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Oral Surgery, Oral Medicine, Oral... Jun 2023This study compared magnetic resonance imaging (MRI) findings and fractal dimension (FD) values in the temporomandibular joints (TMJs) of study patients with disk...
OBJECTIVE
This study compared magnetic resonance imaging (MRI) findings and fractal dimension (FD) values in the temporomandibular joints (TMJs) of study patients with disk perforation vs control patients.
STUDY DESIGN
Of 75 TMJs examined with MRI for characteristics of the disk and condyle, 45 were included in the study group and 30 in the control group. MRI findings and FD values were compared for significance of differences between the groups. The frequency of subclassifications was analyzed for differences between the two forms of disk configuration and grades of effusion. Mean FD values were analyzed for differences among subclassifications of MRI findings and between groups.
RESULTS
Examination of MRI variables revealed that the study group had significantly greater frequencies of flattened disks, disk displacement, flattening and combined defects in condylar morphology, and grade 2 effusion (P = .001) Joints with perforated disks had a large percentage of normal disk-condyle relationships (73.3%). Significant differences were discovered between biconcave and flattened disk configuration in the frequencies of internal disk status and condylar morphology. FD values of all patients varied significantly among the subclassifications of disk configuration, internal disk status, and effusion. Mean FD values were significantly lower in the study group with perforated disks (1.07) compared with the control group (1.20, P = .001).
CONCLUSIONS
MRI variables and FD can be useful in investigating intra-articular TMJ status.
Topics: Humans; Temporomandibular Joint Disc; Fractals; Temporomandibular Joint Disorders; Temporomandibular Joint; Magnetic Resonance Imaging; Joint Dislocations; Mandibular Condyle
PubMed: 36890079
DOI: 10.1016/j.oooo.2023.01.001 -
Acta Neurochirurgica. Supplement 2023Introductionː Cervical disk arthroplasty is a potential alternative procedure to anterior cervical decompression and fusion for the treatment of cervical disk disease....
Introductionː Cervical disk arthroplasty is a potential alternative procedure to anterior cervical decompression and fusion for the treatment of cervical disk disease. The aim of the study was to perform a systematic literature review on long-term clinical and radiological outcomes after Bryan cervical disk arthroplasty.Material and Methodsː A systematic literature review was performed according to PRISMA guidelines via PubMed and Embase, Scopus, and the Cochrane Library database by using the following keywords: "Bryan prosthesis"; "cervical disk arthroplasty"; "outcomes"; and "long-term follow-up." Eight articles with at least 10 years of follow-up were considered for eligibility.Resultsː In total, 481 patients were enrolled in the studies. Because of the occurrence of multiple treated levels, 588 arthroplasties were performed, divided as follows: 12 C3/4 cervical disk arthroplasties (2.01%), 63 C4/5 (10.71%), 325 C5/6 (55.27%), and 188 C6/7 (31.97%). The mean preoperative cervical lordosis was 13.6 ± 9.3°, whereas the last follow-up value was 12.8 ± 8.7°. In the last follow-up, the mean segmental range of motion was 8.2 ± 3.3°.Discussion: Recent studies have suggested that cervical disk arthroplasty should be safely performed in healthy young patients with disk degeneration who may need future revision surgery. The results suggest that this procedure preserves native cervical spinal biomechanics at long-term follow-up with acceptable adjacent segments disease and periprosthetic ossifications.Conclusionsː Cervical disk arthroplasty has good long-term device survival, motility, adjacent segment degeneration, and clinical outcomes. Therefore, it represents a valid alternative for the treatment of cervical spine degenerative pathologies, especially in young patients.
Topics: Animals; Humans; Arthroplasty; Biomechanical Phenomena; Databases, Factual; Intervertebral Disc Degeneration; Intervertebral Disc Displacement
PubMed: 38153488
DOI: 10.1007/978-3-031-36084-8_49 -
Science Progress Oct 2021Disk springs are widely used as preload and isolation due to their unique mechanical properties. In the prior research, the effect of linear friction on the disk spring...
Disk springs are widely used as preload and isolation due to their unique mechanical properties. In the prior research, the effect of linear friction on the disk spring was considered, but contact stiffness, another nonlinear contact factor, is ignored. Accordingly, in this paper, the asymmetric displacements of the contact edges are first derived, and the accurate friction dissipations are obtained, as a way to evaluate the effect of friction on the system. Then the velocity of the edges was obtained to establish a dynamic friction model. Meanwhile, the contact displacement and contact stiffness of the edge are obtained by fractal contact theory. Then the nonlinear static and dynamic models of disk spring with friction and contact stiffness are established by the energy method. The load-deflection relationship, stiffness, and hysteresis of disk spring are studied with different contact states. The results show that the model considering contact stiffness and asymmetric friction dissipation can effectively evaluate the static properties of the disk spring. Friction reinforces the nonlinear behavior of the system, while contact stiffness weakens the nonlinearity of the system. And due to the influence of nonlinear contact factors, the transmissibility curves produce multiple resonance peaks.
PubMed: 34704873
DOI: 10.1177/00368504211052360 -
Current Eye Research May 2023The optic nerve mechanically loads the eye during ocular rotation, thus altering the configuration of the disk and peripapillary tissues. We used optical coherence...
PURPOSE
The optic nerve mechanically loads the eye during ocular rotation, thus altering the configuration of the disk and peripapillary tissues. We used optical coherence tomography (OCT) angiography (OCTA) to investigate mechanical strains and volume changes in disk and peripapillary blood vessels during horizontal duction.
METHODS
Structural OCT and OCTA were performed centered on optic disks; imaging was repeated in central gaze, and in 30° ab- and adduction. By an algorithm employing point-set registration of 3 D features, we developed a novel approach for measuring disk strains, and strains and volumes of the blood vessels associated with horizontal duction. Repeatability was demonstrated in each gaze position.
RESULTS
19 eyes of 10 healthy adults of average age 37 ± 15 (standard deviation, SD) years were imaged. The method was validated by demonstrating numerically consistent vascular volumes and strains for repeated imaging under identical conditions. Compared with central gaze, vascular volume increased by 5.2 ± 4.1% in adduction. Adduction and abduction caused strains of 3.0 ± 1.6% and 2.6 ± 1.8% in the optic disk, whereas blood vessels showed greater strains of 8.1 ± 1.3% and 8.2 ± 1.7%. Decomposition of strain components depending on directionality and regions demonstrated that adduction induces significant net tensile strains, suggesting traction exerted by the optic nerve. The decomposition also showed that nasotemporal compressive strains are larger in temporal hemidisks than nasal hemidisks. The Bruch's membrane opening was significantly compressed horizontally in adduction by 1.1% ( = .009).
CONCLUSION
This novel analysis combining structural OCT and OCTA demonstrates that optic disk compression during adduction is associated with disk and vascular strains much larger than reported for intraocular pressure elevation and pulsatile perfusion, as well as compressing the disk and increasing peripapillary vascular volume. These changes may be relevant to the pathogenesis of optic nerve and retinal vascular disorders.
Topics: Adult; Humans; Young Adult; Middle Aged; Optic Disk; Tomography, Optical Coherence; Optic Nerve Diseases; Optic Nerve; Angiography; Intraocular Pressure; Retinal Vessels; Fluorescein Angiography
PubMed: 36843550
DOI: 10.1080/02713683.2023.2172185 -
Journal of Bodywork and Movement... Jul 2022To investigate the effect of disk training and tape application on diminished proprioception after Lateral Ankle Sprain (LAS) in active populations. (Review)
Review
OBJECTIVE
To investigate the effect of disk training and tape application on diminished proprioception after Lateral Ankle Sprain (LAS) in active populations.
ELIGIBILITY CRITERIA
Only clinical trials investigating the effectiveness of disk training and ankle tape on proprioception deficits following LAS by assessing JPS or kinaesthesia were included.
INFORMATION SOURCES
Electronic databases of PubMed, MEDLINE, SPORTDiscus, CINAHL, Web of Science, Cochrane and PEDro were searched. The main search was conducted in February 2022.
RISK OF BIAS
The physiotherapy Evidence Database (PEDro) scale was utilised to assess the methodological quality of each article.
RESULT
The search yielded six studies investigating the effects of disk training and four studies investigating the effects of inelastic tape. Five articles showed a significant improvement on JPS after disk training. However, no difference across different intervention groups was observed in one study. Only one trial presented an immediate significant improvement when taped, while another study showed that external ankle supports significantly improved JPS after 2 weeks and after 2 months. Three of four studies found no immediate improvement on proprioceptive deficits by the use of tape.
CONCLUSIONS
This review found that disk training may improve impaired proprioception after LAS, whilst the efficacy of inelastic tape was not evident due to methodological quality of the few available studies. Further studies are needed to establish whether these interventions can be used clinically with sufficient evidence.
Topics: Ankle; Ankle Injuries; Ankle Joint; Humans; Physical Therapy Modalities; Proprioception
PubMed: 35710223
DOI: 10.1016/j.jbmt.2022.04.001 -
Materials (Basel, Switzerland) Oct 2022Titanium dioxide (TiO), by its tribological behavior, is known as a solid lubricant. TiO as a solid lubricant, together with tungsten disulfide (WS) and molybdenum...
Titanium dioxide (TiO), by its tribological behavior, is known as a solid lubricant. TiO as a solid lubricant, together with tungsten disulfide (WS) and molybdenum disulfide (MoS) decreases friction and excessive wear. By compacting TiO powder, pellets are formed. Studies and research on the solid lubricant coatings were conducted with success on a tribometer with the possibility of making two simultaneous contacts, pellet/disk, and slider pad/disk. On the disk of a tribometer, we studied the lubrication characteristics of the TiO powder particles as the third body by intentionally transferring. Results show that the TiO pellet behaved like an effective oil-free lubricant by self-repairing and self-replenishing. In experiments, a TiO pellet is intentionally sheared against the surface of the disk, while the slider pad slips loaded on the lubricated surface until the deposited powder film is exhausted. A theoretical model control volume fractional coverage (CVFC) was used to estimate both the wear rate for the lubricated pellet/disk sliding contact and the friction coefficient at the pad/disk separation surface. According to materials properties, disk velocity, pellet and slider pad load, the pellet wear rate, and slider pad friction coefficient, using the CVFC model, can establish the pellet wear rate, and slider pad friction coefficient. The fractional coverage represents a parameter of the CVFC model that varies with time, and it is useful for estimating the film amount from the third body that covers the disk asperities. Model results well enough describe the tribological behavior of the sliding contacts in experiments, both qualitatively and quantitatively. In addition, the theoretical results obtained by modeling and the experimental those obtained in the process of friction, are compared.
PubMed: 36295214
DOI: 10.3390/ma15207145 -
Applied and Environmental Microbiology Mar 2022Bacillus cereus group isolates ( = 85) were screened for phenotypic resistance to 18 antibiotics using broth microdilution and CLSI M45 spp. breakpoints. The...
Comparative Analysis of Bacillus cereus Group Isolates' Resistance Using Disk Diffusion and Broth Microdilution and the Correlation between Antimicrobial Resistance Phenotypes and Genotypes.
Bacillus cereus group isolates ( = 85) were screened for phenotypic resistance to 18 antibiotics using broth microdilution and CLSI M45 spp. breakpoints. The susceptibility to 9 out of 18 antibiotics was also tested using disk diffusion method and M100 Staphylococcus spp. breakpoints when available. Overall, a high prevalence of susceptibility to clinically relevant antibiotics was identified using broth microdilution. For most tested antibiotics, a poor correlation was found between zones of inhibition and MICs. Using the broth microdilution results as a reference for comparison, we identified high error rates and low categorical agreement between results produced using disk diffusion and broth microdilution for the seven tested antibiotics with defined breakpoints. This suggests that disk diffusion should be avoided for AST of B. cereus group isolates. Further, we detected antimicrobial resistance genes with ARIBA and ABRIcate to calculate the sensitivity and specificity for predicting phenotypic resistance determined using broth microdilution based on the presence of detected antimicrobial resistance genes (ARGs). ARGs with poor sensitivity and high specificity included (rifampicin, 0%, 93%), (erythromycin, 0%, 99%), (penicillin, 29%, 100%), and (penicillin, 56%, 100%). Compared to penicillin, and had lower specificity for the prediction of ampicillin resistance. Overall, none of the ARGs had both high sensitivity and specificity, suggesting the need for further study of the mechanisms underlying phenotypic antimicrobial resistance in the B. cereus group. Bacillus cereus group includes human pathogens that can cause severe infections requiring antibiotic treatment. Screening of environmental and food isolates for antimicrobial resistance can provide insight into what antibiotics may be more effective therapeutic options based on the lower prevalence of resistance. Currently, the comparison of antimicrobial susceptibility testing results using the disk diffusion method is complicated by the fact that many previous studies have used Staphylococcus spp. breakpoints to interpret their results. In this study, we compared the results of disk diffusion interpreted using the Staphylococcus spp. breakpoints against the results of broth microdilution interpreted using spp. breakpoints. We demonstrated that the disk diffusion method does not produce reliable results for B. cereus group isolates and should therefore be avoided. This study also provides new insight into poor associations between the presence of antimicrobial resistance genes and resistance phenotypes for the B. cereus group.
Topics: Anti-Bacterial Agents; Anti-Infective Agents; Bacillus; Bacillus cereus; Drug Resistance, Bacterial; Genotype; Microbial Sensitivity Tests; Phenotype
PubMed: 35225691
DOI: 10.1128/aem.02302-21 -
Micromachines Dec 2021Swarming robotic systems, which stem from insect swarms in nature, exhibit a high level of environmental adaptability and enhanced tasking capabilities for targeted...
Swarming robotic systems, which stem from insect swarms in nature, exhibit a high level of environmental adaptability and enhanced tasking capabilities for targeted delivery and micromanipulation. Here, we present a strategy that reconfigures paramagnetic nanoparticles into microswarms energized by a sawtooth magnetic field. A rotary-stepping magnetic-chain mechanism is proposed to address the forming principle of disk-like swarms. Based on programming the sawtooth field, the microswarm can perform reversible transformations between a disk, an ellipse and a ribbon, as well as splitting and merging. In addition, the swarms can be steered in any direction with excellent maneuverability and a high level of pattern stability. Under accurate manipulation of a magnetic microswarm, multiple microparts with complicated shapes were successfully combined into a complete assembly. This reconfigurable swarming microrobot may shed light on the understanding of complex morphological transformations in living systems and provide future practical applications of microfabrication and micromanipulation.
PubMed: 34945379
DOI: 10.3390/mi12121529 -
Current Drug Safety 2023β-lactam antibiotics, mainly cephalosporins, and carbapenems, have been the mainstay of treatment for infections caused by Enterobacterales. However, their role in...
INTRODUCTION
β-lactam antibiotics, mainly cephalosporins, and carbapenems, have been the mainstay of treatment for infections caused by Enterobacterales. However, their role in treating clinical infections has become limited because of the increase in resistance. There is a need to have cost-effective and rapid methods for antimicrobial susceptibility testing methods for newer antibiotics like ceftazidime-avibactam against carbapenem-resistant Enterobacterales (CRE), which can be applied in routine clinical microbiology laboratories. With this aim, the present study was conducted to compare the disk diffusion and gradient diffusion, i.e., the E-test method with the reference broth microdilution (BMD) method for in-vitro testing of ceftazidime-avibactam against CRE.
MATERIALS AND METHODS
A total of 111 CRE isolates from various clinical samples were included. Conventional PCR (Polymerase Chain Reaction) was done for the detection of genes encoding carbapenemases and to see their expression, modified carbapenem inactivation method (mCIM) along with EDTA (Ethylenediaminetetraacetic acid) carbapenem inactivation method (eCIM) was done.
RESULTS
42.3% (47/111) isolates were resistant to ceftazidime-avibactam by the standard broth microdilution method; however, 45.9% (51/111) were resistant by both disk diffusion and E-test. In 5.4% of isolates (similar in both methods), microbroth dilution method results did not match with E-strip and disk diffusion. Very major errors (VME) by both disk diffusion and E-test were found in 2.1% (1/47), and major errors (ME) were found in 7.8% (5/64) isolates (similar isolates in both methods). The overall categorical agreement (CA) rate was 94.6% for both E-test and disk diffusion, and the essential agreement (EA) rate was 90.1% (100/111) for E-test. 98% (109/111) of CRE harbored carbapenemase genes either singly (30.3%) or in combination with others (69.7%).
CONCLUSION
In conclusion, for CRE, E-test and the disk diffusion method for ceftazidimeavibactam depicted an acceptable performance as an alternative to the reference broth microdilution method.
Topics: Humans; Carbapenems; Pseudomonas aeruginosa; Microbial Sensitivity Tests; Anti-Bacterial Agents; Drug Combinations
PubMed: 36503394
DOI: 10.2174/1574886318666221209160323 -
Frontiers in Neurology 2023Over the years, most back pain-related biological studies focused on the pathogenesis of disk degeneration. It is known that nerve distributions at the outer layer of...
INTRODUCTION
Over the years, most back pain-related biological studies focused on the pathogenesis of disk degeneration. It is known that nerve distributions at the outer layer of the annulus fibrosus (AF) may be an important contributor to back pain symptoms. However, the types and origins of sensory nerve terminals in the mouse lumbar disks have not been widely studied. Using disk microinjection and nerve retrograde tracing methods, the current study aimed to characterize the nerve types and neuropathway of the lumbar 5/6 (L5/6) disk in mice.
METHODS
Using an anterior peritoneal approach, the L5/6 disk of adult C57BL/6 mice (males, 8-12 weeks) disk microinjection was performed. Fluorogold (FG) was injected into the L5/6 disk using the Hamilton syringe with a homemade glass needle driven by a pressure microinjector. The lumbar spine and bilateral thoracic 13 (Th13) to L6 DRGs were harvested at 10 days after injection. The number of FG neurons among different levels was counted and analyzed. Different nerve markers, including anti-neurofilament 160/200 (NF160/200), anti-calcitonin gene-related peptide (CGRP), anti-parvalbumin (PV), and anti-tyrosine hydroxylase (TH), were used to identify different types of nerve terminals in AF and their origins in DRG neurons.
RESULTS
There were at least three types of nerve terminals at the outer layer of L5/6 AF in mice, including NF160/200 (indicating Aβ fibers), CGRP (Aδ and C fibers), and PV (proprioceptive fibers). No TH fibers (sympathetic nerve fibers and some C-low threshold mechanoreceptors) were noticed in either. Using retrograde tracing methods, we found that nerve terminals in the L5/6 disk were multi-segmentally from Th13-L6 DRGs, with L1 and L5 predominately. An immunofluorescence analysis revealed that FG neurons in DRGs were co-localized with NF160/200, CGRP, and PV, but not TH.
CONCLUSION
Intervertebral disks were innervated by multiple types of nerve fibers in mice, including Aβ, Aδ, C, and proprioceptive fibers. No sympathetic nerve fibers were found in AF. The nerve network of the L5/6 disk in mice was multi-segmentally innervated by the Th13-L6 DRGs (mainly L1 and L5 DRGs). Our results may serve as a reference for preclinical studies of discogenic pain in mice.
PubMed: 37077575
DOI: 10.3389/fneur.2023.1084209