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1.
Nature ; 627(8002): 101-107, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38418886

RESUMEN

Li-ion batteries (LIBs) for electric vehicles and aviation demand high energy density, fast charging and a wide operating temperature range, which are virtually impossible because they require electrolytes to simultaneously have high ionic conductivity, low solvation energy and low melting point and form an anion-derived inorganic interphase1-5. Here we report guidelines for designing such electrolytes by using small-sized solvents with low solvation energy. The tiny solvent in the secondary solvation sheath pulls out the Li+ in the primary solvation sheath to form a fast ion-conduction ligand channel to enhance Li+ transport, while the small-sized solvent with low solvation energy also allows the anion to enter the first Li+ solvation shell to form an inorganic-rich interphase. The electrolyte-design concept is demonstrated by using fluoroacetonitrile (FAN) solvent. The electrolyte of 1.3 M lithium bis(fluorosulfonyl)imide (LiFSI) in FAN exhibits ultrahigh ionic conductivity of 40.3 mS cm-1 at 25 °C and 11.9 mS cm-1 even at -70 °C, thus enabling 4.5-V graphite||LiNi0.8Mn0.1Co0.1O2 pouch cells (1.2 Ah, 2.85 mAh cm-2) to achieve high reversibility (0.62 Ah) when the cells are charged and discharged even at -65 °C. The electrolyte with small-sized solvents enables LIBs to simultaneously achieve high energy density, fast charging and a wide operating temperature range, which is unattainable for the current electrolyte design but is highly desired for extreme LIBs. This mechanism is generalizable and can be expanded to other metal-ion battery electrolytes.

2.
Proc Natl Acad Sci U S A ; 121(36): e2406343121, 2024 Sep 03.
Artículo en Inglés | MEDLINE | ID: mdl-39186654

RESUMEN

The extinction risk of the giant panda has been demoted from "endangered" to "vulnerable" on the International Union for Conservation of Nature Red List, but its habitat is more fragmented than ever before, resulting in 33 isolated giant panda populations according to the fourth national survey released by the Chinese government. Further comprehensive investigations of the genetic background and in-depth assessments of the conservation status of wild populations are still necessary and urgently needed. Here, we sequenced the genomes of 612 giant pandas with an average depth of ~26× and generated a high-resolution map of genomic variation with more than 20 million variants covering wild individuals from six mountain ranges and captive representatives in China. We identified distinct genetic clusters within the Minshan population by performing a fine-grained genetic structure. The estimation of inbreeding and genetic load associated with historical population dynamics suggested that future conservation efforts should pay special attention to the Qinling and Liangshan populations. Releasing captive individuals with a genetic background similar to the recipient population appears to be an advantageous genetic rescue strategy for recovering the wild giant panda populations, as this approach introduces fewer deleterious mutations into the wild population than mating with differentiated lineages. These findings emphasize the superiority of large-scale population genomics to provide precise guidelines for future conservation of the giant panda.


Asunto(s)
Conservación de los Recursos Naturales , Genoma , Ursidae , Ursidae/genética , Animales , Conservación de los Recursos Naturales/métodos , Genoma/genética , China , Especies en Peligro de Extinción , Variación Genética , Genética de Población/métodos , Dinámica Poblacional , Secuenciación Completa del Genoma/métodos
3.
EMBO J ; 41(4): e106825, 2022 02 15.
Artículo en Inglés | MEDLINE | ID: mdl-35023164

RESUMEN

Despite extensive analysis of pRB phosphorylation in vitro, how this modification influences development and homeostasis in vivo is unclear. Here, we show that homozygous Rb∆K4 and Rb∆K7 knock-in mice, in which either four or all seven phosphorylation sites in the C-terminal region of pRb, respectively, have been abolished by Ser/Thr-to-Ala substitutions, undergo normal embryogenesis and early development, notwithstanding suppressed phosphorylation of additional upstream sites. Whereas Rb∆K4 mice exhibit telomere attrition but no other abnormalities, Rb∆K7 mice are smaller and display additional hallmarks of premature aging including infertility, kyphosis, and diabetes, indicating an accumulative effect of blocking pRb phosphorylation. Diabetes in Rb∆K7 mice is insulin-sensitive and associated with failure of quiescent pancreatic ß-cells to re-enter the cell cycle in response to mitogens, resulting in induction of DNA damage response (DDR), senescence-associated secretory phenotype (SASP), and reduced pancreatic islet mass and circulating insulin level. Pre-treatment with the epigenetic regulator vitamin C reduces DDR, increases cell cycle re-entry, improves islet morphology, and attenuates diabetes. These results have direct implications for cell cycle regulation, CDK-inhibitor therapeutics, diabetes, and longevity.


Asunto(s)
Envejecimiento/fisiología , Ácido Ascórbico/farmacología , Diabetes Mellitus Experimental/prevención & control , Proteína de Retinoblastoma/metabolismo , Animales , Senescencia Celular/efectos de los fármacos , Quinasa 2 Dependiente de la Ciclina/antagonistas & inhibidores , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/patología , Factor de Transcripción E2F1/metabolismo , Desarrollo Embrionario/genética , Femenino , Fibroblastos/efectos de los fármacos , Técnicas de Sustitución del Gen , Células Secretoras de Insulina/patología , Ratones , Fosforilación , Embarazo , Proteína de Retinoblastoma/genética , Telómero/genética
4.
EMBO Rep ; 2024 Jul 18.
Artículo en Inglés | MEDLINE | ID: mdl-39026012

RESUMEN

Genome transcription and replication of influenza A virus (FluA), catalyzed by viral RNA polymerase (FluAPol), are delicately controlled across the virus life cycle. A switch from transcription to replication occurring at later stage of an infection is critical for progeny virion production and viral non-structural protein NS2 has been implicated in regulating the switch. However, the underlying regulatory mechanisms and the structure of NS2 remained elusive for years. Here, we determine the cryo-EM structure of the FluAPol-NS2 complex at ~3.0 Å resolution. Surprisingly, three domain-swapped NS2 dimers arrange three symmetrical FluPol dimers into a highly ordered barrel-like hexamer. Further structural and functional analyses demonstrate that NS2 binding not only hampers the interaction between FluAPol and the Pol II CTD because of steric conflicts, but also impairs FluAPol transcriptase activity by stalling it in the replicase conformation. Moreover, this is the first visualization of the full-length NS2 structure. Our findings uncover key molecular mechanisms of the FluA transcription-replication switch and have implications for the development of antivirals.

5.
Nucleic Acids Res ; 52(D1): D798-D807, 2024 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-37889020

RESUMEN

Influenza viruses undergo frequent genomic mutations, leading to potential cross-species transmission, phenotypic changes, and challenges in diagnostic reagents and vaccines. Accurately evaluating and predicting the risk of such variations remain significant challenges. To address this, we developed the VarEPS-Influ database, an influenza virus variations risk evaluation system (VarEPS-Influ). This database employs a 'multi-dimensional evaluation of mutations' strategy, utilizing various tools to assess the physical and chemical properties, primary, secondary, and tertiary structures, receptor affinity, antibody binding capacity, antigen epitopes, and other aspects of the variation's impact. Additionally, we consider space-time distribution, host species distribution, pedigree analysis, and frequency of mutations to provide a comprehensive risk evaluation of mutations and viruses. The VarEPS-Influ database evaluates both observed variations and virtual variations (variations that have not yet occurred), thereby addressing the time-lag issue in risk predictions. Our current one-stop evaluation system for influenza virus genomic variation integrates 1065290 sequences from 224 927 Influenza A, B and C isolates retrieved from public resources. Researchers can freely access the data at https://nmdc.cn/influvar/.


Asunto(s)
Bases de Datos Genéticas , Gripe Humana , Orthomyxoviridae , Humanos , Anticuerpos/genética , Epítopos , Glicoproteínas Hemaglutininas del Virus de la Influenza/genética , Gripe Humana/epidemiología , Gripe Humana/virología , Mutación , Orthomyxoviridae/genética , Variación Genética , Genoma Viral , Medición de Riesgo
6.
J Virol ; 98(1): e0116623, 2024 Jan 23.
Artículo en Inglés | MEDLINE | ID: mdl-38054704

RESUMEN

Both influenza A virus genome transcription (vRNA→mRNA) and replication (vRNA→cRNA→vRNA), catalyzed by the influenza RNA polymerase (FluPol), are dynamically regulated across the virus life cycle. It has been reported that the last amino acid I121 of the viral NS2 protein plays a critical role in promoting viral genome replication in influenza mini-replicon systems. Here, we performed a 20 natural amino acid substitution screening at residue NS2-I121 in the context of virus infection. We found that the hydrophobicity of the residue 121 is essential for virus survival. Interestingly, through serial passage of the rescued mutant viruses, we further identified adaptive mutations PA-K19E and PB1-S713N on FluPol which could effectively compensate for the replication-promoting defect caused by NS2-I121 mutation in the both mini-replicon and virus infection systems. Structural analysis of different functional states of FluPol indicates that PA-K19E and PB1-S713N could stabilize the replicase conformation of FluPol. By using a cell-based NanoBiT complementary reporter assay, we further demonstrate that both wild-type NS2 and PA-K19E/PB1-S713N could enhance FluPol dimerization, which is necessary for genome replication. These results reveal the critical role NS2 plays in promoting viral genome replication by coordinating with FluPol.IMPORTANCEThe intrinsic mechanisms of influenza RNA polymerase (FluPol) in catalyzing viral genome transcription and replication have been largely resolved. However, the mechanisms of how transcription and replication are dynamically regulated remain elusive. We recently reported that the last amino acid of the viral NS2 protein plays a critical role in promoting viral genome replication in an influenza mini-replicon system. Here, we conducted a 20 amino acid substitution screening at the last residue 121 in virus rescue and serial passage. Our results demonstrate that the replication-promoting function of NS2 is important for virus survival and efficient multiplication. We further show evidence that NS2 and NS2-I121 adaptive mutations PA-K19E/PB1-S713N regulate virus genome replication by promoting FluPol dimerization. This work highlights the coordination between NS2 and FluPol in fulfilling efficient genome replication. It further advances our understanding of the regulation of viral RNA synthesis for influenza A virus.


Asunto(s)
Virus de la Influenza A , Proteínas no Estructurales Virales , Humanos , Sustitución de Aminoácidos , Aminoácidos/genética , ARN Polimerasas Dirigidas por ADN/genética , Virus de la Influenza A/genética , Gripe Humana/genética , Proteínas Virales/genética , Replicación Viral , Proteínas no Estructurales Virales/metabolismo
7.
Brief Bioinform ; 24(2)2023 03 19.
Artículo en Inglés | MEDLINE | ID: mdl-36754847

RESUMEN

Feature gene selection has significant impact on the performance of cell clustering in single-cell RNA sequencing (scRNA-seq) analysis. A well-rounded feature selection (FS) method should consider relevance, redundancy and complementarity of the features. Yet most existing FS methods focus on gene relevance to the cell types but neglect redundancy and complementarity, which undermines the cell clustering performance. We develop a novel computational method GeneClust to select feature genes for scRNA-seq cell clustering. GeneClust groups genes based on their expression profiles, then selects genes with the aim of maximizing relevance, minimizing redundancy and preserving complementarity. It can work as a plug-in tool for FS with any existing cell clustering method. Extensive benchmark results demonstrate that GeneClust significantly improve the clustering performance. Moreover, GeneClust can group cofunctional genes in biological process and pathway into clusters, thus providing a means of investigating gene interactions and identifying potential genes relevant to biological characteristics of the dataset. GeneClust is freely available at https://github.com/ToryDeng/scGeneClust.


Asunto(s)
Algoritmos , Perfilación de la Expresión Génica , Perfilación de la Expresión Génica/métodos , Análisis de Secuencia de ARN/métodos , Análisis de Expresión Génica de una Sola Célula , Análisis de la Célula Individual/métodos , Análisis por Conglomerados
8.
Chem Rev ; 123(11): 7081-7118, 2023 06 14.
Artículo en Inglés | MEDLINE | ID: mdl-37162476

RESUMEN

The regulation and utilization of thermal energy is increasingly important in modern society due to the growing demand for heating and cooling in applications ranging from buildings, to cooling high power electronics, and from personal thermal management to the pursuit of renewable thermal energy technologies. Over billions of years of natural selection, biological organisms have evolved unique mechanisms and delicate structures for efficient and intelligent regulation and utilization of thermal energy. These structures also provide inspiration for developing advanced thermal engineering materials and systems with extraordinary performance. In this review, we summarize research progress in biological and bioinspired thermal energy materials and technologies, including thermal regulation through insulation, radiative cooling, evaporative cooling and camouflage, and conversion and utilization of thermal energy from solar thermal radiation and biological bodies for vapor/electricity generation, temperature/infrared sensing, and communication. Emphasis is placed on introducing bioinspired principles, identifying key bioinspired structures, revealing structure-property-function relationships, and discussing promising and implementable bioinspired strategies. We also present perspectives on current challenges and outlook for future research directions. We anticipate that this review will stimulate further in-depth research in biological and bioinspired thermal energy materials and technologies, and help accelerate the growth of this emerging field.


Asunto(s)
Materiales Biomiméticos , Electrónica , Gases , Calefacción , Energía Renovable
9.
Proc Natl Acad Sci U S A ; 119(15): e2119217119, 2022 04 12.
Artículo en Inglés | MEDLINE | ID: mdl-35344399

RESUMEN

SignificanceOwls, with their largely nocturnal habits, contrast strikingly with the vast majority of diurnal birds. A new spectacular late Miocene owl skeleton from China unexpectedly preserves the oldest evidence for daytime behavior in owls. The extinct owl is a member of the clade Surniini, which contains most living diurnal owl species. Analysis of the preserved eye bones documents them as consistent with diurnal birds, and phylogenetically constrained character mapping coincides with a reconstruction of an early evolutionary reversal away from nocturnal habits in this owl group. These results support a potential Miocene origin of nonnocturnal habits in a globally distributed owl group, which may be linked to steppe habitat expansion and climatic cooling in the late Miocene.


Asunto(s)
Evolución Biológica , Estrigiformes , Animales , Conducta Animal , China , Ritmo Circadiano , Ecosistema , Fósiles , Hábitos
10.
Nano Lett ; 2024 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-38843402

RESUMEN

High-entropy alloys (HEAs) have garnered considerable attention as promising nanocatalysts for effectively utilizing Pt in catalysis toward oxygen reduction reactions due to their unique properties. Nonetheless, there is a relative dearth of attention regarding the structural evolution of HEAs in response to electrochemical conditions. In this work, we propose a thermal reduction method to synthesize high entropy nanoparticles by leveraging the confinement effect and abundant nitrogen-anchored sites provided by pyrolyzed metal-organic frameworks (MOFs). Notably, the prepared catalysts exhibit enhanced activity accompanied by structural reconstruction during electrochemical activation, approaching 1 order of magnitude higher mass activity compared to Pt/C in oxygen reduction. Atomic-scale structural characterization reveals that abundant defects and single atoms are formed during the activation process, contributing to a significant boost in the catalytic performance for oxygen reduction reactions. This study provides deep insights into surface reconstruction engineering during electrochemical operations, with practical implications for fuel cell applications.

11.
Nano Lett ; 24(7): 2157-2164, 2024 Feb 21.
Artículo en Inglés | MEDLINE | ID: mdl-38319745

RESUMEN

Carbon support is essential for electrocatalysis, but limitations remain, as carbon corrosion can lead to electrocatalyst degradation and affect the long-term durability of electrocatalysts. Here, we studied the corrosion dynamics of carbon nanotubes (CNTs) and Vulcan carbon (VC) together with platinum (Pt) nanoparticles in real time by liquid cell (LC) transmission electron microscopy (TEM). The results showed that CNTs with a high degree of graphitization exhibited higher corrosion resistance compared to VC. Furthermore, we observed that the main degradation path of Pt nanoparticles in Pt/CNTs was ripening, while in Pt/VC, it was aggregation and coalescence, which was dominated by the interactions between Pt nanoparticles and different hybridization of carbon supports. Finally, we performed an ex situ CV stability test to confirm the conclusions obtained from in situ experiments. This work provides deep insights into the corrosion mechanism of carbon-supported electrocatalysts to optimize the design of electrocatalysts with a higher durability.

12.
BMC Genomics ; 25(1): 854, 2024 Sep 12.
Artículo en Inglés | MEDLINE | ID: mdl-39266974

RESUMEN

BACKGROUND: Endemic plants are key to understanding the evolutionary history and enhancing biodiversity within their unique regions, while also offering significant economic potential. The East Asian endemic genus Corchoropsis Siebold & Zucc., classified within the subfamily Dombeyoideae of Malvaceae s.l., comprises three species. RESULTS: This study characterizes the complete plastid genomes (plastomes) of C. crenata var. crenata Siebold & Zucc. and C. crenata var. hupehensis Pamp., which range from 160,093 to 160,724 bp. These genomes contain 78 plastid protein-coding genes, 30 tRNA, and four rRNA, except for one pseudogene, infA. A total of 316 molecular diagnostic characters (MDCs) specific to Corchoropsis were identified. In addition, 91 to 92 simple sequence repeats (SSRs) in C. crenata var. crenata and 75 in C. crenata var. hupehensis were found. Moreover, 49 long repeats were identified in both the Chinese C. crenata var. crenata and C. crenata var. hupehensis, while 52 were found in the South Korean C. crenata var. crenata. Our phylogenetic analyses, based on 78 plastid protein-coding genes, reveal nine subfamilies within the Malvaceae s.l. with high support values and confirm Corchoropsis as a member of Dombeyoideae. Molecular dating suggests that Corchoropsis originated in the Oligocene, and diverged during the Miocene, influenced by the climate shift at the Eocene-Oligocene boundary. CONCLUSIONS: The research explores the evolutionary relationships between nine subfamilies within the Malvaceae s.l. family, specifically identifying the position of the Corchoropsis in the Dombeyoideae. Utilizing plastome sequences and fossil data, the study establishes that Corchoropsis first appeared during the Eocene and experienced further evolutionary divergence during the Miocene, paralleling the evolutionary patterns observed in other East Asian endemic species.


Asunto(s)
Genoma de Plastidios , Malvaceae , Filogenia , Asia Oriental , Evolución Molecular , Genómica/métodos , Repeticiones de Microsatélite , Plastidios/genética , Malvaceae/clasificación , Malvaceae/genética
13.
BMC Plant Biol ; 24(1): 350, 2024 Apr 29.
Artículo en Inglés | MEDLINE | ID: mdl-38684982

RESUMEN

BACKGROUND: Dactylicapnos is a climbing herbaceous vine, distributed from the Himalayas to southwestern China, and some of the species have important medicinal values. However, the chloroplast genomes of Dactylicapnos have never been investigated. In this study, chloroplast genomes of seven Dactylicapnos species covering all three sections and one informal group of Dactylicapnos were sequenced and assembled, and the detailed comparative analyses of the chloroplast genome structure were provided for the first time. RESULTS: The results showed that the chloroplast genomes of Dactylicapnos have a typical quadripartite structure with lengths from 172,344 bp to 176,370 bp, encoding a total of 133-140 genes, containing 88-94 protein-coding genes, 8 rRNAs and 37-39 tRNAs. 31 codons were identified as relative synonymous codon usage values greater than one in the chloroplast genome of Dactylicapnos genus based on 80 protein-coding genes. The results of the phylogenetic analysis showed that seven Dactylicapnos species can be divided into three main categories. Phylogenetic analysis revealed that seven species form three major clades which should be treated as three sections. CONCLUSIONS: This study provides the initial report of the chloroplast genomes of Dactylicapnos, their structural variation, comparative genomic and phylogenetic analysis for the first time. The results provide important genetic information for development of medical resources, species identification, infrageneric classification and diversification of Dactylicapnos.


Asunto(s)
Genoma del Cloroplasto , Filogenia , Evolución Molecular
14.
Small ; 20(2): e2305464, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37658520

RESUMEN

The utilization of layered oxides as cathode materials has significantly contributed to the advancement of the lithium-ion batteries (LIBs) with high energy density and reliability. However, the structural and interfacial instability triggered by side reactions when charged to high voltage has plagued their practical applications. Here, this work reports a novel multifunctional additive, id est, 7-Anilino-3-diethylamino-6-methyl fluoran (ADMF), which exhibits unique characteristics such as preferential adsorption, oxygen scavenging, and electropolymerization protection for high-voltage cathodes. The ADMF demonstrates the capability to ameliorate the growth of cathode-electrolyte interphase (CEI), effectively diminishing the dissolution of transition metal (TM) ions, reducing the interface impedance, and facilitating the Li+ transport. As a result, ADMF additive with side reaction-blocking ability significantly enhances the cycling stability of MCMB||NCM811 full-cells at 4.4 V and MCMB||LCO full-cells at 4.55 V, as evidenced by the 80% retention over 600 cycles and 87% retention after 750 cycles, respectively. These findings highlight the potential of the additive design strategy to modulate the CEI chemistry, representing a new paradigm with profound implications for the development of next-generation high-voltage LIBs.

15.
Nat Methods ; 18(5): 528-541, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33941937

RESUMEN

Human pluripotent stem cells (hPSCs) are capable of extensive self-renewal yet remain highly sensitive to environmental perturbations in vitro, posing challenges to their therapeutic use. There is an urgent need to advance strategies that ensure safe and robust long-term growth and functional differentiation of these cells. Here, we deployed high-throughput screening strategies to identify a small-molecule cocktail that improves viability of hPSCs and their differentiated progeny. The combination of chroman 1, emricasan, polyamines, and trans-ISRIB (CEPT) enhanced cell survival of genetically stable hPSCs by simultaneously blocking several stress mechanisms that otherwise compromise cell structure and function. CEPT provided strong improvements for several key applications in stem-cell research, including routine cell passaging, cryopreservation of pluripotent and differentiated cells, embryoid body (EB) and organoid formation, single-cell cloning, and genome editing. Thus, CEPT represents a unique poly-pharmacological strategy for comprehensive cytoprotection, providing a rationale for efficient and safe utilization of hPSCs.


Asunto(s)
Diferenciación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Crioprotectores/farmacología , Células Madre Pluripotentes/efectos de los fármacos , Polifarmacología , Técnicas de Cultivo de Célula , Criopreservación/métodos , Crioprotectores/química , Regulación de la Expresión Génica/efectos de los fármacos , Ensayos Analíticos de Alto Rendimiento , Humanos , Células Madre Pluripotentes/fisiología , Quinasas Asociadas a rho/antagonistas & inhibidores , Quinasas Asociadas a rho/genética , Quinasas Asociadas a rho/metabolismo
16.
J Virol ; 97(5): e0033723, 2023 05 31.
Artículo en Inglés | MEDLINE | ID: mdl-37166301

RESUMEN

In the influenza virus life cycle, viral RNA (vRNA) transcription (vRNA→mRNA) and replication (vRNA→cRNA→vRNA), catalyzed by the viral RNA-dependent RNA polymerase in the host cell nucleus, are delicately controlled, and the levels of the three viral RNA species display very distinct synthesis dynamics. However, the underlying mechanisms remain elusive. Here, we demonstrate that in the context of virus infection with cycloheximide treatment, the expression of viral nonstructural protein 1 (NS1) can stimulate primary transcription, while the expression of viral NS2 inhibits primary transcription. It is known that the NS1 and NS2 proteins are expressed with different timings from unspliced and spliced mRNAs of the viral NS segment. We then simulated the synthesis dynamics of NS1 and NS2 proteins during infection by dose-dependent transfection experiments in ribonucleoprotein (RNP) reconstitution systems. We found that the early-expressed NS1 protein can stimulate viral mRNA synthesis, while the late-expressed NS2 protein can inhibit mRNA synthesis but can promote vRNA synthesis in a manner highly consistent with the dynamic changes in mRNA/vRNA in the virus life cycle. Furthermore, we observed that the coexistence of sufficient NS1 and NS2, close to the status of the NS1 and NS2 levels in the late stage of infection, could boost vRNA synthesis to the highest efficiency. We also identified key functional amino acids of NS1 and NS2 involved in these regulations. Together, we propose that the stoichiometric changes in the viral NS1 and NS2 proteins during infection are responsible for the fine regulation of viral RNA transcription and replication. IMPORTANCE In order to ensure efficient multiplication, influenza virus transcribes and replicates its segmented, negative-sense viral RNA genome in highly ordered dynamics across the virus life cycle. How the virus achieves such regulation remains poorly understood. Here, we demonstrate that the stoichiometric changes in the viral NS1 and NS2 proteins during infection could be responsible for the fine regulation of the distinct dynamics of viral RNA transcription and replication. We thus propose a fundamental mechanism exploited by influenza virus to dynamically regulate the synthesis of its viral RNA through the delicate control of viral NS1 and NS2 protein expression.


Asunto(s)
Virus de la Influenza A , Orthomyxoviridae , Proteínas no Estructurales Virales , Virus de la Influenza A/metabolismo , Orthomyxoviridae/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , ARN Viral/genética , ARN Viral/metabolismo , Proteínas no Estructurales Virales/genética , Proteínas no Estructurales Virales/metabolismo , Replicación Viral/genética
17.
Phys Rev Lett ; 132(10): 104001, 2024 Mar 08.
Artículo en Inglés | MEDLINE | ID: mdl-38518322

RESUMEN

Phototaxis phenomenon is fundamental and critical for optical manipulation of micro-objects. Here, we report the size-dependent negative or positive phototaxis behaviors for microdroplets containing interfacial energy absorber flying in a laser. The critical diameters for such negative-to-positive turnover are studied through both experiments and simulation with different liquids and absorbers, which establishes the mechanism and reveals the role of both the liquid and the absorber inside the microdroplets. This study offers new insight for the manipulation of the phototaxis behavior of micro-objects, showing potential applications in optical trapping and transporting systems that involve light-microdroplet interactions.

18.
Biomacromolecules ; 25(6): 3554-3565, 2024 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-38729918

RESUMEN

Hydrogels are considered as a potential cartilage replacement material based on their structure being similar to natural cartilage, which are of great significance in repairing cartilage defects. However, it is difficult for the existing hydrogels to combine the high load bearing and low friction properties (37 °C) of cartilage through sample methods. Herein, we report a facile and new fabrication strategy to construct the PNIPAm/EYL hydrogel by using the macrophase separation of supersaturated N-isopropylacrylamide (NIPAm) monomer solution to promote the formation of liposomes from egg yolk lecithin (EYL) and asymmetric template method. The PNIPAm/EYL hydrogels possess a relatively high compressive strength (more than 12 MPa), fracture energy (9820 J/m2), good fatigue resistance, lubricating properties, and excellent biocompatibility. Compared with the PNIPAm hydrogel, the friction coefficient (COF 0.046) of PNIPAm/EYL hydrogel is reduced by 50%. More importantly, the COF (0.056) of PNIPAm/EYL hydrogel above lower critical solution temperature (LCST) does not increase significantly, exhibiting heat-tolerant lubricity. The finite element analysis further proves that PNIPAm/EYL hydrogel can effectively disperse the applied stress and dissipate energy under load conditions. This work not only provides new insights for the design of high-strength lubricating hydrogels but also lays a foundation for the treatment of cartilage injury as a substitute material.


Asunto(s)
Resinas Acrílicas , Hidrogeles , Hidrogeles/química , Resinas Acrílicas/química , Animales , Calor , Lubricantes/química , Cartílago/química , Lecitinas/química , Fuerza Compresiva , Liposomas/química , Yema de Huevo/química , Materiales Biocompatibles/química
19.
Artículo en Inglés | MEDLINE | ID: mdl-38865183

RESUMEN

A Gram-stain-negative, aerobic, non-spore-forming, nonmotile, rod-shaped, and yellow-pigmented bacterium, designated strain JXAS1T, was isolated from a freshwater sample collected from Poyang Lake in China. Phylogenetic analysis based on 16S rRNA gene sequence revealed that the isolate belonged to the genus Flavobacterium, being closest to Flavobacterium pectinovorum DSM 6368T (98.61 %). The genome size of strain JXAS1T was 4.66 Mb with DNA G+C content 35.7 mol%. The average nucleotide identity and in silico DNA-DNA hybridization values between strain JXAS1T and its closest relatives were below the threshold values of 95 and 70 %, respectively. The strain contained menaquinone 6 (MK-6) as the predominant menaquinone and the major polar lipids were phosphatidylethanolamine, one unidentified glycolipid, and one unidentified polar lipid. The major fatty acids (>5 %) were iso-C15 : 0, summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c), C15 : 0, iso-C17 : 0 3OH, iso-C15 : 0 3OH, and summed feature 9 (iso-C17 : 1 ω9c and/or 10-methyl C16 : 0). Based on phylogenetic, genotypic, and phenotypic evidence, the isolated strain represents a new species in the genus Flavobacterium, and the name Flavobacterium poyangense is proposed. The type strain is JXAS1T (=GDMCC 1.1378T=KCTC 62719T).


Asunto(s)
Técnicas de Tipificación Bacteriana , Composición de Base , ADN Bacteriano , Ácidos Grasos , Flavobacterium , Lagos , Hibridación de Ácido Nucleico , Filogenia , ARN Ribosómico 16S , Análisis de Secuencia de ADN , Vitamina K 2 , Flavobacterium/genética , Flavobacterium/clasificación , Flavobacterium/aislamiento & purificación , Lagos/microbiología , China , ARN Ribosómico 16S/genética , Vitamina K 2/análogos & derivados , Vitamina K 2/análisis , ADN Bacteriano/genética , Fosfatidiletanolaminas , Glucolípidos/análisis , Fosfolípidos/análisis
20.
J Surg Res ; 296: 182-188, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38277955

RESUMEN

INTRODUCTION: Anastomotic leakage post-esophagectomy remains a significant challenge. Despite the use of both mechanical and manual anastomosis, leakage rates remain high. This study evaluated the effectiveness of the manual layered insertion anastomosis technique in addressing this issue. METHODS: A retrospective analysis was conducted on patients who underwent this technique from September 2020 to December 2021. The process involved thoracoscopic release of the esophagus, mediastinal lymph node dissection, laparoscopic stomach release, and its transformation into a tube. The latter was then guided to the neck for anastomosis. The posterior anastomotic wall was reshaped in the neck first for optimal insertion, followed by layered suturing with the gastric conduit. The anterior wall was subsequently sutured and repositioned into the chest. RESULTS: The study included 56 patients (51 men, five women, mean age 65.4 y), with nine having undergone neoadjuvant therapy. All received minimally invasive esophagectomy. Average intraoperative blood loss was 79.8 mL, operation time averaged 331 min, and feeding resumed after an average of 6.3 d. No anastomotic leakages were reported, with reduced incidences of anastomotic stenosis and gastric acid reflux compared to previous studies. CONCLUSIONS: The manual layered insertion anastomosis technique may reduce anastomotic leakage and associated complications, improving the efficacy of esophagectomy, which may improve postoperative results and patient quality of life, suggesting the method's potential suitability for wider clinical application.


Asunto(s)
Fuga Anastomótica , Neoplasias Esofágicas , Masculino , Humanos , Femenino , Anciano , Fuga Anastomótica/etiología , Fuga Anastomótica/prevención & control , Fuga Anastomótica/cirugía , Esofagectomía/efectos adversos , Esofagectomía/métodos , Neoplasias Esofágicas/cirugía , Neoplasias Esofágicas/complicaciones , Estudios Retrospectivos , Calidad de Vida , Anastomosis Quirúrgica/efectos adversos , Anastomosis Quirúrgica/métodos , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/prevención & control , Complicaciones Posoperatorias/cirugía
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