Unfavourable short-term outcomes of a poly-L/D-lactide scaffold for thumb trapeziometacarpal arthroplasty

2015 ◽  
Vol 41 (3) ◽  
pp. 328-334 ◽  
Author(s):  
S. Mattila ◽  
E. Waris
Keyword(s):  
Foreign Body ◽  
Cyclic Loading ◽  
Pain Relief ◽  
High Frequency ◽  
Recent Attempt ◽  
Short Term ◽  
Trapeziometacarpal Osteoarthritis ◽  
Foreign Body Reactions ◽  
Tissue Reactions

The bioabsorbable poly-L-D-lactide joint scaffold arthroplasty is a recent attempt in the reconstruction of small joints in rheumatoid patients. In this study, we analysed the 1-year clinical, functional and radiologic results of partial trapeziectomy with the poly-L-D-lactide (96/4) joint scaffold in 23 patients with isolated trapeziometacarpal osteoarthritis. The results showed that the procedure provided pain relief and improvement in overall function according to the Quick Disabilities of the Arm, Shoulder and Hand score in most patients. However, radiographs demonstrated a high frequency of osteolysis around the implant. Seven patients developed clinically manifested foreign-body reactions 6 months to 1 year after surgery. The reason for the unexpected tissue reactions may relate to excessive mechanical cyclic loading of the implant. The outcomes of this implant in our patients have not been sufficiently beneficial and we have discontinued use of this implant in isolated trapeziometacarpal osteoarthritis.

Short-Term Pain Relief by Repetitive Peripheral Magnetic Stimulation in Patients with Musculoskeletal Pain: A Pilot Study

Clinical Pain ◽  
2020 ◽  
Vol 19 (1) ◽  
pp. 16-22
Author(s):  
Joonhyun Park ◽  
Hyunseok Kwak ◽  
Wookyung Park ◽  
MinYoung Kim ◽  
Kyunghoon Min
Keyword(s):  
Pilot Study ◽  
Pain Relief ◽  
Musculoskeletal Pain ◽  
Magnetic Stimulation ◽  
Short Term

Prior Return Effect in Indian Stock Market: An Intra-day Analysis

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Vanita Tripathi ◽  
Shalini Aggarwal
Keyword(s):  
Stock Market ◽  
Stock Prices ◽  
High Frequency ◽  
Good News ◽  
High Frequency Data ◽  
Short Term ◽  
Fund Managers ◽  
News Events ◽  
Return Effect ◽  
Indian Stock Market

In a first of this kind, this paper examines the issue of prior return effect in Indian stock market in intra-day analysis using high frequency data. We document that in Indian stock market, security returns exhibit a reversal in their direction within few minutes of extreme price rises as well as price falls. However the speed with which the correction takes place is slightly different for good news events and bad news events. Indian investors tend to be optimistic as they immediately bring stock prices up following unjustified price falls but take time to bring stock prices down following unjustified price rises. These findings lend a further support to short-term overreaction literature. More importantly, these findings serve as a proof of predictability of the direction of future stock prices and consequent returns on an intra-day basis. It forwards important investment implications for traders, fund managers, and investors at large.

scholarly journals Small Floating Target Detection Method Based on Chaotic Long Short-Term Memory Network

2021 ◽  
Vol 9 (6) ◽  
pp. 651
Author(s):  
Yan Yan ◽  
Hongyan Xing
Keyword(s):  
High Frequency ◽  
Short Term Memory ◽  
Detection Method ◽  
Low Frequency ◽  
Sea Clutter ◽  
Short Term ◽  
Term Memory ◽  
Memory Network ◽  
Long Short Term Memory ◽  
Small Targets

In order for the detection ability of floating small targets in sea clutter to be improved, on the basis of the complete ensemble empirical mode decomposition (CEEMD) algorithm, the high-frequency parts and low-frequency parts are determined by the energy proportion of the intrinsic mode function (IMF); the high-frequency part is denoised by wavelet packet transform (WPT), whereas the denoised high-frequency IMFs and low-frequency IMFs reconstruct the pure sea clutter signal together. According to the chaotic characteristics of sea clutter, we proposed an adaptive training timesteps strategy. The training timesteps of network were determined by the width of embedded window, and the chaotic long short-term memory network detection was designed. The sea clutter signals after denoising were predicted by chaotic long short-term memory (LSTM) network, and small target signals were detected from the prediction errors. The experimental results showed that the CEEMD-WPT algorithm was consistent with the target distribution characteristics of sea clutter, and the denoising performance was improved by 33.6% on average. The proposed chaotic long- and short-term memory network, which determines the training step length according to the width of embedded window, is a new detection method that can accurately detect small targets submerged in the background of sea clutter.

scholarly journals Effect of short-term exposure to particulate air pollution on heart rate variability in normal-weight and obese adults

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Luyi Li ◽  
Dayu Hu ◽  
Wenlou Zhang ◽  
Liyan Cui ◽  
Xu Jia ◽  
...  
Keyword(s):  
Heart Rate ◽  
Air Pollution ◽  
Heart Rate Variability ◽  
High Frequency ◽  
Normal Weight ◽  
High Frequency Power ◽  
Short Term ◽  
Particulate Air Pollution ◽  
Short Term Exposure ◽  
Frequency Power

Abstract Background The adverse effects of particulate air pollution on heart rate variability (HRV) have been reported. However, it remains unclear whether they differ by the weight status as well as between wake and sleep. Methods A repeated-measure study was conducted in 97 young adults in Beijing, China, and they were classified by body mass index (BMI) as normal-weight (BMI, 18.5–24.0 kg/m2) and obese (BMI ≥ 28.0 kg/m2) groups. Personal exposures to fine particulate matter (PM2.5) and black carbon (BC) were measured with portable exposure monitors, and the ambient PM2.5/BC concentrations were obtained from the fixed monitoring sites near the subjects’ residences. HRV and heart rate (HR) were monitored by 24-h Holter electrocardiography. The study period was divided into waking and sleeping hours according to time-activity diaries. Linear mixed-effects models were used to investigate the effects of PM2.5/BC on HRV and HR in both groups during wake and sleep. Results The effects of short-term exposure to PM2.5/BC on HRV were more pronounced among obese participants. In the normal-weight group, the positive association between personal PM2.5/BC exposure and high-frequency power (HF) as well as the ratio of low-frequency power to high-frequency power (LF/HF) was observed during wakefulness. In the obese group, personal PM2.5/BC exposure was negatively associated with HF but positively associated with LF/HF during wakefulness, whereas it was negatively correlated to total power and standard deviation of all NN intervals (SDNN) during sleep. An interquartile range (IQR) increase in BC at 2-h moving average was associated with 37.64% (95% confidence interval [CI]: 25.03, 51.51%) increases in LF/HF during wakefulness and associated with 6.28% (95% CI: − 17.26, 6.15%) decreases in SDNN during sleep in obese individuals, and the interaction terms between BC and obesity in LF/HF and SDNN were both statistically significant (p <  0.05). The results also suggested that the effects of PM2.5/BC exposure on several HRV indices and HR differed in magnitude or direction between wake and sleep. Conclusions Short-term exposure to PM2.5/BC is associated with HRV and HR, especially in obese individuals. The circadian rhythm of HRV should be considered in future studies when HRV is applied. Graphical abstract

Cibenzoline for High-Frequency Ventricular Arrhythmias: A Short-Term Comparison With Quinidine and a Long-Term Follow-up

1987 ◽  
Vol 27 (4) ◽  
pp. 283-287 ◽  
Author(s):  
Prasad R. Palakurthy ◽  
Claudio Maldonado ◽  
Gurbachan Sohi ◽  
Nancy C. Flowers
Keyword(s):  
High Frequency ◽  
Ventricular Arrhythmias ◽  
Short Term ◽  
Long Term Follow Up

scholarly journals Multi-Scale Spatiotemporal Change Characteristics Analysis of High-Frequency Disturbance Forest Ecosystem Based on Improved Spatiotemporal Cube Model

2021 ◽  
Vol 13 (13) ◽  
pp. 2537
Author(s):  
Yangcen Zhang ◽  
Xiangnan Liu ◽  
Meiling Liu ◽  
Xinyu Zou ◽  
Qian Zhang ◽  
...  
Keyword(s):  
High Frequency ◽  
Forest Ecosystems ◽  
Satellite Image ◽  
Vegetation Indices ◽  
Anthropogenic Factors ◽  
Residential Areas ◽  
Short Term ◽  
Spatiotemporal Changes ◽  
Spatiotemporal Scales ◽  
The Impact

High-frequency disturbance forest ecosystems undergo complex and frequent changes at various spatiotemporal scales owing to natural and anthropogenic factors. Effectively capturing the characteristics of these spatiotemporal changes from satellite image time series is a powerful and practical means for determining their causes and predicting their trends. Herein, we combined the spatiotemporal cube and vegetation indices to develop the improved spatiotemporal cube (IST-cube) model. We used this to acquire the spatiotemporal dynamics of forest ecosystems from 1987 to 2020 in the study area and then classified it into four spatiotemporal scales. The results showed that the cube-core only exists in the increasing IST-cubes, which are distributed in residential areas and forests. The length of the IST-cube implies the duration of triggers. Human activities result in long-term small-scope IST-cubes, and the impact in the vicinity of residential areas is increasing while there is no change within. Meteorological disasters cause short-term, large scope, and irregular impacts. Land use type change causes short-term small scope IST-cubes and a regular impact. Overall, we report the robustness and strength of the IST-cube model in capturing spatiotemporal changes in forest ecosystems, providing a novel method to examine complex changes in forest ecosystems via remote sensing.

Early Failure of a Polyvinyl Alcohol Hydrogel Implant With Osteolysis and Foreign Body Reactions in an Ovine Model of Cartilage Repair

2021 ◽  
pp. 036354652110336
Author(s):  
Marta Cercone ◽  
Jacqueline Chevalier ◽  
John G. Kennedy ◽  
Andrew D. Miller ◽  
Lisa A. Fortier
Keyword(s):  
Computed Tomography ◽  
Foreign Body ◽  
Polyvinyl Alcohol ◽  
Failure Rate ◽  
Synovial Membrane ◽  
Quantitative Computed Tomography ◽  
Macrophage Infiltration ◽  
Ovine Model ◽  
Foreign Body Reactions ◽  
Pva Hydrogel

Background: Hemiarthroplasty using a polyvinyl alcohol (PVA) hydrogel synthetic implant has been suggested as a good alternative to arthrodesis for the treatment of hallux rigidus. However, failure rates as high as 20% have been recorded. Purpose: To characterize the pathological processes in bone, cartilage, and the synovial membrane after PVA hemiarthroplasty in an ovine model with 6 months of follow-up. Study Design: Controlled laboratory study. Methods: A unilateral osteochondral defect (8-mm diameter × 10-mm depth) was made in the medial femoral condyle in 6 sheep. Animals were randomized to receive a PVA implant (n = 4) or to have an empty defect (n = 2) and were monitored for 6 months. Patellofemoral radiographs were obtained at monthly intervals, and quantitative computed tomography was performed at the end of the study. After death, the joints were macroscopically evaluated and scored. Osteochondral and synovial membrane histological findings were assessed using modified Osteoarthritis Research Society International (OARSI) and aseptic lymphocyte-dominated vasculitis-associated lesion (ALVAL) scoring systems. Immunohistochemistry using Iba1 was performed to evaluate activated macrophage infiltration. Results: Overall, 2 sheep with PVA implants were euthanized at 1 and 5 months because of uncontrollable pain and lameness (failed implants). Quantitative computed tomography showed that sheep with failed implants had 2.1-fold more osteolysis than those with successful implants. The sheep with failed implants had osteoarthritis with extensive glycosaminoglycan loss and cartilage fibrillation of the condyle and opposing tibial surface on histological examination. A foreign body reaction with severe chronic lymphoplasmacytic and granulomatous inflammation with giant cells was detected surrounding the implant. The synovial membrane ALVAL score was 9 of 19 and 14 of 19 in failed implants with synovial hyperplasia and lymphoplasmacytic and macrophage infiltration. In contrast, the synovial membrane in successful implants and empty defects was normal (ALVAL score = 0/19). Immunolabeling for Iba1 in failed implants confirmed extensive and dense macrophage infiltration within the condyle and synovial membrane, with the highest immunoreactive score (9/9). Conclusion: PVA hydrogel implants had a 50% failure rate with uncontrollable pain, severe osteolysis, inflammation, and foreign body reactions. Clinical Relevance: The failure rate and pathological characteristics of the PVA implants suggest that their use should not be continued in human patients without further in vivo safety studies.

Neural tissue reactions to low-intensity laser radiation

1998 ◽  
Vol 79 (3) ◽  
pp. 204-210
Author(s):  
Yu. A. Chelyshev ◽  
K. I. Sitekulov
Keyword(s):  
Laser Radiation ◽  
Pain Relief ◽  
Neural Tissue ◽  
Low Intensity ◽  
The Past ◽  
Tissue Reactions ◽  
High Degree ◽  
Intensity Laser

Over the past 25 years, laser radiation has found wide application in various fields of medicine, including neurology, mainly as a means of pain relief [17]. A high degree of specificity of the photobiological action is determined by its unique properties: monochromaticity, selective focus and coherence.

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