21 Background: At present, PCR-based nucleic acid detection cannot meet the demands 22 for coronavirus infectious disease (COVID-19) diagnosis. Immunosorbent Assay (ELISA) kits based on recombinant SARS-CoV-2 nucleocapsid 27 protein (rN) and spike protein (rS) were used for detecting IgM and IgG antibodies, 28 and their diagnostic feasibility was evaluated.29 Results: Among the 214 patients, 146 (68.2%) and 150 (70.1%) were successfully 30 diagnosed with the rN-based IgM and IgG ELISAs, respectively; 165 (77.1%) and 31 159 (74.3%) were successfully diagnosed with the rS-based IgM and IgG ELISAs, 32 respectively. The positive rates of the rN-based and rS-based ELISAs for antibody 33 (IgM and/or IgG) detection were 80.4% and 82.2%, respectively. The sensitivity of 34 the rS-based ELISA for IgM detection was significantly higher than that of the 35 rN-based ELISA. We observed an increase in the positive rate for IgM and IgG with 36 an increasing number of days post-disease onset (d.p.o.), but the positive rate of IgM 37 dropped after 35 d.p.o. The positive rate of rN-based and rS-based IgM and IgG 38 ELISAs was less than 60% during the early stage of the illness 0-10 d.p.o., and that of 39 IgM and IgG was obviously increased after 10 d.p.o.40 Conclusions: ELISA has a high sensitivity, especially for the detection of serum 41 samples from patients after 10 d.p.o, it can be an important supplementary method for 42 on June 9, 2020 by guest http://jcm.asm.org/ Downloaded from COVID-19 diagnosis.43

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Using rapid prototyping technology, three-dimensional (3D) structures composed of hepatocytes and gelatin hydrogel have been formed. This technique employs a highly accurate 3D micropositioning system with a pressure-controlled syringe to deposit cell/biomaterial structures with a lateral resolution of 10 microm. The pressure-activated micro-syringe is equipped with a fine-bore exit needle for which a wide variety of 3D patterns with different arrays of channels (through-holes) were created. More than 30 layers of a hepatocyte/gelatin mixture were laminated into a high spacial structure using this method. The laminated hepatocytes remained viable and performed biological functions in the construct for more than 2 months. The rapid prototyping technology offers potential for eventual high-throughout production of artificial human tissues or organs.

21 Background: At present, PCR-based nucleic acid detection cannot meet the demands 22 for coronavirus infectious disease (COVID-19) diagnosis. Immunosorbent Assay (ELISA) kits based on recombinant SARS-CoV-2 nucleocapsid 27 protein (rN) and spike protein (rS) were used for detecting IgM and IgG antibodies, 28 and their diagnostic feasibility was evaluated. 29 Results: Among the 214 patients, 146 (68.2%) and 150 (70.1%) were successfully 30 diagnosed with the rN-based IgM and IgG ELISAs, respectively; 165 (77.1%) and 31 159 (74.3%) were successfully diagnosed with the rS-based IgM and IgG ELISAs, 32 respectively. The positive rates of the rN-based and rS-based ELISAs for antibody 33 (IgM and/or IgG) detection were 80.4% and 82.2%, respectively. The sensitivity of 34 the rS-based ELISA for IgM detection was significantly higher than that of the 35 rN-based ELISA. We observed an increase in the positive rate for IgM and IgG with 36 an increasing number of days post-disease onset (d.p.o.), but the positive rate of IgM 37 dropped after 35 d.p.o. The positive rate of rN-based and rS-based IgM and IgG 38 ELISAs was less than 60% during the early stage of the illness 0-10 d.p.o., and that of 39 IgM and IgG was obviously increased after 10 d.p.o.40Conclusions: ELISA has a high sensitivity, especially for the detection of serum

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A run-to-run model-based iterative learning control (ILC) strategy for the tracking control of product quality in batch processes is proposed. A linear perturbation model for product quality, linearized around the nominal trajectories, is identified from process operating data using linear regression. To address the problem of model-plant mismatches, model prediction errors in the previous batch run are added to the model predictions for the current batch run. On the basis of the modified predictions, an ILC law with direct error feedback can be explicitly obtained. The convergence of tracking error under ILC is analyzed. To overcome the detrimental effects of unmeasured disturbances and process variations, it is proposed in this paper that the perturbation model should be updated in a batchwise manner. After the completion of each batch, a batchwise perturbation model, linearized around the control trajectory for that batch, is identified. A forgetting factor is introduced so that data from the more recent batch runs are weighted more than data from earlier batch runs. The proposed technique is successfully applied to a simulated batch reactor and a simulated batch polymerization process.

An organ manufacturing technique was developed that enables the formation of cell/extracellular matrix (ECM) complexes for in vitro or in vivo growth. In this study, a three-dimensional (3D) structure composed of hepatocytes and gelatin/alginate hydrogel was made using a cell assembler-I apparatus to thoroughly control cell assembling. Hepatocytes and ECM were constructed into 10 X 10 X 3mm3 structures according to a designed pattern. The embedded hepatocytes remained viable and performed biological functions in the construct for more than 12 days. This 3D structure has the potential to be used as a precursor for tissue or organ regeneration. This technology offers the potential for high-throughput production of artificial human tissues and organs.

Brain tissue engineering has now emerged as one of the most promising treatments for the traumatic brain injury. In this article, two groups of three-dimensional (3D) hydrogel structures composed of gelatin and gelatin/hyaluronan have been formed using our 3D cell assembly technique for in vivo study in rats, in order to investigate their effects in reparation of injury in the central nervous system (CNS). The structures were implanted into cortical defects created in rat brains, and their abilities to improve the brain tissue reconstruction were then evaluated. After 4, 8, 10, and 13 weeks of implantation, sections of brains were processed with NISSL staining for observing the immigration of host neural cells into the implanted materials and the degradation property of the materials. The results showed that simplex gelatin and gelatin/hyaluronan (20:1) with 3D structures both have good biocompatibility with brain tissue while gelatin/hyaluronan has a better contiguity with the surrounding tissue. Through our primary study, it seems that 3D gelatin/hyaluronan structures may be useful in brain tissue repair.