Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 20
Filtrar
1.
Skin Res Technol ; 30(2): e13577, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38284293

RESUMO

BACKGROUND: Psoriasis is a persistent inflammatory dermatological disorder. Tanshinone IIA (tan-IIA) is a biologically active compound in the self-made Xiao-Yin decoction (SMXYD) and exhibits diverse biological properties, such as anti-proliferative and anti-inflammatory effects. The objective of this investigation was to assess the potential of tan-IIA as a therapeutic agent against psoriasis. METHODS: Network pharmacology was employed to ascertain the active constituents and potential pathways associated with SMXYD and psoriasis. We conducted CCK-8, qRT-PCR, and western blotting to assess the proliferation of HaCaT keratinocytes and the expression of IL-17/IL-23 and PTGS2/NF-κB/AP-1 pathways. Additionally, we used H&E staining, western blotting, and ELISA to evaluate the therapeutic effects and signaling pathways of tan-IIA in psoriasis-like mice induced by imiquimod (IMQ). RESULTS: Network pharmacology analysis identified eight hub compounds. The Th17/IL-17 signaling was found to be a potential therapeutic pathway of SMXYD against psoriasis, with JUN (AP-1) as the core molecule. Next, PTGS2 was selected as the target of tan-IIA against psoriasis using network pharmacology analysis. Molecular docking showed a high affinity between PTGS2 and tan-IIA. Tan-IIA treatment attenuated M-5-induced hyperproliferation and inflammation in HaCaT keratinocytes. Additionally, Tan-IIA downregulated the PTGS2/NF-κB/AP-1 pathway in HaCaT keratinocytes. In the IMQ-induced psoriasis-like mouse, tan-IIA significantly reduced the severity of skin lesions and downregulated the PTGS2/NF-κB/AP-1 pathway. Moreover, the combination of methotrexate (MTX) and tan-IIA further inhibited the IL-17/IL-23 and PTGS2/NF-κB/AP-1 pathways. CONCLUSION: The administration of tan-IIA has shown a positive effect on psoriasis by inhibiting the IL-17/IL-23 and PTGS2/NF-κB/AP-1 pathways. The findings suggest that it has promising qualities that make it a potential candidate for the development of future anti-psoriatic agents.


Assuntos
Abietanos , NF-kappa B , Psoríase , Animais , Camundongos , Ciclo-Oxigenase 2/metabolismo , Modelos Animais de Doenças , Imiquimode/efeitos adversos , Interleucina-17/metabolismo , Interleucina-23/metabolismo , Queratinócitos/metabolismo , Simulação de Acoplamento Molecular , NF-kappa B/metabolismo , Psoríase/tratamento farmacológico , Psoríase/patologia , Fator de Transcrição AP-1/metabolismo
2.
Sensors (Basel) ; 21(15)2021 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-34372356

RESUMO

Porous polytetrafluoroethylene (PTFE) is physically flexible, thermally and chemically stable, relatively inexpensive, and commercially available. It is attractive for various flexible sensors. This paper has studied flexible capacitive humidity sensors fabricated on porous PTFE substrates. Graphene oxide (GO) was used as a sensing material, both hydrophobic and hydrophilic porous PTFE as the substrates, and interdigitated electrodes on the PTFE substrates were screen-printed. SEM and Raman spectrum were utilized to characterize GO and PTFE. An ethanol soak process is developed to increase the yield of the humidity sensors based on hydrophobic porous PTFE substrates. Static and dynamic properties of these sensors are tested and analyzed. It demonstrates that the flexible capacitive humidity sensors fabricated on the ethanol-treated hydrophobic PTFE exhibit high sensitivity, small hysteresis, and fast response/recovery time.

3.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 38(2): 117-122, 2021 Feb 10.
Artigo em Zh | MEDLINE | ID: mdl-33565061

RESUMO

OBJECTIVE: To compare the mRNA level of cell proliferation-related genes Twist1, SIRT1, FGF2 and TGF-ß3 in placenta mesenchymal stem cells (PA-MSCs), umbilical cord mensenchymals (UC-MSCs) and dental pulp mesenchymal stem cells (DP-MSCs). METHODS: The morphology of various passages of PA-MSCs, UC-MSCs and DP-MSCs were observed by microscopy. Proliferation and promoting ability of the three cell lines were detected with the MTT method. Real-time PCR (RT-PCR) was used to determine the mRNA levels of Twist1, SIRT1, FGF2, TGF-ß3. RESULTS: The morphology of UC-MSCs and DP-MSCs was different from that of PA-MSCs. Proliferation ability and promoting ability of the PA-MSCs was superior to that of UC-MSCs and DP-MSCs. In PA-MSCs, expression level of Twist1 and TGF-ß3 was the highest and FGF2 was the lowest. SIRT1 was highly expressed in UC-MSCs. With the cell subcultured, different expression levels of Twist1, SIRT1, FGF2, TGF-ß3 was observed in PA-MSCs, UC-MSCs and DP-MSCs. CONCLUSION: Up-regulated expression of the Twist1, SIRT1 and TGF-ß3 genes can promote proliferation of PA-MSCs, UC-MSCs and DP-MSCs, whilst TGF-ß3 may inhibit these. The regulatory effect of Twist1, SIRT1, FGF2 and TGF-ß3 genes on PA-MSCs, UC-MSCs and DP-MSCs are different.


Assuntos
Proliferação de Células/genética , Fator 2 de Crescimento de Fibroblastos/genética , Células-Tronco Mesenquimais/citologia , Proteínas Nucleares/genética , Sirtuína 1/genética , Fator de Crescimento Transformador beta3/genética , Proteína 1 Relacionada a Twist/genética , Diferenciação Celular , Células Cultivadas , Polpa Dentária/citologia , Feminino , Humanos , Placenta/citologia , Gravidez , Cordão Umbilical/citologia
4.
Nanotechnology ; 28(13): 134004, 2017 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-28164866

RESUMO

Vacuum filtration enables the fabrication of large-area graphene-based membranes (GBMs), possessing a smoother surface than that by spray, spin coating or drop casting. However, due to the strong interaction with substrates, the separation of thin GBMs from the filter is problematic. Conventional stamping separation/transfer of graphene oxide (GO) thin films requires another substrate and pressing for >10 h, which may damage the delicate structure of the transfer substrates. Other methods require GO to be reduced on filters before separation, thus limiting the reduction methods. Inspired by a coagulation bath that enables rapid formation of ultrastrong GO fibers, we present an ultrafast (<1 min) and solution-assisted strategy to fabricate smooth and freestanding GO films. The diverse interfacial energy of hydrogen bonds also demonstrates another reason for the successful separation. The film thickness ranges from 45 nm to several micrometers. When used as a composite of counter electrodes in dye sensitized solar cells, it showed higher (8.58%) power conversion efficiency than its spin-(7.71%) and spray-coated (8.07%) counterparts. It also showed promising performance in capacitive humidity sensors. The capacitance varied by three orders of magnitude in the range of the relative humidity of 15%-95%. Therefore the strategy realizes an ultrafast and high-quality film production which is suitable for various applications.

5.
J Chem Phys ; 146(12): 124706, 2017 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-28388161

RESUMO

A number of electronic devices involve metal/oxide interfaces in their structure where the oxide layer plays the role of electrical insulator. As the downscaling of devices continues, the oxide thickness can spread over only a few atomic layers, making the role of interfaces prominent on its insulating properties. The prototypical Al/SiO2 metal/oxide interface is investigated using first principle calculations, and the effect of the interfacial atomic bonding is evidenced. It is shown that the interface bonding configuration critically dictates the mechanical and electronic properties of the interface. Oxygen atoms are found to better delimit the oxide boundaries than cations. Interfacial cation-metal bonds allow the metal potential to leak inside the oxide layer, without atomic diffusion, leading to a virtual oxide thinning.

6.
Sensors (Basel) ; 15(9): 22692-704, 2015 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-26371001

RESUMO

In this paper, a pressure sensor for low pressure detection (0.5 kPa-40 kPa) is proposed. In one structure (No. 1), the silicon membrane is partly etched to form a crossed beam on its top for stress concentration. An aluminum layer is also deposited as part of the beam. Four piezoresistors are fabricated. Two are located at the two ends of the beam. The other two are located at the membrane periphery. Four piezoresistors connect into a Wheatstone bridge. To demonstrate the stress concentrate effect of this structure, two other structures were designed and fabricated. One is a flat membrane structure (No. 2), the other is a structure with the aluminum beam, but without etched silicon (No. 3). The measurement results of these three structures show that the No.1 structure has the highest sensitivity, which is about 3.8 times that of the No. 2 structure and 2.7 times that of the No. 3 structure. They also show that the residual stress in the beam has some backside effect on the sensor performance.

7.
Heliyon ; 10(17): e37580, 2024 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-39296003

RESUMO

Objective: This study aimed to verify whether pancreatic steatosis (PS) is an independent risk factor for type 2 diabetes mellitus (T2DM). We also developed and validated a deep learning model for the diagnosis of PS using ultrasonography (US) images based on histological classifications. Methods: In this retrospective study, we analysed data from 139 patients who underwent US imaging of the pancreas followed by pancreatic resection at our medical institution. Logistic regression analysis was employed to ascertain the independent predictors of T2DM. The diagnostic efficacy of the deep learning model for PS was assessed using receiver operating characteristic curve analysis and compared with traditional visual assessment methodology in US imaging. Results: The incidence rate of PS in the study cohort was 64.7 %. Logistic regression analysis revealed that age (P = 0.003) and the presence of PS (P = 0.048) were independent factors associated with T2DM. The deep learning model demonstrated robust diagnostic capabilities for PS, with areas under the curve of 0.901 and 0.837, sensitivities of 0.895 and 0.920, specificities of 0.700 and 0.765, accuracies of 0.814 and 0.857, and F1-scores of 0.850 and 0.885 for the training and validation cohorts, respectively. These metrics significantly outperformed those of conventional US imaging (P < 0.001 and P = 0.045, respectively). Conclusion: The deep learning model significantly enhanced the diagnostic accuracy of conventional ultrasound for PS detection. Its high sensitivity could facilitate widespread screening for PS in large populations, aiding in the early identification of individuals at an elevated risk for T2DM in routine clinical practice.

8.
Medicine (Baltimore) ; 103(22): e38390, 2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-39259063

RESUMO

To observe the efficacy of topical antipruritic spray (TAS) in the treatment of epidermal growth factor receptor (EGFR) tyrosine kinase-related rashes, and to evaluate its efficacy and safety. 120 malignant tumor patients with confirmed pathological diagnosis and rash after EGFR application were selected and randomly divided into an experimental group of 60 cases and a control group of 60 cases. The 2 groups were intervened with self-made antipruritic spray and erythromycin ointment for 14 consecutive days. To observe the changes in rash, itching degree, and quality of life index of skin diseases in both groups of patients before and after treatment. The decrease in the number of itching cases in the experimental group reached 53.84%, and after 7 weeks of intervention, the total effective rate of rash treatment in this group of patients (91.67%) was significantly better than that in the control group (36.67%); The symptoms of the dermatology life quality index (DLQI) scale in the experimental group patient table after intervention showed significant changes compared to before intervention. After statistical testing, there was a significant difference between the groups and outside the group (R < 0.05). And the comprehensive effect of the experimental patients with external spray after 14 weeks of intervention reached 93.16%. The self-made antipruritic spray has significant effect on improving EGFR rash and itching, and there is no obvious adverse reaction.


Assuntos
Receptores ErbB , Qualidade de Vida , Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Receptores ErbB/antagonistas & inibidores , Idoso , Adulto , Antipruriginosos/administração & dosagem , Antipruriginosos/uso terapêutico , Prurido/tratamento farmacológico , Prurido/etiologia , Inibidores de Proteínas Quinases/administração & dosagem , Inibidores de Proteínas Quinases/uso terapêutico , Resultado do Tratamento , Eritromicina/administração & dosagem , Eritromicina/uso terapêutico , Dermatite/tratamento farmacológico , Dermatite/etiologia , Administração Tópica , Administração Cutânea
9.
Micromachines (Basel) ; 13(10)2022 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-36295942

RESUMO

Wide-range flexible pressure sensors are in difficulty in research while in demand in application. In this paper, a wide-range capacitive flexible pressure sensor is developed with the foaming agent ammonium bicarbonate (NH4HCO3). By controlling the concentration of NH4HCO3 doped in the polydimethylsiloxane (PDMS) and repeating the curing process, pressure-sensitive dielectrics with various porosity are fabricated to expand the detection range of the capacitive pressure sensor. The shape and the size of each dielectric is defined by the 3D printed mold. To improve the dielectric property of the dielectric, a 1% weight ratio of multi-walled carbon nanotubes (MWCNTs) are doped into PDMS liquid. Besides that, a 5% weight ratio of MWCNTs is dispersed into deionized water and then coated on the electrodes to improve the contact state between copper electrodes and the dielectric. The laminated dielectric layer and two electrodes are assembled and tested. In order to verify the effectiveness of this design, some reference devices are prepared, such as sensors based on the dielectric with uniform porosity and a sensor with common copper electrodes. According to the testing results of these sensors, it can be seen that the sensor based on the dielectric with various porosity has higher sensitivity and a wider pressure detection range, which can detect the pressure range from 0 kPa to 1200 kPa and is extended to 300 kPa compared with the dielectric with uniform porosity. Finally, the sensor is applied to the fingerprint, finger joint, and knee bending test. The results show that the sensor has the potential to be applied to human motion detection.

10.
Nanoscale Horiz ; 5(12): 1618-1627, 2020 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-33165492

RESUMO

The recent revival of research on Na and K ion batteries has two benefits. It not only provides alternate energy storage technologies to Li ion batteries with potential cost advantages but also enhances our understanding of charge storage through systematic studies on alkali-metal ion batteries with increasing insertion ion sizes. Using MoS2 as a model material, the structure evolution upon the uptake of Li, Na, and K ions are compared through in situ TEM. Despite their larger size, insertion of K ions shows both the better electrochemical and structural stability. To understand this paradoxical and counter-intuitive phenomenon, in situ XRD is carried out to examine the phase transitions of MoS2 upon ion insertion, while ex situ TEM is further applied to closely examine the structures at the nanoscale. Complementary DFT calculations are performed to understand the kinetic/thermodynamic origins of the unusual stability. The result reveal that the less electrovalent K-S bond favors the intercalation process, resulting in preservation of the layered structure for stable cycling. This study provides a structural insight to design stable electrodes for the K-ion batteries.

11.
Chem Commun (Camb) ; 55(75): 11311-11314, 2019 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-31478553

RESUMO

KVPO4F is found to be capable of both accepting and donating K ions. As an anode, it delivers a reversible capacity of over 100 mA h g-1 with an average potential of 1.15 V vs. K+/K. The anode is also able to work in a wide temperature range of 0-55 °C.

12.
Nanoscale ; 11(24): 11445-11450, 2019 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-31184685

RESUMO

Li-ion capacitors (LICs) are emerging as complementary energy storage devices to Li-ion batteries to satisfy some specific applications where high power density and long cycle life are required. Due to the wide usage of LICs, LICs with promising energy density are urgently needed; however, at this stage, the achievement of this type of LICs is the main challenge. In this study, we increased the energy density of LICs via both material optimization and charge storage mechanism exploration. Moreover, porous carbon with a high surface area of over 2800 m2 g-1 was fabricated from alkali lignin via a traditional KOH activation method assisted by self-activation. A wide voltage window of 1.0-4.8 V was applied where the synergistic storage of anions and cations was achieved. This shows that a deep discharge down to 1.0 V is necessary for the complete desorption of anions, which also triggers the adsorption of cations (Li+), resulting in increased capacity. However, a compromise must be made in the energy efficiency due to intensified battery polarization upon deep discharging. Furthermore, considering the natural abundance of sodium and potassium over lithium, Na- and K-ion capacitors have been investigated for sustainable development using the as-prepared carbon materials.

13.
Research (Wash D C) ; 2019: 2635310, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31912030

RESUMO

Rechargeable aqueous zinc ion batteries (ZIBs) are considered as one of the most promising systems for large-scale energy storage due to their merits of low cost, environmental friendliness, and high safety. The utilization of aqueous electrolyte also brings about some problems such as low energy density, fast self-discharge, and capacity fading associated with the dissolution of metals in water. To combat the issues, we utilize a freestanding vanadium oxide hydrate/carbon nanotube (V2O5·nH2O/CNT) film as the cathode and probe the performance in aqueous/organic hybrid electrolytes. The corresponding structural and morphological evolution of both V2O5·nH2O/CNT cathode and Zn anode in different electrolytes is explored. The integrity of electrodes and the suppression of zinc dendrites during cycles are largely improved in the hybrid electrolytes. Accordingly, the battery in hybrid electrolyte exhibits high capacities of 549 mAh g-1 at 0.5 A g-1 after 100 cycles and 282 mAh g-1 at 4 A g-1 after 1000 cycles, demonstrating an excellent energy density of 102 Wh kg-1 at a high power of 1500 W kg-1 based on the cathode.

14.
Nanoscale ; 10(45): 21132-21141, 2018 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-30406799

RESUMO

Flexible batteries have become an indispensable component of emerging devices, such as wearable, foldable electronics and sensors. Although various flexible batteries have been explored based on one-dimensional and two-dimensional platforms, developing a high energy density electrode with high structural integrity remains challenging. Herein, a scalable, one-pot wet spinning strategy is used to synthesize a flexible porous cathode for lithium-sulfur batteries (LSBs) for the first time, which consists of reduced graphene oxide (rGO), graphene crumples (GCs) and sulfur powders. The electrode structures are tailored using GCs with different dimensions and functional features that are critical to its robustness under mechanical deformation and electrolyte penetration into the battery components. The optimized rGO/GC/S composite ribbon cathodes deliver a high capacity of 524 mA h g-1 after 100 cycles at a current rate of 0.2 C. A shape-conformable battery prototype comprising an rGO/GC/S cathode and a lithium anode demonstrates a stable discharge characteristic under repeated bending/flattening cycles. The LSB prototype supported by an elastomer presents stable discharge behavior with high mechanical robustness against an extension of up to 50%. The above-mentioned findings shed new light on developing sulfur cathodes for flexible, high performance LSBs based on the rational design of graphene structures.

15.
Mol Biotechnol ; 32(1): 55-63, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16382182

RESUMO

The removal of selected marker genes from transgenic plants is necessary to address biosafety concerns and to carry out further experiments with transgenic organisms. In the present study, the 12-amino-acid membrane translocation sequence (MTS) from the Kaposi fibroblast growth factor (FGF)-4 was used as a carrier to deliver enzymatically active Cre proteins into living plant cells, and to produce a site-specific DNA excision in transgenic rice plants. The process, which made cells permeable to Cre recombinase-mediated DNA recombination, circumvented the need to express Cre under spatiotemporal control and was proved to be a simple and efficient system to achieve marker-free transgenic plants. The ultimate aim of the present study is to develop commercial rice cultivars free from selected marker genes to hasten public acceptance of transgenic crops.


Assuntos
Deleção de Genes , Integrases/genética , Mutagênese Sítio-Dirigida/métodos , Oryza/genética , Proteínas Virais/genética , Southern Blotting , Células Cultivadas , Cinamatos/farmacologia , DNA de Plantas/genética , DNA de Plantas/metabolismo , Escherichia coli/genética , Fator 4 de Crescimento de Fibroblastos/genética , Expressão Gênica/genética , Engenharia Genética/métodos , Vetores Genéticos/genética , Glucuronidase/genética , Glucuronidase/metabolismo , Higromicina B/análogos & derivados , Higromicina B/farmacologia , Integrases/metabolismo , Sinais de Localização Nuclear/genética , Oryza/citologia , Fosfotransferases (Aceptor do Grupo Álcool)/genética , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Folhas de Planta/genética , Plantas Geneticamente Modificadas , Reação em Cadeia da Polimerase , Sinais Direcionadores de Proteínas/genética , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/isolamento & purificação , Proteínas Recombinantes de Fusão/farmacologia , Recombinação Genética/efeitos dos fármacos , Recombinação Genética/genética , Proteínas Virais/metabolismo
16.
Micromachines (Basel) ; 7(5)2016 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-30404251

RESUMO

A capacitive coupling structure is developed to improve the performances of a capacitive complementary metal oxide semiconductor (CMOS) microelectromechanical system (MEMS) humidity sensor. The humidity sensor was fabricated by a post-CMOS process. Silver nanowires were dispersed onto the top of a conventional interdigitated capacitive structure to form a coupling electrode. Unlike a conventional structure, a thinner sensitive layer was employed to increase the coupling capacitance which dominated the sensitive capacitance of the humidity sensor. Not only static properties but also dynamic properties were found to be better with the aid of coupling capacitance. At 25 °C, the sensitive capacitance was 11.3 pF, the sensitivity of the sensor was measured to be 32.8 fF/%RH and the hysteresis was measured to be 1.0 %RH. Both a low temperature coefficient and a fast response (10 s)/recovery time (17 s) were obtained.

17.
ACS Appl Mater Interfaces ; 8(42): 28663-28670, 2016 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-27715003

RESUMO

Three-dimensional graphene aerogel/TiO2/sulfur (GA/TiO2/S) composites are synthesized through a facile, one-pot hydrothermal route as the cathode for lithium-sulfur batteries. With a high sulfur content of 75.1 wt %, the conductive, highly porous composite electrode delivers a high discharge capacity of 512 mA h/g after 250 cycles at a current rate of 1 C with a low capacity decay of 0.128% per cycle. The excellent capacities and cyclic stability arise from several unique functional features of the cathode. (i) The conductive graphene aerogel framework ameliorates ion/electron transfer while accommodating the volume expansion induced during discharge, and (ii) TiO2 nanoparticles play an important role in restricting the dissolution of polysulfides by chemical bonds with sulfur.

18.
ACS Appl Mater Interfaces ; 7(24): 13503-11, 2015 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-26028432

RESUMO

A facile electrospinning method with subsequent heat treatments is employed to prepare carbon nanofibers (CNFs) containing uniformly dispersed Co3O4 nanoparticles as electrodes for supercapacitors. The Co3O4/CNF electrodes with ∼68 wt % active particles deliver a remarkable capacitance of 586 F g(-1) at a current density of 1 A g(-1). When the current density is increased to 50 A g(-1), ∼66% of the original capacitance is retained. The electrodes also present excellent cyclic stability of 74% capacity retention after 2000 cycles at 2 A g(-1). These superior electrochemical properties are attributed to the uniform dispersion of active particles in the CNF matrix, which functions as a conductive support. The onionlike graphitic layers formed around the Co3O4 nanoparticles not only improve the electrical conductivity of the electrode but also prevent the separation of the nanoparticles from the carbon matrix.

19.
ACS Appl Mater Interfaces ; 6(21): 18971-80, 2014 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-25317550

RESUMO

Nanocomposites consisting of ultrafine, cobalt carbonate nanoneedles and 3D porous graphene aerogel (CoCO3/GA) are in situ synthesized based on a one-step hydrothermal route followed by freeze-drying. A further heat treatment produces cobalt oxide nanoparticles embedded in the conductive GA matrix (Co(3)O(4)/GA). Both the composite anodes deliver excellent specific capacities depending on current density employed: the CoCO(3)/GA anode outperforms the Co(3)O(4)/GA anode at low current densities, and vice versa at current densities higher than 500 mA g(-1). Their electrochemical performances are considered among the best of similar composite anodes consisting of CoCO(3) or Co(3)O(4) active particles embedded in a graphene substrate. The stable multistep electrochemical reactions of the carbonate compound with a unique nanoneedle structure contribute to the excellent cyclic stability of the CoCO(3)/GA electrode, whereas the highly conductive networks along with low charge transfer resistance are responsible for the high rate performance of the Co(3)O(4)/GA electrode.

20.
Plant Cell Rep ; 27(3): 489-98, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18004571

RESUMO

In the present study, an efficient Agrobacterium-mediated gene transformation system was developed for soybean [Glycine max (L.) Merrill] based on the examinations of several factors affecting plant transformation efficiency. Increased transformation efficiencies were obtained when the soybean cotyledonary node were inoculated with the Agrobacterium inoculum added with 0.02% (v/v) surfactant (Silwet L-77). The applications of Silwet L-77 (0.02%) during infection and L-cysteine (600 mg l(-1)) during co-cultivation resulted in more significantly improved transformation efficiency than each of the two factors alone. The optimized temperature for infected explant co-cultivation was 22 degrees C. Regenerated transgenic shoots were selected and produced more efficiently with the modified selection scheme (initiation on shoot induction medium without hygromycin for 7 days, with 3 mg l(-1) hygromycin for 10 days, 5 mg l(-1) hygromycin for another 10 days, and elongation on shoot elongation medium with 8 mg l(-1) hygromycin). Using the optimized system, we obtained 145 morphologically normal and fertile independent transgenic plants in five important Chinese soybean varieties. The transformation efficacies ranged from 3.8 to 11.7%. Stable integration, expression and inheritance of the transgenes were confirmed by molecular and genetic analysis. T(1) plants were analyzed and transmission of transgenes to the T(1 )generation in a Mendelian fashion was verified. This optimized transformation system should be employed for efficient Agrobacterium-mediated soybean gene transformation.


Assuntos
Glycine max/genética , Rhizobium/genética , Transformação Genética/genética , Southern Blotting , Cinamatos/farmacologia , Cisteína/farmacologia , Higromicina B/análogos & derivados , Higromicina B/farmacologia , Plantas Geneticamente Modificadas , Reação em Cadeia da Polimerase , Glycine max/efeitos dos fármacos , Glycine max/crescimento & desenvolvimento , Temperatura , Transformação Genética/efeitos dos fármacos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA