1,232 research outputs found
Reduced physical activity in young and older adults: metabolic and musculoskeletal implications
Background: Although the health benefits of regular physical activity and exercise are well established and have been incorporated into national public health recommendations, there is a relative lack of understanding pertaining to the harmful effects of physical inactivity. Experimental paradigms including complete immobilization and bed rest are not physiologically representative of sedentary living. A useful âreal-worldâ approach to contextualize the physiology of societal downward shifts in physical activity patterns is that of short-term daily step reduction.
Results: Step-reduction studies have largely focused on musculoskeletal and metabolic health parameters, providing relevant disease models for metabolic syndrome, type 2 diabetes (T2D), nonalcoholic fatty liver disease (NAFLD), sarcopenia and osteopenia/osteoporosis. In untrained individuals, even a short-term reduction in physical activity has a significant impact on skeletal muscle protein and carbohydrate metabolism, causing anabolic resistance and peripheral insulin resistance, respectively. From a metabolic perspective, short-term inactivity-induced peripheral insulin resistance in skeletal muscle and adipose tissue, with consequent liver triglyceride accumulation, leads to hepatic insulin resistance and a characteristic dyslipidaemia. Concomitantly, various inactivity-related factors contribute to a decline in function; a reduction in cardiorespiratory fitness, muscle mass and muscle strength.
Conclusions: Physical inactivity maybe particularly deleterious in certain patient populations, such as those at high risk of T2D or in the elderly, considering concomitant sarcopenia or osteoporosis. The effects of short-term physical inactivity (with step reduction) are reversible on resumption of habitual physical activity in younger people, but less so in older adults. Nutritional interventions and resistance training offer potential strategies to prevent these deleterious metabolic and musculoskeletal effects.
Impact: Individuals at high risk of/with cardiometabolic disease and older adults may be more prone to these acute periods of inactivity due to acute illness or hospitalization. Understanding the risks is paramount to implementing countermeasures
Injectable Poly-l-Lactic Acid: A Novel Sculpting Agent for the Treatment of Dermal Fat Atrophy After Severe Acne
Acne vulgaris affects up to 80% of people 11 to 30Â years of age, and scarring can occur for up to 95% of these patients. Scarring may be pitted or hypertrophic in nature, although in most cases it is atrophic. Atrophic acne scarring follows dermal collagen and fat loss after moderate to severe acne infection. Injectable poly-L-acid (PLLA) is a biocompatible, biodegradable, synthetic polymer device that is hypothesized to enhance dermal volume via the endogenous production of fibroblasts and, subsequently, collagen. The gradual improvements in cutaneous volume observed after treatment with injectable PLLA have been noted to last up to 2Â years. The case studies presented describe the use of injectable PLLA to correct dermal fat loss in macular atrophic acne scarring of the cheeks. Two female patients underwent three treatment sessions with injectable PLLA over a 12-week period. At each treatment session, the reconstituted product was injected into the deep dermis under the depressed portion of the scar. Both patients were extremely pleased with their results at, respectively, 1- and 4-year follow-up evaluations. Patients experienced minimal swelling and redness after injection and no product-related adverse events such as papule and/or nodule formation. The author believes these data suggest that injectable PLLA is a good treatment option for the correction of macular atropic scarring with thin dermis (off-label use), particularly compared with other injectable fillers currently used for this indication that have shorter durations of effect
Multimodal Management of Atrophic Acne Scarring in the Aging Face
Atrophic facial acne scarring is a widely prevalent condition that can have a negative impact on a patientâs quality of life. The appearance of these scars is often worsened by the normal effects of aging. A number of options are available for the treatment of acne scarring, including chemical peeling, dermabrasion, ablative or nonablative laser resurfacing, dermal fillers, and surgical techniques such as subcision or punch excision. Depending on the type and extent of scarring, a multimodal approach is generally necessary to provide satisfactory results. Resurfacing techniques correct surface irregularities, long-lasting dermal fillers address the volume loss resulting from acne, and sub-superficial musculoaponeurotic system (SMAS) face-lift procedures counter the soft tissue laxity and ptosis associated with aging. This article briefly reviews the evolution of individual approaches to treating atrophic acne scarring, followed by case examples illustrating results that can be achieved using a multimodal approach. Representative cases from patients in their 30s, 40s, and 50s are presented. In the authorâs clinical practice, multimodal approaches incorporating fractionated laser, injectable poly-l-lactic acid, and sub-SMAS face-lift procedures have achieved optimal aesthetic outcomes, high patient satisfaction, and durability of aesthetic effect over time
Stationary Black Holes: Uniqueness and Beyond
The spectrum of known black-hole solutions to the stationary Einstein
equations has been steadily increasing, sometimes in unexpected ways. In
particular, it has turned out that not all black-hole-equilibrium
configurations are characterized by their mass, angular momentum and global
charges. Moreover, the high degree of symmetry displayed by vacuum and
electro-vacuum black-hole spacetimes ceases to exist in self-gravitating
non-linear field theories. This text aims to review some developments in the
subject and to discuss them in light of the uniqueness theorem for the
Einstein-Maxwell system.Comment: Major update of the original version by Markus Heusler from 1998.
Piotr T. Chru\'sciel and Jo\~ao Lopes Costa succeeded to this review's
authorship. Significantly restructured and updated all sections; changes are
too numerous to be usefully described here. The number of references
increased from 186 to 32
Clinical symptoms and chemotherapy completion in elderly patients with newly diagnosed acute leukemia: a retrospective comparison study with a younger cohort
<p>Abstract</p> <p>Background</p> <p>Cancer affects older adults disproportionately. The disease is often difficult to diagnose and treat due to co-morbidities and performance status, and patients tend to discontinue chemotherapy prematurely. There are no systemic studies of the reasons and factors that create a higher withdrawal rate in older acute leukemia patients. This study tried to understand the initial characteristics, blood counts and bone marrow measurements in older acute leukemia patients by comparing them with a younger group to provide information and assistance in early clinical diagnosis, treatment and reasons for treatment withdrawal.</p> <p>Methods</p> <p>Using retrospective medical record reviews, we examined clinical characteristics and chemotherapy completion status in the patients of two groups (age â„ 60, n = 183 and age <60, n = 183) who were diagnosed with acute leukemia for the first time and were hospitalized in Union Hospital Affiliated with Fujian Medical University from 2004 to 2008.</p> <p>Results</p> <p>There were no statistical differences in initial presenting symptoms of fatigue (67.2% vs. 57.9%, <it>P</it>>0.05) and pallor (53% vs. 59.6%, <it>P</it>>0.05) between the two groups, but older patients demonstrated more underlying diseases including lung infections (25.7%, <it>P </it>= <0.001), cardiovascular disease (4.4%, <it>P </it>= 0.007), and hypertension (20.8%, <it>P </it>=< 0.001). The complete remission rate after chemotherapy (1 to 2 courses) was 49.5% in the older group and 66.7% in the younger group (Ï<sup>2 </sup>= 6.202, <it>P </it>= 0.013). The percentage of patients age 60 and older who prematurely discontinued chemotherapy (50.3%), mainly due to the influences of traditional Chinese concept of critical illness, financial difficulties, and intolerance to adverse reactions to chemotherapy, was significantly higher than that of younger patients (37.7%) (Ï<sup>2 </sup>= 5.866, <it>P </it>= 0.015).</p> <p>Conclusions</p> <p>A comprehensive approach to diagnosis, treatment selection, and toxicity management, and implementing strategies to enhance treatment compliance may improve outcomes in older adults with acute leukemia.</p
The Universal One-Loop Effective Action
We present the universal one-loop effective action for all operators of
dimension up to six obtained by integrating out massive, non-degenerate
multiplets. Our general expression may be applied to loops of heavy fermions or
bosons, and has been checked against partial results available in the
literature. The broad applicability of this approach simplifies one-loop
matching from an ultraviolet model to a lower-energy effective field theory
(EFT), a procedure which is now reduced to the evaluation of a combination of
matrices in our universal expression, without any loop integrals to evaluate.
We illustrate the relationship of our results to the Standard Model (SM) EFT,
using as an example the supersymmetric stop and sbottom squark Lagrangian and
extracting from our universal expression the Wilson coefficients of
dimension-six operators composed of SM fields.Comment: 30 pages, v2 contains additional comments and corrects typos, version
accepted for publication in JHE
f(R) theories
Over the past decade, f(R) theories have been extensively studied as one of
the simplest modifications to General Relativity. In this article we review
various applications of f(R) theories to cosmology and gravity - such as
inflation, dark energy, local gravity constraints, cosmological perturbations,
and spherically symmetric solutions in weak and strong gravitational
backgrounds. We present a number of ways to distinguish those theories from
General Relativity observationally and experimentally. We also discuss the
extension to other modified gravity theories such as Brans-Dicke theory and
Gauss-Bonnet gravity, and address models that can satisfy both cosmological and
local gravity constraints.Comment: 156 pages, 14 figures, Invited review article in Living Reviews in
Relativity, Published version, Comments are welcom
Hadronic Mass Moments in Inclusive Semileptonic B Meson Decays
We have measured the first and second moments of the hadronic mass-squared
distribution in B -> X_c l nu, for P(lepton) > 1.5 GeV/c. We find <M_X^2 -
M_D[Bar]^2> = 0.251 +- 0.066 GeV^2, )^2 > = 0.576 +- 0.170
GeV^4, where M_D[Bar] is the spin-averaged D meson mass.
From that first moment and the first moment of the photon energy spectrum in
b -> s gamma, we find the HQET parameter lambda_1 (MS[Bar], to order 1/M^3 and
beta_0 alpha_s^2) to be -0.24 +- 0.11 GeV^2. Using these first moments and the
B semileptonic width, and assuming parton-hadron duality, we obtain |V_cb| =
0.0404 +- 0.0013.Comment: 11 pages postscript, also available through
http://w4.lns.cornell.edu/public/CLNS, submitted to PR
Observation of the Charmed Baryon at CLEO
The CLEO experiment at the CESR collider has used 13.7 fb of data to
search for the production of the (css-ground state) in
collisions at {\rm GeV}. The modes used to
study the are ,
, , , and
. We observe a signal of 40.49.0(stat) events
at a mass of 2694.62.6(stat)1.9(syst) {\rm MeV/}, for all modes
combined.Comment: 10 pages postscript, also available through
http://w4.lns.cornell.edu/public/CLN
Observation of and
We have studied two-body charmless hadronic decays of mesons into the
final states phi K and phi K^*. Using 9.7 million pairs collected
with the CLEO II detector, we observe the decays B- -> phi K- and B0 -> phi K*0
with the following branching fractions: BR(B- -> phi K-)=(5.5 +2.1-1.8 +- 0.6)
x 10^{-6} and BR(B0 -> phi K*0)=(11.5 +4.5-3.7 +1.8-1.7) x 10^{-6}. We also see
evidence for the decays B0 -> phi K0 and B- -> phi K*-. However, since the
statistical significance is not overwhelming for these modes we determine upper
limits of <12.3 x 10^{-6} and <22.5 x 10^{-6} (90% C.L.) respectively.Comment: 9 pages postscript, also available through
http://w4.lns.cornell.edu/public/CLN
- âŠ