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Topological domains in ferroelectrics1-5 have received much attention recently owing to their novel functionalities and potential applications6,7 in electronic devices. So far, however, such topological polar structures have been observed only in superlattices grown on oxide substrates, which limits their applications in silicon-based electronics. Here we report the realization of room-temperature skyrmion-like polar nanodomains in lead titanate/strontium titanate bilayers transferred onto silicon. Moreover, an external electric field can reversibly switch these nanodomains into the other type of polar texture, which substantially modifies their resistive behaviours. The polar-configuration-modulated resistance is ascribed to the distinct band bending and charge carrier distribution in the core of the two types of polar texture. The integration of high-density (more than 200 gigabits per square inch) switchable skyrmion-like polar nanodomains on silicon may enable non-volatile memory applications using topological polar structures in oxides.
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Accurate measurement of the dielectric functions of emerging optical materials is of great importance for advancements in solid-state physics. However, it is rather challenging since most materials are highly active in ambient conditions, which makes in-situ measurements tough. Here, we report an analytical ellipsometry method (AEM) accessible in ambient conditions for measuring the dielectric functions of chemically reactive materials under bulk encapsulation. Taking the highly pursued low-loss plasmonic materials, such as sodium films, as an example, the effectiveness and measuring errors of the proposed AEM have been systematically demonstrated. This verifies AEM's superiority in overcoming the limitations of traditional spectroscopic ellipsometry methodologies, which include complex multi-parameter fitting procedures and the issue of potentially unphysical results, especially in newly developed low-loss materials. Our results will provide a generalized and convenient ellipsometric measurement strategy for sensitive materials under bulk encapsulation.
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The pine wood nematode, Bursaphelenchus xylophilus, is the causal agent of pine wilt disease. Accurately differentiating B. xylophilus from other nematodes species, especially its related species B. mucronatus, is important for pine wood nematode detection. Thus, we attempted to identify a specific protein in the pine wood nematode using proteomics technology. Here, we compared the proteomes of B. xylophilus and B. mucronatus using Two-dimensional gel electrophoresis (2-DE) and matrix-assisted laser desorption/ionization -time-of-flight/time-of-flight (MALDI-TOF/TOF-MS) technologies. In total, 15 highly expressed proteins were identified in B. xylophilus compared with B. mucronatus. Subsequently, the specificity of the proteins identified was confirmed by PCR using the genomic DNA of other nematode species. Finally, a gene encoding a specific protein (Bx-Prx) was obtained. This gene was cloned and expressed in E. coli. The in situ hybridisation pattern of Bx-Prx showed that it was expressed strongly in the tail of B. xylophilus. RNAi was used to assess the function of Bx-Prx, the results indicated that the gene was associated with the reproduction and pathogenicity of B. xylophilus. This discovery provides fundamental information for identifying B. xylophilus via a molecular approach. Moreover, the purified recombinant protein has potential as a candidate diagnostic antigen of pine wilt disease, which may lead to a new immunological detection method for the pine wood nematode.
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Peroxirredoxinas/metabolismo , Tylenchida/metabolismo , Animais , Eletroforese em Gel Bidimensional , Escherichia coli/metabolismo , Hibridização In Situ , Peroxirredoxinas/antagonistas & inibidores , Peroxirredoxinas/genética , Pinus/crescimento & desenvolvimento , Pinus/parasitologia , Doenças das Plantas/parasitologia , Proteoma/análise , Interferência de RNA , RNA de Cadeia Dupla/genética , RNA de Cadeia Dupla/metabolismo , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/farmacologia , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por MatrizRESUMO
Kadsura coccinea is a medicinal plant from the Schisandraceae family that is native to China and has great pharmacological potential due to its lignans. However, there are significant knowledge gaps regarding the genetic and molecular mechanisms of lignans. We used transcriptome sequencing technology to analyze root, stem, and leaf samples, focusing on the identification and phylogenetic analysis of Cytochrome P450 (CYP) genes. High-quality data containing 158,385 transcripts and 68,978 unigenes were obtained. In addition, 36,293 unigenes in at least one database, and 23,335 across five databases (Nr, KEGG, KOG, TrEMBL, and SwissProt) were successfully annotated. The KEGG pathway classification and annotation of these unigenes identified 10,825 categorized into major metabolic pathways, notably phenylpropanoid biosynthesis, which is essential for lignan synthesis. A key focus was the identification and phylogenetic analysis of 233 Cytochrome P450 (CYP) genes, revealing their distribution across 38 families in eight clans, with roots showing specific CYP gene expression patterns indicative of their role in lignan biosynthesis. Sequence alignment identified 22 homologous single genes of these CYPs, with 6 homologous genes of CYP719As and 1 of CYP81Qs highly expressed in roots. Our study significantly advances the understanding of the biosynthesis of dibenzocyclooctadiene lignans, offering valuable insights for future pharmacological research and development.
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Kadsura , Lignanas , Humanos , Transcriptoma/genética , Filogenia , Perfilação da Expressão Gênica , Sistema Enzimático do Citocromo P-450/genética , Lignanas/farmacologiaRESUMO
Hot air (HA) drying caused quality damage of grains with long treatment time. Radio frequency (RF) heating as an emerging technology was applied to improve drying quality of cereals effectively. The effects of HA-RF drying (50 °C, 70 °C, 90 °C) of corn kernels on the morphology, structure, and physicochemical properties of starch were investigated and compared with HA drying. The surface of treated starch became rough, along with fragments and pores. Drying treatments increased the amylose content from 10.59 % to 23.88 % and the residual protein content of starch from 0.58 % to 1.23 %, and reduced the crystallinity from 31.95 % to 17.15 % and short-range order structures of starch from 0.918 to 0.868. The change of structures in turn resulted in the increase of pasting viscosity, gelatinization temperature, storage modulus and loss modulus. Furthermore, the HA-RF dried starch displayed stronger thermal stability, higher gelatinization degree and better gelation properties than the HA-treated starch at the same temperature. The data proved that the synergistic effects of HA and RF were more effective in modulating the starch structure and improving the functional characteristics of corn starch. This paper would like to provide potential reference for better application of HA-RF technologies to corn.
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Temperatura Alta , Amido , Zea mays , Zea mays/química , Amido/química , Amilose/química , Ondas de Rádio , Viscosidade , Dessecação/métodos , ArRESUMO
An increasing body of evidence suggests that the state of hyperalgesia could be socially transferred from one individual to another through a brief empathetic social contact. However, how the social transfer of pain develops during social contact is not well-known. Utilizing a well-established mouse model, the present study aims to study the functional role of visual and olfactory cues in the development of socially-transferred mechanical hypersensitivity. Behavioral tests demonstrated that one hour of brief social contact with a conspecific mouse injected with complete Freund's adjuvant (CFA) was both sufficient and necessary for developing socially-transferred mechanical hypersensitivity. One hour of social contact with visual deprivation could not prevent the development of socially-transferred mechanical hypersensitivity, and screen observation of a CFA cagemate was not sufficient to develop socially-transferred mechanical hypersensitivity in bystanders. Methimazole-induced olfactory deprivation, a compound with reversible toxicity on the nasal olfactory epithelium, was sufficient to prevent the development of socially-transferred mechanical hypersensitivity. Intriguingly, repeated but not acute olfactory exposure to the CFA mouse bedding induced a robust decrease in 50 % paw withdrawal thresholds (50 %PWTs) to mechanical stimuli, an effect returned to the baseline level after two days of washout with clean bedding. The findings strongly indicate that the normal olfactory function is crucial for the induction of mechanical hypersensitivity through brief empathetic contact, offering valuable insights for animal housing in future pain research.
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Hiperalgesia , Dor , Camundongos , Masculino , Animais , Camundongos Endogâmicos C57BL , Hiperalgesia/induzido quimicamente , Modelos Animais de Doenças , InflamaçãoRESUMO
The addition of surface acoustic wave (SAW) technologies to microfluidics has greatly advanced lab-on-a-chip applications due to their unique and powerful attributes, including high-precision manipulation, versatility, integrability, biocompatibility, contactless nature, and rapid actuation. However, the development of SAW microfluidic devices is limited by complex and time-consuming micro/nanofabrication techniques and access to cleanroom facilities for multistep photolithography and vacuum-based processing. To simplify the fabrication of SAW microfluidic devices with customizable dimensions and functions, we utilized the additive manufacturing technique of aerosol jet printing. We successfully fabricated customized SAW microfluidic devices of varying materials, including silver nanowires, graphene, and poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS). To characterize and compare the acoustic actuation performance of these aerosol jet printed SAW microfluidic devices with their cleanroom-fabricated counterparts, the wave displacements and resonant frequencies of the different fabricated devices were directly measured through scanning laser Doppler vibrometry. Finally, to exhibit the capability of the aerosol jet printed devices for lab-on-a-chip applications, we successfully conducted acoustic streaming and particle concentration experiments. Overall, we demonstrated a novel solution-based, direct-write, single-step, cleanroom-free additive manufacturing technique to rapidly develop SAW microfluidic devices that shows viability for applications in the fields of biology, chemistry, engineering, and medicine.
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AIM: General anesthesia can induce cognitive deficits in both humans and rodents, correlating with pathological alterations in the hippocampus. However, whether general anesthesia affects olfactory behaviors remains controversial as clinical studies have produced inconsistent results. Therefore, we aimed to investigate how olfactory behaviors and neuronal activity are affected by isoflurane exposure in adult mice. METHODS: The olfactory detection test, olfactory sensitivity test, and olfactory preference/avoidance test were used to examine olfactory function. In vivo electrophysiology was performed in awake, head-fixed mice to record single-unit spiking and local field potentials in the olfactory bulb (OB). We also performed patch-clamp recordings of mitral cell activity. For morphological studies, immunofluorescence and Golgi-Cox staining were applied. RESULTS: Repeated exposure to isoflurane impaired olfactory detection in adult mice. The main olfactory epithelium, the first region exposed to anesthetics, displayed increased proliferation of basal stem cells. In the OB, a crucial hub for olfactory processing, repeated isoflurane exposure increased the odor responses of mitral/tufted cells. Furthermore, the odor-evoked high gamma response was decreased after isoflurane exposure. Whole-cell recordings further indicated that repeated isoflurane exposure increased the excitability of mitral cells, which may be due to weakened inhibitory input in isoflurane-exposed mice. In addition, elevated astrocyte activation and glutamate transporter-1 expression in the OB were observed in isoflurane-exposed mice. CONCLUSIONS: Our findings indicate that repeated isoflurane exposure impairs olfactory detection by increasing neuronal activity in the OB in adult mice.
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Isoflurano , Olfato , Humanos , Camundongos , Animais , Olfato/fisiologia , Bulbo Olfatório/fisiologia , Isoflurano/toxicidade , Neurônios/fisiologia , OdorantesRESUMO
Reactive astrogliosis and neuronal death are major features of brain tissue damage after transient global cerebral ischemia/reperfusion (I/R). The CA1 subfield in the hippocampus is particularly susceptible to cell death after I/R. Recently, attention has focused on the relationship between the autophagy-lysosomal pathway and cerebral ischemia. Lysosomal-associated membrane protein type-2A (LAMP-2A) is a key protein in chaperone-mediated autophagy (CMA). However, LAMP-2A expression in astrocytes of the hippocampus and its influence on brain injury following I/R remain unknown. Here, we show that LAMP-2A is elevated in astrocytes of the CA1 hippocampal subfield after I/R and in primary cultured astrocytes after transient oxygen-glucose deprivation (OGD). Conditional LAMP-2A knockdown in CA1 astrocytes inhibited astrocyte activation and prevented neuronal death by inhibiting the mitochondrial pathway of apoptosis after I/R, suggesting that elevated astrocytic LAMP-2A contributes to regional ischemic vulnerability. Furthermore, astrocytic LAMP-2A ablation ameliorated the spatial learning and memory deficits caused by I/R. Conditional astrocytic LAMP-2A knockdown also prevented the loss of hippocampal synapses and dendritic spines, improved the synaptic ultrastructure, and inhibited the reduced expression of synaptic proteins after ischemia. Thus, our findings demonstrate that astrocytic LAMP-2A expression increases upon I/R and that LAMP-2A ablation specifically in hippocampal astrocytes contributes to cerebroprotection, suggesting a novel neuroprotective strategy for patients with global ischemia.
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Astrócitos , Isquemia Encefálica , Humanos , Astrócitos/metabolismo , Hipocampo/metabolismo , Isquemia Encefálica/metabolismo , Neurônios/metabolismo , Isquemia/metabolismoRESUMO
Optical filters have aroused tremendous excitement in advanced photonic instruments and modern digital displays due to their flexible capability of spectrum manipulation. Plasmonic metasurfaces of narrow bandwidth, high spectral contrast, and robust structure tolerance are highly desired for optical filtration (especially in the visible regime) but rather challenging as large spectral broadening from intrinsic ohmic loss and design/fabrication deviations. Here the high-performing sodium-based metasurfaces are demonstrated for optical filtration across 450 to 750 nm by unique structure design of spatially decoupled concave surfaces and precise fabrication through templated solidification of liquid metals. Thanks to the distinct suppression of metallic loss as well as fabrication tolerance of interfacial structures, the as-prepared concave metasurfaces enable a minimum linewidth of ≈15 nm, a maximal optical contrast of ≈93%, and a high measure-to-design spectral match ratio ≈1500. These results have for the first time pushed the operation wavelengths of sodium-based plasmonic devices from infrared to visible which in turn demonstrates the capability of filling the blank of commercial dielectric optical filters thus far.
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A recent, unprecedented outbreak of human mpox virus infection has led to cases in non-African nations, and the number of confirmed or suspected cases outside of Africa has exceeded 1,000 within 5 weeks. Mpox may pose a double threat to public health in the context of the ongoing COVID-19 pandemic. It is difficult to distinguish mpox virus infection from other diseases in the early stages, and patients are contagious from the onset of nonspecific symptoms; therefore, it is crucial to develop rapid and specific diagnostic methods. The diagnosis of mpox relies on real-time polymerase chain reaction, a time-consuming method that requires a highly sophisticated thermal cycler, which makes it unsuitable for widespread use in underdeveloped areas, where the outbreak is still severe. In this study, we developed a recombinase-aided amplification (RAA) assay that can detect mpox virus within 5-10 minutes. The conserved regions of the A27L gene and F3L gene were selected as targets, as they amplify well from different mpox virus clades with no cross-reaction from other pathogens. The sensitivity of this RAA assay is 10 copies/reaction for the A27L gene and 102 copies/reaction for the F3L gene. When applied to simulated clinical samples, both targets showed 100% specificity, and the detection limits were consistent with the sensitivity results. Moreover, through clinical blinded sample detection, RAA exhibits the same detection power as RT-PCR. In summary, the RAA mpox assay described here exhibits rapid detection, high sensitivity and specificity, and low operational difficulty, making it suitable for mpox virus detection in less developed countries and regions.
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COVID-19 , Mpox , Humanos , Sensibilidade e Especificidade , Monkeypox virus , Recombinases , PandemiasRESUMO
Our previous studies have shown that high alcohol-producing Klebsiella pneumoniae (HiAlc Kpn) in the intestinal microbiome could be one of the causes of non-alcoholic fatty liver disease (NAFLD). Considering antimicrobial resistance of K. pneumoniae and dysbacteriosis caused by antibiotics, phage therapy might have potential in treatment of HiAlc Kpn-induced NAFLD, because of the specificity targeting the bacteria. Here, we clarified the effectiveness of phage therapy in male mice with HiAlc Kpn-induced steatohepatitis. Comprehensive investigations including transcriptomes and metabolomes revealed that treatment with HiAlc Kpn-specific phage was able to alleviate steatohepatitis caused by HiAlc Kpn, including hepatic dysfunction and expression of cytokines and lipogenic genes. In contrast, such treatment did not cause significantly pathological changes, either in functions of liver and kidney, or in components of gut microbiota. In addition to reducing alcohol attack, phage therapy also regulated inflammation, and lipid and carbohydrate metabolism. Our data suggest that phage therapy targeting gut microbiota is an alternative to antibiotics, with potential efficacy and safety, at least in HiAlc Kpn-caused NAFLD.
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Bacteriófagos , Microbiota , Hepatopatia Gordurosa não Alcoólica , Masculino , Animais , Camundongos , Hepatopatia Gordurosa não Alcoólica/metabolismo , Klebsiella pneumoniae/genética , Etanol/metabolismo , Fígado/metabolismo , Antibacterianos/uso terapêutico , Antibacterianos/metabolismoRESUMO
As the eutrophication of natural water bodies becomes more and more serious, the frequency of outbreaks of harmful algal blooms (HABs) mainly formed by harmful algae also increases. HABs have become a global ecological problem that poses a serious threat to human health and food safety. Therefore, it is extremely important to establish methods that can rapidly detect harmful algal species for early warning of HABs. The traditional morphology-based identification method is inefficient and inaccurate. In recent years, the rapid development of molecular biology techniques has provided new ideas for the detection of harmful algae and has become a research hotspot. The current molecular detection methods for harmful algal species mainly include fluorescence in situ hybridization, sandwich hybridization, and quantitative PCR (qPCR), but all of these methods can only detect single harmful algal species at a time. The establishment of methods for the simultaneous detection of multiple harmful algal species has become a new trend in the development of molecular detection technology because various harmful algal species may coexist in the natural water environment. The established molecular techniques for multiple detections of harmful algae mainly include gene chip, multiplex PCR, multiplex qPCR, massively parallel sequencing, antibody chip, and multiple isothermal amplification. This review mainly focuses on the principles, advantages and disadvantages, application progress, and application prospects of these multiple detection technologies, aiming at providing effective references not only for the fisheries but also for economic activities, environment, and human health.
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Proliferação Nociva de Algas , Tecnologia , Humanos , Hibridização in Situ Fluorescente , Hibridização de Ácido Nucleico , ÁguaRESUMO
Ferroelectric domain wall memories have been proposed as a promising candidate for nonvolatile memories, given their intriguing advantages including low energy consumption and high-density integration. Perovskite oxides possess superior ferroelectric prosperities but perovskite-based domain wall memory integrated on silicon has rarely been reported due to the technical challenges in the sample preparation. Here, we demonstrate a domain wall memory prototype utilizing freestanding BaTiO3 membranes transferred onto silicon. While as-grown BaTiO3 films on (001) SrTiO3 substrate are purely c-axis polarized, we find they exhibit distinct in-plane multidomain structures after released from the substrate and integrated onto silicon due to the collective effects from depolarizing field and strain relaxation. Based on the strong in-plane ferroelectricity, conductive domain walls with reading currents up to nanoampere are observed and can be both created and erased artificially, highlighting the great potential of the integration of perovskite oxides with silicon for ferroelectric domain wall memories.
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The Burkholderia cepacia complex (BCC) is a group of opportunistic pathogens, including Burkholderia cepacia, Burkholderia multivorans, Burkholderia vietnamiensis and Burkholderia ambifaria, which can cause severe respiratory tract infections and lead to high mortality rates among humans. The early diagnosis and effective treatment of BCC infection are therefore crucial. In this study, a novel and rapid recombinase-aided amplification (RAA) assay targeting the 16S rRNA gene was developed for BCC detection. The protocol for this RAA assay could be completed in 10 min at 39°C, with a sensitivity of 10 copies per reaction and no cross-reactivity with other pathogens. To characterize the effectiveness of the RAA assay, we further collected 269 clinical samples from patients with bacterial pneumonia. The sensitivity and specificity of the RAA assay were 100% and 98.5%, respectively. Seven BCC-infected patients were detected using the RAA assay, and three BCC strains were isolated from the 269 clinical samples. Our data showed that the prevalence of BCC infection was 2.60%, which is higher than the 1.40% reported in previous studies, suggesting that high sensitivity is vital to BCC detection. We also screened a patient with B. vietnamiensis infection using the RAA assay in clinic, allowing for appropriate treatment to be initiated rapidly. Together, these data indicate that the RAA assay targeting the 16S rRNA gene can be applied for the early and rapid detection of BCC pathogens in patients with an uncharacterized infection who are immunocompromised or have underlying diseases, thereby providing guidance for effective treatment.
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Infecções por Burkholderia , Complexo Burkholderia cepacia , Fibrose Cística , Infecções por Burkholderia/diagnóstico , Complexo Burkholderia cepacia/genética , Fibrose Cística/microbiologia , Genes de RNAr , Humanos , RNA Ribossômico 16S/genética , RecombinasesRESUMO
Pneumonia caused by multidrug-resistant (MDR) Klebsiella pneumoniae of sequence types ST11 and ST383 have highlighted the necessity for new therapies against these prevalent pathogens. Bacteriophages (phages) may be used as alternatives or complements to antibiotics for treating MDR bacteria because they show potential efficacy in mouse models and even individual clinical cases, and they also cause fewer side effects, such as microbiota-imbalance-induced diseases. In the present study, we screened two phages, pKp11 and pKp383, that targeted ST11 and ST383 MDR K. pneumoniae isolates collected from patients with pneumonia, and they exhibited a broad host range, high lytic activity, and high environmental adaptability. Both phages pKp11 and pKp383 provided an effective treatment for the early stage of pneumonia in a murine infection model without promoting obvious side effects, and cocktails consisting of the two phages were more effective for reducing bacterial loads, inflammation, and pathogenic injuries. Our findings support the application of phages as new medications for refractory ST11 and ST383 K. pneumoniae infections and emphasize the potential of enhancing phage therapy modalities through phage screening. These data provided important resources for assessing and optimizing phage therapies for MDR ST11 and ST383 infection treatment. However, substantial amounts of further work are needed before phage therapy can be translated to human therapeutics. IMPORTANCE K. pneumoniae is recognized as the most common pathogen of hospital- and community-acquired pneumonia across the world. The strains of ST11 and ST383 are frequently reported in patients with pneumonia. However, the efficacy of antibiotics toward K. pneumoniae is decreasing dramatically. As a new approach to combat MDR bacteria, phages have exhibited positive clinical effects and efficacy as synergetic or alternative strategies to antibiotics. Thus, we screened two phages that targeted ST11 and ST383 MDR K. pneumoniae, and they exhibited a broad host range, high lytic activity, and high environmental adaptability. Both phages provided an effective treatment for the early stage of pneumonia in mice, and cocktails consisting of the two phages were more effective in reducing bacterial loads, inflammation, and pathogenic injuries. Although these data suggest that phages are effective alternatives or complements to antibiotics, more research is needed before they can be translated into therapeutics for humans.
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Bacteriófagos , Infecções por Klebsiella , Pneumonia , Humanos , Camundongos , Animais , Klebsiella pneumoniae , Infecções por Klebsiella/tratamento farmacológico , Infecções por Klebsiella/microbiologia , Pneumonia/terapia , Pneumonia/microbiologia , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , InflamaçãoRESUMO
Monkeypox virus (MPXV) is a human pathogenic virus that belongs to the genus Orthopoxvirus. In 2022, MPXV caused an unprecedented number of infections in many countries. As it is difficult to distinguish MPXV from other pathogens by its symptoms in the early stage of infection, a rapid and reliable assay for MPXV detection is needed. In this study, we developed a loop-mediated isothermal amplification (LAMP) assay for the specific detection of MPXV and evaluated its application in simulated clinical samples. The A27L-1 and F3L-1 primer sets were identified as the optimal primers, and 63°C was the most appropriate reaction temperature for sequence amplification. The detection limits of the LAMP assay using primer sets A27L-1 and F3L-1 were both 20 copies/reaction mixture, which were >100-fold higher in terms of sensitivity, compared with conventional PCR. The LAMP assay findings were negative for all 21 non-MPXV pathogens, confirming the high specificity of our assay. All three types of simulated clinical samples were clearly identified by our LAMP assay, and the detection limits were consistent with the sensitivity results, indicating efficient clinical sample identification. Our rapid and reliable MPXV LAMP assay could be useful for MPXV detection and on-site diagnosis, especially in primary hospitals and rural areas. IMPORTANCE MPXV outbreaks rapidly grew in the first half of 2022, and this virus has been recognized as an increasing public health threat, particularly in the context of the COVID-19 pandemic. Thus, developing reliable and fast detection methods for MPXV is necessary.
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COVID-19 , Mpox , Humanos , Monkeypox virus/genética , Pandemias , Sensibilidade e Especificidade , Mpox/diagnóstico , Mpox/epidemiologiaRESUMO
While Klebsiella pneumoniae is a common cause of nosocomial and community-acquired infections, including pneumonia and pyogenic liver abscess, little is known about the population structure of this bacterium. In this study, we investigated the prevalence and molecular characteristics of K. pneumoniae isolates from carriers, pyogenic liver abscess patients, and pneumonia patients, and genomic and phenotypic assays were used to determine the differences among the isolates. A total of 232 K. pneumoniae isolates were subtyped into 74 sequence types (STs). The isolates from different sources had their own STs, and the predominant subtypes in liver abscess and pneumonia patients were ST23 and ST11, respectively. Pangenome analysis also distinguished three phylogroups that were consistent with the isolate sources. The isolates collected from liver abscess patients carried significantly more virulence factors, and those from pneumonia patients harbored significantly more resistance genes and replicons. Almost all isolate STs (93/97 [95.88%]) from liver abscesses strongly correlated with the virulence factor salmochelin, while most pneumonia isolate STs (52/53 [98.11%]) from pneumonia did not correlate with salmochelin. The isolates collected from liver abscesses showed higher virulence in the cytotoxicity and mouse models. These data provide genomic support for the proposal that isolates collected from carriers, liver abscess patients, and pneumonia patients have distinct genomic features. Isolates from the different sources are largely nonoverlapping, suggesting that different patients may be infected via different sources. Further studies on the pathogenic mechanisms of salmochelin and other virulence factors will be required. IMPORTANCE While Klebsiella pneumoniae is a common cause of nosocomial and community-acquired infections, including pneumonia and pyogenic liver abscess, little is known about the population structure of this bacterium. We collected 232 isolates from carriers, pyogenic liver abscess patients, and pneumonia patients, and the isolates from different sources had their own sequence types. Pangenome analysis also distinguished three phylogroups that were consistent with the isolate sources. The isolates collected from liver abscess patients carried significantly more virulence factors, and those from pneumonia patients harbored significantly more resistance genes and replicons. Besides, there was a strong link between salmochelin and liver abscess. The isolates collected from liver abscesses also showed higher virulence in the cytotoxicity and mouse models. Isolates collected from different sources have distinct genomic features, suggesting that different patients may be infected via different sources.
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Infecções Comunitárias Adquiridas , Infecção Hospitalar , Infecções por Klebsiella , Abscesso Hepático Piogênico , Pneumonia , Animais , Variação Genética , Humanos , Infecções por Klebsiella/epidemiologia , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/genética , Abscesso Hepático Piogênico/epidemiologia , Abscesso Hepático Piogênico/microbiologia , Camundongos , Fatores de Virulência/genéticaRESUMO
Interfacial thermal transport plays a prominent role in the thermal management of nanoscale objects and is of fundamental importance for basic research and nanodevices. At metal/insulator interfaces, a configuration commonly found in electronic devices, heat transport strongly depends upon the effective energy transfer from thermalized electrons in the metal to the phonons in the insulator. However, the mechanism of interfacial electron-phonon coupling and thermal transport at metal/insulator interfaces is not well understood. Here, the observation of a substantial enhancement of the interfacial thermal resistance and the important role of surface charges at the metal/ferroelectric interface in an Al/BiFeO3 membrane are reported. By applying uniaxial strain, the interfacial thermal resistance can be varied substantially (up to an order of magnitude), which is attributed to the renormalized interfacial electron-phonon coupling caused by the charge redistribution at the interface due to the polarization rotation. These results imply that surface charges at a metal/insulator interface can substantially enhance the interfacial electron-phonon-mediated thermal coupling, providing a new route to optimize the thermal transport performance in next-generation nanodevices, power electronics, and thermal logic devices.
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Streptococcus pneumoniae (S. pneumoniae) is a common major human pathogen associated with community-acquired pneumonia, septicemia, meningitis, and otitis media. It is difficult to isolate and identify S. pneumoniae form clinical samples. To evaluate a novel, rapid, sensitive, and specific loop-mediated isothermal amplification (LAMP) assay to detect S. pneumoniae pneumonia in children, we designed specific LAMP primers targeting lytA and psaA genes. We optimized the reaction time and reaction system, and evaluated its sensitivity and specificity of detection using real-time turbidity monitoring and visual observation. We also analyzed the molecular characteristics of the isolates obtained from the positive samples. The primer sets LytA-1 and PsaA-2 amplified the genes in the shortest times, and 63°C was confirmed as the optimum reaction temperature. The detection sensitivity of each reaction was 10 and 100 copies/µL with primer sets LytA-1 and PsaA-2, respectively. This LAMP assay showed no cross-reactivity with other 27 pathogens. To describe the availability of this method, we collected 748 clinical samples from children with pneumonia. Among them, 135 were confirmed to be S. pneumoniae positive by LAMP. The sensitivity was 100% (95% CI 96.4-100%), specificity 99.0% (95% CI 97.8-99.6%). Including them, 50 were co-infected with Mycoplasma pneumoniae. This LAMP assay detected S. pneumoniae in 1 h and the results can be identified with visual naked eyes. Thus, it will be a powerful tool for S. pneumoniae early diagnosis and effective antibiotic therapy.