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Publication
Journal: Knee Surgery, Sports Traumatology, Arthroscopy
November/2/2016
Abstract
OBJECTIVE
To construct and evaluate an ankle arthrometer that registers inversion joint deflection at standardized inversion loads and that, moreover, allows conclusions about the mechanical strain of intact ankle joint ligaments at these loads.
METHODS
Twelve healthy ankles and 12 lower limb cadaver specimens were tested in a self-developed measuring device monitoring passive ankle inversion movement (Inv-ROM) at standardized application of inversion loads of 5, 10 and 15 N. To adjust in vivo and in vitro conditions, the muscular inactivity of the evertor muscles was assured by EMG in vivo. Preliminary, test-retest and trial-to-trial reliabilities were tested in vivo. To detect lateral ligament strain, the cadaveric calcaneofibular ligament was instrumented with a buckle transducer. After post-test harvesting of the ligament with its bony attachments, previously obtained resistance strain gauge results were then transferred to tensile loads, mounting the specimens with their buckle transducers into a hydraulic material testing machine.
RESULTS
ICC reliability considering the Inv-ROM and torsional stiffness varied between 0.80 and 0.90. Inv-ROM ranged from 15.3° (±7.3°) at 5 N to 28.3° (±7.6) at 15 N. The different tests revealed a CFL tensile load of 31.9 (±14.0) N at 5 N, 51.0 (±15.8) at 10 N and 75.4 (±21.3) N at 15 N inversion load.
CONCLUSIONS
A highly reliable arthrometer was constructed allowing not only the accurate detection of passive joint deflections at standardized inversion loads but also reveals some objective conclusions of the intact CFL properties in correlation with the individual inversion deflections. The detection of individual joint deflections at predefined loads in correlation with the knowledge of tensile ligament loads in the future could enable more individual preventive measures, e.g., in high-level athletes.
Publication
Journal: Knee Surgery, Sports Traumatology, Arthroscopy
August/6/2016
Abstract
OBJECTIVE
An anatomic study was performed to confirm whether the lateral malleolus could serve as a simple and reproducible anatomic reference for the distal insertion of the calcaneofibular ligament (CFL).
METHODS
Dissection was performed after placement of a Kirschner wire to simulate the calcaneal tunnel for the distal insertion of the CFL. The skin was penetrated 1 cm distal and posterior to the tip of the lateral malleolus. The main information recorded was the distance from the Kirschner wire to the centre of the distal insertion of the CFL. Other elements were noted (characteristics of the CFL, distance between the distal insertion of the CFL-peroneal tubercle, nerve or tendon injuries).
RESULTS
Thirty ankles were dissected. The mean distance from the Kirschner wire to the centre of the distal insertion of the CFL was 2.4 ± 1.8 mm. Only one case of peroneal injury was noted. The sural nerve was usually located a mean 1.8 ± 1.1 mm from the Kirschner wire. The posterior tibial vascular pedicle was a mean 27.8 ± 3.5 mm from the point of exit of the Kirschner wire.
CONCLUSIONS
Using the lateral malleolus as the cutaneous reference for the distal insertion of the CFL seems to be more reliable than the pure arthroscopic technique. This study describes a percutaneous technique to obtain a calcaneal tunnel for distal insertion of the CFL. The sural nerve is at the greatest risk of injury with this technique and requires careful subcutaneous incision to prevent injury. This new percutaneous technique is less invasive than a purely arthroscopic technique and more accurately identifies the location of the tunnel. It can be used to do calcaneal tunnel in clinical practice during anatomic ligament reconstruction for chronic ankle instability.
Publication
Journal: Biochemical and Biophysical Research Communications
November/2/2018
Abstract
Lateral ankle sprains are one of the most common injuries in sports. Recently, arthroscopic lateral ligament reconstruction has been recently advocated, however no biomechanical studies and clinical application of this technique are available. In this biomechanical study, eighteen fresh-frozen cadaveric ankles were randomized into three groups: (1) intact anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL), (2) arthroscopic anatomic reconstruction of ATFL and CFL, and (3) all arthroscopic remnant-preserving reconstruction of ATFL and CFL. The specimens were then tested for stiffness and load to ultimate failure using a customized jig. In biomechanical test, the all arthroscopic remnant-preserving reconstruction of ATFL and CFL produced a reconstruction that could withstand loads to failure and stiffness similar to the arthroscopic anatomic reconstruction. However, both two reconstruction groups were much weaker than the intact, uninjured ATFL and CFL. Moreover, we used the technique of all arthroscopic remnant-preserving reconstruction of ATFL and CFL on 20 patients from September 2016 to September 2017. American Orthopaedic Foot and Ankle Society (AOFAS) scores and Anterior Talar Translation (ATT) were applied for statistical collection at preoperative and postoperative 12 months to evaluate clinical efficacy. The differences of the preoperative and postoperative 12 months AOFAS scores and ATT of patients were both statistical significant (P < 0.01). We confirmed that all arthroscopic remnant-preserving reconstruction of ATFL and CFL exhibited positive effect, thus promoting the recovery of ankle function and had good short-term clinical effect.
Publication
Journal: Foot and Ankle Clinics
April/27/2017
Abstract
Chronic instability is a common complication of lateral ankle sprains. If nonoperative treatment fails, a surgical repair or reconstruction may be indicated. Today, endoscopic techniques to treat ankle instability are becoming more popular. This article describes an endoscopic technique, using a step-by-step approach, to reconstruct the ATFL and CFL with a gracilis graft. The endoscopic technique is reproducible and safe with regard to the surrounding anatomic structures. Short and midterm results confirm the benefits of this technique.
Publication
Journal: Current Opinion in Pediatrics
December/11/2018
Abstract
The purpose of this review is to discuss the epidemiology, pathoanatomy, diagnosis, and treatment for lateral ankle instability in pediatric patients.Chronic ankle instability is a common sequela of lateral ankle sprain in young athletes. Incidence is increasing, possibly due in part to inadequate treatment of first-time ankle sprains, as well as increased youth participation in organized and competitive sports. The anterior talofibular ligament (ATFL) is injured in every case, whereas the calcaneofibular ligament (CFL) and syndesmosis may be involved in severe cases. A clinical history, focused physical exam, and appropriate radiographic studies aid in diagnosis, and predisposing factors must be identified. Early treatment of ankle sprains involves bracing or immobilization, followed by a course of physical therapy. Surgery involves anatomic repair of the torn ligaments, and may be required in cases of severe functional and mechanical instability with recurrent sprains refractory to nonsurgical management. Intraarticular disorders should be identified and may be addressed with ankle arthroscopy.Prompt treatment of lateral ankle instability in young athletes is important to prevent chronic ankle instability. Many patients are successfully treated without surgery, and those requiring operative intervention improve function postoperatively.
Publication
Journal: ACS Applied Materials & Interfaces
February/15/2016
Abstract
A permeability- and surface-energy-controllable polyurethane acrylate (PUA) mold, a "capillary-force material (CFM)" mold, is introduced for capillary-force lithography (CFL). In CFL, the surface energy and gas permeability of the mold are crucial. However, the modulation of these two main factors at a time is difficult. Here, we introduce new CFM molds in which the surface energy and permeability can be modified by controlling the degree of cross-linking of the CFM. As the degree of cross-linking of the CFM mold increases, the surface energy and air permeability decrease. The high average functionality of the mold material makes it possible to produce patterns relatively finely and rapidly due to the high rate of capillary rise and stiffness, and the low functionality allows for patterns to form on a curved surface with conformal contact. CFMs with different functionality and controllable-interfacial properties will extend the capabilities of capillary force lithography to overcome the geometric limitations of patterning on a scale below 100 nm and micro- and nanopatterning on the curved region.
Publication
Journal: British Journal of Dermatology
December/3/2014
Abstract
BACKGROUND
Patients with lupus erythematosus (LE) are often abnormally photosensitive. Ultraviolet (UV) exposure can not only induce cutaneous lesions but may also contribute to systemic flares and disease progression. Various forms of energy-efficient lighting have been shown to emit UV radiation.
OBJECTIVE
To determine the effects of these emissions on individuals with LE.
METHODS
This assessment investigated cutaneous responses to repeated exposures from three types of lighting: compact fluorescent lamp (CFL), light-emitting diode (LED) and energy-efficient halogen (EEH). The subjects were 15 patients with LE and a control group of five healthy volunteers.
RESULTS
No cutaneous LE lesions were induced by any of the light sources. Delayed skin erythema was induced at the site of CFL irradiation in six of the 15 patients with LE and two of the five healthy subjects. Erythema was increased in severity and more persistent in patients with LE. One patient with LE produced a positive delayed erythema to the EEH. A single patient with LE produced immediate abnormal erythemal responses to the CFL, LED and EEH. Further investigation revealed that this patient also had solar urticaria. All other subjects had negative responses to LED exposure.
CONCLUSIONS
Compact fluorescent lamps emit UV that can induce skin erythema in both individuals with LE and healthy individuals when situated in close proximity. However, this occurs to a greater extent and is more persistent in patients with LE. EEHs emit UVA that can induce erythema in patients with LE. LEDs provide a safer alternative light source without risk of UV exposure.
Publication
Journal: eLife
April/30/2020
Abstract
Biophysical mechanisms underlying collective cell migration of eukaryotic cells have been studied extensively in recent years. One mechanism that induces cells to correlate their motions is contact inhibition of locomotion, by which cells migrating away from the contact site. Here, we report that tail-following behavior at the contact site, termed contact following locomotion (CFL), can induce a non-trivial collective behavior in migrating cells. We show the emergence of a traveling band showing polar order in a mutant Dictyostelium cell that lacks chemotactic activity. We find that CFL is the cell-cell interaction underlying this phenomenon, enabling a theoretical description of how this traveling band forms. We further show that the polar order phase consists of subpopulations that exhibit characteristic transversal motions with respect to the direction of band propagation. These findings describe a novel mechanism of collective cell migration involving cell-cell interactions capable of inducing traveling band with polar order.
Publication
Journal: American Journal of Sports Medicine
December/20/2018
Abstract
Acute inversion ankle sprains are among the most common musculoskeletal injuries. Higher grade sprains, including anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL) injury, can be particularly challenging. The precise effect of CFL injury on ankle instability is unclear.CFL injury will result in decreased stiffness, decreased peak torque, and increased talar and calcaneal motion and will alter ankle contact mechanics when compared with the uninjured ankle and the ATFL-only injured ankle in a cadaveric model.Descriptive laboratory study.Ten matched pairs of cadaver specimens with a pressure sensor in the ankle joint and motion trackers on the fibula, talus, and calcaneus were mounted on a material testing system with 20° of ankle plantarflexion and 15° of internal rotation. Intact specimens were axially loaded to body weight and then underwent inversion along the anatomic axis of the ankle from 0° to 20°. The ATFL and CFL were sequentially sectioned and underwent inversion testing for each condition. Linear mixed models were used to determine significance for stiffness, peak torque, peak pressure, contact area, and inversion angles of the talus and calcaneus relative to the fibula across the 3 conditions.Stiffness and peak torque did not significantly decrease after sectioning of the ATFL but decreased significantly after sectioning of the CFL. Peak pressures in the tibiotalar joint decreased and mean contact area increased significantly after CFL release. Significantly more inversion of the talus and calcaneus as well as calcaneal medial displacement was seen with weightbearing inversion after sectioning of the CFL.The CFL contributes considerably to lateral ankle instability. Higher grade sprains that include CFL injury result in significant decreases in rotation stiffness and peak torque, substantial alteration of contact mechanics at the ankle joint, increased inversion of the talus and calcaneus, and increased medial displacement of the calcaneus.Repair of an injured CFL should be considered during lateral ligament reconstruction, and there may be a role for early repair in high-grade injuries to avoid intermediate and long-term consequences of a loose or incompetent CFL.
Publication
Journal: Journal of Sports Medicine and Physical Fitness
March/6/2020
Abstract
The objectives of this study were to find correlation between the clinical and ultrasound grading in anterior talofibular ligament and calcaneofibular ligament tear, and to determine the sensitivity and specificity of the two stability tests among the athletes. Subsequently, we would like to propose a new grading criteria for an ultrasound examination.Two blinded assessors examined thirty-five patients with a history of recent lateral ankle sprain. The first assessor performed physical examination on the injured ankle by using the anterior drawer test and talar tilt test, and the second assessor performed dynamic and static ultrasound assessment for anterior talofibular ligament and calcaneofibular ligament. The clinical laxity grading and sonographic extent of ligamentous injury was graded into a 3-point scale.There was a moderate positive correlation between clinical test and ultrasound grading of anterior talofibular ligament and calcaneofibular ligament with Spearman's correlation coefficient values of 0.58 and 0.66 respectively. Clinical grading of anterior drawer test had 59.1% sensitivity (95% CI 0.36-0.79) while ultrasound grading had 100.0% specificity (95% CI 0.75-1.00), with Likelihood Ratio + of 0.77 and Likelihood Ratio - of 0.44 in detecting a complete (grade 3) anterior talofibular ligament tear (p<0.05). Meanwhile, the clinical grading of talar tilt test had 54.5 % sensitivity (95% C.I 0.23-0.83) and ultrasound grading had 100.0 % specificity (95% CI 0.85-1.00), with Likelihood Ratio + of 1.0 and Likelihood Ratio - of 0.45 in detecting a complete grade 3 calcaneofibular ligament tear (p<0.05).The dynamic ultrasound is recommended to determine the actual degree of disruption of the ligament especially when clinical grading under-grades the degree of tear. Grade 2 tears can vary from 10% tear to 90% tear causing the clinical correlation to become less strong. We recommend a new classification for ultrasound grading of Grade 2 tears, which could result in a stronger correlation between clinical and ultrasound grading.
Publication
Journal: Photochemical and Photobiological Sciences
June/19/2014
Abstract
Worldwide bans on incandescent light bulbs (ILBs) drive the use of compact fluorescent light (CFL) bulbs, which emit ultraviolet (UV) radiation. Potential health issues of these light sources have already been discussed, including speculation about the putative biological effects on light exposed tissues, yet the underlying mechanisms remain unclear. We hypothesized photoisomerization of all-trans retinoic acid (at-RA), a highly light sensitive morphogen, into biologically less active isomers, as a mechanism mediating biological effects of CFLs. Local at-RA is anti-carcinogenic, entrains molecular rhythms and is crucial for skin homeostasis. Therefore, we quantified the impact of CFL irradiation on extra- and intracellular levels of RA isomers using an epidermal cell culture model. Moreover, a biologically relevant impact of CFL irradiation was assessed using highly at-RA-sensitive human neuroblastoma cells. Dose-dependent conversion of extra- and intracellular at-RA into the biologically less active 13-cis-isomer was significantly higher in CFL vs. ILB exposure and completely preventable by employing a UV-filter. Moreover, pre-irradiation of culture media by CFL attenuated at-RA-specific effects on cell viability in human at-RA-sensitive cells in a dose-dependent manner. These findings point towards a biological relevance of CFL-induced at-RA decomposition, providing a mechanism for CFL-mediated effects on environmental health.
Publication
Journal: International Journal of Geriatric Psychiatry
December/6/2018
Abstract
OBJECTIVE
The classification of mild cognitive impairment (MCI) continues to be debated though it has recently been subtyped into late (LMCI) versus early (EMCI) stages. Older adults presenting with both a depressive disorder (DEP) and cognitive impairment (CI) represent a unique, understudied population. Our aim was to examine baseline characteristics of DEP-CI patients in the DOTCODE trial, a randomized controlled trial of open antidepressant treatment for 16 weeks followed by add-on donepezil or placebo for 62 weeks.
METHODS
Key inclusion criteria were diagnosis of major depression or dysthymic disorder with Hamilton Depression Rating Scale (HAM-D) score >14, and cognitive impairment defined by MMSE score ≥21 and impaired performance on the WMS-R Logical Memory II test. Patients were classified as EMCI or LMCI based on the 1.5 SD cutoff on tests of verbal memory, and compared on baseline clinical, neuropsychological, and anatomical characteristics.
RESULTS
Seventy-nine DEP-CI patients were recruited of whom 39 met criteria for EMCI and 40 for LMCI. The mean age was 68.9, and mean HAM-D was 23.0. Late mild cognitive impairment patients had significantly worse ADAS-Cog (P < .001), MMSE (P = .004), Block Design (P = .024), Visual Rep II (P = .006), CFL Animal (P = .006), UPSIT (P = .051), as well as smaller right hippocampal volume (P = .037) compared to EMCI patients. MRI indices of cerebrovascular disease did not differ between EMCI and LMCI patients.
CONCLUSIONS
Cognitive and neuronal loss markers differed between EMCI and LMCI among patients with DEP-CI, with LMCI being more likely to have the clinical and neuronal loss markers known to be associated with Alzheimer's disease.
Publication
Journal: Connective Tissue Research
August/9/1981
Abstract
Autologous fat grafts have been used in a number of surgical procedures, yet properties of fat as a transplant material have remained unclear. This study was designed to compare experimental observations of subcutaneous fat grafts in mice with clinical observations of autologous fat grafts placed over the dura following laminectomy in humans. Subcutaneous fat grafts were observed daily in 75 CFl mice with the use of modified Algire back chambers. Grafts were examined histologically and histochemically at intervals up to 60 days after transplantation. Gross and microscopic observations suggest that fat grafts went through a period of initial breakdown of fat cells which was followed by revascularization. This resulted in normal appearing fat, although a smaller volume than the original graft. Three samples of autologous fat grafts from humans were removed during reoperation in the lumbar region up to 22 months after the original procedure. Histological examination revealed revascularized grafts reduced in size: the fat was normal and never replaced by scar tissue.
Publication
Journal: Chemical Communications
February/15/2016
Abstract
We report here a visible light driven selective nitro-reduction and oxidation of saturated sp(3) C-H bonds using ultrathin (0.8 nm) sheet mediated uniform CdS flowers as catalyst under a household 40 W CFL lamp and molecular oxygen as oxidant. The CdS flowers were synthesized using a simple surfactant assisted hydrothermal method.
Publication
Journal: Clinical and laboratory haematology
July/8/1997
Abstract
Treatment of human polymorphonuclear leucocytes (PMNL) separated by density sedimentation (DS) from normal donors (PMNL-NL-DS) with interferon-gamma (IFN-gamma) + granulocyte colony-stimulating factor (G-CSF) lessens the damage caused by isolation and irradiation. We have studied granulocyte-macrophage colony-stimulating factor (GM-CSF) in this system, as well as the behaviour of PMNL collected by continuous flow leucapheresis (CFL) from donors treated with G-CSF (PMNL-GCSF-CFL). After isolation, PMNLs were treated with IFN-gamma + G-CSF, GM-CSF or IFN-gamma + G-CSF + GM-CSF, irradiated with 0 or 30 Gy and studied after 0 and 20 h in cell culture. All regimens reduced apoptosis of PMNL-NL-DS. Killing of Candida albicans by 20-h-old PMNL-NL-DS was best preserved by IFN-gamma + G-CSF treatment. A similar pattern of results was obtained for assays of PMNL-NL-DS chemotaxis and superoxide production. There was a consistent trend toward reduced function after irradiation in all assays. PMNL-GCSF-CFL less often demonstrated the morphological features of apoptosis, and this was further reduced by cytokine regimens containing IFN-gamma + G-CSF. In assays of C. albicans killing and chemotaxis, 20-h-old untreated PMNL-GCSF-CFL performed as well as freshly isolated PMNL-GCSF-CFL. PMNL-GCSF-CFL showed decay in CD11b (CR3), CD16 (Fc gamma III) and CD64 (Fc gamma R1) expression after 20 h in cell culture, but treatment with IFN-gamma + G-CSF preserved expression. There was a trend toward reduced function after radiation. Comparison of PMNL-GCSF separated by CFL and DS demonstrated that CFL itself is a strong inducer of the morphological features of apoptosis. This study shows that while separation by CFL, and irradiation are damaging to PMNLs, damage may be reduced by use of cytokines.
Publication
Journal: The Scientific World Journal
November/15/2015
Abstract
Leishmaniasis is a vector-borne disease transmitted by phlebotomine sand fly. Susceptibility and refractoriness to Leishmania depend on the outcome of multiple interactions that take place within the sand fly gut. Promastigote attachment to sand fly midgut epithelium is essential to avoid being excreted together with the digested blood meal. Promastigote and gut sand fly surface glycans are important ligands in this attachment. The purpose of the present study was to evaluate the interaction of three lectins isolated from leguminous seeds (Diocleinae subtribe), D-glucose and D-mannose-binding, with glycans on Lutzomyia migonei midgut. To study this interaction the lectins were labeled with FITC and a fluorescence assay was performed. The results showed that only Dioclea violacea lectin (DVL) was able to interact with midgut glycans, unlike Cratylia floribunda lectin (CFL) and Canavalia gladiata lectin (CGL). Furthermore, when DVL was blocked with D-mannose the interaction was inhibited. Differences of spatial arrangement of residues and volume of carbohydrate recognition domain (CRD) may be the cause of the fine specificity of DVL for glycans in the surface on Lu. migonei midgut. The findings in this study showed the presence of glycans in the midgut with glucose/mannose residues in its composition and these residues may be important in interaction between Lu. migonei midgut and Leishmania.
Publication
Journal: Toxicology
November/20/1976
Abstract
The carcinogenic effects of limited and repeated skin applications of propane sultone were investigated in three strains of mice, CF1, C3H and CBah (a hairless strain). Propane sultone was shown to be carcinogenic when given as a single application of a 25% w/v solution in toluene and also following twice weekly application of a 2.5% w/v solution for up to 58 weeks. More limited exposure to 2.5% w/v solutions of propane sultone resulted in a few skin tumours, although the incidences were not statistically significant. Most neoplasms were papillomas or carcinomas, although a small number of mesenchymal tumours of dermal origin also developed. No skin neoplasms were found in any control mice. The skin application of propane sultone was associated with a statistically significant increase in the incidence of systematic neoplasia in CFl and C3H mice. The exposed CFl mice had a higher incidence of neoplasms of lymphoreticular and lung origin, while female C3H mice showed a higher incidence of mammary gland and uterine tumours. In mice exposed to beta-propiolactone as a positive control, neoplasms developed at the site of application but, there was no evidence of increased systemic neoplasis in contrast to the findings with ptopane sultone.
Publication
Journal: Orthopaedic Journal of Sports Medicine
October/21/2019
Abstract
Hockey players sustain a greater incidence of ankle syndesmosis injuries than other athletes. These injuries have a higher morbidity and more unpredictable recovery than lateral ankle sprains. Magnetic resonance imaging (MRI) has been used to establish the diagnosis but has not been evaluated for its ability to predict return to play.We hypothesized that patterns of injury defined on MRI could be used to predict return to play in a cohort of professional hockey players with syndesmosis sprains.Cohort study; Level of evidence, 3.A prospectively collected National Hockey League (NHL) database was analyzed from the 2006-2007 to 2011-2012 seasons to assess return to play after an injury. A separate retrospective review of ankle MRI scans from professional hockey players with a documented high ankle sprain sustained between 2007 and 2012 was performed. Injuries were classified on MRI as complete or partial tears of the anterior-inferior tibiofibular ligament (AITFL), posterior-inferior tibiofibular ligament (PITFL), anterior talofibular ligament (ATFL), posterior talofibular ligament (PTFL), calcaneofibular ligament (CFL), and deltoid ligament. Fractures, bone contusions, and osteochondral lesions were also recorded.A total of 105 NHL athletes sustained high ankle sprains over the 5 seasons studied. Of these athletes, 85 were unable to play and missed a median of 8 games (range, 0-65 games). A retrospective MRI evaluation of 21 scans identified complete AITFL tears in 13 (62%) and high-grade partial tears in 5 (24%) cases. In contrast, the PITFL was partially torn in 9 (43%) and normal in 12 (57%) cases. Bone contusions were seen in 71% of cases and lacked a consistent pattern. The most commonly associated ligamentous injury was of the ATFL, which was injured in 52% of cases (11/21; 3 complete and 8 partial). There was no difference in the mean number of days lost when players were stratified by patterns of injury (incomplete/complete AITFL tear ± additional ligamentous injury, bone contusion, syndesmosis width).A high ankle sprain resulted in significant variations in time of recovery among professional hockey players. A torn AITFL and bone bruising were the most common patterns of injury. Although MRI can be used to confirm the diagnosis of a syndesmosis injury, it did not predict return to play in this population.
Publication
Journal: Experimental Gerontology
January/20/2020
Abstract
Poor lighting has been associated with stair falls in young and older adults. However, current guidelines for illuminating stairs seem arbitrary, differ widely between sources, and are often difficult to interpret.Here we examined the influence of real-world bulb illumination properties on stair descent safety in young and older adults, with a view to generating preliminary evidence for appropriate lightbulb use/stair illumination.Stair tread illumination (lux) was measured in a standard UK home (2.23 m ceiling) from a low (50 W; 630 lm) and a high (103 W, 1450 lm) power compact fluorescent lamp (CFL) bulb from the time they were turned on until they reached full brightness. This enabled modelling of their illumination characteristics during warm up. Illumination was also measured from a low (40 W, 470 lm) and a high (100 W, 1521 lm) power LED bulb at first turn-on. Computer-controlled custom lighting then replicated these profiles, in addition to a Bright control (350 lx), on an instrumented staircase descended (3 × trials per light condition) by 12 young (25.3 ± 4.4 years; 5 males), 12 higher ability older (HAOA: 69.6 ± 4.7 years; 5 males) and 13 lower ability older (LAOA: 72.4 ± 4.2; 3 males) healthy adults. Older adults were allocated to ability groups based on physiological and cognitive function. Stair specific confidence was assessed prior to the first descent in each new lighting condition, and whole-body 3D kinematics (Vicon) quantified margins of stability and foot clearances with respect to the step edges. Mixed ANOVAs examined these measures for within-subject effects of lighting (×5), between-subject effects of age (×3) and interactions between lighting and age.Use of CFL bulbs led to lower self-reported confidence in older adults (20.37%, p = .01), and increased margins of stability (12.47%, p = .015) and foot clearances with respect to the step edges (10.36%, p = .003). Importantly, using CFL bulbs increased foot clearance variability with respect to the bottom step (32.74%, p = .046), which is where a high proportion of falls occur.Stair tread illumination from CFL bulbs at first turn on leads to less safe stair negotiation. We suggest high powered LED bulbs may offer a safer alternative.
Publication
Journal: Vision Research
December/20/2018
Abstract
People with central field loss (CFL) use peripheral vision to identify words. Eccentric vision provides ambiguous visual inputs to the processes leading to lexical access. Our purpose was to explore the hypothesis that this ambiguity leads to strong influences of inferential processes, our prediction being that increasing word frequency would decrease word reading time. Individuals with bilateral CFL induced by macular diseases read French sentences displayed with a self-paced reading method. Reading time of the last word of each sentence (target word) was recorded. Each target word (in sentence n) was matched with a synonym word (in sentence n+1) of the same length. When using absolute frequency value (Analysis 1), we found that reading time of target words decreased when word frequency increases, even when controlling for word length. The amplitude of this effect is larger than reported in previous investigations of reading with normal subjects. When comparing the effect of relative frequency (low vs. high) within each pair of synonyms (Analysis 2), results show the same pattern as the one observed in Analysis 1. Our results demonstrate clear-cut frequency effects on word reading time and suggest that inferential processes are stronger in CFL readers than in normally sighted observers. These results might also help design text simplification tools tailored for low-vision patients.
Publication
Journal: Knee Surgery, Sports Traumatology, Arthroscopy
July/21/2019
Abstract
Ultrasound (US) is a valuable tool for the evaluation of chronic lateral instability of the ankle; however, the feasibility of US for calcaneofibular ligament (CFL) assessment remains unknown. This study aimed to depict and compare CFL on US in various ankle positions to determine the optimal method for evaluating CFL with US and to interpret US findings using cadaveric specimens.The US study included 43 ankles of 25 healthy individuals. The CFL was scanned with US in 20° plantar flexion, neutral position, 20° dorsiflexion and maximum dorsiflexion. The distances between fibula and CFL were compared. The cadaveric study included macroscopic qualitative observation of the dynamic change of CFL in 7 ankles and quantitative observation of the directions of CFL and footprints in 17 ankles.In the US study, the mean distance (mm) between fibula and CFL was 7.3 ± 1.3 in 20° plantar flexion, 6.7 ± 1.6 in neutral position, 4.3 ± 2.5 in 20° dorsiflexion and 3.1 ± 2.1 in maximum dorsiflexion. The more dorsiflexed the ankle was, the shorter the distance between fibula and CFL was (Jonckheere's trend test p < 0.001). In the cadaveric study, the CFL fibres were aligned parallel between the mid-substance and the fibular attachment in maximum dorsiflexion, whilst CFL was reflected and rotated in plantar flexion.The whole length of the CFL, including its fibular attachment, is more likely to be visualized with US in dorsiflexion than in plantar flexion due to the direction of the CFL at the fibular attachment, which is parallel with the mid-substance in maximum dorsiflexion.IV.
Publication
Journal: Physical Chemistry Chemical Physics
May/11/2015
Abstract
An analytical platform with an ultratrace detection limit in the atto-molar (aM) concentration range is vital for forensic, industrial and environmental sectors that handle scarce/highly toxic samples. Superhydrophobic surface-enhanced Raman scattering (SERS) platforms serve as ideal platforms to enhance detection sensitivity by reducing the random spreading of aqueous solution. However, the fabrication of superhydrophobic SERS platforms is generally limited due to the use of sophisticated and expensive protocols and/or suffers structural and signal inconsistency. Herein, we demonstrate a high-throughput fabrication of a stable and uniform superhydrophobic SERS platform for ultratrace molecular sensing. Large-area box-like micropatterns of the polymeric surface are first fabricated using capillary force lithography (CFL). Subsequently, plasmonic properties are incorporated into the patterned surfaces by decorating with Ag nanocubes using the Langmuir-Schaefer technique. To create a stable superhydrophobic SERS platform, an additional 25 nm Ag film is coated over the Ag nanocube-decorated patterned template followed by chemical functionalization with perfluorodecanethiol. Our resulting superhydrophobic SERS platform demonstrates excellent water-repellency with a static contact angle of 165° ± 9° and a consequent analyte concentration factor of 59-fold, as compared to its hydrophilic counterpart. By combining the analyte concentration effect of superhydrophobic surfaces with the intense electromagnetic "hot spots" of Ag nanocubes, our superhydrophobic SERS platform achieves an ultra-low detection limit of 10(-17) M (10 aM) for rhodamine 6G using just 4 μL of analyte solutions, corresponding to an analytical SERS enhancement factor of 10(13). Our fabrication protocol demonstrates a simple, cost- and time-effective approach for the large-scale fabrication of a superhydrophobic SERS platform for ultratrace molecular detection.
Publication
Journal: Chemical Science
November/13/2018
Abstract
A photoredox reaction for cross-dehydrogenative coupling (CDC) was developed to Cα-arylate amides (α to nitrogen) and ethers using a variety of five- and six-membered electron-deficient heteroarenes. A unique decomposition mechanism of ammonium persulfate enhanced by photoexcited benzaldehydes was revealed. This benzaldehyde-mediated photoredox reaction proceeded smoothly with household 23 W CFL bulbs as the energy source under metal-free conditions, allowing the construction of new Csp2 -Csp2 and Csp3 -Csp2 bonds and access to important pharmacophores of broad utility using commercially available reagents.
Publication
Journal: Nano Letters
June/8/2016
Abstract
Various supramolecular nanotubes have recently been built up by lipids, peptides, and other organic molecules. Major light-harvesting (LH) antenna systems in a filamentous anoxygenic phototroph, Chloroflexus (Cfl.) aurantiacus, are called chlorosomes and contain photofunctional single-wall supramolecular nanotubes with approximately 5 nm in their diameter. Chlorosomal supramolecular nanotubes of Cfl. aurantiacus are constructed by a large amount of bacteriochlorophyll(BChl)-c molecules. Such a pigment self-assembles in a chlorosome without any assistance from the peptides, which is in sharp contrast to the other natural photosynthetic LH antennas. To mimic chlorosomal supramolecular nanotubes, synthetic models were prepared by the modification of naturally occurring chlorophyll(Chl)-a molecule. Metal complexes (magnesium, zinc, and cadmium) of the Chl derivative were synthesized as models of natural chlorosomal BChls. These metal Chl derivatives self-assembled in hydrophobic environments, and their supramolecules were analyzed by spectroscopic and microscopic techniques. Cryo-transmission electron microscopic images showed that the zinc and cadmium Chl derivatives could form single-wall supramolecular nanotubes and their outer and inner diameters were approximately 5 and 3 nm, respectively. Atomic force microscopic images suggested that the magnesium Chl derivative formed similar nanotubes to those of the corresponding zinc and cadmium complexes. Three chlorosomal single-wall supramolecular nanotubes of the metal Chl derivatives were prepared in the solid state and would be useful as photofunctional materials.
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