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1.
Quant Imaging Med Surg ; 14(5): 3339-3349, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38720863

RESUMO

Background: Assessing the risk of rupture in intracranial aneurysms is crucial. Advancements in medical imaging now allow for three-dimensional (3D) assessments of aneurysms, providing a more detailed understanding of their morphology and associated risks. This study aimed to compare the 3D morphological parameters of ruptured and unruptured intracranial saccular aneurysms (ISAs) using computed tomography angiography (CTA) and to analyze risk factors linked to ISA rupture. Methods: This retrospective case-control study included patients diagnosed with ISAs via CTA, for which data were sourced from both the Emergency Department and Inpatient Unit in The First Affiliated Hospital of Jinan University. The patients were categorized into rupture and unrupture groups. We used 3D-Slicer (version 5.2.2, Slicer Community) to construct morphological models of the ISAs and their parent arteries. These models facilitated assessments of intracranial aneurysmal volume (IAV), aneurysmal surface area (ASA), and maximum sectional area (MSA). Differences in 3D morphological parameters between ruptured and unruptured ISAs were then analyzed. For statistical analysis, we first performed single factor analysis on the data, constructed a receiver operating characteristic (ROC) curve one by one with statistically significant parameters, and screened out ROC curves that met the sample requirements. Second, we performed multiparameter logistic regression analysis to construct a ROC curve model and analyzed its predictive performance. Results: The analysis encompassed 97 patients comprising 97 ISAs diagnosed from March 2016 to March 2022. Significant differences in morphological parameters were observed between the rupture and unrupture groups (P<0.05), including IAV, ASA, MSA, IAV/diameter (IAV/D), IAV/neck width (IAV/N), MSA/diameter (MSA/D), MSA/neck width (MSA/N), ASA/neck width (ASA/N), and ASA/MSA. It was found that the IAV, ASA, and MSA values of the rupture group were larger than those of the unrupture group. Meanwhile, the IAV/D, IAV/N, MSA/D, MSA/N, and ASA/N values were larger in the rupture group, while ASA/MSA and ASA/IAV were smaller. Conclusions: This study underscores the significance of specific morphological indicators, such as ASA/N and ASA/MSA, in predicting the rupture risk of ISAs. The IAV, MSA, and ASA parameters, especially in relation to diameter and neck width, provide crucial insights into the rupture potential of ISAs.

2.
ACS Omega ; 9(20): 22352-22359, 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38799330

RESUMO

Low-dimensional tin-based halide perovskites are considered as eco-friendly substitutions of the iconic lead-based perovskites to host the potential as optoelectronic materials. However, a fundamental understanding of the structure-property relationship of these Sn(II)-based hybrids is still inadequate due to the limited members of this material family. To our knowledge, there is still lack of reports on a series of Sn(II)-based halide perovskites with the same organic cation but covering chloride, bromide, and iodide. In this work, three new halide perovskites TMPDASnX4 (X = Cl, Br, I) (TMPDA = N,N,N',N'-tetramethyl-1,4-phenylenediamine) are successfully synthesized, which provide the ideal paradigm to study the halogen-dependent evolution of the structure and properties of Sn(II)-based hybrid perovskites. Despite sharing the same monoclinic lattice (P21/m space group), it is demonstrated that TMPDASnCl4 adopts a one-dimensional structure composed of a five-coordinated pyramid configuration due to an extremely long Sn···Cl distance, while the typical two-dimensional motif is still maintained in TMPDASnBr4 and TMPDASnI4. The ambient stability is declined in the order from chloride to bromide and then to iodide. TMPDASnCl4 exhibits a broad-band bluish-white-light emission (centered at 515 nm, full width at half-maximum (fwhm) = 193 nm) with the Commission Internationale de l' Elairage (CIE) coordinates as (0.29, 0.34). Further, the correlated color temperature and color-rendering index were determined as 7617 K and 80.5, respectively. Based on the synthesis of new crystals, our work sheds light on the composition-structure-property relationship of hybrid Sn(II)-based halide perovskites.

3.
Sci Rep ; 14(1): 11799, 2024 05 23.
Artigo em Inglês | MEDLINE | ID: mdl-38782981

RESUMO

To address the issues of low accuracy and slow response speed in tea disease classification and identification, an improved YOLOv7 lightweight model was proposed in this study. The lightweight MobileNeXt was used as the backbone network to reduce computational load and enhance efficiency. Additionally, a dual-layer routing attention mechanism was introduced to enhance the model's ability to capture crucial details and textures in disease images, thereby improving accuracy. The SIoU loss function was employed to mitigate missed and erroneous judgments, resulting in improved recognition amidst complex image backgrounds.The revised model achieved precision, recall, and average precision of 93.5%, 89.9%, and 92.1%, respectively, representing increases of 4.5%, 1.9%, and 2.6% over the original model. Furthermore, the model's volum was reduced by 24.69M, the total param was reduced by 12.88M, while detection speed was increased by 24.41 frames per second. This enhanced model efficiently and accurately identifies tea disease types, offering the benefits of lower parameter count and faster detection, thereby establishing a robust foundation for tea disease monitoring and prevention efforts.


Assuntos
Doenças das Plantas , Chá , Algoritmos , Camellia sinensis/classificação , Processamento de Imagem Assistida por Computador/métodos
4.
Front Plant Sci ; 15: 1327237, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38379942

RESUMO

Introduction: In order to solve the problem of precise identification and counting of tea pests, this study has proposed a novel tea pest identification method based on improved YOLOv7 network. Methods: This method used MPDIoU to optimize the original loss function, which improved the convergence speed of the model and simplifies the calculation process. Replace part of the network structure of the original model using Spatial and Channel reconstruction Convolution to reduce redundant features, lower the complexity of the model, and reduce computational costs. The Vision Transformer with Bi-Level Routing Attention has been incorporated to enhance the flexibility of model calculation allocation and content perception. Results: The experimental results revealed that the enhanced YOLOv7 model significantly boosted Precision, Recall, F1, and mAP by 5.68%, 5.14%, 5.41%, and 2.58% respectively, compared to the original YOLOv7. Furthermore, when compared to deep learning networks such as SSD, Faster Region-based Convolutional Neural Network (RCNN), and the original YOLOv7, this method proves to be superior while being externally validated. It exhibited a noticeable improvement in the FPS rates, with increments of 5.75 HZ, 34.42 HZ, and 25.44 HZ respectively. Moreover, the mAP for actual detection experiences significant enhancements, with respective increases of 2.49%, 12.26%, and 7.26%. Additionally, the parameter size is reduced by 1.39 G relative to the original model. Discussion: The improved model can not only identify and count tea pests efficiently and accurately, but also has the characteristics of high recognition rate, low parameters and high detection speed. It is of great significance to achieve realize the intelligent and precise prevention and control of tea pests.

5.
Inorg Chem ; 62(31): 12413-12422, 2023 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-37489948

RESUMO

Transition metal subchalcogenides involve electron-rich metals and can facilitate an in-depth understanding of the relationships among quantum properties such as superconductivity, charge density wave, and topological band structures. However, effective experimental routes toward synthesizing transition metal subchalcogenides are still lacking, hindering the development of new quantum materials. Herein, we propose a eutectic polytelluride flux strategy as an excellent solution to address phase discovery and crystal growth in transition metal subtelluride systems. We report new phases easily and selectively synthesized using a eutectic "K3Te4" polytelluride flux upon adjusting the ratio of Nb metal to flux in the starting materials (K/Nb/Te = 3:x:4). Using a high Nb content in the solvent (x = 2 and 1), crystals of KNb3Te3O0.38 and K0.9Nb3Te4 are obtained. Both subtellurides exhibit diverse Nb clusters, including face-sharing and edge-sharing Nb6 octahedral columns and zig-zag Nb chains. Reducing the Nb content to x = 0.33 leads to the formation of a layered compound, K1.06NbTe2. This compound comprises a NbTe6 trigonal prism with K intercalated between the layers. Single crystals of known binary Nb tellurides can also be grown using another eutectic flux "KTe3.2", and the obtained NbTe2 exhibits a new polymorphism with extra trimerization along the b-axis in the Nb-Nb bonded double zig-zag cluster. Precise control over the structural dimensionality and oxidation state, combined with the facile crystal growth process, makes our synthetic strategy an efficient route to explore quantum materials in transition metal subchalcogenides.

6.
Foods ; 12(11)2023 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-37297373

RESUMO

To investigate different contents of pu-erh tea polyphenol affected by abiotic stress, this research determined the contents of tea polyphenol in teas produced by Yuecheng, a Xishuangbanna-based tea producer in Yunnan Province. The study drew a preliminary conclusion that eight factors, namely, altitude, nickel, available cadmium, organic matter, N, P, K, and alkaline hydrolysis nitrogen, had a considerable influence on tea polyphenol content with a combined analysis of specific altitudes and soil composition. The nomogram model constructed with three variables, altitude, organic matter, and P, screened by LASSO regression showed that the AUC of the training group and the validation group were respectively 0.839 and 0.750, and calibration curves were consistent. A visualized prediction system for the content of pu-erh tea polyphenol based on the nomogram model was developed and its accuracy rate, supported by measured data, reached 80.95%. This research explored the change of tea polyphenol content under abiotic stress, laying a solid foundation for further predictions for and studies on the quality of pu-erh tea and providing some theoretical scientific basis.

7.
Inorg Chem ; 62(7): 3018-3025, 2023 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-36752343

RESUMO

Zero-dimensional (0D) In-based organic-inorganic metal halides (OIMHs) have received growing interest in recent years as promising luminescent materials. However, the high efficiencies of 0D In-based OIMHs are all dependent on Sb doping in the existing literature. Here, we report a novel 0D In-based OIMH (C10H22N2)2In2Br10, which exhibits intrinsic broadband emission (610 nm), and the photoluminescence quantum yield (PLQY) can reach 70% without Sb doping. (C10H22N2)2In2Br10 shows a typical 0D structure with three different In-Br polyhedra (two octahedra and one tetrahedron) separated by large organic cations. Based on the optical property measurements and theoretical calculations, we demonstrate that (C10H22N2)2In2Br10 is an indirect semiconductor with a band gap of 3.74 eV, and the In-Br inorganic moiety is primarily responsible for the intense emission of (C10H22N2)2In2Br10. Interestingly, the unique double octahedral configuration in (C10H22N2)2In2Br10 may enhance the structural distortion and stimulate the self-trapped excitons (STEs), leading to the related high PLQY. Our work provides a novel 0D In-based OIMH with high-efficiency intrinsic emission, which is helpful for understanding the structure-PL relationships of hybrid halides.

8.
Int J Biol Macromol ; 229: 388-400, 2023 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-36592848

RESUMO

In this study, we successfully isolated 11 species of cadmium-tolerant bacterium from Pu-erh rhizosphere soil, of which Staphylococcus equorum PU1 showed the highest cadmium tolerance, with a minimum inhibitory concentration (MIC) value of 500 mg/L. The cadmium removal efficiency of PU1 in 400 mg/L cadmium medium reached 58.7 %. Based on the Nanopore PromethION and Illumina NovaSeq platforms, we successfully obtained the complete PU1 genome with a size of 2,705,540 bp, which encoded 2729 genes. We further detected 82 and 44 indel mutations in the PU1 genome compared with the KS1039 and KM1031 genomes from the database. Transcriptional analysis showed that the expression of 11 genes in PU1 increased with increasing cadmium concentrations (from 0 to 200, then to 400 mg/L), which encoded cadmium resistance, cadmium transport, and mercury resistance genes. In addition, some genes showed differential expression patterns with changes in cadmium concentration, including quinone oxidoreductase-like protein, ferrous iron transport protein, and flavohemoprotein. Gene Ontology (GO) functions, including oxidation reduction process and oxidoreductase activity functions, and KEGG pathways, including glycolysis/gluconeogenesis and biosynthesis of secondary metals, were also considered closely related to the extreme cadmium tolerance of PU1. This study provides novel insight into the cadmium tolerance mechanism of bacteria.


Assuntos
Metais Pesados , Poluentes do Solo , Cádmio/metabolismo , Transcriptoma , Adsorção , Metais Pesados/metabolismo , Genômica , Bactérias/metabolismo , Oxirredutases/metabolismo , Biodegradação Ambiental , Poluentes do Solo/metabolismo
9.
RSC Adv ; 12(45): 29003-29009, 2022 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-36320726

RESUMO

The magnetic semiconductor in a two-dimensional system is a major subject for both theoretical and experimental investigations. Here we report the synthesis of a new quaternary manganese chalcogenide KMnCuTe2, which shows layered structure and antiferromagnetic (AFM) semiconducting features. Single crystals of KMnCuTe2 were obtained using a self-flux method and based on single-crystal X-ray diffraction, KMnCuTe2 adopts the ThCr2Si2-type structure composed of edge-sharing tetrahedral layers separated by K+ cations. The Mn and Cu atoms randomly distribute in the centre of tetrahedral units. Attributed to the large radius of Te, KMnCuTe2 has large lattice parameters (a = 4.3115(3) Å and c = 14.9360(20) Å), leading to a long metal-metal distance (3.049 Å) in the tetrahedral layers. Based on the experiments and theoretical calculations, KMnCuTe2 exhibits a G-type AFM interaction with the transition temperature at around 225 K and an indirect semiconducting nature with the band gap of 0.95 eV. The magnetic semiconducting property of KMnCuTe2 is unique in AMnMCh2 systems (A = Li, Na, K, M = Cu, Ag and Ch = S, Se, Te), which could be associated with the large metal-metal distance. Our work not only highlights the role of metal-metal interactions on regulating the properties of ThCr2Si2-type compounds, but also provides a feasible strategy to obtain the layered magnetic semiconductor.

10.
Chem Commun (Camb) ; 58(96): 13337-13340, 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36373700

RESUMO

A one-dimensional (1D) halide double perovskite, (BA)10AgBi2Br19, is synthesized, which features 1D corner-sharing perovskite ribbons with a width of three octahedra. It is the first reported 1D derivative of a halide double perovskite, showing an unexpected narrow band gap (2.46 eV) due to the unique Br trimer in structure.

11.
Inorg Chem ; 61(38): 15016-15022, 2022 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-36094900

RESUMO

Recently, excellent optical properties of low-dimensional organic-inorganic metal halides, stemming from their tunable structure and optoelectronic properties, have been demonstrated. The synthetic method is critical because it is highly related to the structure and properties of the halide. Herein, we obtain two different antimony bromides, (Bmpip)2SbBr5 and (Bmpip)3Sb2Br9, which both possess the P21/c space group having different crystal structures, and this confirms the important influence of synthesis on the single-crystal structure. (Bmpip)2SbBr5 contains Bmpip+ and [SbBr5]2- pyramids, and (Bmpip)3Sb2Br9 consists of Bmpip+ and Sb-based dimers [Sb2Br9]3-. Under 400 nm excitation, (Bmpip)2SbBr5 exhibits a 640 nm orange emission with a quantum yield of ∼11.5% owing to Sb 5s2 electron luminescence. A diode was fabricated by (Bmpip)2SbBr5 and commercial phosphors and showed a high color render index of 92. Our work reveals the effect of the preparation method on the crystal structure. A luminescent material was finally identified.

12.
Inorg Chem ; 61(38): 15266-15272, 2022 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-36102177

RESUMO

Hybrid tetrahedral Mn(II)-based halides show great potential for narrow-band green emitters, which could be applied in the liquid crystal display field. However, the strategy to improve the chemical stability of tetrahedral Mn hybrids has not been fully investigated. Here, we demonstrate that Zn doping can be an effective route to significantly improve the stability of tetrahedral Mn hybrids under air conditions without compromising the luminous efficiency. A new bromide (ABI)2MnBr4 (ABI = 2-aminobenzimidazole) is synthesized, which exhibits a typical zero-dimensional structure with isolated [MnBr4]2- tetrahedra in the P1̅ space group. Under 450 nm excitation, a narrow-band green-emitting peak at 516 nm is observed with a full width at half maximum of 42 nm. It is indicated that spontaneous phase transition from the tetrahedral to octahedral motif occurs in this Mn hybrid driven by humidity, combined with the emission color change from green to red. Interestingly, this phase transition could be strongly suppressed by Zn doping with a very low doping amount (5%), leading to the significantly improved chemical stability of (ABI)2MnBr4 without reducing the photoluminescence quantum yield. Our work provides a simple and feasible strategy to enhance the chemical stability of the green-emitting (ABI)2MnBr4, and it may also be applicable for other tetrahedral Mn-based hybrids.

13.
Front Microbiol ; 13: 911226, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35677900

RESUMO

Lightning rods have been developed to prevent damage caused by lightning to organisms. However, the biological effect of the current transmitted into the soil through lightning rods is unknown. In this study, we analyzed the effects of lightning on soil properties, the microbial community, and the active components of Pu-erh tea (Camellia sinensis var. assamica) near lightning rods. The results showed that the contents of organic matter and available potassium, copper, and calcium in rhizosphere soil near the lightning rod were significantly higher than those in control soil (P < 0.05), while the contents of total potassium, phosphorus, iron, magnesium, and aluminum decreased. Lightning significantly increased the bacterial diversity of Pu-erh rhizosphere soil compared to control soil samples (P < 0.05). Sphingomonas, Nitrospira, and Reyranella were significantly enriched in soil samples near the lightning rod compared to soil samples far from the lightning rod. Clusters of Orthologous Groups (COG) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses indicated that adenosine/AMP kinase, chitodextrinase, flavorubredoxin, nucleotide metabolism, and carbohydrate digestion and absorption were significantly enriched in the rhizosphere soil samples near the lightning rod compared to the control samples (P < 0.05). ß diversity analysis indicated the grounding of the lightning rod contributed to the community differentiation of rhizosphere bacteria. Amino acids, polyphenols, and soluble sugar increased in Pu-erh tea near the lightning rod, while the contents of catechin and anthocyanin decreased in Pu-erh tea near the lightning rod compared with the control sample (P < 0.05). Significant correlations were found among microbial indicators, soil properties, and Pu 'er tea components. This study serves as the first report on the effects of lightning rods on soil properties, microecology, and plant metabolism, which promotes the understanding of the biological effects of lightning, and provides a reference for the rational use of lightning resources.

14.
Inorg Chem ; 61(11): 4592-4597, 2022 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-35271274

RESUMO

The newly discovered AMnBi2 (A = Ca, Sr, Ba, Eu, and Yb) materials composed of two-dimensional Bi square nets provide an excellent platform to investigate the effect of magnetism on topological band structures. Effectively tuning the magnetic interaction in AMnBi2 is of great importance to advance this issue. Here, we describe an effective route to tune the magnetism in Dirac semimetal CaMnBi2 through Cu doping. Structural analysis on CaMn1-xCuxBi2 single crystals indicates that Cu atoms occupy the Mn sites randomly, with the maximum doping level of 25%. After Cu doping, the Bi square net in charge of the Dirac band is still retained, but the Bi-Bi bond distance is markedly shortened. The antiferromagnetic interaction of CaMnBi2 is strongly weakened in the Cu-doped crystals, with the transition temperature decreased from 260 to 85 K. On the contrary, the ferromagnetic component that originated from the canted AFM is enhanced, suggesting that the spin canting in this system is tunable. In addition, the magnetoresistance is decreased upon Cu doping, probably due to the disorder in structure. Our work suggests that the CaMn1-xCuxBi2 (0 ≤ x ≤ 0.25) system can offer a suitable playground to address the interplay between magnetism and the topological state.

15.
J Phys Chem Lett ; 13(1): 198-207, 2022 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-34967650

RESUMO

Three new lead-free organic-inorganic metal halides (OIMHs) (C7H8N3)3InX6·H2O (X = Cl, Br) and (C7H8N3)2SbBr5 were synthesized. First-principles calculations indicate that the highest occupied molecular orbitals (HOMOs) of the two In-based OIMHs are constituted of π orbitals from [C7H8N3]+ spacers. (C7H8N3)3InX6·H2O (X = Cl, Br) shows an indirect optical gap, which may result from this organic-contributed band edge. Despite the indirect-gap nature with extra phonon process during absorption, the photoluminescence of (C7H8N3)3InBr6·H2O can still be significantly enhanced through Sb doping, with the internal photoluminescence quantum yields (PLQY) increased 10-fold from 5% to 52%. A white light-emitting diode (WLED) was fabricated based on (C7H8N3)3InBr6·H2O:Sb3+, exhibiting a high color-rendering index of 90. Our work provides new systems to deeply understand the principles for organic spacer choice to obtain the 0D metal OIMHs with specific band structure and also the significant enhancement of luminescence performance by chemical doping.

16.
Inorg Chem ; 60(19): 14629-14635, 2021 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-34523334

RESUMO

The Pb-free hybrid-layered-double perovskites (HLDPs) have been proposed as green and stable semiconducting materials for optoelectronic devices, but the synthesized members are still limited. Here, we report the synthesis of three new HLDPs, (C8H20N2)2AgMBr8 (M = In, Sb, and Bi), by a solution method using 1,4-bis(ammoniomethyl)cyclohexane (C8H20N22+) as the organic spacing cation. All three of these HLDPs show ⟨100⟩-oriented layered structures with Ag and In/Sb/Bi order arranged in corner-sharing octahedral layers. The first-principle calculations indicate the indirect-gap nature of (C8H20N2)2AgInBr8 and (C8H20N2)2AgSbBr8, while their Bi counterpart shows a direct band gap after considering spin-orbit coupling. The band gaps obtained by diffuse-reflectance spectroscopy are 3.11, 2.60, and 2.70 eV for M = In, Sb, and Bi, respectively. (C8H20N2)2AgInBr8 shows a broadband red emission centered at 690 nm, and it is mainly attributed to the self-trapped-excitons mechanism. Our results not only provide a series of new "Pb-free" HLDPs with chemical diversity but also help us to further understand the structure-property relationships of HLDP materials.

17.
Inorg Chem ; 60(15): 11429-11434, 2021 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-34242012

RESUMO

Low-dimensional organic-inorganic metal halides (OIMHs), as emerging light-emitting materials, have aroused widespread attention owing to their unique structural tunability and photoelectric characteristics. OIMHs are also promising materials for optoelectronic equipment, light-emitting diodes, and photodetectors. In this study, (C3H12N2)2Sb2Cl10 (C3H12N22+ is an N-methylethylenediamine cation), a new zero-dimensional OIMH, has been reported, and (C3H12N2)2Sb2Cl10 possesses a P21/n space group. The (C3H12N2)2Sb2Cl10 structure contains [Sb2Cl10]4- dimers (composed of two edge-sharing [SbCl6]3- octahedra) that are surrounded by C3H12N22+ cations. The experimental band gap of (C3H12N2)2Sb2Cl10 is 3.80 eV, and density functional theory calculation demonstrates that (C3H12N2)2Sb2Cl10 possesses a direct band gap, with the edge of the band gap mainly contributed from the inorganic units. (C3H12N2)2Sb2Cl10 exhibits good ambient and thermal stability. Under 395 nm excitation at room temperature, (C3H12N2)2Sb2Cl10 exhibits a broad emission with a full width at half-maximum of ∼114 nm, peaking at 480 nm, and the broad emission was ascribed to self-trapped exciton emission.

18.
Mol Biotechnol ; 62(1): 56-66, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31749084

RESUMO

DNA cloning is the basic step for different fields of life science, and many efforts have been made to simplify this procedure. In this study, we report two general purpose plasmids (pGP), pGP-XB2E and pGP-B2E, for rapid and cost-effective construct of basic clones. The BciVI and XcmI cleavage sites are designed in pGP-XB2E to test plasmid linearization efficiency. The plasmid has better linearization efficiency by using BciVI which could almost completely digest 2 µg plasmid in 10 min with only one-tenth the recommended enzyme concentration. In order to further optimize the pGP-XB2E, a new plasmid, pGP-B2E, which removed XcmI cleavage site was designed. This vector is highly efficient for cloning PCR products up to 1812 bp, and the number of colonies was about five times that of pGP-XB2E. In addition to TA cloning, blunt-end PCR products with T ended in the primer could be positively linked to the T-vector pGP-B2E without A-tailing treatment (TB cloning). Moreover, as an entry vector, pGP-B2E was also compatible for gateway recombination reaction without frameshift mutations. In general, this vector provides a universal, quick, and cost-efficient method for basic molecular cloning.


Assuntos
Clonagem Molecular , Vetores Genéticos , Plasmídeos/genética , Catalase/genética , Catalase/metabolismo , DNA Ligases , Expressão Gênica , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo
19.
Nat Commun ; 9(1): 3750, 2018 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-30217976

RESUMO

Semiconductor pn junctions are elementary building blocks of many electronic devices such as transistors, solar cells, photodetectors, and integrated circuits. Due to the absence of an energy bandgap and massless Dirac-like behaviour of charge carriers, graphene pn junction with electrical current rectification characteristics is hardly achieved. Here we show a graphene pn junction diode can be made exclusively from carbon materials by laminating two layers of positively and negatively charged graphene oxides. As the interdiffusion of oppositely charged mobile counterions, a built-in potential is created to rectify the current by changing the tunnelling probability of electrons across the junction. This graphene diode is semi-transparent, can perform simple logic operations, and since it has carbon nanotubes electrodes, we demonstrate an all carbon materials pn diode. We expect this graphene diode will expand material choices and provide functionalities (e.g. grafting recognition units on graphene oxides) beyond that of traditional semiconductor pn junctions.

20.
Biomed Pharmacother ; 108: 663-669, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30245466

RESUMO

Mesenchymal stem cells (MSCs) are one promising candidate for regenerative therapy of ischaemic stroke through transdifferetiation and paracrine actions. Icariin (ICA) has shown great potential in improving cell activity and VEGF, BDNF secretion in vitro. Whether they will synergistically improve therapy effect on cerebral ischemia is unknown. In this study, male SD rats were subjected to transient middle cerebral artery occlusion (MCAO) followed by reperfusion and ICA/MSC treatment. Results showed that ICA and MSCs combined treatment greatly reduced brain infarction volume, improved neurologic deficits of motor and somatosensory function and neurobehavioral outcomes. The combined therapy increased expression of VEGF and BDNF to a maximum through activating PI3K and ERK1/2 pathways in the hippocampus and frontal cortex in response to transient MCAO. They notably promoted angiogenesis and neurogenesis in vivo. Thus, ICA and MSCs combined treatment may represent a feasible approach for improving the beneficial effects of stem cell therapy for cerebral ischemia.


Assuntos
Isquemia Encefálica/tratamento farmacológico , Flavonoides/farmacologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Células-Tronco Mesenquimais/fisiologia , Neovascularização Fisiológica/efeitos dos fármacos , Neurogênese/efeitos dos fármacos , Fosfatidilinositol 3-Quinases/metabolismo , Animais , Isquemia Encefálica/metabolismo , Isquemia Encefálica/fisiopatologia , Lobo Frontal/metabolismo , Lobo Frontal/fisiologia , Hipocampo/metabolismo , Hipocampo/fisiologia , Infarto da Artéria Cerebral Média/tratamento farmacológico , Infarto da Artéria Cerebral Média/metabolismo , Sistema de Sinalização das MAP Quinases/fisiologia , Masculino , Neovascularização Fisiológica/fisiologia , Neurogênese/fisiologia , Ratos , Ratos Sprague-Dawley , Recuperação de Função Fisiológica/efeitos dos fármacos , Recuperação de Função Fisiológica/fisiologia , Acidente Vascular Cerebral/tratamento farmacológico , Acidente Vascular Cerebral/metabolismo , Acidente Vascular Cerebral/fisiopatologia , Fator A de Crescimento do Endotélio Vascular/metabolismo
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