RESUMO
Hepatocellular carcinoma (HCC), one of the most prevalent forms of cancer worldwide, presents a significant global healthcare challenge. Cancer stem cells (CSCs), which can influence neighboring non-CSCs, are believed to play a crucial role in tumor growth and resistance to treatment, but the specific mechanisms and mediators are not fully understood. Regulation of the CSC state is considered an ideal therapeutic strategy both in the early stages of tumor formation and within established tumors. Exosomes have emerged as key players in intercellular communication, similar to classical hormone signaling, and are essential for facilitating communication between cells in liver cancer. Here, by coupling immunomagnetic bead sorting and exosomal sequencing, we found that exosome-derived circRNAs enriched in liver cancer CSCs were the key subsets with stemness characteristics and ultimately promoted HCC development. Of interest, we found that circ-ZEB1 and circ-AFAP1 are strongly correlated with liver cancer stemness and a poor prognosis, and can regulate the epithelial-mesenchymal transition (EMT) process. Our novel exosome-derived circRNAs play a vital role as key components of various intercellular crosstalk and communication systems in malignant transmission. This finding not only provides valuable support for utilizing plasma exosomal circRNAs as clinical prognostic indicators for HCC patients but also highlights a new research direction in exploring the signaling between liver CSCs and the messenger molecules contained within exosomes.
Assuntos
Carcinoma Hepatocelular , Exossomos , Neoplasias Hepáticas , MicroRNAs , Humanos , Neoplasias Hepáticas/patologia , Carcinoma Hepatocelular/patologia , RNA Circular/genética , Exossomos/genética , Exossomos/patologia , Linhagem Celular Tumoral , Células-Tronco Neoplásicas/patologiaRESUMO
Transition metal selenides are considered as promising anode materials for fast-charging sodium-ion batteries due to their high theoretical specific capacity. However, the low intrinsic conductivity, particle aggregation, and large volume expansion problems can severely inhibit the high-rate and long-cycle performance of the electrode. Herein, FeSe2nanoparticles embedded in nitrogen-doped carbon nanofibers (FeSe2@NCF) have been synthesized using the electrospinning and selenization process, which can alleviate the volume expansion and particle aggregation during the sodiation/desodiation and improve the electrical conductivity of the electrode. The FeSe2@NCF electrode delivers the outstanding specific capacity of 222.3 mAh g-1at a fast current density of 50 A g-1and 262.1 mAh g-1at 10 A g-1with the 87.8% capacity retention after 5000 cycles. Furthermore, the Na-ion full cells assembled with pre-sodiated FeSe2@NCF as anode and Na3V2(PO4)3/C as cathode exhibit the reversible specific capacity of 117.6 mAh g-1at 5 A g-1with the 84.3% capacity retention after 1000 cycles. This work provides a promising way for the conversion-based metal selenides for the applications as fast-charging sodium-ion battery anode.
RESUMO
Over the past decades, liquid biopsy, especially circulating tumor DNA (ctDNA), has received tremendous attention as a noninvasive detection approach for clinical applications, including early diagnosis of cancer and relapse, real-time therapeutic efficacy monitoring, potential target selection and investigation of drug resistance mechanisms. In recent years, the application of next-generation sequencing technology combined with AI technology has significantly improved the accuracy and sensitivity of liquid biopsy, enhancing its potential in solid tumors. However, the increasing integration of such promising tests to improve therapy decision making by oncologists still has complexities and challenges. Here, we propose a conceptual framework of ctDNA technologies and clinical utilities based on bibliometrics and highlight current challenges and future directions, especially in clinical applications such as early detection, minimal residual disease detection, targeted therapy, and immunotherapy. We also discuss the necessities of developing a dynamic field of translational cancer research and rigorous clinical studies that may support therapeutic strategy decision making in the near future.
RESUMO
Fibrinogen-related proteins (FREPs) are distributed universally in vertebrates and invertebrates. These proteins contain fibrinogen-like (FBG) domains in their C-terminal region and involve in immune responses and other aspects of physiology in invertebrates. In this study, 54 proteins that contain FBG domains or a fibrinogen_c domain were identified in Haliotis discus hannai. Comparatively, 88 and 63 FREPs were identified from the genomes of H. rufescens and H. laevigata. Most FREPs of abalones had a conserved motif containing a bound calcium ion site and a second conserved motif containing a polymerization pocket site. By sequence analysis, 394 SNPs and 11 Indels were identified in 20 FREP genes of the whole genome of H. discus hannai; 992 SNPs and 42 Indels were found in 64 FREPs of H. rufescens, and 192 SNPs and 12 Indels were found in 21 FREPs of H. laevigata. Among these SNPs, 92 missense mutation sites were identified in 26 FREP genes of H. rufescens, and 12 were identified in 8 FREP genes of H. laevigata. Due to the poor genomic integrity, annotations of the SNPs or Indels in H. discus hannai did not yield missense mutant sites. FREP genes with polymorphisms were ubiquitously expressed in all the tested tissues; however, the expression is lowest in the hemolymph. In response to Vibrio parahemolyticus infection, expression of FREP genes was significantly upregulated at different exposure times in gills, hepatopancreas, and hemolymph in H. discus hannai. Overall, this study documented the FREP genes of abalones and shed light on the role of FREPs in the innate immune system of these aquaculture species for the prevention and control of diseases.
Assuntos
Gastrópodes , Vibrioses , Vibrio , Animais , Fibrinogênio/genética , Gastrópodes/genética , Genoma , Vibrioses/veterináriaRESUMO
A novel two-dimensional (2D) coordination polymer, [Co(ppad)2]n (1), resulted from the assembly of Co(II) ions based on a versatile ligand termed N(3)-(3-pyridoyl)-3-pyridinecarboxamidrazone. Alternating/direct-current magnetic studies of compound 1 indicate that the spatially separated high-spin Co(II) ions act as single-ion magnets (SIMs). The present work represents the first case of a 2D Co(II)-based SIM composed of a monocomponent organic spacer.
RESUMO
BACKGROUND: Evidence on the association between particulate matter (PM) exposure and prognosis in people living with HIV/AIDS (PWHA) is scarce. We aim to investigate the associations of long-term exposure to PM with AIDS-related deaths and complications. METHODS: We collected follow-up information on 7444 PWHAs from 2000 to 2021 from the HIV/AIDS Comprehensive Response Information Management System of the Wuhan Center for Disease Control and Prevention. The AIDS-related deaths and complications were assessed by physicians every 3 to 6 months, and the monthly average PM concentrations for each PWHA were extracted from the China High Air Pollutants dataset. We employed time-varying Cox regression models to evaluate the associations of the average cumulative PM exposure concentrations with AIDS-related deaths and complications, as well as the mediating effects of AIDS-related complications in PM-induced AIDS-related deaths. RESULTS: For each 1 µg/m3 increase in PM1, PM2.5, and PM10, the adjusted hazard ratios (HRs) for AIDS-related deaths were 1.021 (1.009, 1.033), 1.012 (1.005, 1.020), and 1.010 (1.005, 1.015), respectively; and the HRs for AIDS-related complications were 1.049 (1.034, 1.064), 1.029 (1.020, 1.038), and 1.031 (1.024, 1.037), respectively. AIDS-related complications mediated 18.38 % and 18.68 % of the association of exposure to PM1 and PM2.5 with AIDS-related deaths, respectively. The association of PM exposure with AIDS-related deaths was more significant in older PWHA. Meanwhile, the association between PM exposure and AIDS-related complications was stronger in PWHA with a BMI ≥ 24 kg/m2. CONCLUSION: Long-term exposure to PM is positively associated with AIDS-related deaths and complications, and AIDS-related complications have mediating effects in PM-induced AIDS-related deaths. Our evidence emphasizes that enhanced protection against PM exposure for PWHAs is an additional mitigation strategy to reduce AIDS-related deaths and complications.
Assuntos
Síndrome da Imunodeficiência Adquirida , Poluentes Atmosféricos , Exposição Ambiental , Material Particulado , Material Particulado/análise , Humanos , Estudos Longitudinais , China/epidemiologia , Exposição Ambiental/estatística & dados numéricos , Poluentes Atmosféricos/análise , Masculino , Feminino , Pessoa de Meia-Idade , Adulto , Prognóstico , Poluição do Ar/estatística & dados numéricos , Infecções por HIV/epidemiologiaRESUMO
We aimed to explore the associations of neonatal hypocalcemia with neonatal vitamin D deficiency and maternal vitamin D deficiency. A comprehensive systematic literature search using PubMed and web of science was performed for relevant articles from inception to February 17th, 2023. We used odds ratio (OR) and 95â¯% confidence interval (CI) as effect sizes for our meta-analysis. Publication bias was evaluated using funnel plot, Begg's test, and Egger regression test. All the statistical analyses were performed using Stata 14.0. A total of 11 studies were included and analyzed, including 452 newborns with hypocalcemia and 2,599 newborns with normal serum calcium level. Our research results revealed that vitamin D deficiency in newborns may be related to the higher prevalence of hypocalcemia (OR: 2.87, 95â¯% CI: 1.17-7.04). In addition, maternal vitamin D deficiency might also be a risk factor for neonatal hypocalcemia (OR: 7.83, 95â¯% CI: 3.62-16.92). There was a significant correlation between vitamin D deficiency and neonatal hypocalcemia.This meta-analysis indicates that newborns with vitamin D deficiency have a higher risk of hypocalcemia, and maternal vitamin D level play a crucial role in this association. Vitamin D supplementation may have a positive effect in reducing the prevalence of neonatal hypocalcemia.
RESUMO
OBJECTIVE: To assess the optimal time for removal of a urinary catheter (UC) following caesarean section (CS). METHODS: Several electronic databases were searched from inception to 31 December 2021 regarding the timing of UC removal following CS. The effect of UC removal at different times following CS was calculated using odds ratio (OR) or standardized mean difference and 95% confidence interval (CI). The surface under the cumulative ranking curve (SUCRA) was used to determine the best time for UC removal. All analyses were performed using Stata Version 14.0. RESULTS: In total, 19 studies including 3086 women were included in this review. Compared with UC removal 0-6 h after CS, UC removal 6.1-12 h, 12.1-24 h and > 24 h after CS were more likely to result in urinary tract infection (UTI), with pooled OR of 5.95 (95 % CI 1.58-22.38), 11.26 (95 % CI 2.99-42.44) and 27.25 (95 % CI 6.82-108.90), respectively. UC removal > 24 h after CS was more favourable to prevent urinary retention than immediate UC removal (OR 0.05, 95 % CI 0.00-0.64). UC removal 0-6 h after CS was the optimal timing to prevent UTI and frequent urination, and reduce length of hospital stay as well as time to first ambulation, with maximum SUCRA values of 92.30 %, 85.00 %, 80.60 % and 72.60 %, respectively. CONCLUSION: UC removal 0-6 h after CS may be the optimal timing to prevent several complications in the absence of a clear indication for UC removal after CS. This study may provide a scientific basis for the timing of UC removal after CS.
Assuntos
Retenção Urinária , Infecções Urinárias , Feminino , Humanos , Gravidez , Cesárea/efeitos adversos , Metanálise em Rede , Cateteres Urinários/efeitos adversos , Retenção Urinária/etiologia , Infecções Urinárias/prevenção & controle , Infecções Urinárias/complicaçõesRESUMO
BACKGROUND: The purpose of this study was to develop a 1-step real-time quantitative fluorescence polymerase chain reaction (QF-PCR) method for detecting Bovine Group A Rotavirus (BRVA). The primers and probe were designed targeting the VP6 gene of BRVA. The standard substance was obtained through in vitro transcription. The primers, probe concentration, and annealing temperatures were optimized to determine the optimal system and conditions for the reaction. The specificity, sensitivity, and repeatability of the method were assessed and compared with a reported real-time QF-PCR method for clinical samples. RESULTS: The results indicated that the detection method can achieve a sensitivity of 3.47 copies/µL and exhibit good specificity by exclusively detecting BRVA without cross-reactivity to other common pathogens in cattle and sheep. The standard curve exhibited a robust linear correlation, and the amplification efficiency was calculated to be 105%. The intra-group and inter-group coefficients of variation were less than 2%. A total of 96 clinical samples were tested and compared with the real-time QF-PCR method that was reported. The coincidence rate was 90.63% (87/96). Furthermore, the clinical samples revealed that the prevalence of BRV in cattle from Fujian Province was 85.42% (82/96). CONCLUSION: This study has successfully developed a 1-step real-time QF-PCR method for BRVA, which offers an efficient and sensitive technical support for the rapid diagnosis and epidemiological investigation of BRVA.
Assuntos
Rotavirus , Animais , Bovinos , Ovinos/genética , Rotavirus/genética , Reação em Cadeia da Polimerase em Tempo Real/métodos , Sensibilidade e Especificidade , Primers do DNARESUMO
Pharmacologically-induced persistent hippocampal γ oscillation in area CA3 requires activation of α-Amino-3-hydroxy-5-methyl-4-isoxazolepropionate receptors (AMPARs). However, we demonstrated that exogenous AMPA dose-dependently inhibited carbachol (CCH)-induced γ oscillation in the CA3 area of rat hippocampal slices, but the underlying mechanism is not clear. Application of AMPARs antagonist NBQX (1 µM) did not affect γ oscillation power (γ power), nor AMPA-mediated γ power reduction. At 3 µM, NBQX had no effect on γ power but largely blocked AMPA-mediated γ power reduction. Ca2+-permeable AMPA receptor (CP-AMPAR) antagonist IEM1460 or CaMKK inhibitor STO-609 but not CaMKIIα inhibitor KN93 enhanced γ power, indicating that activation of CP-AMPAR or CaMKK negatively modulated CCH-induced γ oscillation. Either CP-AMPAR antagonist or CaMKK inhibitor alone did not affected AMPA-mediated γ power reduction, but co-administration of IEM1460 and NBQX (1 µM) largely prevented AMPA-mediated downregulation of γ suggesting that CP-AMPARs and CI-AMPARs are involved in AMPA downregulation of γ oscillation. The recurrent excitation recorded at CA3 stratum pyramidale was significantly reduced by AMPA application. Our results indicate that AMPA downregulation of γ oscillation may be related to the reduced recurrent excitation within CA3 local neuronal network due to rapid CI-AMPAR and CP-AMPAR activation.
Assuntos
Quinase da Proteína Quinase Dependente de Cálcio-Calmodulina , Hipocampo , Animais , Ratos , Ácido alfa-Amino-3-hidroxi-5-metil-4-isoxazol Propiônico , Modalidades de Fisioterapia , Região CA3 Hipocampal , Carbacol/farmacologiaRESUMO
Megriviruses have been identified from fecal samples in wild pigeons in Hong Kong (China) and Hungary. In this study, the genomic sequences of pigeon Megriviruses (PiMeVs) were downloaded from GenBank and compared. Based on the genetic comparison results, a pair of primers and TaqMan probe were designed based on the conserved sequences of the 3C gene (located in the P3 gene coding region), and a TaqMan real-time PCR method (TaqMan-qPCR) was established. The standard curve of the TaqMan-qPCR had an axial intercept of 39.74 and a slope of -3.2475 with a linear correlation (R2) of 1.00 and an efficiency of 103.2%. No cross-amplification signal was found from other pigeon viruses (such as avian influenza virus, pigeon paramyxovirus type I, pigeon torque teno virus, pigeon adenovirus, and pigeon circovirus). The limit of detection concentration was 53.6 copies/µL. The intra- and interassay results were less than 1.0% based on the reproducibility test. Furthermore, field samples investigation by the established TaqMan-qPCR method showed that positive signals can be found from racing pigeon fecal samples and embryos. Thus, our data suggested that this visible TaqMan-qPCR method is sensitive, specific, and reproducible. Moreover, we first confirmed the presence of pigeon Megrivirus infection in racing pigeon embryos, indicating that the virus may be vertically transmitted. This study provides a reference basis for further understanding the epidemiology of PiMeVs.
RESUMO
Droplet manipulation on superhydrophobic surfaces (DMSS) without conventional pipetting is an emerging liquid handling technology, which can be potentially used for diagnostic, analysis, and synthetic processes. Despite notable progress, controlling droplet motion on superhydrophobic surfaces by contactless acoustic waves is rarely reported. Herein, we report a contactless acoustic tweezer (CAT) for DMSS based on establishing ultrasonic standing wave between an ultrasound transducer (UST) and a superhydrophobic substrate to manipulate droplets without physical contact. The CAT utilizes acoustic radiation forces to trap and move droplets on superhydrophobic surfaces, which allows for precise and controllable movement of droplets by controlling the movement of the UST. Small droplets with volume less than 20 µL can be levitated in mid-air for out-plane manipulation, and large droplets with volume up to 500 µL can be trapped for in-plane manipulation. Experimental results demonstrate the versatility of the CAT for manipulating droplets with various compositions and volumes on various superhydrophobic substrates, offering a versatile and cross-contamination-free liquid handling approach for applications, including but not limited to high-throughput surface-enhanced Raman scattering.
RESUMO
Pistachio is a nut crop domesticated in the Fertile Crescent and a dioecious species with ZW sex chromosomes. We sequenced the genomes of Pistacia vera cultivar (cv.) Siirt, the female parent, and P. vera cv. Bagyolu, the male parent. Two chromosome-level reference genomes of pistachio were generated, and Z and W chromosomes were assembled. The ZW chromosomes originated from an autosome following the first inversion, which occurred approximately 8.18 Mya. Three inversion events in the W chromosome led to the formation of a 12.7-Mb (22.8% of the W chromosome) non-recombining region. These W-specific sequences contain several genes of interest that may have played a pivotal role in sex determination and contributed to the initiation and evolution of a ZW sex chromosome system in pistachio. The W-specific genes, including defA, defA-like, DYT1, two PTEN1, and two tandem duplications of six VPS13A paralogs, are strong candidates for sex determination or differentiation. Demographic history analysis of resequenced genomes suggest that cultivated pistachio underwent severe domestication bottlenecks approximately 7640 years ago, dating the domestication event close to the archeological record of pistachio domestication in Iran. We identified 390, 211, and 290 potential selective sweeps in 3 cultivar subgroups that underlie agronomic traits such as nut development and quality, grafting success, flowering time shift, and drought tolerance. These findings have improved our understanding of the genomic basis of sex determination/differentiation and horticulturally important traits and will accelerate the improvement of pistachio cultivars and rootstocks.
Assuntos
Pistacia , Pistacia/genética , Árvores/genética , Nozes , Domesticação , Cromossomos Sexuais/genéticaRESUMO
Egg-laying duck flocks in Guangdong province, southern China, have been suffering a widely spreading infectious disease with abrupt egg drops and death since the winter of 2010. However, the causative pathogen was not known. We obtained two independent virus isolates named FS and JM from the diseased layer duck flocks and identified them as duck-origin Tembusu virus by PCR detection, sequencing the entire length of the open reading frames (ORFs). The two isolates FS and JM shared high sequence similarity to the isolates of duck-origin Tembusu virus that was first emerged in eastern China in April 2010. Blast analysis shows that the whole ORF sequences of FS and JM have the highest similarity (>99 %) to BYD-1(the first reported duck-origin Tembusu virus) and JS804 (the first reported goose-origin Tembusu virus), indicating that the full-length genomes were highly conserved in waterfowl-origin Tembusu viruses. The present study suggests that duck-origin Tembusu viruses have spread fast from eastern China to southern China, causing widely spreading infections. The high conservation of duck-origin Tembusu virus strains provides the genomic basis for choosing the strains for vaccine preparation for better protection against this new virus infection.
Assuntos
Patos/virologia , Infecções por Flavivirus/veterinária , Flavivirus/genética , Genoma Viral , Filogenia , Doenças das Aves Domésticas/epidemiologia , Animais , China/epidemiologia , Flavivirus/classificação , Flavivirus/isolamento & purificação , Infecções por Flavivirus/epidemiologia , Infecções por Flavivirus/virologia , Dados de Sequência Molecular , Doenças das Aves Domésticas/virologia , Análise de Sequência de DNARESUMO
Promoting the growth of plants and improving plant stress-resistance by plant growth-promoting microorganism increasingly become a hotpot. While, most researchers focus on their supply role of nutrition or plant hormone. In this study, a novel mechanism that phosphate solubilizing microorganisms promoted plant growth under saline-alkali stress through secretion of organic acids, was proposed. The effects of desulfurization gypsum, humic acid, organic fertilizer and phosphate-solubilizing microorganism Penicillium funicuiosum P1 (KX400570) on the growth of quinoa (Chenopodium quinoa cv. Longli 1), showed that the survival rate, stem length and dry weight of quinoa treated with P1 were 2.5, 1.5, 1 and 1.5 times higher than those of sterile water (CK) under severe saline-alkali stress. The growth-promoting effect of P1 on quinoa was much better than that of other treatment groups. In addition, P1 promoted the growth of quinoa because the organic acids (malic acid, citric acid, succinic acid, etc.) from P1 stimulated the antioxidant system and promote the photosynthesis of quinoa, further promote quinoa growth.
Assuntos
Chenopodium quinoa , Penicillium , Álcalis/farmacologia , Antioxidantes/farmacologia , Fosfatos/farmacologiaRESUMO
Due to the low price and abundant reserves of sodium resources, sodium-ion batteries have become the main candidate for the next generation of energy storage equipment, particularly for large-scale grid storage and low-speed electric vehicles. Transition metal selenides have attracted considerable attention because of their high reversible capacity, superior electrical conductivity and versatile structures. In this study, two-dimensional CuSe nanosheets are synthesized via a simple hydrothermal reaction. When acting as an electrode material for sodium-ion batteries, the CuSe electrode exhibits an initial coulombic efficiency of 96.7% at a current density of 0.1 A g-1 and a specific capacity of 330 mA h g-1 after 100 operation cycles, as well as retains a specific capacity of 211 mA h g-1 even at a high current density of 10 A g-1. Moreover, the anode delivers a specific capacity of 236 mA h g-1 after 3300 cycles at 5 A g-1 with a capacity retention of 91.2%. In sodium-ion hybrid capacitors (SHICs) with the two-dimensional CuSe nanosheets and Ti3C2T x MXene as the negative and positive materials, respectively, the nanosheets without any pre-sodiation present a lifespan of up to 2000 cycles at 2 A g-1 and a capacity retention of about 77.7%.
RESUMO
Orchidaceae, with more than 25,000 species, is one of the largest flowering plant families that can successfully colonize wide ecological niches, such as land, trees, or rocks, and its members are divided into epiphytic, terrestrial, and saprophytic types according to their life forms. Cellulose synthase (CesA) and cellulose synthase-like (Csl) genes are key regulators in the synthesis of plant cell wall polysaccharides, which play an important role in the adaptation of orchids to resist abiotic stresses, such as drought and cold. In this study, nine whole-genome sequenced orchid species with three types of life forms were selected; the CesA/Csl gene family was identified; the evolutionary roles and expression patterns of CesA/Csl genes adapted to different life forms and abiotic stresses were investigated. The CesA/Csl genes of nine orchid species were divided into eight subfamilies: CesA and CslA/B/C/D/E/G/H, among which the CslD subfamily had the highest number of genes, followed by CesA, whereas CslB subfamily had the least number of genes. Expansion of the CesA/Csl gene family in orchids mainly occurred in the CslD and CslF subfamilies. Conserved domain analysis revealed that eight subfamilies were conserved with variations in orchids. In total, 17 pairs of CesA/Csl homologous genes underwent positive selection, of which 86%, 14%, and none belonged to the epiphytic, terrestrial, and saprophytic orchids, respectively. The inter-species collinearity analysis showed that the CslD genes expanded in epiphytic orchids. Compared with terrestrial and saprophytic orchids, epiphytic orchids experienced greater strength of positive selection, with expansion events mostly related to the CslD subfamily, which might have resulted in strong adaptability to stress in epiphytes. Experiments on stem expression changes under abiotic stress showed that the CslA might be a key subfamily in response to drought stress for orchids with different life forms, whereas the CslD might be a key subfamily in epiphytic and saprophytic orchids to adapt to freezing stress. This study provides the basic knowledge for the further systematic study of the adaptive evolution of the CesA/Csl superfamily in angiosperms with different life forms, and research on orchid-specific functional genes related to life-history trait evolution.
RESUMO
The title compound, C(6)H(8)N(4)O(3)·2H(2)O, which crystallized as a dihydrate, has two almost planar segments viz. the pyrimidine ring and the C-N-C(=O)-C group [maxmum deviations of 0.020â (2) and 0.014â (2)â Å, respectively], with a dihedral angle of 87.45°. In the crystal, the components are linked by O-Hâ¯O and N-Hâ¯O hydrogen bonds.
RESUMO
Mycoplasma capricolum subsp.subsp. capripneumonia (Mccp) and Mycoplasma mycoides subsp.sbusp. capri (Mmc) cause caprine pleuropneumonia (CCPP) and mycoplasmal pneumonia in goats and sheep (MPGS), respectively. These diseases cannot be identified on clinical symptoms alone and it is laborious to distinguish them using biochemical methods. It is therefore important to establish a simple, rapid identification method for Mccp and Mmc. Here, we report a high-resolution melting (HRM) curve analysis using specific primers based on the Mmc 95010 strain MLC_0560 and Mccp F38 strain MCCPF38_00984 gene sequences. The method was highly specific with intra- and inter-batch coefficients of variation < 1%. The lower limit of detection for Mccp and Mmc was 55 copies/µL and 58 copies/µL, respectively. HRM and fluorescence qPCR results were compared using 106 nasal swabs and 47 lung tissue samples from goats (HRM-qPCR coincidence rate 94.8%; 145/153). Mycoplasma isolation and identification was performed on 30 lung tissue samples and 16 nasal swabs (HRM-culturing coincidence rate 87.0%; 40/46). HRM analysis was more sensitive than fluorescence qPCR and Mycoplasma isolation, indicating the practicality of HRM for accurate and rapid identification of Mccp and Mmc, and diagnosis and epidemiology of CCPP and MPGS.
Assuntos
DNA Bacteriano/genética , Mycoplasma/genética , Pleuropneumonia Contagiosa/diagnóstico , Pneumonia por Mycoplasma/diagnóstico , Animais , Sequência de Bases , Primers do DNA/síntese química , Primers do DNA/metabolismo , Diagnóstico Diferencial , Cabras/microbiologia , Limite de Detecção , Pulmão/microbiologia , Mycoplasma/classificação , Mycoplasma/isolamento & purificação , Cavidade Nasal/microbiologia , Desnaturação de Ácido Nucleico , Pleuropneumonia Contagiosa/microbiologia , Pneumonia por Mycoplasma/microbiologia , Reação em Cadeia da Polimerase em Tempo Real/métodos , Reprodutibilidade dos Testes , Ovinos/microbiologiaRESUMO
Lithium-rich layered oxide cathodes with high specific energy have become one of the most popular cathode materials for high-performance lithium-ion batteries. However, spinel phase formation due to the migration of transition metals and the release of lattice oxygen leads to the degradation of electrochemical performance. Here, we develop a synthesis approach for Li-rich layered oxide cathodes by a two-step heat-treatment process, which includes precursor calcination and pellet sintering. Compared with the sample prepared by the traditional one-step calcination, the oxide particles prepared by the two-step heat treatment show increased grain size from 217 to 425 nm. The Li-rich layered oxide cathodes with larger crystal grains indicate a mitigated formation of spinel phase and reduced voltage decay, which result in improved specific capacity, cycle stability, and rate capability. In addition, the thermal stability of the oxides is also improved. The improved electrochemical performance is because of the large single grains having a reduced contact area with a liquid electrolyte and the stable crystal lattice during cycling. Our strategy not only provides a simple and effective way to enhance the stability of the Li-rich layered oxide cathodes but also extends to the preparation of oxide powders with large grains.