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1.
ACS Nano ; 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31674755

RESUMO

Two-dimensional (2D) semiconductors have demonstrated great potential in modern nanotechnologies across a variety of research fields, including (opto-)electronics, spintronics, and electro-/photocatalysis. Interestingly, the vast majority of 2D semiconductors, such as the widely explored transition-metal dichalcogenides, are n-type or ambipolar. The search for p-type 2D semiconductors in the past decade has succeeded in identifying only a few promising candidate materials. In this Perspective, we discuss various strategies to obtain p-type conduction in normally n-type or ambipolar 2D semiconductors and, more importantly, the direct synthesis of p-type 2D semiconductors such as black phosphorus, 2D tellurium, and, most recently, α-MnS.

2.
Opt Lett ; 44(21): 5145-5148, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31674952

RESUMO

An optical fiber high-temperature sensor is proposed and demonstrated by use of cascaded multiple Fabry-Perot interferometers in no-core fiber with a waveguide fabricated by femtosecond laser pulse inscription. The device can sustain the high temperature up to 1100°C, and the temperature sensitivity obtained is 8.9 pm/°C within the temperature range 100°C-400°C, and 16.36 pm/°C within the temperature range 400°C-1100°C, respectively. Such a no-core fiber-based device can be fabricated in a simple way and operated reliably, which makes it attractive for extreme environment monitoring.

3.
Nat Methods ; 16(11): 1109-1113, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31673159

RESUMO

We present cleared-tissue axially swept light-sheet microscopy (ctASLM), which enables isotropic, subcellular resolution imaging with high optical sectioning capability and a large field of view over a broad range of immersion media. ctASLM can image live, expanded, and both aqueous and non-aqueous chemically cleared tissue preparations. Depending on the optical configuration, ctASLM provides up to 260 nm of axial resolution, a three to tenfold improvement over confocal and other reported cleared-tissue light-sheet microscopes. We imaged millimeter-scale cleared tissues with subcellular three-dimensional resolution, which enabled automated detection of multicellular tissue architectures, individual cells, synaptic spines and rare cell-cell interactions.

4.
Neuroradiology ; 2019 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-31673748

RESUMO

PURPOSE: Intracranial solitary fibrous tumor/hemangiopericytoma (SFT/HPC) and meningioma are difficult to distinguish owing to their overlapping imaging manifestation on routine magnetic resonance imaging. The purpose of this study was to assess whether SFT/HPC can be differentiated from meningioma with diffusion-weighted imaging (DWI) and susceptibility-weighted imaging (SWI). METHODS: We retrospectively reviewed DWI, SWI, conventreional MR, and CT imaging features of 16 patients with SFT/HPC and 96 patients with meningioma. The apparent diffusion coefficient (ADC) value, normalized ADC (nADC) value, and degree of intratumoral susceptibility signal intensity (ITSS) were compared between SFT/HPCs and meningiomas using two-sample t tests, and among SFT/HPCs, low-grade and high-grade meningioma were tested using one-way analysis of variance (ANOVA). Receiver operating characteristic (ROC) curve and logistic regression analyses were performed to determine the differentiation capacity. RESULTS: The ADC value, nADC value, and the degree of ITSS in SFT/HPC were significantly higher than those in low-grade and high-grade meningiomas (all p < 0.05). The threshold value of > 1.15 for nADC provided 75.00% sensitivity and 60.42% specificity for differentiating SFT/HPC from meningioma. Compared with nADC, the degree of ITSS had a moderate sensitivity (62.50%) and a higher specificity (85.42%) using the threshold value of > 1.00. Furthermore, combining DWI and SWI can achieve a relatively high differentiation capacity with a sensitivity of 81.25% and specificity of 78.12%. CONCLUSIONS: The nADC ratios and ITSS are useful for differentiating SFT/HPC from meningioma. Combining ITSS and nADC value appears to be a promising option for differential diagnosis.

5.
Mikrochim Acta ; 186(11): 733, 2019 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-31673848

RESUMO

Walnut shell was processed for preparing nanoporous carbon, which further underwent element doping in order to boost its performance. A novel electrochemical sensor was then built by using the nitrogen and sulfur co-doped walnut shell carbon (N,S-WSC). Morphology and microstructure of the materials were characterized by scanning electron microscopy and Brunauer-Emmett-Teller (de)sorption which showed that N,S-WSC has a large specific surface with abundant pores. Electrochemical properties of differently modified sensors were investigated by cyclic voltammetry and electrochemical impedance spectroscopy. They demonstrated enhanced conductivity and enlarged surface after N,S co-doping. The modified electrode exhibits good catalytic ability towards paracetamol (ACOP) and p-aminophenol (PAP), and baseline separation of their oxidation peaks (peak potential difference is 0.24 V) allows for simultaneous detection of these two compounds. Under the optimal conditions, the calibration plot is linear in the 0.1 to 220 µM ACOP concentration range, with a 26 nM detection limit. Response to PAP is linear from 1.0 to 300 µM, and the detection limit is 38 nM (at S/N = 3). The sensor was successfully applied to quantify ACOP and PAP in tablets, and the accuracy of results is validated by HPLC. Graphical abstract Schematic representation of a novel electrochemical sensor based on N, S co-doped walnut shell carbon modified glassy carbon electrode for determination of paracetamol and p-aminophenol.

6.
J Mol Histol ; 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31667691

RESUMO

Mutations in the gene encoding family with sequence similarity 20, member A (FAM20A) caused amelogenesis imperfecta (AI), in humans. However, the roles of FAM20A in amelogenesis and dentinogenesis are poorly understood. In this study, we generated a Fam20a knockout (Sox2-Cre;Fam20afl/fl) mouse model by crossing Fam20afl/fl mice with Sox2-Cre transgenic mice, in which Fam20a was ablated in both dental epithelium and dental mesenchyme. We found that these mice developed an enamel phenotype that resembles human AI associated with FAM20A mutations, but did not have apparent dentin defects. The secretory stage ameloblasts in the mandibular incisors from the Sox2-Cre;Fam20afl/fl mice were shorter and detached from the enamel matrix, and subsequently lost their polarity, became disorganized and formed numerous spherical extracellular matrices in place of normal enamel. At the molecular level, the Sox2-Cre;Fam20afl/fl mice displayed dramatically reduced expression levels of the genes encoding the enamel matrix proteins, but unaltered levels of the genes encoding the dentin matrix proteins. Moreover, Fam20a ablation resulted in a great decrease in FAM20C protein level, but it did not alter the intracellular localization of FAM20C protein in ameloblasts and odontoblasts. These results indicate that FAM20A is essential for amelogenesis, but is dispensable for dentinogenesis.

7.
Artigo em Inglês | MEDLINE | ID: mdl-31668814

RESUMO

Glioblastoma (GBM) is the most lethal type of glioma in human adults and frequently recurs. Therefore, identification of the underlying mechanisms of GBM therapy resistance is crucial. Endothelial cell specific molecule-1 (ESM1) expression is elevated in a wide range of malignant tumors and correlates with poor prognosis. However, the functional role of ESM1 in GBM remains unclear. Herein, we sought to determine the relevance of ESM1 in GBM and the potential underlying mechanisms of ESM1 in GBM development, progression, and radioresistance. Using bioinformatics analyses, we identified ESM1 as the gene most highly associated with radioresistance in GBM. Clinically, elevated ESM1 was observed in GBM and correlated with poor prognosis. Functionally, silencing of ESM1 significantly reduced GBM cell proliferation, tumorigenesis, and radioresistance. GSEA revealed a correlation between ESM1 and epithelial-mesenchymal transition (EMT), and exogenous overexpression of ESM1 induced mesenchymal transition in GBM cells, enhancing radioresistance. Lastly, our data suggest that ESM1 regulates nuclear factor kappa B (NFκB) promoter activity, promoting the mesenchymal transition of GBM cells. Taken together, our findings suggest that ESM1-dependent transcriptional regulation of NFκB contributes to mesenchymal transition, and therefore enhances GBM radioresistance and tumorigenesis.

8.
Adv Mater ; : e1903826, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31566269

RESUMO

The rapid development of electrochemical energy storage (EES) systems requires novel electrode materials with high performance. A typical 2D nanomaterial, layered transition metal dichalcogenides (TMDs) are regarded as promising materials used for EES systems due to their large specific surface areas and layer structures benefiting fast ion transport. The typical methods for the preparation of TMDs and TMD-based nanohybrids are first summarized. Then, in order to improve the electrochemical performance of various kinds of rechargeable batteries, such as lithium-ion batteries, lithium-sulfur batteries, sodium-ion batteries, and other types of emerging batteries, the strategies for the design and fabrication of layered TMD-based electrode materials are discussed. Furthermore, the applications of layered TMD-based nanomaterials in supercapacitors, especially in untraditional supercapacitors, are presented. Finally, the existing challenges and promising future research directions in this field are proposed.

9.
Adv Mater ; : e1904589, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31566277

RESUMO

Insertion-type anode materials with beneficial micro- and nanostructures are proved to be promising for high-performance electrochemical metal ion storage. In this work, heterostructured TiO2 shperes with tunable interiors and shells are controllably fabricated through newly proposed programs, resulting in enhanced pseudocapacitive response as well as favorable Na+ storage kinetics and performances. In addition, reasonably designed nanosheets in the extrinsic shells are also able to reduce the excess space generated by hierarchical structure, thus improving the packing density of TiO2 shperes. Lastly, detailed density functional theory calculations with regard to sodium intercalation and diffusion in TiO2 crystal units are also employed, further proving the significance of the surface-controlled pseudocapacitive Na+ storage mechanism. The structure design strategies and experimental results demonstrated in this work are meaningful for electrode material preparation with high rate performance and volume energy density.

10.
J Asian Nat Prod Res ; : 1-6, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31566431

RESUMO

Two new naphthoate derivatives, including a symmetrical dimer (1) and a monomer (2), were separated from the roots of Morinda officinalis var. hirsuta. Their structures were characterized on the basis of spectroscopic means especially MS and NMR methods. Biological evaluations revealed that the two compounds did not show inhibition against both cholinesterases AChE and BChE, while the dimer (1) did exhibit moderate growth inhibitory activity toward one human osteosarcoma cell line U2OS with an IC50 value of 18.5 ± 1.1 µM.

11.
ACS Nano ; 2019 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-31577129

RESUMO

Atomically thin layers of transition-metal dichalcogenides semiconductors, such as MoS2, exhibit strong and circularly polarized light emission due to inherent crystal symmetries, pronounced spin-orbit coupling, and out-of-plane dielectric and spatial confinement. While the layer-by-layer confinement is well-understood, the understanding of the impact of in-plane quantization in their optical spectrum is far behind. Here, we report the optical properties of atomically thin MoS2 colloidal semiconductor nanocrystals. In addition to the spatial-confinement effect leading to their blue wavelength emission, the high quality of our MoS2 nanocrystals is revealed by narrow photoluminescence, which allows us to resolve multiple optically active transitions, originating from quantum-confined excitons (coupled electron-hole pairs). Surprisingly, in stark contrast to monolayer MoS2, the luminescence of the lowest-energy levels is linearly polarized and persists up to room temperature, meaning that it could be exploited in a variety of light-emitting applications.

12.
Clin Exp Hypertens ; : 1-11, 2019 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-31589076

RESUMO

Background: Impaired orthostatic blood pressure (BP) response is a frequent finding in the elderly. The goal of the study was to investigate the association of variability of supine-to-orthostatic BP with cold pressor reflection and heart rate variability in the elderly. Methods: From June 2010 to September 2013, 287 elderly aged ≥ 60 years were enrolled in Jinan area, China. The elderly were classified into lower (n = 96), intermediate (n = 95), and higher (n = 96) tertile groups according to the tertile of the percentage change of supine-to-orthostatic systolic BP. Results: There were significant increasing trends in systolic BP response to the CPT at 0 and 60 sec; the plasma levels of epinephrine, norepinephrine, and angiotensin II; and decreasing trends in DNN, SDNN index, and SDANN from the lower to the higher tertile group, and differences between any two groups were significant (P < .05). The percentage change of supine-to-orthostatic systolic BP was positively correlated with systolic BP response to CPT at 0 and 60 sec, VLF, epinephrine, norepinephrine, and angiotensin II (P < .001) and negatively correlated with SDNN, SDNN index, SDANN, rMSSD, pNN50, LF, and ratio of LF/HF (P < .001). The BP response to CPT, parameters of HRV, and the plasma levels of norepinephrine and angiotensin II were independently associated with the percentage change of supine-to-orthostatic systolic BP after adjustment for confounders. Conclusion: Aggressive variability of supine-to-orthostatic systolic BP might be significantly associated with the imbalance of sympathetic and parasympathetic activity, especially high sensitivity sympathetic response in the elderly. Abbreviations: BP: blood pressure; BMI: body mass index; CPT: cold pressor test; HRV: heart rate variability; SDNN: standard deviation of all normal-to-normal R-R intervals; SDNN index: mean of the standard deviations of all 5-min normal-to-normal R-R intervals of the entire recording; SDANN: standard deviation of the averages of normal-to-normal R-R intervals during all 5-min periods of the entire recording; rMSSD: square root of the mean squared differences between successive normal R-R intervals; pNN50: number of adjacent normal R-R intervals differing by more than 50 ms; VLF: very low frequency; LF: low frequency; HF: high frequency; TCHO: total cholesterol; HDL-c: high-density lipoprotein cholesterol; LDL-c: low-density lipoprotein cholesterol; FPG: fasting plasma glucose; SD: standard deviation.

13.
AAPS PharmSciTech ; 20(8): 316, 2019 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-31602546

RESUMO

Glucocorticoids have been confirmed to be effective in the treatment of a variety of inflammatory diseases. However, their application encounters limitations in terms of tissue distribution and bioavailability in vivo. To address these key issues, we designed and developed a nanopreparation by using egg yolk lecithin/sodium glycocholate (EYL/SGC) and utilize such mixed micelles (MMs) to encapsulate dexamethasone palmitate (DMP) for the treatment of rheumatoid arthritis (RA). The prepared DMP-MMs had an average particle size of 49.18 ± 0.43 nm and were compared with an emulsion-based dexamethasone palmitate. Pharmacokinetic and in vivo fluorescence imaging showed that mixed micelles had higher bioavailability and targeting efficiency in inflammatory sites. An arthritis rat model was established via induction by Complete Freund's Adjuvant (CFA), followed by the efficacy studies by the observations of paw volume, histology, spleen index, pro-inflammatory cytokines, and CT images. It was confirmed that intravenous injection of DMP-MMs exhibited advantages in alleviating joint inflammation compared with the emulsion system. Composed of pharmaceutical adjuvants only, the nanoscale mixed micelles seem a promising carrier system for the RA treatment with lipophilic drugs.

14.
J Stroke Cerebrovasc Dis ; : 104375, 2019 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-31590996

RESUMO

BACKGROUND: Our previous study showed that propofol, one of the widely used anesthetic agents, can attenuate subarachnoid hemorrhage (SAH)-induced early brain injury (EBI) via inhibiting inflammatory and oxidative reaction. However, it is perplexing whether propofol attenuates inflammatory and oxidative reaction through modulating PI3K/Akt pathway. The present study investigated whether PI3K/Akt pathway is involved in propofol's anti-inflammation, antioxidation, and neuroprotection against SAH-induced EBI. MATERIALS AND METHODS: Adult Sprague-Dawley rats underwent SAH and received treatment with propofol or vehicle after 2 and 12 hours of SAH. LY294002 was injected intracerebroventricularly to selectively inhibit PI3K/Akt signaling. Mortality, SAH grading, neurological scores, brain water content, evans blue extravasation, myeloperoxidase, malondialdehyde, superoxide dismutase, and glutathione peroxidase were measured 24 hours after SAH. Immunoreactivity of p-Akt, t-Akt, nuclear factor- kappa B (NF-κB) p65, nuclear factor erythroid-related factor 2 (Nrf2), NAD(P)H:quinone oxidoreductase (NQO1), and cyclooxygenase-2 (COX-2) in rat brain was determined by western blot. Tumor necrosis factor-α (TNF-α) and interleukin-1ß (IL-1ß) in rat brain were examined by ELISA. RESULTS: Propofol significantly reduces neurological dysfunction, BBB permeability, brain edema, inflammation, and oxidative stress, all of which were reversed by LY294002. Propofol significantly upregulates the immunoreactivity of p-Akt, Nrf2, and NQO1, all of which were abolished by LY294002. Propofol significantly downregulates the overexpression of NF-κB p65, COX-2, TNF-α, and IL-1ß, all of which were inhibited by LY294002. CONCLUSION: These results suggest that propofol attenuates SAH-induced EBI by inhibiting inflammatory reaction and oxidative stress, which might be associated with the activation of PI3K/Akt signaling pathway.

15.
Plant Sci ; 289: 110248, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31623783

RESUMO

Microtubule arrays play notable roles in cell division, cell movement, cell morphogenesis and signal transduction. Due to their important regulation of microtubule dynamic instability and array-ordering processes, microtubule-associated proteins have been a cutting-edge issue in research. Here, a new maize microtubule-associated protein, ZmGLR (Zea mays glutamic acid- and lysine-rich), was found. ZmGLR bundles microtubules in vitro and targets the cell membrane through an interaction between 24 conserved N-terminal amino acids and specific phosphatidylinositol phosphates (PtdInsPs). Increased Ca2+ levels in the cytoplasm lead to ZmGLR partially dissociating from the cell membrane and moving into the cytoplasm to associate with microtubule. Overexpression and RNAi of ZmGLR both resulted in misoriented microtubule arrays, which led to dwarf maize plants and curved leaves. In addition, the expression of ZmGLR was regulated by BR and auxin through ZmBES1 and ZmARF9, respectively. This study reveals that the microtubule-associated protein ZmGLR plays a crucial role in cortical microtubule reorientation and maize leaf morphogenesis.

16.
Insect Sci ; 2019 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-31617302

RESUMO

Wolbachia are gram-negative endosymbionts that are known to cause embryonic lethality when infected male insects mate with uninfected females or with females carrying a different strain of Wolbachia, a situation characterized as cytoplasmic incompatibility (CI). However, the mechanism of CI is not yet fully understood, although recent studies on Drosophila melanogaster have achieved great progress. Here, we found that Wolbachia infection caused changes in the expressions of several immunity-related genes, including significant upregulation of kenny (key), in the testes of Drosophila melanogaster. Overexpression of key in fly testes led to a significant decrease in egg hatch rates when these flies mate with wild type females. Wolbachia-infected females could rescue this embryonic lethality. Furthermore, in key overexpressing testes TUNEL signal was significantly stronger than in the control testes, and the level of reactive oxygen species (ROS) was significantly increased. Overexpression of key also resulted in alterations of some other immunity-related gene expressions, including the downregulation of Zn72D. Knockdown of Zn72D in fly testes also led to a significant decrease in egg hatch rates. These results suggest that Wolbachia might induce the defect in male host fertility by immunity-related pathways and thus cause an oxidative damage and cell death in male testes. This article is protected by copyright. All rights reserved.

17.
Anal Chem ; 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31580062

RESUMO

The unrepaired apurinic/apyrimidinic site (AP site) in mitochondrial DNA (mtDNA) promotes misincorporation of nucleotides and further causes serious damage for the living organism. Thus, accurate quantitative detection of AP sites in mtDNA in a rapid, highly sensitive, and highly selective fashion is important for the real-time evaluation of mtDNA oxidative damage. In this study, a targeting mtDNA ultrasensitive AP site-specific fluorescent rotor (BTBM-CN2) was designed by the strategy of molecular conformation torsion adjustment ratio fluorescent signal. The specific recognition reaction is activated when it encountered AP sites in mtDNA within 20 s, and BTBM-CN2 presented a "turn-on" red fluorescence signal at 598 nm. Then, about 100 s later, BTBM-CN2 emitted a new green fluorescence signal at 480 nm, which is mainly due to the activation of the rate-limiting reaction. With increasing numbers of AP sites (1-40 in 1 × 105 bp of mtDNA), the fluorescence emission at 598 nm decreased gradually, and the new emission at 480 nm increased. Intracellular experiments indicated that BTBM-CN2 could detect AP sites in mtDNA in a rapid and quantitative fashion with high selectivity and ultrasensitivity. On the basis of the emergence of the fluorescence signal at 480 nm and its signal strength, the cell whose mtDNA was damaged could be screened by flow cytometry and its degree of damage could be evaluated in real time by comet assay. Hence, the rotor may have potential applications varying from accurate and ultrasensitive detection of AP sites to the real-time evaluation of the oxidative damage in living cells.

18.
Mod Pathol ; 2019 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-31659278

RESUMO

To understand the molecular mechanism of tumorigenesis of pulmonary lymphoepithelioma-like carcinoma and explore potential therapeutic strategies, we investigated the genomic profiles and PD-L1 expression of 29 Chinese pulmonary lymphoepithelioma-like carcinoma patients at various stages. We performed capture-based targeted sequencing on tissue samples collected from 27 patients with sufficient samples using a panel consisting of 520 cancer-related genes, spanning 1.64 Mb of the human genome. We identified 184 somatic mutations in 109 genes from 26 patients. One patient had no mutations detected by this panel. Copy number variations were detected in 52% (14/27) of the patients, with a majority having advanced-stage disease (10/14). Except for the detection of ERBB2 amplification and KRAS mutation in two patients, no other classic lung cancer driver mutations were detected. Interestingly, 78% (21/27) of the patients had mutations in epigenetic regulators. Of the 184 mutations identified, 51 occurred in 29 epigenetics-related genes. Furthermore, we performed PD-L1 immunohistochemistry staining using the Dako 22C3 assay and demonstrated that 69% (20/29) of the cohort had positive PD-L1 expression, of which three patients received and benefited from a PD-1 inhibitor. In conclusion, we elucidated a distinct genomic landscape associated with pulmonary lymphoepithelioma-like carcinoma with no classic lung cancer driver mutation but an enrichment of mutations in epigenetic regulators. The detection of high PD-L1 expression and lack of any canonical druggable driver mutations raises the potential of checkpoint immunotherapy for pulmonary lymphoepithelioma-like carcinoma.

19.
Medicine (Baltimore) ; 98(42): e17558, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31626120

RESUMO

BACKGROUND: Microsurgery is widely utilized for patients with cerebral hemorrhage (CH). The purpose of this study is to assess the efficacy and safety of microsurgery for the treatment of patients with CH secondary to gestational hypertension (GH). METHODS: Relevant randomized controlled trials in eight electronic databases of Cochrane Library, PUBMED, EMBASE, Web of Science, VIP, WANFANG, Chinese Biomedical Literature Database, and China National Knowledge Infrastructure will be included. All electronic databases will be searched from inceptions to the present without language restriction. RevMan 5.3 software will be applied for statistical analysis. RESULTS: This study will summarize a high-quality synthesis of maternal mortality, severe maternal complications, maternal quality of life, limbs function, muscle strength, and muscle tone to evaluate the efficacy and safety of microsurgery for patients with CH secondary to GH. CONCLUSIONS: This study will provide evidence that microsurgery is an effective intervention in patients with CH secondary to GH. PROSPERO REGISTRATION NUMBER: PROSPERO CRD42019145750.


Assuntos
Hemorragia Cerebral/cirurgia , Hipertensão Induzida pela Gravidez/cirurgia , Microcirurgia/métodos , Procedimentos Neurocirúrgicos/métodos , Qualidade de Vida , Ensaios Clínicos Controlados Aleatórios como Assunto , Hemorragia Cerebral/etiologia , Feminino , Humanos , Gravidez , Resultado do Tratamento
20.
Sci Rep ; 9(1): 14922, 2019 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-31624298

RESUMO

Plant microRNAs (miRNAs) are noncoding and endogenous key regulators that play significant functions in regulating plant responses to stress, and plant growth and development. Heat stress is a critical abiotic stress that reduces the yield and quality of flowering Chinese cabbage (Brassica campestris L. ssp. chinensis var. utilis Tsen et Lee). However, limited information is available on whether miRNAs are involved in the regulation of heat stress in B. campestris. A high-throughput sequencing approach was used to identify novel and conserved heat-responsive miRNAs in four small RNA libraries of flowering Chinese cabbage using leaves collected at 0 h, 1 h, 6 h and 12 h after a 38 °C heat-stress treatment. The analysis identified 41 conserved miRNAs (belonging to 19 MIR families), of which MIR156, MIR159, MIR168, MIR171 and MIR1885 had the most abundant molecules. Prediction and evaluation of novel miRNAs using the unannotated reads resulted in 18 candidate miRNAs. Differential expression analysis showed that most of the identified miRNAs were downregulated in heat-treated groups. To better understand functional importance, bioinformatic analysis predicted 432 unique putative target miRNAs involved in cells, cell parts, catalytic activity, cellular processes and abiotic stress responses. Furthermore, the Kyoto Encyclopedia of Genes and Genomes maps of flowering Chinese cabbage identified the significant role of miRNAs in stress adaptation and stress tolerance, and in several mitogen-activated protein kinases signaling pathways including cell death. This work presents a comprehensive study of the miRNAs for understanding the regulatory mechanisms and their participation in the heat stress of flowering Chinese cabbage.

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