المؤلفون: Siyuan Li, Yan Wang, Yunqian Zhang, Hui Zhang, Shenghua Wang, Ke Ma, Lai Jiang, Yanfei Mao

المصدر: Heliyon, Vol 10, Iss 4, Pp e26594- (2024)

مصطلحات موضوعية: Ultrasonography, Nerve block, Pulmonary atelectasis, Postoperative pain, Children, Science (General), Q1-390, Social sciences (General), H1-99

الوصف: Background: Atelectasis is a commonly observed postoperative complication of general anesthesia in children. Pulmonary protective ventilation strategies have been reported to have a beneficial effect on postoperative atelectasis in children. Therefore, the present study aimed to evaluate the efficacy of the ultrasound-guided transversus abdominis plane (TAP) block technique in preventing the incidence of postoperative atelectasis in children. Materials and methods: This study enrolled 100 consecutive children undergoing elective laparoscopic bilateral hernia repair and randomly divided them into the control and TAP groups. Conventional lung-protective ventilation was initiated in both groups after the induction of general anesthesia. The children in the TAP group received an ultrasound-guided TAP block with 0.3 mL/kg of 0.5% ropivacaine after the induction of anesthesia. Results: Anesthesia-induced atelectasis was observed in 24% and 84% of patients in the TAP (n = 50) and control (n = 50) groups, respectively, before discharge from the post-anesthetic care unit (T3; PACU) (odds ratio [OR], 0.062; 95% confidence interval [CI], 0.019–0.179; P

وصف الملف: electronic resource

العلاقة: http://www.sciencedirect.com/science/article/pii/S2405844024026252Test; https://doaj.org/toc/2405-8440Test

الوصول الحر: https://doaj.org/article/bc35bfe3d32b4f4ebc41901d981a31adTest

المؤلفون: Kai Yang, Yanfei Mao, Zhihan Zhang, Jie Xu, Hao Wang, Yong He, Peiyuan Yu, Qiuling Song

المصدر: Nature Communications, Vol 14, Iss 1, Pp 1-10 (2023)

مصطلحات موضوعية: Science

الوصف: Abstract Catalytic dynamic kinetic asymmetric transformation (DyKAT) provides a powerful tool to access chiral stereoisomers from racemic substrates. Such transformation has been widely employed on the construction of central chirality, however, the application in axial chirality remains underexplored because its equilibrium of substrate enantiomers is limited to five-membered metalacyclic intermediate. Here we report a tetracoordinate boron-directed dynamic kinetic asymmetric cross-coupling of racemic, configurationally stable 3-bromo-2,1-azaborines with boronic acid derivatives. A series of challenging C-B axially chiral compounds were prepared with generally good to excellent enantioselectivities. Moreover, this transformation can also be extended to prepare atropisomers bearing adjacent C-B and C-C diaxes with excellent diastereo- and enantio-control. The key to the success relies on the rational design of a reversible tetracoordinate boron intermediate, which is supported by theoretical calculations that dramatically reduces the rotational barrier of the original C-B axis and achieves the goal of DyKAT.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/2041-1723Test

الوصول الحر: https://doaj.org/article/7d859f64391d4720b4c275d64e87144bTest

المؤلفون: Zhixiong Wu, Jiao Liu, Dong Zhang, Kai Kang, Xiangrong Zuo, Qianghong Xu, Aijun Pan, Wei Fang, Fen Liu, You Shang, Haiyan Yin, Juntao Hu, Jinglun Liu, Jiangquan Fu, Wei Zhang, Yuan Zong, Min Shao, Feng Zhao, Mei Meng, Yanfei Mao, Yingchuan Li, Dechang Chen

المصدر: Journal of Intensive Medicine, Vol 2, Iss 3, Pp 131-145 (2022)

مصطلحات موضوعية: Medical emergencies. Critical care. Intensive care. First aid, RC86-88.9

وصف الملف: electronic resource

العلاقة: http://www.sciencedirect.com/science/article/pii/S2667100X22000536Test; https://doaj.org/toc/2667-100XTest

الوصول الحر: https://doaj.org/article/9b419320d5424289a8cea38e59ec5bbfTest

المؤلفون: Yanfei Mao, Xiaoxuan Yang, Yiting Zhou, Zhengjing Zhang, Jose Ramon Botella, Jian-Kang Zhu

المصدر: Genome Biology, Vol 19, Iss 1, Pp 1-15 (2018)

مصطلحات موضوعية: CRISPR, Cas9, Genome editing, Viral suppressor, RNA silencing, TBSV p19, Biology (General), QH301-705.5, Genetics, QH426-470

الوصف: Abstract Background The CRISPR/Cas9 system, composed of a single-guide RNA for target recognition and a Cas9 protein for DNA cleavage, has the potential to revolutionize agriculture as well as medicine. Even though extensive work has been done to improve the gene editing activity of CRISPR/Cas9, little is known about the regulation of this bacterial system in eukaryotic host cells, especially at the post-transcriptional level. Results Here, we evaluate the expression levels of the two CRISPR/Cas9 components and the gene editing efficiency in a set of Arabidopsis mutants involved in RNA silencing. We find that mutants defective in the post-transcriptional gene-silencing pathway display significantly higher Cas9 and sgRNA transcript levels, resulting in higher mutagenesis frequencies than wild-type controls. Accordingly, silencing of AGO1 by introduction of an AGO1-RNAi cassette into the CRISPR/Cas9 vector provides an increase in gene editing efficiency. Co-expression of the viral suppressor p19 from the tomato bushy stunt virus to suppress the plant RNA-silencing pathway shows a strong correlation between the severity of the phenotypic effects caused by p19 and the gene editing efficiency of the CRISPR/Cas9 system for two different target genes, AP1 and TT4. Conclusions This system has useful practical applications in facilitating the detection of CRISPR/Cas9-induced mutations in T1 plants as well as the identification of transgene-free T2 plants by simple visual observation of the symptom severity caused by p19. Our study shows that CRISPR/Cas9 gene editing efficiency can be improved by reducing RNA silencing in plants.

وصف الملف: electronic resource

العلاقة: http://link.springer.com/article/10.1186/s13059-018-1529-7Test; https://doaj.org/toc/1474-760XTest

الوصول الحر: https://doaj.org/article/5bd8a6b32ae3475c8a882bb6b2d9f0beTest

المؤلفون: Yanfei Mao, Bo Xu, Wenbin Guan, Dunfeng Xu, Feng Li, Rongrong Ren, Xiaoyan Zhu, Yuan Gao, Lai Jiang

المصدر: Frontiers in Endocrinology, Vol 11 (2021)

مصطلحات موضوعية: severe acute respiratory syndrome coronavirus 2, coronavirus disease 2019, critically ill patients, adrenal cortex, adrenal insufficiency, Diseases of the endocrine glands. Clinical endocrinology, RC648-665

الوصف: BackgroundThe majority of the critically ill patients may have critical illness-related corticosteroid insufficiency (CIRCI). The therapeutic effect of dexamethasone may be related to its ability to improve cortical function. Recent study showed that dexamethasone can reduce COVID-19 deaths by up to one third in critically ill patients. The aim of this article is to investigate whether SARS-CoV-2 can attack the adrenal cortex to aggravate the relative adrenal insufficiency.MethodsWe summarized the clinical features of COVID-19 reported in currently available observational studies. ACE2 and TMPRSS2 expression was examined in human adrenal glands by immunohistochemical staining. We retrospectively analyzed serum cortisol levels in critically ill patients with or without COVID-19.ResultsHigh percentage of critically ill patients with SARS-COV-2 infection in the study were treated with vasopressors. ACE2 receptor and TMPRSS2 serine protease were colocalized in adrenocortical cells in zona fasciculata and zona reticularis. We collected plasma cortisol concentrations in nine critically ill patients with COVID-19. The cortisol levels of critically ill patients with COVID-19 were lower than those in non-COVID-19 critically ill group. Six of the nine COVID-19 critically ill patients had random plasma cortisol concentrations below 10 µg/dl, which met the criteria for the diagnosis of CIRCI.ConclusionWe demonstrate that ACE2 and TMPRSS2 are colocalized in adrenocortical cells, and that the cortisol levels are lower in critically ill patients with COVID-19 as compared to those of non-COVID-19 critically ill patients. Based on our findings, we recommend measuring plasma cortisol level to guide hormonal therapy.

وصف الملف: electronic resource

العلاقة: https://www.frontiersin.org/articles/10.3389/fendo.2020.593179/fullTest; https://doaj.org/toc/1664-2392Test

الوصول الحر: https://doaj.org/article/e0e4f26f4df84ff0b382041149736630Test

المؤلفون: Xiaodi Yan, Wenqian Li, Liye Yang, Wenwen Dong, Wei Chen, Yanfei Mao, Pingbo Xu, Dongjie Li, Hongbin Yuan, Yong-Hua Li

المصدر: Cellular Physiology and Biochemistry, Vol 48, Iss 3, Pp 1245-1258 (2018)

مصطلحات موضوعية: Mir-135a, Ventilator-induced lung injury, Human umbilical vein endothelial cells, PI3K, PHLPP, Physiology, QP1-981, Biochemistry, QD415-436

الوصف: Background/Aims: Loss of endothelial barrier function plays an important role in the development of ventilator-induced lung injury (VILI). This study aimed to investigate the effects of miR135a on VILI in a model of mechanical stretch (MS)-induced human umbilical vein endothelial cell (HUVEC) injury. Methods: HUVECs were randomly assigned to 7 groups: blank, negative control (NC), NC+MS, miR135a over-expression (mi-miR135a), mi-miR135a + MS, miR135a silencing (si-miR135a) and si-miR135a + MS groups. MS was induced by subjecting cells to cyclic stretch at 20% stretch for 4 h. After 24 h, levels of reactive oxygen species (ROS) were measured by DCFH-DA fluorescence intensity. Apoptosis was measured using annexin V-FITC/propidium iodide assay with flow cytometry. Inflammatory cytokine levels were determined by ELISA. Barrier integrity was determined using FITC-conjugated dextran assay. Expression levels of PI3K, p-PI3K, Akt, p-Akt, Bcl-2 and Bax were examined using western blotting. The interaction between miR135a and PHLPP2 was evaluated by dual-luciferase reporter assay. Results: Our results showed that MS reduced cell numbers, increased the number of apoptotic cells, increased ROS, barrier dysfunction and inflammatory cytokines in HUVECs, and reduced p-PI3K and p-Akt expression; silencing of miR135a worsened MS-induced HUVEC injury. However, miR135a over-expression protected HUVECs against MS-induced increases in apoptotic cells, ROS, barrier dysfunction and inflammatory cytokines, which were accompanied by activation of the PI3K/Akt signaling pathway. Simultaneous silencing of miR135a and PHLPP2 partially salvaged the effects of miR135a silencing, and miR135a was found to interact with PHLPP2. Conclusion: miR135a may protect HUVECs from MS-induced injury by inhibiting PHLPP2 to activate PI3k/Akt signaling pathway.

وصف الملف: electronic resource

العلاقة: https://www.karger.com/Article/FullText/492010Test; https://doaj.org/toc/1015-8987Test; https://doaj.org/toc/1421-9778Test

الوصول الحر: https://doaj.org/article/253fad9d615b48d7a2dece9b7319c9efTest

المؤلفون: Yanfei Mao, Shiju E, Chungeng Zhu

المصدر: Applied Sciences, Vol 11, Iss 16, p 7720 (2021)

مصطلحات موضوعية: end-fire antenna array, planar technology, on-chip antenna design, half wave dipole elements, Technology, Engineering (General). Civil engineering (General), TA1-2040, Biology (General), QH301-705.5, Physics, QC1-999, Chemistry, QD1-999

الوصف: For an RF system, a high-gain antenna helps to improve the equivalent isotropic radiated power (EIRP) of the transmitter and an end-fire antenna array helps to improve the directivity (D) and half power beam width (HP) of the antenna. This work presents a new and simple design method for end-fire antenna array design. The method states that when antenna elements are λ/2 apart, a simple end-fire antenna array could be designed and constructed easily without matching networks between antenna elements. Utilizing Rogers 4350 PCB technology, three 24 GHz high-gain, compact planar two-element end-fire dipole antenna arrays are designed to verify this new design method. The achieved results are three two-element end-fire antennas with gains of 8.8, 9.9 and 9.1 dBi. These antenna arrays are characterized by high gain and simplicity in design. They are also very compact in size, with an area of about 1.9 × 1.7 cm2. The benefit of this work is that a new and simple design for end-fire antenna design is suggested, and three two-element end-fire dipole antenna arrays in planar technology which adopt the design method are presented. A utility model patent was granted for this end-fire dipole array antenna topology, ZL 202022106332.1.

وصف الملف: electronic resource

العلاقة: https://www.mdpi.com/2076-3417/11/16/7720Test; https://doaj.org/toc/2076-3417Test

الوصول الحر: https://doaj.org/article/ac6fbd757ad847adb87c3ca139630eb7Test

المؤلفون: Daisuke Miki, Peiying Zhu, Wencan Zhang, Yanfei Mao, Zhengyan Feng, Huan Huang, Hui Zhang, Yanqiang Li, Renyi Liu, Huiming Zhang, Yijun Qi, Jian-Kang Zhu

المصدر: Scientific Reports, Vol 7, Iss 1, Pp 1-11 (2017)

مصطلحات موضوعية: Medicine, Science

الوصف: Abstract It has been reported that double-stranded break (DSB)-induced small RNAs (diRNAs) are generated via the RNA-directed DNA methylation pathway and function in DSB repair in Arabidposis. However, important questions remain regarding the biogenesis and function of diRNAs. Here, we used CRISPR/Cas9- or TALEN-triggered DSBs to characterize diRNAs in Arabidopsis and rice. We found that 21-nt diRNAs were generated from a 35S promoter::GU-US reporter transgene targeted by CRISPR/Cas9. Unexpectedly, Pol II transcription of the transgene was required for efficient diRNA production and the level of diRNA accumulation correlated with the expression level of the transgene. diRNAs were not detected from CRISPR/Cas9- or TALEN-induced DSBs within the examined endogenous genes in Arabidopsis or rice. We also found that DCL4 and RDR6 that are known to be involved in posttranscriptional gene silencing were required to generate diRNAs. Our results suggest that DSBs are necessary but not sufficient for efficient diRNA generation and a high level of diRNAs is not necessary for DSB repair.

وصف الملف: electronic resource

العلاقة: https://doaj.org/toc/2045-2322Test

الوصول الحر: https://doaj.org/article/832b4b6f88db40e49e7e863c3ee5b1acTest

المؤلفون: Sungkyung Cho, Si-in Yu, Junghoon Park, Yanfei Mao, Jian-Kang Zhu, Dae-Jin Yun, Byeong-ha Lee

المصدر: Frontiers in Plant Science, Vol 8 (2017)

مصطلحات موضوعية: CRISPR, Cas, CBF, cold stress, cold signaling, accessions, Plant culture, SB1-1110

الوصف: The CRISPR/Cas system became a powerful genome editing tool for basic plant research and crop improvement. Thus far, CRISPR/Cas has been applied to many plants, including Arabidopsis, rice and other crop plants. It has been reported that CRISPR/Cas efficiency is generally high in many plants. In this study, we compared the genome editing efficiency of CRISPR/Cas in three different Arabidopsis accessions [Col-0, Ler, and C24RDLUC (C24 accession harboring the stress-responsive RD29A promoter-driven luciferase reporter)]. For the comparison, we chose to target the cold-responsive C-repeat/DRE-Binding Factor (CBF) genes. CBF1, CBF2, and CBF3 genes are tandemly located on Arabidopsis chromosome 4 with redundant functions as the key transcription factors functioning in cold stress signaling and tolerance. Due to the close proximity of these CBFs on the chromosome, it is impossible to generate cbf1, cbf2, cbf3 triple mutants (cbf123) by traditional genetic crosses. Therefore, using the CRISPR/Cas tool, we aimed to generate cbf123 mutants and compared the genome editing efficiency in different Arabidopsis accessions. Among the accessions, Ler was the most resilient to the CRISPR/Cas deletion with the lowest gene deletion ratio in both T1 and T2 generations. Interestingly, while C24RDLUC showed a high CBF123 deletion frequency in T2 only when the gene deletion was observed in T1 generation, Col-0 displayed high ratios of the CBF123 deletions in T2 regardless of the presence or absence of the CBF123 deletion in T1. Isolated cbf123 mutants in C24RDLUC background showed no expression of CBF1, CBF2, and CBF3 genes and proteins with reduction in the CBF target gene expression under cold stress.

وصف الملف: electronic resource

العلاقة: http://journal.frontiersin.org/article/10.3389/fpls.2017.01910/fullTest; https://doaj.org/toc/1664-462XTest

الوصول الحر: https://doaj.org/article/c7b3c5d379dd405f8b4cfb5273cf0b0fTest

المؤلفون: Zhengyan Feng, Zhengjing Zhang, Kai Hua, Xifeng Gao, Yanfei Mao, Jose Ramon Botella, Jian-Kang Zhu

المصدر: International Journal of Molecular Sciences, Vol 19, Iss 12, p 3925 (2018)

مصطلحات موضوعية: Arabidopsis, cell division-specific Cas9 system, CRISPR/Cas9, multiplex gene editing, Pol III promoter, Biology (General), QH301-705.5, Chemistry, QD1-999

الوصف: The CRISPR/Cas9 system has been widely used for targeted genome editing in numerous plant species. In Arabidopsis, constitutive promoters usually result in a low efficiency of heritable mutation in the T1 generation. In this work, CRISPR/Cas9 gene editing efficiencies using different promoters to drive Cas9 expression were evaluated. Expression of Cas9 under the constitutive CaMV 35S promoter resulted in a 2.3% mutation rate in T1 plants and failed to produce homozygous mutations in the T1 and T2 generations. In contrast, expression of Cas9 under two cell division-specific promoters, YAO and CDC45, produced mutation rates of 80.9% to 100% in the T1 generation with nonchimeric mutations in the T1 (4.4⁻10%) and T2 (32.5⁻46.1%) generations. The pCDC45 promoter was used to modify a previously reported multiplex CRISPR/Cas9 system, replacing the original constitutive ubiquitin promoter. The multi-pCDC45-Cas9 system produced higher mutation efficiencies than the multi-pUBQ-Cas9 system in the T1 generation (60.17% vs. 43.71%) as well as higher efficiency of heritable mutations (11.30% vs. 4.31%). Sextuple T2 homozygous mutants were identified from a construct targeting seven individual loci. Our results demonstrate the advantage of using cell division promoters for CRISPR/Cas9 gene editing applications in Arabidopsis, especially in multiplex applications.

وصف الملف: electronic resource

العلاقة: https://www.mdpi.com/1422-0067/19/12/3925Test; https://doaj.org/toc/1422-0067Test

الوصول الحر: https://doaj.org/article/9fefe381e5a1402eb7400eced88a5ddaTest