Nonlinear optical diode effect in a magnetic Weyl semimetal.

Diode effects are of great interest for both fundamental physics and modern technologies. Electrical diode effects (nonreciprocal transport) have been observed in Weyl systems. Optical diode effects arising from the Weyl fermions have been theoretically considered but not probed experimentally. Here, we report the observation of a nonlinear optical diode effect (NODE) in the magnetic Weyl semimetal CeAlSi, where the magnetization introduces a pronounced directionality in the nonlinear optical second-harmonic generation (SHG). We demonstrate a six-fold change of the measured SHG intensity between opposite propagation directions over a bandwidth exceeding 250 meV. Supported by density-functional theory, we establish the linearly dispersive bands emerging from Weyl nodes as the origin of this broadband effect. We further demonstrate current-induced magnetization switching and thus electrical control of the NODE. Our results advance ongoing research to identify novel nonlinear optical/transport phenomena in magnetic topological materials and further opens new pathways for the unidirectional manipulation of light.

Methyl-CpG binding protein 2 is associated with the prognosis and mortality of elderly patients with hip fractures.

OBJECTIVES: To investigate the expression level and clinical significance of Methyl-CpG binding Protein 2 (MECP2) in elderly patients with hip fractures. METHODS: This prospective observational study included 367 elderly patients with hip fractures between April 2016 and December 2018. All the patients were treated with internal fixation or joint replacement. In addition, 50 healthy elderly individuals were enrolled as healthy controls. The serum levels of MECP2 and inflammatory factors Interleukin (IL)-1ß, IL-6, IL-8, and Tumor Necrosis Factor (TNF)-α was determined by enzyme-linked immunosorbent assay. Data on patients' basic characteristics and postoperative complications were collected. The Harris score was used to assess hip function at 1-month, 3-months, and 6-months after surgery. Patient quality of life was measured using the Barthel Index (BI) score 3-months after surgery. The 1-year mortality was analyzed using the Kaplan-Meier curve, and logical regression was used to analyze the risk factors for mortality. RESULTS: No significant differences were observed in the basic clinical characteristics of all patients. The serum MECP2 levels were remarkably high in patients with hip fractures and negatively correlated with serum IL-1ß, IL-6, and TNF-α levels. Patients with higher MECP2 predicted higher dynamic Harris scores, lower postoperative complications, lower 1-year mortality, and higher BI scores. Logical regression showed that age was the only independent risk factor for postoperative 1-year mortality in elderly patients with hip fractures. CONCLUSION: Lower MECP2 predicted poor prognosis and higher 1-year mortality in elderly patients with hip fractures.

Application of 3D printed patient-specific instruments in the treatment of large tibial bone defects by the Ilizarov technique of distraction osteogenesis.

Background: The Ilizarov technique of distraction osteogenesis is an effective treatment for tibia defect. However, repeated attempts to reduce due to the complexity of the bone defect during the operation will increase the operation time and iatrogenic injury, and excessive radiation exposure. Three-dimensional (3D)-printed patient-specific instrument (PSI) for preoperative 3D planning and intraoperative navigation have the advantages of accuracy and visualization. The purpose of this study is to investigate whether 3D-printed PSI is helpful to correct tibial bone defects accurately and effectively. Method: From May 2019 to September 2022, 19 patients with tibial bone defects were treated, including 9 males and 10 females, aged 37 to 64 years. There were 4 cases in proximal tibia, 9 in midshaft tibia and 6 in distal tibia. All were treated with Ilizarov technique of distraction osteogenesis. 3D-printed PSI was used in 9 cases, while traditional surgery was used in 10 cases. All patients underwent computed tomography before surgery. Computer software was used to analyze the measurement results, design and print PSI. During the operation, PSI was used to assist in reduction of tibia. Operation times were recorded in all cases, the number of fluoroscopy during the operation, and the varus/valgus, anteversion/reversion angle after the operation were measured. All measurement data were expressed by means ± SD, and Student's t test was used to examine differences between groups. The chi square test or Fisher's precise test was used to compare the counting data of the two groups. Result: All PSI matched well with the corresponding tibia bone defect, and were consistent with the preoperative plan and intraoperative operation. The affected limb had a good reduction effect. The operation time from the beginning of PSI installation to the completion of Ilizarov ring fixator installation was 31.33 ± 3.20 min, while that in the traditional operation group was 64.10 ± 6.14 min (p < 0.001). The times of fluoroscopy in the PSI group during operation was 10.11 ± 1.83, and that in the traditional operation group was 27.60 ± 5.82. The reduction effect of tibia in PSI group was better than that in traditional operation group, with the average angle of PSI group is 1.21 ± 0.24°, and that of traditional operation group is 2.36 ± 0.33° (p < 0.001). Conclusion: The PSI simplifies procedures, reduces the difficulty of the operation, improves the accuracy of the operation, and provides a good initial position when used in distraction osteogenesis to treat the tibial defects.

Methyl-CpG binding protein 2 is associated with the prognosis and mortality of elderly patients with hip fractures

ABSTRACT Objectives To investigate the expression level and clinical significance of Methyl-CpG binding Protein 2 (MECP2) in elderly patients with hip fractures. Methods This prospective observational study included 367 elderly patients with hip fractures between April 2016 and December 2018. All the patients were treated with internal fixation or joint replacement. In addition, 50 healthy elderly individuals were enrolled as healthy controls. The serum levels of MECP2 and inflammatory factors Interleukin (IL)-1β, IL-6, IL-8, and Tumor Necrosis Factor (TNF)-α was determined by enzyme-linked immunosorbent assay. Data on patients' basic characteristics and postoperative complications were collected. The Harris score was used to assess hip function at 1-month, 3-months, and 6-months after surgery. Patient quality of life was measured using the Barthel Index (BI) score 3-months after surgery. The 1-year mortality was analyzed using the Kaplan-Meier curve, and logical regression was used to analyze the risk factors for mortality. Results No significant differences were observed in the basic clinical characteristics of all patients. The serum MECP2 levels were remarkably high in patients with hip fractures and negatively correlated with serum IL-1β, IL-6, and TNF-α levels. Patients with higher MECP2 predicted higher dynamic Harris scores, lower postoperative complications, lower 1-year mortality, and higher BI scores. Logical regression showed that age was the only independent risk factor for postoperative 1-year mortality in elderly patients with hip fractures. Conclusion Lower MECP2 predicted poor prognosis and higher 1-year mortality in elderly patients with hip fractures.

Kramers nodal line metals.

Recently, it was pointed out that all chiral crystals with spin-orbit coupling (SOC) can be Kramers Weyl semimetals (KWSs) which possess Weyl points pinned at time-reversal invariant momenta. In this work, we show that all achiral non-centrosymmetric materials with SOC can be a new class of topological materials, which we term Kramers nodal line metals (KNLMs). In KNLMs, there are doubly degenerate lines, which we call Kramers nodal lines (KNLs), connecting time-reversal invariant momenta. The KNLs create two types of Fermi surfaces, namely, the spindle torus type and the octdong type. Interestingly, all the electrons on octdong Fermi surfaces are described by two-dimensional massless Dirac Hamiltonians. These materials support quantized optical conductance in thin films. We further show that KNLMs can be regarded as parent states of KWSs. Therefore, we conclude that all non-centrosymmetric metals with SOC are topological, as they can be either KWSs or KNLMs.

[Effect of Aeration Density on Start-up of CANON Process].

The effect of aeration densities (3, 6, 12) on the CANON process start-up were investigated in R1, R2, and R3 inoculated mature anaerobic ammonium oxide granule sludge under the same conditions of aeration and aeration/anaerobic time ratio (1:1) at 25℃. The results showed that R1, R2, and R3 of the CANON process were initiated in 32, 29, and 23 d, respectively. A greater aeration density promoted the start-up of the CANON process. In the cycle test, the pH of R1, R2, and R3 decreased by 0.4, 0.55, and 1.06, respectively. R3 exhibited excellent denitrification performance due to its large aeration density and suitable time interval, which increased system efficiency in DO and better inhibited NOB activity. According to the denitrification route analysis, there were two denitrification pathways of ANA and SNA in the system. The proportion of SNA was 19.3%, 24.5%, and 33.6%, respectively. With the increase in aeration density, the contribution of SNA increased gradually.

[Effects of Different Substrate Concentrations on the Short-term Storage of ANAMMOX Bacteria].

Anaerobic ammonium oxidizing bacteria were stored under NH4+-N and NO2--N conditions (addition ratio 1:1) at a substrate concentration of 0, 60, and 120 mg·L-1at 15℃±1℃ for 15 days. The effect of different substrate concentrations on the short-term storage and recovery of anaerobic ammonia oxidation sludge was investigated. After a short period of storage, a recovery experiment was performed. The results show that the anaerobic ammonia oxidation activities in the reactors 1, 2, and 3 decrease by 41.8%, 17.4%, and 33.4%, respectively. Because of the excessive endogenous respiration and high substrate concentration, the activities of the bacteria in reactors 1 and 3 were inhibited, respectively. Therefore, the activities decreased greatly. Because the substrate concentration was relatively suitable in reactor No. 2, excessive endogenous respiration and high substrate concentration inhibition were avoided such that the activity of the bacteria species was maintained at the substrate concentration. Endogenous respiration occurred during the storage period. Subsequently, the organic matter in the three reactors was consumed. As a result, the EPS content decreased by 50.9%, 41.7%, and 23.7% and the particle size decreased by 31.6%, 16.7%, and 8.2%, respectively. This shows that endogenous respiration is maintained by the bacteria in the matrix-deficient period and the higher concentration of the substrate can to some extent delay the endogenous respiration. During the recovery period, the three reactors recover the denitrification performances after 15, 10, and 7 d respectively. This shows that the denitrification performance of the system has a faster recovery through enhanced strain activities compared with the proliferation of the strain.

MicroRNA­302a suppresses cell proliferation, migration and invasion in osteosarcoma by targeting ADAM9.

Osteosarcoma (OS) is the most frequent malignant primary bone tumor arising from primitive bone­forming mesenchymal cells in children and adolescents. The dysregulation of microRNAs (miRNAs) has been reported in OS, and these aberrantly expressed miRNAs are involved in the initiation and progression of OS. The aim of the present study was to investigate the expression and functions of miRNA­302a (miR­302a) in OS and its underlying mechanism. It was found that the expression of miR­302a was reduced in OS tissues and cell lines. The low expression of miR­302a was significantly correlated with tumor­node­metastasis stage and metastasis. The ectopic overexpression of miR­302a inhibited the proliferation, migration and invasion of OS cells. Bioinformatics analysis showed that a disintegrin and metalloproteinase 9 (ADAM9) was a potential target gene of miR­302a. Subsequently, reverse transcription­quantitative polymerase chain reaction and western blot analyses revealed that miR­302a regulated the expression of ADAM9 at the post­transcriptional level in OS cells. In addition, a luciferase reporter assay demonstrated that miR­302a directly targeted the 3'untranslated region of ADAM9. In clinical OS tissues, the mRNA expression of ADAM9 was upregulated and inversely correlated with the expression of miR­302a. In addition, the effects of ADAM9 knockdown on cell proliferation, migration and invasion were similar to those induced by the overexpression of miR­302a in OS cells. These findings suggested that miR­302a inhibited OS cell growth and metastasis by targeting ADAM9. miR­302a may serve as a potential therapeutic target for patients with OS.

Integrin-ß1 regulates chondrocyte proliferation and apoptosis through the upregulation of GIT1 expression.

Chondrocytes play a critical role in the repair process of osteoarthritis, which is also known as degenerative arthritis. Integrins, as the key family of cell surface receptors, are responsible for the regulation of chondrocyte proliferation, differentiation, survival and apoptosis through the recruitment and activation of downstream adaptor proteins. Moreover, G-protein-coupled receptor kinase interacting protein-1 (GIT1) exerts its effects on cell proliferation and migration through interaction with various cytokines. It has been previously suggested that GIT1 acts as a vital protein downstream of the integrin-mediated pathway. In the present study, we investigated the effects of integrin-ß1 on cell proliferation and apoptosis, as well as the underlying mechanisms in chondrocytes in vitro. Following transfection with a vector expressing integrin-ß1, our results revealed that the overexpression of integrin-ß1 enhanced GIT1 expression, whereas the knockdown of integrin-ß1 by siRNA suppressed GIT1 expression. However, no significant effect was observed on integrin-ß1 expression following the enforced overexpression of GIT1, which suggests that GIT1 is localized downstream of integrin-ß1. In other words, integrin-ß1 regulates the expression of GIT1. Furthermore, this study demonstrated that integrin-ß1 and GIT1 increased the expression levels of aggrecan and type II collagen, thus promoting chondrocyte proliferation; however, they inhibited chondrocyte apoptosis. Taken together, our data demonstrate that integrin-ß1 plays a vital role in chondrocyte proliferation, differentiation and apoptosis. GIT1 exerts effects similar to those of integrin-ß1 and is a downstream target of integrin-ß1.