5,161 research outputs found
Are we missing the target? Are we aiming too low? What are the aerobic exercise prescriptions and their effects on markers of cardiovascular health and systemic inflammation in patients with knee osteoarthritis? A systematic review and meta-analysis
Objectives We systemically reviewed published studies that evaluated aerobic exercise interventions in patients with knee osteoarthritis (OA) to: (1) report the frequency, intensity, type and time (FITT) of exercise prescriptions and (2) quantify the changes in markers of cardiovascular health and systemic inflammation. Data sources PubMed, CINAHL, Scopus; inception to January 2019. Eligibility criteria Randomised clinical trials (RCT), cohort studies, case series. Design We summarised exercise prescriptions for all studies and calculated effect sizes with 95% CIs for between-group (RCTs that compared exercise and control groups) and within-group (pre-post exercise) differences in aerobic capacity (VO2), heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP) and inflammatory markers (interleukin-6 (IL-6), tumour necrosis factor-alpha). We pooled results where possible using random effects models. Results Interventions from 49 studies were summarised; 8% (4/49) met all FITT guidelines; 16% (8/49) met all or most FITT guidelines. Fourteen studies (10 RCTs) reported at least one marker of cardiovascular health or systemic inflammation. Mean differences (95% CI) indicated a small to moderate increase in VO2(0.84 mL/min/kg; 95% CI 0.37 to 1.31), decrease in HR (-3.56 beats per minute; 95% CI -5.60 to -1.52) and DBP (-4.10 mm Hg; 95% CI -4.82 to -3.38) and no change in SBP (-0.36 mm Hg; 95% CI -3.88 to 3.16) and IL-6 (0.37 pg/mL; 95% CI -0.11 to 0.85). Within-group differences were also small to moderate. Conclusions In studies of aerobic exercise in patients with knee OA, very few interventions met guideline-recommended dose; there were small to moderate changes in markers of cardiovascular health and no decrease in markers of systemic inflammation. These findings question whether aerobic exercise is being used to its full potential in patients with knee OA. PROSPERO registration number CRD42018087859
Electronic Liquid Crystal Phases of a Doped Mott Insulator
The character of the ground state of an antiferromagnetic insulator is
fundamentally altered upon addition of even a small amount of charge. The added
charges agglomerate along domain walls at which the spin correlations, which
may or may not remain long-ranged, suffer a phase shift. In two
dimensions, these domain walls are ``stripes'' which are either insulating, or
conducting, i.e. metallic rivers with their own low energy degrees of freedom.
However, quasi one-dimensional metals typically undergo a transition to an
insulating ordered charge density wave (CDW) state at low temperatures. Here it
is shown that such a transition is eliminated if the zero-point energy of
transverse stripe fluctuations is sufficiently large in comparison to the CDW
coupling between stripes. As a consequence, there exist novel,
liquid-crystalline low-temperature phases -- an electron smectic, with
crystalline order in one direction, but liquid-like correlations in the other,
and an electron nematic with orientational order but no long-range positional
order. These phases, which constitute new states of matter, can be either high
temperature supeconductors or two-dimensional anisotropic ``metallic''
non-Fermi liquids. Evidence for the new phases may already have been obtained
by neutron scattering experiments in the cuprate superconductor,
La_{1.6-x}Nd_{0.4}Sr_xCuO_{4}.Comment: 5 pages in RevTex with two figures in ep
Methodological bias in cluster randomised trials
Background: Cluster randomised trials can be susceptible to a range of methodological problems. These problems are not commonly recognised by many researchers. In this paper we discuss the issues that can lead to bias in cluster trials. Methods: We used a sample of cluster randomised trials from a recent review and from a systematic review of hip protectors. We compared the mean age of participants between intervention groups in a sample of 'good' cluster trials with a sample of potentially biased trials. We also compared the effect sizes, in a funnel plot, between hip protector trials that used individual randomisation compared with those that used cluster randomisation. Results: There is a tendency for cluster trials, with evidence methodological biases, to also show an age imbalance between treatment groups. In a funnel plot we show that all cluster trials show a large positive effect of hip protectors whilst individually randomised trials show a range of positive and negative effects, suggesting that cluster trials may be producing a biased estimate of effect. Conclusion: Methodological biases in the design and execution of cluster randomised trials is frequent. Some of these biases associated with the use of cluster designs can be avoided through careful attention to the design of cluster trials. Firstly, if possible, individual allocation should be used. Secondly, if cluster allocation is required, then ideally participants should be identified before random allocation of the clusters. Third, if prior identification is not possible, then an independent recruiter should be used to recruit participants
A systematic review of naturalistic interventions in refugee populations
Naturalistic interventions with refugee populations examine outcomes following mental health interventions in existing refugee service organisations. The current review aimed to examine outcomes of naturalistic interventions and quality of the naturalistic intervention literature in refugee populations with the view to highlight the strengths and limitations of naturalistic intervention studies. Database search was conducted using the search terms ‘refugee’, ‘asylum seeker’, ‘treatment’, ‘therapy’ and ‘intervention. No date limitations were applied, but searches were limited to articles written in English. Seven studies were identified that assessed the outcome of naturalistic interventions on adult refugees or asylum seekers in a country of resettlement using quantitative outcome measures. Results showed significant variation in the outcomes of naturalistic intervention studies, with a trend towards showing decreased symptomatology at post-intervention. However, conclusions are limited by methodological problems of the studies reviewed, particularly poor documentation of intervention methods and lack of control in the design of naturalistic intervention studies. Further examination of outcomes following naturalistic interventions is needed with studies which focus on increasing the rigour of the outcome assessment process
The HAC Trial (Harmonic for Acute Cholecystitis) Study. Randomized, double-blind, controlled trial of Harmonic(H) versus Monopolar Diathermy (M) for laparoscopic cholecystectomy (LC) for acute cholecystitis (AC) in adults
<p>Abstract</p> <p>Background</p> <p>In the developmental stage of laparoscopic cholecystectomy (LC) it was considered 'unsafe' or 'technically difficult' to perform laparoscopic cholecystectomy for acute cholecystitis (AC). With increasing experience in laparoscopic surgery, a number of centers have reported on the use of laparoscopic cholecystectomy for acute cholecystitis, suggesting that it is technically feasible but at the expense of a high conversion rate, which can be up to 35 per cent and common bile duct lesions.</p> <p>The HARMONIC SCALPEL(R) (H) is the leading ultrasonic cutting and coagulating surgical device, offering surgeons important benefits including: minimal lateral thermal tissue damage, minimal charring and desiccation.</p> <p>Harmonic Scalpel technology reduces the need for ligatures with simultaneous cutting and coagulation: moreover there is not electricity to or through the patient Harmonic Scalpel has a greater precision near vital structures and it produces minimal smoke with improved visibility in the surgical field.</p> <p>In retrospective series LC performed with H was demonstrated feasible and effective with minimal operating time and blood loss: it was reported also a low conversion rate (3.9%).</p> <p>However there are not prospective randomized controlled trials showing the advantages of H compared to MD (the commonly used electrical scalpel) in LC.</p> <p>Methods/Design</p> <p>Aim of this RCT is to demonstrate that H can decrease the conversion rate compared to MD in LC for AC, without a significant increase of morbidity.</p> <p>The patients will be allocated in two groups: in the first group the patient will be submitted to early LC within 72 hours after the diagnosis with H while in the second group will be submitted to early LC within 72 hours with MD.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov Identifier: NCT00746850</p
The magnetic nature of disk accretion onto black holes
Although disk accretion onto compact objects - white dwarfs, neutron stars,
and black holes - is central to much of high energy astrophysics, the
mechanisms which enable this process have remained observationally elusive.
Accretion disks must transfer angular momentum for matter to travel radially
inward onto the compact object. Internal viscosity from magnetic processes and
disk winds can in principle both transfer angular momentum, but hitherto we
lacked evidence that either occurs. Here we report that an X-ray-absorbing wind
discovered in an observation of the stellar-mass black hole binary GRO J1655-40
must be powered by a magnetic process that can also drive accretion through the
disk. Detailed spectral analysis and modeling of the wind shows that it can
only be powered by pressure generated by magnetic viscosity internal to the
disk or magnetocentrifugal forces. This result demonstrates that disk accretion
onto black holes is a fundamentally magnetic process.Comment: 15 pages, 2 color figures, accepted for publication in Nature.
Supplemental materials may be obtained by clicking
http://www.astro.lsa.umich.edu/~jonmm/nature1655.p
Вирішення проблеми поводження з твердими побутовими відходами на території м. Павлоград
В Україні практично відсутня система переробки твердих побутових відходів (ТПВ).
Більша кількість ТПВ вивозиться на сміттєві звалища, які не відповідають європейським
стандартам. Звалища ТПВ є джерелом утворення значної кількості токсичних фільтратів і
газів, що негативно впливає на комфортність проживання населення. Тому виникає
необхідність в оцінці рівнів забруднення прилеглих територій та рівня екологічної небезпеки
звалищ ТПВ для довкілля та здоров’я місцевих мешканців. Таку оцінку доцільно проводити
за допомогою методів фітоіндикації
Cancer incidence in British vegetarians
Background:
Few prospective studies have examined cancer incidence among vegetarians.
Methods:
We studied 61 566 British men and women, comprising 32 403 meat eaters, 8562 non-meat eaters who did eat fish ('fish eaters') and 20 601 vegetarians. After an average follow-up of 12.2 years, there were 3350 incident cancers of which 2204 were among meat eaters, 317 among fish eaters and 829 among vegetarians. Relative risks (RRs) were estimated by Cox regression, stratified by sex and recruitment protocol and adjusted for age, smoking, alcohol, body mass index, physical activity level and, for women only, parity and oral contraceptive use.
Results:
There was significant heterogeneity in cancer risk between groups for the following four cancer sites: stomach cancer, RRs (compared with meat eaters) of 0.29 (95% CI: 0.07–1.20) in fish eaters and 0.36 (0.16–0.78) in vegetarians, P for heterogeneity=0.007; ovarian cancer, RRs of 0.37 (0.18–0.77) in fish eaters and 0.69 (0.45–1.07) in vegetarians, P for heterogeneity=0.007; bladder cancer, RRs of 0.81 (0.36–1.81) in fish eaters and 0.47 (0.25–0.89) in vegetarians, P for heterogeneity=0.05; and cancers of the lymphatic and haematopoietic tissues, RRs of 0.85 (0.56–1.29) in fish eaters and 0.55 (0.39–0.78) in vegetarians, P for heterogeneity=0.002. The RRs for all malignant neoplasms were 0.82 (0.73–0.93) in fish eaters and 0.88 (0.81–0.96) in vegetarians (P for heterogeneity=0.001).
Conclusion:
The incidence of some cancers may be lower in fish eaters and vegetarians than in meat eaters
Evaluation of healing prosthetic materials polyester mesh resorbable film and collagen elastin matrix /polypropylene used in rabbits abdominal wall defects
From Luttinger to Fermi liquids in organic conductors
This chapter reviews the effects of interactions in quasi-one dimensional
systems, such as the Bechgaard and Fabre salts, and in particular the Luttinger
liquid physics. It discusses in details how transport measurements both d.c.
and a.c. allow to probe such a physics. It also examine the dimensional
crossover and deconfinement transition occurring between the one dimensional
case and the higher dimensional one resulting from the hopping of electrons
between chains in the quasi-one dimensional structure.Comment: To be published In the book "The Physics of Organic Conductors and
Superconductors", Springer, 2007, ed. A. Lebe
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