Projection Stereolithography 3D-Printed Bio-Polymer with Thermal Assistance.

A stereolithography process with thermal assistance is proposed in this work to address the tradeoff between the flowability and the high concentration of solute loadings at room temperature, through which the improved performance of polymers prepared using stereolithography 3D printing can be achieved. For the experiment, polyethylene glycol diacrylate (PEGDA) with a high molecular weight of 4000 is adopted to improve the mechanical properties of 2-Hydroxyethyl methacrylate (HEMA). For the polymer of HEMA, the highest soluble concentration of PEGDA is about 20 wt% at 25 °C (room temperature) while the concentration could be raised up to 40 wt% as the temperature increases to 60 °C. The 3D printing tests showed that the objects could be easily fabricated with the HEMA polymer loaded with 40 wt% of PEGDA through the thermally assisted projection stereolithography technology. By adding the 40 wt% of PEGDA, the Young's modulus has been enhanced by nearly 390% compared to the HEMA resin without solute, of which the Young's modulus is 63.31 ± 2.72 MPa. The results of the cell proliferation test proved that the HEMA resin loaded with PEGDA led to a better biocompatibility compared to the HEMA resin without the loading of the PEGDA solute. All of the results demonstrate that the polymer loaded with high solute is feasible to be precisely 3D-printed using the projection stereolithography process with thermal assistance, and the improved mechanical properties are beneficial for biomedical applications.

Preassigned-time projective synchronization of delayed fully quaternion-valued discontinuous neural networks with parameter uncertainties.

This paper concerns with the preassigned-time projective synchronization issue for delayed fully quaternion-valued discontinuous neural networks involving parameter uncertainties through the non-separation method. Above all, based on the existing works, a new preassigned-time stability theorem is established. Subsequently, to realize the control goals, two types of novel and simple chattering-free quaternion controllers are designed, one without the power-law term and the other with a hyperbolic-tangent function. They are different from the existing common power-law controller and exponential controller. Thirdly, under the Filippov discontinuity theories and with the aid of quaternion inequality techniques, some novel succinct sufficient criteria are obtained to ensure the addressed systems to achieve the preassigned-time synchronization by using the preassigned-time stability theory. The preassigned settling time is free from any parameter and any initial value of the system, and can be preset according to the actual task demands. Particularly, unlike the existing results, the proposed control methods can effectively avoid the chattering phenomenon, and the time delay part is removed for simplicity. Additionally, the projection coefficient is generic quaternion-valued instead of real-valued or complex-valued, and some of the previous relevant results are extended. Lastly, numerical simulations are reported to substantiate the effectiveness of the control strategies, the merits of preassigned settling time, and the correctness of the acquired results.

p-Coumaric Acid Inhibits Osteosarcoma Growth by Inhibiting PI3K/Akt Signaling Pathway.

BACKGROUND: P-coumaric acid (p-CA) is a kind of phenylpropionic acid derived from aromatic amino acids, which is widely distributed in many plants and human diets. It has strong pharmacological and inhibitory effects on a variety of tumors. However, the role of p-CA in osteosarcoma, a tumor with a poor prognosis, is still unknown. Therefore, we aimed to evaluate the effect of p-CA on osteosarcoma and explore its potential mechanism. OBJECTIVE: This study aimed to investigate whether p-CA has an inhibitory effect on the growth of osteosarcoma cells and explore its potential mechanism. METHODS: MTT assay and clonogenic assay were used to detect the effect of p-CA on the proliferation of osteosarcoma cells. The effect of p-CA on apoptosis of osteosarcoma cells was detected by the Hoechst staining and flow cytometry. The effects of p-CA on the migration and invasion of osteosarcoma cells were detected by scratch healing assay and Transwell invasion assay. Western blot and PI3K/Akt pathway activator 740Y-P were used to detect the anti-tumor mechanism of p-CA on osteosarcoma cells. The effect of p-CA on osteosarcoma cells in vivo was verified by an orthotopic osteosarcoma tumor animal model in nude mice. RESULTS: MTT assay and clonogenic assay showed that p-CA inhibited the proliferation of osteosarcoma cells. Hoechst stain and flow cytometry showed that p-CA could induce apoptosis of osteosarcoma cells and lead to G2 phase arrest of osteosarcoma cells. Transwell assay and scratch healing assay found that p-CA could inhibit the migration and invasion of osteosarcoma cells. Western blot showed that p-CA could inhibit the activity of the PI3K/Akt signaling pathway in osteosarcoma cells, and 740Y-P could reverse its inhibitory effect. In vivo mouse models, p-CA has an antitumor effect on osteosarcoma cells in vivo, and at the same time, it has less toxic side effects on mice. CONCLUSION: This study demonstrated that p-CA could effectively inhibit the proliferation, migration and invasion of osteosarcoma cells and promote apoptosis. p-CA may play an anti-osteosarcoma role by inhibiting PI3K/Akt signaling pathway.

Anammox bacterial abundance and diversity in different temperatures of purple paddy soils by 13C-DNA stable-isotope probing combined with high-throughput sequencing.

Introduction: Anaerobic ammonium oxidation (anammox) plays a vital role in the global nitrogen cycle by oxidizing ammonium to nitrogen under anaerobic environments. However, the existence, abundance, and diversity of anammox bacteria between different temperatures are less studied, particularly in purple paddy soils. Methods: 13C-DNA stable-isotope probe combined with Illumina MiSeq high-throughput sequencing was employed to explore soil abundance and diversity of anammox bacteria. In doing so, 40-60 cm depth soils from typical purple paddy soils in Chongqing, southwest China, were cultured under 12CO2-labeled and 13CO2-labeled at 35°C, 25°C, 15°C, and 5°C for 56 days. Results and Discussion: Anammox bacteria were not labeled at all by 13CO2 at 5°C. The highest abundance of anammox bacteria was found at 25°C (3.52 × 106~3.66 × 106 copies·g-1 dry soil), followed by 35°C and 15°C (2.01 × 106~2.37 × 106 copies·g-1 dry soil) and almost no increase at 5°C. The relative abundance of Candidatus Jettenia sp. was higher at 25°C and 15°C, while Candidatus Brocadia sp. was higher at 35°C and 5°C. Our results revealed differences in anammox bacteria at different temperatures in purple paddy soils, which could provide a better understanding of soil N cycling regulated by anammox bacteria.

Fixed-time projective synchronization of delayed memristive neural networks via aperiodically semi-intermittent switching control.

This paper studies the fixed-time projective synchronization problem for a class of delayed memristive neural networks via aperiodically semi-intermittent switching control. Instead of using the common traditional controller containing two power exponent terms, a novel aperiodically semi-intermittent switching controller is designed, containing only one power exponent term which serves as a function of the state of the error system. With the aid of the extended differential inclusion framework, the analysis method, and the inequality technique, some new sufficient conditions are derived to guarantee fixed-time projective synchronization for the considered systems. Compared with periodically semi-intermittent control methods, the control time width of each section in aperiodically semi-intermittent control can be adjusted. Especially, the settling time is directly reckoned, which is closely related to the number of neurons and the maximum ratio of the second subinterval span in each non-periodic span to all non-periodic time spans rather than the initial value. Additionally, the projection synchronization has a strong practicality, as the projection coefficient can be adjusted for different needs instead of being fixed. Meanwhile, the study improves some previous related works. Ultimately, a numerical example is given to substantiate the correctness of the obtained results.

Finite-/fixed-time synchronization for Cohen-Grossberg neural networks with discontinuous or continuous activations via periodically switching control.

This paper is concerned with finite-/fixed-time synchronization for a class of Cohen-Grossberg neural networks with discontinuous or continuous activations and mixed time delays. Based on the finite-time stability theory, Lyapunov stability theory, the concept of Filippov solution and the differential inclusion theory, some useful finite-/fixed-time synchronization sufficient conditions for the considered Cohen-Grossberg neural networks are established by designing two kinds of novel periodically switching controllers. Instead of using uninterrupted high control strength, the periodically switching controller in each period is used with high strength control in one stage and weak strength in the other. It can overcome the effects caused by the uncertainties of Filippov solution induced by discontinuous neuron activation functions and reduce the control cost. Besides, the period switching control rate is closely related to the settling time T. Finally, two numerical examples are given to demonstrate the effectiveness and feasibility of the obtained results.

Applying the pathogen-targeted next-generation sequencing method to pathogen identification in cerebrospinal fluid.

BACKGROUND: The cerebrospinal fluid (CSF) culture is a widely used method for the diagnosis of meningitis, but its detection sensitivity is low. Several new methods have been developed for pathogen detection, including metagenomic next-generation sequencing (mNGS) and pathogen-targeted NGS (ptNGS). In this study, we aimed to evaluate the performance of ptNGS in pathogen detection in CSF. METHODS: CSF specimens were acquired from 38 patients with meningitis who were diagnosed at Xuanwu Hospital, Capital Medical University between October 2020 and February 2021. DNA was extracted from the CSF samples, and pathogens were identified using both ptNGS and mNGS. SPSS 22.0 software was used to compare the pathogen detection performance of ptNGS and mNGS in CSF. RESULTS: Among the 38 patients with meningitis, 14 had a non-infectious disease (NID) and 24 had an infectious disease (ID). Of the 38 samples, both ptNGS and mNGS detected 9 (23.7%) positive samples, and 12 (31.6%) negative samples. Thirteen (34.2%) samples were detected to be positive by ptNGS only, and 4 (10.5%) were detected to be positive by mNGS only. The positivity rate detected by ptNGS for the ID group was higher than that detected by mNGS (P=0.080), and the positivity rates detected by ptNGS and mNGS for the NID group were comparable. The positive predictive value (PPV) and negative predictive value (NPV) of diagnosing an ID by ptNGS were 77.3% and 56.3%, respectively. While, the PPV and NPV of diagnosing an ID by mNGS were 76.9% and 44.0%, respectively. ptNGS increased the sensitivity rate by approximately 70%. The sensitivity rate of ptNGS was higher than that of mNGS (70.8% vs. 41.7%), while the specificity rate of mNGS was higher than that of ptNGS (78.6% vs. 64.3%). Additionally, ptNGS required a shorter time for pathogen diagnosis (15 vs. 24 hrs) and had lower costs than mNGS. CONCLUSIONS: ptNGS has a number of advantages over mNGS, including its sensitivity, timeliness, and economy, all factors that are important considerations in clinical use.

Application of next generation sequencing-based rapid detection platform for microbiological diagnosis and drug resistance prediction in acute lower respiratory infection.

BACKGROUND: Acute lower respiratory infections (ALRIs) have a high mortality rate. We aimed to apply a platform that rapidly detects 36 microorganisms and 49 antibiotic resistance markers in the clinical diagnosis of ALRI and drug resistance prediction. METHODS: Multicenter collection of clinical samples from patients with ALRIs was carried out from 2017 to 2018. Sputum culture (SC) was performed, which provided two outcomes: the detected pathogens and the resistance to different antibiotics. Additionally, each sputum sample was used to extract deoxyribonucleic acids (DNAs) followed by high-throughput sequencing. RESULTS: Eleven commonly observed pathogens were surveyed, and for all samples with positive SC results (137 cases), the overall coverage was 95.62% according to the sequencing results. The receiver operating characteristic (ROC) curve was drawn, and cutoff reads of the most frequently detected pathogens were acquired. Overall, sequencing exhibited significantly higher sensitivity in the detection of pathogens compared with the traditional SC method, with a generally satisfactory specificity. Furthermore, we investigated the correlation between antibiotic resistance gene phenotypes and the actual outcomes of the drug sensitivity test, and some significant correlations were found, especially for the resistance to Amikacin in the presence of blaOXA7. CONCLUSIONS: Sequencing-based sputum metagenomics can reveal a profile of the lung pathogen microbiome. The sequencing method offers both sufficient accuracy and significantly higher sensitivity in the detection of pathogens, and can be at least a complementary approach to traditional SC reporting. The sequencing technique also revealed some novel potential correlations between the presence of different pathogens, as well as new antimicrobial-resistant genes.

SnS2 /Co3 S4 Hollow Nanocubes Anchored on S-Doped Graphene for Ultrafast and Stable Na-Ion Storage.

SnS2 has been widely studied as an anode material for sodium-ion batteries (SIBs) based on the high theoretical capacity and layered structure. Unfortunately, rapid capacity decay associated with volume variation during cycling limits practical application. Herein, SnS2 /Co3 S4 hollow nanocubes anchored on S-doped graphene are synthesized for the first time via coprecipitation and hydrothermal methods. When applied as the anode for SIBs, the sample delivers a distinguished charge specific capacity of 1141.8 mAh g-1 and there is no significant capacity decay (0.1 A g-1 for 50 cycles). When the rate is increased to 0.5 A g-1 , it presents 845.7 mAh g-1 after cycling 100 times. Furthermore, the composite also exhibits an ultrafast sodium storage capability where 392.9 mAh g-1 can be obtained at 10 A g-1 and the charging time is less than 3 min. The outstanding electrochemical properties can be ascribed to the enhancement of conductivity for the addition of S-doped graphene and the existence of p-n junctions in the SnS2 /Co3 S4 heterostructure. Moreover, the presence of mesopores between nanosheets can alleviate volume expansion during cycling as well as being beneficial for the migration of Na+ .

Exponential synchronization for fuzzy cellular neural networks with time-varying delays and nonlinear impulsive effects.

In this paper, the globally exponential synchronization of delayed fuzzy cellular neural networks with nonlinear impulsive effects are concerned. By utilizing inequality techniques and Lyapunov functional method, some sufficient conditions on the exponential synchronization are obtained based on [Formula: see text]-norm. Finally, a simulation example is given to illustrate the effectiveness of the theoretical results.

Ion concentration polarization on paper-based microfluidic devices and its application to preconcentrate dilute sample solutions.

Microfluidic paper-based analytical devices (µPADs) are a promising solution for a wide range of point-of-care applications. The feasibility of inducing ion concentration polarization (ICP) on µPADs has thus far attracted little attention. Accordingly, this study commences by demonstrating the ICP phenomenon in a µPAD with a Nafion ion-selective membrane. We are the first to measure the current-voltage curve on a Nafion-coated µPAD in order to indicate that the ion depletion occurs and the ICP is triggered when the current reaches the limiting current. The ICP effect is then exploited to preconcentrate fluorescein on µPADs incorporating straight and convergent channels. By an optimal geometric design, it is shown that the convergent channel results in a greater preconcentration effect than the straight channel. Specifically, a 20-fold enhancement in the sample concentration is achieved after 130 s given an initial concentration of [Formula: see text] M and an external potential of 50 V. By contrast, the straight channel yields only a 10-fold improvement in the concentration after 180 s. Further, the practical feasibility of the proposed convergent-channel µPAD is demonstrated using fluorescein isothiocyanate labeled bovine serum albumin. The experimental results show that a 15-fold enhancement of the initial sample concentration ([Formula: see text] M) is obtained after 120 s given an external potential of 50 V.

Correlation between Antistress and Hepatoprotective Effects of Schisandra Lignans Was Related with Its Antioxidative Actions in Liver Cells.

The present study was conducted to investigate the relationship between the anti-stress and hepato-protective effects of Schisandra Lignans Extract (SLE) on stress-induced liver damage. Seven weeks old male mice were fixed in a restraint tube for 18 h to induce liver damage. SLE was orally administered to animals for 5 days at dosages of 100 and 200 mg/kg/day before exposed to restraint stress. Oral administration of SLE significantly reduced restraint-induced liver damage in experimental animal. SLE was further found to significantly alleviate the provocation of corticosterone in stressed mice. SLE also significantly decreased oxidative damage and increased anti-oxidative capability of liver cells by preventing the over production and accumulation of free radicals. In conclusion, the protective effects of SLE on stress-induced liver damage were confirmed, and the correlation between hepatoprotective and anti-stress effects of schisandra lignans was possible related to its alleviation on the malignant effects of stressors for bio-homeostasis, such as balance of oxidation and reduction in cells.