OBJECTIVE: To evaluate the current evidence comparing low level to high level laser therapy to reveal any superiorities in the treatment of musculoskeletal disorders.
METHODS: Five databases were searched till September 2022 to obtain relevant RCTs comparing high intensity and low-level laser therapies in the management of musculoskeletal disorders. Two authors assessed the methodological quality of the included studies using the Physiotherapy Evidence Database scale and meta-analysis was conducted for studies that showed homogeneity.
RESULTS: Twelve articles were included in this systematic review with a total population of 704 participants across various musculoskeletal pathologies including tennis elbow, carpal tunnel syndrome, chronic non-specific low back pain, knee arthritis, plantar fasciitis, and subacromial impingement. There were no statistical differences between the two interventions in pain, electrophysiological parameters, level of disability, quality of life, postural sway or pressure algometer, however, Low level laser therapy showed superiority in increasing grip strength compared to high intensity laser therapy while results were significant in favour of high intensity laser therapy regarding long head of biceps diameter and cross sectional area, supraspinatus thickness and echogenicity and acromio-humeral distance.
CONCLUSIONS: The current literature suggests no superiority of both types of laser therapy in musculoskeletal disorders, however, more RCTs with larger sample size are required to reach a definitive conclusion regarding the superiority of either form of laser therapy in musculoskeletal disorders.

Loss of taste (ageusia) is a symptom observed following recovery from COVID-19 infection. The loss of taste and smell sensation may negatively affect patients\' quality of life (QoL). The present study aimed to evaluate the effectiveness of the Diode Laser in managing loss of taste sensation in patients with post-COVID syndrome versus the placebo.
The study sample was 36 patients who complained of persistent loss of taste sensation following COVID-19. The patients were randomly assigned to one of the two groups according to the received treatment: Group I (laser treatment) and Group II (light treatment), with each patient receiving a diode laser treatment or placebo from the same operator. Taste sensation was subjectively measured after treatment for four weeks.
The results demonstrated a significant difference between both groups regarding taste restoration after one month (p = 0.041), with Group II having a significantly higher percentage of cases 7 (38.9%) with partial taste restoration. In contrast, a significantly higher proportion of Group I 17 cases (94.4%) had complete taste restoration (p < 0.001).
The present study concluded that using a Diode laser 810 nm aided in a more rapid recovery from loss of taste dysfunction.

BACKGROUND: In 2019, the Food and Drug Administration revised the requirement for further testing of anti-HCV-reactive donations testing nucleic acid (NAT)-nonreactive via routine mini-pool (MP)-NAT. Individual donation (ID)-HCV NAT was required as a supplemental test prior to a second FDA-licensed anti-HCV assay; if ID-HCV-NAT is reactive, no further testing is required. This study investigated the rate of low-level RNA in anti-HCV-reactive donation samples prior to and following the implementation of supplemental ID-HCV NAT.
METHODS: A retrospective analysis was conducted on frozen plasma unit samples from 1161 anti-HCV confirmed-positive/HCV-NAT-nonreactive donations collected from December 2014 to January 2020. Samples were tested by multiple replicates on the Grifols Procleix Ultrio Elite (UE) assay and corresponding discriminatory HCV (dHCV) assay on the Procleix Panther System. Prospectively, the prevalence of low-level RNA in 2912 anti-HCV-reactive donations detected through routine screening from April 2020 through March 2021 was determined.
RESULTS: In retrospective analyses, 10 (0.86%) of 1161 plasma samples were UE reactive, of which four (0.34%) were dHCV reactive (in all replicates of UE and dHCV). Of 2912 anti-HCV-reactive donation samples testing NAT-nonreactive via routine MP-NAT, three (0.1%; 95% CI: 0.04-0.30) were dHCV reactive; 37% of the remaining samples were reactive by a second anti-HCV assay and thus serologically confirmed.
CONCLUSIONS: Retrospective and prospective analysis in comparison to earlier studies revealed that low-level HCV-RNA reactivity is decreasing over time. The very low HCV-RNA rates may be due to the widespread use of highly effective, direct-acting anti-viral treatments for those diagnosed with HCV infection.

Introduction: Myofascial pain dysfunction syndrome (MPDS) is a common temporomandibular joint disorder. Due to its multifactorial etiology, treatment usually involves more than one modality to obtain complementary results. The purpose of this study was to compare the combined effect of a low-level laser, a hard occlusal appliance, and conventional pharmacotherapy with pharmacotherapy only in the management of patients with MPDS. Methods: In this study, 15 patients with MPDS were diagnosed and randomly assigned to 3 groups (n=5). Subjects in Group 1 were treated with pharmacotherapy (PT); Group 2 received the diode laser (940 nm gallium arsenide) every other day for a total of 10 sessions, plus pharmacotherapy (PTL) and Group 3 were given hard occlusal splint 12 h/day for 4 weeks, plus pharmacotherapy (PTO). The intensity of pain was measured using the visual analog scale (VAS) prior to the treatment, 2 and 4 weeks after the onset of treatment and 2 weeks later. The maximum painless mouth opening and pain intensity at muscle palpation were also recorded. Comparisons were made between the groups via repeated measure analysis of variance (ANOVA) (P<0.05). Results: Pain relief in the subjective VAS was observed in both laser and appliance groups in the third and fourth examination sessions (P<0.05). No statistically significant reduction in pain was noted using pharmacotherapy only. The maximum painless mouth opening and muscle tenderness were not significantly different between the 3 groups (P>0.05). Conclusion: Both the laser and the occlusal appliance combined with pharmacotherapy proved to be effective for pain reduction in patients with MPDS. All groups, however, failed to result in a significant improvement in the maximum mouth opening or tenderness in masticatory muscles.

Sources of background and background variation in a BEGe type HPGe detector located in a surface laboratory were identified. Different strategies for background reduction were applied. A cosmic veto was installed, and optimised using a digital acquisition system in list-mode with time-stamped data. This resulted in the reduction of total background by a factor of 1.4. Thermal and fast neutron fluxes were also calculated. The radon induced background component and its variation were significantly reduced.

In this study we provide the analysis of eye movement behavior elicited by low-level feature distinctiveness with a dataset of synthetically-generated image patterns. Design of visual stimuli was inspired by the ones used in previous psychophysical experiments, namely in free-viewing and visual searching tasks, to provide a total of 15 types of stimuli, divided according to the task and feature to be analyzed. Our interest is to analyze the influences of low-level feature contrast between a salient region and the rest of distractors, providing fixation localization characteristics and reaction time of landing inside the salient region. Eye-tracking data was collected from 34 participants during the viewing of a 230 images dataset. Results show that saliency is predominantly and distinctively influenced by: 1. feature type, 2. feature contrast, 3. temporality of fixations, 4. task difficulty and 5. center bias. This experimentation proposes a new psychophysical basis for saliency model evaluation using synthetic images.

This commentary attempts to clarify the setting of photobiomodulation (BPM) therapy in the management of oral mucositis. The suggested dose range balances efficacy data with our current understanding about PBM safety. The literature about the molecular basis of photobiomodulation and its controversial relationship to malignant transformation is briefly presented.

The toxicity of engineered nanoparticles (ENPs) on bacteria has aroused much interest. However, few studies have focused on the effects of low-level ENPs on bacterial group behaviors that are regulated by quorum sensing (QS). Herein, we investigated the effects of nine ENPs (Ag, Fe, ZnO, TiO2, SiO2, Fe2O3, single-wall carbon nanotubes (SWCNTs), graphene oxide (GO), and C60) on QS in Pseudomonas aeruginosa PAOl. An ENP concentration of 100 μg L-1 did not impair bacterial growth. However, concentrations of 100 μg L-1 of Ag and GO ENPs induced significant increases in 3OC12-HSL in the culture and significantly promoted protease production and biofilm formation of PAO1. C4-HSL synthase and its transcription factors were less sensitive to 100 μg L-1 Ag and GO ENPs compared with 3OC12-HSL. Fe ENPs induced a significant increase in the 3OC12-HSL concentration, similar to Ag and GO ENPs. However, Fe ENPs did not induce any significant increase in protease production or biofilm formation. Different size distributions, chemical compositions, and aggregation states of the ENPs had different effects on bacterial QS. These whole circuit indicators could clarify the effects of ENPs on bacterial QS. This study furthers our understanding of the effects of low-level ENPs on bacterial social behaviors.

BACKGROUND: BK polyomavirus (BKPyV)-associated nephropathy (PyVAN) is a significant cause of premature renal transplant failure. High-level BKPyV viremia is predictive for PyVAN; however, low-level BKPyV viremia does not necessarily exclude the presence of PyVAN. As data are limited regarding whether or not low-level BKPyV viremia has an effect on intermediate-term graft outcome, this study analyzes the impact of low-level BKPyV viremia on intermediate-term graft function and outcome compared with high-level viremia and non-viremic patients.
METHODS: All renal transplant patients received follow-up examinations at the Department of Nephrology, University Hospital Essen. Patients were screened for BKPyV viremia and stratified into three groups according to their maximum BKPyV load in serum (low-level viremia, high-level viremia, and no viremia).
RESULTS: In 142 of 213 (67%) patients, BKPyV was never detected in serum; 42 of 213 (20%) patients were found positive for low-level viremia (≤104 copies/mL); and 29 of 213 (13%) patients showed high-level viremia (>104 copies/mL). No significant differences regarding transplant function and graft failure were observed between patients without BKPyV viremia (delta estimated glomerular filtration rate [eGFR] +0.1 mL/min [month 1 vs last visit at month 44]) and patients with low-level BKPyV viremia (delta eGFR -1.7 mL/min). In patients with high-level viremia, transplant function was significantly restricted (delta eGFR -6.5 mL/min) compared with low-level viremia until the last visit at 44 ± 9.7 months after transplantation. Although the graft function and graft loss were worse in the high-level viremia group compared with no viremia (eGFR 37 vs 45 mL/min), the difference was not significant.
CONCLUSIONS: High-level viremia was associated with impaired graft function. In contrast, low-level BKPyV viremia had no significant impact on intermediate-term graft function.

Introduction: The purpose of this study was to investigate the effect of low-level laser therapy (LLLT) - 660 nm and 904 nm - before grip strength protocol in healthy subjects. Methods: The study included 45 healthy volunteers with an average age of 22.7 (±1.4) years, subdivided into the following groups, control group: grip strength training associated with placebo LLLT; 660 nm group: LLLT (660 nm, 20 J/cm2, power of 30 mW, and beam area of 0.06 cm2, continuous, energy 1.2 J, and exposure time 40 seconds per point) before grip strength training and 904 nm group: LLLT (904 nm, 10 J/cm2, peak power of 70 W and 0.13 cm2 beam area, with pulsed beam 9.500 Hz and 30 seconds of exposure time per point and emitted energy 1.2 J) before grip strength training. The LLLT was timed to contact 10 points located in the region of the superficial and deep flexor muscles of the fingers, with a total energy of 12.0 J per session. For the strength training protocol, the volunteer exercised their fingers with the dominant hand on a small table, elbow flexed at 90°, forearm in neutral, using a light extension handle. The Oxford protocol was performed during four weeks. The grip strength was assessed using a dynamometer (Jamar™). The data were evaluated by the analysis of variance (ANOVA) statistical method. Results: In the comparison of intragroup evaluation, only the 904 nm group showed a difference compared to the baseline assessment after 4 weeks (P < 0.05), in the final intergroup evaluation, a difference was observed in the comparison between the control and 904 nm groups Conclusion: In conclusion, LLLT (904 nm) applied before resistance training was effective in gaining grip strength when compared to LLLT (660 nm) and isolated strength training after 4 weeks.