Compared with traditional structures, lattice structures show more excellent mechanical properties, e.g., higher rigidity and lighter weight. The additive manufacturing (AM) technology enables ...complex lattice structure to be realized. The path planning problem of AM for lattice structures faces new challenges that have been barely explored before now, because the lattice structures have unique characteristics of complex geometrical features and high-precision processing requirements. Despite many efforts toward path generation, the printing efficiency problem of the lattice structures is more than one single printing path can resolve. Using machine learning method based on a support vector machine (SVM) system, the goal of this paper is to automatically determine a suitable filling path for each sub-domain of the slicing layer of the lattice structures. Moreover, a route is found to traverse every scattered sub-domain by solving a traveling salesman problem (TSP). We demonstrate various testing examples and the experimental results to show the superiority and effectiveness of our method in terms of classification accuracy, filling effects, and linking path length.
Precise and rapid monitoring of metabolites in biofluids is a desirable but unmet goal for disease diagnosis and management. Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) ...exhibits advantages in metabolite analysis. However, the low accuracy in quantification of the technique limits its transformation to clinical usage. We report herein the use of Au nanoparticle arrays self-assembled at liquid–liquid interfaces for mass spectrometry (MS)-based quantitative biofluids metabolic profiling. The two-dimensional arrays feature uniformly and closely packed Au nanoparticles with 3 nm interparticle gaps. The experimental study and theoretical simulation show that the arrays exhibit high photothermal conversion and heat confinement effects, which enhance the laser desorption/ionization efficacy. With the nanoscale roughness, the AuNP arrays as laser desorption/ionization substrates can interrupt the coffee-ring effect during droplet evaporation. Therefore, high reproducibility (RSD <5%) is obtained, enabling accurate quantitative analysis of diverse metabolites from 1 μL of biofluids in seconds. By quantifying glucose in the cerebrospinal fluid (CSF), it allows us to identify patients with brain infection and rapidly evaluate the clinical therapy response. Consequently, the method shows potential in advanced metabolite analysis and biomedical diagnostics.
Computer-aided manufacturing (CAM) software outputs machining data by encoding a tool-path into a series of G-codes which are composed of various lengths of line segments. The discontinuities of ...these line segments may cause inefficiency for computer numerical control (CNC) system. To achieve high-speed continuous motions, corner smoothing algorithms based on look-ahead methods are widely used. However, it is difficult to meet smoothing trajectories in real-time requirements. Based on machine learning method, in this paper, a support vector machine (SVM) system is presented for directly outputting classification results of the various geometric continuities at the transition corners. The feature values used for generating continuity classification model are extracted from sampling paths of the previous publication work: the machining parameters, length, fairness criteria, the root mean square (RMS) contour errors, and dominant stage type of movement of each sampling path are calculated. The acceleration/deceleration (ACC/DEC) feedrate planning scheme is used to determine the feedrate at the transition corners. Simulations and experiments show that the proposed algorithm can realize accurately and efficiently continuity classification in real-time requirements under the conditions of machining accuracy.
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•A novel approach to detect pesticides using liquid crystal droplet patterns.•The detection limit of the baycarb is around 0.01pg.•The detection limit of the dimethoate is around ...0.1pg.•The liquid crystal sensing platform decorated with cationic surfactant.•This low-cost and label-free platform is quite convenient and sensitive.
The alignment of liquid crystal (LC) is known to be sensitive to the properties of a bounding interface. Here, we report a LC droplet pattern platform based on enzymatic event of acetylcholinesterase (AChE) for sensitive detection of pesticides. In this method, the dark cross appearances of LC droplet patterns are obtained due to the formation of myristoylcholine (Myr) monolayer at the aqueous/LC interface after transferring Myr solution, which is corresponding to the perpendicular alignment of LC molecules at the interface. On the one hand, AChE mediates the hydrolysis of Myr to disrupt the surfactant monolayer, and the process leads to the bright fan-shaped images of LC droplet patterns when in contact with the pre-incubated mixture of AChE and Myr, which is indicating a planar orientation of LCs at the interface. On the other hand, the hydrolysis of Myr is inhibited in the presence of AChE-inhibiting pesticides such as baycarb and dimethoate, as a result, the LC droplet patterns present the dark cross appearances. On the basis of the principle, the LC droplet patterns could be utilized as an effective method to detect the pesticides. The results demonstrated that the LC droplet patterns were sensitive to baycarb with a detection limit of 1ng/mL and dimethoate with a detection limit of 0.1ng/mL. The constructed LC-based sensing platform is quite simple and convenient, and shows high promise for label-free detection of pesticides with very high sensitivity.
Space robots can perform some tasks in harsh environment as assistants of astronauts or substitutions of astronauts. Taking the limited working time and the arduous task of the astronauts in the ...space station into account, an astronaut assistant robot (AAR-2) applied in the space station is proposed and designed in this paper. The AAR-2 is achieved with some improvements on the basis of AAR-1 which was designed before. It can exploit its position and attitude sensors and control system to free flight or hover in the space cabin. And it also has a definite environmental awareness and artificial intelligence to complete some specified tasks under the control of astronauts or autonomously. In this paper, it mainly analyzes and controls the 6-DOF motion of the AAR-2. Firstly, the system configuration of AAR-2 is specifically described, and the movement principles are analyzed. Secondly, according to the physical model of the AAR-2, the Newton - Euler equation is applied in the preparation of space dynamics model of 6-DOF motion. Then, according to the mathematical model's characteristics which are nonlinear and strong coupling, a dual closed loop position and attitude controller based on fuzzy sliding mode control is proposed and designed. Finally, simulation experiments are appropriate to provide for AAR-2 control system by using Matlab/Simulink. From the simulation results it can be observed that the designed fuzzy sliding mode controller can control the 6-DOF motion of AAR-2 quickly and precisely.
•An AAR-2 robot is designed for freely flying in the cabin and assisting astronaut to complete tasks.•Dynamics model is established based on Newton-Euler method.•A fuzzy sliding mode controller is designed.•Simulations are made for the designed control system by using Matlab/Simulink.
Proteins are responsible for most biochemical events in human body. It is essential to develop sensitive and selective methods for the detection of proteins. In this study, liquid crystal (LC)-based ...sensor for highly selective and sensitive detection of lysozyme, concanavalin A (Con A), and bovine serum albumin (BSA) was constructed by utilizing the LC interface decorated with a nonionic surfactant, dodecyl β-d-glucopyranoside. A change of the LC optical images from bright to dark appearance was observed after transferring dodecyl β-d-glucopyranoside onto the aqueous/LC interface due to the formation of stable self-assembled surfactant monolayer, regardless of pH and ion concentrations studied in a wide range. The optical images turned back from dark to bright appearance after addition of lysozyme, Con A and BSA, respectively. Noteworthy is that these proteins can be further distinguished by adding enzyme inhibitors and controlling incubation temperature of the protein solutions based on three different interaction mechanisms between proteins and dodecyl β-d-glucopyranoside, viz. enzymatic hydrolysis, specific saccharide binding, and physical absorption. The LC-based sensor decorated with dodecyl β-d-glucopyranoside shows high sensitivity for protein detection. The limit of detection (LOD) for lysozyme, Con A and BSA reaches around 0.1 μg/mL, 0.01 μg/mL and 0.001 μg/mL, respectively. These results might provide new insights into increasing selectivity and sensitivity of LC-based sensors for the detection of proteins.
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•A label-free LC-based sensor with high selectivity and sensitivity for protein detections.•Three proteins including lysozyme, Con A and BSA are detected based on three different mechanisms.•A nonionic surfactant-decorated liquid crystal interface as the sensing platform.•The surfactant monolayer is stable regardless of pH and ionic strength in a wide range.
Thoracic aortic aneurysm (TAA) is a localized or diffuse dilatation of the thoracic aortas, and causes many sudden deaths each year worldwide. However, there is no effective pharmacologic therapy. ...Here, we show that AGGF1 effectively blocks TAA-associated arterial inflammation and remodeling in three different mouse models (mice with transverse aortic constriction, Fbn1
mice, and β-aminopropionitrile-treated mice). AGGF1 expression is reduced in the ascending aortas from the three models and human TAA patients. Aggf1
mice and vascular smooth muscle cell (VSMC)-specific Aggf1
knockout mice show aggravated TAA phenotypes. Mechanistically, AGGF1 enhances the interaction between its receptor integrin α7 and latency-associated peptide (LAP)-TGF-β1, blocks the cleavage of LAP-TGF-β1 to form mature TGF-β1, and inhibits Smad2/3 and ERK1/2 phosphorylation in VSMCs. Pirfenidone, a treatment agent for idiopathic pulmonary fibrosis, inhibits TAA-associated vascular inflammation and remodeling in wild type mice, but not in Aggf1
mice. In conclusion, we identify an innovative AGGF1 protein therapeutic strategy to block TAA-associated vascular inflammation and remodeling, and show that efficacy of TGF-β inhibition therapies require AGGF1.
Schematic representation of the detection process for cellulase and cysteine. &z.rtrif; 5CB: 4-cyano-4′-pentylbiphenyl.
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•A novel method to monitor cellulase and cysteine using liquid ...crystals.•The sensing platform is based on enzymatic activity and reactivation.•The detection limit of cellulase is around 0.00001mg/mL in a solution of cysteine.•The detection limit of cysteine is around 82.5μM.•The label-free and simple platform is quite sensitive and low-cost.
A liquid crystal (LC)-based sensor, which is capable of monitoring enzymatic activity at the aqueous/LC interface and detecting cellulase and cysteine (Cys), was herein reported. When functionalized with a surfactant, dodecyl β-d-glucopyranoside, the 4-cyano-4′-pentylbiphenyl (5CB) displays a dark-to-bright transition in the optical appearance for cellulase. We attribute this change to the orientational transition of LCs, as a result of enzymatic hydrolysis between cellulase and surfactant. Furthermore, by adding cellulase and Cu2+, our surfactant-LCs system performs an interesting ability to detect Cys, even though Cys could not interact with surfactant or LC directly. Alternatively, through the strong binding between Cys and Cu2+, cellulase was able to hydrolyze surfactant in the presence of Cu2+, leading to the transition of LCs from dark to bright. The detection limit of the LC sensor was around 1×10−5mg/mL and 82.5μM for cellulase and Cys, respectively. The LC-based sensor may contribute to the development of low-cost, expedient, and label-free detection for cellulase and Cys and the design strategy may also provide a novel way for detecting multiple analytes.
Reliable monitoring of metabolites in biofluids is critical for diagnosis, treatment, and long‐term management of various diseases. Although widely used, existing enzymatic metabolite assays face ...challenges in clinical practice primarily due to the susceptibility of enzyme activity to external conditions and the low sensitivity of sensing strategies. Inspired by the micro/nanoscale confined catalytic environment in living cells, the coencapsulation of oxidoreductase and metal nanoparticles within the nanopores of macroporous silica foams to fabricate all‐in‐one bio‐nanoreactors is reported herein for use in surface‐enhanced Raman scattering (SERS)‐based metabolic assays. The enhancement of catalytical activity and stability of enzyme against high temperatures, long‐time storage or proteolytic agents are demonstrated. The nanoreactors recognize and catalyze oxidation of the metabolite, and provide ratiometric SERS response in the presence of the enzymatic by‐product H2O2, enabling sensitive metabolite quantification in a “sample in and answer out” manner. The nanoreactor makes any oxidoreductase‐responsible metabolite a candidate for quantitative SERS sensing, as shown for glucose and lactate. Glucose levels of patients with bacterial infection are accurately analyzed with only 20 µL of cerebrospinal fluids, indicating the potential application of the nanoreactor in vitro clinical testing.
Inspired by the spatially confined micro‐/nano‐environment in living cells, a plasmonic bio‐nanoreactor is developed by the coencapsulation of enzyme and surface‐enhanced Raman scattering tags within macroporous silica foams. The nanoreactor shows enhanced biocatalytic activity and stability, and thus the capability of molecular recognition and detection provides an all‐in‐one optical biosensor for reliable in vitro metabolic testing.
Adenoid cystic carcinoma of the external auditory canal is a rare primary malignancy, and surgery is the primary management strategy. This study aims to optimize management strategies and improve ...prognosis of adenoid cystic carcinoma of the external auditory canal.
Seventeen patients with adenoid cystic carcinoma of external auditory canal who had been admitted to a single institution from January 2008 to March 2019 were recruited and retrospectively reviewed. Among patients with T1 tumors, 2 underwent local external auditory canal resection, 1 received lateral temporal bone resection+superficial parotidectomy. Among patients with T2 tumors, all 5 patients underwent lateral temporal bone resection+superficial parotidectomy. Among patients with T3 tumors, 3 underwent subtotal temporal bone resection+superficial parotidectomy, 2 underwent subtotal temporal bone resection+superficial parotidectomy+radiotherapy, and 1 underwent extended temporal bone resection+superficial parotidectomy+radiotherapy. Among patients with T4 tumors, 2 underwent subtotal temporal bone resection+superficial parotidectomy and 1 underwent extended temporal bone resection+total parotidectomy+radiotherapy.
The common manifestations included otalgia (82.4%), hearing loss (23.5%), external auditory canal mass (23.5%), otorrhea (17.6%), and aural fullness (5.9%). In the study, 5/17 (29.4%) patients had been misdiagnosed preoperatively, 5/17 (29.4%) patients revealed local recurrence, and 3/17 patients (17.6%) were identified with distant metastasis postoperatively. The 3- and 5-year overall survival rates were 88.2% and 82.3%, respectively. There was no significant difference in overall survival (P=.746) and disease-free survival (P=.933) between patients receiving different surgical approaches. Three out of 17 patients (17.6%) died of T2, T3, and T4 diseases, respectively.
Otalgia is the most common manifestation of adenoid cystic carcinoma of the external auditory canal, and misdiagnosis is frequently encountered. Surgery is the preferred therapy, and local resection is associated with relapse, lateral temporal bone resection is strongly recommended in patients with early-stage tumor. Regular follow-up should be routinely conducted postoperatively to early identify local recurrence.
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