Multifunctional Electrostatic Droplet Manipulation on the Femtosecond Laser-Prepared Slippery Surfaces.

A strategy to manipulate droplets on the lubricated slippery surfaces using tribostatic electricity is proposed. By employing femtosecond laser-induced porous microstructures, we prepared a slippery surface with ultralow adhesion to various liquids. Electrostatic induction causes the charges within the droplet to be redistributed; thus, the droplet on the as-prepared slippery surfaces can be guided by electrostatic force under the electrostatic field, with controllable sliding direction and unlimited transport distance. The combination of electrostatic interaction and slippery surfaces allows us to manipulate droplets with a wide volume range (from 100 nL to 0.5 mL), charged droplets (including electrostatic attraction and repulsion), corrosive droplets, and even organic droplets with ultralow surface tension. In addition, droplets on tilted surfaces, curved surfaces, and inverted slippery surfaces can also be manipulated. Especially, the slippery surfaces can even allow the electrostatic interaction to manipulate alcohol with surface tension as low as 22.3 mN/m and liquid droplets suspended on a downward surface, which is not possible with reported superhydrophobic substrates. The features of slippery surfaces make the electrostatic manipulation successfully applied in versatile droplet manipulation, droplet patterning, chemical microreaction, transport of solid cargo, targeted delivery of chemicals, and liquid sorting.

Durable Janus membrane with on-demand mode switching fabricated by femtosecond laser.

Despite their notable unidirectional water transport capabilities, Janus membranes are commonly challenged by the fragility of their chemical coatings and the clogging of open microchannels. Here, an on-demand mode-switching strategy is presented to consider the Janus functionality and mechanical durability separately and implement them by simply stretching and releasing the membrane. The stretching Janus mode facilitates unidirectional liquid flow through the hydrophilic micropores-microgrooves channels (PG channels) fabricated by femtosecond laser. The releasing protection mode is designed for the in-situ closure of the PG channels upon encountering external abrasion and impact. The protection mode imparts the Janus membrane robustness to reserve water unidirectional penetration under harsh conditions, such as 2000 cycles mechanical abrasion, 10 days exposure in air and other rigorous tests (sandpaper abrasion, finger rubbing, sand impact and tape peeling). The underlying mechanism of gridded grooves in protecting and enhancing water flow is unveiled. The Janus membrane serves as a fog collector to demonstrate its unwavering mechanical durability in harsh real-world conditions. The presented design strategy could open up new possibilities of Janus membrane in a multitude of applications ranging from multiphase separation devices to fog harvesting and wearable health-monitoring patches.

Data-Driven Linear Quadratic Optimization for Controller Synthesis With Structural Constraints.

For various typical cases and situations where the formulation results in an optimal control problem, the linear quadratic regulator (LQR) approach and its variants continue to be highly attractive. In certain scenarios, it can happen that some prescribed structural constraints on the gain matrix would arise. Consequently then, the algebraic Riccati equation (ARE) is no longer applicable in a straightforward way to obtain the optimal solution. This work presents a rather effective alternative optimization approach based on gradient projection. The utilized gradient is obtained through a data-driven methodology, and then projected onto applicable constrained hyperplanes. Essentially, this projection gradient determines a direction of progression and computation for the gain matrix update with a decreasing functional cost; and then the gain matrix is further refined in an iterative framework. With this formulation, a data-driven optimization algorithm is summarized for controller synthesis with structural constraints. This data-driven approach has the key advantage that it avoids the necessity of precise modeling which is always required in the classical model-based counterpart; and thus the approach can additionally accommodate various model uncertainties. Illustrative examples are also provided in the work to validate the theoretical results.

Development and evaluation of a monoclonal antibody-based blocking ELISA to detect antibodies against the E2 protein of bovine viral diarrhea virus-1.

With the rapid development of cattle industry, bovine viral diarrhea virus (BVDV) is becoming widespread in China, which causes serious economic losses to the industry. Effective vaccination and viral surveillance are critical for the prevent and control of BVDV infection. In the present study, the immunogenic domain of E2 protein of BVDV-1 was expressed by prokaryotic pET-28a vector. Monoclonal antibodies (mAbs) against E2 protein were prepared and systemically examined by western blot, immunofluorescence assay, blocking ELISA (bELISA) and virus neutralization test (VNT). The mAb 1E2B3, which showed good reactivity and neutralizing activity to BVDV-1 strains, was selected for ELISA establishment. After a series of screening and optimization, a novel bELISA for highly sensitive and specific detection of BVDV-1 antibodies was established, using HRP-labeled 1E2B3 and recombinant E2 protein. ROC analysis of 91 positive and 84 negative reference bovine serum samples yielded the area under the curve (AUC) of 0.9903. A diagnostic specificity of 96.43 % and a sensitivity of 95.6 % were achieved when the cutoff value was set at 24.31 %. There was no cross reaction to the positive sera of classical swine fever virus (CSFV), BVDV-2, border disease virus (BDV), bovine parainfluenza virus type 3 (BPIV3), infectious bovine rhinotracheitis virus (IBRV), foot-and-mouth disease virus (FMDV), Mycoplasma bovis (M.bovis) and Brucella. The total agreement rate of bELISA with VNT was 93.96 % (249/265). In addition, the result of bELISA was positively correlated with neutralizing antibody titer, and the bELISA could well distinguish the serum samples before and after BVDV vaccination. These results indicate that the established bELISA in this study is specific, sensitive, simple and convenient, which provides technical support for the vaccine efficacy evaluation, prevention and control of BVD in the future.

The Relationship between Microbial Community Succession and Flavor Formation during the Natural Fermentation of Hongqu sufu.

To study the diversity of microbial flora in Hongqu sufu and analyze the characteristics of special flavor compounds, this study took self-made Hongqu sufu as the research object. Dynamic changes in sufu during fermentation were studied. High-throughput sequencing (HTS) was used to analyze changes in the diversity of fungal and bacterial communities during fermentation. The results showed that at the phylum level, the dominant fungal phyla were identified, Mucormyces and Ascomycetes. The dominant bacterial phyla were Proteobacteria and Firmicutes. At the genus level, the dominant fungal genera were identified as Actinomucor, Monascus, and Aspergillus. The dominant bacterial genera were Pseudomonas, Aneurimibacillus, Sphingobacterium, and Bacillus. Headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS) combined with technology that can dynamically change flavor compounds was explored to investigate the correlation between microbiota and flavor compounds. In different stages of fermentation, 75 main volatile organic compounds were identified, including seven alcohols, four acids, 16 alkanes, 14 olefins, seven kinds of aldehydes, two kinds of ketones, 10 kinds of esters, one kind of phenol, one kind of sulfur-containing compound, one benzene, and 12 other compounds. The correlation analysis between flora and flavor compounds showed that the fungi genera Alternaria and Pichia were significantly correlated with most flavor compounds. Bacteria genera including Weissella, Hafnia-Obesumbacterium, and Leuconostoc had a strong positive correlation with ethyl oleate.

Local Learning Enabled Iterative Linear Quadratic Regulator for Constrained Trajectory Planning.

Trajectory planning is one of the indispensable and critical components in robotics and autonomous systems. As an efficient indirect method to deal with the nonlinear system dynamics in trajectory planning tasks over the unconstrained state and control space, the iterative linear quadratic regulator (iLQR) has demonstrated noteworthy outcomes. In this article, a local-learning-enabled constrained iLQR algorithm is herein presented for trajectory planning based on hybrid dynamic optimization and machine learning. Rather importantly, this algorithm attains the key advantage of circumventing the requirement of system identification, and the trajectory planning task is achieved with a simultaneous refinement of the optimal policy and the neural network system in an iterative framework. The neural network can be designed to represent the local system model with a simple architecture, and thus it leads to a sample-efficient training pipeline. In addition, in this learning paradigm, the constraints of the general form that are typically encountered in trajectory planning tasks are preserved. Several illustrative examples on trajectory planning are scheduled as part of the test itinerary to demonstrate the effectiveness and significance of this work.

Research Progress on Emerging Viral Pathogens of Small Ruminants in China during the Last Decade.

China is the country with the largest number of domestic small ruminants in the world. Recently, the intensive and large-scale sheep/goat raising industry has developed rapidly, especially in nonpastoral regions. Frequent trading, allocation, and transportation result in the introduction and prevalence of new pathogens. Several new viral pathogens (peste des petits ruminants virus, caprine parainfluenza virus type 3, border disease virus, enzootic nasal tumor virus, caprine herpesvirus 1, enterovirus) have been circulating and identified in China, which has attracted extensive attention from both farmers and researchers. During the last decade, studies examining the etiology, epidemiology, pathogenesis, diagnostic methods, and vaccines for these emerging viruses have been conducted. In this review, we focus on the latest findings and research progress related to these newly identified viral pathogens in China, discuss the current situation and problems, and propose research directions and prevention strategies for different diseases in the future. Our aim is to provide comprehensive and valuable information for the prevention and control of these emerging viruses and highlight the importance of surveillance of emerging or re-emerging viruses.

Temporal Dynamics of the Ruminant Type I IFN-Induced Antiviral State against Homologous Parainfluenza Virus 3 Challenge In Vitro.

Viruses have evolved diverse strategies to evade the antiviral response of interferons (IFNs). Exogenous IFNs were applied to eliminate the counteracting effect and possess antiviral properties. Caprine parainfluenza virus 3 (CPIV3) and bovine parainfluenza virus type 3 (BPIV3) are important pathogens associated with respiratory diseases in goat and cattle, respectively. To explore the feasibility of type I IFNs for control of CPIV3 and BPIV3 infection, the activated effects of IFN-stimulated genes (ISGs) and the immunomodulation responses of goat IFN-α were detected by transcriptomic analysis. Then, the antiviral efficacy of goat IFN-α and IFN-τ against CPIV3 and BPIV3 infection in MDBK cells was evaluated using different treatment routes at different infection times. The results showed that CPIV3 infection inhibited the production of type I IFNs, whereas exogenous goat IFN-α induced various ISGs, the IFN-τ encoding gene, and a negligible inflammatory response. Consequently, goat IFN-α prophylaxis but not treatment was found to effectively modulate CPIV3 and BPIV3 infection; the protective effect lasted for 1 week, and the antiviral activity was maintained at a concentration of 0.1 µg/mL. Furthermore, the antiviral activity of goat IFN-τ in response to CPIV3 and BPIV3 infection is comparable to that of goat IFN-α. These results corroborate that goat IFN-α and IFN-τ exhibit prophylactic activities in response to ruminant respiratory viral infection in vitro, and should be further investigated for a potential use in vivo.

Trajectory Generation by Chance-Constrained Nonlinear MPC With Probabilistic Prediction.

Continued great efforts have been dedicated toward high-quality trajectory generation based on optimization methods; however, most of them do not suitably and effectively consider the situation with moving obstacles; and more particularly, the future position of these moving obstacles in the presence of uncertainty within some possible prescribed prediction horizon. To cater to this rather major shortcoming, this work shows how a variational Bayesian Gaussian mixture model (vBGMM) framework can be employed to predict the future trajectory of moving obstacles; and then with this methodology, a trajectory generation framework is proposed which will efficiently and effectively address trajectory generation in the presence of moving obstacles, and incorporate the presence of uncertainty within a prediction horizon. In this work, the full predictive conditional probability density function (PDF) with mean and covariance is obtained and, thus, a future trajectory with uncertainty is formulated as a collision region represented by a confidence ellipsoid. To avoid the collision region, chance constraints are imposed to restrict the collision probability, and subsequently, a nonlinear model predictive control problem is constructed with these chance constraints. It is shown that the proposed approach is able to predict the future position of the moving obstacles effectively; and, thus, based on the environmental information of the probabilistic prediction, it is also shown that the timing of collision avoidance can be earlier than the method without prediction. The tracking error and distance to obstacles of the trajectory with prediction are smaller compared with the method without prediction.

Characteristics and Epidemiological Investigation of Paratuberculosis in Dairy Cattle in Tai'an, China.

Paratuberculosis, a chronic and sometimes fatal disease of ruminants, is caused by Mycobacterium avium subsp. paratuberculosis (MAP). In this study, we examined paratuberculosis cases among 2-4-year-old dairy cows at farms in Shandong Province, China. Paratuberculosis cases were diagnosed based on clinical symptoms, pathological autopsy, and histopathological inspection. Characteristics of paratuberculosis in the affected dairy cattle included poor body condition, persistent diarrhea, subcutaneous edema, granulomatous ileitis (multibacillary), mesenteric lymphadenitis, and hepatitis. Acid-fast bacilli from fecal specimens and lymphocytes were putatively identified as MAP based on Ziehl-Neelsen staining, then confirmed using polymerase chain reaction-based testing and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analyses. Overall, only one MAP strain was isolated from a herd with symptomatic diarrhea. However, analysis of 586 serum samples from nine herds in Tai'an City revealed that 66.7% of herds and 14.2% of animals were seropositive for MAP. Our findings suggest that paratuberculosis is widely prevalent and therefore a significant threat to the dairy industry in Tai'an City, Shandong Province, China.

Natural infection of a variant pseudorabies virus leads to bovine death in China.

Pseudorabies virus (PRV) infects numerous species of domestic and wild animals leading to severe diseases especially in swine and cattle. Since 2011, the variant PRVs were identified in pigs, which were genetically different from classic strains. Although variant PRV infection is widely observed in pigs, there is still no report of variant PRV infection in cattle. Here, we reported a natural infection of variant PRV leading to acute bovine death in Eastern China. Our study suggests that the new variant PRV strains could be a potential threat to cattle industry and possibly to the public health of human.

Emergence of H3N8 equine influenza virus in donkeys in China in 2017.

Equine influenza virus is a major respiratory pathogen in horses. Although both horses and donkeys belong to the genus Equus, donkey infection with influenza viruses is rare. In March 2017, an influenza outbreak occurred in donkeys in Shandong province, China. The causative virus, A/donkey/Shandong/1/2017(H3N8), was isolated from a dead donkey. Genetic analysis indicated that the virus originated from influenza A (H3N8) clade 2 of the Florida sub-lineage that has been circulating in Asian equine populations. Comparison of the deduced amino acid sequence of the HA gene of this causative virus with that of the A/equine/Richmond/1/2007 vaccine strain showed that substitutions had occurred in the antigenic regions A, B, and C. This study provides insight into the currently circulating and newly emerging H3N8 strains in donkeys in China.

Florfenicol induces more severe hemotoxicity and immunotoxicity than equal doses of chloramphenicol and thiamphenicol in Kunming mice.

Amphenicols are effective, broad-spectrum antibiotics that function by inhibiting the peptidyl transferase activity of bacteria, while the drugs can also inhibit mitochondrial protein synthesis in eukaryotes through the same mechanism, which leads to multi-organ toxicity. Some side effects of each drug have been studied, while differences in the severity of the hemotoxicities and immunotoxicities of amphenicols have not been reported. Thus, it is important to identify, evaluate, and compare the potential hemotoxicities and immunotoxicities to guide their proper use in humans and animals, which will guarantee food safety and animal welfare. Ovalbumin-immunized Kunming mice were gavaged daily with amphenicols for seven days. Blood samples were collected for hematology analysis, and measuring anti-ovalbumin antibody levels and serum intereukin-2 concentrations. The bone marrow, spleen and thymus were collected for histopathology and apoptosis analyzes. Bone marrow nucleated cells (BMNCs) and splenocytes were harvested to determine their cell cycle stages and to analyze lymphocyte proliferation. The results demonstrated that amphenicols, especially florfenicol (FLO), induced cell cycle arrest and apoptosis of hematopoietic cells, and it changed the bone marrow hematopoietic microenvironment by decreasing the number of peripheral blood cells. Moreover, amphenicols, especially FLO, induced hypoplasia and atrophy of the spleen and thymus, induced cell cycle arrest, as well as splenocyte apoptosis, and decreased the proliferation and viability of lymphocytes and the humoral and cellular immunity of the treated mice. These results suggest that amphenicols induce hemotoxicity and immunotoxicity to some extent, and that FLO induces more severe toxicity than equal doses of chloramphenicol (CAP) and thiamphenicol (TAP).