities in such a way as to allow for a consistent resummation.Comment: Typos in Appendix C corrected, as well as a typo in eq. 5.6
A non-enzymatic amperometric hydrogen peroxide sensor based on iron nanoparticles decorated reduced graphene oxide nanocomposite
© 2016 Elsevier Inc. A simple and facile green process was used for the synthesis of iron nanoparticles (FeNPs) decorated reduced graphene oxide (rGO) nanocomposite by using Ipomoea pes-tigridis leaf extract as a reducing and stabilizing agent. The as-prepared rGO/FeNPs nanocomposite was characterized by transmission electron microscopy, X-ray spectroscopy and Fourier transform infrared spectroscopy. The nanocomposite was further modified on the glassy carbon electrode and used for non-enzymatic sensing of hydrogen peroxide (H2O2). Cyclic voltammetry results reveal that rGO/FeNPs nanocomposite has excellent electro-reduction behavior to H2O2 when compared to the response of FeNPs and rGO modified electrodes. Furthermore, the nanocomposite modified electrode shows 9 and 6 folds enhanced reduction current response to H2O2 than that of rGO and FeNPs modified electrodes. Amperometric method was further used to quantify the H2O2 using rGO/FeNPs nanocomposite, and the response was linear over the concentration ranging from 0.1 μM to 2.15 mM. The detection limit and sensitivity of the sensor were estimated as 0.056 μM and 0.2085 μA μM−1 cm−2, respectively. The fabricated sensor also utilized for detection of H2O2 in the presence of potentially active interfering species, and found high selectivity towards H2O2
Nonequilibrium Dynamics in Noncommutative Spacetime
We study the effects of spacetime noncommutativity on the nonequilibrium
dynamics of particles in a thermal bath. We show that the noncommutative
thermal bath does not suffer from any further IR/UV mixing problem in the sense
that all the finite-temperature non-planar quantities are free from infrared
singularities. We also point out that the combined effect of finite temperature
and noncommutative geometry has a distinct effect on the nonequilibrium
dynamics of particles propagating in a thermal bath: depending on the momentum
of the mode of concern, noncommutative geometry may switch on or switch off
their decay and thermalization. This momentum dependent alternation of the
decay and thermalization rates could have significant impacts on the
nonequilibrium phenomena in the early universe at which spacetime
noncommutativity may be present. Our results suggest a re-examination of some
of the important processes in the early universe such as reheating after
inflation, baryogenesis and the freeze-out of superheavy dark matter
candidates.Comment: 24 pages, 2 figure
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