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1.
Cell Death Differ ; 2024 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-38605168

RESUMO

Myddosome is an oligomeric complex required for the transmission of inflammatory signals from TLR/IL1Rs and consists of MyD88 and IRAK family kinases. However, the molecular basis for the self-assemble of Myddosome proteins and regulation of intracellular signaling remains poorly understood. Here, we identify OTUD5 acts as an essential regulator for MyD88 oligomerization and Myddosome formation. OTUD5 directly interacts with MyD88 and cleaves its K11-linked polyubiquitin chains at Lys95, Lys231 and Lys250. This polyubiquitin cleavage enhances MyD88 oligomerization after LPS stimulation, which subsequently promotes the recruitment of downstream IRAK4 and IRAK2 to form Myddosome and the activation of NF-κB and MAPK signaling and production of inflammatory cytokines. Consistently, Otud5-deficient mice are less susceptible to LPS- and CLP-induced sepsis. Taken together, our findings reveal a positive regulatory role of OTUD5 in MyD88 oligomerization and Myddosome formation, which provides new sights into the treatment of inflammatory diseases.

2.
Lupus ; : 9612033241243175, 2024 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-38634475

RESUMO

AIM: This study aimed to investigate the expression of H19 and its possible molecular mechanism in systemic lupus erythematosus (SLE). METHODS: The expression of H19 and miR-19b in serum and peripheral blood mononuclear cells (PBMCs) were detected by reverse transcription quantitative polymerase chain reaction (RT-qPCR). Receiver operator characteristic (ROC) curve was constructed to evaluate the diagnostic value of serum H19 in SLE. Pearson correlation coefficient was used to analyze the correlation between serum levels of H19 and miR-19b. Flow cytometry and Cell counting kit-8 (CCK-8) assay were performed to detect cell apoptosis and viability. The levels of pro-inflammatory and anti-inflammatory factors were measured by enzyme-linked immunosorbent assay (ELISA). Luciferase reporter gene assay was conducted to verify the interaction between H19 and miR-19b. RESULTS: The expression of H19 and miR-19b in SLE group were up-regulated and down-regulated, respectively. Serum H19 has certain clinical diagnostic value in SLE. In in vitro studies, overexpression of H19 can significantly inhibit the viability of PBMCs and promote apoptosis and inflammatory response of PBMCs by interacting with miR-19b. CONCLUSIONS: The expression of H19 is upregulated in patients with SLE and plays a role in cell function and inflammation by targeting miR-19b in PBMCs, which may be one of the pathological mechanisms of SLE.

3.
APMIS ; 2024 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-38644557

RESUMO

LncRNAs play an important role in autoimmune diseases. The purpose of this study was to explore the role of lncRNA SNHG1 in systemic lupus erythematosus (SLE), and laid a theoretical foundation for the study of SLE. The basic clinical information of all subjects was first collected for statistical analysis, and SNHG1 expression in the serum of all subjects was detected by RT-qPCR. The value of SNHG1 in the diagnosis of SLE was assessed by ROC. The correlation between SNHG1 and each blood sample index was analyzed by Pearson correlation analysis. The role of SNHG1 in primary peripheral blood mononuclear cells (PBMCs) apoptosis was explored. SNHG1 expression is relatively upregulated in patients with SLE compared to healthy people. SNHG1 expression was positively correlated with SLEDAI score, IgG, CRP, and ESR, and negatively correlated with C3 and C4. ROC indicated that SNHG1 has the potential to assist in the diagnosis of SLE. PBMCs apoptosis in SLE was higher than that in control group, the knockdown and overexpression of SNHG1 could correspondingly inhibit and promote PBMCs apoptosis. SNHG1 has the potential to be a diagnosis marker for SLE and may be involved in regulating PBMCs apoptosis.

4.
Science ; 383(6687): eado5304, 2024 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-38452080

RESUMO

There is an increasing need for the world to be prepared for a myriad of shocks and hazards. Many parts of the world are already experiencing climate change-related extreme weather events such as heatwaves, floods, and wildfires, which are projected to worsen in both intensity and frequency. The World Health Organization (WHO) also warns of "Disease X"-a term that includes both known and unknown infectious diseases capable of posing considerable global public health risks.

5.
Drug Resist Updat ; 73: 101036, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38183874

RESUMO

BACKGROUND: Extended-spectrum ß-lactamases (ESBLs) producing bacteria have spread worldwide and become a global public health concern. Plasmid-mediated transfer of ESBLs is an important route for resistance acquisition. METHODS: We collected 1345 complete sequences of plasmids containing CTX-Ms from public database. The global transmission pattern of plasmids and evolutionary dynamics of CTX-Ms have been inferred. We applied the pan-genome clustering based on plasmid genomes and evolution analysis to demonstrate the transmission events. FINDINGS: Totally, 48 CTX-Ms genotypes and 186 incompatible types of plasmids were identified. The geographical distribution of CTX-Ms showed significant differences across countries and continents. CTX-M-14 and CTX-M-55 were found to be the dominant genotypes in Asia, while CTX-M-1 played a leading role in Europe. The plasmids can be divided into 12 lineages, some of which forming distinct geographical clusters in Asia and Europe, while others forming hybrid populations. The Inc types of plasmids are lineage-specific, with the CTX-M-1_IncI1-I (Alpha) and CTX-M-65_IncFII (pHN7A8)/R being the dominant patterns of cross-host and cross-regional transmission. The IncI-I (Alpha) plasmids with the highest number, were presumed to form communication groups in Europe-Asia and Asia-America-Oceania, showing the transmission model as global dissemination and regional microevolution. Meanwhile, the main kinetic elements of blaCTX-Ms showed genotypic preferences. ISEcpl and IS26 were most frequently involved in the transfer of CTX-M-14 and CTX-M-65, respectively. IS15 has become a crucial participant in mediating the dissemination of blaCTX-Ms. Interestingly, blaTEM and blaCTX-Ms often coexisted in the same transposable unit. Furthermore, antibiotic resistance genes associated with aminoglycosides, sulfonamides and cephalosporins showed a relatively high frequency of synergistic effects with CTX-Ms. CONCLUSIONS: We recognized the dominant blaCTX-Ms and mainstream plasmids of different continents. The results of this study provide support for a more effective response to the risks associated with the evolution of blaCTX-Ms-bearing plasmids, and lay the foundation for genotype-specific epidemiological surveillance of resistance, which are of important public health implications.


Assuntos
Antibacterianos , Escherichia coli , Humanos , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , beta-Lactamases/genética , Escherichia coli/genética , Genômica , Plasmídeos/genética
6.
Appl Environ Microbiol ; 90(2): e0137423, 2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38251894

RESUMO

The acyl-homoserine lactones (AHLs)-mediated LuxI/LuxR quorum sensing (QS) system orchestrates diverse bacterial behaviors in response to changes in population density. The role of the BjaI/BjaR1 QS system in Bradyrhizobium diazoefficiens USDA 110, which shares homology with LuxI/LuxR, remains elusive during symbiotic interaction with soybean. Here this genetic system in wild-type (WT) bacteria residing inside nodules exhibited significantly reduced activity compared to free-living cells, potentially attributed to soybean-mediated suppression. The deletion mutant strain ΔbjaR1 showed significantly enhanced nodulation induction and nitrogen fixation ability. Nevertheless, its ultimate symbiotic outcome (plant dry weight) in soybeans was compromised. Furthermore, comparative analysis of the transcriptome, proteome, and promoter activity revealed that the inactivation of BjaR1 systematically activated and inhibited genomic modules associated with nodulation and nitrogen metabolism. The former appeared to be linked to a significant decrease in the expression of NodD2, a key cell-density-dependent repressor of nodulation genes, while the latter conferred bacterial growth and nitrogen fixation insensitivity to environmental nitrogen. In addition, BjaR1 exerted a positive influence on the transcription of multiple genes involved in a so-called central intermediate metabolism within the nodule. In conclusion, our findings highlight the crucial role of the BjaI/BjaR1 QS circuit in positively regulating bacterial nitrogen metabolism and emphasize the significance of the soybean-mediated suppression of this genetic system for promoting efficient symbiotic nitrogen fixation by B. diazoefficiens.IMPORTANCEThe present study demonstrates, for the first time, that the BjaI/BjaR1 QS system of Bradyrhizobium diazoefficiens has a significant impact on its nodulation and nitrogen fixation capability in soybean by positively regulating NodD2 expression and bacterial nitrogen metabolism. Moreover, it provides novel insights into the importance of suppressing the activity of this QS circuit by the soybean host plant in establishing an efficient mutual relationship between the two symbiotic partners. This research expands our understanding of legumes' role in modulating symbiotic nitrogen fixation through rhizobial QS-mediated metabolic functioning, thereby deepening our comprehension of symbiotic coevolution theory. In addition, these findings may hold great promise for developing quorum quenching technology in agriculture.


Assuntos
Bradyrhizobium , Soja , Percepção de Quorum/fisiologia , Fixação de Nitrogênio , Simbiose/fisiologia , Bradyrhizobium/genética , Bradyrhizobium/metabolismo , Transativadores/metabolismo , Nitrogênio/metabolismo
8.
J Antimicrob Chemother ; 79(1): 27-35, 2024 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-37944030

RESUMO

BACKGROUND: The spread of antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) among humans and food-producing animals has been widely reported. However, the transmission routes and associated risk factors remain incompletely understood. METHODS: Here, we used commensal Escherichia coli bacteria strains from faeces of pigs and local citizens [HEG: high exposure group (pig breeders, butchers or restaurant chefs) and LEG: low exposure group (other occupations)] to explore the dynamics of ARB and ARG transmission between animals and humans. RESULTS: Most ARGs (96%) present in pigs were shared with humans. Carriage rates of the shared ARGs suggest two transmission patterns among pigs, the HEG and LEG: one pattern was highest in pigs, gradually decreasing in the HEG and LEG (e.g. floR and cmlA1); the other pattern was increasing from pigs to the HEG but then decreasing in the LEG (e.g. mcr-1.1). Carriage rates of the HEG were higher than in the LEG in both patterns, implicating the HEG as a crucial medium in transmitting ARB and ARGs between food-producing animals and humans. Moreover, frequent inter/intragroup transmission via strains, plasmids and/or mobile elements was evident. Carriage of mcr-1.1 on human-gut-prevalent plasmids possibly promoted its enrichment in the HEG. CONCLUSIONS: The HEG is a crucial factor in transmitting ARB and ARGs between food-producing animals and humans. Rational measures to contain the risks of occupational exposure are urgently needed to keep dissemination of antibiotic resistance in check and safeguard public health.


Assuntos
Genes Bacterianos , Exposição Ocupacional , Humanos , Suínos , Animais , Antagonistas de Receptores de Angiotensina , Inibidores da Enzima Conversora de Angiotensina , Resistência Microbiana a Medicamentos , Escherichia coli/genética , Antibacterianos/farmacologia
9.
Appl Opt ; 62(33): 8749-8759, 2023 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-38038020

RESUMO

Since there are usually multiple layers present in a real-world sea fog environment, and because previous studies have tended to analyze sea fog as a single layer rather than as refined layered sea fog, this paper splits sea fog into two categories: water fog and salt fog double-layer environments. By adjusting the optical thickness of the two layers of media, we may investigate the issue of the law governing the transmission of polarized light. In this paper, the analysis is mainly carried out through a simulation and experimental tests. The simulation portion is based mostly on the improved layered Monte Carlo approach, which builds a simulation model more appropriate for multilayer non-spherical media by using the accumulation principle to determine the scattering and transmission properties between layers. The tests are conducted by altering the double-layer medium's optical thickness, incoming wavelength, and polarization state, and then getting the polarization information of visible light after transmission through the complicated environment. The findings demonstrate that the optical thickness of the sea fog double-layer media affects polarized light transmission in a non-negligible way. Longer wavelength polarized light may keep polarization information better as the optical thickness increases, and circularly polarized light has polarization-preserving properties that are superior to linearly polarized light. By contrasting the simulation findings with the experimental data, the consistency of the two conclusions is confirmed, and the study offers a helpful resource for the transmission of polarized light in the sea fog environment.

10.
J Glob Antimicrob Resist ; 36: 181-187, 2023 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-38072240

RESUMO

OBJECTIVES: Recently, blaCTX-Ms have become the dominant ESBLs for E. coli strains worldwide. We aim to provide a systematic study on the relationships between sequence types (STs), clinical origins, and the blaCTX-Ms genotypes of E. coli strains. METHODS: Totally, 1005 complete sequences of clinical E. coli were collected from NCBI. Multilocus sequence typing (MLST) and antibiotic resistance genes screening were performed. RESULTS: Faeces (26.27%), urine (16.02%), and blood (8.26%) were shown to be the main sources of clinical E. coli isolates. The isolates belong to 153 STs and 26 clonal complexes (CCs). The most prevalent STs were ST2 (11.3%), ST43 (8.6%), and ST8 (5.7%). The positive rate for blaCTX-Ms was 34.7%. Different samples showed significantly different blaCTX-Ms positive rates (P<0.05). The main genotypes were blaCTX-M-55-like (47.6%), blaCTX-M-1-like (31.8%), and blaCTX-M-2-like (22.1%). The majority of ST2 strains had blaCTX-M-55-like genes. In ST8 strains, there was a homogeneous distribution of blaCTX-M-9, blaCTX-M-65, blaCTX-M-55, blaCTX-M-2, and blaCTX-M-1. Only ST43 strains exhibited the presence of blaCTX-M-79. The blaCTX-Ms showed a pattern of cross-continental transmission with intra-regional spread. Among the 349 blaCTX-Ms-producing E. coli strains, 148 strains also carried carbapenem resistance genes, including blaNDM (119, 34.1%), blaKPC (16, 4.6%), blaOXA-48 (9, 2.6%) and blaIMP (4, 1.1%). Also, 81 strains carried the mcr gene (23.2%). CONCLUSIONS: E. coli has become increasingly rich in blaCTX-Ms genotypes. Our findings about the connection between E. coli STs and blaCTX-Ms can be utilized to identify E. coli strains with high potential to spread drug resistance in the future.

11.
Proc Natl Acad Sci U S A ; 120(52): e2308853120, 2023 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-38109536

RESUMO

The enzyme cyclic GMP-AMP synthase (cGAS) is a key sensor for detecting misplaced double-stranded DNA (dsDNA) of genomic, mitochondrial, and microbial origin. It synthesizes 2'3'-cGAMP, which in turn activates the stimulator of interferon genes pathway, leading to the initiation of innate immune responses. Here, we identified Listerin as a negative regulator of cGAS-mediated innate immune response. We found that Listerin interacts with cGAS on endosomes and promotes its K63-linked ubiquitination through recruitment of the E3 ligase TRIM27. The polyubiquitinated cGAS is then recognized by the endosomal sorting complexes required for transport machinery and sorted into endosomes for degradation. Listerin deficiency enhances the innate antiviral response to herpes simplex virus 1 infection. Genetic deletion of Listerin also deteriorates the neuroinflammation and the ALS disease progress in an ALS mice model; overexpression of Listerin can robustly ameliorate disease progression in ALS mice. Thus, our work uncovers a mechanism for cGAS regulation and suggests that Listerin may be a promising therapeutic target for ALS disease.


Assuntos
Esclerose Amiotrófica Lateral , Ubiquitina-Proteína Ligases , Animais , Camundongos , Esclerose Amiotrófica Lateral/tratamento farmacológico , Esclerose Amiotrófica Lateral/imunologia , Complexos Endossomais de Distribuição Requeridos para Transporte/metabolismo , Imunidade Inata/genética , Nucleotidiltransferases/metabolismo , Proteólise , Transdução de Sinais/fisiologia , Modelos Animais de Doenças , Ubiquitina-Proteína Ligases/antagonistas & inibidores , Ubiquitina-Proteína Ligases/imunologia , Ubiquitina-Proteína Ligases/metabolismo
12.
Microorganisms ; 11(12)2023 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-38137980

RESUMO

A rising incidence of clinical infections has been caused by Kluyvera, a significant opportunistic pathogen. Meanwhile, Kluyvera acts as an important reservoir of blaCTX-Ms, which are the dominant genes of class A extended-spectrum ß-lactamases (ESBLs). In this work, 60 strains of Kluyvera were subjected to phylogenetic relationship reconstruction, antimicrobial susceptibility testing, and antibiotic resistance genes prediction. All mature blaCTX-Ms were gathered to perform subgroup reclassification. The findings demonstrate that Kluyvera has a large gene pool with significant genetic flexibility. Notably, 25% of strains showed simultaneous detection of ESBLs and carbapenem resistance genes. The genotypes of fourteen novel blaCTX-Ms were identified. A new subgroup classification approach for blaCTX-Ms was defined by using 20 amino acid site variants, which could split blaCTX-Ms into 10 subgroups. The results of the subgroup division were consistent with the phylogenetic clustering. More significantly, we proposed a novel blaCTX-M subgroup, KLUS, that is chromosomally encoded in K. sichuanensis and the new species put forward in this study, showing amino acid differences from the currently known sequences. Cloning and transformation tests demonstrated that the recipient bacteria had a robust phenotype of cefotaxime resistance. Closely related Kluyvera species had blaCTX-Ms in the same subgroup. Our research lays the groundwork for a deeper comprehension of Kluyvera and emphasizes how important a blaCTX-M reservoir it is. We provide an update on blaCTX-M subgroups reclassification from the aspects of phylogenetic relationship, amino acid differences, and the new subgroup KLUS, which needs to be strengthen monitored due to its strong resistance phenotype to cefotaxime.

13.
Science ; 382(6670): eadl1522, 2023 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-37917708

RESUMO

Cities are receiving increasing attention in global assessments over the past two decades. It has been a hard-fought shift for many urban researchers, but the biggest impetus stems from the pivotal role cities play both as drivers and bearers of impacts of global environmental change. Notably, cities are home to 57% of the world's population, responsible for over 70% of global consumption-related carbon emissions and contributing to over 80% of gross domestic product in many countries. Within the Intergovernmental Panel for Climate Change (IPCC), cities have shifted from the periphery to center stage, which culminated in the decision to produce a dedicated special report on cities in its next assessment cycle. Expectations are high that this upcoming special report will substantially enhance awareness, shape policy, and catalyze actions across mitigation and adaptation within cities and beyond. With the scoping process expected to begin in early 2024, now is a critical time to consider what should be the focus of the upcoming special report.

14.
Drug Resist Updat ; 71: 101006, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37703625

RESUMO

Polymyxins are the last line of defense in infections caused by multidrug-resistant Gram-negative bacteria. The chromosomal EptA in Aeromonas genus was defined as a nonmobile colistin resistance determinant 3 (NMCR-3). A total of 14 NMCR-3 genotypes were identified. The global prevalence of Aeromonas-borne NMCRs and MCRs indicates an increasing trend from 1968 to 2022. And an index of resistance risk, i.e, the ratio of η = MCR/NMCR, was proposed to evaluate the propagation potential of NMCR-3. The colistin resistance in North America and Europe faced a high risk of increasing incidence of MCR since large proportions of NMCR-3 variants disseminated from Aeromonas sources. We concluded that NMCR-3 variants act natural progenitors for MCR-3/5/7, and the future MCR variant(s) will most likely be MCR-5 or MCR-7, which is also an early warning of next MCR(s) emerging in Aeromonas.


Assuntos
Aeromonas , Colistina , Humanos , Colistina/farmacologia , Aeromonas/genética , Genótipo
15.
Emerg Microbes Infect ; 12(2): 2252522, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37616379

RESUMO

Vibrio metschnikovii is an emergent pathogen that causes human infections which may be fatal. However, the phylogenetic characteristics and pathogenicity determinants of V. metschnikovii are poorly understood. Here, the whole-genome features of 103 V. metschnikovii strains isolated from different sources are described. On phylogenetic analysis V. metschnikovii populations could be divided into two major lineages, defined as lineage 1 (L1) and 2 (L2), of which L1 was more likely to be associated with human activity. Meanwhile, we defined 29 V. metschnikovii O-genotypes (VMOg, named VMOg1-VMOg29) by analysis of the O-antigen biosynthesis gene clusters (O-AGCs). Most VMOgs (VMOg1 to VMOg28) were assembled by the Wzx/Wzy pathway, while only VMOg29 used the ABC transporter pathway. Based on the sequence variation of the wzx and wzt genes, an in silico O-genotyping system for V. metschnikovii was developed. Furthermore, nineteen virulence-associated factors involving 161 genes were identified within the V. metschnikovii genomes, including genes encoding motility, adherence, toxins, and secretion systems. In particular, V. metschnikovii was found to promote a high level of cytotoxicity through the synergistic action of the lateral flagella and T6SS. The lateral flagellar-associated flhA gene played an important role in the adhesion and colonization of V. metschnikovii during the early stages of infection. Overall, this study provides an enhanced understanding of the genomic evolution, O-AGCs diversity, and potential pathogenic features of V. metschnikovii.


Assuntos
Antígenos O , Vibrio , Humanos , Filogenia , Virulência , Vibrio/genética , Fatores de Virulência/genética
16.
Microorganisms ; 11(5)2023 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-37317299

RESUMO

An increase in the carbapenem-hydrolyzing capacity of class D ß-lactamase has been observed in strains of multiple species, posing a significant challenge to the control of antibiotic resistance. In this study, we aimed to investigate the genetic diversity and phylogenetic characteristics of new blaOXA-48-like variants derived from Shewanella xiamenensis. Three ertapenem-non-susceptible S. xiamenensis strains were identified, one isolated from the blood sample of an inpatient, the other two isolated from the aquatic environment. Phenotypic characterization confirmed that the strains were carbapenemase producers and exhibited antimicrobial resistance patterns to ertapenem, with some showing lower susceptibility to imipenem, chloramphenicol, ciprofloxacin, and tetracycline. No significant resistance to cephalosporins was observed. Sequence analysis revealed that one strain harbored blaOXA-181 and the other two strains harbored blaOXA-48-like genes, with open reading frame (ORF) similarities with blaOXA-48 ranging from 98.49% to 99.62%. The two novel blaOXA-48-like genes, named blaOXA-1038 and blaOXA-1039, respectively, were cloned and expressed in E. coli. The three OXA-48-like enzymes demonstrated significant hydrolysis activity against meropenem, and the classical ß-lactamase inhibitor had no significant inhibitory effect. In conclusion, this study demonstrated the diversity of the blaOXA gene and highlighted the emergence of novel OXA carbapenemases in S. xiamenensis. Further attention to S. xiamenensis and OXA carbapenemases is recommended for the effective prevention and control of antibiotic-resistant bacteria.

17.
NPJ Urban Sustain ; 3(1): 32, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37323541

RESUMO

There is a growing recognition that responding to climate change necessitates urban adaptation. We sketch a transdisciplinary research effort, arguing that actionable research on urban adaptation needs to recognize the nature of cities as social networks embedded in physical space. Given the pace, scale and socioeconomic outcomes of urbanization in the Global South, the specificities and history of its cities must be central to the study of how well-known agglomeration effects can facilitate adaptation. The proposed effort calls for the co-creation of knowledge involving scientists and stakeholders, especially those historically excluded from the design and implementation of urban development policies.

18.
Appl Opt ; 62(10): 2510-2521, 2023 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-37132799

RESUMO

True natural environments are more complex, and light travels through non-spherical particle media, which can affect the transmission of light. The medium environment of non-spherical particles is more common than that of spherical particles, and some studies have shown that there are differences between spherical and non-spherical particles in polarized light transmission. Therefore, the use of spherical particles instead of non-spherical particles will result in great error. In view of this feature, this paper samples the scattering angle based on the Monte Carlo method, and then constructs a simulation model of a random sampling fitting phase function suitable for ellipsoidal particles. In this study, yeast spheroids and Ganoderma lucidum spores were prepared. The effects of different polarization states and optical thicknesses on the transmission of polarized light at three wavelengths were investigated using ellipsoidal particles with a ratio of 1.5 transverse to vertical axes. The results show that when the concentration of the medium environment increases, the polarized lights of different states all show obvious depolarization, but circularly polarized light has better polarization-preserving characteristics than linearly polarized light, and polarized light with larger wavelengths also shows more stable optical properties. When yeast and Ganoderma lucidum spores were used as the transport medium, the degree of polarization of polarized light had the same trend. However, the equal volume radius of yeast particles is smaller than that of Ganoderma lucidum spores, so when the laser is in the yeast particle medium, the polarization-maintaining property of polarized light is superior. This study provides an effective reference for the variation of polarized light transmission in an atmospheric transmission environment with heavy smoke.

19.
Nature ; 619(7968): 102-111, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37258676

RESUMO

The stability and resilience of the Earth system and human well-being are inseparably linked1-3, yet their interdependencies are generally under-recognized; consequently, they are often treated independently4,5. Here, we use modelling and literature assessment to quantify safe and just Earth system boundaries (ESBs) for climate, the biosphere, water and nutrient cycles, and aerosols at global and subglobal scales. We propose ESBs for maintaining the resilience and stability of the Earth system (safe ESBs) and minimizing exposure to significant harm to humans from Earth system change (a necessary but not sufficient condition for justice)4. The stricter of the safe or just boundaries sets the integrated safe and just ESB. Our findings show that justice considerations constrain the integrated ESBs more than safety considerations for climate and atmospheric aerosol loading. Seven of eight globally quantified safe and just ESBs and at least two regional safe and just ESBs in over half of global land area are already exceeded. We propose that our assessment provides a quantitative foundation for safeguarding the global commons for all people now and into the future.


Assuntos
Mudança Climática , Planeta Terra , Justiça Ambiental , Internacionalidade , Segurança , Humanos , Aerossóis/metabolismo , Clima , Água/metabolismo , Nutrientes/metabolismo , Segurança/legislação & jurisprudência , Segurança/normas
20.
Genome Biol ; 24(1): 90, 2023 04 24.
Artigo em Inglês | MEDLINE | ID: mdl-37095580

RESUMO

BACKGROUND: DNA double-strand breaks (DSBs) are among the most deleterious DNA lesions, and they can cause cancer if improperly repaired. Recent chromosome conformation capture techniques, such as Hi-C, have enabled the identification of relationships between the 3D chromatin structure and DSBs, but little is known about how to explain these relationships, especially from global contact maps, or their contributions to DSB formation. RESULTS: Here, we propose a framework that integrates graph neural network (GNN) to unravel the relationship between 3D chromatin structure and DSBs using an advanced interpretable technique GNNExplainer. We identify a new chromatin structural unit named the DNA fragility-associated chromatin interaction network (FaCIN). FaCIN is a bottleneck-like structure, and it helps to reveal a universal form of how the fragility of a piece of DNA might be affected by the whole genome through chromatin interactions. Moreover, we demonstrate that neck interactions in FaCIN can serve as chromatin structural determinants of DSB formation. CONCLUSIONS: Our study provides a more systematic and refined view enabling a better understanding of the mechanisms of DSB formation under the context of the 3D genome.


Assuntos
Cromatina , Reparo do DNA , DNA , Quebras de DNA de Cadeia Dupla , Proteínas de Ligação a DNA/metabolismo
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