Despite an increasing number of studies over the past decade examining the interactions between plants and engineered nanomaterials (ENMs), very few have investigated the influence of environmental ...conditions on ENM uptake and toxicity, particularly throughout the entire plant life cycle. In this study, soil-grown herbaceous annual plants (Clarkia unguiculata) were exposed to TiO2, CeO2, or Cu(OH)2 ENMs at different concentrations under distinct light and nutrient levels for 8 weeks. Biweekly fluorescence and gas exchange measurements were recorded, and tissue samples from mature plants were analyzed for metal content. During peak growth, exposure to TiO2 and CeO2 decreased photosynthetic rate and CO2 assimilation efficiency of plants grown under high light and nutrient conditions, possibly by disrupting energy transfer from photosystem II (PSII) to the Calvin cycle. Exposure Cu(OH)2 particles also disrupted photosynthesis but only in plants grown under the most stressful conditions (high light, limited nutrient) likely by preventing the oxidation of a primary PSII reaction center. TiO2 and CeO2 followed similar uptake and distribution patterns with concentrations being highest in roots followed by leaves then stems, while Cu(OH)2 was present at highest concentrations in leaves, likely as ionic Cu. ENM accumulation was highly dependent on both light and nutrient levels and a predictive regression model was developed from these data. These results show that abiotic conditions play an important role in mediating the uptake and physiological impacts of ENMs in terrestrial plants.
Summary Introduction Repetitive peripheral magnetic stimulation (rPMS over spinal root, nerve or muscle belly) is a promising technology in physiopathology research. As compared to electrical ...stimulation, rPMS is deemed to activate deep conductive structures and produce strong muscle contractions and massive proprioceptive afferents with minimal cutaneous recruitment. RPMS may thus act differently on neural plasticity involved in pain reduction and motor recovery in musculoskeletal or neurological conditions. However, literature is very scant and still controversial concerning afferents recruited by rPMS, thus no consensus is reached yet for its clinical use. Study aim This review dealt with stimulation parameters reported in any scientific research that applied rPMS as an intervention to improve somatosensory or motor disorders with a view of proposing recommendations for future applications. Also, controversy on afferents recruitment was discussed. Results The literature search resulted in 24 studies. Literature is scant on the topic but our review presents the rationale and the experimental data that may underlie the selection of parameters in future studies using rPMS as an intervention. Although controversy remains, the review presents that the specific recruitment of sensory afferents by magnetic stimulation may offer advantages and disadvantages depending on the pathology. Conclusions The review proposed recommendations to improve rPMS application in clinical research. However, the development of guidelines still requires methodological and clinical studies enrolling larger samples and with randomized sham-controlled designs.
Abstract Although total hip arthroplasty (THA) is known to be a successful surgical procedure to alleviate hip pain and to improve health-related quality of life, these outcome measures in THA ...patients do not reach those of the general population. As a result, several investigators have assessed THA patients’ gait mechanics, but most of them have ignored adjacent joints, as well as the effect that THA may have on the non-operated limb. The purpose of this investigation was to determine the effect of THA on the pelvis, hip, knee and ankle joint kinematics, as well as the hip, knee and ankle kinetics of both the operated and non-operated limbs during walking. These data were recorded for 20 patients having undergone unilateral THA and 20 healthy, matched control participants. Results revealed that the gait mechanics of THA patients did not return to normal 10.6 months, on average (±2.6 mo), following surgery. THA patients walked with lower operated-hip abduction moments, sagittal-plane range of motion, as well as lower generated and absorbed power, that may be consequential to pain-avoidance strategies adopted pre-operatively or to apprehensions associated with their new prosthesis. They also displayed various kinematic adaptations at the ankle joint of the operated limb and at the non-operated hip joint that may be leaving them at risk of developing other joint diseases. Further investigation is needed to confirm the reasons why THA patients’ gait mechanics do not return to normal following surgery to develop better surgical techniques and/or rehabilitation programs.
Despite the demonstrated benefits of hyperspectral formalism for stem effect corrections in the context of fiber dose measurements, this approach has not been yet translated into volumetric ...measurements where cameras are typically used for their distinguishing spatial resolution. This work investigates demosaicing algorithms for polychromatic cameras based spectral imaging.
The scintillation and Cherenkov signals produced in a radioluminescent phantom are imaged by a polychromatic camera and isolated using the spectral formalism. To do so, five demosaicing algorithms are investigated from calibration to measurements: a clustering method and four interpolation algorithms. The resulting accuracy of scintillation and Cherenkov images is evaluated with measurements of the differences (mean ± standard deviation) between the obtained and expected signals from profiles drawn across a scintillation spot. Signal-to-noise ratio and signal-to-background ratio are further measured and compared in the resulting scintillation images. Finally, the resulting differences on the scintillation signal from a 0.2 × 0.2 cm
region-of-interest (ROI) were reported.
Clustering, OpenCV, bilinear, Malvar and Menon demosaicing algorithms respectively yielded differences of 3 ± 5%, 1 ± 3%, 1 ± 3%, 1 ± 2% and 2 ± 4% in the resulting scintillation images. For the Cherenkov images, all algorithms provided differences below 1%. All methods enabled measurements over the detectability (SBR > 2) and sensitivity (SNR > 5) thresholds with the bilinear algorithm providing the best SNR value. Clustering, OpenCV, bilinear, Malvar and Menon demosaicing algorithms respectively provided differences on the ROI analysis of 7 ± 5%, 3 ± 2%, 3 ± 2%, 4 ± 2%, 7 ± 3%.
Radioluminescent signals can accurately be isolated using a single polychromatic camera. Moreover, demosaicing using a bilinear kernel provided the best results and enabled Cherenkov signal subtraction while preserving the full spatial resolution of the camera.
SLC39A8 is a membrane transporter responsible for manganese uptake into the cell. Via whole-exome sequencing, we studied a child that presented with cranial asymmetry, severe infantile spasms with ...hypsarrhythmia, and dysproportionate dwarfism. Analysis of transferrin glycosylation revealed severe dysglycosylation corresponding to a type II congenital disorder of glycosylation (CDG) and the blood manganese levels were below the detection limit. The variants c.112G>C (p.Gly38Arg) and c.1019T>A (p.Ile340Asn) were identified in SLC39A8. A second individual with the variants c.97G>A (p.Val33Met) and c.1004G>C (p.Ser335Thr) on the paternal allele and c.610G>T (p.Gly204Cys) on the maternal allele was identified among a group of unresolved case subjects with CDG. These data demonstrate that variants in SLC39A8 impair the function of manganese-dependent enzymes, most notably β-1,4-galactosyltransferase, a Golgi enzyme essential for biosynthesis of the carbohydrate part of glycoproteins. Impaired galactosylation leads to a severe disorder with deformed skull, severe seizures, short limbs, profound psychomotor retardation, and hearing loss. Oral galactose supplementation is a treatment option and results in complete normalization of glycosylation. SLC39A8 deficiency links a trace element deficiency with inherited glycosylation disorders.
Summary Introduction Repetitive magnetic stimulation at the periphery (rPMS), i.e. over spinal roots, nerves or muscles, represents a new painless and noninvasive approach that can contribute to ...motor recovery. This method is based on the assumption that, under rPMS, neural networks involved in motor control would be regulated by the large recruitment of proprioceptive afferents, with little activation of cutaneous receptors. Study aim This literature review dealing with rPMS after-effects on motor control aimed at better understanding the outcome measures and further discussing some possible involved mechanisms. Results Our literature search resulted in 13 studies that used different types of outcomes (neurophysiological, biomechanical, clinical) to test the influence of rPMS over spinal roots or muscles in healthy individuals and in persons with stroke or spinal disorders. Dynamic changes were reported post-rPMS, such as spasticity reduction and improvements of movement dynamics. Studies also brought about some interesting insights on the cortical plasticity associated with rPMS effects, such as the activation of fronto-parietal loops that may explain the post-rPMS improvement of motor planning. Conclusions Due to the heterogeneous and scant literature on the topic, no conclusion can be drawn to date. However, the results encourage the concurrent testing of clinical, neurophysiological and biomechanical outcomes to investigate more precisely the relevance of rPMS in neurological rehabilitation.
This review identifies the three-dimensional knee loads that have the highest risk of injuring the anterior cruciate ligament (ACL) in the athlete. It is the combination of the muscular resistance to ...a large knee flexion moment, an external reaction force generating knee compression, an internal tibial torque, and a knee abduction moment during a single-leg athletic manoeuvre such as landing from a jump, abruptly changing direction, or rapidly decelerating that results in the greatest ACL loads. While there is consensus that an anterior tibial shear force is the primary ACL loading mechanism, controversy exists regarding the secondary order of importance of transverse-plane and frontal-plane loading in ACL injury scenarios. Large knee compression forces combined with a posteriorly and inferiorly sloped tibial plateau, especially the lateral plateau-an important ACL injury risk factor-causes anterior tibial translation and internal tibial rotation, which increases ACL loading. Furthermore, while the ACL can fail under a single supramaximal loading cycle, recent evidence shows that it can also fail following repeated submaximal loading cycles due to microdamage accumulating in the ligament with each cycle. This challenges the existing dogma that non-contact ACL injuries are predominantly due to a single manoeuvre that catastrophically overloads the ACL.
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