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1.
Org Biomol Chem ; 2020 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-32167516

RESUMO

A new N2O-type BODIPY probe (LF-Bop) has been proposed for the selective and sensitive detection of biologically relevant small molecular thiols. This detection is based on the Michael addition reaction between the thiol and nitrostyrene groups in the probe, which decreases the quenching effect from the nitro group, thus resulting in the recovery of the deep-red fluorescence from the BODIPY structure. The results show that LF-Bop is able to detect all tested free thiols through a fluorescence turn-on assay. The lowest limit of detection (LOD) for glutathione was found to be down to nanomolar levels (220 nM). Based on this probe, we have developed a new fluorescence assay for the screening of acetylcholinesterase inhibitors. In total, 11 natural and synthetic alkaloids have been evaluated. Both experimental measurements and theoretical molecular docking results reveal that both natural berberine and its synthetic derivative dihydroberberine are potential inhibitors of acetylcholinesterase.

2.
Chem Commun (Camb) ; 2020 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-32195507

RESUMO

A new FRET probe has been prepared for ratiometric fluorescence detection of hydroxyl radicals. It has been successfully used for detecting mitochondria-localized drug activation in living cells and imaging endogenous hydroxyl radicals in zebrafish gastrointestinal (GI) tracts under normal culturing conditions.

3.
Environ Res ; 184: 109295, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32126376

RESUMO

BACKGROUND: Phthalate metabolites in follicular fluid (FF) may negatively affect normal folliculogenesis; however, the predictors of phthalate metabolite concentrations in urine and FF and relationships between urine and FF phthalate metabolite concentrations among women undergoing in vitro fertilization (IVF) are poorly understood. OBJECTIVE: To investigate predictors of phthalate metabolites in urine and FF and correlations between urine and FF phthalate metabolite concentrations among women undergoing IVF. METHOD: We recruited 305 women seeking infertility treatment at a reproductive center in Wuhan, China, from October to November 2016. Information regarding demographic characteristics, personal care product use and plastic material contact was obtained through direct interviews. Concentrations of 8 phthalate metabolites in urine and FF samples were measured using high-performance liquid chromatography and tandem mass spectrometry. Associations regarding metabolite concentrations in urine and FF samples were analysed by Spearman's correlation and linear regression. Generalized linear regression was used to examine potential predictors of phthalate metabolite concentrations in urine and FF. RESULTS: Weak to moderate associations between urine and FF samples were found for monoethyl phthalate (MEP) and mono(2-ethyl-5-oxohexyl) phthalate (MEOHP) (correlation coefficient: MEP, 0.350; MEOHP, 0.377); no associations were observed for other metabolites. The predictive powers of urinary metabolite concentrations in determining FF metabolite concentrations were uniformly low, with R2 ≤ 0.113. Body mass index (BMI) and educational level were inversely associated with the urinary concentrations of certain metabolites. Higher household income, intake of bottled drinks within 48 h, and use of shower gel and soap were frequently associated with higher urinary metabolite concentrations. BMI, higher household income and use of disposable plastic cups within 48 h were associated with higher metabolite concentrations in FF. CONCLUSION: Phthalate metabolite concentrations in urine and FF vary according to sociodemographic characteristics and lifestyle factors. Phthalate metabolite concentrations in urine may not be appropriate for estimating ovary phthalate exposure.

4.
Nanoscale ; 12(7): 4295-4301, 2020 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-32025690

RESUMO

Discrete droplet transport has drawn much interest in a broad range of applications. Controlling the motion direction in droplet transport, however, is a long-lasting challenge. In this work, a simple yet efficient approach is demonstrated to realize the motion of droplets with directional control on nanostructured surfaces with predefined channels. Light is used as the external stimulus to induce the uneven thermal expansion of the substrate, which leads to the tilting of nanostructured channels so that the droplet is driven to move along the channel. Due to the easy manipulation of light, including both the light position and power density, this study demonstrates the controllable entrance of static water droplets into targeted channels and the simultaneous control of the motion of multiple droplets in multi-channel systems, using just one light source. Besides static droplets, this approach can also be applied for the directional control of moving droplets in multi-channel systems. As a proof-of-concept, such an approach has been utilized for efficient multiplexed reactions for chemical sensing or microreactor applications. This work offers an alternative approach for the manipulation of droplet movement in applications that involve the control of droplet motion.

5.
Sci China Life Sci ; 63(3): 319-328, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31942687

RESUMO

In China, the medical guidelines recommend performing noninvasive prenatal testing (NIPT) with caution for pregnant women aged 35 years or older. However, the Mother and Child Health Care Law suggests that all primiparous women whose age is older than 35 years undergo prenatal diagnosis. These two inconsistent suggestions/recommendations have made obstetricians confused about whether to offer NIPT to these older pregnant women. To face this issue and find out the solution we performed a retrospective study of 189,809 NIPT samples collected from 28 provincial-leveled administrative units in China. Of 1,564 women with high-risk pregnancies who underwent NIPT, 459 (29.3%) did not participate in follow-up. The compound sensitivity and specificity of NIPT for trisomies 21, 18 and 13 detection was 99.1% (95% CI, 98.0%-99.6%) and 99.9% (95% CI, 98.8%-99.9%), respectively. In secundiparous women, NIPT showed high sensitivity and specificity similar to that in primiparous women. The observed risk for trisomies 21 and 18 significantly increased when the maternal age was 39 and older. After the publication of the current NIPT policy, the follow-up rate at our center was 91.9%; however, a large number of women are not in maternal and infant care networks nationwide, and that makes the follow-up rate outside our center relatively low. Our study shows that to balance the prevention of major aneuploidies and the limited resources for prenatal diagnosis, the cut-off age of 35 for invasive prenatal diagnosis might be unnecessary. Although the NIPT guidelines are well written, how to practice it effectively, especially in less industrialized areas, is worth discussing.

6.
J Mater Chem B ; 8(7): 1481-1488, 2020 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-31996879

RESUMO

Chlorin e6 (Ce6) is a second generation photosensitizer for photodynamic therapy (PDT). However, free Ce6 still has some defects leading to reduced clinical efficacy, such as easy agglomeration in a physiological environment and poor accumulation in tumor tissue. In order to solve these problems, a hyaluronic acid (HA) modified zeolitic imidazolate framework-8 (ZIF-8) based Ce6 (ZIF-8@Ce6-HA) therapeutic agent is constructed for PDT by one-pot encapsulation and self-assembly. ZIF-8@Ce6-HA exhibits acceptable encapsulation efficiency, effective cell uptake and good biocompatibility. Moreover, the results of in vitro anticancer experiments demonstrated that the ZIF-8@Ce6-HA group exhibited greater cytotoxicity after irradiation than the free Ce6 group, which caused about 88.4% of HepG2 cells to die since ROS is produced by PDT. Additionally, the data of inductively coupled plasma mass spectrometry indicated that modification of HA increased the blood circulation time and reduced the systemic toxicity of ZIF-8@Ce6. In summary, this work created an interesting Ce6 therapeutic agent for PDT and provided the data for HA regarding the improvement in biocompatibility and biological half-life of metal organic frameworks.

7.
Ir J Med Sci ; 189(1): 163-170, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31463894

RESUMO

BACKGROUND: Lipase is one of the diagnostic criteria for acute pancreatitis; however, the value of serum lipase in the early prediction and diagnosis for post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis remains controversial. AIMS: We evaluate the 3-h post-ERCP serum amylase and lipase activities for early prediction of postoperative pancreatitis (PEP) and compare the 24-h post-ERCP serum amylase and lipase activities in the diagnosis of PEP. METHODS: Clinical information of patients who underwent ERCP from January 2017 to December 2018 at our hospital were retrospectively reviewed. Receiver operating characteristic (ROC) curves were performed for 3-h and 24-h post-ERCP serum amylase and lipase activities to evaluate predictive and diagnostic values, respectively. RESULTS: A total of 498 cases with ERCP were finally enrolled, in which 36 cases of PEP were confirmed. ROC curves for 3-h post-ERCP amylase and lipase activities depicted areas under the curve (AUCs) of 0.88 (P < 0.001, 95% confidence intervals [CI] 0.82-0.93) and 0.90 (P < 0.001, 95% CI 0.86-0.93), respectively. The difference showed no significance using Z test (Z = 0.69, P > 0.05). AUCs for 24-h amylase and lipase activities were 0.83 (P < 0.001, 95% CI 0.77-0.89) and 0.94 (P < 0.001, 95% CI 0.90-0.99), respectively, and the difference was significant (Z = 3.04, P < 0.05). CONCLUSIONS: For early prediction of PEP, 3-h post-ERCP serum lipase activity is at least as good as that of amylase. For diagnosis of PEP, 24-h post-ERCP serum lipase is a much better indicator than that of amylase. Together, this study suggests that serum lipase should be given priority in the early prediction and diagnosis of PEP.

8.
Asian-Australas J Anim Sci ; 33(2): 219-229, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31480192

RESUMO

OBJECTIVE: Considering the physiological and clinical importance of leptin receptor (LEPR) in regulating obesity and the fact that porcine LEPR expression is not known to be controlled by lncRNAs and miRNAs, we aim to characterize this gene as a potential target of SSC-miR-323 and the lncRNA TCONS_00010987. METHODS: Bioinformatics analyses revealed that lncRNA TCONS_00010987 and LEPR have SSC-miR-323-binding sites and that LEPR might be a target of lncRNA TCONS_00010987 based on cis prediction. Wild-type and mutant TCONS_00010987-target sequence fragments and wild-type and mutant LEPR 3'-UTR fragments were generated and cloned into pmiR-RB-REPORTTM-Control vectors to construct respective recombinant plasmids. HEK293T cells were co-transfected with the SSC-miR-323 mimics or a negative control with constructs harboring the corresponding binding sites and relative luciferase activities were determined. Tissue expression patterns of lncRNA TCONS_00010987, SSC-miR-323, and LEPR in Anqing six-end-white (AQ, the obese breed) and Large White (LW, the lean breed) pigs were detected by real-time quantitative polymerase chain reaction; backfat expression of LEPR protein was detected by western blotting. RESULTS: Target gene fragments were successfully cloned, and the four recombinant vectors were constructed. Compared to the negative control, SSC-miR-323 mimics significantly inhibited luciferase activity from the wild-type TCONS_00010987-target sequence and wild-type LEPR-3'-UTR (p<0.01 for both) but not from the mutant TCONS_00010987-target sequence and mutant LEPR-3'-UTR (p>0.05 for both). Backfat expression levels of TCONS_ 00010987 and LEPR in AQ pigs were significantly higher than those in LW pigs (p<0.01), whereas levels of SSC-miR-323 in AQ pigs were significantly lower than those in LW pigs (p<0.05). LEPR protein levels in the backfat tissues of AQ pigs were markedly higher than those in LW pigs (p<0.01). CONCLUSION: LEPR is a potential target of SSC-miR-323, and TCONS_00010987 might act as a sponge for SSC-miR-323 to regulate LEPR expression.

9.
Sci Prog ; : 36850419884452, 2019 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-31829894

RESUMO

Long-distance gas pipelines generally have complex, undulating sections. Trapped air pockets are often present at the high points or ends of pipelines. This article carries out an experimental research to figure out the transient changes. First of all, under the condition of using the pig with 231 g and the injection pressure of 0.3 MPa, the hydraulic pulse increases from 0.31 to 0.54 MPa as the liquid level rises from 1 to 8 m. And at the liquid level of 8 m, the injection pressure grows from 0.3 to 0.75 MPa and the hydraulic pulse from 0.54 to 0.95 MPa. When the interception air mass is located at the blind side of the pipeline's end, the injection pressure is 0.75 MPa, and the hydraulic pulse decreases from 4.9 to 3.21 MPa with the increase in the void fraction. The maximum hydraulic pressure generates when the air pocket is located at the rear end of the drainage system (4.9 MPa) is far higher than that when the air pocket is located in front of the pig (1.0 MPa). Therefore, it is necessary to minimize the generation of trapped air pockets at the rear end of the pipeline system to ensure safety.

10.
ACS Omega ; 4(18): 17615-17622, 2019 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-31681868

RESUMO

This paper studied the coalescence, spreading, and rebound of two droplets with different temperatures on a superhydrophobic surface. When the temperature of the impacting droplet was the same as that of the stationary droplet, there was a large deformation of both droplets before the coalescence and the energy dissipation was also large. The coalescence happened at the time close to the maximum spreading. When the temperature of the impacting droplet increased, the deformation of both droplets became smaller before the coalescence and the coalescence happened at or even before the droplets started to spread. The energy dissipation and loss in the later situation is less than those in the previous case. The rebounding characteristics of the merged droplets were also found to be dependent on the temperature. There is an optimum temperature at which the merged droplets can rebound for more times due to the balance of energy loss and also the interaction of the merged droplets with the underlying superhydrophobic substrate. These findings may help further the fundamental understanding of droplet collision on a superhydrophobic surfaces and also offer an alternative strategy to remove droplets from the underlying surfaces for different industrial applications, including condensation heat transfer in steam power plants and phase-change-based thermal management systems.

11.
ACS Nano ; 13(12): 14094-14106, 2019 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-31724845

RESUMO

High specific capacity materials that can store potassium (K) are essential for next-generation K-ion batteries. One such candidate material is phosphorene (the 2D allotrope of phosphorus (P)), but the potassiation capability of phosphorene has not yet been established. Here we systematically investigate the alloying of few-layer phosphorene (FLP) with K. Unlike lithium (Li) and sodium (Na), which form Li3P and Na3P, FLP alloys with K to form K4P3, which was confirmed by ex situ X-ray characterization as well as density functional theory calculations. The formation of K4P3 results in high specific capacity (∼1200 mAh g-1) but poor cyclic stability (only ∼9% capacity retention in subsequent cycles). We show that this capacity fade can be successfully mitigated by the use of reduced graphene oxide (rGO) as buffer layers to suppress the pulverization of FLP. We studied the performance of rGO and single-walled carbon nanotubes (sCNTs) as buffer materials and found that rGO being a 2D material can better encapsulate and protect FLP relative to 1D sCNTs. The half-cell performance of FLP/rGO could also be successfully reproduced in a full-cell configuration, indicating the possibility of high-performance K-ion batteries that could offer a sustainable and low-cost alternative to Li-ion technology.

12.
Anal Bioanal Chem ; 411(30): 8103-8111, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31758198

RESUMO

A novel sensitive and selective probe for the important antibiotic vancomycin (Van) has been synthesized by integrating a coumarin and a fluorescein as dual fluorescence reporters and a Van binding peptide D-Ala-D-Ala. Only weak green fluorescence was initially observed, which was mostly attributed to fluorescence self-quenching induced by fluorophore stacking. Upon the binding of Van with the D-Ala-D-Ala peptide, the fluorescence turned on, probably due the disaggregation of fluorophores. The intensity ratio of the dual emission bands I519/I446 exhibited an excellent linear relationship with the concentration of Van increasing from 0-20 µM in synthetic urine. The lowest detection limit was calculated to be 92.8 nM in urine, which made the probe applicable in clinically relevant concentration ranges. The synthetic probe has also shown the potential for Van detection in human serum. More interestingly, this probe has been successfully applied for in vivo imaging of Van in zebrafish. Graphical Abstract.


Assuntos
Antibacterianos/análise , Corantes Fluorescentes/química , Vancomicina/análise , Antibacterianos/urina , Ensaio de Imunoadsorção Enzimática , Humanos , Limite de Detecção , Espectrometria de Fluorescência/métodos , Vancomicina/urina
13.
Sci Rep ; 9(1): 16602, 2019 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-31719639

RESUMO

Maintaining the viability of the apical shoot is critical for continued vertical growth in plants. Terminal shoot of tree species Paulownia cannot regrow in subsequent years. The short day (SD) treatment leads to apical growth cessation and dormancy. To understand the molecular basis of this, we further conducted global RNA-Seq based transcriptomic analysis in apical shoots to check regulation of gene expression. We obtained ~219 million paired-end 125-bp Illumina reads from five time-courses and de novo assembled them to yield 49,054 unigenes. Compared with the untreated control, we identified 1540 differentially expressed genes (DEGs) which were found to involve in 116 metabolic pathways. Expression of 87% of DEGs exhibited switch-on or switch-off pattern, indicating key roles in growth cessation. Most DEGs were enriched in the biological process of gene ontology categories and at later treatment stages. The pathways of auxin and circadian network were most affected and the expression of associated DEGs was characterised. During SD induction, auxin genes IAA, ARF and SAURs were down-regulated and circadian genes including PIF3 and PRR5 were up-regulated. PEPC in photosynthesis was constitutively upregulated, suggesting a still high CO2 concentrating activity; however, the converting CO2 to G3P in the Calvin cycle is low, supported by reduced expression of GAPDH encoding the catalysing enzyme for this step. This indicates a de-coupling point in the carbon fixation. The results help elucidate the molecular mechanisms for SD inducing dormancy and cessation in apical shoots.

14.
J Vis Exp ; (152)2019 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-31657793

RESUMO

Primaquine (PMQ), an important anti-malarial drug, has been recommended by the World Health Organization (WHO) for the treatment of life-threatening infections caused by P. vivax and ovale. However, PMQ has unwanted adverse effects that lead to acute hemolysis in patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency. There is a need to develop simple and reliable methods for PMQ determination with the purpose of dosage monitoring. In early 2019, we have reported an UV-Vis and naked-eye based approach for PMQ colorimetric quantification. The detection was based on a Griess-like reaction between PMQ and anilines, which can generate colored azo products. The detection limit for direct measurement of PMQ in synthetic urine is in the nanomolar range. Moreover, this method has shown great potential for PMQ quantification from human serum samples at clinically relevant concentrations. In this protocol, we will describe the technical details regarding the syntheses and characterization of colored azo products, the reagent preparation, and the procedures for PMQ determination.

15.
Angew Chem Int Ed Engl ; 58(49): 17820-17826, 2019 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-31571354

RESUMO

The lack of high-power and stable cathodes prohibits the development of rechargeable metal (Na, Mg, Al) batteries. Herein, poly(hexaazatrinaphthalene) (PHATN), an environmentally benign, abundant and sustainable polymer, is employed as a universal cathode material for these batteries. In Na-ion batteries (NIBs), PHATN delivers a reversible capacity of 220 mAh g-1 at 50 mA g-1 , corresponding to the energy density of 440 Wh kg-1 , and still retains 100 mAh g-1 at 10 Ag-1 after 50 000 cycles, which is among the best performances in NIBs. Such an exceptional performance is also observed in more challenging Mg and Al batteries. PHATN retains reversible capacities of 110 mAh g-1 after 200 cycles in Mg batteries and 92 mAh g-1 after 100 cycles in Al batteries. DFT calculations, X-ray photoelectron spectroscopy, Raman, and FTIR show that the electron-deficient pyrazine sites in PHATN are the redox centers to reversibly react with metal ions.

16.
ACS Omega ; 4(15): 16603-16611, 2019 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-31616842

RESUMO

Electrically driven steam generation is a critical process for many heating-related applications such as sterilization and food processing. Current systems, which rely on heating up the bulk water to generate steam, face the dilemma in achieving a large evaporation flux and fast thermal response. Herein, we report a self-floating electrically driven interfacial evaporator for fast high-efficiency steam generation independent of the amount of loaded bulk water in the system. Through localized heating of the wicked water at the air-water interface, the evaporator has achieved an electrical-to-steam energy conversion efficiency of ∼90% at a heating power density of 10 kW/m2 and a fast thermal response of 20 s. The interfacial evaporation design not only achieves a high evaporation efficiency within a broad range of heating power densities by using different wicking materials, but also enables attaining a high evaporation temperature under low heating power densities by tuning the ratio of the vapor outlet area and the evaporation surface area. By integrating an interfacial evaporator within a sanitizer, the resultant system has demonstrated a faster steam temperature rise and superior steam sterilization performance than the commercial bulk heating-based approach.

17.
Adv Mater ; 31(49): e1905099, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31621971

RESUMO

Efficient thermal energy harvesting using phase-change materials (PCMs) has great potential for cost-effective thermal management and energy storage applications. However, the low thermal conductivity of PCMs (KPCM ) is a long-standing bottleneck for high-power-density energy harvesting. Although PCM-based nanocomposites with an enhanced thermal conductivity can address this issue, achieving a higher K (>10 W m-1 K-1 ) at filler loadings below 50 wt% remains challenging. A strategy for synthesizing highly thermally conductive phase-change composites (PCCs) by compression-induced construction of large aligned graphite sheets inside PCCs is demonstrated. The millimeter-sized graphite sheet consists of lateral van-der-Waals-bonded and oriented graphite nanoplatelets at the micro/nanoscale, which together with a thin PCM layer between the sheets synergistically enhance KPCM in the range of 4.4-35.0 W m-1 K-1 at graphite loadings below 40.0 wt%. The resulting PCCs also demonstrate homogeneity, no leakage, and superior phase change behavior, which can be easily engineered into devices for efficient thermal energy harvesting by coordinating the sheet orientation with the thermal transport direction. This method offers a promising route to high-power-density and low-cost applications of PCMs in large-scale thermal energy storage, thermal management of electronics, etc.

18.
Proc Natl Acad Sci U S A ; 116(46): 23192-23201, 2019 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-31659037

RESUMO

Species assemble into communities through ecological and evolutionary processes. Phylogenetic niche conservatism-the tendency of species to retain ancestral ecological distributions-is thought to influence which species from a regional species pool can persist in a particular environment. We analyzed data for seed plants in China to test hypotheses about the distribution of species within regional floras. Of 16 environmental variables, actual evapotranspiration, minimum temperature of the coldest month, and annual precipitation most strongly influenced regional species richness, phylogenetic dispersion, and phylogenetic diversity for both gymnosperms (cone-bearing plants) and angiosperms (flowering plants). For most evolutionary clades at, and above, the family level, the relationships between metrics of phylogenetic dispersion (i.e., average phylogenetic distance among species), or phylogenetic diversity, and the 3 environmental variables were consistent with the tropical niche conservatism hypothesis, which predicts closer phylogenetic relatedness and reduced phylogenetic diversity with increasing environmental stress. The slopes of the relationships between phylogenetic relatedness and the 3 environmental drivers identified in this analysis were steeper for primarily tropical clades, implying greater niche conservatism, than for primarily temperate clades. These observations suggest that the distributions of seed plants across large-scale environmental gradients in China are constrained by conserved adaptations to the physical environment, i.e., phylogenetic niche conservatism.

19.
J Virol ; 93(23)2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31534045

RESUMO

Type A and type B influenza viruses (FluA and FluB viruses) are two major human pathogens that share common structural and functional features. FluA and FluB viruses can reassort within each type but never between the types. Here, we bioinformatically analyzed all promoter sequences of FluA and FluB viruses and confirmed the presence of the type-specific promoter elements. We then studied the promoter elements with cell-based in vivo assays and an in vitro replication initiation assay. Our results identified, for the first time, a type-specific promoter element-the nucleotide at position 5 in the 3' end of the viral RNA (vRNA)-that plays a key role(s) in modulating polymerase activity in a type-specific manner. Interestingly, swapping the promoter element between FluA and FluB recombinant viruses showed different tolerances: the replacement of FluA virus-specific U5 with FluB virus-specific C5 in influenza virus A/WSN/33 (H1N1) could be reverted to U5 after 2 to 3 passages, while the replacement of FluB virus-specific C5 with FluA virus-specific U5 in influenza virus B/Yamagata/88 could be maintained, but with significantly reduced replication efficiency. Therefore, our findings indicate that the nucleotide variation at position 5 in the 3' end of the vRNA promoter between FluA and FluB viruses contributes to their RNP incompatibility, which may shed new light on the mechanisms of intertypic exclusion of reassortment between FluA and FluB viruses.IMPORTANCE Genetic reassortment of influenza virus plays a key role in virus evolution and the emergence of pandemic strains. The reassortment occurs extensively within either FluA or FluB viruses but never between them. Here, we bioinformatically compared available promoter sequences of FluA and FluB viruses and confirmed the presence of the type-specific promoter elements. Our in vivo and in vitro mutagenesis studies showed that a type-specific promoter element-the nucleotide at position 5 in the 3' end of vRNA promoters-plays key roles in modulating polymerase activity. Interestingly, FluA and FluB viruses showed different tolerances upon key promoter element swapping in the context of virus infections. We concluded that the nucleotide at position 5 in the 3' end of the vRNA promoters of FluA and FluB viruses is a critical type-specific determinant. This work has implications for further elucidating the mechanisms of the intertypic exclusion of reassortment between FluA and FluB viruses.

20.
Mol Cytogenet ; 12: 38, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31485271

RESUMO

Background: Pregnancy complications could lead to maternal and fetal morbidity and mortality. Early diagnosing and managing complications have been associated with good outcomes. The placenta was an important organ for development of pregnancy complications. Thus, non-invasive prenatal testing technologies could detect genetic variations, such as aneuploidies and sub-chromosomal copy number variations, reflecting defective placenta by maternal plasma cffDNAs. Maternal cffDNAs had been proved to derive from trophoblast cells of placenta. Results: In order to find out the relationship between genetic variations and pregnancy complications, we reviewed NIPT results for subchromosomal copy number variations in a cohort of 3890 pregnancies without complications and 441 pregnancies with pregnancy complications including gestational diabetes mellitus (GDM), pregnancy-induced hypertension (PIH), preterm prelabor rupture of membranes (PPROM) and placenta implantation abnormalities (PIA). For GDMs, we identified three CNV regions containing some members of alpha- and beta-defensins, such as DEFA1, DEFA3, DEFB1. For PIHs, we found three duplication and one deletion region including Pcdhα, Pcdhß, and Pcdhγ, known as protocadherins, which were complicated by hypertensive disorders. For PPROMs and PIAs, we identified one and two CNV regions, respectively. SFTPA2, SFTPD and SFTPA1, belonging to surfactant protein, was considered to moderated the inflammatory activation within the fetal extra-embryonic compartment, associated to duration of preterm prelabor rupture of fetal membranes, while MEF2C and TM6SF1 could be involved in trophoblast invasion and differentiation. Conclusions: Our findings gave a clue to correlation between genetic variations of maternal cell-free DNAs and pregnancy complications.

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