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1.
Development ; 151(6)2024 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-38421315

RESUMEN

Vision is mainly based on two different tasks, object detection and color discrimination, carried out by photoreceptor (PR) cells. The Drosophila compound eye consists of ∼800 ommatidia. Every ommatidium contains eight PR cells, six outer cells (R1-R6) and two inner cells (R7 and R8), by which object detection and color vision are achieved, respectively. Expression of opsin genes in R7 and R8 is highly coordinated through the instructive signal from R7 to R8, and two major ommatidial subtypes are distributed stochastically; pale type expresses Rh3/Rh5 and yellow type expresses Rh4/Rh6 in R7/R8. The homeodomain protein Defective proventriculus (Dve) is expressed in yellow-type R7 and in six outer PRs, and it is involved in Rh3 repression to specify the yellow-type R7. dve mutant eyes exhibited atypical coupling, Rh3/Rh6 and Rh4/Rh5, indicating that Dve activity is required for proper opsin coupling. Surprisingly, Dve activity in R1 is required for the instructive signal, whereas activity in R6 and R7 blocks the signal. Our results indicate that functional coupling of two different neurons is established through signaling pathways from adjacent neurons that are functionally different.


Asunto(s)
Visión de Colores , Proteínas de Drosophila , Animales , Drosophila/genética , Drosophila/metabolismo , Opsinas/genética , Opsinas/metabolismo , Visión de Colores/genética , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Neuronas/metabolismo , Transducción de Señal/genética , Células Fotorreceptoras de Invertebrados/fisiología , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo
2.
Chemosphere ; 352: 141457, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38378050

RESUMEN

This study assessed the impact of different plant-derived biochar (cornstalk, rice husk, and sawdust) on bacterial community and functions for compost maturity and gaseous emissions during the composting of food waste. Results showed that all biochar strengthened organic biotransformation and caused a higher germination index on day 12 (over 100%), especially for rice husk biochar to enhance the growth of Thermobifida related to aerobic chemoheterotrophy. Rice husk biochar also achieved a relatively higher reduction efficiency of methane (85.8%) and ammonia (82.7%) emissions since its greater porous structure. Besides, the growth of Pseudomonas, Pusillimonas, and Desulfitibacter was restricted to constrict nitrate reduction, nitrite respiration, and sulfate respiration by optimized temperature and air permeability, thus reducing nitrous oxide and hydrogen sulfide emissions by 48.0-57.3% by biochar addition. Therefore, rice husk biochar experienced the optimal potential for maturity increment and gaseous emissions mitigation.


Asunto(s)
Compostaje , Eliminación de Residuos , Gases , Alimento Perdido y Desperdiciado , Nitrógeno/análisis , Alimentos , Suelo/química , Carbón Orgánico , Estiércol
3.
Int J Biol Macromol ; 263(Pt 2): 130443, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38417749

RESUMEN

Peptidylglycine α-hydroxylating monooxygenase (PHM) is pivotal for C-terminal amidation of bioactive peptides in animals, offering substantial potential for customized protein synthesis. However, efficient PHM production has been hindered by the complexity of animal cell culture and the absence of glycosylation in bacterial hosts. Here, we demonstrate the recombinant expression of Caenorhabditis elegans PHM in the yeast Pichia pastoris, achieving a remarkable space-time yield of 28.8 U/L/day. This breakthrough surpasses prior PHM production rates and eliminates the need for specialized cultivation equipment or complex transfection steps. Mass spectrometry revealed N-glycosylation at residue N182 of recombinant CePHM, which impacts the enzyme's activity as indicated by biochemical experiments. To showcase the utility of CePHM, we performed C-terminal amidation on ubiquitin at a substrate loading of 30 g/L, a concentration meeting the requirements for pharmaceutical peptide production. Overall, this work establishes an efficient PHM production method, promising advancements in scalable manufacturing of C-terminally modified bioactive peptides and probe proteins.


Asunto(s)
Complejos Multienzimáticos , Proteína C , Saccharomyces cerevisiae , Animales , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Oxigenasas de Función Mixta/química , Péptidos/metabolismo
4.
Materials (Basel) ; 16(19)2023 Oct 04.
Artículo en Inglés | MEDLINE | ID: mdl-37834693

RESUMEN

In order to advance the utilization rate of multi-source solid wastes in the Ningxia region of China, 16 groups of pavement base mixtures were designed with cement and fly ash (FA) as binders, steel slag (SS), silicon manganese slag (SMS), and recycled crushed stone (RCS) as composite aggregates. The evolution laws of mechanical and frost resistance properties of the mixture were investigated by unconfined compressive strength (UCS), indirect tensile strength (ITS), freeze-thaw (FT), and ultrasonic detection tests. Then, the strength formation mechanisms were revealed by microscopic characterization technology. The mathematical models between UCS-ITS, UCS-ultrasonic amplitude, FT cycles-UCS damage, and frost resistance coefficient-relative dynamic elastic modulus Er were established. The results show that cement content and curing age exhibited a positive effect on the mechanical strength and frost resistance of the mixture. When the replacement rate of SS was 60%, the mechanical strength and frost resistance were preferable. The R2 of the strength relationship models constructed was greater than 0.9, indicating high fitting accuracy. With the extension of the curing age, the cementitious products such as C-S-H (hydrated calcium silicate) and AFt (ettringite) developed entirely, and they were interlocked and cemented with each other, resulting in the micro-morphology developed from the three-dimensional network structure to the dense system. The macroscopic behavior incarnated that the mechanical strength and frost resistance of the mixture were significantly enhanced.

5.
Viruses ; 14(10)2022 10 16.
Artículo en Inglés | MEDLINE | ID: mdl-36298825

RESUMEN

Over the last three years, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-related health crisis has claimed over six million lives and caused USD 12 trillion losses to the global economy. SARS-CoV-2 continuously mutates and evolves with a high basic reproduction number (R0), resulting in a variety of clinical manifestations ranging from asymptomatic infection to acute respiratory distress syndrome (ARDS) and even death. To gain a better understanding of coronavirus disease 2019 (COVID-19), it is critical to investigate the components that cause various clinical manifestations. Single-cell sequencing has substantial advantages in terms of identifying differentially expressed genes among individual cells, which can provide a better understanding of the various physiological and pathological processes. This article reviewed the use of single-cell transcriptomics in COVID-19 research, examined the immune response disparities generated by SARS-CoV-2, and offered insights regarding how to improve COVID-19 diagnosis and treatment plans.


Asunto(s)
COVID-19 , Humanos , SARS-CoV-2/genética , Prueba de COVID-19 , Transcriptoma , Número Básico de Reproducción
6.
Materials (Basel) ; 15(17)2022 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-36079457

RESUMEN

Although fly ash foam concrete (FAFC) is lightweight, heat-retaining, and insulating, its application options are constrained by its weak construction and short lifespan. The effects of various dosage ratios of the foaming agent (i.e., hydrogen peroxide), silica fume, and polypropylene fiber on the dry density, compressive strength, thermal insulation performance, pore structure parameters, and durability of FAFC were analyzed in this study, which sought to address the issues of low strength and low durability of FAFC. According to the findings, there is a negative correlation between the amount of hydrogen peroxide (as the foaming agent) and compressive strength, and, as the silica fume and polypropylene fiber (PP fiber) content rise, the strength will initially rise and then fall. The distribution of pore sizes gradually shifts from being dominated by small pores to large pores as the amount of foaming agent increases, while the porosity and average pore size gradually decrease. When the hydrogen peroxide content is 5%, the pore shape factor is at its lowest. The pore size distribution was first dominated by a small pore size and thereafter by a large pore size when the silica fume and PP fiber concentration increased. Prior to increasing, the porosity, average pore size, and pore shape factor all decreased. Additionally, the impact of PP fiber on the freeze-thaw damage to FAFC was also investigated at the same time. The findings indicate that the freeze-thaw failure of FAFC is essentially frost heave failure of the pore wall. The use of PP fiber is crucial for enhancing FAFC's ability to withstand frost. The best frost resistance is achieved at 0.4% PP fiber content. In conclusion, the ideal ratio for overall performance was found to be 5% hydrogen peroxide content, 4% silica fume content, and 0.1% polypropylene fiber content. The results obtained could be applied in different fields, such as construction and sustainable materials, among others.

7.
Materials (Basel) ; 15(9)2022 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-35591448

RESUMEN

In this study, the silica fume replacement rate, fly ash replacement rate, and curing temperature were regarded as the independent variables, and the compressive and flexural strengths were regarded as the response values. The response surface method was used to construct the response surface polynomial regression model and obtain the optimal preparation parameters of a steel slag cement-based gel slurry (SCGS). The univariate and multivariate effects on the SCGS's strength were investigated via analysis of variance and a three-dimensional surface model, and the hydration products and strength development law were characterized via scanning electron microscopy and X-ray diffraction. The actual compressive strengths at 3 and 28 d of age were 31.78 and 53.94 MPa, respectively, which were close to the predicted values (32.59 and 55.81 MPa, respectively), demonstrating that the optimized strengths were accurate and reliable. Further, the hydration reaction rate of SiO2 in the silica fume and the physical filling effect of the inert components of fly ash and steel slag under the optimal parameters were the key factors for the early strength of the material. Moreover, continuous C3S hydration in steel slag and the continuous excitation of the volcanic ash properties of fly ash were important factors for the later strength.

8.
Materials (Basel) ; 15(10)2022 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-35629707

RESUMEN

To study the shrinkage and freeze-thaw durability of cement-fly-ash-stabilized brick and concrete reclaimed gravel mixture (CFRBCA), recycled gravel was used to replace 100% of the natural gravel in cement-and-fly-ash-stabilized gravel (CFRCA). Five different mixture ratios of recycled brick and recycled concrete were designed. Dry shrinkage tests, temperature shrinkage tests, freeze-thaw cycle tests, ultrasonic tests, and microscopic analyses were then conducted. The test results showed that the water loss rate, dry shrinkage strain, and dry shrinkage coefficient of CFRBCA increased as the age and brick content increased and tended to be stable by approximately the 40th day of age. The reclaimed gravel content had a great influence on the temperature shrinkage of CFRBCA: the temperature shrinkage coefficient first increased and then decreased as the temperature decreased and reached a peak at -10 to 0 °C. The microstructure analysis showed that as the number of freeze-thaw cycles increases, cracks appear and extend in the CFRBCA, hydration products gradually change from dense to loose, and the Ca/Si ratio increases. Through these experiments, the logarithmic relationship model between ultrasonic wave velocity and CFRBCA strength damage, which can better predict the strength loss caused by CFRBCA variation with freeze-thaw cycles, was established. The brick content is the key parameter affecting the durability of the freeze-thawed CFRBCA, and thus the brick slag content should be properly controlled in engineering applications.

9.
Materials (Basel) ; 14(24)2021 Dec 08.
Artículo en Inglés | MEDLINE | ID: mdl-34947128

RESUMEN

In order to promote the application of steel slag in road engineering, improve its utilization rate and solve the environmental problems caused by its large accumulation, unconfined compressive strength (UCS) test, indirect tensile strength (ITS) test, freeze-thaw cycle test, dry shrinkage and temperature shrinkage test tests with different steel slag contents were carried out. And the strength formation mechanism of steel slag in base material was revealed by SEM. The results show that the strength of the mixture initially increased and then decreased with increasing steel slag content. The frost resistance increased with increasing steel slag content, which should be limited to no more than 75%. Increasing the steel slag content improved the drying shrinkage resistance but was not conducive to the temperature shrinkage resistance. Microscopic analysis shows that adding a suitable amount of steel slag generated a gel material that was distributed inside the pores. This increased the density of the hardened slurry structure, which improved the strength. The research can provide scientific basis for the application and promotion of steel slag in road base.

10.
BMC Syst Biol ; 12(Suppl 2): 18, 2018 03 19.
Artículo en Inglés | MEDLINE | ID: mdl-29560823

RESUMEN

BACKGROUND: Gene Ontology (GO) is one of the most popular bioinformatics resources. In the past decade, Gene Ontology-based gene semantic similarity has been effectively used to model gene-to-gene interactions in multiple research areas. However, most existing semantic similarity approaches rely only on GO annotations and structure, or incorporate only local interactions in the co-functional network. This may lead to inaccurate GO-based similarity resulting from the incomplete GO topology structure and gene annotations. RESULTS: We present NETSIM2, a new network-based method that allows researchers to measure GO-based gene functional similarities by considering the global structure of the co-functional network with a random walk with restart (RWR)-based method, and by selecting the significant term pairs to decrease the noise information. Based on the EC number (Enzyme Commission)-based groups of yeast and Arabidopsis, evaluation test shows that NETSIM2 can enhance the accuracy of Gene Ontology-based gene functional similarity. CONCLUSIONS: Using NETSIM2 as an example, we found that the accuracy of semantic similarities can be significantly improved after effectively incorporating the global gene-to-gene interactions in the co-functional network, especially on the species that gene annotations in GO are far from complete.


Asunto(s)
Biología Computacional/métodos , Ontología de Genes , Redes Reguladoras de Genes , Semántica , Anotación de Secuencia Molecular , Procesos Estocásticos
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