Rapid and simple single-chamber nucleic acid detection system prepared through nature-inspired surface engineering

Background: Nucleic acid (NA)-based diagnostics enable a rapid response to various diseases, but current techniques often require multiple labor-intensive steps, which is a major obstacle to successful translation to a clinical setting. Methods: We report on a surface-engineered single-chamber device for NA extraction and in situ amplification without sample transfer. Our system has two reaction sites: A NA extraction chamber whose surface is patterned with micropillars and a reaction chamber filled with reagents for in situ polymerase-based NA amplification. These two sites are integrated in a single microfluidic device; we applied plastic injection molding for cost-effective, mass-production of the designed device. The micropillars were chemically activated via a nature-inspired silica coating to possess a specific affinity to NA. Results: As a proof-of-concept, a colorimetric pH indicator was coupled to the on-chip analysis of NA for the rapid and convenient detection of pathogens. The NA enrichment efficiency was dependent on the lysate incubation time, as diffusion controls the NA contact with the engineered surface. We could detect down to 1×103 CFU by the naked eye within one hour of the total assay time. Conclusion: We anticipate that the surface engineering technique for NA enrichment could be easily integrated as a part of various types of microfluidic chips for rapid and convenient nucleic acid-based diagnostics. © 2021 Ivyspring International Publisher. All rights reserved.1

Swedish Mutant Nerve Growth Factor (NGFR100W): Potential Therapeutic for Neurodegenerative Diseases

Neurodegenerative diseases are characterized by loss of sensory neurons leading to motor, cognitive, and memory deficits. Due to the lack of a cure for such diseases, these diseases are costly in the United States. Extensive studies in the past showed the potential of nerve growth factor (NGF) as a therapeutic measure due to its trophic capabilities affecting the proliferation and regeneration of neurons. Therefore, NGF has been tried in several clinical trials, but all failed because of painful side effects such as site injection hyperalgesia or myalgia. However, the recent discovery of a mutant NGF (NGFR100W) that does not induce pain allowed us to investigate its potential as an alternative. Due to the blood-brain barrier limiting the administration of these NGF, we explored the effect of NGFR100W by injecting it into CharcotMarie Tooth Type 2B mouse models as they closely resemble peripheral neuropathy. We performed a hot plate test for nociception and sensitivity of the peripheral nerves by injecting increasing doses of NGFR100W. NGFR100W injected groups did not show significant pain perception compared to wild-type NGF injected groups even in high doses. Our immunohistochemistry data further indicated that NGFR100W prompted neuronal recovery comparable to that observed in wild-type NGF. We also explored the regenerative aspect of NGFR100W which rescued the sensory perception of the CMT2B mouse. Based on these findings, we validated the capability of NGFR100W in regenerating neurons and sensory function, which can be potentially used to improve the condition of individuals with peripheral neuropathy

A Flexible and Attachable Colorimetric Film Sensor for the Detection of Gaseous Ammonia

A cost-effective, simple, flexible, and disposable colorimetric film sensor was constructed for the rapid detection of gaseous ammonia. The sensor was designed to consist of three layers, namely top, middle, and bottom layers of a polymeric elastomer. The bromocresol (BCG) indicator embedded in the middle layer of the film facilitated a change in color of the sensor from yellow-orange to blue upon exposure to gaseous ammonia. The color change was visually observed by the naked eye. The sensitivity of the sensor was verified by a successful detection of gaseous ammonia at concentrations from 4 to 235 ppm within 3 min, and the corresponding visual detection of ammonia gas was at a concentration as low as 11 ppm. The sensor also achieved a selective detection of gaseous ammonia over a variety of alkaline chemicals. The color of the sensor exposed to ammonia reverted from blue to the original yellow-orange upon subsequent exposure to the fume of acetic acid or aeration for 48 h, and it showed reliable performance for the detection of gaseous ammonia even after five repeated uses. The applicability of the sensor was validated by attaching it onto a safety helmet for a simulation of an industrial ammonia gas leak. The results indicated that our colorimetric film sensor is affordable, disposable, and reproducible, and can serve as an effective alternative for simple and rapid recognition of gaseous ammonia in environmental and air quality monitoring as well as in industrial applications

Supply chain management model for ready mixed concrete

Supplying ready mixed concrete (RMC) in both a timely and cost-effective manner has been a particular challenge for RMC suppliers. To address this issue, a dynamic simulation model is developed using system dynamics. This model represents the generic RMC operation process and can customize its structure and parameters for different operational conditions. Through model simulation, the RMC supply process is analyzed, focusing on the tradeoff between the truck mixer dispatching interval and queuing time on-site. The research findings indicate that the model-generated information helps in achieving an economical RMC supply by maintaining the number of queuing truck mixers at the desired level, while satisfying the contractor`s need. Ultimately, this dynamic model could potentially be used as an effective automated tool to assist RMC suppliers in supply planning. (C) 2010 Elsevier B.V. All rights reserved.Pena-Mora F, 2008, J CONSTR ENG M ASCE, V134, P701, DOI 10.1061/(ASCE)0733-9364(2008)134:9(701)TUREK M, 1995, THESIS MIT CAMBRIDGELU M, 2005, P 2005 WINT SIM C, P2572Feng CW, 2004, AUTOMAT CONSTR, V13, P327, DOI 10.1016/j.autcon.2003.10.001Chua DKH, 2002, J CONSTR ENG M ASCE, V128, P195, DOI 10.1061/(ASCE)0733-9364(2002)128:3(195)ANSON M, 2002, J CONSTRUCTION MANAG, V20, P237WILLIAMS T, 2002, MODELLING COMPLEX PR, P167Pena-Mora F, 2001, J CONSTR ENG M ASCE, V127, P445Zayed TM, 2001, J CONSTR ENG M ASCE, V127, P132BANKS J, 2001, DISCRETE EVENT SYSTE, P12PETRI C, 1966, RADCTR65377 GRIFF AIHALPIN DW, 1977, J CONSTRUCT DIV-ASCE, V103, P489LLUNCH J, 1982, J CONSTR DIV ASCE, V108, P129ABDELHAMID T, 1984, DYNAMICS SOFTWARE DEPAULSON BC, 1987, J CONSTR ENG M ASCE, V113, P302BERNOLD LE, 1989, J CONSTR ENG M ASCE, V115, P163HOMER J, 1993, P 1993 INT SYST DYNCOOPER G, 1994, J PROD INNOVAT MANAG, V11, P381LYNEIS J, 2001, SYSTEM DYNAMICS REV, V17WANG SQ, 2001, J CONSTRUCTION RES, V2, P169STERMAN J, 2000, BUSINESS DYNAMICS SY, P191Sawhney A, 1999, J COMPUT CIVIL ENG, V13, P178Kilmer RA, 1999, COMPUT IND ENG, V36, P391Ng WM, 1998, J COMPUT CIVIL ENG, V12, P101Anson M, 1998, J CONSTR ENG M ASCE, V124, P116SMITH S, 1998, CIVIL ENG ENV SYSTEM, V16, P93FORD D, 1997, 394397 MIT SLOAN SCH

Rare Tokens Degenerate All Tokens: Improving Neural Text Generation via Adaptive Gradient Gating for Rare Token Embeddings

Recent studies have determined that the learned token embeddings of large-scale neural language models are degenerated to be anisotropic with a narrow-cone shape. This phenomenon, called the representation degeneration problem, facilitates an increase in the overall similarity between token embeddings that negatively affect the performance of the models. Although the existing methods that address the degeneration problem based on observations of the phenomenon triggered by the problem improves the performance of the text generation, the training dynamics of token embeddings behind the degeneration problem are still not explored. In this study, we analyze the training dynamics of the token embeddings focusing on rare token embedding. We demonstrate that the specific part of the gradient for rare token embeddings is the key cause of the degeneration problem for all tokens during training stage. Based on the analysis, we propose a novel method called, adaptive gradient gating (AGG). AGG addresses the degeneration problem by gating the specific part of the gradient for rare token embeddings. Experimental results from language modeling, word similarity, and machine translation tasks quantitatively and qualitatively verify the effectiveness of AGG.N

Nonpolar Surface Modification Using Fatty Acids and Its Effect on Calcite from Mineral Carbonation of Desulfurized Gypsum

CaCO3 is often used as an additive in many industries. However, additional functions are required to expand its applicability. This entails modification of its physicochemical properties. Accordingly, in this study, a particle surface modification treatment was performed on CaCO3 produced from desulfurized gypsum for a range of industrial applications. In the experiment, fatty acids were used to modify the CaCO3 surface, and the scale of the modification effect was based on the degree of change associated with a polar surface taking on nonpolar surface properties. In the preliminary modification experiment, stearic acid was dissolved in 2-propanol or chloroform, and the extent of the reaction and the active ratio were measured according to the stearic acid concentration. The results showed that the effective active ratio, considering the activity to unit adsorption, was higher in 2-propanol than in chloroform. Consequently, the modification solvent used in the experiment changed the CaCO3 surface from a hydrophilic, polarized form to a hydrophobic, nonpolarized form. These results will also allow the CaCO3 produced to be used as a filler in a range of chemical industries