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1.
ACS Pharmacol Transl Sci ; 7(5): 1278-1290, 2024 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-38751639

RESUMEN

Triple-negative breast cancer (TNBC) typically manifests as higher invasive carcinoma correlated with a worse prognosis that primarily relies on chemotherapy. There is growing evidence that nitric oxide (NO) donor drugs have the potential for anticancer therapy. On this basis, we constructed and evaluated a novel coumarin-furoxan hybrid 4A93 as an effective antitumor candidate drug. 4A93 exhibits low IC50 values in three TNBC cell lines and inhibits colony formation and DNA synthesis, probably due to the release of high concentrations of NO in mitochondria, which induces oxidative stress, mitochondrial dysfunction, and apoptosis. Further research suggests that 4A93 might destroy mitochondria by opening the mitochondrial permeability transition pore (mPTP), depolarizing the mitochondrial membrane potential (MMP), and promoting the release of cytochrome c into the cytoplasm. Intrinsic apoptosis is induced finally, along with Akt/Erk signaling suppression. Additionally, 4A93 underregulates the Epithelial-mesenchymal transition process to inhibit cell migration and invasion. In 4T1 subcutaneous and hematogenous models of mice, 4A93 therapy suppresses the tumor growth and prevented lung metastasis with favorable biosafety. Our results provide insights into 4A93 in TNBC treatment and validate the contribution of NO donors in tumor therapy.

2.
J Biotechnol ; 390: 50-61, 2024 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-38789049

RESUMEN

To reduce food spoilage and deterioration caused by microbial contamination, antimicrobial peptides (AMPs) have gradually gained attention as a biological preservative. Odorranain-C1 is an α-helical cationic antimicrobial peptide extracted from the skin of frogs with broad-spectrum antimicrobial activity. In this study, we achieved the expression of Odorranain-C1 in Pichia pastoris (P. pastoris) (also known as Komagataella phaffii) by employing DNA recombination technology. The recombinant Odorranain-C1 showed broad-spectrum antibacterial activity and displayed a minimum inhibitory concentration within the range of 8-12 µg.mL-1. Meanwhile, Odorranain-C1 exhibited superior stability and lower hemolytic activity. Mechanistically, Odorranain-C1 disrupted the bacterial membrane's integrity, ultimately causing membrane rupture and subsequent cell death. In tilapia fillets preservation, Odorranain-C1 inhibited the total colony growth and pH variations, while also reducing the production of total volatile basic nitrogen (TVB-N) and thiobarbituric acid (TBA). In conclusion, these studies demonstrated the efficient recombinant expression of Odorranain-C1 in P. pastoris, highlighting its promising utilization in food preservation.


Asunto(s)
Conservación de Alimentos , Saccharomycetales , Animales , Saccharomycetales/genética , Saccharomycetales/metabolismo , Conservación de Alimentos/métodos , Pruebas de Sensibilidad Microbiana , Péptidos Catiónicos Antimicrobianos/genética , Péptidos Catiónicos Antimicrobianos/farmacología , Péptidos Catiónicos Antimicrobianos/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/farmacología , Péptidos Antimicrobianos/genética , Péptidos Antimicrobianos/farmacología , Péptidos Antimicrobianos/metabolismo , Antibacterianos/farmacología , Hemólisis/efectos de los fármacos , Pichia/genética , Pichia/metabolismo , Proteínas Anfibias/genética , Proteínas Anfibias/farmacología , Proteínas Anfibias/metabolismo , Anuros/metabolismo
3.
Biomaterials ; 309: 122607, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38759487

RESUMEN

The use of CAR-T cells in treating solid tumors frequently faces significant challenges, mainly due to the heterogeneity of tumor antigens. This study assessed the efficacy of an acidity-targeting transition-aided universal chimeric antigen receptor T (ATT-CAR-T) cell strategy, which is facilitated by an acidity-targeted transition. Specifically, the EGFRvIII peptide was attached to the N-terminus of a pH-low insertion peptide. Triggered by the acidic conditions of the tumor microenvironment, this peptide alters its structure and selectively integrates into the membrane of solid tumor cells. The acidity-targeted transition component effectively relocated the EGFRvIII peptide across various tumor cell membranes; thus, allowing the direct destruction of these cells by EGFRvIII-specific CAR-T cells. This method was efficient even when endogenous antigens were absent. In vivo tests showed marked antigen modification within the acidic tumor microenvironment using this component. Integrating this component with CAR-T cell therapy showed high effectiveness in combating solid tumors. These results highlight the capability of ATT-CAR-T cell therapy to address the challenges presented by tumor heterogeneity and expand the utility of CAR-T cell therapy in the treatment of solid tumors.


Asunto(s)
Inmunoterapia Adoptiva , Neoplasias , Receptores Quiméricos de Antígenos , Microambiente Tumoral , Receptores Quiméricos de Antígenos/inmunología , Humanos , Animales , Línea Celular Tumoral , Concentración de Iones de Hidrógeno , Inmunoterapia Adoptiva/métodos , Neoplasias/terapia , Neoplasias/inmunología , Ratones , Receptores ErbB/metabolismo , Linfocitos T/inmunología , Femenino
4.
Phenomics ; 4(1): 24-33, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38605905

RESUMEN

Primary ciliary dyskinesia (PCD) is a rare disorder characterized by extensive genetic heterogeneity. However, in the genetic pathogenesis of PCD, copy number variation (CNV) has not received sufficient attention and has rarely been reported, especially in China. Next-generation sequencing (NGS) followed by targeted CNV analysis was used in patients highly suspected to have PCD with negative results in routine whole-exome sequencing (WES) analysis. Quantitative real-time polymerase chain reaction (qPCR) and Sanger sequencing were used to confirm these CNVs. To further characterize the ciliary phenotypes, high-speed video microscopy analysis (HSVA), transmission electron microscopy (TEM), and immunofluorescence (IF) analysis were used. Patient 1 (F1: II-1), a 0.6-year-old girl, came from a nonconsanguineous family-I. She presented with situs inversus totalis, neonatal respiratory distress, and sinusitis. The nasal nitric oxide level was markedly reduced. The respiratory cilia beat with reduced amplitude. TEM revealed shortened outer dynein arms (ODA) of cilia. chr5:13717907-13722661del spanning exons 71-72 was identified by NGS-based CNV analysis. Patient 2 (F2: IV-4), a 37-year-old man, and his eldest brother Patient 3 (F2: IV-2) came from a consanguineous family-II. Both had sinusitis, bronchiectasis and situs inversus totalis. The respiratory cilia of Patient 2 and Patient 3 were found to be uniformly immotile, with ODA defects. Two novel homozygous deletions chr5:13720087_13733030delinsGTTTTC and chr5:13649539_1 3707643del, spanning exons 69-71 and exons 77-79 were identified by NGS-based CNV analysis. Abnormalities in DNA copy number were confirmed by qPCR amplification. IF showed that the respiratory cilia of Patient 1 and Patient 2 were deficient in dynein axonemal heavy chain 5 (DNAH5) protein expression. This report identified three novel DNAH5 disease-associated variants by WES-based CNV analysis. Our study expands the genetic spectrum of PCD with DNAH5 in the Chinese population. Supplementary Information: The online version contains supplementary material available at 10.1007/s43657-023-00130-0.

5.
Vaccines (Basel) ; 12(3)2024 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-38543883

RESUMEN

The gram-negative facultative intracellular pathogen Salmonella enterica serotype Choleraesuis, also known as S. Choleraesuis, is a major financial loss for the pig business. C500 is a vaccine strain that has been used for preventing S. Choleraesuis infection in pigs for many years in China. Although it possessed good immunogenicity and protection efficacy, it still showed severe side effects. The truncation of the key gene rpoS in C500 was believed to take the major responsibility for its attenuation. To achieve a good balance between attenuation and immunogenicity, rpoS was restored to an active state, and other essential virulent genes of crp, fur, phoP, and aroA were evaluated for their effects of deletion on safety and immunogenicity. Animal experiments demonstrated that C5001 (C500 rpoS+ Δcrp10) and C5002 (C500 rpoS+ Δfur9) showed an excellent ability to induce an immune response. To further decrease the endotoxic activity, the combination mutations of ΔpagL7 ΔpagP81::PlpplpxE ΔlpxR9 were introduced into the mutant strains to generate 1'-dephosphorylated lipid A. Animal experiments showed that SC3 (C500 rpoS+ Δfur9 ΔpagL7 ΔpagP81:: PlpplpxE ΔlpxR9) induced higher levels of IgG and secreted IgA antibodies and provided a higher protection rate than SC1 (C500 ΔpagL7 ΔpagP81:: PlpplpxE ΔlpxR9) and SC2 (C500 rpoS+ Δcrp10 ΔpagL7 ΔpagP81:: PlpplpxE ΔlpxR9). We also evaluated the ability of SC3 (C500 rpoS+ Δfur9 ΔpagL7 ΔpagP81:: PlpplpxE ΔlpxR9) as a vaccine carrier to deliver heterologous protein antigens and polysaccharide antigens. The results indicated that SC3 (C500 rpoS+ Δfur9 ΔpagL7 ΔpagP81:: PlpplpxE ΔlpxR9) showed an excellent ability to deliver heterologous antigens and induce the host to produce high levels of antibodies. Together, these results indicate that we constructed a safe and efficient attenuated strain of the S. Choleraesuis vaccine, which demonstrated strong resistance to infection with wild-type S. Choleraesuis and can be employed as a universal vector for the delivery of recombinant antigens.

6.
Biochem Pharmacol ; 222: 116068, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38387529

RESUMEN

Non-small cell lung cancer (NSCLC) still lacks effective treatment because of its extensive mutation diversity and frequent drug resistance. Therefore, it is urgent to develop new therapeutic strategies for NSCLC. In this study, we evaluated the inhibitory effect of a new coumarin-furoxan hybrid compound 9, a nitric oxide (NO) donor drug, on NSCLC proliferation and its mechanism. Our results show that compound 9 can inhibit the growth of four NSCLC cell lines and H1975 xenograft model in a dose-dependent manner. Compound 9 effectively releases high concentrations of NO within the mitochondria, leading to cellular oxidative stress, mitochondrial dysfunction, and apoptosis. Moreover, compound 9 inhibits JAK2/STAT3 protein phosphorylation and induces S-nitrosylation modification of STAT3, ultimately resulting in endogenous apoptosis in NSCLC. Additionally, compound 9 significantly induces NSCLC ferroptosis by depleting intracellular GSH, elevating MDA levels, inhibiting SLC7A11/GSH protein expression, and negatively regulating the JAK2/STAT3 pathway. In summary, this study elucidates the inhibitory effects of compound 9 on NSCLC proliferation and provides insights into the underlying mechanisms, offering new possibilities for NSCLC treatment strategies.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas , Ferroptosis , Neoplasias Pulmonares , Oxadiazoles , Humanos , Carcinoma de Pulmón de Células no Pequeñas/metabolismo , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/metabolismo , Donantes de Óxido Nítrico/farmacología , Donantes de Óxido Nítrico/uso terapéutico , Factor de Transcripción STAT3/metabolismo , Apoptosis , Cumarinas/farmacología , Cumarinas/uso terapéutico , Línea Celular Tumoral , Proliferación Celular , Janus Quinasa 2/metabolismo
7.
Fish Shellfish Immunol ; 146: 109380, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38244821

RESUMEN

Aeromonas hydrophila (A. hydrophila) is a typical zoonotic pathogenic bacterium that infects humans, animals, and fish. It has been reported that the Fur, a Fe2+ regulatory protein, and the Crp, a cAMP receptor protein, play important roles in bacterial virulence in many bacteria, but no research has been investigated on A. hydrophila. In this study, the Δfur and Δcrp mutant strains were constructed by the suicide plasmid method. These two mutant strains exhibited a slightly diminished bacterial growth and also were observed some alterations in the number of outer membrane proteins, and the disappearance of hemolysis in the Δcrp strain. Animal experiments of crucian carp showed that the Δfur and Δcrp mutant strains significantly decreased virulence compared to the wild-type strain, and both mutant strains were able to induce good immune responses by two kinds of administration routes of intraperitoneal immunization (i.p) and immersion immunization, and the protection rates through intraperitoneal injection of Δfur and Δcrp to crucian carp were as high as 83.3 % and 73.3 %, respectively, and immersion immunization route of Δfur and Δcrp to crucian carp provided protection as high as 40 % and 20 %, respectively. These two mutant strains showed abilities to induce changes in enzymatic activities of the non-specific enzymes SOD, LZM, AKP, and ACP in crucian carp. Together, these results indicated the Δfur and Δcrp mutants were safe and effective candidate vaccine strains, showing good protection against the wild-type A. hydrophila challenge.


Asunto(s)
Carpas , Enfermedades de los Peces , Infecciones por Bacterias Gramnegativas , Humanos , Animales , Infecciones por Bacterias Gramnegativas/prevención & control , Infecciones por Bacterias Gramnegativas/veterinaria , Vacunas Atenuadas , Aeromonas hydrophila
8.
Int J Nurs Pract ; 30(3): e13236, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38238976

RESUMEN

AIMS: Dehydration is one of the common complications of dysphagia and poses significant risks including hospitalization and mortality, but the relationship between dysphagia and dehydration has received little attention. This study aims to determine the prevalence and risk factors for dehydration of patients with dysphagia in eastern China, and to provide reference for early identification and prevention of dehydration. METHODS: A descriptive, cross-sectional design was conducted. Three hundred and thirty-seven (n = 337) patients with dysphagia participated in the study between August and December 2022. Information relating to participants' demographic variables, nutrition, cognition, functional, hydration status and fluid intake was collected. Univariate analysis was used to examine related impact factors, and then binary logistic regression analysis was conducted to determine reliable impact factors. RESULTS: Among 337 patients with dysphagia, the average age was 63.47 ± 16.96, most participants were male (72.1%) and married (91.7%). The prevalence of dehydration was calculated to be 43.9%, the mean plasma osmolality score was 293.53 mmol/L. Diseases with the highest prevalence were stroke (78.3%), followed by hypertension (63.5%). The risk for dehydration increased with older age, usage of more medicines such as diuretics and beta-blockers, worse functional status and lower fluid intake. CONCLUSION: This study found a high percentage of dehydration in patients with dysphagia. Findings can provide a basis for targeted nursing interventions for clinical prevention and treatment of dehydration.


Asunto(s)
Trastornos de Deglución , Deshidratación , Humanos , Trastornos de Deglución/epidemiología , Estudios Transversales , Masculino , Deshidratación/epidemiología , Femenino , China/epidemiología , Persona de Mediana Edad , Factores de Riesgo , Prevalencia , Anciano , Anciano de 80 o más Años , Adulto
9.
Materials (Basel) ; 16(23)2023 Nov 27.
Artículo en Inglés | MEDLINE | ID: mdl-38068109

RESUMEN

Organic semiconductor materials featuring lightweight, and flexibility may play a significant role in various future applications, such as foldable displays, wearable devices, and artificial skin. For developing high-performance organic devices, organic crystals are highly desired, while a remaining fundamental issue is their contact problem. Here, we have grown a high-quality rubrene single crystal by utilizing a simple in-air sublimation technique. The contact characteristics (barrier height and contact resistance) are detail-studied by resist-free transfer electrodes (Au metal or graphene/Au). The Schottky barrier of the rubrene/graphene interface is lower and can be also modulated by gate bias, which is confirmed by spatial photocurrent mapping. Finally, we demonstrated the zero-bias photocurrent imaging application by constructing the asymmetrical device employing different electrode contacts. Our work would be of significance for studying the contact issue of organic crystals and wireless imaging.

10.
J Am Chem Soc ; 145(49): 26983-26992, 2023 12 13.
Artículo en Inglés | MEDLINE | ID: mdl-38032103

RESUMEN

Employing living cells as carriers to transport transition metal-based catalysts for target-specific bio-orthogonal catalysis represents a cutting-edge approach in advancing precision biomedical applications. One of the initial hurdles in this endeavor involves effectively attaching the catalysts to the carrier cells while preserving the cells' innate ability to interact with biological systems and maintaining the unaltered catalytic activity. In this study, we have developed an innovative layer-by-layer method that leverages a noncovalent interaction between cucurbit[7]uril and adamantane as the primary driving force for crafting polymeric nanostructures on the surfaces of these carrier cells. The strong binding affinity between the host-guest pair ensures the creation of a durable polymer coating on the cell surfaces. Meanwhile, the layer-by-layer process offers high adaptability, facilitating the efficient loading of bio-orthogonal catalysts onto cell surfaces. Importantly, the polymeric coating shows no discernible impact on the cells' physiological characteristics, including their tropism, migration, and differentiation, while preserving the effectiveness of the bio-orthogonal catalysts.


Asunto(s)
Adamantano , Nanoestructuras , Elementos de Transición , Nanoestructuras/química , Polímeros , Catálisis
11.
Opt Express ; 31(20): 33378-33386, 2023 Sep 25.
Artículo en Inglés | MEDLINE | ID: mdl-37859120

RESUMEN

Fiber optic communication is becoming the central pillar of modern high-speed communication technology, which involves the abundant fiber components. Currently, most of photodetectors are fabricated on the silicon chip, so mass fiber-to-chip interfaces increase the complexity of advanced optoelectronic system, and also grow the risk of optical information loss. Here, we report an all-fiber organic phototransistor by employing rubrene single crystal and few-layer graphene to realize the "plug-to-play" operation. The device shows a broadband photoresponse from the ultraviolet to visible range, with fast response times of approximately 130/170 µs and reasonable specific detectivity of 6 × 109 Jones, which is close to the level of commercial on-chip device. Finally, several imaging applications are successfully demonstrated by deploying this all-fiber device. Our work provided an efficient strategy for fabricating all-fiber organic devices, and confirmed their significant potential in future optical fiber optoelectronics.

12.
ACS Appl Mater Interfaces ; 15(41): 48442-48451, 2023 Oct 18.
Artículo en Inglés | MEDLINE | ID: mdl-37788404

RESUMEN

Organic semiconductors herald new opportunities for fabricating high-performance flexible and wearable optoelectronic devices owing to their intrinsic mechanical flexibility, excellent optical absorption, and cool-free operation. The photocurrent generation mechanisms are of multiple physical origins, including photoconductive, photovoltaic, and photogating effects, and the influence of individual effects on the device figures-of-merit is still not well understood. Here we fabricated a high-performance pentacene single-crystal transistor employing graphene electrodes and demonstrated the modulation from the photogating mechanism to the photoconduction effect by controlling gate bias. Control experiments indicate that the calculation based on transfer curves tends to overestimate the responsivity due to nearby trap states. Using a high frequency-modulated light signal to suppress the trapping process, we successfully measured its intrinsic -3 dB bandwidth of 75 kHz. Finally, high-resolution and UV-NIR high-speed imaging capability was demonstrated. Our work provides new guidelines for understanding the photophysical process and intrinsic performances of organic devices and also confirms the potential of organic single crystals in high-speed imaging applications.

13.
Front Genet ; 14: 1221853, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37795245

RESUMEN

Hereditary spherocytosis (HS), the most common inherited hemolytic anemia disorder, is characterized by osmotically fragile microspherocytic red cells with a reduced surface area on the peripheral blood smear. Pathogenic variants in five erythrocyte membrane structure-related genes ANK1 (Spherocytosis, type 1; MIM#182900), SPTB (Spherocytosis, type 2; MIM#616649), SPTA1 (Spherocytosis, type 3; MIM#270970), SLC4A1 (Spherocytosis, type 4; MIM#612653) and EPB42 (Spherocytosis, type 5; MIM#612690) have been confirmed to be related to HS. There have been many studies on the pathogenic variants and mechanisms of HS, however, studies on how to manage the transmission of HS to the next-generation have not been reported. In this study, we recruited a patient with HS. Targeted next-generation sequencing with a panel of 208 genes related to blood system diseases detected a novel heterozygous variant in the SPTB: c.300+2dup in the proband. Sanger sequencing of variant alleles and haplotype linkage analysis of single nucleotide polymorphism (SNP) based on next-generation sequencing were performed simultaneously. Five embryos were identified with one heterozygous and four not carrying the SPTB variant. Single-cell amplification and whole genome sequencing showed that three embryos had varying degrees of trisomy mosaicism. One of two normal embryos was transferred to the proband. Ultimately, a healthy boy was born, confirmed by noninvasive prenatal testing for monogenic conditions (NIPT-M) to be disease-free. This confirmed our successful application of PGT in preventing transmission of the pathogenic variant allele in the HS family.

14.
Heliyon ; 9(9): e20169, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37809876

RESUMEN

Millions of ethnic children in China live without their parents due to financial constraints and the lure of job opportunities elsewhere, staying in their hometowns primarily for education. Yet, current research inadequately addresses the mental health status of these left-behind children from ethnic minority communities in China. This study aimed to explore the effects of the combined identities-ethnic and left-behind-on depression among children in rural ethnic minority areas. We recruited a sample of 1131 children aged 12 to 16 from the Garzê Tibetan Autonomous Prefecture (also known as Ganzi Prefecture) in Sichuan Province. The Children's Depression Inventory was employed to assess depression levels. Results indicated that left-behind children in this region exhibited significantly higher depression levels than their counterparts who lived with their parents. Notably, children of Han ethnicity were more depressed than other ethnic groups. However, no interactive effects were observed between the dual identity factors. Intriguingly, Han children, despite being the majority ethnicity in China, perceived themselves as ethnic minorities in these areas. Their self-perception of ethnic pressure and differences, coupled with a potential lack of acceptance of their ethnic differences from the native minorities, might be subdued. This study underscores that parental relocation poses a risk to the mental health of adolescents in rural China. While policies and programs supporting left-behind children are crucial, further research is imperative to comprehend the nuances of their experiences fully.

15.
Microb Cell Fact ; 22(1): 164, 2023 Aug 27.
Artículo en Inglés | MEDLINE | ID: mdl-37635252

RESUMEN

BACKGROUND: Recently, researchers have focused on the search for alternatives to conventional antibiotics. Antimicrobial peptides are small bioactive peptides that regulate immune activation and have antibacterial activity with a reduced risk of bacterial resistance. Porcine myeloid antibacterial peptide 37 (PMAP-37) is a small-molecule peptide with broad-spectrum antibacterial activity isolated from pig bone marrow, and PMAP-37(F34-R) is its analogue. In this study, PMAP-37(F34-R) was recombinantly expressed in Pichia pastoris, and the recombinant peptide was further investigated for its antibacterial properties, mechanism and preservative in plums. RESULTS: To obtain a Pichia pastoris strain expressing PMAP-37(F34-R), we constructed a plasmid expressing recombinant PMAP-37(F34-R) (pPICZα-PMAP-37(F34-R)-A) and introduced it into Pichia pastoris. Finally, we obtained a highly active recombinant peptide, PMAP-37(F34-R), which inhibited the activity of both Gram-positive and Gram-negative bacteria. The minimum inhibitory concentration is 0.12-0.24 µg/mL, and it can destroy the integrity of the cell membrane, leading to cell lysis. It has good stability and is not easily affected by the external environment. Hemolysis experiments showed that 0.06 µg/mL-0.36 µg/mL PMAP-37(F34-R) had lower hemolysis ability to mammalian cells, and the hemolysis rate was below 1.5%. Additionally, 0.36 µg/mL PMAP-37(F34-R) showed a good preservative effect in plums. The decay and weight loss rates of the treated samples were significantly lower than those of the control group, and the respiratory intensity of the fruit was delayed in the experimental group. CONCLUSIONS: In this study, we constructed a recombinant Pichia pastoris strain, which is a promising candidate for extending the shelf life of fruits and has potential applications in the development of new preservatives.


Asunto(s)
Prunus domestica , Animales , Porcinos , Antibacterianos/farmacología , Hemólisis , Bacterias Gramnegativas , Bacterias Grampositivas , Péptidos Catiónicos Antimicrobianos/genética , Péptidos Catiónicos Antimicrobianos/farmacología , Bacterias , Mamíferos
16.
Front Neurorobot ; 17: 1205775, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37614967

RESUMEN

Considering the dynamics and non-linear characteristics of biped robots, gait optimization is an extremely challenging task. To tackle this issue, a parallel heterogeneous policy Deep Reinforcement Learning (DRL) algorithm for gait optimization is proposed. Firstly, the Deep Deterministic Policy Gradient (DDPG) algorithm is used as the main architecture to run multiple biped robots in parallel to interact with the environment. And the network is shared to improve the training efficiency. Furthermore, heterogeneous experience replay is employed instead of the traditional experience replay mechanism to optimize the utilization of experience. Secondly, according to the walking characteristics of biped robots, a biped robot periodic gait is designed with reference to sinusoidal curves. The periodic gait takes into account the effects of foot lift height, walking period, foot lift speed and ground contact force of the biped robot. Finally, different environments and different biped robot models pose challenges for different optimization algorithms. Thus, a unified gait optimization framework for biped robots based on the RoboCup3D platform is established. Comparative experiments were conducted using the unified gait optimization framework, and the experimental results show that the method outlined in this paper can make the biped robot walk faster and more stably.

17.
Molecules ; 28(14)2023 Jul 14.
Artículo en Inglés | MEDLINE | ID: mdl-37513276

RESUMEN

Antibiotic resistance to pathogenic bacteria is becoming an increasing public health threat, and identifying alternatives to antibiotics would be an effective solution to the problem of drug resistance. Antimicrobial peptides are small peptides produced by various organisms; they are considered to be adequate antibiotic substitutes because they have intense, broad-spectrum antibacterial activity and stability, are widely available, and target strains do not quickly develop resistance. Recent research on antimicrobial peptides has shown that they have broad potential for applications in medicine, agriculture, food, and animal feed. Turgencin A is a potent antimicrobial peptide isolated from the Arctic sea squirt. We established a His-tagged expression system for Pichia pastoris and developed a rTurgencin A using the recombinant expression in Pichia pastoris with nickel column purification. This antimicrobial peptide showed intense antimicrobial activity against Gram-positive and Gram-negative bacteria and a good stability at most temperatures and pHs, as well as in various protease and salt ion concentrations, but underwent a significant decrease in stability in high-temperature and low-pH environments. Turgencin A induced bacterial membrane rupture, resulting in content leakage and subsequent cell death. It was also shown to have low hemolytic activity. This study provides primary data for the industrial production and application of the antimicrobial peptide Turgencin A.


Asunto(s)
Antibacterianos , Bacterias Gramnegativas , Animales , Pichia/genética , Pichia/metabolismo , Bacterias Grampositivas , Péptidos Catiónicos Antimicrobianos , Bacterias , Pruebas de Sensibilidad Microbiana
18.
J Environ Manage ; 345: 118599, 2023 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-37423185

RESUMEN

Low impact development (LID) is a sustainable practice to managing urban runoff. However, its effectiveness in densely populated areas with intense rainfall, such as Hong Kong, remains unclear due to limited studies with similar climate conditions and urban patterns. The highly mixed land use and complicated drainage network present challenges for preparing a Storm Water Management Model (SWMM). This study proposed a reliable framework for setting up and calibrating SWMM by integrating multiple automated tools to address these issues. With a validated SWMM, we examined LID's effects on runoff control in a densely built catchment of Hong Kong. A designed full-scale LID implementation can reduce total and peak runoffs by around 35-45% for 2, 10 and 50-year return rainfalls. However, LID alone may not be adequate to handle the runoff in densely built areas of Hong Kong. As the rainfall return period increases, total runoff reduction increases, but peak runoff reduction remains close. Percentages of reduction in total and peak runoffs decline. The marginal control diminishes for total runoff while remaining constant for peak runoff when increasing the extent of LID implementation. In addition, the study identifies the crucial design parameters of LID facilities using global sensitivity analysis. Overall, our study contributes to accelerating the reliable application of SWMM and deepening the understanding of the effectiveness of LID in ensuring water security in densely built urban communities located near the humid-tropical climate zone, such as Hong Kong.


Asunto(s)
Lluvia , Agua , Hong Kong , Calibración , Movimientos del Agua
19.
Foods ; 12(13)2023 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-37444178

RESUMEN

Different constituents of the cultivation substrate have significant effect on the yield and quality of edible mushrooms. The residue after the extraction of instant tea has exhibited to be biologically significant, and could be used as a substrate for cultivation. This study aimed to investigate the feasibility of tea extraction residue (TER) on button mushroom (Agaricus bisporus) cultivation, as an ingredient in the substrate, and assess the growth status, nutritional values, and sensory characteristics of fruiting body. The results showed that the strains could grow well on the cultivated substrate with 20% addition of TER. The total amount of hydrolyzed amino acids in the fruiting bodies of three TER-based groups (TER accounted for 10%, 20%, and 37.5%, respectively) was higher than that of the control group, and the total amount of essential amino acids was increased by 33.33%, 22.47%, and 9.92% compared with the control group, respectively. In addition, the results of gas chromatography-mass spectrometry (GC-MS) revealed that the addition of TER to the cultivation of substrate significantly enhanced the content of typical mushroom-flavor compounds in button mushroom, such as 1-octen-3-ol, 3-octanol, and 1-octen-3-one. It can be concluded that TER may be an ideal choice for the substrate in commercial cultivation of button mushroom.

20.
Curr Protein Pept Sci ; 24(8): 640-654, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37497701

RESUMEN

Antimicrobial peptides (AMPs) are widely sourced and have a variety of biological activities such as broad-spectrum antibacterial, antiviral, and anticancer. Since AMPs are less likely to cause drug resistance, they are expected to be an alternative to antibiotics. Compared with natural extraction and chemical synthesis methods, producing AMPs using genetic engineering is a hot research topic for the large-scale production of AMPs. This paper outlines the sources of AMPs, focuses on different expression systems, and reviews the current status of AMPs applications in animal husbandry, food preservation and medicine, and agriculture to provide a theoretical basis and support for using genetic engineering to express AMPs.

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