Accuracy of Measurements of the Structural Reserve for Upper Limb Function in Patients With Moderate-to-Severe Stroke.

BACKGROUND: The structural integrity of the corticospinal tract (CST) is an important biomarker of poststroke upper limb recovery. Injured CST undergoes Wallerian degeneration rostrocaudally during the first few months. However, there is no standardized measurement of the structural integrity of the CST. This study aimed to determine the measurement accuracy of the structural integrity of the CST. METHODS: This cross-sectional study included 50 consecutive patients with middle cerebral artery stroke who underwent diffusion tensor imaging upon transfer from the acute stroke unit to the inpatient rehabilitation facility (2018-2022). We evaluated hemiplegic upper limb function using Shoulder Abduction and Finger Extension (SAFE) scores. Fractional anisotropy values representing the structural integrity of the CST were evaluated using 4 region of interest-based and 2 tract-based measurements, including the posterior limb of internal capsule, cerebral peduncle, pons, pontomedullary junction, entire CST, and CST in the brainstem. Multivariate linear regression models and the area under the curve (AUC) were used to determine measurement accuracy for hemiplegic upper limb function. RESULTS: The structural integrity of the CST at the pontomedullary junction showed the highest explanatory power, followed by the entire CST, in the multivariate linear regression models (adjusted R2=0.459 and 0.425, respectively). The structural integrity of the CST at the pontomedullary junction also showed the highest AUC, followed by the entire CST, in discriminating patients with a SAFE score of <8 or 5 from those with SAFE ≥8 or 5 (SAFE <8: AUC, 0.90 [95% CI, 0.80-1.00]; AUC, 0.83 [0.66-0.99]; SAFE <5: AUC, 0.87 [0.77-0.96]; AUC, 0.83, [0.72-0.95], respectively). CONCLUSIONS: The structural integrity of the CST measured at the pontomedullary junction or entire CST demonstrated the highest accuracy for hemiplegic upper limb function in the subacute phase of stroke.

Evidence of lateralised white matter plasticity: A longitudinal study of balance performance in nonexpert healthy adults.

Training-induced plasticity by practicing expert skills has been of particular interest; however, little is known about white matter plasticity for improving a fundamental element of body function, such as balance or postural control. This study explored white matter plasticity in nonexpert healthy adults, based on stepwise balance training. Seventeen participants were included and performed a home-based balance training program for 4 weeks (30 min/day, 3 days/week). Before commencing training, they underwent a baseline diffusion tensor imaging scan. A second scan was acquired at the end of the 4-week training. Lateralised balance load was applied on the right leg to contrast any lateralised effect on the white matter tracts. The balance function was assessed using the Community Balance & Mobility Scale. We examined changes in the fractional anisotropy values of the tracts of interest between pre- and post-training. After the 4-week training, the fractional anisotropy values were enhanced in the right superior cerebellar peduncle, transverse pontine fibre, body of the corpus callosum, left fornix and left uncinate fasciculus. The Community Balance & Mobility Scale score improved after 4-week training, but an association with changes in fractional anisotropy values cannot be evaluated due to the ceiling effect of the balance assessment tools. Balance training can strengthen the cerebro-cerebellar and interhemispheric structural connections and induce microstructural changes in the limbic structures, including the fornix and uncinate fasciculus. The effect of a lateralised balance load could be projected to the specific white matter tracts in a lateralised manner.

Thermo-Compression Bonding of Cu/SnAg Pillar Bumps with Electroless Palladium Immersion Gold (EPIG) Surface Finish.

Thermo-compression bonding (TCB) properties of Cu/SnAg pillar bumps on electroless palladium immersion gold (EPIG) were evaluated in this study. A test chip with Cu/SnAg pillar bumps was bonded on the surface-finished Cu pads with the TCB method. The surface roughness of the EPIG was 82 nm, which was 1.6 times higher than that of the ENEPIG surface finish because the EPIG was so thin that it could not flatten rough bare Cu pads. From the cross-sectional SEM micrographs, the filler trapping of the TC-bonded EPIG was much higher than that of the ENEPIG sample. The high filler trapping of the EPIG sample was due to the high surface roughness of the EPIG surface finish. The contact resistance increased as the thermal cycle time increased. The increase of the contact resistance with 1500 cycles of the thermal cycle test was 26% higher for the EPIG sample than for the ENEPIG sample.

Detection of post-stroke visual field loss by quantification of the retrogeniculate visual pathway.

Visual field loss is associated with poor post-stroke functional outcomes. However, early detection of visual field loss is often challenging in patients with disabling stroke. This study explored the association between the microstructural integrity of the retrogeniculate pathway and visual field loss in disabling stroke patients undergoing inpatient rehabilitation. Thirty patients with stroke lesions involving the retrogeniculate visual pathway were included. The degree of visual field loss was determined by the visual field index and mean deviation using automated perimetry. The fractional anisotropy (FA) values were obtained for the lateral geniculate nucleus and optic radiation; the FA laterality indices, representing the degree of degeneration, were calculated. The FA values were compared between the affected and unaffected hemispheres. The patients were categorized into complete and incomplete hemianopia groups, and their FA values were compared. The relationship between the FA laterality index and the degree of visual field loss was assessed. FA values of the lateral geniculate nucleus and optic radiation were lower on the affected side than on the unaffected side (P < 0.001 and P < 0.001, respectively). The affected optic radiation in the complete hemianopia group showed a lower FA value than in the incomplete group (P = 0.006). The FA laterality index of the optic radiation was positively correlated with the degree of visual field loss (visual field index, ρ = 0.629; mean deviation, ρ = 0.568). The quantification of the retrogeniculate visual pathway may aid in detecting post-stroke visual field loss. The microstructural integrity of the optic radiation is associated with the severity of visual field loss.

Enhancement of dielectric performance of encapsulation in barium titanate oxide using size-controlled reduced graphene oxide.

Ferroelectric barium titanate (BTO) powder particles were encapsulated by three different sizes of reduced graphene oxide (rGO) platelets. The size of the graphene oxide (GO) platelets is controlled by varying the horn type ultrasonic times, i.e. 0, 30, and 60 min, respectively, and they are reduced with hydrazine to obtain rGO-encapsulated BTO (rGO@BTO) film. The rGO@BTO film exhibits an increase in the dielectric characteristics due to the interfacial polarization. These improved characteristics include a dielectric constant of 194 (a large increment of 111%), along with the dielectric loss of 0.053 (a slight increment of 13%) at 1 kHz, compared to the pure BTO dielectric film. The improvement in the dielectric constant of the rGO@BTO is attributed to the encapsulation degree between the rGO platelets and BTO powder particles, which results in the interfacial polarization and micro-capacitor effect in a dielectric film, and also contributes to a low dielectric loss. Therefore, a suitable size of rGO platelets for encapsulation is essential for high-dielectric performance.

Efficacy and safety of temperature-sensitive acellular dermal matrix in prevention of postoperative adhesion after thyroidectomy: A randomized, multicenter, double-blind, non-inferiority study.

INTRODUCTION: MegaShield® is a newly developed temperature-sensitive anti-adhesive containing micronized acellular dermal matrix. The aim of this study was to investigate the efficacy and safety of MegaShield® compared with Guardix-SG® in the prevention of adhesions in patients undergoing bilateral total thyroidectomy. METHOD: We conducted a multicenter trial between October 2018 and March 2020 in patients undergoing total thyroidectomy. The patients were randomly assigned to either the MegaShield® group or the Guardix-SG® group. The primary outcome was the esophageal movement using marshmallow six weeks after the surgery and the secondary outcome was the assessed adhesion score. The safety assessment was also evaluated. RESULTS: The study included 70 patients each in the MegaShield® and control (Guardix-SG®) groups. Baseline clinical characteristics, the mean score of marshmallow esophagography, and the sum of adhesion scores were not statistically different between the two groups. Inferiority test demonstrated that the efficacy of MegaShield® is not inferior to that of Guardix-SG®. There were no device-related complications in both groups. CONCLUSION: The efficacy and safety of MegaShield® were not inferior than those of Guardix-SG®. MegaShield® demonstrated the potential of ADM as a potential future anti-adhesive agent. TRIAL REGISTRATION: The name of trial registry CRIS (Clinical Research Information Service) https://cris.nih.go.kr/cris/index.jsp. (The full trial protocol can be accessed) Registration number: KCT0003204.

Plasma Polymerized SiCOH Films from Octamethylcyclotetrasiloxane by Dual Radio Frequency Inductively Coupled Plasma Chemical Vapor Deposition System.

We have fabricated porous plasma polymerized SiCOH (ppSiCOH) films with low-dielectric constants (low-k, less than 2.9), by applying dual radio frequency plasma in inductively coupled plasma chemical vapor deposition (ICP-CVD) system. We varied the power of the low radio frequency (LF) of 370 kHz from 0 to 65 W, while fixing the power of the radio frequency (RF) of 13.56 MHz. Although the ppSiCOH thin film without LF had the lowest k value, its mechanical strength is not high to stand the subsequent semiconductor processing. As the power of the LF was increased, the densities of ppSiCOH films became high, accordingly high in the hardness and elastic modulus, with quite satisfactory low-k value of 2.87. Especially, the ppSiCOH film, deposited at 35 W, exhibited the highest mechanical strength (hardness: 1.7 GPa, and elastic modulus: 9.7 GPa), which was explained by Fourier transform infrared spectroscopy. Since the low-k material is widely used as an inter-layer dielectric insulator, good mechanical properties are required to withstand chemical mechanical polishing damage. Therefore, we suggest that plasma polymerized process based on the dual frequency can be a good candidate for the deposition of low-k ppSiCOH films with enhanced mechanical strength.

Characterization of Bilayer Organic Solar Cells with Carbon Nanotubes Using Impedance Analysis.

Four organic solar cell (OSC) devices with the bilayer heterojunction architecture were investigated, where carbon nanotubes (CNTs) were doped within the acceptor layer. The power conversion efficiency (PCE) of the CNT-incorporated device with a concentration of 0.004 wt% is approximately 20% point higher than that of the reference one. As the concentration of CNTs became higher, the PCE of the devices deteriorated; this could be caused by the percolative connection of CNTs within the layer. The voltage dependence on the effective lifetime of the charge carriers, determined by Cole-Cole curves of the impedance analysis, was different for the reference and CNT-incorporating devices-the lifetime of the CNT-incorporated ones was shorter, possibly owing to the high local electric field near the CNTs. Controlling the concentration of CNTs below the critical concentration of percolation is a key factor in achieving high photovoltaic performance.

Physical Activity of Workers in a Hospital.

Purpose: This study aims to evaluate the physical activity of healthcare personnel and the affecting factors of physical activity (PA) in a hospital using an accelerometer device (Actigraph wGT3X-BT). Method: A total of 63 subjects (22 physicians, 19 nurses, and 23 supporting staff) participated and wore an accelerometer for seven days. Among the outputs, the mean counts for a minute, time spent for light, moderate, and vigorous intensity PA, and step count were extracted. As a secondary study, 16 subjects continued for one more week after feedback on their PA of the previous week and counseling to encourage PA. Result: Most of (62/63) the participants fulfilled the recommended amount of PA, which is more than 300 min of moderate to vigorous physical activity (MVPA). Physicians showed significantly less PA than nurses or supporting staffs: Mean counts per minute (210.4 vs. 476.0 and 441.8 respectively), time in MVPA per week (904.7 min vs. 1471.3 min and 1451.0 min), and step counts per week (69,029 vs. 87,119 and 84,700) (p < 0.001). Nurses and supporting staff were not statistically different. There was no significant difference in the PA of workers in the hospital regarding gender and marital status. However, the average calorie expenditure of the child raising group was significantly higher. There was no statistically significant difference in PA before and after counseling. No participants reported a vigorous degree of exercise intensity over the study period. Conclusion: Most of the healthcare personnel met the recommended PA, however, only 57% (36/63) recalled having engaged in MVPA during the study period. The group of physicians showed less PA compared to nurses or supporting staff. Single check-up and counseling were not found to increase PA.

Long-term effect of repetitive transcranial magnetic stimulation on disability in patients with stroke.

High-frequency repetitive transcranial magnetic stimulation (rTMS) is widely used to improve motor function in stroke patients. However, the long-term effects of rTMS on disability and motor function are not clear. We investigated the effects of high-frequency rTMS administered within 1 month of stroke on disability and motor function 6 months after stroke onset. The study was conducted by an open-label longitudinal study, and were included 76 (38 rTMS and 38 control) subacute stroke patients. The rTMS group received 10 Hz stimulation over the primary motor cortex of the affected hemisphere for 10 days with a daily dose of 1000 pulses. The Korean version of the Modified Barthel Index (K-MBI), the Medical Research Council (MRC) scale for motor deficits in the affected arm, the Manual Function Test (MFT), and the Functional Ambulation Classification (FAC) were administered at baseline (within 1 month of stroke onset) and at 3 and 6 months after onset. The K-MBI, MRC scale, MFT, and FAC scores of both groups changed significantly over time (p < 0.001); however, the motor strength, hand function, FAC classification, and K-MBI scores of the rTMS and control groups did not differ. Our findings indicate that rTMS did not have a long-lasting effect (6 months after onset) on disability and motor function in patients with stroke.

Botulinum Toxin Type A Injection for Neuropathic Pain in a Patient With a Brain Tumor: A Case Report.

Neuropathic pain is usually managed pharmacologically, rather than with botulinum toxin type A (BTX-A). However, medications commonly fail to relieve pain effectively or have intolerable side effects. We present the case of a 62-year-old man diagnosed with an intracranial chondrosarcoma, which was removed surgically and treated with radiation therapy. He suffered from neuropathic pain despite combined pharmacological therapy with gabapentin, amitriptyline, tramadol, diazepam, and duloxetine because of adverse effects. BTX-A (100 units) was injected subcutaneously in the most painful area in the posterior left thigh. Immediately after the injection, his pain decreased significantly from 6/10 to 2/10 on a visual analogue scale. Pain relief lasted for 12 weeks. This case report describes intractable neuropathic pain caused by a brain tumor that was treated with subcutaneous BTX-A, which is a useful addition for the management of neuropathic pain related to a brain tumor.