Lightweight and drift-free magnetically actuated millirobots via asymmetric laser-induced graphene.

Millirobots must have low cost, efficient locomotion, and the ability to track target trajectories precisely if they are to be widely deployed. With current materials and fabrication methods, achieving all of these features in one millirobot remains difficult. We develop a series of graphene-based helical millirobots by introducing asymmetric light pattern distortion to a laser-induced polymer-to-graphene conversion process; this distortion resulted in the spontaneous twisting and peeling off of graphene sheets from the polymer substrate. The lightweight nature of graphene in combine with the laser-induced porous microstructure provides a millirobot scaffold with a low density and high surface hydrophobicity. Magnetically driven nickel-coated graphene-based helical millirobots with rapid locomotion, excellent trajectory tracking, and precise drug delivery ability were fabricated from the scaffold. Importantly, such high-performance millirobots are fabricated at a speed of 77 scaffolds per second, demonstrating their potential in high-throughput and large-scale production. By using drug delivery for gastric cancer treatment as an example, we demonstrate the advantages of the graphene-based helical millirobots in terms of their long-distance locomotion and drug transport in a physiological environment. This study demonstrates the potential of the graphene-based helical millirobots to meet performance, versatility, scalability, and cost-effectiveness requirements simultaneously.

Development and validation of a non-invasive model for predicting significant fibrosis based on patients with nonalcoholic fatty liver disease in the United States.

Background: Liver fibrosis is closely related to abnormal liver function and liver cancer. Accurate noninvasive assessment of liver fibrosis is of great significance for preventing disease progression and treatment decisions. The purpose of this study was to develop and validate a non-invasive predictive model for the asses`sment of significant fibrosis in patients with non-alcoholic fatty liver disease. Methods: Information on all participants for 2017-2018 was extracted from the NHANES database. The eligible patients with significant fibrosis (n=123) and non-significant fibrosis (n=898) were selected to form the original dataset. Variable selection was performed using least absolute shrinkage and selection operator (Lasso) regression, and multivariate logistic regression analysis was used to develop a prediction model. The utility of the model is assessed in terms of its discrimination, calibration and clinical usability. Bootstrap-resampling internal validation was used to measure the accuracy of the prediction model. Results: This study established a new model consisting of 9 common clinical indicators and developed an online calculator to show the model. Compared with the previously proposed liver fibrosis scoring system, this model showed the best discrimination and predictive performance in the training cohort (0.812,95%CI 0.769-0.855) and the validation cohort (0.805,95%CI 0.762-0.847), with the highest area under curve. Specificity(0.823), sensitivity(0.699), positive likelihood ratio(3.949) and negative likelihood ratio(0.366) were equally excellent. The calibration plot of the predicted probability and the actual occurrence probability of significant fibrosis shows excellent consistency, indicating that the model calibration is outstanding. Combined with decision curve analysis, this model has a great benefit in the range of 0.1-0.8 threshold probability, and has a good application value for the diagnosis of clinical significant fibrosis. Conclusion: This study proposes a new non-invasive diagnostic model that combines clinical indicators to provide an accurate and convenient individualized diagnosis of significant fibrosis in patients with non-alcoholic fatty liver disease.

Antiosteoporotic effects of benzyl benzoate glucosides from Curculigo orchioides in ovariectomized rats.

OBJECTIVE: To evaluate the antiosteoporotic effects of benzyl benzoate glucosides from Curculigo orchioides (COBG) in ovariectomized (OVX) rats. METHODS: A total of 70 female Sprague-Dawley rats were assigned to sham-operated and OVX model groups. The OVX rats were further divided into six subgroups treated by gavage with vehicle, 1 mg/kg of nylestriol, 6, 18 and 54 mg/kg of COBG and 3.0 g/kg of ethanol extract of Curculigo orchioides respectively for 12 weeks. Bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry. The sections of tibia were prepared for histomorphometric analysis. The biomarkers in serum and urine were determined using reagent kits. RESULTS: Ovariectomy induced the bone loss and microarchitectural deterioration of bone tissue with the activities of increased serum alkaline phosphatase and loss of calcium through the excretion in urine, and decreased levels of antioxidant in serum (P<0.05, P<0.01). Administration of 6, 18 and 54 mg/kg of COBG significantly increased the BMD, improved the microarchitecture of bone tissue, prevented the depletion of antioxidant enzymes like superoxide dismutase and glutathione peroxidase, inhibited the increase of malondialdehyde in serum and reduced the excretion of urine calcium in OVX rats (P<0.05, P<0.01). CONCLUSION: COBG could prevent the bone loss through improving the antioxidant status, which offers a potential new therapeutic drug for postmenopausal osteoporosis.

Phosphorescent chemosensor for Hg2+ and acetonitrile based on iridium(III) complex.

A new phosphorescent chemosensor for Hg(2+) and acetonitrile (MeCN) based on iridium(III) complex Ir(dpp)(2)(dtc) (Ir1, dppH = 4,6-diphenylpyrimidine, dtcH = diethyl dithiocarbamic acid) was realized. Upon addition of a tetrahydrofuran (THF) solution of Hg(2+), the dichloromethane (DCM) solution of Ir1 gave a visual color change and significant fluorescent quenching. When MeCN was added, a new fluorescent emission emerged, which constituted a selective MeCN phosphorescent chemosensor. Complex Ir1 has been developed as an AND logic gate with Hg(2+) and MeCN as inputs.

Curculigoside isolated from Curculigo orchioides prevents hydrogen peroxide-induced dysfunction and oxidative damage in calvarial osteoblasts.

Reactive oxygen species (ROS), including H(2)O(2), play a critical role in the pathophysiology of osteoporosis. Therefore, agents or antioxidants that can inhibit ROS production have a high clinical value in the treatment of osteoporosis. Curculigoside (CUR), one of the main bioactive phenolic compounds isolated from the rhizome of Curculigo orchioides Gaertn., is reported to have potent antioxidant and anti-osteoporotic properties. However, there is no direct evidence to link the antioxidant capacity of CUR with the observed anti-osteoporotic effect, and relevant molecular mechanisms remain unclear. Therefore, we investigated the protective effects of CUR against oxidative stress in calvarial osteoblasts and discussed the related mechanisms. It was found that osteoblast viability decreased significantly after 48-h exposure to 400 µM of H(2)O(2), compared with vehicle-treated cells, and the cytotoxic effect of H(2)O(2) was reversed significantly when pretreated with 0.1-10 µM of CUR (P< 0.05). Pretreatment with 0.1-10 µM of CUR decreased ROS production and lipid peroxidation, and increased the activities of antioxidant enzymes, such as superoxide dismutase and glutathione peroxidase in osteoblasts induced by H(2)O(2). In addition, H(2)O(2)-induced reduction of differentiation markers such as alkaline phosphatase, calcium deposition, and Runx2 level was significantly recovered in the presence of CUR. CUR also reversed H(2)O(2)-induced stimulation of extracellular signal-regulated kinase 1/2, and nuclear factor-κB signaling and the inhibition of p38 mitogen-activated protein kinase activation. These results provide new insights into the osteoblast-protective mechanisms of CUR through reducing the production of ROS, suggesting that CUR may be developed as a bio-safe agent for the prevention and treatment of osteoporosis and other bone-related human diseases.