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1.
J Back Musculoskelet Rehabil ; 36(6): 1237-1250, 2023.
Article in English | MEDLINE | ID: mdl-37458013

ABSTRACT

BACKGROUND: Low back pain is one of the leading causes of disability globally, with a high economic and social burden. A decrease or imbalance in trunk strength has been associated with the occurrence of low back pain and its severity. Trunk strength training is helpful in the treatment of Non-specific low back pain (NSLBP) patients. However, we do not know the effects of trunk isokinetic training (IKT) on pain intensity, disability, and trunk strength. OBJECTIVE: This systematic review aimed to determine the effects of trunk IKT in NSLBP patients on pain intensity, disability, and trunk flexor and extensor isokinetic strength. METHODS: We searched PubMed, Web of Science, Scopus, CENTRAL, and PEDro, from January 2001 until March 2021 and updated to November 2022. Randomized controlled trials (RCTs) that investigated the effect of IKT in adult participants with NSLBP on pain intensity, disability, or isokinetic trunk strength were included. Mean difference (MD) and 95% confidence intervals (95% CI) were calculated for pain. Bias was assessed using the Cochrane risk of bias (RoB) tool and evidence certainty via Grading of Recommendations Assessment, Development and Evaluation (GRADE). RESULTS: Among 1750 retrieved articles, eight were included in this review. Meta-analysis comparing IKT (trunk isokinetic training, n= 134) with control groups (conventional exercises, n= 133) revealed that IKT decreases pain intensity (MD -1.50 (95% CI: -2.60; -0.39)) immediately post-intervention, and one month (MD -1.97 (95% CI: -2.92; -1.03)) and at six months follow-up (MD -2.48 (95% CI: -2.77; -2.19)), although with a very low to low quality according to the GRADE rating. Besides, IKT decreases disability and increases isokinetic trunk strength, but with scant evidence. CONCLUSIONS: Trunk IKT could be a novel clinical tool for pain management in patients with NSLBP, although evidence is scarce. In addition, few RCTs exist for IKT on disability or trunk isokinetic strength in patients with NSLBP. Therefore, further research on this topic is needed.


Subject(s)
Disabled Persons , Low Back Pain , Resistance Training , Adult , Humans , Low Back Pain/therapy , Exercise Therapy , Pain Measurement
2.
J Phys Condens Matter ; 34(2)2021 Oct 29.
Article in English | MEDLINE | ID: mdl-34644692

ABSTRACT

Zircon-type NdVO4and scheelite-type PrVO4have been studied by means of Raman spectroscopy up to approximately 20 GPa. In the first compound, zircon-scheelite and scheelite-fergusonite phase transitions are reported at 6.4(3) and 19.6(4) GPa, respectively. In the case of scheelite-type PrVO4, a reversible phase transition to a PbWO4-III structure is observed at 16.8(5) GPa. In both cases, a scheelite-type structure is recovered in a metastable state at low pressures. The pressure evolution of the Raman modes is also reported. Our experimental findings are supported byab initiocalculations, which allowed us to discuss the role of mechanic and dynamical instabilities in the phase transition mechanisms.

3.
J Phys Condens Matter ; 31(48): 485401, 2019 Dec 04.
Article in English | MEDLINE | ID: mdl-31422945

ABSTRACT

The promising technological material Eu0.1Bi0.9VO4, has been studied for the first time at room-temperature under high-pressure, up to 24.9 GPa, by means of in situ angle dispersive powder x-ray diffraction (XRD). The compound undergoes two phase transitions at 1.9 and 16.1 GPa. The first transition is from the monoclinic fergusonite-type structure (space group I2/a) to a tetragonal scheelite-type structure (space group I41/a), being a ferroelastic-paraelastic transformation similar to that previously reported for isomorphic pristine BiVO4. The second phase transition is first-order in nature. The scheelite-type and the second high-pressure phase coexist in a wide pressure range. A monoclinic structure (space group P21/n) is proposed for the second high-pressure phase. Both transitions are reversible upon decompression. Details of the different crystal structures are reported. All the three observed structures are composed of network of VO4 tetrahedra and BiO8 (or EuO8 due to the substitution of Bi by Eu) dodecahedra. The room-temperature P-V equation of state and axial anisotropic compressibilities of the fergusonite and scheelite polymorphs are also given. In particular, the isothermal compressibility tensor for the monoclinic fergusonite phase has been calculated.

4.
Phys Chem Chem Phys ; 20(43): 27314-27328, 2018 Nov 07.
Article in English | MEDLINE | ID: mdl-30357167

ABSTRACT

We report optical absorption and luminescence measurements in pure and trivalent neodymium (Nd3+) doped LaVO4 crystals up to 25 GPa. Nd3+ luminescence has been employed as a tool to follow the structural changes in the crystal. We also present band-structure and crystal-field calculations that provide the theoretical framework to accurately explain the observed experimental results. In particular, both optical absorption and luminescence measurements evidence that a phase transition takes place close to 12 GPa. They also provide information on the pressure dependence of the band-gap as well as the emission lines under compression. We found drastic changes in the optical properties of LaVO4 when the phase transition to a BaWO4-II structure occurs, which can be related to changes in the coordination number of vanadium ions and in the local sites of Nd3+. Reported results are analyzed in comparison with those of previous X-ray diffraction and Raman experiments, as well as with the features of related compounds. For the first time, a consistent picture is reported explaining the behavior of the optical and electronic properties of LaVO4 at high-pressures.

7.
Nanotechnology ; 28(20): 205701, 2017 May 19.
Article in English | MEDLINE | ID: mdl-28358717

ABSTRACT

This work reports the structural and vibrational properties of nanocrystals of corundum-type In2O3 (rh-In2O3) at high pressures by using angle-dispersive x-ray diffraction and Raman scattering measurements up to 30 GPa. The equation of state and the pressure dependence of the Raman-active modes of the corundum phase in nanocrystals are in good agreement with previous studies on bulk material and theoretical simulations on bulk rh-In2O3. Nanocrystalline rh-In2O3 showed stability under compression at least up to 20 GPa, unlike bulk rh-In2O3 which gradually transforms to the orthorhombic Pbca (Rh2O3-III-type) structure above 12-14 GPa. The different stability range found in nanocrystalline and bulk corundum-type In2O3 is discussed.

9.
Nanotechnology ; 27(2): 025701, 2016 Jan 15.
Article in English | MEDLINE | ID: mdl-26618997

ABSTRACT

A structural transformation from the zircon-type structure to an amorphous phase has been found in YVO4:Eu(3+) nanoboxes at high pressures above 12.7 GPa by means of x-ray diffraction measurements. However, the pair distribution function of the high-pressure phase shows that the local structure of the amorphous phase is similar to the scheelite-type YVO4. These results are confirmed both by Raman spectroscopy and Eu(3+) photoluminescence which detect the phase transition to a scheelite-type structure at 10.1 and 9.1 GPa, respectively. The irreversibility of the phase transition is observed with the three techniques after a maximum pressure in the upstroke of around 20 GPa. The existence of two (5)D0-->(7)F0 photoluminescence peaks confirms the existence of two local environments for Eu(3+), at least for the low-pressure phase. One environment is the expected for substituting Y(3+) and the other is likely a disordered environment possibly found at the surface of the nanoboxes.

10.
Inorg Chem ; 52(1): 355-61, 2013 Jan 07.
Article in English | MEDLINE | ID: mdl-23244465

ABSTRACT

The structural behavior of mineral Stromeyerite, AgCuS, has been studied by means of angle-dispersive X-ray diffraction measurements up to 13 GPa and ab initio total-energy calculations. Two high-pressure phase transitions are found at 1.4 and 5.7 GPa, from the initial distorted Ni(2)In-type phase (AuRbS-type, RP, space group Cmc2(1)) through an anti-PbClF-type phase (HP1, space group P4/nmm) to a monoclinic distortion of this latter phase (HP2, space group P2(1)/m). The collapse of the metal-metal interatomic distances at the RP-HP1 transition suggests a stronger metallic behavior of the high-pressure phase. The compressibility of the lattice parameters and the equation of state of the first pressure-induced phase have been experimentally determined. First-principles calculations present an overall agreement with the experimental results in terms of the high-pressure sequence and provide chemical insight into the AgCuS behavior under hydrostatic pressure.

11.
Gac Med Mex ; 137(4): 323-34, 2001.
Article in Spanish | MEDLINE | ID: mdl-11519356

ABSTRACT

Obesity is complex in its etiology and treatment. Its global incidence is increasing significantly. Favoring weight-loss can only bring beneficial effects. Obesity is a chronic condition with multifactorial origin. The discovery of the ob gene and its product, the OB protein or Leptin, neuropeptide Y, and the alterations of the metabolism of lipogenic tissues that inhibit appetite are significant advances in the understanding of its etiopathogenesis and treatment. This new knowledge will change the philosophy of the management of obesity. Obesity responds poorly to nonsurgical therapies. Its treatment must be long-term in spite of the considerable social and biological pressure that favor the regaining of weight. Treatment of the obese patient must be performed by a multidisciplinary team, and should include a hypoenergetic diet, exercise program, behavioral modifications, and in some instances, family therapy. The treatment of obesity should be tailored for each individual. Drug use in the treatment of obesity is not a substitute for modifying the individual's diet and physical activity. Bariatric surgery is indicated only when the BMI is greater than 30 kg/m2. Physicians and patients must interact closely and assess possible risks that are involved in its treatment against real benefits. A good relation between practitioner and patient is essential.


Subject(s)
Obesity/etiology , Obesity/therapy , Causality , Humans , Obesity/classification , Obesity/complications , Obesity/epidemiology
12.
J Synchrotron Radiat ; 5(Pt 3): 1023-5, 1998 May 01.
Article in English | MEDLINE | ID: mdl-15263732

ABSTRACT

A new method for density measurements by means of X-ray absorption under high pressure and high temperature using synchrotron radiation has been developed. The method has been modified for a large-volume Paris-Edinburgh press and combined with intense high-energy X-rays at the ESRF. In order to overcome effects of deformation of sample shape under pressure, a ruby cylinder was used as a sample container. The density was determined from the intensity profile of transmitted X-rays. The densities of crystalline and liquid Bi were successfully measured up to 750 K at 1 GPa.

13.
Phys Rev B Condens Matter ; 48(18): 13945-13948, 1993 Nov 01.
Article in English | MEDLINE | ID: mdl-10007795
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