Abstract Objective This study evaluated the effects of spinal manipulation on spatiotemporal flexion-relaxation phenomenon parameters in individuals with chronic low back pain. Methods Twenty-seven ...adults with chronic low back pain participated in this study and first performed a block of 5 complete trunk flexion-extensions. The experimental group (n = 13) was then submitted to lumbar spine manipulation, whereas the control group (n = 14) was placed in a side-lying control position for 10 seconds. All study participants performed thereafter a second block of 5 trunk flexion-extensions. Trunk and pelvis angles and surface EMG of erector spinae at L2 and L5 were recorded during the flexion-extension tasks. Flexion angles corresponding to the onset and cessation of myoelectric silence, normalized EMG, and the extension-relaxation ratio were compared across experimental conditions. Results A significant reduction of EMG activity at full trunk flexion at the L2 erector spinae level was observed in the experimental group compared to the control group. No significant effect was seen at L5 in both groups. The experimental group presented a significantly increased postmanipulation FRR at L2, whereas the control group ratio did not vary after the “side-lying control position.” No significant difference was seen at L5 in both groups. Flexion-relaxation phenomenon onset and cessation angle did not differ across groups or conditions. Conclusions This study shows that lumbar spine manipulation can, at least for a brief period, modulate stabilizing neuromuscular responses of the lumbar spine in a group of patients with low back pain.
Spinal manipulation is a widely accepted therapeutic approach in the treatment of back pain. In standard training programs, feedback on student performances is provided by an instructor based on ...teaching and clinical experience. Systematic study of the type of augmented feedback provided and skill learning is lacking in the literature.
The goal of this investigation is to compare the performance of two groups of chiropractic students, one receiving traditional training from experienced instructors, and the other, augmented feedback on specific biomechanical aspects of spinal manipulation therapy using an instrumented manikin.
Randomized controlled study.
Thirty-one fourth-year students from the Department of Chiropractic of Université du Québec à Trois-Rivières participated in this study.
Kinetic parameters (force-time curves) of spinal manipulation were evaluated.
Spinal manipulation parameters were measured before and after a 5-week training period in which one group received standard chiropractic training while a second group received augmented feedback about specific biomechanical parameters of spinal manipulation. For both groups, practice scheduling and time duration were similar and consisted of a weekly practice session of 90 minutes for five consecutive weeks. Both groups had to practice thoracic spine manipulation throughout the training period.
Both groups showed a decrease in peak force applied, with a diminution in the number of trials where a downward incisural point was present in preload force. Participants in the feedback training group significantly reduced their peak force variability and significantly increased their preload force. No significant difference was observed for time to peak force.
The results of this study highlight the merits of practicing with an instrumented manikin or other instrumented training aids. Such a device can provide specific feedback on specific parameters of the task during learning; it can also serve as a tool to assess the progress of students and eliminate the risks relating to repetitive spinal manipulative therapy practice on student colleagues.
We set out to exhaustively characterize the impact of the cis-chromatin environment on prime editing, a precise genome engineering tool. Using a highly sensitive method for mapping the genomic ...locations of randomly integrated reporters, we discover massive position effects, exemplified by editing efficiencies ranging from ∼0% to 94% for an identical target site and edit. Position effects on prime editing efficiency are well predicted by chromatin marks, e.g., positively by H3K79me2 and negatively by H3K9me3. Next, we developed a multiplex perturbational framework to assess the interaction of trans-acting factors with the cis-chromatin environment on editing outcomes. Applying this framework to DNA repair factors, we identify HLTF as a context-dependent repressor of prime editing. Finally, several lines of evidence suggest that active transcriptional elongation enhances prime editing. Consistent with this, we show we can robustly decrease or increase the efficiency of prime editing by preceding it with CRISPR-mediated silencing or activation, respectively.
Display omitted
•T7-assisted reporter mapping assay determines precise locations of integrated constructs•Active transcriptional elongation enhances prime editing•Pooled shRNA screens reveal HLTF as a context-dependent suppressor of prime editing•Epigenetic conditioning of a locus modulates prime editing efficiency
Prime editing exhibits strong, chromatin-related position effects and is promoted by active transcriptional elongation. Leveraging these features via epigenetic conditioning of a locus modulates prime editing efficiency.
Decay of plasmons to hot carriers has recently attracted considerable interest for fundamental studies and applications in quantum plasmonics. Although plasmon-assisted hot carriers in metals have ...already enabled remarkable physical and chemical phenomena, much remains to be understood to engineer devices. Here, we present an analysis of the spatio-temporal dynamics of hot electrons in an emblematic plasmonic device, the adiabatic nanofocusing surface-plasmon taper. With femtosecond-resolution measurements, we confirm the extraordinary capability of plasmonic tapers to generate hot carriers by slowing down plasmons at the taper apex. The measurements also evidence a substantial increase of the "lifetime" of the electron gas temperature at the apex. This interesting effect is interpreted as resulting from an intricate heat flow at the apex. The ability to harness the "lifetime" of hot-carrier gases with nanoscale circuits may provide a multitude of applications, such as hot-spot management, nonequilibrium hot-carrier generation, sensing, and photovoltaics.
We report a plasmon steering method that enables us to dynamically control the direction of surface plasmons generated by a two-mode slit in a thin metal film. By varying the phase between different ...coherent beams that are incident on the slit, individual waveguide modes are excited. Different linear combinations of the two modes lead to different diffracted fields at the exit of the slit. As a result, the direction in which surface plasmons are launched can be controlled. Experiments confirm that it is possible to distribute an approximately constant surface plasmon intensity in any desired proportion over the two launching directions. We also find that the anti-symmetric mode generates surface plasmons more efficiently than the fundamental symmetric mode.
In this Letter, we study the heat dissipated at metal surfaces by the electromagnetic field scattered by isolated subwavelength apertures in metal screens. In contrast to the common belief that the ...intensity of waves created by local sources should decrease with the distance from the sources, we reveal that the dissipated heat at the surface remains constant over a broad spatial interval. This behavior that occurs for noble metals at near infrared wavelengths is observed with nonintrusive thermoreflectance measurements and is explained with an analytical model, which underlines the intricate role played by quasicylindrical waves in the phenomenon. Additionally, we show that, by monitoring the phase of the quasicylindrical waves, the total heat dissipated at the metal surface can be rendered substantially smaller than the heat dissipated by the launched plasmon. This interesting property offers an alternative to amplification for overcoming the loss issue in miniaturized plasmonic devices.
Modern-day sensing and imaging applications increasingly rely on accurate measurements of the primary physical quantities associated with light waves: intensity, wavelength, directionality, and ...polarization. These are conventionally performed with a series of bulky optical elements, but recently, it has been recognized that optical resonances in nanostructures can be engineered to achieve selective photodetection of light waves with a specific set of predetermined properties. Here, we theoretically illustrate how a thin silicon layer can be patterned into a dislocated nanowire-array that affords detection of circularly polarized light with an efficiency that reaches the theoretical limit for circular dichroism of a planar detector in a symmetric external environment. The presence of a periodic arrangement of dislocations is essential in achieving such unparalleled performance as they enable selective excitation of nonlocal, guided-mode resonances for one handedness of light. We also experimentally demonstrate compact, high-performance chiral photodetectors created from these dislocated nanowire-arrays. This work highlights the critical role defects can play in enabling new nanophotonic functions and devices.
Presence in the neonatal intensive care unit (NICU) is a vital step for caregivers initiating involvement, such as skin-to-skin contact, holding or singing/reading to their newborn. Little is known ...about caregiver presence and involvement in Canadian NICU's context by caregiver type (mother, father, other), and the association between maternal presence and key maternal and newborn characteristics.
The primary objective was to examine the presence and involvement of family caregivers in the NICU. The secondary objective was to examine the relationship between maternal presence and maternal and newborn characteristics.
A prospective observational cohort study in an open bay setting of an Eastern Canadian NICU. Presence (physically present at the newborn's bedside) and involvement (e.g., skin-to-skin, singing/reading) were tracked daily by families in the NICU until discharge. Demographic information was also collected.
Participants included 142 mothers and their newborns. Mothers were present 8.7 h/day, fathers were present 4.1 h/day, and other caregivers were present 1.8 h/day in the NICU in the first 34 days. Mothers were involved in care activities 50% of the time they were present in the NICU, whereas fathers and other caregivers were spending 20% and 6% of their time respectively. Regression identified maternal age, distance to home, parity, birthweight, and length of stay to be statistically significant variables related to maternal presence.
There is variation in presence and involvement by caregiver type. Targeted interventions to maintain and increase mothers, fathers and other caregivers' presence and involvement in care throughout their stay in the NICU are recommended.
•Caregiver presence in the NICU, although an essential component, does not ensure caregiver involvement with their newborns.•Mothers are present longer and more actively involved than fathers and other caregivers in the NICU.•Maternal age, distance to home, parity, birthweight, and length of stay are related to maternal presence in the NICU.
Cancer treatment clinical trials face major challenges with patient recruitment. Strategies to address patient indirect costs associated with clinical trial participation may accelerate accrual ...overall. The current study examined the effect of the IMproving Patient Access to Clinical Trials (IMPACT) intervention on patient accrual to cancer treatment clinical trials at an academic medical center. The IMPACT intervention was an onsite patient navigator combined with a financial reimbursement program to address patient out of pocket costs and began on September 2018.
This analysis measured frequency of patient enrollment in cancer treatment clinical trials and available cancer treatment clinical trials per month between January 1, 2016 and March 31, 2020. An interrupted time-series analysis (ITSA) was conducted to estimate changes in patient enrollment attributable to the IMPACT intervention.
During the study period, a mean of 69 patients enrolled in clinical trials per month (standard deviation (SD = 13), with 27 (SD = 7) in early phase vs 41 (SD = 12) in late phase clinical trials. The number of available clinical trials per month was 51 (SD = 2) overall, with 23 (SD = 1) in early phase vs 28 (SD = 1) in late phase context. A total of 3470 patients were enrolled in cancer treatment clinical trials during the evaluated time period, the majority of whom were men (1895, 55 %) and racially white (2267, 65 %). A statistically significant increase in the number of patients accrued as compared to the pre-intervention trend was observed; with approximately 1 additional patient accrued per month, with a larger effect on increase patient accrual for late phase clinical trials.
This study observed that the IMPACT intervention accelerated clinical trial recruitment, especially among late phase clinical trials. Future research will examine strategies to leverage this infrastructure to optimize recruitment among underrepresented patients.
To improve clinical trial recruitment and ensure that trial results are representative of a diverse population it is critical for health policies consider patient out-of-pocket costs and potential reimbursement to alleviate financial burden associated with clinical trial participation. Furthermore, policies for facilitating clinical trial recruitment and participant retention should budget for and incorporate a navigation component to assist patients who may not be familiar with the healthcare system and available financial assistance.
PDF
