Abstract Patients with chronic low back pain exhibit characteristics such as clinical pain, psychological symptoms and neuromuscular adaptations. The purpose of this study was to determine the ...independent contribution of clinical pain, psychological factors and neuromuscular adaptations to disability in patients with chronic low back pain. Clinical pain intensity, pain catastrophizing, fear-avoidance beliefs, anxiety, neuromuscular adaptations to chronic pain and neuromuscular responses to experimental pain were assessed in 52 patients with chronic low back pain. Lumbar muscle electromyographic activity was assessed during a flexion–extension task (flexion relaxation phenomenon) to assess both chronic neuromuscular adaptations and neuromuscular responses to experimental pain during the task. Multiple regressions showed that independent predictors of disability included neuromuscular adaptations to chronic pain ( β = 0.25, p = 0.006, sr2 = 0.06), neuromuscular responses to experimental pain ( β = −0.24, p = 0.011, sr2 = 0.05), clinical pain intensity ( β = 0.28, p = 0.002, sr2 = 0.08) and psychological factors ( β = 0.58, p < 0.001, sr2 = 0.32). Together, these predictors accounted for 65% of variance in disability ( R2 = 0.65 p < 0.001). The current investigation revealed that neuromuscular adaptations are independent from clinical pain intensity and psychological factors, and contribute to inter-individual differences in patients’ disability. This suggests that disability, in chronic low back pain patients, is determined by a combination of factors, including clinical pain, psychological factors and neuromuscular adaptations.
Stratification strategies based on identifying patient's prognosis in order to guide patient care constitute one of the most prominent and recent approach in low back pain research. The STarT Back ...Screening Tool (SBST) although promising, has not been studied in patients with chronic low back pain (cLBP). Considering how challenging it is to translate research into practice, the value of integrating a new tool should be thoroughly assessed. The purpose was therefore to assess associations between the short- and long-terms clinical status and two types of variables, physiologic measures and the SBST, in participants with cLBP. The ability of both types of variables to discriminate between participants with and without higher levels of disability, pain, fear of movement and patient's global impression of change was also investigated.
Fifty-three volunteers with cLBP participated in an initial evaluation and follow-ups at 2-, 4-, 6- and 12-month. Physiologic measures (maximal voluntary contraction, maximal endurance and muscle activity evaluated during prone and lateral isometric tasks) and the SBST were assessed at baseline. Disability (Oswestry Disability Index, ODI), pain intensity (101-point Numerical Rating Scale, NRS), fear of movement (Tampa Scale for Kinesiophobia, TSK) and patient's global impression of change (7-point scale, PGIC) were evaluated at baseline and at each follow-up. Aside the use of correlation analyses to assess potential associations; ROC curves were performed to evaluate the discriminative ability of physiologic measures and the SBST.
The SBST allowed for the identification of participants presenting higher levels of disability (ODI ≥24 %), pain (NRS ≥37 %) or fear of movement (TSK ≥41/68) over a 12-month period (AUC = 0.71 to 0.84, ps < 0.05). The SBST score was also correlated with disability at each follow-up (τ = 0.22 to 0.33, ps < 0.05) and with pain intensity and fear of movement at follow-ups. Among physiologic measures, only maximal voluntary contraction was correlated to disability, pain intensity or fear of movement during the follow-up (|τ| = 0.26 to 0.32, ps < 0.05) and none was able to identify participants presenting higher levels of outcomes (AUC ps > 0.05).
Physiologic measures obtained during prone and lateral tests have limited associations with the clinical status over a 12-month period in patients with nonspecific chronic low back pain. On the other hand, the STarT Back Screening Tool is useful for the identification of patients who will present higher levels of disability, pain intensity and fear of movement over a year.
Clinicaltrials.gov NCT02226692.
Active photothermal effects of aluminum nanoenergetics are demonstrated to control spatially and temporally the ignition of propane/air flames. High-speed chemiluminescence images of hydroxyl (OH*) ...and methylidyne (CH*) radicals and aluminum oxide (AlO) are employed to confirm the local flame ignition and propagation by activation of the nanoenergetics through the use of a single exposure from a xenon flash lamp. The photothermal effects of the nanoenergetics can efficiently activate the localized exothermal aluminum oxidation reactions, leading to sequential flame ignition. Most of the energy required for ignition is provided by the oxidation reaction of the aluminum nanoparticles such that the photothermal MIE (Minimum Ignition Energy) is at least 67 times less than that from regular spark ignition.
Significant reduction of the breakdown threshold in a DC microdischarge via seeding metal nanoparticles has been demonstrated. Compared to standard Paschen curves in dry air, reductions in the ...breakdown voltage of 5% to 25% were obtained for
PD
values (the product of pressure and electrode gap distance) ranging from 20 to 40 Torr-cm by seeding aluminum and iron nanoparticles with mean sizes of 75 nm and 80 nm, respectively. No secondary energy source was required to achieve this breakdown threshold reduction. From high-speed chemiluminescence imaging of the discharge evolution, breakdown was shown to be initiated at reduced voltages. Following breakdown, the increase in temperature ignited some of the nanoparticles near the cathode. Results suggest that possible charging of the nanoparticles within the gap may reduce the effective transient distance, leading to the threshold reduction.
Introduction Changes in sensorimotor function and increased trunk muscle fatigability have been identified in patients with chronic low back pain (cLBP). This study assessed the control of trunk ...force production in conditions with and without local erector spinae muscle vibration and evaluated the influence of muscle fatigue on trunk sensorimotor control. Methods Twenty non-specific cLBP patients and 20 healthy participants were asked to perform submaximal isometric trunk extension torque with and without local vibration stimulation, before and after a trunk extensor muscle fatigue protocol. Constant error (CE), variable error (VE) as well as absolute error (AE) in peak torque were computed and compared across conditions. Trunk extensor muscle activation during isometric contractions and during the fatigue protocol was measured using surface electromyography (sEMG). Results Force reproduction accuracy of the trunk was significantly lower in the patient group (CE = 9.81 plus or minus 2.23 Nm; AE = 18.16 plus or minus 3.97 Nm) than in healthy participants (CE = 4.44 plus or minus 1.68 Nm; AE = 12.23 plus or minus 2.44 Nm). Local erector spinae vibration induced a significant reduction in CE (4.33 plus or minus 2.14 Nm) and AE (13.71 plus or minus 3.45 Nm) mean scores in the patient group. Healthy participants conversely showed a significant increase in CE (8.17 plus or minus 2.10 Nm) and AE (16.29 plus or minus 2.82 Nm) mean scores under vibration conditions. The fatigue protocol induced erector spinae muscle fatigue as illustrated by a significant decrease in sEMG median time-frequency slopes. Following the fatigue protocol, patients with cLBP showed significant decrease in sEMG root mean square activity at L4-5 level and responded in similar manner with and without vibration stimulation in regard to CE mean scores. Conclusions Patients with cLBP have a less accurate force reproduction sense than healthy participants. Local muscle vibration led to significant trunk neuromuscular control improvements in the cLBP patients before and after a muscle fatigue protocol. Muscle vibration stimulation during motor control exercises is likely to influence motor adaptation and could be considered in the treatment of cLBP. Further work is needed to clearly identify at what levels of the sensorimotor system these gains are achievable.
Highlights • A retrospective study was performed to better describe the antimicrobial susceptibility pattern of bacterial isolates in Lebanon. • The susceptibility testing results of a total 20 684 ...Gram-positive and 55 594 Gram-negative bacteria were analyzed. • The prevalence rate of methicillin-resistant Staphylococcus aureus was 27.6% and of vancomycin-resistant enterococci was 1%. • The extended-spectrum beta-lactamase production rate of Escherichia coli and Klebsiella spp was 32.3% and 29.2%, respectively. • Pseudomonas susceptibilities to piperacillin–tazobactam and imipenem were lower than 80%. • Acinetobacter showed high resistance to most antibiotics. • Streptococcus pneumoniae had susceptibilities of 56% to penicillin, 63% to erythromycin, and 98% to levofloxacin. • Streptococcus pyogenes had susceptibilities of 93% to erythromycin and 94% to clindamycin. • The mean ampicillin susceptibility of Haemophilus influenzae , Salmonella, and Shigella isolates was 79%, 81.3%, and 62.2%, respectively..
There is a lack of official national antimicrobial resistance (AMR) data in Lebanon. Individual hospitals generate their own antibiotic susceptibility data in the form of yearly pamphlets.
In this ...study, antibiotic susceptibility data from 13 hospitals distributed across different governorates of Lebanon were collected to conduct a compilation-based surveillance of AMR in Lebanon for the years 2015-2016. The findings were compared with those of a previous nationwide study in this country conducted between 2011 and 2013 as well as with similar data obtained from the 2015 and 2016 European surveillance reports of AMR. To provide a clear presentation of the AMR situation, mean percent susceptibility of different antibiotic-microbe combinations was calculated.
During 2015-2016, the percent susceptibility of
to third-generation cephalosporins and to carbapenems was 59 and 97%, respectively. Among
and
spp., carbapenem susceptibility reached 70 and 12%, respectively. Among Gram positive organisms, the percent susceptibility to methicillin in
was 72%, that to vancomycin in
spp. was 98% and that to penicillin in
was 75%. Compared with results of 2011-2013, there was an overall trend of decreased susceptibility of bacteria to the tested antibiotics, with a variation of 5 to 10%. The antibiotic susceptibility data from Lebanon were found to be comparable with those from Eastern and South-eastern European countries.
This study highlights the need to establish a robust national AMR surveillance system that enables data from Lebanon to be included in global AMR maps.
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