Plasma amyloid ß levels in Alzheimer's disease and cognitively normal controls in Syrian population.

Background: The pathogenesis of Alzheimer's disease (AD) is believed to be occurred by the production of neurotic plaques of the beta-amyloid peptide (Aß) and deposition of them. Therefore, biomarkers of abnormal Aß processing may represent before the AD clinical biomarkers, which could be benefit for a successful disease management that may prevent the AD development. The aim of this study is to investigate of plasma Aß40,42 levels in Alzheimer's patients in Syria and thus determine whether they may have a potential role as biomarker for identifying and predicting AD. Methods: In this cross-sectional study, the plasma levels of Aß1-40 and Aß1-42 were investigated in two groups represent Syrian population, AD group; clinically diagnosed AD patients (n=50) and CN group; cognitively normal participants (n=33). This study first determined the reference interval of plasma Aß1-40 and Aß1-42 for cognitively normal Syrian. Results were analyzed using SPSS, 24, depending on independent-samples t test, considering that the value of p < 0.05 is statistically significant. Results: The results showed that the plasma levels of Aß1-40 (p<0.001, OR=1.031, 95%CI: 1.012-1.051) and Aß1-42 (p<0.001, OR=1.306, 95%CI: 1.145-1.490) were significantly higher in AD patients than in cognitively normal participants, and no significant association was shown between both of education and sex with plasma Aß levels. Conclusion: The plasma levels of Aß1-40 and Aß1-42 could be potential biomarkers for identifying and predicting AD.

Effectiveness of physical therapy treatment of clearly defined subacromial pain: a systematic review of randomised controlled trials.

AIM: To summarise the current evidence regarding the effectiveness of physical therapy on pain, function and range of motion in individuals with subacromial pain syndrome (SAPS). DESIGN: Systematic review. DATA SOURCES: PubMed, Web of Science, CINAHL, Cochrane, Embase, Lilacs, Ibecs and Scielo databases. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Randomised controlled trials (RCTs) investigating physical therapy modalities for SAPS on pain, function/disability or range of motion were included. RESULTS: 64 high-quality RCTs were included. Exercise therapy provided high evidence of being as effective as surgery intervention and better than no treatment or placebo treatment to improve pain, function and range of motion in the short, mid and long terms. The combination of mobilisation and exercises provided high evidence to decrease pain and improve function in the short term. There is limited evidence for improvements on the outcomes with the isolated application of manual therapy. High level of evidence was synthesised regarding the lack of beneficial effects of physical resources such as low-level laser, ultrasound and pulsed electromagnetic field (PEMF) on pain, function or range of motion in the treatment of SAPS. There is limited evidence for microwave diathermy and transcutaneous electrical nerve stimulation. There is moderate evidence to no benefits with taping in the short term. Effects of diacutaneous fibrolysis and acupuncture are not well established yet. CONCLUSIONS: Exercise therapy should be the first-line treatment to improve pain, function and range of motion. The addition of mobilisations to exercises may accelerate reduction of pain in the short term. Low-level laser therapy, PEMF and taping should not be recommended.

Investigating the energy harvesting capabilities of a hybrid ZnO nanowires/carbon fiber polymer composite beam.

Hybrid piezoelectric composite structures that are able to convert mechanical energy into electricity have gained growing attention in the past few years. In this work, an energy harvesting composite beam is developed by growing piezoelectric zinc oxide nanowires on the surface of carbon fiber prior to forming structural composites. The piezoelectric behavior of the composite beam was demonstrated under different vibration sources such as water bath sonicator and permanent magnet vibration shaker. The beam was excited at its fundamental natural frequency (43.2 Hz) and the open circuit voltage and the short circuit current were measured to be 3.1 mV and 23 nA, respectively. Upon connecting an optimal resistor (1.2 kΩ) in series with the beam a maximum power output 2.5 nW was achieved.

Hybrid carbon fiber/carbon nanotube composites for structural damping applications.

Carbon nanotubes (CNTs) were grown on the surface of carbon fibers utilizing a relatively low temperature synthesis technique; graphitic structures by design (GSD). To probe the effects of the synthesis protocols on the mechanical properties, other samples with surface grown CNTs were prepared using catalytic chemical vapor deposition (CCVD). The woven graphite fabrics were thermally shielded with a thin film of SiO2 and CNTs were grown on top of this film. Raman spectroscopy and electron microscopy revealed the grown species to be multi-walled carbon nanotubes (MWCNTs). The damping performance of the hybrid CNT-carbon fiber-reinforced epoxy composite was examined using dynamic mechanical analysis (DMA). Mechanical testing confirmed that the degradations in the strength and stiffness as a result of the GSD process are far less than those encountered through using the CCVD technique and yet are negligible compared to the reference samples. The DMA results indicated that, despite the minimal degradation in the storage modulus, the loss tangent (damping) for the hybrid composites utilizing GSD-grown MWCNTs improved by 56% compared to the reference samples (based on raw carbon fibers with no surface treatment or surface grown carbon nanotubes) over the frequency range 1-60 Hz. These results indicated that the energy dissipation in the GSD-grown MWCNTs composite can be primarily attributed to the frictional sliding at the nanotube/epoxy interface and to a lesser extent to the stiff thermal shielding SiO2 film on the fiber/matrix interface.

Electrical conductivity of synergistically hybridized nanocomposites based on graphite nanoplatelets and carbon nanotubes.

In this investigation, a recent model for assessing the electrical conductivity of nanocomposites comprising a single type of conductive nanofiller was expanded to cases with mixtures of nanofillers. The extended model considers electron tunneling as the effective mechanism for insulator-conductor transition. The model was validated with relevant experimental data based on a mono-nanofiller. Using the extended model, the effective electrical conductivity of a nanocomposite comprising both graphite nanoplatelets and carbon nanotubes was investigated. It was observed that the hybridized nanocomposites filled with a mixture of these conductive nanofillers attain, synergistically, enhanced electrical conductivities at lower volume fractions. The lower filler contents assist in preserving the intrinsic properties of the host polymer in support of several applications. It was also observed that the relative aspect ratios of the conductive fillers play significant roles on the electrical conductivity of the hybrid nanocomposite. Simulations revealed that, generally, the addition of minimal amounts of a higher aspect ratio auxiliary phase to a lower aspect ratio main phase enhances the electrical conductivity of the composite by orders of magnitude.

Effect of chirality and length on the penetrability of single-walled carbon nanotubes into lipid bilayer cell membranes.

The ability of carbon nanotubes to enter the cell membrane acting as drug-delivery vehicles has yielded a plethora of experimental investigations, mostly with inconclusive results because of the wide spectra of carbon nanotube structures. Because of the virtual impossibility of synthesizing CNTs with distinct chirality, we report a parametric study on the use of molecular dynamics to provide better insight into the effect of the carbon nanotube chirality and the aspect ratio on the interaction with a lipid bilayer membrane. The simulation results indicated that a single-walled carbon nanotube utilizes different time-evolving mechanisms to facilitate their internalization within the membrane. These mechanisms comprise both penetration and endocytosis. It was observed that carbon nanotubes with higher aspect ratios penetrate the membrane faster whereas shorter nanotubes undergo significant rotation during the final stages of endocytosis. Furthermore, nanotubes with lower chiral indices developed significant adhesion with the membrane. This adhesion is hypothesized to consume some of the carbon nanotube energy, thus resulting in longer times for the nanotube to translocate through the membrane.

Synthesis of WS2 nanostructures from the reaction of WO3 with CS2 and mechanical characterization of WS2 nanotube composites.

Tungsten disulfide (WS(2)) nanometer sheets, spheres, fibers and tubes were generated by a synthetic pathway that avoids the use of H(2)S as the source of sulfur and employs instead CS(2) vapor, carried by an Ar or N(2)/H(2) stream in a heated tubular furnace, for the reaction with WO(3) precursor powders. The experiments were conducted at temperatures between 700 and 1000 °C, while the reaction times expanded between 30 min and 24 h. Characterization methods used to analyze the products of the synthesis include TEM, SEM, XRD and EDX. We found a strong correlation between precursor and product microstructure, although the temperature and reaction times play a critical role in the products' microstructural features as well. WS(2) inorganic fullerene (IF) nanospheres are generated in a wide window of conditions, while nanotubes and nanofibers are only produced at high temperatures or long reaction times. A proposed growth mechanism based on the CS(2) synthetic approach is presented. Nanoindentation and nano-impulse techniques were used to characterize the mechanical properties of polymer matrix-WS(2) nanotube composites, finding them superior to equivalent SWCNT composites. The improvements in toughness of nanocomposites based on WS(2) can be attributed to geometrical and morphological effects that assisted several toughening mechanisms such as crack pinning and the formation of an immobilized polymeric interphase around the nanotubes.

Pain in workers with shoulder impingement syndrome: an assessment using the DASH and McGill pain questionnaires

OBJECTIVE: This study assessed physical function and pain in male and female workers with shoulder impingement syndrome using the Brazilian Portuguese versions of the Disabilities of the Arm, Shoulder and Hand (DASH) and McGill pain questionnaires. METHODS: Twenty-seven assembly line workers (18 men and 9 women; mean age of 33.26 ± 6.49 years) in the school supply industry were evaluated. The duration of the shoulder impingement pain was 31.74 ± 32.92 months and the amount of time of the workers in this industry was 11.08 ± 6.41 years. The DASH questionnaire was used to evaluate functional status and symptoms of the upper limbs of the workers. Using the McGill Pain Questionnaire, the pain was quantified by the number of words chosen and by the pain rating index (PRI). RESULTS: The women presented higher scores (P< 0.05) than the men for both DASH overall and DASH work scores. The women chose more words (17.00 ± 2.59) than the men (13.33 ± 3.16) and also presented the highest total PRI (P< 0.05). CONCLUSIONS: The results obtained in this group of Brazilian workers with shoulder impingement identify the most commonly used descriptors of shoulder pain. Further, this study shows that females are more likely than males to refer physical disability and pain. Also, the DASH and McGill pain questionnaires are important and helpful tools in the clinical evaluation of shoulder impingement syndrome.

OBJETIVO: Este estudo avaliou função física e dor em trabalhadores com síndrome do impacto através das versões brasileiras dos questionários "Disabilities of the Arm, Shoulder and Hand" (DASH) e McGill de dor. MÉTODO: Vinte e sete trabalhadores (18 homens e 9 mulheres; idade média de 33,26 ± 6,49 anos) de uma linha de produção de uma indústria de material escolar foram avaliados. O tempo de duração de dor no ombro era de 31,74 ± 32,92 meses e o tempo de trabalho na indústria era de 11,08 ± 6,41 anos. O questionário DASH foi utilizado para avaliar o estado funcional e os sintomas dos membros superiores dos trabalhadores. Através do questionário McGill de dor, a dor foi quantificada pelo número de palavras escolhidas e pelo índice de classificação da dor (ICD). RESULTADOS: As mulheres apresentaram maiores escores (P< 0,05) que os homens para ambos os módulos do DASH. As mulheres escolheram mais palavras (17,00 ± 2,59) que os homens (13,33 ± 3,16) e também apresentaram o maior ICD total (P< 0,05). CONCLUSÃO: Os resultados obtidos neste grupo de trabalhadores brasileiros com síndrome do impacto do ombro identificam os mais comuns descritores utilizados para dor no ombro. Além disso, este estudo mostra que as mulheres estão mais propensas a relatarem incapacidade física e dor quando comparadas aos homens. Os questionários DASH e McGill de dor são ferramentas importantes e úteis na avaliação clínica da síndrome do impacto do ombro.