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1.
Nat Chem Biol ; 17(7): 828-836, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-34155402

RESUMEN

The ability to tune RNA and gene expression dynamics is greatly needed for biotechnological applications. Native RNA stabilizers or engineered 5' stability hairpins have been used to regulate transcript half-life to control recombinant protein expression. However, these methods have been mostly ad hoc and hence lack predictability and modularity. Here, we report a library of RNA modules called degradation-tuning RNAs (dtRNAs) that can increase or decrease transcript stability in vivo and in vitro. dtRNAs enable modulation of transcript stability over a 40-fold dynamic range in Escherichia coli with minimal influence on translation initiation. We harness dtRNAs in messenger RNAs and noncoding RNAs to tune gene circuit dynamics and enhance CRISPR interference in vivo. Use of stabilizing dtRNAs in cell-free transcription-translation reactions also tunes gene and RNA aptamer production. Finally, we combine dtRNAs with toehold switch sensors to enhance the performance of paper-based norovirus diagnostics, illustrating the potential of dtRNAs for biotechnological applications.


Asunto(s)
Ingeniería Genética , ARN/genética , Biotecnología , Escherichia coli/genética , Escherichia coli/metabolismo , ARN/metabolismo
2.
Nat Chem Biol ; 16(6): 695-701, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32251409

RESUMEN

Growth-mediated feedback between synthetic gene circuits and host organisms leads to diverse emerged behaviors, including growth bistability and enhanced ultrasensitivity. However, the range of possible impacts of growth feedback on gene circuits remains underexplored. Here we mathematically and experimentally demonstrated that growth feedback affects the functions of memory circuits in a network topology-dependent way. Specifically, the memory of the self-activation switch is quickly lost due to the growth-mediated dilution of the circuit products. Decoupling of growth feedback reveals its memory, manifested by its hysteresis property across a broad range of inducer concentration. On the contrary, the toggle switch is more refractory to growth-mediated dilution and can retrieve its memory after the fast-growth phase. The underlying principle lies in the different dependence of active and repressive regulations in these circuits on the growth-mediated dilution. Our results unveil the topology-dependent mechanism on how growth-mediated feedback influences the behaviors of gene circuits.


Asunto(s)
Proteínas de Escherichia coli/genética , Redes Reguladoras de Genes/genética , Genes Sintéticos/genética , Simulación por Computador , Escherichia coli/genética , Escherichia coli/metabolismo , Regulación Bacteriana de la Expresión Génica , Proteínas Fluorescentes Verdes/genética , Proteínas Fluorescentes Verdes/metabolismo , Cinética , Modelos Genéticos , Imagen Óptica
3.
Zhongguo Yi Liao Qi Xie Za Zhi ; 46(6): 668-672, 2022 Nov 30.
Artículo en Zh | MEDLINE | ID: mdl-36597397

RESUMEN

The international standard ISO 80601-2-90:2021 specifies basic safety and essential performance requirements, including risks associated with oxygen, flow accuracy, oxygen concentration accuracy, humidification output performance, and corresponding test methods for high-flow respiratory therapy equipment. This study focuses on the key points in ISO 80601-2-90:2021 and the key problems in the test evaluation. This study also briefly introduces the relationship between ISO 80601-2-90:2021 and other standards, and explains the countermeasures that stakeholders should take.


Asunto(s)
Oxígeno , Terapia Respiratoria , Estándares de Referencia
4.
PLoS One ; 19(2): e0299331, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38394164

RESUMEN

Drug addiction can cause severe damage to the human brain, leading to significant problems in cognitive processing, such as irritability, speech distortions, and exaggeration of negative stimuli. Speech plays a fundamental role in social interaction, including both the production and perception. The ability to perceive communicative functions conveyed through speech is crucial for successful interpersonal communication and the maintaining good social relationships. However, due to the limited number of previous studies, it remains unclear whether the cognitive disorder caused by drug addiction affects the perception of communicative function conveyed in Mandarin speech. To address this question, we conducted a perception experiment involving sixty male participants, including 25 heroin addicts and 35 healthy controls. The experiment aimed to examine the perception of three communicative functions (i.e., statement, interrogative, and imperative) under three background noise conditions (i.e., no noise, SNR [Signal to Noise Ratio] = 10, and SNR = 0). Eight target sentences were first recorded by two native Mandarin speakers for each of the three communicative functions. Each half was then combined with Gaussian White Noise under two background noise conditions (i.e., SNR = 10 and SNR = 0). Finally, 48 speech stimuli were included in the experiment with four options provided for perceptual judgment. The results showed that, under the three noise conditions, the average perceptual accuracies of the three communicative functions were 80.66% and 38% for the control group and the heroin addicts, respectively. Significant differences were found in the perception of the three communicative functions between the control group and the heroin addicts under the three noise conditions, except for the recognition of imperative under strong noise condition (i.e., SNR = 0). Moreover, heroin addicts showed good accuracy (around 50%) in recognizing imperative and poor accuracy (i.e., lower than the chance level) in recognizing interrogative. This paper not only fills the research gap in the perception of communicative functions in Mandarin speech among drug addicts but also enhances the understanding of the effects of drugs on speech perception and provides a foundation for the speech rehabilitation of drug addicts.


Asunto(s)
Percepción del Habla , Trastornos Relacionados con Sustancias , Humanos , Masculino , Habla , Heroína , China
5.
ACS Synth Biol ; 13(1): 183-194, 2024 01 19.
Artículo en Inglés | MEDLINE | ID: mdl-38166159

RESUMEN

Complex and fluid bacterial community compositions are critical to diversity, stability, and function. However, quantitative and mechanistic descriptions of the dynamics of such compositions are still lacking. Here, we develop a modularized design framework that allows for bottom-up construction and the study of synthetic bacterial consortia with different topologies. We showcase the microbial consortia design and building process by constructing amensalism and competition consortia using only genetic circuit modules to engineer different strains to form the community. Functions of modules and hosting strains are validated and quantified to calibrate dynamic parameters, which are then directly fed into a full mechanistic model to accurately predict consortia composition dynamics for both amensalism and competition without further fitting. More importantly, such quantitative understanding successfully identifies the experimental conditions to achieve coexistence composition dynamics. These results illustrate the process of both computationally and experimentally building up bacteria consortia complexity and hence achieve robust control of such fluid systems.


Asunto(s)
Bacterias , Consorcios Microbianos , Consorcios Microbianos/genética , Bacterias/genética
6.
ACS Appl Mater Interfaces ; 16(11): 13773-13785, 2024 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-38442348

RESUMEN

Conventional ocean wave observation instruments are powered by batteries, limiting the continuous observation time. Besides, the waste of batteries brings environmental contaminations. Triboelectric nanogenerators (TENGs) can reveal ocean wave information through their electrical output, taking the triboelectric charge as the information carrier. However, charge amplification is necessary, consuming additional energy. Herein, taking the photons rather than electrons as the information carrier, we developed a fully self-powered natural light-enabled sensing system for ocean wave monitoring by coupling two rotary-freestanding sliding TENGs (RFS-TENGs) and a polymer network liquid crystal (PNLC)-triggered optical system. The natural light is modulated by the PNLC driven by ocean wave-induced friction. With the assistance of a one-way bearing, the rise and fall of the wave will trigger different RFS-TENGs to power the PNLC in different voltage drops, leading to different transmitted natural light intensities. The wave height information can be obtained through the number of pulse signals with the same trough light intensity, while the wave period can be obtained through the duration between the same two sets of pulse signals. The effectiveness of the developed sensing paradigm in practical applications was verified by flume-based experiments, with the highest accuracies of 90.7% in wave height and 99.8% in wave period.

7.
J Appl Psychol ; 108(3): 403-424, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36006739

RESUMEN

Job-based psychological ownership arises when workers develop personal feelings of possession over various aspects of a job. Drawing on conservation of resources and regulatory focus theory, the current research adopts a resource-based perspective to suggest a double-edged effect on job performance, mediated by three forms of territoriality (marking, defending, expanding) and information exchange and moderated by individual regulatory focus. With a multistep process in Study 1, the authors develop and validate a territorial expanding scale. Among 358 employee-supervisor dyads, Study 2 tests the proposed model; job-based psychological ownership prompts employees to engage in territorial marking, defending, and expanding. Territorial defending correlates negatively with information exchange, territorial expanding is positively related to it, and territorial marking has no relationship with information exchange. Information exchange is positively related to job performance. Job-based psychological ownership impedes job performance through increased territorial defending and reduced information exchange, especially among employees with a prevention focus. It enhances job performance through increased territorial expanding and increased information exchange, particularly if employees have a high promotion focus. These findings have notable implications for research and practice. (PsycInfo Database Record (c) 2023 APA, all rights reserved).


Asunto(s)
Rendimiento Laboral , Humanos , Territorialidad , Propiedad , Satisfacción en el Trabajo
8.
ACS Appl Mater Interfaces ; 15(46): 53476-53487, 2023 Nov 22.
Artículo en Inglés | MEDLINE | ID: mdl-37944167

RESUMEN

Current ocean wave observation is achieved by separate battery-powered sensing and signal transmission modules. Owing to the limited electrical supply and information channel space, the long-time span observation is restricted and only wave height and period information rather than the whole wave profile are sent back to the receiver. In this work, a self-powered ocean wave observation system was achieved by a developed polymer network liquid crystal (PNLC)-based smart reflector powered by a tailored triboelectric nanogenerator embedded with one-way overrunning clutches. The off-shore smart reflector modulated the on-shore emitted laser light, where ocean wave motion information can be revealed from the remotely detected reflected laser light without cable connections. The ocean wave rise and fall are distinguished by the developed one-way overrunning clutch, which selects the TENG to power the PNLC. Through the developed paradigm, ocean wave sensing and signal transmission can be achieved simultaneously, which is fully self-powered and free-of-cable. The flume-based self-powered ocean observation was performed with demonstrated wave height and period sensing accuracies of 92.66 and 97.32%, respectively.

9.
J Voice ; 2023 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-37827893

RESUMEN

AIM: Drug use/addiction has a profound impact on the physical and mental health of individuals. Previous studies have indicated that drug users may experience speech perception disorders, including speech illusion and challenges in recognizing emotional speech. However, the influence of drugs on speech production, as another crucial aspect of speech communication, has not been thoroughly examined. Therefore, the current study aimed to investigate how drugs affect the acoustic characteristics of speech in Chinese male drug users. METHOD: Speech recordings were collected from a total of 160 male drug users (including 106 heroin users, 23 ketamine users, and 31 methamphetamine users) and 55 male healthy controls with no history of drug use. Acoustic analysis was conducted on the collected speech data from these groups, and classification analysis was performed using five supervised learning algorithms. RESULTS: The results demonstrated that drug users exhibited smaller F0 standard deviation, reduced loudness, cepstral peak prominence, and formant relative energies, as well as higher H1-A3, longer unvoiced segments, and fewer voiced segments per second compared to the control group. The classification analyses yielded good performance in classifying drug users and non-drug users, with an accuracy above 86%. Moreover, the identification of the three groups of drug users achieved an accuracy of approximately 70%. Additionally, the study revealed different effects on speech production among the three types of drugs. CONCLUSION: The above findings indicate the presence of speech disorders, such as vocal hoarseness, in drug users, thus confirming the assumption that the acoustic characteristics of speech in drug users deviates from the norm. This study not only fills the knowledge gap regarding the effects of drugs on the speech production of Chinese male drug users but also provides a more comprehensive understanding of how drugs impact human behaviors. Furthermore, this research provides theoretical foundations of detoxification and speech rehabilitation for drug users.

10.
J Agric Food Chem ; 53(14): 5593-7, 2005 Jul 13.
Artículo en Inglés | MEDLINE | ID: mdl-15998120

RESUMEN

The green alga Dunaliella salina is one of the best and most important biological sources of beta-carotene; however, to date the molecular basis of the beta-carotene biosynthesis process in D. salina is still unresolved. The dehydrogenation of phytoene is the second step in the carotenoids biosynthetic pathway, and the phytoene-related desaturases are the key enzymes in the beta-carotene biosynthetic pathway. A phytoene desaturase (Pds) cDNA with a 1752 bp open reading frame was cloned by RT-PCR and RACE-PCR methods on the basis of a modified switching mechanism at 5' end of the RNA transcript (SMART) technology from D. salina. The predicted protein sequence displays a high identity (up to 65%) with phytoene desaturases of higher plants and cyanobacteria. The highest amino acid sequence identity (91%) is shared with the phytoene desaturase sequence of Dunaliella bardawil, and a dinucleotide-binding motif lies in the N-terminal. The phylogenetic analysis shows that D. salina Pds is closer to higher plants and cyanobacteria than bacterial and fungi. These results together demonstrated the cloned Pds cDNA of D. salina is a Pds-type gene, and it is postulated that in D. salina the first two dehydrogenations, by which phytoene is converted into zeta-carotene, are carried out by this putative phytoene desaturase.


Asunto(s)
Chlorophyta/enzimología , ADN Complementario/aislamiento & purificación , Oxidorreductasas/genética , beta Caroteno/biosíntesis , Secuencia de Aminoácidos , Secuencia de Bases , Carotenoides/metabolismo , Clonación Molecular , ADN Complementario/química , ADN Complementario/genética , Datos de Secuencia Molecular , Oxidorreductasas/química , Oxidorreductasas/metabolismo , Alineación de Secuencia
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