[Imaging study of paravertebral muscle degeneration in degenerative lumbar instability].

OBJECTIVES: To compare the paravertebral muscle (such as multifidus, erector spinae, psoas muscle) changes between the patients with degenerative lumbar instability and normal person by MRI and to observe the degeneration of paravertebral muscles. To analyze the relationship between paravertebral muscle degeneration and lumbar curvature of degenerative lumbar instability. METHODS: Sixty patients with degenerative lumbar instability were retrospectively enrolled from December 2011 to July 2013 as degeneration group, meanwhile 60 health persons with no degenerative lumbar instability were selected as control group. No significant differences were found in the gender, age and body mass index between the two groups. The cross-sectional area(CSA) and percentage of fat infiltration area (FIA) of the paravertebral muscles at the L4-S1 levels were measured using T2-weighted axial MRI and Image J soft ware. And the lumbar curvature(expressed as lumbar lordosis angle) of all the patients in lumbar X-ray were measured in the two groups. The measured data were analyzed with independent samples t-test. RESULTS: The difference of multifidus cross-sectional area and the percentage of fat infiltration in the patients of degenerative lumbar instability at the L4-L5, L5-S1 level, compared with the control group, was statistically significant (t = 2.768, t = 6.216, P < 0.05). Between the two groups, the percentage of fatty infiltration in erector spinae showed significant differences (t = 5.862, P < 0.05). The cross-sectional area of erector spinae and the degeneration of the psoas muscle between the two groups was not statistically significant. The lumbar lordsis angle in the patients with degenerative lumbar instability was (43.9 ± 15.6)°, which was higher than the (39.3 ± 14.2)° in control group (t = 2.915, P < 0.05). CONCLUSIONS: Compared with the control group, patients with degenerative lumbar instability exists erector spinae and multifidus muscle degeneration, and erector spinae is more obvious. The degeneration among psoas muscle, erector spinae and multifidus muscle are inconsistent, which may be related to the increasing of the lumbar lordosis angle in the patients with degenerative lumbar instability.

AgCNER, the First Large-Scale Chinese Named Entity Recognition Dataset for Agricultural Diseases and Pests.

Named entity recognition is a fundamental subtask for knowledge graph construction and question-answering in the agricultural diseases and pests field. Although several works have been done, the scarcity of the Chinese annotated dataset has restricted the development of agricultural diseases and pests named entity recognition(ADP-NER). To address the issues, a large-scale corpus for the Chinese ADP-NER task named AgCNER was first annotated. It mainly contains 13 categories, 206,992 entities, and 66,553 samples with 3,909,293 characters. Compared with other datasets, AgCNER maintains the best performance in terms of the number of categories, entities, samples, and characters. Moreover, this is the first publicly available corpus for the agricultural field. In addition, the agricultural language model AgBERT is also fine-tuned and released. Finally, the comprehensive experimental results showed that BiLSTM-CRF achieved F1-score of 93.58%, which would be further improved to 94.14% using BERT. The analysis from multiple aspects has verified the rationality of AgCNER and the effectiveness of AgBERT. The annotated corpus and fine-tuned language model are publicly available at https://doi.org/XXX and https://github.com/guojson/AgCNER.git .

Ultrathin (∼30 µm) flexible monolithic perovskite/silicon tandem solar cell.

The efficiency of rigid perovskite/silicon tandem solar cells has reached 33.9%. However, there has been no report on flexible perovskite/silicon tandem solar cells due to the challenge of overcoming the poor light absorption of ultrathin silicon bottom cells while maintaining their mechanical flexibility. Herein, we report the first demonstration of the perovskite/silicon tandem solar cell based on flexible ultrathin silicon. We show that reducing the wafer thicknesses and feature sizes of the light-trapping textures can significantly improve the flexibility of silicon without sacrificing light utilization. In addition, the capping of the perovskite top cells can further improve the device's mechanical durability by shifting the neutral plane toward the silicon surface that is prone to fracture. Finally, the resulting ultrathin (∼30 µm) flexible perovskite/silicon tandem solar cell achieves a certified stabilized efficiency of 22.8% with an extremely high power-to-weight ratio of 3.12 W g-1. Moreover, the flexible tandems exhibit remarkable bending durability, maintaining 98.2% of their initial performance after 3000 bending cycles at a radius of only 1 cm.

An improved novel quantum image representation and its experimental test on IBM quantum experience.

Quantum image representation (QIR) is a necessary part of quantum image processing (QIP) and plays an important role in quantum information processing. To address the problems that NCQI cannot handle images with inconsistent horizontal and vertical position sizes and multi-channel image processing, an improved color digital image quantum representation (INCQI) model based on NCQI is proposed in this paper. The INCQI model can process color images and facilitate multi-channel quantum image transformations and transparency information processing of images using auxiliary quantum bits. In addition, the quantum image control circuit was designed based on INCQI. And quantum image preparation experiments were conducted on IBM Quantum Experience (IBMQ) to verify the feasibility and effectiveness of INCQI quantum image preparation. The prepared image information was obtained by quantum measurement in the experiment, and the visualization of quantum information was successfully realized. The research in this paper has some reference value for the research related to QIP.

Continuous hydrogen production from glucose/xylose by an anaerobic sequential batch reactor to maximize the energy recovery efficiency.

Fermentation of both glucose and xylose is essential to realize efficient bioconversion of renewable and abundant lignocellulosic biomass to hydrogen. In this study, a mixture of glucose and xylose at different ratios was used as a substrate for biological hydrogen production by an anaerobic sequential batch reactor (ASBR). An average glucose and xylose consumption of 80% and 50% with a high hydrogen production rate of 7.1 ± 0.9 mmol L-1 h-1 was obtained, respectively. Hydraulic retention time (HRT) played a critical role in hydrogen production at high glucose to xylose ratios. A maximum hydrogen production rate of 8.9 mmol L-1 h-1 was achieved at an optimized HRT of 12 h with a high glucose and xylose consumption of 92.2% and 82.2%, respectively. Upon further energy conversion analysis, continuous hydrogen production by ASBR provided the maximum energy conversion efficiency of 21.5%. These results indicate that ASBR can effectively accelerate the hydrogen production rate, improve substrate consumption regardless of the glucose to xylose ratio, and thus provides a new direction for efficient hydrogen production from lignocellulosic feedstock.