An investigation of the association between grip strength and hip and knee joint moments in older adults

Grip strength is a predictor of health outcomes but with differing rates of age-related decline in muscle strength, it is unclear whether handgrip is a reliable indicator of lower limb moments. This study investigated the relationship between grip strength and lower extremity moments in community-dwelling older adults. Eighty-two healthy volunteers aged 60-82 years (mean age 73.2 years) performed maximal voluntary contractions of knee and hip extensors and flexors at three positions and at neutral position for hip abductors and adductors using a custom-built dynamometer. Grip strength was measured using an electronic Jamar dynamometer. The relative reduction in muscle strength of 80s age category compared to 60-year-olds ranged from 14% for grip strength to 27% for hip abductors. Peak torque of flexors and extensors of the knee and hip joints were significantly correlated with grip strength and Pearson's correlation coefficients ranged from 0.56 to 0.78 with the highest correlations observed between knee moments and grip strength. "Good" correlation was found but only 31-60% of the variation in grip strength could be related to changes in joint torques. Hence the assumption that grip strength is an indicator of strength in the lower limb would seem unjustified in the healthy older adult.     

An association study of disease activity score components and patient satisfaction with overall health for early RA patients on non-biologic DMARD therapy

Patient overall satisfaction with health (PSH) was measured by a subset of questions from the Arthritis Impact Measurement Scales II. Based on longitudinal observations for 267 early rheumatoid arthritis (RA) patients of the United States Western Consortium (WC) cohort receiving first non-biologic DMARD treatment, we estimated the 1-year change in PSH ( $\Updelta$ PSH). Logistic regression analysis was used to estimate the association of improvement in $\Updelta$ PSH with the core set of clinical and patient-reported components of disease activity scores (DAS). Most patients were more satisfied with health after 1?year of treatment (80%); few achieved DAS28-ESR minimal disease activity (27%) or remission (7%). Laboratory and joint count measures were not associated with improved 12-month PSH. Patients with greater HAQ-DI (P = 0.0473) and self-reported stiffness (P = 0.0669) were more likely to have a perceived overall health benefit from treatment. Regardless of objective disease status, patients are generally satisfied with first-line treatment, which could present a challenge to implementing DAS-guided treatment change. Patients with greater self-reported functional limitations might have lower expectations for treatment benefit and be less willing to modify their current therapy; subjective assessments of function and stiffness could be particularly useful in identifying these patients.     

Valproic acid enhances the efficacy of radiation therapy by protecting normal hippocampal neurons and sensitizing malignant glioblastoma cells

Neurocognitive deficits are serious sequelae that follow cranial irradiation used to treat patients with medulloblastoma and other brain neoplasms. Cranial irradiation causes apoptosis in the subgranular zone of the hippocampus leading to cognitive deficits. Valproic acid (VPA) treatment protected hippocampal neurons from radiation-induced damage in both cell culture and animal models. Radioprotection was observed in VPA-treated neuronal cells compared to cells treated with radiation alone. This protection is specific to normal neuronal cells and did not extend to cancer cells. In fact, VPA acted as a radiosensitizer in brain cancer cells. VPA treatment induced cell cycle arrest in cancer cells but not in normal neuronal cells. The level of anti-apoptotic protein Bcl-2 was increased and the pro-apoptotic protein Bax was reduced in VPA treated normal cells. VPA inhibited the activities of histone deacetylase (HDAC) and glycogen synthase kinase-3β (GSK3β), the latter of which is only inhibited in normal cells. The combination of VPA and radiation was most effective in inhibiting tumor growth in heterotopic brain tumor models. An intracranial orthotopic glioma tumor model was used to evaluate tumor growth by using dynamic contrast-enhanced magnetic resonance (DCE MRI) and mouse survival following treatment with VPA and radiation. VPA, in combination with radiation, significantly delayed tumor growth and improved mouse survival. Overall, VPA protects normal hippocampal neurons and not cancer cells from radiation-induced cytotoxicity both in vitro and in vivo. VPA treatment has the potential for attenuating neurocognitive deficits associated with cranial irradiation while enhancing the efficiency of glioma radiotherapy.     

Tetrahydropyrazolopyridines as antifriction and antiwear agents: experimental and DFT calculations

Some tetrahydropyrazolopyridines (THPP-H) with the methoxy (THPP-OMe) and methyl (THPP-Me) substituents were synthesized by a one-pot multi-component reaction. NMR spectroscopy (¹H and ¹³C) was used to authenticate the synthesis. According to the results of tribological tests ASTM D4172, and ASTM D5183 on a four-ball tester in paraffin oil (PO) at a concentration of 0.25% w/v, their relative tribo-activity along with a reference additive, zinc dialkyldithiophosphate (ZDDP) could be figured out as mentioned below-THPP-OMe > THPP-Me > THPP-H > ZDDP. The calculation of frictional power loss from the coefficient of friction data of the tested additives supports the given order. As is apparent from AFM and SEM micrographs of the wear scar surface for plain oil with and without different tetrahydropyrazopyridines, surface evenness endorses the above trend. Proof for strong adsorption of the synthesized additives is provided by EDX analysis of the steel ball surface after performing the tribological test, where nitrogen and oxygen are vividly seen as heteroatoms. XPS studies reveal the composition of the in situ formed tribofilm. The moieties containing carbon bonded to oxygen/nitrogen as decomposed products of the additive together with oxides of iron in +II or +III oxidation states are perceptible in the tribofilm, the tribofilm interferes with the proximity of the surfaces keeping them far apart. Consequently, friction and wear are remarkably reduced. Findings from Density Functional Theory (DFT) calculations are in full agreement with the results obtained from tribological experiments.

MWD in the presence of PO and its admixture with THPP-OMe.     

Promoting formic acid oxidation performance of Pd nanoparticles via Pt and Ru atom mediated surface engineering

The alteration of surface functional properties via incorporation of foreign atoms is supposed to be a key strategy for the enhanced catalytic performance of noble-metal based nanocatalysts (NCs). In the present study, carbon-supported palladium (Pd)-based NCs including Pd, PdPt and PdRuPt have been prepared via a polyol reduction method under the same reduction conditions as for formic acid oxidation reaction (FAOR) applications. By cross-referencing the results of the microscopic, spectroscopic and electrochemical analysis we demonstrated that adding a small amount of platinum (Pt) into Pd NCs (i.e. PdPt NCs) significantly promotes the FAOR performance as compared to that of Pd NCs via weakening the CO^ads bond strength at a lower voltage (0.875 V vs. NHE) than Pd (0.891 V vs. NHE). Of special relevance, the PdPt NC shows a mass activity (MA) of 1.0 A mg⁻¹ and 1.9 A mg⁻¹, respectively, in the anodic and cathodic scan. These values are ∼1.7-fold (0.6 A mg⁻¹) and ∼4.8-fold (0.4 A mg⁻¹) higher than those of Pd NC. Moreover, PdPt NC retains a higher MA (54 mA mg⁻¹) than that of Pd NC (9 mA mg⁻¹) after chronoamperometric (CA) stability tests over 2000 s. Meanwhile, further addition of ruthenium (Ru) (i.e. PdRuPt NCs) outstandingly enhances the CO tolerance during the CA test via removal of adsorbed CO^ads and thus shows the highest MA (62 mA mg⁻¹) after CA testing, which is higher than that of PdPt (54 mA mg⁻¹) and Pd (9 mA mg⁻¹) NCs. The intriguing results obtained in this study have great significance to provide further strategic opportunities for tuning the surface electronic properties of Pd-based NCs to design Pd-based NCs with improved electrochemical performance.

Pt atoms attract electrons from neighboring atoms. Ru atoms attract hydroxide ligands. These two characteristics respectively weaken the bonding and recovering of the Pt site from CO oxidation and then facilitate the FAO in ternary PdPtRu NCs.