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1.
J Hazard Mater ; 382: 121025, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31446351

RESUMO

The fate of antibiotic resistance genes (ARGs) in reclaimed water reuse system with integrated membrane process (IMR) was firstly investigated. Results indicated that ARGs, class 1 integrons (intI1) and 16S rRNA gene could be reduced efficiently in the IMR system. The absolute abundance of all detected ARGs in the reuse water after reverse osmosis (RO) filtration of the IMR system was 4.03 × 104 copies/mL, which was about 2-3 orders of magnitude lower than that in the raw influent of the wastewater treatment plants (WWTPs). Maximum removal efficiency of the detected genes was up to 3.8 log removal values. Daily flux of the summation of all selected ARGs in the IMR system decreased sharply to (1.02 ±â€¯1.37) ×1014 copies/day, which was 1-3 orders of magnitude lower than that in the activated sludge system (CAS) system. The strong clustering based on ordination analysis separated the reuse water from other water samples in the WWTPs. Network analysis revealed the existence of potential multi-antibiotic resistant bacteria. The potential multi-antibiotic resistant bacteria, including Clostridium and Defluviicoccus, could be removed effectively by microfiltration and RO filtration. These findings suggested that the IMR system was efficient to remove ARGs and potential multi-antibiotic resistant bacteria in the wastewater reclamation system.

2.
Adv Exp Med Biol ; 1179: 71-107, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31741334

RESUMO

More than 95% of adult infected with HBV show acute self-limited infection and eventually eliminate the virus. In contrast, about 90% of people exposed to HBV in early childhood develop chronic infection. The specificity of the virus and the host's antiviral immune responses together determine the outcome of HBV infection. It is generally believed that viral genome variation, viral titers, and inhibition of viral components against the host immune system are associated with persistent infection and liver damage. The dysfunction of innate immune cells (NK cells, monocyte/macrophages, NKT cells, etc.) and adaptive immune cells (antigen-presenting cells, T cells, B cells) is a key factor leading to virus clearance failure and liver inflammation. In this chapter, we summarize these viral factors and host factors in acute and chronic hepatitis B and update recent understanding of the immune-tolerant phase and pathological mechanisms associated with age and vertical transmission. This will help us to understand more fully the mechanisms of chronic HBV infection and liver injury and to develop combined treatment strategies of direct antiviral drugs for HBV life cycle and immunomodulators.


Assuntos
Vírus da Hepatite B , Hepatite B , Antivirais/uso terapêutico , Hepatite B/tratamento farmacológico , Hepatite B/imunologia , Hepatite B/patologia , Hepatite B/virologia , Vírus da Hepatite B/genética , Vírus da Hepatite B/imunologia , Hepatite B Crônica/imunologia , Hepatite B Crônica/patologia , Hepatite B Crônica/virologia , Humanos , Carga Viral
3.
Chemosphere ; 238: 124694, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31524628

RESUMO

Techniques for reutilization of the discarded bischofite are limited while efficient recovery of the Mg(OH)2 nanoparticles from water during the synthesis and reuse processes is a challenge. In this study, the Fe3O4@Mg(OH)2 core-shell magnetic nanoparticles were firstly prepared from discarded bischofite and used as catalyst for improving the ozonation of metronidazole (MNZ). The removal rate constant of MNZ increased by 694.7% using Fe3O4@Mg(OH)2. Compared with the Mg(OH)2 control, the MNZ removal rate constant of Fe3O4@Mg(OH)2 treatment was almost tripled. The persistent high catalytic activity of the Fe3O4@Mg(OH)2 catalyst was observed since the MNZ removal rate constant decreased by just 13.2% in the third reuse run. The Fe3O4@Mg(OH)2 primarily enhanced ozone decomposition through producing hydroxyl radicals. The MNZ removal rate constant increased from 0.075 min-1 to 0.643 min-1 as catalyst dose increased from 0 to 0.6 g L-1 while it decreased by 96.0% when its initial concentration increased from 10 to 200 mg L-1. The maximum removal rate constant was observed at 25 °C when temperature increased from 15 °C to 35 °C. The Cl-, HCO3-, SO42-, Ca2+, Mg2+ ions could jeopardize MNZ degradation. The antibacterial activity of MNZ was eliminated after catalytic ozonation while the mineralization efficiency was almost doubled. The nitro group reduction and the cleavage of hydroxyethyl bond were two main transformation pathways of MNZ. These findings suggest that Fe3O4@Mg(OH)2 nanoparticle made from discarded bischofite is the promising catalyst for the ozonation of antibiotics in the terms of water purification practice and reutilization of the bischofite.

4.
Ecotoxicol Environ Saf ; 187: 109852, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31670243

RESUMO

Microplastics have become emerging pollutants and served as potential vectors for harmful bacteria, while rare information on the emergency and propagation of antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) on the surface of microplastics is available. This study investigated the enrichment of ARB, especially multi-antibiotic resistant bacteria (MARB), on the surface of microplastics in mariculture system. Polyethylene terephthalate accounted for the highest proportion (75%) in the collected microplastics. The counts of cultivable ARB in microplastic samples were 6.40 × 106-2.48 × 108 cfu/g, which were 100-5000 times higher than those in water samples. The ratios of cultivable ARB to total cultivable bacteria from microplastic samples were higher than those from water samples. High-throughput sequencing showed that the diversity and abundance of cultivable ARB in the microplastic samples was high with the predominant bacterial genera of Vibrio, Muricauda and Ruegeria. Total 160 MARB isolates were obtained and most of isolates were obtained from the microplastic samples. MARB isolates resisting or intermediating to four and three antibiotics accounted for much higher proportions in the microplastic samples, and the higher percentage of antibiotic resistance was to penicillin, sulfafurazole, erythromycin and tetracycline. The dominant multiple antibiotic resistance profile was TET-SFX-ERY-PEN, which accounted for 25.4% in microplastic samples and 23.9% in water samples. In typical MARB isolates, the positive detection rate of ARGs was up to 80.0% in microplastic samples while that was 65.3% in water samples. Five types of class 1 integrons (intI1) associated gene cassette arrays and seven types of gene cassettes were detected in microplastic samples, which were more than those in water samples. These results revealed that microplastics were hazardous pollutants for the enrichment of ARB, especially superbugs, and the spread of antibiotic resistance.

5.
Appl Opt ; 58(27): 7359-7366, 2019 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-31674381

RESUMO

The phase-coding method has been widely used for 3D shape measurement, which uses sinusoidal phase-shifting patterns to recover the wrapped phase and the stair phase-coding patterns to determine the fringe order. However, due to random noises and image blurring, the fringe order is always misaligned with the wrapped phase, which will lead to fringe order errors. This paper presents an enhanced phase-coding method to address this misalignment problem by using half-period codewords, in which each codeword is aligned to the half-period of the sinusoidal patterns. Then, two complementary fringe orders with half-period dislocation can be calculated, which can effectively eliminate the fringe order errors. To extend the coding range of stair phase, this paper further develops a computational scheme based on the geometric constraint method. Simulations and experiments have been carried out, and their results confirm that the enhanced method can reliably recover the 3D shape of the measured objects.

6.
J Opt Soc Am A Opt Image Sci Vis ; 36(10): 1795-1800, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31674446

RESUMO

To solve the imaging distortion problem in a nonuniform temperature field for visual measurement, this paper studies the Runge-Kutta ray tracing algorithm. First, the light ray emitted by the spatial light point will be abstracted by the proposed method. Then, the ray trajectory in a 3D nonuniform temperature gradient environment will be reproduced, and the ray distortion can be corrected. Finally, the distortion is compared with the actual image distortion obtained through the corner detection method. The experimental results show that the correction method for the distortion image caused by nonuniform temperature gradient heat source interference is feasible by using the Runge-Kutta ray tracing algorithm, which can realize the error compensation for image distortion and obtain an accurate corrected image.

7.
Medicine (Baltimore) ; 98(48): e17866, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31770200

RESUMO

BACKGROUND: The association between interleukin-8 (IL-8) gene polymorphism -251 A>T and susceptibility to coronary artery disease (CAD) has been investigated previously; however, results remain controversial. Thus, a meta-analysis was conducted to reassess the effects of this polymorphism on CAD risks. METHODS: The PubMed, Cochrane Library, China National Knowledge Infrastructure, and Wanfang databases were searched for relevant studies published up to December, 2018. The pooled odds ratios (OR) were calculated using STATA 13.0 software for allelic (A vs T) as well as homozygote (AA vs TT), heterozygote (AT vs TT), recessive (AA vs AT + TT), and dominant (AA + AT vs TT) genotype models, respectively. RESULTS: Ten case-control studies (3744 cases and 3660 controls) were included. Overall, a significant association of IL-8 gene -251 A > T polymorphism with an increased risk of CAD was only observed in the dominant genotype model (OR = 1.48), but not others. In the subgroup analysis, significantly increased risks were also found for Chinese (OR = 1.64), polymerase chain reaction-restriction fragment length polymorphism genotyping (OR = 1.61), acute coronary syndrome (ACS) type (OR = 1.92 for 3 datasets; OR = 1.88 for 4 datasets), high quality (OR = 1.64), and age/gender matching status (OR = 1.55) under the dominant model. Furthermore, significantly increased risks were also found for ACS type under allelic (OR = 1.32 for 3 datasets; OR = 127 for 4 datasets), homozygote (OR = 1.64 for 3 datasets; OR = 1.50 for 4 datasets), heterozygote (OR = 1.32 for 3 datasets; OR = 1.30 for 4 datasets), and recessive (OR = 1.40 for 3 datasets; OR = 1.28 for 4 datasets) models. CONCLUSION: This meta-analysis suggests that Chinese patients carrying -251A allele of IL-8 may have an increased risk for the development of CAD, especially ACS.

8.
Sci Rep ; 9(1): 17162, 2019 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-31748581

RESUMO

Ultra-low-loss and large-effective-area fiber has been successfully applied in transoceanic transmission, which is considered as a promising candidate for 100 Gbit/s and beyond 100 Gbit/s coherent long-haul terrestrial optical networks. Several theoretical and experimental investigations have been reported, including provincial terrestrial field trial. To support long-haul terrestrial application, it is urgent to prove that the ultra-low-loss and large-effective-area fiber after terrestrial deployment can significantly enhance the performance of long-haul transmission over 1000 km compared with the conventional single mode fiber. In this paper, we extended our previous work and summarized design methods for complex terrestrial environment. To verify the fiber characteristics in long-haul terrestrial transmission, we installed the longest terrestrial ultra-low-loss and large-effective-area fiber link in the world with a total length of 1539.6 km. The results show that the transmission performances of wavelength-division-multiplexed signals with per-channel data rates of 100 Gbit/s, 200 Gbit/s, and 400 Gbit/s over the ultra-low-loss and large-effective-area fiber are all obviously improved, demonstrating that this fiber is more suitable for ultrahigh-speed long-haul terrestrial transmission.

9.
BMC Nephrol ; 20(1): 409, 2019 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-31722677

RESUMO

BACKGROUND: Delayed graft function (DGF) is an important complication of kidney transplantation and can be diagnosed according to different definitions. DGF has been suggested to be associated with the long-term outcome of kidney transplantation surgery. However, the best DGF definition for predicting renal transplant outcomes in Chinese donations after cardiac death (DCDs) remains to be determined. METHOD: A total of 372 DCD kidney transplant recipients from June 2013 to July 2017 in the First Affiliated Hospital of Xi'an Jiaotong University were included in this retrospective study to compare 6 different DGF definitions. The relationships of the DGF definitions with transplant outcome were analyzed, including graft loss (GL) and death-censored graft loss (death-censored GL). Renal function indicators, including one-year estimated glomerular filtration rate (eGFR) and three-year eGFR, and were compared between different DGF groups. RESULTS: The incidence of DGF varied from 4.19 to 35.22% according to the different DGF diagnoses. All DGF definitions were significantly associated with three-year GL as well as death-censored GL. DGF based on requirement of hemodialysis within the first week had the best predictive value for GL (AUC 0.77), and DGF based on sCr variation during the first 3 days post-transplant had the best predictive value for three-year death-censored GL (AUC 0.79). Combination of the 48-h sCr reduction ratio and classical DGF can improve the AUC for GL (AUC 0.85) as well as the predictive accuracy for death-censored GL (83.3%). CONCLUSION: DGF was an independent risk factor for poor transplant outcome. The combination of need for hemodialysis within the first week and the 48-h serum creatinine reduction rate has a better predictive value for patient and poor graft outcome.

10.
J Mater Chem B ; 2019 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-31746934

RESUMO

The applications of nanoparticulate drug delivery have received abundant interest in the field of cancer diagnosis and treatment. By virtue of their unique features and design, nanomedicines have made remarkable progress in eliminating dreadful tumors. Research in cancer nanomedicine has spanned multitudes of drug delivery systems that possess high tumor targeting ability, sensitivity towards tumor microenvironments and improved efficacy. Various nanocarriers have been developed and approved for anti-tumor drug targeting. These nanocarriers, i.e., liposomes, micelles, nanotubes, dendrimers and peptides, offer a wide range of advantages, such as high selectivity, multi-functionality, specificity, biocompatibility and precise control of drug release. Nanomedicines based on self-assembled peptide carrier systems have been developed in recent years for cancer targeting. Self-assembled peptides have tremendous properties of forming targeted drug delivery vehicles such as nanohydrogels with unique features and functionality. In this review article, we discuss some developments in cancer nanomedicine. We present a diverse range of nanotargeted drug-delivery systems.

11.
Neuroradiology ; 2019 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-31713666

RESUMO

PURPOSE: Myxoma-related intracranial diseases were rarely documented in history. The main purpose of our study is to provide a more comprehensive and detailed understanding of the pathogenesis, imaging features, surgical procedures and pathology of such patients through long-term follow-up. METHODS: From March 2012 to July 2018, baseline information that included neuroimaging and neuropathology data from 12 cardiac myxoma patients with neurological symptoms were retrospectively analysed, and the treatment options were discussed. Nine patients underwent long-term postoperative follow-up. RESULTS: Twelve cardiac myxoma patients with neurological symptoms were identified, and among them, 10 patients were postoperative patients who had undergone excision of cardiac myxoma, 5 patients had received craniotomy, and the others had received conservative treatment. Positive neuroimaging findings were found in all patients, including cerebral infarction (12/12, 100%), multiple intracranial aneurysms (8/12, 67%), and extravascular metastasis (6/12, 50%). After a long-term average follow-up of 27 months, an increased number of metastatic lesions or an enlargement of the intracranial aneurysms was found in 4 patients. CONCLUSIONS: Neuroimaging findings of myxoma-related intracranial lesions were diversed and usually presented as multiple cerebral infarction, aneurysm formation, focal intracranial haemorrhage and space-occupying lesions. Progress is over a long period of time after primary tumour resection. It is necessary for patients to be regularly examined within 2 years after cardiac myxoma resection using MRI+CTA/MRA/DSA in order to be ruled out. Stable and effective chemotherapy drugs are urgently needed.

12.
Int J Nanomedicine ; 14: 8345-8360, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31695371

RESUMO

Background: The protective role of puerarin (PUE) against myocardial infarction is closely related to its regulation on mitochondria. However, free PUE can hardly reach the mitochondria of ischemic cardiomyocytes due to the lack of mitochondrial targeting of PUE. Here PUE was loaded into mitochondria-targeted micelles (PUE@TPP/PEG-PE) for precisely delivering PUE into mitochondria with the aim of enhancing the anti-apoptosis effect. Methods: The mitochondriotropic polymer TPP-PEG-PE was synthesized for the preparation of PUE@TPP/PEG-PE micelles modified with triphenylphosphonium (TPP) cation. The physicochemical properties and anti-apoptosis effect of PUE@TPP/PEG-PE micelles were investigated. The coumarin 6 (C6)-labeled TPP/PEG-PE (C6@TPP/PEG-PE) micelles were used to observe the enhanced cellular uptake, mitochondrial targeting and lysosomes escape. Moreover, in vivo and ex vivo biodistribution of lipophilic near-infrared dye 1,1'-dioctadecyl-3,3,3',3'-tetramethylindotricarbocyanine iodide (DiR)-labeled PUE@TPP/PEG-PE (DiR@TPP/PEG-PE) micelles were detected through fluorescence imaging. Results: The successful synthesis of TPP-PEG-PE conjugate was confirmed. PUE@TPP/PEG-PE micelles had a particle size of 17.1 nm, a zeta potential of -6.2 mV, and a sustained-release behavior. The in vitro results showed that the intracellular uptake of C6@TPP/PEG-PE micelles was significantly enhanced in H9c2 cells. C6@TPP/PEG-PE micelles could deliver C6 to mitochondria and reduce the capture of lysosomes. In addition, compared with the PUE@PEG-PE micelles and free PUE, the PUE@TPP/PEG-PE micelles exerted an enhanced protective effect against isoprenaline-induced H9c2 cell apoptosis, as evident by the decreased percentage of apoptotic cells, Caspase-3 activity, ROS level, Bax expression, and increased Bcl-2 expression. The in vivo detecting results of the targeting effect using DiR probe also indicated that TPP/PEG-PE micelles could accumulate and retain in the ischemic myocardium. Conclusion: The results of this study demonstrate the promising potential of applying PUE@TPP/PEG-PE micelles in mitochondria-targeted drug delivery to achieve maximum therapeutic effects of PUE.

13.
Math Biosci Eng ; 16(6): 7433-7446, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31698621

RESUMO

In this paper we consider a time-delayed mathematical model describing tumor growth with angiogenesis and Gibbs-Thomson relation. In the model there are two unknown functions: One is $\sigma(r,t)$ which is the nutrient concentration at time $t$ and radius $r$, and the other one is $R(t)$ which is the outer tumor radius at time $t$. Since $R(t)$ is unknown and varies with time, this problem has a free boundary. Assume $\alpha(t)$ is the rate at which the tumor attracts blood vessels and the Gibbs-Thomson relation is considered for the concentration of nutrient at outer boundary of the tumor, so that on the outer boundary, the condition $$\dfrac{\partial \sigma}{\partial r}+\alpha(t)\left(\sigma-N(t)\right)=0,~~r=R(t)$$ holds, where $N(t)=\bar{\sigma}\left(1-\dfrac{\gamma}{R(t)}\right)H(R(t))$ is derived from Gibbs-Thomson relation. $H(\cdot)$ is smooth on $(0,\infty)$ satisfying $H(x)=0$ if $x\leq \gamma$, $H(x)=1$ if $x\geq 2\gamma$ and $0\leq H'(x)\leq 2/\gamma$ for all $x\geq 0$. In the case where $\alpha$ is a constant, the existence of steady-state solutions is discussed and the stability of the steady-state solutions is proved. In another case where $\alpha$ depends on time, we show that $R(t)$ will be also bounded if $\alpha(t)$ is bounded and some sufficient conditions for the disappearance of tumors are given.

14.
Chembiochem ; 2019 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-31702879

RESUMO

The activation of toll like receptors (TLRs) plays important roles in the immune response. The ability to control the activities of TLRs could be used as a switch for immune response. Herein, we rationally designed and synthesized a photoswitchable Pam3CSK4 derivative (P10) to control the activation of TLR1/2. The ground state trans-P10 could stimulate and activate antigen-presenting cells (APCs) through promoting the TLR1/2 dimerization. However, the cis-P10, derived from UV irradiation of trans-P10, reduced the activities of APCs by impeding the TLR1/2 dimerization. In the absence of UV radiation, the cis-P10 slowly returned to its ground trans state, restoring the activities of the APCs stimulating. Our results indicated that the optical control of TLR1/2 dimerization mediated by the photoswitchable P10 holds potential to regulate the immune activation and inflammation.

15.
Anal Chem ; 2019 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-31718142

RESUMO

Positron-emission tomography (PET) is routinely used in the clinic for tumor imaging with ultrahigh sensitivity, but tumor-targeted PET imaging probes are quite few. In this work, we rationally designed a furin-responsive radiotracer Acetyl-Arg-Val-Arg-Arg-Cys(StBu)-Lys(DOTA-68Ga)-CBT (CBT-68Ga) and demonstrated that coinjection of the radiotracer with its cold analogue CBT-Ga instructed the formation of 68Ga nanoparticles in furin-overexpressing MDA-MB-468 cancer cells, which significantly enhanced microPET imaging of the tumor in vivo. In vitro results showed that CBT-Ga subjected to furin-initiated CBT-Cys condensation reaction and self-assembly to form the nanoparticles CBT-Ga-NPs with an average diameter of 258.3 nm. In vivo microPET imaging results indicate that the mice coinjected with CBT-68Ga and CBT-Ga, which warrants 68Ga nanoparticle formation in their MDA-MB-468 tumors, had a tumor/liver ratio 9.1-fold of that of the mice only injected with CBT-68Ga. We envisioned that, by replacing the RVRR substrate of CBT-68Ga with other enzyme-specific ones and using the strategy of intracellular nanoparticle formation, a series of radioactive probes could be developed for more sensitive and precise tumor microPET imaging in the near future.

16.
Br J Haematol ; 2019 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-31725190

RESUMO

We explored the prognostic factors for children with very high-risk (VHR) Philadelphia chromosome (Ph) negative B-cell acute lymphoblastic leukaemia (B-ALL) and compared the therapeutic effects of intensive chemotherapy and unmanipulated haploidentical haematopoietic stem cell transplantation (haplo-HSCT) as post-remission treatment in these patients undergoing first complete remission (CR1). A total of 104 paediatric patients with VHR B-ALL in CR1 were retrospectively enrolled in this study, including 42 receiving unmanipulated haplo-HSCT (Group A) and 62 receiving ongoing chemotherapy (Group B). Estimated 3-year overall survival (OS), disease-free survival (DFS) and cumulative incidence of relapse (CIR) at 36·2 months median follow-up were 69·5 ± 4·7%, 63·5 ± 4·8% and 32·4 ± 4·7%, respectively. Maintenance of persistent positive or conversion from negative to positive of measurable residual disease (MRD) and chemotherapy were independent risk factors associated with inferior long-term survival and higher CIR. OS, DFS, and CIR differed significantly between the groups in patients with persistent positive or negative-to-positive MRD. Haplo-HSCT may be an option for children with VHR Ph-negative B-ALL in CR1, especially for patients with persistent positive or negative-to-positive MRD, and could achieve better survival than intensive chemotherapy as post-remission treatment.

17.
Psychol Res ; 2019 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-31741051

RESUMO

It is widely accepted that associative recognition can be supported by familiarity through integrating more than two stimuli into a unit, but the role of unitization in recollection-based associative recognition remains unclear. In this study, we aimed to illustrate how the level of unitization (LOU) affected recollection-based associative recognition and to examine whether the unitization-congruence between original and rearranged picture pairs (UC) could have effect on the relationship between LOU and associative recognition. In encoding, participants were asked to learn related and unrelated picture pairs, and in retrieval, they needed to distinguish intact pairs from rearranged pairs. We also distinguished the LOU of the pairs based on its status at encoding or retrieval separately. The results showed that: (1) LOU-at-encoding could improve associative recognition through increasing recollection-based associative recognition selectively; (2) LOU-at-retrieval could improve associative recognition through increasing familiarity-based and recollection-based associative recognitions; (3) UC did not moderate the relationship between LOU and associative recognition. Hence, in future studies, researchers do not need to pay much attention to the construction of rearranged pairs to ensure that the LOU between original and rearranged picture pairs is matched. It greatly reduces the difficulty of materials selection.

18.
Plant Biotechnol J ; 2019 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-31742855

RESUMO

Because of the frequent breakdown of major resistance (R) genes, identification of new partial R genes against rice blast disease is an important goal of rice breeding. In this study, we used a core collection of the Rice Diversity Panel II (C-RDP-II), which contains 584 rice accessions and are genotyped with 700,000 single-nucleotide polymorphism (SNP) markers. The C-RDP-II accessions were inoculated with three blast strains collected from different rice-growing regions in China. Genome-wide association study identified 27 loci associated with rice blast resistance (LABRs). Among them, 22 LABRs were not associated with any known blast R genes or QTLs. Interestingly, a nucleotide-binding site leucine-rich repeat (NLR) gene cluster exists in the LABR12 region on chromosome 4. One of the NLR genes is highly conserved in multiple partially resistant rice cultivars, and its expression is significantly up-regulated at the early stages of rice blast infection. Knockout of this gene via CRISPR-Cas9 in transgenic plants partially reduced blast resistance to four blast strains. The identification of this new non-strain specific partial R gene, tentatively named rice blast Partial Resistance gene 1 (PiPR1), provides genetic material that will be useful for understanding the partial resistance mechanism and for breeding durably resistant cultivars against blast disease of rice.

19.
Sci Rep ; 9(1): 16464, 2019 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-31712620

RESUMO

Osmosis is the movement of solvent across a permselective membrane induced by a solute-concentration gradient. Now in 'Forward Osmosis' it is empirically observed that the diffusion of the solute is counter to that of the solvent i.e. there is so-called "reverse salt diffusion". However it has been recently suggested, in a theoretical paper, that if allowance is made for minor deviations from ideal semi-permeability then operation in an overlooked mode of "breakthrough" osmosis would be possible and importantly it would yield relatively large rates of osmosis. A consequential prediction was that in "breakthrough mode", Pressure-Retarded Osmosis (PRO) would generate very high power densities exceeding those in the conventional mode by one order of magnitude. The practicality of this suggestion was explored and necessarily questions were then raised regarding the foundation of the Spiegler-Kedem-Katchalsky model.Arising from: Yaroshchuk, A., Sci. Rep. 7, 45168 (2017); https://doi.org/10.1038/srep45168.

20.
Sci Total Environ ; 702: 135049, 2019 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-31715398

RESUMO

Based on their differences in the kinetic values, the nitrifiers could be classified into the fast-growing "r-strategists" and the slow-growing "K-strategists" bacteria. However, the difference in the kinetic values originated not only from the intrinsic differences among the nitrifier species, but also from other factors, i.e. sludge floc morphology, and the environment in which the nitrifiers were cultivated. It is not clear how these factors interact and affect the measured kinetic parameters and the competition among the "r-strategists" and the "K-strategists" bacteria. In this study, the kinetic parameters of nitrifiers cultivated in the SBR (sequencing batch reactor) under different substrate concentrations were monitored, together with the identification of nitrifier species and sludge floc morphology characterization. The results showed that the r-AOB and r-NOB ("r-strategists" ammonium-oxidizing bacteria and nitrite-oxidizing bacteria, i.e., Nitrosomonas and Nitrospira) were the dominant nitrifiers in the SBR reactor. A mathematical model describing the competition between r/K AOB and NOB showed that r-AOB and r-NOB could be enriched in the SBR. The experimental investigation supported the model simulation results. The model simulation also revealed that the different r/K AOB and NOB species could be enriched in different DO concentrations and SRT conditions, which could be manipulated to promote the growth of r-AOB and NO2- accumulation for the autotrophic nitrogen removal using ANAMMX.

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