Fast-switchable, high diffraction-efficiency ferroelectric liquid crystal Fibonacci grating.

Low-voltage fast switchable 1D and 2D Fibonacci grating (FbG), using an electrically suppressed helix ferroelectric liquid crystal (ESHFLC), with high diffraction efficiency for a super-resolution imaging system in far-field are disclosed in this paper. Specifically, the polarization-independent two-domain (0, π) structure is well designed based on photoalignment technology to maximize the total diffraction efficiency that can reach 97.4% (1st order:8.5%, 2nd order: 30%). Apart from that, the FLC gratings offer two tunable states: non-diffractive and diffractive states. Derived from the fast-response property of ferroelectric liquid crystal material, the switching speed of the 1D and 2D ESHFLC-FbG is 103µs at 4 V of the driving voltage. Furthermore, this system achieves the high-resolving power of (λ/2.25) for object detection based upon the intensity map received behind 1D ESHFLC-FbG at far-field. Contribution from the quasi-periodic FbG's special ability to translate the super-resolution information (including at evanescent wave) into the detectable far-field region. Concisely, the proposed ESHFLC-FbG can be a promising candidate for a super-resolution imaging system, superstructure fibre sensor, and other photonic applications.

Fast refocusing lens based on ferroelectric liquid crystals.

Optical devices like virtual reality (VR) headsets present challenges in terms of vergence-accommodation conflict that leads to visual fatigue for the user over time. Lenses available to meet these challenges include liquid crystal (LC) lenses, which possess a response time in the millisecond range. This response time is slow, while accessing multiple focal lengths. A ferroelectric liquid crystal (FLC) has a response time in the microsecond range. In this article, we disclose a switchable lens device having a combination of the fast FLC-based polarization rotation unit and a passive polarization-dependent LC lens. A cascaded combination of three such lens units allows access to eight different focal points quite rapidly and can be a convenient device for VR applications.

Prevalence of bovine leukemia in 1983-2019 in China: A systematic review and meta-analysis.

Bovine leukemia is a chronic, progressive, contagious tumor disease characterized by malignant lymphoid cell hyperplasia and systemic lymphadenopathy, and is caused by bovine leukemia virus (BLV). The disease affects almost all countries and regions where livestock are raised, and may even be a potential zoonotic disease. Monitoring and early prevention of bovine leukemia is very important. Therefore, we conducted this meta-analysis, the first of its type in the country, to estimate the prevalence of bovine leukemia in 1983-2019 in China. We included a total of 35 publications reported in 1983-2019 from the PubMed, ScienceDirect, Chinese Web of Knowledge (CNKI), VIP Chinese, and Wan Fang databases. In those articles, a total of 34,954 cattle had been tested, of which 4701 were positive for BLV infection. The estimated pooled BLV prevalence was 10.0% (4701/34,954). Subgroup analysis showed that there were significant differences for sampling years, detection methods, and age. BLV prevalence was highest in the following subgroups: sampled before 1985 (38.5%, 437/1134), age 3-5 years (22.5%, 231/1044), and detected by PCR (17.9%, 1228/5100). Regarding geographic factors, there were significant differences in the latitude and elevation subgroups. BLV prevalence was lowest in the subgroups of 20-30° latitude (3.3%, 255/5069) 200-1000 m altitude (2.2%, 560/11,990). We also analyzed other subgroups such as region, variety, breeding method, precipitation, humidity, and temperature, however, the differences were not significant. Our research indicated that the BLV was still prevalent in some of areas in China. We recommend strengthening the testing of cattle aged >1 year and using flexible testing methods such as PCR to control the prevalence of bovine leukemia and to prevent persistent infection.

Experimental Study on the Prevention of Posttraumatic Osteoarthritis in the Rabbit Knee Using a Hinged External Fixator in Combination with Exercises.

Objective: To report the design and effect of our proprietary hinged external fixator, used in combination with treadmill exercise for rabbits with intra-articular inflammation and cartilage degeneration. Methods: Thirty-two white rabbits were randomly allocated into four groups: No treatment (NT), Distraction only (D), Exercise only (Ex), and Distraction plus exercise (D + Ex). Each rabbit underwent an anterior cruciate ligament transection on the right knee, with the contralateral knee used as a sham control (C). Results: In the D + Ex group, the levels of Interleukin (IL)-1ß and Tumor necrosis factor (TNF)-α in synovium and TNF-α in joint effusion were significantly lower, while the expression of IL-10 in joint effusion and blood was significantly higher. The ratio of IL-10/TNF-alpha in blood was also the highest in the D + Ex group. The condition of collagen loss was examined: the D + Ex group had the lowest level of type II collagen in effusion and C-telopeptides of type II collagen (CTX-II) in blood. On the other hand, the D + Ex group had the highest expression of cartilage regeneration genes, including type II collagen, Aggrecan (AGN), and SRY-box 9 (SOX9). Finally, the histology showed an attenuation of cartilage degeneration with a lower OA score in the D + Ex group. Conclusion: Our hinged external fixator combined with treadmill exercise up-regulated cartilage regeneration genes, reduced synovial and intra-articular inflammation, and reduced type II collagen and proteoglycan loss, indicating the use of the fixator in combination with treadmill exercise could prevent progression of posttraumatic osteoarthritis of knee joint in rabbits.

Saikosaponin D inhibits proliferation of human osteosarcoma cells via the p53 signaling pathway.

Saikosaponin D (SSd), the major monomeric terpenoid extracted from Radix bupleuri, a traditional Chinese medicinal herb, exerts various pharmacological properties, including antitumor, anti-inflammatory and antiviral. The present study aimed to investigate the role of SSd in human osteosarcoma (OS) cell growth. In the investigation MTS and EdU assays were applied and flow cytometric analyses of cell cycle and apoptosis were performed. Western blotting and reverse transcription-quantitative polymerase chain reaction analyses were used to explore the underlying mechanisms of SSd on cell cycle transition and p53 signaling. Here, it was demonstrated that SSd administration at 80 µmol/l significantly inhibited 143B and MG-63 proliferation. Furthermore, SSd significantly increased the percentage of 143B and MG-63 cells in G0-G1 phase and the number of apoptosis cells compared with the control group. Data further demonstrated that SSd treatment upregulated mRNA and protein levels of tumor protein 53 (p53) and its downstream targets, including p21, p27, B-cell lymphoma-2-like protein 4 and cleaved caspase-3, and downregulated mRNA and protein levels of cyclinD1. The results suggested that SSd was a functional tumor suppressor and inhibited OS proliferation via activation of the p53 signaling pathway and may be used in the treatment of osteosarcoma in future.

Adenovirus-mediated bone morphogenetic protein-2 promotes osteogenic differentiation in human mesenchymal stem cells in vitro.

Delayed and failed bone union following fracture is a common clinical complication that requires treatment in orthopedics. Cell-based therapies and tissue-engineering approaches are potential therapeutic strategies for bone repair and fracture healing. However, the effect of adenovirus expressing bone morphogenetic protein-2 (Ad-BMP-2) on the osteogenic ability of human mesenchymal stem cells (hMSCs) has remained to be fully elucidated. Therefore, in the present study, hMSCs were transduced using Ad-BMP-2 to assess the effects of its application and to determine whether Ad-BMP-2 promotes the osteogenic differentiation of hMSCs. The purity of the hMSC cultures was assessed using flow cytometric analysis. In order to assess the osteogenic activity, alkaline phosphatase activity (ALP) was measured and to estimate the osteoblastic mineralization and calcification, von Kossa staining for phosphates was performed. Cells positive for Src homology 2 domain were determined to be hMSCs and the presence of CD34 was used to distinguish hematopoietic lineages. Following treatment, the Ad-BMP-2 and control group had significantly increased ALP levels (P<0.05). Compared to the blank group and the group transfected with adenoviral vector containing LacZ, the phosphate deposition in the Ad-BMP-2 group and the positive control group treated with dexamethasone was markedly increased. The results of the present study suggested that Ad-BMP-2 promotes osteogenic differentiation in hMSCs and may have a potential application in treating delayed union and nonunion following bone fracture.

Salvia miltiorrhiza prevents deep vein thrombosis via antioxidative effects in endothelial cells.

Deep vein thrombosis (DVT) is a common clinical problem, which represents a significant clinical and economic burden. The present study investigated whether Salvia miltiorrhiza (S. miltiorrhiza) could prevent DVT. A total of 30 rabbits were randomly divided into three groups (n=10 per group): The control, model and Salvia groups. A ligation model was used, where the femoral veins of rabbits were exposed and ligated. Measurements of coagulation function, blood rheological parameters, antioxidative function and effects on endothelial cells were conducted. Treatment with S. miltiorrhiza one week prior to generation of the ligation model did not affect the coagulation function much, except to increase the prothrombin time. There was a statistically significant difference (P<0.05) in whole blood viscosity (1/s, 5/s, 30/s) on the third and seventh days (1/s, 5/s, 30/s and 200/s) following generation of the model. S. miltiorrhiza exhibited promising antioxidative effects, as demonstrated by a significant decrease in malondialdehyde content (P<0.05), and an increase in the activities of superoxide dismutase (P<0.05), as compared with the model group. S. miltiorrhiza was also shown to protect the vascular endothelial cells, as compared with the model group. These results suggest that S. miltiorrhiza may have potential applications for the treatment of DVT.

[Study on the method of nanometer-size zirconium dioxide enrichment separation and inductively coupled plasma mass spectrometry determination of trace barium(II) in water].

Monoclinic fusiform zirconium dioxide (ZrO2) nanoparticles were synthesized by hydrothermal method, a method was established based on monoclinic fusiform nanometer-sized ZrO2 enrichment separation, and trace barium in water was determined by inductively coupled plasma mass spectrometry (ICP-MS). The detection limit for Ba(II) was 0.007 ng x mL(-1), and the relative standard deviation was 0.13% (n = 11). The optimal enrichment separation conditions of nanometer-sized ZrO2 for Ba(II) were studied in detail, it was found that the percentage of adsorbed Ba(II) was more than 99% under pH 10.0 and 2 mL 0.5 mol x L(-1) HCl was sufficient for elution of Ba(II) by more than 98%. The static adsorption capacity of ZrO2 to Ba(II) was 196.6 microg x g(-1) and enrichment factor was 250. Properties of nanometer-sized ZrO2 were discussed through regeneration experiment and effects of co-existing ions and contrast experiment to ordinary ZrO2, adsorption properties of nanometer-sized ZrO2 were applied to real samples in the analysis of Ba(II) and the determination was carried out by ICP-MS with satisfactory results.